version 3.4.90

* NEWS: Record release date.
C++: finish propagating the unsigned->signed conversion in locations
2026-08-09 02:35:15 +00:00 · 2019-10-29 21:41:00 +01:00 · 2019-10-29 09:15:25 +01:00 · 2019-10-29 09:00:46 +01:00 · 2019-10-29 08:59:18 +01:00 · 2019-10-26 10:39:01 +02:00
125 changed files with 5770 additions and 3397 deletions
@@ -1,9 +1,6 @@
-/ABOUT-NLS~
-*.eps
 *.log
 *.o
 *.pdf
-*.png
 *.stamp
 *.trs
 *~
@@ -1 +1 @@
-3.3.2
+3.4.2
@@ -1,8 +1,7 @@
 # Travis defines and exports CC and CXX *after* we have defined our
-# environment variables via 'env'.  So, do not use 'env' to define
-# them.  Instead, put their definitions in MATRIX_EVAL, which we eval
-# after the definitions from Travis.
-
+# environment variables via 'env'.  So, do not use 'env' to define them.
+# Instead, put their definitions in MATRIX_EVAL, which we eval after the
+# definitions from Travis.
 language: cpp

 env:
@@ -11,8 +10,65 @@ env:
    # See https://github.com/nemequ/icc-travis.
    secure: 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

-matrix:
+# Run in two steps:
+# 1. Build the tarball
+#    On a modern distro, with all the needed dependencies, including the whole git history.
+# 2. Check it on various environments.
+#    Less dependencies, and little git content (we would like to have none, but it's not
+#    an option on Travis).
+stages:
+  - dist
+  - check
+
+# The 'check' jobs do not need the repo at all, only the 'dist'
+# does.  Let's save time, bandwith, energy, and polar bears.
+git:
+  clone: false
+
+# matrix.include and jobs.include are aliases
+# (https://docs.travis-ci.com/user/conditional-builds-stages-jobs/).
+jobs:
  include:
+    - stage: dist
+      name: "Make dist"
+      git:
+        clone: true
+      dist: bionic
+      script:
+        - sudo apt-get install -qq autoconf automake autopoint flex gettext graphviz help2man m4 texinfo
+        - autoconf --version
+        - automake --version
+        - autopoint --version
+        - dot -V
+        - gettext --version
+        - help2man --version
+        - makeinfo --version
+        - m4 --version
+
+        # Travis makes a shallow clone, but we need it in full to build the ChangeLog and apply the fixes in git-log-fix.
+        - git fetch --unshallow || true
+        - git submodule update --init --recursive
+
+        - ./bootstrap
+        - ./configure --enable-gcc-warnings || { cat config.log && false; }
+        - make -j2
+        - make -j2 dist
+        # Can help understanding why we get "dirty" tarballs.
+        - git status
+        - dist=$(echo bison*.xz)
+
+        # Unfortunately we cannot deterministically know the name of the tarball without the full
+        # git history (because git describe --abbrev=4 may use more than 4 characters if there are
+        # conflicts).
+        #
+        # So for the sake of the 'check' jobs (that don't even have the repo at all), also expose this
+        # tarball on a name that only depends on the Travis build number.
+        #
+        # Without -b -, exit status is always 0.
+        #
+        # If we rerun a job that was already uploaded, 'ln -s' will fail: remove beforehand.
+        - sftp -b - [email protected] <<< "put $dist"$'\n'"-rm bison-$TRAVIS_BUILD_NUMBER.tar.xz"$'\n'"ln -s $dist bison-$TRAVIS_BUILD_NUMBER.tar.xz"
+
    ## ------- ##
    ## First.  ##
    ## ------- ##
@@ -20,154 +76,167 @@ matrix:
    # Start with three completely different environments, to get
    # errors asap.

-    - name: "GCC 7 -O3"
+    - name: "GCC 9 -O3"
+      stage: check
      os: linux
-      dist: xenial
+      dist: bionic
      addons:
        apt:
          sources:
-            - ubuntu-toolchain-r-test
-          packages:
-            - g++-7
+            # See https://github.com/travis-ci/apt-source-safelist/issues/410.
+            - sourceline: 'ppa:ubuntu-toolchain-r/test'
+          packages: g++-9
      env:
-        - MATRIX_EVAL="CC=gcc-7 && CXX=g++-7 && CONFIGUREFLAGS='CPPFLAGS=-DNDEBUG CFLAGS=-O3 CXXFLAGS=-O3'"
+        - MATRIX_EVAL="CC=gcc-9 && CXX=g++-9 && CONFIGUREFLAGS='CPPFLAGS=-DNDEBUG CFLAGS=-O3 CXXFLAGS=-O3'"

    # ASAN is time consuming, and we timeout the 50min granted by
-    # Travis if we run all the tests in on go.  Run in two parts.
-    - name: "Clang 7 libc++ and ASAN part 1"
+    # Travis if we run all the tests in one go.  Run in two parts.
+    - name: "Clang 9 libc++ and ASAN part 1"
+      stage: check
      os: linux
-      dist: xenial
-      addons:
+      dist: bionic
+      addons: &clang9
        apt:
          sources:
-            - llvm-toolchain-xenial-7
-            - ubuntu-toolchain-r-test
+            # See https://github.com/travis-ci/apt-source-safelist/issues/410.
+            - sourceline: 'ppa:ubuntu-toolchain-r/test'
+            - sourceline: 'deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-9 main'
+              key_url: 'https://apt.llvm.org/llvm-snapshot.gpg.key'
          packages:
-            - clang-7
-            - libc++-7-dev
-            - libc++abi-7-dev
+            - clang-9
+            - libc++-9-dev
+            - libc++abi-9-dev
      env:
        # Do not use ASAN with ubuntu's libc++: https://bugs.llvm.org/show_bug.cgi?id=17379
-        - MATRIX_EVAL="PART=1 CC='clang-7 -fsanitize=address' CXX='clang++-7 -fsanitize=address -stdlib=libc++'"
+        - MATRIX_EVAL="CC='clang-9 -fsanitize=address' CXX='clang++-9 -fsanitize=address -stdlib=libc++'"
+        - PART=1

-    - name: "Clang 7 libc++ and ASAN part 2"
+    - name: "Clang 9 libc++ and ASAN part 2"
+      stage: check
      os: linux
-      dist: xenial
-      addons:
-        apt:
-          sources:
-            - llvm-toolchain-xenial-7
-            - ubuntu-toolchain-r-test
-          packages:
-            - clang-7
-            - libc++-7-dev
-            - libc++abi-7-dev
+      dist: bionic
+      addons: *clang9
      env:
        # Do not use ASAN with ubuntu's libc++: https://bugs.llvm.org/show_bug.cgi?id=17379
-        - MATRIX_EVAL="PART=2 CC='clang-7 -fsanitize=address' CXX='clang++-7 -fsanitize=address -stdlib=libc++'"
+        - MATRIX_EVAL="CC='clang-9 -fsanitize=address' CXX='clang++-9 -fsanitize=address -stdlib=libc++'"
+        - PART=2

-    - name: "ICC"
-      os: linux
-      dist: xenial
-      env:
-        # ICC's warnings are often very wrong (e.g., it thinks foo ?
-        # "bar" : "baz" is char* instead of const char*), so don't try
-        # to work around the, and obviously, don't die on them.
-        - MATRIX_EVAL="CC=icc && CXX=icpc"
-        - MAKE_ARGS='WERROR_CFLAGS= WERROR_CXXFLAGS='
+    # Currently no longer works (https://github.com/nemequ/icc-travis/issues/15).
+    # - name: "ICC"
+    #   stage: check
+    #   # We need the build-aux/install-icc.sh script.
+    #   git:
+    #     clone: true
+    #     submodules: false
+    #     depth: 1
+    #   os: linux
+    #   dist: xenial
+    #   env:
+    #     # ICC's warnings are often very wrong (e.g., it thinks foo ?
+    #     # "bar" : "baz" is char* instead of const char*), so don't try
+    #     # to work around the, and obviously, don't die on them.
+    #     - MATRIX_EVAL="CC=icc && CXX=icpc"
+    #     - MAKE_ARGS='WERROR_CFLAGS= WERROR_CXXFLAGS='


    ## ----- ##
    ## GCC.  ##
    ## ----- ##

-    #- name: "GCC 8 with sanitizers"
-    #  os: linux
-    #  dist: xenial
-    #  addons:
-    #    apt:
-    #      sources:
-    #        - ubuntu-toolchain-r-test
-    #      packages:
-    #        - g++-8
-    #  env:
-    #    # Can't use UBSAN: I get:
-    #    # configure:4951: gcc-8 -fsanitize=undefined,address -fno-omit-frame-pointer conftest.c
-    #    # /usr/bin/ld: unrecognized option '--push-state' (on trusty)
-    #    # /usr/bin/ld: unrecognized option '--push-state--no-as-needed' (on xenial)
-    #    #
-    #    # https://stackoverflow.com/questions/50024731/ suggests using the gold linker.
-    #    - MATRIX_EVAL="CC='gcc-8 -fsanitize=undefined,address -fno-omit-frame-pointer' CXX='g++-8 -fsanitize=undefined,address -fno-omit-frame-pointer'"
+    - name: "GCC 8 with sanitizers part 1"
+      os: linux
+      dist: bionic
+      addons:
+        apt:
+          packages: g++-8
+      env:
+        - MATRIX_EVAL="CC='gcc-8 -fsanitize=undefined,address -fno-omit-frame-pointer' CXX='g++-8 -fsanitize=undefined,address -fno-omit-frame-pointer'"
+        - CONFIGUREFLAGS='CFLAGS=-O1 CXXFLAGS=-O1'
+        - PART=1
+
+    - name: "GCC 8"
+      stage: check
+      os: linux
+      dist: bionic
+      addons:
+        apt:
+          packages: g++-8
+      env:
+        - MATRIX_EVAL="CC=gcc-8 && CXX=g++-8"
+
+    - name: "GCC 7"
+      stage: check
+      os: linux
+      dist: bionic
+      addons:
+        apt:
+          packages: g++-7
+      env:
+        - MATRIX_EVAL="CC=gcc-7 && CXX=g++-7"

    - name: "GCC 6"
+      stage: check
      os: linux
      dist: xenial
      addons:
        apt:
-          sources:
-            - ubuntu-toolchain-r-test
-          packages:
-            - g++-6
+          sources: ubuntu-toolchain-r-test
+          packages: g++-6
      env:
        - MATRIX_EVAL="CC=gcc-6 && CXX=g++-6"

    - name: "GCC 5"
+      stage: check
      os: linux
      dist: xenial
      addons:
        apt:
-          sources:
-            - ubuntu-toolchain-r-test
-          packages:
-            - g++-5
+          sources: ubuntu-toolchain-r-test
+          packages: g++-5
      env:
         - MATRIX_EVAL="CC=gcc-5 && CXX=g++-5"

    - name: "GCC 4.9"
+      stage: check
      os: linux
      dist: xenial
      addons:
        apt:
-          sources:
-            - ubuntu-toolchain-r-test
-          packages:
-            - g++-4.9
+          sources: ubuntu-toolchain-r-test
+          packages: g++-4.9
      env:
         - MATRIX_EVAL="CC=gcc-4.9 && CXX=g++-4.9"

    - name: "GCC 4.8"
+      stage: check
      os: linux
      dist: xenial
      addons:
        apt:
-          sources:
-            - ubuntu-toolchain-r-test
-          packages:
-            - g++-4.8
+          sources: ubuntu-toolchain-r-test
+          packages: g++-4.8
      env:
         - MATRIX_EVAL="CC=gcc-4.8 && CXX=g++-4.8"

    - name: "GCC 4.7"
+      stage: check
      os: linux
      dist: xenial
      addons:
        apt:
-          sources:
-            - ubuntu-toolchain-r-test
-          packages:
-            - g++-4.7
+          sources: ubuntu-toolchain-r-test
+          packages: g++-4.7
      env:
         - MATRIX_EVAL="CC=gcc-4.7 && CXX=g++-4.7"

    - name: "GCC 4.6"
+      stage: check
      os: linux
      dist: xenial
      addons:
        apt:
-          sources:
-            - ubuntu-toolchain-r-test
-          packages:
-            - g++-4.6
+          sources: ubuntu-toolchain-r-test
+          packages: g++-4.6
      env:
         - MATRIX_EVAL="CC=gcc-4.6 && CXX=g++-4.6"

@@ -175,7 +244,35 @@ matrix:
    ## Clang.  ##
    ## ------- ##

-    - name: "Clang 6 -O3 and libc++"
+    - name: "Clang 8 -O3"
+      stage: check
+      os: linux
+      dist: bionic
+      addons:
+        apt:
+          packages:
+            - clang-8
+            - libc++-8-dev
+            - libc++abi-8-dev
+      env:
+        - MATRIX_EVAL="CC=clang-8 && CXX='clang++-8 -stdlib=libc++'"
+        - CONFIGUREFLAGS='CPPFLAGS=-DNDEBUG CFLAGS=-O3 CXXFLAGS=-O3'
+
+    - name: "Clang 7"
+      stage: check
+      os: linux
+      dist: bionic
+      addons:
+        apt:
+          packages:
+            - clang-7
+            - libc++-7-dev
+            - libc++abi-7-dev
+      env:
+        - MATRIX_EVAL="CC=clang-7 && CXX='clang++-7 -stdlib=libc++'"
+
+    - name: "Clang 6 and libc++"
+      stage: check
      os: linux
      dist: xenial
      addons:
@@ -188,15 +285,14 @@ matrix:
            - libc++-dev
      env:
        - MATRIX_EVAL="CC=clang-6.0 && CXX='clang++-6.0 -stdlib=libc++'"
-        - CONFIGUREFLAGS='CPPFLAGS=-DNDEBUG CFLAGS=-O3 CXXFLAGS=-O3'

    - name: "Clang 5"
+      stage: check
      os: linux
      dist: xenial
      addons:
        apt:
-          sources:
-            - llvm-toolchain-xenial-5.0
+          sources: llvm-toolchain-xenial-5.0
          packages:
            - clang-5.0
            - libc++-dev
@@ -204,30 +300,29 @@ matrix:
        - MATRIX_EVAL="CC='clang-5.0' CXX='clang++-5.0'"

    - name: "Clang 4"
+      stage: check
      os: linux
      dist: xenial
      addons:
        apt:
-          sources:
-            - llvm-toolchain-xenial-4.0
-          packages:
-            - clang-4.0
+          sources: llvm-toolchain-xenial-4.0
+          packages: clang-4.0
      env:
        - MATRIX_EVAL="CC=clang-4.0 && CXX=clang++-4.0"

    - name: "Clang 3.9"
+      stage: check
      os: linux
      dist: xenial
      addons:
        apt:
-          sources:
-            - llvm-toolchain-xenial-3.9
-          packages:
-            - clang-3.9
+          sources: llvm-toolchain-xenial-3.9
+          packages: clang-3.9
      env:
        - MATRIX_EVAL="CC=clang-3.9 && CXX=clang++-3.9"

    - name: "Clang 3.8"
+      stage: check
      os: linux
      dist: xenial
      addons:
@@ -235,12 +330,12 @@ matrix:
          sources:
            - ubuntu-toolchain-r-test
            - llvm-toolchain-precise-3.8
-          packages:
-            - clang-3.8
+          packages: clang-3.8
      env:
        - MATRIX_EVAL="CC=clang-3.8 && CXX=clang++-3.8"

    - name: "CLang 3.7"
+      stage: check
      os: linux
      dist: xenial
      addons:
@@ -248,12 +343,12 @@ matrix:
          sources:
            - ubuntu-toolchain-r-test
            - llvm-toolchain-precise-3.7
-          packages:
-            - clang-3.7
+          packages: clang-3.7
      env:
        - MATRIX_EVAL="CC=clang-3.7 && CXX=clang++-3.7"

    - name: "Clang 3.6"
+      stage: check
      os: linux
      dist: xenial
      addons:
@@ -261,12 +356,12 @@ matrix:
          sources:
            - ubuntu-toolchain-r-test
            - llvm-toolchain-precise-3.6
-          packages:
-            - clang-3.6
+          packages: clang-3.6
      env:
        - MATRIX_EVAL="CC=clang-3.6 && CXX=clang++-3.6"

    - name: "Clang 3.5"
+      stage: check
      os: linux
      dist: xenial
      addons:
@@ -274,82 +369,89 @@ matrix:
          sources:
            - ubuntu-toolchain-r-test
            - llvm-toolchain-precise-3.5
-          packages:
-            - clang-3.5
+          packages: clang-3.5
      env:
        - MATRIX_EVAL="CC=clang-3.5 && CXX=clang++-3.5"

    - name: "Clang 3.4"
+      stage: check
      os: linux
      # Not available on Xenial.
      dist: trusty
      addons:
        apt:
-          packages:
-            - clang-3.4
+          packages: clang-3.4
      env:
        # No versioned name installed, but beware that Travis installs
        # a more modern clang earlier in the default PATH.
-        - MATRIX_EVAL='CC=/usr/bin/clang && CXX=/usr/bin/clang++ && GETTEXT_VERSION=0.18.3'
+        - MATRIX_EVAL='CC=/usr/bin/clang && CXX=/usr/bin/clang++'

    - name: "Clang 3.3"
+      stage: check
      os: linux
      # Not available on Xenial.
      dist: trusty
      addons:
        apt:
-          packages:
-            - clang-3.3
+          packages: clang-3.3
      env:
        # See comment for 3.4.
-        - MATRIX_EVAL='CC=/usr/bin/clang && CXX=/usr/bin/clang++ && GETTEXT_VERSION=0.18.3'
+        - MATRIX_EVAL='CC=/usr/bin/clang && CXX=/usr/bin/clang++'

+## From https://docs.gitlab.com/ce/ci/ssh_keys/#ssh-keys-when-using-the-docker-executor.
+## Applies to Travis too.  Applied to all the 'script's (of all the jobs).
+before_script:
+  - 'which ssh-agent || ( sudo apt-get install openssh-client -y )'
+  - eval "$(ssh-agent -s)"
+  # $SSH_PRIVATE_KEY is multiline.  Use $'...' to register its value: $'-----BEGIN OPENSSH PRIVATE KEY-----\nXXXXX...\n...==\n-----END OPENSSH PRIVATE KEY-----'.
+  - echo "$SSH_PRIVATE_KEY" >/tmp/key.id_rsa
+  - chmod 600 /tmp/key.id_rsa
+  - ssh-add /tmp/key.id_rsa </dev/null
+  - mkdir -p ~/.ssh
+  - chmod 700 ~/.ssh
+  - echo '|1|bpc51UGxoDZjCPiwRlCStW32trI=|rfh6mLoLZv/vAvOVrpZXI1hTLxg= ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBIR+ckMoJTNXHvAQLHWSfrRnrNJGW2ZR6kr5pBVDGCkz1v1RcQ5rleq0NAt9kS3v4hgnuLiEVnK7KDRzcEH3ikc=' >>~/.ssh/known_hosts
+  - chmod 600 ~/.ssh/known_hosts

-before_install:
+# Applies only to the jobs that don't have a 'script', i.e., applies to all the 'check' jobs, but not the 'dist' one.
+script:
  - eval "$MATRIX_EVAL"
-  - env
-  - sudo apt-get update -qq
-  - sudo apt-get install -qq autoconf automake autopoint doxygen flex gettext graphviz help2man m4 texinfo
+  # Beware not too leak $SSH_PRIVATE_KEY.
+  # - env
+  - sudo apt-get install -qq doxygen flex m4
+  # Install and activate ICC.
  - if [[ $CC == "icc" ]]; then build-aux/install-icc.sh; fi
  - if [[ -f ~/.bashrc ]]; then source ~/.bashrc; fi
-  # Install and activate dmd
+  # Install and activate dmd.
  - mkdir -p ~/dlang && wget https://dlang.org/install.sh -O ~/dlang/install.sh
  - source $(source ~/dlang/install.sh dmd -a)
-  - autoconf --version
-  - automake --version
-  - autopoint --version
+
  - $CC --version
  - $CXX --version
  - dmd --version
  - doxygen --version
  - flex --version
-  - gettext --version
-  - dot -V
-  - help2man --version
  - ld --version
  - m4 --version
-  - makeinfo --version

-script:
-  - git tag -l
-  # For some reasons, sometimes the checkout does not have any tags,
-  # so `git describe` fails, so bootstrap fails.
-  - git describe || git tag v3.0 -m "Fake version 3.0."
-  - git describe
+  - if [[ -f ~/.bashrc ]]; then source ~/.bashrc; fi
  # Unset this variable, otherwise, Java programs' stderr is cluttered
  # with `Picked up _JAVA_OPTIONS: -Xmx2048m -Xms512m`, which makes
  # the test suite fail.
  - unset _JAVA_OPTIONS
-  - if [[ $GETTEXT_VERSION ]]; then sed -i -re "s/(AM_GNU_GETTEXT_VERSION).*/\1([$GETTEXT_VERSION])/" configure.ac; fi
-  - ./bootstrap
-  # For some reason, gnulib-po/Makefile.in.in is about Gettext 0.19, so it will break here.  Override it.
-  - if [[ $GETTEXT_VERSION ]]; then autopoint --force; fi
-  - if [[ -f ~/.bashrc ]]; then source ~/.bashrc; fi
-  - ./configure --enable-gcc-warnings CC="$CC" CXX="$CXX" $CONFIGUREFLAGS || { cat config.log && false; }
+
+  # Fail fast from now on.
+  - set -e
+  - sftp [email protected]:bison-$TRAVIS_BUILD_NUMBER.tar.xz
+  - tar xf bison-$TRAVIS_BUILD_NUMBER.tar.xz
+  - dir=$(tar tf bison-$TRAVIS_BUILD_NUMBER.tar.xz | sed 1q)
+  - cd $dir
+  - mkdir _build
+  - cd _build
+  - ../configure --enable-gcc-warnings CC="$CC" CXX="$CXX" $CONFIGUREFLAGS || { cat config.log && false; }
  - make -j2 $MAKE_ARGS
  - if test ${PART-1} = 1; then make check                  VERBOSE=1 TESTSUITEFLAGS=-j2 || { cat test-suite.log && cat tests/testsuite.log && false; }; fi
-  - if test ${PART-1} = 1; then make maintainer-check-posix VERBOSE=1 TESTSUITEFLAGS=-j2 || { cat tests/testsuite.log && false; }; fi
+  - if test ${PART-2} = 2; then make maintainer-check-posix VERBOSE=1 TESTSUITEFLAGS=-j2 || { cat tests/testsuite.log && false; }; fi
  - if test ${PART-2} = 2; then make maintainer-check-g++   VERBOSE=1 TESTSUITEFLAGS=-j2 || { cat tests/testsuite.log && false; }; fi

 after_script:
-  - if [[ $CC == "icc" ]]; then uninstall_intel_software; fi
+  - uninstall_intel_software || true
@@ -1,15 +1,149 @@
 GNU Bison NEWS

-* Noteworthy changes in release 3.3.90 (2019-04-28) [beta]
+* Noteworthy changes in release 3.4.90 (2019-10-29) [beta]
+
+** Backward incompatible changes
+
+  Lone carriage-return characters (aka \r or ^M) in the grammar files are no
+  longer treated as end-of-lines.  This changes the diagnostics, and in
+  particular their locations.
+
+  In C++, line numbers and columns are now represented as 'int' not
+  'unsigned', so that integer overflow on positions is easily checkable via
+  'gcc -fsanitize=undefined' and the like.  This affects the API for
+  positions.
+
+** Bug fixes
+
+  In Java, %define api.prefix was ignored.  It now behaves as expected.
+
+** New features
+
+*** Lookahead correction in C++
+
+  Contributed by Adrian Vogelsgesang.
+
+  The C++ deterministic skeleton (lalr1.cc) now supports LAC, via the
+  %define variable parse.lac.
+
+*** Variable api.token.raw: Optimized token numbers (all skeletons)
+
+  In the generated parsers, tokens have two numbers: the "external" token
+  number as returned by yylex (which starts at 257), and the "internal"
+  symbol number (which starts at 3).  Each time yylex is called, a table
+  lookup maps the external token number to the internal symbol number.
+
+  When the %define variable api.token.raw is set, tokens are assigned their
+  internal number, which saves one table lookup per token, and also saves
+  the generation of the mapping table.
+
+  The gain is typically moderate, but in extreme cases (very simple user
+  actions), a 10% improvement can be observed.
+
+*** Diagnostics with insertion
+
+  The diagnostics now display suggestion below the underlined source.
+  Replacement for undeclared symbols are now also suggested.
+
+    $ cat /tmp/foo.y
+    %%
+    list: lis '.' |
+
+    $ bison -Wall foo.y
+    foo.y:2.7-9: error: symbol 'lis' is used, but is not defined as a token and has no rules; did you mean 'list'?
+        2 | list: lis '.' |
+          |       ^~~
+          |       list
+    foo.y:2.16: warning: empty rule without %empty [-Wempty-rule]
+        2 | list: lis '.' |
+          |                ^
+          |                %empty
+    foo.y: warning: fix-its can be applied.  Rerun with option '--update'. [-Wother]
+
+*** Diagnostics about long lines
+
+  Quoted sources may now be truncated to fit the screen.  For instance, on a
+  30-column wide terminal:
+
+    $ cat foo.y
+    %token FOO                       FOO                         FOO
+    %%
+    exp: FOO
+    $ bison foo.y
+    foo.y:1.34-36: warning: symbol FOO redeclared [-Wother]
+        1 | …         FOO                  …
+          |           ^~~
+    foo.y:1.8-10:      previous declaration
+        1 | %token FOO                     …
+          |        ^~~
+    foo.y:1.62-64: warning: symbol FOO redeclared [-Wother]
+        1 | …         FOO
+          |           ^~~
+    foo.y:1.8-10:      previous declaration
+        1 | %token FOO                     …
+          |        ^~~
+
+*** Debug traces in Java
+
+  The Java backend no longer emits code and data for parser tracing if the
+  %define variable parse.trace is not defined.
+
+*** Generated parsers prefer signed integer types
+
+  Bison skeletons now prefer signed to unsigned integer types when either
+  will do, as the signed types are less error-prone and allow for better
+  checking with 'gcc -fsanitize=undefined'.  Also, the types chosen are now
+  portable to unusual machines where char, short and int are all the same
+  width.  On non-GNU platforms this may entail including <limits.h> and (if
+  available) <stdint.h> to define integer types and constants.
+
+*** Generated parsers use better types for states
+
+  Stacks now use the best integral type for state numbers, instead of always
+  using 15 bits.  As a result "small" parsers now have a smaller memory
+  footprint (they use 8 bits), and there is support for large automata (16
+  bits), and extra large (using int, i.e., typically 31 bits).
+
+* Noteworthy changes in release 3.4.2 (2019-09-12) [stable]
+
+** Bug fixes
+
+  In some cases, when warnings are disabled, bison could emit tons of white
+  spaces as diagnostics.
+
+  When running out of memory, bison could crash (found by fuzzing).
+
+  When defining twice the EOF token, bison would crash.
+
+  New warnings from recent compilers have been addressed in the generated
+  parsers (yacc.c, glr.c, glr.cc).
+
+  When lone carriage-return characters appeared in the input file,
+  diagnostics could hang forever.
+
+* Noteworthy changes in release 3.4.1 (2019-05-22) [stable]
+
+** Bug fixes
+
+  Portability fixes.
+
+* Noteworthy changes in release 3.4 (2019-05-19) [stable]
+
+** Deprecated features
+
+  The %pure-parser directive is deprecated in favor of '%define api.pure'
+  since Bison 2.3b (2008-05-27), but no warning was issued; there is one
+  now.  Note that since Bison 2.7 you are strongly encouraged to use
+  '%define api.pure full' instead of '%define api.pure'.

 ** New features

 *** Colored diagnostics

-  As an experimental feature, Bison now generates colored diagnostics,
-  controlled by the new options --color and --style.
+  As an experimental feature, diagnostics are now colored, controlled by the
+  new options --color and --style.

-  Install the libtextstyle library before configuring Bison to use them.
+  To use them, install the libtextstyle library before configuring Bison.
  It is available from

    https://alpha.gnu.org/gnu/gettext/
@@ -25,12 +159,13 @@ GNU Bison NEWS

  To customize the styles, create a CSS file similar to

-    /* black-and-white.css */
+    /* bison-bw.css */
    .warning   { }
    .error     { font-weight: 800; text-decoration: underline; }
    .note      { }

-  then invoke bison with --style=black-and-white.css.
+  then invoke bison with --style=bison-bw.css, or set the BISON_STYLE
+  environment variable to "bison-bw.css".

 *** Disabling output

@@ -869,10 +1004,10 @@ GNU Bison NEWS

  bison used to report:

-    /tmp/foo.yy:2.10-11: error: %printer redeclaration for FOO
+    foo.yy:2.10-11: error: %printer redeclaration for FOO
     %printer {} "foo"
              ^^
-    /tmp/foo.yy:3.10-11:     previous declaration
+    foo.yy:3.10-11:     previous declaration
     %printer {} FOO
              ^^

@@ -3614,12 +3749,12 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 LocalWords:  redeclaration sval fcaret reentrant XSLT xsl Wmaybe yyvsp Tedi
 LocalWords:  pragmas noreturn untyped Rozenman unexpanded Wojciech Polak
 LocalWords:  Alexandre MERCHANTABILITY yytype emplace ptr automove lvalues
- LocalWords:  nonterminal yy args Pragma dereference yyformat rhs docdir
+ LocalWords:  nonterminal yy args Pragma dereference yyformat rhs docdir bw
 LocalWords:  Redeclarations rpcalc Autoconf YFLAGS Makefiles PROG DECL num
 LocalWords:  Heimbigner AST src ast Makefile srcdir MinGW xxlex XXSTYPE
 LocalWords:  XXLTYPE strictfp IDEs ffixit fdiagnostics parseable fixits
 LocalWords:  Wdeprecated yytext Variadic variadic yyrhs yyphrs RCS README
- LocalWords:  noexcept constexpr ispell american deprecations
+ LocalWords:  noexcept constexpr ispell american deprecations backend

 Local Variables:
 ispell-dictionary: "american"
@@ -1,25 +1,25 @@
 This package contains the GNU Bison parser generator.

-* Installation
-** Build from git
+# Installation
+## Build from git
 Here are basic installation instructions for a repository checkout:

-    $ git submodules update --init
+    $ git submodule update --init
    $ ./bootstrap

 then proceed with the usual 'configure && make' steps.

-README-hacking contains more information about building and modifying the
-software.
+Be sure to read README-hacking, which contains all the needed information
+about building, modifying and checking Bison.

-** Build for tarball
+## Build from tarball
 See the file INSTALL for generic compilation and installation instructions.

 Bison requires GNU m4 1.4.6 or later.  See:

      https://ftp.gnu.org/gnu/m4/m4-1.4.6.tar.gz

-** Relocatability
+## Relocatability
 If you pass '--enable-relocatable' to 'configure', Bison is relocatable.

 A relocatable program can be moved or copied to a different location on the
@@ -29,7 +29,7 @@ invoke them through the symlink.

 See "Enabling Relocatability" in the documentation.

-** Internationalization
+## Internationalization
 Bison supports two catalogs: one for Bison itself (i.e., for the
 maintainer-side parser generation), and one for the generated parsers (i.e.,
 for the user-side parser execution).  The requirements between both differ:
@@ -39,7 +39,7 @@ generated parsers could have been localized.  See
 http://lists.gnu.org/archive/html/bug-bison/2009-08/msg00006.html for more
 details.

-* Questions
+# Questions
 See the section FAQ in the documentation (doc/bison.info) for frequently
 asked questions.  The documentation is also available in PDF and HTML,
 provided you have a recent version of Texinfo installed: run "make pdf" or
@@ -48,19 +48,19 @@ provided you have a recent version of Texinfo installed: run "make pdf" or
 If you have questions about using Bison and the documentation does not
 answer them, please send mail to <[email protected]>.

-* Bug reports
+# Bug reports
 Please send bug reports to <[email protected]>.  Be sure to include the
 version number from 'bison --version', and a complete, self-contained test
 case in each bug report.

-* Copyright statements
+# Copyright statements
 For any copyright year range specified as YYYY-ZZZZ in this package, note
 that the range specifies every single year in that closed interval.

-----
+<!--

 Local Variables:
-mode: outline
+mode: markdown
 fill-column: 76
 ispell-dictionary: "american"
 End:
@@ -83,5 +83,7 @@ GNU General Public License for more details.
 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.

-# LocalWords:  parsers ngettext Texinfo pdf html YYYY ZZZZ ispell american
-# LocalWords:  MERCHANTABILITY
+LocalWords:  parsers ngettext Texinfo pdf html YYYY ZZZZ ispell american
+LocalWords:  MERCHANTABILITY
+
+-->
@@ -45,8 +45,8 @@ processes tabs in its input.

 * Working from the repository

-These notes intend to help people working on the checked-out sources.
-These requirements do not apply when building from a distribution tarball.
+These notes intend to help people working on the checked-out sources.  These
+requirements do not apply when building from a distribution tarball.

 ** Requirements

@@ -201,7 +201,6 @@ added the "[-Wother]" part to all the warnings).  Part of the update can be
 done with a crude tool: tests/update-test.  Read it for more information.

 ** TESTSUITEFLAGS
-
 To run just the testsuite (not the tests related to the examples), run `make
 check-local`.

@@ -212,6 +211,10 @@ can be sped up in two ways:
 Using -j, in a make-like fashion, for example:
  $ make check-local TESTSUITEFLAGS='-j8'

+Actually, when using GNU Make, TESTSUITEFLAGS defaults to the -jN passed to
+it, so you may simply run
+  $ make check-local -j8
+
 Running only the tests of a certain category, as specified in the AT files
 with AT_KEYWORDS([[category]]). Categories include:
  - c++, for c++ parsers
@@ -224,6 +227,10 @@ To run a specific set of tests, use -k (for "keyword"). For example:
  $ make check-local TESTSUITEFLAGS='-k c++'

 Both can be combined.
+  $ make check-local TESTSUITEFLAGS='-j8 -k c++'
+
+To rerun the tests that failed:
+  $ make recheck -j5

 ** Typical errors
 If the test suite shows failures such as the following one
@@ -309,7 +316,7 @@ re-run the tests, run:

    ./gnulib-tool --symlink --create-test --dir=/tmp/gnutest bitset-tests
    cd /tmp/gnutest
-    ./configure CC='gcc-mp-8 -fsanitize=undefined'
+    ./configure -C CC='gcc-mp-8 -fsanitize=undefined' CFLAGS='-ggdb'
    make check

 * Release Procedure
@@ -0,0 +1 @@
+README
@@ -10,6 +10,7 @@ Albert Chin-A-Young       [email protected]
 Alexander Belopolsky      [email protected]
 Alexandre Duret-Lutz      [email protected]
 Andre da Costa Barros     [email protected]
+Andreas Damm              [email protected]
 Andreas Schwab            [email protected]
 Andrew Suffield           [email protected]
 Angelo Borsotti           [email protected]
@@ -33,6 +34,7 @@ Bruce Lilly               [email protected]
 Bruno Haible              [email protected]
 Charles-Henri de Boysson  [email protected]
 Christian Burger          [email protected]
+Clément Démoulins         [email protected]
 Colin Daley               [email protected]
 Cris Bailiff              [email protected]
 Cris van Pelt             [email protected]
@@ -66,6 +68,7 @@ Frank Heckenbach          [email protected]
 Frans Englich             [email protected]
 Gabriel Rassoul           [email protected]
 Gary L Peskin             [email protected]
+Gavin Smith               [email protected]
 Georg Sauthoff            [email protected]
 George Neuner             [email protected]
 Gilles Espinasse          [email protected]
@@ -87,15 +90,19 @@ Jonathan Fabrizio         [email protected]
 Jonathan Nieder           [email protected]
 Josh Soref                [email protected]
 Juan Manuel Guerrero      [email protected]
+Karl Berry                [email protected]
 Kees Zeelenberg           [email protected]
 Keith Browne              [email protected]
 Ken Moffat                [email protected]
 Kiyoshi Kanazawa          [email protected]
+Lars Maier                [email protected]
+László Várady             [email protected]
 Laurent Mascherpa         [email protected]
 Lie Yan                   [email protected]
 Magnus Fromreide          [email protected]
 Marc Autret               [email protected]
 Marc Mendiola             [email protected]
+Marc Schönefeld           [email protected]
 Mark Boyall               [email protected]
 Martin Jacobs             [email protected]
 Martin Mokrejs            [email protected]
@@ -116,6 +123,7 @@ Mike Sullivan             [email protected]
 Nate Guerin               [email protected]
 Neil Booth                [email protected]
 Nelson H. F. Beebe        [email protected]
+neok m4700                [email protected]
 Nick Bowler               [email protected]
 Nicolas Bedon             [email protected]
 Nicolas Burrus            [email protected]
@@ -128,6 +136,7 @@ Oliver Mangold            [email protected]
 Paolo Bonzini             [email protected]
 Paolo Simone Gasparello   [email protected]
 Pascal Bart               [email protected]
+Patrice Dumas             [email protected]
 Paul Eggert               [email protected]
 Paul Hilfinger            [email protected]
 Per Allansson             [email protected]
@@ -166,16 +175,20 @@ Sum Wu                    [email protected]
 Théophile Ranquet         [email protected]
 Thiru Ramakrishnan        [email protected]
 Thomas Jahns              [email protected]
+Thomas Petazzoni          [email protected]
 Tim Josling               [email protected]
 Tim Landscheidt           [email protected]
 Tim Van Holder            [email protected]
 Tobias Frost              [email protected]
 Todd Freed                [email protected]
+Tom Kramer                [email protected]
 Tom Lane                  [email protected]
 Tom Tromey                [email protected]
+Tomasz Kłoczko            [email protected]
 Tommy Nordgren            [email protected]
 Troy A. Johnson           [email protected]
 Tys Lefering              [email protected]
+Uxio Prego                [email protected]
 Valentin Tolmer           [email protected]
 wcventure                 [email protected]
 Victor Khomenko           [email protected]
@@ -190,8 +203,10 @@ Wolfgang Thaller          [email protected]
 Wolfram Wagner            [email protected]
 Wwp                       [email protected]
 xolodho                   [email protected]
+Yuichiro Kaneko           [email protected]
 Zack Weinberg             [email protected]
 長田偉伸                   [email protected]
+江 祖铭                    [email protected]

 Many people are not named here because we lost track of them.  We
 thank them!  Please, help us keeping this list up to date.
@@ -1,25 +1,3 @@
-* Bison 3.4
-** bad diagnostics
-%token <val> NUM
-%type  <val> expr term fact
-
-%%
-
-res:  expr { printf ("%d\n", $1); };
-expr: expr '+' term { $$ = $1 + $3; } | term;
-term: NUM | { $$ = 0; };
-
-The second warning about fact is... useless.
-
-$ bison /tmp/bar.y
-/tmp/bar.y:2.24-27: warning: symbol fact is used, but is not defined as a token and has no rules [-Wother]
- %type  <val> expr term fact
-                        ^~~~
-/tmp/bar.y: warning: 1 nonterminal useless in grammar [-Wother]
-/tmp/bar.y:2.24-27: warning: nonterminal useless in grammar: fact [-Wother]
- %type  <val> expr term fact
-                        ^~~~
-
 * Bison 3.5
 ** doc
 I feel its ugly to use the GNU style to declare functions in the doc.  It
@@ -29,9 +7,6 @@ breaks.
 Also, we seem to teach YYPRINT very early on, although it should be
 considered deprecated: %printer is superior.

-** glr.cc
-move glr.c into the yy namespace
-
 ** improve syntax errors (UTF-8, internationalization)
 Bison depends on the current locale.  For instance:

@@ -73,10 +48,15 @@ syntax error, unexpected $end, expecting ↦ or 🎅🐃 or '\n'


 While at it, we should stop using "$end" by default, in favor of "end of
-file", or "end of input", whatever.
+file", or "end of input", whatever.  See how lalr1.java does that.
+
+** api.token.raw
+Maybe we should exhibit the YYUNDEFTOK token.  It could also be assigned a
+semantic value so that yyerror could be used to report invalid lexemes.
+See also the item "$undefined" below.

 * Bison 3.6
-** Unit rules
+** Unit rules / Injection rules (Akim Demaille)
 Maybe we could expand unit rules (or "injections", see
 https://homepages.cwi.nl/~daybuild/daily-books/syntax/2-sdf/sdf.html), i.e.,
 transform
@@ -95,10 +75,12 @@ Practice' is impossible to find, but according to 'Parsing Techniques: a
 Practical Guide', it includes information about this issue.  Does anybody
 have it?

-** Injection rules
-See above.
+** clean up (Akim Demaille)
+Do not work on these items now, as I (Akim) have branches with a lot of
+changes in this area (hitting several files), and no desire to have to fix
+conflicts.  Addressing these items will happen after my branches have been
+merged.

-** clean up
 *** lalr.c
 Introduce a goto struct, and use it in place of from_state/to_state.
 Rename states1 as path, length as pathlen.
@@ -119,7 +101,20 @@ introduce lr(0) and lalr, just the way we have ielr categories.  The
 "set" can still be used for summariring the important sets.  That would make
 tests easy to maintain.

+*** complain.*
+Rename these guys as "diagnostics.*" (or "diagnose.*"), since that's the
+name they have in gcc, clang, etc.  Likewise for the complain_* series of
+functions.

+*** ritem
+states/nstates, rules/nrules, ..., ritem/nritems
+Fix the latter.
+
+* Modernization
+Fix data/skeletons/yacc.c so that it defines YYPTRDIFF_T properly for modern
+and older C++ compilers.  Currently the code defaults to defining it to
+'long' for non-GCC compilers, but it should use the proper C++ magic to
+define it to the same type as the C ptrdiff_t type.

 * Completion
 Several features are not available in all the backends.
@@ -139,8 +134,88 @@ $ ./tests/testsuite -l | grep errors | sed q
  38: input.at:1730      errors

 * Short term
+** Stop indentation in diagnostics
+Before Bison 2.7, we printed "flatly" the dependencies in long diagnostics:
+
+    input.y:2.7-12: %type redeclaration for exp
+    input.y:1.7-12: previous declaration
+
+In Bison 2.7, we indented them
+
+    input.y:2.7-12: error: %type redeclaration for exp
+    input.y:1.7-12:     previous declaration
+
+Later we quoted the source in the diagnostics, and today we have:
+
+    /tmp/foo.y:1.12-14: warning: symbol FOO redeclared [-Wother]
+        1 | %token FOO FOO
+          |            ^~~
+    /tmp/foo.y:1.8-10:      previous declaration
+        1 | %token FOO FOO
+          |        ^~~
+
+The indentation is no longer helping.  We should probably get rid of it, or
+maybe keep it only when -fno-caret. GCC displays this as a "note":
+
+    $ g++-mp-9 -Wall /tmp/foo.c -c
+    /tmp/foo.c:1:10: error: redefinition of 'int foo'
+        1 | int foo, foo;
+          |          ^~~
+    /tmp/foo.c:1:5: note: 'int foo' previously declared here
+        1 | int foo, foo;
+          |     ^~~
+
+Likewise for Clang, contrary to what I believed (because "note:" is written
+in black, so it doesn't show in my terminal :-)
+
+    $ clang++-mp-8.0 -Wall /tmp/foo.c -c
+    clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
+    /tmp/foo.c:1:10: error: redefinition of 'foo'
+    int foo, foo;
+             ^
+    /tmp/foo.c:1:5: note: previous definition is here
+    int foo, foo;
+        ^
+    1 error generated.
+
+See also the item "Complaint submessage indentation" below.
+
+** Better design for diagnostics
+The current implementation of diagnostics is adhoc, it grew organically.  It
+works as a series of calls to several functions, with dependency of the
+latter calls on the former.  For instance:
+
+      complain (&sym->location,
+                sym->content->status == needed ? complaint : Wother,
+                _("symbol %s is used, but is not defined as a token"
+                  " and has no rules; did you mean %s?"),
+                quote_n (0, sym->tag),
+                quote_n (1, best->tag));
+      if (feature_flag & feature_caret)
+        location_caret_suggestion (sym->location, best->tag, stderr);
+
+We should rewrite this in a more FP way:
+
+1. build a rich structure that denotes the (complete) diagnostic.
+   "Complete" in the sense that it also contains the suggestions, the list
+   of possible matches, etc.
+
+2. send this to the pretty-printing routine.  The diagnostic structure
+   should be sufficient so that we can generate all the 'format' of
+   diagnostics, including the fixits.
+
+If properly done, this diagnostic module can be detached from Bison and be
+put in gnulib.  It could be used, for instance, for errors caught by
+xgettext.
+
+There's certainly already something alike in GCC.  At least that's the
+impression I get from reading the "-fdiagnostics-format=FORMAT" part of this
+page:
+
+https://gcc.gnu.org/onlinedocs/gcc/Diagnostic-Message-Formatting-Options.html
+
 ** consistency
-token vs terminal
+token vs terminal, variable vs non terminal.

 ** C++
 Move to int everywhere instead of unsigned?  stack_size, etc.  The parser
@@ -148,11 +223,10 @@ itself uses int (for yylen for instance), yet stack is based on size_t.

 Maybe locations should also move to ints.

-** C
-Introduce state_type rather than spreading yytype_int16 everywhere?
-
-** glr.c
-yyspaceLeft should probably be a pointer diff.
+Paul Eggert already covered most of this.  But before publishing these
+changes, we need to ask our C++ users if they agree with that change, or if
+we need some migration path.  Could be a %define variable, or simply
+%require "3.5".

 ** Graphviz display code thoughts
 The code for the --graph option is over two files: print_graph, and
@@ -173,9 +247,6 @@ Little effort seems to have been given to factoring these files and their
 rint{,-xml} counterpart. We would very much like to re-use the pretty format
 of states from .output for the graphs, etc.

-Also, the underscore in print_graph.[ch] isn't very fitting considering the
-dashes in the other filenames.
-
 Since graphviz dies on medium-to-big grammars, maybe consider an other tool?

 ** push-parser
@@ -233,11 +304,13 @@ since it is no longer bound to a particular parser, it's just a
 (standalone symbol).

 * Various
-** Rewrite glr.cc in C++
+** Rewrite glr.cc in C++ (Valentin Tolmer)
 As a matter of fact, it would be very interesting to see how much we can
 share between lalr1.cc and glr.cc.  Most of the skeletons should be common.
 It would be a very nice source of inspiration for the other languages.

+Valentin Tolmer is working on this.
+
 ** YYERRCODE
 Defined to 256, but not used, not documented.  Probably the token
 number for the error token, which POSIX wants to be 256, but which
@@ -307,10 +380,21 @@ other improvements and also made it faster (probably because memory
 management is performed once instead of three times).  I suggest that
 we do the same in yacc.c.

+(Some time later): it's also very nice to have three stacks: it's more dense
+as we don't lose bits to padding.  For instance the typical stack for states
+will use 8 bits, while it is likely to consume 32 bits in a struct.
+
+We need trustworthy benchmarks for Bison, for all our backends.  Akim has a
+few things scattered around; we need to put them in the repo, and make them
+more useful.
+
 ** yysyntax_error
 The code bw glr.c and yacc.c is really alike, we can certainly factor
 some parts.

+This should be worked on when we also address the expected improvements for
+error generation (e.g., i18n).
+

 * Report

@@ -350,7 +434,26 @@ LORIA, INRIA Nancy - Grand Est, Nancy, France

 * Extensions
 ** Multiple start symbols
-Would be very useful when parsing closely related languages.
+Would be very useful when parsing closely related languages.  The idea is to
+declare several start symbols, for instance
+
+    %start stmt expr
+    %%
+    stmt: ...
+    expr: ...
+
+and to generate parse(), parse_stmt() and parse_expr().  Technically, the
+above grammar would be transformed into
+
+   %start yy_start
+   %token YY_START_STMT YY_START_EXPR
+   %%
+   yy_start: YY_START_STMT stmt | YY_START_EXPR expr
+
+so that there are no new conflicts in the grammar (as would undoubtedly
+happen with yy_start: stmt | expr).  Then adjust the skeletons so that this
+initial token (YY_START_STMT, YY_START_EXPR) be shifted first in the
+corresponding parse function.

 ** Better error messages
 The users are not provided with enough tools to forge their error messages.
@@ -368,6 +471,12 @@ should make this reasonably easy to implement.
 Bruce Mardle <[email protected]>
 https://lists.gnu.org/archive/html/bison-patches/2015-09/msg00000.html

+However, there are many other things to do before having such a feature,
+because I don't want a % equivalent to #include (which we all learned to
+hate).  I want something that builds "modules" of grammars, and assembles
+them together, paying attention to keep separate bits separated, in pseudo
+name spaces.
+
 ** Push parsers
 There is demand for push parsers in Java and C++.  And GLR I guess.

@@ -394,6 +503,10 @@ must be in the scanner: we must not parse what is in a switched off
 part of %if.  Akim Demaille thinks it should be in the parser, so as
 to avoid falling into another CPP mistake.

+(Later): I'm sure there's actually good case for this.  People who need that
+feature can use m4/cpp on top of Bison.  I don't think it is worth the
+trouble in Bison itself.
+
 ** XML Output
 There are couple of available extensions of Bison targeting some XML
 output.  Some day we should consider including them.  One issue is
@@ -413,6 +526,9 @@ XML output for GNU Bison
 https://lists.gnu.org/archive/html/bug-bison/2016-06/msg00000.html
 http://www.cs.cornell.edu/andru/papers/cupex/

+Andrew Myers and Vincent Imbimbo are working on this item, see
+https://github.com/akimd/bison/issues/12
+
 * Coding system independence
 Paul notes:

@@ -430,7 +546,7 @@ Paul notes:
        tokens, either via escapes (e.g., "x\0y") or via a NUL byte in
        the source code.  This should get fixed.

-* Broken options ?
+* Broken options?
 ** %token-table
 ** Skeleton strategy
 Must we keep %token-table?
@@ -442,6 +558,7 @@ It is unfortunate that there is a total order for precedence.  It
 makes it impossible to have modular precedence information.  We should
 move to partial orders (sounds like series/parallel orders to me).

+This is a prerequisite for modules.

 * $undefined
 From Hans:
@@ -166,7 +166,7 @@ bootstrap_epilogue() { :; }
 # specified directory.  Fill in the first %s with the destination
 # directory and the second with the domain name.
 po_download_command_format=\
-"wget --mirror --level=1 -nd -q -A.po -P '%s' \
+"wget --mirror --level=1 -nd -nv -A.po -P '%s' \
 https://translationproject.org/latest/%s/"

 # Prefer a non-empty tarname (4th argument of AC_INIT if given), else
@@ -22,15 +22,16 @@ gnulib_modules='
  calloc-posix close closeout config-h c-strcase
  configmake
  dirname
-  error extensions fdl fopen-safer
+  error extensions
+  fdl fopen-safer fstrcmp
  getopt-gnu
  gettext-h git-version-gen gitlog-to-changelog
-  gpl-3.0 hash inttypes isnan javacomp-script
+  gpl-3.0 intprops inttypes isnan javacomp-script
  javaexec-script
  ldexpl
  libtextstyle-optional
  malloc-gnu
-  mbswidth
+  mbfile mbswidth
  non-recursive-gnulib-prefix-hack
  obstack
  obstack-printf
@@ -45,9 +46,12 @@ gnulib_modules='
  unistd unistd-safer unlink unlocked-io
  update-copyright unsetenv verify
  warnings
+  winsz-ioctl
+  winsz-termios
  xalloc
  xalloc-die
  xconcat-filename
+  xhash
  xlist
  xmemdup0
  xstrndup
@@ -86,6 +90,13 @@ bootstrap_epilogue()
  touch src/parse-gram.[ch]

  perl -pi -e "s/\@PACKAGE\@/$package/g" README-release
+
+  # Bison currently uses Gettext 0.19, but the gnulib-po module
+  # imports files from more recent versions of Gettext that are not
+  # yet available widely enough (e.g., not in bionic, used by the CI).
+  # Work around this.  Don't use autopoint, which sends some other
+  # files in the past.
+  cp po/Makefile.in.in gnulib-po
 }

 # Keep our bootstrap script in sync with gnulib's.  If we ever need to
@@ -12,7 +12,7 @@ while (<STDIN>)
 {
    if (/^\s*             # Initial spaces.
        (?:(-\w),\s+)?    # $1: $short: Possible short option.
-        (--[-\w]+)        # $2: $long:  Long option.
+        (--[-\w]+)        # $2: $long:  Mandatory long option.
        (\[?)             # $3: $opt:   '[' iff the argument is optional.
        (?:=(\S+))?       # $4: $arg:   Possible argument name.
        \s                # Spaces.
@@ -32,7 +32,6 @@ while (<STDIN>)
            # if $opt, $arg contains the closing ].
            substr ($arg, -1) = ''
                if $opt eq '[';
-            $arg =~ s/^=//;
            $arg = lc ($arg);
            my $dir_arg = $arg;
            # If the argument is complete (e.g., for --define[=NAME[=VALUE]]),
@@ -72,12 +71,15 @@ while (<STDIN>)
 my $sep = '';
 foreach my $long (sort keys %option)
 {
-    # Avoid trailing spaces.
-    print $sep;
-    $sep = "\n";
-    print '@item @option{', $long, "}\n\@tab";
-    print ' @option{', $option{$long}, '}' if $option{$long};
-    print "\n\@tab";
-    print ' @code{', $directive{$long}, '}' if $directive{$long};
-    print "\n";
+    # Couldn't find a means to escape @ in the format (for @item, @tab), so
+    # pass it as a literal to print.
+format STDOUT =
+@item @<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< @tab @<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< @tab @<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
+{
+  '@', '@option{' . $long . '}',
+  '@', $option{$long} ? ('@option{' . $option{$long} . '}') : '',
+  '@', $directive{$long} ? ('@code{' . $directive{$long} . '}') : ''
+}
+.
+    write;
 }
@@ -1,7 +1,7 @@
 #! /usr/bin/env python

 # usage:
-# update-test _build/8d/tests/testsuite.dir/*.testsuite.log
+# update-test _build/8d/tests/testsuite.dir/*/testsuite.log

 import argparse
 import os
@@ -11,8 +11,8 @@ import re
 def getargs():
    p = argparse.ArgumentParser(description='Update test cases.')
    opt = p.add_argument
-    opt('tests', metavar='test', nargs='+', type=str, default=None,
-        help='test files to update')
+    opt('logs', metavar='log', nargs='+', type=str, default=None,
+        help='log files to process')
    opt('-v', '--verbose', action='store_true',
        help='Be verbose')
    return p.parse_args()
@@ -21,14 +21,14 @@ args = getargs()
 subst = dict()


-def log(*args_):
+def trace(*args_):
    if args.verbose:
        print(*args_)


 def contents(file):
    '''The contents of a file.'''
-    log(file)
+    trace(file)
    f = open(file)
    return f.read()

@@ -60,9 +60,9 @@ def diff_to_re(match):
 def update(at_file, logfile):
    test = contents(at_file)
    if os.path.isfile(logfile):
-        log("LOG: ", logfile)
+        trace("LOG: ", logfile)
        l = contents(logfile)
-        log("LOG: ", l)
+        trace("LOG: ", l)
        global subst
        subst = {}
        re.sub(r'(?:^@@.*\n)((?:^[-+ ].*\n)+)',
@@ -71,7 +71,7 @@ def update(at_file, logfile):
        if subst:
            # Turn "subst{frm} -> to" into a large RE.
            frm = '|'.join([re.escape(x) for x in subst])
-            log("FROM:", frm)
+            trace("FROM:", frm)
            test = re.sub("(" + frm + ")",
                          lambda m: subst[m.group(1)],
                          test, flags=re.MULTILINE)
@@ -81,13 +81,14 @@ def update(at_file, logfile):
 def process(logfile):
    log = contents(logfile)
    # Look for the file to update.
-    m = re.search(r'^\d+\. (\w+\.at):\d+: ', log, re.MULTILINE)
+    m = re.search(r'^\d+\. ([-\w]+\.at):\d+: ', log, re.MULTILINE)
    if not m:
+        trace("no diff found:", logfile)
        return
    at_file = 'tests/' + m.group(1)
    print(at_file)
    update(at_file, logfile)

-for t in args.tests:
-    log("FILE:", t)
-    process(t)
+for logfile in args.logs:
+    trace("FILE:", logfile)
+    process(logfile)
@@ -26,6 +26,9 @@ regen: _version
 manual_title = The Yacc-compatible Parser Generator
 gendocs_options_ = -I $(abs_top_srcdir)/doc -I $(abs_top_builddir)/doc

+# By default, propagate -j from make to Bison's test suite.
+TESTSUITEFLAGS = $(filter -j%,$(MAKEFLAGS))
+
 # It's useful to run maintainer-check* targets during development, but we
 # don't want to wait on a recompile because of an update to $(VERSION).  Thus,
 # override the _is-dist-target from GNUmakefile so that maintainer-check*
@@ -36,6 +36,9 @@ AC_CONFIG_MACRO_DIR([m4])

 # We use Automake 1.14's %D% and %C%.
 #
+# When we move to Automake 1.16, simplify examples/c/reccalc/local.mk.
+# Our CI runs on Xenial, which has only Automake 1.15.
+#
 # We want gnits strictness only when rolling a stable release.  For
 # release candidates, we use version strings like 2.4.3_rc1, but gnits
 # doesn't like that, so we let the underscore disable gnits.  Between
@@ -94,9 +97,13 @@ AC_ARG_ENABLE([gcc-warnings],
              [enable_gcc_warnings=no])
 AM_CONDITIONAL([ENABLE_GCC_WARNINGS], [test "$enable_gcc_warnings" = yes])
 if test "$enable_gcc_warnings" = yes; then
-  warn_common='-Wall -Wextra -Wno-sign-compare -Wcast-align
+  # -Wno-tautological-constant-out-of-range-compare for Clang 3.3 and
+  # 3.4 on GNU/Linux that choke on intprops.h's INT_MULTIPLY_WRAPV,
+  # etc.
+  warn_common='-Wall -Wextra -Wcast-align
    -fparse-all-comments -Wdocumentation
    -Wformat -Wimplicit-fallthrough -Wnull-dereference
+    -Wno-sign-compare -Wno-tautological-constant-out-of-range-compare
    -Wpointer-arith -Wshadow
    -Wwrite-strings'
  warn_c='-Wbad-function-cast -Wstrict-prototypes'
@@ -112,6 +119,7 @@ if test "$enable_gcc_warnings" = yes; then
  # details for lalr1.cc.
  warn_tests='-Wundef -pedantic -Wconversion
    -Wdeprecated -Wsign-compare -Wsign-conversion
+    -Wtautological-constant-out-of-range-compare
    -fno-color-diagnostics
    -Wno-keyword-macro'

@@ -192,7 +200,7 @@ BISON_CXX_COMPILER_POSIXLY_CORRECT

 # D.
 AC_CHECK_PROGS([DC], [dmd])
-AC_CHECK_PROGS([DCFLAGS], [])
+AC_CHECK_PROGS([DCFLAGS], [-g])
 AM_CONDITIONAL([ENABLE_D], [test x"$DC" != x])

 # Java.
@@ -211,10 +219,11 @@ AC_CONFIG_FILES([src/yacc], [chmod +x src/yacc])
 # Checks for programs.
 AM_MISSING_PROG([DOT], [dot])
 AC_PROG_LEX
-$LEX_IS_FLEX || test "X$LEX" = X: || {
+if ! "$LEX_IS_FLEX" || test "X$LEX" = X:; then
  AC_MSG_WARN([bypassing lex because flex is required])
  LEX=:
-}
+fi
+AM_CONDITIONAL([FLEX_WORKS], [$LEX_IS_FLEX])
 AM_CONDITIONAL([FLEX_CXX_WORKS],
  [$LEX_IS_FLEX && test $bison_cv_cxx_works = yes])
 AC_PROG_YACC
@@ -224,9 +233,6 @@ AC_DEFINE_UNQUOTED([M4], ["$M4"], [Define to the GNU M4 executable name.])
 AC_DEFINE_UNQUOTED([M4_GNU_OPTION], ["$M4_GNU"], [Define to "-g" if GNU M4
 supports -g, otherwise to "".])
 AC_PATH_PROG([PERL], [perl])
-if test -z "$PERL"; then
-   AC_MSG_ERROR([perl not found])
-fi
 AM_MISSING_PROG([HELP2MAN], [help2man])
 AC_PATH_PROG([XSLTPROC], [xsltproc])
 AC_SUBST([XSLTPROC])
@@ -243,7 +249,6 @@ gl_INIT

 # Checks for library functions.
 AC_CHECK_FUNCS_ONCE([setlocale])
-AM_WITH_DMALLOC

 # Gettext.
 # We use gnulib, which is only guaranteed to work properly with the
@@ -296,4 +301,15 @@ AC_SUBST([GCC])
 AC_CONFIG_FILES([Makefile
                 po/Makefile.in
                 doc/yacc.1])
+
+# Fix LIBOBJS to give the Makefile the right file names.  Otherwise
+# compilation works, but with unexpected file names, so clean rules don't
+# remove the actual files and distcheck fails.
+AC_CONFIG_COMMANDS_PRE([
+  case $am__api_version in
+    1.14*|1.15*) gl_LIBOBJS=`echo "$gl_LIBOBJS" | sed -e 's, lib/, lib/lib_libbison_a-,g'`;;
+    *)           gl_LIBOBJS=`echo "$gl_LIBOBJS" | sed -e 's, lib/, lib/libbison_a-,g'`;;
+  esac
+])
+
 AC_OUTPUT
@@ -0,0 +1,31 @@
+/* Default styling rules for Bison when doing terminal output.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* This is an experimental feature.  The class names may change in the
+   future.  */
+
+/* Diagnostics.  */
+.warning   { color: purple; }
+.error     { color: red; }
+.note      { color: cyan; }
+
+.fixit-insert { color: green; }
+
+/* Semantic values in Bison's own parser traces.  */
+.value     { color: green; }
+
+/* "Sections" in traces (--trace).  */
+.trace0    { color: green; }
@@ -1,10 +0,0 @@
-/* CSS style for Bison's diagnostics.
-
-   This is an experimental feature.  The class names may change in the
-   future.  */
-
-.warning   { color: purple; }
-.error     { color: red; }
-.note      { color: cyan; }
-/* Semantic values in Bison's parser traces.  */
-.value     { color: green; }
@@ -16,7 +16,7 @@

 dist_pkgdata_DATA =                             \
  data/README.md                                \
-  data/diagnostics.css
+  data/bison-default.css

 skeletonsdir = $(pkgdatadir)/skeletons
 dist_skeletons_DATA =                           \
@@ -449,7 +449,7 @@ m4_define([b4_symbol_action],
                   [(*yylocationp)])dnl
    _b4_symbol_case([$1])[]dnl
 b4_syncline([b4_symbol([$1], [$2_line])], [b4_symbol([$1], [$2_file])])dnl
-      b4_symbol([$1], [$2])
+b4_symbol([$1], [$2])
 b4_syncline([@oline@], [@ofile@])dnl
        break;

@@ -535,7 +535,7 @@ m4_define([b4_token_format],
 [b4_token_visible_if([$2],
 [m4_quote(m4_format([$1],
                     [b4_symbol([$2], [id])],
-                     [b4_symbol([$2], [user_number])]))])])
+                     [b4_symbol([$2], b4_api_token_raw_if([[number]], [[user_number]]))]))])])


 ## ------- ##
@@ -1002,6 +1002,7 @@ m4_define([b4_percent_code_ifdef],
 # b4_parse_trace_if([IF-DEBUG-TRACES-ARE-ENABLED], [IF-NOT])
 # b4_token_ctor_if([IF-YYLEX-RETURNS-A-TOKEN], [IF-NOT])
 # ----------------------------------------------------------
+b4_percent_define_if_define([api.token.raw])
 b4_percent_define_if_define([token_ctor], [api.token.constructor])
 b4_percent_define_if_define([locations])     # Whether locations are tracked.
 b4_percent_define_if_define([parse.assert])
@@ -532,7 +532,9 @@ m4_define([b4_yytranslate_define],
  ]b4_parser_class[::yytranslate_ (]b4_token_ctor_if([token_type],
                                                          [int])[ t)
  {
-    // YYTRANSLATE[TOKEN-NUM] -- Symbol number corresponding to
+]b4_api_token_raw_if(
+[[    return static_cast<yy::parser::token_number_type> (t);]],
+[[    // YYTRANSLATE[TOKEN-NUM] -- Symbol number corresponding to
    // TOKEN-NUM as returned by yylex.
    static
    const token_number_type
@@ -540,15 +542,15 @@ m4_define([b4_yytranslate_define],
    {
  ]b4_translate[
    };
-    const unsigned user_token_number_max_ = ]b4_user_token_number_max[;
+    const int user_token_number_max_ = ]b4_user_token_number_max[;
    const token_number_type undef_token_ = ]b4_undef_token_number[;

    if (static_cast<int> (t) <= yyeof_)
      return yyeof_;
-    else if (static_cast<unsigned> (t) <= user_token_number_max_)
+    else if (static_cast<int> (t) <= user_token_number_max_)
      return translate_table[t];
    else
-      return undef_token_;
+      return undef_token_;]])[
  }
 ]])

@@ -167,38 +167,110 @@ b4_parse_param_for([Decl], [Formal], [  YYUSE (Formal);

 # b4_int_type(MIN, MAX)
 # ---------------------
-# Return the smallest int type able to handle numbers ranging from
-# MIN to MAX (included).
+# Return a narrow int type able to handle integers ranging from MIN
+# to MAX (included) in portable C code.  Assume MIN and MAX fall in
+# 'int' range.
 m4_define([b4_int_type],
-[m4_if(b4_ints_in($@,      [0],   [255]), [1], [unsigned char],
-       b4_ints_in($@,   [-128],   [127]), [1], [signed char],
+[m4_if(b4_ints_in($@,   [-127],   [127]), [1], [signed char],
+       b4_ints_in($@,      [0],   [255]), [1], [unsigned char],

+       b4_ints_in($@, [-32767], [32767]), [1], [short],
       b4_ints_in($@,      [0], [65535]), [1], [unsigned short],
-       b4_ints_in($@, [-32768], [32767]), [1], [short],
-
-       m4_eval([0 <= $1]),                [1], [unsigned],

                                               [int])])

+# b4_c99_int_type(MIN, MAX)
+# -------------------------
+# Like b4_int_type, but for C99.
+# b4_c99_int_type_define replaces b4_int_type with this.
+m4_define([b4_c99_int_type],
+[m4_if(b4_ints_in($@,   [-127],   [127]), [1], [yytype_int8],
+       b4_ints_in($@,      [0],   [255]), [1], [yytype_uint8],
+
+       b4_ints_in($@, [-32767], [32767]), [1], [yytype_int16],
+       b4_ints_in($@,      [0], [65535]), [1], [yytype_uint16],
+
+                                               [int])])
+
+# b4_c99_int_type_define
+# ----------------------
+# Define private types suitable for holding small integers in C99 or later.
+m4_define([b4_c99_int_type_define],
+[m4_copy_force([b4_c99_int_type], [b4_int_type])dnl
+[/* On compilers that do not define __PTRDIFF_MAX__ etc., make sure
+   <limits.h> and (if available) <stdint.h> are included
+   so that the code can choose integer types of a good width.  */
+
+#ifndef __PTRDIFF_MAX__
+# include <limits.h> /* INFRINGES ON USER NAME SPACE */
+# if defined __STDC_VERSION__ && 199901 <= __STDC_VERSION__
+#  include <stdint.h> /* INFRINGES ON USER NAME SPACE */
+#  define YY_STDINT_H
+# endif
+#endif
+
+/* Narrow types that promote to a signed type and that can represent a
+   signed or unsigned integer of at least N bits.  In tables they can
+   save space and decrease cache pressure.  Promoting to a signed type
+   helps avoid bugs in integer arithmetic.  */
+
+#ifdef __INT_LEAST8_MAX__
+typedef __INT_LEAST8_TYPE__ yytype_int8;
+#elif defined YY_STDINT_H
+typedef int_least8_t yytype_int8;
+#else
+typedef signed char yytype_int8;
+#endif
+
+#ifdef __INT_LEAST16_MAX__
+typedef __INT_LEAST16_TYPE__ yytype_int16;
+#elif defined YY_STDINT_H
+typedef int_least16_t yytype_int16;
+#else
+typedef short yytype_int16;
+#endif
+
+#if defined __UINT_LEAST8_MAX__ && __UINT_LEAST8_MAX__ <= __INT_MAX__
+typedef __UINT_LEAST8_TYPE__ yytype_uint8;
+#elif (!defined __UINT_LEAST8_MAX__ && defined YY_STDINT_H \
+       && UINT_LEAST8_MAX <= INT_MAX)
+typedef uint_least8_t yytype_uint8;
+#elif !defined __UINT_LEAST8_MAX__ && UCHAR_MAX <= INT_MAX
+typedef unsigned char yytype_uint8;
+#else
+typedef short yytype_uint8;
+#endif
+
+#if defined __UINT_LEAST16_MAX__ && __UINT_LEAST16_MAX__ <= __INT_MAX__
+typedef __UINT_LEAST16_TYPE__ yytype_uint16;
+#elif (!defined __UINT_LEAST16_MAX__ && defined YY_STDINT_H \
+       && UINT_LEAST16_MAX <= INT_MAX)
+typedef uint_least16_t yytype_uint16;
+#elif !defined __UINT_LEAST16_MAX__ && USHRT_MAX <= INT_MAX
+typedef unsigned short yytype_uint16;
+#else
+typedef int yytype_uint16;
+#endif]])
+

 # b4_int_type_for(NAME)
 # ---------------------
-# Return the smallest int type able to handle numbers ranging from
+# Return a narrow int type able to handle numbers ranging from
 # 'NAME_min' to 'NAME_max' (included).
 m4_define([b4_int_type_for],
 [b4_int_type($1_min, $1_max)])


-# b4_table_value_equals(TABLE, VALUE, LITERAL)
-# --------------------------------------------
+# b4_table_value_equals(TABLE, VALUE, LITERAL, SYMBOL)
+# ----------------------------------------------------
 # Without inducing a comparison warning from the compiler, check if the
 # literal value LITERAL equals VALUE from table TABLE, which must have
-# TABLE_min and TABLE_max defined.
+# TABLE_min and TABLE_max defined.  SYMBOL denotes
 m4_define([b4_table_value_equals],
 [m4_if(m4_eval($3 < m4_indir([b4_]$1[_min])
               || m4_indir([b4_]$1[_max]) < $3), [1],
       [[0]],
-       [(!!(($2) == ($3)))])])
+       [(($2) == $4)])])


 ## ----------------- ##
@@ -210,22 +282,20 @@ m4_define([b4_table_value_equals],
 # Provide portable compiler "attributes".  If "noreturn" is passed, define
 # _Noreturn.
 m4_define([b4_attribute_define],
-[[#ifndef YY_ATTRIBUTE
-# if (defined __GNUC__                                               \
-      && (2 < __GNUC__ || (__GNUC__ == 2 && 96 <= __GNUC_MINOR__)))  \
-     || defined __SUNPRO_C && 0x5110 <= __SUNPRO_C
-#  define YY_ATTRIBUTE(Spec) __attribute__(Spec)
+[[#ifndef YY_ATTRIBUTE_PURE
+# if defined __GNUC__ && 2 < __GNUC__ + (96 <= __GNUC_MINOR__)
+#  define YY_ATTRIBUTE_PURE __attribute__ ((__pure__))
 # else
-#  define YY_ATTRIBUTE(Spec) /* empty */
+#  define YY_ATTRIBUTE_PURE
 # endif
 #endif

-#ifndef YY_ATTRIBUTE_PURE
-# define YY_ATTRIBUTE_PURE   YY_ATTRIBUTE ((__pure__))
-#endif
-
 #ifndef YY_ATTRIBUTE_UNUSED
-# define YY_ATTRIBUTE_UNUSED YY_ATTRIBUTE ((__unused__))
+# if defined __GNUC__ && 2 < __GNUC__ + (7 <= __GNUC_MINOR__)
+#  define YY_ATTRIBUTE_UNUSED __attribute__ ((__unused__))
+# else
+#  define YY_ATTRIBUTE_UNUSED
+# endif
 #endif

 ]m4_bmatch([$1], [\bnoreturn\b], [[/* The _Noreturn keyword of C11.  */
@@ -545,7 +615,9 @@ m4_if(b4_skeleton, ["yacc.c"],
 # endif
 ]])dnl
 b4_percent_code_get([[pre-printer]])dnl
+  YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
  b4_symbol_actions([printer])
+  YY_IGNORE_MAYBE_UNINITIALIZED_END
 b4_percent_code_get([[post-printer]])dnl
 [}

@@ -38,6 +38,11 @@ m4_define([b4_comment],
 [_b4_comment([$1], [$2/* ], [$2   ], [  */])])


+# b4_sync_start(LINE, FILE)
+# -------------------------
+m4_define([b4_sync_start], [[#]line $1 $2])
+
+
 # b4_list2(LIST1, LIST2)
 # ----------------------
 # Join two lists with a comma if necessary.
@@ -95,12 +100,6 @@ m4_define([b4_location_type_if],
 [b4_percent_define_ifdef([[location_type]], [$1], [$2])])


-# b4_locations_if(TRUE, FALSE)
-# ----------------------------
-m4_define([b4_locations_if],
-[m4_if(b4_locations_flag, 1, [$1], [$2])])
-
-
 # b4_identification
 # -----------------
 m4_define([b4_identification],
@@ -259,10 +259,14 @@ static YYLTYPE yyloc_default][]b4_yyloc_default;])[
 ]b4_user_post_prologue[
 ]b4_percent_code_get[]dnl

-[#include <stdio.h>
+[#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

+]b4_c99_int_type_define[
+
 #ifndef YY_
 # if defined YYENABLE_NLS && YYENABLE_NLS
 #  if ENABLE_NLS
@@ -285,7 +289,7 @@ static YYLTYPE yyloc_default][]b4_yyloc_default;])[
 # define YYREALLOC realloc
 #endif

-#define YYSIZEMAX ((size_t) -1)
+#define YYSIZEMAX (PTRDIFF_MAX < SIZE_MAX ? PTRDIFF_MAX : (ptrdiff_t) SIZE_MAX)

 #ifdef __cplusplus
  typedef bool yybool;
@@ -293,7 +297,7 @@ static YYLTYPE yyloc_default][]b4_yyloc_default;])[
 # define yyfalse false
 #else
  /* When we move to stdbool, get rid of the various casts to yybool.  */
-  typedef unsigned char yybool;
+  typedef signed char yybool;
 # define yytrue 1
 # define yyfalse 0
 #endif
@@ -346,15 +350,17 @@ static YYLTYPE yyloc_default][]b4_yyloc_default;])[

 /* YYTRANSLATE(TOKEN-NUM) -- Symbol number corresponding to TOKEN-NUM
   as returned by yylex, with out-of-bounds checking.  */
-#define YYTRANSLATE(YYX)                                                \
-  ((unsigned) (YYX) <= YYMAXUTOK ? yytranslate[YYX] : YYUNDEFTOK)
+]b4_api_token_raw_if(dnl
+[[#define YYTRANSLATE(YYX) (YYX)]],
+[[#define YYTRANSLATE(YYX)                         \
+  (0 <= (YYX) && (YYX) <= YYMAXUTOK ? yytranslate[YYX] : YYUNDEFTOK)

 /* YYTRANSLATE[TOKEN-NUM] -- Symbol number corresponding to TOKEN-NUM
   as returned by yylex.  */
 static const ]b4_int_type_for([b4_translate])[ yytranslate[] =
 {
  ]b4_translate[
-};
+};]])[

 #if ]b4_api_PREFIX[DEBUG
 /* YYRLINE[YYN] -- source line where rule number YYN was defined.  */
@@ -373,8 +379,8 @@ static const char *const yytname[] =
 };
 #endif

-#define YYPACT_NINF ]b4_pact_ninf[
-#define YYTABLE_NINF ]b4_table_ninf[
+#define YYPACT_NINF (]b4_pact_ninf[)
+#define YYTABLE_NINF (]b4_table_ninf[)

 ]b4_parser_tables_define[

@@ -488,7 +494,7 @@ typedef enum { yyok, yyaccept, yyabort, yyerr } YYRESULTTAG;
 int yydebug;

 struct yyGLRStack;
-static void yypstack (struct yyGLRStack* yystackp, size_t yyk)
+static void yypstack (struct yyGLRStack* yystackp, ptrdiff_t yyk)
  YY_ATTRIBUTE_UNUSED;
 static void yypdumpstack (struct yyGLRStack* yystackp)
  YY_ATTRIBUTE_UNUSED;
@@ -572,12 +578,12 @@ yystpcpy (char *yydest, const char *yysrc)
   backslash-backslash).  YYSTR is taken from yytname.  If YYRES is
   null, do not copy; instead, return the length of what the result
   would have been.  */
-static size_t
+static ptrdiff_t
 yytnamerr (char *yyres, const char *yystr)
 {
  if (*yystr == '"')
    {
-      size_t yyn = 0;
+      ptrdiff_t yyn = 0;
      char const *yyp = yystr;

      for (;;)
@@ -608,25 +614,25 @@ yytnamerr (char *yyres, const char *yystr)
    do_not_strip_quotes: ;
    }

-  if (! yyres)
-    return strlen (yystr);
-
-  return (size_t) (yystpcpy (yyres, yystr) - yyres);
+  if (yyres)
+    return yystpcpy (yyres, yystr) - yyres;
+  else
+    return (ptrdiff_t) strlen (yystr);
 }
 # endif

 #endif /* !YYERROR_VERBOSE */

-/** State numbers, as in LALR(1) machine */
+/** State numbers. */
 typedef int yyStateNum;

-/** Rule numbers, as in LALR(1) machine */
+/** Rule numbers. */
 typedef int yyRuleNum;

-/** Grammar symbol */
+/** Grammar symbol. */
 typedef int yySymbol;

-/** Item references, as in LALR(1) machine */
+/** Item references. */
 typedef short yyItemNum;

 typedef struct yyGLRState yyGLRState;
@@ -646,7 +652,7 @@ struct yyGLRState {
  /** Preceding state in this stack */
  yyGLRState* yypred;
  /** Source position of the last token produced by my symbol */
-  size_t yyposn;
+  ptrdiff_t yyposn;
  union {
    /** First in a chain of alternative reductions producing the
     *  nonterminal corresponding to this state, threaded through
@@ -666,7 +672,8 @@ struct yyGLRStateSet {
   *  operation, yylookaheadNeeds[0] is not maintained since it would merely
   *  duplicate yychar != YYEMPTY.  */
  yybool* yylookaheadNeeds;
-  size_t yysize, yycapacity;
+  ptrdiff_t yysize;
+  ptrdiff_t yycapacity;
 };

 struct yySemanticOption {
@@ -706,7 +713,7 @@ struct yyGLRStack {
  YYJMP_BUF yyexception_buffer;
  yyGLRStackItem* yyitems;
  yyGLRStackItem* yynextFree;
-  size_t yyspaceLeft;
+  ptrdiff_t yyspaceLeft;
  yyGLRState* yysplitPoint;
  yyGLRState* yylastDeleted;
  yyGLRStateSet yytops;
@@ -965,8 +972,8 @@ yylhsNonterm (yyRuleNum yyrule)
  return yyr1[yyrule];
 }

-#define yypact_value_is_default(Yystate) \
-  ]b4_table_value_equals([[pact]], [[Yystate]], [b4_pact_ninf])[
+#define yypact_value_is_default(Yyn) \
+  ]b4_table_value_equals([[pact]], [[Yyn]], [b4_pact_ninf], [YYPACT_NINF])[

 /** True iff LR state YYSTATE has only a default reduction (regardless
 *  of token).  */
@@ -983,8 +990,8 @@ yydefaultAction (yyStateNum yystate)
  return yydefact[yystate];
 }

-#define yytable_value_is_error(Yytable_value) \
-  ]b4_table_value_equals([[table]], [[Yytable_value]], [b4_table_ninf])[
+#define yytable_value_is_error(Yyn) \
+  ]b4_table_value_equals([[table]], [[Yyn]], [b4_table_ninf], [YYTABLE_NINF])[

 /** The action to take in YYSTATE on seeing YYTOKEN.
 *  Result R means
@@ -1064,7 +1071,7 @@ yynewGLRStackItem (yyGLRStack* yystackp, yybool yyisState)
 *  alternative actions for YYSTATE.  Assumes that YYRHS comes from
 *  stack #YYK of *YYSTACKP. */
 static void
-yyaddDeferredAction (yyGLRStack* yystackp, size_t yyk, yyGLRState* yystate,
+yyaddDeferredAction (yyGLRStack* yystackp, ptrdiff_t yyk, yyGLRState* yystate,
                     yyGLRState* yyrhs, yyRuleNum yyrule)
 {
  yySemanticOption* yynewOption =
@@ -1094,17 +1101,22 @@ yyinitStateSet (yyGLRStateSet* yyset)
 {
  yyset->yysize = 1;
  yyset->yycapacity = 16;
-  yyset->yystates = (yyGLRState**) YYMALLOC (16 * sizeof yyset->yystates[0]);
+  yyset->yystates
+    = (yyGLRState**) YYMALLOC ((size_t) yyset->yycapacity
+                               * sizeof yyset->yystates[0]);
  if (! yyset->yystates)
    return yyfalse;
  yyset->yystates[0] = YY_NULLPTR;
-  yyset->yylookaheadNeeds =
-    (yybool*) YYMALLOC (16 * sizeof yyset->yylookaheadNeeds[0]);
+  yyset->yylookaheadNeeds
+    = (yybool*) YYMALLOC ((size_t) yyset->yycapacity
+                          * sizeof yyset->yylookaheadNeeds[0]);
  if (! yyset->yylookaheadNeeds)
    {
      YYFREE (yyset->yystates);
      return yyfalse;
    }
+  memset (yyset->yylookaheadNeeds,
+          0, (size_t) yyset->yycapacity * sizeof yyset->yylookaheadNeeds[0]);
  return yytrue;
 }

@@ -1117,13 +1129,14 @@ static void yyfreeStateSet (yyGLRStateSet* yyset)
 /** Initialize *YYSTACKP to a single empty stack, with total maximum
 *  capacity for all stacks of YYSIZE.  */
 static yybool
-yyinitGLRStack (yyGLRStack* yystackp, size_t yysize)
+yyinitGLRStack (yyGLRStack* yystackp, ptrdiff_t yysize)
 {
  yystackp->yyerrState = 0;
  yynerrs = 0;
  yystackp->yyspaceLeft = yysize;
  yystackp->yyitems =
-    (yyGLRStackItem*) YYMALLOC (yysize * sizeof yystackp->yynextFree[0]);
+    (yyGLRStackItem*) YYMALLOC ((size_t) yysize
+                                * sizeof yystackp->yynextFree[0]);
  if (!yystackp->yyitems)
    return yyfalse;
  yystackp->yynextFree = yystackp->yyitems;
@@ -1147,15 +1160,16 @@ yyexpandGLRStack (yyGLRStack* yystackp)
 {
  yyGLRStackItem* yynewItems;
  yyGLRStackItem* yyp0, *yyp1;
-  size_t yynewSize;
-  size_t yyn;
-  size_t yysize = (size_t) (yystackp->yynextFree - yystackp->yyitems);
+  ptrdiff_t yynewSize;
+  ptrdiff_t yyn;
+  ptrdiff_t yysize = yystackp->yynextFree - yystackp->yyitems;
  if (YYMAXDEPTH - YYHEADROOM < yysize)
    yyMemoryExhausted (yystackp);
  yynewSize = 2*yysize;
  if (YYMAXDEPTH < yynewSize)
    yynewSize = YYMAXDEPTH;
-  yynewItems = (yyGLRStackItem*) YYMALLOC (yynewSize * sizeof yynewItems[0]);
+  yynewItems = (yyGLRStackItem*) YYMALLOC ((size_t) yynewSize
+                                           * sizeof yynewItems[0]);
  if (! yynewItems)
    yyMemoryExhausted (yystackp);
  for (yyp0 = yystackp->yyitems, yyp1 = yynewItems, yyn = yysize;
@@ -1219,7 +1233,7 @@ yyupdateSplit (yyGLRStack* yystackp, yyGLRState* yys)

 /** Invalidate stack #YYK in *YYSTACKP.  */
 static inline void
-yymarkStackDeleted (yyGLRStack* yystackp, size_t yyk)
+yymarkStackDeleted (yyGLRStack* yystackp, ptrdiff_t yyk)
 {
  if (yystackp->yytops.yystates[yyk] != YY_NULLPTR)
    yystackp->yylastDeleted = yystackp->yytops.yystates[yyk];
@@ -1243,7 +1257,7 @@ yyundeleteLastStack (yyGLRStack* yystackp)
 static inline void
 yyremoveDeletes (yyGLRStack* yystackp)
 {
-  size_t yyi, yyj;
+  ptrdiff_t yyi, yyj;
  yyi = yyj = 0;
  while (yyj < yystackp->yytops.yysize)
    {
@@ -1267,8 +1281,8 @@ yyremoveDeletes (yyGLRStack* yystackp)
            yystackp->yytops.yylookaheadNeeds[yyi];
          if (yyj != yyi)
            {
-              YYDPRINTF ((stderr, "Rename stack %lu -> %lu.\n",
-                          (unsigned long) yyi, (unsigned long) yyj));
+              YYDPRINTF ((stderr, "Rename stack %ld -> %ld.\n",
+                          (long) yyi, (long) yyj));
            }
          yyj += 1;
        }
@@ -1280,8 +1294,8 @@ yyremoveDeletes (yyGLRStack* yystackp)
 * state YYLRSTATE, at input position YYPOSN, with (resolved) semantic
 * value *YYVALP and source location *YYLOCP.  */
 static inline void
-yyglrShift (yyGLRStack* yystackp, size_t yyk, yyStateNum yylrState,
-            size_t yyposn,
+yyglrShift (yyGLRStack* yystackp, ptrdiff_t yyk, yyStateNum yylrState,
+            ptrdiff_t yyposn,
            YYSTYPE* yyvalp]b4_locations_if([, YYLTYPE* yylocp])[)
 {
  yyGLRState* yynewState = &yynewGLRStackItem (yystackp, yytrue)->yystate;
@@ -1301,8 +1315,8 @@ yyglrShift (yyGLRStack* yystackp, size_t yyk, yyStateNum yylrState,
 *  state YYLRSTATE, at input position YYPOSN, with the (unresolved)
 *  semantic value of YYRHS under the action for YYRULE.  */
 static inline void
-yyglrShiftDefer (yyGLRStack* yystackp, size_t yyk, yyStateNum yylrState,
-                 size_t yyposn, yyGLRState* yyrhs, yyRuleNum yyrule)
+yyglrShiftDefer (yyGLRStack* yystackp, ptrdiff_t yyk, yyStateNum yylrState,
+                 ptrdiff_t yyposn, yyGLRState* yyrhs, yyRuleNum yyrule)
 {
  yyGLRState* yynewState = &yynewGLRStackItem (yystackp, yytrue)->yystate;
  YYASSERT (yynewState->yyisState);
@@ -1332,15 +1346,14 @@ yyglrShiftDefer (yyGLRStack* yystackp, size_t yyk, yyStateNum yylrState,
 `----------------------------------------------------------------------*/

 static inline void
-yy_reduce_print (yybool yynormal, yyGLRStackItem* yyvsp, size_t yyk,
+yy_reduce_print (yybool yynormal, yyGLRStackItem* yyvsp, ptrdiff_t yyk,
                 yyRuleNum yyrule]b4_user_formals[)
 {
  int yynrhs = yyrhsLength (yyrule);]b4_locations_if([
  int yylow = 1;])[
  int yyi;
-  YYFPRINTF (stderr, "Reducing stack %lu by rule %d (line %lu):\n",
-             (unsigned long) yyk, yyrule - 1,
-             (unsigned long) yyrline[yyrule]);
+  YYFPRINTF (stderr, "Reducing stack %ld by rule %d (line %d):\n",
+             (long) yyk, yyrule - 1, yyrline[yyrule]);
  if (! yynormal)
    yyfillin (yyvsp, 1, -yynrhs);
  /* The symbols being reduced.  */
@@ -1366,7 +1379,7 @@ yy_reduce_print (yybool yynormal, yyGLRStackItem* yyvsp, size_t yyk,
 *  and *YYLOCP to the computed location (if any).  Return value is as
 *  for userAction.  */
 static inline YYRESULTTAG
-yydoAction (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
+yydoAction (yyGLRStack* yystackp, ptrdiff_t yyk, yyRuleNum yyrule,
            YYSTYPE* yyvalp]b4_locuser_formals[)
 {
  int yynrhs = yyrhsLength (yyrule);
@@ -1377,7 +1390,7 @@ yydoAction (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
      yyGLRStackItem* yyrhs = (yyGLRStackItem*) yystackp->yytops.yystates[yyk];
      YYASSERT (yyk == 0);
      yystackp->yynextFree -= yynrhs;
-      yystackp->yyspaceLeft += (size_t) yynrhs;
+      yystackp->yyspaceLeft += yynrhs;
      yystackp->yytops.yystates[0] = & yystackp->yynextFree[-1].yystate;
      YY_REDUCE_PRINT ((yytrue, yyrhs, yyk, yyrule]b4_user_args[));
      return yyuserAction (yyrule, yynrhs, yyrhs, yystackp,
@@ -1385,11 +1398,10 @@ yydoAction (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
    }
  else
    {
-      int yyi;
-      yyGLRState* yys;
      yyGLRStackItem yyrhsVals[YYMAXRHS + YYMAXLEFT + 1];
-      yys = yyrhsVals[YYMAXRHS + YYMAXLEFT].yystate.yypred
-        = yystackp->yytops.yystates[yyk];]b4_locations_if([[
+      yyGLRState* yys = yyrhsVals[YYMAXRHS + YYMAXLEFT].yystate.yypred
+        = yystackp->yytops.yystates[yyk];
+      int yyi;]b4_locations_if([[
      if (yynrhs == 0)
        /* Set default location.  */
        yyrhsVals[YYMAXRHS + YYMAXLEFT - 1].yystate.yyloc = yys->yyloc;]])[
@@ -1418,10 +1430,10 @@ yydoAction (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
 *  added to the options for the existing state's semantic value.
 */
 static inline YYRESULTTAG
-yyglrReduce (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
+yyglrReduce (yyGLRStack* yystackp, ptrdiff_t yyk, yyRuleNum yyrule,
             yybool yyforceEval]b4_user_formals[)
 {
-  size_t yyposn = yystackp->yytops.yystates[yyk]->yyposn;
+  ptrdiff_t yyposn = yystackp->yytops.yystates[yyk]->yyposn;

  if (yyforceEval || yystackp->yysplitPoint == YY_NULLPTR)
    {
@@ -1431,8 +1443,9 @@ yyglrReduce (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
      YYRESULTTAG yyflag = yydoAction (yystackp, yyk, yyrule, &yysval]b4_locuser_args([&yyloc])[);
      if (yyflag == yyerr && yystackp->yysplitPoint != YY_NULLPTR)
        {
-          YYDPRINTF ((stderr, "Parse on stack %lu rejected by rule #%d.\n",
-                     (unsigned long) yyk, yyrule - 1));
+          YYDPRINTF ((stderr,
+                      "Parse on stack %ld rejected by rule %d (line %d).\n",
+                      (long) yyk, yyrule - 1, yyrline[yyrule - 1]));
        }
      if (yyflag != yyok)
        return yyflag;
@@ -1444,7 +1457,7 @@ yyglrReduce (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
    }
  else
    {
-      size_t yyi;
+      ptrdiff_t yyi;
      int yyn;
      yyGLRState* yys, *yys0 = yystackp->yytops.yystates[yyk];
      yyStateNum yynewLRState;
@@ -1458,9 +1471,9 @@ yyglrReduce (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
      yyupdateSplit (yystackp, yys);
      yynewLRState = yyLRgotoState (yys->yylrState, yylhsNonterm (yyrule));
      YYDPRINTF ((stderr,
-                  "Reduced stack %lu by rule #%d; action deferred.  "
+                  "Reduced stack %ld by rule %d (line %d); action deferred.  "
                  "Now in state %d.\n",
-                  (unsigned long) yyk, yyrule - 1, yynewLRState));
+                  (long) yyk, yyrule - 1, yyrline[yyrule - 1], yynewLRState));
      for (yyi = 0; yyi < yystackp->yytops.yysize; yyi += 1)
        if (yyi != yyk && yystackp->yytops.yystates[yyi] != YY_NULLPTR)
          {
@@ -1472,9 +1485,8 @@ yyglrReduce (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
                  {
                    yyaddDeferredAction (yystackp, yyk, yyp, yys0, yyrule);
                    yymarkStackDeleted (yystackp, yyk);
-                    YYDPRINTF ((stderr, "Merging stack %lu into stack %lu.\n",
-                                (unsigned long) yyk,
-                                (unsigned long) yyi));
+                    YYDPRINTF ((stderr, "Merging stack %ld into stack %ld.\n",
+                                (long) yyk, (long) yyi));
                    return yyok;
                  }
                yyp = yyp->yypred;
@@ -1486,8 +1498,8 @@ yyglrReduce (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
  return yyok;
 }

-static size_t
-yysplitStack (yyGLRStack* yystackp, size_t yyk)
+static ptrdiff_t
+yysplitStack (yyGLRStack* yystackp, ptrdiff_t yyk)
 {
  if (yystackp->yysplitPoint == YY_NULLPTR)
    {
@@ -1498,15 +1510,16 @@ yysplitStack (yyGLRStack* yystackp, size_t yyk)
    {
      yyGLRState** yynewStates = YY_NULLPTR;
      yybool* yynewLookaheadNeeds;
+      ptrdiff_t state_size = sizeof yynewStates[0];
+      ptrdiff_t half_max_capacity = YYSIZEMAX / 2 / state_size;

-      if (yystackp->yytops.yycapacity
-          > (YYSIZEMAX / (2 * sizeof yynewStates[0])))
+      if (half_max_capacity < yystackp->yytops.yycapacity)
        yyMemoryExhausted (yystackp);
      yystackp->yytops.yycapacity *= 2;

      yynewStates =
        (yyGLRState**) YYREALLOC (yystackp->yytops.yystates,
-                                  (yystackp->yytops.yycapacity
+                                  ((size_t) yystackp->yytops.yycapacity
                                   * sizeof yynewStates[0]));
      if (yynewStates == YY_NULLPTR)
        yyMemoryExhausted (yystackp);
@@ -1514,7 +1527,7 @@ yysplitStack (yyGLRStack* yystackp, size_t yyk)

      yynewLookaheadNeeds =
        (yybool*) YYREALLOC (yystackp->yytops.yylookaheadNeeds,
-                             (yystackp->yytops.yycapacity
+                             ((size_t) yystackp->yytops.yycapacity
                              * sizeof yynewLookaheadNeeds[0]));
      if (yynewLookaheadNeeds == YY_NULLPTR)
        yyMemoryExhausted (yystackp);
@@ -1716,10 +1729,10 @@ yyreportTree (yySemanticOption* yyx, int yyindent)
               yyindent, "", yytokenName (yylhsNonterm (yyx->yyrule)),
               yyx->yyrule - 1);
  else
-    YYFPRINTF (stderr, "%*s%s -> <Rule %d, tokens %lu .. %lu>\n",
+    YYFPRINTF (stderr, "%*s%s -> <Rule %d, tokens %ld .. %ld>\n",
               yyindent, "", yytokenName (yylhsNonterm (yyx->yyrule)),
-               yyx->yyrule - 1, (unsigned long) (yys->yyposn + 1),
-               (unsigned long) yyx->yystate->yyposn);
+               yyx->yyrule - 1, (long) (yys->yyposn + 1),
+               (long) yyx->yystate->yyposn);
  for (yyi = 1; yyi <= yynrhs; yyi += 1)
    {
      if (yystates[yyi]->yyresolved)
@@ -1728,10 +1741,10 @@ yyreportTree (yySemanticOption* yyx, int yyindent)
            YYFPRINTF (stderr, "%*s%s <empty>\n", yyindent+2, "",
                       yytokenName (yystos[yystates[yyi]->yylrState]));
          else
-            YYFPRINTF (stderr, "%*s%s <tokens %lu .. %lu>\n", yyindent+2, "",
+            YYFPRINTF (stderr, "%*s%s <tokens %ld .. %ld>\n", yyindent+2, "",
                       yytokenName (yystos[yystates[yyi]->yylrState]),
-                       (unsigned long) (yystates[yyi-1]->yyposn + 1),
-                       (unsigned long) yystates[yyi]->yyposn);
+                       (long) (yystates[yyi-1]->yyposn + 1),
+                       (long) yystates[yyi]->yyposn);
        }
      else
        yyreportTree (yystates[yyi]->yysemantics.yyfirstVal, yyindent+2);
@@ -1926,9 +1939,9 @@ yycompressStack (yyGLRStack* yystackp)
       yyr = yyp, yyp = yyq, yyq = yyp->yypred)
    yyp->yypred = yyr;

-  yystackp->yyspaceLeft += (size_t) (yystackp->yynextFree - yystackp->yyitems);
+  yystackp->yyspaceLeft += yystackp->yynextFree - yystackp->yyitems;
  yystackp->yynextFree = ((yyGLRStackItem*) yystackp->yysplitPoint) + 1;
-  yystackp->yyspaceLeft -= (size_t) (yystackp->yynextFree - yystackp->yyitems);
+  yystackp->yyspaceLeft -= yystackp->yynextFree - yystackp->yyitems;
  yystackp->yysplitPoint = YY_NULLPTR;
  yystackp->yylastDeleted = YY_NULLPTR;

@@ -1944,14 +1957,13 @@ yycompressStack (yyGLRStack* yystackp)
 }

 static YYRESULTTAG
-yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
-                   size_t yyposn]b4_pure_formals[)
+yyprocessOneStack (yyGLRStack* yystackp, ptrdiff_t yyk,
+                   ptrdiff_t yyposn]b4_pure_formals[)
 {
  while (yystackp->yytops.yystates[yyk] != YY_NULLPTR)
    {
      yyStateNum yystate = yystackp->yytops.yystates[yyk]->yylrState;
-      YYDPRINTF ((stderr, "Stack %lu Entering state %d\n",
-                  (unsigned long) yyk, yystate));
+      YYDPRINTF ((stderr, "Stack %ld Entering state %d\n", yyk, yystate));

      YYASSERT (yystate != YYFINAL);

@@ -1961,8 +1973,7 @@ yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
          yyRuleNum yyrule = yydefaultAction (yystate);
          if (yyrule == 0)
            {
-              YYDPRINTF ((stderr, "Stack %lu dies.\n",
-                          (unsigned long) yyk));
+              YYDPRINTF ((stderr, "Stack %ld dies.\n", (long) yyk));
              yymarkStackDeleted (yystackp, yyk);
              return yyok;
            }
@@ -1970,9 +1981,9 @@ yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
          if (yyflag == yyerr)
            {
              YYDPRINTF ((stderr,
-                          "Stack %lu dies "
+                          "Stack %ld dies "
                          "(predicate failure or explicit user error).\n",
-                          (unsigned long) yyk));
+                          (long) yyk));
              yymarkStackDeleted (yystackp, yyk);
              return yyok;
            }
@@ -1981,21 +1992,17 @@ yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
        }
      else
        {
-          yySymbol yytoken;
-          int yyaction;
+          yySymbol yytoken = ]b4_yygetToken_call[;
          const short* yyconflicts;
-
+          const int yyaction = yygetLRActions (yystate, yytoken, &yyconflicts);
          yystackp->yytops.yylookaheadNeeds[yyk] = yytrue;
-          yytoken = ]b4_yygetToken_call[;
-          yyaction = yygetLRActions (yystate, yytoken, &yyconflicts);

          while (*yyconflicts != 0)
            {
              YYRESULTTAG yyflag;
-              size_t yynewStack = yysplitStack (yystackp, yyk);
-              YYDPRINTF ((stderr, "Splitting off stack %lu from %lu.\n",
-                          (unsigned long) yynewStack,
-                          (unsigned long) yyk));
+              ptrdiff_t yynewStack = yysplitStack (yystackp, yyk);
+              YYDPRINTF ((stderr, "Splitting off stack %ld from %ld.\n",
+                          (long) yynewStack, (long) yyk));
              yyflag = yyglrReduce (yystackp, yynewStack,
                                    *yyconflicts,
                                    yyimmediate[*yyconflicts]]b4_user_args[);
@@ -2004,8 +2011,7 @@ yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
                                          yyposn]b4_pure_args[));
              else if (yyflag == yyerr)
                {
-                  YYDPRINTF ((stderr, "Stack %lu dies.\n",
-                              (unsigned long) yynewStack));
+                  YYDPRINTF ((stderr, "Stack %ld dies.\n", (long) yynewStack));
                  yymarkStackDeleted (yystackp, yynewStack);
                }
              else
@@ -2017,8 +2023,7 @@ yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
            break;
          else if (yyisErrorAction (yyaction))
            {
-              YYDPRINTF ((stderr, "Stack %lu dies.\n",
-                          (unsigned long) yyk));
+              YYDPRINTF ((stderr, "Stack %ld dies.\n", (long) yyk));
              yymarkStackDeleted (yystackp, yyk);
              break;
            }
@@ -2029,9 +2034,9 @@ yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
              if (yyflag == yyerr)
                {
                  YYDPRINTF ((stderr,
-                              "Stack %lu dies "
+                              "Stack %ld dies "
                              "(predicate failure or explicit user error).\n",
-                              (unsigned long) yyk));
+                              (long) yyk));
                  yymarkStackDeleted (yystackp, yyk);
                  break;
                }
@@ -2053,8 +2058,8 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
 #else
  {
  yySymbol yytoken = yychar == YYEMPTY ? YYEMPTY : YYTRANSLATE (yychar);
-  size_t yysize0 = yytnamerr (YY_NULLPTR, yytokenName (yytoken));
-  size_t yysize = yysize0;
+  ptrdiff_t yysize0 = yytnamerr (YY_NULLPTR, yytokenName (yytoken));
+  ptrdiff_t yysize = yysize0;
  yybool yysize_overflow = yyfalse;
  char* yymsg = YY_NULLPTR;
  enum { YYERROR_VERBOSE_ARGS_MAXIMUM = 5 };
@@ -2115,10 +2120,11 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
                  }
                yyarg[yycount++] = yytokenName (yyx);
                {
-                  size_t yysz = yysize + yytnamerr (YY_NULLPTR, yytokenName (yyx));
-                  if (yysz < yysize)
+                  ptrdiff_t yysz = yytnamerr (YY_NULLPTR, yytokenName (yyx));
+                  if (YYSIZEMAX - yysize < yysz)
                    yysize_overflow = yytrue;
-                  yysize = yysz;
+                  else
+                    yysize += yysz;
                }
              }
        }
@@ -2141,14 +2147,15 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
    }

  {
-    size_t yysz = yysize + strlen (yyformat);
-    if (yysz < yysize)
+    ptrdiff_t yysz = (ptrdiff_t) strlen (yyformat);
+    if (YYSIZEMAX - yysize < yysz)
      yysize_overflow = yytrue;
-    yysize = yysz;
+    else
+      yysize += yysz;
  }

  if (!yysize_overflow)
-    yymsg = (char *) YYMALLOC (yysize);
+    yymsg = (char *) YYMALLOC ((size_t) yysize);

  if (yymsg)
    {
@@ -2225,7 +2232,7 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[)

  /* Reduce to one stack.  */
  {
-    size_t yyk;
+    ptrdiff_t yyk;
    for (yyk = 0; yyk < yystackp->yytops.yysize; yyk += 1)
      if (yystackp->yytops.yystates[yyk] != YY_NULLPTR)
        break;
@@ -2249,14 +2256,15 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
          if (0 <= yyj && yyj <= YYLAST && yycheck[yyj] == YYTERROR
              && yyisShiftAction (yytable[yyj]))
            {
-              /* Shift the error token.  */]b4_locations_if([[
+              /* Shift the error token.  */
+              int yyaction = yytable[yyj];]b4_locations_if([[
              /* First adjust its location.*/
              YYLTYPE yyerrloc;
              yystackp->yyerror_range[2].yystate.yyloc = yylloc;
              YYLLOC_DEFAULT (yyerrloc, (yystackp->yyerror_range), 2);]])[
-              YY_SYMBOL_PRINT ("Shifting", yystos[yytable[yyj]],
+              YY_SYMBOL_PRINT ("Shifting", yystos[yyaction],
                               &yylval, &yyerrloc);
-              yyglrShift (yystackp, 0, yytable[yyj],
+              yyglrShift (yystackp, 0, yyaction,
                          yys->yyposn, &yylval]b4_locations_if([, &yyerrloc])[);
              yys = yystackp->yytops.yystates[0];
              break;
@@ -2298,7 +2306,7 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
  int yyresult;
  yyGLRStack yystack;
  yyGLRStack* const yystackp = &yystack;
-  size_t yyposn;
+  ptrdiff_t yyposn;

  YYDPRINTF ((stderr, "Starting parse\n"));

@@ -2378,7 +2386,7 @@ b4_dollar_popdef])[]dnl
      while (yytrue)
        {
          yySymbol yytoken_to_shift;
-          size_t yys;
+          ptrdiff_t yys;

          for (yys = 0; yys < yystack.yytops.yysize; yys += 1)
            yystackp->yytops.yylookaheadNeeds[yys] = (yybool) (yychar != YYEMPTY);
@@ -2432,12 +2440,12 @@ b4_dollar_popdef])[]dnl
              int yyaction = yygetLRActions (yystate, yytoken_to_shift,
                              &yyconflicts);
              /* Note that yyconflicts were handled by yyprocessOneStack.  */
-              YYDPRINTF ((stderr, "On stack %lu, ", (unsigned long) yys));
+              YYDPRINTF ((stderr, "On stack %ld, ", (long) yys));
              YY_SYMBOL_PRINT ("shifting", yytoken_to_shift, &yylval, &yylloc);
              yyglrShift (&yystack, yys, yyaction, yyposn,
                          &yylval]b4_locations_if([, &yylloc])[);
-              YYDPRINTF ((stderr, "Stack %lu now in state #%d\n",
-                          (unsigned long) yys,
+              YYDPRINTF ((stderr, "Stack %ld now in state #%d\n",
+                          (long) yys,
                          yystack.yytops.yystates[yys]->yylrState));
            }

@@ -2485,8 +2493,8 @@ b4_dollar_popdef])[]dnl
      yyGLRState** yystates = yystack.yytops.yystates;
      if (yystates)
        {
-          size_t yysize = yystack.yytops.yysize;
-          size_t yyk;
+          ptrdiff_t yysize = yystack.yytops.yysize;
+          ptrdiff_t yyk;
          for (yyk = 0; yyk < yysize; yyk += 1)
            if (yystates[yyk])
              {
@@ -2519,8 +2527,7 @@ yy_yypstack (yyGLRState* yys)
      yy_yypstack (yys->yypred);
      YYFPRINTF (stderr, " -> ");
    }
-  YYFPRINTF (stderr, "%d@@%lu", yys->yylrState,
-             (unsigned long) yys->yyposn);
+  YYFPRINTF (stderr, "%d@@%ld", yys->yylrState, (long) yys->yyposn);
 }

 static void
@@ -2534,7 +2541,7 @@ yypstates (yyGLRState* yyst)
 }

 static void
-yypstack (yyGLRStack* yystackp, size_t yyk)
+yypstack (yyGLRStack* yystackp, ptrdiff_t yyk)
 {
  yypstates (yystackp->yytops.yystates[yyk]);
 }
@@ -2547,18 +2554,18 @@ static void
 yypdumpstack (yyGLRStack* yystackp)
 {
  yyGLRStackItem* yyp;
-  size_t yyi;
+  ptrdiff_t yyi;
  for (yyp = yystackp->yyitems; yyp < yystackp->yynextFree; yyp += 1)
    {
-      YYFPRINTF (stderr, "%3lu. ",
-                 (unsigned long) (yyp - yystackp->yyitems));
+      YYFPRINTF (stderr, "%3ld. ",
+                 (long) (yyp - yystackp->yyitems));
      if (*(yybool *) yyp)
        {
          YYASSERT (yyp->yystate.yyisState);
          YYASSERT (yyp->yyoption.yyisState);
-          YYFPRINTF (stderr, "Res: %d, LR State: %d, posn: %lu, pred: %ld",
+          YYFPRINTF (stderr, "Res: %d, LR State: %d, posn: %ld, pred: %ld",
                     yyp->yystate.yyresolved, yyp->yystate.yylrState,
-                     (unsigned long) yyp->yystate.yyposn,
+                     (long) yyp->yystate.yyposn,
                     (long) YYINDEX (yyp->yystate.yypred));
          if (! yyp->yystate.yyresolved)
            YYFPRINTF (stderr, ", firstVal: %ld",
@@ -2578,7 +2585,7 @@ yypdumpstack (yyGLRStack* yystackp)
    }
  YYFPRINTF (stderr, "Tops:");
  for (yyi = 0; yyi < yystackp->yytops.yysize; yyi += 1)
-    YYFPRINTF (stderr, "%lu: %ld; ", (unsigned long) yyi,
+    YYFPRINTF (stderr, "%ld: %ld; ", (long) yyi,
               (long) YYINDEX (yystackp->yytops.yystates[yyi]));
  YYFPRINTF (stderr, "\n");
 }
@@ -184,8 +184,19 @@ b4_percent_define_check_kind([[throws]],            [code], [deprecated])
 m4_define([b4_yystype], [b4_percent_define_get([[api.value.type]])])
 b4_percent_define_default([[api.value.type]], [[Object]])

-# %name-prefix
-m4_define_default([b4_prefix], [[YY]])
+# b4_api_prefix, b4_api_PREFIX
+# ----------------------------
+# Corresponds to %define api.prefix
+b4_percent_define_default([[api.prefix]], [[YY]])
+m4_define([b4_api_prefix],
+[b4_percent_define_get([[api.prefix]])])
+m4_define([b4_api_PREFIX],
+[m4_toupper(b4_api_prefix)])
+
+# b4_prefix
+# ---------
+# If the %name-prefix is not given, it is api.prefix.
+m4_define_default([b4_prefix], [b4_api_prefix])

 b4_percent_define_default([[api.parser.class]], [b4_prefix[]Parser])
 m4_define([b4_parser_class], [b4_percent_define_get([[api.parser.class]])])
@@ -20,14 +20,22 @@ m4_include(b4_skeletonsdir/[c++.m4])
 # api.value.type=variant is valid.
 m4_define([b4_value_type_setup_variant])

+# Check the value of %define parse.lac, where LAC stands for lookahead
+# correction.
+b4_percent_define_default([[parse.lac]], [[none]])
+b4_define_flag_if([lac])
+m4_define([b4_lac_flag],
+          [m4_if(b4_percent_define_get([[parse.lac]]),
+                 [none], [[0]], [[1]])])
+

 # b4_integral_parser_table_declare(TABLE-NAME, CONTENT, COMMENT)
 # --------------------------------------------------------------
 # Declare "parser::yy<TABLE-NAME>_" whose contents is CONTENT.
 m4_define([b4_integral_parser_table_declare],
-[m4_ifval([$3], [b4_comment([$3], [  ])
+[m4_ifval([$3], [b4_comment([$3], [    ])
 ])dnl
-  static const b4_int_type_for([$2]) yy$1_[[]];dnl
+    static const b4_int_type_for([$2]) yy$1_[[]];dnl
 ])

 # b4_integral_parser_table_define(TABLE-NAME, CONTENT, COMMENT)
@@ -220,10 +228,21 @@ m4_define([b4_shared_declarations],
  private:
    /// This class is not copyable.
    ]b4_parser_class[ (const ]b4_parser_class[&);
-    ]b4_parser_class[& operator= (const ]b4_parser_class[&);
+    ]b4_parser_class[& operator= (const ]b4_parser_class[&);]b4_lac_if([[

-    /// State numbers.
-    typedef int state_type;
+    /// Check the lookahead yytoken.
+    /// \returns  true iff the token will be eventually shifted.
+    bool yy_lac_check_ (int yytoken) const;
+    /// Establish the initial context if no initial context currently exists.
+    /// \returns  true iff the token will be eventually shifted.
+    bool yy_lac_establish_ (int yytoken);
+    /// Discard any previous initial lookahead context because of event.
+    /// \param event  the event which caused the lookahead to be discarded.
+    ///               Only used for debbuging output.
+    void yy_lac_discard_ (const char* event);]])[
+
+    /// Stored state numbers (used for stacks).
+    typedef ]b4_int_type(0, m4_eval(b4_states_number - 1))[ state_type;

    /// Generate an error message.
    /// \param yystate   the state where the error occurred.
@@ -234,7 +253,7 @@ m4_define([b4_shared_declarations],
    /// Compute post-reduction state.
    /// \param yystate   the current state
    /// \param yysym     the nonterminal to push on the stack
-    state_type yy_lr_goto_state_ (state_type yystate, int yysym);
+    static state_type yy_lr_goto_state_ (state_type yystate, int yysym);

    /// Whether the given \c yypact_ value indicates a defaulted state.
    /// \param yyvalue   the value to check
@@ -335,6 +354,10 @@ m4_define([b4_shared_declarations],
      /// Assignment, needed by push_back by some old implementations.
      /// Moves the contents of that.
      stack_symbol_type& operator= (stack_symbol_type& that);
+
+      /// Assignment, needed by push_back by other implementations.
+      /// Needed by some other old implementations.
+      stack_symbol_type& operator= (const stack_symbol_type& that);
 #endif
    };

@@ -344,7 +367,16 @@ m4_define([b4_shared_declarations],
    typedef stack<stack_symbol_type> stack_type;

    /// The stack.
-    stack_type yystack_;
+    stack_type yystack_;]b4_lac_if([[
+    /// The stack for LAC.
+    /// Logically, the yy_lac_stack's lifetime is confined to the function
+    /// yy_lac_check_. We just store it as a member of this class to hold
+    /// on to the memory and to avoid frequent reallocations.
+    /// Since yy_lac_check_ is const, this member must be mutable.
+    mutable std::vector<state_type> yylac_stack_;
+    /// Whether an initial LAC context was established.
+    bool yy_lac_established_;
+]])[

    /// Push a new state on the stack.
    /// \param m    a debug message to display
@@ -459,9 +491,6 @@ m4_if(b4_prefix, [yy], [],
 [#define YYRHSLOC(Rhs, K) ((Rhs)[K].location)
 ]b4_yylloc_default_define])[

-// Suppress unused-variable warnings by "using" E.
-#define YYUSE(E) ((void) (E))
-
 // Enable debugging if requested.
 #if ]b4_api_PREFIX[DEBUG

@@ -551,12 +580,14 @@ m4_if(b4_prefix, [yy], [],
 ]])[

  /// Build a parser object.
-  ]b4_parser_class::b4_parser_class[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
-    :])[
+  ]b4_parser_class::b4_parser_class[ (]b4_parse_param_decl[)
 #if ]b4_api_PREFIX[DEBUG
-    ]m4_ifset([b4_parse_param], [  ], [ :])[yydebug_ (false),
-      yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
-#endif]b4_parse_param_cons[
+    : yydebug_ (false),
+      yycdebug_ (&std::cerr)]b4_lac_if([,], [m4_ifset([b4_parse_param], [,])])[
+#else
+]b4_lac_if([    :], [m4_ifset([b4_parse_param], [    :])])[
+#endif]b4_lac_if([[
+      yy_lac_established_ (false)]m4_ifset([b4_parse_param], [,])])[]b4_parse_param_cons[
  {}

  ]b4_parser_class::~b4_parser_class[ ()
@@ -630,6 +661,17 @@ m4_if(b4_prefix, [yy], [],
  }

 #if YY_CPLUSPLUS < 201103L
+  ]b4_parser_class[::stack_symbol_type&
+  ]b4_parser_class[::stack_symbol_type::operator= (const stack_symbol_type& that)
+  {
+    state = that.state;
+    ]b4_variant_if([b4_symbol_variant([that.type_get ()],
+                                      [value], [copy], [that.value])],
+                   [[value = that.value;]])[]b4_locations_if([
+    location = that.location;])[
+    return *this;
+  }
+
  ]b4_parser_class[::stack_symbol_type&
  ]b4_parser_class[::stack_symbol_type::operator= (stack_symbol_type& that)
  {
@@ -761,7 +803,6 @@ m4_if(b4_prefix, [yy], [],
  int
  ]b4_parser_class[::parse ()
  {
-    // State.
    int yyn;
    /// Length of the RHS of the rule being reduced.
    int yylen = 0;
@@ -777,7 +818,11 @@ m4_if(b4_prefix, [yy], [],
    stack_symbol_type yyerror_range[3];]])[

    /// The return value of parse ().
-    int yyresult;
+    int yyresult;]b4_lac_if([[
+
+    /// Discard the LAC context in case there still is one left from a
+    /// previous invocation.
+    yy_lac_discard_ ("init");]])[

 #if YY_EXCEPTIONS
    try
@@ -801,7 +846,7 @@ b4_dollar_popdef])[]dnl
  | yynewstate -- push a new symbol on the stack.  |
  `-----------------------------------------------*/
  yynewstate:
-    YYCDEBUG << "Entering state " << yystack_[0].state << '\n';
+    YYCDEBUG << "Entering state " << int (yystack_[0].state) << '\n';

    // Accept?
    if (yystack_[0].state == yyfinal_)
@@ -846,14 +891,21 @@ b4_dollar_popdef])[]dnl
       to detect an error, take that action.  */
    yyn += yyla.type_get ();
    if (yyn < 0 || yylast_ < yyn || yycheck_[yyn] != yyla.type_get ())
-      goto yydefault;
+      {]b4_lac_if([[
+        if (!yy_lac_establish_ (yyla.type_get ()))
+           goto yyerrlab;]])[
+        goto yydefault;
+      }

    // Reduce or error.
    yyn = yytable_[yyn];
    if (yyn <= 0)
      {
        if (yy_table_value_is_error_ (yyn))
-          goto yyerrlab;
+          goto yyerrlab;]b4_lac_if([[
+        if (!yy_lac_establish_ (yyla.type_get ()))
+           goto yyerrlab;
+]])[
        yyn = -yyn;
        goto yyreduce;
      }
@@ -863,7 +915,8 @@ b4_dollar_popdef])[]dnl
      --yyerrstatus_;

    // Shift the lookahead token.
-    yypush_ ("Shifting", yyn, YY_MOVE (yyla));
+    yypush_ ("Shifting", static_cast<state_type> (yyn), YY_MOVE (yyla));]b4_lac_if([[
+    yy_lac_discard_ ("shift");]])[
    goto yynewstate;


@@ -1023,8 +1076,9 @@ b4_dollar_popdef])[]dnl
      yyerror_range[2].location = yyla.location;
      YYLLOC_DEFAULT (error_token.location, yyerror_range, 2);]])[

-      // Shift the error token.
-      error_token.state = yyn;
+      // Shift the error token.]b4_lac_if([[
+      yy_lac_discard_ ("error recovery");]])[
+      error_token.state = static_cast<state_type> (yyn);
      yypush_ ("Shifting", YY_MOVE (error_token));
    }
    goto yynewstate;
@@ -1088,8 +1142,147 @@ b4_dollar_popdef])[]dnl
  {
    error (]b4_join(b4_locations_if([yyexc.location]),
                    [[yyexc.what ()]])[);
+  }]b4_lac_if([[
+
+  bool
+  ]b4_parser_class[::yy_lac_check_ (int yytoken) const
+  {
+    // Logically, the yylac_stack's lifetime is confined to this function.
+    // Clear it, to get rid of potential left-overs from previous call.
+    yylac_stack_.clear ();
+    // Reduce until we encounter a shift and thereby accept the token.
+#if ]b4_api_PREFIX[DEBUG
+    YYCDEBUG << "LAC: checking lookahead " << yytname_[yytoken] << ':';
+#endif
+    std::ptrdiff_t lac_top = 0;
+    while (true)
+      {
+        state_type top_state = (yylac_stack_.empty ()
+                                ? yystack_[lac_top].state
+                                : yylac_stack_.back ());
+        int yyrule = yypact_[top_state];
+        if (yy_pact_value_is_default_ (yyrule)
+            || (yyrule += yytoken) < 0 || yylast_ < yyrule
+            || yycheck_[yyrule] != yytoken)
+          {
+            // Use the default action.
+            yyrule = yydefact_[top_state];
+            if (yyrule == 0)
+              {
+                YYCDEBUG << " Err\n";
+                return false;
+              }
+          }
+        else
+          {
+            // Use the action from yytable.
+            yyrule = yytable_[yyrule];
+            if (yy_table_value_is_error_ (yyrule))
+              {
+                YYCDEBUG << " Err\n";
+                return false;
+              }
+            if (0 < yyrule)
+              {
+                YYCDEBUG << " S" << yyrule << '\n';
+                return true;
+              }
+            yyrule = -yyrule;
+          }
+        // By now we know we have to simulate a reduce.
+        YYCDEBUG << " R" << yyrule - 1;
+        // Pop the corresponding number of values from the stack.
+        {
+          std::ptrdiff_t yylen = yyr2_[yyrule];
+          // First pop from the LAC stack as many tokens as possible.
+          std::ptrdiff_t lac_size = (std::ptrdiff_t) yylac_stack_.size ();
+          if (yylen < lac_size)
+            {
+              yylac_stack_.resize ((std::size_t) (lac_size - yylen));
+              yylen = 0;
+            }
+          else if (lac_size)
+            {
+              yylac_stack_.clear ();
+              yylen -= lac_size;
+            }
+          // Only afterwards look at the main stack.
+          // We simulate popping elements by incrementing lac_top.
+          lac_top += yylen;
+        }
+        // Keep top_state in sync with the updated stack.
+        top_state = (yylac_stack_.empty ()
+                     ? yystack_[lac_top].state
+                     : yylac_stack_.back ());
+        // Push the resulting state of the reduction.
+        state_type state = yy_lr_goto_state_ (top_state, yyr1_[yyrule]);
+        YYCDEBUG << " G" << state;
+        yylac_stack_.push_back (state);
+      }
  }

+  // Establish the initial context if no initial context currently exists.
+  bool
+  ]b4_parser_class[::yy_lac_establish_ (int yytoken)
+  {
+    /* Establish the initial context for the current lookahead if no initial
+       context is currently established.
+
+       We define a context as a snapshot of the parser stacks.  We define
+       the initial context for a lookahead as the context in which the
+       parser initially examines that lookahead in order to select a
+       syntactic action.  Thus, if the lookahead eventually proves
+       syntactically unacceptable (possibly in a later context reached via a
+       series of reductions), the initial context can be used to determine
+       the exact set of tokens that would be syntactically acceptable in the
+       lookahead's place.  Moreover, it is the context after which any
+       further semantic actions would be erroneous because they would be
+       determined by a syntactically unacceptable token.
+
+       yy_lac_establish_ should be invoked when a reduction is about to be
+       performed in an inconsistent state (which, for the purposes of LAC,
+       includes consistent states that don't know they're consistent because
+       their default reductions have been disabled).
+
+       For parse.lac=full, the implementation of yy_lac_establish_ is as
+       follows.  If no initial context is currently established for the
+       current lookahead, then check if that lookahead can eventually be
+       shifted if syntactic actions continue from the current context.  */
+    if (!yy_lac_established_)
+      {
+#if ]b4_api_PREFIX[DEBUG
+        YYCDEBUG << "LAC: initial context established for "
+                 << yytname_[yytoken] << '\n';
+#endif
+        yy_lac_established_ = true;
+        return yy_lac_check_ (yytoken);
+      }
+    return true;
+  }
+
+  // Discard any previous initial lookahead context.
+  void
+  ]b4_parser_class[::yy_lac_discard_ (const char* evt)
+  {
+   /* Discard any previous initial lookahead context because of Event,
+      which may be a lookahead change or an invalidation of the currently
+      established initial context for the current lookahead.
+
+      The most common example of a lookahead change is a shift.  An example
+      of both cases is syntax error recovery.  That is, a syntax error
+      occurs when the lookahead is syntactically erroneous for the
+      currently established initial context, so error recovery manipulates
+      the parser stacks to try to find a new initial context in which the
+      current lookahead is syntactically acceptable.  If it fails to find
+      such a context, it discards the lookahead.  */
+    if (yy_lac_established_)
+      {
+        YYCDEBUG << "LAC: initial context discarded due to "
+                 << evt << '\n';
+        yy_lac_established_ = false;
+      }
+  }]])[
+
  // Generate an error message.
  std::string
  ]b4_parser_class[::yysyntax_error_ (]dnl
@@ -1098,7 +1291,7 @@ b4_error_verbose_if([state_type yystate, const symbol_type& yyla],
  {]b4_error_verbose_if([[
    // Number of reported tokens (one for the "unexpected", one per
    // "expected").
-    size_t yycount = 0;
+    std::ptrdiff_t yycount = 0;
    // Its maximum.
    enum { YYERROR_VERBOSE_ARGS_MAXIMUM = 5 };
    // Arguments of yyformat.
@@ -1118,24 +1311,40 @@ b4_error_verbose_if([state_type yystate, const symbol_type& yyla],
         a consistent state with a default action.  There might have
         been a previous inconsistent state, consistent state with a
         non-default action, or user semantic action that manipulated
-         yyla.  (However, yyla is currently not documented for users.)
+         yyla.  (However, yyla is currently not documented for users.)]b4_lac_if([[
+         In the first two cases, it might appear that the current syntax
+         error should have been detected in the previous state when
+         yy_lac_check was invoked.  However, at that time, there might
+         have been a different syntax error that discarded a different
+         initial context during error recovery, leaving behind the
+         current lookahead.]], [[
       - Of course, the expected token list depends on states to have
         correct lookahead information, and it depends on the parser not
         to perform extra reductions after fetching a lookahead from the
-         scanner and before detecting a syntax error.  Thus, state
-         merging (from LALR or IELR) and default reductions corrupt the
-         expected token list.  However, the list is correct for
-         canonical LR with one exception: it will still contain any
-         token that will not be accepted due to an error action in a
-         later state.
+         scanner and before detecting a syntax error.  Thus, state merging
+         (from LALR or IELR) and default reductions corrupt the expected
+         token list.  However, the list is correct for canonical LR with
+         one exception: it will still contain any token that will not be
+         accepted due to an error action in a later state.]])[
    */
    if (!yyla.empty ())
      {
        int yytoken = yyla.type_get ();
-        yyarg[yycount++] = yytname_[yytoken];
+        yyarg[yycount++] = yytname_[yytoken];]b4_lac_if([[
+
+#if ]b4_api_PREFIX[DEBUG
+        // Execute LAC once. We don't care if it is succesful, we
+        // only do it for the sake of debugging output.
+        if (!yy_lac_established_)
+          yy_lac_check_ (yytoken);
+#endif]])[
+
        int yyn = yypact_[yystate];
        if (!yy_pact_value_is_default_ (yyn))
-          {
+          {]b4_lac_if([[
+            for (int yyx = 0; yyx < yyntokens_; ++yyx)
+              if (yyx != yyterror_ && yy_lac_check_(yyx))
+                {]], [[
            /* Start YYX at -YYN if negative to avoid negative indexes in
               YYCHECK.  In other words, skip the first -YYN actions for
               this state because they are default actions.  */
@@ -1146,7 +1355,7 @@ b4_error_verbose_if([state_type yystate, const symbol_type& yyla],
            for (int yyx = yyxbegin; yyx < yyxend; ++yyx)
              if (yycheck_[yyx + yyn] == yyx && yyx != yyterror_
                  && !yy_table_value_is_error_ (yytable_[yyx + yyn]))
-                {
+                {]])[
                  if (yycount == YYERROR_VERBOSE_ARGS_MAXIMUM)
                    {
                      yycount = 1;
@@ -1177,7 +1386,7 @@ b4_error_verbose_if([state_type yystate, const symbol_type& yyla],

    std::string yyres;
    // Argument number.
-    size_t yyi = 0;
+    std::ptrdiff_t yyi = 0;
    for (char const* yyp = yyformat; *yyp; ++yyp)
      if (yyp[0] == '%' && yyp[1] == 's' && yyi < yycount)
        {
@@ -1218,7 +1427,7 @@ b4_error_verbose_if([state_type yystate, const symbol_type& yyla],
           i = yystack_.begin (),
           i_end = yystack_.end ();
         i != i_end; ++i)
-      *yycdebug_ << ' ' << i->state;
+      *yycdebug_ << ' ' << int (i->state);
    *yycdebug_ << '\n';
  }

@@ -1226,7 +1435,7 @@ b4_error_verbose_if([state_type yystate, const symbol_type& yyla],
  void
  ]b4_parser_class[::yy_reduce_print_ (int yyrule)
  {
-    unsigned yylno = yyrline_[yyrule];
+    int yylno = yyrline_[yyrule];
    int yynrhs = yyr2_[yyrule];
    // Print the symbols being reduced, and their result.
    *yycdebug_ << "Reducing stack by rule " << yyrule - 1
@@ -1,6 +1,6 @@
-# Java skeleton for Bison -*- autoconf -*-
+# D skeleton for Bison -*- autoconf -*-

-# Copyright (C) 2007-2011, 2019 Free Software Foundation, Inc.
+# Copyright (C) 2007-2012, 2019 Free Software Foundation, Inc.

 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -18,12 +18,11 @@
 m4_include(b4_skeletonsdir/[d.m4])


-m4_divert_push(0)dnl
-@output(b4_parser_file_name@)@
+b4_output_begin([b4_parser_file_name])
 b4_copyright([Skeleton implementation for Bison LALR(1) parsers in D],
-             [2007-2012, 2019])
+             [2007-2012, 2019])[

-b4_percent_define_ifdef([package], [module b4_percent_define_get([package]);
+]b4_percent_define_ifdef([package], [module b4_percent_define_get([package]);
 ])[
 version(D_Version2) {
 } else {
@@ -81,68 +80,14 @@ public interface Lexer
   void yyerror (]b4_locations_if([b4_location_type[ loc, ]])[string s);
 }

-private final struct YYStackElement{
-  int state;
-  ]b4_yystype[ value;]b4_locations_if(
-  b4_location_type[[] location;])[
-}
-
-private final struct YYStack {
-  private YYStackElement[] stack = [];
-
-  public final @@property ulong height()
-  {
-    return stack.length;
-  }
-
-  public final void push (int state, ]b4_yystype[ value]dnl
-b4_locations_if([, ref ]b4_location_type[ loc])[)
-  {
-    stack ~= YYStackElement(state, value]b4_locations_if([, loc])[);
-  }
-
-  public final void pop ()
-  {
-    pop (1);
-  }
-
-  public final void pop (int num)
-  {
-    stack.length -= num;
-  }
-
-  public final int stateAt (int i)
-  {
-    return stack[$-i-1].state;
-  }
-
-  ]b4_locations_if([[public final ref ]b4_location_type[ locationAt (int i)
-  {
-    return stack[$-i-1].location;
-  }
-
-  ]])[public final ref ]b4_yystype[ valueAt (int i)
-  {
-    return stack[$-i-1].value;
-  }
-
-  // Print the state stack on the debug stream.
-  public final void print (File stream)
-  {
-    stream.write ("Stack now");
-    for (int i = 0; i < stack.length; i++)
-      stream.write (" %d", stack[i].state);
-    stream.writeln ();
-  }
-}
-]b4_locations_if(b4_position_type_if([[[
+]b4_locations_if([b4_position_type_if([[
 static assert(__traits(compiles,
              (new ]b4_position_type[[1])[0]=(new ]b4_position_type[[1])[0]),
              "struct/class ]b4_position_type[ must be default-constructible "
              "and assignable");
 static assert(__traits(compiles, (new string[1])[0]=(new ]b4_position_type[).toString()),
              "error: struct/class ]b4_position_type[ must have toString method");
-]]], [[
+]], [[
  /**
   * A struct denoting a point in the input.*/
 public struct ]b4_position_type[ {
@@ -152,15 +97,18 @@ public struct ]b4_position_type[ {
  /** The line number within an input file.  */
  public int line = 1;
  /** The name of the input file.  */
-  public string filename = "(unspecified file)";
+  public string filename = null;

  /**
-   * Return a string representation of the position. */
+   * A string representation of the position. */
  public string toString() const {
-    return format("%s:%d.%d", filename, line, column);
+    if (filename)
+      return format("%s:%d.%d", filename, line, column);
+    else
+      return format("%d.%d", line, column);
  }
 }
-]])b4_location_type_if([[[
+]])b4_location_type_if([[
 static assert(__traits(compiles, (new ]b4_location_type[((new ]b4_position_type[[1])[0]))) &&
              __traits(compiles, (new ]b4_location_type[((new ]b4_position_type[[1])[0], (new ]b4_position_type[[1])[0]))),
              "error: struct/class ]b4_location_type[ must have "
@@ -174,7 +122,7 @@ static assert(__traits(compiles, (new ]b4_location_type[[1])[0].begin=(new ]b4_l
 static assert(__traits(compiles, (new string[1])[0]=(new ]b4_location_type[[1])[0].toString()),
              "error: struct/class ]b4_location_type[ must have toString method.");

-private immutable bool yy_location_is_class = !__traits(compiles, *(new ]b4_location_type[((new ]b4_position_type[[1])[0])));]]], [[
+private immutable bool yy_location_is_class = !__traits(compiles, *(new ]b4_location_type[((new ]b4_position_type[[1])[0])));]], [[
 /**
 * A class defining a pair of positions.  Positions, defined by the
 * <code>]b4_position_type[</code> class, denote a point in the input.
@@ -196,6 +144,9 @@ public class ]b4_location_type[
    this.begin = this.end = loc;
  }

+  public this () {
+  }
+
  /**
   * Create a <code>]b4_location_type[</code> from the endpoints of the range.
   * @@param begin The first position included in the range.
@@ -207,20 +158,25 @@ public class ]b4_location_type[
  }

  /**
-   * Return a representation of the location. For this to be correct,
+   * A representation of the location. For this to be correct,
   * <code>]b4_position_type[</code> should override the <code>toString</code>
   * method.  */
-  public const string toString () const {
-    if (begin==end)
-      return begin.toString ();
-    else
-      return begin.toString () ~ "-" ~ end.toString ();
+  public override string toString () const {
+    auto end_col = 0 < end.column ? end.column - 1 : 0;
+    auto res = begin.toString ();
+    if (end.filename && begin.filename != end.filename)
+      res ~= "-" ~ format("%s:%d.%d", end.filename, end.line, end_col);
+    else if (begin.line < end.line)
+      res ~= "-" ~ format("%d.%d", end.line, end_col);
+    else if (begin.column < end_col)
+      res ~= "-" ~ format("%d", end_col);
+    return res;
  }
 }

 private immutable bool yy_location_is_class = true;

-]]))m4_ifdef([b4_user_union_members], [private union YYSemanticType
+]])])m4_ifdef([b4_user_union_members], [private union YYSemanticType
 {
 b4_user_union_members
 };],
@@ -261,29 +217,27 @@ b4_user_union_members

 ]b4_lexer_if([[
  /**
-   * Instantiates the Bison-generated parser.
+   * Instantiate the Bison-generated parser.
   */
  public this] (b4_parse_param_decl([b4_lex_param_decl])[) {
-    this.yylexer = new YYLexer(]b4_lex_param_call[);
-    this.yyDebugStream = stderr;
-]b4_parse_param_cons[
+    this (new YYLexer(]b4_lex_param_call[));
  }
 ]])[

  /**
-   * Instantiates the Bison-generated parser.
+   * Instantiate the Bison-generated parser.
   * @@param yylexer The scanner that will supply tokens to the parser.
   */
  ]b4_lexer_if([[protected]], [[public]]) [this (]b4_parse_param_decl([[Lexer yylexer]])[) {
-    this.yylexer = yylexer;
-    this.yyDebugStream = stderr;
+    this.yylexer = yylexer;]b4_parse_trace_if([[
+    this.yyDebugStream = stderr;]])[
 ]b4_parse_param_cons[
  }
-
+]b4_parse_trace_if([[
  private File yyDebugStream;

  /**
-   * Return the <tt>File</tt> on which the debugging output is
+   * The <tt>File</tt> on which the debugging output is
   * printed.
   */
  public File getDebugStream () { return yyDebugStream; }
@@ -309,16 +263,17 @@ b4_user_union_members
   */
  public final void setDebugLevel(int level) { yydebug = level; }

+  protected final void yycdebug (string s) {
+    if (0 < yydebug)
+      yyDebugStream.writeln (s);
+  }
+]])[
  private final int yylex () {
    return yylexer.yylex ();
  }
+
  protected final void yyerror (]b4_locations_if(ref [b4_location_type[ loc, ]])[string s) {
    yylexer.yyerror (]b4_locations_if([loc, ])[s);
-  }]
-
-  [protected final void yycdebug (string s) {
-    if (yydebug > 0)
-      yyDebugStream.writeln (s);
  }

  /**
@@ -345,11 +300,11 @@ b4_user_union_members
  private static immutable int YYERRLAB1 = 7;
  private static immutable int YYRETURN = 8;
 ]b4_locations_if([
-  private static immutable YYSemanticType yy_semantic_null = cast(YYSemanticType)null;])[
+  private static immutable YYSemanticType yy_semantic_null;])[
  private int yyerrstatus_ = 0;

  /**
-   * Return whether error recovery is being done.  In this state, the parser
+   * Whether error recovery is being done.  In this state, the parser
   * reads token until it reaches a known state, and then restarts normal
   * operation.  */
  public final bool recovering ()
@@ -373,7 +328,8 @@ b4_user_union_members
    else
      yyval = yystack.valueAt (0);

-    yy_reduce_print (yyn, yystack);
+]b4_parse_trace_if([[
+    yy_reduce_print (yyn, yystack);]])[

    switch (yyn)
    {
@@ -381,7 +337,8 @@ b4_user_union_members
      default: break;
    }

-    yy_symbol_print ("-> $$ =", yyr1_[yyn], yyval]b4_locations_if([, yyloc])[);
+]b4_parse_trace_if([[
+    yy_symbol_print ("-> $$ =", yyr1_[yyn], yyval]b4_locations_if([, yyloc])[);]])[

    yystack.pop (yylen);
    yylen = 0;
@@ -429,12 +386,12 @@ b4_user_union_members
              return yyr;
            }
      }
-    else if (yystr=="$end")
+    else if (yystr == "$end")
      return "end of input";

    return yystr;
  }
-
+]b4_parse_trace_if([[
  /*--------------------------------.
  | Print this symbol on YYOUTPUT.  |
  `--------------------------------*/
@@ -443,11 +400,11 @@ b4_user_union_members
    ref ]b4_yystype[ yyvaluep]dnl
 b4_locations_if([, ref ]b4_location_type[ yylocationp])[)
  {
-    if (yydebug > 0) {
+    if (0 < yydebug) {
      string message = s ~ (yytype < yyntokens_ ? " token " : " nterm ")
              ~ yytname_[yytype] ~ " ("]b4_locations_if([
              ~ yylocationp.toString() ~ ": "])[;
-      static if (__traits(compiles, message~=yyvaluep.toString ()))
+      static if (__traits(compiles, message ~= yyvaluep.toString ()))
              message ~= yyvaluep.toString ();
      else
              message ~= format ("%s", &yyvaluep);
@@ -455,7 +412,7 @@ b4_locations_if([, ref ]b4_location_type[ yylocationp])[)
      yycdebug (message);
    }
  }
-
+]])[
  /**
   * Parse input from the scanner that was specified at object construction
   * time.  Return whether the end of the input was reached successfully.
@@ -490,9 +447,9 @@ b4_locations_if([, ref ]b4_location_type[ yylocationp])[)
    /// Semantic value of the lookahead.
    ]b4_yystype[ yylval;

-    int yyresult;
+    int yyresult;]b4_parse_trace_if([[

-    yycdebug ("Starting parse\n");
+    yycdebug ("Starting parse\n");]])[
    yyerrstatus_ = 0;

 ]m4_ifdef([b4_initial_action], [
@@ -512,10 +469,10 @@ m4_popdef([b4_at_dollar])])dnl
      {
        /* New state.  Unlike in the C/C++ skeletons, the state is already
           pushed when we come here.  */
-      case YYNEWSTATE:
+      case YYNEWSTATE:]b4_parse_trace_if([[
        yycdebug (format("Entering state %d\n", yystate));
-        if (yydebug > 0)
-          yystack.print (yyDebugStream);
+        if (0 < yydebug)
+          yystack.print (yyDebugStream);]])[

        /* Accept?  */
        if (yystate == yyfinal_)
@@ -531,8 +488,8 @@ m4_popdef([b4_at_dollar])])dnl

        /* Read a lookahead token.  */
        if (yychar == yyempty_)
-        {
-          yycdebug ("Reading a token: ");
+        {]b4_parse_trace_if([[
+          yycdebug ("Reading a token: ");]])[
          yychar = yylex ();]b4_locations_if([[
          static if (yy_location_is_class) {
            yylloc = new ]b4_location_type[(yylexer.startPos, yylexer.endPos);
@@ -543,17 +500,9 @@ m4_popdef([b4_at_dollar])])dnl
        }

        /* Convert token to internal form.  */
-        if (yychar <= YYTokenType.EOF)
-        {
-          yychar = yytoken = YYTokenType.EOF;
-          yycdebug ("Now at end of input.\n");
-        }
-        else
-        {
-          yytoken = yytranslate_ (yychar);
-          yy_symbol_print ("Next token is",
-                           yytoken, yylval]b4_locations_if([, yylloc])[);
-        }
+        yytoken = yytranslate_ (yychar);]b4_parse_trace_if([[
+        yy_symbol_print ("Next token is",
+                         yytoken, yylval]b4_locations_if([, yylloc])[);]])[

        /* If the proper action on seeing token YYTOKEN is to reduce or to
           detect an error, take that action.  */
@@ -574,9 +523,9 @@ m4_popdef([b4_at_dollar])])dnl
        }
        else
        {
-            /* Shift the lookahead token.  */
+          /* Shift the lookahead token.  */]b4_parse_trace_if([[
          yy_symbol_print ("Shifting", yytoken,
-                            yylval]b4_locations_if([, yylloc])[);
+                            yylval]b4_locations_if([, yylloc])[);]])[

          /* Discard the token being shifted.  */
          yychar = yyempty_;
@@ -685,9 +634,9 @@ m4_popdef([b4_at_dollar])])dnl

 ]b4_locations_if([          yyerrloc = yystack.locationAt (0);])[
          yystack.pop ();
-          yystate = yystack.stateAt (0);
-          if (yydebug > 0)
-            yystack.print (yyDebugStream);
+          yystate = yystack.stateAt (0);]b4_parse_trace_if([[
+          if (0 < yydebug)
+            yystack.print (yyDebugStream);]])[
        }

 ]b4_locations_if([
@@ -697,9 +646,9 @@ m4_popdef([b4_at_dollar])])dnl
        yyloc = yylloc_from_stack (yystack, 2);
        yystack.pop (2);])[

-        /* Shift the error token.  */
+        /* Shift the error token.  */]b4_parse_trace_if([[
        yy_symbol_print ("Shifting", yystos_[yyn],
-        yylval]b4_locations_if([, yyloc])[);
+        yylval]b4_locations_if([, yyloc])[);]])[

        yystate = yyn;
        yystack.push (yyn, yylval]b4_locations_if([, yyloc])[);
@@ -837,6 +786,7 @@ m4_popdef([b4_at_dollar])])dnl
  ]b4_tname[
  @};

+]b4_parse_trace_if([[
  /* YYRLINE[YYN] -- Source line where rule number YYN was defined.  */
  private static immutable ]b4_int_type_for([b4_rline])[[] yyrline_ =
  @{
@@ -862,19 +812,25 @@ m4_popdef([b4_at_dollar])])dnl
                       ]b4_rhs_value(yynrhs, yyi + 1)b4_locations_if([,
                       b4_rhs_location(yynrhs, yyi + 1)])[);
  }
-
-  /* YYTRANSLATE(YYLEX) -- Bison symbol number corresponding to YYLEX.  */
-  private static immutable ]b4_int_type_for([b4_translate])[[] yytranslate_table_ =
-  @{
-  ]b4_translate[
-  @};
+]])[

  private static ]b4_int_type_for([b4_translate])[ yytranslate_ (int t)
  {
-    if (t >= 0 && t <= yyuser_token_number_max_)
-      return yytranslate_table_[t];
+]b4_api_token_raw_if(
+[[    import std.conv : to;
+    return to!byte (t);]],
+[[    /* YYTRANSLATE(YYLEX) -- Bison symbol number corresponding to YYLEX.  */
+    immutable ]b4_int_type_for([b4_translate])[[] translate_table =
+    @{
+  ]b4_translate[
+    @};
+
+    if (t <= 0)
+      return YYTokenType.EOF;
+    else if (t <= yyuser_token_number_max_)
+      return translate_table[t];
    else
-      return yyundef_token_;
+      return yyundef_token_;]])[
  }

  private static immutable int yylast_ = ]b4_last[;
@@ -888,9 +844,64 @@ m4_popdef([b4_at_dollar])])dnl
  private static immutable int yyuser_token_number_max_ = ]b4_user_token_number_max[;
  private static immutable int yyundef_token_ = ]b4_undef_token_number[;

-]/* User implementation code.  */
-b4_percent_code_get[]dnl
+  private final struct YYStackElement {
+    int state;
+    ]b4_yystype[ value;]b4_locations_if(
+    b4_location_type[[] location;])[
+  }

+  private final struct YYStack {
+    private YYStackElement[] stack = [];
+
+    public final @@property ulong height()
+    {
+      return stack.length;
+    }
+
+    public final void push (int state, ]b4_yystype[ value]dnl
+  b4_locations_if([, ref ]b4_location_type[ loc])[)
+    {
+      stack ~= YYStackElement(state, value]b4_locations_if([, loc])[);
+    }
+
+    public final void pop ()
+    {
+      pop (1);
+    }
+
+    public final void pop (int num)
+    {
+      stack.length -= num;
+    }
+
+    public final int stateAt (int i)
+    {
+      return stack[$-i-1].state;
+    }
+
+]b4_locations_if([[
+    public final ref ]b4_location_type[ locationAt (int i)
+    {
+      return stack[$-i-1].location;
+    }]])[
+
+    public final ref ]b4_yystype[ valueAt (int i)
+    {
+      return stack[$-i-1].value;
+    }
+]b4_parse_trace_if([[
+    // Print the state stack on the debug stream.
+    public final void print (File stream)
+    {
+      stream.write ("Stack now");
+      for (int i = 0; i < stack.length; i++)
+        stream.write (" ", stack[i].state);
+      stream.writeln ();
+    }]])[
+  }
+
+  /* User implementation code.  */
+]b4_percent_code_get[
 }
-b4_epilogue[]dnl
-m4_divert_pop(0)dnl
+]b4_epilogue[]dnl
+b4_output_end
@@ -1,4 +1,4 @@
-# Java skeleton for Bison -*- autoconf -*-
+# Java skeleton for Bison                           -*- autoconf -*-

 # Copyright (C) 2007-2015, 2018-2019 Free Software Foundation, Inc.

@@ -19,10 +19,6 @@ m4_include(b4_skeletonsdir/[java.m4])

 b4_defines_if([b4_complain([%defines does not make sense in Java])])

-# We do not depend on %debug in Java, but pacify warnings about
-# non-used flags.
-b4_parse_trace_if([0], [0])
-
 m4_define([b4_symbol_no_destructor_assert],
 [b4_symbol_if([$1], [has_destructor],
              [b4_complain_at(m4_unquote(b4_symbol([$1], [destructor_loc])),
@@ -70,19 +66,19 @@ m4_define([b4_define_state],[[

    /* Error handling.  */
    int yynerrs_ = 0;
-    ]b4_locations_if([/* The location where the error started.  */
-    b4_location_type yyerrloc = null;
+    ]b4_locations_if([[/* The location where the error started.  */
+    ]b4_location_type[ yyerrloc = null;

    /* Location. */
-    b4_location_type yylloc = new b4_location_type (null, null);])[
+    ]b4_location_type[ yylloc = new ]b4_location_type[ (null, null);]])[

    /* Semantic value of the lookahead.  */
    ]b4_yystype[ yylval = null;
-]])
+]])[

-b4_output_begin([b4_parser_file_name])[
+]b4_output_begin([b4_parser_file_name])[
 ]b4_copyright([Skeleton implementation for Bison LALR(1) parsers in Java],
-             [2007-2015, 2018])[
+              [2007-2015, 2018-2019])[
 ]b4_percent_define_ifdef([package], [package b4_percent_define_get([package]);[
 ]])[
 ]b4_user_pre_prologue[
@@ -103,7 +99,7 @@ b4_output_begin([b4_parser_file_name])[
  private boolean yyErrorVerbose = true;

  /**
-   * Return whether verbose error messages are enabled.
+   * Whether verbose error messages are enabled.
   */
  public final boolean getErrorVerbose() { return yyErrorVerbose; }

@@ -165,12 +161,12 @@ b4_locations_if([[
    }
  }

-]])
+]])[

-  b4_locations_if([[
+]b4_locations_if([[
  private ]b4_location_type[ yylloc (YYStack rhs, int n)
  {
-    if (n > 0)
+    if (0 < n)
      return new ]b4_location_type[ (rhs.locationAt (n-1).begin, rhs.locationAt (0).end);
    else
      return new ]b4_location_type[ (rhs.locationAt (0).end);
@@ -220,10 +216,11 @@ b4_locations_if([[
     *                error message is related]])[
     * @@param msg The string for the error message.
     */
-     void yyerror (]b4_locations_if([b4_location_type[ loc, ]])[String msg);]
+     void yyerror (]b4_locations_if([b4_location_type[ loc, ]])[String msg);
  }

-  b4_lexer_if([[private class YYLexer implements Lexer {
+]b4_lexer_if([[
+  private class YYLexer implements Lexer {
 ]b4_percent_code_get([[lexer]])[
  }

@@ -231,10 +228,10 @@ b4_locations_if([[
   * The object doing lexical analysis for us.
   */
  private Lexer yylexer;
-  ]
-  b4_parse_param_vars

-b4_lexer_if([[
+  ]b4_parse_param_vars[
+
+]b4_lexer_if([[
  /**
   * Instantiates the Bison-generated parser.
   */
@@ -244,24 +241,24 @@ b4_lexer_if([[
    this.yylexer = new YYLexer(]b4_lex_param_call[);
    ]b4_parse_param_cons[
  }
-]])
+]])[

  /**
   * Instantiates the Bison-generated parser.
   * @@param yylexer The scanner that will supply tokens to the parser.
   */
-  b4_lexer_if([[protected]], [[public]]) b4_parser_class[ (]b4_parse_param_decl([[Lexer yylexer]])[) ]b4_maybe_throws([b4_init_throws])[
+  ]b4_lexer_if([[protected]], [[public]]) b4_parser_class[ (]b4_parse_param_decl([[Lexer yylexer]])[) ]b4_maybe_throws([b4_init_throws])[
  {
    ]b4_percent_code_get([[init]])[
    this.yylexer = yylexer;
    ]b4_parse_param_cons[
  }

+]b4_parse_trace_if([[
  private java.io.PrintStream yyDebugStream = System.err;

  /**
-   * Return the <tt>PrintStream</tt> on which the debugging output is
-   * printed.
+   * The <tt>PrintStream</tt> on which the debugging output is printed.
   */
  public final java.io.PrintStream getDebugStream () { return yyDebugStream; }

@@ -285,6 +282,7 @@ b4_lexer_if([[
   * @@param level The verbosity level for debugging output.
   */
  public final void setDebugLevel(int level) { yydebug = level; }
+]])[

  /**
   * Print an error message via the lexer.
@@ -314,12 +312,12 @@ b4_lexer_if([[
  public final void yyerror (]b4_position_type[ pos, String msg)
  {
    yylexer.yyerror (new ]b4_location_type[ (pos), msg);
-  }]])
-
-  [protected final void yycdebug (String s) {
-    if (yydebug > 0)
+  }]])[
+]b4_parse_trace_if([[
+  protected final void yycdebug (String s) {
+    if (0 < yydebug)
      yyDebugStream.println (s);
-  }
+  }]])[

  private final class YYStack {
    private int[] stateStack = new int[16];
@@ -360,7 +358,7 @@ b4_lexer_if([[

    public final void pop (int num) {
      // Avoid memory leaks... garbage collection is a white lie!
-      if (num > 0) {
+      if (0 < num) {
        java.util.Arrays.fill (valueStack, height - num + 1, height + 1, null);
        ]b4_locations_if([[java.util.Arrays.fill (locStack, height - num + 1, height + 1, null);]])[
      }
@@ -430,10 +428,9 @@ b4_lexer_if([[

  private int yyerrstatus_ = 0;

-]b4_push_if([dnl
-b4_define_state])[
+]b4_push_if([b4_define_state])[
  /**
-   * Return whether error recovery is being done.  In this state, the parser
+   * Whether error recovery is being done.  In this state, the parser
   * reads token until it reaches a known state, and then restarts normal
   * operation.
   */
@@ -446,7 +443,7 @@ b4_define_state])[
   * @@param yystate   the current state
   * @@param yysym     the nonterminal to push on the stack
   */
-  private int yy_lr_goto_state_ (int yystate, int yysym)
+  private int yyLRGotoState (int yystate, int yysym)
  {
    int yyr = yypgoto_[yysym - yyntokens_] + yystate;
    if (0 <= yyr && yyr <= yylast_ && yycheck_[yyr] == yystate)
@@ -457,35 +454,30 @@ b4_define_state])[

  private int yyaction (int yyn, YYStack yystack, int yylen) ]b4_maybe_throws([b4_throws])[
  {
-    ]b4_yystype[ yyval;
-    ]b4_locations_if([b4_location_type[ yyloc = yylloc (yystack, yylen);]])[
-
    /* If YYLEN is nonzero, implement the default value of the action:
       '$$ = $1'.  Otherwise, use the top of the stack.

       Otherwise, the following line sets YYVAL to garbage.
       This behavior is undocumented and Bison
       users should not rely upon it.  */
-    if (yylen > 0)
-      yyval = yystack.valueAt (yylen - 1);
-    else
-      yyval = yystack.valueAt (0);
+    ]b4_yystype[ yyval = (0 < yylen) ? yystack.valueAt (yylen - 1) : yystack.valueAt (0);
+    ]b4_locations_if([b4_location_type[ yyloc = yylloc (yystack, yylen);]])[]b4_parse_trace_if([[

-    yy_reduce_print (yyn, yystack);
+    yyReducePrint (yyn, yystack);]])[

    switch (yyn)
      {
        ]b4_user_actions[
        default: break;
-      }
+      }]b4_parse_trace_if([[

-    yy_symbol_print ("-> $$ =", yyr1_[yyn], yyval]b4_locations_if([, yyloc])[);
+    yySymbolPrint ("-> $$ =", yyr1_[yyn], yyval]b4_locations_if([, yyloc])[);]])[

    yystack.pop (yylen);
    yylen = 0;

    /* Shift the result of the reduction.  */
-    int yystate = yy_lr_goto_state_ (yystack.stateAt (0), yyr1_[yyn]);
+    int yystate = yyLRGotoState (yystack.stateAt (0), yyr1_[yyn]);
    yystack.push (yystate, yyval]b4_locations_if([, yyloc])[);
    return YYNEWSTATE;
  }
@@ -526,21 +518,20 @@ b4_define_state])[
    return yystr;
  }
 ]])[
-
+]b4_parse_trace_if([[
  /*--------------------------------.
  | Print this symbol on YYOUTPUT.  |
  `--------------------------------*/

-  private void yy_symbol_print (String s, int yytype,
-                                 ]b4_yystype[ yyvaluep]dnl
-                                 b4_locations_if([, Object yylocationp])[)
+  private void yySymbolPrint (String s, int yytype,
+                             ]b4_yystype[ yyvaluep]dnl
+                              b4_locations_if([, Object yylocationp])[)
  {
-    if (yydebug > 0)
    yycdebug (s + (yytype < yyntokens_ ? " token " : " nterm ")
              + yytname_[yytype] + " ("]b4_locations_if([
              + yylocationp + ": "])[
              + (yyvaluep == null ? "(null)" : yyvaluep.toString ()) + ")");
-  }
+  }]])[

 ]b4_push_if([],[[
  /**
@@ -550,7 +541,7 @@ b4_define_state])[
   * @@return <tt>true</tt> if the parsing succeeds.  Note that this does not
   *          imply that there were no syntax errors.
   */
-   public boolean parse () ]b4_maybe_throws([b4_list2([b4_lex_throws], [b4_throws])])[]])[
+  public boolean parse () ]b4_maybe_throws([b4_list2([b4_lex_throws], [b4_throws])])[]])[
 ]b4_push_if([
  /**
   * Push Parse input from external lexer
@@ -567,8 +558,8 @@ b4_define_state])[
    ]b4_locations_if([/* @@$.  */
    b4_location_type yyloc;])[
 ]b4_push_if([],[[
-]b4_define_state[
-    yycdebug ("Starting parse\n");
+]b4_define_state[]b4_parse_trace_if([[
+    yycdebug ("Starting parse\n");]])[
    yyerrstatus_ = 0;

    /* Initialize the stack.  */
@@ -587,8 +578,8 @@ b4_dollar_popdef[]dnl
 b4_dollar_pushdef([yylval], [], [], [yylloc])dnl
    b4_user_initial_action
 b4_dollar_popdef[]dnl
-])[
-        yycdebug ("Starting parse\n");
+])[]b4_parse_trace_if([[
+        yycdebug ("Starting parse\n");]])[
        yyerrstatus_ = 0;
      } else
        label = YYGETTOKEN;
@@ -600,10 +591,10 @@ b4_dollar_popdef[]dnl
      {
        /* New state.  Unlike in the C/C++ skeletons, the state is already
           pushed when we come here.  */
-      case YYNEWSTATE:
+      case YYNEWSTATE:]b4_parse_trace_if([[
        yycdebug ("Entering state " + yystate + "\n");
-        if (yydebug > 0)
-          yystack.print (yyDebugStream);
+        if (0 < yydebug)
+          yystack.print (yyDebugStream);]])[

        /* Accept?  */
        if (yystate == yyfinal_)
@@ -612,7 +603,7 @@ b4_dollar_popdef[]dnl

        /* Take a decision.  First try without lookahead.  */
        yyn = yypact_[yystate];
-        if (yy_pact_value_is_default_ (yyn))
+        if (yyPactValueIsDefault (yyn))
          {
            label = YYDEFAULT;
            break;
@@ -625,14 +616,13 @@ b4_dollar_popdef[]dnl
          {
 ]b4_push_if([[
            if (!push_token_consumed)
-              return YYPUSH_MORE;
-            yycdebug ("Reading a token: ");
+              return YYPUSH_MORE;]b4_parse_trace_if([[
+            yycdebug ("Reading a token: ");]])[
            yychar = yylextoken;
            yylval = yylexval;]b4_locations_if([
            yylloc = yylexloc;])[
-            push_token_consumed = false;]])[
-]b4_push_if([],[[
-            yycdebug ("Reading a token: ");
+            push_token_consumed = false;]], [b4_parse_trace_if([[
+            yycdebug ("Reading a token: ");]])[
            yychar = yylexer.yylex ();
            yylval = yylexer.getLVal ();]b4_locations_if([
            yylloc = new b4_location_type (yylexer.getStartPos (),
@@ -641,17 +631,9 @@ b4_dollar_popdef[]dnl
          }

        /* Convert token to internal form.  */
-        if (yychar <= Lexer.EOF)
-          {
-            yychar = yytoken = Lexer.EOF;
-            yycdebug ("Now at end of input.\n");
-          }
-        else
-          {
-            yytoken = yytranslate_ (yychar);
-            yy_symbol_print ("Next token is", yytoken,
-                             yylval]b4_locations_if([, yylloc])[);
-          }
+        yytoken = yytranslate_ (yychar);]b4_parse_trace_if([[
+        yySymbolPrint ("Next token is", yytoken,
+                       yylval]b4_locations_if([, yylloc])[);]])[

        /* If the proper action on seeing token YYTOKEN is to reduce or to
           detect an error, take that action.  */
@@ -662,7 +644,7 @@ b4_dollar_popdef[]dnl
        /* <= 0 means reduce or error.  */
        else if ((yyn = yytable_[yyn]) <= 0)
          {
-            if (yy_table_value_is_error_ (yyn))
+            if (yyTableValueIsError (yyn))
              label = YYERRLAB;
            else
              {
@@ -673,10 +655,10 @@ b4_dollar_popdef[]dnl

        else
          {
-            /* Shift the lookahead token.  */
-            yy_symbol_print ("Shifting", yytoken,
-                             yylval]b4_locations_if([, yylloc])[);
-
+            /* Shift the lookahead token.  */]b4_parse_trace_if([[
+            yySymbolPrint ("Shifting", yytoken,
+                           yylval]b4_locations_if([, yylloc])[);
+]])[
            /* Discard the token being shifted.  */
            yychar = yyempty_;

@@ -727,17 +709,17 @@ b4_dollar_popdef[]dnl
        ]b4_locations_if([yyerrloc = yylloc;])[
        if (yyerrstatus_ == 3)
          {
-        /* If just tried and failed to reuse lookahead token after an
-         error, discard it.  */
+            /* If just tried and failed to reuse lookahead token after an
+               error, discard it.  */

-        if (yychar <= Lexer.EOF)
-          {
-          /* Return failure if at end of input.  */
-          if (yychar == Lexer.EOF)
-            ]b4_push_if([{label = YYABORT; break;}],[return false;])[
-          }
-        else
-            yychar = yyempty_;
+            if (yychar <= Lexer.EOF)
+              {
+                /* Return failure if at end of input.  */
+                if (yychar == Lexer.EOF)
+                  ]b4_push_if([{label = YYABORT; break;}], [return false;])[
+              }
+            else
+              yychar = yyempty_;
          }

        /* Else will try to reuse lookahead token after shifting the error
@@ -749,7 +731,6 @@ b4_dollar_popdef[]dnl
      | errorlab -- error raised explicitly by YYERROR.  |
      `-------------------------------------------------*/
      case YYERROR:
-
        ]b4_locations_if([yyerrloc = yystack.locationAt (yylen - 1);])[
        /* Do not reclaim the symbols of the rule which action triggered
           this YYERROR.  */
@@ -768,7 +749,7 @@ b4_dollar_popdef[]dnl
        for (;;)
          {
            yyn = yypact_[yystate];
-            if (!yy_pact_value_is_default_ (yyn))
+            if (!yyPactValueIsDefault (yyn))
              {
                yyn += yyterror_;
                if (0 <= yyn && yyn <= yylast_ && yycheck_[yyn] == yyterror_)
@@ -786,9 +767,9 @@ b4_dollar_popdef[]dnl

            ]b4_locations_if([yyerrloc = yystack.locationAt (0);])[
            yystack.pop ();
-            yystate = yystack.stateAt (0);
-            if (yydebug > 0)
-              yystack.print (yyDebugStream);
+            yystate = yystack.stateAt (0);]b4_parse_trace_if([[
+            if (0 < yydebug)
+              yystack.print (yyDebugStream);]])[
          }

        if (label == YYABORT)
@@ -802,9 +783,9 @@ b4_dollar_popdef[]dnl
        yyloc = yylloc (yystack, 2);
        yystack.pop (2);])[

-        /* Shift the error token.  */
-        yy_symbol_print ("Shifting", yystos_[yyn],
-                         yylval]b4_locations_if([, yyloc])[);
+        /* Shift the error token.  */]b4_parse_trace_if([[
+        yySymbolPrint ("Shifting", yystos_[yyn],
+                       yylval]b4_locations_if([, yyloc])[);]])[

        yystate = yyn;
        yystack.push (yyn, yylval]b4_locations_if([, yyloc])[);
@@ -870,9 +851,9 @@ b4_dollar_popdef[]dnl
  {
    return push_parse (yylextoken, yylexval, new b4_location_type (yylexpos));
  }
-])[]])
+])[]])[

-b4_both_if([[
+]b4_both_if([[
  /**
   * Parse input from the scanner that was specified at object construction
   * time.  Return whether the end of the input was reached successfully.
@@ -881,21 +862,21 @@ b4_both_if([[
   * @@return <tt>true</tt> if the parsing succeeds.  Note that this does not
   *          imply that there were no syntax errors.
   */
-   public boolean parse () ]b4_maybe_throws([b4_list2([b4_lex_throws], [b4_throws])])[
-   {
-      if (yylexer == null)
-        throw new NullPointerException("Null Lexer");
-      int status;
-      do {
-        int token = yylexer.yylex();
-        ]b4_yystype[ lval = yylexer.getLVal();
+  public boolean parse () ]b4_maybe_throws([b4_list2([b4_lex_throws], [b4_throws])])[
+  {
+    if (yylexer == null)
+      throw new NullPointerException("Null Lexer");
+    int status;
+    do {
+      int token = yylexer.yylex();
+      ]b4_yystype[ lval = yylexer.getLVal();
 ]b4_locations_if([dnl
-        b4_location_type yyloc = new b4_location_type (yylexer.getStartPos (),
-                                              yylexer.getEndPos ());])[
-        ]b4_locations_if([status = push_parse(token,lval,yyloc);],[
-        status = push_parse(token,lval);])[
-      } while (status == YYPUSH_MORE);
-      return (status == YYACCEPT);
+      b4_location_type yyloc = new b4_location_type (yylexer.getStartPos (),
+                                            yylexer.getEndPos ());])[
+      ]b4_locations_if([status = push_parse(token,lval,yyloc);],[
+      status = push_parse(token,lval);])[
+    } while (status == YYPUSH_MORE);
+    return (status == YYACCEPT);
  }
 ]])[

@@ -938,7 +919,7 @@ b4_both_if([[
              new StringBuffer ("syntax error, unexpected ");
            res.append (yytnamerr_ (yytname_[tok]));
            int yyn = yypact_[yystate];
-            if (!yy_pact_value_is_default_ (yyn))
+            if (!yyPactValueIsDefault (yyn))
              {
                /* Start YYX at -YYN if negative to avoid negative
                   indexes in YYCHECK.  In other words, skip the first
@@ -951,14 +932,14 @@ b4_both_if([[
                int count = 0;
                for (int x = yyxbegin; x < yyxend; ++x)
                  if (yycheck_[x + yyn] == x && x != yyterror_
-                      && !yy_table_value_is_error_ (yytable_[x + yyn]))
+                      && !yyTableValueIsError (yytable_[x + yyn]))
                    ++count;
                if (count < 5)
                  {
                    count = 0;
                    for (int x = yyxbegin; x < yyxend; ++x)
                      if (yycheck_[x + yyn] == x && x != yyterror_
-                          && !yy_table_value_is_error_ (yytable_[x + yyn]))
+                          && !yyTableValueIsError (yytable_[x + yyn]))
                        {
                          res.append (count++ == 0 ? ", expecting " : " or ");
                          res.append (yytnamerr_ (yytname_[x]));
@@ -976,7 +957,7 @@ b4_both_if([[
   * Whether the given <code>yypact_</code> value indicates a defaulted state.
   * @@param yyvalue   the value to check
   */
-  private static boolean yy_pact_value_is_default_ (int yyvalue)
+  private static boolean yyPactValueIsDefault (int yyvalue)
  {
    return yyvalue == yypact_ninf_;
  }
@@ -986,7 +967,7 @@ b4_both_if([[
   * value indicates a syntax error.
   * @@param yyvalue the value to check
   */
-  private static boolean yy_table_value_is_error_ (int yyvalue)
+  private static boolean yyTableValueIsError (int yyvalue)
  {
    return yyvalue == yytable_ninf_;
  }
@@ -1003,12 +984,13 @@ b4_both_if([[
     First, the terminals, then, starting at \a yyntokens_, nonterminals.  */
  ]b4_typed_parser_table_define([String], [tname], [b4_tname])[

+]b4_parse_trace_if([[
  ]b4_integral_parser_table_define([rline], [b4_rline],
  [[YYRLINE[YYN] -- Source line where rule number YYN was defined.]])[


  // Report on the debug stream that the rule yyrule is going to be reduced.
-  private void yy_reduce_print (int yyrule, YYStack yystack)
+  private void yyReducePrint (int yyrule, YYStack yystack)
  {
    if (yydebug == 0)
      return;
@@ -1021,23 +1003,30 @@ b4_both_if([[

    /* The symbols being reduced.  */
    for (int yyi = 0; yyi < yynrhs; yyi++)
-      yy_symbol_print ("   $" + (yyi + 1) + " =",
-                       yystos_[yystack.stateAt(yynrhs - (yyi + 1))],
-                       ]b4_rhs_data(yynrhs, yyi + 1)b4_locations_if([,
-                       b4_rhs_location(yynrhs, yyi + 1)])[);
-  }
+      yySymbolPrint ("   $" + (yyi + 1) + " =",
+                     yystos_[yystack.stateAt(yynrhs - (yyi + 1))],
+                     ]b4_rhs_data(yynrhs, yyi + 1)b4_locations_if([,
+                     b4_rhs_location(yynrhs, yyi + 1)])[);
+  }]])[

-  /* YYTRANSLATE(TOKEN-NUM) -- Symbol number corresponding to TOKEN-NUM
+  /* YYTRANSLATE_(TOKEN-NUM) -- Symbol number corresponding to TOKEN-NUM
     as returned by yylex, with out-of-bounds checking.  */
-  ]b4_integral_parser_table_define([translate_table], [b4_translate])[
-
  private static final ]b4_int_type_for([b4_translate])[ yytranslate_ (int t)
-  {
-    if (t >= 0 && t <= yyuser_token_number_max_)
+]b4_api_token_raw_if(dnl
+[[  {
+    return t;
+  }
+]],
+[[  {
+    if (t <= 0)
+      return Lexer.EOF;
+    else if (t <= yyuser_token_number_max_)
      return yytranslate_table_[t];
    else
      return yyundef_token_;
  }
+  ]b4_integral_parser_table_define([translate_table], [b4_translate])[
+]])[

  private static final int yylast_ = ]b4_last[;
  private static final int yynnts_ = ]b4_nterms_number[;
@@ -1050,8 +1039,8 @@ b4_both_if([[
  private static final int yyuser_token_number_max_ = ]b4_user_token_number_max[;
  private static final int yyundef_token_ = ]b4_undef_token_number[;

-]/* User implementation code.  */
-b4_percent_code_get[]dnl
+/* User implementation code.  */
+]b4_percent_code_get[]dnl

 }

@@ -65,8 +65,8 @@ m4_define([b4_location_define],
  public:]m4_ifdef([b4_location_constructors], [[
    /// Construct a position.
    explicit position (]b4_percent_define_get([[filename_type]])[* f = YY_NULLPTR,
-                       unsigned l = ]b4_location_initial_line[u,
-                       unsigned c = ]b4_location_initial_column[u)
+                       int l = ]b4_location_initial_line[,
+                       int c = ]b4_location_initial_column[)
      : filename (f)
      , line (l)
      , column (c)
@@ -75,8 +75,8 @@ m4_define([b4_location_define],
 ]])[
    /// Initialization.
    void initialize (]b4_percent_define_get([[filename_type]])[* fn = YY_NULLPTR,
-                     unsigned l = ]b4_location_initial_line[u,
-                     unsigned c = ]b4_location_initial_column[u)
+                     int l = ]b4_location_initial_line[,
+                     int c = ]b4_location_initial_column[)
    {
      filename = fn;
      line = l;
@@ -90,7 +90,7 @@ m4_define([b4_location_define],
    {
      if (count)
        {
-          column = ]b4_location_initial_column[u;
+          column = ]b4_location_initial_column[;
          line = add_ (line, count, ]b4_location_initial_line[);
        }
    }
@@ -105,16 +105,15 @@ m4_define([b4_location_define],
    /// File name to which this position refers.
    ]b4_percent_define_get([[filename_type]])[* filename;
    /// Current line number.
-    unsigned line;
+    int line;
    /// Current column number.
-    unsigned column;
+    int column;

  private:
    /// Compute max (min, lhs+rhs).
-    static unsigned add_ (unsigned lhs, int rhs, int min)
+    static int add_ (int lhs, int rhs, int min)
    {
-      return static_cast<unsigned> (std::max (min,
-                                              static_cast<int> (lhs) + rhs));
+      return lhs + rhs < min ? min : lhs + rhs;
    }
  };

@@ -197,8 +196,8 @@ m4_define([b4_location_define],

    /// Construct a 0-width location in \a f, \a l, \a c.
    explicit location (]b4_percent_define_get([[filename_type]])[* f,
-                       unsigned l = ]b4_location_initial_line[u,
-                       unsigned c = ]b4_location_initial_column[u)
+                       int l = ]b4_location_initial_line[,
+                       int c = ]b4_location_initial_column[)
      : begin (f, l, c)
      , end (f, l, c)
    {}
@@ -206,8 +205,8 @@ m4_define([b4_location_define],
 ])[
    /// Initialization.
    void initialize (]b4_percent_define_get([[filename_type]])[* f = YY_NULLPTR,
-                     unsigned l = ]b4_location_initial_line[u,
-                     unsigned c = ]b4_location_initial_column[u)
+                     int l = ]b4_location_initial_line[,
+                     int c = ]b4_location_initial_column[)
    {
      begin.initialize (f, l, c);
      end = begin;
@@ -305,7 +304,7 @@ m4_define([b4_location_define],
  std::basic_ostream<YYChar>&
  operator<< (std::basic_ostream<YYChar>& ostr, const location& loc)
  {
-    unsigned end_col = 0 < loc.end.column ? loc.end.column - 1 : 0;
+    int end_col = 0 < loc.end.column ? loc.end.column - 1 : 0;
    ostr << loc.begin;
    if (loc.end.filename
        && (!loc.begin.filename
@@ -327,7 +326,7 @@ m4_ifdef([b4_position_file], [[
 // used to define is now defined in "]b4_location_file[".
 //
 // To get rid of this file:
-// 1. add 'require "3.2"' (or newer) to your grammar file
+// 1. add '%require "3.2"' (or newer) to your grammar file
 // 2. remove references to this file from your build system
 // 3. if you used to include it, include "]b4_location_file[" instead.

@@ -346,7 +345,6 @@ m4_ifdef([b4_location_file], [[

 ]b4_cpp_guard_open([b4_location_path])[

-# include <algorithm> // std::max
 # include <iostream>
 # include <string>

@@ -35,6 +35,7 @@ m4_define([b4_stack_define],
      typedef typename S::reverse_iterator iterator;
      typedef typename S::const_reverse_iterator const_iterator;
      typedef typename S::size_type size_type;
+      typedef typename std::ptrdiff_t index_type;

      stack (size_type n = 200)
        : seq_ (n)
@@ -43,37 +44,19 @@ m4_define([b4_stack_define],
      /// Random access.
      ///
      /// Index 0 returns the topmost element.
-      T&
-      operator[] (size_type i)
+      const T&
+      operator[] (index_type i) const
      {
-        return seq_[size () - 1 - i];
+        return seq_[size_type (size () - 1 - i)];
      }

      /// Random access.
      ///
      /// Index 0 returns the topmost element.
      T&
-      operator[] (int i)
+      operator[] (index_type i)
      {
-        return operator[] (size_type (i));
-      }
-
-      /// Random access.
-      ///
-      /// Index 0 returns the topmost element.
-      const T&
-      operator[] (size_type i) const
-      {
-        return seq_[size () - 1 - i];
-      }
-
-      /// Random access.
-      ///
-      /// Index 0 returns the topmost element.
-      const T&
-      operator[] (int i) const
-      {
-        return operator[] (size_type (i));
+        return seq_[size_type (size () - 1 - i)];
      }

      /// Steal the contents of \a t.
@@ -88,7 +71,7 @@ m4_define([b4_stack_define],

      /// Pop elements from the stack.
      void
-      pop (int n = 1) YY_NOEXCEPT
+      pop (std::ptrdiff_t n = 1) YY_NOEXCEPT
      {
        for (; 0 < n; --n)
          seq_.pop_back ();
@@ -102,10 +85,15 @@ m4_define([b4_stack_define],
      }

      /// Number of elements on the stack.
-      size_type
+      index_type
      size () const YY_NOEXCEPT
      {
-        return seq_.size ();
+        return index_type (seq_.size ());
+      }
+      std::ptrdiff_t
+      ssize () const YY_NOEXCEPT
+      {
+        return (std::ptrdiff_t) size ();
      }

      /// Iterator on top of the stack (going downwards).
@@ -126,20 +114,20 @@ m4_define([b4_stack_define],
      class slice
      {
      public:
-        slice (const stack& stack, int range)
+        slice (const stack& stack, index_type range)
          : stack_ (stack)
          , range_ (range)
        {}

        const T&
-        operator[] (int i) const
+        operator[] (index_type i) const
        {
          return stack_[range_ - i];
        }

      private:
        const stack& stack_;
-        int range_;
+        index_type range_;
      };

    private:
@@ -157,7 +145,7 @@ m4_ifdef([b4_stack_file],
 // used to define is now defined with the parser itself.
 //
 // To get rid of this file:
-// 1. add 'require "3.2"' (or newer) to your grammar file
+// 1. add '%require "3.2"' (or newer) to your grammar file
 // 2. remove references to this file from your build system.
 ]b4_output_end[
 ]])
@@ -1,4 +1,4 @@
-                                                             -*- C -*-
+#                                                            -*- C -*-
 # Yacc compatible skeleton for Bison

 # Copyright (C) 1984, 1989-1990, 2000-2015, 2018-2019 Free Software
@@ -20,51 +20,11 @@ m4_pushdef([b4_copyright_years],
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.

-# Check the value of %define api.push-pull.
-b4_percent_define_default([[api.push-pull]], [[pull]])
-b4_percent_define_check_values([[[[api.push-pull]],
-                                 [[pull]], [[push]], [[both]]]])
-b4_define_flag_if([pull]) m4_define([b4_pull_flag], [[1]])
-b4_define_flag_if([push]) m4_define([b4_push_flag], [[1]])
-m4_case(b4_percent_define_get([[api.push-pull]]),
-        [pull], [m4_define([b4_push_flag], [[0]])],
-        [push], [m4_define([b4_pull_flag], [[0]])])
-
-# Handle BISON_USE_PUSH_FOR_PULL for the test suite.  So that push parsing
-# tests function as written, do not let BISON_USE_PUSH_FOR_PULL modify the
-# behavior of Bison at all when push parsing is already requested.
-b4_define_flag_if([use_push_for_pull])
-b4_use_push_for_pull_if([
-  b4_push_if([m4_define([b4_use_push_for_pull_flag], [[0]])],
-             [m4_define([b4_push_flag], [[1]])])])
-
-# Check the value of %define parse.lac and friends, where LAC stands for
-# lookahead correction.
-b4_percent_define_default([[parse.lac]], [[none]])
-b4_percent_define_default([[parse.lac.es-capacity-initial]], [[20]])
-b4_percent_define_default([[parse.lac.memory-trace]], [[failures]])
-b4_percent_define_check_values([[[[parse.lac]], [[full]], [[none]]]],
-                               [[[[parse.lac.memory-trace]],
-                                 [[failures]], [[full]]]])
-b4_define_flag_if([lac])
-m4_define([b4_lac_flag],
-          [m4_if(b4_percent_define_get([[parse.lac]]),
-                 [none], [[0]], [[1]])])
-
 m4_include(b4_skeletonsdir/[c.m4])

-## ---------------- ##
-## Default values.  ##
-## ---------------- ##
-
-# Stack parameters.
-m4_define_default([b4_stack_depth_max], [10000])
-m4_define_default([b4_stack_depth_init],  [200])
-
-
-## ------------------------ ##
-## Pure/impure interfaces.  ##
-## ------------------------ ##
+## ---------- ##
+## api.pure.  ##
+## ---------- ##

 b4_percent_define_default([[api.pure]], [[false]])
 b4_percent_define_check_values([[[[api.pure]],
@@ -84,6 +44,51 @@ m4_define([b4_pure_if],
         [2], [$1])])
         [m4_fatal([invalid api.pure value: ]$1)])])

+## --------------- ##
+## api.push-pull.  ##
+## --------------- ##
+
+b4_percent_define_default([[api.push-pull]], [[pull]])
+b4_percent_define_check_values([[[[api.push-pull]],
+                                 [[pull]], [[push]], [[both]]]])
+b4_define_flag_if([pull]) m4_define([b4_pull_flag], [[1]])
+b4_define_flag_if([push]) m4_define([b4_push_flag], [[1]])
+m4_case(b4_percent_define_get([[api.push-pull]]),
+        [pull], [m4_define([b4_push_flag], [[0]])],
+        [push], [m4_define([b4_pull_flag], [[0]])])
+
+# Handle BISON_USE_PUSH_FOR_PULL for the test suite.  So that push parsing
+# tests function as written, do not let BISON_USE_PUSH_FOR_PULL modify the
+# behavior of Bison at all when push parsing is already requested.
+b4_define_flag_if([use_push_for_pull])
+b4_use_push_for_pull_if([
+  b4_push_if([m4_define([b4_use_push_for_pull_flag], [[0]])],
+             [m4_define([b4_push_flag], [[1]])])])
+
+## ----------- ##
+## parse.lac.  ##
+## ----------- ##
+
+b4_percent_define_default([[parse.lac]], [[none]])
+b4_percent_define_default([[parse.lac.es-capacity-initial]], [[20]])
+b4_percent_define_default([[parse.lac.memory-trace]], [[failures]])
+b4_percent_define_check_values([[[[parse.lac]], [[full]], [[none]]]],
+                               [[[[parse.lac.memory-trace]],
+                                 [[failures]], [[full]]]])
+b4_define_flag_if([lac])
+m4_define([b4_lac_flag],
+          [m4_if(b4_percent_define_get([[parse.lac]]),
+                 [none], [[0]], [[1]])])
+
+## ---------------- ##
+## Default values.  ##
+## ---------------- ##
+
+# Stack parameters.
+m4_define_default([b4_stack_depth_max], [10000])
+m4_define_default([b4_stack_depth_init],  [200])
+
+
 # b4_yyerror_arg_loc_if(ARG)
 # --------------------------
 # Expand ARG iff yyerror is to be given a location as argument.
@@ -101,28 +106,6 @@ m4_ifset([b4_parse_param], [b4_args(b4_parse_param), ])])



-## ------------ ##
-## Data Types.  ##
-## ------------ ##
-
-# b4_int_type(MIN, MAX)
-# ---------------------
-# Return the smallest int type able to handle numbers ranging from
-# MIN to MAX (included).  Overwrite the version from c.m4, which
-# uses only C89 types, so that the user can override the shorter
-# types, and so that pre-C89 compilers are handled correctly.
-m4_define([b4_int_type],
-[m4_if(b4_ints_in($@,      [0],   [255]), [1], [yytype_uint8],
-       b4_ints_in($@,   [-128],   [127]), [1], [yytype_int8],
-
-       b4_ints_in($@,      [0], [65535]), [1], [yytype_uint16],
-       b4_ints_in($@, [-32768], [32767]), [1], [yytype_int16],
-
-       m4_eval([0 <= $1]),                [1], [unsigned],
-
-                                               [int])])
-
-
 ## ----------------- ##
 ## Semantic Values.  ##
 ## ----------------- ##
@@ -199,7 +182,7 @@ m4_define([b4_declare_parser_state_variables], [b4_pure_if([[
    /* Number of syntax errors so far.  */
    int yynerrs;
 ]])[
-    int yystate;
+    yy_state_fast_t yystate;
    /* Number of tokens to shift before error messages enabled.  */
    int yyerrstatus;

@@ -212,9 +195,9 @@ m4_define([b4_declare_parser_state_variables], [b4_pure_if([[
       to reallocate them elsewhere.  */

    /* The state stack.  */
-    yytype_int16 yyssa[YYINITDEPTH];
-    yytype_int16 *yyss;
-    yytype_int16 *yyssp;
+    yy_state_t yyssa[YYINITDEPTH];
+    yy_state_t *yyss;
+    yy_state_t *yyssp;

    /* The semantic value stack.  */
    YYSTYPE yyvsa[YYINITDEPTH];
@@ -229,11 +212,11 @@ m4_define([b4_declare_parser_state_variables], [b4_pure_if([[
    /* The locations where the error started and ended.  */
    YYLTYPE yyerror_range[3];]])[

-    YYSIZE_T yystacksize;]b4_lac_if([[
+    YYPTRDIFF_T yystacksize;]b4_lac_if([[

-    yytype_int16 yyesa@{]b4_percent_define_get([[parse.lac.es-capacity-initial]])[@};
-    yytype_int16 *yyes;
-    YYSIZE_T yyes_capacity;]])])
+    yy_state_t yyesa@{]b4_percent_define_get([[parse.lac.es-capacity-initial]])[@};
+    yy_state_t *yyes;
+    YYPTRDIFF_T yyes_capacity;]])])


 # _b4_declare_yyparse_push
@@ -386,28 +369,22 @@ m4_if(b4_api_prefix, [yy], [],
 # undef short
 #endif

-#ifdef YYTYPE_UINT8
-typedef YYTYPE_UINT8 yytype_uint8;
-#else
-typedef unsigned char yytype_uint8;
-#endif
+]b4_c99_int_type_define[

-#ifdef YYTYPE_INT8
-typedef YYTYPE_INT8 yytype_int8;
-#else
-typedef signed char yytype_int8;
-#endif
-
-#ifdef YYTYPE_UINT16
-typedef YYTYPE_UINT16 yytype_uint16;
-#else
-typedef unsigned short yytype_uint16;
-#endif
-
-#ifdef YYTYPE_INT16
-typedef YYTYPE_INT16 yytype_int16;
-#else
-typedef short yytype_int16;
+#ifndef YYPTRDIFF_T
+# if defined __PTRDIFF_TYPE__ && defined __PTRDIFF_MAX__
+#  define YYPTRDIFF_T __PTRDIFF_TYPE__
+#  define YYPTRDIFF_MAXIMUM __PTRDIFF_MAX__
+# elif defined PTRDIFF_MAX
+#  ifndef ptrdiff_t
+#   include <stddef.h> /* INFRINGES ON USER NAME SPACE */
+#  endif
+#  define YYPTRDIFF_T ptrdiff_t
+#  define YYPTRDIFF_MAXIMUM PTRDIFF_MAX
+# else
+#  define YYPTRDIFF_T long
+#  define YYPTRDIFF_MAXIMUM LONG_MAX
+# endif
 #endif

 #ifndef YYSIZE_T
@@ -415,7 +392,7 @@ typedef short yytype_int16;
 #  define YYSIZE_T __SIZE_TYPE__
 # elif defined size_t
 #  define YYSIZE_T size_t
-# elif ! defined YYSIZE_T
+# elif defined __STDC_VERSION__ && 199901 <= __STDC_VERSION__
 #  include <stddef.h> /* INFRINGES ON USER NAME SPACE */
 #  define YYSIZE_T size_t
 # else
@@ -423,7 +400,16 @@ typedef short yytype_int16;
 # endif
 #endif

-#define YYSIZE_MAXIMUM ((YYSIZE_T) -1)
+#define YYSIZE_MAXIMUM ((YYPTRDIFF_T) (YYPTRDIFF_MAXIMUM < (YYSIZE_T) -1 \
+                                       ? YYPTRDIFF_MAXIMUM : (YYSIZE_T) -1))
+
+#define YYSIZEOF(X) ((YYPTRDIFF_T) sizeof (X))
+
+/* Stored state numbers (used for stacks). */
+typedef ]b4_int_type(0, m4_eval(b4_states_number - 1))[ yy_state_t;
+
+/* State numbers in computations.  */
+typedef int yy_state_fast_t;

 #ifndef YY_
 # if defined YYENABLE_NLS && YYENABLE_NLS
@@ -526,22 +512,23 @@ void free (void *); /* INFRINGES ON USER NAME SPACE */
 /* A type that is properly aligned for any stack member.  */
 union yyalloc
 {
-  yytype_int16 yyss_alloc;
+  yy_state_t yyss_alloc;
  YYSTYPE yyvs_alloc;]b4_locations_if([
  YYLTYPE yyls_alloc;])[
 };

 /* The size of the maximum gap between one aligned stack and the next.  */
-# define YYSTACK_GAP_MAXIMUM (sizeof (union yyalloc) - 1)
+# define YYSTACK_GAP_MAXIMUM (YYSIZEOF (union yyalloc) - 1)

 /* The size of an array large to enough to hold all stacks, each with
   N elements.  */
 ]b4_locations_if(
 [# define YYSTACK_BYTES(N) \
-     ((N) * (sizeof (yytype_int16) + sizeof (YYSTYPE) + sizeof (YYLTYPE)) \
+     ((N) * (YYSIZEOF (yy_state_t) + YYSIZEOF (YYSTYPE) \
+             + YYSIZEOF (YYLTYPE)) \
      + 2 * YYSTACK_GAP_MAXIMUM)],
 [# define YYSTACK_BYTES(N) \
-     ((N) * (sizeof (yytype_int16) + sizeof (YYSTYPE)) \
+     ((N) * (YYSIZEOF (yy_state_t) + YYSIZEOF (YYSTYPE)) \
      + YYSTACK_GAP_MAXIMUM)])[

 # define YYCOPY_NEEDED 1
@@ -554,11 +541,11 @@ union yyalloc
 # define YYSTACK_RELOCATE(Stack_alloc, Stack)                           \
    do                                                                  \
      {                                                                 \
-        YYSIZE_T yynewbytes;                                            \
+        YYPTRDIFF_T yynewbytes;                                         \
        YYCOPY (&yyptr->Stack_alloc, Stack, yysize);                    \
        Stack = &yyptr->Stack_alloc;                                    \
-        yynewbytes = yystacksize * sizeof (*Stack) + YYSTACK_GAP_MAXIMUM; \
-        yyptr += yynewbytes / sizeof (*yyptr);                          \
+        yynewbytes = yystacksize * YYSIZEOF (*Stack) + YYSTACK_GAP_MAXIMUM; \
+        yyptr += yynewbytes / YYSIZEOF (*yyptr);                        \
      }                                                                 \
    while (0)

@@ -570,12 +557,12 @@ union yyalloc
 # ifndef YYCOPY
 #  if defined __GNUC__ && 1 < __GNUC__
 #   define YYCOPY(Dst, Src, Count) \
-      __builtin_memcpy (Dst, Src, (Count) * sizeof (*(Src)))
+      __builtin_memcpy (Dst, Src, (YYSIZE_T) (Count) * sizeof (*(Src)))
 #  else
 #   define YYCOPY(Dst, Src, Count)              \
      do                                        \
        {                                       \
-          YYSIZE_T yyi;                         \
+          YYPTRDIFF_T yyi;                      \
          for (yyi = 0; yyi < (Count); yyi++)   \
            (Dst)[yyi] = (Src)[yyi];            \
        }                                       \
@@ -601,17 +588,20 @@ union yyalloc
 #define YYUNDEFTOK  ]b4_undef_token_number[
 #define YYMAXUTOK   ]b4_user_token_number_max[

+
 /* YYTRANSLATE(TOKEN-NUM) -- Symbol number corresponding to TOKEN-NUM
   as returned by yylex, with out-of-bounds checking.  */
-#define YYTRANSLATE(YYX)                                                \
-  ((unsigned) (YYX) <= YYMAXUTOK ? yytranslate[YYX] : YYUNDEFTOK)
+]b4_api_token_raw_if(dnl
+[[#define YYTRANSLATE(YYX) (YYX)]],
+[[#define YYTRANSLATE(YYX)                                                \
+  (0 <= (YYX) && (YYX) <= YYMAXUTOK ? yytranslate[YYX] : YYUNDEFTOK)

 /* YYTRANSLATE[TOKEN-NUM] -- Symbol number corresponding to TOKEN-NUM
   as returned by yylex.  */
 static const ]b4_int_type_for([b4_translate])[ yytranslate[] =
 {
  ]b4_translate[
-};
+};]])[

 #if ]b4_api_PREFIX[DEBUG
 ]b4_integral_parser_table_define([rline], [b4_rline],
@@ -636,15 +626,15 @@ static const ]b4_int_type_for([b4_toknum])[ yytoknum[] =
 };
 # endif

-#define YYPACT_NINF ]b4_pact_ninf[
+#define YYPACT_NINF (]b4_pact_ninf[)

-#define yypact_value_is_default(Yystate) \
-  ]b4_table_value_equals([[pact]], [[Yystate]], [b4_pact_ninf])[
+#define yypact_value_is_default(Yyn) \
+  ]b4_table_value_equals([[pact]], [[Yyn]], [b4_pact_ninf], [YYPACT_NINF])[

-#define YYTABLE_NINF ]b4_table_ninf[
+#define YYTABLE_NINF (]b4_table_ninf[)

-#define yytable_value_is_error(Yytable_value) \
-  ]b4_table_value_equals([[table]], [[Yytable_value]], [b4_table_ninf])[
+#define yytable_value_is_error(Yyn) \
+  ]b4_table_value_equals([[table]], [[Yyn]], [b4_table_ninf], [YYTABLE_NINF])[

 ]b4_parser_tables_define[

@@ -722,8 +712,8 @@ do {                                                                      \
 `------------------------------------------------------------------*/

 ]b4_function_define([yy_stack_print], [static void],
-                   [[yytype_int16 *yybottom], [yybottom]],
-                   [[yytype_int16 *yytop],    [yytop]])[
+                   [[yy_state_t *yybottom], [yybottom]],
+                   [[yy_state_t *yytop],    [yytop]])[
 {
  YYFPRINTF (stderr, "Stack now");
  for (; yybottom <= yytop; yybottom++)
@@ -746,16 +736,16 @@ do {                                                            \
 `------------------------------------------------*/

 ]b4_function_define([yy_reduce_print], [static void],
-                   [[yytype_int16 *yyssp], [yyssp]],
+                   [[yy_state_t *yyssp], [yyssp]],
                   [[YYSTYPE *yyvsp], [yyvsp]],
    b4_locations_if([[[YYLTYPE *yylsp], [yylsp]],
                   ])[[int yyrule], [yyrule]]m4_ifset([b4_parse_param], [,
                   b4_parse_param]))[
 {
-  unsigned long yylno = yyrline[yyrule];
+  int yylno = yyrline[yyrule];
  int yynrhs = yyr2[yyrule];
  int yyi;
-  YYFPRINTF (stderr, "Reducing stack by rule %d (line %lu):\n",
+  YYFPRINTF (stderr, "Reducing stack by rule %d (line %d):\n",
             yyrule - 1, yylno);
  /* The symbols being reduced.  */
  for (yyi = 0; yyi < yynrhs; yyi++)
@@ -814,22 +804,22 @@ int yydebug;
   using YYSTACK_FREE.  Return 0 if successful or if no reallocation is
   required.  Return 1 if memory is exhausted.  */
 static int
-yy_lac_stack_realloc (YYSIZE_T *yycapacity, YYSIZE_T yyadd,
+yy_lac_stack_realloc (YYPTRDIFF_T *yycapacity, YYPTRDIFF_T yyadd,
 #if ]b4_api_PREFIX[DEBUG
                      char const *yydebug_prefix,
                      char const *yydebug_suffix,
 #endif
-                      yytype_int16 **yybottom,
-                      yytype_int16 *yybottom_no_free,
-                      yytype_int16 **yytop, yytype_int16 *yytop_empty)
+                      yy_state_t **yybottom,
+                      yy_state_t *yybottom_no_free,
+                      yy_state_t **yytop, yy_state_t *yytop_empty)
 {
-  YYSIZE_T yysize_old =
-    (YYSIZE_T) (*yytop == yytop_empty ? 0 : *yytop - *yybottom + 1);
-  YYSIZE_T yysize_new = yysize_old + yyadd;
+  YYPTRDIFF_T yysize_old =
+    *yytop == yytop_empty ? 0 : *yytop - *yybottom + 1;
+  YYPTRDIFF_T yysize_new = yysize_old + yyadd;
  if (*yycapacity < yysize_new)
    {
-      YYSIZE_T yyalloc = 2 * yysize_new;
-      yytype_int16 *yybottom_new;
+      YYPTRDIFF_T yyalloc = 2 * yysize_new;
+      yy_state_t *yybottom_new;
      /* Use YYMAXDEPTH for maximum stack size given that the stack
         should never need to grow larger than the main state stack
         needs to grow without LAC.  */
@@ -842,7 +832,8 @@ yy_lac_stack_realloc (YYSIZE_T *yycapacity, YYSIZE_T yyadd,
      if (YYMAXDEPTH < yyalloc)
        yyalloc = YYMAXDEPTH;
      yybottom_new =
-        (yytype_int16*) YYSTACK_ALLOC (yyalloc * sizeof *yybottom_new);
+        (yy_state_t *) YYSTACK_ALLOC ((YYSIZE_T)
+                                        (yyalloc * YYSIZEOF (*yybottom_new)));
      if (!yybottom_new)
        {
          YYDPRINTF ((stderr, "%srealloc failed%s", yydebug_prefix,
@@ -859,8 +850,8 @@ yy_lac_stack_realloc (YYSIZE_T *yycapacity, YYSIZE_T yyadd,
      *yybottom = yybottom_new;
      *yycapacity = yyalloc;]m4_if(b4_percent_define_get([[parse.lac.memory-trace]]),
                                   [full], [[
-      YYDPRINTF ((stderr, "%srealloc to %lu%s", yydebug_prefix,
-                  (unsigned long) yyalloc, yydebug_suffix));]])[
+      YYDPRINTF ((stderr, "%srealloc to %ld%s", yydebug_prefix,
+                  (long) yyalloc, yydebug_suffix));]])[
    }
  return 0;
 }
@@ -945,11 +936,11 @@ do {                                                                     \
   contents of either array, alter *YYES and *YYES_CAPACITY, and free
   any old *YYES other than YYESA.  */
 static int
-yy_lac (yytype_int16 *yyesa, yytype_int16 **yyes,
-        YYSIZE_T *yyes_capacity, yytype_int16 *yyssp, int yytoken)
+yy_lac (yy_state_t *yyesa, yy_state_t **yyes,
+        YYPTRDIFF_T *yyes_capacity, yy_state_t *yyssp, int yytoken)
 {
-  yytype_int16 *yyes_prev = yyssp;
-  yytype_int16 *yyesp = yyes_prev;
+  yy_state_t *yyes_prev = yyssp;
+  yy_state_t *yyesp = yyes_prev;
  YYDPRINTF ((stderr, "LAC: checking lookahead %s:", yytname[yytoken]));
  if (yytoken == YYUNDEFTOK)
    {
@@ -986,11 +977,11 @@ yy_lac (yytype_int16 *yyesa, yytype_int16 **yyes,
          yyrule = -yyrule;
        }
      {
-        YYSIZE_T yylen = yyr2[yyrule];
+        YYPTRDIFF_T yylen = yyr2[yyrule];
        YYDPRINTF ((stderr, " R%d", yyrule - 1));
        if (yyesp != yyes_prev)
          {
-            YYSIZE_T yysize = (YYSIZE_T) (yyesp - *yyes + 1);
+            YYPTRDIFF_T yysize = yyesp - *yyes + 1;
            if (yylen < yysize)
              {
                yyesp -= yylen;
@@ -1006,19 +997,18 @@ yy_lac (yytype_int16 *yyesa, yytype_int16 **yyes,
          yyesp = yyes_prev -= yylen;
      }
      {
-        yytype_int16 yystate;
+        yy_state_fast_t yystate;
        {
          const int yylhs = yyr1[yyrule] - YYNTOKENS;
          const int yyi = yypgoto[yylhs] + *yyesp;
-          yystate = ((yytype_int16)
-                     (0 <= yyi && yyi <= YYLAST && yycheck[yyi] == *yyesp
-                      ? yytable[yyi]
-                      : yydefgoto[yylhs]));
+          yystate = (0 <= yyi && yyi <= YYLAST && yycheck[yyi] == *yyesp
+                     ? yytable[yyi]
+                     : yydefgoto[yylhs]);
        }
        if (yyesp == yyes_prev)
          {
            yyesp = *yyes;
-            *yyesp = yystate;
+            *yyesp = (yy_state_t) yystate;
          }
        else
          {
@@ -1031,9 +1021,9 @@ yy_lac (yytype_int16 *yyesa, yytype_int16 **yyes,
                YYDPRINTF ((stderr, "\n"));
                return 2;
              }
-            *++yyesp = yystate;
+            *++yyesp = (yy_state_t) yystate;
          }
-        YYDPRINTF ((stderr, " G%d", (int) yystate));
+        YYDPRINTF ((stderr, " G%d", yystate));
      }
    }
 }]])[
@@ -1043,13 +1033,13 @@ yy_lac (yytype_int16 *yyesa, yytype_int16 **yyes,

 # ifndef yystrlen
 #  if defined __GLIBC__ && defined _STRING_H
-#   define yystrlen strlen
+#   define yystrlen(S) ((YYPTRDIFF_T) strlen (S))
 #  else
 /* Return the length of YYSTR.  */
-]b4_function_define([yystrlen], [static YYSIZE_T],
+]b4_function_define([yystrlen], [static YYPTRDIFF_T],
   [[const char *yystr], [yystr]])[
 {
-  YYSIZE_T yylen;
+  YYPTRDIFF_T yylen;
  for (yylen = 0; yystr[yylen]; yylen++)
    continue;
  return yylen;
@@ -1085,12 +1075,12 @@ yy_lac (yytype_int16 *yyesa, yytype_int16 **yyes,
   backslash-backslash).  YYSTR is taken from yytname.  If YYRES is
   null, do not copy; instead, return the length of what the result
   would have been.  */
-static YYSIZE_T
+static YYPTRDIFF_T
 yytnamerr (char *yyres, const char *yystr)
 {
  if (*yystr == '"')
    {
-      YYSIZE_T yyn = 0;
+      YYPTRDIFF_T yyn = 0;
      char const *yyp = yystr;

      for (;;)
@@ -1121,10 +1111,10 @@ yytnamerr (char *yyres, const char *yystr)
    do_not_strip_quotes: ;
    }

-  if (! yyres)
+  if (yyres)
+    return yystpcpy (yyres, yystr) - yyres;
+  else
    return yystrlen (yystr);
-
-  return (YYSIZE_T) (yystpcpy (yyres, yystr) - yyres);
 }
 # endif

@@ -1139,12 +1129,12 @@ yytnamerr (char *yyres, const char *yystr)
   required number of bytes is too large to store]b4_lac_if([[ or if
   yy_lac returned 2]])[.  */
 static int
-yysyntax_error (YYSIZE_T *yymsg_alloc, char **yymsg,
-                ]b4_lac_if([[yytype_int16 *yyesa, yytype_int16 **yyes,
-                YYSIZE_T *yyes_capacity, ]])[yytype_int16 *yyssp, int yytoken)
+yysyntax_error (YYPTRDIFF_T *yymsg_alloc, char **yymsg,
+                ]b4_lac_if([[yy_state_t *yyesa, yy_state_t **yyes,
+                YYPTRDIFF_T *yyes_capacity, ]])[yy_state_t *yyssp, int yytoken)
 {
-  YYSIZE_T yysize0 = yytnamerr (YY_NULLPTR, yytname[yytoken]);
-  YYSIZE_T yysize = yysize0;
+  YYPTRDIFF_T yysize0 = yytnamerr (YY_NULLPTR, yytname[yytoken]);
+  YYPTRDIFF_T yysize = yysize0;
  enum { YYERROR_VERBOSE_ARGS_MAXIMUM = 5 };
  /* Internationalized format string. */
  const char *yyformat = YY_NULLPTR;
@@ -1188,15 +1178,8 @@ yysyntax_error (YYSIZE_T *yymsg_alloc, char **yymsg,
      YYDPRINTF ((stderr, "Constructing syntax error message\n"));]])[
      yyarg[yycount++] = yytname[yytoken];
      if (!yypact_value_is_default (yyn))
-        {]b4_lac_if([], [[
-          /* Start YYX at -YYN if negative to avoid negative indexes in
-             YYCHECK.  In other words, skip the first -YYN actions for
-             this state because they are default actions.  */
-          int yyxbegin = yyn < 0 ? -yyn : 0;
-          /* Stay within bounds of both yycheck and yytname.  */
-          int yychecklim = YYLAST - yyn + 1;
-          int yyxend = yychecklim < YYNTOKENS ? yychecklim : YYNTOKENS;]])[
-          int yyx;]b4_lac_if([[
+        {]b4_lac_if([[
+          int yyx;

          for (yyx = 0; yyx < YYNTOKENS; ++yyx)
            if (yyx != YYTERROR && yyx != YYUNDEFTOK)
@@ -1209,6 +1192,14 @@ yysyntax_error (YYSIZE_T *yymsg_alloc, char **yymsg,
                  if (yy_lac_status == 1)
                    continue;
                }]], [[
+          /* Start YYX at -YYN if negative to avoid negative indexes in
+             YYCHECK.  In other words, skip the first -YYN actions for
+             this state because they are default actions.  */
+          int yyxbegin = yyn < 0 ? -yyn : 0;
+          /* Stay within bounds of both yycheck and yytname.  */
+          int yychecklim = YYLAST - yyn + 1;
+          int yyxend = yychecklim < YYNTOKENS ? yychecklim : YYNTOKENS;
+          int yyx;

          for (yyx = yyxbegin; yyx < yyxend; ++yyx)
            if (yycheck[yyx + yyn] == yyx && yyx != YYTERROR
@@ -1222,7 +1213,8 @@ yysyntax_error (YYSIZE_T *yymsg_alloc, char **yymsg,
                  }
                yyarg[yycount++] = yytname[yyx];
                {
-                  YYSIZE_T yysize1 = yysize + yytnamerr (YY_NULLPTR, yytname[yyx]);
+                  YYPTRDIFF_T yysize1 = yysize + yytnamerr (YY_NULLPTR,
+                                                            yytname[yyx]);
                  if (yysize <= yysize1 && yysize1 <= YYSTACK_ALLOC_MAXIMUM)
                    yysize = yysize1;
                  else
@@ -1253,7 +1245,7 @@ yysyntax_error (YYSIZE_T *yymsg_alloc, char **yymsg,
    }

  {
-    YYSIZE_T yysize1 = yysize + yystrlen (yyformat);
+    YYPTRDIFF_T yysize1 = yysize + yystrlen (yyformat);
    if (yysize <= yysize1 && yysize1 <= YYSTACK_ALLOC_MAXIMUM)
      yysize = yysize1;
    else
@@ -1434,7 +1426,7 @@ b4_function_define([[yyparse]], [[int]], b4_parse_param)[
  /* Buffer for error messages, and its allocated size.  */
  char yymsgbuf[128];
  char *yymsg = yymsgbuf;
-  YYSIZE_T yymsg_alloc = sizeof yymsgbuf;
+  YYPTRDIFF_T yymsg_alloc = sizeof yymsgbuf;
 #endif

 #define YYPOPSTACK(N)   (yyvsp -= (N), yyssp -= (N)]b4_locations_if([, yylsp -= (N)])[)
@@ -1455,7 +1447,7 @@ b4_function_define([[yyparse]], [[int]], b4_parse_param)[
  yystacksize = YYINITDEPTH;]b4_lac_if([[

  yyes = yyesa;
-  yyes_capacity = sizeof yyesa / sizeof *yyes;
+  yyes_capacity = ]b4_percent_define_get([[parse.lac.es-capacity-initial]])[;
  if (YYMAXDEPTH < yyes_capacity)
    yyes_capacity = YYMAXDEPTH;]])[

@@ -1487,12 +1479,12 @@ yynewstate:


 /*--------------------------------------------------------------------.
-| yynewstate -- set current state (the top of the stack) to yystate.  |
+| yysetstate -- set current state (the top of the stack) to yystate.  |
 `--------------------------------------------------------------------*/
 yysetstate:
  YYDPRINTF ((stderr, "Entering state %d\n", yystate));
  YY_ASSERT (0 <= yystate && yystate < YYNSTATES);
-  *yyssp = (yytype_int16) yystate;
+   *yyssp = (yy_state_t) yystate;

  if (yyss + yystacksize - 1 <= yyssp)
 #if !defined yyoverflow && !defined YYSTACK_RELOCATE
@@ -1500,15 +1492,15 @@ yysetstate:
 #else
    {
      /* Get the current used size of the three stacks, in elements.  */
-      YYSIZE_T yysize = (YYSIZE_T) (yyssp - yyss + 1);
+      YYPTRDIFF_T yysize = yyssp - yyss + 1;

 # if defined yyoverflow
      {
        /* Give user a chance to reallocate the stack.  Use copies of
           these so that the &'s don't force the real ones into
           memory.  */
-        YYSTYPE *yyvs1 = yyvs;
-        yytype_int16 *yyss1 = yyss;]b4_locations_if([
+        yy_state_t *yyss1 = yyss;
+        YYSTYPE *yyvs1 = yyvs;]b4_locations_if([
        YYLTYPE *yyls1 = yyls;])[

        /* Each stack pointer address is followed by the size of the
@@ -1516,9 +1508,9 @@ yysetstate:
           conditional around just the two extra args, but that might
           be undefined if yyoverflow is a macro.  */
        yyoverflow (YY_("memory exhausted"),
-                    &yyss1, yysize * sizeof (*yyssp),
-                    &yyvs1, yysize * sizeof (*yyvsp),]b4_locations_if([
-                    &yyls1, yysize * sizeof (*yylsp),])[
+                    &yyss1, yysize * YYSIZEOF (*yyssp),
+                    &yyvs1, yysize * YYSIZEOF (*yyvsp),]b4_locations_if([
+                    &yyls1, yysize * YYSIZEOF (*yylsp),])[
                    &yystacksize);
        yyss = yyss1;
        yyvs = yyvs1;]b4_locations_if([
@@ -1533,9 +1525,10 @@ yysetstate:
        yystacksize = YYMAXDEPTH;

      {
-        yytype_int16 *yyss1 = yyss;
+        yy_state_t *yyss1 = yyss;
        union yyalloc *yyptr =
-          (union yyalloc *) YYSTACK_ALLOC (YYSTACK_BYTES (yystacksize));
+          (union yyalloc *) YYSTACK_ALLOC ((YYSIZE_T)
+                                           YYSTACK_BYTES (yystacksize));
        if (! yyptr)
          goto yyexhaustedlab;
        YYSTACK_RELOCATE (yyss_alloc, yyss);
@@ -1551,8 +1544,8 @@ yysetstate:
      yyvsp = yyvs + yysize - 1;]b4_locations_if([
      yylsp = yyls + yysize - 1;])[

-      YYDPRINTF ((stderr, "Stack size increased to %lu\n",
-                  (unsigned long) yystacksize));
+      YYDPRINTF ((stderr, "Stack size increased to %ld\n",
+                  (long) yystacksize));

      if (yyss + yystacksize - 1 <= yyssp)
        YYABORT;
@@ -1642,16 +1635,15 @@ yyread_pushed_token:]])[

  /* Shift the lookahead token.  */
  YY_SYMBOL_PRINT ("Shifting", yytoken, &yylval, &yylloc);
-
-  /* Discard the shifted token.  */
-  yychar = YYEMPTY;]b4_lac_if([[
-  YY_LAC_DISCARD ("shift");]])[
-
  yystate = yyn;
  YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
  *++yyvsp = yylval;
  YY_IGNORE_MAYBE_UNINITIALIZED_END]b4_locations_if([
  *++yylsp = yylloc;])[
+
+  /* Discard the shifted token.  */
+  yychar = YYEMPTY;]b4_lac_if([[
+  YY_LAC_DISCARD ("shift");]])[
  goto yynewstate;


@@ -1766,7 +1758,7 @@ yyerrlab:
          {
            if (yymsg != yymsgbuf)
              YYSTACK_FREE (yymsg);
-            yymsg = (char *) YYSTACK_ALLOC (yymsg_alloc);
+            yymsg = (char *) YYSTACK_ALLOC ((YYSIZE_T) yymsg_alloc);
            if (!yymsg)
              {
                yymsg = yymsgbuf;
@@ -31,3 +31,5 @@
 /version.texi
 /yacc.1
 /relocatable.texi
+/figs/*.eps
+/figs/*.svg
@@ -14,7 +14,12 @@
 ## You should have received a copy of the GNU General Public License
 ## along with this program.  If not, see <http://www.gnu.org/licenses/>.

-AM_MAKEINFOFLAGS = --no-split
+AM_MAKEINFOFLAGS =                                              \
+  --no-split                                                    \
+  --set-customization-variable=SECTION_NAME_IN_TITLE=true       \
+  --set-customization-variable=AVOID_MENU_REDUNDANCY=true       \
+  --set-customization-variable=ICONS=true
+
 info_TEXINFOS = doc/bison.texi
 doc_bison_TEXINFOS =                            \
  $(CROSS_OPTIONS_TEXI)                         \
@@ -28,7 +33,7 @@ doc_bison = doc/bison
 $(doc_bison).dvi: $(FIGS_GV:.gv=.eps)
 $(doc_bison).info: $(FIGS_GV:.gv=.txt)
 $(doc_bison).pdf: $(FIGS_GV:.gv=.pdf)
-$(doc_bison).html: $(FIGS_GV:.gv=.png)
+$(doc_bison).html: $(FIGS_GV:.gv=.svg)

 TEXI2DVI = texi2dvi --build-dir=doc/bison.t2d -I doc
 CLEANDIRS += doc/bison.t2d
@@ -137,14 +142,14 @@ endif
 ## Graphviz examples generation. ##
 ## ----------------------------- ##

-CLEANFILES += $(FIGS_GV:.gv=.eps) $(FIGS_GV:.gv=.pdf) $(FIGS_GV:.gv=.png)
+CLEANFILES += $(FIGS_GV:.gv=.eps) $(FIGS_GV:.gv=.pdf) $(FIGS_GV:.gv=.svg)
 FIGS_GV =                                               \
  doc/figs/example.gv                                   \
  doc/figs/example-reduce.gv doc/figs/example-shift.gv
 EXTRA_DIST +=                                                   \
  $(FIGS_GV) $(FIGS_GV:.gv=.txt)                                \
-  $(FIGS_GV:.gv=.eps) $(FIGS_GV:.gv=.pdf) $(FIGS_GV:.gv=.png)
-SUFFIXES += .gv .eps .pdf .png
+  $(FIGS_GV:.gv=.eps) $(FIGS_GV:.gv=.pdf) $(FIGS_GV:.gv=.svg)
+SUFFIXES += .gv .eps .pdf .svg

 .gv.eps:
 	$(AM_V_GEN) $(MKDIR_P) `echo "./$@" | sed -e 's,/[^/]*$$,,'`
@@ -156,9 +161,9 @@ SUFFIXES += .gv .eps .pdf .png
 	$(AM_V_at) $(DOT) -Gmargin=0 -Tpdf $< >$@.tmp
 	$(AM_V_at) mv $@.tmp $@

-.gv.png:
+.gv.svg:
 	$(AM_V_GEN) $(MKDIR_P) `echo "./$@" | sed -e 's,/[^/]*$$,,'`
-	$(AM_V_at) $(DOT) -Gmargin=0 -Tpng $< >$@.tmp
+	$(AM_V_at) $(DOT) -Gmargin=0 -Tsvg $< >$@.tmp
 	$(AM_V_at) mv $@.tmp $@

 ## -------------- ##
@@ -0,0 +1 @@
+/simple.yy
@@ -117,7 +117,7 @@ namespace yy
    static int count = 0;
    const int stage = count;
    ++count;
-    auto loc = parser::location_type{nullptr, unsigned (stage + 1), unsigned (stage + 1)};
+    auto loc = parser::location_type{nullptr, stage + 1, stage + 1};
    if (stage == 0)
      return parser::make_TEXT (make_string_uptr ("I have numbers for you."), std::move (loc));
    else if (stage < max)
@@ -117,7 +117,7 @@ namespace yy
    static int count = 0;
    const int stage = count;
    ++count;
-    parser::location_type loc (NULLPTR, unsigned (stage + 1), unsigned (stage + 1));
+    parser::location_type loc (NULLPTR, stage + 1, stage + 1);
    switch (stage)
      {
      case 0:
@@ -15,19 +15,21 @@

 lexcalcdir = $(docdir)/%D%

-## ------ ##
-## Calc.  ##
-## ------ ##
+## --------- ##
+## LexCalc.  ##
+## --------- ##
+
+if FLEX_WORKS
+  check_PROGRAMS += %D%/lexcalc
+  TESTS += %D%/lexcalc.test
+  nodist_%C%_lexcalc_SOURCES = %D%/parse.y %D%/parse.h %D%/scan.l
+  # Don't use gnulib's system headers.
+  %C%_lexcalc_CPPFLAGS = -I$(top_srcdir)/%D% -I$(top_builddir)/%D%
+endif FLEX_WORKS

-check_PROGRAMS += %D%/lexcalc
-TESTS += %D%/lexcalc.test
-EXTRA_DIST += %D%/lexcalc.test
-nodist_%C%_lexcalc_SOURCES = %D%/parse.y %D%/parse.h %D%/scan.l
 %D%/parse.c: $(dependencies)

-# Don't use gnulib's system headers.
-%C%_lexcalc_CPPFLAGS = -I$(top_srcdir)/%D% -I$(top_builddir)/%D%
-
+EXTRA_DIST += %D%/lexcalc.test
 dist_lexcalc_DATA = %D%/parse.y %D%/scan.l %D%/Makefile %D%/README.md
 CLEANFILES += %D%/parse.[ch] %D%/scan.c %D%/parse.output
 CLEANDIRS += %D%/*.dSYM
@@ -4,6 +4,7 @@
 %option nodefault noinput nounput noyywrap

 %{
+#include <errno.h> /* errno, ERANGE */
 #include <limits.h> /* INT_MIN */
 #include <stdlib.h> /* strtol */

@@ -0,0 +1,2 @@
+/scan.c
+/scan.h
@@ -15,15 +15,19 @@

 reccalcdir = $(docdir)/%D%

-## ------ ##
-## Calc.  ##
-## ------ ##
+## --------- ##
+## RecCalc.  ##
+## --------- ##
+
+if FLEX_WORKS
+  check_PROGRAMS += %D%/reccalc
+  TESTS += %D%/reccalc.test
+  nodist_%C%_reccalc_SOURCES = %D%/parse.y %D%/scan.h %D%/scan.c
+  BUILT_SOURCES += $(nodist_%C%_reccalc_SOURCES)
+  # Don't use gnulib's system headers.
+  %C%_reccalc_CPPFLAGS = -I$(top_srcdir)/%D% -I$(top_builddir)/%D%
+endif FLEX_WORKS

-check_PROGRAMS += %D%/reccalc
-TESTS += %D%/reccalc.test
-EXTRA_DIST += %D%/reccalc.test %D%/scan.l
-nodist_%C%_reccalc_SOURCES = %D%/parse.y %D%/scan.h %D%/scan.c
-BUILT_SOURCES += $(nodist_%C%_reccalc_SOURCES)
 %D%/parse.c: $(dependencies)

 # Tell Make that parse.o depends on scan.h, so that scan.h is built
@@ -32,21 +36,44 @@ BUILT_SOURCES += $(nodist_%C%_reccalc_SOURCES)
 # additional dependency.
 DASH = -
 %D%/reccalc$(DASH)parse.o: %D%/scan.h
+# Tell Make scan.o depends on parse.h, except that Make sees only
+# parse.c, not parse.h.  We can't use BUILT_SOURCES to this end, since
+# we use the built bison.
+%D%/reccalc$(DASH)scan.o: %D%/parse.c

+# Likewise, but for Automake before 1.16.
+%D%/examples_c_reccalc_reccalc$(DASH)parse.o: %D%/scan.h
+%D%/examples_c_reccalc_reccalc$(DASH)scan.o: %D%/parse.c
+
+## See "info automake 'Multiple Outputs'" for this rule.
 %D%/scan.c %D%/scan.h: %D%/scan.stamp
-	@test -f $@ || rm -f %D%/scan.stamp
-	@test -f $@ || $(MAKE) $(AM_MAKEFLAGS) %D%/scan.stamp
+## Recover from the removal of $@
+	@if test -f $@; then :; else \
+	  trap 'rm -rf %D%/scan.lock %D%/scan.stamp' 1 2 13 15; \
+## mkdir is a portable test-and-set
+	  if mkdir %D%/scan.lock 2>/dev/null; then \
+## This code is being executed by the first process.
+	    rm -f %D%/scan.stamp; \
+	    $(MAKE) $(AM_MAKEFLAGS) %D%/scan.stamp; \
+	    result=$$?; rm -rf %D%/scan.lock; exit $$result; \
+	  else \
+## This code is being executed by the follower processes.
+## Wait until the first process is done.
+	    while test -d %D%/scan.lock; do sleep 1; done; \
+## Succeed if and only if the first process succeeded.
+	    test -f %D%/scan.stamp; \
+	  fi; \
+	fi

 %D%/scan.stamp: %D%/scan.l
 	$(AM_V_LEX)rm -f $@ $@.tmp
 	$(AM_V_at)$(MKDIR_P) %D%
 	$(AM_V_at)touch $@.tmp
-	$(AM_V_at) $(LEX) -o %D%/scan.c --header-file=%D%/scan.h $<
+	$(AM_V_at)$(LEX) $(AM_LFLAGS) $(LFLAGS) -o%D%/scan.c --header-file=%D%/scan.h $(srcdir)/%D%/scan.l
 	$(AM_V_at)mv $@.tmp $@

-# Don't use gnulib's system headers.
-%C%_reccalc_CPPFLAGS = -I$(top_srcdir)/%D% -I$(top_builddir)/%D%

+EXTRA_DIST += %D%/reccalc.test %D%/scan.l
 dist_reccalc_DATA = %D%/parse.y %D%/scan.l %D%/Makefile %D%/README.md
 CLEANFILES += %D%/parse.[ch] %D%/parse.output %D%/scan.[ch] %D%/*.stamp
 CLEANDIRS += %D%/*.dSYM
@@ -3,11 +3,6 @@
 %define api.parser.class {Calc}
 %define parse.error verbose

-%code imports {
-  import std.ascii;
-  import std.stdio;
-}
-
 %union {
  int ival;
 }
@@ -102,16 +97,14 @@ class CalcLexer(R) : Lexer

    // Skip initial spaces
    while (!input.empty && input.front != '\n' && isWhite (input.front))
-    {
      input.popFront;
-    }

    // Handle EOF.
    if (input.empty)
      return YYTokenType.EOF;

    // Numbers.
-    if (input.front == '.' || input.front.isNumber)
+    if (input.front.isNumber)
      {
        import std.conv : parse;
        semanticVal_.ival = input.parse!int;
@@ -27,10 +27,10 @@ EXTRA_DIST += %D%/calc.test

 %D%/calc.d: %D%/calc.y $(dependencies)
 	$(AM_V_GEN)$(MKDIR_P) %D%
-	$(AM_V_at)$(BISON) $< -o $@
+	$(AM_V_at)$(BISON) $(srcdir)/%D%/calc.y -o $@

 %D%/calc: %D%/calc.d
-	$(AM_V_GEN) $(DC) $(DCFLAGS) -of$@ $<
+	$(AM_V_GEN) $(DC) $(DCFLAGS) -of$@ %D%/calc.d

 dist_d_DATA = %D%/calc.y %D%/Makefile %D%/README.md
 CLEANFILES += %D%/calc %D%/calc.[do]
@@ -78,9 +78,9 @@ class CalcLexer implements Calc.Lexer {
    st = new StreamTokenizer (new InputStreamReader (is));
    st.resetSyntax ();
    st.eolIsSignificant (true);
-    st.whitespaceChars (9, 9);
-    st.whitespaceChars (32, 32);
-    st.wordChars (48, 57);
+    st.whitespaceChars ('\t', '\t');
+    st.whitespaceChars (' ', ' ');
+    st.wordChars ('0', '9');
  }


@@ -27,10 +27,10 @@ EXTRA_DIST += %D%/Calc.test

 %D%/Calc.java: %D%/Calc.y $(dependencies)
 	$(AM_V_GEN)$(MKDIR_P) %D%
-	$(AM_V_at)$(BISON) $< -o $@
+	$(AM_V_at)$(BISON) $(srcdir)/%D%/Calc.y -o $@

 %D%/Calc.class: %D%/Calc.java
-	$(AM_V_GEN) $(SHELL) $(top_builddir)/javacomp.sh $<
+	$(AM_V_GEN) $(SHELL) $(top_builddir)/javacomp.sh %D%/Calc.java

 dist_java_DATA = %D%/Calc.y %D%/Makefile %D%/README.md
 CLEANFILES += %D%/*.class %D%/Calc.java
@@ -33,7 +33,7 @@
 ## which guarantees that parse.y is indeed shipped.

 dist_noinst_SCRIPTS = %D%/extexi %D%/test
-TEST_LOG_COMPILER = $(top_srcdir)/%D%/test
+TEST_LOG_COMPILER = $(SHELL) $(top_srcdir)/%D%/test

 AM_CXXFLAGS =							\
  $(WARN_CXXFLAGS) $(WARN_CXXFLAGS_TEST) $(WERROR_CXXFLAGS)
@@ -0,0 +1,20 @@
+/*.gmo
+/*.po
+/LINGUAS
+/Makefile
+/Makefile.in
+/Makefile.in.in
+/Makevars
+/Makevars.template
+/POTFILES
+/POTFILES.in
+/Rules-quot
+/bison-gnulib.pot
+/boldquot.sed
+/[email protected]
+/[email protected]
+/insert-header.sin
+/quot.sed
+/remove-potcdate.sed
+/remove-potcdate.sin
+/stamp-po
@@ -16,6 +16,7 @@
 /argmatch.c
 /argmatch.h
 /asnprintf.c
+/assure.h
 /basename-lgpl.c
 /basename.c
 /binary-io.c
@@ -38,6 +39,7 @@
 /canonicalize-lgpl.c
 /careadlinkat.c
 /careadlinkat.h
+/cdefs.h
 /charset.alias
 /cloexec.c
 /cloexec.h
@@ -51,6 +53,7 @@
 /config.h
 /config.in.h
 /configmake.h
+/diffseq.h
 /dirname-lgpl.c
 /dirname.c
 /dirname.h
@@ -89,9 +92,13 @@
 /fseterr.c
 /fseterr.h
 /fstat.c
+/fstrcmp.c
+/fstrcmp.h
+/fsync.c
 /getdtablesize.c
 /gethrxtime.c
 /gethrxtime.h
+/getopt-cdefs.h
 /getopt-cdefs.in.h
 /getopt-core.h
 /getopt-ext.h
@@ -129,8 +136,10 @@
 /isnanf.c
 /isnanl-nolibm.h
 /isnanl.c
+/iswblank.c
 /itold.c
 /ldexpl.c
+/libc-config.h
 /limits.h
 /limits.in.h
 /localcharset.c
@@ -144,6 +153,10 @@
 /math.c
 /math.h
 /math.in.h
+/mbchar.c
+/mbchar.h
+/mbfile.c
+/mbfile.h
 /mbrtowc.c
 /mbsinit.c
 /mbswidth.c
@@ -189,6 +202,9 @@
 /relocatable.c
 /relocatable.h
 /relocwrapper.c
+/rename.c
+/rmdir.c
+/same-inode.h
 /sched.h
 /sched.in.h
 /setenv.c
@@ -264,6 +280,8 @@
 /sys_types.in.h
 /sys_wait.in.h
 /sysexits.in.h
+/textstyle.h
+/textstyle.in.h
 /time.h
 /time.in.h
 /timespec.c
@@ -300,10 +318,22 @@
 /wctype.h
 /wctype.in.h
 /wcwidth.c
+/windows-initguard.h
+/windows-mutex.c
+/windows-mutex.h
+/windows-once.c
+/windows-once.h
+/windows-recmutex.c
+/windows-recmutex.h
+/windows-rwlock.c
+/windows-rwlock.h
+/windows-tls.c
+/windows-tls.h
 /xalloc-die.c
 /xalloc-oversized.h
 /xalloc.h
 /xconcat-filename.c
+/xhash.c
 /xmalloc.c
 /xmemdup0.c
 /xmemdup0.h
@@ -315,9 +345,3 @@
 /xstrndup.h
 /xtime.c
 /xtime.h
-/rename.c
-/rmdir.c
-/same-inode.h
-/assure.h
-/fsync.c
-/textstyle.in.h
@@ -1,3 +1,5 @@
 /lock.c
 /lock.h
 /threadlib.c
+/tls.c
+/tls.h
@@ -1,5 +1,6 @@
 /*~
 /00gnulib.m4
+/__inline.m4
 /absolute-header.m4
 /alloca.m4
 /asm-underscore.m4
@@ -7,9 +8,7 @@
 /calloc.m4
 /canonicalize.m4
 /clock_time.m4
-/close-stream.m4
 /close.m4
-/closeout.m4
 /codeset.m4
 /config-h.m4
 /configmake.m4
@@ -44,23 +43,14 @@
 /getopt.m4
 /getprogname.m4
 /getrusage.m4
-/gettext.m4
 /gettime.m4
 /gettimeofday.m4
-/glibc2.m4
-/glibc21.m4
 /gnulib-cache.m4
 /gnulib-common.m4
 /gnulib-comp.m4
 /gnulib-tool.m4
 /host-cpu-c-abi.m4
-/iconv.m4
 /include_next.m4
-/intdiv0.m4
-/intl.m4
-/intldir.m4
-/intlmacosx.m4
-/intmax.m4
 /intmax_t.m4
 /inttypes-pri.m4
 /inttypes.m4
@@ -69,10 +59,12 @@
 /isnand.m4
 /isnanf.m4
 /isnanl.m4
+/iswblank.m4
 /javacomp.m4
 /javaexec.m4
+/jm-winsz1.m4
+/jm-winsz2.m4
 /largefile.m4
-/lcmessage.m4
 /ldexp.m4
 /ldexpl.m4
 /lib-ld.m4
@@ -93,6 +85,8 @@
 /malloc.m4
 /malloca.m4
 /math_h.m4
+/mbchar.m4
+/mbfile.m4
 /mbrtowc.m4
 /mbsinit.m4
 /mbstate_t.m4
@@ -104,25 +98,22 @@
 /msvc-inval.m4
 /msvc-nothrow.m4
 /multiarch.m4
-/nls.m4
 /nocrash.m4
 /non-recursive-gnulib-prefix-hack.m4
 /obstack-printf.m4
 /obstack.m4
 /off_t.m4
 /open-cloexec.m4
+/open-slash.m4
 /open.m4
 /pathmax.m4
 /perror.m4
 /pipe2.m4
-/po.m4
 /posix_spawn.m4
 /printf-frexp.m4
 /printf-frexpl.m4
 /printf-posix-rpl.m4
-/printf-posix.m4
 /printf.m4
-/progtest.m4
 /pthread_rwlock_rdlock.m4
 /quote.m4
 /quotearg.m4
@@ -177,14 +168,13 @@
 /threadlib.m4
 /time_h.m4
 /timespec.m4
-/uintmax_t.m4
+/tls.m4
 /unistd-safer.m4
 /unistd_h.m4
 /unlink.m4
 /unlocked-io.m4
 /vasnprintf.m4
 /vfprintf-posix.m4
-/visibility.m4
 /vsnprintf-posix.m4
 /vsnprintf.m4
 /vsprintf-posix.m4
@@ -63,6 +63,9 @@ m4_define([_BISON_CXXSTD_11_snippet],
    for (int r: std::set<int>{1, 2})
      continue;
  }
+
+  // GCC 4.8.2 on Solaris 11.3 does not support to_string.
+  auto e = std::to_string(42);
 ])

 m4_define([_BISON_CXXSTD_14_snippet],
@@ -1,22 +0,0 @@
-## ----------------------------------- ##
-## Check if --with-dmalloc was given.  ##
-## From Franc,ois Pinard               ##
-## ----------------------------------- ##
-
-# serial 1
-
-AC_DEFUN([AM_WITH_DMALLOC],
-[AC_MSG_CHECKING([if malloc debugging is wanted])
-AC_ARG_WITH(dmalloc,
-[  --with-dmalloc          use dmalloc, as in
-                          http://www.dmalloc.com/dmalloc.tar.gz],
-[if test "$withval" = yes; then
-  AC_MSG_RESULT(yes)
-  AC_DEFINE([WITH_DMALLOC],1,
-            [Define if using the dmalloc debugging malloc package])
-  LIBS="$LIBS -ldmalloc"
-  LDFLAGS="$LDFLAGS -g"
-else
-  AC_MSG_RESULT(no)
-fi], [AC_MSG_RESULT(no)])
-])
@@ -15,7 +15,10 @@ AC_DEFUN_ONCE([AC_PROG_LEX],
 [AC_CHECK_PROGS([LEX], [flex lex], [:])
 if test "x$LEX" != "x:"; then
  _AC_PROG_LEX_YYTEXT_DECL
-fi])
+fi
+AC_SUBST([LEX_IS_FLEX],
+         [`test "$ac_cv_prog_lex_is_flex" = yes && echo true || echo false`])dnl
+])


 # _AC_PROG_LEX_YYTEXT_DECL
@@ -37,8 +40,6 @@ else
  ac_cv_prog_lex_is_flex=no
 fi
 ])
-AC_SUBST([LEX_IS_FLEX],
-         [`test "$ac_cv_prog_lex_is_flex" = yes && echo true || echo false`])dnl

 cat >conftest.l <<_ACEOF[
 %%
@@ -269,7 +269,7 @@ AnnotationList__computePredecessorAnnotations (
                  if (item_number_is_rule_number (ritem[s->items[self_item]
                                                        - 2]))
                    {
-                      unsigned rulei;
+                      int rulei;
                      for (rulei = s->items[self_item];
                           !item_number_is_rule_number (ritem[rulei]);
                           ++rulei)
@@ -25,7 +25,7 @@
 # include "InadequacyList.h"
 # include "state.h"

-typedef unsigned AnnotationIndex;
+typedef int AnnotationIndex;

 /**
 * A node in a list of annotations on a particular LR(0) state.  Each
@@ -22,6 +22,8 @@

 #include "InadequacyList.h"

+#include <intprops.h>
+
 ContributionIndex const ContributionIndex__none = -1;
 ContributionIndex const ContributionIndex__error_action = -2;

@@ -31,8 +33,11 @@ InadequacyList__new_conflict (state *manifesting_state, symbol *token,
                              InadequacyListNodeCount *node_count)
 {
  InadequacyList *result = xmalloc (sizeof *result);
-  result->id = (*node_count)++;
-  aver (*node_count != 0);
+  result->id = *node_count;
+  IGNORE_TYPE_LIMITS_BEGIN
+  if (INT_ADD_WRAPV (*node_count, 1, node_count))
+    aver (false);
+  IGNORE_TYPE_LIMITS_END
  result->next = NULL;
  result->manifestingState = manifesting_state;
  result->contributionCount = bitset_count (actions);
@@ -27,11 +27,8 @@

 /**
 * A unique ID assigned to every \c InadequacyList node.
- *
- * This must remain unsigned so that the overflow check in
- * \c InadequacyList__new_conflict works properly.
 */
-typedef unsigned long long InadequacyListNodeCount;
+typedef long long InadequacyListNodeCount;

 /**
 * For a conflict, each rule in the grammar can have at most one contributing
@@ -170,7 +170,7 @@ set_fderives (void)


 void
-closure_new (unsigned n)
+closure_new (int n)
 {
  itemset = xnmalloc (n, sizeof *itemset);

@@ -27,7 +27,7 @@
   data so that closure can be called.  n is the number of elements to
   allocate for itemset.  */

-void closure_new (unsigned n);
+void closure_new (int n);


 /* Given the kernel (aka core) of a state (a sorted vector of item numbers
@@ -63,8 +63,6 @@ typedef enum
 /** For each warning type, its severity.  */
 static severity warnings_flag[warnings_size];

-static unsigned *indent_ptr = NULL;
-
 styled_ostream_t errstream = NULL;

 void
@@ -72,7 +70,7 @@ begin_use_class (const char *s, FILE *out)
 {
  if (out == stderr)
    {
-      if (style_debug)
+      if (color_debug)
        fprintf (out, "<%s>", s);
      else
        {
@@ -87,7 +85,7 @@ end_use_class (const char *s, FILE *out)
 {
  if (out == stderr)
    {
-      if (style_debug)
+      if (color_debug)
        fprintf (out, "</%s>", s);
      else
        {
@@ -109,46 +107,59 @@ flush (FILE *out)
 | --warnings's handling.  |
 `------------------------*/

-static const char * const warnings_args[] =
+ARGMATCH_DEFINE_GROUP (warning, warnings)
+
+static const argmatch_warning_doc argmatch_warning_docs[] =
 {
-  "none",
-  "midrule-values",
-  "yacc",
-  "conflicts-sr",
-  "conflicts-rr",
-  "deprecated",
-  "empty-rule",
-  "precedence",
-  "other",
-  "all",
-  "error",
-  "everything",
-  0
+  { "conflicts-sr",     N_("S/R conflicts (enabled by default)") },
+  { "conflicts-rr",     N_("R/R conflicts (enabled by default)") },
+  { "deprecated",       N_("obsolete constructs") },
+  { "empty-rule",       N_("empty rules without %empty") },
+  { "midrule-values",   N_("unset or unused midrule values") },
+  { "precedence",       N_("useless precedence and associativity") },
+  { "yacc",             N_("incompatibilities with POSIX Yacc") },
+  { "other",            N_("all other warnings (enabled by default)") },
+  { "all",              N_("all the warnings except 'yacc'") },
+  { "no-CATEGORY",      N_("turn off warnings in CATEGORY") },
+  { "none",             N_("turn off all the warnings") },
+  { "error[=CATEGORY]", N_("treat warnings as errors") },
+  { NULL, NULL }
 };

-static const warnings warnings_types[] =
+static const argmatch_warning_arg argmatch_warning_args[] =
 {
-  Wnone,
-  Wmidrule_values,
-  Wyacc,
-  Wconflicts_sr,
-  Wconflicts_rr,
-  Wdeprecated,
-  Wempty_rule,
-  Wprecedence,
-  Wother,
-  Wall,
-  Werror,
-  Weverything
+  { "none",           Wnone },
+  { "midrule-values", Wmidrule_values },
+  { "yacc",           Wyacc },
+  { "conflicts-sr",   Wconflicts_sr },
+  { "conflicts-rr",   Wconflicts_rr },
+  { "deprecated",     Wdeprecated },
+  { "empty-rule",     Wempty_rule },
+  { "precedence",     Wprecedence },
+  { "other",          Wother },
+  { "all",            Wall },
+  { "everything",     Weverything },
+  { NULL, Wnone }
 };

-ARGMATCH_VERIFY (warnings_args, warnings_types);
+const argmatch_warning_group_type argmatch_warning_group =
+{
+  argmatch_warning_args,
+  argmatch_warning_docs,
+  N_("Warning categories include:"),
+  NULL
+};
+
+void
+warning_usage (FILE *out)
+{
+  argmatch_warning_usage (out);
+}

 void
 warning_argmatch (char const *arg, size_t no, size_t err)
 {
-  int value = XARGMATCH ("--warning", arg + no + err,
-                         warnings_args, warnings_types);
+  int value = *argmatch_warning_value ("--warning", arg + no + err);

  /* -Wnone == -Wno-everything, and -Wno-none == -Weverything.  */
  if (!value)
@@ -187,7 +198,14 @@ warning_argmatch (char const *arg, size_t no, size_t err)
 void
 warnings_argmatch (char *args)
 {
-  if (args)
+  if (!args)
+    warning_argmatch ("all", 0, 0);
+  else if (STREQ (args, "help"))
+    {
+      warning_usage (stdout);
+      exit (EXIT_SUCCESS);
+    }
+  else
    for (args = strtok (args, ","); args; args = strtok (NULL, ","))
      if (STREQ (args, "error"))
        warnings_are_errors = true;
@@ -203,8 +221,6 @@ warnings_argmatch (char *args)

          warning_argmatch (args, no, err);
        }
-  else
-    warning_argmatch ("all", 0, 0);
 }

 static const char*
@@ -252,30 +268,48 @@ complain_init_color (void)
 {
 #if HAVE_LIBTEXTSTYLE
  if (color_mode == color_yes
+      || color_mode == color_html
      || (color_mode == color_tty && isatty (STDERR_FILENO)))
    {
-      style_file_prepare ("BISON_DIAGNOSTICS_STYLE", NULL,
-                          pkgdatadir (),
-                          "diagnostics.css");
+      style_file_prepare ("BISON_STYLE", "BISON_STYLEDIR", pkgdatadir (),
+                          "bison-default.css");
      /* As a fallback, use the default in the current directory.  */
      struct stat statbuf;
      if ((style_file_name == NULL || stat (style_file_name, &statbuf) < 0)
-          && stat ("diagnostics.css", &statbuf) == 0)
-        style_file_name = "diagnostics.css";
+          && stat ("bison-default.css", &statbuf) == 0)
+        style_file_name = "bison-default.css";
    }
  else
    /* No styling.  */
    style_file_name = NULL;
 #endif

+  /* Workaround clang's warning (starting at Clang 3.5) about the stub
+     code of html_styled_ostream_create:
+
+     | src/complain.c:274:7: error: code will never be executed [-Werror,-Wunreachable-code]
+     |     ? html_styled_ostream_create (file_ostream_create (stderr),
+     |       ^~~~~~~~~~~~~~~~~~~~~~~~~~ */
+#if defined __clang__
+# pragma clang diagnostic push
+# pragma clang diagnostic ignored "-Wunreachable-code"
+#endif
  errstream =
-    styled_ostream_create (STDERR_FILENO, "(stderr)", TTYCTL_AUTO,
-                           style_file_name);
+    color_mode == color_html
+    ? html_styled_ostream_create (file_ostream_create (stderr),
+                                  style_file_name)
+    : styled_ostream_create (STDERR_FILENO, "(stderr)", TTYCTL_AUTO,
+                             style_file_name);
+#if defined __clang__
+# pragma clang diagnostic pop
+#endif
 }

 void
 complain_init (void)
 {
+  caret_init ();
+
  warnings warnings_default =
    Wconflicts_sr | Wconflicts_rr | Wdeprecated | Wother;

@@ -349,16 +383,17 @@ warning_is_enabled (warnings flags)
 static void
 warnings_print_categories (warnings warn_flags, FILE *out)
 {
-  for (size_t i = 0; warnings_args[i]; ++i)
-    if (warn_flags & warnings_types[i])
+  for (int wbit = 0; wbit < warnings_size; ++wbit)
+    if (warn_flags & (1 << wbit))
      {
-        severity s = warning_severity (warnings_types[i]);
+        warnings w = 1 << wbit;
+        severity s = warning_severity (w);
        const char* style = severity_style (s);
        fputs (" [", out);
        begin_use_class (style, out);
        fprintf (out, "-W%s%s",
                 s == severity_error ? "error=" : "",
-                 warnings_args[i]);
+                 argmatch_warning_argument (&w));
        end_use_class (style, out);
        fputc (']', out);
        /* Display only the first match, the second is "-Wall".  */
@@ -370,6 +405,7 @@ warnings_print_categories (warnings warn_flags, FILE *out)
 *
 * \param loc     the location, defaulting to the current file,
 *                or the program name.
+ * \param indent  optional indentation for the error message.
 * \param flags   the category for this message.
 * \param sever   to decide the prefix to put before the message
 *                (e.g., "warning").
@@ -381,26 +417,25 @@ warnings_print_categories (warnings warn_flags, FILE *out)
 */
 static
 void
-error_message (const location *loc, warnings flags, severity sever,
-               const char *message, va_list args)
+error_message (const location *loc, int *indent, warnings flags,
+               severity sever, const char *message, va_list args)
 {
-  unsigned pos = 0;
+  int pos = 0;

  if (loc)
    pos += location_print (*loc, stderr);
  else
-    pos += fprintf (stderr, "%s", current_file ? current_file : program_name);
+    pos += fprintf (stderr, "%s", grammar_file ? grammar_file : program_name);
  pos += fprintf (stderr, ": ");

-  if (indent_ptr)
+  if (indent)
    {
-      if (*indent_ptr)
+      if (*indent)
        sever = severity_disabled;
-      if (!*indent_ptr)
-        *indent_ptr = pos;
-      else if (*indent_ptr > pos)
-        fprintf (stderr, "%*s", *indent_ptr - pos, "");
-      indent_ptr = NULL;
+      if (!*indent)
+        *indent = pos;
+      else if (*indent > pos)
+        fprintf (stderr, "%*s", *indent - pos, "");
    }

  const char* style = severity_style (sever);
@@ -435,8 +470,8 @@ error_message (const location *loc, warnings flags, severity sever,
 /** Raise a complaint (fatal error, error or just warning).  */

 static void
-complains (const location *loc, warnings flags, const char *message,
-           va_list args)
+complains (const location *loc, int *indent, warnings flags,
+           const char *message, va_list args)
 {
  severity s = warning_severity (flags);
  if ((flags & complaint) && complaint_status < status_complaint)
@@ -446,7 +481,7 @@ complains (const location *loc, warnings flags, const char *message,
    {
      if (severity_error <= s && ! complaint_status)
        complaint_status = status_warning_as_error;
-      error_message (loc, flags, s, message, args);
+      error_message (loc, indent, flags, s, message, args);
    }

  if (flags & fatal)
@@ -458,23 +493,22 @@ complain (location const *loc, warnings flags, const char *message, ...)
 {
  va_list args;
  va_start (args, message);
-  complains (loc, flags, message, args);
+  complains (loc, NULL, flags, message, args);
  va_end (args);
 }

 void
-complain_indent (location const *loc, warnings flags, unsigned *indent,
+complain_indent (location const *loc, warnings flags, int *indent,
                 const char *message, ...)
 {
  va_list args;
-  indent_ptr = indent;
  va_start (args, message);
-  complains (loc, flags, message, args);
+  complains (loc, indent, flags, message, args);
  va_end (args);
 }

 void
-complain_args (location const *loc, warnings w, unsigned *indent,
+complain_args (location const *loc, warnings w, int *indent,
               int argc, char *argv[])
 {
  switch (argc)
@@ -512,24 +546,23 @@ bison_directive (location const *loc, char const *directive)
 void
 deprecated_directive (location const *loc, char const *old, char const *upd)
 {
-  if (feature_flag & feature_caret)
-    complain (loc, Wdeprecated,
-              _("deprecated directive, use %s"),
-              quote_n (1, upd));
-  else
-    complain (loc, Wdeprecated,
-              _("deprecated directive: %s, use %s"),
-              quote (old), quote_n (1, upd));
-  /* Register updates only if -Wdeprecated is enabled.  */
-  if (warnings_flag[warning_deprecated] != severity_disabled)
-    fixits_register (loc, upd);
+  if (warning_is_enabled (Wdeprecated))
+    {
+      complain (loc, Wdeprecated,
+                _("deprecated directive: %s, use %s"),
+                quote (old), quote_n (1, upd));
+      if (feature_flag & feature_caret)
+        location_caret_suggestion (*loc, upd, stderr);
+      /* Register updates only if -Wdeprecated is enabled.  */
+      fixits_register (loc, upd);
+    }
 }

 void
 duplicate_directive (char const *directive,
                     location first, location second)
 {
-  unsigned i = 0;
+  int i = 0;
  if (feature_flag & feature_caret)
    complain_indent (&second, Wother, &i, _("duplicate directive"));
  else
@@ -543,7 +576,7 @@ void
 duplicate_rule_directive (char const *directive,
                          location first, location second)
 {
-  unsigned i = 0;
+  int i = 0;
  complain_indent (&second, complaint, &i,
                   _("only one %s allowed per rule"), directive);
  i += SUB_INDENT;
@@ -45,14 +45,14 @@ void flush (FILE *out);
 /** The bits assigned to each warning type.  */
 typedef enum
  {
-    warning_midrule_values, /**< Unset or unused midrule values.  */
+    warning_conflicts_rr,
+    warning_conflicts_sr,
+    warning_deprecated,
+    warning_empty_rule,
+    warning_midrule_values,
+    warning_other,
+    warning_precedence,
    warning_yacc,           /**< POSIXME.  */
-    warning_conflicts_sr,   /**< S/R conflicts.  */
-    warning_conflicts_rr,   /**< R/R conflicts.  */
-    warning_empty_rule,     /**< Implicitly empty rules.  */
-    warning_deprecated,     /**< Obsolete constructs.  */
-    warning_precedence,     /**< Useless precedence and associativity.  */
-    warning_other,          /**< All other warnings.  */

    warnings_size           /**< The number of warnings.  Must be last.  */
  } warning_bit;
@@ -60,6 +60,8 @@ typedef enum
 /** Whether -Werror was set. */
 extern bool warnings_are_errors;

+void warning_usage (FILE *out);
+
 /** Decode a single argument from -W.
 *
 *  \param arg      the subarguments to decode.
@@ -100,16 +102,14 @@ typedef enum
  {
    Wnone             = 0,       /**< Issue no warnings.  */

-    Wmidrule_values   = 1 << warning_midrule_values,
-    Wyacc             = 1 << warning_yacc,
-    Wconflicts_sr     = 1 << warning_conflicts_sr,
    Wconflicts_rr     = 1 << warning_conflicts_rr,
+    Wconflicts_sr     = 1 << warning_conflicts_sr,
    Wdeprecated       = 1 << warning_deprecated,
    Wempty_rule       = 1 << warning_empty_rule,
-    Wprecedence       = 1 << warning_precedence,
+    Wmidrule_values   = 1 << warning_midrule_values,
    Wother            = 1 << warning_other,
-
-    Werror            = 1 << 10, /** This bit is no longer used. */
+    Wprecedence       = 1 << warning_precedence,
+    Wyacc             = 1 << warning_yacc,

    complaint         = 1 << 11, /**< All complaints.  */
    fatal             = 1 << 12, /**< All fatal errors.  */
@@ -133,11 +133,11 @@ void complain (location const *loc, warnings flags, char const *message, ...)
  __attribute__ ((__format__ (__printf__, 3, 4)));

 /** Likewise, but with an \a argc/argv interface.  */
-void complain_args (location const *loc, warnings w, unsigned *indent,
+void complain_args (location const *loc, warnings w, int *indent,
                    int argc, char *arg[]);

 /** Make a complaint with location and some indentation.  */
-void complain_indent (location const *loc, warnings flags, unsigned *indent,
+void complain_indent (location const *loc, warnings flags, int *indent,
                      char const *message, ...)
  __attribute__ ((__format__ (__printf__, 4, 5)));

@@ -38,7 +38,10 @@
 /* -1 stands for not specified. */
 int expected_sr_conflicts = -1;
 int expected_rr_conflicts = -1;
-static char *conflicts;
+
+/* CONFLICTS[STATE-NUM] -- Whether that state has unresolved conflicts.  */
+static bool *conflicts;
+
 static struct obstack solved_conflicts_obstack;
 static struct obstack solved_conflicts_xml_obstack;

@@ -73,8 +76,9 @@ log_resolution (rule *r, symbol_number token,
        {
        case shift_resolution:
        case right_resolution:
+          obstack_sgrow (&solved_conflicts_obstack, "    ");
          obstack_printf (&solved_conflicts_obstack,
-                          _("    Conflict between rule %d and token %s"
+                          _("Conflict between rule %d and token %s"
                            " resolved as shift"),
                          r->number,
                          symbols[token]->tag);
@@ -82,16 +86,18 @@ log_resolution (rule *r, symbol_number token,

        case reduce_resolution:
        case left_resolution:
+          obstack_sgrow (&solved_conflicts_obstack, "    ");
          obstack_printf (&solved_conflicts_obstack,
-                          _("    Conflict between rule %d and token %s"
+                          _("Conflict between rule %d and token %s"
                            " resolved as reduce"),
                          r->number,
                          symbols[token]->tag);
          break;

        case nonassoc_resolution:
+          obstack_sgrow (&solved_conflicts_obstack, "    ");
          obstack_printf (&solved_conflicts_obstack,
-                          _("    Conflict between rule %d and token %s"
+                          _("Conflict between rule %d and token %s"
                            " resolved as an error"),
                          r->number,
                          symbols[token]->tag);
@@ -376,7 +382,7 @@ set_conflicts (state *s, symbol **errors)
    for (int i = 0; i < reds->num; ++i)
      {
        if (!bitset_disjoint_p (reds->lookahead_tokens[i], lookahead_set))
-          conflicts[s->number] = 1;
+          conflicts[s->number] = true;
        bitset_or (lookahead_set, lookahead_set, reds->lookahead_tokens[i]);
      }
 }
@@ -428,7 +434,7 @@ conflicts_update_state_numbers (state_number old_to_new[],
 `---------------------------------------------*/

 static size_t
-count_state_sr_conflicts (state *s)
+count_state_sr_conflicts (const state *s)
 {
  transitions *trans = s->transitions;
  reductions *reds = s->reductions;
@@ -476,7 +482,7 @@ count_sr_conflicts (void)
 `-----------------------------------------------------------------*/

 static size_t
-count_state_rr_conflicts (state *s)
+count_state_rr_conflicts (const state *s)
 {
  reductions *reds = s->reductions;
  size_t res = 0;
@@ -588,24 +594,22 @@ conflicts_output (FILE *out)
 {
  bool printed_sth = false;
  for (state_number i = 0; i < nstates; ++i)
-    {
-      state *s = states[i];
-      if (conflicts[i])
-        {
-          int src = count_state_sr_conflicts (s);
-          int rrc = count_state_rr_conflicts (s);
-          fprintf (out, _("State %d "), i);
-          if (src && rrc)
-            fprintf (out,
-                     _("conflicts: %d shift/reduce, %d reduce/reduce\n"),
-                     src, rrc);
-          else if (src)
-            fprintf (out, _("conflicts: %d shift/reduce\n"), src);
-          else if (rrc)
-            fprintf (out, _("conflicts: %d reduce/reduce\n"), rrc);
-          printed_sth = true;
-        }
-    }
+    if (conflicts[i])
+      {
+        const state *s = states[i];
+        int src = count_state_sr_conflicts (s);
+        int rrc = count_state_rr_conflicts (s);
+        fprintf (out, _("State %d "), i);
+        if (src && rrc)
+          fprintf (out,
+                   _("conflicts: %d shift/reduce, %d reduce/reduce\n"),
+                   src, rrc);
+        else if (src)
+          fprintf (out, _("conflicts: %d shift/reduce\n"), src);
+        else if (rrc)
+          fprintf (out, _("conflicts: %d reduce/reduce\n"), rrc);
+        printed_sth = true;
+      }
  if (printed_sth)
    fputs ("\n\n", out);
 }
@@ -40,11 +40,9 @@ rule ***derives;
 static void
 print_derives (void)
 {
-  int i;
-
  fputs ("DERIVES\n", stderr);

-  for (i = ntokens; i < nsyms; i++)
+  for (symbol_number i = ntokens; i < nsyms; ++i)
    {
      fprintf (stderr, "  %s derives\n", symbols[i]->tag);
      for (rule **rp = derives[i - ntokens]; *rp; ++rp)
@@ -88,7 +86,7 @@ derives_compute (void)
  /* Q is the storage for DERIVES[...] (DERIVES[0] = q).  */
  rule **q = xnmalloc (nvars + nrules, sizeof *q);

-  for (symbol_number i = ntokens; i < nsyms; i++)
+  for (symbol_number i = ntokens; i < nsyms; ++i)
    {
      rule_list *p = dset[i - ntokens];
      derives[i - ntokens] = q;
@@ -111,6 +109,9 @@ derives_compute (void)
 void
 derives_free (void)
 {
-  free (derives[0]);
-  free (derives);
+  if (derives)
+    {
+      free (derives[0]);
+      free (derives);
+    }
 }
@@ -68,7 +68,6 @@ static generated_file *generated_files = NULL;
 static int generated_files_size = 0;

 uniqstr grammar_file = NULL;
-uniqstr current_file = NULL;

 /* If --output=dir/foo.c was specified,
   DIR_PREFIX is 'dir/' and ALL_BUT_EXT and ALL_BUT_TAB_EXT are 'dir/foo'.
@@ -58,9 +58,6 @@ extern char *dir_prefix;
   and therefore GCC warns about a name clash. */
 extern uniqstr grammar_file;

-/* The current file name.  Might change with #line.  */
-extern uniqstr current_file;
-
 /* The computed base for output file names.  */
 extern char *all_but_ext;

@@ -52,6 +52,11 @@ fixit_new (location const *loc, char const* fix)
  return res;
 }

+static int
+fixit_cmp (const  fixit *a, const fixit *b)
+{
+  return location_cmp (a->location, b->location);
+}

 static void
 fixit_free (fixit *f)
@@ -85,8 +90,8 @@ fixits_register (location const *loc, char const* fix)
                                   (gl_listelement_dispose_fn) fixit_free,
                                   true);
  fixit *f = fixit_new (loc, fix);
-  gl_list_add_last (fixits, f);
-  if (feature_flag & feature_fixit_parsable)
+  gl_sortedlist_add (fixits, (gl_listelement_compar_fn) fixit_cmp, f);
+  if (feature_flag & feature_fixit)
    fixit_print (f, stderr);
 }

@@ -45,7 +45,7 @@ bool no_lines_flag = false;
 bool token_table_flag = false;
 location yacc_loc = EMPTY_LOCATION_INIT;
 bool update_flag = false; /* for -u */
-bool style_debug = false; /* --style=debug. */
+bool color_debug = false;

 bool nondeterministic_parser = false;
 bool glr_parser = false;
@@ -68,28 +68,28 @@ const char *skeleton = NULL;
 int language_prio = default_prio;
 struct bison_language const *language = &valid_languages[0];

+typedef int* (xargmatch_fn) (const char *context, const char *arg);
+
 /** Decode an option's key.
 *
- *  \param opt      option being decoded.
- *  \param keys     array of valid subarguments.
- *  \param values   array of corresponding (int) values.
- *  \param all      the all value.
- *  \param flags    the flags to update
- *  \param arg      the subarguments to decode.
- *                  If null, then activate all the flags.
- *  \param no       length of the potential "no-" prefix.
- *                  Can be 0 or 3. If 3, negate the action of the subargument.
+ *  \param opt        option being decoded.
+ *  \param xargmatch  matching function.
+ *  \param all        the value of the argument 'all'.
+ *  \param flags      the flags to update
+ *  \param arg        the subarguments to decode.
+ *                    If null, then activate all the flags.
+ *  \param no         length of the potential "no-" prefix.
+ *                    Can be 0 or 3. If 3, negate the action of the subargument.
 *
 *  If VALUE != 0 then KEY sets flags and no-KEY clears them.
 *  If VALUE == 0 then KEY clears all flags from \c all and no-KEY sets all
 *  flags from \c all.  Thus no-none = all and no-all = none.
 */
 static void
-flag_argmatch (const char *opt,
-               const char *const keys[], const int values[],
+flag_argmatch (const char *opt, xargmatch_fn xargmatch,
               int all, int *flags, char *arg, size_t no)
 {
-  int value = XARGMATCH (opt, arg + no, keys, values);
+  int value = *xargmatch (opt, arg + no);

  /* -rnone == -rno-all, and -rno-none == -rall.  */
  if (!value)
@@ -104,30 +104,38 @@ flag_argmatch (const char *opt,
    *flags |= value;
 }

+typedef void (usage_fn) (FILE *out);
+
 /** Decode an option's set of keys.
 *
- *  \param opt      option being decoded (e.g., --report).
- *  \param keys     array of valid subarguments.
- *  \param values   array of corresponding (int) values.
- *  \param all      the all value.
- *  \param flags    the flags to update
- *  \param args     comma separated list of effective subarguments to decode.
- *                  If 0, then activate all the flags.
+ *  \param opt        option being decoded (e.g., --report).
+ *  \param xargmatch  matching function.
+ *  \param usage      function that implement --help for this option.
+ *  \param all        the value of the argument 'all'.
+ *  \param flags      the flags to update
+ *  \param args       comma separated list of effective subarguments to decode.
+ *                    If 0, then activate all the flags.
 */
 static void
 flags_argmatch (const char *opt,
-                const char * const keys[], const int values[],
+                xargmatch_fn xargmatch,
+                usage_fn usage,
                int all, int *flags, char *args)
 {
-  if (args)
+  if (!args)
+    *flags |= all;
+  else if (STREQ (args, "help"))
+    {
+      usage (stdout);
+      exit (EXIT_SUCCESS);
+    }
+  else
    for (args = strtok (args, ","); args; args = strtok (NULL, ","))
      {
        size_t no = STRPREFIX_LIT ("no-", args) ? 3 : 0;
-        flag_argmatch (opt, keys,
-                       values, all, flags, args, no);
+        flag_argmatch (opt, xargmatch,
+                       all, flags, args, no);
      }
-  else
-    *flags |= all;
 }


@@ -142,116 +150,188 @@ flags_argmatch (const char *opt,
 *  \arg FlagName_flag   the flag to update.
 */
 #define FLAGS_ARGMATCH(FlagName, Args, All)                             \
-  flags_argmatch ("--" #FlagName, FlagName ## _args, FlagName ## _types, \
+  flags_argmatch ("--" #FlagName,                                       \
+                  (xargmatch_fn*) argmatch_## FlagName ## _value,        \
+                  argmatch_## FlagName ## _usage,                       \
                  All, &FlagName ## _flag, Args)

+/*---------------------.
+| --color's handling.  |
+`---------------------*/
+
+enum color
+  {
+    color_always,
+    color_never,
+    color_auto
+  };
+
+ARGMATCH_DEFINE_GROUP (color, enum color)
+
+static const argmatch_color_doc argmatch_color_docs[] =
+{
+  { "always",     N_("colorize the output") },
+  { "never",      N_("don't colorize the output") },
+  { "auto",       N_("colorize if the output device is a tty") },
+  { NULL, NULL },
+};
+
+static const argmatch_color_arg argmatch_color_args[] =
+{
+  { "always",   color_always },
+  { "yes",      color_always },
+  { "never",    color_never },
+  { "no",       color_never },
+  { "auto",     color_auto },
+  { "tty",      color_auto },
+  { NULL, color_always },
+};
+
+const argmatch_color_group_type argmatch_color_group =
+{
+  argmatch_color_args,
+  argmatch_color_docs,
+  /* TRANSLATORS: Use the same translation for WHEN as in the
+     --color=WHEN help message.  */
+  N_("WHEN can be one of the following:"),
+  NULL
+};
+

 /*----------------------.
 | --report's handling.  |
 `----------------------*/

-static const char * const report_args[] =
+ARGMATCH_DEFINE_GROUP (report, enum report)
+
+static const argmatch_report_doc argmatch_report_docs[] =
 {
-  /* In a series of synonyms, present the most meaningful first, so
-     that argmatch_valid be more readable.  */
-  "none",
-  "state", "states",
-  "itemset", "itemsets",
-  "lookahead", "lookaheads", "look-ahead",
-  "solved",
-  "all",
-  0
+  { "states",     N_("describe the states") },
+  { "itemsets",   N_("complete the core item sets with their closure") },
+  { "lookaheads", N_("explicitly associate lookahead tokens to items") },
+  { "solved",     N_("describe shift/reduce conflicts solving") },
+  { "all",        N_("include all the above information") },
+  { "none",       N_("disable the report") },
+  { NULL, NULL },
 };

-static const int report_types[] =
+static const argmatch_report_arg argmatch_report_args[] =
 {
-  report_none,
-  report_states, report_states,
-  report_states | report_itemsets, report_states | report_itemsets,
-  report_states | report_lookahead_tokens,
-  report_states | report_lookahead_tokens,
-  report_states | report_lookahead_tokens,
-  report_states | report_solved_conflicts,
-  report_all
+  { "none",        report_none },
+  { "states",      report_states },
+  { "itemsets",    report_states | report_itemsets },
+  { "lookaheads",  report_states | report_lookahead_tokens },
+  { "solved",      report_states | report_solved_conflicts },
+  { "all",         report_all },
+  { NULL, report_none },
 };

-ARGMATCH_VERIFY (report_args, report_types);
-
+const argmatch_report_group_type argmatch_report_group =
+{
+  argmatch_report_args,
+  argmatch_report_docs,
+  /* TRANSLATORS: Use the same translation for THINGS as in the
+     --report=THINGS help message.  */
+  N_("THINGS is a list of comma separated words that can include:"),
+  NULL
+};

 /*---------------------.
 | --trace's handling.  |
 `---------------------*/

-static const char * const trace_args[] =
+ARGMATCH_DEFINE_GROUP (trace, enum trace)
+
+static const argmatch_trace_doc argmatch_trace_docs[] =
 {
-  "none       - no traces",
-  "locations  - full display of the locations",
-  "scan       - grammar scanner traces",
-  "parse      - grammar parser traces",
-  "automaton  - construction of the automaton",
-  "bitsets    - use of bitsets",
-  "closure    - input/output of closure",
-  "grammar    - reading, reducing the grammar",
-  "resource   - memory consumption (where available)",
-  "sets       - grammar sets: firsts, nullable etc.",
-  "muscles    - m4 definitions passed to the skeleton",
-  "tools      - m4 invocation",
-  "m4         - m4 traces",
-  "skeleton   - skeleton postprocessing",
-  "time       - time consumption",
-  "ielr       - IELR conversion",
-  "all        - all of the above",
-  0
+  /* Meant for developers only, don't translate them.  */
+  { "none",       "no traces" },
+  { "locations",  "full display of the locations" },
+  { "scan",       "grammar scanner traces" },
+  { "parse",      "grammar parser traces" },
+  { "automaton",  "construction of the automaton" },
+  { "bitsets",    "use of bitsets" },
+  { "closure",    "input/output of closure" },
+  { "grammar",    "reading, reducing the grammar" },
+  { "resource",   "memory consumption (where available)" },
+  { "sets",       "grammar sets: firsts, nullable etc." },
+  { "muscles",    "m4 definitions passed to the skeleton" },
+  { "tools",      "m4 invocation" },
+  { "m4",         "m4 traces" },
+  { "skeleton",   "skeleton postprocessing" },
+  { "time",       "time consumption" },
+  { "ielr",       "IELR conversion" },
+  { "all",        "all of the above" },
+  { NULL, NULL},
 };

-static const int trace_types[] =
+static const argmatch_trace_arg argmatch_trace_args[] =
 {
-  trace_none,
-  trace_locations,
-  trace_scan,
-  trace_parse,
-  trace_automaton,
-  trace_bitsets,
-  trace_closure,
-  trace_grammar,
-  trace_resource,
-  trace_sets,
-  trace_muscles,
-  trace_tools,
-  trace_m4,
-  trace_skeleton,
-  trace_time,
-  trace_ielr,
-  trace_all
+  { "none",      trace_none },
+  { "locations", trace_locations },
+  { "scan",      trace_scan },
+  { "parse",     trace_parse },
+  { "automaton", trace_automaton },
+  { "bitsets",   trace_bitsets },
+  { "closure",   trace_closure },
+  { "grammar",   trace_grammar },
+  { "resource",  trace_resource },
+  { "sets",      trace_sets },
+  { "muscles",   trace_muscles },
+  { "tools",     trace_tools },
+  { "m4",        trace_m4 },
+  { "skeleton",  trace_skeleton },
+  { "time",      trace_time },
+  { "ielr",      trace_ielr },
+  { "all",       trace_all },
+  { NULL,        trace_none},
 };

-ARGMATCH_VERIFY (trace_args, trace_types);
-
+const argmatch_trace_group_type argmatch_trace_group =
+{
+  argmatch_trace_args,
+  argmatch_trace_docs,
+  N_("TRACES is a list of comma separated words that can include:"),
+  NULL
+};

 /*-----------------------.
 | --feature's handling.  |
 `-----------------------*/

-static const char * const feature_args[] =
+ARGMATCH_DEFINE_GROUP (feature, enum feature)
+
+static const argmatch_feature_doc argmatch_feature_docs[] =
 {
-  "none",
-  "caret", "diagnostics-show-caret",
-  "fixit", "diagnostics-parseable-fixits",
-  "syntax-only",
-  "all",
-  0
+  { "caret",       N_("show errors with carets") },
+  { "fixit",       N_("show machine-readable fixes") },
+  { "syntax-only", N_("do not generate any file") },
+  { "all",         N_("all of the above") },
+  { "none",        N_("disable all of the above") },
+  { NULL, NULL }
 };

-static const int feature_types[] =
+static const argmatch_feature_arg argmatch_feature_args[] =
 {
-  feature_none,
-  feature_caret, feature_caret,
-  feature_fixit_parsable, feature_fixit_parsable,
-  feature_syntax_only,
-  feature_all
+  { "none",                          feature_none },
+  { "caret",                         feature_caret },
+  { "diagnostics-show-caret",        feature_caret },
+  { "fixit",                         feature_fixit },
+  { "diagnostics-parseable-fixits",  feature_fixit },
+  { "syntax-only",                   feature_syntax_only },
+  { "all",                           feature_all },
+  { NULL, feature_none}
 };

-ARGMATCH_VERIFY (feature_args, feature_types);
+const argmatch_feature_group_type argmatch_feature_group =
+{
+  argmatch_feature_args,
+  argmatch_feature_docs,
+  /* TRANSLATORS: Use the same translation for FEATURES as in the
+     --feature=FEATURES help message.  */
+  N_("FEATURES is a list of comma separated words that can include:"),
+  NULL
+};

 /*-------------------------------------------.
 | Display the help message and exit STATUS.  |
@@ -275,8 +355,7 @@ usage (int status)
      printf (_("Usage: %s [OPTION]... FILE\n"), program_name);
      fputs (_("\
 Generate a deterministic LR or generalized LR (GLR) parser employing\n\
-LALR(1), IELR(1), or canonical LR(1) parser tables.  IELR(1) and\n\
-canonical LR(1) support is experimental.\n\
+LALR(1), IELR(1), or canonical LR(1) parser tables.\n\
 \n\
 "), stdout);

@@ -286,10 +365,10 @@ Mandatory arguments to long options are mandatory for short options too.\n\
      fputs (_("\
 The same is true for optional arguments.\n\
 "), stdout);
+      putc ('\n', stdout);

      fputs (_("\
-\n\
-Operation modes:\n\
+Operation Modes:\n\
  -h, --help                 display this help and exit\n\
  -V, --version              output version information and exit\n\
      --print-localedir      output directory containing locale-dependent data\n\
@@ -297,32 +376,48 @@ Operation modes:\n\
      --print-datadir        output directory containing skeletons and XSLT\n\
                             and exit\n\
  -u, --update               apply fixes to the source grammar file and exit\n\
-  -y, --yacc                 emulate POSIX Yacc\n\
-  -W, --warnings[=CATEGORY]  report the warnings falling in CATEGORY\n\
  -f, --feature[=FEATURES]   activate miscellaneous features\n\
 \n\
 "), stdout);

+      argmatch_feature_usage (stdout);
+      putc ('\n', stdout);
+
      fputs (_("\
-Parser:\n\
+Diagnostics:\n\
+  -W, --warnings[=CATEGORY]  report the warnings falling in CATEGORY\n\
+      --color[=WHEN]         whether to colorize the diagnostics\n\
+      --style=FILE           specify the CSS FILE for colorizer diagnostics\n\
+\n\
+"), stdout);
+
+      warning_usage (stdout);
+      putc ('\n', stdout);
+
+      argmatch_color_usage (stdout);
+      putc ('\n', stdout);
+
+      fputs (_("\
+Tuning the Parser:\n\
  -L, --language=LANGUAGE          specify the output programming language\n\
  -S, --skeleton=FILE              specify the skeleton to use\n\
  -t, --debug                      instrument the parser for tracing\n\
                                   same as '-Dparse.trace'\n\
      --locations                  enable location support\n\
-  -D, --define=NAME[=VALUE]        similar to '%define NAME \"VALUE\"'\n\
-  -F, --force-define=NAME[=VALUE]  override '%define NAME \"VALUE\"'\n\
+  -D, --define=NAME[=VALUE]        similar to '%define NAME VALUE'\n\
+  -F, --force-define=NAME[=VALUE]  override '%define NAME VALUE'\n\
  -p, --name-prefix=PREFIX         prepend PREFIX to the external symbols\n\
-                                   deprecated by '-Dapi.prefix=PREFIX'\n\
+                                   deprecated by '-Dapi.prefix={PREFIX}'\n\
  -l, --no-lines                   don't generate '#line' directives\n\
  -k, --token-table                include a table of token names\n\
+  -y, --yacc                       emulate POSIX Yacc\n\
 "), stdout);
      putc ('\n', stdout);

      /* Keep -d and --defines separate so that ../build-aux/cross-options.pl
       * won't assume that -d also takes an argument.  */
      fputs (_("\
-Output:\n\
+Output Files:\n\
      --defines[=FILE]       also produce a header file\n\
  -d                         likewise but cannot specify FILE (for POSIX Yacc)\n\
  -r, --report=THINGS        also produce details on the automaton\n\
@@ -332,53 +427,12 @@ Output:\n\
  -o, --output=FILE          leave output to FILE\n\
  -g, --graph[=FILE]         also output a graph of the automaton\n\
  -x, --xml[=FILE]           also output an XML report of the automaton\n\
-                             (the XML schema is experimental)\n\
 "), stdout);
      putc ('\n', stdout);

-      fputs (_("\
-Warning categories include:\n\
-  'conflicts-sr'      S/R conflicts (enabled by default)\n\
-  'conflicts-rr'      R/R conflicts (enabled by default)\n\
-  'deprecated'        obsolete constructs\n\
-  'empty-rule'        empty rules without %empty\n\
-  'midrule-values'    unset or unused midrule values\n\
-  'precedence'        useless precedence and associativity\n\
-  'yacc'              incompatibilities with POSIX Yacc\n\
-  'other'             all other warnings (enabled by default)\n\
-  'all'               all the warnings except 'yacc'\n\
-  'no-CATEGORY'       turn off warnings in CATEGORY\n\
-  'none'              turn off all the warnings\n\
-  'error[=CATEGORY]'  treat warnings as errors\n\
-"), stdout);
+      argmatch_report_usage (stdout);
      putc ('\n', stdout);

-      fputs (_("\
-THINGS is a list of comma separated words that can include:\n\
-  'state'        describe the states\n\
-  'itemset'      complete the core item sets with their closure\n\
-  'lookahead'    explicitly associate lookahead tokens to items\n\
-  'solved'       describe shift/reduce conflicts solving\n\
-  'all'          include all the above information\n\
-  'none'         disable the report\n\
-"), stdout);
-      putc ('\n', stdout);
-
-      fputs (_("\
-FEATURES is a list of comma separated words that can include:\n\
-  'caret', 'diagnostics-show-caret'\n\
-    show errors with carets\n\
-  'fixit', 'diagnostics-parseable-fixits'\n\
-    show machine-readable fixes\n\
-  'syntax-only'\n\
-    do not generate any file\n\
-  'all'\n\
-    all of the above\n\
-  'none'\n\
-    disable all of the above\n\
-  "), stdout);
-
-      putc ('\n', stdout);
      printf (_("Report bugs to <%s>.\n"), PACKAGE_BUGREPORT);
      printf (_("%s home page: <%s>.\n"), PACKAGE_NAME, PACKAGE_URL);
      fputs (_("General help using GNU software: "
@@ -452,7 +506,7 @@ skeleton_arg (char const *arg, int prio, location loc)
 void
 language_argmatch (char const *arg, int prio, location loc)
 {
-  char const *msg;
+  char const *msg = NULL;

  if (prio < language_prio)
    {
@@ -467,10 +521,9 @@ language_argmatch (char const *arg, int prio, location loc)
    }
  else if (language_prio == prio)
    msg = _("multiple language declarations are invalid");
-  else
-    return;

-  complain (&loc, complaint, msg, quotearg_colon (arg));
+  if (msg)
+    complain (&loc, complaint, msg, quotearg_colon (arg));
 }

 /*----------------------.
@@ -508,6 +561,7 @@ static char const short_options[] =
 enum
 {
  COLOR_OPTION = CHAR_MAX + 1,
+  FIXED_OUTPUT_FILES_OPTION,
  LOCATIONS_OPTION,
  PRINT_DATADIR_OPTION,
  PRINT_LOCALEDIR_OPTION,
@@ -515,6 +569,7 @@ enum
  STYLE_OPTION
 };

+/* In the same order as in usage(), and in the documentation.  */
 static struct option const long_options[] =
 {
  /* Operation modes. */
@@ -523,55 +578,43 @@ static struct option const long_options[] =
  { "print-localedir", no_argument,       0,   PRINT_LOCALEDIR_OPTION },
  { "print-datadir",   no_argument,       0,   PRINT_DATADIR_OPTION   },
  { "update",          no_argument,       0,   'u' },
-  { "warnings",        optional_argument, 0,   'W' },
+  { "feature",         optional_argument, 0,   'f' },

-  /* Parser. */
-  { "name-prefix",   required_argument,   0,   'p' },
+  /* Diagnostics.  */
+  { "warnings",        optional_argument,  0, 'W' },
+  { "color",           optional_argument,  0,  COLOR_OPTION },
+  { "style",           optional_argument,  0,  STYLE_OPTION },

-  /* Output. */
-  { "file-prefix", required_argument,   0,   'b' },
-  { "output",      required_argument,   0,   'o' },
-  { "output-file", required_argument,   0,   'o' },
-  { "graph",       optional_argument,   0,   'g' },
-  { "xml",         optional_argument,   0,   'x' },
+  /* Tuning the Parser. */
+  { "language",       required_argument,   0, 'L' },
+  { "skeleton",       required_argument,   0, 'S' },
+  { "debug",          no_argument,         0, 't' },
+  { "locations",      no_argument,         0, LOCATIONS_OPTION },
+  { "define",         required_argument,   0, 'D' },
+  { "force-define",   required_argument,   0, 'F' },
+  { "name-prefix",    required_argument,   0, 'p' },
+  { "no-lines",       no_argument,         0, 'l' },
+  { "token-table",    no_argument,         0, 'k' },
+  { "yacc",           no_argument,         0, 'y' },
+
+  /* Output Files. */
+  { "defines",     optional_argument,   0,   'd' },
  { "report",      required_argument,   0,   'r' },
  { "report-file", required_argument,   0,   REPORT_FILE_OPTION },
  { "verbose",     no_argument,         0,   'v' },
+  { "file-prefix", required_argument,   0,   'b' },
+  { "output",      required_argument,   0,   'o' },
+  { "graph",       optional_argument,   0,   'g' },
+  { "xml",         optional_argument,   0,   'x' },

  /* Hidden. */
-  { "trace",       optional_argument,   0,  'T' },
-  { "color",       optional_argument,   0,  COLOR_OPTION },
-  { "style",       optional_argument,   0,  STYLE_OPTION },
-
-  /* Output.  */
-  { "defines",     optional_argument,   0,   'd' },
-  { "feature",     optional_argument,   0,   'f' },
-
-  /* Operation modes.  */
-  { "fixed-output-files", no_argument,  0,   'y' },
-  { "yacc",               no_argument,  0,   'y' },
-
-  /* Parser.  */
-  { "debug",          no_argument,               0,   't' },
-  { "define",         required_argument,         0,   'D' },
-  { "force-define",   required_argument,         0,   'F' },
-  { "locations",      no_argument,               0, LOCATIONS_OPTION },
-  { "no-lines",       no_argument,               0,   'l' },
-  { "skeleton",       required_argument,         0,   'S' },
-  { "language",       required_argument,         0,   'L' },
-  { "token-table",    no_argument,               0,   'k' },
+  { "fixed-output-files", no_argument,       0,  FIXED_OUTPUT_FILES_OPTION },
+  { "output-file",        required_argument, 0,  'o' },
+  { "trace",              optional_argument, 0,  'T' },

  {0, 0, 0, 0}
 };

-/* Under DOS, there is no difference on the case.  This can be
-   troublesome when looking for '.tab' etc.  */
-#ifdef MSDOS
-# define AS_FILE_NAME(File) (strlwr (File), (File))
-#else
-# define AS_FILE_NAME(File) (File)
-#endif
-
 /* Build a location for the current command line argument. */
 static
 location
@@ -596,14 +639,19 @@ getargs_colors (int argc, char *argv[])
    {
      const char *arg = argv[i];
      if (STRPREFIX_LIT ("--color=", arg))
-        handle_color_option (arg + strlen ("--color="));
+        {
+          const char *color = arg + strlen ("--color=");
+          if (STREQ (color, "debug"))
+            color_debug = true;
+          else
+            handle_color_option (color);
+        }
+      else if (STREQ ("--color", arg))
+        handle_color_option (NULL);
      else if (STRPREFIX_LIT ("--style=", arg))
        {
          const char *style = arg + strlen ("--style=");
-          if (STREQ (style, "debug"))
-            style_debug = true;
-          else
-            handle_style_option (style);
+          handle_style_option (style);
        }
    }
  complain_init_color ();
@@ -618,6 +666,8 @@ getargs (int argc, char *argv[])
  int c;
  while ((c = getopt_long (argc, argv, short_options, long_options, NULL))
         != -1)
+  {
+    location loc = command_line_location ();
    switch (c)
      {
        /* ASCII Sorting for short options (i.e., upper case then
@@ -650,7 +700,7 @@ getargs (int argc, char *argv[])
                  *end = 0;
                }
            }
-          muscle_percent_define_insert (name, command_line_location (),
+          muscle_percent_define_insert (name, loc,
                                        kind, value ? value : "",
                                        c == 'D' ? MUSCLE_PERCENT_DEFINE_D
                                                 : MUSCLE_PERCENT_DEFINE_F);
@@ -658,13 +708,11 @@ getargs (int argc, char *argv[])
        break;

      case 'L':
-        language_argmatch (optarg, command_line_prio,
-                           command_line_location ());
+        language_argmatch (optarg, command_line_prio, loc);
        break;

      case 'S':
-        skeleton_arg (AS_FILE_NAME (optarg), command_line_prio,
-                      command_line_location ());
+        skeleton_arg (optarg, command_line_prio, loc);
        break;

      case 'T':
@@ -684,7 +732,7 @@ getargs (int argc, char *argv[])
        break;

      case 'b':
-        spec_file_prefix = AS_FILE_NAME (optarg);
+        spec_file_prefix = optarg;
        break;

      case 'd':
@@ -693,7 +741,7 @@ getargs (int argc, char *argv[])
        if (optarg)
          {
            free (spec_header_file);
-            spec_header_file = xstrdup (AS_FILE_NAME (optarg));
+            spec_header_file = xstrdup (optarg);
          }
        break;

@@ -702,7 +750,7 @@ getargs (int argc, char *argv[])
        if (optarg)
          {
            free (spec_graph_file);
-            spec_graph_file = xstrdup (AS_FILE_NAME (optarg));
+            spec_graph_file = xstrdup (optarg);
          }
        break;

@@ -718,7 +766,7 @@ getargs (int argc, char *argv[])
        break;

      case 'o':
-        spec_outfile = AS_FILE_NAME (optarg);
+        spec_outfile = optarg;
        break;

      case 'p':
@@ -731,7 +779,7 @@ getargs (int argc, char *argv[])

      case 't':
        muscle_percent_define_insert ("parse.trace",
-                                      command_line_location (),
+                                      loc,
                                      muscle_keyword, "",
                                      MUSCLE_PERCENT_DEFINE_D);
        break;
@@ -750,22 +798,28 @@ getargs (int argc, char *argv[])
        if (optarg)
          {
            free (spec_xml_file);
-            spec_xml_file = xstrdup (AS_FILE_NAME (optarg));
+            spec_xml_file = xstrdup (optarg);
          }
        break;

      case 'y':
        warning_argmatch ("yacc", 0, 0);
-        yacc_loc = command_line_location ();
+        yacc_loc = loc;
        break;

      case COLOR_OPTION:
        /* Handled in getargs_colors. */
        break;

+      case FIXED_OUTPUT_FILES_OPTION:
+        complain (&loc, Wdeprecated,
+                  _("deprecated option: %s, use %s"),
+                  quote ("--fixed-output-files"), quote_n (1, "-o y.tab.c"));
+        spec_outfile = "y.tab.c";
+        break;
+
      case LOCATIONS_OPTION:
-        muscle_percent_define_ensure ("locations",
-                                      command_line_location (), true);
+        muscle_percent_define_ensure ("locations", loc, true);
        break;

      case PRINT_LOCALEDIR_OPTION:
@@ -778,7 +832,7 @@ getargs (int argc, char *argv[])

      case REPORT_FILE_OPTION:
        free (spec_verbose_file);
-        spec_verbose_file = xstrdup (AS_FILE_NAME (optarg));
+        spec_verbose_file = xstrdup (optarg);
        break;

      case STYLE_OPTION:
@@ -788,6 +842,7 @@ getargs (int argc, char *argv[])
      default:
        usage (EXIT_FAILURE);
      }
+  }

  if (argc - optind != 1)
    {
@@ -798,7 +853,7 @@ getargs (int argc, char *argv[])
      usage (EXIT_FAILURE);
    }

-  current_file = grammar_file = uniqstr_new (argv[optind]);
+  grammar_file = uniqstr_new (argv[optind]);
  MUSCLE_INSERT_C_STRING ("file_name", grammar_file);
 }

@@ -41,7 +41,7 @@ extern bool no_lines_flag;              /* for -l */
 extern bool token_table_flag;           /* for -k */
 extern location yacc_loc;               /* for -y */
 extern bool update_flag;                /* for -u */
-extern bool style_debug;                /* --style=debug. */
+extern bool color_debug;                /* --color=debug. */
 /* GLR_PARSER is true if the input file says to use the GLR
   (Generalized LR) parser, and to output some additional information
   used by the GLR algorithm.  */
@@ -118,7 +118,7 @@ enum feature
  {
    feature_none             = 0,      /**< No additional feature.  */
    feature_caret            = 1 << 0, /**< Output errors with carets.  */
-    feature_fixit_parsable   = 1 << 1, /**< Issue instructions to fix the sources.  */
+    feature_fixit            = 1 << 1, /**< Issue instructions to fix the sources.  */
    feature_syntax_only      = 1 << 2, /**< Don't generate output.  */
    feature_all              = ~0      /**< All above features.  */
  };
@@ -32,7 +32,7 @@
 /* Comments for these variables are in gram.h.  */

 item_number *ritem = NULL;
-unsigned nritems = 0;
+int nritems = 0;

 rule *rules = NULL;
 rule_number nrules = 0;
@@ -165,7 +165,7 @@ void
 ritem_print (FILE *out)
 {
  fputs ("RITEM\n", out);
-  for (unsigned i = 0; i < nritems; ++i)
+  for (int i = 0; i < nritems; ++i)
    if (ritem[i] >= 0)
      fprintf (out, "  %s", symbols[ritem[i]]->tag);
    else
@@ -280,8 +280,8 @@ grammar_dump (FILE *out, const char *title)
    for (rule_number i = 0; i < nrules + nuseless_productions; ++i)
      {
        rule const *rule_i = &rules[i];
-        unsigned const rhs_itemno = rule_i->rhs - ritem;
-        unsigned length = rule_rhs_length (rule_i);
+        int const rhs_itemno = rule_i->rhs - ritem;
+        int length = rule_rhs_length (rule_i);
        aver (item_number_as_rule_number (rule_i->rhs[length] == i));
        fprintf (out, "%3d (%2d, %2d, %2s, %2s)   %2d -> (%2u-%2u)",
                 i,
@@ -115,7 +115,7 @@ extern int nvars;
 typedef int item_number;
 # define ITEM_NUMBER_MAX INT_MAX
 extern item_number *ritem;
-extern unsigned nritems;
+extern int nritems;

 /* There is weird relationship between OT1H item_number and OTOH
   symbol_number and rule_number: we store the latter in
@@ -203,7 +203,7 @@ typedef struct
  int expected_rr_conflicts;

  const char *action;
-  location action_location;
+  location action_loc;
 } rule;

 /* The used rules (size NRULES).  */
@@ -78,7 +78,7 @@ static bitset
 ielr_compute_ritem_sees_lookahead_set (void)
 {
  bitset result = bitset_create (nritems, BITSET_FIXED);
-  unsigned i = nritems-1;
+  int i = nritems-1;
  while (0 < i)
    {
      --i;
@@ -418,7 +418,7 @@ ielr_item_has_lookahead (state *s, symbol_number lhs, size_t item,
             top-level invocation), go get it.  */
          if (!lhs)
            {
-              unsigned i;
+              int i;
              for (i = s->items[item];
                   !item_number_is_rule_number (ritem[i]);
                   ++i)
@@ -496,7 +496,7 @@ ielr_compute_annotation_lists (bitsetv follow_kernel_items,
  AnnotationIndex *annotation_counts =
    xnmalloc (nstates, sizeof *annotation_counts);
  ContributionIndex max_contributions = 0;
-  unsigned total_annotations = 0;
+  int total_annotations = 0;

  *inadequacy_listsp = xnmalloc (nstates, sizeof **inadequacy_listsp);
  *annotation_listsp = xnmalloc (nstates, sizeof **annotation_listsp);
@@ -633,7 +633,7 @@ ielr_compute_lookaheads (bitsetv follow_kernel_items, bitsetv always_follows,
        {
          if (item_number_is_rule_number (ritem[t->items[t_item] - 2]))
            {
-              unsigned rule_item;
+              int rule_item;
              for (rule_item = t->items[t_item];
                   !item_number_is_rule_number (ritem[rule_item]);
                   ++rule_item)
@@ -550,6 +550,14 @@ lookahead_tokens_print (FILE *out)
 void
 lalr (void)
 {
+  if (trace_flag & trace_automaton)
+    {
+      fputc ('\n', stderr);
+      begin_use_class ("trace0", stderr);
+      fprintf (stderr, "lalr: begin");
+      end_use_class ("trace0", stderr);
+      fputc ('\n', stderr);
+    }
  initialize_LA ();
  set_goto_map ();
  initialize_goto_follows ();
@@ -560,6 +568,13 @@ lalr (void)

  if (trace_flag & trace_sets)
    lookahead_tokens_print (stderr);
+  if (trace_flag & trace_automaton)
+    {
+      begin_use_class ("trace0", stderr);
+      fprintf (stderr, "lalr: done");
+      end_use_class ("trace0", stderr);
+      fputc ('\n', stderr);
+    }
 }


@@ -21,16 +21,67 @@
 #include <config.h>
 #include "system.h"

+#include <mbfile.h>
 #include <mbswidth.h>
 #include <quotearg.h>
 #include <stdio.h>    /* fileno */
+#include <sys/ioctl.h>
 #include <sys/stat.h> /* fstat */
+#include <termios.h>
+
+#ifdef WINSIZE_IN_PTEM
+# include <sys/stream.h>
+# include <sys/ptem.h>
+#endif

 #include "complain.h"
 #include "getargs.h"
 #include "location.h"

-location const empty_location = EMPTY_LOCATION_INIT;
+location const empty_loc = EMPTY_LOCATION_INIT;
+
+static int
+min_int (int a, int b)
+{
+  return a < b ? a : b;
+}
+
+static int
+max_int (int a, int b)
+{
+  return a >= b ? a : b;
+}
+
+/* The terminal width.  Not less than 40.  */
+static int
+columns (void)
+{
+  const char *cp = getenv ("COLUMNS");
+  int res = 80;
+  if (cp && *cp)
+    {
+      long l = strtol (cp, NULL, 10);
+      res = 0 <= l && l <= INT_MAX ? l : INT_MAX;
+    }
+  else
+    {
+#ifdef TIOCGWINSZ
+      struct winsize ws;
+      if (ioctl (STDERR_FILENO, TIOCGWINSZ, &ws) != -1
+          && 0 < ws.ws_col && ws.ws_col == (size_t) ws.ws_col)
+        res = ws.ws_col;
+#endif
+    }
+  return max_int (res, 40);
+}
+
+/* Available screen width.  */
+static int screen_width = 80;
+
+/* The ellipsis symbol to use for this locale, and the number of
+   screen-columns it uses.  */
+static const char *ellipsis = "...";
+static int ellipsize = 3;

 /* If BUF is null, add BUFSIZE (which in this case must be less than
   INT_MAX) to COLUMN; otherwise, add mbsnwidth (BUF, BUFSIZE, 0) to
@@ -46,11 +97,8 @@ add_column_width (int column, char const *buf, size_t bufsize)
  return column <= INT_MAX - width ? column + width : INT_MAX;
 }

-/* Set *LOC and adjust scanner cursor to account for token TOKEN of
-   size SIZE.  */
-
-void
-location_compute (location *loc, boundary *cur, char const *token, size_t size)
+static void
+boundary_compute (boundary *cur, char const *token, size_t size)
 {
  int line = cur->line;
  int column = cur->column;
@@ -59,8 +107,6 @@ location_compute (location *loc, boundary *cur, char const *token, size_t size)
  char const *p = token;
  char const *lim = token + size;

-  loc->start = *cur;
-
  for (p = token; p < lim; ++p)
    switch (*p)
      {
@@ -82,22 +128,34 @@ location_compute (location *loc, boundary *cur, char const *token, size_t size)
        byte += byte < INT_MAX;
        break;
      }
+  column = add_column_width (column, p0, p - p0);

  cur->line = line;
-  cur->column = column = add_column_width (column, p0, p - p0);
+  cur->column = column;
  cur->byte = byte;
+}

+
+/* Set *LOC and adjust scanner cursor to account for token TOKEN of
+   size SIZE.  */
+
+void
+location_compute (location *loc, boundary *cur, char const *token, size_t size)
+{
+  loc->start = *cur;
+  boundary_compute (cur, token, size);
  loc->end = *cur;

-  if (line == INT_MAX && loc->start.line != INT_MAX)
+  if (loc->end.line == INT_MAX && loc->start.line != INT_MAX)
    complain (loc, Wother, _("line number overflow"));
-  if (column == INT_MAX && loc->start.column != INT_MAX)
+  if (loc->end.column == INT_MAX && loc->start.column != INT_MAX)
    complain (loc, Wother, _("column number overflow"));
-  if (byte == INT_MAX && loc->start.byte != INT_MAX)
+  /* TRANSLATORS: we are counting bytes, and there are too many.  */
+  if (loc->end.byte == INT_MAX && loc->start.byte != INT_MAX)
    complain (loc, Wother, _("byte number overflow"));
 }

-static unsigned
+static int
 boundary_print (boundary const *b, FILE *out)
 {
  return fprintf (out, "%s:%d.%d@%d",
@@ -105,10 +163,10 @@ boundary_print (boundary const *b, FILE *out)
                  b->line, b->column, b->byte);
 }

-unsigned
+int
 location_print (location loc, FILE *out)
 {
-  unsigned res = 0;
+  int res = 0;
  if (trace_flag & trace_locations)
    {
      res += boundary_print (&loc.start, out);
@@ -120,10 +178,10 @@ location_print (location loc, FILE *out)
      int end_col = 0 != loc.end.column ? loc.end.column - 1 : 0;
      res += fprintf (out, "%s",
                      quotearg_n_style (3, escape_quoting_style, loc.start.file));
-      if (0 <= loc.start.line)
+      if (0 < loc.start.line)
        {
          res += fprintf (out, ":%d", loc.start.line);
-          if (0 <= loc.start.column)
+          if (0 < loc.start.column)
            res += fprintf (out, ".%d", loc.start.column);
        }
      if (loc.start.file != loc.end.file)
@@ -131,14 +189,14 @@ location_print (location loc, FILE *out)
          res += fprintf (out, "-%s",
                          quotearg_n_style (3, escape_quoting_style,
                                            loc.end.file));
-          if (0 <= loc.end.line)
+          if (0 < loc.end.line)
            {
              res += fprintf (out, ":%d", loc.end.line);
              if (0 <= end_col)
                res += fprintf (out, ".%d", end_col);
            }
        }
-      else if (0 <= loc.end.line)
+      else if (0 < loc.end.line)
        {
          if (loc.start.line < loc.end.line)
            {
@@ -159,128 +217,286 @@ location_print (location loc, FILE *out)
   same file all over for each error.  */
 static struct
 {
-  FILE *source;
-  /* The last file we tried to open.  If non NULL, but SOURCE is NULL,
-     it means this file is special and should not be quoted. */
-  uniqstr file;
-  size_t line;
-  /* Offset in SOURCE where line LINE starts.  */
+  /* Raw input file.  */
+  FILE *file;
+  /* Input file as a stream of multibyte characters.  */
+  mb_file_t mbfile;
+  /* The position within the last file we quoted.  If POS.FILE is non
+     NULL, but FILE is NULL, it means this file is special and should
+     not be quoted. */
+  boundary pos;
+  /* Offset in FILE of the current line (i.e., where line POS.LINE
+     starts).  */
  size_t offset;
+  /* Length of the current line.  */
+  int line_len;
+  /* Given the initial column to display, the offset (number of
+     characters to skip at the beginning of the line). */
+  int skip;
+
+  /* Available width to quote the source file.  Eight chars are
+     consumed by the left-margin (with line number).  */
+  int width;
 } caret_info;

-void
-caret_free ()
+void caret_init (void)
 {
-  if (caret_info.source)
-    {
-      fclose (caret_info.source);
-      caret_info.source = NULL;
-    }
+  screen_width = columns ();
+  /* TRANSLATORS: This is used when a line is too long, and is
+     displayed truncated.  Use an ellipsis appropriate for your
+     language, remembering that "…" (U+2026 HORIZONTAL ELLIPSIS)
+     sometimes misdisplays and that "..." (three ASCII periods) is a
+     safer choice in some locales.  */
+  ellipsis = _("...");
+  ellipsize = mbswidth (ellipsis, 0);
 }

 void
-location_caret (location loc, const char *style, FILE *out)
+caret_free (void)
 {
-  if (loc.start.column == -1 || loc.start.line == -1)
-    return;
-  /* If a different source than before, close and let the rest open
-     the new one. */
-  if (caret_info.file && caret_info.file != loc.start.file)
+  if (caret_info.file)
    {
-      caret_free ();
+      fclose (caret_info.file);
      caret_info.file = NULL;
    }
-  if (!caret_info.file)
+}
+
+/* Open FILE for quoting, if needed, and if possible.  Return whether
+   the file can quoted. */
+static bool
+caret_set_file (const char *file)
+{
+  /* If a different file than before, close and let the rest open
+     the new one. */
+  if (caret_info.pos.file && caret_info.pos.file != file)
    {
-      caret_info.file = loc.start.file;
-      if ((caret_info.source = fopen (caret_info.file, "r")))
+      caret_free ();
+      caret_info.pos.file = NULL;
+    }
+  if (!caret_info.pos.file)
+    {
+      caret_info.pos.file = file;
+      if ((caret_info.file = fopen (caret_info.pos.file, "r")))
        {
          /* If the file is not regular (imagine #line 1 "/dev/stdin"
             in the input file for instance), don't try to quote the
-             source.  Keep caret_info.file set so that we don't try to
-             open it again, but leave caret_info.source NULL so that
-             we don't try to quote it. */
+             file.  Keep caret_info.file set so that we don't try to
+             open it again, but leave caret_info.file NULL so that we
+             don't try to quote it. */
          struct stat buf;
-          if (fstat (fileno (caret_info.source), &buf) == 0
+          if (fstat (fileno (caret_info.file), &buf) == 0
              && buf.st_mode & S_IFREG)
            {
-              caret_info.line = 1;
-              caret_info.offset = 0;
+              caret_info.pos.line = 1;
+              mbf_init (caret_info.mbfile, caret_info.file);
            }
          else
            caret_free ();
        }
    }
-  if (!caret_info.source)
-    return;
+  return !!caret_info.file;
+}

+/* Getc, but smash \r\n as \n.  */
+static void
+caret_getc_internal (mbchar_t *res)
+{
+  mbf_getc (*res, caret_info.mbfile);
+  if (mb_iseq (*res, '\r'))
+    {
+      mbchar_t c;
+      mbf_getc (c, caret_info.mbfile);
+      if (mb_iseq (c, '\n'))
+        mb_copy (res, &c);
+      else
+        mbf_ungetc (c, caret_info.mbfile);
+    }
+}

+#define caret_getc(Var) caret_getc_internal(&Var)
+
+/* Move CARET_INFO (which has a valid FILE) to the line number LINE.
+   Compute and cache that line's length in CARET_INFO.LINE_LEN.
+   Return whether succesful.*/
+static bool
+caret_set_line (int line)
+{
  /* If the line we want to quote is seekable (the same line as the previous
     location), just seek it. If it was a previous line, we lost track of it,
     so return to the start of file.  */
-  if (caret_info.line <= loc.start.line)
-    fseek (caret_info.source, caret_info.offset, SEEK_SET);
-  else
+  if (line < caret_info.pos.line)
    {
-      caret_info.line = 1;
+      caret_info.pos.line = 1;
      caret_info.offset = 0;
-      fseek (caret_info.source, caret_info.offset, SEEK_SET);
    }
+  if (fseek (caret_info.file, caret_info.offset, SEEK_SET))
+    return false;
+
+  /* If this is the same line as the previous one, we are done. */
+  if (line < caret_info.pos.line)
+    return true;

  /* Advance to the line's position, keeping track of the offset.  */
-  while (caret_info.line < loc.start.line)
-    caret_info.line += getc (caret_info.source) == '\n';
-  caret_info.offset = ftell (caret_info.source);
+  while (caret_info.pos.line < line)
+    {
+      mbchar_t c;
+      caret_getc (c);
+      if (mb_iseof (c))
+        /* Something is wrong, that line number does not exist.  */
+        return false;
+      caret_info.pos.line += mb_iseq (c, '\n');
+    }
+  caret_info.offset = ftell (caret_info.file);
+  caret_info.pos.column = 1;
+  /* Reset mbf's internal state.
+     FIXME: should be done in mbfile.  */
+  caret_info.mbfile.eof_seen = 0;
+
+  /* Find the number of columns of this line.  */
+  while (true)
+    {
+      mbchar_t c;
+      caret_getc (c);
+      if (mb_iseof (c) || mb_iseq (c, '\n'))
+        break;
+      boundary_compute (&caret_info.pos, mb_ptr (c), mb_len (c));
+    }
+  caret_info.line_len = caret_info.pos.column;
+  /* Go back to the beginning of line.  */
+  if (fseek (caret_info.file, caret_info.offset, SEEK_SET))
+    return false;
+  /* Reset mbf's internal state.
+     FIXME: should be done in mbfile.  */
+  caret_info.mbfile.eof_seen = 0;
+  caret_info.pos.column = 1;
+  return true;
+}
+
+/* Compute CARET_INFO.WIDTH and CARET_INFO.SKIP based on the fact that
+   the first column to display in the current line is COL.  */
+static bool
+caret_set_column (int col)
+{
+  /* Available width.  Eight chars are consumed by the left-margin
+     (with line number).  */
+  caret_info.width = screen_width - 8;
+  caret_info.skip = 0;
+  if (caret_info.width < caret_info.line_len)
+    {
+      /* We cannot quote the whole line.  Make sure we can see the
+         beginning of the location.  */
+      caret_info.skip = caret_info.width < col ? col - 10 : 0;
+    }
+  /* If we skip the initial part, we insert "..." before.  */
+  if (caret_info.skip)
+    caret_info.width -= ellipsize;
+  /* If the end of line does not fit, we also need to truncate the
+     end, and leave "..." there.  */
+  if (caret_info.width < caret_info.line_len - caret_info.skip)
+    caret_info.width -= ellipsize;
+  return true;
+}
+
+void
+location_caret (location loc, const char *style, FILE *out)
+{
+  if (!loc.start.line)
+    return;
+  if (!caret_set_file (loc.start.file))
+    return;
+  if (!caret_set_line (loc.start.line))
+    return;
+  if (!caret_set_column (loc.start.column))
+    return;
+
+  const int width = caret_info.width;
+  const int skip = caret_info.skip;

  /* Read the actual line.  Don't update the offset, so that we keep a pointer
     to the start of the line.  */
  {
-    int c = getc (caret_info.source);
-    if (c != EOF)
+    mbchar_t c;
+    caret_getc (c);
+    if (!mb_iseof (c))
      {
+        /* The last column to highlight.  Only the first line of
+           multiline locations are quoted, in which case the ending
+           column is the end of line.  Single point locations (with
+           equal boundaries) denote the character that they
+           follow.  */
+        int col_end
+          = loc.start.line == loc.end.line
+          ? loc.end.column + (loc.start.column == loc.end.column)
+          : caret_info.line_len;
        /* Quote the file (at most the first line in the case of
           multiline locations).  */
-        fprintf (out, "%5d | ", loc.start.line);
-        bool single_line = loc.start.line == loc.end.line;
-        /* Consider that single point location (with equal boundaries)
-           actually denote the character that they follow.  */
-        int byte_end = loc.end.byte +
-          (single_line && loc.start.byte == loc.end.byte);
-        /* Byte number.  */
-        int byte = 1;
-        while (c != EOF && c != '\n')
-          {
-            if (byte == loc.start.byte)
-              begin_use_class (style, out);
-            fputc (c, out);
-            c = getc (caret_info.source);
-            ++byte;
-            if (single_line
-                ? byte == byte_end
-                : c == '\n' || c == EOF)
-              end_use_class (style, out);
-          }
-        putc ('\n', out);
-
        {
-          /* Print the carets with the same indentation as above.  */
-          fprintf (out, "      | %*s", loc.start.column - 1, "");
+          fprintf (out, "%5d | %s", loc.start.line, skip ? ellipsis : "");
+          /* Whether we opened the style.  If the line is not as
+             expected (maybe the file was changed since the scanner
+             ran), we might reach the end before we actually saw the
+             opening column.  */
+          bool opened = false;
+          while (!mb_iseof (c) && !mb_iseq (c, '\n'))
+            {
+              if (caret_info.pos.column == loc.start.column)
+                {
+                  begin_use_class (style, out);
+                  opened = true;
+                }
+              if (skip < caret_info.pos.column)
+                mb_putc (c, out);
+              boundary_compute (&caret_info.pos, mb_ptr (c), mb_len (c));
+              caret_getc (c);
+              if (opened
+                  && (caret_info.pos.column == col_end
+                      || width < caret_info.pos.column - skip))
+                {
+                  end_use_class (style, out);
+                  opened = false;
+                }
+              if (width < caret_info.pos.column - skip)
+                {
+                  fputs (ellipsis, out);
+                  break;
+                }
+            }
+          putc ('\n', out);
+        }
+
+        /* Print the carets with the same indentation as above.  */
+        {
+          fprintf (out, "      | %*s",
+                   loc.start.column - 1 - skip + (skip ? ellipsize : 0), "");
          begin_use_class (style, out);
          putc ('^', out);
          /* Underlining a multiline location ends with the first
             line.  */
-          int len = single_line
-            ? loc.end.column
-            : ftell (caret_info.source) - caret_info.offset;
-          for (int i = loc.start.column + 1; i < len; ++i)
+          for (int i = loc.start.column - 1 - skip + 1,
+                 i_end = min_int (col_end - 1 - skip, width);
+               i < i_end; ++i)
            putc ('~', out);
          end_use_class (style, out);
+          putc ('\n', out);
        }
-        putc ('\n', out);
      }
  }
 }

+void
+location_caret_suggestion (location loc, const char *s, FILE *out)
+{
+  const char *style = "fixit-insert";
+  fprintf (out, "      | %*s",
+           loc.start.column - 1 - caret_info.skip
+           + (caret_info.skip ? ellipsize : 0),
+           "");
+  begin_use_class (style, out);
+  fputs (s, out);
+  end_use_class (style, out);
+  putc ('\n', out);
+}
+
 bool
 location_empty (location loc)
 {
@@ -33,25 +33,25 @@ typedef struct
  /* The name of the file that contains the boundary.  */
  uniqstr file;

-  /* If nonnegative, the (origin-1) line that contains the boundary.
+  /* If positive, the line (starting at 1) that contains the boundary.
     If this is INT_MAX, the line number has overflowed.

-     Meaningless and not displayed if negative.
+     Meaningless and not displayed if nonpositive.
  */
  int line;

-  /* If nonnegative, the (origin-1) column just after the boundary.
+  /* If positive, the column (starting at 1) just after the boundary.
     This is neither a byte count, nor a character count; it is a
     column count.  If this is INT_MAX, the column number has
     overflowed.

-     Meaningless and not displayed if negative.
+     Meaningless and not displayed if nonpositive.
  */
  int column;

-  /* If nonnegative, (origin-0) bytes number in the current line.
+  /* If nonnegative, the byte number (starting at 0) in the current line.
     Never displayed, used when printing error messages with colors to
-     know where colors start and ends.  */
+     know where colors start and end.  */
  int byte;

 } boundary;
@@ -71,7 +71,12 @@ boundary_set (boundary *p, const char *f, int l, int c, int b)
 static inline int
 boundary_cmp (boundary a, boundary b)
 {
-  int res = strcmp (a.file, b.file);
+  /* Locations with no file first.  */
+  int res =
+    a.file && b.file ? strcmp (a.file, b.file)
+    : a.file ? 1
+    : b.file ? -1
+    : 0;
  if (!res)
    res = a.line - b.line;
  if (!res)
@@ -102,7 +107,7 @@ typedef struct
 # define GRAM_LTYPE location

 # define EMPTY_LOCATION_INIT {{NULL, 0, 0, 0}, {NULL, 0, 0, 0}}
-extern location const empty_location;
+extern location const empty_loc;

 /* Set *LOC and adjust scanner cursor to account for token TOKEN of
   size SIZE.  */
@@ -112,15 +117,23 @@ void location_compute (location *loc,
 /* Print location to file.
   Return number of actually printed characters.
   Warning: uses quotearg's slot 3. */
-unsigned location_print (location loc, FILE *out);
+int location_print (location loc, FILE *out);
+
+/* Prepare the use of location_caret.  */
+void caret_init (void);

 /* Free any allocated resources and close any open file handles that are
   left-over by the usage of location_caret.  */
 void caret_free (void);

-/* Output to OUT the line and caret corresponding to location LOC.  */
+/* Quote the line containing LOC onto OUT.  Highlight the part of LOC
+   with the color STYLE.  */
 void location_caret (location loc, const char* style, FILE *out);

+/* Display a suggestion of replacement for LOC with S.  To call after
+   location_caret.  */
+void location_caret_suggestion (location loc, const char *s, FILE *out);
+
 /* Return -1, 0, 1, depending whether a is before, equal, or
   after b.  */
 static inline int
@@ -158,6 +158,14 @@ kernel_print (FILE *out)
      }
 }

+/* Make sure the kernel is in sane state. */
+static void
+kernel_check (void)
+{
+  for (symbol_number i = 0; i < nsyms - 1; ++i)
+    assert (kernel_base[i] + kernel_size[i] <= kernel_base[i + 1]);
+}
+
 static void
 allocate_storage (void)
 {
@@ -209,9 +217,21 @@ new_itemsets (state *s)

  bitset_zero (shift_symbol);

+  if (trace_flag & trace_automaton)
+    {
+      fprintf (stderr, "initial kernel:\n");
+      kernel_print (stderr);
+    }
+
  for (size_t i = 0; i < nitemset; ++i)
    if (item_number_is_symbol_number (ritem[itemset[i]]))
      {
+        if (trace_flag & trace_automaton)
+          {
+            fputs ("working on: ", stderr);
+            item_print (ritem + itemset[i], NULL, stderr);
+            fputc ('\n', stderr);
+          }
        symbol_number sym = item_number_as_symbol_number (ritem[itemset[i]]);
        bitset_set (shift_symbol, sym);
        kernel_base[sym][kernel_size[sym]] = itemset[i] + 1;
@@ -220,9 +240,11 @@ new_itemsets (state *s)

  if (trace_flag & trace_automaton)
    {
+      fprintf (stderr, "final kernel:\n");
      kernel_print (stderr);
      fprintf (stderr, "new_itemsets: end: state = %d\n\n", s->number);
    }
+  kernel_check ();
 }


@@ -309,6 +331,17 @@ save_reductions (state *s)
        }
    }

+  if (trace_flag & trace_automaton)
+    {
+      fprintf (stderr, "reduction[%d] = {\n", s->number);
+      for (int i = 0; i < count; ++i)
+        {
+          rule_print (redset[i], NULL, stderr);
+          fputc ('\n', stderr);
+        }
+      fputs ("}\n", stderr);
+    }
+
  /* Make a reductions structure and copy the data into it.  */
  state_reductions_set (s, count, redset);
 }
@@ -101,7 +101,7 @@ main (int argc, char *argv[])
     the grammar; see gram.h.  */

  timevar_push (tv_reader);
-  reader ();
+  reader (grammar_file);
  timevar_pop (tv_reader);

  if (complaint_status == status_complaint)
@@ -207,6 +207,8 @@ main (int argc, char *argv[])
      timevar_pop (tv_parser);
    }

+ finish:
+
  timevar_push (tv_free);
  nullable_free ();
  derives_free ();
@@ -223,14 +225,11 @@ main (int argc, char *argv[])
  muscle_free ();
  code_scanner_free ();
  skel_scanner_free ();
-  quotearg_free ();
  timevar_pop (tv_free);

  if (trace_flag & trace_bitsets)
    bitset_stats_dump (stderr);

- finish:
-
  /* Stop timing and print the times.  */
  timevar_stop (tv_total);
  timevar_print (stderr);
@@ -249,6 +248,7 @@ main (int argc, char *argv[])
  uniqstrs_free ();

  complain_free ();
+  quotearg_free ();

  return complaint_status ? EXIT_FAILURE : EXIT_SUCCESS;
 }
@@ -126,8 +126,8 @@ muscle_init (void)
  /* Initialize the muscle obstack.  */
  obstack_init (&muscle_obstack);

-  muscle_table = hash_initialize (HT_INITIAL_CAPACITY, NULL, hash_muscle,
-                                  hash_compare_muscles, muscle_entry_free);
+  muscle_table = hash_xinitialize (HT_INITIAL_CAPACITY, NULL, hash_muscle,
+                                   hash_compare_muscles, muscle_entry_free);

  /* Version and input file.  */
  MUSCLE_INSERT_STRING ("version", VERSION);
@@ -525,7 +525,7 @@ muscle_percent_define_insert (char const *var, location variable_loc,
            = atoi (muscle_find_const (how_name));
          if (how_old == MUSCLE_PERCENT_DEFINE_F)
            goto end;
-          unsigned i = 0;
+          int i = 0;
          /* If assigning the same value, make it a warning.  */
          warnings warn = STREQ (value, current_value) ? Wother : complaint;
          complain_indent (&variable_loc, warn, &i,
@@ -739,7 +739,7 @@ muscle_percent_define_check_values (char const * const *values)
          if (!*values)
            {
              location loc = muscle_percent_define_get_loc (*variablep);
-              unsigned i = 0;
+              int i = 0;
              complain_indent (&loc, complaint, &i,
                               _("invalid value for %%define variable %s: %s"),
                               quote (*variablep), quote_n (1, value));
@@ -91,7 +91,6 @@ Name (char const *name, Type *table_data, Type first,                   \
  MUSCLE_INSERT_LONG_INT (obstack_finish0 (&format_obstack), lmax);     \
 }

-GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_unsigned_table, unsigned)
 GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_int_table, int)
 GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_base_table, base_number)
 GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_rule_number_table, rule_number)
@@ -214,17 +213,17 @@ prepare_symbols (void)
 static void
 prepare_rules (void)
 {
-  unsigned *prhs = xnmalloc (nrules, sizeof *prhs);
+  int *prhs = xnmalloc (nrules, sizeof *prhs);
  item_number *rhs = xnmalloc (nritems, sizeof *rhs);
-  unsigned *rline = xnmalloc (nrules, sizeof *rline);
+  int *rline = xnmalloc (nrules, sizeof *rline);
  symbol_number *r1 = xnmalloc (nrules, sizeof *r1);
-  unsigned *r2 = xnmalloc (nrules, sizeof *r2);
+  int *r2 = xnmalloc (nrules, sizeof *r2);
  int *dprec = xnmalloc (nrules, sizeof *dprec);
  int *merger = xnmalloc (nrules, sizeof *merger);
  int *immediate = xnmalloc (nrules, sizeof *immediate);

  /* Index in RHS.  */
-  unsigned i = 0;
+  int i = 0;
  for (rule_number r = 0; r < nrules; ++r)
    {
      /* Index of rule R in RHS. */
@@ -251,10 +250,10 @@ prepare_rules (void)
  aver (i == nritems);

  muscle_insert_item_number_table ("rhs", rhs, ritem[0], 1, nritems);
-  muscle_insert_unsigned_table ("prhs", prhs, 0, 0, nrules);
-  muscle_insert_unsigned_table ("rline", rline, 0, 0, nrules);
+  muscle_insert_int_table ("prhs", prhs, 0, 0, nrules);
+  muscle_insert_int_table ("rline", rline, 0, 0, nrules);
  muscle_insert_symbol_number_table ("r1", r1, 0, 0, nrules);
-  muscle_insert_unsigned_table ("r2", r2, 0, 0, nrules);
+  muscle_insert_int_table ("r2", r2, 0, 0, nrules);
  muscle_insert_int_table ("dprec", dprec, 0, 0, nrules);
  muscle_insert_int_table ("merger", merger, 0, 0, nrules);
  muscle_insert_int_table ("immediate", immediate, 0, 0, nrules);
@@ -359,9 +358,9 @@ symbol_numbers_output (FILE *out)
 }


-/*---------------------------------.
-| Output the user actions to OUT.  |
-`---------------------------------*/
+/*-------------------------------------------.
+| Output the user reduction actions to OUT.  |
+`-------------------------------------------*/

 static void
 user_actions_output (FILE *out)
@@ -370,11 +369,20 @@ user_actions_output (FILE *out)
  for (rule_number r = 0; r < nrules; ++r)
    if (rules[r].action)
      {
-        fprintf (out, "%s(%d, [b4_syncline(%d, ",
+        /* The useless "" is there to pacify syntax-check.  */
+        fprintf (out, "%s""(%d, [",
                 rules[r].is_predicate ? "b4_predicate_case" : "b4_case",
-                 r + 1, rules[r].action_location.start.line);
-        string_output (out, rules[r].action_location.start.file);
-        fprintf (out, ")dnl\n[    %s]])\n\n", rules[r].action);
+                 r + 1);
+        if (!no_lines_flag)
+          {
+            fprintf (out, "b4_syncline(%d, ",
+                     rules[r].action_loc.start.line);
+            string_output (out, rules[r].action_loc.start.file);
+            fprintf (out, ")dnl\n");
+          }
+        fprintf (out, "[%*s%s]])\n\n",
+                 rules[r].action_loc.start.column - 1, "",
+                 rules[r].action);
      }
  fputs ("])\n\n", out);
 }
@@ -482,7 +490,9 @@ prepare_symbol_definitions (void)
              muscle_location_grow (key, p->location);

              SET_KEY (pname);
-              MUSCLE_INSERT_STRING_RAW (key, p->code);
+              obstack_printf (&muscle_obstack,
+                              "%*s%s", p->location.start.column - 1, "", p->code);
+              muscle_insert (key, obstack_finish0 (&muscle_obstack));
            }
        }
 #undef SET_KEY2
@@ -532,10 +542,10 @@ prepare_actions (void)
     parser, so we could avoid accidents by not writing them out in
     that case.  Nevertheless, it seems even better to be able to use
     the GLR skeletons even without the non-deterministic tables.  */
-  muscle_insert_unsigned_table ("conflict_list_heads", conflict_table,
-                                conflict_table[0], 1, high + 1);
-  muscle_insert_unsigned_table ("conflicting_rules", conflict_list,
-                                0, 1, conflict_list_cnt);
+  muscle_insert_int_table ("conflict_list_heads", conflict_table,
+                           conflict_table[0], 1, high + 1);
+  muscle_insert_int_table ("conflicting_rules", conflict_list,
+                           0, 1, conflict_list_cnt);
 }


@@ -1,4 +1,4 @@
-/* A Bison parser, made by GNU Bison 3.3.2.153-f5a4-dirty.  */
+/* A Bison parser, made by GNU Bison 3.4.2.213-aa24.  */

 /* Bison interface for Yacc-like parsers in C

@@ -78,62 +78,63 @@ extern int gram_debug;
  enum gram_tokentype
  {
    GRAM_EOF = 0,
-    STRING = 258,
-    PERCENT_TOKEN = 259,
-    PERCENT_NTERM = 260,
-    PERCENT_TYPE = 261,
-    PERCENT_DESTRUCTOR = 262,
-    PERCENT_PRINTER = 263,
-    PERCENT_LEFT = 264,
-    PERCENT_RIGHT = 265,
-    PERCENT_NONASSOC = 266,
-    PERCENT_PRECEDENCE = 267,
-    PERCENT_PREC = 268,
-    PERCENT_DPREC = 269,
-    PERCENT_MERGE = 270,
-    PERCENT_CODE = 271,
-    PERCENT_DEFAULT_PREC = 272,
-    PERCENT_DEFINE = 273,
-    PERCENT_DEFINES = 274,
-    PERCENT_ERROR_VERBOSE = 275,
-    PERCENT_EXPECT = 276,
-    PERCENT_EXPECT_RR = 277,
-    PERCENT_FLAG = 278,
-    PERCENT_FILE_PREFIX = 279,
-    PERCENT_GLR_PARSER = 280,
-    PERCENT_INITIAL_ACTION = 281,
-    PERCENT_LANGUAGE = 282,
-    PERCENT_NAME_PREFIX = 283,
-    PERCENT_NO_DEFAULT_PREC = 284,
-    PERCENT_NO_LINES = 285,
-    PERCENT_NONDETERMINISTIC_PARSER = 286,
-    PERCENT_OUTPUT = 287,
-    PERCENT_REQUIRE = 288,
-    PERCENT_SKELETON = 289,
-    PERCENT_START = 290,
-    PERCENT_TOKEN_TABLE = 291,
-    PERCENT_VERBOSE = 292,
-    PERCENT_YACC = 293,
-    BRACED_CODE = 294,
-    BRACED_PREDICATE = 295,
-    BRACKETED_ID = 296,
-    CHAR = 297,
-    COLON = 298,
-    EPILOGUE = 299,
-    EQUAL = 300,
-    ID = 301,
-    ID_COLON = 302,
-    PERCENT_PERCENT = 303,
-    PIPE = 304,
-    PROLOGUE = 305,
-    SEMICOLON = 306,
-    TAG = 307,
-    TAG_ANY = 308,
-    TAG_NONE = 309,
-    INT = 310,
-    PERCENT_PARAM = 311,
-    PERCENT_UNION = 312,
-    PERCENT_EMPTY = 313
+    STRING = 3,
+    PERCENT_TOKEN = 4,
+    PERCENT_NTERM = 5,
+    PERCENT_TYPE = 6,
+    PERCENT_DESTRUCTOR = 7,
+    PERCENT_PRINTER = 8,
+    PERCENT_LEFT = 9,
+    PERCENT_RIGHT = 10,
+    PERCENT_NONASSOC = 11,
+    PERCENT_PRECEDENCE = 12,
+    PERCENT_PREC = 13,
+    PERCENT_DPREC = 14,
+    PERCENT_MERGE = 15,
+    PERCENT_CODE = 16,
+    PERCENT_DEFAULT_PREC = 17,
+    PERCENT_DEFINE = 18,
+    PERCENT_DEFINES = 19,
+    PERCENT_ERROR_VERBOSE = 20,
+    PERCENT_EXPECT = 21,
+    PERCENT_EXPECT_RR = 22,
+    PERCENT_FLAG = 23,
+    PERCENT_FILE_PREFIX = 24,
+    PERCENT_GLR_PARSER = 25,
+    PERCENT_INITIAL_ACTION = 26,
+    PERCENT_LANGUAGE = 27,
+    PERCENT_NAME_PREFIX = 28,
+    PERCENT_NO_DEFAULT_PREC = 29,
+    PERCENT_NO_LINES = 30,
+    PERCENT_NONDETERMINISTIC_PARSER = 31,
+    PERCENT_OUTPUT = 32,
+    PERCENT_PURE_PARSER = 33,
+    PERCENT_REQUIRE = 34,
+    PERCENT_SKELETON = 35,
+    PERCENT_START = 36,
+    PERCENT_TOKEN_TABLE = 37,
+    PERCENT_VERBOSE = 38,
+    PERCENT_YACC = 39,
+    BRACED_CODE = 40,
+    BRACED_PREDICATE = 41,
+    BRACKETED_ID = 42,
+    CHAR = 43,
+    COLON = 44,
+    EPILOGUE = 45,
+    EQUAL = 46,
+    ID = 47,
+    ID_COLON = 48,
+    PERCENT_PERCENT = 49,
+    PIPE = 50,
+    PROLOGUE = 51,
+    SEMICOLON = 52,
+    TAG = 53,
+    TAG_ANY = 54,
+    TAG_NONE = 55,
+    INT = 56,
+    PERCENT_PARAM = 57,
+    PERCENT_UNION = 58,
+    PERCENT_EMPTY = 59
  };
 #endif

@@ -159,9 +160,9 @@ union GRAM_STYPE
  /* "integer"  */
  int INT;
  /* int.opt  */
-  int yytype_80;
+  int yytype_81;
  /* named_ref.opt  */
-  named_ref* yytype_92;
+  named_ref* yytype_93;
  /* "%param"  */
  param_type PERCENT_PARAM;
  /* token_decl  */
@@ -177,7 +178,7 @@ union GRAM_STYPE
  /* string_as_id  */
  symbol* string_as_id;
  /* string_as_id.opt  */
-  symbol* yytype_99;
+  symbol* yytype_100;
  /* generic_symlist  */
  symbol_list* generic_symlist;
  /* generic_symlist_item  */
@@ -187,15 +188,15 @@ union GRAM_STYPE
  /* token_decls  */
  symbol_list* token_decls;
  /* token_decl.1  */
-  symbol_list* yytype_78;
+  symbol_list* yytype_79;
  /* token_decls_for_prec  */
  symbol_list* token_decls_for_prec;
  /* token_decl_for_prec.1  */
-  symbol_list* yytype_82;
+  symbol_list* yytype_83;
  /* symbol_decls  */
  symbol_list* symbol_decls;
  /* symbol_decl.1  */
-  symbol_list* yytype_85;
+  symbol_list* yytype_86;
  /* "%error-verbose"  */
  uniqstr PERCENT_ERROR_VERBOSE;
  /* "%<flag>"  */
@@ -204,8 +205,8 @@ union GRAM_STYPE
  uniqstr PERCENT_FILE_PREFIX;
  /* "%name-prefix"  */
  uniqstr PERCENT_NAME_PREFIX;
-  /* "%yacc"  */
-  uniqstr PERCENT_YACC;
+  /* "%pure-parser"  */
+  uniqstr PERCENT_PURE_PARSER;
  /* "[identifier]"  */
  uniqstr BRACKETED_ID;
  /* "identifier"  */
@@ -215,12 +216,12 @@ union GRAM_STYPE
  /* "<tag>"  */
  uniqstr TAG;
  /* tag.opt  */
-  uniqstr yytype_72;
+  uniqstr yytype_73;
  /* tag  */
  uniqstr tag;
  /* variable  */
  uniqstr variable;
-  /* "char"  */
+  /* "character literal"  */
  unsigned char CHAR;
  /* value  */
  value_type value;
@@ -32,24 +32,26 @@
 %code
 {
  #include "system.h"
-  #include <errno.h>

-  #include "c-ctype.h"
+  #include <c-ctype.h>
+  #include <errno.h>
+  #include <intprops.h>
+  #include <quotearg.h>
+  #include <vasnprintf.h>
+  #include <xmemdup0.h>
+
  #include "complain.h"
  #include "conflicts.h"
  #include "files.h"
  #include "getargs.h"
  #include "gram.h"
  #include "named-ref.h"
-  #include "quotearg.h"
  #include "reader.h"
  #include "scan-code.h"
  #include "scan-gram.h"
-  #include "vasnprintf.h"
-  #include "xmemdup0.h"

  static int current_prec = 0;
-  static location current_lhs_location;
+  static location current_lhs_loc;
  static named_ref *current_lhs_named_ref;
  static symbol *current_lhs_symbol;
  static symbol_class current_class = unknown_sym;
@@ -94,6 +96,9 @@
  static void handle_name_prefix (location const *loc,
                                  char const *directive, char const *value);

+  /* Handle a %pure-parser directive.  */
+  static void handle_pure_parser (location const *loc, char const *directive);
+
  /* Handle a %require directive.  */
  static void handle_require (location const *loc, char const *version);

@@ -101,18 +106,14 @@
  static void handle_skeleton (location const *loc, char const *skel);

  /* Handle a %yacc directive.  */
-  static void handle_yacc (location const *loc, char const *directive);
+  static void handle_yacc (location const *loc);

+  /* Implementation of yyerror.  */
  static void gram_error (location const *, char const *);

  /* A string that describes a char (e.g., 'a' -> "'a'").  */
  static char const *char_name (char);

-  #define YYTYPE_INT16 int_fast16_t
-  #define YYTYPE_INT8 int_fast8_t
-  #define YYTYPE_UINT16 uint_fast16_t
-  #define YYTYPE_UINT8 uint_fast8_t
-
  /* Add style to semantic values in traces.  */
  static void tron (FILE *yyo);
  static void troff (FILE *yyo);
@@ -121,6 +122,7 @@
 %define api.header.include {"parse-gram.h"}
 %define api.prefix {gram_}
 %define api.pure full
+%define api.token.raw
 %define api.value.type union
 %define locations
 %define parse.error verbose
@@ -134,8 +136,8 @@
 {
  /* Bison's grammar can initial empty locations, hence a default
     location is needed. */
-  boundary_set (&@$.start, current_file, 1, 1, 1);
-  boundary_set (&@$.end, current_file, 1, 1, 1);
+  boundary_set (&@$.start, grammar_file, 1, 1, 1);
+  boundary_set (&@$.end, grammar_file, 1, 1, 1);
 }

 /* Define the tokens together with their human representation.  */
@@ -181,6 +183,7 @@
  PERCENT_NONDETERMINISTIC_PARSER
                          "%nondeterministic-parser"
  PERCENT_OUTPUT          "%output"
+  PERCENT_PURE_PARSER     "%pure-parser"
  PERCENT_REQUIRE         "%require"
  PERCENT_SKELETON        "%skeleton"
  PERCENT_START           "%start"
@@ -192,7 +195,7 @@
 %token BRACED_CODE     "{...}"
 %token BRACED_PREDICATE "%?{...}"
 %token BRACKETED_ID    "[identifier]"
-%token CHAR            "char"
+%token CHAR            "character literal"
 %token COLON           ":"
 %token EPILOGUE        "epilogue"
 %token EQUAL           "="
@@ -219,7 +222,7 @@
 %type <uniqstr>
  BRACKETED_ID ID ID_COLON
  PERCENT_ERROR_VERBOSE PERCENT_FILE_PREFIX PERCENT_FLAG PERCENT_NAME_PREFIX
-  PERCENT_YACC
+  PERCENT_PURE_PARSER
  TAG tag tag.opt variable
 %printer { fputs ($$, yyo); } <uniqstr>
 %printer { fprintf (yyo, "[%s]", $$); } BRACKETED_ID
@@ -343,11 +346,12 @@ prologue_declaration:
 | "%nondeterministic-parser"    { nondeterministic_parser = true; }
 | "%output" STRING              { spec_outfile = $2; }
 | "%param" { current_param = $1; } params { current_param = param_none; }
+| "%pure-parser"                { handle_pure_parser (&@$, $1); }
 | "%require" STRING             { handle_require (&@2, $2); }
 | "%skeleton" STRING            { handle_skeleton (&@2, $2); }
 | "%token-table"                { token_table_flag = true; }
 | "%verbose"                    { report_flag |= report_states; }
-| "%yacc"                       { handle_yacc (&@$, $1); }
+| "%yacc"                       { handle_yacc (&@$); }
 | error ";"                     { current_class = unknown_sym; yyerrok; }
 | /*FIXME: Err?  What is this horror doing here? */ ";"
 ;
@@ -651,7 +655,7 @@ rhses.1:
 %token PERCENT_EMPTY "%empty";
 rhs:
  %empty
-    { grammar_current_rule_begin (current_lhs_symbol, current_lhs_location,
+    { grammar_current_rule_begin (current_lhs_symbol, current_lhs_loc,
                                  current_lhs_named_ref); }
 | rhs symbol named_ref.opt
    { grammar_current_rule_symbol_append ($2, @2, $3); }
@@ -727,12 +731,24 @@ id:
    { $$ = symbol_from_uniqstr ($1, @1); }
 | CHAR
    {
+      const char *var = "api.token.raw";
      if (current_class == nterm_sym)
        {
-          gram_error (&@1,
-                      _("character literals cannot be nonterminals"));
+          complain (&@1, complaint,
+                    _("character literals cannot be nonterminals"));
          YYERROR;
        }
+      if (muscle_percent_define_ifdef (var))
+        {
+          int indent = 0;
+          complain_indent (&@1, complaint, &indent,
+                           _("character literals cannot be used together"
+                             " with %s"), var);
+          indent += SUB_INDENT;
+          location loc = muscle_percent_define_get_loc (var);
+          complain_indent (&loc, complaint, &indent,
+                           _("definition of %s"), var);
+        }
      $$ = symbol_get (char_name ($1), @1);
      symbol_class_set ($$, token_sym, @1, false);
      symbol_user_token_number_set ($$, $1, @1);
@@ -910,6 +926,7 @@ handle_file_prefix (location const *loc,
    deprecated_directive (dir_loc, directive, "%file-prefix");
 }

+
 static void
 handle_name_prefix (location const *loc,
                    char const *directive, char const *value)
@@ -944,36 +961,65 @@ handle_name_prefix (location const *loc,
 }


+static void
+handle_pure_parser (location const *loc, char const *directive)
+{
+  bison_directive (loc, directive);
+  deprecated_directive (loc, directive, "%define api.pure");
+  muscle_percent_define_insert ("api.pure", *loc, muscle_keyword, "",
+                                MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
+}
+
+
+/* Convert VERSION into an int (MAJOR * 100 + MINOR).  Return -1 on
+   errors.
+
+   Changes of behavior are only on minor version changes, so "3.0.5"
+   is the same as "3.0": 300. */
+static int
+str_to_version (char const *version)
+{
+  IGNORE_TYPE_LIMITS_BEGIN
+  int res = 0;
+  errno = 0;
+  char *cp = NULL;
+  long major = strtol (version, &cp, 10);
+  if (errno || cp == version || *cp != '.' || major < 0
+      || INT_MULTIPLY_WRAPV (major, 100, &res))
+    return -1;
+
+  ++cp;
+  char *cp1 = NULL;
+  long minor = strtol (cp, &cp1, 10);
+  if (errno || cp1 == cp || (*cp1 != '\0' && *cp1 != '.')
+      || ! (0 <= minor && minor < 100)
+      || INT_ADD_WRAPV (minor, res, &res))
+    return -1;
+
+  IGNORE_TYPE_LIMITS_END
+  return res;
+}
+
+
 static void
 handle_require (location const *loc, char const *version)
 {
-  /* Changes of behavior are only on minor version changes, so "3.0.5"
-     is the same as "3.0". */
-  errno = 0;
-  char* cp = NULL;
-  unsigned long major = strtoul (version, &cp, 10);
-  if (errno || *cp != '.')
+  required_version = str_to_version (version);
+  if (required_version == -1)
    {
      complain (loc, complaint, _("invalid version requirement: %s"),
                version);
+      required_version = 0;
      return;
    }
-  ++cp;
-  unsigned long minor = strtoul (cp, NULL, 10);
-  if (errno)
-    {
-      complain (loc, complaint, _("invalid version requirement: %s"),
-                version);
-      return;
-    }
-  required_version = major * 100 + minor;
+
  /* Pretend to be at least 3.4, to check features published in 3.4
     while developping it.  */
  const char* api_version = "3.4";
  const char* package_version =
-    strverscmp (api_version, PACKAGE_VERSION) > 0
+    0 < strverscmp (api_version, PACKAGE_VERSION)
    ? api_version : PACKAGE_VERSION;
-  if (strverscmp (version, package_version) > 0)
+  if (0 < strverscmp (version, package_version))
    {
      complain (loc, complaint, _("require bison %s, but have %s"),
                version, package_version);
@@ -987,16 +1033,16 @@ handle_skeleton (location const *loc, char const *skel)
  char const *skeleton_user = skel;
  if (strchr (skeleton_user, '/'))
    {
-      size_t dir_length = strlen (current_file);
-      while (dir_length && current_file[dir_length - 1] != '/')
+      size_t dir_length = strlen (grammar_file);
+      while (dir_length && grammar_file[dir_length - 1] != '/')
        --dir_length;
-      while (dir_length && current_file[dir_length - 1] == '/')
+      while (dir_length && grammar_file[dir_length - 1] == '/')
        --dir_length;
      char *skeleton_build =
        xmalloc (dir_length + 1 + strlen (skeleton_user) + 1);
      if (dir_length > 0)
        {
-          memcpy (skeleton_build, current_file, dir_length);
+          memcpy (skeleton_build, grammar_file, dir_length);
          skeleton_build[dir_length++] = '/';
        }
      strcpy (skeleton_build + dir_length, skeleton_user);
@@ -1006,26 +1052,19 @@ handle_skeleton (location const *loc, char const *skel)
  skeleton_arg (skeleton_user, grammar_prio, *loc);
 }

-static void
-handle_yacc (location const *loc, char const *directive)
-{
-  bison_directive (loc, directive);
-  bool warned = false;

+static void
+handle_yacc (location const *loc)
+{
+  const char *directive = "%yacc";
+  bison_directive (loc, directive);
  if (location_empty (yacc_loc))
    yacc_loc = *loc;
  else
-    {
-      duplicate_directive (directive, yacc_loc, *loc);
-      warned = true;
-    }
-
-  if (!warned
-      && STRNEQ (directive, "%fixed-output-files")
-      && STRNEQ (directive, "%yacc"))
-    deprecated_directive (loc, directive, "%fixed-output-files");
+    duplicate_directive (directive, yacc_loc, *loc);
 }

+
 static void
 gram_error (location const *loc, char const *msg)
 {
@@ -1050,7 +1089,7 @@ void
 current_lhs (symbol *sym, location loc, named_ref *ref)
 {
  current_lhs_symbol = sym;
-  current_lhs_location = loc;
+  current_lhs_loc = loc;
  if (sym)
    symbol_location_as_lhs_set (sym, loc);
  /* In order to simplify memory management, named references for lhs
@@ -62,7 +62,7 @@ grammar_start_symbol_set (symbol *sym, location loc)
    {
      start_flag = true;
      startsymbol = sym;
-      startsymbol_location = loc;
+      startsymbol_loc = loc;
    }
 }

@@ -124,19 +124,19 @@ record_merge_function_type (int merger, uniqstr type, location declaration_loc)
  aver (merge_function != NULL && merger_find == merger);
  if (merge_function->type != NULL && !UNIQSTR_EQ (merge_function->type, type))
    {
-      unsigned indent = 0;
+      int indent = 0;
      complain_indent (&declaration_loc, complaint, &indent,
                       _("result type clash on merge function %s: "
                         "<%s> != <%s>"),
                       quote (merge_function->name), type,
                       merge_function->type);
      indent += SUB_INDENT;
-      complain_indent (&merge_function->type_declaration_location, complaint,
+      complain_indent (&merge_function->type_declaration_loc, complaint,
                       &indent,
                       _("previous declaration"));
    }
  merge_function->type = uniqstr_new (type);
-  merge_function->type_declaration_location = declaration_loc;
+  merge_function->type_declaration_loc = declaration_loc;
 }

 /*--------------------------------------.
@@ -295,7 +295,7 @@ grammar_rule_check_and_complete (symbol_list *r)
          char const *rhs_type =
            first_rhs->content->type_name ? first_rhs->content->type_name : "";
          if (!UNIQSTR_EQ (lhs_type, rhs_type))
-            complain (&r->location, Wother,
+            complain (&r->rhs_loc, Wother,
                      _("type clash on default action: <%s> != <%s>"),
                      lhs_type, rhs_type);
          else
@@ -308,7 +308,7 @@ grammar_rule_check_and_complete (symbol_list *r)
              if (is_cxx)
                {
                  code_props_rule_action_init (&r->action_props, "{ $$ = $1; }",
-                                               r->location, r,
+                                               r->rhs_loc, r,
                                               /* name */ NULL,
                                               /* type */ NULL,
                                               /* is_predicate */ false);
@@ -318,7 +318,7 @@ grammar_rule_check_and_complete (symbol_list *r)
        }
      /* Warn if there is no default for $$ but we need one.  */
      else
-        complain (&r->location, Wother,
+        complain (&r->rhs_loc, Wother,
                  _("empty rule for typed nonterminal, and no action"));
    }

@@ -335,9 +335,9 @@ grammar_rule_check_and_complete (symbol_list *r)
          {
            warnings warn_flag = midrule_warning ? Wmidrule_values : Wother;
            if (n)
-              complain (&l->location, warn_flag, _("unused value: $%d"), n);
+              complain (&l->sym_loc, warn_flag, _("unused value: $%d"), n);
            else
-              complain (&l->location, warn_flag, _("unset value: $$"));
+              complain (&l->rhs_loc, warn_flag, _("unset value: $$"));
          }
      }
  }
@@ -357,9 +357,12 @@ grammar_rule_check_and_complete (symbol_list *r)
      && !r->percent_empty_loc.start.file
      && warning_is_enabled (Wempty_rule))
    {
-      complain (&r->location, Wempty_rule,
-                _("empty rule without %%empty"));
-      fixits_register (&r->location, " %empty ");
+      complain (&r->rhs_loc, Wempty_rule, _("empty rule without %%empty"));
+      if (feature_flag & feature_caret)
+        location_caret_suggestion (r->rhs_loc, "%empty", stderr);
+      location loc = r->rhs_loc;
+      loc.end = loc.start;
+      fixits_register (&loc, " %empty ");
    }

  /* See comments in grammar_current_rule_prec_set for how POSIX
@@ -369,12 +372,12 @@ grammar_rule_check_and_complete (symbol_list *r)
      && r->ruleprec->tag[0] != '\'' && r->ruleprec->tag[0] != '"'
      && r->ruleprec->content->status != declared
      && !r->ruleprec->content->prec)
-    complain (&r->location, Wother,
+    complain (&r->rhs_loc, Wother,
              _("token for %%prec is not defined: %s"), r->ruleprec->tag);

  /* Check that the (main) action was not typed.  */
  if (r->action_props.type)
-    complain (&r->location, Wother,
+    complain (&r->rhs_loc, Wother,
              _("only midrule actions can be typed: %s"), r->action_props.type);
 }

@@ -387,8 +390,8 @@ void
 grammar_current_rule_end (location loc)
 {
  /* Put an empty link in the list to mark the end of this rule  */
-  grammar_symbol_append (NULL, grammar_end->location);
-  current_rule->location = loc;
+  grammar_symbol_append (NULL, grammar_end->rhs_loc);
+  current_rule->rhs_loc = loc;
 }


@@ -408,11 +411,11 @@ grammar_midrule_action (void)

  /* Make a DUMMY nonterminal, whose location is that of the midrule
     action.  Create the MIDRULE.  */
-  location dummy_location = current_rule->action_props.location;
-  symbol *dummy = dummy_symbol_get (dummy_location);
+  location dummy_loc = current_rule->action_props.location;
+  symbol *dummy = dummy_symbol_get (dummy_loc);
  symbol_type_set(dummy,
                  current_rule->action_props.type, current_rule->action_props.location);
-  symbol_list *midrule = symbol_list_sym_new (dummy, dummy_location);
+  symbol_list *midrule = symbol_list_sym_new (dummy, dummy_loc);

  /* Remember named_ref of previous action. */
  named_ref *action_name = current_rule->action_props.named_ref;
@@ -422,7 +425,7 @@ grammar_midrule_action (void)
  ++nrules;
  ++nritems;
  /* Attach its location and actions to that of the DUMMY.  */
-  midrule->location = dummy_location;
+  midrule->rhs_loc = dummy_loc;
  code_props_rule_action_init (&midrule->action_props,
                               current_rule->action_props.code,
                               current_rule->action_props.location,
@@ -443,14 +446,14 @@ grammar_midrule_action (void)
    grammar = midrule;

  /* End the dummy's rule.  */
-  midrule->next = symbol_list_sym_new (NULL, dummy_location);
+  midrule->next = symbol_list_sym_new (NULL, dummy_loc);
  midrule->next->next = current_rule;

  previous_rule_end = midrule->next;

  /* Insert the dummy nonterminal replacing the midrule action into
     the current rule.  Bind it to its dedicated rule.  */
-  grammar_current_rule_symbol_append (dummy, dummy_location,
+  grammar_current_rule_symbol_append (dummy, dummy_loc,
                                      action_name);
  grammar_end->midrule = midrule;
  midrule->midrule_parent_rule = current_rule;
@@ -509,11 +512,11 @@ grammar_current_rule_dprec_set (int dprec, location loc)
              "%dprec");
  else if (current_rule->dprec != 0)
    duplicate_rule_directive ("%dprec",
-                              current_rule->dprec_location, loc);
+                              current_rule->dprec_loc, loc);
  else
    {
      current_rule->dprec = dprec;
-      current_rule->dprec_location = loc;
+      current_rule->dprec_loc = loc;
    }
 }

@@ -528,11 +531,11 @@ grammar_current_rule_merge_set (uniqstr name, location loc)
              "%merge");
  if (current_rule->merger != 0)
    duplicate_rule_directive ("%merge",
-                              current_rule->merger_declaration_location, loc);
+                              current_rule->merger_declaration_loc, loc);
  else
    {
      current_rule->merger = get_merge_function (name);
-      current_rule->merger_declaration_location = loc;
+      current_rule->merger_declaration_loc = loc;
    }
 }

@@ -602,15 +605,14 @@ grammar_current_rule_expect_rr (int count, location loc)
 }


-/*---------------------------------------------------------------.
-| Convert the rules into the representation using RRHS, RLHS and |
-| RITEM.                                                         |
-`---------------------------------------------------------------*/
+/*---------------------------------------------.
+| Build RULES and RITEM from what was parsed.  |
+`---------------------------------------------*/

 static void
 packgram (void)
 {
-  unsigned itemno = 0;
+  int itemno = 0;
  ritem = xnmalloc (nritems + 1, sizeof *ritem);
  /* This sentinel is used by build_relations in gram.c.  */
  *ritem++ = 0;
@@ -622,7 +624,7 @@ packgram (void)
    {
      symbol_list *lhs = p;
      record_merge_function_type (lhs->merger, lhs->content.sym->content->type_name,
-                                  lhs->merger_declaration_location);
+                                  lhs->merger_declaration_loc);
      /* If the midrule's $$ is set or its $n is used, remove the '$' from the
         symbol name so that it's a user-defined symbol so that the default
         %destructor and %printer apply.  */
@@ -647,10 +649,10 @@ packgram (void)
      rules[ruleno].dprec = lhs->dprec;
      rules[ruleno].merger = lhs->merger;
      rules[ruleno].precsym = NULL;
-      rules[ruleno].location = lhs->location;
+      rules[ruleno].location = lhs->rhs_loc;
      rules[ruleno].useful = true;
      rules[ruleno].action = lhs->action_props.code;
-      rules[ruleno].action_location = lhs->action_props.location;
+      rules[ruleno].action_loc = lhs->action_props.location;
      rules[ruleno].is_predicate = lhs->action_props.is_predicate;
      rules[ruleno].expected_sr_conflicts = lhs->expected_sr_conflicts;
      rules[ruleno].expected_rr_conflicts = lhs->expected_rr_conflicts;
@@ -698,7 +700,8 @@ packgram (void)
  if (trace_flag & trace_sets)
    ritem_print (stderr);
 }
-
+
+
 /*------------------------------------------------------------------.
 | Read in the grammar specification and record it in the format     |
 | described in gram.h.  All actions are copied into ACTION_OBSTACK, |
@@ -707,39 +710,20 @@ packgram (void)
 `------------------------------------------------------------------*/

 void
-reader (void)
+reader (const char *gram)
 {
-  /* Initialize the symbol table.  */
+  /* Set up symbol_table, semantic_type_table, and the built-in
+     symbols.  */
  symbols_new ();

-  /* Construct the accept symbol. */
-  accept = symbol_get ("$accept", empty_location);
-  accept->content->class = nterm_sym;
-  accept->content->number = nvars++;
-
-  /* Construct the error token */
-  errtoken = symbol_get ("error", empty_location);
-  errtoken->content->class = token_sym;
-  errtoken->content->number = ntokens++;
-
-  /* Construct a token that represents all undefined literal tokens.
-     It is always token number 2.  */
-  undeftoken = symbol_get ("$undefined", empty_location);
-  undeftoken->content->class = token_sym;
-  undeftoken->content->number = ntokens++;
-
-  gram_in = xfopen (grammar_file, "r");
-
-  gram__flex_debug = trace_flag & trace_scan;
-  gram_debug = trace_flag & trace_parse;
-  gram_scanner_initialize ();
+  gram_scanner_open (gram);
  gram_parse ();
+  gram_scanner_close ();
+
  prepare_percent_define_front_end_variables ();

  if (complaint_status  < status_complaint)
    check_and_convert_grammar ();
-
-  xfclose (gram_in);
 }

 static void
@@ -801,7 +785,7 @@ check_and_convert_grammar (void)
  /* If the user did not define her ENDTOKEN, do it now. */
  if (!endtoken)
    {
-      endtoken = symbol_get ("$end", empty_location);
+      endtoken = symbol_get ("$end", empty_loc);
      endtoken->content->class = token_sym;
      endtoken->content->number = 0;
      /* Value specified by POSIX.  */
@@ -823,11 +807,11 @@ check_and_convert_grammar (void)

     $accept: %start $end.  */
  {
-    symbol_list *p = symbol_list_sym_new (accept, empty_location);
-    p->location = grammar->location;
-    p->next = symbol_list_sym_new (startsymbol, empty_location);
-    p->next->next = symbol_list_sym_new (endtoken, empty_location);
-    p->next->next->next = symbol_list_sym_new (NULL, empty_location);
+    symbol_list *p = symbol_list_sym_new (accept, empty_loc);
+    p->rhs_loc = grammar->rhs_loc;
+    p->next = symbol_list_sym_new (startsymbol, empty_loc);
+    p->next->next = symbol_list_sym_new (endtoken, empty_loc);
+    p->next->next->next = symbol_list_sym_new (NULL, empty_loc);
    p->next->next->next->next = grammar;
    nrules += 1;
    nritems += 3;
@@ -32,7 +32,7 @@ typedef struct merger_list
  struct merger_list* next;
  uniqstr name;
  uniqstr type;
-  location type_declaration_location;
+  location type_declaration_loc;
 } merger_list;

 /* From the parser.  */
@@ -60,7 +60,7 @@ void grammar_current_rule_action_append (const char *action, location loc,
                                         named_ref *nref, uniqstr tag);
 /* Attach a PREDICATE to the current rule.  */
 void grammar_current_rule_predicate_append (const char *predicate, location loc);
-void reader (void);
+void reader (const char *gram);
 void free_merger_functions (void);

 extern merger_list *merge_functions;
@@ -52,8 +52,8 @@ static bitset V;
   'useless', but no warning should be issued).  */
 static bitset V1;

-unsigned nuseless_productions;
-unsigned nuseless_nonterminals;
+int nuseless_productions;
+int nuseless_nonterminals;

 #define bitset_swap(Lhs, Rhs)                   \
  do {                                          \
@@ -195,10 +195,10 @@ inaccessable_symbols (void)
  bitset_free (P);
  P = Pp;

-  unsigned nuseful_productions = bitset_count (P);
+  int nuseful_productions = bitset_count (P);
  nuseless_productions = nrules - nuseful_productions;

-  unsigned nuseful_nonterminals = 0;
+  int nuseful_nonterminals = 0;
  for (symbol_number i = ntokens; i < nsyms; ++i)
    nuseful_nonterminals += bitset_test (V, i);
  nuseless_nonterminals = nvars - nuseful_nonterminals;
@@ -382,7 +382,7 @@ reduce_grammar (void)
      reduce_print ();

      if (!bitset_test (N, accept->content->number - ntokens))
-        complain (&startsymbol_location, fatal,
+        complain (&startsymbol_loc, fatal,
                  _("start symbol %s does not derive any sentence"),
                  startsymbol->tag);

@@ -36,7 +36,7 @@ void reduce_free (void);
 * reduce_grammar.  Size nvars + nuseless_nonterminals.  */
 extern symbol_number *nterm_map;

-extern unsigned nuseless_nonterminals;
-extern unsigned nuseless_productions;
+extern int nuseless_nonterminals;
+extern int nuseless_productions;

 #endif /* !REDUCE_H_ */
@@ -33,14 +33,14 @@ relation_print (const char *title,
 {
  if (title)
    fprintf (out, "%s:\n", title);
-  for (size_t i = 0; i < size; ++i)
+  for (relation_node i = 0; i < size; ++i)
    if (r[i])
      {
        fputs ("    ", out);
        if (print)
          print (i, out);
        else
-          fprintf (out, "%3lu", (unsigned long) i);
+          fprintf (out, "%3ld", (long) i);
        fputc (':', out);
        for (relation_node j = 0; r[i][j] != END_NODE; ++j)
          {
@@ -48,7 +48,7 @@ relation_print (const char *title,
            if (print)
              print (r[i][j], out);
            else
-              fprintf (out, "%3lu", (unsigned long) r[i][j]);
+              fprintf (out, "%3ld", (long) r[i][j]);
          }
        fputc ('\n', out);
      }
@@ -48,17 +48,18 @@ YY_DECL;
 #define YY_USER_ACTION  location_compute (loc, &loc->end, yytext, yyleng);

 static char *fetch_type_name (char *cp, char const **type_name,
-                              location dollar_loc);
+                              const location *dollar_loc);

 static void handle_action_dollar (symbol_list *rule, char *cp,
-                                  location dollar_loc);
-static void handle_action_at (symbol_list *rule, char *cp, location at_loc);
+                                  const location *dollar_loc);
+static void handle_action_at (symbol_list *rule, char *cp,
+                              const location *at_loc);

 /* A string to be pushed to obstack after dollar/at has been handled. */
 static char *ref_tail_fields;

-static location the_location;
-static location *loc = &the_location;
+static location current_loc;
+static location *loc = &current_loc;

 /* A string representing the most recent translation.  */
 static char *last_string;
@@ -163,13 +164,13 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
 {
  "$"("<"{tag}">")?{ref}  {
    ref_tail_fields = NULL;
-    handle_action_dollar (self->rule, yytext, *loc);
+    handle_action_dollar (self->rule, yytext, loc);
    if (ref_tail_fields)
      obstack_sgrow (&obstack_for_string, ref_tail_fields);
  }
  "@"{ref} {
    ref_tail_fields = NULL;
-    handle_action_at (self->rule, yytext, *loc);
+    handle_action_at (self->rule, yytext, loc);
    if (ref_tail_fields)
      obstack_sgrow (&obstack_for_string, ref_tail_fields);
  }
@@ -179,7 +180,7 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
 {
  "$"("<"{tag}">")?"$" {
    const char *type_name = NULL;
-    fetch_type_name (yytext + 1, &type_name, *loc)[-1] = 0;
+    fetch_type_name (yytext + 1, &type_name, loc)[-1] = 0;
    obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar(");
    obstack_quote (&obstack_for_string, type_name);
    obstack_sgrow (&obstack_for_string, ")[");
@@ -187,7 +188,7 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
  }
  "@$" {
    obstack_sgrow (&obstack_for_string, "]b4_at_dollar[");
-    muscle_percent_define_ensure("locations", the_location, true);
+    muscle_percent_define_ensure("locations", *loc, true);
  }
 }

@@ -215,14 +216,14 @@ is_dot_or_dash (char ch)
 static inline bool
 contains_dot_or_dash (const char* p)
 {
-  return strpbrk(p, ".-");
+  return !!strpbrk (p, ".-");
 }

 /* Defines a variant of a symbolic name resolution. */
 typedef struct
 {
  /* Index in symbol list. */
-  unsigned symbol_index;
+  int symbol_index;

  /* Matched symbol id and loc. */
  uniqstr id;
@@ -249,8 +250,8 @@ typedef struct
 #define VARIANT_NOT_VISIBLE_FROM_MIDRULE (1 << 2)

 static variant *variant_table = NULL;
-static unsigned variant_table_size = 0;
-static unsigned variant_count = 0;
+static int variant_table_size = 0;
+static int variant_count = 0;

 static variant *
 variant_table_grow (void)
@@ -285,7 +286,7 @@ find_prefix_end (char const *prefix, char const *cp, char const *end)
 }

 static variant *
-variant_add (uniqstr id, location id_loc, unsigned symbol_index,
+variant_add (uniqstr id, location id_loc, int symbol_index,
             char const *cp, char const *cp_end, bool explicit_bracketing)
 {
  char const *prefix_end = find_prefix_end (id, cp, cp_end);
@@ -306,7 +307,7 @@ variant_add (uniqstr id, location id_loc, unsigned symbol_index,
 }

 static const char *
-get_at_spec(unsigned symbol_index)
+get_at_spec(int symbol_index)
 {
  static char at_buf[20];
  if (symbol_index == 0)
@@ -320,7 +321,7 @@ static void
 show_sub_message (warnings warning,
                  const char* cp, bool explicit_bracketing,
                  int midrule_rhs_index, char dollar_or_at,
-                  unsigned indent, const variant *var)
+                  int indent, const variant *var)
 {
  const char *at_spec = get_at_spec (var->symbol_index);

@@ -384,9 +385,9 @@ static void
 show_sub_messages (warnings warning,
                   const char* cp, bool explicit_bracketing,
                   int midrule_rhs_index, char dollar_or_at,
-                   unsigned indent)
+                   int indent)
 {
-  for (unsigned i = 0; i < variant_count; ++i)
+  for (int i = 0; i < variant_count; ++i)
    show_sub_message (warning | silent,
                      cp, explicit_bracketing,
                      midrule_rhs_index, dollar_or_at,
@@ -406,7 +407,7 @@ show_sub_messages (warnings warning,
   accesses. */
 static long
 parse_ref (char *cp, symbol_list *rule, int rule_length,
-           int midrule_rhs_index, char *text, location text_loc,
+           int midrule_rhs_index, char *text, const location *text_loc,
           char dollar_or_at)
 {
  if ('$' == *cp)
@@ -419,7 +420,7 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
        return num;
      else
        {
-          complain (&text_loc, complaint, _("integer out of range: %s"),
+          complain (text_loc, complaint, _("integer out of range: %s"),
                    quote (text));
          return INVALID_REF;
        }
@@ -436,7 +437,7 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,

  /* Add all relevant variants. */
  {
-    unsigned symbol_index;
+    int symbol_index;
    symbol_list *l;
    variant_count = 0;
    for (symbol_index = 0, l = rule; !symbol_list_null (l);
@@ -458,12 +459,12 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
  }

  /* Check errors. */
-  unsigned valid_variants = 0;
-  unsigned valid_variant_index = 0;
-  for (unsigned i = 0; i < variant_count; ++i)
+  int valid_variants = 0;
+  int valid_variant_index = 0;
+  for (int i = 0; i < variant_count; ++i)
    {
      variant *var = &variant_table[i];
-      unsigned symbol_index = var->symbol_index;
+      int symbol_index = var->symbol_index;

      /* Check visibility from midrule actions. */
      if (midrule_rhs_index != 0
@@ -489,16 +490,16 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
    {
    case 0:
      {
-        unsigned len = (explicit_bracketing || !ref_tail_fields) ?
+        int len = (explicit_bracketing || !ref_tail_fields) ?
          cp_end - cp : ref_tail_fields - cp;
-        unsigned indent = 0;
+        int indent = 0;

-        complain_indent (&text_loc, complaint, &indent,
+        complain_indent (text_loc, complaint, &indent,
                         _("invalid reference: %s"), quote (text));
        indent += SUB_INDENT;
        if (len == 0)
          {
-            location sym_loc = text_loc;
+            location sym_loc = *text_loc;
            sym_loc.start.column += 1;
            sym_loc.end = sym_loc.start;
            complain_indent (&sym_loc, complaint, &indent,
@@ -507,12 +508,12 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
                             dollar_or_at);
          }
        else if (midrule_rhs_index)
-          complain_indent (&rule->location, complaint, &indent,
+          complain_indent (&rule->rhs_loc, complaint, &indent,
                           _("symbol not found in production before $%d: "
                             "%.*s"),
                           midrule_rhs_index, len, cp);
        else
-          complain_indent (&rule->location, complaint, &indent,
+          complain_indent (&rule->rhs_loc, complaint, &indent,
                           _("symbol not found in production: %.*s"),
                           len, cp);

@@ -524,17 +525,17 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
      }
    case 1:
      {
-        unsigned indent = 0;
+        int indent = 0;
        if (variant_count > 1)
          {
-            complain_indent (&text_loc, Wother, &indent,
+            complain_indent (text_loc, Wother, &indent,
                             _("misleading reference: %s"), quote (text));
            show_sub_messages (Wother,
                               cp, explicit_bracketing, midrule_rhs_index,
                               dollar_or_at, indent + SUB_INDENT);
          }
        {
-          unsigned symbol_index =
+          int symbol_index =
            variant_table[valid_variant_index].symbol_index;
          return (symbol_index == midrule_rhs_index) ? LHS_REF : symbol_index;
        }
@@ -542,8 +543,8 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
    case 2:
    default:
      {
-        unsigned indent = 0;
-        complain_indent (&text_loc, complaint, &indent,
+        int indent = 0;
+        complain_indent (text_loc, complaint, &indent,
                         _("ambiguous reference: %s"), quote (text));
        show_sub_messages (complaint,
                           cp, explicit_bracketing, midrule_rhs_index,
@@ -566,7 +567,7 @@ int max_left_semantic_context = 0;
 static
 char *
 fetch_type_name (char *cp, char const **type_name,
-                 location dollar_loc)
+                 const location *dollar_loc)
 {
  if (*cp == '<')
    {
@@ -579,7 +580,7 @@ fetch_type_name (char *cp, char const **type_name,
         'text' is needed for error messages. */
      ++cp;
      if (untyped_var_seen)
-        complain (&dollar_loc, complaint,
+        complain (dollar_loc, complaint,
                  _("explicit type given in untyped grammar"));
      tag_seen = true;
    }
@@ -595,7 +596,7 @@ fetch_type_name (char *cp, char const **type_name,
 `------------------------------------------------------------------*/

 static void
-handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
+handle_action_dollar (symbol_list *rule, char *text, const location *dollar_loc)
 {
  symbol_list *effective_rule;
  int effective_rule_length;
@@ -634,13 +635,13 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
            if (union_seen || tag_seen)
              {
                if (rule->midrule_parent_rule)
-                  complain (&dollar_loc, complaint,
+                  complain (dollar_loc, complaint,
                            _("$$ for the midrule at $%d of %s"
                              " has no declared type"),
                            rule->midrule_parent_rhs_index,
                            quote (effective_rule->content.sym->tag));
                else
-                  complain (&dollar_loc, complaint,
+                  complain (dollar_loc, complaint,
                            _("$$ of %s has no declared type"),
                            quote (rule->content.sym->tag));
              }
@@ -666,7 +667,7 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
            && (!sym || !sym->content.sym->content->type_name))
          {
            if (union_seen || tag_seen)
-              complain (&dollar_loc, complaint,
+              complain (dollar_loc, complaint,
                        _("$%s of %s has no declared type"), cp,
                        quote (effective_rule->content.sym->tag));
            else
@@ -689,7 +690,7 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
          {
            if (muscle_percent_define_ifdef ("api.value.automove")
                && sym->action_props.is_value_used)
-              complain (&dollar_loc, Wother,
+              complain (dollar_loc, Wother,
                        _("multiple occurrences of $%d with api.value.automove"),
                        n);
            sym->action_props.is_value_used = true;
@@ -706,7 +707,7 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
 `------------------------------------------------------*/

 static void
-handle_action_at (symbol_list *rule, char *text, location at_loc)
+handle_action_at (symbol_list *rule, char *text, const location *at_loc)
 {
  symbol_list *effective_rule;
  int effective_rule_length;
@@ -722,7 +723,7 @@ handle_action_at (symbol_list *rule, char *text, location at_loc)
      effective_rule_length = symbol_list_length (rule->next);
    }

-  muscle_percent_define_ensure("locations", at_loc, true);
+  muscle_percent_define_ensure ("locations", *at_loc, true);

  int n = parse_ref (text + 1, effective_rule, effective_rule_length,
                     rule->midrule_parent_rhs_index, text, at_loc, '@');
@@ -21,18 +21,15 @@
 #ifndef SCAN_GRAM_H_
 # define SCAN_GRAM_H_

-/* From the scanner.  */
-extern FILE *gram_in;
-extern int gram__flex_debug;
-void gram_scanner_initialize (void);
+/* Initialize the scanner to read file GRAM. */
+void gram_scanner_open (const char *gram);
+/* Close the open files.  */
+void gram_scanner_close (void);
+
+/* Free all the memory allocated to the scanner. */
 void gram_scanner_free (void);
 void gram_scanner_last_string_free (void);

-/* These are declared by the scanner, but not used.  We put them here
-   to pacify "make syntax-check".  */
-extern FILE *gram_out;
-extern int gram_lineno;
-
 # define GRAM_LEX_DECL int gram_lex (GRAM_STYPE *val, location *loc)
 GRAM_LEX_DECL;

@@ -21,6 +21,8 @@
 %option prefix="gram_" outfile="lex.yy.c"

 %{
+#include <errno.h>
+
 #include <c-ctype.h>
 #include <mbswidth.h>
 #include <quote.h>
@@ -49,9 +51,6 @@ static boundary scanner_cursor;

 #define YY_USER_ACTION  location_compute (loc, &scanner_cursor, yytext, yyleng);

-static size_t no_cr_read (FILE *, char *, size_t);
-#define YY_INPUT(buf, result, size) ((result) = no_cr_read (yyin, buf, size))
-
 /* Report that yytext is an extension, and evaluate to its token type.  */
 #define BISON_DIRECTIVE(Directive)                              \
  (bison_directive (loc, yytext), PERCENT_ ## Directive)
@@ -84,6 +83,9 @@ static size_t no_cr_read (FILE *, char *, size_t);
      unput (Msg[i - 1]);                                       \
  } while (0)

+/* The current file name.  Might change with #line.  */
+static uniqstr current_file = NULL;
+
 /* A string representing the most recently saved token.  */
 static char *last_string = NULL;

@@ -100,7 +102,7 @@ gram_scanner_last_string_free (void)
 }

 static void handle_syncline (char *, location);
-static unsigned long scan_integer (char const *p, int base, location loc);
+static int scan_integer (char const *p, int base, location loc);
 static int convert_ucn_to_byte (char const *hex_text);
 static void unexpected_eof (boundary, char const *);
 static void unexpected_newline (boundary, char const *);
@@ -139,12 +141,14 @@ id        {letter}({letter}|[-0-9])*
 int       [0-9]+
 xint      0[xX][0-9abcdefABCDEF]+

+eol       \n|\r\n
+
 /* UTF-8 Encoded Unicode Code Point, from Flex's documentation. */
 mbchar    [\x09\x0A\x0D\x20-\x7E]|[\xC2-\xDF][\x80-\xBF]|\xE0[\xA0-\xBF][\x80-\xBF]|[\xE1-\xEC\xEE\xEF]([\x80-\xBF]{2})|\xED[\x80-\x9F][\x80-\xBF]|\xF0[\x\90-\xBF]([\x80-\xBF]{2})|[\xF1-\xF3]([\x80-\xBF]{3})|\xF4[\x80-\x8F]([\x80-\xBF]{2})

 /* Zero or more instances of backslash-newline.  Following GCC, allow
   white space between the backslash and the newline.  */
-splice   (\\[ \f\t\v]*\n)*
+splice   (\\[ \f\t\v]*{eol})*

 /* An equal sign, with optional leading whitespaces. This is used in some
   deprecated constructs. */
@@ -161,7 +165,7 @@ eqopt    ({sp}=)?
  int context_state PACIFY_CC (= 0);

  /* Location of most recent identifier, when applicable.  */
-  location id_loc PACIFY_CC (= empty_location);
+  location id_loc PACIFY_CC (= empty_loc);

  /* Where containing code started, when applicable.  Its initial
     value is relevant only when yylex is invoked in the SC_EPILOGUE
@@ -193,7 +197,7 @@ eqopt    ({sp}=)?
  "," {
     complain (loc, Wother, _("stray ',' treated as white space"));
  }
-  [ \f\n\t\v]  |
+  [ \f\t\v\r]|{eol}  |
  "//".*       continue;
  "/*" {
    token_start = loc->start;
@@ -201,9 +205,7 @@ eqopt    ({sp}=)?
    BEGIN SC_YACC_COMMENT;
  }

-  /* #line directives are not documented, and may be withdrawn or
-     modified in future versions of Bison.  */
-  ^"#line "{int}(" \"".*"\"")?"\n" {
+  ^"#line "{int}(" \"".*"\"")?{eol} {
    handle_syncline (yytext + sizeof "#line " - 1, *loc);
  }
 }
@@ -233,7 +235,6 @@ eqopt    ({sp}=)?
  "%expect"                         return BISON_DIRECTIVE (EXPECT);
  "%expect-rr"                      return BISON_DIRECTIVE (EXPECT_RR);
  "%file-prefix"                    RETURN_VALUE (PERCENT_FILE_PREFIX, uniqstr_new (yytext));
-  "%fixed-output-files"             RETURN_VALUE (PERCENT_YACC, uniqstr_new (yytext));
  "%initial-action"                 return BISON_DIRECTIVE (INITIAL_ACTION);
  "%glr-parser"                     return BISON_DIRECTIVE (GLR_PARSER);
  "%language"                       return BISON_DIRECTIVE (LANGUAGE);
@@ -252,7 +253,6 @@ eqopt    ({sp}=)?
  "%prec"                           return PERCENT_PREC;
  "%precedence"                     return BISON_DIRECTIVE (PRECEDENCE);
  "%printer"                        return BISON_DIRECTIVE (PRINTER);
-  "%pure-parser"                    RETURN_PERCENT_FLAG ("api.pure");
  "%require"                        return BISON_DIRECTIVE (REQUIRE);
  "%right"                          return PERCENT_RIGHT;
  "%skeleton"                       return BISON_DIRECTIVE (SKELETON);
@@ -263,7 +263,11 @@ eqopt    ({sp}=)?
  "%type"                           return PERCENT_TYPE;
  "%union"                          return PERCENT_UNION;
  "%verbose"                        return BISON_DIRECTIVE (VERBOSE);
-  "%yacc"                           RETURN_VALUE (PERCENT_YACC, uniqstr_new (yytext));
+  "%yacc"                           return PERCENT_YACC;
+
+  /* Deprecated since Bison 2.3b (2008-05-27), but the warning is
+     issued only since Bison 3.4. */
+  "%pure"[-_]"parser"               RETURN_VALUE (PERCENT_PURE_PARSER, uniqstr_new (yytext));

  /* Deprecated since Bison 3.0 (2013-07-25), but the warning is
     issued only since Bison 3.3. */
@@ -278,11 +282,10 @@ eqopt    ({sp}=)?
  "%error"[-_]"verbose"             RETURN_VALUE (PERCENT_ERROR_VERBOSE, uniqstr_new (yytext));
  "%expect"[-_]"rr"                 DEPRECATED ("%expect-rr");
  "%file-prefix"{eqopt}             RETURN_VALUE (PERCENT_FILE_PREFIX, uniqstr_new (yytext));
-  "%fixed"[-_]"output"[-_]"files"   RETURN_VALUE (PERCENT_YACC, uniqstr_new (yytext));
+  "%fixed"[-_]"output"[-_]"files"   DEPRECATED ("%output \"y.tab.c\"");
  "%no"[-_]"default"[-_]"prec"      DEPRECATED ("%no-default-prec");
  "%no"[-_]"lines"                  DEPRECATED ("%no-lines");
  "%output"{eqopt}                  DEPRECATED ("%output");
-  "%pure"[-_]"parser"               DEPRECATED ("%pure-parser");
  "%token"[-_]"table"               DEPRECATED ("%token-table");

  "%"{id} {
@@ -328,7 +331,7 @@ eqopt    ({sp}=)?
  }

  /* Semantic predicate. */
-  "%?"[ \f\n\t\v]*"{" {
+  "%?"([ \f\t\v]|{eol})*"{" {
    nesting = 0;
    code_start = loc->start;
    BEGIN SC_PREDICATE;
@@ -357,7 +360,7 @@ eqopt    ({sp}=)?
    BEGIN SC_BRACKETED_ID;
  }

-  [^\[%A-Za-z0-9_<>{}\"\'*;|=/, \f\n\t\v]+|. {
+  [^\[%A-Za-z0-9_<>{}\"\'*;|=/, \f\r\n\t\v]+|. {
    complain (loc, complaint, "%s: %s",
              ngettext ("invalid character", "invalid characters", yyleng),
              quote_mem (yytext, yyleng));
@@ -456,7 +459,7 @@ eqopt    ({sp}=)?
      complain (loc, complaint, _("an identifier expected"));
  }

-  [^\].A-Za-z0-9_/ \f\n\t\v]+|. {
+  [^\].A-Za-z0-9_/ \f\r\n\t\v]+|. {
    complain (loc, complaint, "%s: %s",
              ngettext ("invalid character in bracketed name",
                        "invalid characters in bracketed name", yyleng),
@@ -489,7 +492,7 @@ eqopt    ({sp}=)?
 <SC_YACC_COMMENT>
 {
  "*/"     BEGIN context_state;
-  .|\n     continue;
+  .|{eol}  continue;
  <<EOF>>  unexpected_eof (token_start, "*/"); BEGIN context_state;
 }

@@ -511,7 +514,7 @@ eqopt    ({sp}=)?

 <SC_LINE_COMMENT>
 {
-  "\n"           STRING_GROW; BEGIN context_state;
+  {eol}          STRING_GROW; BEGIN context_state;
  {splice}       STRING_GROW;
  <<EOF>>        BEGIN context_state;
 }
@@ -533,7 +536,7 @@ eqopt    ({sp}=)?
    RETURN_VALUE (STRING, last_string);
  }
  <<EOF>>   unexpected_eof (token_start, "\"");
-  "\n"      unexpected_newline (token_start, "\"");
+  {eol}     unexpected_newline (token_start, "\"");
 }

  /*----------------------------------------------------------.
@@ -562,7 +565,7 @@ eqopt    ({sp}=)?
    BEGIN INITIAL;
    return CHAR;
  }
-  "\n"      unexpected_newline (token_start, "'");
+  {eol}     unexpected_newline (token_start, "'");
  <<EOF>>   unexpected_eof (token_start, "'");
 }

@@ -602,22 +605,22 @@ eqopt    ({sp}=)?
 {
  \\[0-7]{1,3} {
    verify (UCHAR_MAX < ULONG_MAX);
-    unsigned long c = strtoul (yytext + 1, NULL, 8);
-    if (!c || UCHAR_MAX < c)
+    long c = strtol (yytext + 1, NULL, 8);
+    if (0 < c && c <= UCHAR_MAX)
+      obstack_1grow (&obstack_for_string, c);
+    else
      complain (loc, complaint, _("invalid number after \\-escape: %s"),
                yytext+1);
-    else
-      obstack_1grow (&obstack_for_string, c);
  }

  \\x[0-9abcdefABCDEF]+ {
    verify (UCHAR_MAX < ULONG_MAX);
-    unsigned long c = strtoul (yytext + 2, NULL, 16);
-    if (!c || UCHAR_MAX < c)
+    long c = strtol (yytext + 2, NULL, 16);
+    if (0 < c && c <= UCHAR_MAX)
+      obstack_1grow (&obstack_for_string, c);
+    else
      complain (loc, complaint, _("invalid number after \\-escape: %s"),
                yytext+1);
-    else
-      obstack_1grow (&obstack_for_string, c);
  }

  \\a   obstack_1grow (&obstack_for_string, '\a');
@@ -639,7 +642,7 @@ eqopt    ({sp}=)?
    else
      obstack_1grow (&obstack_for_string, c);
  }
-  \\(.|\n)      {
+  \\(.|{eol})      {
    char const *p = yytext + 1;
    /* Quote only if escaping won't make the character visible.  */
    if (c_isspace ((unsigned char) *p) && c_isprint ((unsigned char) *p))
@@ -663,14 +666,14 @@ eqopt    ({sp}=)?
 <SC_CHARACTER>
 {
  "'"           STRING_GROW; BEGIN context_state;
-  \n            unexpected_newline (token_start, "'");
+  {eol}         unexpected_newline (token_start, "'");
  <<EOF>>       unexpected_eof (token_start, "'");
 }

 <SC_STRING>
 {
  "\""          STRING_GROW; BEGIN context_state;
-  \n            unexpected_newline (token_start, "\"");
+  {eol}         unexpected_newline (token_start, "\"");
  <<EOF>>       unexpected_eof (token_start, "\"");
 }

@@ -807,59 +810,12 @@ eqopt    ({sp}=)?

 %%

-/* Read bytes from FP into buffer BUF of size SIZE.  Return the
-   number of bytes read.  Remove '\r' from input, treating \r\n
-   and isolated \r as \n.  */
-
-static size_t
-no_cr_read (FILE *fp, char *buf, size_t size)
-{
-  size_t bytes_read = fread (buf, 1, size, fp);
-  if (bytes_read)
-    {
-      char *w = memchr (buf, '\r', bytes_read);
-      if (w)
-        {
-          char const *r = ++w;
-          char const *lim = buf + bytes_read;
-
-          for (;;)
-            {
-              /* Found an '\r'.  Treat it like '\n', but ignore any
-                 '\n' that immediately follows.  */
-              w[-1] = '\n';
-              if (r == lim)
-                {
-                  int ch = getc (fp);
-                  if (ch != '\n' && ungetc (ch, fp) != ch)
-                    break;
-                }
-              else if (*r == '\n')
-                r++;
-
-              /* Copy until the next '\r'.  */
-              do
-                {
-                  if (r == lim)
-                    return w - buf;
-                }
-              while ((*w++ = *r++) != '\r');
-            }
-
-          return w - buf;
-        }
-    }
-
-  return bytes_read;
-}
-
-

 /*------------------------------------------------------.
 | Scan NUMBER for a base-BASE integer at location LOC.  |
 `------------------------------------------------------*/

-static unsigned long
+static int
 scan_integer (char const *number, int base, location loc)
 {
  verify (INT_MAX < ULONG_MAX);
@@ -867,9 +823,10 @@ scan_integer (char const *number, int base, location loc)
    complain (&loc, Wyacc,
              _("POSIX Yacc does not support hexadecimal literals"));

-  unsigned long num = strtoul (number, NULL, base);
+  errno = 0;
+  long num = strtol (number, NULL, base);

-  if (INT_MAX < num)
+  if (! (0 <= num && num <= INT_MAX && errno == 0))
    {
      complain (&loc, complaint, _("integer out of range: %s"),
                quote (number));
@@ -890,7 +847,7 @@ static int
 convert_ucn_to_byte (char const *ucn)
 {
  verify (UCHAR_MAX <= INT_MAX);
-  unsigned long code = strtoul (ucn + 2, NULL, 16);
+  long code = strtol (ucn + 2, NULL, 16);

  /* FIXME: Currently we assume Unicode-compatible unibyte characters
     on ASCII hosts (i.e., Latin-1 on hosts with 8-bit bytes).  On
@@ -898,7 +855,7 @@ convert_ucn_to_byte (char const *ucn)
     These limitations should be removed once we add support for
     multibyte characters.  */

-  if (UCHAR_MAX < code)
+  if (! (0 <= code && code <= UCHAR_MAX))
    return -1;

 #if ! ('$' == 0x24 && '@' == 0x40 && '`' == 0x60 && '~' == 0x7e)
@@ -945,8 +902,9 @@ static void
 handle_syncline (char *args, location loc)
 {
  char *file;
-  unsigned long lineno = strtoul (args, &file, 10);
-  if (INT_MAX <= lineno)
+  errno = 0;
+  long lineno = strtol (args, &file, 10);
+  if (! (0 <= lineno && lineno <= INT_MAX && errno == 0))
    {
      complain (&loc, Wother, _("line number overflow"));
      lineno = INT_MAX;
@@ -1016,25 +974,29 @@ unexpected_newline (boundary start, char const *token_end)
 }


-/*-------------------------.
-| Initialize the scanner.  |
-`-------------------------*/
-
 void
-gram_scanner_initialize (void)
+gram_scanner_open (const char *gram)
 {
+  gram__flex_debug = trace_flag & trace_scan;
+  gram_debug = trace_flag & trace_parse;
  obstack_init (&obstack_for_string);
+  current_file = gram;
+  gram_in = xfopen (gram, "r");
+}
+
+
+void
+gram_scanner_close ()
+{
+  xfclose (gram_in);
+  /* Reclaim Flex's buffers.  */
+  yylex_destroy ();
 }


-/*-----------------------------------------------.
-| Free all the memory allocated to the scanner.  |
-`-----------------------------------------------*/

 void
 gram_scanner_free (void)
 {
  obstack_free (&obstack_for_string, 0);
-  /* Reclaim Flex's buffers.  */
-  yylex_destroy ();
 }
@@ -209,7 +209,7 @@ at_basename (int argc, char *argv[], char **out_namep, int *out_linenop)
 static void
 at_complain (int argc, char *argv[], char **out_namep, int *out_linenop)
 {
-  static unsigned indent;
+  static int indent;
  warnings w = flag (argv[1]);
  location loc;
  location *locp = NULL;
@@ -359,11 +359,11 @@ state_hasher (void const *s, size_t tablesize)
 void
 state_hash_new (void)
 {
-  state_table = hash_initialize (HT_INITIAL_CAPACITY,
-                                 NULL,
-                                 state_hasher,
-                                 state_comparator,
-                                 NULL);
+  state_table = hash_xinitialize (HT_INITIAL_CAPACITY,
+                                  NULL,
+                                  state_hasher,
+                                  state_comparator,
+                                  NULL);
 }


@@ -34,7 +34,7 @@ symbol_list_sym_new (symbol *sym, location loc)

  res->content_type = SYMLIST_SYMBOL;
  res->content.sym = sym;
-  res->location = res->sym_loc = loc;
+  res->sym_loc = loc;
  res->named_ref = NULL;

  res->midrule = NULL;
@@ -42,13 +42,14 @@ symbol_list_sym_new (symbol *sym, location loc)
  res->midrule_parent_rhs_index = 0;

  /* Members used for LHS only.  */
+  res->rhs_loc = empty_loc;
  res->ruleprec = NULL;
-  res->percent_empty_loc = empty_location;
+  res->percent_empty_loc = empty_loc;
  code_props_none_init (&res->action_props);
  res->dprec = 0;
-  res->dprec_location = empty_location;
+  res->dprec_loc = empty_loc;
  res->merger = 0;
-  res->merger_declaration_location = empty_location;
+  res->merger_declaration_loc = empty_loc;
  res->expected_sr_conflicts = -1;
  res->expected_rr_conflicts = -1;

@@ -73,7 +74,7 @@ symbol_list_type_new (uniqstr type_name, location loc)
  res->content.sem_type->location = loc;
  res->content.sem_type->status = undeclared;

-  res->location = res->sym_loc = loc;
+  res->sym_loc = loc;
  res->named_ref = NULL;
  res->next = NULL;

@@ -50,7 +50,6 @@ typedef struct symbol_list
     */
    semantic_type *sem_type;
  } content;
-  location location;

  /* Named reference. */
  named_ref *named_ref;
@@ -74,6 +73,9 @@ typedef struct symbol_list
  | when several RHSs are bound to a single lhs via "|").         |
  `--------------------------------------------------------------*/

+  /* Location of the RHS. */
+  location rhs_loc;
+
  /* Precedence/associativity.  */
  symbol *ruleprec;

@@ -82,13 +84,13 @@ typedef struct symbol_list
  code_props action_props;

  /* The location of the first %empty for this rule, or \a
-     empty_location.  */
+     empty_loc.  */
  location percent_empty_loc;

  int dprec;
-  location dprec_location;
+  location dprec_loc;
  int merger;
-  location merger_declaration_location;
+  location merger_declaration_loc;

  /* Counts of the number of expected conflicts for this rule, or -1 if none
     given. */
@@ -24,18 +24,27 @@
 #include "system.h"

 #include <assure.h>
+#include <fstrcmp.h>
 #include <hash.h>

 #include "complain.h"
+#include "getargs.h"
 #include "gram.h"
+#include "intprops.h"
+#include "quote.h"

-/*-------------------------------------------------------------------.
-| Symbols sorted by tag.  Allocated by the first invocation of       |
-| symbols_do, after which no more symbols should be created.         |
-`-------------------------------------------------------------------*/
+
+static struct hash_table *symbol_table = NULL;
+static struct hash_table *semantic_type_table = NULL;
+
+/*----------------------------------------------------------------.
+| Symbols sorted by tag.  Allocated by table_sort, after which no |
+| more symbols should be created.                                 |
+`----------------------------------------------------------------*/

 static symbol **symbols_sorted = NULL;
-static symbol **semantic_types_sorted = NULL;
+static semantic_type **semantic_types_sorted = NULL;
+

 /*------------------------.
 | Distinguished symbols.  |
@@ -46,7 +55,7 @@ symbol *undeftoken = NULL;
 symbol *endtoken = NULL;
 symbol *accept = NULL;
 symbol *startsymbol = NULL;
-location startsymbol_location;
+location startsymbol_loc;

 /* Precedence relation graph. */
 static symgraph **prec_nodes;
@@ -149,8 +158,8 @@ symbol_free (void *ptr)
   declaration first.
 */

-static
-void symbols_sort (symbol **first, symbol **second)
+static void
+symbols_sort (symbol **first, symbol **second)
 {
  if (0 < location_cmp ((*first)->location, (*second)->location))
    {
@@ -162,8 +171,8 @@ void symbols_sort (symbol **first, symbol **second)

 /* Likewise, for locations.  */

-static
-void locations_sort (location *first, location *second)
+static void
+locations_sort (location *first, location *second)
 {
  if (0 < location_cmp (*first, *second))
    {
@@ -198,7 +207,7 @@ semantic_type_new (uniqstr tag, const location *loc)

  uniqstr_assert (tag);
  res->tag = tag;
-  res->location = loc ? *loc : empty_location;
+  res->location = loc ? *loc : empty_loc;
  res->status = undeclared;
  for (int i = 0; i < CODE_PROPS_SIZE; ++i)
    code_props_none_init (&res->props[i]);
@@ -279,7 +288,7 @@ static void
 complain_symbol_redeclared (symbol *s, const char *what, location first,
                            location second)
 {
-  unsigned i = 0;
+  int i = 0;
  locations_sort (&first, &second);
  complain_indent (&second, complaint, &i,
                   _("%s redeclaration for %s"), what, s->tag);
@@ -292,7 +301,7 @@ static void
 complain_semantic_type_redeclared (semantic_type *s, const char *what, location first,
                                   location second)
 {
-  unsigned i = 0;
+  int i = 0;
  locations_sort (&first, &second);
  complain_indent (&second, complaint, &i,
                   _("%s redeclaration for <%s>"), what, s->tag);
@@ -304,7 +313,7 @@ complain_semantic_type_redeclared (semantic_type *s, const char *what, location
 static void
 complain_class_redeclared (symbol *sym, symbol_class class, location second)
 {
-  unsigned i = 0;
+  int i = 0;
  complain_indent (&second, complaint, &i,
                   class == token_sym
                   ? _("symbol %s redeclared as a token")
@@ -317,6 +326,55 @@ complain_class_redeclared (symbol *sym, symbol_class class, location second)
    }
 }

+static const symbol *
+symbol_from_uniqstr_fuzzy (const uniqstr key)
+{
+  aver (symbols_sorted);
+#define FSTRCMP_THRESHOLD 0.6
+  double best_similarity = FSTRCMP_THRESHOLD;
+  const symbol *res = NULL;
+  size_t count = hash_get_n_entries (symbol_table);
+  for (int i = 0; i < count; ++i)
+    {
+      symbol *sym = symbols_sorted[i];
+      if (STRNEQ (key, sym->tag)
+          && (sym->content->status == declared
+              || sym->content->status == undeclared))
+        {
+          double similarity = fstrcmp_bounded (key, sym->tag, best_similarity);
+          if (best_similarity < similarity)
+            {
+              res = sym;
+              best_similarity = similarity;
+            }
+        }
+    }
+  return res;
+}
+
+static void
+complain_symbol_undeclared (symbol *sym)
+{
+  assert (sym->content->status != declared);
+  const symbol *best = symbol_from_uniqstr_fuzzy (sym->tag);
+  if (best)
+    {
+      complain (&sym->location,
+                sym->content->status == needed ? complaint : Wother,
+                _("symbol %s is used, but is not defined as a token"
+                  " and has no rules; did you mean %s?"),
+                quote_n (0, sym->tag),
+                quote_n (1, best->tag));
+      if (feature_flag & feature_caret)
+        location_caret_suggestion (sym->location, best->tag, stderr);
+    }
+  else
+    complain (&sym->location,
+              sym->content->status == needed ? complaint : Wother,
+              _("symbol %s is used, but is not defined as a token"
+                " and has no rules"),
+              quote (sym->tag));
+}

 void
 symbol_location_as_lhs_set (symbol *sym, location loc)
@@ -339,12 +397,12 @@ symbol_type_set (symbol *sym, uniqstr type_name, location loc)
      tag_seen = true;
      if (sym->content->type_name)
        complain_symbol_redeclared (sym, "%type",
-                                    sym->content->type_location, loc);
+                                    sym->content->type_loc, loc);
      else
        {
          uniqstr_assert (type_name);
          sym->content->type_name = type_name;
-          sym->content->type_location = loc;
+          sym->content->type_loc = loc;
        }
    }
 }
@@ -426,12 +484,12 @@ symbol_precedence_set (symbol *sym, int prec, assoc a, location loc)
      sym_content *s = sym->content;
      if (s->prec)
        complain_symbol_redeclared (sym, assoc_to_string (a),
-                                    s->prec_location, loc);
+                                    s->prec_loc, loc);
      else
        {
          s->prec = prec;
          s->assoc = a;
-          s->prec_location = loc;
+          s->prec_loc = loc;
        }
    }

@@ -462,7 +520,14 @@ symbol_class_set (symbol *sym, symbol_class class, location loc, bool declaring)
      if (declaring)
        {
          if (s->status == declared)
-            complain (&loc, Wother, _("symbol %s redeclared"), sym->tag);
+            {
+              int i = 0;
+              complain_indent (&loc, Wother, &i,
+                               _("symbol %s redeclared"), sym->tag);
+              i += SUB_INDENT;
+              complain_indent (&sym->location, Wother, &i,
+                               _("previous declaration"));
+            }
          else
            s->status = declared;
        }
@@ -485,11 +550,14 @@ symbol_user_token_number_set (symbol *sym, int user_token_number, location loc)
           && *user_token_numberp != user_token_number)
    complain (&loc, complaint, _("redefining user token number of %s"),
              sym->tag);
+  else if (user_token_number == INT_MAX)
+    complain (&loc, complaint, _("user token number of %s too large"),
+              sym->tag);
  else
    {
      *user_token_numberp = user_token_number;
      /* User defined $end token? */
-      if (user_token_number == 0)
+      if (user_token_number == 0 && !endtoken)
        {
          endtoken = sym->content->symbol;
          /* It is always mapped to 0, so it was already counted in
@@ -507,18 +575,13 @@ symbol_user_token_number_set (symbol *sym, int user_token_number, location loc)
 | nonterminal.                                              |
 `----------------------------------------------------------*/

-static inline bool
+static void
 symbol_check_defined (symbol *sym)
 {
  sym_content *s = sym->content;
  if (s->class == unknown_sym)
    {
-      assert (s->status != declared);
-      complain (&sym->location,
-                s->status == needed ? complaint : Wother,
-                _("symbol %s is used, but is not defined as a token"
-                  " and has no rules"),
-                  sym->tag);
+      complain_symbol_undeclared (sym);
      s->class = nterm_sym;
      s->number = nvars++;
    }
@@ -534,11 +597,9 @@ symbol_check_defined (symbol *sym)
      if (sem_type)
        sem_type->status = declared;
    }
-
-  return true;
 }

-static inline bool
+static void
 semantic_type_check_defined (semantic_type *sem_type)
 {
  /* <*> and <> do not have to be "declared".  */
@@ -557,24 +618,8 @@ semantic_type_check_defined (semantic_type *sem_type)
    complain (&sem_type->location, Wother,
              _("type <%s> is used, but is not associated to any symbol"),
              sem_type->tag);
-
-  return true;
 }

-static bool
-symbol_check_defined_processor (void *sym, void *null ATTRIBUTE_UNUSED)
-{
-  return symbol_check_defined (sym);
-}
-
-static bool
-semantic_type_check_defined_processor (void *sem_type,
-                                       void *null ATTRIBUTE_UNUSED)
-{
-  return semantic_type_check_defined (sem_type);
-}
-
-
 /*-------------------------------------------------------------------.
 | Merge the properties (precedence, associativity, etc.) of SYM, and |
 | its string-named alias STR; check consistency.                     |
@@ -587,10 +632,10 @@ symbol_merge_properties (symbol *sym, symbol *str)
    {
      if (str->content->type_name)
        symbol_type_set (sym,
-                         str->content->type_name, str->content->type_location);
+                         str->content->type_name, str->content->type_loc);
      else
        symbol_type_set (str,
-                         sym->content->type_name, sym->content->type_location);
+                         sym->content->type_name, sym->content->type_loc);
    }


@@ -604,10 +649,10 @@ symbol_merge_properties (symbol *sym, symbol *str)
    {
      if (str->content->prec)
        symbol_precedence_set (sym, str->content->prec, str->content->assoc,
-                               str->content->prec_location);
+                               str->content->prec_loc);
      else
        symbol_precedence_set (str, sym->content->prec, sym->content->assoc,
-                               sym->content->prec_location);
+                               sym->content->prec_loc);
    }
 }

@@ -641,7 +686,7 @@ symbol_make_alias (symbol *sym, symbol *str, location loc)
 | into FDEFINES.  Put in SYMBOLS.                                    |
 `-------------------------------------------------------------------*/

-static inline bool
+static void
 symbol_pack (symbol *this)
 {
  aver (this->content->number != NUMBER_UNDEFINED);
@@ -649,19 +694,12 @@ symbol_pack (symbol *this)
    this->content->number += ntokens;

  symbols[this->content->number] = this->content->symbol;
-  return true;
-}
-
-static bool
-symbol_pack_processor (void *this, void *null ATTRIBUTE_UNUSED)
-{
-  return symbol_pack (this);
 }

 static void
 complain_user_token_number_redeclared (int num, symbol *first, symbol *second)
 {
-  unsigned i = 0;
+  int i = 0;
  symbols_sort (&first, &second);
  complain_indent (&second->location, complaint, &i,
                   _("user token number %d redeclaration for %s"),
@@ -676,7 +714,7 @@ complain_user_token_number_redeclared (int num, symbol *first, symbol *second)
 | Put THIS in TOKEN_TRANSLATIONS if it is a token.  |
 `--------------------------------------------------*/

-static inline bool
+static void
 symbol_translation (symbol *this)
 {
  /* Nonterminal? */
@@ -693,14 +731,6 @@ symbol_translation (symbol *this)
        token_translations[this->content->user_token_number]
          = this->content->number;
    }
-
-  return true;
-}
-
-static bool
-symbol_translation_processor (void *this, void *null ATTRIBUTE_UNUSED)
-{
-  return symbol_translation (this);
 }


@@ -711,9 +741,6 @@ symbol_translation_processor (void *this, void *null ATTRIBUTE_UNUSED)
 /* Initial capacity of symbol and semantic type hash table.  */
 #define HT_INITIAL_CAPACITY 257

-static struct hash_table *symbol_table = NULL;
-static struct hash_table *semantic_type_table = NULL;
-
 static inline bool
 hash_compare_symbol (const symbol *m1, const symbol *m2)
 {
@@ -773,16 +800,33 @@ hash_semantic_type_hasher (void const *m, size_t tablesize)
 void
 symbols_new (void)
 {
-  symbol_table = hash_initialize (HT_INITIAL_CAPACITY,
-                                  NULL,
-                                  hash_symbol_hasher,
-                                  hash_symbol_comparator,
-                                  symbol_free);
-  semantic_type_table = hash_initialize (HT_INITIAL_CAPACITY,
-                                         NULL,
-                                         hash_semantic_type_hasher,
-                                         hash_semantic_type_comparator,
-                                         free);
+  symbol_table = hash_xinitialize (HT_INITIAL_CAPACITY,
+                                   NULL,
+                                   hash_symbol_hasher,
+                                   hash_symbol_comparator,
+                                   symbol_free);
+
+  /* Construct the accept symbol. */
+  accept = symbol_get ("$accept", empty_loc);
+  accept->content->class = nterm_sym;
+  accept->content->number = nvars++;
+
+  /* Construct the error token */
+  errtoken = symbol_get ("error", empty_loc);
+  errtoken->content->class = token_sym;
+  errtoken->content->number = ntokens++;
+
+  /* Construct a token that represents all undefined literal tokens.
+     It is always token number 2.  */
+  undeftoken = symbol_get ("$undefined", empty_loc);
+  undeftoken->content->class = token_sym;
+  undeftoken->content->number = ntokens++;
+
+  semantic_type_table = hash_xinitialize (HT_INITIAL_CAPACITY,
+                                          NULL,
+                                          hash_semantic_type_hasher,
+                                          hash_semantic_type_comparator,
+                                          free);
 }


@@ -899,36 +943,25 @@ symbols_free (void)
 }


-/*---------------------------------------------------------------.
-| Look for undefined symbols, report an error, and consider them |
-| terminals.                                                     |
-`---------------------------------------------------------------*/
-
 static int
-symbols_cmp (symbol const *a, symbol const *b)
+symbol_cmp (void const *a, void const *b)
 {
-  return strcmp (a->tag, b->tag);
+  return location_cmp ((*(symbol * const *)a)->location,
+                       (*(symbol * const *)b)->location);
 }

-static int
-symbols_cmp_qsort (void const *a, void const *b)
-{
-  return symbols_cmp (*(symbol * const *)a, *(symbol * const *)b);
-}
+/* Store in *SORTED an array of pointers to the symbols contained in
+   TABLE, sorted (alphabetically) by tag. */

 static void
-symbols_do (Hash_processor processor, void *processor_data,
-            struct hash_table *table, symbol ***sorted)
+table_sort (struct hash_table *table, symbol ***sorted)
 {
+  aver (!*sorted);
  size_t count = hash_get_n_entries (table);
-  if (!*sorted)
-    {
-      *sorted = xnmalloc (count, sizeof **sorted);
-      hash_get_entries (table, (void**)*sorted, count);
-      qsort (*sorted, count, sizeof **sorted, symbols_cmp_qsort);
-    }
-  for (size_t i = 0; i < count; ++i)
-    processor ((*sorted)[i], processor_data);
+  *sorted = xnmalloc (count + 1, sizeof **sorted);
+  hash_get_entries (table, (void**)*sorted, count);
+  qsort (*sorted, count, sizeof **sorted, symbol_cmp);
+  (*sorted)[count] = NULL;
 }

 /*--------------------------------------------------------------.
@@ -939,10 +972,20 @@ symbols_do (Hash_processor processor, void *processor_data,
 void
 symbols_check_defined (void)
 {
-  symbols_do (symbol_check_defined_processor, NULL,
-              symbol_table, &symbols_sorted);
-  symbols_do (semantic_type_check_defined_processor, NULL,
-              semantic_type_table, &semantic_types_sorted);
+  table_sort (symbol_table, &symbols_sorted);
+  /* semantic_type, like symbol, starts with a 'tag' field and then a
+     'location' field.  And here we only deal with arrays/hashes of
+     pointers, sizeof is not an issue.
+
+     So instead of implementing table_sort (and symbol_cmp) once for
+     each type, let's lie a bit to the typing system, and treat
+     'semantic_type' as if it were 'symbol'. */
+  table_sort (semantic_type_table, (symbol ***) &semantic_types_sorted);
+
+  for (int i = 0; symbols_sorted[i]; ++i)
+    symbol_check_defined (symbols_sorted[i]);
+  for (int i = 0; semantic_types_sorted[i]; ++i)
+    semantic_type_check_defined (semantic_types_sorted[i]);
 }

 /*------------------------------------------------------------------.
@@ -983,7 +1026,13 @@ symbols_token_translations_init (void)
    {
      sym_content *this = symbols[i]->content;
      if (this->user_token_number == USER_NUMBER_UNDEFINED)
-        this->user_token_number = ++max_user_token_number;
+        {
+          IGNORE_TYPE_LIMITS_BEGIN
+          if (INT_ADD_WRAPV (max_user_token_number, 1, &max_user_token_number))
+            complain (NULL, fatal, _("token number too large"));
+          IGNORE_TYPE_LIMITS_END
+          this->user_token_number = max_user_token_number;
+        }
      if (this->user_token_number > max_user_token_number)
        max_user_token_number = this->user_token_number;
    }
@@ -993,10 +1042,10 @@ symbols_token_translations_init (void)

  /* Initialize all entries for literal tokens to the internal token
     number for $undefined, which represents all invalid inputs.  */
-  for (int i = 0; i < max_user_token_number + 1; i++)
+  for (int i = 0; i < max_user_token_number + 1; ++i)
    token_translations[i] = undeftoken->content->number;
-  symbols_do (symbol_translation_processor, NULL,
-              symbol_table, &symbols_sorted);
+  for (int i = 0; symbols_sorted[i]; ++i)
+    symbol_translation (symbols_sorted[i]);
 }


@@ -1009,7 +1058,8 @@ void
 symbols_pack (void)
 {
  symbols = xcalloc (nsyms, sizeof *symbols);
-  symbols_do (symbol_pack_processor, NULL, symbol_table, &symbols_sorted);
+  for (int i = 0; symbols_sorted[i]; ++i)
+    symbol_pack (symbols_sorted[i]);

  /* Aliases leave empty slots in symbols, so remove them.  */
  {
@@ -1034,11 +1084,11 @@ symbols_pack (void)
  symbols_token_translations_init ();

  if (startsymbol->content->class == unknown_sym)
-    complain (&startsymbol_location, fatal,
+    complain (&startsymbol_loc, fatal,
              _("the start symbol %s is undefined"),
              startsymbol->tag);
  else if (startsymbol->content->class == token_sym)
-    complain (&startsymbol_location, fatal,
+    complain (&startsymbol_loc, fatal,
              _("the start symbol %s is a token"),
              startsymbol->tag);
 }
@@ -1209,14 +1259,14 @@ print_precedence_warnings (void)
          && !prec_nodes[i]->succ)
        {
          if (is_assoc_useless (s))
-            complain (&s->content->prec_location, Wprecedence,
+            complain (&s->content->prec_loc, Wprecedence,
                      _("useless precedence and associativity for %s"), s->tag);
          else if (s->content->assoc == precedence_assoc)
-            complain (&s->content->prec_location, Wprecedence,
+            complain (&s->content->prec_loc, Wprecedence,
                      _("useless precedence for %s"), s->tag);
        }
      else if (is_assoc_useless (s))
-        complain (&s->content->prec_location, Wprecedence,
+        complain (&s->content->prec_loc, Wprecedence,
                  _("useless associativity for %s, use %%precedence"), s->tag);
    }
  free (used_assoc);
@@ -122,7 +122,7 @@ struct sym_content
  uniqstr type_name;

  /** Its \c \%type's location.  */
-  location type_location;
+  location type_loc;

  /** Any \c \%destructor (resp. \%printer) declared specificially for this
      symbol.
@@ -134,7 +134,7 @@ struct sym_content
  code_props props[CODE_PROPS_SIZE];

  symbol_number number;
-  location prec_location;
+  location prec_loc;
  int prec;
  assoc assoc;

@@ -246,7 +246,7 @@ extern symbol *accept;
 /** The user start symbol. */
 extern symbol *startsymbol;
 /** The location of the \c \%start declaration.  */
-extern location startsymbol_location;
+extern location startsymbol_loc;

 /** Whether a symbol declared with a type tag.  */
 extern bool tag_seen;
@@ -345,7 +345,8 @@ void semantic_type_code_props_set (semantic_type *type,
 | Symbol and semantic type tables.  |
 `----------------------------------*/

-/** Create the symbol and semantic type tables.  */
+/** Create the symbol and semantic type tables, and the built-in
+    symbols.  */
 void symbols_new (void);

 /** Free all the memory allocated for symbols and semantic types.  */
@@ -74,6 +74,19 @@ typedef size_t uintptr_t;
 # include <xalloc.h>


+/* See https://lists.gnu.org/archive/html/bug-bison/2019-10/msg00061.html. */
+# if defined __GNUC__ && ! defined __clang__ && ! defined __ICC && __GNUC__ < 5
+#  define IGNORE_TYPE_LIMITS_BEGIN \
+     _Pragma ("GCC diagnostic push") \
+     _Pragma ("GCC diagnostic ignored \"-Wtype-limits\"")
+#  define IGNORE_TYPE_LIMITS_END \
+     _Pragma ("GCC diagnostic pop")
+# else
+#  define IGNORE_TYPE_LIMITS_BEGIN
+#  define IGNORE_TYPE_LIMITS_END
+# endif
+
+
 /*-----------------.
 | GCC extensions.  |
 `-----------------*/
@@ -249,14 +262,4 @@ typedef size_t uintptr_t;
      }                                         \
  } while (0)

-
-/*---------------------------------------------.
-| Debugging memory allocation (must be last).  |
-`---------------------------------------------*/
-
-# if WITH_DMALLOC
-#  define DMALLOC_FUNC_CHECK
-#  include <dmalloc.h>
-# endif /* WITH_DMALLOC */
-
 #endif  /* ! BISON_SYSTEM_H */
@@ -84,7 +84,7 @@ int nvectors;

 static base_number **froms;
 static base_number **tos;
-static unsigned **conflict_tos;
+static int **conflict_tos;
 static size_t *tally;
 static base_number *width;

@@ -115,9 +115,9 @@ base_number base_ninf = 0;
   -nstates..table_size (as an upper bound) */
 static bitset pos_set = NULL;

-static unsigned *conflrow;
-unsigned *conflict_table;
-unsigned *conflict_list;
+static int *conflrow;
+int *conflict_table;
+int *conflict_list;
 int conflict_list_cnt;
 static int conflict_list_free;

@@ -391,7 +391,7 @@ save_row (state_number s)
      /* Allocate non defaulted actions.  */
      base_number *sp1 = froms[s] = xnmalloc (count, sizeof *sp1);
      base_number *sp2 = tos[s] = xnmalloc (count, sizeof *sp2);
-      unsigned *sp3 = conflict_tos[s] =
+      int *sp3 = conflict_tos[s] =
        nondeterministic_parser ? xnmalloc (count, sizeof *sp3) : NULL;

      /* Store non defaulted actions.  */
@@ -646,7 +646,7 @@ pack_vector (vector_number vector)
  size_t t = tally[i];
  base_number *from = froms[i];
  base_number *to = tos[i];
-  unsigned *conflict_to = conflict_tos[i];
+  int *conflict_to = conflict_tos[i];

  aver (t != 0);

@@ -122,8 +122,8 @@ extern base_number *base;
   keep parser tables small.  */
 extern base_number base_ninf;

-extern unsigned *conflict_table;
-extern unsigned *conflict_list;
+extern int *conflict_table;
+extern int *conflict_list;
 extern int conflict_list_cnt;

 extern base_number *table;
@@ -157,11 +157,11 @@ hash_uniqstr (void const *m, size_t tablesize)
 void
 uniqstrs_new (void)
 {
-  uniqstrs_table = hash_initialize (HT_INITIAL_CAPACITY,
-                                    NULL,
-                                    hash_uniqstr,
-                                    hash_compare_uniqstr,
-                                    free);
+  uniqstrs_table = hash_xinitialize (HT_INITIAL_CAPACITY,
+                                     NULL,
+                                     hash_uniqstr,
+                                     hash_compare_uniqstr,
+                                     free);
 }


--- a/Show More
+++ b/Show More
@@ -1 +1 @@
 .3.2
 .4.2