version 3.5.1

* NEWS: Record release date.

.gitignore

@@ -1,9 +1,6 @@
-/ABOUT-NLS~
-*.eps
 *.log
 *.o
 *.pdf
-*.png
 *.stamp
 *.trs
 *~

.prev-version

@@ -1 +1 @@
-3.4
+3.5

.travis.yml

@@ -1,14 +1,8 @@
-# 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.
-language: cpp
+version: ~> 1.0
 
-env:
-  global:
-    # ICC serial number.
-    # See https://github.com/nemequ/icc-travis.
-    secure: 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
+# If the language is set to C or C++, Travis defines and exports CC
+# and CXX *after* we have defined our environment variables via 'env'.
+language: minimal
 
 # Run in two steps:
 # 1. Build the tarball
@@ -17,24 +11,23 @@ env:
 #    Less dependencies, and little git content (we would like to have none, but it's not
 #    an option on Travis).
 stages:
-  - compile
-  - test
+  - 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:
-  # Manually handle submodules so that we don't have to uselessly waste 150s
-  # to download gnulib in the 'test' jobs.
-  submodules: false
-
-  # For the same reasons, we would like to not clone the repo either, but it
-  # does not seem to be possible.
-  depth: 1
+  clone: false
 
 # matrix.include and jobs.include are aliases
 # (https://docs.travis-ci.com/user/conditional-builds-stages-jobs/).
 jobs:
   include:
-    - stage: "compile"
-      dist: xenial
+    - 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
@@ -51,16 +44,24 @@ jobs:
         - git submodule update --init --recursive
 
         - ./bootstrap
-        - ./configure --enable-gcc-warnings CC="$CC" CXX="$CXX" $CONFIGUREFLAGS || { cat config.log && false; }
+        - ./configure --enable-gcc-warnings || { cat config.log && false; }
         - make -j2
         - make -j2 dist
+        # Can help understanding why we get "dirty" tarballs.
+        - git status
         - dist=$(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).  Besides, one day we would like not to depend on the repository at all in the
-        # 'test' jobs.  So also expose this tarball on a name that only depends on the Travis build
-        # number.
-        - sftp [email protected] <<< "put $dist"$'\n'"ln -s $dist bison-$TRAVIS_BUILD_NUMBER.tar.xz"
+        # 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.  ##
@@ -69,173 +70,217 @@ jobs:
     # Start with three completely different environments, to get
     # errors asap.
 
-    - name: "GCC 7 -O3"
-      stage: test
+    - 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'"
+        - 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 one go.  Run in two parts.
-    - name: "Clang 7 libc++ and ASAN part 1"
-      stage: test
+    - 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++'"
+        - CC='clang-9 -fsanitize=address'
+        - CXX='clang++-9 -fsanitize=address -stdlib=libc++'
+        - PART=1
 
-    - name: "Clang 7 libc++ and ASAN part 2"
-      stage: test
+    - 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++'"
+        - CC='clang-9 -fsanitize=address'
+        - CXX='clang++-9 -fsanitize=address -stdlib=libc++'
+        - PART=2
 
     - name: "ICC"
-      stage: test
+      stage: check
       os: linux
-      dist: xenial
+      compiler: icc
       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='
-
+        - CC=icc
+        - CXX=icpc
+      install:
+        - source /opt/intel/inteloneapi/compiler/latest/env/vars.sh
+      addons:
+        apt:
+          sources:
+          - sourceline: 'deb https://apt.repos.intel.com/oneapi all main'
+            key_url: 'https://apt.repos.intel.com/intel-gpg-keys/GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB'
+          packages:
+          - intel-oneapi-icc
 
     ## ----- ##
     ## 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:
+        - 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:
+        - CC=gcc-8
+        - CXX=g++-8
+
+    - name: "GCC 7"
+      stage: check
+      os: linux
+      dist: bionic
+      addons:
+        apt:
+          packages: g++-7
+      env:
+        - CC=gcc-7
+        - CXX=g++-7
 
     - name: "GCC 6"
-      stage: test
+      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"
+        - CC=gcc-6
+        - CXX=g++-6
 
     - name: "GCC 5"
-      stage: test
+      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"
+         - CC=gcc-5
+         - CXX=g++-5
 
     - name: "GCC 4.9"
-      stage: test
+      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"
+         - CC=gcc-4.9
+         - CXX=g++-4.9
 
     - name: "GCC 4.8"
-      stage: test
+      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"
+         - CC=gcc-4.8
+         - CXX=g++-4.8
 
     - name: "GCC 4.7"
-      stage: test
+      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"
+         - CC=gcc-4.7
+         - CXX=g++-4.7
 
     - name: "GCC 4.6"
-      stage: test
+      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"
+         - CC=gcc-4.6
+         - CXX=g++-4.6
 
     ## ------- ##
     ## Clang.  ##
     ## ------- ##
 
-    - name: "Clang 6 -O3 and libc++"
-      stage: test
+    - name: "Clang 8 -O3"
+      stage: check
+      os: linux
+      dist: bionic
+      addons:
+        apt:
+          packages:
+            - clang-8
+            - libc++-8-dev
+            - libc++abi-8-dev
+      env:
+        - 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:
+        - CC=clang-7
+        - CXX='clang++-7 -stdlib=libc++'
+
+    - name: "Clang 6 and libc++"
+      stage: check
       os: linux
       dist: xenial
       addons:
@@ -247,51 +292,49 @@ jobs:
             - clang-6.0
             - libc++-dev
       env:
-        - MATRIX_EVAL="CC=clang-6.0 && CXX='clang++-6.0 -stdlib=libc++'"
-        - CONFIGUREFLAGS='CPPFLAGS=-DNDEBUG CFLAGS=-O3 CXXFLAGS=-O3'
+        - CC=clang-6.0
+        - CXX='clang++-6.0 -stdlib=libc++'
 
     - name: "Clang 5"
-      stage: test
+      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
       env:
-        - MATRIX_EVAL="CC='clang-5.0' CXX='clang++-5.0'"
+        - CC='clang-5.0'
+        - CXX='clang++-5.0'
 
     - name: "Clang 4"
-      stage: test
+      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"
+        - CC=clang-4.0
+        - CXX=clang++-4.0
 
     - name: "Clang 3.9"
-      stage: test
+      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"
+        - CC=clang-3.9
+        - CXX=clang++-3.9
 
     - name: "Clang 3.8"
-      stage: test
+      stage: check
       os: linux
       dist: xenial
       addons:
@@ -299,13 +342,13 @@ jobs:
           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"
+        - CC=clang-3.8
+        - CXX=clang++-3.8
 
     - name: "CLang 3.7"
-      stage: test
+      stage: check
       os: linux
       dist: xenial
       addons:
@@ -313,13 +356,13 @@ jobs:
           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"
+        - CC=clang-3.7
+        - CXX=clang++-3.7
 
     - name: "Clang 3.6"
-      stage: test
+      stage: check
       os: linux
       dist: xenial
       addons:
@@ -327,13 +370,13 @@ jobs:
           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"
+        - CC=clang-3.6
+        - CXX=clang++-3.6
 
     - name: "Clang 3.5"
-      stage: test
+      stage: check
       os: linux
       dist: xenial
       addons:
@@ -341,37 +384,37 @@ jobs:
           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"
+        - CC=clang-3.5
+        - CXX=clang++-3.5
 
     - name: "Clang 3.4"
-      stage: test
+      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++'
+        - CC=/usr/bin/clang
+        - CXX=/usr/bin/clang++
 
     - name: "Clang 3.3"
-      stage: test
+      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++'
+        - 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).
@@ -387,15 +430,11 @@ before_script:
   - echo '|1|bpc51UGxoDZjCPiwRlCStW32trI=|rfh6mLoLZv/vAvOVrpZXI1hTLxg= ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBIR+ckMoJTNXHvAQLHWSfrRnrNJGW2ZR6kr5pBVDGCkz1v1RcQ5rleq0NAt9kS3v4hgnuLiEVnK7KDRzcEH3ikc=' >>~/.ssh/known_hosts
   - chmod 600 ~/.ssh/known_hosts
 
-# Applies only to the jobs that don't have a 'script', i.e., applies to all the 'test' jobs, but not the 'compile' one.
+# 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"
   # 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.
   - mkdir -p ~/dlang && wget https://dlang.org/install.sh -O ~/dlang/install.sh
   - source $(source ~/dlang/install.sh dmd -a)
@@ -413,6 +452,9 @@ script:
   # with `Picked up _JAVA_OPTIONS: -Xmx2048m -Xms512m`, which makes
   # the test suite fail.
   - unset _JAVA_OPTIONS
+
+  # Fail fast from now on.
+  - set -e
   - sftp [email protected]:bison-$TRAVIS_BUILD_NUMBER.tar.xz
   - tar xf bison-$TRAVIS_BUILD_NUMBER.tar.xz
   - dir=$(tar tf bison-$TRAVIS_BUILD_NUMBER.tar.xz | sed 1q)
@@ -422,8 +464,5 @@ script:
   - ../configure --enable-gcc-warnings CC="$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

AUTHORS

@@ -24,7 +24,7 @@ and nasty bugs.
 
 -----
 
-Copyright (C) 1998-2015, 2018-2019 Free Software Foundation, Inc.
+Copyright (C) 1998-2015, 2018-2020 Free Software Foundation, Inc.
 
 This file is part of Bison, the GNU Compiler Compiler.
 

ChangeLog-2012

@@ -26733,7 +26733,7 @@
 
 	-----
 
-	Copyright (C) 1987-1988, 1991-2015, 2018-2019 Free Software
+	Copyright (C) 1987-1988, 1991-2015, 2018-2020 Free Software
 	Foundation, Inc.
 
 	Copying and distribution of this file, with or without

Makefile.am

@@ -1,6 +1,6 @@
 ## Process this file with automake to produce Makefile.in.
 
-# Copyright (C) 2001-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2001-2015, 2018-2020 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

NEWS

@@ -1,5 +1,237 @@
 GNU Bison NEWS
 
+* Noteworthy changes in release 3.5.1 (2020-01-19) [stable]
+
+** Bug fixes
+
+  Portability fixes.
+
+  Fix compiler warnings.
+
+* Noteworthy changes in release 3.5 (2019-12-11) [stable]
+
+** 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.  The default position and location classes now expose
+  'counter_type' (int), used to define line and column numbers.
+
+** Deprecated features
+
+  The YYPRINT macro, which works only with yacc.c and only for tokens, was
+  obsoleted long ago by %printer, introduced in Bison 1.50 (November 2002).
+  It is deprecated and its support will be removed eventually.
+
+** 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.
+
+*** 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).
+
+*** 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.
+
+*** A skeleton for the D programming language
+
+  For the last few releases, Bison has shipped a stealth experimental
+  skeleton: lalr1.d.  It was first contributed by Oliver Mangold, based on
+  Paolo Bonzini's lalr1.java, and was cleaned and improved thanks to
+  H. S. Teoh.
+
+  However, because nobody has committed to improving, testing, and
+  documenting this skeleton, it is not clear that it will be supported in
+  the future.
+
+  The lalr1.d skeleton *is functional*, and works well, as demonstrated in
+  examples/d/calc.d.  Please try it, enjoy it, and... commit to support it.
+
+*** 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.
+
+** Diagnostics
+
+*** New diagnostic: -Wdangling-alias
+
+  String literals, which allow for better error messages, are (too)
+  liberally accepted by Bison, which might result in silent errors.  For
+  instance
+
+    %type <exVal> cond "condition"
+
+  does not define "condition" as a string alias to 'cond' (nonterminal
+  symbols do not have string aliases).  It is rather equivalent to
+
+    %nterm <exVal> cond
+    %token <exVal> "condition"
+
+  i.e., it gives the type 'exVal' to the "condition" token, which was
+  clearly not the intention.
+
+  Also, because string aliases need not be defined, typos such as "baz"
+  instead of "bar" will be not reported.
+
+  The option -Wdangling-alias catches these situations.  On
+
+    %token BAR "bar"
+    %type <ival> foo "foo"
+    %%
+    foo: "baz" {}
+
+  bison -Wdangling-alias reports
+
+    warning: string literal not attached to a symbol
+          | %type <ival> foo "foo"
+          |                  ^~~~~
+    warning: string literal not attached to a symbol
+          | foo: "baz" {}
+          |      ^~~~~
+
+   The -Wall option does not (yet?) include -Wdangling-alias.
+
+*** Better POSIX Yacc compatibility diagnostics
+
+  POSIX Yacc restricts %type to nonterminals.  This is now diagnosed by
+  -Wyacc.
+
+    %token TOKEN1
+    %type  <ival> TOKEN1 TOKEN2 't'
+    %token TOKEN2
+    %%
+    expr:
+
+  gives with -Wyacc
+
+    input.y:2.15-20: warning: POSIX yacc reserves %type to nonterminals [-Wyacc]
+        2 | %type  <ival> TOKEN1 TOKEN2 't'
+          |               ^~~~~~
+    input.y:2.29-31: warning: POSIX yacc reserves %type to nonterminals [-Wyacc]
+        2 | %type  <ival> TOKEN1 TOKEN2 't'
+          |                             ^~~
+    input.y:2.22-27: warning: POSIX yacc reserves %type to nonterminals [-Wyacc]
+        2 | %type  <ival> TOKEN1 TOKEN2 't'
+          |                      ^~~~~~
+
+*** Diagnostics with insertion
+
+  The diagnostics now display the 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                     …
+          |        ^~~
+
+** Changes
+
+*** Debugging glr.c and glr.cc
+
+  The glr.c skeleton always had asserts to check its own behavior (not the
+  user's).  These assertions are now under the control of the parse.assert
+  %define variable (disabled by default).
+
+*** Clean up
+
+  Several new compiler warnings in the generated output have been avoided.
+  Some unused features are no longer emitted.  Cleaner generated code in
+  general.
+
+** Bug Fixes
+
+  Portability issues in the test suite.
+
+  In theory, parsers using %nonassoc could crash when reporting verbose
+  error messages. This unlikely bug has been fixed.
+
+  In Java, %define api.prefix was ignored.  It now behaves as expected.
+
+* 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
@@ -883,10 +1115,10 @@ 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
               ^^
 
@@ -3587,7 +3819,7 @@ Output file does not redefine const for C++.
 
 -----
 
-Copyright (C) 1995-2015, 2018-2019 Free Software Foundation, Inc.
+Copyright (C) 1995-2015, 2018-2020 Free Software Foundation, Inc.
 
 This file is part of Bison, the GNU Parser Generator.
 
@@ -3633,7 +3865,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
  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 Teoh
+ LocalWords:  YYPRINT Mangold Bonzini's Wdangling exVal baz checkable gcc
+ LocalWords:  fsanitize Vogelsgesang lis redeclared stdint automata
 
 Local Variables:
 ispell-dictionary: "american"

PACKAGING

@@ -36,7 +36,7 @@ to the bison package.
 
 -----
 
-Copyright (C) 2002, 2005, 2009-2015, 2018-2019 Free Software Foundation,
+Copyright (C) 2002, 2005, 2009-2015, 2018-2020 Free Software Foundation,
 Inc.
 
 This file is part of Bison, the GNU Compiler Compiler.

README

@@ -1,26 +1,47 @@
 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.
+then proceed with the usual `configure && make` steps.
 
-README-hacking contains more information about building and modifying the
-software.
+The file README-hacking.md is 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:
+Bison requires GNU m4 1.4.6 or later.  See
+https://ftp.gnu.org/gnu/m4/m4-1.4.6.tar.gz.
 
-      https://ftp.gnu.org/gnu/m4/m4-1.4.6.tar.gz
+## Colored diagnostics
+As an experimental feature, diagnostics are now colored, controlled by the
+`--color` and `--style` options.
 
-** Relocatability
-If you pass '--enable-relocatable' to 'configure', Bison is relocatable.
+To use them, install the libtextstyle library before configuring Bison.  It
+is available from https://alpha.gnu.org/gnu/gettext/, for instance
+https://alpha.gnu.org/gnu/gettext/libtextstyle-0.8.tar.gz.
+
+The option --color supports the following arguments:
+- always, yes: Enable colors.
+- never, no: Disable colors.
+- auto, tty (default): Enable colors if the output device is a tty.
+
+To customize the styles, create a CSS file, say `bison-bw.css`, similar to
+
+    /* bison-bw.css */
+    .warning   { }
+    .error     { font-weight: 800; text-decoration: underline; }
+    .note      { }
+
+then invoke bison with `--style=bison-bw.css`, or set the `BISON_STYLE`
+environment variable to `bison-bw.css`.
+
+## 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
 file system.  It can also be used through mount points for network sharing.
@@ -29,7 +50,7 @@ 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:
@@ -39,33 +60,27 @@ 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
-"make html".
+provided you have a recent version of Texinfo installed: run `make pdf` or
+`make html`.
 
 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
+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
-fill-column: 76
-ispell-dictionary: "american"
-End:
-
-Copyright (C) 1992, 1998-1999, 2003-2005, 2008-2015, 2018-2019 Free
+Copyright (C) 1992, 1998-1999, 2003-2005, 2008-2015, 2018-2020 Free
 Software Foundation, Inc.
 
 This file is part of GNU bison, the GNU Compiler Compiler.
@@ -83,5 +98,13 @@ 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
+Local Variables:
+mode: markdown
+fill-column: 76
+ispell-dictionary: "american"
+End:
+
+LocalWords:  parsers ngettext Texinfo pdf html YYYY ZZZZ ispell american
+LocalWords:  MERCHANTABILITY
+
+-->

README-alpha

@@ -12,7 +12,7 @@ the problems you encounter.
 
 -----
 
-Copyright (C) 2002, 2004, 2009-2015, 2018-2019 Free Software Foundation,
+Copyright (C) 2002, 2004, 2009-2015, 2018-2020 Free Software Foundation,
 Inc.
 
 This file is part of GNU Bison.

README-hacking.md

@@ -2,20 +2,19 @@ This file attempts to describe the rules to use when hacking Bison.
 Don't put this file into the distribution.
 
 Everything related to the development of Bison is on Savannah:
-
-        http://savannah.gnu.org/projects/bison/
+http://savannah.gnu.org/projects/bison/.
 
 
-* Administrivia
+# Administrivia
 
-** If you incorporate a change from somebody on the net:
+## If you incorporate a change from somebody on the net:
 First, if it is a large change, you must make sure they have signed the
 appropriate paperwork.  Second, be sure to add their name and email address
 to THANKS.
 
-** If a change fixes a test, mention the test in the commit message.
+## If a change fixes a test, mention the test in the commit message.
 
-** Bug reports
+## Bug reports
 If somebody reports a new bug, mention his name in the commit message and in
 the test case you write.  Put him into THANKS.
 
@@ -24,18 +23,18 @@ demonstrates the bug.  Then fix the bug, re-run the test suite, and check
 everything in.
 
 
-* Hacking
+# Hacking
 
-** Visible changes
+## Visible changes
 Which include serious bug fixes, must be mentioned in NEWS.
 
-** Translations
+## Translations
 Only user visible strings are to be translated: error messages, bits of the
 .output file etc.  This excludes impossible error messages (comparable to
 assert/abort), and all the --trace output which is meant for the maintainers
 only.
 
-** Horizontal tabs
+## Horizontal tabs
 Do not add horizontal tab characters to any file in Bison's repository
 except where required.  For example, do not use tabs to format C code.
 However, make files, ChangeLog, and some regular expressions require tabs.
@@ -43,12 +42,12 @@ Also, test cases might need to contain tabs to check that Bison properly
 processes tabs in its input.
 
 
-* Working from the repository
+# 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
+## Requirements
 
 We've opted to keep only the highest-level sources in the repository.  This
 eases our maintenance burden, (fewer merges etc.), but imposes more
@@ -75,8 +74,8 @@ If you're using a GNU/Linux distribution, the easiest way to install the
 above packages depends on your system.  The following shell command should
 work for Debian-based systems such as Ubuntu:
 
-  sudo apt-get install \
-    autoconf automake autopoint flex graphviz help2man texinfo valgrind
+    sudo apt-get install \
+      autoconf automake autopoint flex graphviz help2man texinfo valgrind
 
 Bison is written using Bison grammars, so there are bootstrapping issues.
 The bootstrap script attempts to discover when the C code generated from the
@@ -89,53 +88,51 @@ after synchronizing from the repository a plain 'make' should be sufficient.
 Note, however, that when gnulib is updated, running './bootstrap' again
 might be needed.
 
-** First checkout
+## First checkout
 
 Obviously, if you are reading these notes, you did manage to check out this
 package from the repository.  For the record, you will find all the relevant
-information on:
-
-        http://savannah.gnu.org/git/?group=bison
+information on http://savannah.gnu.org/git/?group=bison.
 
 Bison uses Git submodules: subscriptions to other Git repositories.  In
 particular it uses gnulib, the GNU portability library.  To ask Git to
 perform the first checkout of the submodules, run
 
-        $ git submodule update --init
+    $ git submodule update --init
 
 The next step is to get other files needed to build, which are extracted
 from other source packages:
 
-        $ ./bootstrap
+    $ ./bootstrap
 
 Bootstrapping updates the submodules to the versions registered in the
 top-level directory.  To change gnulib, first check out the version you want
 in `gnulib`, then commit this change in Bison's repository, and finally run
 bootstrap.
 
-If it fails with missing symbols (e.g., "error: possibly undefined macro:
-AC_PROG_GNU_M4"), you are likely to have forgotten the submodule
+If it fails with missing symbols (e.g., `error: possibly undefined macro:
+AC_PROG_GNU_M4`), you are likely to have forgotten the submodule
 initialization part.  To recover from it, run `git reset --hard HEAD`, and
 restart with the submodule initialization.  Otherwise, there you are!  Just
 
-        $ ./configure
-        $ make
-        $ make check
+    $ ./configure
+    $ make
+    $ make check
 
 At this point, there should be no difference between your local copy, and
 the master copy:
 
-        $ git diff
+    $ git diff
 
 should output no difference.
 
 Enjoy!
 
-** Updating
+## Updating
 
 If you have git at version 1.8.2 or later, the command
 
-        $ git submodule update --recursive --remote
+    $ git submodule update --recursive --remote
 
 will be useful for updating to the latest version of all submodules.
 
@@ -143,102 +140,132 @@ Under earlier versions, use of submodules make things somewhat different
 because git does not yet support recursive operations: submodules must be
 taken care of explicitly.
 
-*** Updating Bison
+### Updating Bison
 
-If you pull a newer version of a branch, say via "git pull", you might
-import requests for updated submodules.  A simple "git diff" will reveal if
+If you pull a newer version of a branch, say via `git pull`, you might
+import requests for updated submodules.  A simple `git diff` will reveal if
 the current version of the submodule (i.e., the actual contents of the
 gnulib directory) and the current request from the subscriber (i.e., the
 reference of the version of gnulib that the Bison repository requests)
 differ.  To upgrade the submodules (i.e., to check out the version that is
-actually requested by the subscriber, run "git submodule update".
+actually requested by the subscriber, run `git submodule update`.
 
-        $ git pull
-        $ git submodule update
+    $ git pull
+    $ git submodule update
 
-*** Updating a submodule
+### Updating a submodule
 To update a submodule, say gnulib, do as follows:
 
 Get the most recent version of the master branch from git.
 
-        $ cd gnulib
-        $ git fetch
-        $ git checkout -b master --track origin/master
+    $ cd gnulib
+    $ git fetch
+    $ git checkout -b master --track origin/master
 
 Make sure Bison can live with that version of gnulib.
 
-        $ cd ..
-        $ ./bootstrap
-        $ make distcheck
+    $ cd ..
+    $ ./bootstrap
+    $ make distcheck
 
 Register your changes.
 
-        $ git checkin ...
+    $ git commit ...
 
 For a suggestion of what gnulib commit might be stable enough for a formal
-release, see the ChangeLog in the latest gnulib snapshot at:
-
-        http://erislabs.net/ianb/projects/gnulib/
+release, see the ChangeLog in the latest gnulib snapshot at
+http://erislabs.net/ianb/projects/gnulib/.
 
 The Autoconf files we use are currently:
-
-        m4/m4.m4
-        lib/m4sugar/m4sugar.m4
-        lib/m4sugar/foreach.m4
+- m4/m4.m4
+- lib/m4sugar/m4sugar.m4
+- lib/m4sugar/foreach.m4
 
 These files don't change very often in Autoconf, so it should be relatively
 straight-forward to examine the differences in order to decide whether to
 update.
 
-* Test suite
+# Test Suite
 
-** make check
-Use liberally.
+## make check
+Consume without moderation.  It is composed of two kinds of tests: the
+examples, and the main test suite.
 
-** Updating the expectations
-Sometimes some changes have a large impact on the test suite (e.g., when we
-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.
+### The Examples
+In examples/, there is a number of ready-to-use examples (see
+examples/README.md).  These examples have small test suites run by `make
+check`.  The test results are in local `*.log` files (e.g.,
+`$build/examples/c/calc/calc.log`).
 
-** TESTSUITEFLAGS
+### The Main Test Suite
+The main test suite, in tests/, is written on top of GNU Autotest, which is
+part of Autoconf.  Run `info autoconf 'Using Autotest'` to read the
+documentation, not only about how to write tests, but also where are the
+logs, how to read them etc.
 
-To run just the testsuite (not the tests related to the examples), run `make
-check-local`.
+The main test suite generates a log for each test (e.g.,
+`$build/tests/testsuite.dir/004/testsuite.log` for test #4), and a main log
+file in `$build/tests/testsuite.log`.  The latter is meant for end users: it
+contains lots of details that should help diagnosing issues, including build
+issues.  The per-test logs are more convenient when working locally.
+
+#### TESTSUITEFLAGS
+To run just the main test suite, run `make check-local`.
 
 The default is for make check-local to run all tests sequentially.  This can
 be very time consuming when checking repeatedly or on slower setups.  This
 can be sped up in two ways:
 
 Using -j, in a make-like fashion, for example:
-  $ make check-local TESTSUITEFLAGS='-j8'
+
+    $ 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
-  - deprec, for tests concerning deprecated constructs.
-  - glr, for glr parsers
-  - java, for java parsers
-  - report, for automaton dumps
+- c++, for c++ parsers
+- deprec, for tests concerning deprecated constructs.
+- glr, for glr parsers
+- java, for java parsers
+- report, for automaton dumps
+
+To get a list of all the tests (and their keywords for -k), run
+
+    $ ./tests/testsuite -l
 
 To run a specific set of tests, use -k (for "keyword"). For example:
-  $ make check-local TESTSUITEFLAGS='-k c++'
+
+    $ make check-local TESTSUITEFLAGS='-k c++'
 
 Both can be combined.
 
-** Typical errors
-If the test suite shows failures such as the following one
+    $ make check-local TESTSUITEFLAGS='-j8 -k c++'
 
-  .../bison/lib/getopt.h:196:8: error: redefinition of 'struct option'
-  /usr/include/getopt.h:54:8: error: previous definition of 'struct option'
+To rerun the tests that failed:
 
-it probably means that some file was compiled without
-AT_DATA_SOURCE_PROLOGUE.  This error is due to the fact that our -I options
-pick up gnulib's replacement headers, such as getopt.h, and this will go
-wrong if config.h was not included first.
+    $ make recheck -j5
 
-See tests/local.at for details.
+#### Updating the Expectations
+Sometimes some changes have a large impact on the test suite (e.g., when we
+added the `[-Wother]` part to all the warnings).  Part of the update can be
+done with a crude tool: `build-aux/update-test`.
 
-** make maintainer-check-valgrind
+Once you ran the test suite, and therefore have many `testsuite.log` files,
+run, from the source tree:
+
+    $ ./build-aux/update-test $build/tests/testsuite.dir/*/testsuite.log
+
+where `$build` would be your build tree.  This will hopefully update most
+tests.  Re-run the test suite.  It might be interesting to run `update-test`
+again, since some early failures may stop latter tests from being run.  Yet
+at some point, you'll have to fix remaining issues by hand...
+
+
+## make maintainer-check-valgrind
 This target uses valgrind both to check bison, and the generated parsers.
 
 This is not mature on Mac OS X.  First, Valgrind does support the way bison
@@ -249,13 +276,13 @@ bison.  build-aux/darwin11.4.0.valgrind addresses some of them.
 
 Third, valgrind issues warnings such as:
 
-  --99312:0:syswrap- WARNING: Ignoring sigreturn( ..., UC_RESET_ALT_STACK );
+    --99312:0:syswrap- WARNING: Ignoring sigreturn( ..., UC_RESET_ALT_STACK );
 
 which cause the test to fail uselessly.  It is hard to ignore these errors
 with a major overhaul of the way instrumentation is performed in the test
 suite.  So currently, do not try to run valgrind on Mac OS X.
 
-** Release checks
+## Release checks
 Try to run the test suite with more severe conditions before a
 release:
 
@@ -267,25 +294,25 @@ release:
   its warnings; there's no need to obey blindly to it
   (<http://lists.gnu.org/archive/html/bison-patches/2012-05/msg00057.html>).
 
-- Check with "make syntax-check" if there are issues diagnosed by gnulib.
+- Check with `make syntax-check` if there are issues diagnosed by gnulib.
 
-- run "make maintainer-check" which:
-  - runs "valgrind -q bison" to run Bison under Valgrind.
+- run `make maintainer-check` which:
+  - runs `valgrind -q bison` to run Bison under Valgrind.
   - runs the parsers under Valgrind.
   - runs the test suite with G++ as C compiler...
 
-- run "make maintainer-check-push", which runs "make maintainer-check" while
+- run `make maintainer-check-push`, which runs `make maintainer-check` while
   activating the push implementation and its pull interface wrappers in many
   test cases that were originally written to exercise only the pull
   implementation.  This makes certain the push implementation can perform
   every task the pull implementation can.
 
-- run "make maintainer-check-xml", which runs "make maintainer-check" while
+- run `make maintainer-check-xml`, which runs `make maintainer-check` while
   checking Bison's XML automaton report for every working grammar passed to
   Bison in the test suite.  The check just diffs the output of Bison's
   included XSLT style sheets with the output of --report=all and --graph.
 
-- running "make maintainer-check-release" takes care of running
+- running `make maintainer-check-release` takes care of running
   maintainer-check, maintainer-check-push and maintainer-check-xml.
 
 - Change tests/atlocal/CFLAGS to add your preferred options.
@@ -293,7 +320,7 @@ release:
 - Test with a very recent version of GCC for both C and C++.  Testing with
   older versions that are still in use is nice too.
 
-** gnulib
+## gnulib
 To run tests on gnulib components (e.g., on bitset):
 
     cd gnulib
@@ -309,61 +336,61 @@ 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
+# Release Procedure
 This section needs to be updated to take into account features from gnulib.
 In particular, be sure to read README-release.
 
-** Update the submodules.  See above.
+## Update the submodules.  See above.
 
-** Update maintainer tools, such as Autoconf.  See above.
+## Update maintainer tools, such as Autoconf.  See above.
 
-** Try to get the *.pot files to the Translation Project at least one
+## Try to get the *.pot files to the Translation Project at least one
 week before a stable release, to give them time to translate them.  Before
 generating the *.pot files, make sure that po/POTFILES.in and
 runtime-po/POTFILES.in list all files with translatable strings.  This
-helps: grep -l '\<_(' *.
+helps: `grep -l '\<_(' *`.
 
-** Tests
+## Tests
 See above.
 
-** Update the foreign files
-Running "./bootstrap" in the top level should update them all for you.  This
+## Update the foreign files
+Running `./bootstrap` in the top level should update them all for you.  This
 covers PO files too.  Sometimes a PO file contains problems that causes it
 to be rejected by recent Gettext releases; please report these to the
 Translation Project.
 
-** Update README
+## Update README
 Make sure the information in README is current.  Most notably, make sure it
 recommends a version of GNU M4 that is compatible with the latest Bison
 sources.
 
-** Check copyright years.
+## Check copyright years.
 We update years in copyright statements throughout Bison once at the start
-of every year by running "make update-copyright".  However, before a
+of every year by running `make update-copyright`.  However, before a
 release, it's good to verify that it's actually been run.  Besides the
 copyright statement for each Bison file, check the copyright statements that
 the skeletons insert into generated parsers, and check all occurrences of
-PACKAGE_COPYRIGHT_YEAR in configure.ac.
+`PACKAGE_COPYRIGHT_YEAR` in configure.ac.
 
-** Update NEWS, commit and tag.
+## Update NEWS, commit and tag.
 See do-release-commit-and-tag in README-release.  For a while, we used beta
-names such as "2.6_rc1".  Now that we use gnulib in the release procedure,
-we must use "2.5.90", which has the additional benefit of being properly
-sorted in "git tag -l".
+names such as `2.6_rc1`.  Now that we use gnulib in the release procedure,
+we must use `2.5.90`, which has the additional benefit of being properly
+sorted in `git tag -l`.
 
-** make alpha, beta, or stable
+## make alpha, beta, or stable
 See README-release.
 
-** Upload
+## Upload
 There are two ways to upload the tarballs to the GNU servers: using gnupload
 (from gnulib), or by hand.  Obviously prefer the former.  But in either
 case, be sure to read the following paragraph.
 
-*** Setup
-You need "gnupg".
+### Setup
+You need `gnupg`.
 
 Make sure your public key has been uploaded at least to keys.gnupg.net.  You
 can upload it with:
@@ -372,106 +399,105 @@ can upload it with:
 
 where F125BDF3 should be replaced with your key ID.
 
-*** Using gnupload
-You need "ncftp".
+### Using gnupload
+You need `ncftp`.
 
-At the end "make stable" (or alpha/beta) will display the procedure to run.
+At the end `make stable` (or alpha/beta) will display the procedure to run.
 Just copy and paste it in your shell.
 
-*** By hand
+### By hand
 
-The generic GNU upload procedure is at:
-
-  http://www.gnu.org/prep/maintain/maintain.html#Automated-FTP-Uploads
+The generic GNU upload procedure is at
+http://www.gnu.org/prep/maintain/maintain.html#Automated-FTP-Uploads.
 
 Follow the instructions there to register your information so you're permitted
 to upload.
 
 Here's a brief reminder of how to roll the tarballs and upload them:
 
-*** make distcheck
-*** gpg -b bison-2.3b.tar.gz
-*** In a file named "bison-2.3b.tar.gz.directive", type:
+### make distcheck
+### gpg -b bison-2.3b.tar.gz
+### In a file named `bison-2.3b.tar.gz.directive`, type:
 
-      version: 1.1
-      directory: bison
-      filename: bison-2.3b.tar.gz
+    version: 1.1
+    directory: bison
+    filename: bison-2.3b.tar.gz
 
-*** gpg --clearsign bison-2.3b.tar.gz.directive
-*** ftp ftp-upload.gnu.org # Log in as anonymous.
-*** cd /incoming/alpha # cd /incoming/ftp for full release.
-*** put bison-2.3b.tar.gz # This can take a while.
-*** put bison-2.3b.tar.gz.sig
-*** put bison-2.3b.tar.gz.directive.asc
-*** Repeat all these steps for bison-2.3b.tar.xz.
+### gpg --clearsign bison-2.3b.tar.gz.directive
+### ftp ftp-upload.gnu.org # Log in as anonymous.
+### cd /incoming/alpha # cd /incoming/ftp for full release.
+### put bison-2.3b.tar.gz # This can take a while.
+### put bison-2.3b.tar.gz.sig
+### put bison-2.3b.tar.gz.directive.asc
+### Repeat all these steps for bison-2.3b.tar.xz.
 
-** Update Bison manual on www.gnu.org.
+## Update Bison manual on www.gnu.org.
 
 The instructions below are obsolete, and left in case one would like to run
 the commands by hand.  Today, one just needs to run
 
-  $ make web-manual-update
+    $ make web-manual-update
 
 See README-release.
 
-*** You need a non-anonymous checkout of the web pages directory.
+### You need a non-anonymous checkout of the web pages directory.
 
-  $ cvs -d YOUR_USERID@cvs.savannah.gnu.org:/web/bison checkout bison
+    $ cvs -d YOUR_USERID@cvs.savannah.gnu.org:/web/bison checkout bison
 
-*** Get familiar with the instructions for web page maintainers.
+### Get familiar with the instructions for web page maintainers.
 http://www.gnu.org/server/standards/readme_index.html
 http://www.gnu.org/server/standards/README.software.html
 especially the note about symlinks.
 
-*** Build the web pages.
+### Build the web pages.
 Assuming BISON_CHECKOUT refers to a checkout of the Bison dir, and
 BISON_WWW_CHECKOUT refers to the web directory created above, do:
 
-  $ cd $BISON_CHECKOUT/doc
-  $ make stamp-vti
-  $ ../build-aux/gendocs.sh -o "$BISON_WWW_CHECKOUT/manual" \
-    bison "Bison - GNU parser generator"
-  $ cd $BISON_WWW_CHECKOUT
+    $ cd $BISON_CHECKOUT/doc
+    $ make stamp-vti
+    $ ../build-aux/gendocs.sh -o "$BISON_WWW_CHECKOUT/manual" \
+      bison "Bison - GNU parser generator"
+    $ cd $BISON_WWW_CHECKOUT
 
 Verify that the result looks sane.
 
-*** Commit the modified and the new files.
+### Commit the modified and the new files.
 
-*** Remove old files.
+### Remove old files.
 Find the files which have not been overwritten (because they belonged to
 sections that have been removed or renamed):
 
-   $ cd manual/html_node
-   $ ls -lt
+     $ cd manual/html_node
+     $ ls -lt
 
 Remove these files and commit their removal to CVS.  For each of these
 files, add a line to the file .symlinks.  This will ensure that hyperlinks
 to the removed files will redirect to the entire manual; this is better than
 a 404 error.
 
-** Announce
+## Announce
 The "make release" command just created a template,
-$HOME/announce-bison-X.Y.  Otherwise, to generate it, run:
+`$HOME/announce-bison-X.Y`.  Otherwise, to generate it, run:
 
-  make RELEASE_TYPE=alpha gpg_key_ID=F125BDF3 announcement
+    make RELEASE_TYPE=alpha gpg_key_ID=F125BDF3 announcement
 
-where alpha can be replaced by beta or stable and F125BDF3 should be
+where alpha can be replaced by `beta` or `table` and F125BDF3 should be
 replaced with your key ID.
 
 Complete/fix the announcement file.  The generated list of recipients
-(info-gnu@gnu.org, bug-bison@gnu.org, help-bison@gnu.org,
-bison-patches@gnu.org, and coordinator@translationproject.org) is
-appropriate for a stable release or a "serious beta".  For any other
-release, drop at least info-gnu@gnu.org.  For an example of how to fill out
-the rest of the template, search the mailing list archives for the most
-recent release announcement.
+(info-gnu@gnu.org, bison-announce@gnu.org, bug-bison@gnu.org,
+help-bison@gnu.org, bison-patches@gnu.org, and
+coordinator@translationproject.org) is appropriate for a stable release or a
+"serious beta".  For any other release, drop at least info-gnu@gnu.org.  For
+an example of how to fill out the rest of the template, search the mailing
+list archives for the most recent release announcement.
 
 For a stable release, send the same announcement on the comp.compilers
 newsgroup by sending email to compilers@iecc.com.  Do not make any Cc as the
 moderator will throw away anything cross-posted or Cc'ed.  It really needs
 to be a separate message.
 
-** Prepare NEWS
+## Prepare NEWS
 So that developers don't accidentally add new items to the old NEWS entry,
 create a new empty entry in line 3 (without the two leading spaces):
 
@@ -479,9 +505,9 @@ create a new empty entry in line 3 (without the two leading spaces):
 
 Push these changes.
 
------
+<!--
 
-Copyright (C) 2002-2005, 2007-2015, 2018-2019 Free Software Foundation,
+Copyright (C) 2002-2005, 2007-2015, 2018-2020 Free Software Foundation,
 Inc.
 
 This file is part of GNU Bison.
@@ -499,13 +525,20 @@ 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:  Automake Autoconf Gettext Gzip Rsync Valgrind gnulib submodules
- LocalWords:  submodule init cd distcheck checkin ChangeLog valgrind sigreturn
- LocalWords:  UC gcc DGNULIB POSIXCHECK xml XSLT glr lalr README po runtime rc
- LocalWords:  gnupload gnupg gpg keyserver BDF ncftp filename clearsign cvs dir
- LocalWords:  symlinks vti html lt POSIX Cc'ed
-
 Local Variables:
-mode: outline
+mode: markdown
 fill-column: 76
+ispell-dictionary: "american"
 End:
+
+LocalWords:  Automake Autoconf Gettext Gzip Rsync Valgrind gnulib submodules
+LocalWords:  submodule init cd distcheck ChangeLog valgrind sigreturn sudo
+LocalWords:  UC gcc DGNULIB POSIXCHECK xml XSLT glr lalr README po runtime rc
+LocalWords:  gnupload gnupg gpg keyserver BDF ncftp filename clearsign cvs dir
+LocalWords:  symlinks vti html lt POSIX Cc'ed Graphviz Texinfo autoconf jN
+LocalWords:  automake autopoint graphviz texinfo PROG Wother parsers
+LocalWords:  TESTSUITEFLAGS deprec struct gnulib's getopt config ggdb
+LocalWords:  bitset fsanitize symlink CFLAGS MERCHANTABILITY ispell
+LocalWords:  american
+
+-->

README.md

@@ -0,0 +1 @@
+README

THANKS

@@ -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]
@@ -59,6 +60,7 @@ Enrico Scholz             [email protected]
 Eric Blake                [email protected]
 Eric S. Raymond           [email protected]
 Étienne Renault           [email protected]
+Evan Nemerson             [email protected]
 Evgeny Stambulchik        [email protected]
 Fabrice Bauzac            [email protected]
 Ferdinand Thiessen        [email protected]
@@ -78,6 +80,7 @@ Hans Åberg                [email protected]
 Horst Von Brand           [email protected]
 Jan Nieuwenhuizen         [email protected]
 Jannick                   [email protected]
+Jeff Hammond              [email protected]
 Jerry Quinn               [email protected]
 Jesse Thilo               [email protected]
 Jim Kent                  [email protected]
@@ -94,11 +97,14 @@ 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]
@@ -171,17 +177,20 @@ 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                uxio[email protected]
+Uxio Prego                uxio@uma.es
 Valentin Tolmer           [email protected]
 wcventure                 [email protected]
 Victor Khomenko           [email protected]
@@ -196,8 +205,11 @@ Wolfgang Thaller          [email protected]
 Wolfram Wagner            [email protected]
 Wwp                       [email protected]
 xolodho                   [email protected]
+Yuichiro Kaneko           [email protected]
 Zack Weinberg             [email protected]
+江 祖铭                    [email protected]
 長田偉伸                   [email protected]
+马俊                       [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.
@@ -209,7 +221,7 @@ End:
 
 -----
 
-Copyright (C) 2000-2015, 2018-2019 Free Software Foundation, Inc.
+Copyright (C) 2000-2015, 2018-2020 Free Software Foundation, Inc.
 
 This file is part of Bison, the GNU Parser Generator.
 

TODO

@@ -1,26 +1,4 @@
-* 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
+* Bison 3.6
 ** doc
 I feel its ugly to use the GNU style to declare functions in the doc.  It
 generates tons of white space in the page, and may contribute to bad page
@@ -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 +48,75 @@ 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.
 
-* Bison 3.6
-** Unit rules
+** consistency
+token vs terminal, variable vs non terminal.
+
+** 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.
+
+** 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.
+
+** C++
+Move to int everywhere instead of unsigned?  stack_size, etc.  The parser
+itself uses int (for yylen for instance), yet stack is based on size_t.
+
+Maybe locations should also move to ints.
+
+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".
+
+* Bison 3.7
+** 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 +135,12 @@ 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 +161,20 @@ 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.
@@ -139,20 +194,42 @@ $ ./tests/testsuite -l | grep errors | sed q
   38: input.at:1730      errors
 
 * Short term
-** consistency
-token vs terminal
+** Get rid of YYPRINT and b4_toknum
+Besides yytoknum is wrong when api.token.raw is defined.
 
-** C++
-Move to int everywhere instead of unsigned?  stack_size, etc.  The parser
-itself uses int (for yylen for instance), yet stack is based on size_t.
+** 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:
 
-Maybe locations should also move to ints.
+      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);
 
-** C
-Introduce state_type rather than spreading yytype_int16 everywhere?
+We should rewrite this in a more FP way:
 
-** glr.c
-yyspaceLeft should probably be a pointer diff.
+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
 
 ** Graphviz display code thoughts
 The code for the --graph option is over two files: print_graph, and
@@ -173,9 +250,6 @@ 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 +307,13 @@ 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 +383,21 @@ 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 +437,26 @@ 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 +474,12 @@ 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 +506,10 @@ 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 +529,9 @@ 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 +549,7 @@ 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 +561,7 @@ 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:
@@ -483,23 +603,6 @@ to bison. If you're interested, I'll work on a patch.
 * Better graphics
 Equip the parser with a means to create the (visual) parse tree.
 
-* Complaint submessage indentation.
-We already have an implementation that works fairly well for named
-reference messages, but it would be nice to use it consistently for all
-submessages from Bison.  For example, the "previous definition"
-submessage or the list of correct values for a %define variable might
-look better with indentation.
-
-However, the current implementation makes the assumption that the
-location printed on the first line is not usually much shorter than the
-locations printed on the submessage lines that follow.  That assumption
-may not hold true as often for some kinds of submessages especially if
-we ever support multiple grammar files.
-
-Here's a proposal for how a new implementation might look:
-
-  http://lists.gnu.org/archive/html/bison-patches/2009-09/msg00086.html
-
 
 Local Variables:
 mode: outline
@@ -509,7 +612,7 @@ End:
 
 -----
 
-Copyright (C) 2001-2004, 2006, 2008-2015, 2018-2019 Free Software
+Copyright (C) 2001-2004, 2006, 2008-2015, 2018-2020 Free Software
 Foundation, Inc.
 
 This file is part of Bison, the GNU Compiler Compiler.

bootstrap

@@ -4,7 +4,7 @@ scriptversion=2019-01-04.17; # UTC
 
 # Bootstrap this package from checked-out sources.
 
-# Copyright (C) 2003-2019 Free Software Foundation, Inc.
+# Copyright (C) 2003-2020 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
@@ -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

bootstrap.conf

@@ -1,6 +1,6 @@
 # Bootstrap configuration.
 
-# Copyright (C) 2006-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2006-2015, 2018-2020 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
@@ -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
@@ -56,6 +60,8 @@ gnulib_modules='
   vsnprintf-posix vsprintf-posix
 '
 
+checkout_only_file=README-hacking.md
+
 # Additional xgettext options to use.  Use "\\\newline" to break lines.
 XGETTEXT_OPTIONS=$XGETTEXT_OPTIONS'\\\
  --from-code=UTF-8\\\
@@ -86,6 +92,13 @@ 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

build-aux/Darwin.valgrind

@@ -1,4 +1,4 @@
-# Copyright (C) 2012-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2012-2015, 2018-2020 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

build-aux/Linux.valgrind

@@ -1,4 +1,4 @@
-# Copyright (C) 2012-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2012-2015, 2018-2020 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

build-aux/cross-options.pl

@@ -1,5 +1,24 @@
 #! /usr/bin/env perl
 
+# Generate a release announcement message.
+
+# Copyright (C) 2007-2020 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/>.
+#
+# Written by Akimn Demaille.
+
 use warnings;
 use 5.005;
 use strict;
@@ -12,7 +31,7 @@ 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 +51,6 @@ 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 +90,15 @@ 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;
 }

build-aux/local.mk

@@ -1,4 +1,4 @@
-## Copyright (C) 2000-2015, 2018-2019 Free Software Foundation, Inc.
+## Copyright (C) 2000-2015, 2018-2020 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

build-aux/update-b4-copyright

@@ -3,7 +3,7 @@
 # Update b4_copyright invocations or b4_copyright_years definitions to
 # include the current year.
 
-# Copyright (C) 2009-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2009-2015, 2018-2020 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

build-aux/update-package-copyright-year

@@ -2,7 +2,7 @@
 
 # In configure.ac, update PACKAGE_COPYRIGHT_YEAR to the current year.
 
-# Copyright (C) 2010-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2010-2015, 2018-2020 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

build-aux/update-test

@@ -1,8 +1,29 @@
 #! /usr/bin/env python
 
-# usage:
-# update-test _build/8d/tests/testsuite.dir/*.testsuite.log
+# Update expectations in an Autotest test suite.
 
+# Copyright (C) 2019-2020 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/>.
+#
+# Written by Akim Demaille.
+
+# usage:
+#
+#    update-test _build/8d/tests/testsuite.dir/*/testsuite.log
+#
+# from your source tree.
 import argparse
 import os
 import re
@@ -11,8 +32,8 @@ 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 +42,14 @@ 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 +81,9 @@ 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 +92,7 @@ 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 +102,14 @@ 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)

cfg.mk

@@ -1,5 +1,5 @@
 ## Customize maint.mk                           -*- makefile -*-
-## Copyright (C) 2008-2015, 2018-2019 Free Software Foundation, Inc.
+## Copyright (C) 2008-2015, 2018-2020 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
@@ -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*
@@ -153,7 +156,7 @@ exclude = \
 $(call exclude,                                                                 \
   bindtextdomain=^lib/main.c$$                                                  \
   cast_of_argument_to_free=^src/muscle-tab.c$$                                  \
-  po_check=^po/POTFILES.in$$                                                    \
+  po_check=(^po/POTFILES.in|.md)$$		                                \
   preprocessor_indentation=^data/|^lib/|^src/parse-gram.[ch]$$                  \
   program_name=^lib/main.c$$                                                    \
   prohibit_always-defined_macros=^data/skeletons/yacc.c$$                       \

configure.ac

@@ -1,6 +1,6 @@
 # Configure template for GNU Bison.                   -*-Autoconf-*-
 #
-# Copyright (C) 2001-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2001-2015, 2018-2020 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
@@ -26,8 +26,10 @@ m4_pattern_allow([^BISON_USE_NLS$])
 
 AC_INIT([GNU Bison],
         m4_esyscmd([build-aux/git-version-gen .tarball-version]),
-        [[email protected]])
-AC_SUBST([PACKAGE_COPYRIGHT_YEAR], [2019])
+        [[email protected]],
+        [],
+        [https://www.gnu.org/software/bison/])
+AC_SUBST([PACKAGE_COPYRIGHT_YEAR], [2020])
 AC_DEFINE_UNQUOTED([PACKAGE_COPYRIGHT_YEAR], [$PACKAGE_COPYRIGHT_YEAR],
                    [The copyright year for this package])
 
@@ -36,6 +38,9 @@ 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
@@ -94,13 +99,47 @@ 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.
+  #
+  # ICC: -wr188
+  #
+  # 1669  warnings warnings_default =
+  # ../src/complain.c(318): error #188: enumerated type mixed with another type
+  # 1670      Wconflicts_sr | Wconflicts_rr | Wdeprecated | Wother;
+  # 1671      ^
+  # 1672
+  # 1673../src/complain.c(393): error #188: enumerated type mixed with another type
+  # 1674          warnings w = 1 << wbit;
+  # 1675                       ^
+  #
+  # ICC: -wr3179
+  #
+  # char const *usefulness
+  #   = rule_useless_in_grammar_p (&rules[r]) ? "useless-in-grammar"
+  #   : rule_useless_in_parser_p (&rules[r])  ? "useless-in-parser"
+  #   :                                         "useful";
+  #
+  # gives
+  #
+  # error #3179: deprecated conversion of string literal to char* (should be const char*)
+  #
+  # ICC: -wr2259 (that's in C, in spite of what the error messages which seems to be about C++).
+  # error #2259: non-pointer conversion from "int" to "yybool={signed char}" may lose significant bits
+  #   yybool yynormal YY_ATTRIBUTE_UNUSED = yystackp->yysplitPoint == YY_NULLPTR;
+  #                                         ^
+  warn_common='-Wall -Wextra
+    -Wcast-align -Wchar-subscripts
     -fparse-all-comments -Wdocumentation
     -Wformat -Wimplicit-fallthrough -Wnull-dereference
+    -Wno-sign-compare -Wno-tautological-constant-out-of-range-compare
     -Wpointer-arith -Wshadow
-    -Wwrite-strings'
+    -Wwrite-strings
+    -wr188 -wr2259 -wr3179'
   warn_c='-Wbad-function-cast -Wstrict-prototypes'
-  warn_cxx='-Wextra-semi -Wnoexcept -Wundefined-func-template -Wweak-vtables'
+  warn_cxx='-Wextra-semi -Wnoexcept -Wold-style-cast -Wundefined-func-template
+    -Wweak-vtables'
   # Warnings for the test suite only.
   #
   # -fno-color-diagnostics: Clang's use of colors in the error
@@ -112,6 +151,7 @@ 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'
 
@@ -142,8 +182,6 @@ if test "$enable_gcc_warnings" = yes; then
 
   # Warnings for the test suite, and maybe for bison if GCC is modern
   # enough.
-  gl_WARN_ADD([-Wmissing-declarations], [WARN_CFLAGS_TEST])
-  gl_WARN_ADD([-Wmissing-prototypes], [WARN_CFLAGS_TEST])
   test $lv_cv_gcc_pragma_push_works = yes &&
     AS_VAR_APPEND([WARN_CFLAGS], [" $WARN_CFLAGS_TEST"])
 
@@ -170,6 +208,14 @@ if test "$enable_gcc_warnings" = yes; then
               [[if (sizeof (long) < sizeof (int)) return 1;]])])
   gl_WARN_ADD([-Wzero-as-null-pointer-constant], [WARN_CXXFLAGS],
               [AC_LANG_PROGRAM([], [nullptr])])
+  # Before GCC6, the pragmas don't work well enough to neutralize
+  # this warning.
+  gl_WARN_ADD([-Wuseless-cast], [WARN_CXXFLAGS],
+              [AC_LANG_PROGRAM([], [
+              #if defined __GNUC__ && ! defined __ICC && ! defined __clang__ && __GNUC__ < 6
+              syntax error
+              #endif
+              ])])
   gl_WARN_ADD([-Werror], [WERROR_CXXFLAGS])
   # Warnings for the test suite only.
   for i in $warn_tests;
@@ -192,7 +238,7 @@ 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 +257,10 @@ 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 $bison_cv_cxx_works = yes])
@@ -225,9 +271,6 @@ AC_DEFINE_UNQUOTED([M4], ["$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])
@@ -244,7 +287,6 @@ 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
@@ -274,7 +316,7 @@ uname=`uname`
 case $VALGRIND:$uname in
   '':*) ;;
   *:Darwin)
-    # See README-hacking.
+    # See README-hacking.md.
     VALGRIND=;;
   *:*)
     suppfile=build-aux/$uname.valgrind
@@ -297,4 +339,15 @@ 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

data/README.md

@@ -174,7 +174,7 @@ fill-column: 76
 ispell-dictionary: "american"
 End:
 
-Copyright (C) 2002, 2008-2015, 2018-2019 Free Software Foundation, Inc.
+Copyright (C) 2002, 2008-2015, 2018-2020 Free Software Foundation, Inc.
 
 This file is part of GNU Bison.
 

data/bison-default.css

@@ -1,5 +1,5 @@
 /* Default styling rules for Bison when doing terminal output.
-   Copyright (C) 2019 Free Software Foundation, Inc.
+   Copyright (C) 2019-2020 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
@@ -17,8 +17,15 @@
 /* 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; }

data/local.mk

@@ -1,4 +1,4 @@
-## Copyright (C) 2002, 2005-2015, 2018-2019 Free Software Foundation,
+## Copyright (C) 2002, 2005-2015, 2018-2020 Free Software Foundation,
 ## Inc.
 
 ## This program is free software: you can redistribute it and/or modify

data/skeletons/bison.m4

@@ -2,7 +2,7 @@
 
 # Language-independent M4 Macros for Bison.
 
-# Copyright (C) 2002, 2004-2015, 2018-2019 Free Software Foundation,
+# Copyright (C) 2002, 2004-2015, 2018-2020 Free Software Foundation,
 # Inc.
 
 # This program is free software: you can redistribute it and/or modify
@@ -192,7 +192,7 @@ m4_define([b4_error],
 #   @warn(1@)
 #   @warn(1@,2@)
 m4_define([b4_warn],
-[b4_error([[warn]], [], [], $@)])
+[b4_warn_at([], [], $@)])
 
 # b4_warn_at(START, END, FORMAT, [ARG1], [ARG2], ...)
 # ---------------------------------------------------
@@ -210,7 +210,7 @@ m4_define([b4_warn_at],
 #
 # See b4_warn example.
 m4_define([b4_complain],
-[b4_error([[complain]], [], [], $@)])
+[b4_complain_at([], [], $@)])
 
 # b4_complain_at(START, END, FORMAT, [ARG1], [ARG2], ...)
 # -------------------------------------------------------
@@ -226,8 +226,7 @@ m4_define([b4_complain_at],
 #
 # See b4_warn example.
 m4_define([b4_fatal],
-[b4_error([[fatal]], [], [], $@)dnl
-m4_exit(1)])
+[b4_fatal_at([], [], $@)])
 
 # b4_fatal_at(START, END, FORMAT, [ARG1], [ARG2], ...)
 # ----------------------------------------------------
@@ -449,7 +448,7 @@ 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 +534,7 @@ 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]]))]))])])
 
 
 ## ------- ##
@@ -976,8 +975,8 @@ m4_define([b4_percent_code_get],
 [m4_pushdef([b4_macro_name], [[b4_percent_code(]$1[)]])dnl
 m4_ifval([$1], [m4_define([b4_percent_code_bison_qualifiers(]$1[)])])dnl
 m4_ifdef(b4_macro_name,
-[b4_comment([m4_if([$#], [0], [[Unqualified %code]],
-                   [["%code ]$1["]])[ blocks.]])
+[b4_comment(m4_if([$#], [0], [[[Unqualified %code blocks.]]],
+                  [[["%code ]$1[" blocks.]]]))
 b4_user_code([m4_indir(b4_macro_name)])])dnl
 m4_popdef([b4_macro_name])])
 
@@ -1002,6 +1001,7 @@ 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])

data/skeletons/c++-skel.m4

@@ -2,7 +2,7 @@
 
 # C++ skeleton dispatching for Bison.
 
-# Copyright (C) 2006-2007, 2009-2015, 2018-2019 Free Software
+# Copyright (C) 2006-2007, 2009-2015, 2018-2020 Free Software
 # Foundation, Inc.
 
 # This program is free software: you can redistribute it and/or modify

data/skeletons/c++.m4

@@ -2,7 +2,7 @@
 
 # C++ skeleton for Bison
 
-# Copyright (C) 2002-2019 Free Software Foundation, Inc.
+# Copyright (C) 2002-2020 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
@@ -367,9 +367,6 @@ m4_define([b4_symbol_type_define],
       /// \a empty when empty.
       symbol_number_type type_get () const YY_NOEXCEPT;
 
-      /// The token.
-      token_type token () const YY_NOEXCEPT;
-
       /// The symbol type.
       /// \a empty_symbol when empty.
       /// An int, not token_number_type, to be able to store empty_symbol.
@@ -498,22 +495,7 @@ m4_define([b4_public_types_define],
   {
     return type;
   }
-]b4_token_ctor_if([[
-  ]b4_inline([$1])b4_parser_class[::token_type
-  ]b4_parser_class[::by_type::token () const YY_NOEXCEPT
-  {
-    // YYTOKNUM[NUM] -- (External) token number corresponding to the
-    // (internal) symbol number NUM (which must be that of a token).  */
-    static
-    const ]b4_int_type_for([b4_toknum])[
-    yytoken_number_[] =
-    {
-  ]b4_toknum[
-    };
-    return token_type (yytoken_number_[type]);
-  }
-]])[]dnl
-])
+]])
 
 
 # b4_token_constructor_define
@@ -529,10 +511,11 @@ m4_define([b4_token_constructor_define], [])
 # sometimes in the cc file.
 m4_define([b4_yytranslate_define],
 [  b4_inline([$1])b4_parser_class[::token_number_type
-  ]b4_parser_class[::yytranslate_ (]b4_token_ctor_if([token_type],
-                                                          [int])[ t)
+  ]b4_parser_class[::yytranslate_ (int t)
   {
-    // YYTRANSLATE[TOKEN-NUM] -- Symbol number corresponding to
+]b4_api_token_raw_if(
+[[    return static_cast<token_number_type> (t);]],
+[[    // YYTRANSLATE[TOKEN-NUM] -- Symbol number corresponding to
     // TOKEN-NUM as returned by yylex.
     static
     const token_number_type
@@ -540,15 +523,14 @@ m4_define([b4_yytranslate_define],
     {
   ]b4_translate[
     };
-    const unsigned user_token_number_max_ = ]b4_user_token_number_max[;
-    const token_number_type undef_token_ = ]b4_undef_token_number[;
+    const int user_token_number_max_ = ]b4_user_token_number_max[;
 
-    if (static_cast<int> (t) <= yyeof_)
+    if (t <= 0)
       return yyeof_;
-    else if (static_cast<unsigned> (t) <= user_token_number_max_)
+    else if (t <= user_token_number_max_)
       return translate_table[t];
     else
-      return undef_token_;
+      return yy_undef_token_;]])[
   }
 ]])
 

data/skeletons/c-like.m4

@@ -2,7 +2,7 @@
 
 # Common code for C-like languages (C, C++, Java, etc.)
 
-# Copyright (C) 2012-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2012-2015, 2018-2020 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

data/skeletons/c-skel.m4

@@ -2,7 +2,7 @@
 
 # C skeleton dispatching for Bison.
 
-# Copyright (C) 2006-2007, 2009-2015, 2018-2019 Free Software
+# Copyright (C) 2006-2007, 2009-2015, 2018-2020 Free Software
 # Foundation, Inc.
 
 # This program is free software: you can redistribute it and/or modify

data/skeletons/c.m4

@@ -2,7 +2,7 @@
 
 # C M4 Macros for Bison.
 
-# Copyright (C) 2002, 2004-2015, 2018-2019 Free Software Foundation,
+# Copyright (C) 2002, 2004-2015, 2018-2020 Free Software Foundation,
 # Inc.
 
 # This program is free software: you can redistribute it and/or modify
@@ -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.  */
@@ -257,11 +327,11 @@ m4_define([b4_attribute_define],
 
 #if defined __GNUC__ && ! defined __ICC && 407 <= __GNUC__ * 100 + __GNUC_MINOR__
 /* Suppress an incorrect diagnostic about yylval being uninitialized.  */
-# define YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN \
-    _Pragma ("GCC diagnostic push") \
-    _Pragma ("GCC diagnostic ignored \"-Wuninitialized\"")\
+# define YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN                            \
+    _Pragma ("GCC diagnostic push")                                     \
+    _Pragma ("GCC diagnostic ignored \"-Wuninitialized\"")              \
     _Pragma ("GCC diagnostic ignored \"-Wmaybe-uninitialized\"")
-# define YY_IGNORE_MAYBE_UNINITIALIZED_END \
+# define YY_IGNORE_MAYBE_UNINITIALIZED_END      \
     _Pragma ("GCC diagnostic pop")
 #else
 # define YY_INITIAL_VALUE(Value) Value
@@ -273,9 +343,36 @@ m4_define([b4_attribute_define],
 #ifndef YY_INITIAL_VALUE
 # define YY_INITIAL_VALUE(Value) /* Nothing. */
 #endif
+
+#if defined __cplusplus && defined __GNUC__ && ! defined __ICC && 6 <= __GNUC__
+# define YY_IGNORE_USELESS_CAST_BEGIN                          \
+    _Pragma ("GCC diagnostic push")                            \
+    _Pragma ("GCC diagnostic ignored \"-Wuseless-cast\"")
+# define YY_IGNORE_USELESS_CAST_END            \
+    _Pragma ("GCC diagnostic pop")
+#endif
+#ifndef YY_IGNORE_USELESS_CAST_BEGIN
+# define YY_IGNORE_USELESS_CAST_BEGIN
+# define YY_IGNORE_USELESS_CAST_END
+#endif
 ]])
 
 
+# b4_cast_define
+# --------------
+m4_define([b4_cast_define],
+[# ifndef YY_CAST
+#  ifdef __cplusplus
+#   define YY_CAST(Type, Val) static_cast<Type> (Val)
+#   define YY_REINTERPRET_CAST(Type, Val) reinterpret_cast<Type> (Val)
+#  else
+#   define YY_CAST(Type, Val) ((Type) (Val))
+#   define YY_REINTERPRET_CAST(Type, Val) ((Type) (Val))
+#  endif
+# endif[]dnl
+])
+
+
 # b4_null_define
 # --------------
 # Portability issues: define a YY_NULLPTR appropriate for the current
@@ -545,7 +642,9 @@ 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
 [}
 

data/skeletons/d-skel.m4

@@ -2,7 +2,7 @@
 
 # D skeleton dispatching for Bison.
 
-# Copyright (C) 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2018-2020 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

data/skeletons/d.m4

@@ -2,7 +2,7 @@
 
 # D language support for Bison
 
-# Copyright (C) 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2018-2020 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
@@ -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],

data/skeletons/glr.cc

@@ -1,6 +1,6 @@
 # C++ GLR skeleton for Bison
 
-# Copyright (C) 2002-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2002-2015, 2018-2020 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
@@ -257,6 +257,21 @@ b4_percent_code_get([[requires]])[
 ]b4_attribute_define[
 ]b4_null_define[
 
+// This skeleton is based on C, yet compiles it as C++.
+// So expect warnings about C style casts.
+#if defined __clang__ && 306 <= __clang_major__ * 100 + __clang_minor__
+# pragma clang diagnostic ignored "-Wold-style-cast"
+#elif defined __GNUC__ && 406 <= __GNUC__ * 100 + __GNUC_MINOR__
+# pragma GCC diagnostic ignored "-Wold-style-cast"
+#endif
+
+// On MacOS, PTRDIFF_MAX is defined as long long, which Clang's
+// -pedantic reports as being a C++11 extension.
+#if defined __APPLE__ && YY_CPLUSPLUS < 201103L \
+    && defined __clang__ && 4 <= __clang_major__
+# pragma clang diagnostic ignored "-Wc++11-long-long"
+#endif
+
 // Whether we are compiled with exception support.
 #ifndef YY_EXCEPTIONS
 # if defined __GNUC__ && !defined __EXCEPTIONS
@@ -353,7 +368,7 @@ b4_percent_define_flag_if([[global_tokens_and_yystype]],
 b4_defines_if(
 [b4_output_begin([b4_spec_header_file])
 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
-             [2002-2015, 2018-2019])[
+             [2002-2015, 2018-2020])[
 // C++ GLR parser skeleton written by Akim Demaille.
 
 ]b4_disclaimer[

data/skeletons/java-skel.m4

@@ -2,7 +2,7 @@
 
 # Java skeleton dispatching for Bison.
 
-# Copyright (C) 2007, 2009-2015, 2018-2019 Free Software Foundation,
+# Copyright (C) 2007, 2009-2015, 2018-2020 Free Software Foundation,
 # Inc.
 
 # This program is free software: you can redistribute it and/or modify

data/skeletons/java.m4

@@ -2,7 +2,7 @@
 
 # Java language support for Bison
 
-# Copyright (C) 2007-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2007-2015, 2018-2020 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
@@ -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]])])

data/skeletons/lalr1.cc

@@ -1,6 +1,6 @@
 # C++ skeleton for Bison
 
-# Copyright (C) 2002-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2002-2015, 2018-2020 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
@@ -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)
@@ -135,7 +143,7 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))])])
 
 
 m4_pushdef([b4_copyright_years],
-           [2002-2015, 2018-2019])
+           [2002-2015, 2018-2020])
 
 m4_define([b4_parser_class],
           [b4_percent_define_get([[api.parser.class]])])
@@ -166,6 +174,7 @@ m4_define([b4_shared_declarations],
 ]b4_variant_if([b4_variant_includes])[
 
 ]b4_attribute_define[
+]b4_cast_define[
 ]b4_null_define[
 
 ]b4_YYDEBUG_define[
@@ -220,10 +229,21 @@ 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 +254,7 @@ 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
@@ -248,7 +268,9 @@ m4_define([b4_shared_declarations],
     static const ]b4_int_type(b4_table_ninf, b4_table_ninf)[ yytable_ninf_;
 
     /// Convert a scanner token number \a t to a symbol number.
-    static token_number_type yytranslate_ (]b4_token_ctor_if([token_type], [int])[ t);
+    /// In theory \a t should be a token_type, but character literals
+    /// are valid, yet not members of the token_type enum.
+    static token_number_type yytranslate_ (int t);
 
     // Tables.
 ]b4_parser_tables_declare[]b4_error_verbose_if([
@@ -313,7 +335,8 @@ m4_define([b4_shared_declarations],
       symbol_number_type type_get () const YY_NOEXCEPT;
 
       /// The state number used to denote an empty symbol.
-      enum { empty_state = -1 };
+      /// We use the initial state, as it does not have a value.
+      enum { empty_state = 0 };
 
       /// The state.
       /// \a empty when empty.
@@ -335,6 +358,10 @@ 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 +371,16 @@ 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
@@ -364,6 +400,10 @@ m4_define([b4_shared_declarations],
     /// Pop \a n symbols from the stack.
     void yypop_ (int n = 1);
 
+    /// Some specific tokens.
+    static const token_number_type yy_error_token_ = 1;
+    static const token_number_type yy_undef_token_ = ]b4_undef_token_number[;
+
     /// Constants.
     enum
     {
@@ -371,8 +411,6 @@ m4_define([b4_shared_declarations],
       yylast_ = ]b4_last[,     ///< Last index in yytable_.
       yynnts_ = ]b4_nterms_number[,  ///< Number of nonterminal symbols.
       yyfinal_ = ]b4_final_state_number[, ///< Termination state number.
-      yyterror_ = 1,
-      yyerrcode_ = 256,
       yyntokens_ = ]b4_tokens_number[  ///< Number of tokens.
     };
 
@@ -459,9 +497,6 @@ 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 +586,14 @@ 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[ ()
@@ -603,7 +640,7 @@ m4_if(b4_prefix, [yy], [],
     if (state == empty_state)
       return empty_symbol;
     else
-      return yystos_[state];
+      return yystos_[+state];
   }
 
   ]b4_parser_class[::stack_symbol_type::stack_symbol_type ()
@@ -630,6 +667,17 @@ 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 +809,6 @@ 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 +824,11 @@ 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 +852,7 @@ 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_)
@@ -815,7 +866,7 @@ b4_dollar_popdef])[]dnl
   `-----------*/
   yybackup:
     // Try to take a decision without lookahead.
-    yyn = yypact_[yystack_[0].state];
+    yyn = yypact_[+yystack_[0].state];
     if (yy_pact_value_is_default_ (yyn))
       goto yydefault;
 
@@ -846,14 +897,21 @@ 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 +921,8 @@ b4_dollar_popdef])[]dnl
       --yyerrstatus_;
 
     // Shift the lookahead token.
-    yypush_ ("Shifting", yyn, YY_MOVE (yyla));
+    yypush_ ("Shifting", state_type (yyn), YY_MOVE (yyla));]b4_lac_if([[
+    yy_lac_discard_ ("shift");]])[
     goto yynewstate;
 
 
@@ -871,7 +930,7 @@ b4_dollar_popdef])[]dnl
   | yydefault -- do the default action for the current state.  |
   `-----------------------------------------------------------*/
   yydefault:
-    yyn = yydefact_[yystack_[0].state];
+    yyn = yydefact_[+yystack_[0].state];
     if (yyn == 0)
       goto yyerrlab;
     goto yyreduce;
@@ -998,11 +1057,11 @@ b4_dollar_popdef])[]dnl
       stack_symbol_type error_token;
       for (;;)
         {
-          yyn = yypact_[yystack_[0].state];
+          yyn = yypact_[+yystack_[0].state];
           if (!yy_pact_value_is_default_ (yyn))
             {
-              yyn += yyterror_;
-              if (0 <= yyn && yyn <= yylast_ && yycheck_[yyn] == yyterror_)
+              yyn += yy_error_token_;
+              if (0 <= yyn && yyn <= yylast_ && yycheck_[yyn] == yy_error_token_)
                 {
                   yyn = yytable_[yyn];
                   if (0 < yyn)
@@ -1023,8 +1082,9 @@ 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 = state_type (yyn);
       yypush_ ("Shifting", YY_MOVE (error_token));
     }
     goto yynewstate;
@@ -1088,8 +1148,147 @@ 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 +1297,7 @@ 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 +1317,41 @@ 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];
-        int yyn = yypact_[yystate];
+        symbol_number_type yytoken = yyla.type_get ();
+        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 != yy_error_token_ && yyx != yy_undef_token_
+                  && 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.  */
@@ -1144,9 +1360,9 @@ b4_error_verbose_if([state_type yystate, const symbol_type& yyla],
             int yychecklim = yylast_ - yyn + 1;
             int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_;
             for (int yyx = yyxbegin; yyx < yyxend; ++yyx)
-              if (yycheck_[yyx + yyn] == yyx && yyx != yyterror_
+              if (yycheck_[yyx + yyn] == yyx && yyx != yy_error_token_
                   && !yy_table_value_is_error_ (yytable_[yyx + yyn]))
-                {
+                {]])[
                   if (yycount == YYERROR_VERBOSE_ARGS_MAXIMUM)
                     {
                       yycount = 1;
@@ -1177,7 +1393,7 @@ 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 +1434,7 @@ 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 +1442,7 @@ 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

data/skeletons/lalr1.d

@@ -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, 2019-2020 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, 2019-2020])[
 
-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
 };],
@@ -231,9 +187,6 @@ b4_user_union_members
 {
   ]b4_identification[
 
-  /** True if verbose error messages are enabled.  */
-  public bool errorVerbose = ]b4_flag_value([error_verbose])[;
-
 ]b4_locations_if([[
   private final ]b4_location_type[ yylloc_from_stack (ref YYStack rhs, int n)
   {
@@ -261,29 +214,27 @@ 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 +260,17 @@ 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 +297,11 @@ 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 +325,8 @@ 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 +334,8 @@ 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 +383,12 @@ 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 +397,12 @@ 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 +410,7 @@ 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 +445,9 @@ 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 +467,10 @@ 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 +486,8 @@ 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 +498,9 @@ 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 +521,9 @@ 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_;
@@ -670,8 +617,8 @@ m4_popdef([b4_at_dollar])])dnl
           yyn = yypact_[yystate];
           if (!yy_pact_value_is_default_ (yyn))
           {
-            yyn += yyterror_;
-            if (0 <= yyn && yyn <= yylast_ && yycheck_[yyn] == yyterror_)
+            yyn += yy_error_token_;
+            if (0 <= yyn && yyn <= yylast_ && yycheck_[yyn] == yy_error_token_)
             {
               yyn = yytable_[yyn];
               if (0 < yyn)
@@ -685,9 +632,9 @@ 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 +644,9 @@ 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])[);
@@ -718,78 +665,74 @@ m4_popdef([b4_at_dollar])])dnl
 
   // Generate an error message.
   private final string yysyntax_error (int yystate, int tok)
-  {
-    if (errorVerbose)
+  {]b4_error_verbose_if([[
+    /* There are many possibilities here to consider:
+       - Assume YYFAIL is not used.  It's too flawed to consider.
+         See
+         <http://lists.gnu.org/archive/html/bison-patches/2009-12/msg00024.html>
+         for details.  YYERROR is fine as it does not invoke this
+         function.
+       - If this state is a consistent state with a default action,
+         then the only way this function was invoked is if the
+         default action is an error action.  In that case, don't
+         check for expected tokens because there are none.
+       - The only way there can be no lookahead present (in tok) is
+         if this state is a consistent state with a default action.
+         Thus, detecting the absence of a lookahead is sufficient to
+         determine that there is no unexpected or expected token to
+         report.  In that case, just report a simple "syntax error".
+       - Don't assume there isn't a lookahead just because this
+         state is 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 yychar.  (However, yychar is currently out
+         of scope during semantic actions.)
+       - 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.
+      */
+    if (tok != yyempty_)
     {
-      /* There are many possibilities here to consider:
-         - Assume YYFAIL is not used.  It's too flawed to consider.
-           See
-           <http://lists.gnu.org/archive/html/bison-patches/2009-12/msg00024.html>
-           for details.  YYERROR is fine as it does not invoke this
-           function.
-         - If this state is a consistent state with a default action,
-           then the only way this function was invoked is if the
-           default action is an error action.  In that case, don't
-           check for expected tokens because there are none.
-         - The only way there can be no lookahead present (in tok) is
-           if this state is a consistent state with a default action.
-           Thus, detecting the absence of a lookahead is sufficient to
-           determine that there is no unexpected or expected token to
-           report.  In that case, just report a simple "syntax error".
-         - Don't assume there isn't a lookahead just because this
-           state is 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 yychar.  (However, yychar is currently out
-           of scope during semantic actions.)
-         - 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.
-        */
-      if (tok != yyempty_)
+      // FIXME: This method of building the message is not compatible
+      // with internationalization.
+      string res = "syntax error, unexpected ";
+      res ~= yytnamerr_ (yytname_[tok]);
+      int yyn = yypact_[yystate];
+      if (!yy_pact_value_is_default_ (yyn))
       {
-        // FIXME: This method of building the message is not compatible
-        // with internationalization.
-        string res = "syntax error, unexpected ";
-        res ~= yytnamerr_ (yytname_[tok]);
-        int yyn = yypact_[yystate];
-        if (!yy_pact_value_is_default_ (yyn))
-        {
-          /* 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 count = 0;
-          for (int x = yyxbegin; x < yyxend; ++x)
-            if (yycheck_[x + yyn] == x && x != yyterror_
-                && !yy_table_value_is_error_ (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]))
-                 {
-                    res ~= count++ == 0 ? ", expecting " : " or ";
-                    res ~= yytnamerr_ (yytname_[x]);
-                 }
-            }
-        }
-        return res;
+        /* 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 count = 0;
+        for (int x = yyxbegin; x < yyxend; ++x)
+          if (yycheck_[x + yyn] == x && x != yy_error_token_
+              && !yy_table_value_is_error_ (yytable_[x + yyn]))
+             ++count;
+          if (count < 5)
+          {
+             count = 0;
+             for (int x = yyxbegin; x < yyxend; ++x)
+               if (yycheck_[x + yyn] == x && x != yy_error_token_
+                   && !yy_table_value_is_error_ (yytable_[x + yyn]))
+               {
+                  res ~= count++ == 0 ? ", expecting " : " or ";
+                  res ~= yytnamerr_ (yytname_[x]);
+               }
+          }
       }
-    }
-
+      return res;
+    }]])[
     return "syntax error";
   }
 
@@ -822,14 +765,6 @@ m4_popdef([b4_at_dollar])])dnl
 
   ]b4_parser_tables_define[
 
-  /* TOKEN_NUMBER_[YYLEX-NUM] -- Internal symbol number corresponding
-     to YYLEX-NUM.  */
-  private static immutable ]b4_int_type_for([b4_toknum])[[]
-  yytoken_number_ =
-  @{
-  ]b4_toknum[
-  @};
-
   /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
      First, the terminals, then, starting at \a yyntokens_, nonterminals.  */
   private static immutable string[] yytname_ =
@@ -837,6 +772,7 @@ 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_ =
   @{
@@ -862,35 +798,98 @@ 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)
+  private static token_number_type 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 token_number_type[] translate_table =
+    @{
+  ]b4_translate[
+    @};
+
+    immutable int user_token_number_max_ = ]b4_user_token_number_max[;
+    immutable token_number_type undef_token_ = ]b4_undef_token_number[;
+
+    if (t <= 0)
+      return YYTokenType.EOF;
+    else if (t <= user_token_number_max_)
+      return translate_table[t];
     else
-      return yyundef_token_;
+      return undef_token_;]])[
   }
 
+  alias ]b4_int_type_for([b4_translate])[ token_number_type;
+
+  private static immutable token_number_type yy_error_token_ = 1;
+
   private static immutable int yylast_ = ]b4_last[;
   private static immutable int yynnts_ = ]b4_nterms_number[;
   private static immutable int yyempty_ = -2;
   private static immutable int yyfinal_ = ]b4_final_state_number[;
-  private static immutable int yyterror_ = 1;
-  private static immutable int yyerrcode_ = 256;
   private static immutable int yyntokens_ = ]b4_tokens_number[;
 
-  private static immutable int yyuser_token_number_max_ = ]b4_user_token_number_max[;
-  private static immutable int yyundef_token_ = ]b4_undef_token_number[;
+  private final struct YYStackElement {
+    int state;
+    ]b4_yystype[ value;]b4_locations_if(
+    b4_location_type[[] location;])[
+  }
 
-]/* User implementation code.  */
-b4_percent_code_get[]dnl
+  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

data/skeletons/lalr1.java

@@ -1,6 +1,6 @@
-# Java skeleton for Bison -*- autoconf -*-
+# Java skeleton for Bison                           -*- autoconf -*-
 
-# Copyright (C) 2007-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2007-2015, 2018-2020 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
@@ -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, 2018-2020])[
 ]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.  */
@@ -768,10 +749,10 @@ 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_)
+                yyn += yy_error_token_;
+                if (0 <= yyn && yyn <= yylast_ && yycheck_[yyn] == yy_error_token_)
                   {
                     yyn = yytable_[yyn];
                     if (0 < yyn)
@@ -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
@@ -950,15 +931,15 @@ b4_both_if([[
                 int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_;
                 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]))
+                  if (yycheck_[x + yyn] == x && x != yy_error_token_
+                      && !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]))
+                      if (yycheck_[x + yyn] == x && x != yy_error_token_
+                          && !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_;
   }
@@ -995,20 +976,18 @@ b4_both_if([[
   private static final ]b4_int_type_for([b4_table])[ yytable_ninf_ = ]b4_table_ninf[;
 
   ]b4_parser_tables_define[
-  ]b4_integral_parser_table_define([token_number], [b4_toknum],
-     [[YYTOKEN_NUMBER[YYLEX-NUM] -- Internal symbol number corresponding
-   to YYLEX-NUM.]])[
 
   /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
      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;
@@ -1021,37 +1000,44 @@ 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;
+  }
+]],
+[[  {
+    int user_token_number_max_ = ]b4_user_token_number_max[;
+    ]b4_int_type_for([b4_translate])[ undef_token_ = ]b4_undef_token_number[;
+
+    if (t <= 0)
+      return Lexer.EOF;
+    else if (t <= user_token_number_max_)
       return yytranslate_table_[t];
     else
-      return yyundef_token_;
+      return undef_token_;
   }
+  ]b4_integral_parser_table_define([translate_table], [b4_translate])[
+]])[
+
+  private static final ]b4_int_type_for([b4_translate])[ yy_error_token_ = 1;
 
   private static final int yylast_ = ]b4_last[;
   private static final int yynnts_ = ]b4_nterms_number[;
   private static final int yyempty_ = -2;
   private static final int yyfinal_ = ]b4_final_state_number[;
-  private static final int yyterror_ = 1;
-  private static final int yyerrcode_ = 256;
   private static final int yyntokens_ = ]b4_tokens_number[;
 
-  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
 
 }
 

data/skeletons/location.cc

@@ -1,6 +1,6 @@
 # C++ skeleton for Bison
 
-# Copyright (C) 2002-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2002-2015, 2018-2020 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
@@ -16,7 +16,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 m4_pushdef([b4_copyright_years],
-           [2002-2015, 2018-2019])
+           [2002-2015, 2018-2020])
 
 
 # b4_position_file
@@ -62,11 +62,14 @@ m4_define([b4_location_define],
 [[  /// A point in a source file.
   class position
   {
-  public:]m4_ifdef([b4_location_constructors], [[
+  public:
+    /// Type for line and column numbers.
+    typedef int counter_type;
+]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)
+                       counter_type l = ]b4_location_initial_line[,
+                       counter_type c = ]b4_location_initial_column[)
       : filename (f)
       , line (l)
       , column (c)
@@ -75,8 +78,8 @@ 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)
+                     counter_type l = ]b4_location_initial_line[,
+                     counter_type c = ]b4_location_initial_column[)
     {
       filename = fn;
       line = l;
@@ -86,17 +89,17 @@ m4_define([b4_location_define],
     /** \name Line and Column related manipulators
      ** \{ */
     /// (line related) Advance to the COUNT next lines.
-    void lines (int count = 1)
+    void lines (counter_type count = 1)
     {
       if (count)
         {
-          column = ]b4_location_initial_column[u;
+          column = ]b4_location_initial_column[;
           line = add_ (line, count, ]b4_location_initial_line[);
         }
     }
 
     /// (column related) Advance to the COUNT next columns.
-    void columns (int count = 1)
+    void columns (counter_type count = 1)
     {
       column = add_ (column, count, ]b4_location_initial_column[);
     }
@@ -105,22 +108,21 @@ m4_define([b4_location_define],
     /// File name to which this position refers.
     ]b4_percent_define_get([[filename_type]])[* filename;
     /// Current line number.
-    unsigned line;
+    counter_type line;
     /// Current column number.
-    unsigned column;
+    counter_type column;
 
   private:
     /// Compute max (min, lhs+rhs).
-    static unsigned add_ (unsigned lhs, int rhs, int min)
+    static counter_type add_ (counter_type lhs, counter_type rhs, counter_type min)
     {
-      return static_cast<unsigned> (std::max (min,
-                                              static_cast<int> (lhs) + rhs));
+      return lhs + rhs < min ? min : lhs + rhs;
     }
   };
 
   /// Add \a width columns, in place.
   inline position&
-  operator+= (position& res, int width)
+  operator+= (position& res, position::counter_type width)
   {
     res.columns (width);
     return res;
@@ -128,21 +130,21 @@ m4_define([b4_location_define],
 
   /// Add \a width columns.
   inline position
-  operator+ (position res, int width)
+  operator+ (position res, position::counter_type width)
   {
     return res += width;
   }
 
   /// Subtract \a width columns, in place.
   inline position&
-  operator-= (position& res, int width)
+  operator-= (position& res, position::counter_type width)
   {
     return res += -width;
   }
 
   /// Subtract \a width columns.
   inline position
-  operator- (position res, int width)
+  operator- (position res, position::counter_type width)
   {
     return res -= width;
   }
@@ -182,6 +184,8 @@ m4_define([b4_location_define],
   class location
   {
   public:
+    /// Type for line and column numbers.
+    typedef position::counter_type counter_type;
 ]m4_ifdef([b4_location_constructors], [
     /// Construct a location from \a b to \a e.
     location (const position& b, const position& e)
@@ -197,8 +201,8 @@ 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)
+                       counter_type l = ]b4_location_initial_line[,
+                       counter_type c = ]b4_location_initial_column[)
       : begin (f, l, c)
       , end (f, l, c)
     {}
@@ -206,8 +210,8 @@ 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)
+                     counter_type l = ]b4_location_initial_line[,
+                     counter_type c = ]b4_location_initial_column[)
     {
       begin.initialize (f, l, c);
       end = begin;
@@ -223,13 +227,13 @@ m4_define([b4_location_define],
     }
 
     /// Extend the current location to the COUNT next columns.
-    void columns (int count = 1)
+    void columns (counter_type count = 1)
     {
       end += count;
     }
 
     /// Extend the current location to the COUNT next lines.
-    void lines (int count = 1)
+    void lines (counter_type count = 1)
     {
       end.lines (count);
     }
@@ -244,39 +248,45 @@ m4_define([b4_location_define],
   };
 
   /// Join two locations, in place.
-  inline location& operator+= (location& res, const location& end)
+  inline location&
+  operator+= (location& res, const location& end)
   {
     res.end = end.end;
     return res;
   }
 
   /// Join two locations.
-  inline location operator+ (location res, const location& end)
+  inline location
+  operator+ (location res, const location& end)
   {
     return res += end;
   }
 
   /// Add \a width columns to the end position, in place.
-  inline location& operator+= (location& res, int width)
+  inline location&
+  operator+= (location& res, location::counter_type width)
   {
     res.columns (width);
     return res;
   }
 
   /// Add \a width columns to the end position.
-  inline location operator+ (location res, int width)
+  inline location
+  operator+ (location res, location::counter_type width)
   {
     return res += width;
   }
 
   /// Subtract \a width columns to the end position, in place.
-  inline location& operator-= (location& res, int width)
+  inline location&
+  operator-= (location& res, location::counter_type width)
   {
     return res += -width;
   }
 
   /// Subtract \a width columns to the end position.
-  inline location operator- (location res, int width)
+  inline location
+  operator- (location res, location::counter_type width)
   {
     return res -= width;
   }
@@ -305,7 +315,8 @@ 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;
+    location::counter_type end_col
+      = 0 < loc.end.column ? loc.end.column - 1 : 0;
     ostr << loc.begin;
     if (loc.end.filename
         && (!loc.begin.filename
@@ -327,7 +338,7 @@ 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 +357,6 @@ m4_ifdef([b4_location_file], [[
 
 ]b4_cpp_guard_open([b4_location_path])[
 
-# include <algorithm> // std::max
 # include <iostream>
 # include <string>
 

data/skeletons/stack.hh

@@ -1,6 +1,6 @@
 # C++ skeleton for Bison
 
-# Copyright (C) 2002-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2002-2015, 2018-2020 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
@@ -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 +85,16 @@ 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 +115,20 @@ 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 +146,7 @@ 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[
 ]])

data/skeletons/variant.hh

@@ -1,6 +1,6 @@
 # C++ skeleton for Bison
 
-# Copyright (C) 2002-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2002-2015, 2018-2020 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
@@ -72,9 +72,9 @@ m4_map([      b4_symbol_tag_comment], [$@])dnl
 # The needed includes for variants support.
 m4_define([b4_variant_includes],
 [b4_parse_assert_if([[#include <typeinfo>]])[
-#ifndef YYASSERT
+#ifndef YY_ASSERT
 # include <cassert>
-# define YYASSERT assert
+# define YY_ASSERT assert
 #endif
 ]])
 
@@ -111,14 +111,14 @@ m4_define([b4_value_type_declare],
     semantic_type (YY_RVREF (T) t)]b4_parse_assert_if([
       : yytypeid_ (&typeid (T))])[
     {
-      YYASSERT (sizeof (T) <= size);
+      YY_ASSERT (sizeof (T) <= size);
       new (yyas_<T> ()) T (YY_MOVE (t));
     }
 
     /// Destruction, allowed only if empty.
     ~semantic_type () YY_NOEXCEPT
     {]b4_parse_assert_if([
-      YYASSERT (!yytypeid_);
+      YY_ASSERT (!yytypeid_);
     ])[}
 
 # if 201103L <= YY_CPLUSPLUS
@@ -127,8 +127,8 @@ m4_define([b4_value_type_declare],
     T&
     emplace (U&&... u)
     {]b4_parse_assert_if([
-      YYASSERT (!yytypeid_);
-      YYASSERT (sizeof (T) <= size);
+      YY_ASSERT (!yytypeid_);
+      YY_ASSERT (sizeof (T) <= size);
       yytypeid_ = & typeid (T);])[
       return *new (yyas_<T> ()) T (std::forward <U>(u)...);
     }
@@ -138,8 +138,8 @@ m4_define([b4_value_type_declare],
     T&
     emplace ()
     {]b4_parse_assert_if([
-      YYASSERT (!yytypeid_);
-      YYASSERT (sizeof (T) <= size);
+      YY_ASSERT (!yytypeid_);
+      YY_ASSERT (sizeof (T) <= size);
       yytypeid_ = & typeid (T);])[
       return *new (yyas_<T> ()) T ();
     }
@@ -149,8 +149,8 @@ m4_define([b4_value_type_declare],
     T&
     emplace (const T& t)
     {]b4_parse_assert_if([
-      YYASSERT (!yytypeid_);
-      YYASSERT (sizeof (T) <= size);
+      YY_ASSERT (!yytypeid_);
+      YY_ASSERT (sizeof (T) <= size);
       yytypeid_ = & typeid (T);])[
       return *new (yyas_<T> ()) T (t);
     }
@@ -179,9 +179,9 @@ m4_define([b4_value_type_declare],
     T&
     as () YY_NOEXCEPT
     {]b4_parse_assert_if([
-      YYASSERT (yytypeid_);
-      YYASSERT (*yytypeid_ == typeid (T));
-      YYASSERT (sizeof (T) <= size);])[
+      YY_ASSERT (yytypeid_);
+      YY_ASSERT (*yytypeid_ == typeid (T));
+      YY_ASSERT (sizeof (T) <= size);])[
       return *yyas_<T> ();
     }
 
@@ -190,9 +190,9 @@ m4_define([b4_value_type_declare],
     const T&
     as () const YY_NOEXCEPT
     {]b4_parse_assert_if([
-      YYASSERT (yytypeid_);
-      YYASSERT (*yytypeid_ == typeid (T));
-      YYASSERT (sizeof (T) <= size);])[
+      YY_ASSERT (yytypeid_);
+      YY_ASSERT (*yytypeid_ == typeid (T));
+      YY_ASSERT (sizeof (T) <= size);])[
       return *yyas_<T> ();
     }
 
@@ -208,8 +208,8 @@ m4_define([b4_value_type_declare],
     void
     swap (self_type& that) YY_NOEXCEPT
     {]b4_parse_assert_if([
-      YYASSERT (yytypeid_);
-      YYASSERT (*yytypeid_ == *that.yytypeid_);])[
+      YY_ASSERT (yytypeid_);
+      YY_ASSERT (*yytypeid_ == *that.yytypeid_);])[
       std::swap (as<T> (), that.as<T> ());
     }
 
@@ -401,7 +401,7 @@ m4_define([_b4_token_constructor_define],
                               b4_symbol_if([$1], [has_type], [std::move (v)]),
                               b4_locations_if([std::move (l)]))[)
       {
-        YYASSERT (]m4_join([ || ], m4_map_sep([_b4_type_clause], [, ], [$@]))[);
+        YY_ASSERT (]m4_join([ || ], m4_map_sep([_b4_type_clause], [, ], [$@]))[);
       }
 #else
       symbol_type (]b4_join(
@@ -413,7 +413,7 @@ m4_define([_b4_token_constructor_define],
                               b4_symbol_if([$1], [has_type], [v]),
                               b4_locations_if([l]))[)
       {
-        YYASSERT (]m4_join([ || ], m4_map_sep([_b4_type_clause], [, ], [$@]))[);
+        YY_ASSERT (]m4_join([ || ], m4_map_sep([_b4_type_clause], [, ], [$@]))[);
       }
 #endif
 ]])])

data/skeletons/yacc.c

@@ -1,11 +1,11 @@
-                                                             -*- C -*-
+#                                                            -*- C -*-
 # Yacc compatible skeleton for Bison
 
-# Copyright (C) 1984, 1989-1990, 2000-2015, 2018-2019 Free Software
+# Copyright (C) 1984, 1989-1990, 2000-2015, 2018-2020 Free Software
 # Foundation, Inc.
 
 m4_pushdef([b4_copyright_years],
-           [1984, 1989-1990, 2000-2015, 2018-2019])
+           [1984, 1989-1990, 2000-2015, 2018-2020])
 
 # 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
@@ -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
@@ -356,13 +339,13 @@ m4_if(b4_api_prefix, [yy], [],
 #define yylex           ]b4_prefix[lex
 #define yyerror         ]b4_prefix[error
 #define yydebug         ]b4_prefix[debug
-#define yynerrs         ]b4_prefix[nerrs
-]]b4_pure_if([], [[
+#define yynerrs         ]b4_prefix[nerrs]]b4_pure_if([], [[
 #define yylval          ]b4_prefix[lval
 #define yychar          ]b4_prefix[char]b4_locations_if([[
 #define yylloc          ]b4_prefix[lloc]])]))[
 
 ]b4_user_pre_prologue[
+]b4_cast_define[
 ]b4_null_define[
 
 /* Enabling verbose error messages.  */
@@ -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 +400,19 @@ typedef short yytype_int16;
 # endif
 #endif
 
-#define YYSIZE_MAXIMUM ((YYSIZE_T) -1)
+#define YYSIZE_MAXIMUM                                  \
+  YY_CAST (YYPTRDIFF_T,                                 \
+           (YYPTRDIFF_MAXIMUM < YY_CAST (YYSIZE_T, -1)  \
+            ? YYPTRDIFF_MAXIMUM                         \
+            : YY_CAST (YYSIZE_T, -1)))
+
+#define YYSIZEOF(X) YY_CAST (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 +515,23 @@ 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 +544,11 @@ 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 +560,12 @@ 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, YY_CAST (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 +591,20 @@ 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 +629,15 @@ 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 +715,8 @@ 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++)
@@ -746,23 +739,23 @@ 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++)
     {
       YYFPRINTF (stderr, "   $%d = ", yyi + 1);
       yy_symbol_print (stderr,
-                       yystos[yyssp[yyi + 1 - yynrhs]],
+                       yystos[+yyssp[yyi + 1 - yynrhs]],
                        &]b4_rhs_value(yynrhs, yyi + 1)[
                        ]b4_locations_if([, &]b4_rhs_location(yynrhs, yyi + 1))[]dnl
                        b4_user_args[);
@@ -814,22 +807,22 @@ 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 +835,9 @@ 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_CAST (yy_state_t *,
+                 YYSTACK_ALLOC (YY_CAST (YYSIZE_T,
+                                         yyalloc * YYSIZEOF (*yybottom_new))));
       if (!yybottom_new)
         {
           YYDPRINTF ((stderr, "%srealloc failed%s", yydebug_prefix,
@@ -859,8 +854,10 @@ 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));]])[
+      YY_IGNORE_USELESS_CAST_BEGIN
+      YYDPRINTF ((stderr, "%srealloc to %ld%s", yydebug_prefix,
+                  YY_CAST (long, yyalloc), yydebug_suffix));
+      YY_IGNORE_USELESS_CAST_END]])[
     }
   return 0;
 }
@@ -945,11 +942,11 @@ 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)
     {
@@ -958,12 +955,12 @@ yy_lac (yytype_int16 *yyesa, yytype_int16 **yyes,
     }
   while (1)
     {
-      int yyrule = yypact[*yyesp];
+      int yyrule = yypact[+*yyesp];
       if (yypact_value_is_default (yyrule)
           || (yyrule += yytoken) < 0 || YYLAST < yyrule
           || yycheck[yyrule] != yytoken)
         {
-          yyrule = yydefact[*yyesp];
+          yyrule = yydefact[+*yyesp];
           if (yyrule == 0)
             {
               YYDPRINTF ((stderr, " Err\n"));
@@ -986,11 +983,11 @@ 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 +1003,20 @@ 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;
+            YY_IGNORE_USELESS_CAST_BEGIN
+            *yyesp = YY_CAST (yy_state_t, yystate);
+            YY_IGNORE_USELESS_CAST_END
           }
         else
           {
@@ -1031,9 +1029,11 @@ yy_lac (yytype_int16 *yyesa, yytype_int16 **yyes,
                 YYDPRINTF ((stderr, "\n"));
                 return 2;
               }
-            *++yyesp = yystate;
+            YY_IGNORE_USELESS_CAST_BEGIN
+            *++yyesp = YY_CAST (yy_state_t, yystate);
+            YY_IGNORE_USELESS_CAST_END
           }
-        YYDPRINTF ((stderr, " G%d", (int) yystate));
+        YYDPRINTF ((stderr, " G%d", yystate));
       }
     }
 }]])[
@@ -1043,13 +1043,13 @@ yy_lac (yytype_int16 *yyesa, yytype_int16 **yyes,
 
 # ifndef yystrlen
 #  if defined __GLIBC__ && defined _STRING_H
-#   define yystrlen strlen
+#   define yystrlen(S) (YY_CAST (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 +1085,12 @@ 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 +1121,10 @@ 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
 
@@ -1139,20 +1139,20 @@ 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;
   enum { YYERROR_VERBOSE_ARGS_MAXIMUM = 5 };
   /* Internationalized format string. */
   const char *yyformat = YY_NULLPTR;
-  /* Arguments of yyformat. */
+  /* Arguments of yyformat: reported tokens (one for the "unexpected",
+     one per "expected"). */
   char const *yyarg[YYERROR_VERBOSE_ARGS_MAXIMUM];
-  /* Number of reported tokens (one for the "unexpected", one per
-     "expected"). */
+  /* Actual size of YYARG. */
   int yycount = 0;
+  /* Cumulated lengths of YYARG.  */
+  YYPTRDIFF_T yysize = 0;
 
   /* There are many possibilities here to consider:
      - If this state is a consistent state with a default action, then
@@ -1184,19 +1184,14 @@ yysyntax_error (YYSIZE_T *yymsg_alloc, char **yymsg,
   */
   if (yytoken != YYEMPTY)
     {
-      int yyn = yypact[*yyssp];]b4_lac_if([[
+      int yyn = yypact[+*yyssp];
+      YYPTRDIFF_T yysize0 = yytnamerr (YY_NULLPTR, yytname[yytoken]);
+      yysize = yysize0;]b4_lac_if([[
       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 +1204,14 @@ 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 +1225,8 @@ 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 +1257,9 @@ yysyntax_error (YYSIZE_T *yymsg_alloc, char **yymsg,
     }
 
   {
-    YYSIZE_T yysize1 = yysize + yystrlen (yyformat);
+    /* Don't count the "%s"s in the final size, but reserve room for
+       the terminator.  */
+    YYPTRDIFF_T yysize1 = yysize + (yystrlen (yyformat) - 2 * yycount) + 1;
     if (yysize <= yysize1 && yysize1 <= YYSTACK_ALLOC_MAXIMUM)
       yysize = yysize1;
     else
@@ -1283,8 +1289,8 @@ yysyntax_error (YYSIZE_T *yymsg_alloc, char **yymsg,
         }
       else
         {
-          yyp++;
-          yyformat++;
+          ++yyp;
+          ++yyformat;
         }
   }
   return 0;
@@ -1350,7 +1356,7 @@ b4_function_define([[yyparse]], [[int]], b4_parse_param)[
   yypstate *yyps;]b4_pure_if([], [[
   if (yypstate_allocated)
     return YY_NULLPTR;]])[
-  yyps = (yypstate *) malloc (sizeof *yyps);
+  yyps = YY_CAST (yypstate *, malloc (sizeof *yyps));
   if (!yyps)
     return YY_NULLPTR;
   yyps->yynew = 1;]b4_pure_if([], [[
@@ -1434,7 +1440,7 @@ 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 +1461,7 @@ 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 +1493,14 @@ 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;
+  YY_IGNORE_USELESS_CAST_BEGIN
+  *yyssp = YY_CAST (yy_state_t, yystate);
+  YY_IGNORE_USELESS_CAST_END
 
   if (yyss + yystacksize - 1 <= yyssp)
 #if !defined yyoverflow && !defined YYSTACK_RELOCATE
@@ -1500,15 +1508,15 @@ 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 +1524,9 @@ 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 +1541,10 @@ yysetstate:
         yystacksize = YYMAXDEPTH;
 
       {
-        yytype_int16 *yyss1 = yyss;
+        yy_state_t *yyss1 = yyss;
         union yyalloc *yyptr =
-          (union yyalloc *) YYSTACK_ALLOC (YYSTACK_BYTES (yystacksize));
+          YY_CAST (union yyalloc *,
+                   YYSTACK_ALLOC (YY_CAST (YYSIZE_T, YYSTACK_BYTES (yystacksize))));
         if (! yyptr)
           goto yyexhaustedlab;
         YYSTACK_RELOCATE (yyss_alloc, yyss);
@@ -1551,8 +1560,10 @@ yysetstate:
       yyvsp = yyvs + yysize - 1;]b4_locations_if([
       yylsp = yyls + yysize - 1;])[
 
-      YYDPRINTF ((stderr, "Stack size increased to %lu\n",
-                  (unsigned long) yystacksize));
+      YY_IGNORE_USELESS_CAST_BEGIN
+      YYDPRINTF ((stderr, "Stack size increased to %ld\n",
+                  YY_CAST (long, yystacksize)));
+      YY_IGNORE_USELESS_CAST_END
 
       if (yyss + yystacksize - 1 <= yyssp)
         YYABORT;
@@ -1642,16 +1653,15 @@ 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 +1776,7 @@ yyerrlab:
           {
             if (yymsg != yymsgbuf)
               YYSTACK_FREE (yymsg);
-            yymsg = (char *) YYSTACK_ALLOC (yymsg_alloc);
+            yymsg = YY_CAST (char *, YYSTACK_ALLOC (YY_CAST (YYSIZE_T, yymsg_alloc)));
             if (!yymsg)
               {
                 yymsg = yymsgbuf;
@@ -1930,7 +1940,7 @@ yyreturn:
   while (yyssp != yyss)
     {
       yydestruct ("Cleanup: popping",
-                  yystos[*yyssp], yyvsp]b4_locations_if([, yylsp])[]b4_user_args[);
+                  yystos[+*yyssp], yyvsp]b4_locations_if([, yylsp])[]b4_user_args[);
       YYPOPSTACK (1);
     }
 #ifndef yyoverflow

data/xslt/bison.xsl

@@ -3,7 +3,7 @@
 <!--
     bison.xsl - common templates for Bison XSLT.
 
-    Copyright (C) 2007-2015, 2018-2019 Free Software Foundation, Inc.
+    Copyright (C) 2007-2015, 2018-2020 Free Software Foundation, Inc.
 
     This file is part of Bison, the GNU Compiler Compiler.
 

data/xslt/xml2dot.xsl

@@ -3,7 +3,7 @@
 <!--
     xml2dot.xsl - transform Bison XML Report into DOT.
 
-    Copyright (C) 2007-2015, 2018-2019 Free Software Foundation, Inc.
+    Copyright (C) 2007-2015, 2018-2020 Free Software Foundation, Inc.
 
     This file is part of Bison, the GNU Compiler Compiler.
 

data/xslt/xml2text.xsl

@@ -3,7 +3,7 @@
 <!--
     xml2text.xsl - transform Bison XML Report into plain text.
 
-    Copyright (C) 2007-2015, 2018-2019 Free Software Foundation, Inc.
+    Copyright (C) 2007-2015, 2018-2020 Free Software Foundation, Inc.
 
     This file is part of Bison, the GNU Compiler Compiler.
 

data/xslt/xml2xhtml.xsl

@@ -3,7 +3,7 @@
 <!--
     xml2html.xsl - transform Bison XML Report into XHTML.
 
-    Copyright (C) 2007-2015, 2018-2019 Free Software Foundation, Inc.
+    Copyright (C) 2007-2015, 2018-2020 Free Software Foundation, Inc.
 
     This file is part of Bison, the GNU Compiler Compiler.
 

doc/.gitignore

@@ -16,6 +16,7 @@
 /bison.help
 /bison.html
 /bison.info
+/bison.info.bak
 /bison.log
 /bison.pdf
 /bison.ps
@@ -31,3 +32,5 @@
 /version.texi
 /yacc.1
 /relocatable.texi
+/figs/*.eps
+/figs/*.svg

doc/local.mk

@@ -1,4 +1,4 @@
-## Copyright (C) 2001-2003, 2005-2015, 2018-2019 Free Software
+## Copyright (C) 2001-2003, 2005-2015, 2018-2020 Free Software
 ## Foundation, Inc.
 
 ## This program is free software: you can redistribute it and/or modify
@@ -54,6 +54,23 @@ $(CROSS_OPTIONS_TEXI): doc/bison.help $(CROSS_OPTIONS_PL)
 	$(AM_V_at)mv $@.tmp $@
 MAINTAINERCLEANFILES = $(CROSS_OPTIONS_TEXI)
 
+
+# Fix Info's @code in @deftype
+# https://lists.gnu.org/archive/html/help-texinfo/2019-11/msg00004.html
+all: $(srcdir)/$(doc_bison).info.bak
+$(srcdir)/$(doc_bison).info.bak: $(srcdir)/$(doc_bison).info
+	$(AM_V_GEN) $(PERL) -pi.bak -0777	\
+	  -e 's{(^ --.*\n(?: {10}.*\n)*)}'	\
+	  -e '{'				\
+	  -e '  $$def = $$1;'			\
+	  -e '  $$def =~ s/‘|’//g;'		\
+	  -e '  $$def;'				\
+	  -e '}gem;' $(srcdir)/$(doc_bison).info
+	@ touch $@
+EXTRA_DIST += $(srcdir)/$(doc_bison).info.bak
+MAINTAINERCLEANFILES += $(srcdir)/$(doc_bison).info.bak
+
+
 ## ---------- ##
 ## Ref card.  ##
 ## ---------- ##

doc/refcard.tex

@@ -19,7 +19,7 @@
 \def\finalout{\overfullrule=0pt}
 %\finalout
 
-% Copyright (c) 1998, 2001, 2009-2015, 2018-2019 Free Software
+% Copyright (c) 1998, 2001, 2009--2015, 2018--2020 Free Software
 % Foundation, Inc.
 %
 % This file is part of Bison.

etc/README

@@ -16,7 +16,7 @@ straightforward use of _build/src/bison would.)
 
 --
 
-Copyright (C) 2006, 2009-2015, 2018-2019 Free Software Foundation, Inc.
+Copyright (C) 2006, 2009-2015, 2018-2020 Free Software Foundation, Inc.
 
 This file is part of Bison, the GNU Compiler Compiler.
 

etc/bench.pl.in

@@ -1,6 +1,6 @@
 #! /usr/bin/perl -w
 
-# Copyright (C) 2006, 2008-2015, 2018-2019 Free Software Foundation,
+# Copyright (C) 2006, 2008-2015, 2018-2020 Free Software Foundation,
 # Inc.
 #
 # This file is part of Bison, the GNU Compiler Compiler.

etc/local.mk

@@ -1,4 +1,4 @@
-## Copyright (C) 2006, 2008-2015, 2018-2019 Free Software Foundation,
+## Copyright (C) 2006, 2008-2015, 2018-2020 Free Software Foundation,
 ## Inc.
 
 ## This program is free software: you can redistribute it and/or modify

examples/README.md

@@ -17,7 +17,7 @@ fill-column: 76
 ispell-dictionary: "american"
 End:
 
-Copyright (C) 2018-2019 Free Software Foundation, Inc.
+Copyright (C) 2018-2020 Free Software Foundation, Inc.
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or

examples/c++/.gitignore

@@ -0,0 +1 @@
+/simple.yy

examples/c++/README.md

@@ -46,7 +46,7 @@ fill-column: 76
 ispell-dictionary: "american"
 End:
 
-Copyright (C) 2018-2019 Free Software Foundation, Inc.
+Copyright (C) 2018-2020 Free Software Foundation, Inc.
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or

examples/c++/calc++/README.md

@@ -36,7 +36,7 @@ fill-column: 76
 ispell-dictionary: "american"
 End:
 
-Copyright (C) 2018-2019 Free Software Foundation, Inc.
+Copyright (C) 2018-2020 Free Software Foundation, Inc.
 
 This file is part of Bison, the GNU Compiler Compiler.
 

examples/c++/calc++/calc++.test

@@ -1,6 +1,6 @@
 #! /bin/sh
 
-# Copyright (C) 2005-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2005-2015, 2018-2020 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

examples/c++/calc++/local.mk

@@ -1,4 +1,4 @@
-## Copyright (C) 2005-2006, 2008-2015, 2018-2019 Free Software
+## Copyright (C) 2005-2006, 2008-2015, 2018-2020 Free Software
 ## Foundation, Inc.
 ##
 ## This program is free software: you can redistribute it and/or modify

examples/c++/local.mk

@@ -1,4 +1,4 @@
-## Copyright (C) 2018-2019 Free Software Foundation, Inc.
+## Copyright (C) 2018-2020 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

examples/c++/variant-11.test

@@ -1,6 +1,6 @@
 #! /bin/sh
 
-# Copyright (C) 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2018-2020 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

examples/c++/variant-11.yy

@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2008-2015, 2018-2019 Free Software Foundation, Inc.
+  Copyright (C) 2008-2015, 2018-2020 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
@@ -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)

examples/c++/variant.test

@@ -1,6 +1,6 @@
 #! /bin/sh
 
-# Copyright (C) 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2018-2020 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

examples/c++/variant.yy

@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2008-2015, 2018-2019 Free Software Foundation, Inc.
+  Copyright (C) 2008-2015, 2018-2020 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
@@ -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:

examples/c/README.md

@@ -45,7 +45,7 @@ fill-column: 76
 ispell-dictionary: "american"
 End:
 
-Copyright (C) 2018-2019 Free Software Foundation, Inc.
+Copyright (C) 2018-2020 Free Software Foundation, Inc.
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or

examples/c/calc/README.md

@@ -9,7 +9,7 @@ fill-column: 76
 ispell-dictionary: "american"
 End:
 
-Copyright (C) 2019 Free Software Foundation, Inc.
+Copyright (C) 2019-2020 Free Software Foundation, Inc.
 
 This file is part of Bison, the GNU Compiler Compiler.
 

examples/c/calc/calc.test

@@ -1,6 +1,6 @@
 #! /bin/sh
 
-# Copyright (C) 2019 Free Software Foundation, Inc.
+# Copyright (C) 2019-2020 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

examples/c/calc/local.mk

@@ -1,4 +1,4 @@
-## Copyright (C) 2019 Free Software Foundation, Inc.
+## Copyright (C) 2019-2020 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

examples/c/lexcalc/README.md

@@ -9,7 +9,7 @@ fill-column: 76
 ispell-dictionary: "american"
 End:
 
-Copyright (C) 2018-2019 Free Software Foundation, Inc.
+Copyright (C) 2018-2020 Free Software Foundation, Inc.
 
 This file is part of Bison, the GNU Compiler Compiler.
 

examples/c/lexcalc/lexcalc.test

@@ -1,6 +1,6 @@
 #! /bin/sh
 
-# Copyright (C) 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2018-2020 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

examples/c/lexcalc/local.mk

@@ -1,4 +1,4 @@
-## Copyright (C) 2018-2019 Free Software Foundation, Inc.
+## Copyright (C) 2018-2020 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
@@ -15,9 +15,9 @@
 
 lexcalcdir = $(docdir)/%D%
 
-## ------ ##
-## Calc.  ##
-## ------ ##
+## --------- ##
+## LexCalc.  ##
+## --------- ##
 
 if FLEX_WORKS
   check_PROGRAMS += %D%/lexcalc

examples/c/lexcalc/scan.l

@@ -4,6 +4,7 @@
 %option nodefault noinput nounput noyywrap
 
 %{
+#include <errno.h> /* errno, ERANGE */
 #include <limits.h> /* INT_MIN */
 #include <stdlib.h> /* strtol */
 

examples/c/local.mk

@@ -1,4 +1,4 @@
-## Copyright (C) 2018-2019 Free Software Foundation, Inc.
+## Copyright (C) 2018-2020 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

examples/c/mfcalc/local.mk

@@ -1,4 +1,4 @@
-## Copyright (C) 2005-2006, 2008-2015, 2018-2019 Free Software
+## Copyright (C) 2005-2006, 2008-2015, 2018-2020 Free Software
 ## Foundation, Inc.
 ##
 ## This program is free software: you can redistribute it and/or modify

examples/c/mfcalc/mfcalc.test

@@ -1,6 +1,6 @@
 #! /bin/sh
 
-# Copyright (C) 2005-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2005-2015, 2018-2020 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

examples/c/reccalc/.gitignore

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

examples/c/reccalc/README.md

@@ -26,7 +26,7 @@ fill-column: 76
 ispell-dictionary: "american"
 End:
 
-Copyright (C) 2018-2019 Free Software Foundation, Inc.
+Copyright (C) 2018-2020 Free Software Foundation, Inc.
 
 This file is part of Bison, the GNU Compiler Compiler.
 

examples/c/reccalc/local.mk

@@ -1,4 +1,4 @@
-## Copyright (C) 2019 Free Software Foundation, Inc.
+## Copyright (C) 2019-2020 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
@@ -15,9 +15,9 @@
 
 reccalcdir = $(docdir)/%D%
 
-## ------ ##
-## Calc.  ##
-## ------ ##
+## --------- ##
+## RecCalc.  ##
+## --------- ##
 
 if FLEX_WORKS
   check_PROGRAMS += %D%/reccalc
@@ -36,16 +36,40 @@ endif FLEX_WORKS
 # 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 $(srcdir)/%D%/scan.l
+	$(AM_V_at)$(LEX) $(AM_LFLAGS) $(LFLAGS) -o%D%/scan.c --header-file=%D%/scan.h $(srcdir)/%D%/scan.l
 	$(AM_V_at)mv $@.tmp $@
 
 

examples/c/reccalc/reccalc.test

@@ -1,6 +1,6 @@
 #! /bin/sh
 
-# Copyright (C) 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2018-2020 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
@@ -15,6 +15,8 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+seq 0 >/dev/null || exit 77
+
 cat >input <<EOF
 1+2*3
 EOF

examples/c/rpcalc/local.mk

@@ -1,4 +1,4 @@
-## Copyright (C) 2005-2006, 2008-2015, 2018-2019 Free Software
+## Copyright (C) 2005-2006, 2008-2015, 2018-2020 Free Software
 ## Foundation, Inc.
 ##
 ## This program is free software: you can redistribute it and/or modify

examples/c/rpcalc/rpcalc.test

@@ -1,6 +1,6 @@
 #! /bin/sh
 
-# Copyright (C) 2005-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2005-2015, 2018-2020 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

examples/d/README.md

@@ -15,7 +15,7 @@ fill-column: 76
 ispell-dictionary: "american"
 End:
 
-Copyright (C) 2018-2019 Free Software Foundation, Inc.
+Copyright (C) 2018-2020 Free Software Foundation, Inc.
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or

examples/d/calc.test

@@ -1,6 +1,6 @@
 #! /bin/sh
 
-# Copyright (C) 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2018-2020 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

examples/d/calc.y

@@ -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;

examples/d/local.mk

@@ -1,4 +1,4 @@
-## Copyright (C) 2018-2019 Free Software Foundation, Inc.
+## Copyright (C) 2018-2020 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

examples/extexi

@@ -3,7 +3,7 @@
 
 # This file is part of GNU Bison
 
-# Copyright (C) 1992, 2000-2001, 2005-2006, 2009-2015, 2018-2019 Free
+# Copyright (C) 1992, 2000-2001, 2005-2006, 2009-2015, 2018-2020 Free
 # Software Foundation, Inc.
 #
 # This program is free software: you can redistribute it and/or modify

examples/java/Calc.test

@@ -1,6 +1,6 @@
 #! /bin/sh
 
-# Copyright (C) 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2018-2020 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

examples/java/Calc.y

@@ -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');
   }
 
 

examples/java/README.md

@@ -16,7 +16,7 @@ fill-column: 76
 ispell-dictionary: "american"
 End:
 
-Copyright (C) 2018-2019 Free Software Foundation, Inc.
+Copyright (C) 2018-2020 Free Software Foundation, Inc.
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or

examples/java/local.mk

@@ -1,4 +1,4 @@
-## Copyright (C) 2018-2019 Free Software Foundation, Inc.
+## Copyright (C) 2018-2020 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

examples/local.mk

@@ -1,4 +1,4 @@
-## Copyright (C) 2005, 2008-2015, 2018-2019 Free Software Foundation,
+## Copyright (C) 2005, 2008-2015, 2018-2020 Free Software Foundation,
 ## Inc.
 ##
 ## This program is free software: you can redistribute it and/or modify
@@ -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)

examples/test

@@ -1,6 +1,6 @@
 #! /bin/sh
 
-# Copyright (C) 2005-2015, 2018-2019 Free Software Foundation, Inc.
+# Copyright (C) 2005-2015, 2018-2020 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

gnulib-po/.gitignore

@@ -1,9 +1,12 @@
 /*.gmo
 /*.po
 /LINGUAS
+/Makefile
+/Makefile.in
 /Makefile.in.in
 /Makevars
 /Makevars.template
+/POTFILES
 /POTFILES.in
 /Rules-quot
 /bison-gnulib.pot
@@ -12,4 +15,6 @@
 /[email protected]
 /insert-header.sin
 /quot.sed
+/remove-potcdate.sed
 /remove-potcdate.sin
+/stamp-po

lib/.gitignore

@@ -16,6 +16,8 @@
 /argmatch.c
 /argmatch.h
 /asnprintf.c
+/asprintf.c
+/assure.h
 /basename-lgpl.c
 /basename.c
 /binary-io.c
@@ -38,6 +40,7 @@
 /canonicalize-lgpl.c
 /careadlinkat.c
 /careadlinkat.h
+/cdefs.h
 /charset.alias
 /cloexec.c
 /cloexec.h
@@ -51,6 +54,7 @@
 /config.h
 /config.in.h
 /configmake.h
+/diffseq.h
 /dirname-lgpl.c
 /dirname.c
 /dirname.h
@@ -89,9 +93,13 @@
 /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
@@ -129,12 +137,17 @@
 /isnanf.c
 /isnanl-nolibm.h
 /isnanl.c
+/iswblank.c
 /itold.c
+/lc-charset-dispatch.c
+/lc-charset-dispatch.h
 /ldexpl.c
+/libc-config.h
 /limits.h
 /limits.in.h
 /localcharset.c
 /localcharset.h
+/locale.in.h
 /localtime-buffer.c
 /localtime-buffer.h
 /lstat.c
@@ -144,10 +157,18 @@
 /math.c
 /math.h
 /math.in.h
+/mbchar.c
+/mbchar.h
+/mbfile.c
+/mbfile.h
+/mbrtowc-impl-utf8.h
+/mbrtowc-impl.h
 /mbrtowc.c
 /mbsinit.c
 /mbswidth.c
 /mbswidth.h
+/mbtowc-lock.c
+/mbtowc-lock.h
 /memchr.c
 /memchr.valgrind
 /minmax.h
@@ -189,9 +210,15 @@
 /relocatable.c
 /relocatable.h
 /relocwrapper.c
+/rename.c
+/rmdir.c
+/same-inode.h
 /sched.h
 /sched.in.h
 /setenv.c
+/setlocale-lock.c
+/setlocale_null.c
+/setlocale_null.h
 /sig-handler.c
 /sig-handler.h
 /sigaction.c
@@ -264,6 +291,8 @@
 /sys_types.in.h
 /sys_wait.in.h
 /sysexits.in.h
+/textstyle.h
+/textstyle.in.h
 /time.h
 /time.in.h
 /timespec.c
@@ -285,6 +314,7 @@
 /unsetenv.c
 /vasnprintf.c
 /vasnprintf.h
+/vasprintf.c
 /verify.h
 /vfprintf.c
 /vsnprintf.c
@@ -300,10 +330,22 @@
 /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 +357,3 @@
 /xstrndup.h
 /xtime.c
 /xtime.h
-/rename.c
-/rmdir.c
-/same-inode.h
-/assure.h
-/fsync.c
-/textstyle.in.h