b4_yaxx macro enables saving parsing trees into XML, tested on 1.875-3.0.4, see https://github.com/yijunyu/yaxx

Merge remote-tracking branch 'origin/maint'
* origin/maint: maint: post-release administrivia version 3.0.4 gnulib: update build: re-enable compiler warnings, and fix them tests: c++: fix a C++03 conformance issue tests: fix a title c++: reserve 200 slots in the parser's stack tests: be more robust to unrecognized synclines, and try to recognize xlc tests: fix C++ conformance build: fix some warnings build: avoid infinite recursions on include_next
2026-08-09 02:35:15 +00:00 · 2017-03-11 17:33:40 +00:00 · 2015-01-23 15:17:35 +01:00 · 2015-01-23 14:13:40 +01:00 · 2015-01-23 13:53:53 +01:00 · 2015-01-23 11:27:10 +01:00
216 changed files with 10188 additions and 5559 deletions
@@ -1,7 +1,16 @@
+*.eps
+*.log
+*.o
+*.pdf
+*.png
+*.stamp
+*.trs
+*~
+.deps
+.dirstamp
 /*.cache
 /*.flc
 /*.prj
-/*~
 /.tarball-version
 /.version
 /ABOUT-NLS
@@ -1 +1 @@
-2.7
+3.0.4
@@ -24,7 +24,7 @@ and nasty bugs.

 -----

-Copyright (C) 1998-2013 Free Software Foundation, Inc.
+Copyright (C) 1998-2015 Free Software Foundation, Inc.

 This file is part of Bison, the GNU Compiler Compiler.

@@ -26733,7 +26733,7 @@

 	-----

-	Copyright (C) 1987-1988, 1991-2013 Free Software Foundation,
+	Copyright (C) 1987-1988, 1991-2015 Free Software Foundation,
 	Inc.

 	Copying and distribution of this file, with or without
@@ -1,6 +1,6 @@
 ## Process this file with automake to produce Makefile.in.

-# Copyright (C) 2001-2013 Free Software Foundation, Inc.
+# Copyright (C) 2001-2015 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
@@ -24,21 +24,24 @@ SUBDIRS = po runtime-po .
 aclocaldir = @aclocaldir@
 aclocal_DATA = m4/bison-i18n.m4

-EXTRA_DIST = .prev-version .version \
-  cfg.mk ChangeLog-1998 ChangeLog-2012 PACKAGING
+EXTRA_DIST = .prev-version .version cfg.mk PACKAGING \
+  ChangeLog-1998 ChangeLog-2012 ChangeLog
+
+dist_doc_DATA = AUTHORS COPYING NEWS README THANKS TODO

 ## Running the bison from this tarball.  To generate our own parser,
 ## but also to run the tests.  Of course, you ought to keep a sane
 ## version of Bison nearby...
 BISON = $(top_builddir)/tests/bison
 BISON_IN = $(top_srcdir)/tests/bison.in
-YACC = $(BISON) -y
-AM_YFLAGS = -d -v --warnings=all,error --report=all
+YACC = $(BISON) -o y.tab.c
+AM_YFLAGS = -d -v -Werror -Wall -Wno-yacc --report=all

 # Initialization before completion by local.mk's.
 AM_CFLAGS = $(WARN_CFLAGS)
-# Find builddir/src/scan-code.c etc.
-AM_CPPFLAGS = -I. -Ilib -I$(top_srcdir) -I$(top_srcdir)/lib
+# Find builddir/src/scan-code.c etc.  For some reason "-I./lib"
+# instead of "-Ilib" avoids infinite recursions on #include_next.
+AM_CPPFLAGS = -I. -I./lib -I$(top_srcdir) -I$(top_srcdir)/lib
 BUILT_SOURCES =
 CLEANFILES =
 DISTCLEANFILES =
@@ -78,11 +81,11 @@ dist-hook: gen-ChangeLog

 .PHONY: update-b4-copyright update-package-copyright-year
 update-b4-copyright:
-	find $(srcdir)/data -type f          \
+	$(AM_V_GEN)find $(srcdir)/data -type f          \
 	  | xargs $(srcdir)/build-aux/$@
 	@echo 'warning: src/parse-gram.[hc] may need to be regenerated.'
 update-package-copyright-year:
-	$(srcdir)/build-aux/$@ $(srcdir)/configure.ac
+	$(AM_V_GEN)$(srcdir)/build-aux/$@ $(srcdir)/configure.ac

 gen_start_date = 2012-01-16
 .PHONY: gen-ChangeLog
@@ -2,16 +2,176 @@ GNU Bison NEWS

 * Noteworthy changes in release ?.? (????-??-??) [?]

+** Diagnostics about useless rules
+
+  In the following grammar, the 'exp' nonterminal is trivially useless.  So,
+  of course, its rules are useless too.
+
+    %%
+    input: '0' | exp
+    exp: exp '+' exp | exp '-' exp | '(' exp ')'
+
+  Previously all the useless rules were reported, including those whose
+  left-hand side is the 'exp' nonterminal:
+
+    warning: 1 nonterminal useless in grammar [-Wother]
+    warning: 4 rules useless in grammar [-Wother]
+    2.14-16: warning: nonterminal useless in grammar: exp [-Wother]
+     input: '0' | exp
+                  ^^^
+    2.14-16: warning: rule useless in grammar [-Wother]
+     input: '0' | exp
+                  ^^^
+    3.6-16: warning: rule useless in grammar [-Wother]
+     exp: exp '+' exp | exp '-' exp | '(' exp ')'
+          ^^^^^^^^^^^
+    3.20-30: warning: rule useless in grammar [-Wother]
+     exp: exp '+' exp | exp '-' exp | '(' exp ')'
+                        ^^^^^^^^^^^
+    3.34-44: warning: rule useless in grammar [-Wother]
+     exp: exp '+' exp | exp '-' exp | '(' exp ')'
+                                      ^^^^^^^^^^^
+
+  Now, rules whose left-hand side symbol is useless are no longer reported
+  as useless.  The locations of the errors have also been adjusted to point
+  to the first use of the nonterminal as a left-hand side of a rule:
+
+    warning: 1 nonterminal useless in grammar [-Wother]
+    warning: 4 rules useless in grammar [-Wother]
+    3.1-3: warning: nonterminal useless in grammar: exp [-Wother]
+     exp: exp '+' exp | exp '-' exp | '(' exp ')'
+     ^^^
+    2.14-16: warning: rule useless in grammar [-Wother]
+     input: '0' | exp
+                  ^^^
+
+* Noteworthy changes in release 3.0.4 (2015-01-23) [stable]
+
+** Bug fixes
+
+*** C++ with Variants (lalr1.cc)
+
+  Fix a compiler warning when no %destructor use $$.
+
+*** Test suites
+
+  Several portability issues in tests were fixed.
+
+* Noteworthy changes in release 3.0.3 (2015-01-15) [stable]
+
+** Bug fixes
+
+*** C++ with Variants (lalr1.cc)
+
+  Problems with %destructor and '%define parse.assert' have been fixed.
+
+*** Named %union support (yacc.c, glr.c)
+
+  Bison 3.0 introduced a regression on named %union such as
+
+    %union foo { int ival; };
+
+  The possibility to use a name was introduced "for Yacc compatibility".
+  It is however not required by POSIX Yacc, and its usefulness is not clear.
+
+*** %define api.value.type union with %defines (yacc.c, glr.c)
+
+  The C parsers were broken when %defines was used together with "%define
+  api.value.type union".
+
+*** Redeclarations are reported in proper order
+
+  On
+
+    %token FOO "foo"
+    %printer {} "foo"
+    %printer {} FOO
+
+  bison used to report:
+
+    /tmp/foo.yy:2.10-11: error: %printer redeclaration for FOO
+     %printer {} "foo"
+              ^^
+    /tmp/foo.yy:3.10-11:     previous declaration
+     %printer {} FOO
+              ^^
+
+  Now, the "previous" declaration is always the first one.
+
+
+** Documentation
+
+  Bison now installs various files in its docdir (which defaults to
+  '/usr/local/share/doc/bison'), including the three fully blown examples
+  extracted from the documentation:
+
+   - rpcalc
+     Reverse polish calculator, a simple introductory example.
+   - mfcalc
+     Multi-function Calc, a calculator with memory and functions and located
+     error messages.
+   - calc++
+     a calculator in C++ using variant support and token constructors.
+
+* Noteworthy changes in release 3.0.2 (2013-12-05) [stable]
+
+** Bug fixes
+
+*** Generated source files when errors are reported
+
+  When warnings are issued and -Werror is set, bison would still generate
+  the source files (*.c, *.h...).  As a consequence, some runs of "make"
+  could fail the first time, but not the second (as the files were generated
+  anyway).
+
+  This is fixed: bison no longer generates this source files, but, of
+  course, still produces the various reports (*.output, *.xml, etc.).
+
+*** %empty is used in reports
+
+  Empty right-hand sides are denoted by '%empty' in all the reports (text,
+  dot, XML and formats derived from it).
+
+*** YYERROR and variants
+
+  When C++ variant support is enabled, an error triggered via YYERROR, but
+  not caught via error recovery, resulted in a double deletion.
+
+* Noteworthy changes in release 3.0.1 (2013-11-12) [stable]
+
+** Bug fixes
+
+*** Errors in caret diagnostics
+
+  On some platforms, some errors could result in endless diagnostics.
+
+*** Fixes of the -Werror option
+
+  Options such as "-Werror -Wno-error=foo" were still turning "foo"
+  diagnostics into errors instead of warnings.  This is fixed.
+
+  Actually, for consistency with GCC, "-Wno-error=foo -Werror" now also
+  leaves "foo" diagnostics as warnings.  Similarly, with "-Werror=foo
+  -Wno-error", "foo" diagnostics are now errors.
+
+*** GLR Predicates
+
+  As demonstrated in the documentation, one can now leave spaces between
+  "%?" and its "{".
+
+*** Installation
+
+  The yacc.1 man page is no longer installed if --disable-yacc was
+  specified.
+
+*** Fixes in the test suite
+
+  Bugs and portability issues.
+
+* Noteworthy changes in release 3.0 (2013-07-25) [stable]
+
 ** WARNING: Future backward-incompatibilities!

-  Bison will stop adding a semicolon at the end of the actions (as announced
-  in the release 2.5):
-
-    foo.y:2.22: warning: a ';' might be needed at the end of action code
-     exp: "num" { $$ = $1 }
-                          ^
-    foo.y:2.22:     future versions of Bison will not add the ';'
-
  Like other GNU packages, Bison will start using some of the C99 features
  for its own code, especially the definition of variables after statements.
  The generated C parsers still aim at C90.
@@ -28,9 +188,32 @@ GNU Bison NEWS
  Support for YYLEX_PARAM and YYPARSE_PARAM is removed (deprecated in Bison
  1.875): use %lex-param, %parse-param, or %param.

+  Missing semicolons at the end of actions are no longer added (as announced
+  in the release 2.5).
+
+*** Use of YACC='bison -y'
+
+  TL;DR: With Autoconf <= 2.69, pass -Wno-yacc to (AM_)YFLAGS if you use
+  Bison extensions.
+
+  Traditional Yacc generates 'y.tab.c' whatever the name of the input file.
+  Therefore Makefiles written for Yacc expect 'y.tab.c' (and possibly
+  'y.tab.h' and 'y.outout') to be generated from 'foo.y'.
+
+  To this end, for ages, AC_PROG_YACC, Autoconf's macro to look for an
+  implementation of Yacc, was using Bison as 'bison -y'.  While it does
+  ensure compatible output file names, it also enables warnings for
+  incompatibilities with POSIX Yacc.  In other words, 'bison -y' triggers
+  warnings for Bison extensions.
+
+  Autoconf 2.70+ fixes this incompatibility by using YACC='bison -o y.tab.c'
+  (which also generates 'y.tab.h' and 'y.output' when needed).
+  Alternatively, disable Yacc warnings by passing '-Wno-yacc' to your Yacc
+  flags (YFLAGS, or AM_YFLAGS with Automake).
+
 ** Bug fixes

-*** The epilogue is no longer affected by internal #defines
+*** The epilogue is no longer affected by internal #defines (glr.c)

  The glr.c skeleton uses defines such as #define yylval (yystackp->yyval) in
  generated code.  These weren't properly undefined before the inclusion of
@@ -39,7 +222,7 @@ GNU Bison NEWS

    int yylex (YYSTYPE *yylval);

-  This is has been fixed: yylval, yynerrs, yychar, and yylloc are now valid
+  This is fixed: yylval, yynerrs, yychar, and yylloc are now valid
  identifiers for user-provided variables.

 *** stdio.h is no longer needed when locations are enabled (yacc.c)
@@ -47,6 +230,8 @@ GNU Bison NEWS
  Changes in Bison 2.7 introduced a dependency on FILE and fprintf when
  locations are enabled.  This is fixed.

+*** Warnings about useless %pure-parser/%define api.pure are restored
+
 ** Diagnostics reported by Bison

  Most of these features were contributed by Théophile Ranquet and Victor
@@ -58,6 +243,29 @@ GNU Bison NEWS
  activated by default.  The old format can still be used by invoking Bison
  with -fno-caret (or -fnone).

+  Some error messages that reproduced excerpts of the grammar are now using
+  the caret information only.  For instance on:
+
+    %%
+    exp: 'a' | 'a';
+
+  Bison 2.7 reports:
+
+    in.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+    in.y:2.12-14: warning: rule useless in parser due to conflicts: exp: 'a' [-Wother]
+
+  Now bison reports:
+
+    in.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+    in.y:2.12-14: warning: rule useless in parser due to conflicts [-Wother]
+     exp: 'a' | 'a';
+                ^^^
+
+  and "bison -fno-caret" reports:
+
+    in.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+    in.y:2.12-14: warning: rule useless in parser due to conflicts [-Wother]
+
 *** Enhancements of the -Werror option

  The -Werror=CATEGORY option is now recognized, and will treat specified
@@ -198,12 +406,10 @@ GNU Bison NEWS
    bar.y: error: shift/reduce conflicts: 1 found, 0 expected
    bar.y: error: reduce/reduce conflicts: 2 found, 0 expected

-*** Useless precedence
+** Incompatibilities with POSIX Yacc

-  Bison now warns about symbols with a declared precedence but no declared
-  associativity (i.e. declared with %precedence), and whose precedence is
-  never used.  In that case, the symbol can be safely declared with %token
-  instead, without modifying the parsing tables.
+  The 'yacc' category is no longer part of '-Wall', enable it explicitly
+  with '-Wyacc'.

 ** Additional yylex/yyparse arguments

@@ -220,13 +426,271 @@ GNU Bison NEWS

    %param {arg1_type *arg1} {arg2_type *arg2}

-** Java skeleton improvements
+** Types of values for %define variables

-  Contributed by Paolo Bonzini.
+  Bison used to make no difference between '%define foo bar' and '%define
+  foo "bar"'.  The former is now called a 'keyword value', and the latter a
+  'string value'.  A third kind was added: 'code values', such as '%define
+  foo {bar}'.
+
+  Keyword variables are used for fixed value sets, e.g.,
+
+    %define lr.type lalr
+
+  Code variables are used for value in the target language, e.g.,
+
+    %define api.value.type {struct semantic_type}
+
+  String variables are used remaining cases, e.g. file names.
+
+** Variable api.token.prefix
+
+  The variable api.token.prefix changes the way tokens are identified in
+  the generated files.  This is especially useful to avoid collisions
+  with identifiers in the target language.  For instance
+
+    %token FILE for ERROR
+    %define api.token.prefix {TOK_}
+    %%
+    start: FILE for ERROR;
+
+  will generate the definition of the symbols TOK_FILE, TOK_for, and
+  TOK_ERROR in the generated sources.  In particular, the scanner must
+  use these prefixed token names, although the grammar itself still
+  uses the short names (as in the sample rule given above).
+
+** Variable api.value.type
+
+  This new %define variable supersedes the #define macro YYSTYPE.  The use
+  of YYSTYPE is discouraged.  In particular, #defining YYSTYPE *and* either
+  using %union or %defining api.value.type results in undefined behavior.
+
+  Either define api.value.type, or use "%union":
+
+    %union
+    {
+      int ival;
+      char *sval;
+    }
+    %token <ival> INT "integer"
+    %token <sval> STRING "string"
+    %printer { fprintf (yyo, "%d", $$); } <ival>
+    %destructor { free ($$); } <sval>
+
+    /* In yylex().  */
+    yylval.ival = 42; return INT;
+    yylval.sval = "42"; return STRING;
+
+  The %define variable api.value.type supports both keyword and code values.
+
+  The keyword value 'union' means that the user provides genuine types, not
+  union member names such as "ival" and "sval" above (WARNING: will fail if
+  -y/--yacc/%yacc is enabled).
+
+    %define api.value.type union
+    %token <int> INT "integer"
+    %token <char *> STRING "string"
+    %printer { fprintf (yyo, "%d", $$); } <int>
+    %destructor { free ($$); } <char *>
+
+    /* In yylex().  */
+    yylval.INT = 42; return INT;
+    yylval.STRING = "42"; return STRING;
+
+  The keyword value variant is somewhat equivalent, but for C++ special
+  provision is made to allow classes to be used (more about this below).
+
+    %define api.value.type variant
+    %token <int> INT "integer"
+    %token <std::string> STRING "string"
+
+  Code values (in braces) denote user defined types.  This is where YYSTYPE
+  used to be used.
+
+    %code requires
+    {
+      struct my_value
+      {
+        enum
+        {
+          is_int, is_string
+        } kind;
+        union
+        {
+          int ival;
+          char *sval;
+        } u;
+      };
+    }
+    %define api.value.type {struct my_value}
+    %token <u.ival> INT "integer"
+    %token <u.sval> STRING "string"
+    %printer { fprintf (yyo, "%d", $$); } <u.ival>
+    %destructor { free ($$); } <u.sval>
+
+    /* In yylex().  */
+    yylval.u.ival = 42; return INT;
+    yylval.u.sval = "42"; return STRING;
+
+** Variable parse.error
+
+  This variable controls the verbosity of error messages.  The use of the
+  %error-verbose directive is deprecated in favor of "%define parse.error
+  verbose".
+
+** Renamed %define variables
+
+  The following variables have been renamed for consistency.  Backward
+  compatibility is ensured, but upgrading is recommended.
+
+    lr.default-reductions      -> lr.default-reduction
+    lr.keep-unreachable-states -> lr.keep-unreachable-state
+    namespace                  -> api.namespace
+    stype                      -> api.value.type
+
+** Semantic predicates
+
+  Contributed by Paul Hilfinger.
+
+  The new, experimental, semantic-predicate feature allows actions of the
+  form "%?{ BOOLEAN-EXPRESSION }", which cause syntax errors (as for
+  YYERROR) if the expression evaluates to 0, and are evaluated immediately
+  in GLR parsers, rather than being deferred.  The result is that they allow
+  the programmer to prune possible parses based on the values of run-time
+  expressions.
+
+** The directive %expect-rr is now an error in non GLR mode
+
+  It used to be an error only if used in non GLR mode, _and_ if there are
+  reduce/reduce conflicts.
+
+** Tokens are numbered in their order of appearance
+
+  Contributed by Valentin Tolmer.
+
+  With '%token A B', A had a number less than the one of B.  However,
+  precedence declarations used to generate a reversed order.  This is now
+  fixed, and introducing tokens with any of %token, %left, %right,
+  %precedence, or %nonassoc yields the same result.
+
+  When mixing declarations of tokens with a litteral character (e.g., 'a')
+  or with an identifier (e.g., B) in a precedence declaration, Bison
+  numbered the litteral characters first.  For example
+
+    %right A B 'c' 'd'
+
+  would lead to the tokens declared in this order: 'c' 'd' A B.  Again, the
+  input order is now preserved.
+
+  These changes were made so that one can remove useless precedence and
+  associativity declarations (i.e., map %nonassoc, %left or %right to
+  %precedence, or to %token) and get exactly the same output.
+
+** Useless precedence and associativity
+
+  Contributed by Valentin Tolmer.
+
+  When developing and maintaining a grammar, useless associativity and
+  precedence directives are common.  They can be a nuisance: new ambiguities
+  arising are sometimes masked because their conflicts are resolved due to
+  the extra precedence or associativity information.  Furthermore, it can
+  hinder the comprehension of a new grammar: one will wonder about the role
+  of a precedence, where in fact it is useless.  The following changes aim
+  at detecting and reporting these extra directives.
+
+*** Precedence warning category
+
+  A new category of warning, -Wprecedence, was introduced. It flags the
+  useless precedence and associativity directives.
+
+*** Useless associativity
+
+  Bison now warns about symbols with a declared associativity that is never
+  used to resolve conflicts.  In that case, using %precedence is sufficient;
+  the parsing tables will remain unchanged.  Solving these warnings may raise
+  useless precedence warnings, as the symbols no longer have associativity.
+  For example:
+
+    %left '+'
+    %left '*'
+    %%
+    exp:
+      "number"
+    | exp '+' "number"
+    | exp '*' exp
+    ;
+
+  will produce a
+
+    warning: useless associativity for '+', use %precedence [-Wprecedence]
+     %left '+'
+           ^^^
+
+*** Useless precedence
+
+  Bison now warns about symbols with a declared precedence and no declared
+  associativity (i.e., declared with %precedence), and whose precedence is
+  never used.  In that case, the symbol can be safely declared with %token
+  instead, without modifying the parsing tables.  For example:
+
+    %precedence '='
+    %%
+    exp: "var" '=' "number";
+
+  will produce a
+
+    warning: useless precedence for '=' [-Wprecedence]
+     %precedence '='
+                 ^^^
+
+*** Useless precedence and associativity
+
+  In case of both useless precedence and associativity, the issue is flagged
+  as follows:
+
+    %nonassoc '='
+    %%
+    exp: "var" '=' "number";
+
+  The warning is:
+
+    warning: useless precedence and associativity for '=' [-Wprecedence]
+     %nonassoc '='
+               ^^^
+
+** Empty rules
+
+  With help from Joel E. Denny and Gabriel Rassoul.
+
+  Empty rules (i.e., with an empty right-hand side) can now be explicitly
+  marked by the new %empty directive.  Using %empty on a non-empty rule is
+  an error.  The new -Wempty-rule warning reports empty rules without
+  %empty.  On the following grammar:
+
+    %%
+    s: a b c;
+    a: ;
+    b: %empty;
+    c: 'a' %empty;
+
+  bison reports:
+
+    3.4-5: warning: empty rule without %empty [-Wempty-rule]
+     a: {}
+        ^^
+    5.8-13: error: %empty on non-empty rule
+     c: 'a' %empty {};
+            ^^^^^^
+
+** Java skeleton improvements

  The constants for token names were moved to the Lexer interface.  Also, it
  is possible to add code to the parser's constructors using "%code init"
  and "%define init_throws".
+  Contributed by Paolo Bonzini.
+
+  The Java skeleton now supports push parsing.
+  Contributed by Dennis Heimbigner.

 ** C++ skeletons improvements

@@ -249,59 +713,66 @@ GNU Bison NEWS
  used by the scanner, or rejecting invalid combinations from a
  factory invoked by the user actions).

-** Renamed %define variables
+*** %define api.value.type variant

-  The following variables have been renamed for consistency.  Backward
-  compatibility is ensured, but upgrading is recommended.
+  This is based on a submission from Michiel De Wilde.  With help
+  from Théophile Ranquet.

-    lr.default-reductions      -> lr.default-reduction
-    lr.keep-unreachable-states -> lr.keep-unreachable-state
-    namespace                  -> api.namespace
-    stype                      -> api.value.type
+  In this mode, complex C++ objects can be used as semantic values.  For
+  instance:

-** Variable api.token.prefix
-
-  The variable api.token.prefix changes the way tokens are identified in
-  the generated files.  This is especially useful to avoid collisions
-  with identifiers in the target language.  For instance
-
-    %token FILE for ERROR
-    %define api.token.prefix "TOK_"
+    %token <::std::string> TEXT;
+    %token <int> NUMBER;
+    %token SEMICOLON ";"
+    %type <::std::string> item;
+    %type <::std::list<std::string>> list;
    %%
-    start: FILE for ERROR;
+    result:
+      list  { std::cout << $1 << std::endl; }
+    ;

-  will generate the definition of the symbols TOK_FILE, TOK_for, and
-  TOK_ERROR in the generated sources.  In particular, the scanner must
-  use these prefixed token names, although the grammar itself still
-  uses the short names (as in the sample rule given above).
+    list:
+      %empty        { /* Generates an empty string list. */ }
+    | list item ";" { std::swap ($$, $1); $$.push_back ($2); }
+    ;

-** Variable parse.error
+    item:
+      TEXT    { std::swap ($$, $1); }
+    | NUMBER  { $$ = string_cast ($1); }
+    ;

-  This variable controls the verbosity of error messages.  The use of the
-  %error-verbose directive is deprecated in favor of "%define parse.error
-  verbose".
+*** %define api.token.constructor

-** Semantic predicates
+  When variants are enabled, Bison can generate functions to build the
+  tokens.  This guarantees that the token type (e.g., NUMBER) is consistent
+  with the semantic value (e.g., int):

-  Contributed by Paul Hilfinger.
+    parser::symbol_type yylex ()
+    {
+      parser::location_type loc = ...;
+      ...
+      return parser::make_TEXT ("Hello, world!", loc);
+      ...
+      return parser::make_NUMBER (42, loc);
+      ...
+      return parser::make_SEMICOLON (loc);
+      ...
+    }

-  The new, experimental, semantic-predicate feature allows actions of the
-  form "%?{ BOOLEAN-EXPRESSION }", which cause syntax errors (as for
-  YYERROR) if the expression evaluates to 0, and are evaluated immediately
-  in GLR parsers, rather than being deferred.  The result is that they allow
-  the programmer to prune possible parses based on the values of run-time
-  expressions.
+*** C++ locations

-** The directive %expect-rr is now an error in non GLR mode
+  There are operator- and operator-= for 'location'.  Negative line/column
+  increments can no longer underflow the resulting value.

-  It used to be an error only if used in non GLR mode, _and_ if there are
-  reduce/reduce conflicts.
+* Noteworthy changes in release 2.7.1 (2013-04-15) [stable]

-** Token numbering has changed to preserve the user-defined order
+** Bug fixes

-  When declaring %token A B, the numbering for A is inferior to B. Up to now,
-  when declaring associativity at the same time, with %left (or %right,
-  %precedence, %nonassoc), B was inferior to A.
+*** Fix compiler attribute portability (yacc.c)
+
+  With locations enabled, __attribute__ was used unprotected.
+
+*** Fix some compiler warnings (lalr1.cc)

 * Noteworthy changes in release 2.7 (2012-12-12) [stable]

@@ -353,8 +824,8 @@ GNU Bison NEWS
     exp: exp '+' exp { $exp = $1 + $3; };
                  ^^^

-  The default behaviour for now is still not to display these unless
-  explictly asked with -fcaret (or -fall). However, in a later release, it
+  The default behavior for now is still not to display these unless
+  explicitly asked with -fcaret (or -fall). However, in a later release, it
  will be made the default behavior (but may still be deactivated with
  -fno-caret).

@@ -441,7 +912,7 @@ GNU Bison NEWS

  Other issues in the test suite have been addressed.

-  Nul characters are correctly displayed in error messages.
+  Null characters are correctly displayed in error messages.

  When possible, yylloc is correctly initialized before calling yylex.  It
  is no longer necessary to initialize it in the %initial-action.
@@ -2322,7 +2793,7 @@ Output file does not redefine const for C++.

 -----

-Copyright (C) 1995-2013 Free Software Foundation, Inc.
+Copyright (C) 1995-2015 Free Software Foundation, Inc.

 This file is part of Bison, the GNU Parser Generator.

@@ -2357,7 +2828,12 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 LocalWords:  Automake TMPDIR LESSEQ ylwrap endif yydebug YYTOKEN YYLSP ival hh
 LocalWords:  extern YYTOKENTYPE TOKENTYPE yytokentype tokentype STYPE lval pdf
 LocalWords:  lang yyoutput dvi html ps POSIX lvalp llocp Wother nterm arg init
- LocalWords:  TOK calc yyo fval Wconflicts
+ LocalWords:  TOK calc yyo fval Wconflicts parsers yystackp yyval yynerrs
+ LocalWords:  Théophile Ranquet Santet fno fnone stype associativity Tolmer
+ LocalWords:  Wprecedence Rassoul Wempty Paolo Bonzini parser's Michiel loc
+ LocalWords:  redeclaration sval fcaret reentrant XSLT xsl Wmaybe yyvsp Tedi
+ LocalWords:  pragmas noreturn untyped Rozenman unexpanded Wojciech Polak
+ LocalWords:  Alexandre MERCHANTABILITY yytype

 Local Variables:
 mode: outline
@@ -36,7 +36,7 @@ to the bison package.

 -----

-Copyright (C) 2002, 2005, 2009-2013 Free Software Foundation, Inc.
+Copyright (C) 2002, 2005, 2009-2015 Free Software Foundation, Inc.

 This file is part of Bison, the GNU Compiler Compiler.

@@ -30,7 +30,7 @@ not answer them, please send mail to <[email protected]>.

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

 * Copyright statements
@@ -44,7 +44,7 @@ End:

 -----

-Copyright (C) 1992, 1998-1999, 2003-2005, 2008-2013 Free Software
+Copyright (C) 1992, 1998-1999, 2003-2005, 2008-2015 Free Software
 Foundation, Inc.

 This file is part of Bison, the GNU Compiler Compiler.
@@ -12,7 +12,7 @@ the problems you encounter.

 -----

-Copyright (C) 2002, 2004, 2009-2013 Free Software Foundation, Inc.
+Copyright (C) 2002, 2004, 2009-2015 Free Software Foundation, Inc.

 This file is part of GNU Bison.

@@ -62,13 +62,22 @@ tools we depend upon, including:
 - Gettext <http://www.gnu.org/software/gettext/>
 - Graphviz <http://www.graphviz.org>
 - Gzip <http://www.gnu.org/software/gzip/>
+- Help2man <http://www.gnu.org/software/help2man/>
 - Perl <http://www.cpan.org/>
 - Rsync <http://samba.anu.edu.au/rsync/>
 - Tar <http://www.gnu.org/software/tar/>
+- Texinfo <http://www.gnu.org/software/texinfo/>

 Valgrind <http://valgrind.org/> is also highly recommended, if it supports
 your architecture.

+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
+
 Bison is written using Bison grammars, so there are bootstrapping issues.
 The bootstrap script attempts to discover when the C code generated from the
 grammars is out of date, and to bootstrap with an out-of-date version of the
@@ -94,15 +103,17 @@ to perform the first checkout of the submodules, run

       $ git submodule update --init

-Git submodule support is weak before versions 1.6 and later, you
-should probably upgrade Git if your version is older.
+Git submodule support is weak before versions 1.6 and later, upgrade Git if
+your version is older.

 The next step is to get other files needed to build, which are
 extracted from other source packages:

        $ ./bootstrap

-And there you are!  Just
+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.  Otherwise, there you are!  Just

        $ ./configure
        $ make
@@ -440,7 +451,7 @@ Push these changes.

 -----

-Copyright (C) 2002-2005, 2007-2013 Free Software Foundation, Inc.
+Copyright (C) 2002-2005, 2007-2015 Free Software Foundation, Inc.

 This file is part of GNU Bison.

@@ -9,7 +9,7 @@ Bison supports the @N construction, which gives you access to
 the starting and ending line number and character number associated
 with any of the symbols in the current rule.

-Also, Bison supports the command `%expect N' which says not to mention
+Also, Bison supports the command '%expect N' which says not to mention
 the conflicts if there are N shift/reduce conflicts and no reduce/reduce
 conflicts.

@@ -1,7 +1,8 @@
 Bison was originally written by Robert Corbett.  It would not be what
 it is today without the invaluable help of these people:

-Аскар Сафин              [email protected]
+Aaro Koskinen             [email protected]
+Аскар Сафин               [email protected]
 Airy Andre                [email protected]
 Akim Demaille             [email protected]
 Albert Chin-A-Young       [email protected]
@@ -11,11 +12,13 @@ Andreas Schwab            [email protected]
 Andrew Suffield           [email protected]
 Angelo Borsotti           [email protected]
 Anthony Heading           [email protected]
+Antonio Silva Correia     [email protected]
 Arnold Robbins            [email protected]
 Art Haas                  [email protected]
 Baron Schwartz            [email protected]
 Ben Pfaff                 [email protected]
 Benoit Perrot             [email protected]
+Bernd Edlinger            [email protected]
 Bernd Kiefer              [email protected]
 Bert Deknuydt             [email protected]
 Bill Allombert            [email protected]
@@ -25,10 +28,13 @@ Bruce Lilly               [email protected]
 Bruno Haible              [email protected]
 Charles-Henri de Boysson  [email protected]
 Christian Burger          [email protected]
+Colin Daley               [email protected]
 Cris Bailiff              [email protected]
 Cris van Pelt             [email protected]
 Csaba Raduly              [email protected]
 Dagobert Michelsen        [email protected]
+Daniel Frużyński          [email protected]
+Daniel Galloway           [email protected]
 Daniel Hagerty            [email protected]
 David J. MacKenzie        [email protected]
 David Kastrup             [email protected]
@@ -37,6 +43,7 @@ Derek M. Jones            [email protected]
 Di-an Jan                 [email protected]
 Dick Streefland           [email protected]
 Didier Godefroy           [email protected]
+Efi Fogel                 [email protected]
 Enrico Scholz             [email protected]
 Eric Blake                [email protected]
 Evgeny Stambulchik        [email protected]
@@ -44,6 +51,7 @@ Fabrice Bauzac            [email protected]
 Florian Krohm             [email protected]
 Frank Heckenbach          [email protected]
 Frans Englich             [email protected]
+Gabriel Rassoul           [email protected]
 Georg Sauthoff            [email protected]
 George Neuner             [email protected]
 Gilles Espinasse          [email protected]
@@ -58,11 +66,13 @@ Jim Kent                  [email protected]
 Jim Meyering              [email protected]
 Joel E. Denny             [email protected]
 Johan van Selst           [email protected]
+John Horigan              [email protected]
 Jonathan Fabrizio         [email protected]
 Jonathan Nieder           [email protected]
 Juan Manuel Guerrero      [email protected]
 Kees Zeelenberg           [email protected]
 Keith Browne              [email protected]
+Ken Moffat                [email protected]
 Laurent Mascherpa         [email protected]
 Lie Yan                   [email protected]
 Magnus Fromreide          [email protected]
@@ -74,14 +84,19 @@ Martin Mokrejs            [email protected]
 Martin Nylin              [email protected]
 Matt Kraai                [email protected]
 Matt Rosing               [email protected]
+Michael Catanzaro         [email protected]
+Michael Felt              [email protected]
 Michael Hayes             [email protected]
 Michael Raskin            [email protected]
+Michel d'Hooge            [email protected]
 Michiel De Wilde          [email protected]
 Mickael Labau             [email protected]
 Mike Castle               [email protected]
+Mike Sullivan             [email protected]
 Neil Booth                [email protected]
 Nelson H. F. Beebe        [email protected]
 Nick Bowler               [email protected]
+Nicolas Bedon             [email protected]
 Nicolas Burrus            [email protected]
 Nicolas Tisserand         [email protected]
 Noah Friedman             [email protected]
@@ -89,6 +104,7 @@ Odd Arild Olsen           [email protected]
 Oleg Smolsky              [email protected]
 Oleksii Taran             [email protected]
 Paolo Bonzini             [email protected]
+Paolo Simone Gasparello   [email protected]
 Pascal Bart               [email protected]
 Paul Eggert               [email protected]
 Paul Hilfinger            [email protected]
@@ -97,13 +113,18 @@ Peter Eisentraut          [email protected]
 Peter Fales               [email protected]
 Peter Hamorsky            [email protected]
 Peter Simons              [email protected]
+Petr Machata              [email protected]
+Pho                       [email protected]
 Piotr Gackiewicz          [email protected]
 Quentin Hocquet           [email protected]
 Quoc Peyrot               [email protected]
 R Blake                   [email protected]
 Raja R Harinath           [email protected]
 Ralf Wildenhues           [email protected]
+Rich Wilson               [email protected]
 Richard Stallman          [email protected]
+Rici Lake                 [email protected]
+Rob Conde                 [email protected]
 Rob Vermaas               [email protected]
 Robert Anisko             [email protected]
 Roland Levillain          [email protected]
@@ -113,19 +134,23 @@ Sebastien Fricker         [email protected]
 Sergei Steshenko          [email protected]
 Shura                     [email protected]
 Stefano Lattarini         [email protected]
+Stephen Cameron           [email protected]
 Steve Murphy              [email protected]
 Sum Wu                    [email protected]
 Théophile Ranquet         [email protected]
 Thiru Ramakrishnan        [email protected]
+Thomas Jahns              [email protected]
 Tim Josling               [email protected]
 Tim Landscheidt           [email protected]
 Tim Van Holder            [email protected]
+Tobias Frost              [email protected]
 Tom Lane                  [email protected]
 Tom Tromey                [email protected]
 Tommy Nordgren            [email protected]
 Troy A. Johnson           [email protected]
 Tys Lefering              [email protected]
 Valentin Tolmer           [email protected]
+Victor Khomenko           [email protected]
 Vin Shelton               [email protected]
 W.C.A. Wijngaards         [email protected]
 Wayne Green               [email protected]
@@ -134,6 +159,7 @@ Wojciech Polak            [email protected]
 Wolfgang S. Kechel        [email protected]
 Wolfram Wagner            [email protected]
 Wwp                       [email protected]
+xolodho                   [email protected]
 Zack Weinberg             [email protected]

 Many people are not named here because we lost track of them.  We
@@ -146,7 +172,7 @@ End:

 -----

-Copyright (C) 2000-2013 Free Software Foundation, Inc.
+Copyright (C) 2000-2015 Free Software Foundation, Inc.

 This file is part of Bison, the GNU Parser Generator.

@@ -1,16 +1,27 @@
 * Short term
 ** Graphviz display code thoughts
 The code for the --graph option is over two files: print_graph, and
-graphviz. I believe this is because Bison used to also produce VCG graphs,
-but since this is no longer true, maybe we could consider these files for
-fusion.
+graphviz. This is because Bison used to also produce VCG graphs, but since
+this is no longer true, maybe we could consider these files for fusion.

-Little effort factoring seems to have been given to factoring in these files,
-and their print-xml and print counterpart. We would very much like to re-use
-the pretty format of states from .output in the .dot
+An other consideration worth noting is that print_graph.c (correct me if I
+am wrong) should contain generic functions, whereas graphviz.c and other
+potential files should contain just the specific code for that output
+format. It will probably prove difficult to tell if the implementation is
+actually generic whilst only having support for a single format, but it
+would be nice to keep stuff a bit tidier: right now, the construction of the
+bitset used to show reductions is in the graphviz-specific code, and on the
+opposite side we have some use of \l, which is graphviz-specific, in what
+should be generic code.

-Also, the underscore in print_graph.[ch] isn't very fitting considering
-the dashes in the other filenames.
+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
 Check it too when checking the different kinds of parsers.  And be
@@ -165,13 +176,13 @@ part of $default.  Should we make the two reductions explicit, or just
 keep $default?  See the following point.

 ** Disabled Reductions
-See `tests/conflicts.at (Defaulted Conflicted Reduction)', and decide
+See 'tests/conflicts.at (Defaulted Conflicted Reduction)', and decide
 what we want to do.

 ** Documentation
 Extend with error productions.  The hard part will probably be finding
 the right rule so that a single state does not exhibit too many yet
-undocumented ``features''.  Maybe an empty action ought to be
+undocumented ''features''.  Maybe an empty action ought to be
 presented too.  Shall we try to make a single grammar with all these
 features, or should we have several very small grammars?

@@ -232,9 +243,9 @@ into
        exp: exp '+' exp | exp '&' exp;

 when there are no actions.  This can significantly speed up some
-grammars.  I can't find the papers.  In particular the book `LR
+grammars.  I can't find the papers.  In particular the book 'LR
 parsing: Theory and Practice' is impossible to find, but according to
-`Parsing Techniques: a Practical Guide', it includes information about
+'Parsing Techniques: a Practical Guide', it includes information about
 this issue.  Does anybody have it?


@@ -358,7 +369,7 @@ End:

 -----

-Copyright (C) 2001-2004, 2006, 2008-2013 Free Software Foundation, Inc.
+Copyright (C) 2001-2004, 2006, 2008-2015 Free Software Foundation, Inc.

 This file is part of Bison, the GNU Compiler Compiler.

@@ -1,10 +1,10 @@
 #! /bin/sh
 # Print a version string.
-scriptversion=2012-12-28.10; # UTC
+scriptversion=2014-12-08.12; # UTC

 # Bootstrap this package from checked-out sources.

-# Copyright (C) 2003-2013 Free Software Foundation, Inc.
+# Copyright (C) 2003-2015 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
@@ -42,6 +42,9 @@ export LC_ALL

 local_gl_dir=gl

+# Honour $PERL, but work even if there is none
+PERL="${PERL-perl}"
+
 me=$0

 usage() {
@@ -140,20 +143,21 @@ po_download_command_format2=\
 "wget --mirror -nd -q -np -A.po -P '%s' \
 http://translationproject.org/latest/%s/"

+# Prefer a non-empty tarname (4th argument of AC_INIT if given), else
+# fall back to the package name (1st argument with munging)
 extract_package_name='
-  /^AC_INIT(/{
-     /.*,.*,.*, */{
-       s///
-       s/[][]//g
-       s/)$//
+  /^AC_INIT(\[*/{
+     s///
+     /^[^,]*,[^,]*,[^,]*,[ []*\([^][ ,)]\)/{
+       s//\1/
+       s/[],)].*//
       p
       q
     }
-     s/AC_INIT(\[*//
-     s/]*,.*//
+     s/[],)].*//
     s/^GNU //
     y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/
-     s/[^A-Za-z0-9_]/-/g
+     s/[^abcdefghijklmnopqrstuvwxyz0123456789_]/-/g
     p
  }
 '
@@ -208,12 +212,26 @@ bootstrap_sync=false
 # Use git to update gnulib sources
 use_git=true

+check_exists() {
+  if test "$1" = "--verbose"; then
+    ($2 --version </dev/null) >/dev/null 2>&1
+    if test $? -ge 126; then
+      # If not found, run with diagnostics as one may be
+      # presented with env variables to set to find the right version
+      ($2 --version </dev/null)
+    fi
+  else
+    ($1 --version </dev/null) >/dev/null 2>&1
+  fi
+
+  test $? -lt 126
+}
+
 # find_tool ENVVAR NAMES...
 # -------------------------
 # Search for a required program.  Use the value of ENVVAR, if set,
-# otherwise find the first of the NAMES that can be run (i.e.,
-# supports --version).  If found, set ENVVAR to the program name,
-# die otherwise.
+# otherwise find the first of the NAMES that can be run.
+# If found, set ENVVAR to the program name, die otherwise.
 #
 # FIXME: code duplication, see also gnu-web-doc-update.
 find_tool ()
@@ -223,27 +241,21 @@ find_tool ()
  find_tool_names=$@
  eval "find_tool_res=\$$find_tool_envvar"
  if test x"$find_tool_res" = x; then
-    for i
-    do
-      if ($i --version </dev/null) >/dev/null 2>&1; then
-       find_tool_res=$i
-       break
+    for i; do
+      if check_exists $i; then
+        find_tool_res=$i
+        break
      fi
    done
-  else
-    find_tool_error_prefix="\$$find_tool_envvar: "
  fi
-  test x"$find_tool_res" != x \
-    || die "one of these is required: $find_tool_names"
-  ($find_tool_res --version </dev/null) >/dev/null 2>&1 \
-    || die "${find_tool_error_prefix}cannot run $find_tool_res --version"
+  if test x"$find_tool_res" = x; then
+    warn_ "one of these is required: $find_tool_names;"
+    die   "alternatively set $find_tool_envvar to a compatible tool"
+  fi
  eval "$find_tool_envvar=\$find_tool_res"
  eval "export $find_tool_envvar"
 }

-# Find sha1sum, named gsha1sum on MacPorts, and shasum on Mac OS X 10.6.
-find_tool SHA1SUM sha1sum gsha1sum shasum
-
 # Override the default configuration, if necessary.
 # Make sure that bootstrap.conf is sourced from the current directory
 # if we were invoked as "sh bootstrap".
@@ -255,12 +267,12 @@ esac
 # Extra files from gnulib, which override files from other sources.
 test -z "${gnulib_extra_files}" && \
  gnulib_extra_files="
-        $build_aux/install-sh
-        $build_aux/mdate-sh
-        $build_aux/texinfo.tex
-        $build_aux/depcomp
-        $build_aux/config.guess
-        $build_aux/config.sub
+        build-aux/install-sh
+        build-aux/mdate-sh
+        build-aux/texinfo.tex
+        build-aux/depcomp
+        build-aux/config.guess
+        build-aux/config.sub
        doc/INSTALL
 "

@@ -306,34 +318,34 @@ if test -n "$checkout_only_file" && test ! -r "$checkout_only_file"; then
  die "Bootstrapping from a non-checked-out distribution is risky."
 fi

-# Ensure that lines starting with ! sort last, per gitignore conventions
-# for whitelisting exceptions after a more generic blacklist pattern.
-sort_patterns() {
-  sort -u "$@" | sed '/^!/ {
-    H
-    d
-  }
-  $ {
-    P
-    x
-    s/^\n//
-  }' | sed '/^$/d'
+# Strip blank and comment lines to leave significant entries.
+gitignore_entries() {
+  sed '/^#/d; /^$/d' "$@"
 }

-# If $STR is not already on a line by itself in $FILE, insert it,
-# sorting the new contents of the file and replacing $FILE with the result.
-insert_sorted_if_absent() {
+# If $STR is not already on a line by itself in $FILE, insert it at the start.
+# Entries are inserted at the start of the ignore list to ensure existing
+# entries starting with ! are not overridden.  Such entries support
+# whitelisting exceptions after a more generic blacklist pattern.
+insert_if_absent() {
  file=$1
  str=$2
  test -f $file || touch $file
-  echo "$str" | sort_patterns - $file | cmp -s - $file > /dev/null \
-    || { echo "$str" | sort_patterns - $file > $file.bak \
-      && mv $file.bak $file; } \
-    || die "insert_sorted_if_absent $file $str: failed"
+  test -r $file || die "Error: failed to read ignore file: $file"
+  duplicate_entries=$(gitignore_entries $file | sort | uniq -d)
+  if [ "$duplicate_entries" ] ; then
+    die "Error: Duplicate entries in $file: " $duplicate_entries
+  fi
+  linesold=$(gitignore_entries $file | wc -l)
+  linesnew=$( { echo "$str"; cat $file; } | gitignore_entries | sort -u | wc -l)
+  if [ $linesold != $linesnew ] ; then
+    { echo "$str" | cat - $file > $file.bak && mv $file.bak $file; } \
+      || die "insert_if_absent $file $str: failed"
+  fi
 }

 # Adjust $PATTERN for $VC_IGNORE_FILE and insert it with
-# insert_sorted_if_absent.
+# insert_if_absent.
 insert_vc_ignore() {
  vc_ignore_file="$1"
  pattern="$2"
@@ -344,7 +356,7 @@ insert_vc_ignore() {
    # .gitignore entry.
    pattern=$(echo "$pattern" | sed s,^,/,);;
  esac
-  insert_sorted_if_absent "$vc_ignore_file" "$pattern"
+  insert_if_absent "$vc_ignore_file" "$pattern"
 }

 # Die if there is no AC_CONFIG_AUX_DIR($build_aux) line in configure.ac.
@@ -409,7 +421,7 @@ sort_ver() { # sort -V is not generally available
 get_version() {
  app=$1

-  $app --version >/dev/null 2>&1 || return 1
+  $app --version >/dev/null 2>&1 || { $app --version; return 1; }

  $app --version 2>&1 |
  sed -n '# Move version to start of line.
@@ -447,6 +459,7 @@ check_versions() {
    test "$appvar" = TAR && appvar=AMTAR
    case $appvar in
        GZIP) ;; # Do not use $GZIP:  it contains gzip options.
+        PERL::*) ;; # Keep perl modules as-is
        *) eval "app=\${$appvar-$app}" ;;
    esac

@@ -464,12 +477,22 @@ check_versions() {
          ret=1
          continue
        } ;;
+      # Another check is for perl modules.  These can be written as
+      # e.g. perl::XML::XPath in case of XML::XPath module, etc.
+      perl::*)
+        # Extract module name
+        app="${app#perl::}"
+        if ! $PERL -m"$app" -e 'exit 0' >/dev/null 2>&1; then
+          warn_ "Error: perl module '$app' not found"
+          ret=1
+        fi
+        continue
+        ;;
    esac
    if [ "$req_ver" = "-" ]; then
      # Merely require app to exist; not all prereq apps are well-behaved
      # so we have to rely on $? rather than get_version.
-      $app --version >/dev/null 2>&1
-      if [ 126 -le $? ]; then
+      if ! check_exists --verbose $app; then
        warn_ "Error: '$app' not found"
        ret=1
      fi
@@ -502,6 +525,12 @@ print_versions() {
  # can't depend on column -t
 }

+# Find sha1sum, named gsha1sum on MacPorts, shasum on Mac OS X 10.6.
+# Also find the compatible sha1 utility on the BSDs
+if test x"$SKIP_PO" = x; then
+  find_tool SHA1SUM sha1sum gsha1sum shasum sha1
+fi
+
 use_libtool=0
 # We'd like to use grep -E, to see if any of LT_INIT,
 # AC_PROG_LIBTOOL, AM_PROG_LIBTOOL is used in configure.ac,
@@ -547,13 +576,21 @@ if ! printf "$buildreq" | check_versions; then
  fi
 fi

+# Warn the user if autom4te appears to be broken; this causes known
+# issues with at least gettext 0.18.3.
+probe=$(echo 'm4_quote([hi])' | autom4te -l M4sugar -t 'm4_quote:$%' -)
+if test "x$probe" != xhi; then
+  warn_ "WARNING: your autom4te wrapper eats stdin;"
+  warn_ "if bootstrap fails, consider upgrading your autotools"
+fi
+
 echo "$0: Bootstrapping from checked-out $package sources..."

 # See if we can use gnulib's git-merge-changelog merge driver.
-if test -d .git && (git --version) >/dev/null 2>/dev/null ; then
+if $use_git && test -d .git && check_exists git; then
  if git config merge.merge-changelog.driver >/dev/null ; then
    :
-  elif (git-merge-changelog --version) >/dev/null 2>/dev/null ; then
+  elif check_exists git-merge-changelog; then
    echo "$0: initializing git-merge-changelog driver"
    git config merge.merge-changelog.name 'GNU-style ChangeLog merge driver'
    git config merge.merge-changelog.driver 'git-merge-changelog %O %A %B'
@@ -573,17 +610,21 @@ git_modules_config () {
  test -f .gitmodules && git config --file .gitmodules "$@"
 }

-gnulib_path=$(git_modules_config submodule.gnulib.path)
-test -z "$gnulib_path" && gnulib_path=gnulib
+if $use_git; then
+  gnulib_path=$(git_modules_config submodule.gnulib.path)
+  test -z "$gnulib_path" && gnulib_path=gnulib
+fi

-# Get gnulib files.
+# Get gnulib files.  Populate $GNULIB_SRCDIR, possibly updating a
+# submodule, for use in the rest of the script.

 case ${GNULIB_SRCDIR--} in
 -)
+  # Note that $use_git is necessarily true in this case.
  if git_modules_config submodule.gnulib.url >/dev/null; then
    echo "$0: getting gnulib files..."
-    git submodule init || exit $?
-    git submodule update || exit $?
+    git submodule init -- "$gnulib_path" || exit $?
+    git submodule update -- "$gnulib_path" || exit $?

  elif [ ! -d "$gnulib_path" ]; then
    echo "$0: getting gnulib files..."
@@ -600,8 +641,8 @@ case ${GNULIB_SRCDIR--} in
  GNULIB_SRCDIR=$gnulib_path
  ;;
 *)
-  # Use GNULIB_SRCDIR as a reference.
-  if test -d "$GNULIB_SRCDIR"/.git && \
+  # Use GNULIB_SRCDIR directly or as a reference.
+  if $use_git && test -d "$GNULIB_SRCDIR"/.git && \
        git_modules_config submodule.gnulib.url >/dev/null; then
    echo "$0: getting gnulib files..."
    if git submodule -h|grep -- --reference > /dev/null; then
@@ -612,13 +653,14 @@ case ${GNULIB_SRCDIR--} in
      # This fallback allows at least git 1.5.5.
      if test -f "$gnulib_path"/gnulib-tool; then
        # Since file already exists, assume submodule init already complete.
-        git submodule update || exit $?
+        git submodule update -- "$gnulib_path" || exit $?
      else
        # Older git can't clone into an empty directory.
        rmdir "$gnulib_path" 2>/dev/null
        git clone --reference "$GNULIB_SRCDIR" \
          "$(git_modules_config submodule.gnulib.url)" "$gnulib_path" \
-          && git submodule init && git submodule update \
+          && git submodule init -- "$gnulib_path" \
+          && git submodule update -- "$gnulib_path" \
          || exit $?
      fi
    fi
@@ -627,12 +669,19 @@ case ${GNULIB_SRCDIR--} in
  ;;
 esac

+# $GNULIB_SRCDIR now points to the version of gnulib to use, and
+# we no longer need to use git or $gnulib_path below here.
+
 if $bootstrap_sync; then
  cmp -s "$0" "$GNULIB_SRCDIR/build-aux/bootstrap" || {
    echo "$0: updating bootstrap and restarting..."
+    case $(sh -c 'echo "$1"' -- a) in
+      a) ignored=--;;
+      *) ignored=ignored;;
+    esac
    exec sh -c \
      'cp "$1" "$2" && shift && exec "${CONFIG_SHELL-/bin/sh}" "$@"' \
-      -- "$GNULIB_SRCDIR/build-aux/bootstrap" \
+      $ignored "$GNULIB_SRCDIR/build-aux/bootstrap" \
      "$0" "$@" --no-bootstrap-sync
  }
 fi
@@ -680,11 +729,10 @@ update_po_files() {
    cksum_file="$ref_po_dir/$po.s1"
    if ! test -f "$cksum_file" ||
        ! test -f "$po_dir/$po.po" ||
-        ! $SHA1SUM -c --status "$cksum_file" \
-            < "$new_po" > /dev/null; then
+        ! $SHA1SUM -c "$cksum_file" < "$new_po" > /dev/null 2>&1; then
      echo "$me: updated $po_dir/$po.po..."
      cp "$new_po" "$po_dir/$po.po" \
-          && $SHA1SUM < "$new_po" > "$cksum_file"
+          && $SHA1SUM < "$new_po" > "$cksum_file" || return
    fi
  done
 }
@@ -1,6 +1,6 @@
 # Bootstrap configuration.

-# Copyright (C) 2006-2013 Free Software Foundation, Inc.
+# Copyright (C) 2006-2015 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
@@ -33,8 +33,9 @@ gnulib_modules='
  quote quotearg
  readme-release
  realloc-posix
-  spawn-pipe stdbool stpcpy strdup-posix strerror strtoul strverscmp
-  unistd unistd-safer unlocked-io update-copyright unsetenv verify
+  spawn-pipe stdbool stpcpy strdup-posix strerror strverscmp
+  unistd unistd-safer unlink unlocked-io
+  update-copyright unsetenv verify
  warnings
  xalloc
  xalloc-die
@@ -1,4 +1,4 @@
-# Copyright (C) 2012-2013 Free Software Foundation, Inc.
+# Copyright (C) 2012-2015 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
@@ -2,6 +2,9 @@
 # option.  It specifies what changes to make to each given SHA1's commit
 # log and metadata, using Perl-eval'able expressions.

+975bb564319aa4f4204c48aba265757ba207a80f
+s/Edligner/Edlinger/;
+
 0db2648930e3b6c376a539aabe368aade83ee29a
 s/--flags/--feature/;
 s/flag_flag/feature_flag/;
@@ -0,0 +1,16 @@
+# Linux seattle 2.6.32-5-amd64 #1 SMP Thu Mar 22 17:26:33 UTC 2012
+# x86_64 GNU/Linux
+{
+   index
+   Memcheck:Cond
+   fun:index
+   fun:expand_dynamic_string_token
+   fun:_dl_map_object
+   fun:map_doit
+   fun:_dl_catch_error
+   fun:do_preload
+   fun:dl_main
+   fun:_dl_sysdep_start
+   fun:_dl_start
+   obj:/lib/ld-2.11.3.so
+}
@@ -1,6 +1,4 @@
-## Makefile for Bison testsuite.
-
-# Copyright (C) 2000-2013 Free Software Foundation, Inc.
+# Copyright (C) 2000-2015 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
@@ -18,6 +16,7 @@
 EXTRA_DIST +=                                   \
  build-aux/cross-options.pl                    \
  build-aux/darwin11.4.0.valgrind               \
+  build-aux/linux-gnu.valgrind                  \
  build-aux/move-if-change                      \
  build-aux/prev-version.txt                    \
  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) 2009-2013 Free Software Foundation, Inc.
+# Copyright (C) 2009-2015 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
@@ -2,7 +2,7 @@

 # In configure.ac, update PACKAGE_COPYRIGHT_YEAR to the current year.

-# Copyright (C) 2010-2013 Free Software Foundation, Inc.
+# Copyright (C) 2010-2015 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
@@ -1,5 +1,5 @@
 # Customize maint.mk                           -*- makefile -*-
-# Copyright (C) 2008-2013 Free Software Foundation, Inc.
+# Copyright (C) 2008-2015 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
@@ -135,7 +135,7 @@ _sed_rm_comments_q = $(subst ','\'',$(_sed_remove_comments))

 _space_before_paren_exempt =? \\n\\$$
 _space_before_paren_exempt = \
-  (^ *\#|\\n\\$$|%s\(to %s|(date|group|character)\(s\))
+  (^ *\#|(LA)?LR\([01]\)|percent_(code|define)|b4_syncline|m4_(define|init)|symbol)
 # Ensure that there is a space before each open parenthesis in C code.
 sc_space_before_open_paren:
 	@if $(VC_LIST_EXCEPT) | grep -l '\.[ch]$$' > /dev/null; then	\
@@ -175,5 +175,6 @@ $(call exclude,								\
  prohibit_strcmp=^doc/bison\.texi|tests/local\.at$$			\
  prohibit_tab_based_indentation=\.(am|mk)$$|^djgpp/|^\.git		\
  require_config_h_first=^(lib/yyerror|data/(glr|yacc))\.c$$		\
+  space_before_open_paren=^(data/|djgpp/)                               \
  unmarked_diagnostics=^(djgpp/|doc/bison.texi$$|tests/c\+\+\.at$$)	\
 )
@@ -1,6 +1,6 @@
 # Configure template for GNU Bison.                   -*-Autoconf-*-
 #
-# Copyright (C) 2001-2013 Free Software Foundation, Inc.
+# Copyright (C) 2001-2015 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
@@ -18,7 +18,7 @@
 # In order for some versions of Sun Studio to compile our C++ test cases
 # correctly, we need Autoconf 2.64 or better to handle the restrict
 # keyword in at least string.h from gnulib.  We need Autoconf 2.68 or
-# better to avoid a typo in the `configure --help' entry for the YACC
+# better to avoid a typo in the 'configure --help' entry for the YACC
 # environment variable.
 AC_PREREQ([2.68])
 m4_pattern_forbid([^gl_[A-Z]])
@@ -26,18 +26,14 @@ m4_pattern_forbid([^gl_[A-Z]])
 AC_INIT([GNU Bison],
        m4_esyscmd([build-aux/git-version-gen .tarball-version]),
        [[email protected]])
-AC_SUBST([PACKAGE_COPYRIGHT_YEAR], [2013])
+AC_SUBST([PACKAGE_COPYRIGHT_YEAR], [2015])
 AC_DEFINE_UNQUOTED([PACKAGE_COPYRIGHT_YEAR], [$PACKAGE_COPYRIGHT_YEAR],
                   [The copyright year for this package])

 AC_CONFIG_AUX_DIR([build-aux])
 AC_CONFIG_MACRO_DIR([m4])

-# Automake 1.10.3 and 1.11.1 fix a security flaw discussed here:
-#
-#   http://thread.gmane.org/gmane.comp.sysutils.autotools.announce/131
-#
-# To avoid 1.11, we make 1.11.1 the minimum version.
+# We use Automake 1.14's %D% and %C%.
 #
 # We want gnits strictness only when rolling a stable release.  For
 # release candidates, we use version strings like 2.4.3_rc1, but gnits
@@ -45,7 +41,7 @@ AC_CONFIG_MACRO_DIR([m4])
 # releases, we want to be able run make dist without being required to
 # add a bogus NEWS entry.  In that case, the version string
 # automatically contains a dash, which we also let disable gnits.
-AM_INIT_AUTOMAKE([1.11.1 dist-xz nostdinc
+AM_INIT_AUTOMAKE([1.14 dist-xz nostdinc
                 color-tests parallel-tests
                 silent-rules]
                 m4_bmatch(m4_defn([AC_PACKAGE_VERSION]), [[-_]],
@@ -75,14 +71,17 @@ AC_CACHE_CHECK([whether pragma GCC diagnostic push works],
  CFLAGS=$save_CFLAGS])

 AC_ARG_ENABLE([gcc-warnings],
-[  --enable-gcc-warnings   turn on lots of GCC warnings (not recommended)],
+[  --enable-gcc-warnings   turn on lots of GCC warnings (not recommended).
+                           Also, issue synclines from the examples/ to
+                           the corresponding source in the Texinfo doc.],
 [case $enable_gcc_warnings in
   yes|no) ;;
   *)  AC_MSG_ERROR([invalid value for --gcc-warnings: $enable_gcc_warnings]);;
 esac],
              [enable_gcc_warnings=no])
+AM_CONDITIONAL([ENABLE_GCC_WARNINGS], [test "$enable_gcc_warnings" = yes])
 if test "$enable_gcc_warnings" = yes; then
-  warn_common='-Wall -Wextra -Wno-sign-compare -Wcast-align
+  warn_common='-Wall -Wextra -Wno-sign-compare -Wcast-align -Wdocumentation
    -Wformat -Wpointer-arith -Wwrite-strings'
  warn_c='-Wbad-function-cast -Wshadow -Wstrict-prototypes'
  warn_cxx='-Wnoexcept'
@@ -91,7 +90,7 @@ if test "$enable_gcc_warnings" = yes; then
  # -fno-color-diagnostics: Clang's use of colors in the error
  # messages is confusing the tests looking at the compiler's output
  # (e.g., synclines.at).
-  warn_tests='-Wundef -pedantic -fno-color-diagnostics'
+  warn_tests='-Wundef -pedantic -Wsign-compare -fno-color-diagnostics'

  AC_LANG_PUSH([C])
  # Clang supports many of GCC's -W options, but only issues warnings
@@ -143,9 +142,11 @@ if test "$enable_gcc_warnings" = yes; then
    gl_WARN_ADD([$i], [WARN_CXXFLAGS_TEST])
  done
  # Clang++ 3.2+ reject C code generated by Flex.
-  gl_WARN_ADD([-Wno-null-conversion], [WARN_NO_NULL_CONVERSION_CXXFLAGS])
-  # Variants break strict aliasing analysis.
-  gl_WARN_ADD([-fno-strict-aliasing], [NO_STRICT_ALIAS_CXXFLAGS])
+  gl_WARN_ADD([-Wno-null-conversion], [FLEX_SCANNER_CXXFLAGS])
+  # So does G++ 4.8...
+  gl_WARN_ADD([-Wno-sign-compare], [FLEX_SCANNER_CXXFLAGS])
+  # ... possiby in std=c++11 mode.
+  gl_WARN_ADD([-Wno-zero-as-null-pointer-constant], [FLEX_SCANNER_CXXFLAGS])
  CXXFLAGS=$save_CXXFLAGS
  AC_LANG_POP([C++])
 fi
@@ -159,21 +160,17 @@ AC_ARG_ENABLE([yacc],
  [AC_HELP_STRING([--disable-yacc],
     [do not build a yacc command or an -ly library])],
  , [enable_yacc=yes])
-case $enable_yacc in
-yes)
-  YACC_SCRIPT=src/yacc
-  YACC_LIBRARY=lib/liby.a;;
-*)
-  YACC_SCRIPT=
-  YACC_LIBRARY=;;
-esac
-AC_SUBST([YACC_SCRIPT])
-AC_SUBST([YACC_LIBRARY])
+AM_CONDITIONAL([ENABLE_YACC], [test "$enable_yacc" = yes])

 # Checks for programs.
 AM_MISSING_PROG([DOT], [dot])
 AC_PROG_LEX
-$LEX_IS_FLEX || AC_MSG_ERROR([Flex is required])
+$LEX_IS_FLEX || test "X$LEX" = X: || {
+  AC_MSG_WARN([bypassing lex because flex is required])
+  LEX=:
+}
+AM_CONDITIONAL([FLEX_CXX_WORKS],
+  [$LEX_IS_FLEX && test $bison_cv_cxx_works = yes])
 AC_PROG_YACC
 AC_PROG_RANLIB
 AC_PROG_GNU_M4
@@ -220,7 +217,7 @@ AC_SUBST([aclocaldir])
 AC_CONFIG_FILES([etc/bench.pl], [chmod +x etc/bench.pl])

 # Initialize the test suite.
-AC_CONFIG_TESTDIR([tests], [$ac_abs_top_builddir/tests])
+AC_CONFIG_TESTDIR(tests)
 AC_CONFIG_FILES([tests/atlocal])
 AC_CONFIG_FILES([tests/bison], [chmod +x tests/bison])
 AC_CHECK_PROGS([VALGRIND], [valgrind])
@@ -228,12 +225,21 @@ case $VALGRIND:$host_os in
  '':*) ;;
  *:darwin*)
    # See README-hacking.
-    # VALGRIND+=' --suppressions=$(abs_top_srcdir)/build-aux/darwin11.4.0.valgrind'
+    # VALGRIND+='-q --suppressions=$(abs_top_srcdir)/build-aux/darwin11.4.0.valgrind'
    VALGRIND=;;
  *:*)
-    AC_SUBST([VALGRIND_PREBISON], ["$VALGRIND -q"]);;
+    suppfile=build-aux/$host_os.valgrind
+    if test -f "$srcdir/$suppfile"; then
+      VALGRIND="$VALGRIND --gen-suppressions=all"
+      VALGRIND="$VALGRIND --suppressions=\$(abs_top_srcdir)/$suppfile"
+    fi
+    AC_SUBST([VALGRIND_PREBISON], ["$VALGRIND -q"])
+    ;;
 esac

+# Whether we cannot run the compiled bison.
+AM_CONDITIONAL([CROSS_COMPILING], [test "$cross_compiling" = yes])
+
 AM_MISSING_PROG([AUTOM4TE], [autom4te])
 # Needed by tests/atlocal.in.
 AC_SUBST([GCC])
@@ -27,7 +27,7 @@ Currently, the supported skeletons are:
 These skeletons are the only ones supported by the Bison team.
 Because the interface between skeletons and the bison program is not
 finished, *we are not bound to it*.  In particular, Bison is not
-mature enough for us to consider that ``foreign skeletons'' are
+mature enough for us to consider that "foreign skeletons" are
 supported.

 * m4sugar
@@ -52,7 +52,7 @@ into various formats.

 -----

-Copyright (C) 2002, 2008-2013 Free Software Foundation, Inc.
+Copyright (C) 2002, 2008-2015 Free Software Foundation, Inc.

 This file is part of GNU Bison.

@@ -2,7 +2,7 @@

 # Language-independent M4 Macros for Bison.

-# Copyright (C) 2002, 2004-2013 Free Software Foundation, Inc.
+# Copyright (C) 2002, 2004-2015 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
@@ -85,6 +85,20 @@ m4_changecom([#])
 ])


+# b4_divert_kill(CODE)
+# --------------------
+# Expand CODE for its side effects, discard its output.
+m4_define([b4_divert_kill],
+[m4_divert_text([KILL], [$1])])
+
+
+# b4_define_silent(MACRO, CODE)
+# -----------------------------
+# Same as m4_define, but throw away the expansion of CODE.
+m4_define([b4_define_silent],
+[m4_define([$1], [b4_divert_kill([$2])])])
+
+
 ## ---------------- ##
 ## Error handling.  ##
 ## ---------------- ##
@@ -313,7 +327,7 @@ m4_define([b4_define_flag_if],
 # _b4_define_flag_if($1, $2, FLAG)
 # --------------------------------
 # Work around the impossibility to define macros inside macros,
-# because issuing `[$1]' is not possible in M4.  GNU M4 should provide
+# because issuing '[$1]' is not possible in M4.  GNU M4 should provide
 # $$1 a la M5/TeX.
 m4_define([_b4_define_flag_if],
 [m4_if([$1$2], $[1]$[2], [],
@@ -347,6 +361,7 @@ b4_define_flag_if([yacc])               # Whether POSIX Yacc is emulated.
 #   Whether the symbol has an id.
 # - id: string
 #   If has_id, the id.  Guaranteed to be usable as a C identifier.
+#   Prefixed by api.token.prefix if defined.
 # - tag: string.
 #   A representat of the symbol.  Can be 'foo', 'foo.id', '"foo"' etc.
 # - user_number: integer
@@ -357,9 +372,13 @@ b4_define_flag_if([yacc])               # Whether POSIX Yacc is emulated.
 #   The internalized number (used after yytranslate).
 # - has_type: 0, 1
 #   Whether has a semantic value.
+# - type_tag: string
+#   When api.value.type=union, the generated name for the union member.
+#   yytype_INT etc. for symbols that has_id, otherwise yytype_1 etc.
 # - type
 #   If it has a semantic value, its type tag, or, if variant are used,
 #   its type.
+#   In the case of api.value.type=union, type is the real type (e.g. int).
 # - has_printer: 0, 1
 # - printer: string
 # - printer_file: string
@@ -418,7 +437,6 @@ m4_define([b4_symbol_action_location],
 # b4_symbol_action(SYMBOL-NUM, KIND)
 # ----------------------------------
 # Run the action KIND (destructor or printer) for SYMBOL-NUM.
-# Same as in C, but using references instead of pointers.
 m4_define([b4_symbol_action],
 [b4_symbol_if([$1], [has_$2],
 [b4_dollar_pushdef([(*yyvaluep)],
@@ -442,6 +460,24 @@ m4_define([b4_symbol_destructor], [b4_symbol_action([$1], [destructor])])
 m4_define([b4_symbol_printer],    [b4_symbol_action([$1], [printer])])


+# b4_symbol_actions(KIND, [TYPE = yytype])
+# ----------------------------------------
+# Emit the symbol actions for KIND ("printer" or "destructor").
+# Dispatch on TYPE.
+m4_define([b4_symbol_actions],
+[m4_pushdef([b4_actions_], m4_expand([b4_symbol_foreach([b4_symbol_$1])]))dnl
+m4_ifval(m4_defn([b4_actions_]),
+[switch (m4_default([$2], [yytype]))
+    {
+      m4_defn([b4_actions_])
+      default:
+        break;
+    }dnl
+],
+[YYUSE (m4_default([$2], [yytype]));])dnl
+m4_popdef([b4_actions_])dnl
+])
+
 # b4_symbol_case_(SYMBOL-NUM)
 # ---------------------------
 # Issue a "case NUM" for SYMBOL-NUM.
@@ -577,14 +613,14 @@ m4_define([b4_define_user_code],
 # b4_user_initial_action
 # b4_user_post_prologue
 # b4_user_pre_prologue
-# b4_user_stype
+# b4_user_union_members
 # ----------------------
 # Macros that issue user code, ending with synclines.
 b4_define_user_code([actions])
 b4_define_user_code([initial_action])
 b4_define_user_code([post_prologue])
 b4_define_user_code([pre_prologue])
-b4_define_user_code([stype])
+b4_define_user_code([union_members])


 # b4_check_user_names(WHAT, USER-LIST, BISON-NAMESPACE)
@@ -665,9 +701,9 @@ m4_define([b4_percent_define_use],
 #   b4_percent_define_get([[foo]])
 m4_define([b4_percent_define_get],
 [b4_percent_define_use([$1])dnl
-m4_ifdef([b4_percent_define(]$1[)],
-         [m4_indir([b4_percent_define(]$1[)])],
-         [$2])])
+b4_percent_define_ifdef_([$1],
+                         [m4_indir([b4_percent_define(]$1[)])],
+                         [$2])])

 # b4_percent_define_get_loc(VARIABLE)
 # -----------------------------------
@@ -686,7 +722,21 @@ m4_define([b4_percent_define_get_loc],
          [m4_pushdef([b4_loc], m4_indir([b4_percent_define_loc(]$1[)]))dnl
 b4_loc[]dnl
 m4_popdef([b4_loc])],
-          [b4_fatal([[b4_percent_define_get_loc: undefined %%define variable '%s']], [$1])])])
+          [b4_fatal([[$0: undefined %%define variable '%s']], [$1])])])
+
+# b4_percent_define_get_kind(VARIABLE)
+# ------------------------------------
+# Get the kind (code, keyword, string) of VARIABLE, i.e., how its
+# value was defined (braces, not delimiters, quotes).
+#
+# If the %define variable VARIABLE is undefined, complain fatally
+# since that's a Bison or skeleton error.  Don't record this as a
+# Bison usage of VARIABLE as there's no reason to suspect that the
+# user-supplied value has yet influenced the output.
+m4_define([b4_percent_define_get_kind],
+[m4_ifdef([b4_percent_define_kind(]$1[)],
+          [m4_indir([b4_percent_define_kind(]$1[)])],
+          [b4_fatal([[$0: undefined %%define variable '%s']], [$1])])])

 # b4_percent_define_get_syncline(VARIABLE)
 # ----------------------------------------
@@ -703,7 +753,20 @@ m4_popdef([b4_loc])],
 m4_define([b4_percent_define_get_syncline],
 [m4_ifdef([b4_percent_define_syncline(]$1[)],
          [m4_indir([b4_percent_define_syncline(]$1[)])],
-          [b4_fatal([[b4_percent_define_get_syncline: undefined %%define variable '%s']], [$1])])])
+          [b4_fatal([[$0: undefined %%define variable '%s']], [$1])])])
+
+# b4_percent_define_ifdef_(VARIABLE, IF-TRUE, [IF-FALSE])
+# ------------------------------------------------------
+# If the %define variable VARIABLE is defined, expand IF-TRUE, else expand
+# IF-FALSE.  Don't record usage of VARIABLE.
+#
+# For example:
+#
+#   b4_percent_define_ifdef_([[foo]], [[it's defined]], [[it's undefined]])
+m4_define([b4_percent_define_ifdef_],
+[m4_ifdef([b4_percent_define(]$1[)],
+          [$2],
+          [$3])])

 # b4_percent_define_ifdef(VARIABLE, IF-TRUE, [IF-FALSE])
 # ------------------------------------------------------
@@ -716,9 +779,9 @@ m4_define([b4_percent_define_get_syncline],
 #
 #   b4_percent_define_ifdef([[foo]], [[it's defined]], [[it's undefined]])
 m4_define([b4_percent_define_ifdef],
-[m4_ifdef([b4_percent_define(]$1[)],
-          [b4_percent_define_use([$1])$2],
-          [$3])])
+[b4_percent_define_ifdef_([$1],
+                         [b4_percent_define_use([$1])$2],
+                         [$3])])


 ## --------- ##
@@ -747,11 +810,11 @@ m4_define([b4_percent_define_flag_if],
                                           [[invalid value for %%define Boolean variable '%s']],
                                           [$1])],
                           [[b4_percent_define_flag_if($1)]])])],
-  [b4_fatal([[b4_percent_define_flag_if: undefined %%define variable '%s']], [$1])])])
+  [b4_fatal([[$0: undefined %%define variable '%s']], [$1])])])


-# b4_percent_define_default(VARIABLE, DEFAULT)
-# --------------------------------------------
+# b4_percent_define_default(VARIABLE, DEFAULT, [KIND = keyword])
+# --------------------------------------------------------------
 # Mimic muscle_percent_define_default in ../src/muscle-tab.h exactly.  That is,
 # if the %define variable VARIABLE is undefined, set its value to DEFAULT.
 # Don't record this as a Bison usage of VARIABLE as there's no reason to
@@ -761,8 +824,10 @@ m4_define([b4_percent_define_flag_if],
 #
 #   b4_percent_define_default([[foo]], [[default value]])
 m4_define([b4_percent_define_default],
-[m4_ifndef([b4_percent_define(]$1[)],
+[b4_percent_define_ifdef_([$1], [],
           [m4_define([b4_percent_define(]$1[)], [$2])dnl
+            m4_define([b4_percent_define_kind(]$1[)],
+                      [m4_default([$3], [keyword])])dnl
            m4_define([b4_percent_define_loc(]$1[)],
                      [[[[<skeleton default value>:-1.-1]],
                        [[<skeleton default value>:-1.-1]]]])dnl
@@ -772,8 +837,8 @@ m4_define([b4_percent_define_default],
 # b4_percent_define_if_define(NAME, [VARIABLE = NAME])
 # ----------------------------------------------------
 # Define b4_NAME_if that executes its $1 or $2 depending whether
-# VARIABLE was %defined.  The characters `.' and `-' in VARIABLE are mapped
-# to `_'.
+# VARIABLE was %defined.  The characters '.' and `-' in VARIABLE are mapped
+# to '_'.
 m4_define([b4_percent_define_if_define_],
 [m4_define(m4_bpatsubst([b4_$1_if], [[-.]], [_]),
           [b4_percent_define_flag_if(m4_default([$2], [$1]),
@@ -783,6 +848,21 @@ m4_define([b4_percent_define_if_define],
 b4_percent_define_if_define_([$1], [$2], $[1], $[2])])


+# b4_percent_define_check_kind(VARIABLE, KIND, [DIAGNOSTIC = complain])
+# ---------------------------------------------------------------------
+m4_define([b4_percent_define_check_kind],
+[b4_percent_define_ifdef_([$1],
+  [m4_if(b4_percent_define_get_kind([$1]), [$2], [],
+    [b4_error([m4_default([$3], [complain])],
+              b4_percent_define_get_loc([$1]),
+              [m4_case([$2],
+                 [code], [[%%define variable '%s' requires '{...}' values]],
+                 [keyword], [[%%define variable '%s' requires keyword values]],
+                 [string], [[%%define variable '%s' requires '"..."' values]])],
+              [$1])])])dnl
+])
+
+
 # b4_percent_define_check_values(VALUES)
 # --------------------------------------
 # Mimic muscle_percent_define_check_values in ../src/muscle-tab.h exactly
@@ -804,8 +884,9 @@ m4_define([b4_percent_define_check_values],
            [_b4_percent_define_check_values(b4_sublist)])])

 m4_define([_b4_percent_define_check_values],
-[m4_ifdef([b4_percent_define(]$1[)],
-  [m4_pushdef([b4_good_value], [0])dnl
+[b4_percent_define_ifdef_([$1],
+  [b4_percent_define_check_kind(]$1[, [keyword], [deprecated])dnl
+   m4_pushdef([b4_good_value], [0])dnl
   m4_if($#, 1, [],
         [m4_foreach([b4_value], m4_dquote(m4_shift($@)),
                     [m4_if(m4_indir([b4_percent_define(]$1[)]), b4_value,
@@ -820,7 +901,7 @@ m4_define([_b4_percent_define_check_values],
                                     [[accepted value: '%s']],
                                     m4_dquote(b4_value))])])dnl
   m4_popdef([b4_good_value])],
-  [b4_fatal([[b4_percent_define_check_values: undefined %%define variable '%s']], [$1])])])
+  [b4_fatal([[$0: undefined %%define variable '%s']], [$1])])])

 # b4_percent_code_get([QUALIFIER])
 # --------------------------------
@@ -861,10 +942,6 @@ m4_define([b4_percent_code_ifdef],
 ## Common variables.  ##
 ## ------------------ ##

-# Default values for %define.
-# ---------------------------
-# If the api.token.prefix, it is empty.
-m4_percent_define_default([[api.token.prefix]], [[]])

 # b4_parse_assert_if([IF-ASSERTIONS-ARE-USED], [IF-NOT])
 # b4_parse_trace_if([IF-DEBUG-TRACES-ARE-ENABLED], [IF-NOT])
@@ -904,9 +981,11 @@ b4_error_verbose_if([m4_define([b4_token_table_flag], [1])])
 # b4_variant_if([IF-VARIANT-ARE-USED], [IF-NOT])
 # ----------------------------------------------
 b4_percent_define_if_define([variant])
-m4_case(b4_percent_define_get([[api.value.type]]),
-        [variant], [m4_define([b4_variant_flag], [[1]])],
-                   [m4_define([b4_variant_flag], [[0]])])
+m4_define([b4_variant_flag], [[0]])
+b4_percent_define_ifdef([[api.value.type]],
+   [m4_case(b4_percent_define_get_kind([[api.value.type]]), [keyword],
+            [m4_case(b4_percent_define_get([[api.value.type]]), [variant],
+                    [m4_define([b4_variant_flag], [[1]])])])])
 b4_define_flag_if([variant])


@@ -941,10 +1020,46 @@ m4_define_default([b4_parse_param], [])
 m4_define_default([b4_location_initial_column], [1])
 m4_define_default([b4_location_initial_line],   [1])

-# Sanity checks.
+
+## --------------- ##
+## Sanity checks.  ##
+## --------------- ##
+
+# api.location.prefix={...} (Java and C++).
+b4_percent_define_check_kind([api.location.type], [code], [deprecated])
+
+# api.position.prefix={...} (Java).
+b4_percent_define_check_kind([api.position.type], [code], [deprecated])
+
+# api.prefix >< %name-prefix.
+b4_percent_define_check_kind([api.prefix], [code], [deprecated])
 b4_percent_define_ifdef([api.prefix],
 [m4_ifdef([b4_prefix],
 [b4_complain_at(b4_percent_define_get_loc([api.prefix]),
                [['%s' and '%s' cannot be used together]],
                [%name-prefix],
                [%define api.prefix])])])
+
+# api.token.prefix={...}
+# Make it a warning for those who used betas of Bison 3.0.
+b4_percent_define_check_kind([api.token.prefix], [code], [deprecated])
+
+# api.value.type >< %union.
+b4_percent_define_ifdef([api.value.type],
+[m4_ifdef([b4_union_members],
+[b4_complain_at(b4_percent_define_get_loc([api.value.type]),
+                [['%s' and '%s' cannot be used together]],
+                [%union],
+                [%define api.value.type])])])
+
+# api.value.type=union >< %yacc.
+b4_percent_define_ifdef([api.value.type],
+[m4_if(b4_percent_define_get([api.value.type]), [union],
+[b4_yacc_if(dnl
+[b4_complain_at(b4_percent_define_get_loc([api.value.type]),
+                [['%s' and '%s' cannot be used together]],
+                [%yacc],
+                [%define api.value.type "union"])])])])
+
+# api.value.union.name.
+b4_percent_define_check_kind([api.value.union.name], [keyword])
@@ -2,7 +2,7 @@

 # C++ skeleton dispatching for Bison.

-# Copyright (C) 2006-2007, 2009-2013 Free Software Foundation, Inc.
+# Copyright (C) 2006-2007, 2009-2015 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
@@ -2,7 +2,7 @@

 # C++ skeleton for Bison

-# Copyright (C) 2002-2013 Free Software Foundation, Inc.
+# Copyright (C) 2002-2015 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
@@ -17,6 +17,11 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.

+# Sanity checks, before defaults installed by c.m4.
+b4_percent_define_ifdef([[api.value.union.name]],
+  [b4_complain_at(b4_percent_define_get_loc([[api.value.union.name]]),
+                  [named %union is invalid in C++])])
+
 m4_include(b4_pkgdatadir/[c.m4])

 # b4_comment(TEXT, [PREFIX])
@@ -25,6 +30,12 @@ m4_include(b4_pkgdatadir/[c.m4])
 m4_define([b4_comment],
 [b4_comment_([$1], [$2// ], [$2// ])])

+## -------- ##
+## Checks.  ##
+## -------- ##
+
+b4_percent_define_check_kind([api.namespace], [code], [deprecated])
+b4_percent_define_check_kind([parser_class_name], [code], [deprecated])

 ## ---------------- ##
 ## Default values.  ##
@@ -38,6 +49,7 @@ b4_percent_define_default([[parser_class_name]], [[parser]])
 # b4_percent_define_default([[api.location.type]], [[location]])

 b4_percent_define_default([[filename_type]], [[std::string]])
+# Make it a warning for those who used betas of Bison 3.0.
 b4_percent_define_default([[api.namespace]], m4_defn([b4_prefix]))

 b4_percent_define_default([[global_tokens_and_yystype]], [[false]])
@@ -54,8 +66,8 @@ b4_percent_define_default([[define_location_comparison]],
 m4_define([b4_namespace_ref], [b4_percent_define_get([[api.namespace]])])


-# Don't permit an empty b4_namespace_ref.  Any `::parser::foo' appended to it
-# would compile as an absolute reference with `parser' in the global namespace.
+# Don't permit an empty b4_namespace_ref.  Any '::parser::foo' appended to it
+# would compile as an absolute reference with 'parser' in the global namespace.
 # b4_namespace_open would open an anonymous namespace and thus establish
 # internal linkage.  This would compile.  However, it's cryptic, and internal
 # linkage for the parser would be specified in all translation units that
@@ -112,19 +124,24 @@ m4_define([b4_token_enums],
 ## Semantic Values.  ##
 ## ----------------- ##

-# b4_semantic_type_declare
-# ------------------------
+
+
+# b4_value_type_declare
+# ---------------------
 # Declare semantic_type.
-m4_define([b4_semantic_type_declare],
+m4_define([b4_value_type_declare],
+[b4_value_type_setup[]dnl
 [    /// Symbol semantic values.
-m4_ifdef([b4_stype],
-[    union semantic_type
+]m4_bmatch(b4_percent_define_get_kind([[api.value.type]]),
+[code],
+[[    typedef ]b4_percent_define_get([[api.value.type]])[ semantic_type;]],
+[m4_bmatch(b4_percent_define_get([[api.value.type]]),
+[union\|union-directive],
+[[    union semantic_type
    {
-b4_user_stype
-    };],
-[m4_if(b4_tag_seen_flag, 0,
-[[    typedef int semantic_type;]],
-[[    typedef ]b4_api_PREFIX[STYPE semantic_type;]])])])
+    ]b4_user_union_members[
+    };]])])dnl
+])


 # b4_public_types_declare
@@ -133,7 +150,7 @@ b4_user_stype
 # Depending on %define token_lex, may be output in the header or source file.
 m4_define([b4_public_types_declare],
 [[#ifndef ]b4_api_PREFIX[STYPE
-]b4_semantic_type_declare[
+]b4_value_type_declare[
 #else
    typedef ]b4_api_PREFIX[STYPE semantic_type;
 #endif]b4_locations_if([
@@ -157,9 +174,12 @@ m4_define([b4_public_types_declare],
    /// (External) token type, as returned by yylex.
    typedef token::yytokentype token_type;

-    /// Internal symbol number.
+    /// Symbol type: an internal symbol number.
    typedef int symbol_number_type;

+    /// The symbol type number to denote an empty symbol.
+    enum { empty_symbol = -2 };
+
    /// Internal symbol number for tokens (subsumed by symbol_number_type).
    typedef ]b4_int_type_for([b4_translate])[ token_number_type;

@@ -192,8 +212,15 @@ m4_define([b4_public_types_declare],
                    const semantic_type& v]b4_locations_if([,
                    const location_type& l])[);

+      /// Destroy the symbol.
      ~basic_symbol ();

+      /// Destroy contents, and record that is empty.
+      void clear ();
+
+      /// Whether empty.
+      bool empty () const;
+
      /// Destructive move, \a s is emptied into this.
      void move (basic_symbol& s);

@@ -223,21 +250,23 @@ m4_define([b4_public_types_declare],
      /// Constructor from (external) token numbers.
      by_type (kind_type t);

+      /// Record that this symbol is empty.
+      void clear ();
+
      /// Steal the symbol type from \a that.
      void move (by_type& that);

      /// The (internal) type number (corresponding to \a type).
-      /// -1 when this symbol is empty.
+      /// \a empty when empty.
      symbol_number_type type_get () const;

      /// The token.
      token_type token () const;

-      enum { empty = 0 };
-
      /// The symbol type.
-      /// -1 when this symbol is empty.
-      token_number_type type;
+      /// \a empty_symbol when empty.
+      /// An int, not token_number_type, to be able to store empty_symbol.
+      int type;
    };

    /// "External" symbols: returned by the scanner.
@@ -306,9 +335,19 @@ m4_define([b4_public_types_define],
  template <typename Base>
  inline
  ]b4_parser_class_name[::basic_symbol<Base>::~basic_symbol ()
+  {
+    clear ();
+  }
+
+  template <typename Base>
+  inline
+  void
+  ]b4_parser_class_name[::basic_symbol<Base>::clear ()
  {]b4_variant_if([[
    // User destructor.
    symbol_number_type yytype = this->type_get ();
+    basic_symbol<Base>& yysym = *this;
+    (void) yysym;
    switch (yytype)
    {
 ]b4_symbol_foreach([b4_symbol_destructor])dnl
@@ -318,6 +357,15 @@ m4_define([b4_public_types_define],

    // Type destructor.
  ]b4_symbol_variant([[yytype]], [[value]], [[template destroy]])])[
+    Base::clear ();
+  }
+
+  template <typename Base>
+  inline
+  bool
+  ]b4_parser_class_name[::basic_symbol<Base>::empty () const
+  {
+    return Base::type_get () == empty_symbol;
  }

  template <typename Base>
@@ -335,7 +383,7 @@ m4_define([b4_public_types_define],
  // by_type.
  inline
  ]b4_parser_class_name[::by_type::by_type ()
-     : type (empty)
+    : type (empty_symbol)
  {}

  inline
@@ -348,12 +396,19 @@ m4_define([b4_public_types_define],
    : type (yytranslate_ (t))
  {}

+  inline
+  void
+  ]b4_parser_class_name[::by_type::clear ()
+  {
+    type = empty_symbol;
+  }
+
  inline
  void
  ]b4_parser_class_name[::by_type::move (by_type& that)
  {
    type = that.type;
-    that.type = empty;
+    that.clear ();
  }

  inline
@@ -520,3 +575,13 @@ m4_define([b4_yylloc_default_define],
    while (/*CONSTCOND*/ false)
 # endif
 ]])
+
+## -------- ##
+## Checks.  ##
+## -------- ##
+
+b4_token_ctor_if([b4_variant_if([],
+  [b4_fatal_at(b4_percent_define_get_loc(api.token.constructor),
+               [cannot use '%s' without '%s'],
+               [%define api.token.constructor],
+               [%define api.value.type variant]))])])
@@ -2,7 +2,7 @@

 # Common code for C-like languages (C, C++, Java, etc.)

-# Copyright (C) 2012-2013 Free Software Foundation, Inc.
+# Copyright (C) 2012-2015 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
@@ -2,7 +2,7 @@

 # C skeleton dispatching for Bison.

-# Copyright (C) 2006-2007, 2009-2013 Free Software Foundation, Inc.
+# Copyright (C) 2006-2007, 2009-2015 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
@@ -2,7 +2,7 @@

 # C M4 Macros for Bison.

-# Copyright (C) 2002, 2004-2013 Free Software Foundation, Inc.
+# Copyright (C) 2002, 2004-2015 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
@@ -97,7 +97,8 @@ m4_define([b4_api_PREFIX],
 m4_define_default([b4_prefix], [b4_api_prefix])

 # If the %union is not named, its name is YYSTYPE.
-m4_define_default([b4_union_name], [b4_api_PREFIX[]STYPE])
+b4_percent_define_default([[api.value.union.name]],
+                          [b4_api_PREFIX[][STYPE]])


 ## ------------------------ ##
@@ -150,7 +151,7 @@ m4_popdef([$1])dnl

 # b4_parse_param_use([VAL], [LOC])
 # --------------------------------
-# `YYUSE' VAL, LOC if locations are enabled, and all the parse-params.
+# 'YYUSE' VAL, LOC if locations are enabled, and all the parse-params.
 m4_define([b4_parse_param_use],
 [m4_ifvaln([$1], [  YYUSE ([$1]);])dnl
 b4_locations_if([m4_ifvaln([$2], [  YYUSE ([$2]);])])dnl
@@ -182,7 +183,7 @@ m4_define([b4_int_type],
 # b4_int_type_for(NAME)
 # ---------------------
 # Return the smallest int type able to handle numbers ranging from
-# `NAME_min' to `NAME_max' (included).
+# 'NAME_min' to 'NAME_max' (included).
 m4_define([b4_int_type_for],
 [b4_int_type($1_min, $1_max)])

@@ -199,6 +200,69 @@ m4_define([b4_table_value_equals],
       [(!!(($2) == ($3)))])])


+## ----------------- ##
+## Compiler issues.  ##
+## ----------------- ##
+
+# b4_attribute_define
+# -------------------
+# Provide portable compiler "attributes".
+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)
+# else
+#  define YY_ATTRIBUTE(Spec) /* empty */
+# 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__))
+#endif
+
+#if !defined _Noreturn \
+     && (!defined __STDC_VERSION__ || __STDC_VERSION__ < 201112)
+# if defined _MSC_VER && 1200 <= _MSC_VER
+#  define _Noreturn __declspec (noreturn)
+# else
+#  define _Noreturn YY_ATTRIBUTE ((__noreturn__))
+# endif
+#endif
+
+/* Suppress unused-variable warnings by "using" E.  */
+#if ! defined lint || defined __GNUC__
+# define YYUSE(E) ((void) (E))
+#else
+# define YYUSE(E) /* empty */
+#endif
+
+#if defined __GNUC__ && 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\"")\
+    _Pragma ("GCC diagnostic ignored \"-Wmaybe-uninitialized\"")
+# define YY_IGNORE_MAYBE_UNINITIALIZED_END \
+    _Pragma ("GCC diagnostic pop")
+#else
+# define YY_INITIAL_VALUE(Value) Value
+#endif
+#ifndef YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
+# define YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
+# define YY_IGNORE_MAYBE_UNINITIALIZED_END
+#endif
+#ifndef YY_INITIAL_VALUE
+# define YY_INITIAL_VALUE(Value) /* Nothing. */
+#endif
+])
+
+
 ## ---------##
 ## Values.  ##
 ## ---------##
@@ -206,14 +270,14 @@ m4_define([b4_table_value_equals],

 # b4_null_define
 # --------------
-# Portability issues: define a YY_NULL appropriate for the current
+# Portability issues: define a YY_NULLPTR appropriate for the current
 # language (C, C++98, or C++11).
 m4_define([b4_null_define],
-[# ifndef YY_NULL
+[# ifndef YY_NULLPTR
 #  if defined __cplusplus && 201103L <= __cplusplus
-#   define YY_NULL nullptr
+#   define YY_NULLPTR nullptr
 #  else
-#   define YY_NULL 0
+#   define YY_NULLPTR 0
 #  endif
 # endif[]dnl
 ])
@@ -222,7 +286,7 @@ m4_define([b4_null_define],
 # b4_null
 # -------
 # Return a null pointer constant.
-m4_define([b4_null], [YY_NULL])
+m4_define([b4_null], [YY_NULLPTR])

 # b4_integral_parser_table_define(TABLE-NAME, CONTENT, COMMENT)
 # -------------------------------------------------------------
@@ -421,12 +485,9 @@ m4_ifset([b4_parse_param], [, b4_parse_param]))[
    yymsg = "Deleting";
  YY_SYMBOL_PRINT (yymsg, yytype, yyvaluep, yylocationp);

-  switch (yytype)
-    {
-]b4_symbol_foreach([b4_symbol_destructor])dnl
-[      default:
-        break;
-    }
+  YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
+  ]b4_symbol_actions([destructor])[
+  YY_IGNORE_MAYBE_UNINITIALIZED_END
 }]dnl
 ])

@@ -436,9 +497,9 @@ m4_ifset([b4_parse_param], [, b4_parse_param]))[
 # Define the "yy_symbol_print" function.
 m4_define_default([b4_yy_symbol_print_define],
 [[
-/*--------------------------------.
-| Print this symbol on YYOUTPUT.  |
-`--------------------------------*/
+/*----------------------------------------.
+| Print this symbol's value on YYOUTPUT.  |
+`----------------------------------------*/

 ]b4_function_define([yy_symbol_value_print],
    [static void],
@@ -459,12 +520,7 @@ m4_if(b4_skeleton, ["yacc.c"],
    YYPRINT (yyoutput, yytoknum[yytype], *yyvaluep);
 # endif
 ]])dnl
-[  switch (yytype)
-    {
-]b4_symbol_foreach([b4_symbol_printer])dnl
-[      default:
-        break;
-    }
+  b4_symbol_actions([printer])[
 }


@@ -492,28 +548,155 @@ b4_locations_if([, yylocationp])[]b4_user_args[);
 }]dnl
 ])

+
+## ---------------- ##
+## api.value.type.  ##
+## ---------------- ##
+
+
+# ---------------------- #
+# api.value.type=union.  #
+# ---------------------- #
+
+# b4_symbol_type_register(SYMBOL-NUM)
+# -----------------------------------
+# Symbol SYMBOL-NUM has a type (for variant) instead of a type-tag.
+# Extend the definition of %union's body (b4_union_members) with a
+# field of that type, and extend the symbol's "type" field to point to
+# the field name, instead of the type name.
+m4_define([b4_symbol_type_register],
+[m4_define([b4_symbol($1, type_tag)],
+           [b4_symbol_if([$1], [has_id],
+                         [b4_symbol([$1], [id])],
+                         [yytype_[]b4_symbol([$1], [number])])])dnl
+m4_append([b4_union_members],
+m4_expand([
+  b4_symbol_tag_comment([$1])dnl
+  b4_symbol([$1], [type]) b4_symbol([$1], [type_tag]);]))
+])
+
+
+# b4_type_define_tag(SYMBOL1-NUM, ...)
+# ------------------------------------
+# For the batch of symbols SYMBOL1-NUM... (which all have the same
+# type), enhance the %union definition for each of them, and set
+# there "type" field to the field tag name, instead of the type name.
+m4_define([b4_type_define_tag],
+[b4_symbol_if([$1], [has_type],
+              [m4_map([b4_symbol_type_register], [$@])])
+])
+
+
+# b4_symbol_value_union(VAL, [TYPE])
+# ----------------------------------
+# Same of b4_symbol_value, but when api.value.type=union.
+m4_define([b4_symbol_value_union],
+[m4_ifval([$2],
+          [(*($2*)(&$1))],
+          [$1])])
+])
+
+
+# b4_value_type_setup_union
+# -------------------------
+# Setup support for api.value.type=union.  Symbols are defined with a
+# type instead of a union member name: build the corresponding union,
+# and give the symbols their tag.
+m4_define([b4_value_type_setup_union],
+[m4_define([b4_union_members])
+b4_type_foreach([b4_type_define_tag])
+m4_copy_force([b4_symbol_value_union], [b4_symbol_value])
+])
+
+
+# -------------------------- #
+# api.value.type = variant.  #
+# -------------------------- #
+
+# b4_value_type_setup_variant
+# ---------------------------
+# Setup support for api.value.type=variant.  By default, fail, specialized
+# by other skeletons.
+m4_define([b4_value_type_setup_variant],
+[b4_complain_at(b4_percent_define_get_loc([[api.value.type]]),
+                [['%s' does not support '%s']],
+                [b4_skeleton],
+                [%define api.value.type variant])])
+
+
+# _b4_value_type_setup_keyword
+# ----------------------------
+# api.value.type is defined with a keyword/string syntax.  Check if
+# that is properly defined, and prepare its use.
+m4_define([_b4_value_type_setup_keyword],
+[b4_percent_define_check_values([[[[api.value.type]],
+                                  [[none]],
+                                  [[union]],
+                                  [[union-directive]],
+                                  [[variant]],
+                                  [[yystype]]]])dnl
+m4_case(b4_percent_define_get([[api.value.type]]),
+        [union],   [b4_value_type_setup_union],
+        [variant], [b4_value_type_setup_variant])])
+
+
+# b4_value_type_setup
+# -------------------
+# Check if api.value.type is properly defined, and possibly prepare
+# its use.
+b4_define_silent([b4_value_type_setup],
+[# Define default value.
+b4_percent_define_ifdef([[api.value.type]], [],
+[# %union => api.value.type=union-directive
+m4_ifdef([b4_union_members],
+[m4_define([b4_percent_define_kind(api.value.type)], [keyword])
+m4_define([b4_percent_define(api.value.type)], [union-directive])],
+[# no tag seen => api.value.type={int}
+m4_if(b4_tag_seen_flag, 0,
+[m4_define([b4_percent_define_kind(api.value.type)], [code])
+m4_define([b4_percent_define(api.value.type)], [int])],
+[# otherwise api.value.type=yystype
+m4_define([b4_percent_define_kind(api.value.type)], [keyword])
+m4_define([b4_percent_define(api.value.type)], [yystype])])])])
+
+# Set up.
+m4_bmatch(b4_percent_define_get_kind([[api.value.type]]),
+   [keyword\|string], [_b4_value_type_setup_keyword])
+])
+
+
 ## -------------- ##
 ## Declarations.  ##
 ## -------------- ##

+
 # b4_value_type_define
 # --------------------
 m4_define([b4_value_type_define],
-[[/* Value type.  */
-#if ! defined ]b4_api_PREFIX[STYPE && ! defined ]b4_api_PREFIX[STYPE_IS_DECLARED
-]m4_ifdef([b4_stype],
-[[typedef union ]b4_union_name[ ]b4_api_PREFIX[STYPE;
-union ]b4_union_name[
-{
-]b4_user_stype[
-};
-# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1]],
-[m4_if(b4_tag_seen_flag, 0,
-[[typedef int ]b4_api_PREFIX[STYPE;
-# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1]])])[
+[b4_value_type_setup[]dnl
+/* Value type.  */
+m4_bmatch(b4_percent_define_get_kind([[api.value.type]]),
+[code],
+[[#if ! defined ]b4_api_PREFIX[STYPE && ! defined ]b4_api_PREFIX[STYPE_IS_DECLARED
+typedef ]b4_percent_define_get([[api.value.type]])[ ]b4_api_PREFIX[STYPE;
+# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1
 # define ]b4_api_PREFIX[STYPE_IS_DECLARED 1
 #endif
-]])
+]],
+[m4_bmatch(b4_percent_define_get([[api.value.type]]),
+[union\|union-directive],
+[[#if ! defined ]b4_api_PREFIX[STYPE && ! defined ]b4_api_PREFIX[STYPE_IS_DECLARED
+]b4_percent_define_get_syncline([[api.value.union.name]])[
+union ]b4_percent_define_get([[api.value.union.name]])[
+{
+]b4_user_union_members[
+};
+]b4_percent_define_get_syncline([[api.value.union.name]])[
+typedef union ]b4_percent_define_get([[api.value.union.name]])[ ]b4_api_PREFIX[STYPE;
+# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1
+# define ]b4_api_PREFIX[STYPE_IS_DECLARED 1
+#endif
+]])])])


 # b4_location_type_define
@@ -549,7 +732,7 @@ b4_pure_if([], [[extern ]b4_api_PREFIX[STYPE ]b4_prefix[lval;


 # b4_YYDEBUG_define
-# ------------------
+# -----------------
 m4_define([b4_YYDEBUG_define],
 [[/* Debug traces.  */
 ]m4_if(b4_api_prefix, [yy],
@@ -621,7 +804,7 @@ m4_define([b4_yy_location_print_define],

 /* Print *YYLOCP on YYO.  Private, do not rely on its existence. */

-__attribute__((__unused__))
+YY_ATTRIBUTE_UNUSED
 ]b4_function_define([yy_location_print_],
    [static unsigned],
               [[FILE *yyo],                    [yyo]],
@@ -2,7 +2,7 @@

 # GLR skeleton for Bison

-# Copyright (C) 2002-2013 Free Software Foundation, Inc.
+# Copyright (C) 2002-2015 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
@@ -178,9 +178,42 @@ m4_if(b4_skeleton, ["glr.c"],
 ## Output files.  ##
 ## -------------- ##

+# Unfortunately the order of generation between the header and the
+# implementation file matters (for glr.c) because of the current
+# implementation of api.value.type=union.  In that case we still use a
+# union for YYSTYPE, but we generate the contents of this union when
+# setting up YYSTYPE.  This is needed for other aspects, such as
+# defining yy_symbol_value_print, since we need to now the name of the
+# members of this union.
+#
+# To avoid this issue, just generate the header before the
+# implementation file.  But we should also make them more independant.
+
+# ----------------- #
+# The header file.  #
+# ----------------- #
+
+# glr.cc produces its own header.
+m4_if(b4_skeleton, ["glr.c"],
+[b4_defines_if(
+[b4_output_begin([b4_spec_defines_file])
+b4_copyright([Skeleton interface for Bison GLR parsers in C],
+             [2002-2015])[
+
+]b4_cpp_guard_open([b4_spec_defines_file])[
+]b4_shared_declarations[
+]b4_cpp_guard_close([b4_spec_defines_file])[
+]b4_output_end()
+])])
+
+
+# ------------------------- #
+# The implementation file.  #
+# ------------------------- #
+
 b4_output_begin([b4_parser_file_name])
 b4_copyright([Skeleton implementation for Bison GLR parsers in C],
-             [2002-2013])[
+             [2002-2015])[

 /* C GLR parser skeleton written by Paul Hilfinger.  */

@@ -246,13 +279,6 @@ b4_percent_code_get[]dnl
 # endif
 #endif

-/* Suppress unused-variable warnings by "using" E.  */
-#ifdef __GNUC__
-# define YYUSE(E) ((void) (E))
-#else
-# define YYUSE(E) /* empty */
-#endif
-
 #ifndef YYFREE
 # define YYFREE free
 #endif
@@ -281,17 +307,7 @@ b4_percent_code_get[]dnl
 # define YYLONGJMP(Env, Val) (longjmp (Env, Val), YYASSERT (0))
 #endif

-/*-----------------.
-| GCC extensions.  |
-`-----------------*/
-
-#ifndef __attribute__
-/* This feature is available in gcc versions 2.5 and later.  */
-# if (! defined __GNUC__ || __GNUC__ < 2 \
-      || (__GNUC__ == 2 && __GNUC_MINOR__ < 5))
-#  define __attribute__(Spec) /* empty */
-# endif
-#endif
+]b4_attribute_define[

 #ifndef YYASSERT
 # define YYASSERT(Condition) ((void) ((Condition) || (abort (), 0)))
@@ -462,9 +478,9 @@ int yydebug;

 struct yyGLRStack;
 static void yypstack (struct yyGLRStack* yystackp, size_t yyk)
-  __attribute__ ((__unused__));
+  YY_ATTRIBUTE_UNUSED;
 static void yypdumpstack (struct yyGLRStack* yystackp)
-  __attribute__ ((__unused__));
+  YY_ATTRIBUTE_UNUSED;

 #else /* !]b4_api_PREFIX[DEBUG */

@@ -686,19 +702,15 @@ struct yyGLRStack {
 static void yyexpandGLRStack (yyGLRStack* yystackp);
 #endif

-static void yyFail (yyGLRStack* yystackp]b4_pure_formals[, const char* yymsg)
-  __attribute__ ((__noreturn__));
-static void
+static _Noreturn void
 yyFail (yyGLRStack* yystackp]b4_pure_formals[, const char* yymsg)
 {
-  if (yymsg != YY_NULL)
+  if (yymsg != YY_NULLPTR)
    yyerror (]b4_yyerror_args[yymsg);
  YYLONGJMP (yystackp->yyexception_buffer, 1);
 }

-static void yyMemoryExhausted (yyGLRStack* yystackp)
-  __attribute__ ((__noreturn__));
-static void
+static _Noreturn void
 yyMemoryExhausted (yyGLRStack* yystackp)
 {
  YYLONGJMP (yystackp->yyexception_buffer, 2);
@@ -719,7 +731,7 @@ yytokenName (yySymbol yytoken)
 /** Fill in YYVSP[YYLOW1 .. YYLOW0-1] from the chain of states starting
 *  at YYVSP[YYLOW0].yystate.yypred.  Leaves YYVSP[YYLOW1].yystate.yypred
 *  containing the pointer to the next state in the chain.  */
-static void yyfillin (yyGLRStackItem *, int, int) __attribute__ ((__unused__));
+static void yyfillin (yyGLRStackItem *, int, int) YY_ATTRIBUTE_UNUSED;
 static void
 yyfillin (yyGLRStackItem *yyvsp, int yylow0, int yylow1)
 {
@@ -736,7 +748,7 @@ yyfillin (yyGLRStackItem *yyvsp, int yylow0, int yylow1)
      else
        /* The effect of using yysval or yyloc (in an immediate rule) is
         * undefined.  */
-        yyvsp[i].yystate.yysemantics.yyfirstVal = YY_NULL;]b4_locations_if([[
+        yyvsp[i].yystate.yysemantics.yyfirstVal = YY_NULLPTR;]b4_locations_if([[
      yyvsp[i].yystate.yyloc = s->yyloc;]])[
      s = yyvsp[i].yystate.yypred = s->yypred;
    }
@@ -746,7 +758,7 @@ yyfillin (yyGLRStackItem *yyvsp, int yylow0, int yylow1)
 * YYVSP[YYLOW1 .. *YYLOW-1] as in yyfillin and set *YYLOW = YYLOW1.
 * For convenience, always return YYLOW1.  */
 static inline int yyfill (yyGLRStackItem *, int *, int, yybool)
-     __attribute__ ((__unused__));
+     YY_ATTRIBUTE_UNUSED;
 static inline int
 yyfill (yyGLRStackItem *yyvsp, int *yylow, int yylow1, yybool yynormal)
 {
@@ -768,8 +780,7 @@ yyuserAction (yyRuleNum yyn, size_t yyrhslen, yyGLRStackItem* yyvsp,
              yyGLRStack* yystackp,
              YYSTYPE* yyvalp]b4_locuser_formals[)
 {
-  yybool yynormal __attribute__ ((__unused__)) =
-    (yystackp->yysplitPoint == YY_NULL);
+  yybool yynormal YY_ATTRIBUTE_UNUSED = (yystackp->yysplitPoint == YY_NULLPTR);
  int yylow;
 ]b4_parse_param_use([yyvalp], [yylocp])dnl
 [  YYUSE (yyrhslen);
@@ -853,12 +864,10 @@ yydestroyGLRState (char const *yymsg, yyGLRState *yys]b4_user_formals[)
      if (yydebug)
        {
          if (yys->yysemantics.yyfirstVal)
-            YYFPRINTF (stderr, "%s unresolved ", yymsg);
+            YYFPRINTF (stderr, "%s unresolved", yymsg);
          else
-            YYFPRINTF (stderr, "%s incomplete ", yymsg);
-          yy_symbol_print (stderr, yystos[yys->yylrState],
-                           YY_NULL]b4_locuser_args([&yys->yyloc])[);
-          YYFPRINTF (stderr, "\n");
+            YYFPRINTF (stderr, "%s incomplete", yymsg);
+          YY_SYMBOL_PRINT ("", yystos[yys->yylrState], YY_NULLPTR, &yys->yyloc);
        }
 #endif

@@ -934,14 +943,18 @@ yygetLRActions (yyStateNum yystate, int yytoken,
    }
 }

+/** Compute post-reduction state.
+ * \param yystate   the current state
+ * \param yysym     the nonterminal to push on the stack
+ */
 static inline yyStateNum
-yyLRgotoState (yyStateNum yystate, yySymbol yylhs)
+yyLRgotoState (yyStateNum yystate, yySymbol yysym)
 {
-  int yyr = yypgoto[yylhs - YYNTOKENS] + yystate;
+  int yyr = yypgoto[yysym - YYNTOKENS] + yystate;
  if (0 <= yyr && yyr <= YYLAST && yycheck[yyr] == yystate)
    return yytable[yyr];
  else
-    return yydefgoto[yylhs - YYNTOKENS];
+    return yydefgoto[yysym - YYNTOKENS];
 }

 static inline yybool
@@ -983,6 +996,7 @@ yyaddDeferredAction (yyGLRStack* yystackp, size_t yyk, yyGLRState* yystate,
 {
  yySemanticOption* yynewOption =
    &yynewGLRStackItem (yystackp, yyfalse)->yyoption;
+  YYASSERT (!yynewOption->yyisState);
  yynewOption->yystate = yyrhs;
  yynewOption->yyrule = yyrule;
  if (yystackp->yytops.yylookaheadNeeds[yyk])
@@ -1010,7 +1024,7 @@ yyinitStateSet (yyGLRStateSet* yyset)
  yyset->yystates = (yyGLRState**) YYMALLOC (16 * sizeof yyset->yystates[0]);
  if (! yyset->yystates)
    return yyfalse;
-  yyset->yystates[0] = YY_NULL;
+  yyset->yystates[0] = YY_NULLPTR;
  yyset->yylookaheadNeeds =
    (yybool*) YYMALLOC (16 * sizeof yyset->yylookaheadNeeds[0]);
  if (! yyset->yylookaheadNeeds)
@@ -1040,8 +1054,8 @@ yyinitGLRStack (yyGLRStack* yystackp, size_t yysize)
  if (!yystackp->yyitems)
    return yyfalse;
  yystackp->yynextFree = yystackp->yyitems;
-  yystackp->yysplitPoint = YY_NULL;
-  yystackp->yylastDeleted = YY_NULL;
+  yystackp->yysplitPoint = YY_NULLPTR;
+  yystackp->yylastDeleted = YY_NULLPTR;
  return yyinitStateSet (&yystackp->yytops);
 }

@@ -1080,10 +1094,10 @@ yyexpandGLRStack (yyGLRStack* yystackp)
        {
          yyGLRState* yys0 = &yyp0->yystate;
          yyGLRState* yys1 = &yyp1->yystate;
-          if (yys0->yypred != YY_NULL)
+          if (yys0->yypred != YY_NULLPTR)
            yys1->yypred =
              YYRELOC (yyp0, yyp1, yys0->yypred, yystate);
-          if (! yys0->yyresolved && yys0->yysemantics.yyfirstVal != YY_NULL)
+          if (! yys0->yyresolved && yys0->yysemantics.yyfirstVal != YY_NULLPTR)
            yys1->yysemantics.yyfirstVal =
              YYRELOC (yyp0, yyp1, yys0->yysemantics.yyfirstVal, yyoption);
        }
@@ -1091,18 +1105,18 @@ yyexpandGLRStack (yyGLRStack* yystackp)
        {
          yySemanticOption* yyv0 = &yyp0->yyoption;
          yySemanticOption* yyv1 = &yyp1->yyoption;
-          if (yyv0->yystate != YY_NULL)
+          if (yyv0->yystate != YY_NULLPTR)
            yyv1->yystate = YYRELOC (yyp0, yyp1, yyv0->yystate, yystate);
-          if (yyv0->yynext != YY_NULL)
+          if (yyv0->yynext != YY_NULLPTR)
            yyv1->yynext = YYRELOC (yyp0, yyp1, yyv0->yynext, yyoption);
        }
    }
-  if (yystackp->yysplitPoint != YY_NULL)
+  if (yystackp->yysplitPoint != YY_NULLPTR)
    yystackp->yysplitPoint = YYRELOC (yystackp->yyitems, yynewItems,
-                                 yystackp->yysplitPoint, yystate);
+                                      yystackp->yysplitPoint, yystate);

  for (yyn = 0; yyn < yystackp->yytops.yysize; yyn += 1)
-    if (yystackp->yytops.yystates[yyn] != YY_NULL)
+    if (yystackp->yytops.yystates[yyn] != YY_NULLPTR)
      yystackp->yytops.yystates[yyn] =
        YYRELOC (yystackp->yyitems, yynewItems,
                 yystackp->yytops.yystates[yyn], yystate);
@@ -1126,7 +1140,7 @@ yyfreeGLRStack (yyGLRStack* yystackp)
 static inline void
 yyupdateSplit (yyGLRStack* yystackp, yyGLRState* yys)
 {
-  if (yystackp->yysplitPoint != YY_NULL && yystackp->yysplitPoint > yys)
+  if (yystackp->yysplitPoint != YY_NULLPTR && yystackp->yysplitPoint > yys)
    yystackp->yysplitPoint = yys;
 }

@@ -1134,9 +1148,9 @@ yyupdateSplit (yyGLRStack* yystackp, yyGLRState* yys)
 static inline void
 yymarkStackDeleted (yyGLRStack* yystackp, size_t yyk)
 {
-  if (yystackp->yytops.yystates[yyk] != YY_NULL)
+  if (yystackp->yytops.yystates[yyk] != YY_NULLPTR)
    yystackp->yylastDeleted = yystackp->yytops.yystates[yyk];
-  yystackp->yytops.yystates[yyk] = YY_NULL;
+  yystackp->yytops.yystates[yyk] = YY_NULLPTR;
 }

 /** Undelete the last stack in *YYSTACKP that was marked as deleted.  Can
@@ -1145,12 +1159,12 @@ yymarkStackDeleted (yyGLRStack* yystackp, size_t yyk)
 static void
 yyundeleteLastStack (yyGLRStack* yystackp)
 {
-  if (yystackp->yylastDeleted == YY_NULL || yystackp->yytops.yysize != 0)
+  if (yystackp->yylastDeleted == YY_NULLPTR || yystackp->yytops.yysize != 0)
    return;
  yystackp->yytops.yystates[0] = yystackp->yylastDeleted;
  yystackp->yytops.yysize = 1;
  YYDPRINTF ((stderr, "Restoring last deleted stack as stack #0.\n"));
-  yystackp->yylastDeleted = YY_NULL;
+  yystackp->yylastDeleted = YY_NULLPTR;
 }

 static inline void
@@ -1160,7 +1174,7 @@ yyremoveDeletes (yyGLRStack* yystackp)
  yyi = yyj = 0;
  while (yyj < yystackp->yytops.yysize)
    {
-      if (yystackp->yytops.yystates[yyi] == YY_NULL)
+      if (yystackp->yytops.yystates[yyi] == YY_NULLPTR)
        {
          if (yyi == yyj)
            {
@@ -1218,12 +1232,13 @@ yyglrShiftDefer (yyGLRStack* yystackp, size_t yyk, yyStateNum yylrState,
                 size_t yyposn, yyGLRState* yyrhs, yyRuleNum yyrule)
 {
  yyGLRState* yynewState = &yynewGLRStackItem (yystackp, yytrue)->yystate;
+  YYASSERT (yynewState->yyisState);

  yynewState->yylrState = yylrState;
  yynewState->yyposn = yyposn;
  yynewState->yyresolved = yyfalse;
  yynewState->yypred = yystackp->yytops.yystates[yyk];
-  yynewState->yysemantics.yyfirstVal = YY_NULL;
+  yynewState->yysemantics.yyfirstVal = YY_NULLPTR;
  yystackp->yytops.yystates[yyk] = yynewState;

  /* Invokes YY_RESERVE_GLRSTACK.  */
@@ -1283,7 +1298,7 @@ yydoAction (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
 {
  int yynrhs = yyrhsLength (yyrule);

-  if (yystackp->yysplitPoint == YY_NULL)
+  if (yystackp->yysplitPoint == YY_NULLPTR)
    {
      /* Standard special case: single stack.  */
      yyGLRStackItem* yyrhs = (yyGLRStackItem*) yystackp->yytops.yystates[yyk];
@@ -1335,14 +1350,13 @@ yyglrReduce (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
 {
  size_t yyposn = yystackp->yytops.yystates[yyk]->yyposn;

-  if (yyforceEval || yystackp->yysplitPoint == YY_NULL)
+  if (yyforceEval || yystackp->yysplitPoint == YY_NULLPTR)
    {
-      YYRESULTTAG yyflag;
-      YYSTYPE yysval;]b4_locations_if([
-      YYLTYPE yyloc;])[
+      YYSTYPE yysval;]b4_locations_if([[
+      YYLTYPE yyloc;]])[

-      yyflag = yydoAction (yystackp, yyk, yyrule, &yysval]b4_locuser_args([&yyloc])[);
-      if (yyflag == yyerr && yystackp->yysplitPoint != YY_NULL)
+      YYRESULTTAG yyflag = yydoAction (yystackp, yyk, yyrule, &yysval]b4_locuser_args([&yyloc])[);
+      if (yyflag == yyerr && yystackp->yysplitPoint != YY_NULLPTR)
        {
          YYDPRINTF ((stderr, "Parse on stack %lu rejected by rule #%d.\n",
                     (unsigned long int) yyk, yyrule - 1));
@@ -1375,7 +1389,7 @@ yyglrReduce (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
                  "Now in state %d.\n",
                  (unsigned long int) yyk, yyrule - 1, yynewLRState));
      for (yyi = 0; yyi < yystackp->yytops.yysize; yyi += 1)
-        if (yyi != yyk && yystackp->yytops.yystates[yyi] != YY_NULL)
+        if (yyi != yyk && yystackp->yytops.yystates[yyi] != YY_NULLPTR)
          {
            yyGLRState *yysplit = yystackp->yysplitPoint;
            yyGLRState *yyp = yystackp->yytops.yystates[yyi];
@@ -1402,7 +1416,7 @@ yyglrReduce (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
 static size_t
 yysplitStack (yyGLRStack* yystackp, size_t yyk)
 {
-  if (yystackp->yysplitPoint == YY_NULL)
+  if (yystackp->yysplitPoint == YY_NULLPTR)
    {
      YYASSERT (yyk == 0);
      yystackp->yysplitPoint = yystackp->yytops.yystates[yyk];
@@ -1412,7 +1426,7 @@ yysplitStack (yyGLRStack* yystackp, size_t yyk)
      yyGLRState** yynewStates;
      yybool* yynewLookaheadNeeds;

-      yynewStates = YY_NULL;
+      yynewStates = YY_NULLPTR;

      if (yystackp->yytops.yycapacity
          > (YYSIZEMAX / (2 * sizeof yynewStates[0])))
@@ -1423,7 +1437,7 @@ yysplitStack (yyGLRStack* yystackp, size_t yyk)
        (yyGLRState**) YYREALLOC (yystackp->yytops.yystates,
                                  (yystackp->yytops.yycapacity
                                   * sizeof yynewStates[0]));
-      if (yynewStates == YY_NULL)
+      if (yynewStates == YY_NULLPTR)
        yyMemoryExhausted (yystackp);
      yystackp->yytops.yystates = yynewStates;

@@ -1431,7 +1445,7 @@ yysplitStack (yyGLRStack* yystackp, size_t yyk)
        (yybool*) YYREALLOC (yystackp->yytops.yylookaheadNeeds,
                             (yystackp->yytops.yycapacity
                              * sizeof yynewLookaheadNeeds[0]));
-      if (yynewLookaheadNeeds == YY_NULL)
+      if (yynewLookaheadNeeds == YY_NULLPTR)
        yyMemoryExhausted (yystackp);
      yystackp->yytops.yylookaheadNeeds = yynewLookaheadNeeds;
    }
@@ -1495,9 +1509,9 @@ yymergeOptionSets (yySemanticOption* yyy0, yySemanticOption* yyy1)
          yySemanticOption* yyz1 = yys1->yysemantics.yyfirstVal;
          while (yytrue)
            {
-              if (yyz1 == *yyz0p || yyz1 == YY_NULL)
+              if (yyz1 == *yyz0p || yyz1 == YY_NULLPTR)
                break;
-              else if (*yyz0p == YY_NULL)
+              else if (*yyz0p == YY_NULLPTR)
                {
                  *yyz0p = yyz1;
                  break;
@@ -1618,7 +1632,7 @@ yyreportTree (yySemanticOption* yyx, int yyindent)

  for (yyi = yynrhs, yys = yyx->yystate; 0 < yyi; yyi -= 1, yys = yys->yypred)
    yystates[yyi] = yys;
-  if (yys == YY_NULL)
+  if (yys == YY_NULLPTR)
    {
      yyleftmost_state.yyposn = 0;
      yystates[0] = &yyleftmost_state;
@@ -1678,7 +1692,7 @@ yyreportAmbiguity (yySemanticOption* yyx0,
 *  ending at YYS1.  Has no effect on previously resolved states.
 *  The first semantic option of a state is always chosen.  */
 static void
-yyresolveLocations (yyGLRState* yys1, int yyn1,
+yyresolveLocations (yyGLRState *yys1, int yyn1,
                    yyGLRStack *yystackp]b4_user_formals[)
 {
  if (0 < yyn1)
@@ -1689,9 +1703,9 @@ yyresolveLocations (yyGLRState* yys1, int yyn1,
          yyGLRStackItem yyrhsloc[1 + YYMAXRHS];
          int yynrhs;
          yySemanticOption *yyoption = yys1->yysemantics.yyfirstVal;
-          YYASSERT (yyoption != YY_NULL);
+          YYASSERT (yyoption);
          yynrhs = yyrhsLength (yyoption->yyrule);
-          if (yynrhs > 0)
+          if (0 < yynrhs)
            {
              yyGLRState *yys;
              int yyn;
@@ -1714,18 +1728,7 @@ yyresolveLocations (yyGLRState* yys1, int yyn1,
              yyGLRState *yyprevious = yyoption->yystate;
              yyrhsloc[0].yystate.yyloc = yyprevious->yyloc;
            }
-          {
-            int yychar_current = yychar;
-            YYSTYPE yylval_current = yylval;
-            YYLTYPE yylloc_current = yylloc;
-            yychar = yyoption->yyrawchar;
-            yylval = yyoption->yyval;
-            yylloc = yyoption->yyloc;
-            YYLLOC_DEFAULT ((yys1->yyloc), yyrhsloc, yynrhs);
-            yychar = yychar_current;
-            yylval = yylval_current;
-            yylloc = yylloc_current;
-          }
+          YYLLOC_DEFAULT ((yys1->yyloc), yyrhsloc, yynrhs);
        }
    }
 }]])[
@@ -1748,7 +1751,7 @@ yyresolveValue (yyGLRState* yys, yyGLRStack* yystackp]b4_user_formals[)
  YYRESULTTAG yyflag;]b4_locations_if([
  YYLTYPE *yylocp = &yys->yyloc;])[

-  for (yypp = &yyoptionList->yynext; *yypp != YY_NULL; )
+  for (yypp = &yyoptionList->yynext; *yypp != YY_NULLPTR; )
    {
      yySemanticOption* yyp = *yypp;

@@ -1790,7 +1793,7 @@ yyresolveValue (yyGLRState* yys, yyGLRStack* yystackp]b4_user_formals[)
      int yyprec = yydprec[yybest->yyrule];
      yyflag = yyresolveAction (yybest, yystackp, &yysval]b4_locuser_args[);
      if (yyflag == yyok)
-        for (yyp = yybest->yynext; yyp != YY_NULL; yyp = yyp->yynext)
+        for (yyp = yybest->yynext; yyp != YY_NULLPTR; yyp = yyp->yynext)
          {
            if (yyprec == yydprec[yyp->yyrule])
              {
@@ -1817,14 +1820,14 @@ yyresolveValue (yyGLRState* yys, yyGLRStack* yystackp]b4_user_formals[)
      yys->yysemantics.yysval = yysval;
    }
  else
-    yys->yysemantics.yyfirstVal = YY_NULL;
+    yys->yysemantics.yyfirstVal = YY_NULLPTR;
  return yyflag;
 }

 static YYRESULTTAG
 yyresolveStack (yyGLRStack* yystackp]b4_user_formals[)
 {
-  if (yystackp->yysplitPoint != YY_NULL)
+  if (yystackp->yysplitPoint != YY_NULLPTR)
    {
      yyGLRState* yys;
      int yyn;
@@ -1844,10 +1847,10 @@ yycompressStack (yyGLRStack* yystackp)
 {
  yyGLRState* yyp, *yyq, *yyr;

-  if (yystackp->yytops.yysize != 1 || yystackp->yysplitPoint == YY_NULL)
+  if (yystackp->yytops.yysize != 1 || yystackp->yysplitPoint == YY_NULLPTR)
    return;

-  for (yyp = yystackp->yytops.yystates[0], yyq = yyp->yypred, yyr = YY_NULL;
+  for (yyp = yystackp->yytops.yystates[0], yyq = yyp->yypred, yyr = YY_NULLPTR;
       yyp != yystackp->yysplitPoint;
       yyr = yyp, yyp = yyq, yyq = yyp->yypred)
    yyp->yypred = yyr;
@@ -1855,10 +1858,10 @@ yycompressStack (yyGLRStack* yystackp)
  yystackp->yyspaceLeft += yystackp->yynextFree - yystackp->yyitems;
  yystackp->yynextFree = ((yyGLRStackItem*) yystackp->yysplitPoint) + 1;
  yystackp->yyspaceLeft -= yystackp->yynextFree - yystackp->yyitems;
-  yystackp->yysplitPoint = YY_NULL;
-  yystackp->yylastDeleted = YY_NULL;
+  yystackp->yysplitPoint = YY_NULLPTR;
+  yystackp->yylastDeleted = YY_NULLPTR;

-  while (yyr != YY_NULL)
+  while (yyr != YY_NULLPTR)
    {
      yystackp->yynextFree->yystate = *yyr;
      yyr = yyr->yypred;
@@ -1873,7 +1876,7 @@ static YYRESULTTAG
 yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
                   size_t yyposn]b4_pure_formals[)
 {
-  while (yystackp->yytops.yystates[yyk] != YY_NULL)
+  while (yystackp->yytops.yystates[yyk] != YY_NULLPTR)
    {
      yyStateNum yystate = yystackp->yytops.yystates[yyk]->yylrState;
      YYDPRINTF ((stderr, "Stack %lu Entering state %d\n",
@@ -1995,13 +1998,13 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
 #else
  {
  yySymbol yytoken = yychar == YYEMPTY ? YYEMPTY : YYTRANSLATE (yychar);
-  size_t yysize0 = yytnamerr (YY_NULL, yytokenName (yytoken));
+  size_t yysize0 = yytnamerr (YY_NULLPTR, yytokenName (yytoken));
  size_t yysize = yysize0;
  yybool yysize_overflow = yyfalse;
-  char* yymsg = YY_NULL;
+  char* yymsg = YY_NULLPTR;
  enum { YYERROR_VERBOSE_ARGS_MAXIMUM = 5 };
  /* Internationalized format string. */
-  const char *yyformat = YY_NULL;
+  const char *yyformat = YY_NULLPTR;
  /* Arguments of yyformat. */
  char const *yyarg[YYERROR_VERBOSE_ARGS_MAXIMUM];
  /* Number of reported tokens (one for the "unexpected", one per
@@ -2057,7 +2060,7 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
                  }
                yyarg[yycount++] = yytokenName (yyx);
                {
-                  size_t yysz = yysize + yytnamerr (YY_NULL, yytokenName (yyx));
+                  size_t yysz = yysize + yytnamerr (YY_NULLPTR, yytokenName (yyx));
                  yysize_overflow |= yysz < yysize;
                  yysize = yysz;
                }
@@ -2135,7 +2138,7 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
      {
        yySymbol yytoken;
        if (yychar == YYEOF)
-          yyFail (yystackp][]b4_lpure_args[, YY_NULL);
+          yyFail (yystackp][]b4_lpure_args[, YY_NULLPTR);
        if (yychar != YYEMPTY)
          {]b4_locations_if([[
            /* We throw away the lookahead, but the error range
@@ -2176,10 +2179,10 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[)

  /* Reduce to one stack.  */
  for (yyk = 0; yyk < yystackp->yytops.yysize; yyk += 1)
-    if (yystackp->yytops.yystates[yyk] != YY_NULL)
+    if (yystackp->yytops.yystates[yyk] != YY_NULLPTR)
      break;
  if (yyk >= yystackp->yytops.yysize)
-    yyFail (yystackp][]b4_lpure_args[, YY_NULL);
+    yyFail (yystackp][]b4_lpure_args[, YY_NULLPTR);
  for (yyk += 1; yyk < yystackp->yytops.yysize; yyk += 1)
    yymarkStackDeleted (yystackp, yyk);
  yyremoveDeletes (yystackp);
@@ -2187,7 +2190,7 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[)

  /* Now pop stack until we find a state that shifts the error token.  */
  yystackp->yyerrState = 3;
-  while (yystackp->yytops.yystates[0] != YY_NULL)
+  while (yystackp->yytops.yystates[0] != YY_NULLPTR)
    {
      yyGLRState *yys = yystackp->yytops.yystates[0];
      yyj = yypact[yys->yylrState];
@@ -2211,14 +2214,14 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
            }
        }]b4_locations_if([[
      yystackp->yyerror_range[1].yystate.yyloc = yys->yyloc;]])[
-      if (yys->yypred != YY_NULL)
+      if (yys->yypred != YY_NULLPTR)
        yydestroyGLRState ("Error: popping", yys]b4_user_args[);
      yystackp->yytops.yystates[0] = yys->yypred;
      yystackp->yynextFree -= 1;
      yystackp->yyspaceLeft += 1;
    }
-  if (yystackp->yytops.yystates[0] == YY_NULL)
-    yyFail (yystackp][]b4_lpure_args[, YY_NULL);
+  if (yystackp->yytops.yystates[0] == YY_NULLPTR)
+    yyFail (yystackp][]b4_lpure_args[, YY_NULLPTR);
 }

 #define YYCHK1(YYE)                                                          \
@@ -2461,7 +2464,7 @@ b4_dollar_popdef])[]dnl
                  {
                    yyGLRState *yys = yystates[yyk];
 ]b4_locations_if([[                 yystack.yyerror_range[1].yystate.yyloc = yys->yyloc;]]
-)[                  if (yys->yypred != YY_NULL)
+)[                  if (yys->yypred != YY_NULLPTR)
                      yydestroyGLRState ("Cleanup: popping", yys]b4_user_args[);
                    yystates[yyk] = yys->yypred;
                    yystack.yynextFree -= 1;
@@ -2493,7 +2496,7 @@ yy_yypstack (yyGLRState* yys)
 static void
 yypstates (yyGLRState* yyst)
 {
-  if (yyst == YY_NULL)
+  if (yyst == YY_NULLPTR)
    YYFPRINTF (stderr, "<null>");
  else
    yy_yypstack (yyst);
@@ -2507,7 +2510,7 @@ yypstack (yyGLRStack* yystackp, size_t yyk)
 }

 #define YYINDEX(YYX)                                                         \
-    ((YYX) == YY_NULL ? -1 : (yyGLRStackItem*) (YYX) - yystackp->yyitems)
+    ((YYX) == YY_NULLPTR ? -1 : (yyGLRStackItem*) (YYX) - yystackp->yyitems)


 static void
@@ -2521,6 +2524,8 @@ yypdumpstack (yyGLRStack* yystackp)
                 (unsigned long int) (yyp - yystackp->yyitems));
      if (*(yybool *) yyp)
        {
+          YYASSERT (yyp->yystate.yyisState);
+          YYASSERT (yyp->yyoption.yyisState);
          YYFPRINTF (stderr, "Res: %d, LR State: %d, posn: %lu, pred: %ld",
                     yyp->yystate.yyresolved, yyp->yystate.yylrState,
                     (unsigned long int) yyp->yystate.yyposn,
@@ -2532,6 +2537,8 @@ yypdumpstack (yyGLRStack* yystackp)
        }
      else
        {
+          YYASSERT (!yyp->yystate.yyisState);
+          YYASSERT (!yyp->yyoption.yyisState);
          YYFPRINTF (stderr, "Option. rule: %d, state: %ld, next: %ld",
                     yyp->yyoption.yyrule - 1,
                     (long int) YYINDEX (yyp->yyoption.yystate),
@@ -2565,16 +2572,3 @@ m4_if(b4_prefix, [yy], [],

 ]b4_epilogue[]dnl
 b4_output_end()
-
-# glr.cc produces its own header.
-m4_if(b4_skeleton, ["glr.c"],
-[b4_defines_if(
-[b4_output_begin([b4_spec_defines_file])
-b4_copyright([Skeleton interface for Bison GLR parsers in C],
-             [2002-2013])[
-
-]b4_cpp_guard_open([b4_spec_defines_file])[
-]b4_shared_declarations[
-]b4_cpp_guard_close([b4_spec_defines_file])[
-]b4_output_end()
-])])
@@ -1,6 +1,6 @@
 # C++ GLR skeleton for Bison

-# Copyright (C) 2002-2013 Free Software Foundation, Inc.
+# Copyright (C) 2002-2015 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
@@ -43,12 +43,6 @@
 #   user must initialize the first positions (in particular the
 #   filename member).

-b4_token_ctor_if([b4_variant_if([],
-  [b4_fatal_at(b4_percent_define_get_loc(api.token.constructor),
-               [cannot use '%s' without '%s'],
-               [%define api.token.constructor],
-               [%define api.value.type variant]))])])
-
 # We require a pure interface.
 m4_define([b4_pure_flag],      [1])

@@ -193,12 +187,7 @@ m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
    std::ostream& yyoutput = debug_stream ();
    std::ostream& yyo = yyoutput;
    YYUSE (yyo);
-    switch (yytype)
-      {
-]b4_symbol_foreach([b4_symbol_printer])dnl
-[        default:
-          break;
-      }
+    ]b4_symbol_actions([printer])[
  }


@@ -340,7 +329,7 @@ b4_percent_define_flag_if([[global_tokens_and_yystype]],
 b4_defines_if(
 [b4_output_begin([b4_spec_defines_file])
 b4_copyright([Skeleton interface for Bison GLR parsers in C++],
-             [2002-2013])[
+             [2002-2015])[

 // C++ GLR parser skeleton written by Akim Demaille.

@@ -2,7 +2,7 @@

 # Java skeleton dispatching for Bison.

-# Copyright (C) 2007, 2009-2013 Free Software Foundation, Inc.
+# Copyright (C) 2007, 2009-2015 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
@@ -2,7 +2,7 @@

 # Java language support for Bison

-# Copyright (C) 2007-2013 Free Software Foundation, Inc.
+# Copyright (C) 2007-2015 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
@@ -103,7 +103,7 @@ m4_define([b4_int_type],
 # b4_int_type_for(NAME)
 # ---------------------
 # Return the smallest int type able to handle numbers ranging from
-# `NAME_min' to `NAME_max' (included).
+# 'NAME_min' to 'NAME_max' (included).
 m4_define([b4_int_type_for],
 [b4_int_type($1_min, $1_max)])

@@ -169,6 +169,22 @@ m4_define([b4_predicate_case], [  case $1:
    ])


+## -------- ##
+## Checks.  ##
+## -------- ##
+
+b4_percent_define_check_kind([[api.value.type]],    [code], [deprecated])
+
+b4_percent_define_check_kind([[annotations]],       [code], [deprecated])
+b4_percent_define_check_kind([[extends]],           [code], [deprecated])
+b4_percent_define_check_kind([[implements]],        [code], [deprecated])
+b4_percent_define_check_kind([[init_throws]],       [code], [deprecated])
+b4_percent_define_check_kind([[lex_throws]],        [code], [deprecated])
+b4_percent_define_check_kind([[parser_class_name]], [code], [deprecated])
+b4_percent_define_check_kind([[throws]],            [code], [deprecated])
+
+
+
 ## ---------------- ##
 ## Default values.  ##
 ## ---------------- ##
@@ -1,6 +1,6 @@
 # C++ skeleton for Bison

-# Copyright (C) 2002-2013 Free Software Foundation, Inc.
+# Copyright (C) 2002-2015 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
@@ -17,6 +17,8 @@

 m4_include(b4_pkgdatadir/[c++.m4])

+# api.value.type=variant is valid.
+m4_define([b4_value_type_setup_variant])

 # b4_integral_parser_table_declare(TABLE-NAME, CONTENT, COMMENT)
 # --------------------------------------------------------------
@@ -38,13 +40,14 @@ m4_define([b4_integral_parser_table_define],
  };dnl
 ])

-
 # b4_symbol_value_template(VAL, [TYPE])
 # -------------------------------------
 # Same as b4_symbol_value, but used in a template method.  It makes
-# a difference when using variants.
+# a difference when using variants.  Note that b4_value_type_setup_union
+# overrides b4_symbol_value, so we must override it again.
 m4_copy([b4_symbol_value], [b4_symbol_value_template])
-
+m4_append([b4_value_type_setup_union],
+          [m4_copy_force([b4_symbol_value_union], [b4_symbol_value_template])])

 # b4_lhs_value([TYPE])
 # --------------------
@@ -128,7 +131,7 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))])])


 m4_pushdef([b4_copyright_years],
-           [2002-2013])
+           [2002-2015])

 m4_define([b4_parser_class_name],
          [b4_percent_define_get([[parser_class_name]])])
@@ -146,14 +149,16 @@ b4_variant_if([m4_include(b4_pkgdatadir/[variant.hh])])
 m4_define([b4_shared_declarations],
 [b4_percent_code_get([[requires]])[
 ]b4_parse_assert_if([# include <cassert>])[
-# include <vector>
+# include <cstdlib> // std::abort
 # include <iostream>
 # include <stdexcept>
-# include <string>]b4_defines_if([[
+# include <string>
+# include <vector>]b4_defines_if([[
 # include "stack.hh"
 ]b4_bison_locations_if([[# include "location.hh"]])])[
 ]b4_variant_if([b4_variant_includes])[

+]b4_attribute_define[
 ]b4_YYDEBUG_define[

 ]b4_namespace_open[
@@ -180,14 +185,14 @@ b4_location_define])])[

 #if ]b4_api_PREFIX[DEBUG
    /// The current debugging stream.
-    std::ostream& debug_stream () const;
+    std::ostream& debug_stream () const YY_ATTRIBUTE_PURE;
    /// Set the current debugging stream.
    void set_debug_stream (std::ostream &);

    /// Type for debugging levels.
    typedef int debug_level_type;
    /// The current debugging level.
-    debug_level_type debug_level () const;
+    debug_level_type debug_level () const YY_ATTRIBUTE_PURE;
    /// Set the current debugging level.
    void set_debug_level (debug_level_type l);
 #endif
@@ -201,19 +206,23 @@ b4_location_define])])[
    void error (const syntax_error& err);

  private:
+    /// This class is not copyable.
+    ]b4_parser_class_name[ (const ]b4_parser_class_name[&);
+    ]b4_parser_class_name[& operator= (const ]b4_parser_class_name[&);
+
    /// State numbers.
    typedef int state_type;

    /// Generate an error message.
    /// \param yystate   the state where the error occurred.
-    /// \param yytoken   the lookahead token type, or yyempty_.
+    /// \param yyla      the lookahead token.
    virtual std::string yysyntax_error_ (state_type yystate,
-                                         symbol_number_type yytoken) const;
+                                         const symbol_type& yyla) const;

    /// Compute post-reduction state.
    /// \param yystate   the current state
-    /// \param yylhs     the nonterminal to push on the stack
-    state_type yy_lr_goto_state_ (state_type yystate, int yylhs);
+    /// \param yysym     the nonterminal to push on the stack
+    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
@@ -260,7 +269,7 @@ b4_location_define])])[
    /// \brief Reclaim the memory associated to a symbol.
    /// \param yymsg     Why this token is reclaimed.
    ///                  If null, print nothing.
-    /// \param s         The symbol.
+    /// \param yysym     The symbol.
    template <typename Base>
    void yy_destroy_ (const char* yymsg, basic_symbol<Base>& yysym) const;

@@ -280,16 +289,21 @@ b4_location_define])])[
      /// Copy constructor.
      by_state (const by_state& other);

+      /// Record that this symbol is empty.
+      void clear ();
+
      /// Steal the symbol type from \a that.
      void move (by_state& that);

      /// The (internal) type number (corresponding to \a state).
-      /// "empty" when empty.
+      /// \a empty_symbol when empty.
      symbol_number_type type_get () const;

-      enum { empty = 0 };
+      /// The state number used to denote an empty symbol.
+      enum { empty_state = -1 };

      /// The state.
+      /// \a empty when empty.
      state_type state;
    };

@@ -330,17 +344,16 @@ b4_location_define])])[
    /// Pop \a n symbols the three stacks.
    void yypop_ (unsigned int n = 1);

-    // Constants.
+    /// Constants.
    enum
    {
      yyeof_ = 0,
-      yylast_ = ]b4_last[,           //< Last index in yytable_.
-      yynnts_ = ]b4_nterms_number[,  //< Number of nonterminal symbols.
-      yyempty_ = -2,
-      yyfinal_ = ]b4_final_state_number[, //< Termination state number.
+      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.
+      yyntokens_ = ]b4_tokens_number[  ///< Number of tokens.
    };

 ]b4_parse_param_vars[
@@ -456,7 +469,7 @@ m4_if(b4_prefix, [yy], [],
 #endif // !]b4_api_PREFIX[DEBUG

 #define yyerrok         (yyerrstatus_ = 0)
-#define yyclearin       (yyempty = true)
+#define yyclearin       (yyla.clear ())

 #define YYACCEPT        goto yyacceptlab
 #define YYABORT         goto yyabortlab
@@ -525,7 +538,7 @@ m4_if(b4_prefix, [yy], [],
  // by_state.
  inline
  ]b4_parser_class_name[::by_state::by_state ()
-    : state (empty)
+    : state (empty_state)
  {}

  inline
@@ -533,12 +546,19 @@ m4_if(b4_prefix, [yy], [],
    : state (other.state)
  {}

+  inline
+  void
+  ]b4_parser_class_name[::by_state::clear ()
+  {
+    state = empty_state;
+  }
+
  inline
  void
  ]b4_parser_class_name[::by_state::move (by_state& that)
  {
    state = that.state;
-    that.state = empty;
+    that.clear ();
  }

  inline
@@ -550,7 +570,10 @@ m4_if(b4_prefix, [yy], [],
  ]b4_parser_class_name[::symbol_number_type
  ]b4_parser_class_name[::by_state::type_get () const
  {
-    return state == empty ? 0 : yystos_[state];
+    if (state == empty_state)
+      return empty_symbol;
+    else
+      return yystos_[state];
  }

  inline
@@ -566,7 +589,7 @@ m4_if(b4_prefix, [yy], [],
                                      [value], [move], [that.value])],
                   [[value = that.value;]])[
    // that is emptied.
-    that.type = empty;
+    that.type = empty_symbol;
  }

  inline
@@ -591,13 +614,7 @@ m4_if(b4_prefix, [yy], [],
      YY_SYMBOL_PRINT (yymsg, yysym);]b4_variant_if([], [

    // User destructor.
-    symbol_number_type yytype = yysym.type_get ();
-    switch (yytype)
-      {
-]b4_symbol_foreach([b4_symbol_destructor])dnl
-[       default:
-          break;
-      }])[
+    b4_symbol_actions([destructor], [yysym.type_get ()])])[
  }

 #if ]b4_api_PREFIX[DEBUG
@@ -609,15 +626,14 @@ m4_if(b4_prefix, [yy], [],
    std::ostream& yyoutput = yyo;
    YYUSE (yyoutput);
    symbol_number_type yytype = yysym.type_get ();
+    // Avoid a (spurious) G++ 4.8 warning about "array subscript is
+    // below array bounds".
+    if (yysym.empty ())
+      std::abort ();
    yyo << (yytype < yyntokens_ ? "token" : "nterm")
        << ' ' << yytname_[yytype] << " ("]b4_locations_if([
        << yysym.location << ": "])[;
-    switch (yytype)
-      {
-]b4_symbol_foreach([b4_symbol_printer])dnl
-[       default:
-          break;
-      }
+    ]b4_symbol_actions([printer])[
    yyo << ')';
  }
 #endif
@@ -674,13 +690,13 @@ m4_if(b4_prefix, [yy], [],
 #endif // ]b4_api_PREFIX[DEBUG

  inline ]b4_parser_class_name[::state_type
-  ]b4_parser_class_name[::yy_lr_goto_state_ (state_type yystate, int yylhs)
+  ]b4_parser_class_name[::yy_lr_goto_state_ (state_type yystate, int yysym)
  {
-    int yyr = yypgoto_[yylhs - yyntokens_] + yystate;
+    int yyr = yypgoto_[yysym - yyntokens_] + yystate;
    if (0 <= yyr && yyr <= yylast_ && yycheck_[yyr] == yystate)
      return yytable_[yyr];
    else
-      return yydefgoto_[yylhs - yyntokens_];
+      return yydefgoto_[yysym - yyntokens_];
  }

  inline bool
@@ -698,11 +714,9 @@ m4_if(b4_prefix, [yy], [],
  int
  ]b4_parser_class_name[::parse ()
  {
-    /// Whether yyla contains a lookahead.
-    bool yyempty = true;
-
    // State.
    int yyn;
+    /// Length of the RHS of the rule being reduced.
    int yylen = 0;

    // Error handling.
@@ -715,9 +729,6 @@ m4_if(b4_prefix, [yy], [],
    /// The locations where the error started and ended.
    stack_symbol_type yyerror_range[3];]])[

-    /// $$ and @@$.
-    stack_symbol_type yylhs;
-
    /// The return value of parse ().
    int yyresult;

@@ -737,8 +748,8 @@ b4_dollar_popdef])[]dnl
       yynewstate, since the latter expects the semantical and the
       location values to have been already stored, initialize these
       stacks with a primary value.  */
-    yystack_ = stack_type (0);
-    yypush_ (YY_NULL, 0, yyla);
+    yystack_.clear ();
+    yypush_ (YY_NULLPTR, 0, yyla);

    // A new symbol was pushed on the stack.
  yynewstate:
@@ -759,7 +770,7 @@ b4_dollar_popdef])[]dnl
      goto yydefault;

    // Read a lookahead token.
-    if (yyempty)
+    if (yyla.empty ())
      {
        YYCDEBUG << "Reading a token: ";
        try
@@ -773,7 +784,6 @@ b4_dollar_popdef])[]dnl
            error (yyexc);
            goto yyerrlab1;
          }
-        yyempty = false;
      }
    YY_SYMBOL_PRINT ("Next token is", yyla);

@@ -793,9 +803,6 @@ b4_dollar_popdef])[]dnl
        goto yyreduce;
      }

-    // Discard the token being shifted.
-    yyempty = true;
-
    // Count tokens shifted since error; after three, turn off error status.
    if (yyerrstatus_)
      --yyerrstatus_;
@@ -818,52 +825,55 @@ b4_dollar_popdef])[]dnl
  `-----------------------------*/
  yyreduce:
    yylen = yyr2_[yyn];
-    yylhs.state = yy_lr_goto_state_(yystack_[yylen].state, yyr1_[yyn]);]b4_variant_if([
-    /* Variants are always initialized to an empty instance of the
-       correct type. The default $$=$1 action is NOT applied when using
-       variants.  */
-    b4_symbol_variant([[yyr1_@{yyn@}]], [yylhs.value], [build])],[
-    /* If YYLEN is nonzero, implement the default value of the action:
-       `$$ = $1'.  Otherwise, use the top of the stack.
+    {
+      stack_symbol_type yylhs;
+      yylhs.state = yy_lr_goto_state_(yystack_[yylen].state, yyr1_[yyn]);]b4_variant_if([
+      /* Variants are always initialized to an empty instance of the
+         correct type. The default '$$ = $1' action is NOT applied
+         when using variants.  */
+      b4_symbol_variant([[yyr1_@{yyn@}]], [yylhs.value], [build])], [
+      /* If YYLEN is nonzero, implement the default value of the
+         action: '$$ = $1'.  Otherwise, use the top of the stack.

-       Otherwise, the following line sets YYLHS.VALUE to garbage.
-       This behavior is undocumented and Bison
-       users should not rely upon it.  */
-    if (yylen)
-      yylhs.value = yystack_@{yylen - 1@}.value;
-    else
-      yylhs.value = yystack_@{0@}.value;])[
+         Otherwise, the following line sets YYLHS.VALUE to garbage.
+         This behavior is undocumented and Bison users should not rely
+         upon it.  */
+      if (yylen)
+        yylhs.value = yystack_@{yylen - 1@}.value;
+      else
+        yylhs.value = yystack_@{0@}.value;])[
 ]b4_locations_if([dnl
 [
-    // Compute the default @@$.
-    {
-      slice<stack_symbol_type, stack_type> slice (yystack_, yylen);
-      YYLLOC_DEFAULT (yylhs.location, slice, yylen);
-    }]])[
-
-    // Perform the reduction.
-    YY_REDUCE_PRINT (yyn);
-    try
+      // Compute the default @@$.
      {
-        switch (yyn)
-          {
+        slice<stack_symbol_type, stack_type> slice (yystack_, yylen);
+        YYLLOC_DEFAULT (yylhs.location, slice, yylen);
+      }]])[
+
+      // Perform the reduction.
+      YY_REDUCE_PRINT (yyn);
+      try
+        {
+          switch (yyn)
+            {
 ]b4_user_actions[
-          default:
-            break;
-          }
-      }
-    catch (const syntax_error& yyexc)
-      {
-        error (yyexc);
-        YYERROR;
-      }
-    YY_SYMBOL_PRINT ("-> $$ =", yylhs);
-    yypop_ (yylen);
-    yylen = 0;
-    YY_STACK_PRINT ();
+            default:
+              break;
+            }
+        }
+      catch (const syntax_error& yyexc)
+        {
+          error (yyexc);
+          YYERROR;
+        }
+      YY_SYMBOL_PRINT ("-> $$ =", yylhs);
+      yypop_ (yylen);
+      yylen = 0;
+      YY_STACK_PRINT ();

-    // Shift the result of the reduction.
-    yypush_ (YY_NULL, yylhs);
+      // Shift the result of the reduction.
+      yypush_ (YY_NULLPTR, yylhs);
+    }
    goto yynewstate;

  /*--------------------------------------.
@@ -875,8 +885,7 @@ b4_dollar_popdef])[]dnl
      {
        ++yynerrs_;
        error (]b4_join(b4_locations_if([yyla.location]),
-                        [[yysyntax_error_ (yystack_[0].state,
-                                           yyempty ? yyempty_ : yyla.type_get ())]])[);
+                        [[yysyntax_error_ (yystack_[0].state, yyla)]])[);
      }

 ]b4_locations_if([[
@@ -889,10 +898,10 @@ b4_dollar_popdef])[]dnl
        // Return failure if at end of input.
        if (yyla.type_get () == yyeof_)
          YYABORT;
-        else if (!yyempty)
+        else if (!yyla.empty ())
          {
            yy_destroy_ ("Error: discarding", yyla);
-            yyempty = true;
+            yyla.clear ();
          }
      }

@@ -910,10 +919,7 @@ b4_dollar_popdef])[]dnl
       code.  */
    if (false)
      goto yyerrorlab;]b4_locations_if([[
-    yyerror_range[1].location = yystack_[yylen - 1].location;]])b4_variant_if([[
-    /* $$ was initialized before running the user action.  */
-    YY_SYMBOL_PRINT ("Error: discarding", yylhs);
-    yylhs.~stack_symbol_type();]])[
+    yyerror_range[1].location = yystack_[yylen - 1].location;]])[
    /* Do not reclaim the symbols of the rule whose action triggered
       this YYERROR.  */
    yypop_ (yylen);
@@ -971,7 +977,7 @@ b4_dollar_popdef])[]dnl
    goto yyreturn;

  yyreturn:
-    if (!yyempty)
+    if (!yyla.empty ())
      yy_destroy_ ("Cleanup: discarding lookahead", yyla);

    /* Do not reclaim the symbols of the rule whose action triggered
@@ -991,12 +997,12 @@ b4_dollar_popdef])[]dnl
                 << std::endl;
        // Do not try to display the values of the reclaimed symbols,
        // as their printer might throw an exception.
-        if (!yyempty)
-          yy_destroy_ (YY_NULL, yyla);
+        if (!yyla.empty ())
+          yy_destroy_ (YY_NULLPTR, yyla);

        while (1 < yystack_.size ())
          {
-            yy_destroy_ (YY_NULL, yystack_[0]);
+            yy_destroy_ (YY_NULLPTR, yystack_[0]);
            yypop_ ();
          }
        throw;
@@ -1013,10 +1019,9 @@ b4_dollar_popdef])[]dnl
  // Generate an error message.
  std::string
  ]b4_parser_class_name[::yysyntax_error_ (]dnl
-b4_error_verbose_if([state_type yystate, symbol_number_type yytoken],
-                    [state_type, symbol_number_type])[) const
+b4_error_verbose_if([state_type yystate, const symbol_type& yyla],
+                    [state_type, const symbol_type&])[) const
  {]b4_error_verbose_if([[
-    std::string yyres;
    // Number of reported tokens (one for the "unexpected", one per
    // "expected").
    size_t yycount = 0;
@@ -1030,7 +1035,7 @@ b4_error_verbose_if([state_type yystate, symbol_number_type yytoken],
         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 yytoken) is
+       - The only way there can be no lookahead present (in yyla) 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
@@ -1050,8 +1055,9 @@ b4_error_verbose_if([state_type yystate, symbol_number_type yytoken],
         token that will not be accepted due to an error action in a
         later state.
    */
-    if (yytoken != yyempty_)
+    if (!yyla.empty ())
      {
+        int yytoken = yyla.type_get ();
        yyarg[yycount++] = yytname_[yytoken];
        int yyn = yypact_[yystate];
        if (!yy_pact_value_is_default_ (yyn))
@@ -1078,7 +1084,7 @@ b4_error_verbose_if([state_type yystate, symbol_number_type yytoken],
          }
      }

-    char const* yyformat = YY_NULL;
+    char const* yyformat = YY_NULLPTR;
    switch (yycount)
      {
 #define YYCASE_(N, S)                         \
@@ -1094,6 +1100,7 @@ b4_error_verbose_if([state_type yystate, symbol_number_type yytoken],
 #undef YYCASE_
      }

+    std::string yyres;
    // Argument number.
    size_t yyi = 0;
    for (char const* yyp = yyformat; *yyp; ++yyp)
@@ -1,6 +1,6 @@
 # Java skeleton for Bison -*- autoconf -*-

-# Copyright (C) 2007-2013 Free Software Foundation, Inc.
+# Copyright (C) 2007-2015 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
@@ -20,7 +20,8 @@ m4_include(b4_pkgdatadir/[java.m4])
 b4_defines_if([b4_fatal([%s: %%defines does not make sense in Java],
              [b4_skeleton])])

-# We don't depend on %debug in Java, but pacify warnings about non-used flags.
+# 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],
@@ -30,9 +31,60 @@ m4_define([b4_symbol_no_destructor_assert],
                        [b4_symbol_action_location([$1], [destructor])])])])
 b4_symbol_foreach([b4_symbol_no_destructor_assert])

+# Setup some macros for api.push-pull.
+b4_percent_define_default([[api.push-pull]], [[pull]])
+b4_percent_define_check_values([[[[api.push-pull]],
+                                 [[pull]], [[push]], [[both]]]])
+
+# Define m4 conditional macros that encode the value
+# of the api.push-pull flag.
+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]])])
+
+# Define a macro to be true when api.push-pull has the value "both".
+m4_define([b4_both_if],[b4_push_if([b4_pull_if([$1],[$2])],[$2])])
+
+# 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]])])])
+
+# Define a macro to encapsulate the parse state variables.
+# This allows them to be defined either in parse() when doing
+# pull parsing, or as class instance variable when doing push parsing.
+m4_define([b4_define_state],[[
+    /* Lookahead and lookahead in internal form.  */
+    int yychar = yyempty_;
+    int yytoken = 0;
+
+    /* State.  */
+    int yyn = 0;
+    int yylen = 0;
+    int yystate = 0;
+    YYStack yystack = new YYStack ();
+    int label = YYNEWSTATE;
+
+    /* Error handling.  */
+    int yynerrs_ = 0;
+    ]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);])[
+
+    /* Semantic value of the lookahead.  */
+    ]b4_yystype[ yylval = null;
+]])
+
 b4_output_begin([b4_parser_file_name])
 b4_copyright([Skeleton implementation for Bison LALR(1) parsers in Java],
-             [2007-2013])
+             [2007-2015])

 b4_percent_define_ifdef([package], [package b4_percent_define_get([package]);
 ])[/* First part of user declarations.  */
@@ -55,7 +107,9 @@ b4_percent_define_get3([implements], [ implements ])[
 {
  ]b4_identification[
 ]b4_error_verbose_if([[
-  /** True if verbose error messages are enabled.  */
+  /**
+   * True if verbose error messages are enabled.
+   */
  private boolean yyErrorVerbose = true;

  /**
@@ -76,18 +130,24 @@ b4_locations_if([[
   * A class defining a pair of positions.  Positions, defined by the
   * <code>]b4_position_type[</code> class, denote a point in the input.
   * Locations represent a part of the input through the beginning
-   * and ending positions.  */
+   * and ending positions.
+   */
  public class ]b4_location_type[ {
-    /** The first, inclusive, position in the range.  */
+    /**
+     * The first, inclusive, position in the range.
+     */
    public ]b4_position_type[ begin;

-    /** The first position beyond the range.  */
+    /**
+     * The first position beyond the range.
+     */
    public ]b4_position_type[ end;

    /**
     * Create a <code>]b4_location_type[</code> denoting an empty range located at
     * a given point.
-     * @@param loc The position at which the range is anchored.  */
+     * @@param loc The position at which the range is anchored.
+     */
    public ]b4_location_type[ (]b4_position_type[ loc) {
      this.begin = this.end = loc;
    }
@@ -95,7 +155,8 @@ b4_locations_if([[
    /**
     * Create a <code>]b4_location_type[</code> from the endpoints of the range.
     * @@param begin The first position included in the range.
-     * @@param end   The first position beyond the range.  */
+     * @@param end   The first position beyond the range.
+     */
    public ]b4_location_type[ (]b4_position_type[ begin, ]b4_position_type[ end) {
      this.begin = begin;
      this.end = end;
@@ -104,7 +165,8 @@ b4_locations_if([[
    /**
     * Print a representation of the location.  For this to be correct,
     * <code>]b4_position_type[</code> should override the <code>equals</code>
-     * method.  */
+     * method.
+     */
    public String toString () {
      if (begin.equals (end))
        return begin.toString ();
@@ -136,24 +198,28 @@ b4_locations_if([[

    ]b4_locations_if([[/**
     * Method to retrieve the beginning position of the last scanned token.
-     * @@return the position at which the last scanned token starts.  */
+     * @@return the position at which the last scanned token starts.
+     */
    ]b4_position_type[ getStartPos ();

    /**
     * Method to retrieve the ending position of the last scanned token.
-     * @@return the first position beyond the last scanned token.  */
+     * @@return the first position beyond the last scanned token.
+     */
    ]b4_position_type[ getEndPos ();]])[

    /**
     * Method to retrieve the semantic value of the last scanned token.
-     * @@return the semantic value of the last scanned token.  */
+     * @@return the semantic value of the last scanned token.
+     */
    ]b4_yystype[ getLVal ();

    /**
     * Entry point for the scanner.  Returns the token identifier corresponding
     * to the next token and prepares to return the semantic value
     * ]b4_locations_if([and beginning/ending positions ])[of the token.
-     * @@return the token identifier corresponding to the next token. */
+     * @@return the token identifier corresponding to the next token.
+     */
    int yylex () ]b4_maybe_throws([b4_lex_throws])[;

    /**
@@ -162,7 +228,8 @@ b4_locations_if([[
     *
     * ]b4_locations_if([[@@param loc The location of the element to which the
     *                error message is related]])[
-     * @@param msg The string for the error message.  */
+     * @@param msg The string for the error message.
+     */
     void yyerror (]b4_locations_if([b4_location_type[ loc, ]])[String msg);]
  }

@@ -170,7 +237,9 @@ b4_locations_if([[
 ]b4_percent_code_get([[lexer]])[
  }

-  ]])[/** The object doing lexical analysis for us.  */
+  ]])[/**
+   * The object doing lexical analysis for us.
+   */
  private Lexer yylexer;
  ]
  b4_parse_param_vars
@@ -336,46 +405,74 @@ b4_lexer_if([[

  /**
   * Returned by a Bison action in order to stop the parsing process and
-   * return success (<tt>true</tt>).  */
+   * return success (<tt>true</tt>).
+   */
  public static final int YYACCEPT = 0;

  /**
   * Returned by a Bison action in order to stop the parsing process and
-   * return failure (<tt>false</tt>).  */
+   * return failure (<tt>false</tt>).
+   */
  public static final int YYABORT = 1;

+]b4_push_if([
+  /**
+   * Returned by a Bison action in order to request a new token.
+   */
+  public static final int YYPUSH_MORE = 4;])[
+
  /**
   * Returned by a Bison action in order to start error recovery without
-   * printing an error message.  */
+   * printing an error message.
+   */
  public static final int YYERROR = 2;

-  // Internal return codes that are not supported for user semantic
-  // actions.
+  /**
+   * Internal return codes that are not supported for user semantic
+   * actions.
+   */
  private static final int YYERRLAB = 3;
  private static final int YYNEWSTATE = 4;
  private static final int YYDEFAULT = 5;
  private static final int YYREDUCE = 6;
  private static final int YYERRLAB1 = 7;
  private static final int YYRETURN = 8;
+]b4_push_if([[  private static final int YYGETTOKEN = 9; /* Signify that a new token is expected when doing push-parsing.  */]])[

  private int yyerrstatus_ = 0;

+]b4_push_if([dnl
+b4_define_state])[
  /**
   * Return whether error recovery is being done.  In this state, the parser
   * reads token until it reaches a known state, and then restarts normal
-   * operation.  */
+   * operation.
+   */
  public final boolean recovering ()
  {
    return yyerrstatus_ == 0;
  }

+  /** Compute post-reduction 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)
+  {
+    int yyr = yypgoto_[yysym - yyntokens_] + yystate;
+    if (0 <= yyr && yyr <= yylast_ && yycheck_[yyr] == yystate)
+      return yytable_[yyr];
+    else
+      return yydefgoto_[yysym - yyntokens_];
+  }
+
  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:
-       `$$ = $1'.  Otherwise, use the top of the stack.
+       '$$ = $1'.  Otherwise, use the top of the stack.

       Otherwise, the following line sets YYVAL to garbage.
       This behavior is undocumented and Bison
@@ -399,14 +496,7 @@ b4_lexer_if([[
    yylen = 0;

    /* Shift the result of the reduction.  */
-    yyn = yyr1_[yyn];
-    int yystate = yypgoto_[yyn - yyntokens_] + yystack.stateAt (0);
-    if (0 <= yystate && yystate <= yylast_
-        && yycheck_[yystate] == yystack.stateAt (0))
-      yystate = yytable_[yystate];
-    else
-      yystate = yydefgoto_[yyn - yyntokens_];
-
+    int yystate = yy_lr_goto_state_ (yystack.stateAt (0), yyr1_[yyn]);
    yystack.push (yystate, yyval]b4_locations_if([, yyloc])[);
    return YYNEWSTATE;
  }
@@ -463,6 +553,7 @@ b4_lexer_if([[
              + (yyvaluep == null ? "(null)" : yyvaluep.toString ()) + ")");
  }

+]b4_push_if([],[[
  /**
   * Parse input from the scanner that was specified at object construction
   * time.  Return whether the end of the input was reached successfully.
@@ -470,46 +561,53 @@ b4_lexer_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])])[
+   public boolean parse () ]b4_maybe_throws([b4_list2([b4_lex_throws], [b4_throws])])[]])[
+]b4_push_if([
+  /**
+   * Push Parse input from external lexer
+   *
+   * @@param yylextoken current token
+   * @@param yylexval current lval
+]b4_locations_if([   * @@param yylexloc current position])[
+   *
+   * @@return <tt>YYACCEPT, YYABORT, YYPUSH_MORE</tt>
+   */
+  public int push_parse (int yylextoken, b4_yystype yylexval[]b4_locations_if([, b4_location_type yylexloc]))
+      b4_maybe_throws([b4_list2([b4_lex_throws], [b4_throws])])])[
  {
-    /// Lookahead and lookahead in internal form.
-    int yychar = yyempty_;
-    int yytoken = 0;
-
-    /* State.  */
-    int yyn = 0;
-    int yylen = 0;
-    int yystate = 0;
-
-    YYStack yystack = new YYStack ();
-
-    /* Error handling.  */
-    int yynerrs_ = 0;
-    ]b4_locations_if([/// The location where the error started.
-    ]b4_location_type[ yyerrloc = null;
-
-    /// ]b4_location_type[ of the lookahead.
-    ]b4_location_type[ yylloc = new ]b4_location_type[ (null, null);
-
-    /// @@$.
-    ]b4_location_type[ yyloc;])
-
-    /// Semantic value of the lookahead.
-    b4_yystype[ yylval = null;
-
+    ]b4_locations_if([/* @@$.  */
+    b4_location_type yyloc;])[
+]b4_push_if([],[[
+]b4_define_state[
    yycdebug ("Starting parse\n");
    yyerrstatus_ = 0;

+    /* Initialize the stack.  */
+    yystack.push (yystate, yylval ]b4_locations_if([, yylloc])[);
 ]m4_ifdef([b4_initial_action], [
 b4_dollar_pushdef([yylval], [], [yylloc])dnl
    /* User initialization code.  */
    b4_user_initial_action
-b4_dollar_popdef])[]dnl
+b4_dollar_popdef[]dnl
+])[
+]])[
+]b4_push_if([[
+    if (!this.push_parse_initialized)
+      {
+        push_parse_initialize ();
+]m4_ifdef([b4_initial_action], [
+b4_dollar_pushdef([yylval], [], [yylloc])dnl
+    /* User initialization code.  */
+    b4_user_initial_action
+b4_dollar_popdef[]dnl
+])[
+        yycdebug ("Starting parse\n");
+        yyerrstatus_ = 0;
+      } else
+        label = YYGETTOKEN;

-  [  /* Initialize the stack.  */
-    yystack.push (yystate, yylval]b4_locations_if([, yylloc])[);
-
-    int label = YYNEWSTATE;
+    boolean push_token_consumed = true;
+]])[
    for (;;)
      switch (label)
      {
@@ -522,7 +620,8 @@ b4_dollar_popdef])[]dnl

        /* Accept?  */
        if (yystate == yyfinal_)
-          return true;
+          ]b4_push_if([{label = YYACCEPT; break;}],
+                      [return true;])[

        /* Take a decision.  First try without lookahead.  */
        yyn = yypact_[yystate];
@@ -531,16 +630,27 @@ b4_dollar_popdef])[]dnl
            label = YYDEFAULT;
            break;
          }
+]b4_push_if([        /* Fall Through */

+      case YYGETTOKEN:])[
        /* Read a lookahead token.  */
        if (yychar == yyempty_)
          {
+]b4_push_if([[
+            if (!push_token_consumed)
+              return YYPUSH_MORE;
            yycdebug ("Reading a token: ");
-            yychar = yylexer.yylex ();]
-            b4_locations_if([[
-            yylloc = new ]b4_location_type[(yylexer.getStartPos (),
-                            yylexer.getEndPos ());]])
-            yylval = yylexer.getLVal ();[
+            yychar = yylextoken;
+            yylval = yylexval;]b4_locations_if([
+            yylloc = yylexloc;])[
+            push_token_consumed = false;]])[
+]b4_push_if([],[[
+            yycdebug ("Reading a token: ");
+            yychar = yylexer.yylex ();
+            yylval = yylexer.getLVal ();]b4_locations_if([
+            yylloc = new b4_location_type (yylexer.getStartPos (),
+                            yylexer.getEndPos ());])[
+]])[
          }

        /* Convert token to internal form.  */
@@ -637,10 +747,10 @@ b4_dollar_popdef])[]dnl
          {
          /* Return failure if at end of input.  */
          if (yychar == Lexer.EOF)
-            return false;
+            ]b4_push_if([{label = YYABORT; break;}],[return false;])[
          }
        else
-              yychar = yyempty_;
+            yychar = yyempty_;
          }

        /* Else will try to reuse lookahead token after shifting the error
@@ -648,9 +758,9 @@ b4_dollar_popdef])[]dnl
        label = YYERRLAB1;
        break;

-      /*---------------------------------------------------.
+      /*-------------------------------------------------.
      | errorlab -- error raised explicitly by YYERROR.  |
-      `---------------------------------------------------*/
+      `-------------------------------------------------*/
      case YYERROR:

        ]b4_locations_if([yyerrloc = yystack.locationAt (yylen - 1);])[
@@ -682,9 +792,10 @@ b4_dollar_popdef])[]dnl
                  }
              }

-            /* Pop the current state because it cannot handle the error token.  */
+            /* Pop the current state because it cannot handle the
+             * error token.  */
            if (yystack.height == 0)
-              return false;
+              ]b4_push_if([{label = YYABORT; break;}],[return false;])[

            ]b4_locations_if([yyerrloc = yystack.locationAt (0);])[
            yystack.pop ();
@@ -693,7 +804,11 @@ b4_dollar_popdef])[]dnl
              yystack.print (yyDebugStream);
          }

-        ]b4_locations_if([
+        if (label == YYABORT)
+            /* Leave the switch.  */
+            break;
+
+]b4_locations_if([
        /* Muck with the stack to setup for yylloc.  */
        yystack.push (0, null, yylloc);
        yystack.push (0, null, yyerrloc);
@@ -711,13 +826,91 @@ b4_dollar_popdef])[]dnl

        /* Accept.  */
      case YYACCEPT:
-        return true;
+        ]b4_push_if([this.push_parse_initialized = false; return YYACCEPT;],
+                    [return true;])[

        /* Abort.  */
      case YYABORT:
-        return false;
+        ]b4_push_if([this.push_parse_initialized = false; return YYABORT;],
+                    [return false;])[
      }
+}
+]b4_push_if([[
+  boolean push_parse_initialized = false;
+
+    /**
+     * (Re-)Initialize the state of the push parser.
+     */
+  public void push_parse_initialize()
+  {
+    /* Lookahead and lookahead in internal form.  */
+    this.yychar = yyempty_;
+    this.yytoken = 0;
+
+    /* State.  */
+    this.yyn = 0;
+    this.yylen = 0;
+    this.yystate = 0;
+    this.yystack = new YYStack ();
+    this.label = YYNEWSTATE;
+
+    /* Error handling.  */
+    this.yynerrs_ = 0;
+    ]b4_locations_if([/* The location where the error started.  */
+    this.yyerrloc = null;
+    this.yylloc = new b4_location_type (null, null);])[
+
+    /* Semantic value of the lookahead.  */
+    this.yylval = null;
+
+    yystack.push (this.yystate, this.yylval]b4_locations_if([, this.yylloc])[);
+
+    this.push_parse_initialized = true;
+
  }
+]b4_locations_if([
+  /**
+   * Push parse given input from an external lexer.
+   *
+   * @@param yylextoken current token
+   * @@param yylexval current lval
+   * @@param yyylexpos current position
+   *
+   * @@return <tt>YYACCEPT, YYABORT, YYPUSH_MORE</tt>
+   */
+  public int push_parse (int yylextoken, b4_yystype yylexval, b4_position_type yylexpos)
+      b4_maybe_throws([b4_list2([b4_lex_throws], [b4_throws])])
+  {
+    return push_parse (yylextoken, yylexval, new b4_location_type (yylexpos));
+  }
+])[]])
+
+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.
+   * This version of parse () is defined only when api.push-push=both.
+   *
+   * @@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();
+]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);
+  }
+]])[

  // Generate an error message.
  private String yysyntax_error (int yystate, int tok)
@@ -752,8 +945,8 @@ b4_dollar_popdef])[]dnl
        */
        if (tok != yyempty_)
          {
-            // FIXME: This method of building the message is not compatible
-            // with internationalization.
+            /* FIXME: This method of building the message is not compatible
+               with internationalization.  */
            StringBuffer res =
              new StringBuffer ("syntax error, unexpected ");
            res.append (yytnamerr_ (yytname_[tok]));
@@ -802,8 +995,9 @@ b4_dollar_popdef])[]dnl
  }

  /**
-   * Whether the given <code>yytable_</code> value indicates a syntax error.
-   * @@param yyvalue   the value to check
+   * Whether the given <code>yytable_</code>
+   * value indicates a syntax error.
+   * @@param yyvalue the value to check
   */
  private static boolean yy_table_value_is_error_ (int yyvalue)
  {
@@ -825,6 +1019,7 @@ b4_dollar_popdef])[]dnl
  ]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)
  {
@@ -1,4 +1,4 @@
-## Copyright (C) 2002, 2005-2013 Free Software Foundation, Inc.
+## Copyright (C) 2002, 2005-2015 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
@@ -1,6 +1,6 @@
 # C++ skeleton for Bison

-# Copyright (C) 2002-2013 Free Software Foundation, Inc.
+# Copyright (C) 2002-2015 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],
-           [2002-2013])
+           [2002-2015])

 # b4_position_define
 # ------------------
@@ -25,10 +25,9 @@ m4_define([b4_position_define],
 [[  /// Abstract a position.
  class position
  {
-  public:
-]m4_ifdef([b4_location_constructors], [[
+  public:]m4_ifdef([b4_location_constructors], [[
    /// Construct a position.
-    explicit position (]b4_percent_define_get([[filename_type]])[* f = YY_NULL,
+    explicit position (]b4_percent_define_get([[filename_type]])[* f = YY_NULLPTR,
                       unsigned int l = ]b4_location_initial_line[u,
                       unsigned int c = ]b4_location_initial_column[u)
      : filename (f)
@@ -39,7 +38,7 @@ m4_define([b4_position_define],

 ]])[
    /// Initialization.
-    void initialize (]b4_percent_define_get([[filename_type]])[* fn = YY_NULL,
+    void initialize (]b4_percent_define_get([[filename_type]])[* fn = YY_NULLPTR,
                     unsigned int l = ]b4_location_initial_line[u,
                     unsigned int c = ]b4_location_initial_column[u)
    {
@@ -53,14 +52,17 @@ m4_define([b4_position_define],
    /// (line related) Advance to the COUNT next lines.
    void lines (int count = 1)
    {
-      column = ]b4_location_initial_column[u;
-      line += count;
+      if (count)
+        {
+          column = ]b4_location_initial_column[u;
+          line = add_ (line, count, ]b4_location_initial_line[);
+        }
    }

    /// (column related) Advance to the COUNT next columns.
    void columns (int count = 1)
    {
-      column = std::max (]b4_location_initial_column[u, column + count);
+      column = add_ (column, count, ]b4_location_initial_column[);
    }
    /** \} */

@@ -70,36 +72,44 @@ m4_define([b4_position_define],
    unsigned int line;
    /// Current column number.
    unsigned int column;
+
+  private:
+    /// Compute max(min, lhs+rhs) (provided min <= lhs).
+    static unsigned int add_ (unsigned int lhs, int rhs, unsigned int min)
+    {
+      return (0 < rhs || -static_cast<unsigned int>(rhs) < lhs
+              ? rhs + lhs
+              : min);
+    }
  };

-  /// Add and assign a position.
+  /// Add \a width columns, in place.
  inline position&
-  operator+= (position& res, const int width)
+  operator+= (position& res, int width)
  {
    res.columns (width);
    return res;
  }

-  /// Add two position objects.
-  inline const position
-  operator+ (const position& begin, const int width)
+  /// Add \a width columns.
+  inline position
+  operator+ (position res, int width)
  {
-    position res = begin;
    return res += width;
  }

-  /// Add and assign a position.
+  /// Subtract \a width columns, in place.
  inline position&
-  operator-= (position& res, const int width)
+  operator-= (position& res, int width)
  {
    return res += -width;
  }

-  /// Add two position objects.
-  inline const position
-  operator- (const position& begin, const int width)
+  /// Subtract \a width columns.
+  inline position
+  operator- (position res, int width)
  {
-    return begin + -width;
+    return res -= width;
  }
 ]b4_percent_define_flag_if([[define_location_comparison]], [[
  /// Compare two position objects.
@@ -168,7 +178,7 @@ m4_define([b4_location_define],

 ])[
    /// Initialization.
-    void initialize (]b4_percent_define_get([[filename_type]])[* f = YY_NULL,
+    void initialize (]b4_percent_define_get([[filename_type]])[* f = YY_NULLPTR,
                     unsigned int l = ]b4_location_initial_line[u,
                     unsigned int c = ]b4_location_initial_column[u)
    {
@@ -186,13 +196,13 @@ m4_define([b4_location_define],
    }

    /// Extend the current location to the COUNT next columns.
-    void columns (unsigned int count = 1)
+    void columns (int count = 1)
    {
      end += count;
    }

    /// Extend the current location to the COUNT next lines.
-    void lines (unsigned int count = 1)
+    void lines (int count = 1)
    {
      end.lines (count);
    }
@@ -206,27 +216,42 @@ m4_define([b4_location_define],
    position end;
  };

-  /// Join two location objects to create a location.
-  inline const location operator+ (const location& begin, const location& end)
+  /// Join two locations, in place.
+  inline location& operator+= (location& res, const location& end)
  {
-    location res = begin;
    res.end = end.end;
    return res;
  }

-  /// Add two location objects.
-  inline const location operator+ (const location& begin, unsigned int width)
+  /// Join two locations.
+  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)
  {
-    location res = begin;
    res.columns (width);
    return res;
  }

-  /// Add and assign a location.
-  inline location& operator+= (location& res, unsigned int width)
+  /// Add \a width columns to the end position.
+  inline location operator+ (location res, int width)
  {
-    res.columns (width);
-    return res;
+    return res += width;
+  }
+
+  /// Subtract \a width columns to the end position, in place.
+  inline location& operator-= (location& res, int width)
+  {
+    return res += -width;
+  }
+
+  /// Subtract \a width columns to the end position.
+  inline location operator- (location res, int width)
+  {
+    return res -= width;
  }
 ]b4_percent_define_flag_if([[define_location_comparison]], [[
  /// Compare two location objects.
@@ -254,8 +279,7 @@ m4_define([b4_location_define],
  operator<< (std::basic_ostream<YYChar>& ostr, const location& loc)
  {
    unsigned int end_col = 0 < loc.end.column ? loc.end.column - 1 : 0;
-    ostr << loc.begin// << "(" << loc.end << ") "
-;
+    ostr << loc.begin;
    if (loc.end.filename
        && (!loc.begin.filename
            || *loc.begin.filename != *loc.end.filename))
@@ -1,6 +1,6 @@
 # C++ skeleton for Bison

-# Copyright (C) 2002-2013 Free Software Foundation, Inc.
+# Copyright (C) 2002-2015 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],
-           [2002-2013])
+           [2002-2015])

 # b4_stack_define
 # ---------------
@@ -32,12 +32,12 @@ m4_define([b4_stack_define],
    stack ()
      : seq_ ()
    {
+      seq_.reserve (200);
    }

    stack (unsigned int n)
      : seq_ (n)
-    {
-    }
+    {}

    inline
    T&
@@ -72,6 +72,12 @@ m4_define([b4_stack_define],
        seq_.pop_back ();
    }

+    void
+    clear ()
+    {
+      seq_.clear ();
+    }
+
    inline
    typename S::size_type
    size () const
@@ -94,6 +100,8 @@ m4_define([b4_stack_define],
    }

  private:
+    stack (const stack&);
+    stack& operator= (const stack&);
    /// The wrapped container.
    S seq_;
  };
@@ -106,8 +114,7 @@ m4_define([b4_stack_define],
    slice (const S& stack, unsigned int range)
      : stack_ (stack)
      , range_ (range)
-    {
-    }
+    {}

    inline
    const T&
@@ -1,6 +1,6 @@
 # C++ skeleton for Bison

-# Copyright (C) 2002-2013 Free Software Foundation, Inc.
+# Copyright (C) 2002-2015 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
@@ -26,7 +26,7 @@
 # YYTYPE.
 m4_define([b4_symbol_variant],
 [m4_pushdef([b4_dollar_dollar],
-            [$2.$3< $][3 >(m4_shift3($@))])dnl
+            [$2.$3< $][3 > (m4_shift3($@))])dnl
  switch ($1)
    {
 b4_type_foreach([b4_type_action_])[]dnl
@@ -63,7 +63,7 @@ m4_define([b4_char_sizeof],
 [b4_symbol_if([$1], [has_type],
 [
 m4_map([      b4_symbol_tag_comment], [$@])dnl
-      char _b4_char_sizeof_dummy@{sizeof([b4_symbol([$1], [type])])@};
+      char _b4_char_sizeof_dummy@{sizeof(b4_symbol([$1], [type]))@};
 ])])


@@ -95,22 +95,22 @@ m4_define([b4_variant_define],

    /// Empty construction.
    variant ()]b4_parse_assert_if([
-      : tname (YY_NULL)])[
+      : yytypeid_ (YY_NULLPTR)])[
    {}

    /// Construct and fill.
    template <typename T>
    variant (const T& t)]b4_parse_assert_if([
-      : tname (typeid (T).name ())])[
+      : yytypeid_ (&typeid (T))])[
    {
      YYASSERT (sizeof (T) <= S);
-      new (buffer.raw) T (t);
+      new (yyas_<T> ()) T (t);
    }

    /// Destruction, allowed only if empty.
    ~variant ()
    {]b4_parse_assert_if([
-      YYASSERT (!tname);
+      YYASSERT (!yytypeid_);
    ])[}

    /// Instantiate an empty \a T in here.
@@ -118,10 +118,10 @@ m4_define([b4_variant_define],
    T&
    build ()
    {]b4_parse_assert_if([
-      YYASSERT (!tname);
+      YYASSERT (!yytypeid_);
      YYASSERT (sizeof (T) <= S);
-      tname = typeid (T).name ();])[
-      return *new (buffer.raw) T;
+      yytypeid_ = & typeid (T);])[
+      return *new (yyas_<T> ()) T;
    }

    /// Instantiate a \a T in here from \a t.
@@ -129,10 +129,10 @@ m4_define([b4_variant_define],
    T&
    build (const T& t)
    {]b4_parse_assert_if([
-      YYASSERT (!tname);
+      YYASSERT (!yytypeid_);
      YYASSERT (sizeof (T) <= S);
-      tname = typeid (T).name ();])[
-      return *new (buffer.raw) T (t);
+      yytypeid_ = & typeid (T);])[
+      return *new (yyas_<T> ()) T (t);
    }

    /// Accessor to a built \a T.
@@ -140,9 +140,9 @@ m4_define([b4_variant_define],
    T&
    as ()
    {]b4_parse_assert_if([
-      YYASSERT (tname == typeid (T).name ());
+      YYASSERT (*yytypeid_ == typeid (T));
      YYASSERT (sizeof (T) <= S);])[
-      return reinterpret_cast<T&> (buffer.raw);
+      return *yyas_<T> ();
    }

    /// Const accessor to a built \a T (for %printer).
@@ -150,9 +150,9 @@ m4_define([b4_variant_define],
    const T&
    as () const
    {]b4_parse_assert_if([
-      YYASSERT (tname == typeid (T).name ());
+      YYASSERT (*yytypeid_ == typeid (T));
      YYASSERT (sizeof (T) <= S);])[
-      return reinterpret_cast<const T&> (buffer.raw);
+      return *yyas_<T> ();
    }

    /// Swap the content with \a other, of same type.
@@ -167,9 +167,9 @@ m4_define([b4_variant_define],
    void
    swap (self_type& other)
    {]b4_parse_assert_if([
-      YYASSERT (tname);
-      YYASSERT (tname == other.tname);])[
-      std::swap (as<T>(), other.as<T>());
+      YYASSERT (yytypeid_);
+      YYASSERT (*yytypeid_ == *other.yytypeid_);])[
+      std::swap (as<T> (), other.as<T> ());
    }

    /// Move the content of \a other to this.
@@ -178,11 +178,10 @@ m4_define([b4_variant_define],
    template <typename T>
    void
    move (self_type& other)
-    {]b4_parse_assert_if([
-      YYASSERT (!tname);])[
-      build<T>();
-      swap<T>(other);
-      other.destroy<T>();
+    {
+      build<T> ();
+      swap<T> (other);
+      other.destroy<T> ();
    }

    /// Copy the content of \a other to this.
@@ -199,7 +198,7 @@ m4_define([b4_variant_define],
    destroy ()
    {
      as<T> ().~T ();]b4_parse_assert_if([
-      tname = YY_NULL;])[
+      yytypeid_ = YY_NULLPTR;])[
    }

  private:
@@ -207,17 +206,34 @@ m4_define([b4_variant_define],
    self_type& operator=(const self_type&);
    variant (const self_type&);

-    /// A buffer large enough to store any of the semantic values.
-    /// Long double is chosen as it has the strongest alignment
-    /// constraints.
+    /// Accessor to raw memory as \a T.
+    template <typename T>
+    T*
+    yyas_ ()
+    {
+      void *yyp = yybuffer_.yyraw;
+      return static_cast<T*> (yyp);
+     }
+
+    /// Const accessor to raw memory as \a T.
+    template <typename T>
+    const T*
+    yyas_ () const
+    {
+      const void *yyp = yybuffer_.yyraw;
+      return static_cast<const T*> (yyp);
+     }
+
    union
    {
-      long double align_me;
-      char raw[S];
-    } buffer;]b4_parse_assert_if([
+      /// Strongest alignment constraints.
+      long double yyalign_me;
+      /// A buffer large enough to store any of the semantic values.
+      char yyraw[S];
+    } yybuffer_;]b4_parse_assert_if([

    /// Whether the content is built: if defined, the name of the stored type.
-    const char* tname;])[
+    const std::type_info *yytypeid_;])[
  };
 ]])

@@ -227,16 +243,16 @@ m4_define([b4_variant_define],
 ## -------------------------- ##


-# b4_semantic_type_declare
-# ------------------------
+# b4_value_type_declare
+# ---------------------
 # Declare semantic_type.
-m4_define([b4_semantic_type_declare],
-[    /// An auxiliary type to compute the largest semantic type.
+m4_define([b4_value_type_declare],
+[[    /// An auxiliary type to compute the largest semantic type.
    union union_type
    {]b4_type_foreach([b4_char_sizeof])[};

    /// Symbol semantic values.
-    typedef variant<sizeof(union_type)> semantic_type;dnl
+    typedef variant<sizeof(union_type)> semantic_type;][]dnl
 ])


@@ -246,7 +262,7 @@ m4_define([b4_semantic_type_declare],
 # ----------------------------
 m4_define([b4_symbol_value],
 [m4_ifval([$2],
-          [$1.as< $2 >()],
+          [$1.as< $2 > ()],
          [$1])])

 # b4_symbol_value_template(VAL, [TYPE])
@@ -254,7 +270,7 @@ m4_define([b4_symbol_value],
 # Same as b4_symbol_value, but used in a template method.
 m4_define([b4_symbol_value_template],
 [m4_ifval([$2],
-          [$1.template as< $2 >()],
+          [$1.template as< $2 > ()],
          [$1])])


@@ -304,14 +320,13 @@ b4_join(b4_symbol_if([$1], [has_type],
    return symbol_type (b4_join([token::b4_symbol([$1], [id])],
                                b4_symbol_if([$1], [has_type], [v]),
                                b4_locations_if([l])));
-
  }

 ])])])


 # b4_basic_symbol_constructor_declare
-# ----------------------------------
+# -----------------------------------
 # Generate a constructor declaration for basic_symbol from given type.
 m4_define([b4_basic_symbol_constructor_declare],
 [[
@@ -3,7 +3,7 @@
 <!--
    bison.xsl - common templates for Bison XSLT.

-    Copyright (C) 2007-2013 Free Software Foundation, Inc.
+    Copyright (C) 2007-2015 Free Software Foundation, Inc.

    This file is part of Bison, the GNU Compiler Compiler.

@@ -3,7 +3,7 @@
 <!--
    xml2dot.xsl - transform Bison XML Report into DOT.

-    Copyright (C) 2007-2013 Free Software Foundation, Inc.
+    Copyright (C) 2007-2015 Free Software Foundation, Inc.

    This file is part of Bison, the GNU Compiler Compiler.

@@ -201,6 +201,8 @@
  <xsl:if test="$point = 0">
    <xsl:text> .</xsl:text>
  </xsl:if>
+
+  <!-- RHS -->
  <xsl:for-each select="rhs/symbol|rhs/empty">
    <xsl:apply-templates select="."/>
    <xsl:if test="$point = position()">
@@ -214,7 +216,9 @@
  <xsl:value-of select="."/>
 </xsl:template>

-<xsl:template match="empty"/>
+<xsl:template match="empty">
+  <xsl:text> %empty</xsl:text>
+</xsl:template>

 <xsl:template match="lookaheads">
  <xsl:text>  [</xsl:text>
@@ -3,7 +3,7 @@
 <!--
    xml2text.xsl - transform Bison XML Report into plain text.

-    Copyright (C) 2007-2013 Free Software Foundation, Inc.
+    Copyright (C) 2007-2015 Free Software Foundation, Inc.

    This file is part of Bison, the GNU Compiler Compiler.

@@ -350,12 +350,7 @@
    <xsl:if test="position() = $point + 1">
      <xsl:text> .</xsl:text>
    </xsl:if>
-    <xsl:if test="$itemset = 'true' and name(.) != 'empty'">
-      <xsl:apply-templates select="."/>
-    </xsl:if>
-    <xsl:if test="$itemset != 'true'">
-      <xsl:apply-templates select="."/>
-    </xsl:if>
+    <xsl:apply-templates select="."/>
    <xsl:if test="position() = last() and position() = $point">
      <xsl:text> .</xsl:text>
    </xsl:if>
@@ -373,7 +368,7 @@
 </xsl:template>

 <xsl:template match="empty">
-  <xsl:text> /* empty */</xsl:text>
+  <xsl:text> %empty</xsl:text>
 </xsl:template>

 <xsl:template match="lookaheads">
@@ -3,7 +3,7 @@
 <!--
    xml2html.xsl - transform Bison XML Report into XHTML.

-    Copyright (C) 2007-2013 Free Software Foundation, Inc.
+    Copyright (C) 2007-2015 Free Software Foundation, Inc.

    This file is part of Bison, the GNU Compiler Compiler.

@@ -532,12 +532,7 @@
      <xsl:text> </xsl:text>
      <span class="point">.</span>
    </xsl:if>
-    <xsl:if test="$itemset = 'true' and name(.) != 'empty'">
-      <xsl:apply-templates select="."/>
-    </xsl:if>
-    <xsl:if test="$itemset != 'true'">
-      <xsl:apply-templates select="."/>
-    </xsl:if>
+    <xsl:apply-templates select="."/>
    <xsl:if test="position() = last() and position() = $point">
      <xsl:text> </xsl:text>
      <span class="point">.</span>
@@ -563,7 +558,7 @@
 </xsl:template>

 <xsl:template match="empty">
-  <xsl:text> &#949;</xsl:text>
+  <xsl:text> %empty</xsl:text>
 </xsl:template>

 <xsl:template match="lookaheads">
@@ -1,11 +1,11 @@
                                                             -*- C -*-
 # Yacc compatible skeleton for Bison

-# Copyright (C) 1984, 1989-1990, 2000-2013 Free Software Foundation,
+# Copyright (C) 1984, 1989-1990, 2000-2015 Free Software Foundation,
 # Inc.

 m4_pushdef([b4_copyright_years],
-           [1984, 1989-1990, 2000-2013])
+           [1984, 1989-1990, 2000-2015])

 # 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
@@ -52,6 +52,8 @@ m4_define([b4_lac_flag],
                 [none], [[0]], [[1]])])

 m4_include(b4_pkgdatadir/[c.m4])
+m4_define([b4_yaxx],[$1])
+m4_define([b4_not_yaxx],[])

 ## ---------------- ##
 ## Default values.  ##
@@ -143,7 +145,6 @@ m4_define([b4_rhs_value],
          [b4_symbol_value([yyvsp@{b4_subtract([$2], [$1])@}], [$3])])


-
 ## ----------- ##
 ## Locations.  ##
 ## ----------- ##
@@ -176,36 +177,19 @@ m4_define([b4_declare_scanner_communication_variables], [[
 int yychar;

 ]b4_pure_if([[
-#if defined __GNUC__ && 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\"")\
-    _Pragma ("GCC diagnostic ignored \"-Wmaybe-uninitialized\"")
-# define YY_IGNORE_MAYBE_UNINITIALIZED_END \
-    _Pragma ("GCC diagnostic pop")
-#else
+/* The semantic value of the lookahead symbol.  */
 /* Default value used for initialization, for pacifying older GCCs
   or non-GCC compilers.  */
-static YYSTYPE yyval_default;
-# define YY_INITIAL_VALUE(Value) = Value
-#endif]b4_locations_if([[
-static YYLTYPE yyloc_default][]b4_yyloc_default[;]])])[
-#ifndef YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
-# define YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
-# define YY_IGNORE_MAYBE_UNINITIALIZED_END
-#endif
-#ifndef YY_INITIAL_VALUE
-# define YY_INITIAL_VALUE(Value) /* Nothing. */
-#endif
-
-/* The semantic value of the lookahead symbol.  */
-YYSTYPE yylval YY_INITIAL_VALUE(yyval_default);]b4_locations_if([[
+YY_INITIAL_VALUE (static YYSTYPE yyval_default;)
+YYSTYPE yylval YY_INITIAL_VALUE (= yyval_default);]b4_locations_if([[

 /* Location data for the lookahead symbol.  */
-YYLTYPE yylloc]b4_pure_if([ = yyloc_default], [b4_yyloc_default])[;
-]])b4_pure_if([], [[
-
+static YYLTYPE yyloc_default]b4_yyloc_default[;
+YYLTYPE yylloc = yyloc_default;]])],
+[[/* The semantic value of the lookahead symbol.  */
+YYSTYPE yylval;]b4_locations_if([[
+/* Location data for the lookahead symbol.  */
+YYLTYPE yylloc]b4_yyloc_default[;]])[
 /* Number of syntax errors so far.  */
 int yynerrs;]])])

@@ -223,9 +207,9 @@ m4_define([b4_declare_parser_state_variables], [b4_pure_if([[
    int yyerrstatus;

    /* The stacks and their tools:
-       `yyss': related to states.
-       `yyvs': related to semantic values.]b4_locations_if([[
-       `yyls': related to locations.]])[
+       'yyss': related to states.
+       'yyvs': related to semantic values.]b4_locations_if([[
+       'yyls': related to locations.]])[

       Refer to the stacks through separate pointers, to allow yyoverflow
       to reallocate them elsewhere.  */
@@ -349,7 +333,11 @@ m4_if(b4_api_prefix, [yy], [],
 #define yydebug         ]b4_prefix[debug
 #define yynerrs         ]b4_prefix[nerrs
 ]]b4_pure_if([], [[
-#define yylval          ]b4_prefix[lval
+#define yylval          ]b4_prefix[lval]b4_yaxx([
+#define yytext  	]b4_prefix[text
+#define YYYAXX_XML  "b4_prefix[]yaxx.xml"
+#define YYYAXX_DTD  "b4_prefix[]yaxx.dtd"
+])[
 #define yychar          ]b4_prefix[char]b4_locations_if([[
 #define yylloc          ]b4_prefix[lloc]])]))[

@@ -431,18 +419,17 @@ typedef short int yytype_int16;
 # endif
 #endif

-/* Suppress unused-variable warnings by "using" E.  */
-#ifdef __GNUC__
-# define YYUSE(E) ((void) (E))
-#else
-# define YYUSE(E) /* empty */
-#endif
+]b4_attribute_define[

 #if ]b4_lac_if([[1]], [[! defined yyoverflow || YYERROR_VERBOSE]])[

 /* The parser invokes alloca or malloc; define the necessary symbols.  */]dnl
 b4_push_if([], [b4_lac_if([], [[

+]b4_yaxx([
+#define XML_ALLOC(X) malloc(X)
+#define XML_FREE(X) free(X)
+])[
 # ifdef YYSTACK_USE_ALLOCA
 #  if YYSTACK_USE_ALLOCA
 #   ifdef __GNUC__
@@ -468,7 +455,7 @@ b4_push_if([], [b4_lac_if([], [[
 # endif]])])[

 # ifdef YYSTACK_ALLOC
-   /* Pacify GCC's `empty if-body' warning.  */
+   /* Pacify GCC's 'empty if-body' warning.  */
 #  define YYSTACK_FREE(Ptr) do { /* empty */; } while (0)
 #  ifndef YYSTACK_ALLOC_MAXIMUM
    /* The OS might guarantee only one guard page at the bottom of the stack,
@@ -517,7 +504,7 @@ void free (void *); /* INFRINGES ON USER NAME SPACE */
 union yyalloc
 {
  yytype_int16 yyss_alloc;
-  YYSTYPE yyvs_alloc;]b4_locations_if([
+  YYSTYPE yyvs_alloc;]b4_yaxx([char *yyxs_alloc;])[]b4_locations_if([
  YYLTYPE yyls_alloc;])[
 };

@@ -528,10 +515,10 @@ union yyalloc
   N elements.  */
 ]b4_locations_if(
 [# define YYSTACK_BYTES(N) \
-     ((N) * (sizeof (yytype_int16) + sizeof (YYSTYPE) + sizeof (YYLTYPE)) \
+     ((N) * (sizeof (yytype_int16) + sizeof (YYSTYPE) + sizeof (YYLTYPE) ]b4_yaxx([+ sizeof(char*) ])[) \
      + 2 * YYSTACK_GAP_MAXIMUM)],
 [# define YYSTACK_BYTES(N) \
-     ((N) * (sizeof (yytype_int16) + sizeof (YYSTYPE)) \
+     ((N) * (sizeof (yytype_int16) + sizeof (YYSTYPE) ]b4_yaxx([+ sizeof(char*) ])[) \
      + YYSTACK_GAP_MAXIMUM)])[

 # define YYCOPY_NEEDED 1
@@ -603,19 +590,27 @@ static const ]b4_int_type_for([b4_translate])[ yytranslate[] =
  ]b4_translate[
 };

+]b4_not_yaxx([
 #if ]b4_api_PREFIX[DEBUG
+])[
 ]b4_integral_parser_table_define([rline], [b4_rline],
     [[YYRLINE[YYN] -- Source line where rule number YYN was defined.]])[
+]b4_not_yaxx([
 #endif
+])[

+]b4_not_yaxx([
 #if ]b4_api_PREFIX[DEBUG || YYERROR_VERBOSE || ]b4_token_table_flag[
+])[
 /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
   First, the terminals, then, starting at YYNTOKENS, nonterminals.  */
 static const char *const yytname[] =
 {
  ]b4_tname[
 };
+]b4_not_yaxx([
 #endif
+])

 # ifdef YYPRINT
 /* YYTOKNUM[NUM] -- (External) token number corresponding to the
@@ -1131,11 +1126,11 @@ 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)
 {
-  YYSIZE_T yysize0 = yytnamerr (YY_NULL, yytname[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_NULL;
+  const char *yyformat = YY_NULLPTR;
  /* Arguments of yyformat. */
  char const *yyarg[YYERROR_VERBOSE_ARGS_MAXIMUM];
  /* Number of reported tokens (one for the "unexpected", one per
@@ -1210,7 +1205,7 @@ yysyntax_error (YYSIZE_T *yymsg_alloc, char **yymsg,
                  }
                yyarg[yycount++] = yytname[yyx];
                {
-                  YYSIZE_T yysize1 = yysize + yytnamerr (YY_NULL, yytname[yyx]);
+                  YYSIZE_T yysize1 = yysize + yytnamerr (YY_NULLPTR, yytname[yyx]);
                  if (! (yysize <= yysize1
                         && yysize1 <= YYSTACK_ALLOC_MAXIMUM))
                    return 2;
@@ -1294,7 +1289,7 @@ static char yypstate_allocated = 0;]])b4_pull_if([

 b4_function_define([[yyparse]], [[int]], b4_parse_param)[
 {
-  return yypull_parse (YY_NULL]m4_ifset([b4_parse_param],
+  return yypull_parse (YY_NULLPTR]m4_ifset([b4_parse_param],
                                  [[, ]b4_args(b4_parse_param)])[);
 }

@@ -1336,10 +1331,10 @@ b4_function_define([[yyparse]], [[int]], b4_parse_param)[
 {
  yypstate *yyps;]b4_pure_if([], [[
  if (yypstate_allocated)
-    return YY_NULL;]])[
+    return YY_NULLPTR;]])[
  yyps = (yypstate *) malloc (sizeof *yyps);
  if (!yyps)
-    return YY_NULL;
+    return YY_NULLPTR;
  yyps->yynew = 1;]b4_pure_if([], [[
  yypstate_allocated = 1;]])[
  return yyps;
@@ -1389,7 +1384,194 @@ b4_function_define([[yyparse]], [[int]], b4_parse_param)[
  [[[YYSTYPE const *yypushed_val]], [[yypushed_val]]]b4_locations_if([,
  [[[YYLTYPE *yypushed_loc]], [[yypushed_loc]]]])])m4_ifset([b4_parse_param], [,
  b4_parse_param]))], [[
+]b4_yaxx([
+extern char *b4_prefix[]text;
+// Yijun Yu: utility functions -----------------------------------------------
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stddef.h>
+/// replace character terminals into symbolic terminals
+static char *YYTNAME(int r)
+{
+  static char yytname_buf[[8]];
+  if (strlen(yytname[[r]])==3 && yytname[[r]][[0]] == '\'' && yytname[[r]][[2]] == '\'') 
+  { 
+        sprintf(yytname_buf, "CHAR%d", (int)yytname[[r]][[1]]);
+        return yytname_buf;
+  } 
+  else if (strlen(yytname[[r]])>=2 && yytname[[r]][[0]] == 64 )
+  {
+    strcpy(yytname_buf,"ACTION");
+    strcat(yytname_buf,&(yytname[[r]][[1]]));
+    return yytname_buf;
+  }

+  return (char *)yytname[[r]];
+}
+#include <stdio.h>
+#include <stddef.h>
+static char *yytext_buf = NULL;
+
+/// replace a special character in the text into an entity
+static
+void replace_entity(char c, char *s)
+{
+    char *buf;
+    char *i;
+    int len, l;
+    i = yytext_buf;
+    do {
+        i =  (char *)index(i, c);
+        if (i) {
+            l = i - yytext_buf;
+            len = strlen(yytext_buf) + strlen(s) - 1;
+            //buf = (char*)YYSTACK_ALLOC(1000000);
+            buf = (char*)YYSTACK_ALLOC(len + 1); // Myo M Thein
+            if (l>0) {
+#if 1 // Myo M Thein
+		strncpy(buf, yytext_buf, l);
+#else
+		int t = 0;
+		while (t < l) {
+			buf[t] = yytext_buf[t]; 
+			t++;
+		}
+                buf[t] = 0;
+#endif
+            } else {
+                buf[[0]] = 0;
+            }
+            strcat(buf, s); 
+            strncat(buf, yytext_buf + l + 1, strlen(yytext_buf) - l); 
+            buf[[len]] = 0;
+            YYSTACK_FREE(yytext_buf); 
+            //yytext_buf = buf;
+	    memcpy(yytext_buf,buf,len+1);
+        i++;
+        if (*i=='\0')
+            i=NULL;
+        }
+    } while (i);
+}
+
+/// replace the special characters in the text into entities 
+static
+char* xml_encode( char ch)
+{
+  static char text[[2]];
+    switch(ch)
+    {
+    case '&':
+        return ( "&amp;");
+        break;
+    case '>':
+        return ( "&gt;");
+        break;
+    case '<' :
+        return ( "&lt;" );
+        break;
+    case  '\"':
+        return ( "&quot;");
+        break;
+    case '\'':
+        return ( "&apos;");
+        break;
+    default:
+        text[[0]]=ch;
+        text[[1]]=0;
+        return text;
+        break;
+    }
+}
+
+static
+void replace_special_entities(char *text,char *text_out)
+{
+  int i,lg;
+    if (!text) { strcpy(text_out,"??");return ; }
+    lg = strlen(text);
+    strcpy(text_out,"");
+    for (i=0;i<lg;i++)
+    {
+       strcat(text_out,xml_encode(text[[i]]));
+    }
+}
+static
+void generate_xml_output(char **yyxsp,char **yyxs)
+{
+#ifndef YYYAXX_XML 
+#define YYYAXX_XML  "yaxx.xml"
+#endif
+#ifndef YYYAXX_DTD
+#define YYYAXX_DTD "yaxx.dtd"
+#endif
+       int r, i, j;
+       char buf[[2000]];
+       int old_rule = 0;
+       FILE *stdout = fopen(YYYAXX_XML, "w");
+       char *p = *yyxsp + 6;
+#if 0
+       char *v = strsep(&p, ">");
+       strcpy(buf, v);
+#else
+	   i = 0;
+	   while (p[[i]]!='>') {
+		buf[[i]] = p[[i]];
+		i++;
+	   }
+	   buf[[i]]  = 0;
+#endif
+       /// Generating the XML document 
+       /// version 
+       fprintf(stdout,"<?xml version=\"1.0\"?>\n");
+       /// DTD reference
+       fprintf(stdout,"<?xml-stylesheet type=\"text/xsl\" href=\"yaxx.xsl\"?>");
+       fprintf(stdout,"<!DOCTYPE %s SYSTEM \"" YYYAXX_DTD "\">\n", buf);
+       /// inserting name space before the XML data
+       fprintf(stdout,"<yaxx:%s xmlns:yaxx=\"urn:YAcc-Xml-eXtension\"%s\n", buf,
+            yyxs[[1]]+i+6); //ffprintf(stdout,f, "%s\n", yyxs[[1]]);
+       /// Generating the document type definition (DTD) 
+       stdout = fopen(YYYAXX_DTD , "w");
+       /// DTD for non-terminals
+       for (r = 2; r < sizeof(yyr1)/sizeof(unsigned short); r++) 
+       {
+        j = yyr1[[r]];
+        if (j != old_rule) {
+        	if (old_rule!=0)
+        		fprintf(stdout,")>\n");
+	        fprintf(stdout,"<!ELEMENT %s (", YYTNAME(yyr1[[r]]));
+        } else
+	    	fprintf(stdout," | ");
+        if (yyr2[[r]]==0) 
+           fprintf(stdout,"EMPTY");
+        else {
+		/*
+        	int multiple = 0;
+            for (i = yyprhs[[r]]; yyrhs[[i]] > 0 ; i++)
+               if (i!=yyprhs[[r]]) {
+               	multiple = 1; break;
+               }
+       		if (multiple) fprintf(stdout,"(");
+            for (i = yyprhs[[r]]; yyrhs[[i]] > 0 ; i++) {
+               if (i!=yyprhs[[r]])
+                   fprintf(stdout,",");
+               fprintf(stdout,"%s", YYTNAME(yyrhs[[i]]));
+            }
+       		if (multiple) fprintf(stdout,")");
+		 */
+         }
+         old_rule = j;
+       }
+       fprintf(stdout,")>\n");
+       /// DTD for terminals
+       for (r = 3; r < YYNTOKENS; r++) 
+       {
+            fprintf(stdout,"<!ELEMENT %s (#PCDATA)>\n", YYTNAME(r));
+       }
+    
+}
+])[

 /*----------.
 | yyparse.  |
@@ -1421,7 +1603,26 @@ b4_function_define([[yyparse]], [[int]], b4_parse_param)[
  YYSIZE_T yymsg_alloc = sizeof yymsgbuf;
 #endif

+]b4_yaxx([
+
+  /* The tags stack. */
+  char *yyxsa[[YYINITDEPTH]];
+  char **yyxs = yyxsa;
+  char **yyxsp;
+])[
 #define YYPOPSTACK(N)   (yyvsp -= (N), yyssp -= (N)]b4_locations_if([, yylsp -= (N)])[)
+]b4_yaxx([
+#include <stdio.h>
+#include <string.h>
+#undef __GNUC_PREREQ
+#define __GNUC_PREREQ(maj, min) (maj < 4)
+#include <stdlib.h>
+#include <stddef.h>
+static char * yyxml_str=NULL; // for XML
+// for id attribute generation (by William Candillon)
+int _id = 0; 
+char str[[256]];
+])[

  /* The number of symbols on the RHS of the reduced rule.
     Keep to zero when no symbol should be popped.  */
@@ -1433,7 +1634,9 @@ b4_function_define([[yyparse]], [[int]], b4_parse_param)[
      goto yyread_pushed_token;
    }]])[

-  yyssp = yyss = yyssa;
+  yyssp = yyss = yyssa;]b4_yaxx([
+  yyxsp = yyxs = yyxsa;
+])[
  yyvsp = yyvs = yyvsa;]b4_locations_if([[
  yylsp = yyls = yylsa;]])[
  yystacksize = YYINITDEPTH;]b4_lac_if([[
@@ -1483,7 +1686,7 @@ b4_locations_if([[  yylsp[0] = ]b4_push_if([b4_pure_if([*])yypushed_loc], [yyllo
           these so that the &'s don't force the real ones into
           memory.  */
        YYSTYPE *yyvs1 = yyvs;
-        yytype_int16 *yyss1 = yyss;]b4_locations_if([
+        yytype_int16 *yyss1 = yyss;]b4_yaxx([ char **yyxs1 = yyxs;])[]b4_locations_if([
        YYLTYPE *yyls1 = yyls;])[

        /* Each stack pointer address is followed by the size of the
@@ -1492,9 +1695,9 @@ b4_locations_if([[  yylsp[0] = ]b4_push_if([b4_pure_if([*])yypushed_loc], [yyllo
           be undefined if yyoverflow is a macro.  */
        yyoverflow (YY_("memory exhausted"),
                    &yyss1, yysize * sizeof (*yyssp),
-                    &yyvs1, yysize * sizeof (*yyvsp),]b4_locations_if([
+                    &yyvs1, yysize * sizeof (*yyvsp),]b4_yaxx([&yyxs1, yysize * sizeof (*yyxsp),])[]b4_locations_if([
                    &yyls1, yysize * sizeof (*yylsp),])[
-                    &yystacksize);
+                    &yystacksize);]b4_yaxx([yyxs = yyxs1;])[
 ]b4_locations_if([
        yyls = yyls1;])[
        yyss = yyss1;
@@ -1518,7 +1721,7 @@ b4_locations_if([[  yylsp[0] = ]b4_push_if([b4_pure_if([*])yypushed_loc], [yyllo
        if (! yyptr)
          goto yyexhaustedlab;
        YYSTACK_RELOCATE (yyss_alloc, yyss);
-        YYSTACK_RELOCATE (yyvs_alloc, yyvs);]b4_locations_if([
+        YYSTACK_RELOCATE (yyvs_alloc, yyvs);]b4_yaxx([YYSTACK_RELOCATE (yyxs_alloc, yyxs);])[]b4_locations_if([
        YYSTACK_RELOCATE (yyls_alloc, yyls);])[
 #  undef YYSTACK_RELOCATE
        if (yyss1 != yyssa)
@@ -1528,7 +1731,7 @@ b4_locations_if([[  yylsp[0] = ]b4_push_if([b4_pure_if([*])yypushed_loc], [yyllo
 #endif /* no yyoverflow */

      yyssp = yyss + yysize - 1;
-      yyvsp = yyvs + yysize - 1;]b4_locations_if([
+      yyvsp = yyvs + yysize - 1;]b4_yaxx([yyxsp = yyxs + yysize - 1;])[]b4_locations_if([
      yylsp = yyls + yysize - 1;])[

      YYDPRINTF ((stderr, "Stack size increased to %lu\n",
@@ -1593,7 +1796,33 @@ yyread_pushed_token:]])[
    }
  else
    {
-      yytoken = YYTRANSLATE (yychar);
+      yytoken = YYTRANSLATE (yychar);]b4_yaxx([
+{ // Yijun Yu: process the terminal
+      yyxml_str = (char *) XML_ALLOC(200);
+      strcpy(yyxml_str, "<yaxx:");
+      strcat(yyxml_str, YYTNAME(yytoken));      
+#if 1 //William Candillon
+      strcat(yyxml_str, " id=\"");
+      sprintf(str, "%x", _id);
+      strcat(yyxml_str, str);
+      strcat(yyxml_str, "\"");
+      _id++;
+#endif
+      strcat(yyxml_str, ">");
+      if (yytoken < YYNTOKENS) {
+	  if (yytext) {
+		  char *tmp;
+		  tmp=(char *)YYSTACK_ALLOC(6*strlen(yytext)+1); 
+		  replace_special_entities(yytext,tmp);
+		  strcat(yyxml_str, tmp);
+		  YYSTACK_FREE(tmp);
+	  }
+      }
+      strcat(yyxml_str, "</yaxx:");
+      strcat(yyxml_str, YYTNAME(yytoken));
+      strcat(yyxml_str, ">\n");
+    }
+])[
      YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc);
    }

@@ -1630,6 +1859,10 @@ yyread_pushed_token:]])[

  yystate = yyn;
  YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
+]b4_yaxx([
+  *++yyxsp = yyxml_str;
+  yyxml_str = 0;
+])[
  *++yyvsp = yylval;
  YY_IGNORE_MAYBE_UNINITIALIZED_END
 ]b4_locations_if([  *++yylsp = yylloc;])[
@@ -1654,7 +1887,7 @@ yyreduce:
  yylen = yyr2[yyn];

  /* If YYLEN is nonzero, implement the default value of the action:
-     `$$ = $1'.
+     '$$ = $1'.

     Otherwise, the following line sets YYVAL to garbage.
     This behavior is undocumented and Bison
@@ -1677,6 +1910,53 @@ yyreduce:
    if (yychar_backup != yychar)
      YY_LAC_DISCARD ("yychar change");
  }]], [[
+]b4_yaxx([
+  {
+      int len = 0;
+      int alloc_len=0;
+      int n = 0;
+      int yyi;
+      for (yyi = 0; yyi < yylen; yyi++)
+      {
+          int l;
+          char * yyxml_str = yyxsp[[yyi+1-yylen]];
+          if (yyxml_str==NULL) {
+            l = 0;
+          } else
+            l = strlen(yyxml_str);
+          len += l;
+	  n++;
+      }
+      alloc_len =len+100+2*strlen(YYTNAME(yyr1[[yyn]]));
+      yyxml_str = (char *) XML_ALLOC(alloc_len);
+      strcpy(yyxml_str, "<yaxx:");
+      strcat(yyxml_str, YYTNAME(yyr1[[yyn]]));
+#if 1 //William Candillon
+      strcat(yyxml_str, " id=\"");
+      sprintf(str, "%x", _id);
+      strcat(yyxml_str, str);
+      strcat(yyxml_str, "\"");
+      _id++;
+#endif
+      strcat(yyxml_str, ">\n");
+      for (yyi = 0; yyi < yylen; yyi++)
+      {
+          char * xml_str = yyxsp[[yyi+1-yylen]];
+          if (xml_str) {
+              strcat(yyxml_str, xml_str); 
+              XML_FREE(xml_str);
+              yyxsp[[yyi+1-yylen]] = NULL;
+          } else {
+            fprintf(stderr, "Warning! the %d-th argument is empty", yyi+1);
+          }
+      }
+      strcat(yyxml_str, "</yaxx:");
+      strcat(yyxml_str, YYTNAME(yyr1[[yyn]]));
+      strcat(yyxml_str, ">\n");
+      yyxsp -= n;
+      *++yyxsp = yyxml_str;
+      yyxml_str = NULL;
+    }])[
  switch (yyn)
    {
      ]b4_user_actions[
@@ -1702,7 +1982,7 @@ yyreduce:
  *++yyvsp = yyval;]b4_locations_if([
  *++yylsp = yyloc;])[

-  /* Now `shift' the result of the reduction.  Determine what state
+  /* Now 'shift' the result of the reduction.  Determine what state
     that goes to, based on the state we popped back to and the rule
     number reduced by.  */

@@ -1852,6 +2132,10 @@ yyerrlab1:
  YY_LAC_DISCARD ("error recovery");]])[

  YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
+]b4_yaxx([
+  *++yyxsp = yyxml_str;
+  yyxml_str = 0;
+])[
  *++yyvsp = yylval;
  YY_IGNORE_MAYBE_UNINITIALIZED_END
 ]b4_locations_if([[
@@ -1871,7 +2155,7 @@ yyerrlab1:
 /*-------------------------------------.
 | yyacceptlab -- YYACCEPT comes here.  |
 `-------------------------------------*/
-yyacceptlab:
+yyacceptlab:]b4_yaxx([generate_xml_output(--yyxsp,yyxs);])[
  yyresult = 0;
  goto yyreturn;

@@ -1,7 +1,7 @@
 # DJGPP Maintainer's Makefile                                    -*-Makefile-*-
 # Requires GNU sed

-## Copyright (C) 2005-2013 Free Software Foundation, Inc.
+## Copyright (C) 2005-2015 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
@@ -1,6 +1,6 @@
 This is a port of GNU Bison @VERSION@ to MSDOS/DJGPP.

-Copyright (C) 2005-2013 Free Software Foundation, Inc.
+Copyright (C) 2005-2015 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
@@ -4,7 +4,7 @@ Rem Configure Bison for DJGPP.
 Rem WARNING WARNING WARNING: This file needs to have DOS CRLF end-of-line
 Rem format, or else stock DOS/Windows shells will refuse to run it.

-Rem Copyright (C) 2005-2013 Free Software Foundation, Inc.
+Rem Copyright (C) 2005-2015 Free Software Foundation, Inc.

 Rem This program is free software: you can redistribute it and/or modify
 Rem it under the terms of the GNU General Public License as published by
@@ -2,7 +2,7 @@
 # Sed script for additional DJGPP specific editing
 # of the configure script generated by autoconf 2.62.

-# Copyright (C) 2005-2013 Free Software Foundation, Inc.
+# Copyright (C) 2005-2015 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
@@ -3,7 +3,7 @@
 # This is the config.site file for configuring GNU packages
 # which are to be built with DJGPP tools.

-# Copyright (C) 2005-2013 Free Software Foundation, Inc.
+# Copyright (C) 2005-2015 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
@@ -1,6 +1,6 @@
 # sed script for DJGPP specific editing of config.hin

-# Copyright (C) 2005-2013 Free Software Foundation, Inc.
+# Copyright (C) 2005-2015 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
@@ -7,7 +7,7 @@ Rem This batch file unpacks the Bison distribution while simultaneously
 Rem renaming some of the files whose names are invalid on DOS or conflict
 Rem with other file names after truncation to DOS 8+3 namespace.
 Rem
-Rem Copyright (C) 2005-2013 Free Software Foundation, Inc.
+Rem Copyright (C) 2005-2015 Free Software Foundation, Inc.
 Rem
 Rem This program is free software: you can redistribute it and/or modify
 Rem it under the terms of the GNU General Public License as published by
@@ -1,4 +1,4 @@
-## Copyright (C) 2008-2013 Free Software Foundation, Inc.
+## Copyright (C) 2008-2015 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
@@ -1,6 +1,6 @@
 /* Subprocesses with pipes.

-   Copyright (C) 2005-2013 Free Software Foundation, Inc.
+   Copyright (C) 2005-2015 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
@@ -1,6 +1,6 @@
 /* Subprocesses with pipes.

-   Copyright (C) 2005-2013 Free Software Foundation, Inc.
+   Copyright (C) 2005-2015 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
@@ -2,7 +2,7 @@
 # Sed script for additional DJGPP specific editing
 # of the testsuite script generated by autoconf 2.61.

-# Copyright (C) 2007-2013 Free Software Foundation, Inc.
+# Copyright (C) 2007-2015 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
@@ -27,3 +27,4 @@
 /stamp-vti
 /version.texi
 /yacc.1
+/gendocs_template_min
@@ -0,0 +1,2 @@
+This file is a stub, not used by the documentation.  If you feel like
+contributing ASCII art for example.gv, please step forward!
@@ -1,4 +1,4 @@
-## Copyright (C) 2001-2003, 2005-2013 Free Software Foundation, Inc.
+## Copyright (C) 2001-2003, 2005-2015 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
@@ -23,9 +23,10 @@ doc_bison_TEXINFOS =                            \
 # Cannot express dependencies directly on file names because of Automake.
 # Obfuscate with a variable.
 doc_bison = doc/bison
-$(doc_bison).dvi: $(FIGS_DOT:.dot=.eps)
-$(doc_bison).pdf: $(FIGS_DOT:.dot=.pdf)
-$(doc_bison).html: $(FIGS_DOT:.dot=.png)
+$(doc_bison).dvi: $(FIGS_GV:.gv=.eps)
+$(doc_bison).info: $(FIGS_GV:.gv=.txt)
+$(doc_bison).pdf: $(FIGS_GV:.gv=.pdf)
+$(doc_bison).html: $(FIGS_GV:.gv=.png)

 TEXI2DVI = texi2dvi --build-dir=doc/bison.t2d -I doc
 CLEANDIRS = doc/bison.t2d
@@ -37,7 +38,7 @@ MOSTLYCLEANFILES += $(top_srcdir)/doc/*.t
 CROSS_OPTIONS_PL = $(top_srcdir)/build-aux/cross-options.pl
 CROSS_OPTIONS_TEXI = $(top_srcdir)/doc/cross-options.texi
 $(CROSS_OPTIONS_TEXI): doc/bison.help $(CROSS_OPTIONS_PL)
-# Create $@~ which is the previous contents.  Don't use `mv' here so
+# Create $@~ which is the previous contents.  Don't use 'mv' here so
 # that even if we are interrupted, the file is still available for
 # diff in the next run.  Note that $@ might not exist yet.
 	$(AM_V_GEN){ test ! -f $@ || cat $@; } >$@~
@@ -84,11 +85,13 @@ doc/refcard.pdf: doc/refcard.tex
 # repeated builds of bison.help.

 EXTRA_DIST += $(top_srcdir)/doc/bison.help
+if ! CROSS_COMPILING
 MAINTAINERCLEANFILES += $(top_srcdir)/doc/bison.help
 $(top_srcdir)/doc/bison.help: src/bison$(EXEEXT)
 	$(AM_V_GEN)src/bison$(EXEEXT) --version >doc/bison.help.tmp
 	$(AM_V_at) src/bison$(EXEEXT) --help   >>doc/bison.help.tmp
 	$(AM_V_at)$(top_srcdir)/build-aux/move-if-change doc/bison.help.tmp $@
+endif ! CROSS_COMPILING


 ## ----------- ##
@@ -105,7 +108,11 @@ remove_time_stamp = \
  sed 's/^\(\.TH[^"]*"[^"]*"[^"]*\)"[^"]*"/\1/'

 # Depend on configure to get version number changes.
-$(top_srcdir)/doc/bison.1: doc/bison.help doc/bison.x $(top_srcdir)/configure
+if ! CROSS_COMPILING
+MAN_DEPS = doc/bison.help doc/bison.x $(top_srcdir)/configure
+endif
+
+$(top_srcdir)/doc/bison.1: $(MAN_DEPS)
 	$(AM_V_GEN)$(HELP2MAN)			\
 	    --include=$(top_srcdir)/doc/bison.x	\
 	    --output=$@.t src/bison$(EXEEXT)
@@ -117,32 +124,34 @@ $(top_srcdir)/doc/bison.1: doc/bison.help doc/bison.x $(top_srcdir)/configure
 	fi
 	$(AM_V_at)rm -f $@*.t

+if ENABLE_YACC
 nodist_man_MANS = doc/yacc.1
+endif

 ## ----------------------------- ##
 ## Graphviz examples generation. ##
 ## ----------------------------- ##

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

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

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

-.dot.png:
+.gv.png:
 	$(AM_V_GEN) $(MKDIR_P) `echo "./$@" | sed -e 's,/[^/]*$$,,'`
 	$(AM_V_at) $(DOT) -Gmargin=0 -Tpng $< >$@.tmp
 	$(AM_V_at) mv $@.tmp $@
@@ -19,7 +19,7 @@
 \def\finalout{\overfullrule=0pt}
 %\finalout

-% Copyright (c) 1998, 2001, 2009-2013 Free Software Foundation, Inc.
+% Copyright (c) 1998, 2001, 2009-2015 Free Software Foundation, Inc.
 %
 % This file is part of Bison.
 %
@@ -16,7 +16,7 @@ straightforward use of _build/src/bison would.)

 --

-Copyright (C) 2006, 2009-2013 Free Software Foundation, Inc.
+Copyright (C) 2006, 2009-2015 Free Software Foundation, Inc.

 This file is part of Bison, the GNU Compiler Compiler.

@@ -1,6 +1,6 @@
 #! /usr/bin/perl -w

-# Copyright (C) 2006, 2008-2013 Free Software Foundation, Inc.
+# Copyright (C) 2006, 2008-2015 Free Software Foundation, Inc.
 #
 # This file is part of Bison, the GNU Compiler Compiler.
 #
@@ -204,9 +204,9 @@ Format the list of directives for Bison for bench named C<$bench>.
 sub directives($@)
 {
  my ($bench, @directive) = @_;
-  my $res = "/* Directives for bench `$bench'. */\n";
+  my $res = "/* Directives for bench '$bench'. */\n";
  $res .= join ("\n", @directive) . "\n";
-  $res .= "/* End of directives for bench `$bench'. */\n";
+  $res .= "/* End of directives for bench '$bench'. */\n";
  return $res;
 }

@@ -1,4 +1,4 @@
-## Copyright (C) 2006, 2008-2013 Free Software Foundation, Inc.
+## Copyright (C) 2006, 2008-2015 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
@@ -1,6 +1,6 @@
 #! /bin/sh

-# Copyright (C) 2005-2013 Free Software Foundation, Inc.
+# Copyright (C) 2005-2015 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
@@ -1,4 +1,4 @@
-# Copyright (C) 2005-2006, 2008-2013 Free Software Foundation, Inc.
+# Copyright (C) 2005-2006, 2008-2015 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
@@ -19,7 +19,7 @@

 # Don't depend on $(BISON) otherwise we would rebuild these files
 # in srcdir, including during distcheck, which is forbidden.
-examples/calc++/calc++-parser.stamp: $(BISON_IN)
+%D%/calc++-parser.stamp: $(BISON_IN)
 SUFFIXES += .yy .stamp
 .yy.stamp:
 	$(AM_V_YACC)rm -f $@
@@ -27,14 +27,14 @@ SUFFIXES += .yy .stamp
 	$(AM_V_at)$(YACCCOMPILE) -o $*.cc $<
 	$(AM_V_at)mv -f $@.tmp $@

-$(calc_sources_generated): examples/calc++/calc++-parser.stamp
-	@test -f $@ || rm -f examples/calc++/calc++-parser.stamp
-	@test -f $@ || $(MAKE) $(AM_MAKEFLAGS) examples/calc++/calc++-parser.stamp
+$(calcxx_sources_generated): %D%/calc++-parser.stamp
+	@test -f $@ || rm -f %D%/calc++-parser.stamp
+	@test -f $@ || $(MAKE) $(AM_MAKEFLAGS) %D%/calc++-parser.stamp
 CLEANFILES +=                                   \
-  $(calc_sources_generated)                     \
-  examples/calc++/calc++-parser.output          \
-  examples/calc++/calc++-parser.stamp           \
-  examples/calc++/calc++-scanner.cc
+  $(calcxx_sources_generated)                   \
+  %D%/calc++-parser.output                      \
+  %D%/calc++-parser.stamp                       \
+  %D%/calc++-scanner.cc


 ## -------------------- ##
@@ -42,34 +42,43 @@ CLEANFILES +=                                   \
 ## -------------------- ##

 # Avoid using BUILT_SOURCES which is too global.
-$(examples_calc___calc___OBJECTS): $(calc_sources_generated)
+$(%C%_calc___OBJECTS): $(calcxx_sources_generated)

-calc_sources_extracted =			\
-  examples/calc++/calc++-driver.cc		\
-  examples/calc++/calc++-driver.hh		\
-  examples/calc++/calc++-scanner.ll		\
-  examples/calc++/calc++.cc
-calc_extracted =				\
-  $(calc_sources_extracted)			\
-  examples/calc++/calc++-parser.yy
-extracted += $(calc_extracted)
-calc_sources_generated =			\
-  examples/calc++/calc++-parser.cc		\
-  examples/calc++/calc++-parser.hh		\
-  examples/calc++/location.hh			\
-  examples/calc++/position.hh			\
-  examples/calc++/stack.hh
-calc_sources =					\
-  $(calc_sources_extracted)			\
-  $(calc_sources_generated)
+calcxx_sources_extracted =                      \
+  %D%/calc++-driver.cc                          \
+  %D%/calc++-driver.hh                          \
+  %D%/calc++-scanner.ll                         \
+  %D%/calc++.cc
+calcxx_extracted =                              \
+  $(calcxx_sources_extracted)                   \
+  %D%/calc++-parser.yy
+extracted += $(calcxx_extracted)
+calcxx_sources_generated =                      \
+  %D%/calc++-parser.cc                          \
+  %D%/calc++-parser.hh                          \
+  %D%/location.hh                               \
+  %D%/position.hh                               \
+  %D%/stack.hh
+calcxx_sources =                                \
+  $(calcxx_sources_extracted)                   \
+  $(calcxx_sources_generated)

-if BISON_CXX_WORKS
-check_PROGRAMS += examples/calc++/calc++
-nodist_examples_calc___calc___SOURCES =		\
-  $(calc_sources)
+if FLEX_CXX_WORKS
+check_PROGRAMS += %D%/calc++
+nodist_%C%_calc___SOURCES =                     \
+  $(calcxx_sources)

-examples_calc___calc___CPPFLAGS = -I$(top_builddir)/examples/calc++
-examples_calc___calc___CXXFLAGS =			\
-  $(AM_CXXFLAGS) $(WARN_NO_NULL_CONVERSION_CXXFLAGS)
-dist_TESTS += examples/calc++/calc++.test
+%C%_calc___CPPFLAGS = -I$(top_builddir)/%D%
+%C%_calc___CXXFLAGS = $(AM_CXXFLAGS) $(FLEX_SCANNER_CXXFLAGS)
+dist_TESTS += %D%/calc++.test
+else
+EXTRA_DIST += %D%/calc++.test
 endif
+
+
+## ------------ ##
+## Installing.  ##
+## ------------ ##
+
+calcxxdir = $(docdir)/examples/calc++
+calcxx_DATA = $(calcxx_extracted)
@@ -3,7 +3,7 @@

 # This file is part of GNU Bison

-# Copyright (C) 1992, 2000-2001, 2005-2006, 2009-2013 Free Software
+# Copyright (C) 1992, 2000-2001, 2005-2006, 2009-2015 Free Software
 # Foundation, Inc.
 #
 # This program is free software: you can redistribute it and/or modify
@@ -19,7 +19,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.

-# Usage: extexi input-file.texi ... -- [FILES to extract]
+# Usage: extexi [OPTION...] input-file.texi ... -- [FILES to extract]

 # Look for @example environments preceded with lines such as:
 #
@@ -35,6 +35,9 @@

 use strict;

+# Whether we generate synclines.
+my $synclines = 0;
+
 # normalize($block)
 # -----------------
 # Remove Texinfo mark up.
@@ -102,7 +105,7 @@ sub process ($)
            {
              # Bison supports synclines, but not Flex.
              $input .= sprintf ("#line %s \"$in\"\n", $. + 1)
-                if $file =~ /\.[chy]*$/;
+                if $synclines && $file =~ /\.[chy]*$/;
              next;
            }
          elsif (/^\@end (small)?example$/)
@@ -136,15 +139,19 @@ my @input;
 my $seen_dash = 0;
 for my $arg (@ARGV)
 {
-  if ($arg eq '--')
-    {
-      $seen_dash = 1;
-    }
-  elsif ($seen_dash)
+  if ($seen_dash)
    {
      use File::Basename;
      $file_wanted{basename($arg)} = $arg;
    }
+  elsif ($arg eq '--')
+    {
+      $seen_dash = 1;
+    }
+  elsif ($arg eq '--synclines')
+    {
+      $synclines = 1;
+    }
  else
    {
      push @input, $arg;
@@ -1,4 +1,4 @@
-# Copyright (C) 2005, 2008-2013 Free Software Foundation, Inc.
+# Copyright (C) 2005, 2008-2015 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
@@ -13,11 +13,10 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.

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

 AM_CXXFLAGS =							\
-  $(NO_STRICT_ALIAS_CXXFLAGS)					\
  $(WARN_CXXFLAGS) $(WARN_CXXFLAGS_TEST) $(WERROR_CXXFLAGS)

 ## ------------ ##
@@ -25,20 +24,23 @@ AM_CXXFLAGS =							\
 ## ------------ ##

 doc = $(top_srcdir)/doc/bison.texi
-extexi = $(top_srcdir)/examples/extexi
-extract = VERSION="$(VERSION)" $(PERL) -f $(extexi) $(doc) --
+extexi = $(top_srcdir)/%D%/extexi
+if ENABLE_GCC_WARNINGS
+extexiFLAGS = --synclines
+endif
+extract = VERSION="$(VERSION)" $(PERL) $(extexi) $(extexiFLAGS) $(doc) --
 extracted =
-CLEANFILES += $(extracted) examples/extracted.stamp
-examples/extracted.stamp: $(doc) $(extexi)
+CLEANFILES += $(extracted) %D%/extracted.stamp
+%D%/extracted.stamp: $(doc) $(extexi)
 	$(AM_V_GEN)rm -f $@ $@.tmp
 	$(AM_V_at)touch $@.tmp
 	$(AM_V_at)$(extract) $(extracted)
 	$(AM_V_at)mv $@.tmp $@

-$(extracted): examples/extracted.stamp
-	@test -f $@ || rm -f examples/extracted.stamp
-	@test -f $@ || $(MAKE) $(AM_MAKEFLAGS) examples/extracted.stamp
+$(extracted): %D%/extracted.stamp
+	@test -f $@ || rm -f %D%/extracted.stamp
+	@test -f $@ || $(MAKE) $(AM_MAKEFLAGS) %D%/extracted.stamp

-include examples/calc++/local.mk
-include examples/mfcalc/local.mk
-include examples/rpcalc/local.mk
+include %D%/calc++/local.mk
+include %D%/mfcalc/local.mk
+include %D%/rpcalc/local.mk
@@ -1,4 +1,4 @@
-# Copyright (C) 2005-2006, 2008-2013 Free Software Foundation, Inc.
+# Copyright (C) 2005-2006, 2008-2015 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
@@ -18,19 +18,22 @@
 ## -------------------- ##

 BUILT_SOURCES += $(mfcalc_sources)
-CLEANFILES +=  examples/mfcalc/mfcalc.[ch] examples/mfcalc/mfcalc.output
+CLEANFILES +=  %D%/mfcalc.[ch] %D%/mfcalc.output

-mfcalc_extracted =				\
-  examples/mfcalc/calc.h			\
-  examples/mfcalc/mfcalc.y
-mfcalc_sources =				\
-  $(mfcalc_extracted)
+mfcalc_extracted = %D%/calc.h %D%/mfcalc.y
+mfcalc_sources = $(mfcalc_extracted)
 extracted += $(mfcalc_extracted)

-check_PROGRAMS += examples/mfcalc/mfcalc
-examples_mfcalc_mfcalc_LDADD = -lm
-nodist_examples_mfcalc_mfcalc_SOURCES =		\
-  $(mfcalc_sources)
+check_PROGRAMS += %D%/mfcalc
+%C%_mfcalc_LDADD = -lm
+nodist_%C%_mfcalc_SOURCES = $(mfcalc_sources)

-examples_mfcalc_mfcalc_CPPFLAGS = -I$(top_builddir)/examples/mfcalc
-dist_TESTS += examples/mfcalc/mfcalc.test
+%C%_mfcalc_CPPFLAGS = -I$(top_builddir)/%D%
+dist_TESTS += %D%/mfcalc.test
+
+## ------------ ##
+## Installing.  ##
+## ------------ ##
+
+mfcalcdir = $(docdir)/examples/mfcalc
+mfcalc_DATA = $(mfcalc_extracted)
@@ -1,6 +1,6 @@
 #! /bin/sh

-# Copyright (C) 2005-2013 Free Software Foundation, Inc.
+# Copyright (C) 2005-2015 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
@@ -1,4 +1,5 @@
 /calc.h
+/rpcalc
 /rpcalc.c
 /rpcalc.h
 /rpcalc.output
@@ -1,4 +1,4 @@
-# Copyright (C) 2005-2006, 2008-2013 Free Software Foundation, Inc.
+# Copyright (C) 2005-2006, 2008-2015 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
@@ -18,18 +18,22 @@
 ## -------------------- ##

 BUILT_SOURCES += $(rpcalc_sources)
-CLEANFILES +=  examples/rpcalc/rpcalc.[ch] examples/rpcalc/rpcalc.output
+CLEANFILES +=  %D%/rpcalc.[ch] %D%/rpcalc.output

-rpcalc_extracted =				\
-  examples/rpcalc/rpcalc.y
-rpcalc_sources =				\
-  $(rpcalc_extracted)
+rpcalc_extracted = %D%/rpcalc.y
+rpcalc_sources = $(rpcalc_extracted)
 extracted += $(rpcalc_extracted)

-check_PROGRAMS += examples/rpcalc/rpcalc
-examples_rpcalc_rpcalc_LDADD = -lm
-nodist_examples_rpcalc_rpcalc_SOURCES =		\
-  $(rpcalc_sources)
+check_PROGRAMS += %D%/rpcalc
+%C%_rpcalc_LDADD = -lm
+nodist_%C%_rpcalc_SOURCES = $(rpcalc_sources)

-examples_rpcalc_rpcalc_CPPFLAGS = -I$(top_builddir)/examples/rpcalc
-dist_TESTS += examples/rpcalc/rpcalc.test
+%C%_rpcalc_CPPFLAGS = -I$(top_builddir)/%D%
+dist_TESTS += %D%/rpcalc.test
+
+## ------------ ##
+## Installing.  ##
+## ------------ ##
+
+rpcalcdir = $(docdir)/examples/rpcalc
+rpcalc_DATA = $(rpcalc_extracted)
@@ -1,6 +1,6 @@
 #! /bin/sh

-# Copyright (C) 2005-2013 Free Software Foundation, Inc.
+# Copyright (C) 2005-2015 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
@@ -1,6 +1,6 @@
 #! /bin/sh

-# Copyright (C) 2005-2013 Free Software Foundation, Inc.
+# Copyright (C) 2005-2015 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
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2008-2013 Free Software Foundation, Inc.
+  Copyright (C) 2008-2015 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 @@
 */

 %debug
-%skeleton "lalr1.cc"
+%language "c++"
 %defines
 %define api.token.constructor
 %define api.value.type variant
@@ -48,11 +48,17 @@ typedef std::list<std::string> strings_type;
  namespace std
  {
    std::ostream&
-    operator<< (std::ostream& o, const strings_type& s)
+    operator<< (std::ostream& o, const strings_type& ss)
    {
-      std::copy (s.begin (), s.end (),
-                 std::ostream_iterator<strings_type::value_type> (o, "\n"));
-      return o;
+      o << "(" << &ss << ") {";
+      const char *sep = "";
+      for (strings_type::const_iterator i = ss.begin(), end = ss.end();
+           i != end; ++i)
+        {
+          o << sep << *i;
+          sep = ", ";
+        }
+      return o << "}";
    }
  }

@@ -211,8 +211,6 @@
 /stripslash.c
 /strndup.c
 /strnlen.c
-/strtol.c
-/strtoul.c
 /strverscmp.c
 /sys
 /sys_ioctl.h
@@ -272,3 +270,7 @@
 /sig-handler.c
 /unistd.c
 /wctype-h.c
+/lstat.c
+/unlink.c
+/gettimeofday.c
+/sys_time.in.h
@@ -1,6 +1,6 @@
 /* Array bitsets.

-   Copyright (C) 2002-2003, 2006, 2009-2013 Free Software Foundation,
+   Copyright (C) 2002-2003, 2006, 2009-2015 Free Software Foundation,
   Inc.

   Contributed by Michael Hayes (m.hayes@elec.canterbury.ac.nz).
@@ -1,6 +1,6 @@
 /* Functions to support abitsets.

-   Copyright (C) 2002, 2004, 2009-2013 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2004, 2009-2015 Free Software Foundation, Inc.

   Contributed by Michael Hayes (m.hayes@elec.canterbury.ac.nz).

@@ -1,6 +1,6 @@
 /* Base bitset stuff.

-   Copyright (C) 2002-2004, 2006, 2009-2013 Free Software Foundation,
+   Copyright (C) 2002-2004, 2006, 2009-2015 Free Software Foundation,
   Inc.

   Contributed by Michael Hayes (m.hayes@elec.canterbury.ac.nz).
@@ -1,6 +1,6 @@
 /* General bitsets.

-   Copyright (C) 2002-2006, 2009-2013 Free Software Foundation, Inc.
+   Copyright (C) 2002-2006, 2009-2015 Free Software Foundation, Inc.

   Contributed by Michael Hayes (m.hayes@elec.canterbury.ac.nz).

@@ -1,6 +1,6 @@
 /* Generic bitsets.

-   Copyright (C) 2002-2004, 2009-2013 Free Software Foundation, Inc.
+   Copyright (C) 2002-2004, 2009-2015 Free Software Foundation, Inc.

   Contributed by Michael Hayes (m.hayes@elec.canterbury.ac.nz).

@@ -1,6 +1,6 @@
 /* Bitset statistics.

-   Copyright (C) 2002-2006, 2009-2013 Free Software Foundation, Inc.
+   Copyright (C) 2002-2006, 2009-2015 Free Software Foundation, Inc.

   Contributed by Michael Hayes (m.hayes@elec.canterbury.ac.nz).

@@ -1,6 +1,6 @@
 /* Functions to support bitset statistics.

-   Copyright (C) 2002-2004, 2009-2013 Free Software Foundation, Inc.
+   Copyright (C) 2002-2004, 2009-2015 Free Software Foundation, Inc.

   Contributed by Michael Hayes (m.hayes@elec.canterbury.ac.nz).

@@ -1,6 +1,6 @@
 /* Bitset vectors.

-   Copyright (C) 2001-2002, 2004, 2006, 2009-2013 Free Software
+   Copyright (C) 2001-2002, 2004, 2006, 2009-2015 Free Software
   Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
@@ -1,6 +1,6 @@
 /* Bitset vectors.

-   Copyright (C) 2002, 2004, 2009-2013 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2004, 2009-2015 Free Software Foundation, Inc.

   Contributed by Akim Demaille (akim@freefriends.org).

@@ -1,6 +1,6 @@
 /* Bitset vectors.

-   Copyright (C) 2001-2002, 2004-2006, 2009-2013 Free Software
+   Copyright (C) 2001-2002, 2004-2006, 2009-2015 Free Software
   Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
@@ -1,6 +1,6 @@
 /* Bitset vectors.

-   Copyright (C) 2002, 2004, 2009-2013 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2004, 2009-2015 Free Software Foundation, Inc.

   Contributed by Michael Hayes (m.hayes@elec.canterbury.ac.nz).

@@ -1,6 +1,6 @@
 /* Functions to support expandable bitsets.

-   Copyright (C) 2002-2006, 2009-2013 Free Software Foundation, Inc.
+   Copyright (C) 2002-2006, 2009-2015 Free Software Foundation, Inc.

   Contributed by Michael Hayes (m.hayes@elec.canterbury.ac.nz).

@@ -1,6 +1,6 @@
 /* Functions to support ebitsets.

-   Copyright (C) 2002, 2004, 2009-2013 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2004, 2009-2015 Free Software Foundation, Inc.

   Contributed by Michael Hayes (m.hayes@elec.canterbury.ac.nz).

@@ -1,6 +1,6 @@
 /* get-errno.c - get and set errno.

-   Copyright (C) 2002, 2006, 2009-2013 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2006, 2009-2015 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
@@ -1,6 +1,6 @@
 /* get-errno.h - get and set errno.

-   Copyright (C) 2002, 2009-2013 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2009-2015 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
@@ -1,6 +1,6 @@
 /* Functions to support link list bitsets.

-   Copyright (C) 2002-2004, 2006, 2009-2013 Free Software Foundation,
+   Copyright (C) 2002-2004, 2006, 2009-2015 Free Software Foundation,
   Inc.

   Contributed by Michael Hayes (m.hayes@elec.canterbury.ac.nz).
@@ -1,6 +1,6 @@
 /* Functions to support lbitsets.

-   Copyright (C) 2002, 2004, 2009-2013 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2004, 2009-2015 Free Software Foundation, Inc.

   Contributed by Michael Hayes (m.hayes@elec.canterbury.ac.nz).

@@ -1,6 +1,6 @@
 /* Fake libiberty.h for Bison.

-   Copyright (C) 2002-2004, 2009-2013 Free Software Foundation, Inc.
+   Copyright (C) 2002-2004, 2009-2015 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
@@ -17,7 +17,7 @@


 /* Bison depends on libiberty's implementation of bitsets, which
-   requires a `libiberty.h' file.  This file provides the minimum
+   requires a 'libiberty.h' file.  This file provides the minimum
   services.  */

 #ifndef BISON_LIBIBERTY_H_
@@ -1,4 +1,4 @@
-# Copyright (C) 2001-2013 Free Software Foundation, Inc.
+# Copyright (C) 2001-2015 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
@@ -51,6 +51,8 @@ lib_libbison_a_SOURCES +=                       \
  lib/get-errno.c

 # The Yacc compatibility library.
-lib_LIBRARIES = $(YACC_LIBRARY)
+if ENABLE_YACC
+lib_LIBRARIES = lib/liby.a
 EXTRA_LIBRARIES = lib/liby.a
 lib_liby_a_SOURCES = lib/main.c lib/yyerror.c
+endif
--- a/Show More
+++ b/Show More
@@ -1 +1 @@
 .7
 .0.4