version 3.6

* NEWS: Record release date.
examples: beware of portability issue on Windows
2026-08-08 18:25:13 +00:00 · 2020-05-08 09:57:14 +02:00 · 2020-05-08 09:45:29 +02:00 · 2020-05-08 09:45:29 +02:00 · 2020-05-08 09:02:45 +02:00 · 2020-05-08 07:34:30 +02:00
41 changed files with 878 additions and 509 deletions
@@ -1 +1 @@
-3.5.90
+3.5.94
@@ -1,27 +1,6 @@
 GNU Bison NEWS

-* Noteworthy changes in release 3.5.91 (2020-04-29) [stable]
-
-** New features
-
-*** Returning the error token
-
-  When the scanner returns an invalid token or the undefined token
-  (YYUNDEF), the parser generates an error message and enters error
-  recovery.  Because of that error message, most scanners that find lexical
-  errors generate an error message, and then ignore the invalid input
-  without entering the error-recovery.
-
-  The scanners may now return YYerror, the error token, to enter the
-  error-recovery mode without triggering an additional error message.  See
-  the bistromathic for an example.
-
-*** The bistromathic features internationalization
-
-  Its way to build the error message is more general and is easy to use in
-  other projects.
-
-* Noteworthy changes in release 3.5.90 (2020-04-18) [beta]
+* Noteworthy changes in release 3.6 (2020-05-08) [stable]

 ** Backward incompatible changes

@@ -126,6 +105,18 @@ GNU Bison NEWS
  It makes little sense to use this feature without enabling LAC (lookahead
  correction).

+*** Returning the error token
+
+  When the scanner returns an invalid token or the undefined token
+  (YYUNDEF), the parser generates an error message and enters error
+  recovery.  Because of that error message, most scanners that find lexical
+  errors generate an error message, and then ignore the invalid input
+  without entering the error-recovery.
+
+  The scanners may now return YYerror, the error token, to enter the
+  error-recovery mode without triggering an additional error message.  See
+  the bistromathic for an example.
+
 *** Deep overhaul of the symbol and token kinds

  To avoid the confusion with types in programming languages, we now refer
@@ -213,8 +204,8 @@ GNU Bison NEWS

 *** Examples

-  There are now two examples in examples/java: a very simple calculator, and
-  one that tracks locations to provide accurate error messages.
+  There are now examples/java: a very simple calculator, and a more complete
+  one (push-parser, location tracking, and debug traces).

  The lexcalc example (a simple example in C based on Flex and Bison) now
  also demonstrates location tracking.
@@ -2545,7 +2536,7 @@ GNU Bison NEWS
  Running "make install-pdf" (or -dvi, -html, -info, and -ps) no longer
  halts in the middle of its course.

-* Changes in version 2.5 (2011-05-14):
+* Noteworthy changes in release 2.5 (2011-05-14)

 ** Grammar symbol names can now contain non-initial dashes:

@@ -2900,7 +2891,7 @@ GNU Bison NEWS

  This bug has been fixed.

-* Changes in version 2.4.3 (2010-08-05):
+* Noteworthy changes in release 2.4.3 (2010-08-05)

 ** Bison now obeys -Werror and --warnings=error for warnings about
   grammar rules that are useless in the parser due to conflicts.
@@ -2920,7 +2911,7 @@ GNU Bison NEWS

 ** Minor documentation fixes.

-* Changes in version 2.4.2 (2010-03-20):
+* Noteworthy changes in release 2.4.2 (2010-03-20)

 ** Some portability problems that resulted in failures and livelocks
   in the test suite on some versions of at least Solaris, AIX, HP-UX,
@@ -3014,7 +3005,7 @@ GNU Bison NEWS
  message translations were not installed although supported by the
  host system.

-* Changes in version 2.4.1 (2008-12-11):
+* Noteworthy changes in release 2.4.1 (2008-12-11)

 ** In the GLR defines file, unexpanded M4 macros in the yylval and yylloc
   declarations have been fixed.
@@ -3039,7 +3030,7 @@ GNU Bison NEWS

 ** A few minor improvements to the Bison manual.

-* Changes in version 2.4 (2008-11-02):
+* Noteworthy changes in release 2.4 (2008-11-02)

 ** %language is an experimental feature.

@@ -3054,7 +3045,7 @@ GNU Bison NEWS
 ** Several bugs in the C++ skeleton and the experimental Java skeleton have been
  fixed.

-* Changes in version 2.3b (2008-05-27):
+* Noteworthy changes in release 2.3b (2008-05-27)

 ** The quotes around NAME that used to be required in the following directive
  are now deprecated:
@@ -3240,7 +3231,7 @@ GNU Bison NEWS
 ** The nonfunctional --no-parser, -n, and %no-parser options have been
  completely removed from Bison.

-* Changes in version 2.3a, 2006-09-13:
+* Noteworthy changes in release 2.3a (2006-09-13)

 ** Instead of %union, you can define and use your own union type
  YYSTYPE if your grammar contains at least one <type> tag.
@@ -3354,7 +3345,7 @@ GNU Bison NEWS
  The old spelling still works, but is not documented and may be removed
  in a future release.

-* Changes in version 2.3, 2006-06-05:
+* Noteworthy changes in release 2.3 (2006-06-05)

 ** GLR grammars should now use "YYRECOVERING ()" instead of "YYRECOVERING",
  for compatibility with LALR(1) grammars.
@@ -3362,7 +3353,7 @@ GNU Bison NEWS
 ** It is now documented that any definition of YYSTYPE or YYLTYPE should
  be to a type name that does not contain parentheses or brackets.

-* Changes in version 2.2, 2006-05-19:
+* Noteworthy changes in release 2.2 (2006-05-19)

 ** The distribution terms for all Bison-generated parsers now permit
  using the parsers in nonfree programs.  Previously, this permission
@@ -3444,7 +3435,7 @@ GNU Bison NEWS

 ** DJGPP support added.

-* Changes in version 2.1, 2005-09-16:
+* Noteworthy changes in release 2.1 (2005-09-16)

 ** The C++ lalr1.cc skeleton supports %lex-param.

@@ -3470,7 +3461,7 @@ GNU Bison NEWS
  print 'syntax error, unexpected number' instead of 'syntax error,
  unexpected "number"'.

-* Changes in version 2.0, 2004-12-25:
+* Noteworthy changes in release 2.0 (2004-12-25)

 ** Possibly-incompatible changes

@@ -3533,7 +3524,7 @@ GNU Bison NEWS

  - Semicolons are now allowed before "|" in grammar rules, as POSIX requires.

-* Changes in version 1.875, 2003-01-01:
+* Noteworthy changes in release 1.875 (2003-01-01)

 ** The documentation license has been upgraded to version 1.2
  of the GNU Free Documentation License.
@@ -3653,7 +3644,7 @@ GNU Bison NEWS
  ago, but nobody noticed until we recently asked someone to try
  building Bison with a K&R C compiler.

-* Changes in version 1.75, 2002-10-14:
+* Noteworthy changes in release 1.75 (2002-10-14)

 ** Bison should now work on 64-bit hosts.

@@ -3684,7 +3675,7 @@ GNU Bison NEWS
  was incorrectly rejected: $1 is defined in the second midrule
  action, and is equal to the $$ of the first midrule action.

-* Changes in version 1.50, 2002-10-04:
+* Noteworthy changes in release 1.50 (2002-10-04)

 ** GLR parsing
  The declaration
@@ -3828,7 +3819,7 @@ GNU Bison NEWS

 ** GNU M4 is now required when using Bison.

-* Changes in version 1.35, 2002-03-25:
+* Noteworthy changes in release 1.35 (2002-03-25)

 ** C Skeleton
  Some projects use Bison's C parser with C++ compilers, and define
@@ -3843,7 +3834,7 @@ GNU Bison NEWS
  This kludge also addresses some C++ problems when the stack was
  extended.

-* Changes in version 1.34, 2002-03-12:
+* Noteworthy changes in release 1.34 (2002-03-12)

 ** File name clashes are detected
  $ bison foo.y -d -o foo.x
@@ -3863,7 +3854,7 @@ GNU Bison NEWS

 ** Fix test suite portability problems.

-* Changes in version 1.33, 2002-02-07:
+* Noteworthy changes in release 1.33 (2002-02-07)

 ** Fix C++ issues
  Groff could not be compiled for the definition of size_t was lacking
@@ -3872,7 +3863,7 @@ GNU Bison NEWS
 ** Catch invalid @n
  As is done with $n.

-* Changes in version 1.32, 2002-01-23:
+* Noteworthy changes in release 1.32 (2002-01-23)

 ** Fix Yacc output file names

@@ -3880,7 +3871,7 @@ GNU Bison NEWS

 ** Italian, Dutch translations

-* Changes in version 1.31, 2002-01-14:
+* Noteworthy changes in release 1.31 (2002-01-14)

 ** Many Bug Fixes

@@ -3967,7 +3958,7 @@ GNU Bison NEWS
 ** --output
  New, aliasing "--output-file".

-* Changes in version 1.30, 2001-10-26:
+* Noteworthy changes in release 1.30 (2001-10-26)

 ** "--defines" and "--graph" have now an optional argument which is the
  output file name. "-d" and "-g" do not change; they do not take any
@@ -3978,7 +3969,7 @@ GNU Bison NEWS

 ** Portability fixes.

-* Changes in version 1.29, 2001-09-07:
+* Noteworthy changes in release 1.29 (2001-09-07)

 ** The output file does not define const, as this caused problems when used
  with common autoconfiguration schemes.  If you still use ancient compilers
@@ -4013,7 +4004,7 @@ GNU Bison NEWS
 ** @$
  Automatic location tracking.

-* Changes in version 1.28, 1999-07-06:
+* Noteworthy changes in release 1.28 (1999-07-06)

 ** Should compile better now with K&R compilers.

@@ -4023,12 +4014,12 @@ GNU Bison NEWS

 ** There is now a FAQ.

-* Changes in version 1.27:
+* Noteworthy changes in release 1.27

 ** The make rule which prevented bison.simple from being created on
  some systems has been fixed.

-* Changes in version 1.26:
+* Noteworthy changes in release 1.26

 ** Bison now uses Automake.

@@ -4045,7 +4036,7 @@ GNU Bison NEWS
 ** Generated parsers should now work even on operating systems which do
  not provide alloca().

-* Changes in version 1.25, 1995-10-16:
+* Noteworthy changes in release 1.25 (1995-10-16)

 ** Errors in the input grammar are not fatal; Bison keeps reading
 the grammar file, and reports all the errors found in it.
@@ -4070,7 +4061,7 @@ the parser engine; a project can now use its own parser engine.
 The actions go into a separate file called NAME.act, in the form of
 a switch statement body.

-* Changes in version 1.23:
+* Noteworthy changes in release 1.23

 The user can define YYPARSE_PARAM as the name of an argument to be
 passed into yyparse.  The argument should have type void *.  It should
@@ -4079,11 +4070,11 @@ by casting it to the proper pointer type.

 Line numbers in output file corrected.

-* Changes in version 1.22:
+* Noteworthy changes in release 1.22

 --help option added.

-* Changes in version 1.20:
+* Noteworthy changes in release 1.20

 Output file does not redefine const for C++.

@@ -20,6 +20,7 @@ Anthony Heading           [email protected]
 Antonio Silva Correia     [email protected]
 Arnold Robbins            [email protected]
 Art Haas                  [email protected]
+Arthur Schwarz            [email protected]
 Askar Safin               [email protected]
 Balázs Scheidler          [email protected]
 Baron Schwartz            [email protected]
@@ -57,6 +58,7 @@ Derek M. Jones            [email protected]
 Di-an Jan                 [email protected]
 Dick Streefland           [email protected]
 Didier Godefroy           [email protected]
+Don Macpherson            [email protected]
 Efi Fogel                 [email protected]
 Enrico Scholz             [email protected]
 Eric Blake                [email protected]
@@ -154,6 +156,7 @@ Petr Machata              [email protected]
 Pho                       [email protected]
 Piotr Gackiewicz          [email protected]
 Piotr Marcińczyk          [email protected]
+Pramod Kumbhar            [email protected]
 Quentin Hocquet           [email protected]
 Quoc Peyrot               [email protected]
 R Blake                   [email protected]
@@ -1,4 +1,7 @@
 * Bison 3.6
+** Doc
+*** api.header.include
+
 ** Questions
 *** Java
 - Should i18n be part of the Lexer?  Currently it's a static method of
@@ -25,9 +28,6 @@ should be updated to not use YYERRCODE.  Returning an undef token is good
 enough.

 ** Java
-*** Examples
-Have an example with a push parser.  Use autocompletion in that case.
-
 *** calc.at
 Stop hard-coding "Calc".  Adjust local.at (look for FIXME).

@@ -71,6 +71,55 @@ a bad feature.  On the other hand, that would make it much harder to sit
 push parsers on top of pull parser.  Which is currently not relevant, since
 push parsers are measurably slower.

+** %define parse.error formatted
+How about pushing bistromathics' yyreport_syntax_error as another standard
+way to generate the error message, and leave to the user the task of
+providing the message formats?  Currently in bistro, it reads:
+
+    const char *
+    error_format_string (int argc)
+    {
+      switch (argc)
+        {
+        default: /* Avoid compiler warnings. */
+        case 0: return _("%@: syntax error");
+        case 1: return _("%@: syntax error: unexpected %u");
+          // TRANSLATORS: '%@' is a location in a file, '%u' is an
+          // "unexpected token", and '%0e', '%1e'... are expected tokens
+          // at this point.
+          //
+          // For instance on the expression "1 + * 2", you'd get
+          //
+          // 1.5: syntax error: expected - or ( or number or function or variable before *
+        case 2: return _("%@: syntax error: expected %0e before %u");
+        case 3: return _("%@: syntax error: expected %0e or %1e before %u");
+        case 4: return _("%@: syntax error: expected %0e or %1e or %2e before %u");
+        case 5: return _("%@: syntax error: expected %0e or %1e or %2e or %3e before %u");
+        case 6: return _("%@: syntax error: expected %0e or %1e or %2e or %3e or %4e before %u");
+        case 7: return _("%@: syntax error: expected %0e or %1e or %2e or %3e or %4e or %5e before %u");
+        case 8: return _("%@: syntax error: expected %0e or %1e or %2e or %3e or %4e or %5e or %6e before %u");
+        }
+    }
+
+The message would have to be generated in a string, and pushed to yyerror.
+Which will be a pain in the neck in yacc.c.
+
+If we want to do that, we should think very carefully about the syntax of
+the format string.
+
+** yyclearin does not invoke the lookahead token's %destructor
+https://lists.gnu.org/r/bug-bison/2018-02/msg00000.html
+Rici:
+
+> Modifying yyclearin so that it calls yydestruct seems like the simplest
+> solution to this issue, but it is conceivable that such a change would
+> break programs which already perform some kind of workaround in order to
+> destruct the lookahead symbol. So it might be necessary to use some kind of
+> compatibility %define, or to create a new replacement macro with a
+> different name such as yydiscardin.
+>
+> At a minimum, the fact that yyclearin does not invoke the %destructor
+> should be highlighted in the documentation, since it is not at all obvious.

 * Bison 3.8
 ** Unit rules / Injection rules (Akim Demaille)
@@ -146,10 +195,10 @@ define it to the same type as the C ptrdiff_t type.
 * Completion
 Several features are not available in all the backends.

- push parsers: glr.c, glr.cc, lalr1.cc
- lac: D, Java
- glr: D, Java
- token constructors: Java, C, D
+- lac: D, Java (easy)
+- push parsers: glr.c, glr.cc, lalr1.cc (not very difficult)
+- token constructors: Java, C, D (a bit difficult)
+- glr: D, Java (super difficult)

 * Bugs
 ** Autotest has quotation issues
@@ -353,8 +402,12 @@ LORIA, INRIA Nancy - Grand Est, Nancy, France
 ** More languages?
 Well, only if there is really some demand for it.

+*** PHP
 https://github.com/scfc/bison-php/blob/master/data/lalr1.php

+*** Python
+https://lists.gnu.org/r/bison-patches/2013-09/msg00000.html and following
+
 ** Multiple start symbols
 Would be very useful when parsing closely related languages.  The idea is to
 declare several start symbols, for instance
@@ -261,9 +261,9 @@ if ! "$LEX_IS_FLEX" || test "X$LEX" = X:; then
  AC_MSG_WARN([bypassing lex because flex is required])
  LEX=:
 fi
-AM_CONDITIONAL([FLEX_WORKS], [$LEX_IS_FLEX])
+AM_CONDITIONAL([FLEX_WORKS], [$LEX_IS_FLEX && $FLEX_SUPPORTS_HEADER_OPT])
 AM_CONDITIONAL([FLEX_CXX_WORKS],
-  [$LEX_IS_FLEX && test $bison_cv_cxx_works = yes])
+  [$LEX_IS_FLEX && $FLEX_SUPPORTS_HEADER_OPT && test $bison_cv_cxx_works = yes])
 AC_PROG_YACC
 AC_PROG_RANLIB
 AC_PROG_GNU_M4
@@ -332,6 +332,13 @@ AC_MSG_RESULT([$suppfile])
 # Whether we cannot run the compiled bison.
 AM_CONDITIONAL([CROSS_COMPILING], [test "$cross_compiling" = yes])

+# Build bistromathic if we have the lib and both readline/readline.h
+# and readline/history.h.
+AM_CONDITIONAL([ENABLE_BISTROMATHIC],
+[test "$gl_cv_lib_readline" != no &&
+  test "$ac_cv_header_readline_readline_h" = yes &&
+  test "$ac_cv_header_readline_history_h" = yes])
+
 AM_MISSING_PROG([AUTOM4TE], [autom4te])
 # Needed by tests/atlocal.in.
 AC_SUBST([GCC])
@@ -259,14 +259,14 @@ m4_define([b4_public_types_declare],
    struct token
    {
      ]b4_token_enums[
-      /// Backward compatibility alias.
+      /// Backward compatibility alias (Bison 3.6).
      typedef token_kind_type yytokentype;
    };

    /// Token kind, as returned by yylex.
    typedef token::yytokentype token_kind_type;

-    /// Backward compatibility alias.
+    /// Backward compatibility alias (Bison 3.6).
    typedef token_kind_type token_type;

    /// Symbol kinds.
@@ -357,7 +357,7 @@ m4_define([b4_symbol_type_define],
        Base::clear ();
      }

-      /// Backward compatibility.
+      /// Backward compatibility (Bison 3.6).
      symbol_kind_type type_get () const YY_NOEXCEPT;

      /// Whether empty.
@@ -409,11 +409,17 @@ m4_define([b4_symbol_type_define],
      /// \a empty when empty.
      symbol_kind_type kind () const YY_NOEXCEPT;

+      /// Backward compatibility (Bison 3.6).
+      symbol_kind_type type_get () const YY_NOEXCEPT;
+
      /// The symbol kind.
      /// \a ]b4_symbol_prefix[YYEMPTY when empty.
      symbol_kind_type kind_;
    };

+    /// Backward compatibility for a private implementation detail (Bison 3.6).
+    typedef by_kind by_type;
+
    /// "External" symbols: returned by the scanner.
    struct symbol_type : basic_symbol<by_kind>
    {]b4_variant_if([[
@@ -531,6 +537,12 @@ m4_define([b4_public_types_define],
  {
    return kind_;
  }
+
+  ]b4_inline([$1])[]b4_parser_class[::symbol_kind_type
+  ]b4_parser_class[::by_kind::type_get () const YY_NOEXCEPT
+  {
+    return this->kind ();
+  }
 ]])


@@ -205,7 +205,11 @@ m4_define([b4_c99_int_type],
 # Define private types suitable for holding small integers in C99 or later.
 m4_define([b4_c99_int_type_define],
 [m4_copy_force([b4_c99_int_type], [b4_int_type])dnl
-[/* On compilers that do not define __PTRDIFF_MAX__ etc., make sure
+[#ifdef short
+# undef short
+#endif
+
+/* On compilers that do not define __PTRDIFF_MAX__ etc., make sure
   <limits.h> and (if available) <stdint.h> are included
   so that the code can choose integer types of a good width.  */

@@ -261,6 +265,50 @@ typedef int yytype_uint16;
 #endif]])


+# b4_sizes_types_define
+# ---------------------
+# Define YYPTRDIFF_T/YYPTRDIFF_MAXIMUM, YYSIZE_T/YYSIZE_MAXIMUM,
+# and YYSIZEOF.
+m4_define([b4_sizes_types_define],
+[[#ifndef YYPTRDIFF_T
+# if defined __PTRDIFF_TYPE__ && defined __PTRDIFF_MAX__
+#  define YYPTRDIFF_T __PTRDIFF_TYPE__
+#  define YYPTRDIFF_MAXIMUM __PTRDIFF_MAX__
+# elif defined PTRDIFF_MAX
+#  ifndef ptrdiff_t
+#   include <stddef.h> /* INFRINGES ON USER NAME SPACE */
+#  endif
+#  define YYPTRDIFF_T ptrdiff_t
+#  define YYPTRDIFF_MAXIMUM PTRDIFF_MAX
+# else
+#  define YYPTRDIFF_T long
+#  define YYPTRDIFF_MAXIMUM LONG_MAX
+# endif
+#endif
+
+#ifndef YYSIZE_T
+# ifdef __SIZE_TYPE__
+#  define YYSIZE_T __SIZE_TYPE__
+# elif defined size_t
+#  define YYSIZE_T size_t
+# elif defined __STDC_VERSION__ && 199901 <= __STDC_VERSION__
+#  include <stddef.h> /* INFRINGES ON USER NAME SPACE */
+#  define YYSIZE_T size_t
+# else
+#  define YYSIZE_T unsigned
+# endif
+#endif
+
+#define YYSIZE_MAXIMUM                                  \
+  YY_CAST (YYPTRDIFF_T,                                 \
+           (YYPTRDIFF_MAXIMUM < YY_CAST (YYSIZE_T, -1)  \
+            ? YYPTRDIFF_MAXIMUM                         \
+            : YY_CAST (YYSIZE_T, -1)))
+
+#define YYSIZEOF(X) YY_CAST (YYPTRDIFF_T, sizeof (X))
+]])
+
+
 # b4_int_type_for(NAME)
 # ---------------------
 # Return a narrow int type able to handle numbers ranging from
@@ -249,6 +249,7 @@ static YYLTYPE yyloc_default][]b4_yyloc_default;])[
 #include <string.h>

 ]b4_c99_int_type_define[
+]b4_sizes_types_define[

 #ifndef YY_
 # if defined YYENABLE_NLS && YYENABLE_NLS
@@ -277,9 +278,6 @@ static YYLTYPE yyloc_default][]b4_yyloc_default;])[
 # define YYREALLOC realloc
 #endif

-#define YYSIZEMAX \
-  (PTRDIFF_MAX < SIZE_MAX ? PTRDIFF_MAX : YY_CAST (ptrdiff_t, SIZE_MAX))
-
 #ifdef __cplusplus
  typedef bool yybool;
 # define yytrue true
@@ -507,7 +505,7 @@ struct yyGLRState {
  /** Preceding state in this stack */
  yyGLRState* yypred;
  /** Source position of the last token produced by my symbol */
-  ptrdiff_t yyposn;
+  YYPTRDIFF_T yyposn;
  union {
    /** First in a chain of alternative reductions producing the
     *  nonterminal corresponding to this state, threaded through
@@ -527,8 +525,8 @@ struct yyGLRStateSet {
   *  operation, yylookaheadNeeds[0] is not maintained since it would merely
   *  duplicate yychar != ]b4_symbol(-2, id)[.  */
  yybool* yylookaheadNeeds;
-  ptrdiff_t yysize;
-  ptrdiff_t yycapacity;
+  YYPTRDIFF_T yysize;
+  YYPTRDIFF_T yycapacity;
 };

 struct yySemanticOption {
@@ -568,7 +566,7 @@ struct yyGLRStack {
  YYJMP_BUF yyexception_buffer;
  yyGLRStackItem* yyitems;
  yyGLRStackItem* yynextFree;
-  ptrdiff_t yyspaceLeft;
+  YYPTRDIFF_T yyspaceLeft;
  yyGLRState* yysplitPoint;
  yyGLRState* yylastDeleted;
  yyGLRStateSet yytops;
@@ -680,7 +678,7 @@ yysymbol_name (yysymbol_kind_t yysymbol)
   multiple parsers can coexist.  */
 int yydebug;

-static void yypstack (yyGLRStack* yystackp, ptrdiff_t yyk)
+static void yypstack (yyGLRStack* yystackp, YYPTRDIFF_T yyk)
  YY_ATTRIBUTE_UNUSED;
 static void yypdumpstack (yyGLRStack* yystackp)
  YY_ATTRIBUTE_UNUSED;
@@ -696,7 +694,7 @@ static void yypdumpstack (yyGLRStack* yystackp)
         [simple],
 [[]],
 [[#ifndef yystrlen
-# define yystrlen(S) (YY_CAST (ptrdiff_t, strlen (S)))
+# define yystrlen(S) (YY_CAST (YYPTRDIFF_T, strlen (S)))
 #endif

 ]b4_parse_error_bmatch(
@@ -731,12 +729,12 @@ yystpcpy (char *yydest, const char *yysrc)
   backslash-backslash).  YYSTR is taken from yytname.  If YYRES is
   null, do not copy; instead, return the length of what the result
   would have been.  */
-static ptrdiff_t
+static YYPTRDIFF_T
 yytnamerr (char *yyres, const char *yystr)
 {
  if (*yystr == '"')
    {
-      ptrdiff_t yyn = 0;
+      YYPTRDIFF_T yyn = 0;
      char const *yyp = yystr;

      for (;;)
@@ -1104,7 +1102,7 @@ yynewGLRStackItem (yyGLRStack* yystackp, yybool yyisState)
 *  alternative actions for YYSTATE.  Assumes that YYRHS comes from
 *  stack #YYK of *YYSTACKP. */
 static void
-yyaddDeferredAction (yyGLRStack* yystackp, ptrdiff_t yyk, yyGLRState* yystate,
+yyaddDeferredAction (yyGLRStack* yystackp, YYPTRDIFF_T yyk, yyGLRState* yystate,
                     yyGLRState* yyrhs, yyRuleNum yyrule)
 {
  yySemanticOption* yynewOption =
@@ -1136,14 +1134,14 @@ yyinitStateSet (yyGLRStateSet* yyset)
  yyset->yycapacity = 16;
  yyset->yystates
    = YY_CAST (yyGLRState**,
-               YYMALLOC (YY_CAST (size_t, yyset->yycapacity)
+               YYMALLOC (YY_CAST (YYSIZE_T, yyset->yycapacity)
                         * sizeof yyset->yystates[0]));
  if (! yyset->yystates)
    return yyfalse;
  yyset->yystates[0] = YY_NULLPTR;
  yyset->yylookaheadNeeds
    = YY_CAST (yybool*,
-               YYMALLOC (YY_CAST (size_t, yyset->yycapacity)
+               YYMALLOC (YY_CAST (YYSIZE_T, yyset->yycapacity)
                         * sizeof yyset->yylookaheadNeeds[0]));
  if (! yyset->yylookaheadNeeds)
    {
@@ -1152,7 +1150,7 @@ yyinitStateSet (yyGLRStateSet* yyset)
    }
  memset (yyset->yylookaheadNeeds,
          0,
-          YY_CAST (size_t, yyset->yycapacity) * sizeof yyset->yylookaheadNeeds[0]);
+          YY_CAST (YYSIZE_T, yyset->yycapacity) * sizeof yyset->yylookaheadNeeds[0]);
  return yytrue;
 }

@@ -1165,14 +1163,14 @@ static void yyfreeStateSet (yyGLRStateSet* yyset)
 /** Initialize *YYSTACKP to a single empty stack, with total maximum
 *  capacity for all stacks of YYSIZE.  */
 static yybool
-yyinitGLRStack (yyGLRStack* yystackp, ptrdiff_t yysize)
+yyinitGLRStack (yyGLRStack* yystackp, YYPTRDIFF_T yysize)
 {
  yystackp->yyerrState = 0;
  yynerrs = 0;
  yystackp->yyspaceLeft = yysize;
  yystackp->yyitems
    = YY_CAST (yyGLRStackItem*,
-               YYMALLOC (YY_CAST (size_t, yysize)
+               YYMALLOC (YY_CAST (YYSIZE_T, yysize)
                         * sizeof yystackp->yynextFree[0]));
  if (!yystackp->yyitems)
    return yyfalse;
@@ -1198,9 +1196,9 @@ yyexpandGLRStack (yyGLRStack* yystackp)
 {
  yyGLRStackItem* yynewItems;
  yyGLRStackItem* yyp0, *yyp1;
-  ptrdiff_t yynewSize;
-  ptrdiff_t yyn;
-  ptrdiff_t yysize = yystackp->yynextFree - yystackp->yyitems;
+  YYPTRDIFF_T yynewSize;
+  YYPTRDIFF_T yyn;
+  YYPTRDIFF_T yysize = yystackp->yynextFree - yystackp->yyitems;
  if (YYMAXDEPTH - YYHEADROOM < yysize)
    yyMemoryExhausted (yystackp);
  yynewSize = 2*yysize;
@@ -1208,7 +1206,7 @@ yyexpandGLRStack (yyGLRStack* yystackp)
    yynewSize = YYMAXDEPTH;
  yynewItems
    = YY_CAST (yyGLRStackItem*,
-               YYMALLOC (YY_CAST (size_t, yynewSize)
+               YYMALLOC (YY_CAST (YYSIZE_T, yynewSize)
                         * sizeof yynewItems[0]));
  if (! yynewItems)
    yyMemoryExhausted (yystackp);
@@ -1273,7 +1271,7 @@ yyupdateSplit (yyGLRStack* yystackp, yyGLRState* yys)

 /** Invalidate stack #YYK in *YYSTACKP.  */
 static inline void
-yymarkStackDeleted (yyGLRStack* yystackp, ptrdiff_t yyk)
+yymarkStackDeleted (yyGLRStack* yystackp, YYPTRDIFF_T yyk)
 {
  if (yystackp->yytops.yystates[yyk] != YY_NULLPTR)
    yystackp->yylastDeleted = yystackp->yytops.yystates[yyk];
@@ -1297,7 +1295,7 @@ yyundeleteLastStack (yyGLRStack* yystackp)
 static inline void
 yyremoveDeletes (yyGLRStack* yystackp)
 {
-  ptrdiff_t yyi, yyj;
+  YYPTRDIFF_T yyi, yyj;
  yyi = yyj = 0;
  while (yyj < yystackp->yytops.yysize)
    {
@@ -1330,8 +1328,8 @@ yyremoveDeletes (yyGLRStack* yystackp)
 * state YYLRSTATE, at input position YYPOSN, with (resolved) semantic
 * value *YYVALP and source location *YYLOCP.  */
 static inline void
-yyglrShift (yyGLRStack* yystackp, ptrdiff_t yyk, yy_state_t yylrState,
-            ptrdiff_t yyposn,
+yyglrShift (yyGLRStack* yystackp, YYPTRDIFF_T yyk, yy_state_t yylrState,
+            YYPTRDIFF_T yyposn,
            YYSTYPE* yyvalp]b4_locations_if([, YYLTYPE* yylocp])[)
 {
  yyGLRState* yynewState = &yynewGLRStackItem (yystackp, yytrue)->yystate;
@@ -1351,8 +1349,8 @@ yyglrShift (yyGLRStack* yystackp, ptrdiff_t yyk, yy_state_t yylrState,
 *  state YYLRSTATE, at input position YYPOSN, with the (unresolved)
 *  semantic value of YYRHS under the action for YYRULE.  */
 static inline void
-yyglrShiftDefer (yyGLRStack* yystackp, ptrdiff_t yyk, yy_state_t yylrState,
-                 ptrdiff_t yyposn, yyGLRState* yyrhs, yyRuleNum yyrule)
+yyglrShiftDefer (yyGLRStack* yystackp, YYPTRDIFF_T yyk, yy_state_t yylrState,
+                 YYPTRDIFF_T yyposn, yyGLRState* yyrhs, yyRuleNum yyrule)
 {
  yyGLRState* yynewState = &yynewGLRStackItem (yystackp, yytrue)->yystate;
  YY_ASSERT (yynewState->yyisState);
@@ -1382,7 +1380,7 @@ yyglrShiftDefer (yyGLRStack* yystackp, ptrdiff_t yyk, yy_state_t yylrState,
 `----------------------------------------------------------------------*/

 static inline void
-yy_reduce_print (yybool yynormal, yyGLRStackItem* yyvsp, ptrdiff_t yyk,
+yy_reduce_print (yybool yynormal, yyGLRStackItem* yyvsp, YYPTRDIFF_T yyk,
                 yyRuleNum yyrule]b4_user_formals[)
 {
  int yynrhs = yyrhsLength (yyrule);]b4_locations_if([
@@ -1415,7 +1413,7 @@ yy_reduce_print (yybool yynormal, yyGLRStackItem* yyvsp, ptrdiff_t yyk,
 *  and *YYLOCP to the computed location (if any).  Return value is as
 *  for userAction.  */
 static inline YYRESULTTAG
-yydoAction (yyGLRStack* yystackp, ptrdiff_t yyk, yyRuleNum yyrule,
+yydoAction (yyGLRStack* yystackp, YYPTRDIFF_T yyk, yyRuleNum yyrule,
            YYSTYPE* yyvalp]b4_locuser_formals[)
 {
  int yynrhs = yyrhsLength (yyrule);
@@ -1467,10 +1465,10 @@ yydoAction (yyGLRStack* yystackp, ptrdiff_t yyk, yyRuleNum yyrule,
 *  added to the options for the existing state's semantic value.
 */
 static inline YYRESULTTAG
-yyglrReduce (yyGLRStack* yystackp, ptrdiff_t yyk, yyRuleNum yyrule,
+yyglrReduce (yyGLRStack* yystackp, YYPTRDIFF_T yyk, yyRuleNum yyrule,
             yybool yyforceEval]b4_user_formals[)
 {
-  ptrdiff_t yyposn = yystackp->yytops.yystates[yyk]->yyposn;
+  YYPTRDIFF_T yyposn = yystackp->yytops.yystates[yyk]->yyposn;

  if (yyforceEval || yystackp->yysplitPoint == YY_NULLPTR)
    {
@@ -1492,7 +1490,7 @@ yyglrReduce (yyGLRStack* yystackp, ptrdiff_t yyk, yyRuleNum yyrule,
    }
  else
    {
-      ptrdiff_t yyi;
+      YYPTRDIFF_T yyi;
      int yyn;
      yyGLRState* yys, *yys0 = yystackp->yytops.yystates[yyk];
      yy_state_t yynewLRState;
@@ -1534,8 +1532,8 @@ yyglrReduce (yyGLRStack* yystackp, ptrdiff_t yyk, yyRuleNum yyrule,
  return yyok;
 }

-static ptrdiff_t
-yysplitStack (yyGLRStack* yystackp, ptrdiff_t yyk)
+static YYPTRDIFF_T
+yysplitStack (yyGLRStack* yystackp, YYPTRDIFF_T yyk)
 {
  if (yystackp->yysplitPoint == YY_NULLPTR)
    {
@@ -1544,8 +1542,8 @@ yysplitStack (yyGLRStack* yystackp, ptrdiff_t yyk)
    }
  if (yystackp->yytops.yycapacity <= yystackp->yytops.yysize)
    {
-      ptrdiff_t state_size = sizeof yystackp->yytops.yystates[0];
-      ptrdiff_t half_max_capacity = YYSIZEMAX / 2 / state_size;
+      YYPTRDIFF_T state_size = YYSIZEOF (yystackp->yytops.yystates[0]);
+      YYPTRDIFF_T half_max_capacity = YYSIZE_MAXIMUM / 2 / state_size;
      if (half_max_capacity < yystackp->yytops.yycapacity)
        yyMemoryExhausted (yystackp);
      yystackp->yytops.yycapacity *= 2;
@@ -1554,7 +1552,7 @@ yysplitStack (yyGLRStack* yystackp, ptrdiff_t yyk)
        yyGLRState** yynewStates
          = YY_CAST (yyGLRState**,
                     YYREALLOC (yystackp->yytops.yystates,
-                                (YY_CAST (size_t, yystackp->yytops.yycapacity)
+                                (YY_CAST (YYSIZE_T, yystackp->yytops.yycapacity)
                                 * sizeof yynewStates[0])));
        if (yynewStates == YY_NULLPTR)
          yyMemoryExhausted (yystackp);
@@ -1565,7 +1563,7 @@ yysplitStack (yyGLRStack* yystackp, ptrdiff_t yyk)
        yybool* yynewLookaheadNeeds
          = YY_CAST (yybool*,
                     YYREALLOC (yystackp->yytops.yylookaheadNeeds,
-                                (YY_CAST (size_t, yystackp->yytops.yycapacity)
+                                (YY_CAST (YYSIZE_T, yystackp->yytops.yycapacity)
                                 * sizeof yynewLookaheadNeeds[0])));
        if (yynewLookaheadNeeds == YY_NULLPTR)
          yyMemoryExhausted (yystackp);
@@ -1996,8 +1994,8 @@ yycompressStack (yyGLRStack* yystackp)
 }

 static YYRESULTTAG
-yyprocessOneStack (yyGLRStack* yystackp, ptrdiff_t yyk,
-                   ptrdiff_t yyposn]b4_pure_formals[)
+yyprocessOneStack (yyGLRStack* yystackp, YYPTRDIFF_T yyk,
+                   YYPTRDIFF_T yyposn]b4_pure_formals[)
 {
  while (yystackp->yytops.yystates[yyk] != YY_NULLPTR)
    {
@@ -2040,7 +2038,7 @@ yyprocessOneStack (yyGLRStack* yystackp, ptrdiff_t yyk,
          for (/* nothing */; *yyconflicts; yyconflicts += 1)
            {
              YYRESULTTAG yyflag;
-              ptrdiff_t yynewStack = yysplitStack (yystackp, yyk);
+              YYPTRDIFF_T yynewStack = yysplitStack (yystackp, yyk);
              YY_DPRINTF ((stderr, "Splitting off stack %ld from %ld.\n",
                           YY_CAST (long, yynewStack), YY_CAST (long, yyk)));
              yyflag = yyglrReduce (yystackp, yynewStack,
@@ -2121,6 +2119,8 @@ yypcontext_expected_tokens (const yyGLRStack* yystackp,
              yyarg[yycount++] = YY_CAST (yysymbol_kind_t, yyx);
          }
    }
+  if (yyarg && yycount == 0 && 0 < yyargn)
+    yyarg[0] = ]b4_symbol(-2, kind)[;
  return yycount;
 }]])[

@@ -2228,7 +2228,7 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
     one per "expected"). */
  yysymbol_kind_t yyarg[YYARGS_MAX];
  /* Cumulated lengths of YYARG.  */
-  ptrdiff_t yysize = 0;
+  YYPTRDIFF_T yysize = 0;

  /* Actual size of YYARG. */
  int yycount
@@ -2259,11 +2259,11 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
    int yyi;
    for (yyi = 0; yyi < yycount; ++yyi)
      {
-        ptrdiff_t yysz
+        YYPTRDIFF_T yysz
          = ]b4_parse_error_case(
                     [verbose], [[yytnamerr (YY_NULLPTR, yytname[yyarg[yyi]])]],
                     [[yystrlen (yysymbol_name (yyarg[yyi]))]]);[
-        if (YYSIZEMAX - yysize < yysz)
+        if (YYSIZE_MAXIMUM - yysize < yysz)
          yysize_overflow = yytrue;
        else
          yysize += yysz;
@@ -2271,7 +2271,7 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
  }

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

  if (yymsg)
    {
@@ -2348,7 +2348,7 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[)

  /* Reduce to one stack.  */
  {
-    ptrdiff_t yyk;
+    YYPTRDIFF_T yyk;
    for (yyk = 0; yyk < yystackp->yytops.yysize; yyk += 1)
      if (yystackp->yytops.yystates[yyk] != YY_NULLPTR)
        break;
@@ -2423,7 +2423,7 @@ yyparse (]m4_ifset([b4_parse_param], [b4_formals(b4_parse_param)], [void])[)
  int yyresult;
  yyGLRStack yystack;
  yyGLRStack* const yystackp = &yystack;
-  ptrdiff_t yyposn;
+  YYPTRDIFF_T yyposn;

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

@@ -2505,7 +2505,7 @@ b4_dollar_popdef])[]dnl
      while (yytrue)
        {
          yysymbol_kind_t yytoken_to_shift;
-          ptrdiff_t yys;
+          YYPTRDIFF_T yys;

          for (yys = 0; yys < yystack.yytops.yysize; yys += 1)
            yystackp->yytops.yylookaheadNeeds[yys] = yychar != ]b4_symbol(-2, id)[;
@@ -2612,8 +2612,8 @@ b4_dollar_popdef])[]dnl
      yyGLRState** yystates = yystack.yytops.yystates;
      if (yystates)
        {
-          ptrdiff_t yysize = yystack.yytops.yysize;
-          ptrdiff_t yyk;
+          YYPTRDIFF_T yysize = yystack.yytops.yysize;
+          YYPTRDIFF_T yyk;
          for (yyk = 0; yyk < yysize; yyk += 1)
            if (yystates[yyk])
              {
@@ -2660,7 +2660,7 @@ yypstates (yyGLRState* yyst)
 }

 static void
-yypstack (yyGLRStack* yystackp, ptrdiff_t yyk)
+yypstack (yyGLRStack* yystackp, YYPTRDIFF_T yyk)
 {
  yypstates (yystackp->yytops.yystates[yyk]);
 }
@@ -2705,7 +2705,7 @@ yypdumpstack (yyGLRStack* yystackp)

  YY_FPRINTF ((stderr, "Tops:"));
  {
-    ptrdiff_t yyi;
+    YYPTRDIFF_T yyi;
    for (yyi = 0; yyi < yystackp->yytops.yysize; yyi += 1)
      YY_FPRINTF ((stderr, "%ld: %ld; ", YY_CAST (long, yyi),
                   YYINDEX (yystackp->yytops.yystates[yyi])));
@@ -204,6 +204,13 @@ m4_define([b4_shared_declarations],
    ]b4_parser_class[ (]b4_parse_param_decl[);
    virtual ~]b4_parser_class[ ();

+#if 201103L <= YY_CPLUSPLUS
+    /// Non copyable.
+    ]b4_parser_class[ (const ]b4_parser_class[&) = delete;
+    /// Non copyable.
+    ]b4_parser_class[& operator= (const ]b4_parser_class[&) = delete;
+#endif
+
    /// Parse.  An alias for parse ().
    /// \returns  0 iff parsing succeeded.
    int operator() ();
@@ -255,10 +262,13 @@ m4_define([b4_shared_declarations],
    };
 ]])[
  private:
-    /// This class is not copyable.
+#if YY_CPLUSPLUS < 201103L
+    /// Non copyable.
    ]b4_parser_class[ (const ]b4_parser_class[&);
-    ]b4_parser_class[& operator= (const ]b4_parser_class[&);]b4_lac_if([[
-
+    /// Non copyable.
+    ]b4_parser_class[& operator= (const ]b4_parser_class[&);
+#endif
+]b4_lac_if([[
    /// Check the lookahead yytoken.
    /// \returns  true iff the token will be eventually shifted.
    bool yy_lac_check_ (symbol_kind_type yytoken) const;
@@ -1316,6 +1326,8 @@ b4_dollar_popdef])[]dnl
            }
      }
 ]])[
+    if (yyarg && yycount == 0 && 0 < yyargn)
+      yyarg[0] = symbol_kind::]b4_symbol(-2, kind)[;
    return yycount;
  }

@@ -121,7 +121,7 @@ import java.text.MessageFormat;
   * Locations represent a part of the input through the beginning
   * and ending positions.
   */
-  public class ]b4_location_type[ {
+  public static class ]b4_location_type[ {
    /**
     * The first, inclusive, position in the range.
     */
@@ -182,25 +182,24 @@ import java.text.MessageFormat;
 ]b4_token_enums[
    /** Deprecated, use ]b4_symbol(0, id)[ instead.  */
    public static final int EOF = ]b4_symbol(0, id)[;
-
-]b4_locations_if([[
+]b4_pull_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.
     */
-    ]b4_position_type[ getStartPos ();
+    ]b4_position_type[ getStartPos();

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

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

    /**
     * Entry point for the scanner.  Returns the token identifier corresponding
@@ -208,24 +207,25 @@ import java.text.MessageFormat;
     * ]b4_locations_if([and beginning/ending positions ])[of the token.
     * @@return the token identifier corresponding to the next token.
     */
-    int yylex ()]b4_maybe_throws([b4_lex_throws])[;
-
+    int yylex()]b4_maybe_throws([b4_lex_throws])[;
+]])[
    /**
-     * Entry point for error reporting.  Emits an error
-     * ]b4_locations_if([referring to the given location ])[in a user-defined way.
+     * Emit an error]b4_locations_if([ referring to the given location])[in a user-defined way.
     *
     *]b4_locations_if([[ @@param loc The location of the element to which the
-     *                error message is related]])[
+     *                error message is related.]])[
     * @@param msg The string for the error message.
     */
-     void yyerror (]b4_locations_if([b4_location_type[ loc, ]])[String msg);
+     void yyerror(]b4_locations_if([b4_location_type[ loc, ]])[String msg);

 ]b4_parse_error_bmatch(
           [custom], [[
    /**
-     * Build and emit a syntax error message.
+     * Build and emit a "syntax error" message in a user-defined way.
+     *
+     * @@param ctx  The context of the error.
     */
-     void reportSyntaxError (][Context yyctx);
+     void reportSyntaxError (][Context ctx);
 ]])[
  }

@@ -307,9 +307,8 @@ import java.text.MessageFormat;
   *]b4_locations_if([[ Use a <code>null</code> location.]])[
   * @@param msg The error message.
   */
-  public final void yyerror (String msg)
-  {
-    yylexer.yyerror (]b4_locations_if([[(]b4_location_type[)null, ]])[msg);
+  public final void yyerror(String msg) {
+      yylexer.yyerror(]b4_locations_if([[(]b4_location_type[)null, ]])[msg);
  }
 ]b4_locations_if([[
  /**
@@ -317,9 +316,8 @@ import java.text.MessageFormat;
   * @@param loc The location associated with the message.
   * @@param msg The error message.
   */
-  public final void yyerror (]b4_location_type[ loc, String msg)
-  {
-    yylexer.yyerror (loc, msg);
+  public final void yyerror(]b4_location_type[ loc, String msg) {
+      yylexer.yyerror(loc, msg);
  }

  /**
@@ -327,9 +325,8 @@ import java.text.MessageFormat;
   * @@param pos The position associated with the message.
   * @@param msg The error message.
   */
-  public final void yyerror (]b4_position_type[ pos, String msg)
-  {
-    yylexer.yyerror (new ]b4_location_type[ (pos), msg);
+  public final void yyerror(]b4_position_type[ pos, String msg) {
+      yylexer.yyerror(new ]b4_location_type[ (pos), msg);
  }]])[
 ]b4_parse_trace_if([[
  protected final void yycdebug (String s) {
@@ -469,7 +466,7 @@ import java.text.MessageFormat;
      return yydefgoto_[yysym - YYNTOKENS_];
  }

-  private int yyaction (int yyn, YYStack yystack, int yylen)]b4_maybe_throws([b4_throws])[
+  private int yyaction(int yyn, YYStack yystack, int yylen)]b4_maybe_throws([b4_throws])[
  {
    /* If YYLEN is nonzero, implement the default value of the action:
       '$$ = $1'.  Otherwise, use the top of the stack.
@@ -477,10 +474,10 @@ import java.text.MessageFormat;
       Otherwise, the following line sets YYVAL to garbage.
       This behavior is undocumented and Bison
       users should not rely upon it.  */
-    ]b4_yystype[ yyval = (0 < yylen) ? yystack.valueAt (yylen - 1) : yystack.valueAt (0);]b4_locations_if([[
-    ]b4_location_type[ yyloc = yylloc (yystack, yylen);]])[]b4_parse_trace_if([[
+    ]b4_yystype[ yyval = (0 < yylen) ? yystack.valueAt(yylen - 1) : yystack.valueAt(0);]b4_locations_if([[
+    ]b4_location_type[ yyloc = yylloc(yystack, yylen);]])[]b4_parse_trace_if([[

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

    switch (yyn)
      {
@@ -488,13 +485,13 @@ import java.text.MessageFormat;
        default: break;
      }]b4_parse_trace_if([[

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

-    yystack.pop (yylen);
+    yystack.pop(yylen);
    yylen = 0;
    /* Shift the result of the reduction.  */
-    int yystate = yyLRGotoState (yystack.stateAt (0), yyr1_[yyn]);
-    yystack.push (yystate, yyval]b4_locations_if([, yyloc])[);
+    int yystate = yyLRGotoState(yystack.stateAt(0), yyr1_[yyn]);
+    yystack.push(yystate, yyval]b4_locations_if([, yyloc])[);
    return YYNEWSTATE;
  }

@@ -504,13 +501,14 @@ import java.text.MessageFormat;
  `--------------------------------*/

  private void yySymbolPrint(String s, SymbolKind yykind,
-                             ]b4_yystype[ yyvalue]b4_locations_if([, ]b4_location_type[ yylocation])[)
-  {
-    yycdebug (s
-              + (yykind.getCode() < YYNTOKENS_ ? " token " : " nterm ")
-              + yykind.getName() + " ("]b4_locations_if([
-              + yylocation + ": "])[
-              + (yyvalue == null ? "(null)" : yyvalue.toString()) + ")");
+                             ]b4_yystype[ yyvalue]b4_locations_if([, ]b4_location_type[ yylocation])[) {
+      if (0 < yydebug) {
+          yycdebug(s
+                   + (yykind.getCode() < YYNTOKENS_ ? " token " : " nterm ")
+                   + yykind.getName() + " ("]b4_locations_if([
+                   + yylocation + ": "])[
+                   + (yyvalue == null ? "(null)" : yyvalue.toString()) + ")");
+      }
  }]])[

 ]b4_push_if([],[[
@@ -521,7 +519,7 @@ import java.text.MessageFormat;
   * @@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
@@ -532,7 +530,7 @@ import java.text.MessageFormat;
   *
   * @@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])])])[
+  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])])])[
  {]b4_locations_if([[
    /* @@$.  */
    ]b4_location_type[ yyloc;]])[
@@ -612,8 +610,8 @@ b4_dollar_popdef[]dnl

        /* Convert token to internal form.  */
        yytoken = yytranslate_ (yychar);]b4_parse_trace_if([[
-        yySymbolPrint ("Next token is", yytoken,
-                       yylval]b4_locations_if([, yylloc])[);]])[
+        yySymbolPrint("Next token is", yytoken,
+                      yylval]b4_locations_if([, yylloc])[);]])[

        if (yytoken == SymbolKind.]b4_symbol_prefix[YYerror)
          {
@@ -649,8 +647,8 @@ b4_dollar_popdef[]dnl
            else
              {
                /* Shift the lookahead token.  */]b4_parse_trace_if([[
-                yySymbolPrint ("Shifting", yytoken,
-                               yylval]b4_locations_if([, yylloc])[);
+                yySymbolPrint("Shifting", yytoken,
+                              yylval]b4_locations_if([, yylloc])[);
 ]])[
                /* Discard the token being shifted.  */
                yychar = YYEMPTY_;
@@ -683,7 +681,7 @@ b4_dollar_popdef[]dnl
      `-----------------------------*/
      case YYREDUCE:
        yylen = yyr2_[yyn];
-        label = yyaction (yyn, yystack, yylen);
+        label = yyaction(yyn, yystack, yylen);
        yystate = yystack.stateAt (0);
        break;

@@ -781,8 +779,8 @@ b4_dollar_popdef[]dnl
        yystack.pop (2);]])[

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

        yystate = yyn;
        yystack.push (yyn, yylval]b4_locations_if([, yyloc])[);
@@ -833,7 +831,7 @@ b4_dollar_popdef[]dnl
    this.push_parse_initialized = true;

  }
-]b4_locations_if([
+]b4_locations_if([[
  /**
   * Push parse given input from an external lexer.
   *
@@ -843,36 +841,32 @@ b4_dollar_popdef[]dnl
   *
   * @@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));
+  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.
+   * 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);
+  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([[
+          ]b4_location_type[ yyloc = new ]b4_location_type[(yylexer.getStartPos(), yylexer.getEndPos());
+          status = push_parse(token, lval, yyloc);]], [[
+          status = push_parse(token, lval);]])[
+      } while (status == YYPUSH_MORE);
+      return status == YYACCEPT;
  }
 ]])[

@@ -950,6 +944,8 @@ b4_dollar_popdef[]dnl
                  yyarg[yycount++] = SymbolKind.get (yyx);
              }
        }
+      if (yyarg != null && yycount == yyoffset && yyoffset < yyargn)
+        yyarg[yycount] = null;
      return yycount - yyoffset;
    }
  }
@@ -996,39 +992,39 @@ b4_dollar_popdef[]dnl
  }
 ]])[

-/**
-   * Report a syntax error.
+  /**
+   * Build and emit a "syntax error" message in a user-defined way.
+   *
+   * @@param ctx  The context of the error.
   */
-  private void yyreportSyntaxError (Context yyctx)
-  {]b4_parse_error_bmatch(
+  private void yyreportSyntaxError(Context yyctx) {]b4_parse_error_bmatch(
 [custom], [[
-    yylexer.reportSyntaxError (yyctx);]],
+      yylexer.reportSyntaxError(yyctx);]],
 [detailed\|verbose], [[
-    if (yyErrorVerbose)
-      {
-        final int argmax = 5;
-        SymbolKind[] yyarg = new SymbolKind[argmax];
-        int yycount = yysyntaxErrorArguments (yyctx, yyarg, argmax);
-        String[] yystr = new String[yycount];
-        for (int yyi = 0; yyi < yycount; ++yyi)
-          yystr[yyi] = yyarg[yyi].getName();
-        String yyformat;
-        switch (yycount)
-          {
-            default:
-            case 0: yyformat = ]b4_trans(["syntax error"])[; break;
-            case 1: yyformat = ]b4_trans(["syntax error, unexpected {0}"])[; break;
-            case 2: yyformat = ]b4_trans(["syntax error, unexpected {0}, expecting {1}"])[; break;
-            case 3: yyformat = ]b4_trans(["syntax error, unexpected {0}, expecting {1} or {2}"])[; break;
-            case 4: yyformat = ]b4_trans(["syntax error, unexpected {0}, expecting {1} or {2} or {3}"])[; break;
-            case 5: yyformat = ]b4_trans(["syntax error, unexpected {0}, expecting {1} or {2} or {3} or {4}"])[; break;
+      if (yyErrorVerbose) {
+          final int argmax = 5;
+          SymbolKind[] yyarg = new SymbolKind[argmax];
+          int yycount = yysyntaxErrorArguments(yyctx, yyarg, argmax);
+          String[] yystr = new String[yycount];
+          for (int yyi = 0; yyi < yycount; ++yyi) {
+              yystr[yyi] = yyarg[yyi].getName();
          }
-        yyerror (]b4_locations_if([[yyctx.yylocation, ]])[new MessageFormat (yyformat).format (yystr));
-        return;
-      }
-    yyerror (]b4_locations_if([[yyctx.yylocation, ]])["syntax error");]],
+          String yyformat;
+          switch (yycount) {
+              default:
+              case 0: yyformat = ]b4_trans(["syntax error"])[; break;
+              case 1: yyformat = ]b4_trans(["syntax error, unexpected {0}"])[; break;
+              case 2: yyformat = ]b4_trans(["syntax error, unexpected {0}, expecting {1}"])[; break;
+              case 3: yyformat = ]b4_trans(["syntax error, unexpected {0}, expecting {1} or {2}"])[; break;
+              case 4: yyformat = ]b4_trans(["syntax error, unexpected {0}, expecting {1} or {2} or {3}"])[; break;
+              case 5: yyformat = ]b4_trans(["syntax error, unexpected {0}, expecting {1} or {2} or {3} or {4}"])[; break;
+          }
+          yyerror(]b4_locations_if([[yyctx.yylocation, ]])[new MessageFormat(yyformat).format(yystr));
+      } else {
+          yyerror(]b4_locations_if([[yyctx.yylocation, ]])[]b4_trans(["syntax error"])[);
+      }]],
 [simple], [[
-    yyerror (]b4_locations_if([[yyctx.yylocation, ]])["syntax error");]])[
+      yyerror(]b4_locations_if([[yyctx.yylocation, ]])[]b4_trans(["syntax error"])[);]])[
  }

  /**
@@ -1074,10 +1070,10 @@ b4_dollar_popdef[]dnl

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

  /* YYTRANSLATE_(TOKEN-NUM) -- Symbol number corresponding to TOKEN-NUM
@@ -41,6 +41,13 @@ m4_define([b4_stack_define],
        : seq_ (n)
      {}

+#if 201103L <= YY_CPLUSPLUS
+      /// Non copyable.
+      stack (const stack&) = delete;
+      /// Non copyable.
+      stack& operator= (const stack&) = delete;
+#endif
+
      /// Random access.
      ///
      /// Index 0 returns the topmost element.
@@ -126,8 +133,12 @@ m4_define([b4_stack_define],
      };

    private:
+#if YY_CPLUSPLUS < 201103L
+      /// Non copyable.
      stack (const stack&);
+      /// Non copyable.
      stack& operator= (const stack&);
+#endif
      /// The wrapped container.
      S seq_;
    };
@@ -115,6 +115,13 @@ m4_define([b4_value_type_declare],
      new (yyas_<T> ()) T (YY_MOVE (t));
    }

+#if 201103L <= YY_CPLUSPLUS
+    /// Non copyable.
+    semantic_type (const self_type&) = delete;
+    /// Non copyable.
+    self_type& operator= (const self_type&) = delete;
+#endif
+
    /// Destruction, allowed only if empty.
    ~semantic_type () YY_NOEXCEPT
    {]b4_parse_assert_if([
@@ -258,9 +265,12 @@ m4_define([b4_value_type_declare],
    }

  private:
-    /// Prohibit blind copies.
-    self_type& operator= (const self_type&);
+#if YY_CPLUSPLUS < 201103L
+    /// Non copyable.
    semantic_type (const self_type&);
+    /// Non copyable.
+    self_type& operator= (const self_type&);
+#endif

    /// Accessor to raw memory as \a T.
    template <typename T>
@@ -132,6 +132,7 @@ m4_define([b4_rhs_value],
 # b4_lhs_location()
 # -----------------
 # Expansion of @$.
+# Overparenthetized to avoid obscure problems with "foo$$bar = foo$1bar".
 m4_define([b4_lhs_location],
 [(yyloc)])

@@ -140,6 +141,7 @@ m4_define([b4_lhs_location],
 # ---------------------------------
 # Expansion of @POS, where the current rule has RULE-LENGTH symbols
 # on RHS.
+# Overparenthetized to avoid obscure problems with "foo$$bar = foo$1bar".
 m4_define([b4_rhs_location],
 [(yylsp@{b4_subtract([$2], [$1])@})])

@@ -401,50 +403,10 @@ m4_if(b4_api_prefix, [yy], [],
 ]b4_declare_symbol_enum[

 ]b4_user_post_prologue[
-]b4_percent_code_get[]dnl
-
-[#ifdef short
-# undef short
-#endif
-
+]b4_percent_code_get[
 ]b4_c99_int_type_define[

-#ifndef YYPTRDIFF_T
-# if defined __PTRDIFF_TYPE__ && defined __PTRDIFF_MAX__
-#  define YYPTRDIFF_T __PTRDIFF_TYPE__
-#  define YYPTRDIFF_MAXIMUM __PTRDIFF_MAX__
-# elif defined PTRDIFF_MAX
-#  ifndef ptrdiff_t
-#   include <stddef.h> /* INFRINGES ON USER NAME SPACE */
-#  endif
-#  define YYPTRDIFF_T ptrdiff_t
-#  define YYPTRDIFF_MAXIMUM PTRDIFF_MAX
-# else
-#  define YYPTRDIFF_T long
-#  define YYPTRDIFF_MAXIMUM LONG_MAX
-# endif
-#endif
-
-#ifndef YYSIZE_T
-# ifdef __SIZE_TYPE__
-#  define YYSIZE_T __SIZE_TYPE__
-# elif defined size_t
-#  define YYSIZE_T size_t
-# elif defined __STDC_VERSION__ && 199901 <= __STDC_VERSION__
-#  include <stddef.h> /* INFRINGES ON USER NAME SPACE */
-#  define YYSIZE_T size_t
-# else
-#  define YYSIZE_T unsigned
-# endif
-#endif
-
-#define YYSIZE_MAXIMUM                                  \
-  YY_CAST (YYPTRDIFF_T,                                 \
-           (YYPTRDIFF_MAXIMUM < YY_CAST (YYSIZE_T, -1)  \
-            ? YYPTRDIFF_MAXIMUM                         \
-            : YY_CAST (YYSIZE_T, -1)))
-
-#define YYSIZEOF(X) YY_CAST (YYPTRDIFF_T, sizeof (X))
+]b4_sizes_types_define[

 /* Stored state numbers (used for stacks). */
 typedef ]b4_int_type(0, m4_eval(b4_states_number - 1))[ yy_state_t;
@@ -826,9 +788,8 @@ yy_reduce_print (yy_state_t *yyssp, YYSTYPE *yyvsp,]b4_locations_if([[ YYLTYPE *
      YYFPRINTF (stderr, "   $%d = ", yyi + 1);
      yy_symbol_print (stderr,
                       YY_ACCESSING_SYMBOL (+yyssp[yyi + 1 - yynrhs]),
-                       &]b4_rhs_value(yynrhs, yyi + 1)[
-                       ]b4_locations_if([, &]b4_rhs_location(yynrhs, yyi + 1))[]dnl
-                       b4_user_args[);
+                       &]b4_rhs_value(yynrhs, yyi + 1)[]b4_locations_if([,
+                       &]b4_rhs_location(yynrhs, yyi + 1))[]b4_user_args[);
      YYFPRINTF (stderr, "\n");
    }
 }
@@ -1197,6 +1158,8 @@ yypcontext_expected_tokens (const yypcontext_t *yyctx,
              yyarg[yycount++] = YY_CAST (yysymbol_kind_t, yyx);
          }
    }]])[
+  if (yyarg && yycount == 0 && 0 < yyargn)
+    yyarg[0] = ]b4_symbol(-2, kind)[;
  return yycount;
 }

@@ -2052,10 +2015,8 @@ yyerrlab1:
  YY_IGNORE_MAYBE_UNINITIALIZED_END
 ]b4_locations_if([[
  yyerror_range[2] = yylloc;
-  /* Using YYLLOC is tempting, but would change the location of
-     the lookahead.  YYLOC is available though.  */
-  YYLLOC_DEFAULT (yyloc, yyerror_range, 2);
-  *++yylsp = yyloc;]])[
+  ++yylsp;
+  YYLLOC_DEFAULT (*yylsp, yyerror_range, 2);]])[

  /* Shift the error token.  */
  YY_SYMBOL_PRINT ("Shifting", YY_ACCESSING_SYMBOL (yyn), yyvsp, yylsp);
@@ -300,10 +300,7 @@ Bison Declarations
 Parser C-Language Interface

 * Parser Function::         How to call @code{yyparse} and what it returns.
-* Push Parser Function::    How to call @code{yypush_parse} and what it returns.
-* Pull Parser Function::    How to call @code{yypull_parse} and what it returns.
-* Parser Create Function::  How to call @code{yypstate_new} and what it returns.
-* Parser Delete Function::  How to call @code{yypstate_delete} and what it returns.
+* Push Parser Interface::   How to create, use, and destroy push parsers.
 * Lexical::                 You must supply a function @code{yylex}
                              which reads tokens.
 * Error Reporting::         Passing error messages to the user.
@@ -2369,9 +2366,9 @@ yylex (void)
@end group
@end example

-Basically, the lexical analyzer performs the same processing as before:
-it skips blanks and tabs, and reads numbers or single-character tokens.
-In addition, it updates @code{yylloc}, the global variable (of type
+Basically, the lexical analyzer performs the same processing as before: it
+skips blanks and tabs, and reads numbers or single-character tokens.  In
+addition, it updates @code{yylloc}, the global variable (of type
@code{YYLTYPE}) containing the token's location.

 Now, each time this function returns a token, the parser has its kind as
@@ -4505,12 +4502,17 @@ typedef struct YYLTYPE
@} YYLTYPE;
@end example

+While default locations represent a range in the source file(s), this is not
+a requirement.  It could be a single point or just a line number, or even
+more complex structures.
+
 When @code{YYLTYPE} is not defined, at the beginning of the parsing, Bison
 initializes all these fields to 1 for @code{yylloc}.  To initialize
@code{yylloc} with a custom location type (or to chose a different
 initialization), use the @code{%initial-action} directive.  @xref{Initial
 Action Decl}.

+
@node Actions and Locations
@subsection Actions and Locations
@cindex location actions
@@ -6132,7 +6134,7 @@ the @code{full} value was introduced in Bison 2.7
@deffn Directive {%define api.push-pull} @var{kind}

@itemize @bullet
-@item Language(s): C (deterministic parsers only)
+@item Language(s): C (deterministic parsers only), Java

@item Purpose: Request a pull parser, a push parser, or both.
@xref{Push Decl}.
@@ -6922,10 +6924,7 @@ in the grammar file, you are likely to run into trouble.

@menu
 * Parser Function::         How to call @code{yyparse} and what it returns.
-* Push Parser Function::    How to call @code{yypush_parse} and what it returns.
-* Pull Parser Function::    How to call @code{yypull_parse} and what it returns.
-* Parser Create Function::  How to call @code{yypstate_new} and what it returns.
-* Parser Delete Function::  How to call @code{yypstate_delete} and what it returns.
+* Push Parser Interface::   How to create, use, and destroy push parsers.
 * Lexical::                 You must supply a function @code{yylex}
                              which reads tokens.
 * Error Reporting::         Passing error messages to the user.
@@ -7028,16 +7027,40 @@ void yyerror (YYLTYPE *llocp, int *randomness, const char *msg);
 int  yyparse (int *randomness);
@end example

-@node Push Parser Function
-@section The Push Parser Function @code{yypush_parse}
-@findex yypush_parse
+@node Push Parser Interface
+@section Push Parser Interface

-You call the function @code{yypush_parse} to parse a single token.  This
+@findex yypstate_new
+You call the function @code{yypstate_new} to create a new parser instance.
+This function is available if either the @samp{%define api.push-pull push}
+or @samp{%define api.push-pull both} declaration is used.  @xref{Push Decl}.
+
+@deftypefun {yypstate*} yypstate_new (@code{void})
+@anchor{yypstate_new}
+Return a valid parser instance if there is memory available, 0 otherwise.
+In impure mode, it will also return 0 if a parser instance is currently
+allocated.
+@end deftypefun
+
+@findex yypstate_delete
+You call the function @code{yypstate_delete} to delete a parser instance.
 function is available if either the @samp{%define api.push-pull push} or
@samp{%define api.push-pull both} declaration is used.
@xref{Push Decl}.

+@deftypefun void yypstate_delete (@code{yypstate *}@var{yyps})
+@anchor{yypstate_delete}
+Reclaim the memory associated with a parser instance.  After this call, you
+should no longer attempt to use the parser instance.
+@end deftypefun
+
+@findex yypush_parse
+You call the function @code{yypush_parse} to parse a single token.  This
+function is available if either the @samp{%define api.push-pull push} or
+@samp{%define api.push-pull both} declaration is used.  @xref{Push Decl}.
+
@deftypefun int yypush_parse (@code{yypstate *}@var{yyps})
+@anchor{yypush_parse}
 The value returned by @code{yypush_parse} is the same as for @code{yyparse}
 with the following exception: it returns @code{YYPUSH_MORE} if more input is
 required to finish parsing the grammar.
@@ -7051,50 +7074,35 @@ reuse.  For example, a calculator application which parses each input line
 as an expression can just keep reusing the same @code{yyps} even if an input
 was invalid.

-@node Pull Parser Function
-@section The Pull Parser Function @code{yypull_parse}
-@findex yypull_parse
-
 You call the function @code{yypull_parse} to parse the rest of the input
 stream.  This function is available if the @samp{%define api.push-pull both}
-declaration is used.
-@xref{Push Decl}.
+declaration is used.  @xref{Push Decl}.

@deftypefun int yypull_parse (@code{yypstate *}@var{yyps})
+@anchor{yypull_parse}
 The value returned by @code{yypull_parse} is the same as for @code{yyparse}.

 The parser instance @code{yyps} may be reused for new parses.
@end deftypefun

-@node Parser Create Function
-@section The Parser Create Function @code{yystate_new}
-@findex yypstate_new
+@deftypefun int yypstate_expected_tokens (@code{const yypstate *}yyps, @code{yysymbol_kind_t} @var{argv}@code{[]}, @code{int} @var{argc})
+Fill @var{argv} with the expected tokens, which never includes
+@code{YYSYMBOL_YYEMPTY}, @code{YYSYMBOL_YYerror}, or
+@code{YYSYMBOL_YYUNDEF}.

-You call the function @code{yypstate_new} to create a new parser instance.
-This function is available if either the @samp{%define api.push-pull push} or
-@samp{%define api.push-pull both} declaration is used.
-@xref{Push Decl}.
+Never put more than @var{argc} elements into @var{argv}, and on success
+return the number of tokens stored in @var{argv}.  If there are more
+expected tokens than @var{argc}, fill @var{argv} up to @var{argc} and return
+0.  If there are no expected tokens, also return 0, but set @code{argv[0]}
+to @code{YYSYMBOL_YYEMPTY}.

-@deftypefun {yypstate*} yypstate_new (@code{void})
-The function will return a valid parser instance if there was memory available
-or 0 if no memory was available.
-In impure mode, it will also return 0 if a parser instance is currently
-allocated.
+When LAC is enabled, may return a negative number on errors,
+such as @code{YYENOMEM} on memory exhaustion.
+
+If @var{argv} is null, return the size needed to store all the possible
+values, which is always less than @code{YYNTOKENS}.
@end deftypefun

-@node Parser Delete Function
-@section The Parser Delete Function @code{yystate_delete}
-@findex yypstate_delete
-
-You call the function @code{yypstate_delete} to delete a parser instance.
-function is available if either the @samp{%define api.push-pull push} or
-@samp{%define api.push-pull both} declaration is used.
-@xref{Push Decl}.
-
-@deftypefun void yypstate_delete (@code{yypstate *}@var{yyps})
-This function will reclaim the memory associated with a parser instance.
-After this call, you should no longer attempt to use the parser instance.
-@end deftypefun

@node Lexical
@section The Lexical Analyzer Function @code{yylex}
@@ -7546,9 +7554,12 @@ Fill @var{argv} with the expected tokens, which never includes
@code{YYSYMBOL_YYUNDEF}.

 Never put more than @var{argc} elements into @var{argv}, and on success
-return the effective number of tokens stored in @var{argv}.  Return 0 if
-there are more than @var{argc} expected tokens, yet fill @var{argv} up to
-@var{argc}.  When LAC is enabled, may return a negative number on errors,
+return the number of tokens stored in @var{argv}.  If there are more
+expected tokens than @var{argc}, fill @var{argv} up to @var{argc} and return
+0.  If there are no expected tokens, also return 0, but set @code{argv[0]}
+to @code{YYSYMBOL_YYEMPTY}.
+
+When LAC is enabled, may return a negative number on errors,
 such as @code{YYENOMEM} on memory exhaustion.

 If @var{argv} is null, return the size needed to store all the possible
@@ -7655,11 +7666,11 @@ recovery.
 In either case, the rest of the action is not executed.
@end deffn

-@deffn {Macro} YYEMPTY
+@deffn {Value} YYEMPTY
 Value stored in @code{yychar} when there is no lookahead token.
@end deffn

-@deffn {Macro} YYEOF
+@deffn {Value} YYEOF
 Value stored in @code{yychar} when the lookahead is the end of the input
 stream.
@end deffn
@@ -9645,10 +9656,10 @@ and understand the parser run-time traces (@pxref{Tracing}).
@node Understanding
@section Understanding Your Parser

-As documented elsewhere (@pxref{Algorithm})
-Bison parsers are @dfn{shift/reduce automata}.  In some cases (much more
-frequent than one would hope), looking at this automaton is required to
-tune or simply fix a parser.
+As documented elsewhere (@pxref{Algorithm}) Bison parsers are
+@dfn{shift/reduce automata}.  In some cases (much more frequent than one
+would hope), looking at this automaton is required to tune or simply fix a
+parser.

 The textual file is generated when the options @option{--report} or
@option{--verbose} are specified, see @ref{Invocation}.  Its name is made by
@@ -10604,6 +10615,26 @@ For compatibility with POSIX, the standard Bison distribution also contains
 a shell script called @command{yacc} that invokes Bison with the @option{-y}
 option.

+@sp 1
+
+The exit status of @command{bison} is:
+@table @asis
+@item 0 (success)
+when there were no errors.  Warnings, which are diagnostics about dubious
+constructs, do not change the exit status, unless they are turned into
+errors (@pxref{-Werror,,@option{-Werror}}).
+
+@item 1 (failure)
+when there were errors.  No file was generated (except the reports generated
+by @option{--verbose}, etc.).  In particular, the output files that possibly
+existed were not changed.
+
+@item 63 (mistmatch)
+when @command{bison} does not meet the version requirements of the grammar
+file. @xref{Require Decl}.  No file was generated or changed.
+@end table
+
+
@menu
 * Bison Options::     All the options described in detail,
                        in alphabetical order by short options.
@@ -10997,6 +11028,7 @@ instance, @option{-Wno-yacc} will hide the warnings about
 POSIX Yacc incompatibilities.

@item -Werror
+@anchor{-Werror}
 Turn enabled warnings for every @var{category} into errors, unless they are
 explicitly disabled by @option{-Wno-error=@var{category}}.

@@ -12111,9 +12143,10 @@ Fill @var{argv} with the expected tokens, which never includes
@code{symbol_kind::S_YYUNDEF}.

 Never put more than @var{argc} elements into @var{argv}, and on success
-return the effective number of tokens stored in @var{argv}.  Return 0 if
-there are more than @var{argc} expected tokens, yet fill @var{argv} up to
-@var{argc}.
+return the number of tokens stored in @var{argv}.  If there are more
+expected tokens than @var{argc}, fill @var{argv} up to @var{argc} and return
+0.  If there are no expected tokens, also return 0, but set @code{argv[0]}
+to @code{symbol_kind::S_YYEMPTY}.

 If @var{argv} is null, return the size needed to store all the possible
 values, which is always less than @code{YYNTOKENS}.
@@ -13001,9 +13034,6 @@ of the parser is always local to an instance of the parser class.
 Therefore, all Java parsers are ``pure'', and the @code{%define api.pure}
 directive does nothing when used in Java.

-Push parsers are currently unsupported in Java and @code{%define
-api.push-pull} have no effect.
-
 GLR parsers are currently unsupported in Java.  Do not use the
@code{glr-parser} directive.

@@ -13275,9 +13305,10 @@ Fill @var{argv} with the expected tokens, which never includes
@code{SymbolKind.S_YYERROR}, or @code{SymbolKind.S_YYUNDEF}.

 Never put more than @var{argc} elements into @var{argv}, and on success
-return the effective number of tokens stored in @var{argv}.  Return 0 if
-there are more than @var{argc} expected tokens, yet fill @var{argv} up to
-@var{argc}.
+return the number of tokens stored in @var{argv}.  If there are more
+expected tokens than @var{argc}, fill @var{argv} up to @var{argc} and return
+0.  If there are no expected tokens, also return 0, but set @code{argv[0]}
+to @code{null}.

 If @var{argv} is null, return the size needed to store all the possible
 values, which is always less than @code{YYNTOKENS}.
@@ -13318,9 +13349,9 @@ changed using @code{%define api.location.type @{@var{class-name}@}}.
@end deftypemethod

@deftypemethod {Lexer} {int} yylex ()
-Return the next token.  Its type is the return value, its semantic
-value and location are saved and returned by the their methods in the
-interface.
+Return the next token.  Its type is the return value, its semantic value and
+location are saved and returned by the their methods in the interface.  Not
+needed for push-only parsers.

 Use @samp{%define lex_throws} to specify any uncaught exceptions.
 Default is @code{java.io.IOException}.
@@ -13330,7 +13361,7 @@ Default is @code{java.io.IOException}.
@deftypemethodx {Lexer} {Position} getEndPos ()
 Return respectively the first position of the last token that @code{yylex}
 returned, and the first position beyond it.  These methods are not needed
-unless location tracking is active.
+unless location tracking and pull parsing are active.

 They should return new objects for each call, to avoid that all the symbol
 share the same Position boundaries.
@@ -13340,7 +13371,8 @@ The return type can be changed using @code{%define api.position.type
@end deftypemethod

@deftypemethod {Lexer} {Object} getLVal ()
-Return the semantic value of the last token that yylex returned.
+Return the semantic value of the last token that yylex returned.  Not needed
+for push-only parsers.

 The return type can be changed using @samp{%define api.value.type
@{@var{class-name}@}}.
@@ -14668,6 +14700,14 @@ is given a nonzero value, the parser will output information on input
 symbols and parser action.  @xref{Tracing}.
@end deffn

+@deffn {Value} YYEMPTY
+The pseudo token kind when there is no lookahead token.
+@end deffn
+
+@deffn {Value} YYEOF
+The token kind denoting is the end of the input stream.
+@end deffn
+
@deffn {Macro} yyerrok
 Macro to cause parser to recover immediately to its normal mode
 after a syntax error.  @xref{Error Recovery}.
@@ -14717,8 +14757,8 @@ In semantic actions, it stores the location of the lookahead token.
@end deffn

@deffn {Type} YYLTYPE
-Data type of @code{yylloc}; by default, a structure with four
-members.  @xref{Location Type}.
+Data type of @code{yylloc}.  By default in C, a structure with four members
+(start/end line/column).  @xref{Location Type}.
@end deffn

@deffn {Variable} yylval
@@ -14757,24 +14797,26 @@ Deprecated, use @code{%printer} instead (@pxref{Printer Decl}).
@deffn {Function} yypstate_delete
 The function to delete a parser instance, produced by Bison in push mode;
 call this function to delete the memory associated with a parser.
-@xref{Parser Delete Function}.  Does nothing when called with a null pointer.
+@xref{yypstate_delete,,@code{yypstate_delete}}.  Does nothing when called
+with a null pointer.
@end deffn

@deffn {Function} yypstate_new
 The function to create a parser instance, produced by Bison in push mode;
 call this function to create a new parser.
-@xref{Parser Create Function}.
+@xref{yypstate_new,,@code{yypstate_new}}.
@end deffn

@deffn {Function} yypull_parse
 The parser function produced by Bison in push mode; call this function to
 parse the rest of the input stream.
-@xref{Pull Parser Function}.
+@xref{yypull_parse,,@code{yypull_parse}}.
@end deffn

@deffn {Function} yypush_parse
 The parser function produced by Bison in push mode; call this function to
-parse a single token.  @xref{Push Parser Function}.
+parse a single token.
+@xref{yypush_parse,,@code{yypush_parse}}.
@end deffn

@deffn {Macro} YYRECOVERING
@@ -14822,6 +14864,10 @@ should not be confused with the @emph{symbol kinds}, used internally by the
 parser.
@end deffn

+@deffn {Value} YYUNDEF
+The token kind denoting an unknown token.
+@end deffn
+

@node Glossary
@appendix Glossary
@@ -14908,12 +14954,21 @@ A continuous flow of data between devices or programs.
@item Kind
 ``Token'' and ``symbol'' are each overloaded to mean either a grammar symbol
 (kind) or all parse info (kind, value, location) associated with occurrences
-of that grammar symbol from the input.  To disambiguate, we use ``token
-kind'' and ``symbol kind'' to mean both grammar symbols and the types that
-represent them in a base programming language (C, C++, etc.). However, we
-use ``token'' and ``symbol'' without the word ``kind'' to mean parsed
+of that grammar symbol from the input.  To disambiguate,
+
+@itemize
+@item
+we use ``token kind'' and ``symbol kind'' to mean both grammar symbols and
+the values that represent them in a base programming language (C, C++,
+etc.).  The names of the types of these values are typically
+@code{token_kind_t}, or @code{token_kind_type}, or @code{TokenKind},
+depending on the programming language.
+
+@item
+we use ``token'' and ``symbol'' without the word ``kind'' to mean parsed
 occurrences, and we append the word ``type'' to refer to the types that
 represent them in a base programming language.
+@end itemize

 In summary: When you see ``kind'', interpret ``symbol'' or ``token'' to mean
 a @emph{grammar symbol}.  When you don't see ``kind'' (including when you
@@ -131,7 +131,7 @@ dist_man_MANS = $(top_srcdir)/%D%/bison.1
 EXTRA_DIST += $(dist_man_MANS:.1=.x)
 MAINTAINERCLEANFILES += $(dist_man_MANS)

-# Differences to ignore when comparing the man page (the date).
+# Differences to ignore when comparing man pages (the date).
 remove_time_stamp = \
  sed 's/^\(\.TH[^"]*"[^"]*"[^"]*\)"[^"]*"/\1/'

@@ -140,17 +140,31 @@ if ! CROSS_COMPILING
 MAN_DEPS = %D%/bison.help %D%/bison.x $(top_srcdir)/configure
 endif

+# If we don't have help2man, just touch the target.  Maintainers must
+# have the real thing, so if there's a .git directory, fail hard.
+#
+# We shouldn't need this, but on some OS the timestamps in the tarball
+# leave us no choice.  See
+# https://lists.gnu.org/r/bug-bison/2020-05/msg00055.html.
 $(top_srcdir)/%D%/bison.1: $(MAN_DEPS)
-	$(AM_V_GEN)$(HELP2MAN)			\
-	    --include=$(top_srcdir)/%D%/bison.x	\
-	    --output=$@.tmp tests/bison
-	$(AM_V_at)if $(remove_time_stamp) $@ >$@a.tmp 2>/dev/null &&		\
-	   $(remove_time_stamp) $@.tmp | cmp $@a.tmp - >/dev/null 2>&1; then	\
-	  touch $@;								\
-	else									\
-	  mv $@.tmp $@;								\
+	$(AM_V_GEN)if $(HELP2MAN) --version >/dev/null 2>&1; then	\
+	  $(HELP2MAN)							\
+	    --include=$(top_srcdir)/%D%/bison.x				\
+	    --output=$@.tmp tests/bison &&				\
+	  { $(remove_time_stamp) $@     >$@a.tmp || true; } &&		\
+	    $(remove_time_stamp) $@.tmp >$@b.tmp &&			\
+	  if diff $@a.tmp $@b.tmp >/dev/null 2>&1; then			\
+	    touch $@;							\
+	  else								\
+	    mv $@.tmp $@;						\
+	  fi &&								\
+	  rm -f $@*.tmp;						\
+	elif test -d $(srcdir)/.git; then				\
+	  echo >&2 "ERROR: $@: help2man is needed";			\
+	  exit 1;							\
+	else								\
+	  touch $@;							\
 	fi
-	$(AM_V_at)rm -f $@*.tmp

 if ENABLE_YACC
 nodist_man_MANS = %D%/yacc.1
@@ -139,7 +139,7 @@ namespace yy
 int
 main (int argc, const char *argv[])
 {
-  if (2 <= argc && isdigit (*argv[1]))
+  if (2 <= argc && isdigit (static_cast<unsigned char> (*argv[1])))
    {
      auto maxl = strtol (argv[1], nullptr, 10);
      max = INT_MIN <= maxl && maxl <= INT_MAX ? int(maxl) : 4;
@@ -5,7 +5,7 @@ BASE = bistromathic
 BISON = bison
 XSLTPROC = xsltproc

-# We need to find the headers and libs for readline and intl.
+# We need to find the headers and libs for readline (and possibly intl).
 # You probably need to customize this for your own environment.
 CPPFLAGS = -I/opt/local/include
 LDFLAGS = -L/opt/local/lib
@@ -14,7 +14,7 @@ LDFLAGS = -L/opt/local/lib
 BISON_LOCALEDIR = $(shell $(BISON) $(BISON_FLAGS) --print-localedir)
 CPPFLAGS += -DENABLE_NLS -DBISON_LOCALEDIR='"$(BISON_LOCALEDIR)"'

-LIBS = -lreadline -lintl
+LIBS = -lreadline -lm # In some environments, -lintl is needed.

 all: $(BASE)

@@ -15,12 +15,43 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.

-# macOS' version of readline does not repeat stdin on stdout in
-# non-interactive mode.
-if ! echo '1-1' | prog | grep '1-1' >/dev/null; then
-   strip_prompt=true
+
+# Beware of portability issues of readline when not feeding it from a
+# terminal.
+#
+# With recent versions of GNU Readline, input "1+2*3\n" gives
+# "> 1+2*3\n7\n> \n"
+#
+# macOS' version does not display the prompt and does not repeat stdin
+# on stdout, so input "1+2*3\n" gives "7\n" as output.  Let's try to
+# cope with this.
+#
+# On OpenBSD 6.5 the prompt is displayed, but the input is not
+# repeated (!).  So input "1+2*3\n" gives "> 7\n> \n" as output.
+#
+# On AIX, you get some escaping sequence before the prompt:
+# "<ESC>[?1034h> 1+2*3".  It appears to pass the terminfo capability
+# "smm", to put the terminal in "meta mode": as if the user had hit
+# META.
+
+echo >perfect '> 0
+0
+> '
+
+echo >ok '0'
+echo '0' | prog >effective
+
+echo "checking for readline output"
+if diff perfect effective; then
+    # Alles ist gut.
+    strip_prompt=false
+elif diff ok effective; then
+    strip_prompt=true
+else
+    skip "this is not the GNU Readline we expect"
 fi

+
 cat >input <<EOF
 1+2*3
 EOF
@@ -66,7 +97,7 @@ cat >input <<EOF
 EOF
 run 0 '> *
 > ''
-err: 1.1: syntax error: expected end of file or - or ( or exit or number or function or variable before *'
+err: 1.1: syntax error: expected end of file or - or ( or exit or number or function etc., before *'

 cat >input <<EOF
 1 + 2 * * 3
@@ -227,14 +258,22 @@ err: Cleanup: popping nterm input (1.1-4: )' -p
 # From now on, the differences between versions of GNU Readline are
 # too painful to try to cope with.
 if $strip_prompt; then
-    echo "SKIP: this is not the GNU Readline we expect"
-    if $exit; then
-        exit 0
-    else
-        exit 1
-    fi
+  echo "SKIP: this is not the GNU Readline we expect"
+  exit $status
 fi

+# On Windows10/MSYS2 the ^G coming from <tab> completion is not
+# emitted the same way
+# (https://lists.gnu.org/r/bug-bison/2020-05/msg00076.html).
+echo "checking for kernel name"
+case `uname -s` in
+  (MSYS*)
+    echo "SKIP: this is Windows/MSYS"
+    exit $status
+    ;;
+esac
+
+
 # Check completion after an operator.
 sed -e 's/\\t/	/g' >input <<EOF
 (1+\t\t
@@ -19,19 +19,22 @@ bistromathicdir = $(docdir)/%D%
 ## Bistromathics.  ##
 ## --------------- ##

-check_PROGRAMS += %D%/bistromathic
-TESTS += %D%/bistromathic.test
-EXTRA_DIST += %D%/bistromathic.test
-nodist_%C%_bistromathic_SOURCES = %D%/parse.y %D%/parse.h
 %D%/parse.c: $(dependencies)

-# Don't use gnulib's system headers.
-%C%_bistromathic_CPPFLAGS =			\
-  -DBISON_LOCALEDIR='"$(localdir)"'		\
-  -DLOCALEDIR='"$(localdir)"'			\
-  -I$(top_srcdir)/%D% -I$(top_builddir)/%D%
-%C%_bistromathic_LDADD = -lm -lreadline $(LIBINTL)
+if ENABLE_BISTROMATHIC
+  check_PROGRAMS += %D%/bistromathic
+  TESTS += %D%/bistromathic.test
+  nodist_%C%_bistromathic_SOURCES = %D%/parse.y

+  # Don't use gnulib's system headers.
+  %C%_bistromathic_CPPFLAGS =			\
+    -DBISON_LOCALEDIR='"$(localdir)"'		\
+    -DLOCALEDIR='"$(localdir)"'			\
+    -I$(top_srcdir)/%D% -I$(top_builddir)/%D%
+  %C%_bistromathic_LDADD = -lm $(LIBREADLINE) $(LIBINTL)
+endif
+
+EXTRA_DIST += %D%/bistromathic.test
 dist_bistromathic_DATA = %D%/parse.y %D%/Makefile %D%/README.md
 CLEANFILES += %D%/parse.[ch] %D%/parse.output
 CLEANDIRS += %D%/*.dSYM
@@ -1,7 +1,9 @@
 %require "3.6"

 %code top {
+  #include <assert.h>
  #include <ctype.h>  // isdigit
+  #include <locale.h> // LC_ALL
  #include <math.h>   // cos, sin, etc.
  #include <stdarg.h> // va_start
  #include <stdio.h>  // printf
@@ -315,7 +317,7 @@ error_format_string (int argc)
 {
  switch (argc)
    {
-    default: /* Avoid compiler warnings. */
+    default: // Avoid compiler warnings.
    case 0: return _("%@: syntax error");
    case 1: return _("%@: syntax error: unexpected %u");
      // TRANSLATORS: '%@' is a location in a file, '%u' is an
@@ -331,7 +333,7 @@ error_format_string (int argc)
    case 5: return _("%@: syntax error: expected %0e or %1e or %2e or %3e before %u");
    case 6: return _("%@: syntax error: expected %0e or %1e or %2e or %3e or %4e before %u");
    case 7: return _("%@: syntax error: expected %0e or %1e or %2e or %3e or %4e or %5e before %u");
-    case 8: return _("%@: syntax error: expected %0e or %1e or %2e or %3e or %4e or %5e or %6e before %u");
+    case 8: return _("%@: syntax error: expected %0e or %1e or %2e or %3e or %4e or %5e etc., before %u");
    }
 }

@@ -339,12 +341,15 @@ error_format_string (int argc)
 int
 yyreport_syntax_error (const yypcontext_t *ctx)
 {
-  enum { ARGS_MAX = 7 };
+  enum { ARGS_MAX = 6 };
  yysymbol_kind_t arg[ARGS_MAX];
  int argsize = yypcontext_expected_tokens (ctx, arg, ARGS_MAX);
  if (argsize < 0)
    return argsize;
-  const char *format = error_format_string (1 + argsize);
+  const int too_many_expected_tokens = argsize == 0 && arg[0] != YYSYMBOL_YYEMPTY;
+  if (too_many_expected_tokens)
+    argsize = ARGS_MAX;
+  const char *format = error_format_string (1 + argsize + too_many_expected_tokens);

  while (*format)
    // %@: location.
@@ -361,7 +366,7 @@ yyreport_syntax_error (const yypcontext_t *ctx)
      }
    // %0e, %1e...: expected token.
    else if (format[0] == '%'
-             && isdigit (format[1])
+             && isdigit ((unsigned char) format[1])
             && format[2] == 'e'
             && (format[1] - '0') < argsize)
      {
@@ -392,6 +397,22 @@ void yyerror (YYLTYPE *loc, char const *format, ...)
 }


+// Return a newly allocated copy of at most N bytes of STRING.  In
+// other words, return a copy of the initial segment of length N of
+// STRING.
+static char *
+xstrndup (const char *string, size_t n)
+{
+  // len = strnlen (string, n), portably.
+  const char *end = memchr (string, '\0', n);
+  size_t len = end ? (size_t) (end - string) : n;
+  char *new = malloc (len + 1);
+  assert (new);
+  new[len] = '\0';
+  return memcpy (new, string, len);
+}
+
+
 /*-----------.
 | Readline.  |
 `-----------*/
@@ -437,11 +458,11 @@ expected_tokens (const char *input,
  return res;
 }

-/* Attempt to complete on the contents of TEXT.  START and END bound the
-   region of rl_line_buffer that contains the word to complete.  TEXT is
-   the word to complete.  We can use the entire contents of rl_line_buffer
-   in case we want to do some simple parsing.  Return the array of matches,
-   or NULL if there aren't any. */
+// Attempt to complete on the contents of TEXT.  START and END bound
+// the region of rl_line_buffer that contains the word to complete.
+// TEXT is the word to complete.  We can use the entire contents of
+// rl_line_buffer in case we want to do some simple parsing.  Return
+// the array of matches, or NULL if there aren't any.
 char **
 completion (const char *text, int start, int end)
 {
@@ -452,7 +473,7 @@ completion (const char *text, int start, int end)

  // Get list of token numbers.
  int tokens[YYNTOKENS];
-  char *line = strndup (rl_line_buffer, start);
+  char *line = xstrndup (rl_line_buffer, start);
  int ntokens = expected_tokens (line, tokens, YYNTOKENS);
  free (line);

@@ -494,7 +515,7 @@ completion (const char *text, int start, int end)
        for (int j = 0; j < lcplen; ++j)
          if (matches[1][j] != matches[i][j])
            lcplen = j;
-      matches[0] = strndup (matches[1], lcplen);
+      matches[0] = xstrndup (matches[1], lcplen);
    }

  if (yydebug)
@@ -12,7 +12,7 @@ all: $(BASE)
 	$(BISON) $(BISONFLAGS) --defines --xml --graph=$*.gv -o $*.c $<

 %.c %.h: %.l
-	$(FLEX) $(FLEXFLAGS) -o$*.c --header-file=$*.h $<
+	$(FLEX) $(FLEXFLAGS) -o$*.c --header=$*.h $<

 scan.o: parse.h
 parse.o: scan.h
@@ -69,7 +69,9 @@ DASH = -
 	$(AM_V_LEX)rm -f $@ $@.tmp
 	$(AM_V_at)$(MKDIR_P) %D%
 	$(AM_V_at)touch $@.tmp
-	$(AM_V_at)$(LEX) $(AM_LFLAGS) $(LFLAGS) -o%D%/scan.c --header-file=%D%/scan.h $(srcdir)/%D%/scan.l
+## --header introduced in 2.5.6, renamed as --header-file in 2.6.4.
+## Backward compatibility ensured since --header is an unambiguous prefix.
+	$(AM_V_at)$(LEX) $(AM_LFLAGS) $(LFLAGS) -o%D%/scan.c --header=%D%/scan.h $(srcdir)/%D%/scan.l
 	$(AM_V_at)mv $@.tmp $@


@@ -15,7 +15,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.

-seq 0 >/dev/null || exit 77
+(seq 0) >/dev/null 2>&1 || skip "gimme one seq"

 cat >input <<EOF
 1+2*3
@@ -9,7 +9,7 @@ afterwards.
 The usual calculator, a very simple version.

 ## calc/Calc.y
-The calculator, but with location tracking and debug traces.
+The calculator, but with location tracking, debug traces, and a push parser.

 <!---

@@ -2,6 +2,7 @@

 %define api.parser.class {Calc}
 %define api.parser.public
+%define api.push-pull push

 %define parse.error custom
 %define parse.trace
@@ -20,12 +21,19 @@

 %code {
  public static void main(String[] args) throws IOException {
-    CalcLexer l = new CalcLexer(System.in);
-    Calc p = new Calc(l);
+    CalcLexer scanner = new CalcLexer(System.in);
+    Calc parser = new Calc(scanner);
    for (String arg : args)
      if (arg.equals("-p"))
-        p.setDebugLevel(1);
-    if (!p.parse())
+        parser.setDebugLevel(1);
+    int status;
+    do {
+      int token = scanner.getToken();
+      Object lval = scanner.getValue();
+      Calc.Location yyloc = scanner.getLocation();
+      status = parser.push_parse(token, lval, yyloc);
+    } while (status == Calc.YYPUSH_MORE);
+    if (status != Calc.YYACCEPT)
      System.exit(1);
  }

@@ -105,14 +113,17 @@ class CalcLexer implements Calc.Lexer {
  Position start = new Position(1, 0);
  Position end = new Position(1, 0);

-  public Position getStartPos() {
-    return new Position(start);
-  }
-
-  public Position getEndPos() {
-    return new Position(end);
+  /**
+   * The location of the last token read.
+   * Implemented with getStartPos and getEndPos in pull parsers.
+   */
+  public Calc.Location getLocation() {
+    return new Calc.Location(new Position(start), new Position(end));
  }

+  /**
+   * Build and emit a syntax error message.
+   */
  public void reportSyntaxError(Calc.Context ctx) {
    System.err.print(ctx.getLocation() + ": syntax error");
    {
@@ -131,20 +142,33 @@ class CalcLexer implements Calc.Lexer {
    System.err.println("");
  }

-  public void yyerror(Calc.Location l, String s) {
-    if (l == null)
-      System.err.println(s);
+  /**
+   * Emit an error referring to the given location in a user-defined way.
+   *
+   * @@param loc The location of the element to which the
+   *                error message is related.
+   * @@param msg The string for the error message.
+   */
+  public void yyerror(Calc.Location loc, String msg) {
+    if (loc == null)
+      System.err.println(msg);
    else
-      System.err.println(l + ": " + s);
+      System.err.println(loc + ": " + msg);
  }

  Integer yylval;

-  public Object getLVal() {
+  /**
+   * The value of the last token read.  Called getLVal in pull parsers.
+   */
+  public Object getValue() {
    return yylval;
  }

-  public int yylex() throws IOException {
+  /**
+   * Fetch the next token.  Called yylex in pull parsers.
+   */
+  public int getToken() throws IOException {
    start.set(reader.getPosition());
    int ttype = st.nextToken();
    end.set(reader.getPosition());
@@ -160,7 +184,7 @@ class CalcLexer implements Calc.Lexer {
      end.set(reader.getPreviousPosition());
      return NUM;
    case ' ': case '\t':
-      return yylex();
+      return getToken();
    case '!':
      return BANG;
    case '+':
@@ -185,7 +209,9 @@ class CalcLexer implements Calc.Lexer {
  }
 }

-
+/**
+ * A class defining a point in the input.
+ */
 class Position {
  public int line = 1;
  public int column = 1;
@@ -227,6 +253,9 @@ class Position {
  }
 }

+/**
+ * A Stream reader that keeps track of the current Position.
+ */
 class PositionReader extends BufferedReader {

  private Position position = new Position();
@@ -25,7 +25,7 @@ medir=$(dirname "$1" | sed -e 's,.*examples/,,')
 number=1

 # Exit status of this script.
-exit=true
+status=0

 # top_builddir.
 cwd=$(pwd)
@@ -34,6 +34,13 @@ cwd=$(pwd)
 # See bistromathic.test.
 strip_prompt=false

+# If diff supports --strip-trailing-cr, use it, to avoid EOL issues
+# when testing Java programs on Windows.
+echo "checking for diff --strip-trailing-cr"
+if diff --strip-trailing-cr "$1" "$1"; then
+  diff_opts=--strip-trailing-cr
+fi
+
 # The exercised program.
 abs_medir=$cwd/examples/$medir
 if test -x "$abs_medir/$me"; then
@@ -68,6 +75,20 @@ trap cleanup 0 1 2 13 15
 mkdir $$.dir
 cd $$.dir

+
+# skip [MSG]
+# ----------
+# Skip this test.
+skip ()
+{
+  if test x"$1" != x; then
+    echo "SKIP: $1"
+  fi
+  # See Autoconf's doc on 'trap'.
+  (exit 77); exit 77
+}
+
+
 # run [-noerr, -n] EXPECTED-EXIT-STATUS EXPECTED-OUTPUT [PARSER-OPTIONS]
 # ----------------------------------------------------------------------
 # -noerr: ignore stderr, otherwise merge it into effective output.
@@ -115,7 +136,7 @@ run ()
  } >eff

  if test $sta_eff -eq $sta_exp; then
-    if cmp eff exp 2>/dev/null; then
+    if diff $diff_opts eff exp >/dev/null 2>&1; then
      echo "$me: PASS: $number"
    else
      echo "$me: FAIL: $number"
@@ -126,21 +147,21 @@ run ()
      echo "$me: effective output:"
      sed -e 's/^/  /' eff
      echo "$me: diff:"
-      diff -u exp eff | sed -e 's/^/  /'
-      exit=false
+      diff $diff_opts -u exp eff | sed -e 's/^/  /'
+      status=1
    fi
  else
    echo "$me: FAIL: $number (expected status: $sta_exp, effective: $sta_eff)"
    cat err_eff
-    exit=false
+    status=1
  fi
  number=$(expr $number + 1)
 }

 # We have cd'd one level deeper.
 case $1 in
-  /*) . "$1";;
-  *)  . "../$1";;
+  /*) . "$1" || status=2;;
+  *)  . "../$1" || status=2;;
 esac

-$exit
+exit $status
@@ -41,6 +41,22 @@ else
 fi
 ])

+
+AC_CACHE_CHECK([whether flex supports --header=FILE],
+                [ac_cv_prog_lex_supports_header_opt],
+[if _AC_DO_VAR([LEX --header=conftest.h conftest.l]); then
+  ac_cv_prog_lex_supports_header_opt=yes
+else
+  ac_cv_prog_lex_supports_header_opt=no
+fi
+])
+if test "$ac_cv_prog_lex_supports_header_opt" = yes; then
+  FLEX_SUPPORTS_HEADER_OPT=true
+else
+  FLEX_SUPPORTS_HEADER_OPT=false
+fi
+
+
 cat >conftest.l <<_ACEOF[
 %%
 a { ECHO; }
@@ -23,7 +23,7 @@
 #include "system.h"

 #include <argmatch.h>
-#include <ctype.h>
+#include <c-ctype.h>
 #include <progname.h>
 #include <stdarg.h>
 #include <sys/stat.h>
@@ -609,7 +609,7 @@ syntax_error (location loc,

  while (*format)
    if (format[0] == '%'
-        && isdigit (format[1])
+        && c_isdigit (format[1])
        && format[2] == '$'
        && format[3] == 's'
        && (format[1] - '0') < argc)
@@ -124,10 +124,11 @@ fixits_run (void)
  FILE *out = xfopen (input, "w");
  size_t line = 1;
  size_t offset = 1;
-  fixit const *f = NULL;
+  void const *p = NULL;
  gl_list_iterator_t iter = gl_list_iterator (fixits);
-  while (gl_list_iterator_next (&iter, (const void**) &f, NULL))
+  while (gl_list_iterator_next (&iter, &p, NULL))
    {
+      fixit const *f = p;
      /* Look for the correct line. */
      while (line < f->location.start.line)
        {
@@ -92,7 +92,7 @@ goto_print (goto_number i, FILE *out)
  const state_number dst = to_state[i];
  symbol_number var = states[dst]->accessing_symbol;
  fprintf (out,
-           "goto[%ld] = (%d, %s, %d)", i, src, symbols[var]->tag, dst);
+           "goto[%zu] = (%d, %s, %d)", i, src, symbols[var]->tag, dst);
 }

 void
@@ -117,6 +117,7 @@ BUILT_SOURCES +=                                \
 # definition of libbison, beware that they might expand as flags such as
 # `-lm`.  Keep them here.  Or use a Libtool convenience library.
 src_bison_LDADD =                               \
+  lib/libbison.a                                \
  $(ISNAND_LIBM)                                \
  $(ISNANF_LIBM)                                \
  $(ISNANL_LIBM)                                \
@@ -126,8 +127,7 @@ src_bison_LDADD =                               \
  $(LIBTHREAD)                                  \
  $(LIB_CLOCK_GETTIME)                          \
  $(LIB_GETHRXTIME)                             \
-  $(LIBTEXTSTYLE)                               \
-  lib/libbison.a
+  $(LIBTEXTSTYLE)


 EXTRA_DIST += %D%/i18n-strings.c
@@ -1,4 +1,4 @@
-/* A Bison parser, made by GNU Bison 3.5.90.  */
+/* A Bison parser, made by GNU Bison 3.6.  */

 /* Bison implementation for Yacc-like parsers in C

@@ -49,7 +49,7 @@
 #define YYBISON 1

 /* Bison version.  */
-#define YYBISON_VERSION "3.5.90"
+#define YYBISON_VERSION "3.6"

 /* Skeleton name.  */
 #define YYSKELETON_NAME "yacc.c"
@@ -408,6 +408,7 @@ typedef int yytype_uint16;

 #define YYSIZEOF(X) YY_CAST (YYPTRDIFF_T, sizeof (X))

+
 /* Stored state numbers (used for stacks). */
 typedef yytype_uint8 yy_state_t;

@@ -1304,8 +1305,8 @@ yy_reduce_print (yy_state_t *yyssp, YYSTYPE *yyvsp, YYLTYPE *yylsp,
      YYFPRINTF (stderr, "   $%d = ", yyi + 1);
      yy_symbol_print (stderr,
                       YY_ACCESSING_SYMBOL (+yyssp[yyi + 1 - yynrhs]),
-                       &yyvsp[(yyi + 1) - (yynrhs)]
-                       , &(yylsp[(yyi + 1) - (yynrhs)])                       );
+                       &yyvsp[(yyi + 1) - (yynrhs)],
+                       &(yylsp[(yyi + 1) - (yynrhs)]));
      YYFPRINTF (stderr, "\n");
    }
 }
@@ -1631,6 +1632,8 @@ yypcontext_expected_tokens (const yypcontext_t *yyctx,
              yyarg[yycount++] = yysym;
          }
    }
+  if (yyarg && yycount == 0 && 0 < yyargn)
+    yyarg[0] = YYSYMBOL_YYEMPTY;
  return yycount;
 }

@@ -2738,10 +2741,8 @@ yyerrlab1:
  YY_IGNORE_MAYBE_UNINITIALIZED_END

  yyerror_range[2] = yylloc;
-  /* Using YYLLOC is tempting, but would change the location of
-     the lookahead.  YYLOC is available though.  */
-  YYLLOC_DEFAULT (yyloc, yyerror_range, 2);
-  *++yylsp = yyloc;
+  ++yylsp;
+  YYLLOC_DEFAULT (*yylsp, yyerror_range, 2);

  /* Shift the error token.  */
  YY_SYMBOL_PRINT ("Shifting", YY_ACCESSING_SYMBOL (yyn), yyvsp, yylsp);
@@ -1,4 +1,4 @@
-/* A Bison parser, made by GNU Bison 3.5.90.  */
+/* A Bison parser, made by GNU Bison 3.6.  */

 /* Bison interface for Yacc-like parsers in C

@@ -67,7 +67,10 @@
   Conflict resolution can decide that certain tokens in certain
   states should explicitly be errors (for implementing %nonassoc).
   For each state, the tokens that are errors for this reason are
-   recorded in an errs structure, which holds the token numbers.
+   recorded in an errs structure.  The generated parser does not
+   depend on this errs structure, it is used only in the reports
+   (*.output, etc.) to describe conflicted actions that have been
+   discarded.

   There is at least one goto transition present in state zero.  It
   leads to a next-to-final state whose accessing_symbol is the
@@ -144,3 +144,44 @@ export LC_CTYPE

 # Empty if no xsltproc was found
 : ${XSLTPROC='@XSLTPROC@'}
+
+
+# Some tests expect a precise diff format.  See AT_DIFF_U_CHECK.
+# See https://lists.gnu.org/r/bug-bison/2020-05/msg00049.html.
+cat >conftest.1 <<EOF
+1
+2
+3
+4
+5
+6
+EOF
+
+cat >conftest.2 <<EOF
+1
+22
+3
+4
+55
+6
+EOF
+
+cat >conftest.expected <<EOF
+@@ -1,6 +1,6 @@
+ 1
+-2
+22
+ 3
+ 4
+-5
+55
+ 6
+EOF
+
+diff -u conftest.1 conftest.2 2>/dev/null | sed -n '/^@@/,$p' | sed 's/^ $//' >conftest.diff
+if diff conftest.expected conftest.diff >/dev/null; then
+    DIFF_U_WORKS=true
+else
+    DIFF_U_WORKS=false
+fi
+rm conftest.*
@@ -19,7 +19,7 @@ AT_BANNER([[Diagnostics.]])


 # AT_TEST($1: TITLE, $2: GRAMMAR, $3: EXIT-STATUS, $4: OUTPUT-WITH-STYLE,
-#         $5: EXTRA_ENV
+#         $5: EXTRA_ENV, $6: SKIP-IF)
 # -----------------------------------------------------------------------
 # Run Bison on GRAMMAR with debugging style enabled, and expect
 # OUTPUT-WITH-STYLE as diagnostics.
@@ -33,6 +33,9 @@ AT_KEYWORDS([diagnostics])
 locale=`locale -a | $EGREP '^en_US\.(UTF-8|utf8)$' | sed 1q`
 AT_SKIP_IF([test x == x"$locale"])

+m4_ifval([$6],
+[AT_SKIP_IF([$6])])
+
 AT_BISON_OPTION_PUSHDEFS

 AT_DATA_GRAMMAR([[input.y]], [$2])
@@ -220,15 +223,14 @@ exp: an\005error.

 AT_TEST([[Tabulations and multibyte characters]],
 [[%%
-exp: a b c d e f g h
+exp: a b c d e f g
 a: {		}
 b: {            }
 c: {------------}
 d: {éééééééééééé}
-e: {∇⃗×𝐸⃗ = -∂𝐵⃗/∂t}
-f: {	42	}
-g: {	"฿¥$€₦"	}
-h: {	🐃	}
+e: {	42	}
+f: {	"฿¥$€₦"	}
+g: {	🐃	}
 ]],
 [0],
 [[input.y:11.4-17: <warning>warning:</warning> empty rule without %empty [<warning>-Wempty-rule</warning>]
@@ -248,25 +250,37 @@ input.y:14.4-17: <warning>warning:</warning> empty rule without %empty [<warning
      |    <warning>^~~~~~~~~~~~~~</warning>
      |    <fixit-insert>%empty</fixit-insert>
 input.y:15.4-17: <warning>warning:</warning> empty rule without %empty [<warning>-Wempty-rule</warning>]
-   15 | e: <warning>{∇⃗×𝐸⃗ = -∂𝐵⃗/∂t}</warning>
+   15 | e: <warning>{	42	}</warning>
      |    <warning>^~~~~~~~~~~~~~</warning>
      |    <fixit-insert>%empty</fixit-insert>
 input.y:16.4-17: <warning>warning:</warning> empty rule without %empty [<warning>-Wempty-rule</warning>]
-   16 | f: <warning>{	42	}</warning>
+   16 | f: <warning>{	"฿¥$€₦"	}</warning>
      |    <warning>^~~~~~~~~~~~~~</warning>
      |    <fixit-insert>%empty</fixit-insert>
 input.y:17.4-17: <warning>warning:</warning> empty rule without %empty [<warning>-Wempty-rule</warning>]
-   17 | g: <warning>{	"฿¥$€₦"	}</warning>
-      |    <warning>^~~~~~~~~~~~~~</warning>
-      |    <fixit-insert>%empty</fixit-insert>
-input.y:18.4-17: <warning>warning:</warning> empty rule without %empty [<warning>-Wempty-rule</warning>]
-   18 | h: <warning>{	🐃	}</warning>
+   17 | g: <warning>{	🐃	}</warning>
      |    <warning>^~~~~~~~~~~~~~</warning>
      |    <fixit-insert>%empty</fixit-insert>
 input.y: <warning>warning:</warning> fix-its can be applied.  Rerun with option '--update'. [<warning>-Wother</warning>]
 ]])


+# Likewise, but currently not portable to AIX and Cygwin.
+# https://lists.gnu.org/r/bug-bison/2020-05/msg00050.html
+# https://lists.gnu.org/r/bug-bison/2020-05/msg00003.html.
+AT_TEST([[Tabulations and multibyte characters]],
+[[%%
+e: {∇⃗×𝐸⃗ = -∂𝐵⃗/∂t}
+]],
+[0],
+[[input.y:10.4-17: <warning>warning:</warning> empty rule without %empty [<warning>-Wempty-rule</warning>]
+   10 | e: <warning>{∇⃗×𝐸⃗ = -∂𝐵⃗/∂t}</warning>
+      |    <warning>^~~~~~~~~~~~~~</warning>
+      |    <fixit-insert>%empty</fixit-insert>
+input.y: <warning>warning:</warning> fix-its can be applied.  Rerun with option '--update'. [<warning>-Wother</warning>]
+]], [], [uname -a | $EGREP -i 'aix|cygwin'])
+
+
 ## --------------- ##
 ## Special files.  ##
 ## --------------- ##
@@ -35,14 +35,9 @@ dnl time comes, just use sed to drop the line numbers.  For now, as LR(1)
 dnl support is rapidly evolving, let's keep that information to be careful.
 dnl However, we don't do diffs for canonical LR(1) because the diff is huge.
 m4_pushdef([AT_LALR1_DIFF_CHECK],
-[dnl We need diff -u, which is not portable.
-AT_CHECK([diff -u /dev/null /dev/null || exit 77], [0], [ignore])
-
-AT_CHECK([[sed 's/^%define lr.type .*$//' input.y > input-lalr.y]])
+[AT_CHECK([[sed 's/^%define lr.type .*$//' input.y > input-lalr.y]])
 AT_BISON_CHECK([[--report=all input-lalr.y]], [[0]], [ignore], [ignore])
-AT_CHECK([[diff -u input-lalr.output input.output \
-           | sed -n '/^@@/,$p' | sed 's/^ $//']],
-         [[0]], [$1])])
+AT_DIFF_U_CHECK([[input-lalr.output input.output]], [$1])])

 AT_TEST_TABLES_AND_PARSE([$2[: LALR(1)]], [[LALR]], [[last-state]],
                         [[%define lr.type lalr
@@ -18,9 +18,9 @@
 AT_BANNER([[Java Calculator.]])


-# ------------------------- #
-# Java invalid directives.  #
-# ------------------------- #
+## ------------------------- ##
+## Java invalid directives.  ##
+## ------------------------- ##

 AT_SETUP([Java invalid directives])

@@ -42,9 +42,9 @@ YYParser.y:4.13-30: error: %destructor does not make sense in Java
 AT_CLEANUP


-# ------------------------- #
-# Helping Autotest macros.  #
-# ------------------------- #
+## ------------------------- ##
+## Helping Autotest macros.  ##
+## ------------------------- ##


 # AT_JAVA_POSITION_DEFINE_OLD
@@ -91,9 +91,9 @@ m4_define([AT_JAVA_POSITION_DEFINE_OLD],



-# -----------------#
-# Java Parameters. #
-# -----------------#
+## ----------------- ##
+## Java Parameters.  ##
+## ----------------- ##

 AT_BANNER([Java Parameters.])

@@ -146,7 +146,7 @@ m4_define([AT_CHECK_JAVA_MINIMAL_W_LEXER],
    System.err.println (loc + ": " + s);
  }

-  public int yylex ()$2
+  public int yylex()$2
  {
    $3
  }
@@ -164,9 +164,9 @@ m4_define([AT_CHECK_JAVA_GREP],
 ])])


-# ------------------------------------- #
-# Java parser class and package names.  #
-# ------------------------------------- #
+## ------------------------------------- ##
+## Java parser class and package names.  ##
+## ------------------------------------- ##

 AT_SETUP([Java parser class and package names])

@@ -191,9 +191,9 @@ AT_CHECK_JAVA_GREP([[package user_java_package;]])
 AT_CLEANUP


-# ----------------------------- #
-# Java parser class modifiers.  #
-# ----------------------------- #
+## ----------------------------- ##
+## Java parser class modifiers.  ##
+## ----------------------------- ##

 AT_SETUP([Java parser class modifiers])

@@ -255,9 +255,9 @@ AT_CHECK_JAVA_GREP([[/\*@Deprecated @SuppressWarnings("unchecked") @SuppressWarn
 AT_CLEANUP


-# ---------------------------------------- #
-# Java parser class extends and implements #
-# ---------------------------------------- #
+## ---------------------------------------- ##
+## Java parser class extends and implements ##
+## ---------------------------------------- ##

 AT_SETUP([Java parser class extends and implements])

@@ -275,9 +275,9 @@ AT_CHECK_JAVA_GREP([[class YYParser extends Thread implements Cloneable]])
 AT_CLEANUP


-# -------------------------------- #
-# Java %parse-param and %lex-param #
-# -------------------------------- #
+## -------------------------------- ##
+## Java %parse-param and %lex-param ##
+## -------------------------------- ##

 AT_SETUP([Java %parse-param and %lex-param])

@@ -349,9 +349,9 @@ AT_CHECK_JAVA_GREP([[ *this.parse_param2 = parse_param2;]], [2])
 AT_CLEANUP


-# ------------------------- #
-# Java throw specifications #
-# ------------------------- #
+## --------------------------- ##
+## Java throw specifications.  ##
+## --------------------------- ##

 AT_SETUP([Java throws specifications])

@@ -430,17 +430,17 @@ AT_JT_initial_action],
 [AT_JT_yylex_action],
 [],
 [AT_JT_parse_action])])
-AT_CHECK_JAVA_GREP([[ *int yylex ()]AT_JT_yylex_throws *[;]])
-AT_CHECK_JAVA_GREP([[ *private int yyaction ([^)]*)]AT_JT_yyaction_throws[ *]])
-AT_CHECK_JAVA_GREP([[ *public boolean parse ()]AT_JT_parse_throws[ *]])
+AT_CHECK_JAVA_GREP([[ *int yylex()]AT_JT_yylex_throws *[;]])
+AT_CHECK_JAVA_GREP([[ *private int yyaction([^)]*)]AT_JT_yyaction_throws[ *]])
+AT_CHECK_JAVA_GREP([[ *public boolean parse()]AT_JT_parse_throws[ *]])
 ])])])

 AT_CLEANUP


-# ------------------------------------- #
-# Java constructor init and init_throws #
-# ------------------------------------- #
+## --------------------------------------- ##
+## Java constructor init and init_throws.  ##
+## --------------------------------------- ##

 AT_SETUP([Java constructor init and init_throws])

@@ -465,9 +465,9 @@ m4_popdef([AT_Witness])
 AT_CLEANUP


-# ------------------------------------------ #
-# Java value, position, and location types.  #
-# ------------------------------------------ #
+## ------------------------------------------ ##
+## Java value, position, and location types.  ##
+## ------------------------------------------ ##

 AT_SETUP([Java value, position, and location types])

@@ -496,9 +496,9 @@ AT_CHECK([[$EGREP -v ' */?\*' YYParser.java | grep -w 'Location']], [1], [ignore
 AT_CLEANUP


-# ----------------------------------------------- #
-# Java syntax error handling without error token. #
-# ----------------------------------------------- #
+## ------------------------------------------------ ##
+## Java syntax error handling without error token.  ##
+## ------------------------------------------------ ##

 AT_SETUP([Java syntax error handling without error token])

@@ -180,28 +180,28 @@ AT_DATA([[input.y]],
 # Verify that the proper procedure(s) are generated for each case.
 AT_BISON_CHECK([[-Dapi.push-pull=pull -o Main.java input.y]])
 AT_CHECK_JAVA_GREP([[Main.java]],
-                   [[.*public boolean parse ().*]],
+                   [[.*public boolean parse().*]],
                   [1])
 # If BISON_USE_PUSH_FOR_PULL is set, then we have one occurrence of
 # this function, otherwise it should not be there.
 AT_CHECK_JAVA_GREP([[Main.java]],
-        [[.*public int push_parse (int yylextoken, Object yylexval).*]],
+        [[.*public int push_parse(int yylextoken, Object yylexval).*]],
        [${BISON_USE_PUSH_FOR_PULL-0}])

 AT_BISON_CHECK([[-Dapi.push-pull=both -o Main.java input.y]])
 AT_CHECK_JAVA_GREP([[Main.java]],
-                   [[.*public boolean parse ().*]],
+                   [[.*public boolean parse().*]],
                   [1])
 AT_CHECK_JAVA_GREP([[Main.java]],
-        [[.*public int push_parse (int yylextoken, Object yylexval).*]],
+        [[.*public int push_parse(int yylextoken, Object yylexval).*]],
        [1])

 AT_BISON_CHECK([[-Dapi.push-pull=push -o Main.java input.y]])
 AT_CHECK_JAVA_GREP([[Main.java]],
-                   [[.*public boolean parse ().*]],
+                   [[.*public boolean parse().*]],
                   [0])
 AT_CHECK_JAVA_GREP([[Main.java]],
-        [[.*public int push_parse (int yylextoken, Object yylexval).*]],
+        [[.*public int push_parse(int yylextoken, Object yylexval).*]],
        [1])

 AT_JAVA_COMPILE([[Main.java]])
@@ -83,6 +83,16 @@ set x `LC_ALL=C ls -l '$1'` &&
 ## ------------- ##


+# AT_DIFF_U_CHECK(DIFF-ARGS, EXPECTED-DIFF)
+# -----------------------------------------
+# If diff -u works as we expect, use it, with headers stripped.
+m4_define([AT_DIFF_U_CHECK],
+[if $DIFF_U_WORKS; then
+  AT_CHECK([diff -u $1 | sed -n '/^@@/,$p' | sed 's/^ $//'], [0], [$2])
+fi
+])
+
+
 # AT_PERL_CHECK(PERL-ARGS, ...)
 # -----------------------------
 # If Perl is available, run this test.
Author	SHA1	Message	Date
Akim Demaille	307fcdee00	version 3.6 * NEWS: Record release date.	2020-05-08 09:57:14 +02:00
Akim Demaille	d26d10ad6c	examples: beware of portability issue on Windows Reported by Jannick. https://lists.gnu.org/r/bug-bison/2020-05/msg00040.html https://lists.gnu.org/r/bug-bison/2020-05/msg00066.html * examples/test (diff_opts): Use --strip-trailing-cr if supported, to avoid \n vs. \r\n issues. * examples/c/bistromathic/bistromathic.test: When on MSYS, don't try to check autocompletion.	2020-05-08 09:45:29 +02:00
Akim Demaille	1b4108da3e	regen	2020-05-08 09:45:29 +02:00
Akim Demaille	53bfc7df94	doc: fix the generation of the man page When there is no bison.1 at all, the procedure fails. * doc/local.mk (bison.1): Be robust to cold starts.	2020-05-08 09:02:45 +02:00
Akim Demaille	a5fb4a88ef	news: prepare for 3.6	2020-05-08 07:34:30 +02:00
Akim Demaille	54df196d49	doc: complete the table of symbols * doc/bison.texi: Add YYEMPTY, YYEOF and YYUNDEF.	2020-05-08 07:34:30 +02:00
Akim Demaille	52bb6f0525	doc: clarify the glossary item about kinds * doc/bison.texi (Glossary): here.	2020-05-07 08:38:58 +02:00
Akim Demaille	76dab18af3	maint: post-release administrivia * NEWS: Add header line for next release. * .prev-version: Record previous version. * cfg.mk (old_NEWS_hash): Auto-update.	2020-05-06 08:48:05 +02:00
Akim Demaille	c982974f33	version 3.5.94 * NEWS: Record release date.	2020-05-06 08:28:36 +02:00
Akim Demaille	dc2a3578b7	doc: document yypstate_expected_tokens * doc/bison.texi (Push Parser Interface): Here.	2020-05-06 08:11:52 +02:00
Akim Demaille	9661b2fcbc	doc: restructure the push parser documentation I don't think it's fair to have yypstate_new, yypstate_delete, yypush_parse and yypull_parse to have their own section, on par with yyparse and yylex. Let them be in a single section about push parsers. And show new/delete first. * doc/bison.texi (Push Parser Interface): New. Fuse the aforementioned sections into it.	2020-05-06 08:11:52 +02:00
Akim DemailleandAkim Demaille	d9a9b054ae	all: fix the interface of yyexpected_tokens The user gives yyexpected_tokens a limit: the max number of tokens she wants to hear about. That's because an error message that reports a bazillion of possible tokens is useless. In that case yyexpected_tokens returned 0, so the user would not know if there are too many expected tokens or none (yes, that's possible). There are several ways to tell the user in which situation she's in: - return some E2MANY, a negative value. Then it makes the pattern int argsize = yypcontext_expected_tokens (ctx, arg, ARGS_MAX); if (argsize < 0) return argsize; no longer valid, as for E2MANY (i) the user must generate the error message anyway, and (ii) she should not return E2MANY - return ARGS_MAX + 1. Then it makes it dangerous for the user, as she has to iterate update `min (ARGS_MAX, argsize)`. Returning 0 is definitely simpler and safer for the user, as it tells her "this is not an error, just generate your message without a list of expecting tokens". So let's still return 0, but set arg[0] to the empty token when the list is really empty. * data/skeletons/glr.c, data/skeletons/lalr1.cc, data/skeletons/lalr1.java * data/skeletons/yacc.c (yyexpected_tokens): Put the empty symbol first if there are no possible tokens at all. * examples/c/bistromathic/parse.y: Demonstrate how to use that.	2020-05-06 08:11:52 +02:00
Akim Demaille	cb9f4cb543	examples: fix handling of syntax errors The shell grammar does not allow empty statements in then/else part of an if, but examples/test failed to catch the syntax errors from the script it ran. So exited with success anyway. You would expect 'set -e' to suffice, but with bash 3.2 actually it does not. As a matter of fact, I could find a way to have this behave properly: $ cat test.sh set -e cleanup () { status=$? echo "cleanup: $status" exit $status } trap cleanup 0 1 2 13 15 . $1 s=$? echo "test.sh: $s" exit $s $ cat bistro.test if true; then fi $ /bin/sh ./test.sh ./bistro.test ./bistro.test: line 2: syntax error near unexpected token `fi' cleanup: 0 $ echo $? 0 Remove the set -e (or the trap), and tada, it works... So we have to deal with the error by hand. * examples/test ($exit): Replace with... ($status): this. Preserve the exit status of the test case. * examples/c/bistromathic/bistromathic.test: Fix syntax error.	2020-05-05 08:21:12 +02:00
Akim Demaille	b86dcaf40b	doc: beware of timestamp issues on Haiku On Haiku, help2man is fired on a freshly extracted tarball. Reported by Bruno Haible. https://lists.gnu.org/r/bug-bison/2020-05/msg00055.html * doc/local.mk (bison.1): Be robust to a missing help2man.	2020-05-04 19:06:59 +02:00
Akim Demaille	0fafbbdefb	tests: beware of wchar_t portability issues on AIX https://lists.gnu.org/r/bug-bison/2020-05/msg00050.html Reported by Bruno Haible. * tests/diagnostics.at: here.	2020-05-04 08:09:22 +02:00
Akim Demaille	4b85b969d0	glr.c: beware of portability issues with PTRDIFF_MAX For instance test 386, "glr.cc api.value.type={double}": types.at:366: $CXX $CXXFLAGS $CPPFLAGS $LDFLAGS -o test test.cc $LIBS stderr: test.cc: In function 'ptrdiff_t yysplitStack(yyGLRStack, ptrdiff_t)': test.cc:490:4: error: 'PTRDIFF_MAX' was not declared in this scope (PTRDIFF_MAX < SIZE_MAX ? PTRDIFF_MAX : YY_CAST (ptrdiff_t, SIZE_MAX)) ^ test.cc:1805:37: note: in expansion of macro 'YYSIZEMAX' ptrdiff_t half_max_capacity = YYSIZEMAX / 2 / state_size; ^~~~~~~~~ test.cc:490:4: note: suggested alternative: '__PTRDIFF_MAX__' (PTRDIFF_MAX < SIZE_MAX ? PTRDIFF_MAX : YY_CAST (ptrdiff_t, SIZE_MAX)) ^ test.cc:1805:37: note: in expansion of macro 'YYSIZEMAX' ptrdiff_t half_max_capacity = YYSIZEMAX / 2 / state_size; ^~~~~~~~~ The failing tests are using glr.cc only, which I don't understand, the problem is rather in glr.c, so I would expect glr.c tests to also fail. Reported by Bruno Haible. https://lists.gnu.org/archive/html/bug-bison/2020-05/msg00053.html data/skeletons/yacc.c: Move the block that defines YYPTRDIFF_T/YYPTRDIFF_MAXIMUM, YYSIZE_T/YYSIZE_MAXIMUM, and YYSIZEOF to... * data/skeletons/c.m4 (b4_sizes_types_define): Here. (b4_c99_int_type): Also take care of the #undefinition of short. * data/skeletons/yacc.c, data/skeletons/glr.c: Use b4_sizes_types_define. * data/skeletons/glr.c: Adjust to use YYPTRDIFF_T/YYPTRDIFF_MAXIMUM, YYSIZE_T/YYSIZE_MAXIMUM.	2020-05-04 07:44:42 +02:00
Akim Demaille	7727693711	todo: update	2020-05-04 07:37:40 +02:00
Akim Demaille	ce27796b74	examples: beware of strnlen portability issues One function missing on Solaris 10 Sparc: CCLD examples/c/bistromathic/bistromathic Undefined first referenced symbol in file strnlen examples/c/bistromathic/bistromathic-parse.o ld: fatal: symbol referencing errors. No output written to examples/c/bistromathic/bistromathic Reported by Dagobert Michelsen. https://lists.gnu.org/r/bug-bison/2020-05/msg00048.html * examples/c/bistromathic/parse.y (xstrndup): Don't use strnlen. xstrndup is assembled from gnulib's xstrndup, strndup and strnlen...	2020-05-04 06:48:00 +02:00
Akim Demaille	6135fdc152	examples: beware of portability issues with sh's trap On AIX 7.2, when invoking "exit 77", we actually exit with 127. The "cleanup" function, called via trap, received an incorrect exit status, something described in Autoconf's doc. Reported by Bruno Haible. https://lists.gnu.org/archive/html/bug-bison/2020-05/msg00029.html https://lists.gnu.org/archive/html/bug-bison/2020-05/msg00047.html * examples/test (skip): New. * examples/c/bistromathic/bistromathic.test, * examples/c/reccalc/reccalc.test: Use it, to ensure $? is set to 77 when the trap is called.	2020-05-04 06:48:00 +02:00
Akim Demaille	f1497356e8	tests: beware of portability issues with diff -u AIX 7.1 supports diff -u, but its output does not match the expected one. Reported by Bruno Haible. https://lists.gnu.org/r/bug-bison/2020-05/msg00049.html * tests/atlocal.in (DIFF_U_WORKS): New. * tests/local.at (AT_DIFF_U_CHECK): New. * tests/existing.at (_AT_TEST_EXISTING_GRAMMAR): Use AT_DIFF_U_CHECK.	2020-05-04 06:48:00 +02:00
Akim Demaille	1429569362	maint: post-release administrivia * NEWS: Add header line for next release. * .prev-version: Record previous version. * cfg.mk (old_NEWS_hash): Auto-update.	2020-05-03 19:52:38 +02:00
Akim Demaille	506c368ab2	version 3.5.93 * NEWS: Record release date.	2020-05-03 19:32:15 +02:00
Akim Demaille	4f9dc3bdc1	news: update for 3.5.93	2020-05-03 19:32:03 +02:00
Akim Demaille	0d81be2dc7	gnulib: update	2020-05-03 19:32:03 +02:00
Akim Demaille	32f44f4bfb	tests: really skip tricky multichar test on Cygwin In Autotest, anything outside AT_SETUP/AT_CLEANUP is discarded. * tests/diagnostics.at (AT_TEST): Accept a skip-if test. Use it to skip on cygwin.	2020-05-03 19:08:16 +02:00
Akim Demaille	38a8287813	bistromathic: beware of portability issues of readline on AIX Readline may emit escape sequences before the prompt. Reported by Bruno Haible. https://lists.gnu.org/r/platform-testers/2020-05/msg00001.html. * examples/c/bistromathic/bistromathic.test: Trust readline _only_ if we get what we expect on some reference computation.	2020-05-03 18:10:58 +02:00
Akim Demaille	df752784c2	examples: beware of portability issues with cmp As someone wrote nearly 20 years ago in Autoconf's documentation, don't use cmp to compare text files, but diff. https://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=abad4f0576a7dc361e5385e19c7681449103cdb1 Reported by Jannick. * examples/test: Use diff, not cmp.	2020-05-03 17:53:47 +02:00
Akim Demaille	292409e91e	build: fix warnings (shown on IRIX) Appearing on IRIX with gcc -mabi=n32. Reported by Bruno Haible. https://lists.gnu.org/r/bug-bison/2020-05/msg00039.html * examples/c++/variant-11.yy, examples/c/bistromathic/parse.y: Don't give chars to isdigit, cast them to unsigned char before. * src/complain.c: Use c_isdigit. * src/fixits.c (fixits_run): Avoid casts. * src/lalr.c (goto_print): Use %zu for a size_t.	2020-05-03 17:37:34 +02:00
Akim Demaille	eea56d70d9	c++: be compatible with the pre-3.6 way to get a symbol's kind Reported by Pramod Kumbhar. https://lists.gnu.org/r/bug-bison/2020-05/msg00025.html * data/skeletons/c++.m4: here.	2020-05-03 17:06:13 +02:00
Akim Demaille	6e2de439e6	bistromathic: beware of portability issues with strndup Reported by Dagobert Michelsen. https://lists.gnu.org/r/bug-bison/2020-05/msg00026.html * examples/c/bistromathic/parse.y (xstrndup): New. Use it.	2020-05-03 17:06:13 +02:00
Akim Demaille	e33cd4b824	flex: fix incorrect use of Automake conditional AM_CONDITIONAL does _not_ define a shell variable... Reported privately by Denis Excoffier. * configure.ac (LEX_CXX_WORKS): Fix its definition.	2020-05-03 17:04:15 +02:00
Bruno HaibleandAkim Demaille	0669780ff8	package: fix a link error on IRIX https://lists.gnu.org/r/bug-bison/2020-05/msg00035.html * src/local.mk (src_bison_LDADD): Mention libbison.a before, not after, the system libraries.	2020-05-03 16:49:29 +02:00
Akim Demaille	160df220b1	bistromathic: beware of portability of readline Don't try to build bistromathic if we don't have readline. Reported by Bruno Haible. https://lists.gnu.org/r/bug-bison/2020-05/msg00028.html * configure.ac (ENABLE_BISTROMATHIC): New. * examples/c/bistromathic/local.mk: Use it. * examples/c/bistromathic/bistromathic.test: Exit 77 for skip.	2020-05-03 16:38:34 +02:00
Akim Demaille	da5c072a62	tests: beware of portability issues of sh "foo \|\| bar" does not invoke bar on AIX 7.2 when foo does not exist. It just dies. Reported by Bruno Haible. https://lists.gnu.org/r/bug-bison/2020-05/msg00029.html * examples/c/reccalc/reccalc.test: Check for seq in a subshell.	2020-05-03 16:38:34 +02:00
Akim Demaille	73ac8ff409	maint: post-release administrivia * NEWS: Add header line for next release. * .prev-version: Record previous version. * cfg.mk (old_NEWS_hash): Auto-update.	2020-05-03 13:07:08 +02:00
Akim Demaille	0e0fb0efc9	version 3.5.92 * NEWS: Record release date.	2020-05-03 12:48:16 +02:00
Akim Demaille	bb1d776be0	news: update for 3.5.92	2020-05-03 12:47:21 +02:00
Akim Demaille	d7e1abe656	gnulib: update	2020-05-03 12:43:55 +02:00
Akim Demaille	13a1537dba	java: demonstrate push parsers * data/skeletons/lalr1.java (Location): Make it a static class. (Lexer.yylex, Lexer.getLVal, Lexer.getStartPos, Lexer.getEndPos): These are not needed in push parsers. * examples/java/calc/Calc.y: Demonstrate push parsers in the Java. * doc/bison.texi: Push parsers have been supported for a long time, remove incorrect statements stating the opposite.	2020-05-03 11:28:36 +02:00
Akim Demaille	ac2ba46053	doc: clarify what a location is Reported by Arthur Schwarz <[email protected]> https://lists.gnu.org/r/help-bison/2013-12/msg00009.html * doc/bison.texi (Location Type): here.	2020-05-03 11:28:36 +02:00
Akim Demaille	2a7a2c1d3a	tests: beware of mbswidth portability issues Shy away from these issues on Cygwin. Reported Denis Excoffier. https://lists.gnu.org/r/bug-bison/2020-05/msg00003.html * tests/diagnostics.at (Tabulations and multibyte characters): Split in two.	2020-05-03 11:28:36 +02:00
Akim Demaille	c9b5b68c73	examples: beware of intl portability issues Reported by Horst von Brand. https://lists.gnu.org/r/bug-bison/2020-04/msg00033.html * examples/c/bistromathic/Makefile: libintl might not be needed, but libm probably is. * examples/c/bistromathic/parse.y: Include locale.h.	2020-05-03 10:32:33 +02:00
Akim Demaille	26aef31552	examples: beware of portability issues with readline On OpenBSD 6.5, the prompt is repeated, but not the actual command line... Don't try to cope with that. Reported by Bruno Haible. https://lists.gnu.org/r/bug-bison/2020-05/msg00015.html * examples/c/bistromathic/bistromathic.test: Skip when readline behave this way.	2020-05-03 10:32:33 +02:00
Akim Demaille	392f3caef6	examples: beware of the portability of flex --header-file The option --header was introduced in version 2.5.6. The option --header-file was introduced in version 2.6.4. Reported by Bruno Haible. https://lists.gnu.org/r/bug-bison/2020-05/msg00013.html So use --header, and do bother with versions that don't support it. * m4/flex.m4: Check whether flex supports --header. * configure.ac (FLEX_WORKS, FLEX_CXX_WORKS): Set to false if it doesn't. * * examples/c/reccalc/local.mk, examples/c/reccalc/Makefile: Use --header rather than --header-file.	2020-05-03 10:32:32 +02:00
Akim Demaille	ccaa8e29f9	c++: provide backward compatibility on by_type To write unit tests for their scanners, some users depended on symbol_type::token(): Lexer lex("12345"); symbol_type t = lex.nextToken(); assert(t.token() == token::INTLIT); assert(t.value.as<int>() == 12345); But symbol_type::token() was removed in Bison 3.5 because it relied on a conversion table. So users had to find other patterns, such as assert(t.type_get() == by_type(token::INTLIT).type_get()); which relies on several private implementation details. As part of transitioning from "token type" to "token kind", and making this a public and documented interface, "by_type" was renamed "by_kind" and "type_get()" was renamed as "kind()". The latter had backward compatibility mechanisms, not the former. In Bison 3.6 none of this should be used, but rather assert(t.kind() == symbol_kind::S_INTLIT); Reported by Pramod Kumbhar. https://lists.gnu.org/r/bug-bison/2020-05/msg00012.html * data/skeletons/c++.m4 (by_type): Make it an alias to by_kind.	2020-05-03 09:20:08 +02:00
Akim Demaille	76c3bccf40	yacc.c: improve formatting of the generated code * data/skeletons/yacc.c (yy_reduce_print): here.	2020-05-02 10:17:01 +02:00
Akim Demaille	6275137378	doc: java supports push parsers since 3.0 (2013-07-25) * doc/bison.texi: Clarify this.	2020-05-02 09:29:05 +02:00
Akim Demaille	d0571c846f	java: fix coding style I don't plan to fix everything in one go. But this was in the way of the next commit. * data/skeletons/lalr1.java: Avoid space before parens. * tests/java.at: Adjust.	2020-05-02 09:27:16 +02:00
Akim Demaille	8c1002e4b7	style: comment changes * tests/java.at: here.	2020-05-02 09:08:26 +02:00
Akim Demaille	dbd8fd71ba	todo: more	2020-05-02 08:18:20 +02:00
Akim Demaille	95bac741c3	style: more documentation about errs Suggested by Angelo Borsotti. https://lists.gnu.org/r/bug-bison/2014-02/msg00003.html * src/state.h: here.	2020-05-02 08:18:20 +02:00
Akim Demaille	f8ab4d81c0	doc: document the exit status Suggested by Alexandre Duret-Lutz. https://lists.gnu.org/r/bug-bison/2013-09/msg00015.html * doc/bison.texi (Invocation): Here.	2020-05-01 10:48:44 +02:00
Akim Demaille	d55c9b001a	java: add missing i18n requests * data/skeletons/lalr1.java (reportSyntaxError): Here.	2020-05-01 10:36:05 +02:00
Akim Demaille	611495999f	java: style: fix coding style of yyerror/reportSyntaxError * data/skeletons/lalr1.java: here.	2020-05-01 10:36:05 +02:00
Akim Demaille	01d5f232a9	java: avoid useless work * data/skeletons/lalr1.java (yySymbolPrint): Avoid the computation of the argument if useless. While at it, fix Java coding style.	2020-05-01 10:36:05 +02:00
Akim Demaille	0407acbc59	java: comment changes * data/skeletons/lalr1.java, examples/java/calc/Calc.y: here.	2020-05-01 10:36:05 +02:00
Akim Demaille	0c0e778bd1	news: make it more consistent * NEWS: Use the same pattern for titles.	2020-05-01 10:36:05 +02:00
Akim Demaille	30357ae942	c++: use modern idioms to make classes non-copyable Reported by Don Macpherson. https://lists.gnu.org/r/bug-bison/2019-05/msg00015.html https://github.com/akimd/bison/issues/36 * data/skeletons/lalr1.cc, data/skeletons/stack.hh, * data/skeletons/variant.hh: Delete the copy-ctor and the copy operator.	2020-05-01 06:52:04 +02:00
Akim Demaille	fb1d76d9a9	yacc.c: avoid the use of a temporary * data/skeletons/yacc.c: Use YYLLOC_DEFAULT directly with the final destination.	2020-04-30 08:07:55 +02:00
Akim Demaille	a61bc3f9f8	maint: post-release administrivia * NEWS: Add header line for next release. * .prev-version: Record previous version. * cfg.mk (old_NEWS_hash): Auto-update.	2020-04-29 09:07:50 +02:00
@@ -1 +1 @@
 .5.90
 .5.94