version 3.5.94

* NEWS: Record release date.

.prev-version

@@ -1 +1 @@
-3.5.91
+3.5.93

NEWS

@@ -1,5 +1,13 @@
 GNU Bison NEWS
 
+* Noteworthy changes in release 3.5.94 (2020-05-06) [beta]
+
+  Portability issues.
+
+* Noteworthy changes in release 3.5.93 (2020-05-03) [beta]
+
+  Portability issues.
+
 * Noteworthy changes in release 3.5.92 (2020-05-03) [beta]
 
   Portability issues.

TODO

@@ -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
@@ -192,10 +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 (easy)
-- lac: D, Java
+- push parsers: glr.c, glr.cc, lalr1.cc (not very difficult)
-- glr: D, Java
+- token constructors: Java, C, D (a bit difficult)
-- token constructors: Java, C, D
+- glr: D, Java (super difficult)
 
 * Bugs
 ** Autotest has quotation issues

configure.ac

@@ -262,7 +262,8 @@ if ! "$LEX_IS_FLEX" || test "X$LEX" = X:; then
   LEX=:
 fi
 AM_CONDITIONAL([FLEX_WORKS], [$LEX_IS_FLEX && $FLEX_SUPPORTS_HEADER_OPT])
-AM_CONDITIONAL([FLEX_CXX_WORKS], [$LEX_WORKS && test $bison_cv_cxx_works = yes])
+AM_CONDITIONAL([FLEX_CXX_WORKS],
+  [$LEX_IS_FLEX && $FLEX_SUPPORTS_HEADER_OPT && test $bison_cv_cxx_works = yes])
 AC_PROG_YACC
 AC_PROG_RANLIB
 AC_PROG_GNU_M4
@@ -331,6 +332,13 @@ AC_MSG_RESULT([$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])

data/skeletons/c++.m4

@@ -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.
@@ -409,12 +409,15 @@ 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.
+    /// Backward compatibility for a private implementation detail (Bison 3.6).
     typedef by_kind by_type;
 
     /// "External" symbols: returned by the scanner.
@@ -534,6 +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 ();
+  }
 ]])
 
 

data/skeletons/c.m4

@@ -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

data/skeletons/glr.c

@@ -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;
+  YYPTRDIFF_T yysize;
-  ptrdiff_t yycapacity;
+  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;
+  YYPTRDIFF_T yynewSize;
-  ptrdiff_t yyn;
+  YYPTRDIFF_T yyn;
-  ptrdiff_t yysize = yystackp->yynextFree - yystackp->yyitems;
+  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,
+yyglrShift (yyGLRStack* yystackp, YYPTRDIFF_T yyk, yy_state_t yylrState,
-            ptrdiff_t yyposn,
+            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,
+yyglrShiftDefer (yyGLRStack* yystackp, YYPTRDIFF_T yyk, yy_state_t yylrState,
-                 ptrdiff_t yyposn, yyGLRState* yyrhs, yyRuleNum yyrule)
+                 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
+static YYPTRDIFF_T
-yysplitStack (yyGLRStack* yystackp, ptrdiff_t yyk)
+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];
+      YYPTRDIFF_T state_size = YYSIZEOF (yystackp->yytops.yystates[0]);
-      ptrdiff_t half_max_capacity = YYSIZEMAX / 2 / state_size;
+      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,
+yyprocessOneStack (yyGLRStack* yystackp, YYPTRDIFF_T yyk,
-                   ptrdiff_t yyposn]b4_pure_formals[)
+                   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;
+          YYPTRDIFF_T yysize = yystack.yytops.yysize;
-          ptrdiff_t yyk;
+          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])));

data/skeletons/lalr1.cc

@@ -1326,6 +1326,8 @@ b4_dollar_popdef])[]dnl
             }
       }
 ]])[
+    if (yyarg && yycount == 0 && 0 < yyargn)
+      yyarg[0] = symbol_kind::]b4_symbol(-2, kind)[;
     return yycount;
   }
 

data/skeletons/lalr1.java

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

data/skeletons/yacc.c

@@ -403,50 +403,10 @@ m4_if(b4_api_prefix, [yy], [],
 ]b4_declare_symbol_enum[
 
 ]b4_user_post_prologue[
-]b4_percent_code_get[]dnl
+]b4_percent_code_get[
-
-[#ifdef short
-# undef short
-#endif
-
 ]b4_c99_int_type_define[
 
-#ifndef YYPTRDIFF_T
+]b4_sizes_types_define[
-# 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))
 
 /* Stored state numbers (used for stacks). */
 typedef ]b4_int_type(0, m4_eval(b4_states_number - 1))[ yy_state_t;
@@ -1198,6 +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;
 }
 

doc/bison.texi

@@ -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.
+* Push Parser Interface::   How to create, use, and destroy push parsers.
-* 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.
 * Lexical::                 You must supply a function @code{yylex}
                               which reads tokens.
 * Error Reporting::         Passing error messages to the user.
@@ -6927,10 +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.
+* Push Parser Interface::   How to create, use, and destroy push parsers.
-* 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.
 * Lexical::                 You must supply a function @code{yylex}
                               which reads tokens.
 * Error Reporting::         Passing error messages to the user.
@@ -7033,16 +7027,40 @@ void yyerror (YYLTYPE *llocp, int *randomness, const char *msg);
 int  yyparse (int *randomness);
 @end example
 
-@node Push Parser Function
+@node Push Parser Interface
-@section The Push Parser Function @code{yypush_parse}
+@section Push Parser Interface
-@findex yypush_parse
 
-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.
@@ -7056,50 +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.
+declaration is used.  @xref{Push Decl}.
-@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
+@deftypefun int yypstate_expected_tokens (@code{const yypstate *}yyps, @code{yysymbol_kind_t} @var{argv}@code{[]}, @code{int} @var{argc})
-@section The Parser Create Function @code{yystate_new}
+Fill @var{argv} with the expected tokens, which never includes
-@findex yypstate_new
+@code{YYSYMBOL_YYEMPTY}, @code{YYSYMBOL_YYerror}, or
+@code{YYSYMBOL_YYUNDEF}.
 
-You call the function @code{yypstate_new} to create a new parser instance.
+Never put more than @var{argc} elements into @var{argv}, and on success
-This function is available if either the @samp{%define api.push-pull push} or
+return the number of tokens stored in @var{argv}.  If there are more
-@samp{%define api.push-pull both} declaration is used.
+expected tokens than @var{argc}, fill @var{argv} up to @var{argc} and return
-@xref{Push Decl}.
+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})
+When LAC is enabled, may return a negative number on errors,
-The function will return a valid parser instance if there was memory available
+such as @code{YYENOMEM} on memory exhaustion.
-or 0 if no memory was available.
+
-In impure mode, it will also return 0 if a parser instance is currently
+If @var{argv} is null, return the size needed to store all the possible
-allocated.
+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}
@@ -7551,9 +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
+return the number of tokens stored in @var{argv}.  If there are more
-there are more than @var{argc} expected tokens, yet fill @var{argv} up to
+expected tokens than @var{argc}, fill @var{argv} up to @var{argc} and return
-@var{argc}.  When LAC is enabled, may return a negative number on errors,
+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
@@ -12137,9 +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
+return the number of tokens stored in @var{argv}.  If there are more
-there are more than @var{argc} expected tokens, yet fill @var{argv} up to
+expected tokens than @var{argc}, fill @var{argv} up to @var{argc} and return
-@var{argc}.
+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}.
@@ -13298,9 +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
+return the number of tokens stored in @var{argv}.  If there are more
-there are more than @var{argc} expected tokens, yet fill @var{argv} up to
+expected tokens than @var{argc}, fill @var{argv} up to @var{argc} and return
-@var{argc}.
+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}.
@@ -14781,24 +14789,26 @@ 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

doc/local.mk

@@ -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
+# leaves 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)			\
+	$(AM_V_GEN)if $(HELP2MAN) --version >/dev/null 2>&1; then	\
-	    --include=$(top_srcdir)/%D%/bison.x	\
+	  $(HELP2MAN)							\
-	    --output=$@.tmp tests/bison
+	    --include=$(top_srcdir)/%D%/bison.x				\
-	$(AM_V_at)if $(remove_time_stamp) $@ >$@a.tmp 2>/dev/null &&		\
+	    --output=$@.tmp tests/bison &&				\
-	   $(remove_time_stamp) $@.tmp | cmp $@a.tmp - >/dev/null 2>&1; then	\
+	  $(remove_time_stamp) $@     >$@a.tmp 2>/dev/null &&		\
-	  touch $@;								\
+	  $(remove_time_stamp) $@.tmp >$@b.tmp 2>/dev/null &&		\
-	else									\
+	  if diff $@a.tmp $@b.tmp >/dev/null 2>&1; then			\
-	  mv $@.tmp $@;								\
+	    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

examples/c++/variant-11.yy

@@ -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;

examples/c/bistromathic/bistromathic.test

@@ -28,14 +28,26 @@
 #
 # 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.
 
-if ! echo '1-1' | prog | grep '>' >/dev/null; then
+echo >perfect '> 0
-    # macOS.
+0
+> '
+
+echo >ok '0'
+echo '0' | prog >effective
+
+if diff perfect effective >/dev/null 2>&1; then
+    # Alles ist gut.
+    strip_prompt=false
+elif diff ok effective >/dev/null 2>&1; then
     strip_prompt=true
-elif ! echo '1-1' | prog | grep '1-1' >/dev/null; then
+else
-    # OpenBSD 6.5.  I don't want to spend time on this.
+    skip "this is not the GNU Readline we expect"
-    echo "SKIP: this is not the GNU Readline we expect"
-    exit 0
 fi
 
 
@@ -84,7 +96,7 @@ 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

examples/c/bistromathic/local.mk

@@ -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.
+if ENABLE_BISTROMATHIC
-%C%_bistromathic_CPPFLAGS =			\
+  check_PROGRAMS += %D%/bistromathic
-  -DBISON_LOCALEDIR='"$(localdir)"'		\
+  TESTS += %D%/bistromathic.test
-  -DLOCALEDIR='"$(localdir)"'			\
+  nodist_%C%_bistromathic_SOURCES = %D%/parse.y
-  -I$(top_srcdir)/%D% -I$(top_builddir)/%D%
-%C%_bistromathic_LDADD = -lm -lreadline $(LIBINTL)
 
+  # 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

examples/c/bistromathic/parse.y

@@ -1,6 +1,7 @@
 %require "3.6"
 
 %code top {
+  #include <assert.h>
   #include <ctype.h>  // isdigit
   #include <locale.h> // LC_ALL
   #include <math.h>   // cos, sin, etc.
@@ -316,7 +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
@@ -332,7 +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");
     }
 }
 
@@ -340,12 +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.
@@ -362,7 +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)
       {
@@ -393,6 +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.  |
 `-----------*/
@@ -438,11 +458,11 @@ expected_tokens (const char *input,
   return res;
 }
 
-/* Attempt to complete on the contents of TEXT.  START and END bound the
+// Attempt to complete on the contents of TEXT.  START and END bound
-   region of rl_line_buffer that contains the word to complete.  TEXT is
+// the region of rl_line_buffer that contains the word to complete.
-   the word to complete.  We can use the entire contents of rl_line_buffer
+// TEXT is the word to complete.  We can use the entire contents of
-   in case we want to do some simple parsing.  Return the array of matches,
+// rl_line_buffer in case we want to do some simple parsing.  Return
-   or NULL if there aren't any. */
+// the array of matches, or NULL if there aren't any.
 char **
 completion (const char *text, int start, int end)
 {
@@ -453,7 +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);
 
@@ -495,7 +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)

examples/c/reccalc/reccalc.test

@@ -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

examples/test

@@ -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)
@@ -68,6 +68,20 @@ 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 +129,7 @@ run ()
   } >eff
 
   if test $sta_eff -eq $sta_exp; then
-    if cmp eff exp 2>/dev/null; then
+    if diff eff exp >/dev/null 2>&1; then
       echo "$me: PASS: $number"
     else
       echo "$me: FAIL: $number"
@@ -127,20 +141,20 @@ run ()
       sed -e 's/^/  /' eff
       echo "$me: diff:"
       diff -u exp eff | sed -e 's/^/  /'
-      exit=false
+      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" || status=2;;
-  *)  . "../$1";;
+  *)  . "../$1" || status=2;;
 esac
 
-$exit
+exit $status

src/complain.c

@@ -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)

src/fixits.c

@@ -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)
         {

src/lalr.c

@@ -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

src/local.mk

@@ -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)                               \
+  $(LIBTEXTSTYLE)
-  lib/libbison.a
 
 
 EXTRA_DIST += %D%/i18n-strings.c

src/parse-gram.c

@@ -1,4 +1,4 @@
-/* A Bison parser, made by GNU Bison 3.5.91.  */
+/* A Bison parser, made by GNU Bison 3.5.93.  */
 
 /* Bison implementation for Yacc-like parsers in C
 
@@ -49,7 +49,7 @@
 #define YYBISON 1
 
 /* Bison version.  */
-#define YYBISON_VERSION "3.5.91"
+#define YYBISON_VERSION "3.5.93"
 
 /* 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;
 

src/parse-gram.h

@@ -1,4 +1,4 @@
-/* A Bison parser, made by GNU Bison 3.5.91.  */
+/* A Bison parser, made by GNU Bison 3.5.93.  */
 
 /* Bison interface for Yacc-like parsers in C
 

tests/atlocal.in

@@ -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.*

tests/diagnostics.at

@@ -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])
@@ -261,11 +264,10 @@ input.y:17.4-17: <warning>warning:</warning> empty rule without %empty [<warning
 input.y: <warning>warning:</warning> fix-its can be applied.  Rerun with option '--update'. [<warning>-Wother</warning>]
 ]])
 
-# Likewise, but currently not portable to Cygwin.
+
+# 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.
-case `uname -a` in
-  (CYGWIN*);;
-  (*)
 AT_TEST([[Tabulations and multibyte characters]],
 [[%%
 e: {∇⃗×𝐸⃗ = -∂𝐵⃗/∂t}
@@ -276,9 +278,7 @@ e: {∇⃗×𝐸⃗ = -∂𝐵⃗/∂t}
       |    <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'])
-;;
-esac
 
 
 ## --------------- ##

tests/existing.at

@@ -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([[sed 's/^%define lr.type .*$//' input.y > input-lalr.y]])
-AT_CHECK([diff -u /dev/null /dev/null || exit 77], [0], [ignore])
-
-AT_CHECK([[sed 's/^%define lr.type .*$//' input.y > input-lalr.y]])
 AT_BISON_CHECK([[--report=all input-lalr.y]], [[0]], [ignore], [ignore])
-AT_CHECK([[diff -u input-lalr.output input.output \
+AT_DIFF_U_CHECK([[input-lalr.output input.output]], [$1])])
-           | sed -n '/^@@/,$p' | sed 's/^ $//']],
-         [[0]], [$1])])
 
 AT_TEST_TABLES_AND_PARSE([$2[: LALR(1)]], [[LALR]], [[last-state]],
                          [[%define lr.type lalr

tests/local.at

@@ -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.