Pacify "gcc -Wunused" for the input function from Flex.

[bison.git] / src / output.c

diff --git a/src/output.c b/src/output.c
index 1f3bbcaaa8e5a38f3086f958855ac5e4618e6116..c5e9aab99948c21c21ed294de50fdec7f3c75353 100644 (file)
--- a/src/output.c
+++ b/src/output.c
@@ -1,28 +1,27 @@
 /* Output the generated parsing program for Bison.
 
 /* Output the generated parsing program for Bison.
 

-   Copyright (C) 1984, 1986, 1989, 1992, 2000, 2001, 2002, 2003, 2004, 2005
-   Free Software Foundation, Inc.
+   Copyright (C) 1984, 1986, 1989, 1992, 2000, 2001, 2002, 2003, 2004,
+   2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.

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

-   Bison is free software; you can redistribute it and/or modify it
-   under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.

 
 

-   Bison is distributed in the hope that it will be useful, but
-   WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   General Public License for more details.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.

 
    You should have received a copy of the GNU General Public License
 
    You should have received a copy of the GNU General Public License

-   along with Bison; see the file COPYING.  If not, write to the Free
-   Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
-   02110-1301, USA.  */
-
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

 
 

+#include <config.h>

 #include "system.h"
 
 #include "system.h"
 

+#include <configmake.h>

 #include <error.h>
 #include <get-errno.h>
 #include <quotearg.h>
 #include <error.h>
 #include <get-errno.h>
 #include <quotearg.h>


@@ -33,9 +32,10 @@
 #include "files.h"
 #include "getargs.h"
 #include "gram.h"
 #include "files.h"
 #include "getargs.h"
 #include "gram.h"

-#include "muscle_tab.h"
+#include "muscle-tab.h"

 #include "output.h"
 #include "reader.h"
 #include "output.h"
 #include "reader.h"

+#include "scan-code.h"    /* max_left_semantic_context */

 #include "scan-skel.h"
 #include "symtab.h"
 #include "tables.h"
 #include "scan-skel.h"
 #include "symtab.h"
 #include "tables.h"


@@ -43,9 +43,6 @@
 
 static struct obstack format_obstack;
 
 
 static struct obstack format_obstack;
 

-bool error_verbose = false;
-
-

 
 /*-------------------------------------------------------------------.
 | Create a function NAME which associates to the muscle NAME the     |
 
 /*-------------------------------------------------------------------.
 | Create a function NAME which associates to the muscle NAME the     |


@@ -107,7 +104,6 @@ GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_int_table, int)
 GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_base_table, base_number)
 GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_rule_number_table, rule_number)
 GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_symbol_number_table, symbol_number)
 GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_base_table, base_number)
 GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_rule_number_table, rule_number)
 GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_symbol_number_table, symbol_number)

-GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_item_number_table, item_number)

 GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_state_number_table, state_number)
 
 
 GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_state_number_table, state_number)
 
 


@@ -146,6 +142,7 @@ prepare_symbols (void)
   MUSCLE_INSERT_BOOL ("token_table", token_table_flag);
   MUSCLE_INSERT_INT ("tokens_number", ntokens);
   MUSCLE_INSERT_INT ("nterms_number", nvars);
   MUSCLE_INSERT_BOOL ("token_table", token_table_flag);
   MUSCLE_INSERT_INT ("tokens_number", ntokens);
   MUSCLE_INSERT_INT ("nterms_number", nvars);

+  MUSCLE_INSERT_INT ("symbols_number", nsyms);

   MUSCLE_INSERT_INT ("undef_token_number", undeftoken->number);
   MUSCLE_INSERT_INT ("user_token_number_max", max_user_token_number);
 
   MUSCLE_INSERT_INT ("undef_token_number", undeftoken->number);
   MUSCLE_INSERT_INT ("user_token_number_max", max_user_token_number);
 


@@ -159,9 +156,12 @@ prepare_symbols (void)
     int i;
     /* We assume that the table will be output starting at column 2. */
     int j = 2;
     int i;
     /* We assume that the table will be output starting at column 2. */
     int j = 2;

+    struct quoting_options *qo = clone_quoting_options (0);
+    set_quoting_style (qo, c_quoting_style);
+    set_quoting_flags (qo, QA_SPLIT_TRIGRAPHS);

     for (i = 0; i < nsyms; i++)
       {
     for (i = 0; i < nsyms; i++)
       {

-       char const *cp = quotearg_style (c_quoting_style, symbols[i]->tag);
+       char *cp = quotearg_alloc (symbols[i]->tag, -1, qo);

        /* Width of the next token, including the two quotes, the
           comma and the space.  */
        int width = strlen (cp) + 2;
        /* Width of the next token, including the two quotes, the
           comma and the space.  */
        int width = strlen (cp) + 2;


@@ -175,12 +175,12 @@ prepare_symbols (void)
        if (i)
          obstack_1grow (&format_obstack, ' ');
        MUSCLE_OBSTACK_SGROW (&format_obstack, cp);
        if (i)
          obstack_1grow (&format_obstack, ' ');
        MUSCLE_OBSTACK_SGROW (&format_obstack, cp);

+        free (cp);

        obstack_1grow (&format_obstack, ',');
        j += width;
       }
        obstack_1grow (&format_obstack, ',');
        j += width;
       }

-    /* Add a NULL entry to list of tokens (well, 0, as NULL might not be
-       defined).  */
-    obstack_sgrow (&format_obstack, " 0");
+    free (qo);
+    obstack_sgrow (&format_obstack, " ]b4_null[");

 
     /* Finish table and store. */
     obstack_1grow (&format_obstack, 0);
 
     /* Finish table and store. */
     obstack_1grow (&format_obstack, 0);


@@ -200,38 +200,27 @@ prepare_symbols (void)
 }
 
 
 }
 
 

-/*-------------------------------------------------------------.
-| Prepare the muscles related to the rules: rhs, prhs, r1, r2, |
-| rline, dprec, merger.                                        |
-`-------------------------------------------------------------*/
+/*----------------------------------------------------------------.
+| Prepare the muscles related to the rules: r1, r2, rline, dprec, |
+| merger.                                                         |
+`----------------------------------------------------------------*/

 
 static void
 prepare_rules (void)
 {
 
 static void
 prepare_rules (void)
 {

-  rule_number r;
-  unsigned int i = 0;
-  item_number *rhs = xnmalloc (nritems, sizeof *rhs);
-  unsigned int *prhs = xnmalloc (nrules, sizeof *prhs);

   unsigned int *rline = xnmalloc (nrules, sizeof *rline);
   symbol_number *r1 = xnmalloc (nrules, sizeof *r1);
   unsigned int *r2 = xnmalloc (nrules, sizeof *r2);
   int *dprec = xnmalloc (nrules, sizeof *dprec);
   int *merger = xnmalloc (nrules, sizeof *merger);
 
   unsigned int *rline = xnmalloc (nrules, sizeof *rline);
   symbol_number *r1 = xnmalloc (nrules, sizeof *r1);
   unsigned int *r2 = xnmalloc (nrules, sizeof *r2);
   int *dprec = xnmalloc (nrules, sizeof *dprec);
   int *merger = xnmalloc (nrules, sizeof *merger);
 

+  rule_number r;

   for (r = 0; r < nrules; ++r)
     {
   for (r = 0; r < nrules; ++r)
     {

-      item_number *rhsp = NULL;
-      /* Index of rule R in RHS. */
-      prhs[r] = i;
-      /* RHS of the rule R. */
-      for (rhsp = rules[r].rhs; *rhsp >= 0; ++rhsp)
-       rhs[i++] = *rhsp;

       /* LHS of the rule R. */
       r1[r] = rules[r].lhs->number;
       /* Length of rule R's RHS. */
       /* LHS of the rule R. */
       r1[r] = rules[r].lhs->number;
       /* Length of rule R's RHS. */

-      r2[r] = i - prhs[r];
-      /* Separator in RHS. */
-      rhs[i++] = -1;
+      r2[r] = rule_rhs_length(&rules[r]);

       /* Line where rule was defined. */
       rline[r] = rules[r].location.start.line;
       /* Dynamic precedence (GLR).  */
       /* Line where rule was defined. */
       rline[r] = rules[r].location.start.line;
       /* Dynamic precedence (GLR).  */


@@ -239,11 +228,7 @@ prepare_rules (void)
       /* Merger-function index (GLR).  */
       merger[r] = rules[r].merger;
     }
       /* Merger-function index (GLR).  */
       merger[r] = rules[r].merger;
     }

-  if (i != nritems)
-    abort ();

 
 

-  muscle_insert_item_number_table ("rhs", rhs, ritem[0], 1, nritems);
-  muscle_insert_unsigned_int_table ("prhs", prhs, 0, 0, nrules);

   muscle_insert_unsigned_int_table ("rline", rline, 0, 0, nrules);
   muscle_insert_symbol_number_table ("r1", r1, 0, 0, nrules);
   muscle_insert_unsigned_int_table ("r2", r2, 0, 0, nrules);
   muscle_insert_unsigned_int_table ("rline", rline, 0, 0, nrules);
   muscle_insert_symbol_number_table ("r1", r1, 0, 0, nrules);
   muscle_insert_unsigned_int_table ("r2", r2, 0, 0, nrules);


@@ -253,8 +238,6 @@ prepare_rules (void)
   MUSCLE_INSERT_INT ("rules_number", nrules);
   MUSCLE_INSERT_INT ("max_left_semantic_context", max_left_semantic_context);
 
   MUSCLE_INSERT_INT ("rules_number", nrules);
   MUSCLE_INSERT_INT ("max_left_semantic_context", max_left_semantic_context);
 

-  free (rhs);
-  free (prhs);

   free (rline);
   free (r1);
   free (r2);
   free (rline);
   free (r1);
   free (r2);


@@ -283,6 +266,73 @@ prepare_states (void)
 }
 
 
 }
 
 

+/*-------------------------------------------------------.
+| Compare two symbols by type-name, and then by number.  |
+`-------------------------------------------------------*/
+
+static int
+symbol_type_name_cmp (const symbol **lhs, const symbol **rhs)
+{
+  int res = UNIQSTR_CMP((*lhs)->type_name, (*rhs)->type_name);
+  if (res)
+    return res;
+  return (*lhs)->number - (*rhs)->number;
+}
+
+
+/*----------------------------------------------------------------.
+| Return a (malloc'ed) table of the symbols sorted by type-name.  |
+`----------------------------------------------------------------*/
+
+static symbol **
+symbols_by_type_name (void)
+{
+  typedef int (*qcmp_type) (const void *, const void *);
+  symbol **res = xmemdup (symbols, nsyms * sizeof *res);
+  qsort (res, nsyms, sizeof *res, (qcmp_type) &symbol_type_name_cmp);
+  return res;
+}
+
+
+/*------------------------------------------------------------------.
+| Define b4_type_names, which is a list of (lists of the numbers of |
+| symbols with same type-name).                                     |
+`------------------------------------------------------------------*/
+
+static void
+type_names_output (FILE *out)
+{
+  int i;
+  symbol **syms = symbols_by_type_name ();
+  fputs ("m4_define([b4_type_names],\n[", out);
+  for (i = 0; i < nsyms; /* nothing */)
+    {
+      // The index of the first symbol of the current type-name.
+      int i0 = i;
+      fputs (i ? ",\n[" : "[", out);
+      for (; i < nsyms && syms[i]->type_name == syms[i0]->type_name; ++i)
+        fprintf (out, "%s%d", i != i0 ? ", " : "", syms[i]->number);
+      fputs ("]", out);
+    }
+  fputs ("])\n\n", out);
+  free (syms);
+}
+
+
+/*-------------------------------------.
+| The list of all the symbol numbers.  |
+`-------------------------------------*/
+
+static void
+symbol_numbers_output (FILE *out)
+{
+  int i;
+  fputs ("m4_define([b4_symbol_numbers],\n[", out);
+  for (i = 0; i < nsyms; ++i)
+    fprintf (out, "%s[%d]", i ? ", " : "", i);
+  fputs ("])\n\n", out);
+}
+

 
 /*---------------------------------.
 | Output the user actions to OUT.  |
 
 /*---------------------------------.
 | Output the user actions to OUT.  |


@@ -293,25 +343,21 @@ user_actions_output (FILE *out)
 {
   rule_number r;
 
 {
   rule_number r;
 

-  fputs ("m4_define([b4_actions], \n[[", out);
+  fputs ("m4_define([b4_actions], \n[", out);

   for (r = 0; r < nrules; ++r)
     if (rules[r].action)
       {
   for (r = 0; r < nrules; ++r)
     if (rules[r].action)
       {

-       fprintf (out, "  case %d:\n", r + 1);
-
-       fprintf (out, "]b4_syncline(%d, ",
+       fprintf (out, "b4_case(%d, [b4_syncline(%d, ", r + 1,

                 rules[r].action_location.start.line);
        escaped_output (out, rules[r].action_location.start.file);
                 rules[r].action_location.start.line);
        escaped_output (out, rules[r].action_location.start.file);

-       fprintf (out, ")[\n");
-       fprintf (out, "    %s\n    break;\n\n",
-                rules[r].action);
+       fprintf (out, ")\n[    %s]])\n\n", rules[r].action);

       }
       }

-  fputs ("]])\n\n", out);
+  fputs ("])\n\n", out);

 }
 
 }
 

-/*--------------------------------------.
-| Output the merge functions to OUT.   |
-`--------------------------------------*/
+/*------------------------------------.
+| Output the merge functions to OUT.  |
+`------------------------------------*/

 
 static void
 merger_output (FILE *out)
 
 static void
 merger_output (FILE *out)


@@ -332,6 +378,82 @@ merger_output (FILE *out)
   fputs ("]])\n\n", out);
 }
 
   fputs ("]])\n\n", out);
 }
 

+
+/*---------------------------------------------.
+| Prepare the muscles for symbol definitions.  |
+`---------------------------------------------*/
+
+static void
+prepare_symbol_definitions (void)
+{
+  int i;
+  for (i = 0; i < nsyms; ++i)
+    {
+      symbol *sym = symbols[i];
+      const char *key;
+      const char *value;
+
+#define SET_KEY(Entry)                                                  \
+      obstack_fgrow2 (&format_obstack, "symbol(%d, %s)", i, Entry);     \
+      obstack_1grow (&format_obstack, 0);                               \
+      key = obstack_finish (&format_obstack);
+
+      // Whether the symbol has an identifier.
+      value = symbol_id_get (sym);
+      SET_KEY("has_id");
+      MUSCLE_INSERT_INT (key, !!value);
+
+      // Its identifier.
+      SET_KEY("id");
+      MUSCLE_INSERT_STRING (key, value ? value : "");
+
+      // Its tag.  Typically for documentation purpose.
+      SET_KEY("tag");
+      MUSCLE_INSERT_STRING (key, sym->tag);
+
+      SET_KEY("user_number");
+      MUSCLE_INSERT_INT (key, sym->user_token_number);
+
+      SET_KEY("is_token");
+      MUSCLE_INSERT_INT (key,
+                         i < ntokens && sym != errtoken && sym != undeftoken);
+
+      SET_KEY("number");
+      MUSCLE_INSERT_INT (key, sym->number);
+
+      SET_KEY("has_type");
+      MUSCLE_INSERT_INT (key, !!sym->type_name);
+
+      SET_KEY("type");
+      MUSCLE_INSERT_STRING (key, sym->type_name ? sym->type_name : "");
+
+#define CODE_PROP(PropName)                                             \
+      do {                                                              \
+        code_props const *p = symbol_ ## PropName ## _get (sym);        \
+        SET_KEY("has_" #PropName);                                      \
+        MUSCLE_INSERT_INT (key, !!p->code);                             \
+                                                                        \
+        if (p->code)                                                    \
+          {                                                             \
+            SET_KEY(#PropName "_file");                                 \
+            MUSCLE_INSERT_STRING (key, p->location.start.file);         \
+                                                                        \
+            SET_KEY(#PropName "_line");                                 \
+            MUSCLE_INSERT_INT (key, p->location.start.line);            \
+                                                                        \
+            SET_KEY(#PropName);                                         \
+            MUSCLE_INSERT_STRING_RAW (key, p->code);                    \
+          }                                                             \
+      } while (0)
+
+      CODE_PROP(destructor);
+      CODE_PROP(printer);
+#undef CODE_PROP
+#undef SET_KEY
+    }
+}
+
+

 /*--------------------------------------.
 | Output the tokens definition to OUT.  |
 `--------------------------------------*/
 /*--------------------------------------.
 | Output the tokens definition to OUT.  |
 `--------------------------------------*/


@@ -347,112 +469,30 @@ token_definitions_output (FILE *out)
     {
       symbol *sym = symbols[i];
       int number = sym->user_token_number;
     {
       symbol *sym = symbols[i];
       int number = sym->user_token_number;

+      uniqstr id = symbol_id_get (sym);

 
       /* At this stage, if there are literal aliases, they are part of
         SYMBOLS, so we should not find symbols which are the aliases
         here.  */
 
       /* At this stage, if there are literal aliases, they are part of
         SYMBOLS, so we should not find symbols which are the aliases
         here.  */

-      if (number == USER_NUMBER_ALIAS)
-       abort ();
-
-      /* Skip error token.  */
-      if (sym == errtoken)
-       continue;
-
-      /* If this string has an alias, then it is necessarily the alias
-        which is to be output.  */
-      if (sym->alias)
-       sym = sym->alias;
-
-      /* Don't output literal chars or strings (when defined only as a
-        string).  Note that must be done after the alias resolution:
-        think about `%token 'f' "f"'.  */
-      if (sym->tag[0] == '\'' || sym->tag[0] == '\"')
-       continue;
-
-      /* Don't #define nonliteral tokens whose names contain periods
-        or '$' (as does the default value of the EOF token).  */
-      if (strchr (sym->tag, '.') || strchr (sym->tag, '$'))
-       continue;
-
-      fprintf (out, "%s[[[%s]], %d]",
-              sep, sym->tag, number);
-      sep = ",\n";
+      aver (number != USER_NUMBER_ALIAS);
+
+      /* Skip error token and tokens without identifier.  */
+      if (sym != errtoken && id)
+        {
+          fprintf (out, "%s[[[%s]], %d]",
+                   sep, id, number);
+          sep = ",\n";
+        }

     }
   fputs ("])\n\n", out);
 }
 
 
     }
   fputs ("])\n\n", out);
 }
 
 

-/*---------------------------------------.
-| Output the symbol destructors to OUT.  |
-`---------------------------------------*/
-
-static void
-symbol_destructors_output (FILE *out)
-{
-  int i;
-  char const *sep = "";
-
-  fputs ("m4_define([b4_symbol_destructors], \n[", out);
-  for (i = 0; i < nsyms; ++i)
-    if (symbols[i]->destructor)
-      {
-       symbol *sym = symbols[i];
-
-       /* Filename, lineno,
-          Symbol-name, Symbol-number,
-          destructor, optional typename.  */
-       fprintf (out, "%s[", sep);
-       sep = ",\n";
-       escaped_output (out, sym->destructor_location.start.file);
-       fprintf (out, ", %d, ", sym->destructor_location.start.line);
-       escaped_output (out, sym->tag);
-       fprintf (out, ", %d, [[%s]]", sym->number, sym->destructor);
-       if (sym->type_name)
-         fprintf (out, ", [[%s]]", sym->type_name);
-       fputc (']', out);
-      }
-  fputs ("])\n\n", out);
-}
-
-
-/*------------------------------------.
-| Output the symbol printers to OUT.  |
-`------------------------------------*/
-
-static void
-symbol_printers_output (FILE *out)
-{
-  int i;
-  char const *sep = "";
-
-  fputs ("m4_define([b4_symbol_printers], \n[", out);
-  for (i = 0; i < nsyms; ++i)
-    if (symbols[i]->printer)
-      {
-       symbol *sym = symbols[i];
-
-       /* Filename, lineno,
-          Symbol-name, Symbol-number,
-          printer, optional typename.  */
-       fprintf (out, "%s[", sep);
-       sep = ",\n";
-       escaped_output (out, sym->printer_location.start.file);
-       fprintf (out, ", %d, ", sym->printer_location.start.line);
-       escaped_output (out, sym->tag);
-       fprintf (out, ", %d, [[%s]]", sym->number, sym->printer);
-       if (sym->type_name)
-         fprintf (out, ", [[%s]]", sym->type_name);
-       fputc (']', out);
-      }
-  fputs ("])\n\n", out);
-}
-
-

 static void
 prepare_actions (void)
 {
   /* Figure out the actions for the specified state, indexed by
 static void
 prepare_actions (void)
 {
   /* Figure out the actions for the specified state, indexed by

-     look-ahead token type.  */
+     lookahead token type.  */

 
   muscle_insert_rule_number_table ("defact", yydefact,
                                   yydefact[0], 1, nstates);
 
   muscle_insert_rule_number_table ("defact", yydefact,
                                   yydefact[0], 1, nstates);


@@ -495,6 +535,23 @@ prepare_actions (void)
                                    0, 1, conflict_list_cnt);
 }
 
                                    0, 1, conflict_list_cnt);
 }
 

+
+/*--------------------------------------------.
+| Output the definitions of all the muscles.  |
+`--------------------------------------------*/
+
+static void
+muscles_output (FILE *out)
+{
+  fputs ("m4_init()\n", out);
+  merger_output (out);
+  symbol_numbers_output (out);
+  token_definitions_output (out);
+  type_names_output (out);
+  user_actions_output (out);
+  // Must be last.
+  muscles_m4_output (out);
+}

 \f
 /*---------------------------.
 | Call the skeleton parser.  |
 \f
 /*---------------------------.
 | Call the skeleton parser.  |


@@ -504,22 +561,19 @@ static void
 output_skeleton (void)
 {
   FILE *in;
 output_skeleton (void)
 {
   FILE *in;

-  FILE *out;

   int filter_fd[2];
   int filter_fd[2];

-  char const *argv[6];
+  char const *argv[9];

   pid_t pid;
 
   pid_t pid;
 

-  /* Compute the names of the package data dir and skeleton file.
-     Test whether m4sugar.m4 is readable, to check for proper
-     installation.  A faulty installation can cause deadlock, so a
-     cheap sanity check is worthwhile.  */
+  /* Compute the names of the package data dir and skeleton files.  */

   char const m4sugar[] = "m4sugar/m4sugar.m4";
   char const m4sugar[] = "m4sugar/m4sugar.m4";

+  char const m4bison[] = "bison.m4";

   char *full_m4sugar;
   char *full_m4sugar;

-  char *full_cm4;
+  char *full_m4bison;

   char *full_skeleton;
   char const *p;
   char const *m4 = (p = getenv ("M4")) ? p : M4;
   char *full_skeleton;
   char const *p;
   char const *m4 = (p = getenv ("M4")) ? p : M4;

-  char const *pkgdatadir = (p = getenv ("BISON_PKGDATADIR")) ? p : PKGDATADIR;
+  char const *pkgdatadir = compute_pkgdatadir ();

   size_t skeleton_size = strlen (skeleton) + 1;
   size_t pkgdatadirlen = strlen (pkgdatadir);
   while (pkgdatadirlen && pkgdatadir[pkgdatadirlen - 1] == '/')
   size_t skeleton_size = strlen (skeleton) + 1;
   size_t pkgdatadirlen = strlen (pkgdatadir);
   while (pkgdatadirlen && pkgdatadir[pkgdatadirlen - 1] == '/')


@@ -527,53 +581,83 @@ output_skeleton (void)
   full_skeleton = xmalloc (pkgdatadirlen + 1
                           + (skeleton_size < sizeof m4sugar
                              ? sizeof m4sugar : skeleton_size));
   full_skeleton = xmalloc (pkgdatadirlen + 1
                           + (skeleton_size < sizeof m4sugar
                              ? sizeof m4sugar : skeleton_size));

-  strcpy (full_skeleton, pkgdatadir);
+  strncpy (full_skeleton, pkgdatadir, pkgdatadirlen);

   full_skeleton[pkgdatadirlen] = '/';
   strcpy (full_skeleton + pkgdatadirlen + 1, m4sugar);
   full_m4sugar = xstrdup (full_skeleton);
   full_skeleton[pkgdatadirlen] = '/';
   strcpy (full_skeleton + pkgdatadirlen + 1, m4sugar);
   full_m4sugar = xstrdup (full_skeleton);

-  strcpy (full_skeleton + pkgdatadirlen + 1, "c.m4");
-  full_cm4 = xstrdup (full_skeleton);
-  strcpy (full_skeleton + pkgdatadirlen + 1, skeleton);
+  strcpy (full_skeleton + pkgdatadirlen + 1, m4bison);
+  full_m4bison = xstrdup (full_skeleton);
+  if (strchr (skeleton, '/'))
+    strcpy (full_skeleton, skeleton);
+  else
+    strcpy (full_skeleton + pkgdatadirlen + 1, skeleton);
+
+  /* Test whether m4sugar.m4 is readable, to check for proper
+     installation.  A faulty installation can cause deadlock, so a
+     cheap sanity check is worthwhile.  */

   xfclose (xfopen (full_m4sugar, "r"));
 
   /* Create an m4 subprocess connected to us via two pipes.  */
 
   if (trace_flag & trace_tools)
     fprintf (stderr, "running: %s %s - %s %s\n",
   xfclose (xfopen (full_m4sugar, "r"));
 
   /* Create an m4 subprocess connected to us via two pipes.  */
 
   if (trace_flag & trace_tools)
     fprintf (stderr, "running: %s %s - %s %s\n",

-            m4, full_m4sugar, full_cm4, full_skeleton);
+             m4, full_m4sugar, full_m4bison, full_skeleton);

 
 

-  argv[0] = m4;
-  argv[1] = full_m4sugar;
-  argv[2] = "-";
-  argv[3] = full_cm4;
-  argv[4] = full_skeleton;
-  argv[5] = NULL;
+  /* Some future version of GNU M4 (most likely 1.6) may treat the -dV in a
+     position-dependent manner.  Keep it as the first argument so that all
+     files are traced.

 
 

+     See the thread starting at
+     <http://lists.gnu.org/archive/html/bug-bison/2008-07/msg00000.html>
+     for details.  */
+  {
+    int i = 0;
+    argv[i++] = m4;
+    argv[i++] = "-I";
+    argv[i++] = pkgdatadir;
+    if (trace_flag & trace_m4)
+      argv[i++] = "-dV";
+    argv[i++] = full_m4sugar;
+    argv[i++] = "-";
+    argv[i++] = full_m4bison;
+    argv[i++] = full_skeleton;
+    argv[i++] = NULL;
+  }
+  /* When POSIXLY_CORRECT is set, some future versions of GNU M4 (most likely
+     2.0) may drop some of the GNU extensions that Bison's skeletons depend
+     upon.  So that the next release of Bison is forward compatible with those
+     future versions of GNU M4, we unset POSIXLY_CORRECT here.
+
+     FIXME: A user might set POSIXLY_CORRECT to affect processes run from
+     macros like m4_syscmd in a custom skeleton.  For now, Bison makes no
+     promises about the behavior of custom skeletons, so this scenario is not a
+     concern.  However, we eventually want to eliminate this shortcoming.  The
+     next release of GNU M4 (1.4.12 or 1.6) will accept the -g command-line
+     option as a no-op, and later releases will accept it to indicate that
+     POSIXLY_CORRECT should be ignored.  Once the GNU M4 versions that accept
+     -g are pervasive, Bison should use -g instead of unsetting
+     POSIXLY_CORRECT.
+
+     See the thread starting at
+     <http://lists.gnu.org/archive/html/bug-bison/2008-07/msg00000.html>
+     for details.  */
+  unsetenv ("POSIXLY_CORRECT");

   init_subpipe ();
   pid = create_subpipe (argv, filter_fd);
   free (full_m4sugar);
   init_subpipe ();
   pid = create_subpipe (argv, filter_fd);
   free (full_m4sugar);

-  free (full_cm4);
+  free (full_m4bison);

   free (full_skeleton);
 
   free (full_skeleton);
 

-  out = fdopen (filter_fd[0], "w");
-  if (! out)
-    error (EXIT_FAILURE, get_errno (),
-          "fdopen");
-
-  /* Output the definitions of all the muscles.  */
-  fputs ("m4_init()\n", out);
-
-  user_actions_output (out);
-  merger_output (out);
-  token_definitions_output (out);
-  symbol_destructors_output (out);
-  symbol_printers_output (out);
-
-  muscles_m4_output (out);
-
-  fputs ("m4_wrap([m4_divert_pop(0)])\n", out);
-  fputs ("m4_divert_push(0)dnl\n", out);
-  xfclose (out);
+  if (trace_flag & trace_muscles)
+    muscles_output (stderr);
+  {
+    FILE *out = fdopen (filter_fd[0], "w");
+    if (! out)
+      error (EXIT_FAILURE, get_errno (),
+             "fdopen");
+    muscles_output (out);
+    xfclose (out);
+  }

 
   /* Read and process m4's output.  */
   timevar_push (TV_M4);
 
   /* Read and process m4's output.  */
   timevar_push (TV_M4);


@@ -591,16 +675,30 @@ output_skeleton (void)
 static void
 prepare (void)
 {
 static void
 prepare (void)
 {

+  /* BISON_USE_PUSH_FOR_PULL is for the test suite and should not be documented
+     for the user.  */
+  char const *use_push_for_pull_env = getenv ("BISON_USE_PUSH_FOR_PULL");
+  bool use_push_for_pull_flag = false;
+  if (use_push_for_pull_env != NULL
+      && use_push_for_pull_env[0] != '\0'
+      && 0 != strcmp (use_push_for_pull_env, "0"))
+    use_push_for_pull_flag = true;
+

   /* Flags. */
   /* Flags. */

-  MUSCLE_INSERT_BOOL ("debug", debug_flag);

   MUSCLE_INSERT_BOOL ("defines_flag", defines_flag);
   MUSCLE_INSERT_BOOL ("defines_flag", defines_flag);

-  MUSCLE_INSERT_BOOL ("error_verbose", error_verbose);
-  MUSCLE_INSERT_BOOL ("locations_flag", locations_flag);
-  MUSCLE_INSERT_BOOL ("pure", pure_parser);
+  MUSCLE_INSERT_BOOL ("glr_flag", glr_parser);
+  MUSCLE_INSERT_BOOL ("nondeterministic_flag", nondeterministic_parser);

   MUSCLE_INSERT_BOOL ("synclines_flag", !no_lines_flag);
   MUSCLE_INSERT_BOOL ("synclines_flag", !no_lines_flag);

+  MUSCLE_INSERT_BOOL ("tag_seen_flag", tag_seen);
+  MUSCLE_INSERT_BOOL ("use_push_for_pull_flag", use_push_for_pull_flag);
+  MUSCLE_INSERT_BOOL ("yacc_flag", yacc_flag);

 
   /* File names.  */
 
   /* File names.  */

-  MUSCLE_INSERT_STRING ("prefix", spec_name_prefix ? spec_name_prefix : "yy");
+  if (spec_name_prefix)
+    MUSCLE_INSERT_STRING ("prefix", spec_name_prefix);
+
+  MUSCLE_INSERT_STRING ("file_name_all_but_ext", all_but_ext);
+

 #define DEFINE(Name) MUSCLE_INSERT_STRING (#Name, Name ? Name : "")
   DEFINE (dir_prefix);
   DEFINE (parser_file_name);
 #define DEFINE(Name) MUSCLE_INSERT_STRING (#Name, Name ? Name : "")
   DEFINE (dir_prefix);
   DEFINE (parser_file_name);


@@ -612,26 +710,18 @@ prepare (void)
   DEFINE (spec_verbose_file);
 #undef DEFINE
 
   DEFINE (spec_verbose_file);
 #undef DEFINE
 

-  /* User Code.  */
-  obstack_1grow (&pre_prologue_obstack, 0);
-  obstack_1grow (&post_prologue_obstack, 0);
-  muscle_insert ("pre_prologue", obstack_finish (&pre_prologue_obstack));
-  muscle_insert ("post_prologue", obstack_finish (&post_prologue_obstack));
-
-  /* Find the right skeleton file.  */
-  if (!skeleton)
-    {
-      if (glr_parser || nondeterministic_parser)
-       skeleton = "glr.c";
-      else
-       skeleton = "yacc.c";
-    }
+  /* Find the right skeleton file, and add muscles about the skeletons.  */
+  if (skeleton)
+    MUSCLE_INSERT_C_STRING ("skeleton", skeleton);
+  else
+    skeleton = language->skeleton;

 
 

-  /* About the skeletons. */
+  /* About the skeletons.  */

   {
   {

-    char const *pkgdatadir = getenv ("BISON_PKGDATADIR");
-    MUSCLE_INSERT_STRING ("pkgdatadir", pkgdatadir ? pkgdatadir : PKGDATADIR);
-    MUSCLE_INSERT_C_STRING ("skeleton", skeleton);
+    /* b4_pkgdatadir is used inside m4_include in the skeletons, so digraphs
+       would never be expanded.  Hopefully no one has M4-special characters in
+       his Bison installation path.  */
+    MUSCLE_INSERT_STRING_RAW ("pkgdatadir", compute_pkgdatadir ());

   }
 }
 
   }
 }
 


@@ -649,6 +739,7 @@ output (void)
   prepare_rules ();
   prepare_states ();
   prepare_actions ();
   prepare_rules ();
   prepare_states ();
   prepare_actions ();

+  prepare_symbol_definitions ();

 
   prepare ();
 
 
   prepare ();
 


@@ -656,6 +747,11 @@ output (void)
   output_skeleton ();
 
   obstack_free (&format_obstack, NULL);
   output_skeleton ();
 
   obstack_free (&format_obstack, NULL);

-  obstack_free (&pre_prologue_obstack, NULL);
-  obstack_free (&post_prologue_obstack, NULL);
+}
+
+char const *
+compute_pkgdatadir (void)
+{
+  char const *pkgdatadir = getenv ("BISON_PKGDATADIR");
+  return pkgdatadir ? pkgdatadir : PKGDATADIR;

 }
 }