lalr1.cc: check (and fix) %initial-action exception safety

[bison.git] / src / scan-code.l

diff --git a/src/scan-code.l b/src/scan-code.l
index fc35513a10f93cd5b4a6ba92c2903f54f19ec2ec..fa593beb8da889aeeb3c9685dacf0497f7422508 100644 (file)
--- a/src/scan-code.l
+++ b/src/scan-code.l
@@ -1,6 +1,6 @@
 /* Bison Action Scanner                             -*- C -*-
 
 /* Bison Action Scanner                             -*- C -*-
 

-   Copyright (C) 2006, 2007, 2008-2009 Free Software Foundation, Inc.
+   Copyright (C) 2006-2012 Free Software Foundation, Inc.

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


@@ -46,6 +46,9 @@ YY_DECL;
 
 #define YY_USER_ACTION  location_compute (loc, &loc->end, yytext, yyleng);
 
 
 #define YY_USER_ACTION  location_compute (loc, &loc->end, yytext, yyleng);
 

+static char *fetch_type_name (char *cp, char const **type_name,
+                              location dollar_loc);
+

 static void handle_action_dollar (symbol_list *rule, char *cp,
                                  location dollar_loc);
 static void handle_action_at (symbol_list *rule, char *cp, location at_loc);
 static void handle_action_dollar (symbol_list *rule, char *cp,
                                  location dollar_loc);
 static void handle_action_at (symbol_list *rule, char *cp, location at_loc);


@@ -84,8 +87,8 @@ splice         (\\[ \f\t\v]*\n)*
 /* C style identifier. Must start with letter. Will be used for
    named symbol references. Shall be kept synchronized with
    scan-gram.l "letter" and "id". */
 /* C style identifier. Must start with letter. Will be used for
    named symbol references. Shall be kept synchronized with
    scan-gram.l "letter" and "id". */

-letter   [-.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_]
-id       {letter}({letter}|[0-9])*
+letter   [.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_]
+id       {letter}({letter}|[-0-9])*

 ref      -?[0-9]+|{id}|"["{id}"]"|"$"
 
 %%
 ref      -?[0-9]+|{id}|"["{id}"]"|"$"
 
 %%


@@ -95,11 +98,15 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
   int braces_level = 0;
 
   /* Whether a semicolon is probably needed.
   int braces_level = 0;
 
   /* Whether a semicolon is probably needed.

-     The heuristic is that a semicolon is not needed after `{', `}', `;',
-     or a C preprocessor directive, and that whitespaces and comments
-     do not affect this flag.
-     Note that `{' does not need a semicolon because of `{}'.
-     A semicolon may be needed before a cpp direcive, but don't bother.  */
+
+     The heuristic is that a semicolon is not needed after '{', '}',
+     ';', or a C preprocessor directive, and that whitespaces and
+     comments do not affect this flag.  Note that '{' does not need a
+     semicolon because of '{}'.  A semicolon may be needed before a
+     cpp directive, but don't bother.
+
+     While it is maintained in several start-conditions (factoring
+     opportunities), it is meaningful only for SC_RULE_ACTION. */

   bool need_semicolon = false;
 
   /* Whether in a C preprocessor directive.  Don't use a start condition
   bool need_semicolon = false;
 
   /* Whether in a C preprocessor directive.  Don't use a start condition


@@ -117,7 +124,7 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
 %}
 
   /*------------------------------------------------------------.
 %}
 
   /*------------------------------------------------------------.

-  | Scanning a C comment.  The initial `/ *' is already eaten.  |
+  | Scanning a C comment.  The initial '/ *' is already eaten.  |

   `------------------------------------------------------------*/
 
 <SC_COMMENT>
   `------------------------------------------------------------*/
 
 <SC_COMMENT>


@@ -127,7 +134,7 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
 
 
   /*--------------------------------------------------------------.
 
 
   /*--------------------------------------------------------------.

-  | Scanning a line comment.  The initial `//' is already eaten.  |
+  | Scanning a line comment.  The initial '//' is already eaten.  |

   `--------------------------------------------------------------*/
 
 <SC_LINE_COMMENT>
   `--------------------------------------------------------------*/
 
 <SC_LINE_COMMENT>


@@ -157,7 +164,8 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
 }
 
 
 }
 
 

-<SC_RULE_ACTION,SC_SYMBOL_ACTION>{
+<SC_RULE_ACTION,SC_SYMBOL_ACTION>
+{

   "'" {
     STRING_GROW;
     BEGIN SC_CHARACTER;
   "'" {
     STRING_GROW;
     BEGIN SC_CHARACTER;


@@ -176,42 +184,31 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
     STRING_GROW;
     BEGIN SC_LINE_COMMENT;
   }
     STRING_GROW;
     BEGIN SC_LINE_COMMENT;
   }

+  [$@]  {
+    warn_at (*loc, _("stray '%s'"), yytext);
+    obstack_escape (&obstack_for_string, yytext);
+    need_semicolon = true;
+  }
+  [\[\]]  {
+    obstack_escape (&obstack_for_string, yytext);
+    need_semicolon = true;
+  }

 }
 
 <SC_RULE_ACTION>
 {
   "$"("<"{tag}">")?{ref}  {
 }
 
 <SC_RULE_ACTION>
 {
   "$"("<"{tag}">")?{ref}  {

-    ref_tail_fields = 0;
+    ref_tail_fields = NULL;

     handle_action_dollar (self->rule, yytext, *loc);
     handle_action_dollar (self->rule, yytext, *loc);

-    if (ref_tail_fields) {
+    if (ref_tail_fields)

       obstack_sgrow (&obstack_for_string, ref_tail_fields);
       obstack_sgrow (&obstack_for_string, ref_tail_fields);

-    }

     need_semicolon = true;
   }
   "@"{ref} {
     need_semicolon = true;
   }
   "@"{ref} {

-    ref_tail_fields = 0;
+    ref_tail_fields = NULL;

     handle_action_at (self->rule, yytext, *loc);
     handle_action_at (self->rule, yytext, *loc);

-    if (ref_tail_fields) {
+    if (ref_tail_fields)

       obstack_sgrow (&obstack_for_string, ref_tail_fields);
       obstack_sgrow (&obstack_for_string, ref_tail_fields);

-    }
-    need_semicolon = true;
-  }
-  "$"  {
-    warn_at (*loc, _("stray `$'"));
-    obstack_sgrow (&obstack_for_string, "$][");
-    need_semicolon = true;
-  }
-  "@"  {
-    warn_at (*loc, _("stray `@'"));
-    obstack_sgrow (&obstack_for_string, "@@");
-    need_semicolon = true;
-  }
-  "["  {
-    obstack_sgrow (&obstack_for_string, "@{");
-    need_semicolon = true;
-  }
-  "]"  {
-    obstack_sgrow (&obstack_for_string, "@}");

     need_semicolon = true;
   }
 
     need_semicolon = true;
   }
 


@@ -220,16 +217,16 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
   "}"  {
     bool outer_brace = --braces_level == 0;
 
   "}"  {
     bool outer_brace = --braces_level == 0;
 

-    /* As an undocumented Bison extension, append `;' before the last
+    /* As an undocumented Bison extension, append ';' before the last

        brace in braced code, so that the user code can omit trailing
        brace in braced code, so that the user code can omit trailing

-       `;'.  But do not append `;' if emulating Yacc, since Yacc does
+       ';'.  But do not append ';' if emulating Yacc, since Yacc does

        not append one.  */
     if (outer_brace && !yacc_flag && language_prio == default_prio
         && skeleton_prio == default_prio && need_semicolon && ! in_cpp)
       {
        not append one.  */
     if (outer_brace && !yacc_flag && language_prio == default_prio
         && skeleton_prio == default_prio && need_semicolon && ! in_cpp)
       {

-       warn_at (*loc, _("a `;' might be needed at the end of action code"));
-       warn_at (*loc, _("future versions of Bison will not add the `;'"));
-       obstack_1grow (&obstack_for_string, ';');
+        warn_at (*loc, _("a ';' might be needed at the end of action code"));
+        warn_at (*loc, _("future versions of Bison will not add the ';'"));
+        obstack_1grow (&obstack_for_string, ';');

       }
 
     STRING_GROW;
       }
 
     STRING_GROW;


@@ -238,20 +235,37 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
 
   /* Preprocessing directives should only be recognized at the beginning
      of lines, allowing whitespace including comments, but in C/C++,
 
   /* Preprocessing directives should only be recognized at the beginning
      of lines, allowing whitespace including comments, but in C/C++,

-     `#' can only be the start of preprocessor directives or within
-     `#define' directives anyway, so don't bother with begin of line.  */
+     '#' can only be the start of preprocessor directives or within
+     '#define' directives anyway, so don't bother with begin of line.  */

   "#"       STRING_GROW; in_cpp = true;
 
   {splice}  STRING_GROW;
   "#"       STRING_GROW; in_cpp = true;
 
   {splice}  STRING_GROW;

-  [\n\r]    STRING_GROW; if (in_cpp) in_cpp = need_semicolon = false; 
+  [\n\r]    STRING_GROW; if (in_cpp) in_cpp = need_semicolon = false;

   [ \t\f]   STRING_GROW;
   [ \t\f]   STRING_GROW;

-  .         STRING_GROW; need_semicolon = true;
+
+  /* YYFAIL is undocumented and was formally deprecated in Bison
+     2.4.2.  */
+  YYFAIL {
+    STRING_GROW; need_semicolon = true;
+    warn_at (*loc, _("use of YYFAIL, which is deprecated and will be"
+                     " removed"));
+  }
+
+  /* The sole purpose of this is to make sure identifiers that merely
+     contain YYFAIL don't produce the above warning.  */
+  [A-Za-z_][0-9A-Za-z_]* STRING_GROW; need_semicolon = true;
+
+  . STRING_GROW; need_semicolon = true;

 }
 
 <SC_SYMBOL_ACTION>
 {
 }
 
 <SC_SYMBOL_ACTION>
 {

-  "$$" {
-    obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar[");
+  "$"("<"{tag}">")?"$" {
+    const char *type_name = NULL;
+    fetch_type_name (yytext + 1, &type_name, *loc)[-1] = 0;
+    obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar(");
+    obstack_quote (&obstack_for_string, type_name);
+    obstack_sgrow (&obstack_for_string, ")[");

     self->is_value_used = true;
   }
   "@$" {
     self->is_value_used = true;
   }
   "@$" {


@@ -261,29 +275,17 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
 }
 
 
 }
 
 

-  /*-----------------------------------------.
-  | Escape M4 quoting characters in C code.  |
-  `-----------------------------------------*/
-

 <*>
 {
 <*>
 {

-  \$   obstack_sgrow (&obstack_for_string, "$][");
-  \@   obstack_sgrow (&obstack_for_string, "@@");
-  \[   obstack_sgrow (&obstack_for_string, "@{");
-  \]   obstack_sgrow (&obstack_for_string, "@}");
-}
-
-  /*-----------------------------------------------------.
-  | By default, grow the string obstack with the input.  |
-  `-----------------------------------------------------*/
+  /* Escape M4 quoting characters in C code.  */
+  [$@\[\]]    obstack_escape (&obstack_for_string, yytext);

 
 

-<*>.|\n        STRING_GROW;
+  /* By default, grow the string obstack with the input.  */
+  .|\n        STRING_GROW;

 
 

- /* End of processing. */
-<*><<EOF>>      {
-                   STRING_FINISH;
-                   return last_string;
-                 }
+  /* End of processing. */
+  <<EOF>>     STRING_FINISH; return last_string;
+}

 
 %%
 
 
 %%
 


@@ -332,7 +334,7 @@ typedef struct
    not visible from current midrule. */
 #define VARIANT_NOT_VISIBLE_FROM_MIDRULE (1 << 2)
 
    not visible from current midrule. */
 #define VARIANT_NOT_VISIBLE_FROM_MIDRULE (1 << 2)
 

-static variant *variant_table = 0;
+static variant *variant_table = NULL;

 static unsigned variant_table_size = 0;
 static unsigned variant_count = 0;
 
 static unsigned variant_table_size = 0;
 static unsigned variant_count = 0;
 


@@ -354,7 +356,7 @@ static void
 variant_table_free (void)
 {
   free (variant_table);
 variant_table_free (void)
 {
   free (variant_table);

-  variant_table = 0;
+  variant_table = NULL;

   variant_table_size = variant_count = 0;
 }
 
   variant_table_size = variant_count = 0;
 }
 


@@ -375,14 +377,14 @@ find_prefix_end (const char *prefix, char *begin, char *end)
 
 static variant *
 variant_add (uniqstr id, location id_loc, unsigned symbol_index,
 
 static variant *
 variant_add (uniqstr id, location id_loc, unsigned symbol_index,

-            char *cp, char *cp_end, bool exact_mode)
+            char *cp, char *cp_end, bool explicit_bracketing)

 {
   char *prefix_end;
 
   prefix_end = find_prefix_end (id, cp, cp_end);
   if (prefix_end &&
       (prefix_end == cp_end ||
 {
   char *prefix_end;
 
   prefix_end = find_prefix_end (id, cp, cp_end);
   if (prefix_end &&
       (prefix_end == cp_end ||

-       (!exact_mode && is_dot_or_dash (*prefix_end))))
+       (!explicit_bracketing && is_dot_or_dash (*prefix_end))))

     {
       variant *r = variant_table_grow ();
       r->symbol_index = symbol_index;
     {
       variant *r = variant_table_grow ();
       r->symbol_index = symbol_index;


@@ -397,7 +399,7 @@ variant_add (uniqstr id, location id_loc, unsigned symbol_index,
 }
 
 static const char *
 }
 
 static const char *

-get_at_spec(unsigned symbol_index)
+get_at_spec (unsigned symbol_index)

 {
   static char at_buf[20];
   if (symbol_index == 0)
 {
   static char at_buf[20];
   if (symbol_index == 0)


@@ -408,8 +410,9 @@ get_at_spec(unsigned symbol_index)
 }
 
 static void
 }
 
 static void

-show_sub_messages (const char* cp, bool exact_mode, int midrule_rhs_index,
-                   char dollar_or_at, bool is_warning)
+show_sub_messages (const char* cp, bool explicit_bracketing,
+                   int midrule_rhs_index, char dollar_or_at,
+                   bool is_warning, unsigned indent)

 {
   unsigned i;
 
 {
   unsigned i;
 


@@ -421,16 +424,16 @@ show_sub_messages (const char* cp, bool exact_mode, int midrule_rhs_index,
       if (var->err == 0)
         {
           if (is_warning)
       if (var->err == 0)
         {
           if (is_warning)

-            warn_at (var->loc, _("  refers to: %c%s at %s"),
-                     dollar_or_at, var->id, at_spec);
+            warn_at_indent (var->loc, &indent, _("refers to: %c%s at %s"),
+                            dollar_or_at, var->id, at_spec);

           else
           else

-            complain_at (var->loc, _("  refers to: %c%s at %s"),
-                         dollar_or_at, var->id, at_spec);
+            complain_at_indent (var->loc, &indent, _("refers to: %c%s at %s"),
+                                dollar_or_at, var->id, at_spec);

         }
       else
        {
          static struct obstack msg_buf;
         }
       else
        {
          static struct obstack msg_buf;

-         const char *tail = exact_mode ? "" :
+         const char *tail = explicit_bracketing ? "" :

            cp + strlen (var->id);
          const char *id = var->hidden_by ? var->hidden_by->id :
            var->id;
            cp + strlen (var->id);
          const char *id = var->hidden_by ? var->hidden_by->id :
            var->id;


@@ -440,34 +443,39 @@ show_sub_messages (const char* cp, bool exact_mode, int midrule_rhs_index,
          /* Create the explanation message. */
          obstack_init (&msg_buf);
 
          /* Create the explanation message. */
          obstack_init (&msg_buf);
 

-         obstack_fgrow1 (&msg_buf, "  possibly meant: %c", dollar_or_at);
+         obstack_printf (&msg_buf, _("possibly meant: %c"), dollar_or_at);

          if (contains_dot_or_dash (id))
          if (contains_dot_or_dash (id))

-           obstack_fgrow1 (&msg_buf, "[%s]", id);
+           obstack_printf (&msg_buf, "[%s]", id);

          else
            obstack_sgrow (&msg_buf, id);
          obstack_sgrow (&msg_buf, tail);
 
          if (var->err & VARIANT_HIDDEN)
            {
          else
            obstack_sgrow (&msg_buf, id);
          obstack_sgrow (&msg_buf, tail);
 
          if (var->err & VARIANT_HIDDEN)
            {

-             obstack_fgrow1 (&msg_buf, ", hiding %c", dollar_or_at);
+             obstack_printf (&msg_buf, _(", hiding %c"), dollar_or_at);

              if (contains_dot_or_dash (var->id))
              if (contains_dot_or_dash (var->id))

-               obstack_fgrow1 (&msg_buf, "[%s]", var->id);
+               obstack_printf (&msg_buf, "[%s]", var->id);

              else
                obstack_sgrow (&msg_buf, var->id);
              obstack_sgrow (&msg_buf, tail);
            }
 
              else
                obstack_sgrow (&msg_buf, var->id);
              obstack_sgrow (&msg_buf, tail);
            }
 

-         obstack_fgrow1 (&msg_buf, " at %s", at_spec);
+         obstack_printf (&msg_buf, _(" at %s"), at_spec);

 
          if (var->err & VARIANT_NOT_VISIBLE_FROM_MIDRULE)
 
          if (var->err & VARIANT_NOT_VISIBLE_FROM_MIDRULE)

-           obstack_fgrow1 (&msg_buf, ", cannot be accessed from "
-                           "mid-rule action at $%d", midrule_rhs_index);
+            {
+              const char *format =
+                _(", cannot be accessed from mid-rule action at $%d");
+              obstack_printf (&msg_buf, format, midrule_rhs_index);
+            }

 
          obstack_1grow (&msg_buf, '\0');
           if (is_warning)
 
          obstack_1grow (&msg_buf, '\0');
           if (is_warning)

-            warn_at (id_loc, _("%s"), (char *) obstack_finish (&msg_buf));
+            warn_at_indent (id_loc, &indent, "%s",
+                            (char *) obstack_finish (&msg_buf));

           else
           else

-            complain_at (id_loc, _("%s"), (char *) obstack_finish (&msg_buf));
+            complain_at_indent (id_loc, &indent, "%s",
+                                (char *) obstack_finish (&msg_buf));

          obstack_free (&msg_buf, 0);
        }
     }
          obstack_free (&msg_buf, 0);
        }
     }


@@ -481,6 +489,9 @@ show_sub_messages (const char* cp, bool exact_mode, int midrule_rhs_index,
    points to LHS ($$) of the current rule or midrule. */
 #define LHS_REF (INT_MIN + 1)
 
    points to LHS ($$) of the current rule or midrule. */
 #define LHS_REF (INT_MIN + 1)
 

+/* Sub-messages indent. */
+#define SUB_INDENT (4)
+

 /* Parse named or positional reference. In case of positional
    references, can return negative values for $-n "deep" stack
    accesses. */
 /* Parse named or positional reference. In case of positional
    references, can return negative values for $-n "deep" stack
    accesses. */


@@ -491,7 +502,7 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
 {
   symbol_list *l;
   char *cp_end;
 {
   symbol_list *l;
   char *cp_end;

-  bool exact_mode;
+  bool explicit_bracketing;

   unsigned i;
   unsigned valid_variants = 0;
   unsigned valid_variant_index = 0;
   unsigned i;
   unsigned valid_variants = 0;
   unsigned valid_variant_index = 0;


@@ -520,7 +531,7 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
        continue;
       cp_end = p;
 
        continue;
       cp_end = p;
 

-      exact_mode = true;
+      explicit_bracketing = true;

     }
   else
     {
     }
   else
     {


@@ -536,7 +547,7 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
        continue;
       cp_end = p;
 
        continue;
       cp_end = p;
 

-      exact_mode = false;
+      explicit_bracketing = false;

     }
 
   /* Add all relevant variants. */
     }
 
   /* Add all relevant variants. */


@@ -551,13 +562,13 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
          continue;
 
        var = variant_add (l->content.sym->tag, l->sym_loc,
          continue;
 
        var = variant_add (l->content.sym->tag, l->sym_loc,

-                           symbol_index, cp, cp_end, exact_mode);
+                           symbol_index, cp, cp_end, explicit_bracketing);

        if (var && l->named_ref)
          var->hidden_by = l->named_ref;
 
        if (l->named_ref)
          variant_add (l->named_ref->id, l->named_ref->loc,
        if (var && l->named_ref)
          var->hidden_by = l->named_ref;
 
        if (l->named_ref)
          variant_add (l->named_ref->id, l->named_ref->loc,

-                       symbol_index, cp, cp_end, exact_mode);
+                       symbol_index, cp, cp_end, explicit_bracketing);

       }
   }
 
       }
   }
 


@@ -573,7 +584,7 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
         var->err |= VARIANT_NOT_VISIBLE_FROM_MIDRULE;
 
       /* Check correct bracketing. */
         var->err |= VARIANT_NOT_VISIBLE_FROM_MIDRULE;
 
       /* Check correct bracketing. */

-      if (!exact_mode && contains_dot_or_dash (var->id))
+      if (!explicit_bracketing && contains_dot_or_dash (var->id))

         var->err |= VARIANT_BAD_BRACKETING;
 
       /* Check using of hidden symbols. */
         var->err |= VARIANT_BAD_BRACKETING;
 
       /* Check using of hidden symbols. */


@@ -590,25 +601,53 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
   switch (valid_variants)
     {
     case 0:
   switch (valid_variants)
     {
     case 0:

-      if (variant_count == 0)
-        complain_at (text_loc, _("invalid reference: %s, symbol not found"),
-                     quote (text));
-      else
-        {
-          complain_at (text_loc, _("invalid reference: %s"),
-                       quote (text));
-          show_sub_messages (cp, exact_mode, midrule_rhs_index,
-                             dollar_or_at, false);
-        }
-      return INVALID_REF;
+      {
+        unsigned len = (explicit_bracketing || !ref_tail_fields) ?
+          cp_end - cp : ref_tail_fields - cp;
+        unsigned indent = 0;
+
+        complain_at_indent (text_loc, &indent, _("invalid reference: %s"),
+                            quote (text));
+        indent += SUB_INDENT;
+        if (len == 0)
+          {
+            location sym_loc = text_loc;
+            sym_loc.start.column += 1;
+            sym_loc.end = sym_loc.start;
+            const char *format =
+              _("syntax error after '%c', expecting integer, letter,"
+                " '_', '[', or '$'");
+            complain_at_indent (sym_loc, &indent, format, dollar_or_at);
+          }
+        else if (midrule_rhs_index)
+          {
+            const char *format =
+              _("symbol not found in production before $%d: %.*s");
+            complain_at_indent (rule->location, &indent, format,
+                                midrule_rhs_index, len, cp);
+          }
+        else
+          {
+            const char *format =
+              _("symbol not found in production: %.*s");
+            complain_at_indent (rule->location, &indent, format,
+                                len, cp);
+          }
+
+        if (variant_count > 0)
+          show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
+                             dollar_or_at, false, indent);
+        return INVALID_REF;
+      }

     case 1:
       {
     case 1:
       {

+        unsigned indent = 0;

         if (variant_count > 1)
           {
         if (variant_count > 1)
           {

-            warn_at (text_loc, _("misleading reference: %s"),
-                     quote (text));
-            show_sub_messages (cp, exact_mode, midrule_rhs_index,
-                               dollar_or_at, true);
+            warn_at_indent (text_loc, &indent, _("misleading reference: %s"),
+                            quote (text));
+            show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
+                               dollar_or_at, true, indent + SUB_INDENT);

           }
         {
           unsigned symbol_index =
           }
         {
           unsigned symbol_index =


@@ -618,11 +657,14 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
       }
     case 2:
     default:
       }
     case 2:
     default:

-      complain_at (text_loc, _("ambiguous reference: %s"),
-                   quote (text));
-      show_sub_messages (cp, exact_mode, midrule_rhs_index,
-                         dollar_or_at, false);
-      return INVALID_REF;
+      {
+        unsigned indent = 0;
+        complain_at_indent (text_loc, &indent, _("ambiguous reference: %s"),
+                            quote (text));
+        show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
+                           dollar_or_at, false, indent + SUB_INDENT);
+        return INVALID_REF;
+      }

     }
 
   /* Not reachable. */
     }
 
   /* Not reachable. */


@@ -635,8 +677,33 @@ parse_ref (char *cp, symbol_list *rule, int rule_length,
 int max_left_semantic_context = 0;
 
 
 int max_left_semantic_context = 0;
 
 

+/* If CP points to a typename (i.e., <.*?>), set TYPE_NAME to its
+   beginning (i.e., after the opening "<", and return the pointer
+   immediately after it.  */
+
+static
+char *
+fetch_type_name (char *cp, char const **type_name,
+                 location dollar_loc)
+{
+  if (*cp == '<')
+    {
+      *type_name = ++cp;
+      while (*cp != '>')
+       ++cp;
+
+      /* The '>' symbol will be later replaced by '\0'. Original
+        'text' is needed for error messages. */
+      ++cp;
+      if (untyped_var_seen)
+       complain_at (dollar_loc, _("explicit type given in untyped grammar"));
+      tag_seen = true;
+    }
+  return cp;
+}
+

 /*------------------------------------------------------------------.
 /*------------------------------------------------------------------.

-| TEXT is pointing to a wannabee semantic value (i.e., a `$').      |
+| TEXT is pointing to a wannabee semantic value (i.e., a '$').      |

 |                                                                   |
 | Possible inputs: $[<TYPENAME>]($|integer)                         |
 |                                                                   |
 |                                                                   |
 | Possible inputs: $[<TYPENAME>]($|integer)                         |
 |                                                                   |


@@ -648,7 +715,6 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
 {
   char const *type_name = NULL;
   char *cp = text + 1;
 {
   char const *type_name = NULL;
   char *cp = text + 1;

-  char *gt_ptr = 0;

   symbol_list *effective_rule;
   int effective_rule_length;
   int n;
   symbol_list *effective_rule;
   int effective_rule_length;
   int n;


@@ -665,26 +731,14 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
     }
 
   /* Get the type name if explicit. */
     }
 
   /* Get the type name if explicit. */

-  if (*cp == '<')
-    {
-      type_name = ++cp;
-      while (*cp != '>')
-       ++cp;
-
-      /* The '>' symbol will be later replaced by '\0'. Original
-        'text' is needed for error messages. */
-      gt_ptr = cp;
-      ++cp;
-      if (untyped_var_seen)
-       complain_at (dollar_loc, _("explicit type given in untyped grammar"));
-      tag_seen = true;
-    }
+  cp = fetch_type_name (cp, &type_name, dollar_loc);

 
   n = parse_ref (cp, effective_rule, effective_rule_length,
                 rule->midrule_parent_rhs_index, text, dollar_loc, '$');
 
 
   n = parse_ref (cp, effective_rule, effective_rule_length,
                 rule->midrule_parent_rhs_index, text, dollar_loc, '$');
 

-  if (gt_ptr)
-    *gt_ptr = '\0';
+  /* End type_name. */
+  if (type_name)
+    cp[-1] = '\0';

 
   switch (n)
     {
 
   switch (n)
     {


@@ -696,26 +750,26 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
        type_name = symbol_list_n_type_name_get (rule, dollar_loc, 0);
 
       if (!type_name)
        type_name = symbol_list_n_type_name_get (rule, dollar_loc, 0);
 
       if (!type_name)

-       {
-         if (union_seen | tag_seen)
-           {
-             if (rule->midrule_parent_rule)
-               complain_at (dollar_loc,
-                            _("$$ for the midrule at $%d of `%s'"
-                              " has no declared type"),
-                            rule->midrule_parent_rhs_index,
-                            effective_rule->content.sym->tag);
-             else
-               complain_at (dollar_loc, _("$$ of `%s' has no declared type"),
-                            rule->content.sym->tag);
-           }
-         else
-           untyped_var_seen = true;
-         type_name = "";
-       }
+        {
+          if (union_seen | tag_seen)
+            {
+              if (rule->midrule_parent_rule)
+                complain_at (dollar_loc,
+                             _("$$ for the midrule at $%d of %s"
+                               " has no declared type"),
+                             rule->midrule_parent_rhs_index,
+                             quote (effective_rule->content.sym->tag));
+              else
+                complain_at (dollar_loc, _("$$ of %s has no declared type"),
+                             quote (rule->content.sym->tag));
+            }
+          else
+            untyped_var_seen = true;
+        }

 
 

-      obstack_fgrow1 (&obstack_for_string,
-                     "]b4_lhs_value([%s])[", type_name);
+      obstack_sgrow (&obstack_for_string, "]b4_lhs_value(");
+      obstack_quote (&obstack_for_string, type_name);
+      obstack_sgrow (&obstack_for_string, ")[");

       rule->action_props.is_value_used = true;
       break;
 
       rule->action_props.is_value_used = true;
       break;
 


@@ -726,18 +780,18 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
        type_name =
          symbol_list_n_type_name_get (effective_rule, dollar_loc, n);
       if (!type_name)
        type_name =
          symbol_list_n_type_name_get (effective_rule, dollar_loc, n);
       if (!type_name)

-       {
-         if (union_seen | tag_seen)
-           complain_at (dollar_loc, _("$%s of `%s' has no declared type"),
-                        cp, effective_rule->content.sym->tag);
-         else
-           untyped_var_seen = true;
-         type_name = "";
-       }
+        {
+          if (union_seen | tag_seen)
+            complain_at (dollar_loc, _("$%s of %s has no declared type"),
+                         cp, quote (effective_rule->content.sym->tag));
+          else
+            untyped_var_seen = true;
+        }

 
 

-      obstack_fgrow3 (&obstack_for_string,
-                     "]b4_rhs_value(%d, %d, [%s])[",
-                     effective_rule_length, n, type_name);
+      obstack_printf (&obstack_for_string,
+                     "]b4_rhs_value(%d, %d, ", effective_rule_length, n);
+      obstack_quote (&obstack_for_string, type_name);
+      obstack_sgrow (&obstack_for_string, ")[");

       if (n > 0)
        symbol_list_n_get (effective_rule, n)->action_props.is_value_used =
          true;
       if (n > 0)
        symbol_list_n_get (effective_rule, n)->action_props.is_value_used =
          true;


@@ -747,7 +801,7 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
 
 
 /*------------------------------------------------------.
 
 
 /*------------------------------------------------------.

-| TEXT is a location token (i.e., a `@...').  Output to |
+| TEXT is a location token (i.e., a '@...').  Output to |

 | OBSTACK_FOR_STRING a reference to this location.      |
 `------------------------------------------------------*/
 
 | OBSTACK_FOR_STRING a reference to this location.      |
 `------------------------------------------------------*/
 


@@ -773,7 +827,7 @@ handle_action_at (symbol_list *rule, char *text, location at_loc)
   locations_flag = true;
 
   n = parse_ref (cp, effective_rule, effective_rule_length,
   locations_flag = true;
 
   n = parse_ref (cp, effective_rule, effective_rule_length,

-                      rule->midrule_parent_rhs_index, text, at_loc, '@');
+                 rule->midrule_parent_rhs_index, text, at_loc, '@');

   switch (n)
     {
     case INVALID_REF:
   switch (n)
     {
     case INVALID_REF:


@@ -784,7 +838,7 @@ handle_action_at (symbol_list *rule, char *text, location at_loc)
       break;
 
     default:
       break;
 
     default:

-      obstack_fgrow2 (&obstack_for_string, "]b4_rhs_location(%d, %d)[",
+      obstack_printf (&obstack_for_string, "]b4_rhs_location(%d, %d)[",

                      effective_rule_length, n);
       break;
     }
                      effective_rule_length, n);
       break;
     }