X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/34f98f46ee16dd3719d19e002dc27b2665a2514f..faff3bef5b72ac85093799f997596631c3202c12:/src/parse-gram.y?ds=sidebyside

diff --git a/src/parse-gram.y b/src/parse-gram.y
index bf80f1e1..eb034b08 100644
--- a/src/parse-gram.y
+++ b/src/parse-gram.y
@@ -1,12 +1,12 @@
 %{/* Bison Grammar Parser                             -*- C -*-
 
-   Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
+   Copyright (C) 2002-2012 Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
-   This program is free software; you can redistribute it and/or modify
+   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 2 of the License, or
+   the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
@@ -15,10 +15,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; 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"
@@ -28,13 +25,14 @@
 #include "files.h"
 #include "getargs.h"
 #include "gram.h"
-#include "muscle_tab.h"
+#include "muscle-tab.h"
+#include "named-ref.h"
 #include "quotearg.h"
 #include "reader.h"
 #include "symlist.h"
 #include "scan-gram.h"
 #include "scan-code.h"
-#include "strverscmp.h"
+#include "xmemdup0.h"
 
 #define YYLLOC_DEFAULT(Current, Rhs, N)  (Current) = lloc_default (Rhs, N)
 static YYLTYPE lloc_default (YYLTYPE const *, int);
@@ -53,26 +51,45 @@ static void gram_error (location const *, char const *);
 
 static char const *char_name (char);
 
-static void add_param (char const *, char *, location);
+/** Add a lex-param or a parse-param.
+ *
+ * \param type  \a lex_param or \a parse_param
+ * \param decl  the formal argument
+ * \param loc   the location in the source.
+ */
+static void add_param (char const *type, char *decl, location loc);
+
 
 static symbol_class current_class = unknown_sym;
-static uniqstr current_type = 0;
-static symbol *current_lhs;
+static uniqstr current_type = NULL;
+static symbol *current_lhs_symbol;
 static location current_lhs_location;
+static named_ref *current_lhs_named_ref;
 static int current_prec = 0;
 
-#ifdef UINT_FAST8_MAX
-# define YYTYPE_UINT8 uint_fast8_t
-#endif
-#ifdef INT_FAST8_MAX
-# define YYTYPE_INT8 int_fast8_t
-#endif
-#ifdef UINT_FAST16_MAX
-# define YYTYPE_UINT16 uint_fast16_t
-#endif
-#ifdef INT_FAST16_MAX
-# define YYTYPE_INT16 int_fast16_t
-#endif
+/** Set the new current left-hand side symbol, possibly common
+ * to several right-hand side parts of rule.
+ */
+static
+void
+current_lhs(symbol *sym, location loc, named_ref *ref)
+{
+  current_lhs_symbol = sym;
+  current_lhs_location = loc;
+  /* In order to simplify memory management, named references for lhs
+     are always assigned by deep copy into the current symbol_list
+     node.  This is because a single named-ref in the grammar may
+     result in several uses when the user factors lhs between several
+     rules using "|".  Therefore free the parser's original copy.  */
+  free (current_lhs_named_ref);
+  current_lhs_named_ref = ref;
+}
+
+
+#define YYTYPE_INT16 int_fast16_t
+#define YYTYPE_INT8 int_fast8_t
+#define YYTYPE_UINT16 uint_fast16_t
+#define YYTYPE_UINT8 uint_fast8_t
 %}
 
 %debug
@@ -81,27 +98,29 @@ static int current_prec = 0;
 %locations
 %pure-parser
 %error-verbose
-%defines
+%define parse.lac full
 %name-prefix="gram_"
+%expect 0
 
 %initial-action
 {
   /* Bison's grammar can initial empty locations, hence a default
      location is needed. */
-  boundary_set (&@$.start, current_file, 1, 0);
-  boundary_set (&@$.end, current_file, 1, 0);
+  boundary_set (&@$.start, current_file, 1, 1);
+  boundary_set (&@$.end, current_file, 1, 1);
 }
 
-/* Only NUMBERS have a value.  */
 %union
 {
   symbol *symbol;
   symbol_list *list;
   int integer;
-  char *chars;
+  char const *chars;
+  char *code;
   assoc assoc;
   uniqstr uniqstr;
   unsigned char character;
+  named_ref *named_ref;
 };
 
 /* Define the tokens together with their human representation.  */
@@ -130,19 +149,18 @@ static int current_prec = 0;
 `----------------------*/
 
 %token
-  PERCENT_AFTER_HEADER    "%after-header"
-  PERCENT_BEFORE_HEADER   "%before-header"
+  PERCENT_CODE            "%code"
   PERCENT_DEBUG           "%debug"
   PERCENT_DEFAULT_PREC    "%default-prec"
   PERCENT_DEFINE          "%define"
   PERCENT_DEFINES         "%defines"
-  PERCENT_END_HEADER      "%end-header"
   PERCENT_ERROR_VERBOSE   "%error-verbose"
   PERCENT_EXPECT          "%expect"
   PERCENT_EXPECT_RR	  "%expect-rr"
   PERCENT_FILE_PREFIX     "%file-prefix"
   PERCENT_GLR_PARSER      "%glr-parser"
   PERCENT_INITIAL_ACTION  "%initial-action"
+  PERCENT_LANGUAGE        "%language"
   PERCENT_LEX_PARAM       "%lex-param"
   PERCENT_LOCATIONS       "%locations"
   PERCENT_NAME_PREFIX     "%name-prefix"
@@ -156,13 +174,13 @@ static int current_prec = 0;
   PERCENT_REQUIRE	  "%require"
   PERCENT_SKELETON        "%skeleton"
   PERCENT_START           "%start"
-  PERCENT_START_HEADER    "%start-header"
   PERCENT_TOKEN_TABLE     "%token-table"
   PERCENT_VERBOSE         "%verbose"
   PERCENT_YACC            "%yacc"
 ;
 
 %token BRACED_CODE     "{...}"
+%token BRACKETED_ID    "[identifier]"
 %token CHAR            "char"
 %token EPILOGUE        "epilogue"
 %token EQUAL           "="
@@ -173,33 +191,42 @@ static int current_prec = 0;
 %token PROLOGUE        "%{...%}"
 %token SEMICOLON       ";"
 %token TYPE            "type"
+%token TYPE_TAG_ANY    "<*>"
+%token TYPE_TAG_NONE   "<>"
 
 %type <character> CHAR
 %printer { fputs (char_name ($$), stderr); } CHAR
 
-%type <chars> STRING string_content "{...}" PROLOGUE EPILOGUE
+/* braceless is not to be used for rule or symbol actions, as it
+   calls code_props_plain_init.  */
+%type <chars> STRING "%{...%}" EPILOGUE braceless content.opt
+%type <code> "{...}"
 %printer { fputs (quotearg_style (c_quoting_style, $$), stderr); }
-         STRING string_content
-%printer { fprintf (stderr, "{\n%s\n}", $$); } "{...}" PROLOGUE EPILOGUE
+	 STRING
+%printer { fprintf (stderr, "{\n%s\n}", $$); }
+	 braceless content.opt "{...}" "%{...%}" EPILOGUE
 
-%type <uniqstr> TYPE ID ID_COLON
-%printer { fprintf (stderr, "<%s>", $$); } TYPE
-%printer { fputs ($$, stderr); } ID
+%type <uniqstr> BRACKETED_ID ID ID_COLON TYPE variable
+%printer { fputs ($$, stderr); } <uniqstr>
+%printer { fprintf (stderr, "[%s]", $$); } BRACKETED_ID
 %printer { fprintf (stderr, "%s:", $$); } ID_COLON
+%printer { fprintf (stderr, "<%s>", $$); } TYPE
 
 %type <integer> INT
-%printer { fprintf (stderr, "%d", $$); } INT
+%printer { fprintf (stderr, "%d", $$); } <integer>
 
-%type <symbol> id id_colon symbol string_as_id
-%printer { fprintf (stderr, "%s", $$->tag); } id symbol string_as_id
+%type <symbol> id id_colon string_as_id symbol symbol.prec
+%printer { fprintf (stderr, "%s", $$->tag); } <symbol>
 %printer { fprintf (stderr, "%s:", $$->tag); } id_colon
 
 %type <assoc> precedence_declarator
-%type <list>  symbols.1
+%type <list>  symbols.1 symbols.prec generic_symlist generic_symlist_item
+%type <named_ref> named_ref.opt
+
 %%
 
 input:
-  declarations "%%" grammar epilogue.opt
+  prologue_declarations "%%" grammar epilogue.opt
 ;
 
 
@@ -207,47 +234,40 @@ input:
 	| Declarations: before the first %%.  |
 	`------------------------------------*/
 
-declarations:
+prologue_declarations:
   /* Nothing */
-| declarations declaration
+| prologue_declarations prologue_declaration
 ;
 
-declaration:
+prologue_declaration:
   grammar_declaration
-| PROLOGUE
-    {
-      prologue_augment (translate_code ($1, @1), @1, typed);
-    }
-| "%after-header" "{...}"
+| "%{...%}"
     {
-      /* Remove the '{', and replace the '}' with '\n'.  */
-      $2[strlen ($2) - 1] = '\n';
-      prologue_augment (translate_code ($2+1, @2), @2, true);
-    }
-| "%before-header" "{...}"
-    {
-      /* Remove the '{', and replace the '}' with '\n'.  */
-      $2[strlen ($2) - 1] = '\n';
-      prologue_augment (translate_code ($2+1, @2), @2, false);
+      code_props plain_code;
+      code_props_plain_init (&plain_code, $1, @1);
+      code_props_translate_code (&plain_code);
+      gram_scanner_last_string_free ();
+      muscle_code_grow (union_seen ? "post_prologue" : "pre_prologue",
+                        plain_code.code, @1);
+      code_scanner_last_string_free ();
     }
-| "%debug"                                 { debug_flag = true; }
-| "%define" string_content
+| "%debug"                         { debug_flag = true; }
+| "%define" variable content.opt
     {
-      static char one[] = "1";
-      muscle_insert ($2, one);
+      muscle_percent_define_insert ($2, @2, $3,
+                                    MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
     }
-| "%define" string_content string_content  { muscle_insert ($2, $3); }
-| "%defines"                               { defines_flag = true; }
-| "%end-header" "{...}"
+| "%defines"                       { defines_flag = true; }
+| "%defines" STRING
     {
-      /* Remove the '{', and replace the '}' with '\n'.  */
-      $2[strlen ($2) - 1] = '\n';
-      muscle_code_grow ("end_header", translate_code ($2+1, @2), @2);
+      defines_flag = true;
+      spec_defines_file = xstrdup ($2);
     }
-| "%error-verbose"                         { error_verbose = true; }
-| "%expect" INT                            { expected_sr_conflicts = $2; }
-| "%expect-rr" INT			   { expected_rr_conflicts = $2; }
-| "%file-prefix" "=" string_content        { spec_file_prefix = $3; }
+| "%error-verbose"                 { error_verbose = true; }
+| "%expect" INT                    { expected_sr_conflicts = $2; }
+| "%expect-rr" INT		   { expected_rr_conflicts = $2; }
+| "%file-prefix" STRING            { spec_file_prefix = $2; }
+| "%file-prefix" "=" STRING        { spec_file_prefix = $3; } /* deprecated */
 | "%glr-parser"
     {
       nondeterministic_parser = true;
@@ -255,27 +275,66 @@ declaration:
     }
 | "%initial-action" "{...}"
     {
-      muscle_code_grow ("initial_action", translate_symbol_action ($2, @2), @2);
+      code_props action;
+      code_props_symbol_action_init (&action, $2, @2);
+      code_props_translate_code (&action);
+      gram_scanner_last_string_free ();
+      muscle_code_grow ("initial_action", action.code, @2);
+      code_scanner_last_string_free ();
+    }
+| "%language" STRING		{ language_argmatch ($2, grammar_prio, @1); }
+| "%lex-param" "{...}"		{ add_param ("lex_param", $2, @2); }
+| "%locations"                  { locations_flag = true; }
+| "%name-prefix" STRING         { spec_name_prefix = $2; }
+| "%name-prefix" "=" STRING     { spec_name_prefix = $3; } /* deprecated */
+| "%no-lines"                   { no_lines_flag = true; }
+| "%nondeterministic-parser"	{ nondeterministic_parser = true; }
+| "%output" STRING              { spec_outfile = $2; }
+| "%output" "=" STRING          { spec_outfile = $3; }  /* deprecated */
+| "%parse-param" "{...}"	{ add_param ("parse_param", $2, @2); }
+| "%pure-parser"
+    {
+      /* %pure-parser is deprecated in favor of `%define api.pure', so use
+         `%define api.pure' in a backward-compatible manner here.  First, don't
+         complain if %pure-parser is specified multiple times.  */
+      if (!muscle_find_const ("percent_define(api.pure)"))
+        muscle_percent_define_insert ("api.pure", @1, "",
+                                      MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
+      /* In all cases, use api.pure now so that the backend doesn't complain if
+         the skeleton ignores api.pure, but do warn now if there's a previous
+         conflicting definition from an actual %define.  */
+      if (!muscle_percent_define_flag_if ("api.pure"))
+        muscle_percent_define_insert ("api.pure", @1, "",
+                                      MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
     }
-| "%lex-param" "{...}"			   { add_param ("lex_param", $2, @2); }
-| "%locations"                             { locations_flag = true; }
-| "%name-prefix" "=" string_content        { spec_name_prefix = $3; }
-| "%no-lines"                              { no_lines_flag = true; }
-| "%nondeterministic-parser"		   { nondeterministic_parser = true; }
-| "%output" "=" string_content             { spec_outfile = $3; }
-| "%parse-param" "{...}"		   { add_param ("parse_param", $2, @2); }
-| "%pure-parser"                           { pure_parser = true; }
-| "%require" string_content                { version_check (&@2, $2); }
-| "%skeleton" string_content               { skeleton = $2; }
-| "%start-header" "{...}"
+| "%require" STRING             { version_check (&@2, $2); }
+| "%skeleton" STRING
     {
-      /* Remove the '{', and replace the '}' with '\n'.  */
-      $2[strlen ($2) - 1] = '\n';
-      muscle_code_grow ("start_header", translate_code ($2+1, @2), @2);
+      char const *skeleton_user = $2;
+      if (mbschr (skeleton_user, '/'))
+        {
+          size_t dir_length = strlen (current_file);
+          char *skeleton_build;
+          while (dir_length && current_file[dir_length - 1] != '/')
+            --dir_length;
+          while (dir_length && current_file[dir_length - 1] == '/')
+            --dir_length;
+          skeleton_build =
+            xmalloc (dir_length + 1 + strlen (skeleton_user) + 1);
+          if (dir_length > 0)
+            {
+              memcpy (skeleton_build, current_file, dir_length);
+              skeleton_build[dir_length++] = '/';
+            }
+          strcpy (skeleton_build + dir_length, skeleton_user);
+          skeleton_user = uniqstr_new (skeleton_build);
+          free (skeleton_build);
+        }
+      skeleton_arg (skeleton_user, grammar_prio, @1);
     }
-| "%token-table"                           { token_table_flag = true; }
-| "%verbose"                               { report_flag = report_states; }
-| "%yacc"                                  { yacc_flag = true; }
+| "%token-table"                { token_table_flag = true; }
+| "%verbose"                    { report_flag |= report_states; }
+| "%yacc"                       { yacc_flag = true; }
 | /*FIXME: Err?  What is this horror doing here? */ ";"
 ;
 
@@ -286,20 +345,18 @@ grammar_declaration:
     {
       grammar_start_symbol_set ($2, @2);
     }
-| "%destructor" "{...}" symbols.1
+| "%destructor" "{...}" generic_symlist
     {
       symbol_list *list;
-      const char *action = translate_symbol_action ($2, @2);
       for (list = $3; list; list = list->next)
- 	symbol_destructor_set (list->sym, action, @2);
+	symbol_list_destructor_set (list, $2, @2);
       symbol_list_free ($3);
     }
-| "%printer" "{...}" symbols.1
+| "%printer" "{...}" generic_symlist
     {
       symbol_list *list;
-      const char *action = translate_symbol_action ($2, @2);
       for (list = $3; list; list = list->next)
-	symbol_printer_set (list->sym, action, @2);
+	symbol_list_printer_set (list, $2, @2);
       symbol_list_free ($3);
     }
 | "%default-prec"
@@ -310,6 +367,18 @@ grammar_declaration:
     {
       default_prec = false;
     }
+| "%code" braceless
+    {
+      /* Do not invoke muscle_percent_code_grow here since it invokes
+         muscle_user_name_list_grow.  */
+      muscle_code_grow ("percent_code()", $2, @2);
+      code_scanner_last_string_free ();
+    }
+| "%code" ID braceless
+    {
+      muscle_percent_code_grow ($2, @2, $3, @3);
+      code_scanner_last_string_free ();
+    }
 ;
 
 
@@ -325,21 +394,11 @@ union_name:
 ;
 
 grammar_declaration:
-  "%union" union_name "{...}"
+  "%union" union_name braceless
     {
-      char const *body = $3;
-
-      if (typed)
-	{
-	  /* Concatenate the union bodies, turning the first one's
-	     trailing '}' into '\n', and omitting the second one's '{'.  */
-	  char *code = muscle_find ("stype");
-	  code[strlen (code) - 1] = '\n';
-	  body++;
-	}
-
-      typed = true;
-      muscle_code_grow ("stype", body, @3);
+      union_seen = true;
+      muscle_code_grow ("stype", $3, @3);
+      code_scanner_last_string_free ();
     }
 ;
 
@@ -360,21 +419,22 @@ symbol_declaration:
 | "%type" TYPE symbols.1
     {
       symbol_list *list;
+      tag_seen = true;
       for (list = $3; list; list = list->next)
-	symbol_type_set (list->sym, $2, @2);
+	symbol_type_set (list->content.sym, $2, @2);
       symbol_list_free ($3);
     }
 ;
 
 precedence_declaration:
-  precedence_declarator type.opt symbols.1
+  precedence_declarator type.opt symbols.prec
     {
       symbol_list *list;
       ++current_prec;
       for (list = $3; list; list = list->next)
 	{
-	  symbol_type_set (list->sym, current_type, @2);
-	  symbol_precedence_set (list->sym, current_prec, $1, @1);
+	  symbol_type_set (list->content.sym, current_type, @2);
+	  symbol_precedence_set (list->content.sym, current_prec, $1, @1);
 	}
       symbol_list_free ($3);
       current_type = NULL;
@@ -389,13 +449,40 @@ precedence_declarator:
 
 type.opt:
   /* Nothing. */ { current_type = NULL; }
-| TYPE           { current_type = $1; }
+| TYPE           { current_type = $1; tag_seen = true; }
 ;
 
-/* One or more nonterminals to be %typed. */
+/* Just like symbols.1 but accept INT for the sake of POSIX.  */
+symbols.prec:
+  symbol.prec
+    { $$ = symbol_list_sym_new ($1, @1); }
+| symbols.prec symbol.prec
+    { $$ = symbol_list_prepend ($1, symbol_list_sym_new ($2, @2)); }
+;
+
+symbol.prec:
+    symbol { $$ = $1; }
+  | symbol INT { $$ = $1; symbol_user_token_number_set ($1, $2, @2); }
+  ;
+
+/* One or more symbols to be %typed. */
 symbols.1:
-  symbol            { $$ = symbol_list_new ($1, @1); }
-| symbols.1 symbol  { $$ = symbol_list_prepend ($1, $2, @2); }
+  symbol
+    { $$ = symbol_list_sym_new ($1, @1); }
+| symbols.1 symbol
+    { $$ = symbol_list_prepend ($1, symbol_list_sym_new ($2, @2)); }
+;
+
+generic_symlist:
+  generic_symlist_item { $$ = $1; }
+| generic_symlist generic_symlist_item { $$ = symbol_list_prepend ($1, $2); }
+;
+
+generic_symlist_item:
+  symbol            { $$ = symbol_list_sym_new ($1, @1); }
+| TYPE              { $$ = symbol_list_type_new ($1, @1); }
+| "<*>"             { $$ = symbol_list_default_tagged_new (@1); }
+| "<>"             { $$ = symbol_list_default_tagless_new (@1); }
 ;
 
 /* One token definition.  */
@@ -403,6 +490,7 @@ symbol_def:
   TYPE
      {
        current_type = $1;
+       tag_seen = true;
      }
 | id
      {
@@ -458,7 +546,11 @@ rules_or_grammar_declaration:
 ;
 
 rules:
-  id_colon { current_lhs = $1; current_lhs_location = @1; } rhses.1
+  id_colon named_ref.opt { current_lhs ($1, @1, $2); } rhses.1
+  {
+    /* Free the current lhs. */
+    current_lhs (0, @1, 0);
+  }
 ;
 
 rhses.1:
@@ -469,12 +561,12 @@ rhses.1:
 
 rhs:
   /* Nothing.  */
-    { grammar_current_rule_begin (current_lhs, current_lhs_location); }
-| rhs symbol
-    { grammar_current_rule_symbol_append ($2, @2); }
-| rhs "{...}"
-    { grammar_current_rule_action_append (gram_last_string,
-					  gram_last_braced_code_loc); }
+    { grammar_current_rule_begin (current_lhs_symbol, current_lhs_location,
+				  current_lhs_named_ref); }
+| rhs symbol named_ref.opt
+    { grammar_current_rule_symbol_append ($2, @2, $3); }
+| rhs "{...}" named_ref.opt
+    { grammar_current_rule_action_append ($2, @2, $3); }
 | rhs "%prec" symbol
     { grammar_current_rule_prec_set ($3, @3); }
 | rhs "%dprec" INT
@@ -483,6 +575,48 @@ rhs:
     { grammar_current_rule_merge_set ($3, @3); }
 ;
 
+named_ref.opt:
+  /* Nothing. */ { $$ = 0; }
+|
+  BRACKETED_ID   { $$ = named_ref_new($1, @1); }
+;
+
+
+/*----------------------------*
+ | variable and content.opt.  |
+ *---------------------------*/
+
+/* The STRING form of variable is deprecated and is not M4-friendly.
+   For example, M4 fails for `%define "[" "value"'.  */
+variable:
+  ID
+| STRING { $$ = uniqstr_new ($1); }
+;
+
+/* Some content or empty by default. */
+content.opt:
+  /* Nothing. */   { $$ = ""; }
+| ID { $$ = $1; }
+| STRING
+;
+
+
+/*-------------*
+ | braceless.  |
+ *-------------*/
+
+braceless:
+  "{...}"
+    {
+      code_props plain_code;
+      $1[strlen ($1) - 1] = '\n';
+      code_props_plain_init (&plain_code, $1+1, @1);
+      code_props_translate_code (&plain_code);
+      gram_scanner_last_string_free ();
+      $$ = plain_code.code;
+    }
+;
+
 
 /*---------------*
  | Identifiers.  |
@@ -521,19 +655,16 @@ string_as_id:
     }
 ;
 
-/* A string used for its contents.  Don't quote it.  */
-string_content:
-  STRING
-    { $$ = $1; }
-;
-
-
 epilogue.opt:
   /* Nothing.  */
 | "%%" EPILOGUE
     {
-      muscle_code_grow ("epilogue", translate_code ($2, @2), @2);
+      code_props plain_code;
+      code_props_plain_init (&plain_code, $2, @2);
+      code_props_translate_code (&plain_code);
       gram_scanner_last_string_free ();
+      muscle_code_grow ("epilogue", plain_code.code, @2);
+      code_scanner_last_string_free ();
     }
 ;
 
@@ -556,7 +687,7 @@ lloc_default (YYLTYPE const *rhs, int n)
   loc.start = rhs[n].end;
   loc.end = rhs[n].end;
 
-  /* Ignore empty nonterminals the start of the the right-hand side.
+  /* Ignore empty nonterminals the start of the right-hand side.
      Do not bother to ignore them at the end of the right-hand side,
      since empty nonterminals have the same end as their predecessors.  */
   for (i = 1; i <= n; i++)
@@ -603,17 +734,7 @@ add_param (char const *type, char *decl, location loc)
     complain_at (loc, _("missing identifier in parameter declaration"));
   else
     {
-      char *name;
-      size_t name_len;
-
-      for (name_len = 1;
-	   memchr (alphanum, name_start[name_len], sizeof alphanum);
-	   name_len++)
-	continue;
-
-      name = xmalloc (name_len + 1);
-      memcpy (name, name_start, name_len);
-      name[name_len] = '\0';
+      char *name = xmemdup0 (name_start, strspn (name_start, alphanum));
       muscle_pair_list_grow (type, decl, name);
       free (name);
     }
@@ -621,14 +742,15 @@ add_param (char const *type, char *decl, location loc)
   gram_scanner_last_string_free ();
 }
 
+
 static void
 version_check (location const *loc, char const *version)
 {
   if (strverscmp (version, PACKAGE_VERSION) > 0)
     {
       complain_at (*loc, "require bison %s, but have %s",
-		   version, PACKAGE_VERSION);
-      exit (63);
+                   version, PACKAGE_VERSION);
+      exit (EX_MISMATCH);
     }
 }