* src/gram.h (rule_t): guard' and guard_line' are new members.

* src/reader.c (symbol_list): `guard' and `guard_line' are new
members.
(symbol_list_new): Adjust.
(copy_action): action_line is the first line, not the last.
(copy_guard): Just as for actions, store the `action' only, not
the switch/case/break flesh.
Don't parse the user action that might follow the guard, let...
(readgram): do it, i.e., now, there can be an action after a
guard.
In other words the guard is just explicitly optional.
(packgram): Adjust.
* src/output.c (guards_output): New.
(output_parser): Call it when needed.
(output): Also free the guard and attrs obstacks.
* src/files.c, src/files.h (obstack_save): Remove.
(output_files): Remove.
As a result, if one needs the former `.act' file, using an
appropriate skeleton which requires actions and guards is now
required.
* src/main.c (main): Adjust.
* tests/semantic.at: New.
* tests/regression.at: Use `input.y' as input file name.
Avoid 8+3 problems by requiring input.c when the test needs the
parser.

ChangeLog

@@ -1,3 +1,31 @@
+2001-12-27  Akim Demaille  <akim@epita.fr>
+
+	* src/gram.h (rule_t): `guard' and `guard_line' are new members.
+	* src/reader.c (symbol_list): `guard' and `guard_line' are new
+	members.
+	(symbol_list_new): Adjust.
+	(copy_action): action_line is the first line, not the last.
+	(copy_guard): Just as for actions, store the `action' only, not
+	the switch/case/break flesh.
+	Don't parse the user action that might follow the guard, let...
+	(readgram): do it, i.e., now, there can be an action after a
+	guard.
+	In other words the guard is just explicitly optional.
+	(packgram): Adjust.
+	* src/output.c (guards_output): New.
+	(output_parser): Call it when needed.
+	(output): Also free the guard and attrs obstacks.
+	* src/files.c, src/files.h (obstack_save): Remove.
+	(output_files): Remove.
+	As a result, if one needs the former `.act' file, using an
+	appropriate skeleton which requires actions and guards is now
+	required.
+	* src/main.c (main): Adjust.
+	* tests/semantic.at: New.
+	* tests/regression.at: Use `input.y' as input file name.
+	Avoid 8+3 problems by requiring input.c when the test needs the
+	parser.
+
 2001-12-27  Akim Demaille  <akim@epita.fr>
 
 	* src/reader.c (symbol_list_new): Be sure to initialize all the

src/files.c

@@ -164,18 +164,6 @@ xfclose (FILE *ptr)
   return result;
 }
 
-/*--------------------------------------------------.
-| Save the content of the obstack OBS in FILENAME.  |
-`--------------------------------------------------*/
-
-static void
-obstack_save (struct obstack *obs, const char *filename)
-{
-  FILE *out = xfopen (filename, "w");
-  size_t size = obstack_object_size (obs);
-  fwrite (obstack_finish (obs), 1, size, out);
-  xfclose (out);
-}
 
 /*------------------------------------------------------------------.
 | Return the path to the skeleton which locaction might be given in |
@@ -436,38 +424,3 @@ compute_output_file_names (void)
   attrsfile = stringappend (attrsfile, header_extension);
 #endif /* MSDOS */
 }
-
-
-/*---------------------------.
-| Produce the output files.  |
-`---------------------------*/
-
-void
-output_files (void)
-{
-#if 0
-  /* Seems to be invalid now --akim. */
-
-  /* If we output only the table, dump the actions in ACTFILE. */
-  if (no_parser_flag)
-    obstack_save (&action_obstack, stringappend (short_base_name, ".act"));
-  obstack_free (&action_obstack, NULL);
-#endif
-
-  /* If we produced a semantic parser ATTRS_OBSTACK must be dumped
-     into its own file, ATTTRSFILE.  */
-  if (semantic_parser)
-    {
-      char *temp_name;
-
-      obstack_save (&attrs_obstack, attrsfile);
-      temp_name = stringappend (short_base_name, EXT_GUARD_C);
-#ifndef MSDOS
-      temp_name = stringappend (temp_name, src_extension);
-#endif /* MSDOS */
-      obstack_save (&guard_obstack, temp_name);
-    }
-
-  obstack_free (&guard_obstack, NULL);
-  obstack_free (&attrs_obstack, NULL);
-}

src/files.h

@@ -62,13 +62,12 @@ extern char *infile;
 extern char *attrsfile;
 
 void compute_output_file_names PARAMS((void));
-void output_files PARAMS((void));
 
 FILE *xfopen PARAMS ((const char *name, const char *mode));
 int xfclose PARAMS ((FILE *ptr));
 
 /* Compute the double inclusion guard's name. */
-char * compute_header_macro PARAMS ((void));
+char *compute_header_macro PARAMS ((void));
 
 const char *skeleton_find PARAMS ((const char *envvar,
 				   const char *skeleton_name));

src/gram.h

@@ -122,8 +122,12 @@ typedef struct rule_s
   short assoc;
   short line;
   bool useful;
+
   const char *action;
   short action_line;
+
+  const char *guard;
+  short guard_line;
 } rule_t;
 
 extern struct rule_s *rule_table;

src/main.c

@@ -110,8 +110,6 @@ main (int argc, char *argv[])
   free_nullable ();
   free_derives ();
 
-  output_files ();
-
   /* If using alloca.c, flush the alloca'ed memory for the benefit of
      people running Bison as a library in IDEs.  */
 #if C_ALLOCA

src/output.c

@@ -536,6 +536,38 @@ actions_output (FILE *out, size_t *line)
 }
 
 
+/*----------------------------.
+| Output the guards to OOUT.  |
+`----------------------------*/
+
+static void
+guards_output (FILE *out, size_t *line)
+{
+  int rule;
+  for (rule = 1; rule < nrules + 1; ++rule)
+    if (rule_table[rule].action)
+      {
+	fprintf (out, "  case %d:\n", rule);
+
+	if (!no_lines_flag)
+	  fprintf (out, muscle_find ("linef"),
+		   rule_table[rule].guard_line,
+		   quotearg_style (c_quoting_style,
+				   muscle_find ("filename")));
+	fprintf (out, "{ %s; }\n    break;\n\n",
+		 rule_table[rule].guard);
+
+	/* We always output 4 '\n' per action.  */
+	*line += 4;
+	/* Plus one if !no_lines_flag.  */
+	if (!no_lines_flag)
+	  ++*line;
+	/* Get the number of lines written by the user.  */
+	*line += get_lines_number (rule_table[rule].guard);
+      }
+}
+
+
 static void
 save_column (int symbol, int default_state)
 {
@@ -928,6 +960,8 @@ output_parser (const char *skel_filename, FILE *out)
 	  muscle_value = muscle_find (muscle_key);
 	  if (!strcmp (muscle_key, "actions"))
 	    actions_output (out, &output_line);
+	  else if (!strcmp (muscle_key, "guards"))
+	    guards_output (out, &output_line);
 	  else if (!strcmp (muscle_key, "line"))
 	    fprintf (out, "%d", output_line);
 	  else if (!strcmp (muscle_key, "skeleton-line"))
@@ -1091,7 +1125,9 @@ output (void)
     header_output ();
 
   free (rule_table + 1);
-  obstack_free (&muscle_obstack, 0);
+  obstack_free (&muscle_obstack, NULL);
-  obstack_free (&format_obstack, 0);
+  obstack_free (&format_obstack, NULL);
-  obstack_free (&action_obstack, 0);
+  obstack_free (&action_obstack, NULL);
+  obstack_free (&guard_obstack, NULL);
+  obstack_free (&attrs_obstack, NULL);
 }

src/reader.c

@@ -40,9 +40,14 @@ typedef struct symbol_list
   struct symbol_list *next;
   bucket *sym;
   int line;
+
   /* The action is attached to the LHS of a rule. */
   const char *action;
   int action_line;
+
+  /* The guard is attached to the LHS of a rule. */
+  const char *guard;
+  int guard_line;
   bucket *ruleprec;
 } symbol_list;
 
@@ -76,6 +81,8 @@ symbol_list_new (bucket *sym)
   res->line = lineno;
   res->action = NULL;
   res->action_line = 0;
+  res->guard = NULL;
+  res->guard_line = 0;
   res->ruleprec = NULL;
   return res;
 }
@@ -1088,6 +1095,8 @@ copy_action (symbol_list *rule, int stack_offset)
   count = 1;
   c = getc (finput);
 
+  rule->action_line = lineno;
+
   while (count > 0)
     {
       while (c != '}')
@@ -1144,7 +1153,6 @@ copy_action (symbol_list *rule, int stack_offset)
 
   obstack_1grow (&action_obstack, '\0');
   rule->action = obstack_finish (&action_obstack);
-  rule->action_line = lineno;
 }
 
 /*-------------------------------------------------------------------.
@@ -1167,12 +1175,7 @@ copy_guard (symbol_list *rule, int stack_offset)
   if (semantic_parser)
     stack_offset = 0;
 
-  obstack_fgrow1 (&guard_obstack, "\ncase %d:\n", nrules);
+  rule->guard_line = lineno;
-  if (!no_lines_flag)
-    obstack_fgrow2 (&guard_obstack, muscle_find ("linef"),
-		    lineno, quotearg_style (c_quoting_style,
-					    muscle_find ("filename")));
-  obstack_1grow (&guard_obstack, '{');
 
   count = 0;
   c = getc (finput);
@@ -1231,19 +1234,8 @@ copy_guard (symbol_list *rule, int stack_offset)
 	c = getc (finput);
     }
 
-  c = skip_white_space ();
+  obstack_1grow (&guard_obstack, '\0');
-
+  rule->guard = obstack_finish (&guard_obstack);
-  obstack_sgrow (&guard_obstack, ";\n    break;}");
-  if (c == '{')
-    copy_action (rule, stack_offset);
-  else if (c == '=')
-    {
-      c = getc (finput);	/* why not skip_white_space -wjh */
-      if (c == '{')
-	copy_action (rule, stack_offset);
-    }
-  else
-    ungetc (c, finput);
 }
 
 
@@ -1466,6 +1458,7 @@ readgram (void)
 	    crule->ruleprec = symval;
 	    t = lex ();
 	  }
+
 	if (t == tok_guard)
 	  {
 	    if (!semantic_parser)
@@ -1474,7 +1467,8 @@ readgram (void)
 	    copy_guard (crule, rulelength);
 	    t = lex ();
 	  }
-	else if (t == tok_left_curly)
+
+	if (t == tok_left_curly)
 	  {
 	    /* This case never occurs -wjh */
 	    if (action_flag)
@@ -1781,6 +1775,8 @@ packgram (void)
       rule_table[ruleno].useful = TRUE;
       rule_table[ruleno].action = p->action;
       rule_table[ruleno].action_line = p->action_line;
+      rule_table[ruleno].guard = p->guard;
+      rule_table[ruleno].guard_line = p->guard_line;
 
       p = p->next;
       while (p && p->sym)

tests/Makefile.am

@@ -25,7 +25,9 @@ MAINTAINERCLEANFILES = Makefile.in $(TESTSUITE)
 
 TESTSUITE_AT = \
 	testsuite.at \
-	output.at sets.at reduce.at calc.at torture.at regression.at
+	output.at sets.at reduce.at calc.at torture.at regression.at \
+        semantic.at
+
 TESTSUITE = $(srcdir)/testsuite
 
 AUTOTEST = $(AUTOM4TE) --language=autotest

tests/regression.at

@@ -25,7 +25,7 @@ AT_BANNER([[Regression tests.]])
 
 AT_SETUP([Duplicate string])
 
-AT_DATA([duplicate.y],
+AT_DATA([input.y],
 [[/* `Bison -v' used to dump core when two tokens are defined with the same
    string, as LE and GE below. */
 
@@ -38,7 +38,7 @@ exp: '(' exp ')' | NUM ;
 %%
 ]])
 
-AT_CHECK([bison -v duplicate.y -o duplicate.c], 0, ignore, ignore)
+AT_CHECK([bison -v input.y -o input.c], 0, ignore, ignore)
 
 AT_CLEANUP
 
@@ -478,7 +478,7 @@ AT_CLEANUP
 
 AT_SETUP([%union and --defines])
 
-AT_DATA([union.y],
+AT_DATA([input.y],
 [%union
 {
   int   integer;
@@ -488,7 +488,7 @@ AT_DATA([union.y],
 exp: {};
 ])
 
-AT_CHECK([bison --defines union.y])
+AT_CHECK([bison --defines input.y])
 
 AT_CLEANUP
 
@@ -500,7 +500,7 @@ AT_CLEANUP
 
 AT_SETUP([%union and C comments])
 
-AT_DATA([union-comment.y],
+AT_DATA([input.y],
 [%union
 {
   /* The int.  */	int   integer;
@@ -510,8 +510,8 @@ AT_DATA([union-comment.y],
 exp: {};
 ])
 
-AT_CHECK([bison union-comment.y])
+AT_CHECK([bison input.y -o input.c])
-AT_CHECK([fgrep '//*' union-comment.tab.c], [1], [])
+AT_CHECK([fgrep '//*' input.c], [1], [])
 
 AT_CLEANUP
 

tests/semantic.at

@@ -0,0 +1,47 @@
+# Bison Semantic Parsers.                               -*- Autotest -*-
+# Copyright 2001 Free Software Foundation, Inc.
+
+# 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, or (at your option)
+# any later version.
+
+# 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
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+# 02111-1307, USA.
+
+AT_BANNER([[Semantic Parsers.]])
+
+# Well, nothing, or almost, is known about semantic parsers.  For the
+# time being, just make sure we still parse them properly.
+
+## ---------------- ##
+## Parsing Guards.  ##
+## ---------------- ##
+
+
+AT_SETUP([Parsing Guards])
+
+AT_DATA([input.y],
+[[%semantic-parser
+%union {
+  int ival;
+}
+%token <ival> INT
+%type  <ival> exp
+%%
+exp: exp '+' exp { $$ = $1 + $3 }
+   | exp '/' exp %guard { if ($3 == 0) yyerror = 1 } { $$ = $1 / $3 }
+   | INT
+%%
+]])
+
+AT_CHECK([bison -v input.y -o input.c], 0, ignore, ignore)
+
+AT_CLEANUP

tests/testsuite.at

@@ -31,3 +31,4 @@ m4_include([reduce.at])
 m4_include([calc.at])
 m4_include([torture.at])
 m4_include([regression.at])
+m4_include([semantic.at])