* tests/calc.at: Exercise prologue splitting.

* data/bison.simple, data/bison.c++: Use `b4_pre_prologue' and
`b4_post_prologue' instead of `b4_prologue'.
* src/output.c (prepare): Add the `pre_prologue' and `post_prologue'
muscles.
(output): Free pre_prologue_obstack and post_prologue_obstack.
* src/files.h, src/files.c (attrs_obstack): Remove.
(pre_prologue_obstack, post_prologue_obstack): New.
* src/reader.c (copy_definition): Add a parameter to specify the
obstack to fill, instead of using attrs_obstack unconditionally.
(read_declarations): Pass pre_prologue_obstack to copy_definition if
`%union' has not yet been seen, pass post_prologue_obstack otherwise.

src/files.c

@@ -33,8 +33,9 @@ const char *base_name PARAMS ((char const *name));
 FILE *finput = NULL;
 
 struct obstack action_obstack;
-struct obstack attrs_obstack;
 struct obstack output_obstack;
+struct obstack pre_prologue_obstack;
+struct obstack post_prologue_obstack;
 
 /* Initializing some values below (such SPEC_NAME_PREFIX to `yy') is
    tempting, but don't do that: for the time being our handling of the

src/files.h

@@ -50,7 +50,8 @@ extern FILE *finput;
 extern struct obstack action_obstack;
 
 /* If semantic parser, output a .h file that defines YYSTYPE... */
-extern struct obstack attrs_obstack;
+extern struct obstack pre_prologue_obstack;
+extern struct obstack post_prologue_obstack;
 
 /* The verbose output. */
 extern struct obstack output_obstack;

src/output.c

@@ -1092,8 +1092,10 @@ prepare (void)
   MUSCLE_INSERT_INT ("defines_flag", defines_flag);
 
   /* Copy definitions in directive.  */
-  obstack_1grow (&attrs_obstack, 0);
-  muscle_insert ("prologue", obstack_finish (&attrs_obstack));
+  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)
@@ -1131,5 +1133,6 @@ output (void)
   obstack_free (&muscle_obstack, NULL);
   obstack_free (&format_obstack, NULL);
   obstack_free (&action_obstack, NULL);
-  obstack_free (&attrs_obstack, NULL);
+  obstack_free (&pre_prologue_obstack, NULL);
+  obstack_free (&post_prologue_obstack, NULL);
 }

src/reader.c

@@ -591,7 +591,7 @@ copy_dollar (FILE *fin, struct obstack *oout,
 `-------------------------------------------------------------------*/
 
 static void
-copy_definition (void)
+copy_definition (struct obstack *oout)
 {
   int c;
   /* -1 while reading a character if prev char was %. */
@@ -599,7 +599,7 @@ copy_definition (void)
 
   if (!no_lines_flag)
     {
-      obstack_fgrow2 (&attrs_obstack, muscle_find ("linef"),
+      obstack_fgrow2 (oout, muscle_find ("linef"),
 		      lineno, quotearg_style (c_quoting_style,
 					      muscle_find ("filename")));
     }
@@ -613,7 +613,7 @@ copy_definition (void)
       switch (c)
 	{
 	case '\n':
-	  obstack_1grow (&attrs_obstack, c);
+	  obstack_1grow (oout, c);
 	  ++lineno;
 	  break;
 
@@ -623,18 +623,18 @@ copy_definition (void)
 
 	case '\'':
 	case '"':
-	  copy_string (finput, &attrs_obstack, c);
+	  copy_string (finput, oout, c);
 	  break;
 
 	case '/':
-	  copy_comment (finput, &attrs_obstack);
+	  copy_comment (finput, oout);
 	  break;
 
 	case EOF:
 	  fatal ("%s", _("unterminated `%{' definition"));
 
 	default:
-	  obstack_1grow (&attrs_obstack, c);
+	  obstack_1grow (oout, c);
 	}
 
       c = getc (finput);
@@ -643,7 +643,7 @@ copy_definition (void)
 	{
 	  if (c == '}')
 	    return;
-	  obstack_1grow (&attrs_obstack, '%');
+	  obstack_1grow (oout, '%');
 	}
       after_percent = 0;
     }
@@ -1154,7 +1154,7 @@ parse_skel_decl (void)
 /*----------------------------------------------------------------.
 | Read from finput until `%%' is seen.  Discard the `%%'.  Handle |
 | any `%' declarations, and copy the contents of any `%{ ... %}'  |
-| groups to ATTRS_OBSTACK.                                        |
+| groups to PRE_PROLOGUE_OBSTACK or POST_PROLOGUE_OBSTACK.        |
 `----------------------------------------------------------------*/
 
 static void
@@ -1174,7 +1174,10 @@ read_declarations (void)
 	      return;
 
 	    case tok_percent_left_curly:
-	      copy_definition ();
+              if (!typed)
+		copy_definition (&pre_prologue_obstack);
+	      else
+		copy_definition (&post_prologue_obstack);
 	      break;
 
 	    case tok_token:
@@ -1854,8 +1857,9 @@ reader (void)
 
   /* Initialize the obstacks. */
   obstack_init (&action_obstack);
-  obstack_init (&attrs_obstack);
   obstack_init (&output_obstack);
+  obstack_init (&pre_prologue_obstack);
+  obstack_init (&post_prologue_obstack);
 
   finput = xfopen (infile, "r");