X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/2dfb4daf9b3032f4740d1f8d4906077ecc72bdef..e89a22bfab22e4d2ee73be49dcb66b51f8d0e892:/src/reader.c?ds=sidebyside

diff --git a/src/reader.c b/src/reader.c
index 028ffc0b..529cebe9 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -304,13 +304,15 @@ copy_comment (FILE *fin, struct obstack *oout)
 /*-----------------------------------------------------------------.
 | FIN is pointing to a location (i.e., a `@').  Output to OOUT a   |
 | reference to this location. STACK_OFFSET is the number of values |
-| in the current rule so far, which says where to find `$0' with   |
+| in the current rule so far, which says where to find `@0' with   |
 | respect to the top of the stack.                                 |
 `-----------------------------------------------------------------*/
 
 static inline void
-copy_at (FILE *fin, struct obstack *oout, int stack_offset)
+copy_at (FILE *fin, struct obstack *oout,
+	 struct symbol_list *rule, int stack_offset)
 {
+  symbol_list *rp;
   int c;
 
   c = getc (fin);
@@ -321,11 +323,25 @@ copy_at (FILE *fin, struct obstack *oout, int stack_offset)
     }
   else if (isdigit (c) || c == '-')
     {
-      int n;
+      int n, i;
 
       ungetc (c, fin);
       n = read_signed_integer (fin);
 
+      rp = rule;
+      i = 0;
+
+      while (i < n)
+	{
+	  rp = rp->next;
+	  if (rp == NULL)
+	    {
+	      complain (_("invalid @ value"));
+	      return;
+	    }
+	  i++;
+	}
+
       obstack_fgrow1 (oout, "yylsp[%d]", n - stack_offset);
       locations_flag = 1;
     }
@@ -1103,7 +1119,7 @@ copy_action (symbol_list *rule, int stack_offset)
 
 	    case '@':
 	      copy_at (finput, &action_obstack,
-		       stack_offset);
+		       rule, stack_offset);
 	      break;
 
 	    case EOF:
@@ -1125,7 +1141,13 @@ copy_action (symbol_list *rule, int stack_offset)
 	}
     }
 
-  obstack_sgrow (&action_obstack, ";\n    break;}");
+  /* As a Bison extension, add the ending semicolon.  Since some Yacc
+     don't do that, help people using bison as a Yacc finding their
+     missing semicolons.  */
+  if (yacc_flag)
+    obstack_sgrow (&action_obstack, "}\n    break;");
+  else
+    obstack_sgrow (&action_obstack, ";\n    break;}");
 }
 
 /*-------------------------------------------------------------------.
@@ -1197,7 +1219,7 @@ copy_guard (symbol_list *rule, int stack_offset)
 	  break;
 
 	case '@':
-	  copy_at (finput, &guard_obstack, stack_offset);
+	  copy_at (finput, &guard_obstack, rule, stack_offset);
 	  break;
 
 	case EOF: