Re: bug bison 1.31

[Akim Demaille]

| hello,
| 
| le programme suivant genere un segfault avec bison-1.31 :
| 
| --- [test3.y]
| %%
| %{
| #include <stdio.h>
| }%
| 
| %%
| A       :       {printf("hallo\n");}
| --- [end test3.y]
| 
| $ bison test3.y
| Segmentation fault
| $
| 
| [Reference : http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=129483 ]


Thanks for the report.  I'm applying this:

Index: ChangeLog
from  Akim Demaille  <address@hidden>

        Bison dumps core when trying to complain about broken input files.
        Reported by Cris van Pelt.

        * src/lex.c (parse_percent_token): Be sure to set token_buffer.
        * tests/regression.at (Invalid input: 1, Invalid input: 2): Merge
        into...
        (Invalid inputs): Strengthen: exercise parse_percent_token.

Index: THANKS
===================================================================
RCS file: /cvsroot/bison/bison/THANKS,v
retrieving revision 1.10.2.23
diff -u -u -r1.10.2.23 THANKS
--- THANKS 21 Jan 2002 15:48:25 -0000 1.10.2.23
+++ THANKS 22 Jan 2002 10:29:01 -0000
@@ -6,6 +6,7 @@
 Albert Chin-A-Young     address@hidden
 Alexander Belopolsky    address@hidden
 Arnold Robbins         address@hidden
+Cris van Pelt           address@hidden
 Daniel Hagerty          address@hidden
 David J. MacKenzie      address@hidden
 Dick Streefland                address@hidden
Index: src/lex.c
===================================================================
RCS file: /cvsroot/bison/bison/src/lex.c,v
retrieving revision 1.33.2.12
diff -u -u -r1.33.2.12 lex.c
--- src/lex.c 14 Nov 2001 14:42:14 -0000 1.33.2.12
+++ src/lex.c 22 Jan 2002 10:29:02 -0000
@@ -590,43 +590,54 @@
   size_t arg_offset = 0;
 
   int c = getc (finput);
+  obstack_1grow (&token_obstack, '%');
+  obstack_1grow (&token_obstack, c);
 
   switch (c)
     {
     case '%':
+      token_buffer = obstack_finish (&token_obstack);
       return tok_two_percents;
 
     case '{':
+      token_buffer = obstack_finish (&token_obstack);
       return tok_percent_left_curly;
 
-      /* FIXME: Who the heck are those 5 guys!?! `%<' = `%left'!!!
-        Let's ask for there removal.  */
+      /* The following guys are here for backward compatibility with
+        very ancient Yacc versions.  The paper of Johnson mentions
+        them (as ancient :).  */
     case '<':
+      token_buffer = obstack_finish (&token_obstack);
       return tok_left;
 
     case '>':
+      token_buffer = obstack_finish (&token_obstack);
       return tok_right;
 
     case '2':
+      token_buffer = obstack_finish (&token_obstack);
       return tok_nonassoc;
 
     case '0':
+      token_buffer = obstack_finish (&token_obstack);
       return tok_token;
 
     case '=':
+      token_buffer = obstack_finish (&token_obstack);
       return tok_prec;
     }
 
   if (!isalpha (c))
-    return tok_illegal;
+    {
+      token_buffer = obstack_finish (&token_obstack);
+      return tok_illegal;
+    }
 
-  obstack_1grow (&token_obstack, '%');
-  while (isalpha (c) || c == '_' || c == '-')
+  while (c = getc (finput), isalpha (c) || c == '_' || c == '-')
     {
       if (c == '_')
        c = '-';
       obstack_1grow (&token_obstack, c);
-      c = getc (finput);
     }
 
   /* %DIRECTIVE="ARG".  Separate into
Index: tests/regression.at
===================================================================
RCS file: /cvsroot/bison/bison/tests/regression.at,v
retrieving revision 1.1.2.26
diff -u -u -r1.1.2.26 regression.at
--- tests/regression.at 14 Jan 2002 10:16:49 -0000 1.1.2.26
+++ tests/regression.at 22 Jan 2002 10:29:02 -0000
@@ -545,40 +545,30 @@
 AT_CLEANUP
 
 
-## ----------------- ##
-## Invalid input 1.  ##
-## ----------------- ##
+## ---------------- ##
+## Invalid inputs.  ##
+## ---------------- ##
 
 
-AT_SETUP([Invalid input: 1])
+AT_SETUP([Invalid inputs])
 
 AT_DATA([input.y],
 [[%%
 ?
-]])
-
-AT_CHECK([bison input.y], [1], [],
-[[input.y:2: invalid input: `?'
-input.y:3: fatal error: no rules in the input grammar
-]])
-
-AT_CLEANUP
-
-
-## ----------------- ##
-## Invalid input 2.  ##
-## ----------------- ##
-
-
-AT_SETUP([Invalid input: 2])
-
-AT_DATA([input.y],
-[[%%
 default: 'a' }
+%{
+%&
+%a
+%-
 ]])
 
 AT_CHECK([bison input.y], [1], [],
-[[input.y:2: invalid input: `}'
+[[input.y:2: invalid input: `?'
+input.y:3: invalid input: `}'
+input.y:4: invalid input: `%{'
+input.y:5: invalid input: `%&'
+input.y:6: invalid input: `%a'
+input.y:7: invalid input: `%-'
 ]])
 
 AT_CLEANUP