Re: Valgrind and Bison memory leaks

[Joel E. Denny]

On Wed, 8 Nov 2006, Joel E. Denny wrote:

> On Wed, 8 Nov 2006, Paul Eggert wrote:
> 
> > OK, I reviewed that patch and installed the following
> > slightly-different one.  The main thing was that funny union, which
> > confused me, and so I replaced it with a char const * value and a char
> > * storage pointer (which might be null, but can be freed).
> 
> Thanks, I'll look it over later today.

I commited the following to address a few minor issues.

Index: ChangeLog
===================================================================
RCS file: /sources/bison/bison/ChangeLog,v
retrieving revision 1.1601
diff -p -u -r1.1601 ChangeLog
--- ChangeLog   8 Nov 2006 20:41:55 -0000       1.1601
+++ ChangeLog   9 Nov 2006 18:13:02 -0000
@@ -1,3 +1,15 @@
+2006-11-09  Joel E. Denny  <address@hidden>
+
+       * src/files.c (tr): Change return type to void.
+       * src/muscle_tab.c (muscle_insert): Free storage in case muscle_grow
+       has been called previously for the same key.
+       (muscle_find): Return storage instead of value so that
+       --enable-gcc-warnings doesn't produce warnings that the return discards
+       const.  aver that the value and storage are the same since storage
+       could potentially be NULL when value is not.
+       * tests/testsuite.at (AT_CHECK): Treat an unspecified exit value the
+       same as 0.
+
 2006-11-08  Paul Eggert  <address@hidden>
 
        * bootstrap.conf (excluded_files): Exclude m4/codeset.m4 (undoing
Index: src/files.c
===================================================================
RCS file: /sources/bison/bison/src/files.c,v
retrieving revision 1.98
diff -p -u -r1.98 files.c
--- src/files.c 8 Nov 2006 20:28:57 -0000       1.98
+++ src/files.c 9 Nov 2006 18:13:02 -0000
@@ -137,7 +137,7 @@ xfclose (FILE *ptr)
 `------------------------------------------------------------------*/
 
 /* In the string S, replace all characters FROM by TO.  */
-static char *
+static void
 tr (char *s, char from, char to)
 {
   for (; *s; s++)
Index: src/muscle_tab.c
===================================================================
RCS file: /sources/bison/bison/src/muscle_tab.c,v
retrieving revision 1.40
diff -p -u -r1.40 muscle_tab.c
--- src/muscle_tab.c    8 Nov 2006 20:28:57 -0000       1.40
+++ src/muscle_tab.c    9 Nov 2006 18:13:02 -0000
@@ -123,9 +123,11 @@ muscle_insert (char const *key, char con
       entry = xmalloc (sizeof *entry);
       entry->key = key;
       hash_insert (muscle_table, entry);
-      entry->storage = NULL;
     }
+  else
+    free (entry->storage);
   entry->value = value;
+  entry->storage = NULL;
 }
 
 
@@ -207,9 +209,11 @@ void muscle_pair_list_grow (const char *
   obstack_free (&muscle_obstack, pair);
 }
 
-/*-------------------------------.
-| Find the value of muscle KEY.  |
-`-------------------------------*/
+/*----------------------------------------------------------------------------.
+| Find the value of muscle KEY.  Abort if muscle_insert was invoked more      |
+| recently than muscle_grow for KEY since muscle_find can't return a          |
+| char const *.                                                               |
+`----------------------------------------------------------------------------*/
 
 char *
 muscle_find (const char *key)
@@ -219,7 +223,12 @@ muscle_find (const char *key)
 
   probe.key = key;
   result = hash_lookup (muscle_table, &probe);
-  return result ? result->value : NULL;
+  if (result)
+    {
+      aver (result->value == result->storage);
+      return result->storage;
+    }
+  return NULL;
 }
 
 
Index: tests/testsuite.at
===================================================================
RCS file: /sources/bison/bison/tests/testsuite.at,v
retrieving revision 1.29
diff -p -u -r1.29 testsuite.at
--- tests/testsuite.at  8 Nov 2006 20:28:57 -0000       1.29
+++ tests/testsuite.at  9 Nov 2006 18:13:02 -0000
@@ -25,7 +25,7 @@ m4_pushdef([ORIGINAL_AT_CHECK], m4_defn(
 m4_pushdef([AT_CHECK],
 [ORIGINAL_AT_CHECK(
    m4_if(m4_quote(m4_substr(m4_quote($1), 0, 5)), [bison],
-        m4_if([$2], [0], [],
+        m4_if([$2], [0], [], [$2], [], [],
               [[VALGRIND_OPTS="$VALGRIND_OPTS --leak-check=summary 
--show-reachable=no"; export VALGRIND_OPTS; ]]))$@)])
 
 # Testing resistance to user bugs.