re PR middle-end/54327 (Segmentation fault in init_ggc)

2012-08-20  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/54327
	* gimple-fold.c (get_maxval_strlen): Do not walk use-def chains
	if the use is registered for SSA update.

	* gcc.dg/torture/pr54327.c: New testcase.

From-SVN: r190528

gcc/ChangeLog

+2012-08-20  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/54327
+	* gimple-fold.c (get_maxval_strlen): Do not walk use-def chains
+	if the use is registered for SSA update.
+
 2012-08-20  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/54321

gcc/gimple-fold.c

@@ -736,6 +736,11 @@ get_maxval_strlen (tree arg, tree *length, bitmap visited, int type)
       return true;
     }
 
+  /* If ARG is registered for SSA update we cannot look at its defining
+     statement.  */
+  if (name_registered_for_update_p (arg))
+    return false;
+
   /* If we were already here, break the infinite cycle.  */
   if (!bitmap_set_bit (visited, SSA_NAME_VERSION (arg)))
     return true;

gcc/testsuite/ChangeLog

+2012-08-20  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/54327
+	* gcc.dg/torture/pr54327.c: New testcase.
+
 2012-08-20  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/54321

gcc/testsuite/gcc.dg/torture/pr54327.c

+/* { dg-do compile } */
+
+#include <string.h>
+#include <stdlib.h>
+void treathead ()
+{
+  char *a = ';' == '\0' ? : 0;
+  if (*a == '=')
+    {
+      while (*a == (*a == 0) || *a == '\'')
+	a++;
+      if (strlen (a) < 2)
+	abort ();
+    }
+}