re PR tree-optimization/25481 (Segfault in tree-ssa-structalias.c)

2005-12-18  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/25481
	* tree-ssa-structalias.c (handle_ptr_arith): Handle
	accesses we don't have a varinfo for.

	* gcc.dg/torture/pr25481.c: New testcase.

From-SVN: r108763

gcc/ChangeLog

+2005-12-18  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/25481
+	* tree-ssa-structalias.c (handle_ptr_arith): Handle
+	accesses we don't have a varinfo for.
+
 2005-12-17  Jon Grimm  <jgrimm2@us.ibm.com>
 	    Janis Johnson  <janis187@us.ibm.com>
 	    Ben Elliston  <bje@au.ibm.com>

gcc/testsuite/ChangeLog

+2005-12-18  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/25481
+	* gcc.dg/torture/pr25481.c: New testcase.
+
 2005-12-18  Ulrich Weigand  <uweigand@de.ibm.com>
 
 	PR rtl-optimization/21041

gcc/testsuite/gcc.dg/torture/pr25481.c

+/* { dg-do compile } */
+
+struct s {
+  int *blah;
+};
+
+static struct s array[] = {
+  { 0 }
+};
+
+void
+foo (struct s *p)
+{
+  unsigned int n = 1;
+  struct s *q = &array[n];
+  while (p < q)
+    p++;
+}

gcc/tree-ssa-structalias.c

@@ -3184,9 +3184,13 @@ handle_ptr_arith (VEC (ce_s, heap) *lhsc, tree expr)
 	if (c2->type == ADDRESSOF && rhsoffset != 0)
 	  {
 	    varinfo_t temp = get_varinfo (c2->var);
-	    
-	    gcc_assert (first_vi_for_offset (temp, rhsoffset) != NULL);
-	    c2->var = first_vi_for_offset (temp, rhsoffset)->id;
+
+	    /* An access one after the end of an array is valid,
+	       so simply punt on accesses we cannot resolve.  */
+	    temp = first_vi_for_offset (temp, rhsoffset);
+	    if (temp == NULL)
+	      continue;
+	    c2->var = temp->id;
 	    c2->offset = 0;
 	  }
 	else