re PR middle-end/36154 (internal compiler error: in…

re PR middle-end/36154 (internal compiler error: in get_constraint_for_component_ref, at tree-ssa-structalias.c:2727)

2008-05-08  Richard Guenther  <rguenther@suse.de>

	PR middle-end/36154
	* tree-ssa-structalias.c (push_fields_onto_fieldstack): Make
	sure to create a representative for trailing arrays for PTA.

	* gcc.c-torture/compile/pr36154.c: New testcase.

From-SVN: r135071

gcc/ChangeLog

 2008-05-08  Richard Guenther  <rguenther@suse.de>
 
+	PR middle-end/36154
+	* tree-ssa-structalias.c (push_fields_onto_fieldstack): Make
+	sure to create a representative for trailing arrays for PTA.
+
+2008-05-08  Richard Guenther  <rguenther@suse.de>
+
 	PR middle-end/36172
 	* fold-const.c (operand_equal_p): Two objects which types
 	differ in pointerness are not equal.

gcc/testsuite/ChangeLog

 2008-05-08  Richard Guenther  <rguenther@suse.de>
 
+	PR middle-end/36154
+	* gcc.c-torture/compile/pr36154.c: New testcase.
+
+2008-05-08  Richard Guenther  <rguenther@suse.de>
+
 	PR middle-end/36172
 	* gcc.c-torture/compile/pr36172.c: New testcase.
 

gcc/testsuite/gcc.c-torture/compile/pr36154.c

+struct eth_test_pkt {
+  unsigned short len;
+  unsigned short ctr;
+  unsigned char packet[];
+} __attribute__ ((packed));
+struct eth_test_pkt pkt_unaligned = { .packet = { 0xFC } };
+int cmd_unaligned(const void *p)
+{
+  return memcmp(p, pkt_unaligned.packet, 1);
+}
+

gcc/tree-ssa-structalias.c

@@ -4160,11 +4160,15 @@ push_fields_onto_fieldstack (tree type, VEC(fieldoff_s,heap) **fieldstack,
 		        (DECL_NONADDRESSABLE_P (field)
 		         ? addressable_type
 		         : TREE_TYPE (field))))
-		     && DECL_SIZE (field)
-		     && !integer_zerop (DECL_SIZE (field)))
-	      /* Empty structures may have actual size, like in C++. So
+		     && ((DECL_SIZE (field)
+			  && !integer_zerop (DECL_SIZE (field)))
+			 || (!DECL_SIZE (field)
+			     && TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE)))
+	      /* Empty structures may have actual size, like in C++.  So
 	         see if we didn't push any subfields and the size is
-	         nonzero, push the field onto the stack */
+	         nonzero, push the field onto the stack.  Trailing flexible
+		 array members also need a representative to be able to
+		 treat taking their address in PTA.  */
 	      push = true;
 
 	    if (push)