re PR sanitizer/65367 (indefinite loop occurs with sanitize enabled and certain…

re PR sanitizer/65367 (indefinite loop occurs with sanitize enabled and certain optimization options)

	PR sanitizer/65367
	* ubsan.c (ubsan_expand_objsize_ifn): Update GSI instead of GSI_ORIG
	when only removing the statement.  Handle expanding UBSAN_OBJECT_SIZE
	separately.

	* c-c++-common/ubsan/pr65367.c: New test.

Co-Authored-By: Jakub Jelinek <jakub@redhat.com>

From-SVN: r221325

gcc/ChangeLog

+2015-03-10  Marek Polacek  <polacek@redhat.com>
+	    Jakub Jelinek  <jakub@redhat.com>
+
+	PR sanitizer/65367
+	* ubsan.c (ubsan_expand_objsize_ifn): Update GSI instead of GSI_ORIG
+	when only removing the statement.  Handle expanding UBSAN_OBJECT_SIZE
+	separately.
+
 2015-03-10  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/65286

gcc/testsuite/ChangeLog

+2015-03-10  Marek Polacek  <polacek@redhat.com>
+
+	PR sanitizer/65367
+	* c-c++-common/ubsan/pr65367.c: New test.
+
 2015-03-10  Ilya Enkovich  <ilya.enkovich@intel.com>
 
 	* lib/mpx-dg.exp (mpx_link_flags): Set path to wrappers library.

gcc/testsuite/c-c++-common/ubsan/pr65367.c

+/* PR sanitizer/65367 */
+/* { dg-do compile } */
+/* { dg-options "-fno-tree-ccp -fno-tree-copy-prop -fno-tree-dominator-opts -fno-tree-fre -fsanitize=object-size" } */
+
+int
+foo (char *p)
+{
+  return *((const char *) "") - *p;
+}

gcc/ubsan.c

@@ -1022,11 +1022,16 @@ ubsan_expand_objsize_ifn (gimple_stmt_iterator *gsi)
 
       /* Point GSI to next logical statement.  */
       *gsi = gsi_start_bb (fallthru_bb);
+
+      /* Get rid of the UBSAN_OBJECT_SIZE call from the IR.  */
+      unlink_stmt_vdef (stmt);
+      gsi_remove (&gsi_orig, true);
+      return true;
     }
 
   /* Get rid of the UBSAN_OBJECT_SIZE call from the IR.  */
   unlink_stmt_vdef (stmt);
-  gsi_remove (&gsi_orig, true);
+  gsi_remove (gsi, true);
   return true;
 }