re PR sanitizer/64906 (-fsanitize=integer-divide-by-zero creates false…

re PR sanitizer/64906 (-fsanitize=integer-divide-by-zero creates false -Wmaybe-uninitialized warning)

	PR sanitizer/64906
	* c-ubsan.c (ubsan_instrument_division): Also pre-evaluate OP1.

	* c-c++-common/ubsan/pr64906.c: New test.

From-SVN: r228112

gcc/c-family/ChangeLog

+2015-09-25  Marek Polacek  <polacek@redhat.com>
+
+	PR sanitizer/64906
+	* c-ubsan.c (ubsan_instrument_division): Also pre-evaluate OP1.
+
 2015-09-24  Patrick Palka  <ppalka@gcc.gnu.org>
 
 	* c-indentation.c (should_warn_for_misleading_indentation):

gcc/c-family/c-ubsan.c

@@ -104,6 +104,7 @@ ubsan_instrument_division (location_t loc, tree op0, tree op1)
 	}
     }
   t = fold_build2 (COMPOUND_EXPR, TREE_TYPE (t), unshare_expr (op0), t);
+  t = fold_build2 (COMPOUND_EXPR, TREE_TYPE (t), unshare_expr (op1), t);
   if (flag_sanitize_undefined_trap_on_error)
     tt = build_call_expr_loc (loc, builtin_decl_explicit (BUILT_IN_TRAP), 0);
   else

gcc/testsuite/ChangeLog

+2015-09-25  Marek Polacek  <polacek@redhat.com>
+
+	PR sanitizer/64906
+	* c-c++-common/ubsan/pr64906.c: New test.
+
 2015-09-24  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* gcc.target/i386/pr66749.c (dg-options): Replace -mtune=iamcu

gcc/testsuite/c-c++-common/ubsan/pr64906.c

+/* PR sanitizer/64906 */
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=integer-divide-by-zero -O -Werror=maybe-uninitialized" } */
+
+int
+fn1 (int f, int s)
+{
+  int ret = 0;
+  if (f)
+    ret = s / (f ? (unsigned long) 8 : 0);
+  return ret;
+}