re PR c/80097 (internal compiler error in c_fully_fold_internal with std=c89 and…

re PR c/80097 (internal compiler error in c_fully_fold_internal with std=c89 and -fsanitize=float-divide-by-zero)

	PR c/80097
	* c-typeck.c (build_binary_op): Add EXCESS_PRECISION_EXPR only around
	optional COMPOUND_EXPR with ubsan instrumentation.

	* gcc.dg/ubsan/pr80097.c: New test.

From-SVN: r246302

gcc/c/ChangeLog

+2017-03-21  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/80097
+	* c-typeck.c (build_binary_op): Add EXCESS_PRECISION_EXPR only around
+	optional COMPOUND_EXPR with ubsan instrumentation.
+
 2017-03-17  Marek Polacek  <polacek@redhat.com>
 
 	* c-parser.c: Add C11 references.

gcc/c/c-typeck.c

@@ -11856,14 +11856,16 @@ build_binary_op (location_t location, enum tree_code code,
   else if (TREE_CODE (ret) != INTEGER_CST && int_operands
 	   && !in_late_binary_op)
     ret = note_integer_operands (ret);
-  if (semantic_result_type)
-    ret = build1 (EXCESS_PRECISION_EXPR, semantic_result_type, ret);
   protected_set_expr_location (ret, location);
 
   if (instrument_expr != NULL)
     ret = fold_build2 (COMPOUND_EXPR, TREE_TYPE (ret),
 		       instrument_expr, ret);
 
+  if (semantic_result_type)
+    ret = build1_loc (location, EXCESS_PRECISION_EXPR,
+		      semantic_result_type, ret);
+
   return ret;
 }
 

gcc/testsuite/ChangeLog

+2017-03-21  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/80097
+	* gcc.dg/ubsan/pr80097.c: New test.
+
 2017-03-20  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
 
 	PR tree-optimization/80054

gcc/testsuite/gcc.dg/ubsan/pr80097.c

+/* PR c/80097 */
+/* { dg-do compile } */
+/* { dg-options "-std=c89 -fsanitize=float-divide-by-zero" } */
+
+int
+foo (double a)
+{
+  int b = (1 / a >= 1);
+  return b;
+}