Handle location wrappers better in warn_logical_operator.

When we introduced location wrappers, we added fold_for_warn to warnings
that are interested in a constant value, or wrapper-stripping to warnings
that are interested in literal constants.  This particular warning is
looking for a literal constant, but was wrongly changed to use
fold_for_warn; this patch makes it strip instead.

	* c-warn.c (warn_logical_operator): Strip location wrappers.  Don't
	fold_for_warn in "|| mask" warning.

From-SVN: r275743

gcc/c-family/ChangeLog

+2019-09-15  Jason Merrill  <jason@redhat.com>
+
+	* c-warn.c (warn_logical_operator): Strip location wrappers.  Don't
+	fold_for_warn in "|| mask" warning.
+
 2019-09-10  Martin Liska  <mliska@suse.cz>
 
 	* c.opt: Use newly added WarnRemoved.

gcc/c-family/c-warn.c

@@ -208,18 +208,19 @@ warn_logical_operator (location_t location, enum tree_code code, tree type,
      programmer. That is, an expression such as op && MASK
      where op should not be any boolean expression, nor a
      constant, and mask seems to be a non-boolean integer constant.  */
+  STRIP_ANY_LOCATION_WRAPPER (op_right);
   if (TREE_CODE (op_right) == CONST_DECL)
     /* An enumerator counts as a constant.  */
     op_right = DECL_INITIAL (op_right);
+  tree stripped_op_left = tree_strip_any_location_wrapper (op_left);
   if (!truth_value_p (code_left)
       && INTEGRAL_TYPE_P (TREE_TYPE (op_left))
-      && !CONSTANT_CLASS_P (op_left)
-      && !TREE_NO_WARNING (op_left))
-    {
-      tree folded_op_right = fold_for_warn (op_right);
-      if (TREE_CODE (folded_op_right) == INTEGER_CST
-	  && !integer_zerop (folded_op_right)
-	  && !integer_onep (folded_op_right))
+      && !CONSTANT_CLASS_P (stripped_op_left)
+      && TREE_CODE (stripped_op_left) != CONST_DECL
+      && !TREE_NO_WARNING (op_left)
+      && TREE_CODE (op_right) == INTEGER_CST
+      && !integer_zerop (op_right)
+      && !integer_onep (op_right))
     {
       bool warned;
       if (or_op)
@@ -234,7 +235,6 @@ warn_logical_operator (location_t location, enum tree_code code, tree type,
 	TREE_NO_WARNING (op_left) = true;
       return;
     }
-    }
 
   /* We do not warn for constants because they are typical of macro
      expansions that test for features.  */