c-common.c (shorten_compare): Don't -Wtype-limits if the non-constant operand comes from a macro.

	* c-common.c (shorten_compare): Don't -Wtype-limits if the
	non-constant operand comes from a macro.

From-SVN: r230589

gcc/c-family/ChangeLog

+2015-11-18  Jason Merrill  <jason@redhat.com>
+
+	* c-common.c (shorten_compare): Don't -Wtype-limits if the
+	non-constant operand comes from a macro.
+
 2015-11-17  Jason Merrill  <jason@redhat.com>
 
 	PR bootstrap/68346

gcc/c-family/c-common.c

@@ -4650,7 +4650,9 @@ shorten_compare (location_t loc, tree *op0_ptr, tree *op1_ptr,
 	  type = c_common_unsigned_type (type);
 	}
 
-      if (TREE_CODE (primop0) != INTEGER_CST)
+      if (TREE_CODE (primop0) != INTEGER_CST
+	  /* Don't warn if it's from a macro.  */
+	  && !from_macro_expansion_at (EXPR_LOCATION (primop0)))
 	{
 	  if (val == truthvalue_false_node)
 	    warning_at (loc, OPT_Wtype_limits,

gcc/testsuite/g++.dg/warn/Wtype-limits2.C

+// { dg-options -Wtype-limits }
+
+unsigned char array[4];
+bool b;
+#define VAL (b ? array[0] : (unsigned char)0)
+
+int main()
+{
+  if (VAL > 1000)
+    __builtin_abort();
+}