c-typeck.c (c_build_va_arg): Clarify the error message.

	* c-typeck.c (c_build_va_arg): Clarify the error message.

	* gcc.dg/pr65901.c (foo): Adjust dg-error.
	* gcc.c-torture/compile/pr48767.c (foo): Likewise.

From-SVN: r222626

gcc/c/ChangeLog

@@ -6,6 +6,8 @@
 	* c-typeck.c (c_incomplete_type_error): Refactor to use %qT.  Print
 	the type of a decl.
 
+	* c-typeck.c (c_build_va_arg): Clarify the error message.
+
 2015-04-29  Thomas Schwinge  <thomas@codesourcery.com>
 
 	* c-parser.c (c_parser_oacc_enter_exit_data): Use

gcc/c/c-typeck.c

@@ -12635,14 +12635,17 @@ c_build_qualified_type (tree type, int type_quals)
 tree
 c_build_va_arg (location_t loc, tree expr, tree type)
 {
-  if (warn_cxx_compat && TREE_CODE (type) == ENUMERAL_TYPE)
-    warning_at (loc, OPT_Wc___compat,
-		"C++ requires promoted type, not enum type, in %<va_arg%>");
-  if (type == error_mark_node || !COMPLETE_TYPE_P (type))
+  if (error_operand_p (type))
+    return error_mark_node;
+  else if (!COMPLETE_TYPE_P (type))
     {
-      c_incomplete_type_error (NULL_TREE, type);
+      error_at (loc, "second argument to %<va_arg%> is of incomplete "
+		"type %qT", type);
       return error_mark_node;
     }
+  else if (warn_cxx_compat && TREE_CODE (type) == ENUMERAL_TYPE)
+    warning_at (loc, OPT_Wc___compat,
+		"C++ requires promoted type, not enum type, in %<va_arg%>");
   return build_va_arg (loc, expr, type);
 }
 

gcc/testsuite/ChangeLog

@@ -2,6 +2,9 @@
 
 	* c-c++-common/Wbool-compare-3.c: New test.
 
+	* gcc.dg/pr65901.c (foo): Adjust dg-error.
+	* gcc.c-torture/compile/pr48767.c (foo): Likewise.
+
 2015-04-30  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/57610

gcc/testsuite/gcc.c-torture/compile/pr48767.c

@@ -3,5 +3,5 @@
 void
 foo (__builtin_va_list ap)
 {
-  __builtin_va_arg (ap, void);  /* { dg-error "invalid use of void expression" } */
+  __builtin_va_arg (ap, void); /* { dg-error "second argument to .va_arg. is of incomplete type .void." } */
 }

gcc/testsuite/gcc.dg/pr65901.c

@@ -9,8 +9,8 @@ union U;
 void
 foo (__builtin_va_list ap)
 {
-  __builtin_va_arg (ap, void);  /* { dg-error "invalid use of void expression" } */
-  __builtin_va_arg (ap, struct S);  /* { dg-error "invalid use of undefined type" } */
-  __builtin_va_arg (ap, enum E);  /* { dg-error "invalid use of undefined type" } */
-  __builtin_va_arg (ap, union U);  /* { dg-error "invalid use of undefined type" } */
+  __builtin_va_arg (ap, void);  /* { dg-error "second argument to .va_arg. is of incomplete type .void." } */
+  __builtin_va_arg (ap, struct S);  /* { dg-error "second argument to .va_arg. is of incomplete type .struct S." } */
+  __builtin_va_arg (ap, enum E);  /* { dg-error "second argument to .va_arg. is of incomplete type .enum E." } */
+  __builtin_va_arg (ap, union U);  /* { dg-error "second argument to .va_arg. is of incomplete type .union U." } */
 }