builtin-attrs.def: Update copyright years.

* builtin-attrs.def: Update copyright years.
(ATTR_NONNULL): New attribute identifier.
(ATTR_NONNULL_1, ATTR_NONNULL_2, ATTR_NONNULL_3): New
attribute tree lists.
(DEF_FORMAT_ATTRIBUTE): Chain a nonnull attribute for the
format operand.
(ATTR_FORMAT_ARG_1, ATTR_FORMAT_ARG_2): Use...
(DEF_FORMAT_ARG_ATTRIBUTE): ...this to generate format_arg
attribute lists.  Chain the appropriate nonnull attribute.
* c-format.c (check_format_arg): Remove null format string
warning.
* testsuite/gcc.dg/format/null-1.c: New test.

From-SVN: r53801

4 files changed, 70 insertions, 22 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e5f063f..83b976d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,18 @@
+2002-05-23  Jason Thorpe  <thorpej@wasabisystems.com>
+
+	* builtin-attrs.def: Update copyright years.
+	(ATTR_NONNULL): New attribute identifier.
+	(ATTR_NONNULL_1, ATTR_NONNULL_2, ATTR_NONNULL_3): New
+	attribute tree lists.
+	(DEF_FORMAT_ATTRIBUTE): Chain a nonnull attribute for the
+	format operand.
+	(ATTR_FORMAT_ARG_1, ATTR_FORMAT_ARG_2): Use...
+	(DEF_FORMAT_ARG_ATTRIBUTE): ...this to generate format_arg
+	attribute lists.  Chain the appropriate nonnull attribute.
+	* c-format.c (check_format_arg): Remove null format string
+	warning.
+	* testsuite/gcc.dg/format/null-1.c: New test.
+
 2002-05-23  Rainer Orth  <ro@TechFak.Uni-Bielefeld.DE>
 
 	* Makefile.in (ADAC): Define.
diff --git a/gcc/builtin-attrs.def b/gcc/builtin-attrs.def
index 10b3708..56081d1 100644
--- a/gcc/builtin-attrs.def
+++ b/gcc/builtin-attrs.def
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001 Free Software Foundation, Inc.
+/* Copyright (C) 2001, 2002 Free Software Foundation, Inc.
    Contributed by Joseph Myers <jsm28@cam.ac.uk>.
 
 This file is part of GCC.
@@ -85,28 +85,39 @@ DEF_ATTR_IDENT (ATTR_STRFMON, "strfmon")
 DEF_ATTR_IDENT (ATTR_FORMAT, "format")
 DEF_ATTR_IDENT (ATTR_FORMAT_ARG, "format_arg")
 
+DEF_ATTR_IDENT (ATTR_NONNULL, "nonnull")
+
+DEF_ATTR_TREE_LIST (ATTR_NONNULL_1, ATTR_NONNULL, ATTR_LIST_1, ATTR_NULL)
+DEF_ATTR_TREE_LIST (ATTR_NONNULL_2, ATTR_NONNULL, ATTR_LIST_2, ATTR_NULL)
+DEF_ATTR_TREE_LIST (ATTR_NONNULL_3, ATTR_NONNULL, ATTR_LIST_3, ATTR_NULL)
+
 /* Construct a tree for a format attribute.  */
-#define DEF_FORMAT_ATTRIBUTE(TYPE, VALUES)				 \
+#define DEF_FORMAT_ATTRIBUTE(TYPE, FA, VALUES)				 \
   DEF_ATTR_TREE_LIST (CONCAT4 (ATTR_,TYPE,_,VALUES), ATTR_NULL,		 \
 		      CONCAT2 (ATTR_,TYPE), CONCAT2 (ATTR_LIST_,VALUES)) \
   DEF_ATTR_TREE_LIST (CONCAT4 (ATTR_FORMAT_,TYPE,_,VALUES), ATTR_FORMAT, \
-		      CONCAT4 (ATTR_,TYPE,_,VALUES), ATTR_NULL)
-DEF_FORMAT_ATTRIBUTE(PRINTF,1_0)
-DEF_FORMAT_ATTRIBUTE(PRINTF,1_2)
-DEF_FORMAT_ATTRIBUTE(PRINTF,2_0)
-DEF_FORMAT_ATTRIBUTE(PRINTF,2_3)
-DEF_FORMAT_ATTRIBUTE(PRINTF,3_0)
-DEF_FORMAT_ATTRIBUTE(PRINTF,3_4)
-DEF_FORMAT_ATTRIBUTE(SCANF,1_0)
-DEF_FORMAT_ATTRIBUTE(SCANF,1_2)
-DEF_FORMAT_ATTRIBUTE(SCANF,2_0)
-DEF_FORMAT_ATTRIBUTE(SCANF,2_3)
-DEF_FORMAT_ATTRIBUTE(STRFTIME,3_0)
-DEF_FORMAT_ATTRIBUTE(STRFMON,3_4)
+		      CONCAT4 (ATTR_,TYPE,_,VALUES), CONCAT2 (ATTR_NONNULL_,FA))
+DEF_FORMAT_ATTRIBUTE(PRINTF,1,1_0)
+DEF_FORMAT_ATTRIBUTE(PRINTF,1,1_2)
+DEF_FORMAT_ATTRIBUTE(PRINTF,2,2_0)
+DEF_FORMAT_ATTRIBUTE(PRINTF,2,2_3)
+DEF_FORMAT_ATTRIBUTE(PRINTF,3,3_0)
+DEF_FORMAT_ATTRIBUTE(PRINTF,3,3_4)
+DEF_FORMAT_ATTRIBUTE(SCANF,1,1_0)
+DEF_FORMAT_ATTRIBUTE(SCANF,1,1_2)
+DEF_FORMAT_ATTRIBUTE(SCANF,2,2_0)
+DEF_FORMAT_ATTRIBUTE(SCANF,2,2_3)
+DEF_FORMAT_ATTRIBUTE(STRFTIME,3,3_0)
+DEF_FORMAT_ATTRIBUTE(STRFMON,3,3_4)
 #undef DEF_FORMAT_ATTRIBUTE
 
-DEF_ATTR_TREE_LIST (ATTR_FORMAT_ARG_1, ATTR_FORMAT_ARG, ATTR_LIST_1, ATTR_NULL)
-DEF_ATTR_TREE_LIST (ATTR_FORMAT_ARG_2, ATTR_FORMAT_ARG, ATTR_LIST_2, ATTR_NULL)
+/* Construct a tree for a format_arg attribute.  */
+#define DEF_FORMAT_ARG_ATTRIBUTE(FA)					\
+  DEF_ATTR_TREE_LIST (CONCAT2 (ATTR_FORMAT_ARG_,FA), ATTR_FORMAT_ARG,	\
+		      CONCAT2 (ATTR_LIST_,FA), CONCAT2 (ATTR_NONNULL_,FA))
+DEF_FORMAT_ARG_ATTRIBUTE(1)
+DEF_FORMAT_ARG_ATTRIBUTE(2)
+#undef DEF_FORMAT_ARG_ATTRIBUTE
 
 /* Define an attribute for a function, along with the IDENTIFIER_NODE.  */
 #define DEF_FN_ATTR_IDENT(NAME, ATTRS, PREDICATE)	\
diff --git a/gcc/c-format.c b/gcc/c-format.c
index b3640c5..7e8b137 100644
--- a/gcc/c-format.c
+++ b/gcc/c-format.c
@@ -1418,11 +1418,6 @@ check_format_arg (ctx, format_tree, arg_num)
 
   if (integer_zerop (format_tree))
     {
-      /* FIXME: instead of warning about a null format string here,
-	 functions for which we want to perform this check should be
-	 marked with the "nonnull" attribute on the appropriate arguments.  */
-      status_warning (status, "null format string");
-
       /* Skip to first argument to check, so we can see if this format
 	 has any arguments (it shouldn't).  */
       while (arg_num + 1 < info->first_arg_num)
diff --git a/gcc/testsuite/gcc.dg/format/null-1.c b/gcc/testsuite/gcc.dg/format/null-1.c
new file mode 100644
index 0000000..63501a39
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/format/null-1.c
@@ -0,0 +1,27 @@
+/* Test for some aspects of null format string handling.  */
+/* Origin: Jason Thorpe <thorpej@wasabisystems.com> */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu99 -Wformat" } */
+
+#include "format.h"
+
+extern void my_printf (const char *, ...) __attribute__((format(printf,1,2)));
+extern const char *my_format (const char *, const char *)
+  __attribute__((format_arg(2)));
+
+void
+foo (int i1)
+{
+  /* Warning about a null format string has been decoupled from the actual
+     format check.  However, we still expect to be warned about any excess
+     arguments after a null format string.  */
+  my_printf (NULL);
+  my_printf (NULL, i1); /* { dg-warning "too many" "null format with arguments" } */
+
+  my_printf (my_format ("", NULL));
+  my_printf (my_format ("", NULL), i1); /* { dg-warning "too many" "null format_arg with arguments" } */
+
+  /* While my_printf allows a null argument, dgettext does not, so we expect
+     a null argument warning here.  */
+  my_printf (dgettext ("", NULL)); /* { dg-warning "null" "null format with dgettext" } */
+}