c.opt: (fallow-parameterless-variadic-functions): New.

c-family/ChangeLog
2011-10-11  Tristan Gingold  <gingold@adacore.com>

        * c.opt: (fallow-parameterless-variadic-functions): New.

ChangeLog
2011-10-11  Tristan Gingold  <gingold@adacore.com>

        * doc/invoke.texi (C Dialect Options): Document
        -fallow-parameterless-variadic-functions.
        * c-parser.c (c_parser_parms_list_declarator): Handle it.

testsuite/ChangeLog
2011-10-11  Tristan Gingold  <gingold@adacore.com>

        * gcc.dg/va-arg-4.c: New test.
        * gcc.dg/va-arg-5.c: Ditto.

From-SVN: r179786

gcc/ChangeLog

+2011-10-11  Tristan Gingold  <gingold@adacore.com>
+
+	* doc/invoke.texi (C Dialect Options): Document
+	-fallow-parameterless-variadic-functions.
+	* c-parser.c (c_parser_parms_list_declarator): Handle it.
+
 2011-10-10  Georg-Johann Lay  <avr@gjlay.de>
 
 	* config/avr/avr.c (avr_option_override): Set

gcc/c-family/ChangeLog

+2011-10-11  Tristan Gingold  <gingold@adacore.com>
+
+	* c.opt: (fallow-parameterless-variadic-functions): New.
+
 2011-09-08  Dodji Seketeli  <dodji@redhat.com>
 
 	PR c++/33255 - Support -Wunused-local-typedefs warning

gcc/c-family/c.opt

@@ -700,6 +700,10 @@ Enforce class member access control semantics
 fall-virtual
 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
 
+fallow-parameterless-variadic-functions
+C ObjC Var(flag_allow_parameterless_variadic_functions)
+Allow variadic functions without named parameter
+
 falt-external-templates
 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
 No longer supported

gcc/c-parser.c

@@ -3159,10 +3159,19 @@ c_parser_parms_list_declarator (c_parser *parser, tree attrs, tree expr)
   if (c_parser_next_token_is (parser, CPP_ELLIPSIS))
     {
       struct c_arg_info *ret = build_arg_info ();
-      /* Suppress -Wold-style-definition for this case.  */
-      ret->types = error_mark_node;
-      error_at (c_parser_peek_token (parser)->location,
-		"ISO C requires a named argument before %<...%>");
+
+      if (flag_allow_parameterless_variadic_functions)
+        {
+          /* F (...) is allowed.  */
+          ret->types = NULL_TREE;
+        }
+      else
+        {
+          /* Suppress -Wold-style-definition for this case.  */
+          ret->types = error_mark_node;
+          error_at (c_parser_peek_token (parser)->location,
+                    "ISO C requires a named argument before %<...%>");
+        }
       c_parser_consume_token (parser);
       if (c_parser_next_token_is (parser, CPP_CLOSE_PAREN))
 	{

gcc/doc/invoke.texi

@@ -170,7 +170,7 @@ in the following sections.
 @item C Language Options
 @xref{C Dialect Options,,Options Controlling C Dialect}.
 @gccoptlist{-ansi  -std=@var{standard}  -fgnu89-inline @gol
--aux-info @var{filename} @gol
+-aux-info @var{filename} -fallow-parameterless-variadic-functions @gol
 -fno-asm  -fno-builtin  -fno-builtin-@var{function} @gol
 -fhosted  -ffreestanding -fopenmp -fms-extensions -fplan9-extensions @gol
 -trigraphs  -no-integrated-cpp  -traditional  -traditional-cpp @gol
@@ -1622,6 +1622,13 @@ character).  In the case of function definitions, a K&R-style list of
 arguments followed by their declarations is also provided, inside
 comments, after the declaration.
 
+@item -fallow-parameterless-variadic-functions
+Accept variadic functions without named parameters.
+
+Although it is possible to define such a function, this is not very
+useful as it is not possible to read the arguments.  This is only
+supported for C as this construct is allowed by C++.
+
 @item -fno-asm
 @opindex fno-asm
 Do not recognize @code{asm}, @code{inline} or @code{typeof} as a

gcc/testsuite/ChangeLog

+2011-10-11  Tristan Gingold  <gingold@adacore.com>
+
+	* gcc.dg/va-arg-4.c: New test.
+	* gcc.dg/va-arg-5.c: Ditto.
+
 2011-10-11  Uros Bizjak  <ubizjak@gmail.com>
 
 	* lib/target-supports.exp (check_effective_target_fd_truncate):

gcc/testsuite/gcc.dg/va-arg-4.c

+/* { dg-do compile } */
+#include <stdarg.h>
+extern void baz(...);	/* { dg-error "requires a named argument" } */

gcc/testsuite/gcc.dg/va-arg-5.c

+/* { dg-do compile } */
+/* { dg-options "-fallow-parameterless-variadic-functions" } */
+#include <stdarg.h>
+extern void baz(...);