Re: -Wvariadic-macros does not print warning

[Manuel López-Ibáñez <lopezibanez at gmail dot com>]

This hunk in your patch doesn't seem related:

@@ -509,6 +509,9 @@ Warn about missing fields in struct init
 Wsizeof-pointer-memaccess
 C ObjC C++ ObjC++ Var(warn_sizeof_pointer_memaccess) Warning
LangEnabledBy(C ObjC C++ ObjC++,Wall)

+Wsizeof-array-argument
+C Var(warn_sizeof_array_argument) Warning LangEnabledBy(C,Wall)
+
 Wsuggest-attribute=format
 C ObjC C++ ObjC++ Var(warn_suggest_attribute_format) Warning
 Warn about functions which might be candidates for format attributes

Also, it would be good to update doc/invoke.texi, the current
description is a bit confusing. It says it is enabled by default when
it actually isn't (nor after your patch). I propose something like:


Index: gcc/doc/invoke.texi
===================================================================
--- gcc/doc/invoke.texi (revision 208669)
+++ gcc/doc/invoke.texi (working copy)
@@ -4997,9 +4997,10 @@
 @item -Wvariadic-macros
 @opindex Wvariadic-macros
 @opindex Wno-variadic-macros
-Warn if variadic macros are used in pedantic ISO C90 mode, or the GNU
-alternate syntax when in pedantic ISO C99 mode.  This is default.
-To inhibit the warning messages, use @option{-Wno-variadic-macros}.
+Warn if variadic macros are used in ISO C90 mode, or if the GNU
+alternate syntax is used in ISO C99 mode.  This is enabled by either
+@option{-Wpedantic} or @option{-Wtraditional}.  To inhibit the warning
+messages, use @option{-Wno-variadic-macros}.

 @item -Wvarargs
 @opindex Wvarargs

On 29 April 2014 14:41, Prathamesh Kulkarni <bilbotheelffriend@gmail.com> wrote:
> On Tue, Apr 29, 2014 at 2:07 PM, Manuel López-Ibáñez
> <lopezibanez@gmail.com> wrote:
>> On 23 April 2014 20:03, Prathamesh Kulkarni <bilbotheelffriend@gmail.com> wrote:
>>> I didn't attach the patch, I am extremely sorry for the noise.
>>> I am re-posting the mail.
>>> This is a follow up mail to http://gcc.gnu.org/ml/gcc-help/2014-04/msg00096.html
>>> I have attached patch that prints the warning when passed -Wvariadic-macros
>>> (I mostly followed it along lines of -Wlong-long).
>>> OK for trunk ?
>>
>> Hi Prathamesh,
>>
>> Thanks for CCing me! I cannot approve patches, but it looks almost
>> perfect to me. Did you run the regression testsuite and compare the
>> results before/after your patch? I would expect at least one testcase
>> testing this warning that would be affected by the change. If not, it
>> would be nice to add testcases for this. Also, there is another place
>> that tests for both Wpedantic and Wvariadic-macros just above the one
>> that you modify. I think you should update all of them to just test
>> for Wvariadic-macros.
>>
>> Once you do that, I hope Joseph will approve it quickly, it seems an
>> obvious fix to me for consistency with Wlong-long and to allow people
>> to use this warning without enabling Wpedantic (also, it will enable
>> the warning with Wtraditional as intended, which is currently broken).
>>
> Thanks, I modified the patch to remove Wpedantic check and added a new
> test-case.
> For changes to libcpp, do I need to run the entire test-suite or only runinng
> libcpp tests (RUNTESTFLAGS=cpp.exp) is fine ?
> I ran libcpp tests, and there appeared to be no failures.
>
> [libcpp]
> * macro.c (parse_params): Remove check for Wpedantic for variadic macros.
>
> [gcc/c-family]
> * c.opt (-Wvariadic-macros): Init(-1) instead of Init(1).
> * c-opts.c (c_common_handle_option): Add case OPT_Wvariadic_macros.
>                (sanitize_cpp_opts): Check condition for pedantic or
> warn_traditional.
>
> [gcc/testsuite/gcc.dg/cpp]
> * Wvariadic-5.c: New test-case.
>
> Thanks and Regards,
> Prathamesh
>
>> Cheers,
>>
>> Manuel.