[Geany-devel] [PATCH 2/3] Prevent -Wmissing-prototypes report warning when compiling a plugin

[Jiří Techet]

2010/6/12 Enrico Tröger <enrico.troeger at uvena.de>:
> On Thu, 10 Jun 2010 13:33:44 +0200, Jiří wrote:
>
>> On Thu, Jun 10, 2010 at 13:05, Nick Treleaven
>> <nick.treleaven at btinternet.com> wrote:
>> > On Wed,  9 Jun 2010 21:40:58 +0200
>> > Jiří Techet <techet at gmail.com> wrote:
>> >
>> >> Signed-off-by: Jiří Techet <techet at gmail.com>
>> >> ---
>> >>  src/plugindata.h |    2 ++
>> >
>> >> +     gint plugin_version_check(gint abi_ver);\
>> >>       gint plugin_version_check(gint abi_ver) \
>> >>       { \
>> >
>> > Why is this necessary?
>> >
>>
>> If you don't compile the plugins with -Wmissing-prototypes then you
>> don't get any warnings if you use a function that hasn't been
>> declared (imagine you make a typo in a call of an API function or any
>> of your internal functions). The plugin compiles just fine, but then
>> it doesn't get loaded by geany on runtime and you have to start
>> searching for what symbol is missing (using LD_DEBUG).
>>
>> -Wmissing-prototypes requires that for every non-static function there
>> is a previous declaration before it is defined/used. This is normally
>> satisfied because these are in the header files - this macro is just
>> an exceptional case.
>>
>> In general, I would recommend that geany uses a slightly more strict
>> set of warning options. I find the options used by gnome-common as a
>> reasonable set:
>>
>> -Wall -Wmissing-prototypes -Wnested-externs -Wpointer-arith
>> -Wno-sign-compare
>>
>> You might consider using them for the whole geany.
>
> Just as an additional note:
> compiler flags should always be used by individual developers/users,
> not by the used build system directly.

Why? If you want to ensure that the sources satisfy some standards,
then it's alright. You use -Wall after all.

> -Wmissing-prototypes and friends are gcc specific and would break
> building with other compilers.
>
> I guess you didn't mean to add them to the build system directly :).

You can use gnome-compiler-flags.m4 from the gnome-common package that
checks whether you use gcc for compilation and only in this case the
above flags are added (it adds a configure parameter where the set of
flags can be configured).

Regards,

Jiri