[dpdk-dev] [dpdk-ci] [PATCH] eal/windows: fix build warnings in MinGW

[Aaron Conole]

Thomas Monjalon <thomas at monjalon.net> writes:

> 19/04/2021 20:06, Tal Shnaiderman:
>> > > 2021-04-18 19:04 (UTC+0000), Tal Shnaiderman:
>> > > > > 18/04/2021 19:08, Tal Shnaiderman:
>> > > > > > the strncasecmp marco defined in rte_os_shim.h is already
>> > > > > > defined in MinGW-w64, as a result the compiler prints out the
>> > > > > > warning below on function redefinition whenever compiling a file
>> > > > > > including the
>> > > header.
>> > > > > >
>> > > > > > ..\lib/librte_eal/windows/include/rte_os_shim.h:21:
>> > > > > > warning: "strncasecmp" redefined #define strncasecmp(s1, s2,
>> > > > > > count) _strnicmp(s1, s2, count)
>> > > > >
>> > > > > Why the tests are passing? Are we allowing warnings in build test?
>> > > >
>> > > > It's a good question, I see CI is passing without warnings, Dmitry
>> > > > can you
>> > > reproduce it?
>> > > >
>> > > > On my side the collision is with the following file:
>> > > >
>> > > > C:/mingw-w64/x86_64/mingw64/x86_64-w64-
>> > > mingw32/include/string.h:119:
>> > > > note: this is the location of the previous definition  #define
>> > > > strncasecmp _strnicmp
>> > > >
>> > > > I'm using:
>> > > > -gcc (x86_64-win32-seh-rev0, Built by MinGW-W64 project) 8.1.0
>> > > > -meson
>> > > > 0.53.2
>> > >
>> > > I can't reproduce it using the same versions.
>> > > Do you invoke meson with other options than "-Dexamples=..."?
>> > 
>> > This is the meson line I'm using:
>> > 
>> > meson "-Dexamples=helloworld" build --wipe --default-library=static --
>> > buildtype debug
>> > 
>> > The problem however is that MinGW's string.h defines the macro in line 119,
>> > for some reason my build includes it and the rest doesn't.
>> 
>> Hi Dmitry,
>> 
>> I also noticed warnings in clang on my setup that are related to rte_os_shim.h:
>> 
>> [185/314] Compiling C object drivers/a715181@@tmp_rte_common_mlx5 at sta/common_mlx5_mlx5_common_mp.c.obj.
>> In file included from ../drivers/common/mlx5/mlx5_common_mp.c:13:
>> In file included from ..\drivers\common/mlx5/mlx5_common_utils.h:8:
>> In file included from ..\drivers\common/mlx5/mlx5_common.h:17:
>> ..\lib/librte_eal/windows/include\rte_os_shim.h:22:51: warning:
>> token pasting of ',' and __VA_ARGS__ is a GNU extension
>> [-Wgnu-zero-variadic-macro-arguments]
>> #define open(path, flags, ...) _open(path, flags, ##__VA_ARGS__)
>>                                                   ^
>> However don't see it in CI, I'm using clang version 9.0.1
>
> It seems we should improve our CI.
> Please open suggestions in the CI bugzilla.

Please do.

Will this only be caught by mingw64 on windows?  Will we get the same
issues with a linux mingw install?  I'm guessing yes, but don't know
mingw very well.  We may be able to install the mingw package under our
github actions pipeline.