[Buildroot] [PATCH] argp-standalone: fix build with > GCC5.1

[Thomas Petazzoni]

Hello,

On Tue, 31 Oct 2017 01:18:34 -0500, Matt Weber wrote:
> The problem is the change of the default C standard from gnu89 to gnu11
> which changes the semantics of 'inline'. The issue is described in the
> Porting guide at https://gcc.gnu.org/gcc-5/porting_to.html. Adding the
> '-fgnu89-inline' option fixes the issue.
> 
> Similar issue:
> https://www.mail-archive.com/ptxdist@pengutronix.de/msg09746.html
> 
> Fixes:
> http://autobuild.buildroot.net/results/a9c/a9cedc54829b7bd2dd7ae6ff2bd6c6db242f1c35//
> 
> Tested via test-pkg with the following cfg
> BR2_PACKAGE_ARGP_STANDALONE=y
> 
> Signed-off-by: Matthew Weber <matthew.weber at rockwellcollins.com>

So, I've applied, but with those tweaks. Indeed, your patch could
definitely not be fixing an issue with gcc >= 5.x, because we have been
using gcc 5.x for a while, and this build error was not popping up with
anything but gcc 7.x.

So, what happened is that in commit
a662ff7e79630ca0875dd8529fe54db27a275007, we added a patch that fixes
the build with C99 compilers (in fact this means gcc 5.x, which uses
C99 inline semantics). This changed "extern inline" to just "inline".
But that broke again with gcc 7.x, and causes the problem we're seeing
now.

So instead, I've dropped the chunk of the patch that changed from
extern inline to inline, and passsed -fgnu89-inline as you suggested. I
updated the commit log accordingly.

See
https://git.buildroot.org/buildroot/commit/?id=f0b65bd90ce4429d6b7e952ce7de2d5f92a2dd26
for more details.

Thanks for all your research behind this issue!

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com