[PATCH] fstests: use '-std=gnu11' to fix build errors with gcc-15

[PATCH] fstests: use '-std=gnu11' to fix build errors with gcc-15

[Zorro Lang]

GCC-15 does a big change, it changes the default C compilation
language standard to -std=gnu23. That cause lots of "old style"
C codes hit building errors. On the other word, current xfstests
can't be used with GCC-15. So use a fixed language standard --
"-std=gnu11" (to match the kernel and xfsprogs).

Signed-off-by: Zorro Lang <zlang@kernel.org>
---

Hi,

The upcoming gcc-15 does lots of changes, a big change is using C23
by default:

  https://gcc.gnu.org/gcc-15/porting_to.html

xfstests has many old style C codes, they hard to be built with gcc-15.

Thanks,
Zorro

 include/builddefs.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/builddefs.in b/include/builddefs.in
index 7274cde8d..631e5d83f 100644
--- a/include/builddefs.in
+++ b/include/builddefs.in
@@ -75,7 +75,7 @@ HAVE_RLIMIT_NOFILE = @have_rlimit_nofile@
 NEED_INTERNAL_XFS_IOC_EXCHANGE_RANGE = @need_internal_xfs_ioc_exchange_range@
 HAVE_FICLONE = @have_ficlone@
 
-GCCFLAGS = -funsigned-char -fno-strict-aliasing -Wall
+GCCFLAGS = -funsigned-char -fno-strict-aliasing -std=gnu11 -Wall
 
 ifeq ($(PKG_PLATFORM),linux)
 PCFLAGS = -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 $(GCCFLAGS)
-- 
2.47.1

Re: [PATCH] fstests: use '-std=gnu11' to fix build errors with gcc-15

[Darrick J. Wong]

On Tue, Feb 11, 2025 at 12:57:15AM +0800, Zorro Lang wrote:
> GCC-15 does a big change, it changes the default C compilation
> language standard to -std=gnu23. That cause lots of "old style"
> C codes hit building errors. On the other word, current xfstests
> can't be used with GCC-15. So use a fixed language standard --
> "-std=gnu11" (to match the kernel and xfsprogs).
> 
> Signed-off-by: Zorro Lang <zlang@kernel.org>
> ---
> 
> Hi,
> 
> The upcoming gcc-15 does lots of changes, a big change is using C23
> by default:
> 
>   https://gcc.gnu.org/gcc-15/porting_to.html
> 
> xfstests has many old style C codes, they hard to be built with gcc-15.

Quick question -- does the same need to be applied to CXXFLAGS?  There
aren't any C++ modules in fstests, but it'd be nice not to leave a
weirdness where cpp files aren't built with a roughly contemporaneous
language specification.

That said, this at least gets us to the same behavior as the linux
kernel and xfsprogs, so:

Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> 
> Thanks,
> Zorro
> 
>  include/builddefs.in | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/builddefs.in b/include/builddefs.in
> index 7274cde8d..631e5d83f 100644
> --- a/include/builddefs.in
> +++ b/include/builddefs.in
> @@ -75,7 +75,7 @@ HAVE_RLIMIT_NOFILE = @have_rlimit_nofile@
>  NEED_INTERNAL_XFS_IOC_EXCHANGE_RANGE = @need_internal_xfs_ioc_exchange_range@
>  HAVE_FICLONE = @have_ficlone@
>  
> -GCCFLAGS = -funsigned-char -fno-strict-aliasing -Wall
> +GCCFLAGS = -funsigned-char -fno-strict-aliasing -std=gnu11 -Wall
>  
>  ifeq ($(PKG_PLATFORM),linux)
>  PCFLAGS = -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 $(GCCFLAGS)
> -- 
> 2.47.1
> 
>