[Mesa-dev] [PATCH] mesa/autoconf: attempt to use gnu99 on older gcc compilers

[Ian Romanick]

On 01/21/2015 05:35 PM, Matt Turner wrote:
> On Wed, Jan 21, 2015 at 5:28 PM, Dave Airlie <airlied at gmail.com> wrote:
>> From: Dave Airlie <airlied at redhat.com>
>>
>> anonymous structs/union don't work with c99 but do work with gnu99
>> on gcc 4.4.
>>
>> This on top of Jason's designated initialisers changes, make
>> Mesa build on RHEL6 again.
>>
>> Signed-off-by: Dave Airlie <airlied at redhat.com>
>> ---
>>  configure.ac |   12 +++++++++++-
>>  1 files changed, 11 insertions(+), 1 deletions(-)
>>
>> diff --git a/configure.ac b/configure.ac
>> index a4c5c74..9420a90 100644
>> --- a/configure.ac
>> +++ b/configure.ac
>> @@ -145,6 +145,7 @@ AC_MSG_RESULT([$acv_mesa_CLANG])
>>  dnl If we're using GCC, make sure that it is at least version 4.2.0.  Older
>>  dnl versions are explictly not supported.
>>  GEN_ASM_OFFSETS=no
>> +USE_GNU99=no
>>  if test "x$GCC" = xyes -a "x$acv_mesa_CLANG" = xno; then
>>      AC_MSG_CHECKING([whether gcc version is sufficient])
>>      major=0
>> @@ -163,6 +164,9 @@ if test "x$GCC" = xyes -a "x$acv_mesa_CLANG" = xno; then
>>          AC_MSG_RESULT([yes])
>>      fi
>>
>> +    if test $GCC_VERSION_MAJOR -lt 4 -o $GCC_VERSION_MAJOR -eq 4 -a $GCC_VERSION_MINOR -lt 6 ; then
> 
> Can't we just do this test...
> 
>> +        USE_GNU99=yes
>> +    fi
>>      if test "x$cross_compiling" = xyes; then
>>          GEN_ASM_OFFSETS=yes
>>      fi
>> @@ -221,7 +225,13 @@ esac
>>
>>  dnl Add flags for gcc and g++
>>  if test "x$GCC" = xyes; then
>> -    CFLAGS="$CFLAGS -Wall -std=c99"
>> +    CFLAGS="$CFLAGS -Wall"
>> +
>> +    if test "x$USE_GNU99" = xyes; then
> 
> ... right here?

It would happen on clang if we did.  Above, it's inside a block of "am I
GCC and definitely not clang".  That said, I don't know how important
that is...

>> +       CFLAGS="$CFLAGS -std=gnu99"
>> +    else
>> +       CFLAGS="$CFLAGS -std=c99"
>> +    fi
>>
>>      # Enable -Werror=implicit-function-declaration and
>>      # -Werror=missing-prototypes, if available, or otherwise, just
>> --
>> 1.7.1
>>
>> _______________________________________________
>> mesa-dev mailing list
>> mesa-dev at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
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