[Mesa-dev] [PATCH] configure: Don't override user -g or -O options for debug builds

[Ilia Mirkin]

On Mon, Jul 14, 2014 at 4:41 PM, Matt Turner <mattst88 at gmail.com> wrote:
> On Mon, Jul 14, 2014 at 11:49 AM, Ian Romanick <idr at freedesktop.org> wrote:
>> From: Ian Romanick <ian.d.romanick at intel.com>
>>
>> I already pass '-ggdb3 -O1' or '-ggdb3 -Og' for CFLAGS, and I don't want
>> configure to change them for me.
>>
>> Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
>> ---
>>  configure.ac | 14 ++++++++++++--
>>  1 file changed, 12 insertions(+), 2 deletions(-)
>>
>> diff --git a/configure.ac b/configure.ac
>> index 4646212..04abcc0 100644
>> --- a/configure.ac
>> +++ b/configure.ac
>> @@ -308,10 +308,20 @@ AC_ARG_ENABLE([debug],
>>  if test "x$enable_debug" = xyes; then
>>      DEFINES="$DEFINES -DDEBUG"
>>      if test "x$GCC" = xyes; then
>> -        CFLAGS="$CFLAGS -g -O0"
>> +        if ! echo "$CFLAGS" | grep -q -e '-g'; then
>> +            CFLAGS="$CFLAGS -g"
>> +        fi
>> +        if ! echo "$CFLAGS" | grep -q -e '-O'; then
>> +            CFLAGS="$CFLAGS -O0"
>> +        fi
>>      fi
>>      if test "x$GXX" = xyes; then
>> -        CXXFLAGS="$CXXFLAGS -g -O0"
>> +        if ! echo "$CXXFLAGS" | grep -q -e '-g'; then
>> +            CXXFLAGS="$CXXFLAGS -g"
>> +        fi
>> +        if ! echo "$CXXFLAGS" | grep -q -e '-O'; then
>> +            CXXFLAGS="$CXXFLAGS -O0"
>> +        fi
>>      fi
>>  fi
>>
>> --
>> 1.8.1.4
>
> This looks like strictly an improvement, so my feedback shouldn't hold
> this up, but maybe it's time to fight about whether --enable-debug
> should add -O0 at all. :)
>
> Reviewed-by: Matt Turner <mattst88 at gmail.com>
>
> Autotools defaults are -g -O2. Some people want debug builds to use
> -g, others -ggdb*. Some people want -O2 (optimize, but with assertions
> enabled), others -O0, others -Og. It'd be nice to not have
> --enable-debug turn on one combination of these.

IIRC I've only seen negative comments on this rather than
defend/praise. Does anyone actually _like_ this feature? Personally, I
find it incredibly counter-intuitive.

  -ilia