Re: having trouble with XTRA_CFLAGS showing up on AM_CXXFLAGS

[Carnë Draug]

On 7 February 2016 at 07:34, John W. Eaton <address@hidden> wrote:
> On 02/06/2016 10:42 PM, Carnë Draug wrote:
>>
>> Hi
>>
>> I've been playing around with our configure and I'm having a problem
>> that maybe someone can help me with.
>>
>> I'm adding a flag to XTRA_CFLAGS in our configure script and it seems to
>> somehow be creeping into AM_CXXFLAGS.  The weird thing is that looking
>> into
>> the generate Makefiled, it is not there.  However, when I run "make -n", I
>> see it showing up in AM_CXXFLAGS.
>>
>> Here's what I've been doing.  I've been adding the following lines to
>> configure.ac:
>>
>>      XTRA_CFLAGS="$XTRA_CFLAGS -std=c11"
>>      XTRA_CXXFLAGS="$XTRA_CXXFLAGS -std=c++11"
>>      CFLAGS="$CFLAGS -std=c11"
>>      CXXFLAGS="$CXXFLAGS -std=c++11"
>>
>> After running configure, everything looks fine, the displayed resume
>> looks correct.  However, once the build actually starts I get warnings
>> like:
>>
>>        GEN      libinterp/octave-value/ov-flt-re-mat.df
>>      cc1plus: warning: command line option ‘-std=c11’ is valid for
>> C/ObjC but not for C++
>>
>> And indeed, running "make -n", I get g++ being called with -std=c11.  For
>> example, the recipe for octave-value/ov-flt-re-mat.df
>>
>>      g++ -E -DHAVE_CONFIG_H -I. -I/home/carandraug/dev/octave  \
>>        -I. [....] \
>>        -std=c11 -pthread -fopenmp [...] \
>>        [...]
>>      mv libinterp/octave-value/ov-flt-re-mat.df-t
>> libinterp/octave-value/ov-flt-re-mat.df
>>
>> Anyone can explain me what I'm doing wrong?
>
>
> Oops, I fixed it in this changeset:
>
>   http://hg.savannah.gnu.org/hgweb/octave/rev/b7a191eb0c3c
>
> Thanks.
>
> jwe

I spent a lot of time yesterday looking for this.  Is there any tip
so that next time I can find it myself?  Or one just needs to be more
familiar with Octave's build?

Carnë