Re: Abusing XTRA_CXXFLAGS

[John W. Eaton]

On 10/30/2013 11:45 AM, Rik wrote:
> 10/30/13
>
> All,
>
> Someone may know why were doing this, otherwise I think it should change.
>
> The build variable XTRA_CXXFLAGS is mostly used for machine-dependent
> compiler flags necessary to guarantee IEEE numeric behavior.  However,
> configure.ac is also adding in LLVM_CPPFLAGS, FreeType CPPFLAGS, etc.
> Since XTRA_CXXFLAGS are added to every C++ compile it means that really
> low-level numeric stuff like liboctave/array/ is being compiled with '-I'
> includes for FreeType.  It would seem better to move these very specific
> flags out of the general compile command and use them only for the file or
> Autotool sub-library that needs them.

I agree that we should only use extra flags where they are needed.

> Is this just evolutionary cruft left over from previous versions of
> configure.ac

Yes, like so many other things in Octave.

I think the idea behind this was that I needed a place to collect these 
additional flags and they couldn't just be added to CFLAGS or CXXFLAGS 
because those are supposed to be left for the user to define.  That was 
long before automake and it worked well enough in beginning.  If there 
is a better way now, then let's use it.

jwe