Re: Order of AM_CPPFLAGS and other xxx_CFLAGS

[Michael Goffioul]

On Thu, Nov 14, 2013 at 10:57 PM, Michael Goffioul <address@hidden> wrote:

Rik,

This changeset breaks my compilation with MSVC:

http://hg.savannah.gnu.org/hgweb/octave/rev/a230b996ae8a

The problem is that compilation of (among others) __init_fltk__.cc uses now the following CPPFLAGS definition:

$(GRAPHICS_CFLAGS) $(FT2_CPPFLAGS) $(FONTCONFIG_CPPFLAGS) $(AM_CPPFLAGS)

The variable GRAPHICS_CFLAGS, pulled from fltk-config, contains a -Ixxx statement containing the base installation directory of my MXE system. The libgnu directory, on the other hand, is part of AM_CPPFLAGS. As a result, gnulib header substitution fails for some headers. A similar problem could also occur on Linux if any of the variables preceding AM_CPPFLAGS happen to contain -I/usr/include. I believe the libgnu directory should appear early in the include chain, otherwise it'll fail to override what it's supposed to override.

To be precise, my problem is that I have a hand-crafted math.h in my MXE base installation dir (to compensate some MSVC deficiencies). Due to variable ordering, __init_fltk__.cc ends up including that version instead of gnulib's replacement. Then compilation fails because gnulib::floor is not defined.

Michael.