From: Stefan Salewski <mail@...>
Date: 2013-10-17T15:03:33+02:00
Subject: [ruby-core:57913] cxxflags for C++ library bindings not working for Ruby 1.9.x and 2.0?

Dear Sirs,

in the last months I wrote some Ruby bindings for a few C++ libraries,
including CGAL and BOOST library. (Some initial releases are already
available at http://www.ssalewski.de/ , but I still have to cleanup the
code.)

My feeling is, that there is some problem in the handling of CXXFLAGS
used for the C++ compiler.

CGAL code need the flag -frounding-math.
For Ruby 1.9.3 I gave
$CFLAGS += " -frounding-math"

in extconfig.rb, and "ruby extconfig.rb; make" was working fine.
For Ruby 2.0 this was not working any more -- I found
$CPPLAGS += " -frounding-math"
working as entry in extconfig.rb. (But CPPLAGS are for preprocessor.)

Yesterday I tried (Ruby 1.9.3) some C++11 features (nullpointer) and
tried

ruby extconfig.rb
make cxxflags+=-std=c++11

from command line. That is not working, but

make cppflags+=-std=c++11

is working. So my feeling is that there may be something wrong with C++
flags cxxflags support in Ruby 1.9.x and Ruby 2.0.

This is for Gentoo Linux AMD64, gcc version 4.7.3

Can you confirm this problem?

Best regards,

Stefan Salewski