Project

General

Profile

Actions

Bug #17578

open

mkmf experimental C++ Support

Added by cfis (Charlie Savage) over 1 year ago. Updated over 1 year ago.

Status:
Assigned
Priority:
Normal
Target version:
-
ruby -v:
ruby 2.7.2p137 (2020-10-01 revision 5445e04352) [x64-mingw32]
[ruby-core:102230]

Description

I've been working on the Rice gem (https://github.com/jasonroelofs/rice) that wraps C++ code for use in Ruby.

I noticed that some c++ support was added to mkmf for Ruby 2.7. However, if I try to use it find a header it fails to work. For example:

find_header('rice.hpp')

The reason is the conftest uses gcc -E instead of g++ -E. To fix that requires overlading the cpp_command to support C++.

This the fix I have put in that works:

MakeMakefile['C++'].module_eval do
  def cpp_command(outfile, opt="")
    conf = cc_config(opt)
    if $universal and (arch_flag = conf['ARCH_FLAG']) and !arch_flag.empty?
      conf['ARCH_FLAG'] = arch_flag.gsub(/(?:\G|\s)-arch\s+\S+/, '')
    end
    RbConfig::expand("$(CXX) -E #$INCFLAGS #$CPPFLAGS #$CFLAGS #{opt} #{CONFTEST_CXX} #{outfile}",
                     conf)
  end
end

The two changes over the default method are:

$(CC) -> $(CXX) -E
#{CONFTEST_c} -> #{CONFTEST_cxx}

Could this change be merged in? I can provide a patch file if you would like.

Last, it wasn't obvious to me how to activate the C++ support in mkfm. I ended up doing this:

include MakeMakefile['C++']

Is that correct?

Actions

Also available in: Atom PDF