build with bundled onigmo fails when c++ API is enabled

[lutter]

When I put conf.enable_cxx_api into my build_config.rb, building mruby-onig-regexp fails because it tries to build onigmo with a C++ compiler, but onigmo can not be built with a C++ compiler (e.g., it uses not as a field name in a struct, but that is a keyword in C++).

I see two ways to fix this: (1) build this mrbgem with CC even if the C++ API is enabled or (2) try to change Onigmo to build with a C++ compiler.

[mattn]

@take-cheeze do you have any idea?

[take-cheeze]

Use enable_cxx_exception instead.
( https://github.com/mruby/mruby/blob/0bcf9e28fc6b41f75e78557295decfdcdb947b7a/doc/guides/compile.md#c-abi )
Somehow the Shopify wants to compile C code with C++ compiler when enable_cxx_abi is enabled.

[lutter]

Thanks for the quick reply ! Unfortunately, I do need to build mruby with a C++ compiler, as my project needs to both call into mruby from C++, and call into C++ code from mruby.

If there's no easy solution on this end, I might try and set things up with a discrete onigmo build before I build mruby.