mruby/mruby — pull request #1769 by take-cheeze (2014-02-28 17:28:55+00:00)
Title: build_mrbconf.h

With this patch mruby build system can separate `mrbconf.h` macro and compiler flag macro.
To use `mrbconf.h` macro use `MRuby::Build#enable_mrbconf` method to enable specific macro easily instead of appending to `defines` property.
(if you need to enable `MRB_GC_FIXED_ARENA` call `enable_mrbconf :gc_fixed_arena`)

Additionally when you change **mrbconf** in **build_config.rb** the whole code would be recompiled with new **mrbconf** so that it's safer.

Though it has some limitation:
* it can't specify macro with value
* it can't disable mrbconf
* it can't detect conflict of mrbconfs