mruby-mruby/doc/mrbconf

mruby configuration macros.

How to use these macros.

You can use mrbconfs with following ways:

• Write them in mrbconf.h.
• Using compiler flags is prefered when building a cross binaries or multiple mruby binaries since it's easier to use different mrbconf per each MRuby::Build.
• Most flags can be enabled by just commenting in.
• Pass them as compiler flags.
• Make sure you pass the same flags to all compilers since some mrbconf(e.g., MRB_GC_FIXED_ARENA) changes struct layout and cause memory access error when C and other language(e.g., C++) is mixed.

stdio setting.

ENABLE_STDIO

• Will be defined automatically if DISABLE_STDIO isn't defined.
• Uses <stdio.h> functions.

DISABLE_STDIO

• When defined <stdio.h> functions won't be used.

Debug macros.

ENABLE_DEBUG

• When defined code fetch hook and debug OP hook will be enabled.
• When using any of the hook set function pointer code_fetch_hook and/or debug_op_hook of mrb_state.
• Fetch hook will be called before any OP.
• Debug OP hook will be called when dispatching OP_DEBUG.

DISABLE_DEBUG

• Will be define automatically if ENABLE_DEBUG isn't defined.

MRB_DEBUG

• When defined mrb_assert* macro will be defined with macros from <assert.h>.
• Could be enabled via enable_debug method of MRuby::Build.

Stack configuration

MRB_STACK_EXTEND_DOUBLING

• If defined doubles the stack size when extending it.
• Else extends stack with MRB_STACK_GROWTH.

MRB_STACK_GROWTH

• Default value is 128.
• Used in stack extending.
• Ignored when MRB_STACK_EXTEND_DOUBLING is defined.

MRB_STACK_MAX

• Default value is 0x40000 - MRB_STACK_GROWTH.
• Raises RuntimeError when stack size exceeds this value.