mruby-mruby/doc/compile

Compile

mruby is using Rake to compile and cross-compile all libraries and binaries.

Prerequisites

To compile mruby out of the source code you need the following tools:

• C Compiler (i.e. gcc)
• Linker (i.e. gcc)
• Archive utility (i.e. ar)
• Parser generator (i.e. bison)
• Ruby 1.8 or 1.9 (i.e. ruby or jruby)

Optional:

• GIT (to update mruby source and integrate mrbgems easier)
• C++ compiler (to use GEMs which include *.cpp)
• Assembler (to use GEMs which include *.asm)

Usage

Inside of the root directory of the mruby source exist a file called build_config.rb. This file contains the build configuration of mruby and looks like this for example:

MRuby::Build.new do |conf|
  toolchain :gcc
end

All tools necessary to compile mruby can be set or modified here. In case you want to maintain an additional build_config.rb you can define a customized path using the $MRUBY_CONFIG environment variable.

To compile just call ./minirake inside of the mruby source root. To generate and execute the test tools call ./minirake test. To clean all build files call ./minirake clean.

Build Configuration

Inside of the build_config.rb the following options can be configurated based on your environment.

Toolchains

The mruby build system contains already a set of toolchain templates which configurates the build environment for specific compiler infrastructures.

GCC

Toolchain configuration for the GNU C Compiler.

toolchain :gcc

clang

Toolchain configuration for the LLVM C Compiler clang. Mainly equal to the GCC toolchain.

toolchain :clang

Visual Studio 2012

Toolchain configuration for Visual Studio 2012 on Windows.

toolchain :vs2012

Binaries

It is possible to select which tools should be compiled during the compilation process. The following tools can be selected:

• mrbc (mruby compiler)
• mruby (mruby interpreter)
• mirb (mruby interactive shell

To select all define an array in conf.bins:

conf.bins = %(mrbc mruby mirb)

File Separator

Some environments require a different file separator character. It is possible to set the character via conf.file_separator.

conf.file_separator = '/'

C Compiler

Configuration of the C compiler binary, flags and include paths.

conf.cc do |cc|
  cc.command = ...
  cc.flags = ...
  cc.include_paths = ...
  cc.defines = ...
  cc.option_include_path = ...
  cc.option_define = ...
  cc.compile_options = ...
end

Linker

Configuration of the Linker binary, flags and library paths.

conf.linker do |linker|
  linker.command = ...
  linker.flags = ...
  linker.libraries = ...
  linker.library_paths = ....
  linker.option_library = ...
  linker.option_library_path = ...
  linker.link_options = ...
end

Archiver

Configuration of the Archiver binary and flags.

conf.archiver do |archiver|
  archiver.command = ...
  archiver.archive_options = ...
end

Parser Generator

Configuration of the Parser Generator binary and flags.

conf.yacc do |yacc|
  yacc.command = ...
  yacc.compile_options = ...
end

GPerf

Configuration of the GPerf binary and flags.

conf.gperf do |gperf|
  gperf.command = ...
  gperf.compile_options = ...
end

File Extensions

conf.exts do |exts
  exts.object = ...
  exts.executable = ...
  exts.library = ...
end

Mrbgems

Integrate GEMs in the build process.

# Integrate GEM with additional configuration
conf.gem 'path/to/gem' do |g|
  g.cc.flags << ...
end

# Integrate GEM without additional configuration
conf.gem 'path/to/another/gem'

Cross-Compilation

mruby can also be cross-compiled from one platform to another. To achive this the build_config.rb needs to contain an instance of MRuby::CrossBuild. This instance defines the compilation tools and flags for the target platform. An example could look like this:

MRuby::CrossBuild.new('32bit') do |conf|
  toolchain :gcc

  conf.cc.flags << "-m32"
  conf.linker.flags << "-m32
end

All configuration options of MRuby::Build can also be used in MRuby::CrossBuild.

Build process

During the build process the directory build will be created in the root directory. The structure of this directory will look like this:

+- build
   |
   +-  host
       |
       +- bin          <- Binaries (mirb, mrbc and mruby)
       |
       +- lib          <- Libraries (libmruby.a and libmruby_core.a)
       |
       +- mrblib
       |
       +- src
       |
       +- test         <- mrbtest tool
       |
       +- tools
          |
          +- mirb
          |
          +- mrbc
          | 
          +- mruby

The compilation workflow will look like this:

• compile all files under src (object files will be stored in build/host/src
• generate parser grammar out of src/parse.y (generated result will be stored in build/host/src/y.tab.c
• compile build/host/src/y.tab.c to build/host/src/y.tab.o
• create build/host/lib/libmruby_core.a out of all object files (C only)
• create build/host/bin/mrbc by compile tools/mrbc/mrbc.c and link with build/host/lib/libmruby_core.a
• create build/host/mrblib/mrblib.c by compiling all *.rb files under mrblib with build/host/bin/mrbc
• compile build/host/mrblib/mrblib.c to build/host/mrblib/mrblib.o
• create build/host/lib/libmruby.a out of all object files (C and Ruby)
• create build/host/bin/mruby by compile tools/mruby/mruby.c and link with build/host/lib/libmruby.a
• create build/host/bin/mirb by compile tools/mirb/mirb.c and link with build/host/lib/libmruby.a

 _____    _____    ______    ____    ____    _____    _____    ____
| CC  |->|GEN  |->|AR    |->|CC  |->|CC  |->|AR   |->|CC   |->|CC  |
| *.c |  |y.tab|  |core.a|  |mrbc|  |*.rb|  |lib.a|  |mruby|  |mirb|
 -----    -----    ------    ----    ----    -----    -----    ----

Cross-Compilation

In case of a cross-compilation to i386 the build directory structure looks like this:

+- build
   |
   +-  host
   |   |
   |   +- bin           <- Native Binaries
   |   |
   |   +- lib           <- Native Libraries
   |   |
   |   +- mrblib
   |   |
   |   +- src
   |   |
   |   +- test          <- Native mrbtest tool
   |   |
   |   +- tools
   |      |
   |      +- mirb
   |      |
   |      +- mrbc
   |      | 
   |      +- mruby 
   +- i386
      |
      +- bin            <- Cross-compiled Binaries
      |
      +- lib            <- Cross-compiled Libraries
      |
      +- mrblib
      |
      +- src
      |
      +- test           <- Cross-compiled mrbtest tool
      |
      +- tools
         |
         +- mirb
         |
         +- mrbc
         | 
         +- mruby

An extra directory is created for the target platform. In case you compile for i386 a directory called i386 is created under the build direcotry.

The cross compilation workflow starts in the same way as the normal compilation by compiling all native libraries and binaries. Aftwards the cross compilation process proceeds like this:

• cross-compile all files under src (object files will be stored in build/i386/src
• generate parser grammar out of src/parse.y (generated result will be stored in build/i386/src/y.tab.c
• cross-compile build/i386/src/y.tab.c to build/i386/src/y.tab.o
• create build/i386/mrblib/mrblib.c by compiling all *.rb files under mrblib with the native build/host/bin/mrbc
• cross-compile build/host/mrblib/mrblib.c to build/host/mrblib/mrblib.o
• create build/i386/lib/libmruby.a out of all object files (C and Ruby)
• create build/i386/bin/mruby by cross-compile tools/mruby/mruby.c and link with build/i386/lib/libmruby.a
• create build/i386/bin/mirb by cross-compile tools/mirb/mirb.c and link with build/i386/lib/libmruby.a
• create build/i386/lib/libmruby_core.a out of all object files (C only)
• create build/i386/bin/mrbc by cross-compile tools/mrbc/mrbc.c and link with build/i386/lib/libmruby_core.a

 _____________________________________________________________
|              Native Compilation for Host System             |
| _____      ______      _____      ____      ____      _____ |
|| CC  | -> |AR    | -> |GEN  | -> |CC  | -> |CC  | -> |AR   ||
|| *.c |    |core.a|    |y.tab|    |mrbc|    |*.rb|    |lib.a||
| -----      ------      -----      ----      ----      ----- |
 -------------------------------------------------------------
                                ||
                               \||/
                                \/
 ______________________________________________________________
|             Cross Compilation for Target System              |
| _____      _____      _____      ____      ______      _____ |
|| CC  | -> |AR   | -> |CC   | -> |CC  | -> |AR    | -> |CC   ||
|| *.c |    |lib.a|    |mruby|    |mirb|    |core.a|    |mrbc ||
| -----      -----      -----      ----      ------      ----- |
 --------------------------------------------------------------

Test Environment

mruby's build process includes a test environment. In case you start the testing of mruby, a native binary called mrbtest will be generated and executed. This binary contains all test cases which are defined under test/t. In case of a cross-compilation an additional cross-compiled mrbtest binary is generated. This binary you can copy and run on your target system.