Compile
mruby uses 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 (e.g. gcc)
* Linker (e.g. gcc)
* Archive utility (e.g. ar)
* Parser generator (e.g. bison)
* Ruby 2.0 or later (e.g. ruby or jruby)
Optional: * GIT (to update mruby source and integrate mrbgems easier) * C++ compiler (to use GEMs which include *.cpp, *.cxx, *.cc) * Assembler (to use GEMs which include *.asm)
Usage
Inside of the root directory of the mruby source a file exists
called build_config.rb. This file contains the build configuration
of mruby and looks like this for example:
ruby
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. To see full command line on
build, call ./minirake -v.
Build Configuration
Inside of the build_config.rb the following options can be configured based on your environment.
Toolchains
The mruby build system already contains a set of toolchain templates which configure the build environment for specific compiler infrastructures.
GCC
Toolchain configuration for the GNU C Compiler.
ruby
toolchain :gcc
clang
Toolchain configuration for the LLVM C Compiler clang. Mainly equal to the
GCC toolchain.
ruby
toolchain :clang
Visual Studio 2010, 2012 and 2013
Toolchain configuration for Visual Studio on Windows. If you use the
Visual Studio Command Prompt,
you normally do not have to specify this manually, since it gets automatically detected by our build process.
ruby
toolchain :visualcpp
Android
Toolchain configuration for Android.
ruby
toolchain :android
Requires the custom standalone Android NDK and the toolchain path
in ANDROID_STANDALONE_TOOLCHAIN.
Binaries
It is possible to select which tools should be compiled during the compilation process. The following tools can be selected: * mruby (mruby interpreter) * mirb (mruby interactive shell)
To select them declare conf.gem as follows:
ruby
conf.gem "#{root}/mrbgems/mruby-bin-mruby"
conf.gem "#{root}/mrbgems/mruby-bin-mirb"
File Separator
Some environments require a different file separator character. It is possible to
set the character via conf.file_separator.
ruby
conf.file_separator = '/'
C Compiler
Configuration of the C compiler binary, flags and include paths.
ruby
conf.cc do |cc|
cc.command = ...
cc.flags = ...
cc.include_paths = ...
cc.defines = ...
cc.option_include_path = ...
cc.option_define = ...
cc.compile_options = ...
end
C Compiler has header searcher to detect installed library.
If you need a include path of header file use search_header_path:
ruby
# Searchesiconv.h.
# If found it will return include path of the header file.
# Otherwise it will return nil .
fail 'iconv.h not found' unless conf.cc.search_header_path 'iconv.h'
If you need a full file name of header file use search_header:
ruby
# Searchesiconv.h.
# If found it will return full path of the header file.
# Otherwise it will return nil .
iconv_h = conf.cc.search_header 'iconv.h'
print "iconv.h found: #{iconv_h}\n"
Header searcher uses compiler’s include_paths by default.
When you are using GCC toolchain (including clang toolchain since its base is gcc toolchain)
it will use compiler specific include paths too. (For example /usr/local/include, /usr/include)
If you need a special header search paths define a singleton method header_search_paths to C compiler:
ruby
def conf.cc.header_search_paths
['/opt/local/include'] + include_paths
end
Linker
Configuration of the Linker binary, flags and library paths.
ruby
conf.linker do |linker|
linker.command = ...
linker.flags = ...
linker.flags_before_libraries = ...
linker.libraries = ...
linker.flags_after_libraries = ...
linker.library_paths = ....
linker.option_library = ...
linker.option_library_path = ...
linker.link_options = ...
end
Archiver
Configuration of the Archiver binary and flags.
ruby
conf.archiver do |archiver|
archiver.command = ...
archiver.archive_options = ...
end
Parser Generator
Configuration of the Parser Generator binary and flags.
ruby
conf.yacc do |yacc|
yacc.command = ...
yacc.compile_options = ...
end
GPerf
Configuration of the GPerf binary and flags.
ruby
conf.gperf do |gperf|
gperf.command = ...
gperf.compile_options = ...
end
File Extensions
ruby
conf.exts do |exts|
exts.object = ...
exts.executable = ...
exts.library = ...
end
Mrbgems
Integrate GEMs in the build process. ```ruby # 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’ ```
See doc/mrbgems/README.md for more option about mrbgems.
Mrbtest
Configuration Mrbtest build process.
If you want mrbtest.a only, You should set conf.build_mrbtest_lib_only
ruby
conf.build_mrbtest_lib_only
Bintest
Tests for mrbgem tools using CRuby.
To have bintests place *.rb scripts to bintest/ directory of mrbgems.
See mruby-bin-*/bintest/*.rb if you need examples.
If you want a temporary files use tempfile module of CRuby instead of /tmp/.
You can enable it with following:
ruby
conf.enable_bintest
C++ ABI
By default, mruby uses setjmp/longjmp to implement its exceptions. But it doesn’t release C++ stack object correctly. To support mrbgems written in C++, mruby can be configured to use C++ exception.
There are two levels of C++ exception handling. The one is
enable_cxx_exception that enables C++ exception, but
uses C ABI. The other is enable_cxx_abi where all
files are compiled by C++ compiler.
When you mix C++ code, C++ exception would be enabled automatically.
If you need to enable C++ exception explicitly add the following:
ruby
conf.enable_cxx_exception
C++ exception disabling.
If your compiler does not support C++ and you want to ensure
you don’t use mrbgem written in C++, you can explicitly disable
C++ exception, add following:
ruby
conf.disable_cxx_exception
and you will get an error when you try to use C++ gem.
Note that it must be called before enable_cxx_exception or gem method.
Debugging mode
To enable debugging mode add the following:
ruby
conf.enable_debug
When debugging mode is enabled
* Macro MRB_DEBUG would be defined.
* Which means mrb_assert() macro is enabled.
* Debug information of irep would be generated by mrbc.
* Because -g flag would be added to mrbc runner.
* You can have better backtrace of mruby scripts with this.
Cross-Compilation
mruby can also be cross-compiled from one platform to another. To
achieve 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:
```ruby
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.
Mrbtest in Cross-Compilation
In cross compilation, you can run mrbtest on emulator if
you have it by changing configuration of test runner.
```ruby
conf.test_runner do |t|
t.command = … # set emulator. this value must be non nil or false
t.flags = … # set flags of emulator
def t.run(bin) # override run if you need to change the behavior of it
… # bin is the full path of mrbtest
end
end
```
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 compiling tools/mrbc/mrbc.c and
linking 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 compiling mrbgems/mruby-bin-mruby/tools/mruby/mruby.c and
linking with build/host/lib/libmruby.a
* create build/host/bin/mirb by compiling mrbgems/mruby-bin-mirb/tools/mirb/mirb.c and
linking 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 directory.
The cross compilation workflow starts in the same way as the normal
compilation by compiling all native libraries and binaries.
Afterwards 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-compiling mrbgems/mruby-bin-mruby/tools/mruby/mruby.c and
linking with build/i386/lib/libmruby.a
* create build/i386/bin/mirb by cross-compiling mrbgems/mruby-bin-mirb/tools/mirb/mirb.c and
linking 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-compiling tools/mrbc/mrbc.c and
linking 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 | |
| ----- ----- ----- ---- ------ ----- |
----------------------------------------------------------------
Build Configuration Examples
Minimal Library
To build a minimal mruby library you need to use the Cross Compiling feature due to the reason that there are functions (e.g. stdio) which can’t be disabled for the main build.
```ruby MRuby::CrossBuild.new(‘Minimal’) do |conf| toolchain :gcc
conf.cc.defines = %w(MRB_DISABLE_STDIO) conf.bins = [] end ```
This configuration defines a cross compile build called ‘Minimal’ which is using the GCC and compiles for the host machine. It also disables all usages of stdio and doesn’t compile any binaries (e.g. 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. You can copy this binary and run on your target system.