mruby uses Rake to compile and cross-compile all libraries and binaries.
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
orjruby
)
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)
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:
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
.
Inside of the build_config.rb the following options can be configured based on your environment.
The mruby build system already contains a set of toolchain templates which configure the build environment for specific compiler infrastructures.
Toolchain configuration for the GNU C Compiler.
toolchain :gcc
Toolchain configuration for the LLVM C Compiler clang. Mainly equal to the GCC toolchain.
toolchain :clang
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.
toolchain :visualcpp
Toolchain configuration for Android.
toolchain :android
Requires the custom standalone Android NDK and the toolchain path
in ANDROID_STANDALONE_TOOLCHAIN
.
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:
conf.gem "#{root}/mrbgems/mruby-bin-mruby"
conf.gem "#{root}/mrbgems/mruby-bin-mirb"
Some environments require a different file separator character. It is possible to
set the character via conf.file_separator
.
conf.file_separator = '/'
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
C Compiler has header searcher to detect installed library.
If you need a include path of header file use search_header_path
:
# Searches ```iconv.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
:
# Searches ```iconv.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:
def conf.cc.header_search_paths
['/opt/local/include'] + include_paths
end
Configuration of the Linker binary, flags and library paths.
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
Configuration of the Archiver binary and flags.
conf.archiver do |archiver|
archiver.command = ...
archiver.archive_options = ...
end
Configuration of the Parser Generator binary and flags.
conf.yacc do |yacc|
yacc.command = ...
yacc.compile_options = ...
end
Configuration of the GPerf binary and flags.
conf.gperf do |gperf|
gperf.command = ...
gperf.compile_options = ...
end
conf.exts do |exts|
exts.object = ...
exts.executable = ...
exts.library = ...
end
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'
See doc/mrbgems/README.md for more option about mrbgems.
Configuration Mrbtest build process.
If you want mrbtest.a only, You should set conf.build_mrbtest_lib_only
conf.build_mrbtest_lib_only
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:
conf.enable_bintest
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:
conf.enable_cxx_exception
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:
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.
To enable debugging mode add the following:
conf.enable_debug
When debugging mode is enabled
- Macro
MRB_DEBUG
would be defined.- Which means
mrb_assert()
macro is enabled.
- Which means
- Debug information of irep would be generated by
mrbc
.- Because
-g
flag would be added tomrbc
runner. - You can have better backtrace of mruby scripts with this.
- Because
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:
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
.
In cross compilation, you can run mrbtest
on emulator if
you have it by changing configuration of test runner.
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
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|
----- ----- ------ ---- ---- ----- ----- ----
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 | |
| ----- ----- ----- ---- ------ ----- |
----------------------------------------------------------------
To build a minimal mruby library you need to use the Cross Compiling feature due to the reason that there are functions (i.e. stdio) which can't be disabled for the main build.
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 (i.e. mrbc).
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.