class Gem::Ext::CmakeBuilder
This builder creates extensions defined using CMake. Its is invoked if a Gem’s spec file sets the ‘extension` property to a string that contains `CMakeLists.txt`.
In general, CMake projects are built in two steps:
* configure* build
The builder follow this convention. First it runs a configuration step and then it runs a build step.
CMake projects can be quite configurable - it is likely you will want to specify options when installing a gem. To pass options to CMake specify them after ‘–` in the gem install command. For example:
gem install <gem_name> -- --preset <preset_name>
Note that options are ONLY sent to the configure step - it is not currently possible to specify options for the build step. If this becomes and issue then the CMake builder can be updated to support build options.
Useful options to know are:
-G to specify a generator (-G Ninja is recommended)-D<CMAKE_VARIABLE> to set a CMake variable (for example -DCMAKE_BUILD_TYPE=Release)--preset <preset_name> to use a preset
If theGem author provides presets, via CMakePresets.json file, you will likely want to use one of them. If not, you may wish to specify a generator. Ninja is recommended because it can build projects in parallel and thus much faster than building them serially like Make does.
Attributes
Public Class Methods
Source
# File lib/rubygems/ext/cmake_builder.rb, line 34definitialize@runner =self.class.method(:run)@profile =:releaseend
Public Instance Methods
Source
# File lib/rubygems/ext/cmake_builder.rb, line 39defbuild(extension,dest_path,results,args = [],lib_dir =nil,cmake_dir =Dir.pwd,target_rbconfig =Gem.target_rbconfig)iftarget_rbconfig.pathwarn"--target-rbconfig is not yet supported for CMake extensions. Ignoring"end# Figure the build dirbuild_dir =File.join(cmake_dir,"build")# Check if the gem defined presetscheck_presets(cmake_dir,args,results)# Configureconfigure(cmake_dir,build_dir,dest_path,args,results)# Compilecompile(cmake_dir,build_dir,args,results)resultsend
Source
# File lib/rubygems/ext/cmake_builder.rb, line 73defcompile(cmake_dir,build_dir,args,results)cmd = ["cmake","--build",build_dir.to_s,"--config",@profile.to_s]runner.call(cmd,results,"cmake_compile",cmake_dir)end
Source
# File lib/rubygems/ext/cmake_builder.rb, line 60defconfigure(cmake_dir,build_dir,install_dir,args,results)cmd = ["cmake",cmake_dir,"-B",build_dir,"-DCMAKE_RUNTIME_OUTPUT_DIRECTORY=#{install_dir}",# Windows"-DCMAKE_LIBRARY_OUTPUT_DIRECTORY=#{install_dir}",# Not Windows*Gem::Command.build_args,*args]runner.call(cmd,results,"cmake_configure",cmake_dir)end
Private Instance Methods
Source
# File lib/rubygems/ext/cmake_builder.rb, line 85defcheck_presets(cmake_dir,args,results)# Return if the user specified a presetreturnunlessargs.grep(/--preset/i).empty?cmd = ["cmake","--list-presets"]presets =Array.newbeginrunner.call(cmd,presets,"cmake_presets",cmake_dir)# Remove the first two lines of the array which is the current_directory and the command# that was runpresets =presets[2..].joinresults<<<<~EOS The gem author provided a list of presets that can be used to build the gem. To use a preset specify it on the command line: gem install <gem_name> -- --preset <preset_name> #{presets} EOSrescueGem::InstallError# Do nothing, CMakePresets.json was not included in the Gemendend