#!/usr/bin/env python # # Copyright 2016 Google Inc. # # Use of this source code is governed by a BSD-style license that can be # found in the LICENSE file. """ Usage: gn_to_cmake.py <json_file_name> gn gen out/config --ide=json --json-ide-script=../../gn/gn_to_cmake.py or gn gen out/config --ide=json python gn/gn_to_cmake.py out/config/project.json The first is recommended, as it will auto-update. """ import itertools import functools import json import posixpath import os import string import sys def CMakeStringEscape(a): """Escapes the string 'a' for use inside a CMake string. This means escaping '\' otherwise it may be seen as modifying the next character '"' otherwise it will end the string ';' otherwise the string becomes a list The following do not need to be escaped '#' when the lexer is in string state, this does not start a comment """ return a.replace('\\', '\\\\').replace(';', '\\;').replace('"', '\\"') def CMakeTargetEscape(a): """Escapes the string 'a' for use as a CMake target name. CMP0037 in CMake 3.0 restricts target names to "^[A-Za-z0-9_.:+-]+$" The ':' is only allowed for imported targets. """ def Escape(c): if c in string.ascii_letters or c in string.digits or c in '_.+-': return c else: return '__' return ''.join(map(Escape, a)) def SetVariable(out, variable_name, value): """Sets a CMake variable.""" out.write('set("') out.write(CMakeStringEscape(variable_name)) out.write('" "') out.write(CMakeStringEscape(value)) out.write('")\n') def SetVariableList(out, variable_name, values): """Sets a CMake variable to a list.""" if not values: return SetVariable(out, variable_name, "") if len(values) == 1: return SetVariable(out, variable_name, values[0]) out.write('list(APPEND "') out.write(CMakeStringEscape(variable_name)) out.write('"\n "') out.write('"\n "'.join([CMakeStringEscape(value) for value in values])) out.write('")\n') def SetFilesProperty(output, variable, property_name, values, sep): """Given a set of source files, sets the given property on them.""" output.write('set_source_files_properties(') WriteVariable(output, variable) output.write(' PROPERTIES ') output.write(property_name) output.write(' "') for value in values: output.write(CMakeStringEscape(value)) output.write(sep) output.write('")\n') def SetCurrentTargetProperty(out, property_name, values, sep=''): """Given a target, sets the given property.""" out.write('set_target_properties("${target}" PROPERTIES ') out.write(property_name) out.write(' "') for value in values: out.write(CMakeStringEscape(value)) out.write(sep) out.write('")\n') def WriteVariable(output, variable_name, prepend=None): if prepend: output.write(prepend) output.write('${') output.write(variable_name) output.write('}') # See GetSourceFileType in gn source_file_types = { '.cc': 'cxx', '.cpp': 'cxx', '.cxx': 'cxx', '.m': 'objc', '.mm': 'objcc', '.c': 'c', '.s': 'asm', '.S': 'asm', '.asm': 'asm', '.o': 'obj', '.obj': 'obj', } class CMakeTargetType(object): def __init__(self, command, modifier, property_modifier, is_linkable): self.command = command self.modifier = modifier self.property_modifier = property_modifier self.is_linkable = is_linkable CMakeTargetType.custom = CMakeTargetType('add_custom_target', 'SOURCES', None, False) # See GetStringForOutputType in gn cmake_target_types = { 'unknown': CMakeTargetType.custom, 'group': CMakeTargetType.custom, 'executable': CMakeTargetType('add_executable', None, 'RUNTIME', True), 'loadable_module': CMakeTargetType('add_library', 'MODULE', 'LIBRARY', True), 'shared_library': CMakeTargetType('add_library', 'SHARED', 'LIBRARY', True), 'static_library': CMakeTargetType('add_library', 'STATIC', 'ARCHIVE', True), 'source_set': CMakeTargetType('add_library', 'OBJECT', None, False), 'copy': CMakeTargetType.custom, 'action': CMakeTargetType.custom, 'action_foreach': CMakeTargetType.custom, 'bundle_data': CMakeTargetType.custom, 'create_bundle': CMakeTargetType.custom, } def FindFirstOf(s, a): return min(s.find(i) for i in a if i in s) class Project(object): def __init__(self, project_json): self.targets = project_json['targets'] build_settings = project_json['build_settings'] self.root_path = build_settings['root_path'] self.build_path = self.GetAbsolutePath(build_settings['build_dir']) def GetAbsolutePath(self, path): if path.startswith('//'): return posixpath.join(self.root_path, path[2:]) else: return path def GetObjectSourceDependencies(self, gn_target_name, object_dependencies): """All OBJECT libraries whose sources have not been absorbed.""" dependencies = self.targets[gn_target_name].get('deps', []) for dependency in dependencies: dependency_type = self.targets[dependency].get('type', None) if dependency_type == 'source_set': object_dependencies.add(dependency) if dependency_type not in gn_target_types_that_absorb_objects: self.GetObjectSourceDependencies(dependency, object_dependencies) def GetObjectLibraryDependencies(self, gn_target_name, object_dependencies): """All OBJECT libraries whose libraries have not been absorbed.""" dependencies = self.targets[gn_target_name].get('deps', []) for dependency in dependencies: dependency_type = self.targets[dependency].get('type', None) if dependency_type == 'source_set': object_dependencies.add(dependency) self.GetObjectLibraryDependencies(dependency, object_dependencies) def GetCMakeTargetName(self, gn_target_name): # See <chromium>/src/tools/gn/label.cc#Resolve # //base/test:test_support(//build/toolchain/win:msvc) path_separator = FindFirstOf(gn_target_name, (':', '(')) location = None name = None toolchain = None if not path_separator: location = gn_target_name[2:] else: location = gn_target_name[2:path_separator] toolchain_separator = gn_target_name.find('(', path_separator) if toolchain_separator == -1: name = gn_target_name[path_separator + 1:] else: if toolchain_separator > path_separator: name = gn_target_name[path_separator + 1:toolchain_separator] assert gn_target_name.endswith(')') toolchain = gn_target_name[toolchain_separator + 1:-1] assert location or name cmake_target_name = None if location.endswith('/' + name): cmake_target_name = location elif location: cmake_target_name = location + '_' + name else: cmake_target_name = name if toolchain: cmake_target_name += '--' + toolchain return CMakeTargetEscape(cmake_target_name) class Target(object): def __init__(self, gn_target_name, project): self.gn_name = gn_target_name self.properties = project.targets[self.gn_name] self.cmake_name = project.GetCMakeTargetName(self.gn_name) self.gn_type = self.properties.get('type', None) self.cmake_type = cmake_target_types.get(self.gn_type, None) def WriteAction(out, target, project, sources, synthetic_dependencies): outputs = [] output_directories = set() for output in target.properties.get('outputs', []): output_abs_path = project.GetAbsolutePath(output) outputs.append(output_abs_path) output_directory = posixpath.dirname(output_abs_path) if output_directory: output_directories.add(output_directory) outputs_name = '${target}__output' SetVariableList(out, outputs_name, outputs) out.write('add_custom_command(OUTPUT ') WriteVariable(out, outputs_name) out.write('\n') if output_directories: out.write(' COMMAND ${CMAKE_COMMAND} -E make_directory "') out.write('" "'.join(map(CMakeStringEscape, output_directories))) out.write('"\n') script = target.properties['script'] arguments = target.properties['args'] out.write(' COMMAND python "') out.write(CMakeStringEscape(project.GetAbsolutePath(script))) out.write('"') if arguments: out.write('\n "') out.write('"\n "'.join(map(CMakeStringEscape, arguments))) out.write('"') out.write('\n') out.write(' DEPENDS ') for sources_type_name in sources.values(): WriteVariable(out, sources_type_name, ' ') out.write('\n') #TODO: CMake 3.7 is introducing DEPFILE out.write(' WORKING_DIRECTORY "') out.write(CMakeStringEscape(project.build_path)) out.write('"\n') out.write(' COMMENT "Action: ${target}"\n') out.write(' VERBATIM)\n') synthetic_dependencies.add(outputs_name) def ExpandPlaceholders(source, a): source_dir, source_file_part = posixpath.split(source) source_name_part, _ = posixpath.splitext(source_file_part) #TODO: {{source_gen_dir}}, {{source_out_dir}}, {{response_file_name}} return a.replace('{{source}}', source) \ .replace('{{source_file_part}}', source_file_part) \ .replace('{{source_name_part}}', source_name_part) \ .replace('{{source_dir}}', source_dir) \ .replace('{{source_root_relative_dir}}', source_dir) def WriteActionForEach(out, target, project, sources, synthetic_dependencies): all_outputs = target.properties.get('outputs', []) inputs = target.properties.get('sources', []) # TODO: consider expanding 'output_patterns' instead. outputs_per_input = len(all_outputs) / len(inputs) for count, source in enumerate(inputs): source_abs_path = project.GetAbsolutePath(source) outputs = [] output_directories = set() for output in all_outputs[outputs_per_input * count: outputs_per_input * (count+1)]: output_abs_path = project.GetAbsolutePath(output) outputs.append(output_abs_path) output_directory = posixpath.dirname(output_abs_path) if output_directory: output_directories.add(output_directory) outputs_name = '${target}__output_' + str(count) SetVariableList(out, outputs_name, outputs) out.write('add_custom_command(OUTPUT ') WriteVariable(out, outputs_name) out.write('\n') if output_directories: out.write(' COMMAND ${CMAKE_COMMAND} -E make_directory "') out.write('" "'.join(map(CMakeStringEscape, output_directories))) out.write('"\n') script = target.properties['script'] # TODO: need to expand {{xxx}} in arguments arguments = target.properties['args'] out.write(' COMMAND python "') out.write(CMakeStringEscape(project.GetAbsolutePath(script))) out.write('"') if arguments: out.write('\n "') expand = functools.partial(ExpandPlaceholders, source_abs_path) out.write('"\n "'.join(map(CMakeStringEscape, map(expand,arguments)))) out.write('"') out.write('\n') out.write(' DEPENDS') if 'input' in sources: WriteVariable(out, sources['input'], ' ') out.write(' "') out.write(CMakeStringEscape(source_abs_path)) out.write('"\n') #TODO: CMake 3.7 is introducing DEPFILE out.write(' WORKING_DIRECTORY "') out.write(CMakeStringEscape(project.build_path)) out.write('"\n') out.write(' COMMENT "Action ${target} on ') out.write(CMakeStringEscape(source_abs_path)) out.write('"\n') out.write(' VERBATIM)\n') synthetic_dependencies.add(outputs_name) def WriteCopy(out, target, project, sources, synthetic_dependencies): inputs = target.properties.get('sources', []) raw_outputs = target.properties.get('outputs', []) # TODO: consider expanding 'output_patterns' instead. outputs = [] for output in raw_outputs: output_abs_path = project.GetAbsolutePath(output) outputs.append(output_abs_path) outputs_name = '${target}__output' SetVariableList(out, outputs_name, outputs) out.write('add_custom_command(OUTPUT ') WriteVariable(out, outputs_name) out.write('\n') for src, dst in zip(inputs, outputs): abs_src_path = CMakeStringEscape(project.GetAbsolutePath(src)) # CMake distinguishes between copying files and copying directories but # gn does not. We assume if the src has a period in its name then it is # a file and otherwise a directory. if "." in os.path.basename(abs_src_path): out.write(' COMMAND ${CMAKE_COMMAND} -E copy "') else: out.write(' COMMAND ${CMAKE_COMMAND} -E copy_directory "') out.write(abs_src_path) out.write('" "') out.write(CMakeStringEscape(dst)) out.write('"\n') out.write(' DEPENDS ') for sources_type_name in sources.values(): WriteVariable(out, sources_type_name, ' ') out.write('\n') out.write(' WORKING_DIRECTORY "') out.write(CMakeStringEscape(project.build_path)) out.write('"\n') out.write(' COMMENT "Copy ${target}"\n') out.write(' VERBATIM)\n') synthetic_dependencies.add(outputs_name) def WriteCompilerFlags(out, target, project, sources): # Hack, set linker language to c if no c or cxx files present. if not 'c' in sources and not 'cxx' in sources: SetCurrentTargetProperty(out, 'LINKER_LANGUAGE', ['C']) # Mark uncompiled sources as uncompiled. if 'input' in sources: SetFilesProperty(out, sources['input'], 'HEADER_FILE_ONLY', ('True',), '') if 'other' in sources: SetFilesProperty(out, sources['other'], 'HEADER_FILE_ONLY', ('True',), '') # Mark object sources as linkable. if 'obj' in sources: SetFilesProperty(out, sources['obj'], 'EXTERNAL_OBJECT', ('True',), '') # TODO: 'output_name', 'output_dir', 'output_extension' # This includes using 'source_outputs' to direct compiler output. # Includes includes = target.properties.get('include_dirs', []) if includes: out.write('set_property(TARGET "${target}" ') out.write('APPEND PROPERTY INCLUDE_DIRECTORIES') for include_dir in includes: out.write('\n "') out.write(project.GetAbsolutePath(include_dir)) out.write('"') out.write(')\n') # Defines defines = target.properties.get('defines', []) if defines: SetCurrentTargetProperty(out, 'COMPILE_DEFINITIONS', defines, ';') # Compile flags # "arflags", "asmflags", "cflags", # "cflags_c", "clfags_cc", "cflags_objc", "clfags_objcc" # CMake does not have per target lang compile flags. # TODO: $<$<COMPILE_LANGUAGE:CXX>:cflags_cc style generator expression. # http://public.kitware.com/Bug/view.php?id=14857 flags = [] flags.extend(target.properties.get('cflags', [])) cflags_asm = target.properties.get('asmflags', []) cflags_c = target.properties.get('cflags_c', []) cflags_cxx = target.properties.get('cflags_cc', []) cflags_objc = cflags_c[:] cflags_objc.extend(target.properties.get('cflags_objc', [])) cflags_objcc = cflags_cxx[:] cflags_objcc.extend(target.properties.get('cflags_objcc', [])) if 'c' in sources and not any(k in sources for k in ('asm', 'cxx', 'objc', 'objcc')): flags.extend(cflags_c) elif 'cxx' in sources and not any(k in sources for k in ('asm', 'c', 'objc', 'objcc')): flags.extend(cflags_cxx) elif 'objc' in sources and not any(k in sources for k in ('asm', 'c', 'cxx', 'objcc')): flags.extend(cflags_objc) elif 'objcc' in sources and not any(k in sources for k in ('asm', 'c', 'cxx', 'objc')): flags.extend(cflags_objcc) else: # TODO: This is broken, one cannot generally set properties on files, # as other targets may require different properties on the same files. if 'asm' in sources and cflags_asm: SetFilesProperty(out, sources['asm'], 'COMPILE_FLAGS', cflags_asm, ' ') if 'c' in sources and cflags_c: SetFilesProperty(out, sources['c'], 'COMPILE_FLAGS', cflags_c, ' ') if 'cxx' in sources and cflags_cxx: SetFilesProperty(out, sources['cxx'], 'COMPILE_FLAGS', cflags_cxx, ' ') if 'objc' in sources and cflags_objc: SetFilesProperty(out, sources['objc'], 'COMPILE_FLAGS', cflags_objc, ' ') if 'objcc' in sources and cflags_objcc: SetFilesProperty(out, sources['objcc'], 'COMPILE_FLAGS', cflags_objcc, ' ') if flags: SetCurrentTargetProperty(out, 'COMPILE_FLAGS', flags, ' ') # Linker flags ldflags = target.properties.get('ldflags', []) if ldflags: SetCurrentTargetProperty(out, 'LINK_FLAGS', ldflags, ' ') gn_target_types_that_absorb_objects = ( 'executable', 'loadable_module', 'shared_library', 'static_library' ) def WriteSourceVariables(out, target, project): # gn separates the sheep from the goats based on file extensions. # A full separation is done here because of flag handing (see Compile flags). source_types = {'cxx':[], 'c':[], 'asm':[], 'objc':[], 'objcc':[], 'obj':[], 'obj_target':[], 'input':[], 'other':[]} all_sources = target.properties.get('sources', []) # As of cmake 3.11 add_library must have sources. If there are # no sources, add empty.cpp as the file to compile. if len(all_sources) == 0: all_sources.append(posixpath.join(project.build_path, 'empty.cpp')) # TODO .def files on Windows for source in all_sources: _, ext = posixpath.splitext(source) source_abs_path = project.GetAbsolutePath(source) source_types[source_file_types.get(ext, 'other')].append(source_abs_path) for input_path in target.properties.get('inputs', []): input_abs_path = project.GetAbsolutePath(input_path) source_types['input'].append(input_abs_path) # OBJECT library dependencies need to be listed as sources. # Only executables and non-OBJECT libraries may reference an OBJECT library. # https://gitlab.kitware.com/cmake/cmake/issues/14778 if target.gn_type in gn_target_types_that_absorb_objects: object_dependencies = set() project.GetObjectSourceDependencies(target.gn_name, object_dependencies) for dependency in object_dependencies: cmake_dependency_name = project.GetCMakeTargetName(dependency) obj_target_sources = '$<TARGET_OBJECTS:' + cmake_dependency_name + '>' source_types['obj_target'].append(obj_target_sources) sources = {} for source_type, sources_of_type in source_types.items(): if sources_of_type: sources[source_type] = '${target}__' + source_type + '_srcs' SetVariableList(out, sources[source_type], sources_of_type) return sources def WriteTarget(out, target, project): out.write('\n#') out.write(target.gn_name) out.write('\n') if target.cmake_type is None: print ('Target %s has unknown target type %s, skipping.' % ( target.gn_name, target.gn_type ) ) return SetVariable(out, 'target', target.cmake_name) sources = WriteSourceVariables(out, target, project) synthetic_dependencies = set() if target.gn_type == 'action': WriteAction(out, target, project, sources, synthetic_dependencies) if target.gn_type == 'action_foreach': WriteActionForEach(out, target, project, sources, synthetic_dependencies) if target.gn_type == 'copy': WriteCopy(out, target, project, sources, synthetic_dependencies) out.write(target.cmake_type.command) out.write('("${target}"') if target.cmake_type.modifier is not None: out.write(' ') out.write(target.cmake_type.modifier) for sources_type_name in sources.values(): WriteVariable(out, sources_type_name, ' ') if synthetic_dependencies: out.write(' DEPENDS') for synthetic_dependencie in synthetic_dependencies: WriteVariable(out, synthetic_dependencie, ' ') out.write(')\n') if target.cmake_type.command != 'add_custom_target': WriteCompilerFlags(out, target, project, sources) libraries = set() nonlibraries = set() dependencies = set(target.properties.get('deps', [])) # Transitive OBJECT libraries are in sources. # Those sources are dependent on the OBJECT library dependencies. # Those sources cannot bring in library dependencies. object_dependencies = set() if target.gn_type != 'source_set': project.GetObjectLibraryDependencies(target.gn_name, object_dependencies) for object_dependency in object_dependencies: dependencies.update(project.targets.get(object_dependency).get('deps', [])) for dependency in dependencies: gn_dependency_type = project.targets.get(dependency, {}).get('type', None) cmake_dependency_type = cmake_target_types.get(gn_dependency_type, None) cmake_dependency_name = project.GetCMakeTargetName(dependency) if cmake_dependency_type.command != 'add_library': nonlibraries.add(cmake_dependency_name) elif cmake_dependency_type.modifier != 'OBJECT': if target.cmake_type.is_linkable: libraries.add(cmake_dependency_name) else: nonlibraries.add(cmake_dependency_name) # Non-library dependencies. if nonlibraries: out.write('add_dependencies("${target}"') for nonlibrary in nonlibraries: out.write('\n "') out.write(nonlibrary) out.write('"') out.write(')\n') # Non-OBJECT library dependencies. external_libraries = target.properties.get('libs', []) if target.cmake_type.is_linkable and (external_libraries or libraries): library_dirs = target.properties.get('lib_dirs', []) if library_dirs: SetVariableList(out, '${target}__library_directories', library_dirs) system_libraries = [] for external_library in external_libraries: if '/' in external_library: libraries.add(project.GetAbsolutePath(external_library)) else: if external_library.endswith('.framework'): external_library = external_library[:-len('.framework')] system_library = 'library__' + external_library if library_dirs: system_library = system_library + '__for_${target}' out.write('find_library("') out.write(CMakeStringEscape(system_library)) out.write('" "') out.write(CMakeStringEscape(external_library)) out.write('"') if library_dirs: out.write(' PATHS "') WriteVariable(out, '${target}__library_directories') out.write('"') out.write(')\n') system_libraries.append(system_library) out.write('target_link_libraries("${target}"') for library in libraries: out.write('\n "') out.write(CMakeStringEscape(library)) out.write('"') for system_library in system_libraries: WriteVariable(out, system_library, '\n "') out.write('"') out.write(')\n') def WriteProject(project): out = open(posixpath.join(project.build_path, 'CMakeLists.txt'), 'w+') extName = posixpath.join(project.build_path, 'CMakeLists.ext') out.write('# Generated by gn_to_cmake.py.\n') out.write('cmake_minimum_required(VERSION 2.8.8 FATAL_ERROR)\n') out.write('cmake_policy(VERSION 2.8.8)\n') out.write('project(Skia)\n\n') out.write('file(WRITE "') out.write(CMakeStringEscape(posixpath.join(project.build_path, "empty.cpp"))) out.write('")\n') # Update the gn generated ninja build. # If a build file has changed, this will update CMakeLists.ext if # gn gen out/config --ide=json --json-ide-script=../../gn/gn_to_cmake.py # style was used to create this config. out.write('execute_process(COMMAND\n') out.write(' ninja -C "') out.write(CMakeStringEscape(project.build_path)) out.write('" build.ninja\n') out.write(' RESULT_VARIABLE ninja_result)\n') out.write('if (ninja_result)\n') out.write(' message(WARNING ') out.write('"Regeneration failed running ninja: ${ninja_result}")\n') out.write('endif()\n') out.write('include("') out.write(CMakeStringEscape(extName)) out.write('")\n') out.close() out = open(extName, 'w+') out.write('# Generated by gn_to_cmake.py.\n') out.write('cmake_minimum_required(VERSION 2.8.8 FATAL_ERROR)\n') out.write('cmake_policy(VERSION 2.8.8)\n') # The following appears to be as-yet undocumented. # http://public.kitware.com/Bug/view.php?id=8392 out.write('enable_language(ASM)\n\n') # ASM-ATT does not support .S files. # output.write('enable_language(ASM-ATT)\n') # Current issues with automatic re-generation: # The gn generated build.ninja target uses build.ninja.d # but build.ninja.d does not contain the ide or gn. # Currently the ide is not run if the project.json file is not changed # but the ide needs to be run anyway if it has itself changed. # This can be worked around by deleting the project.json file. out.write('file(READ "') gn_deps_file = posixpath.join(project.build_path, 'build.ninja.d') out.write(CMakeStringEscape(gn_deps_file)) out.write('" "gn_deps_string" OFFSET ') out.write(str(len('build.ninja: '))) out.write(')\n') # One would think this would need to worry about escaped spaces # but gn doesn't escape spaces here (it generates invalid .d files). out.write('string(REPLACE " " ";" "gn_deps" ${gn_deps_string})\n') out.write('foreach("gn_dep" ${gn_deps})\n') out.write(' configure_file("') out.write(CMakeStringEscape(project.build_path)) out.write('${gn_dep}" "CMakeLists.devnull" COPYONLY)\n') out.write('endforeach("gn_dep")\n') out.write('list(APPEND other_deps "') out.write(CMakeStringEscape(os.path.abspath(__file__))) out.write('")\n') out.write('foreach("other_dep" ${other_deps})\n') out.write(' configure_file("${other_dep}" "CMakeLists.devnull" COPYONLY)\n') out.write('endforeach("other_dep")\n') for target_name in project.targets.keys(): out.write('\n') WriteTarget(out, Target(target_name, project), project) def main(): if len(sys.argv) != 2: print('Usage: ' + sys.argv[0] + ' <json_file_name>') exit(1) json_path = sys.argv[1] project = None with open(json_path, 'r') as json_file: project = json.loads(json_file.read()) WriteProject(Project(project)) if __name__ == "__main__": main()