blob: bdbd1c009d07254d1edfd68d0528fe29c51460f8 [file] [log] [blame]
#!/usr/bin/env python3
# Copyright 2016 The Chromium Authors
# 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.
"""
from __future__ import print_function
import functools
import json
import posixpath
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_.:+-]+$"
The ':' is only allowed for imported targets.
"""
def Escape(c):
if c in string.ascii_letters or c in string.digits or c in '_.+-':
return c
return '__'
return ''.join([Escape(c) for c in a])
def SetVariable(out, variable_name, value):
"""Sets a CMake variable."""
out.write('set("')
out.write(CMakeStringEscape(variable_name))
out.write('" "')
out.write(CMakeStringEscape(value))
out.write('")\n')
def SetVariableList(out, variable_name, values):
"""Sets a CMake variable to a list."""
if not values:
SetVariable(out, variable_name, "")
return
if len(values) == 1:
SetVariable(out, variable_name, values[0])
return
out.write('list(APPEND "')
out.write(CMakeStringEscape(variable_name))
out.write('"\n "')
out.write('"\n "'.join([CMakeStringEscape(value) for value in values]))
out.write('")\n')
def SetFilesProperty(output, variable, property_name, values, sep):
"""Given a set of source files, sets the given property on them."""
output.write('set_source_files_properties(')
WriteVariable(output, variable)
output.write(' PROPERTIES ')
output.write(property_name)
output.write(' "')
for value in values:
output.write(CMakeStringEscape(value))
output.write(sep)
output.write('")\n')
def SetCurrentTargetProperty(out, property_name, values, sep=''):
"""Given a target, sets the given property."""
out.write('set_target_properties("${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',
'.c': 'c',
'.s': 'asm',
'.S': 'asm',
'.asm': 'asm',
'.o': 'obj',
'.obj': 'obj',
}
class CMakeTargetType:
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', False),
'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)
def GetCMakeTargetName(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 Project:
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 = posixpath.join(self.root_path,
build_settings['build_dir'][2:])
self.object_source_deps = {}
def GetAbsolutePath(self, path):
if path.startswith("//"):
return self.root_path + "/" + path[2:]
return path
def GetObjectSourceDependencies(self, gn_target_name, object_dependencies):
"""All OBJECT libraries whose sources have not been absorbed."""
if gn_target_name in self.object_source_deps:
object_dependencies.update(self.object_source_deps[gn_target_name])
return
target_deps = set()
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':
target_deps.add(dependency)
if dependency_type not in gn_target_types_that_absorb_objects:
self.GetObjectSourceDependencies(dependency, target_deps)
self.object_source_deps[gn_target_name] = target_deps
object_dependencies.update(target_deps)
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)
class Target:
def __init__(self, gn_target_name, project):
self.gn_name = gn_target_name
self.properties = project.targets[self.gn_name]
self.cmake_name = 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([CMakeStringEscape(d) for d in 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([CMakeStringEscape(a) for a in 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([CMakeStringEscape(d) for d in 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(
[CMakeStringEscape(expand(a)) for a in 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):
out.write(' COMMAND ${CMAKE_COMMAND} -E copy "')
out.write(CMakeStringEscape(project.GetAbsolutePath(src)))
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', [])
if 'c' in sources and not any(k in sources for k in ('asm', 'cxx')):
flags.extend(cflags_c)
elif 'cxx' in sources and not any(k in sources for k in ('asm', 'c')):
flags.extend(cflags_cxx)
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 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':[],
'obj':[], 'obj_target':[], 'input':[], 'other':[]}
# TODO .def files on Windows
for source in target.properties.get('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 = 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 {} has unknown target type {}, skipping.'.format(
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('("${target}"')
if target.cmake_type.modifier is not None:
out.write(' ')
out.write(target.cmake_type.modifier)
for sources_type_name in sources.values():
WriteVariable(out, sources_type_name, ' ')
if synthetic_dependencies:
out.write(' DEPENDS')
for synthetic_dependencie in synthetic_dependencies:
WriteVariable(out, synthetic_dependencie, ' ')
out.write(')\n')
if target.cmake_type.command != 'add_custom_target':
WriteCompilerFlags(out, target, project, sources)
libraries = set()
nonlibraries = set()
dependencies = set(target.properties.get('deps', []))
# Transitive OBJECT libraries are in sources.
# Those sources are dependent on the OBJECT library dependencies.
# Those sources cannot bring in library dependencies.
object_dependencies = set()
if target.gn_type != 'source_set':
project.GetObjectLibraryDependencies(target.gn_name, object_dependencies)
for object_dependency in object_dependencies:
dependencies.update(project.targets.get(object_dependency).get('deps', []))
for dependency in dependencies:
gn_dependency_type = project.targets.get(dependency, {}).get('type', None)
cmake_dependency_type = cmake_target_types.get(gn_dependency_type, None)
cmake_dependency_name = GetCMakeTargetName(dependency)
if cmake_dependency_type.command != 'add_library':
nonlibraries.add(cmake_dependency_name)
elif cmake_dependency_type.modifier != 'OBJECT':
if target.cmake_type.is_linkable:
libraries.add(cmake_dependency_name)
else:
nonlibraries.add(cmake_dependency_name)
# Non-library dependencies.
if nonlibraries:
out.write('add_dependencies("${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+')
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\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 ninja -C "')
out.write(CMakeStringEscape(project.build_path))
out.write('" build.ninja)\n')
out.write('include(CMakeLists.ext)\n')
out.close()
out = open(posixpath.join(project.build_path, 'CMakeLists.ext'), '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" ${gn_deps})\n')
out.write(' configure_file(${gn_dep} "CMakeLists.devnull" COPYONLY)\n')
out.write('endforeach("gn_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>')
sys.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()