| # Copyright (C) 2019 The Android Open Source Project |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| |
| # A collection of utilities for extracting build rule information from GN |
| # projects. |
| |
| from __future__ import print_function |
| import collections |
| import errno |
| import filecmp |
| import json |
| import os |
| import re |
| import shutil |
| import subprocess |
| import sys |
| from compat import iteritems |
| |
| BUILDFLAGS_TARGET = '//gn:gen_buildflags' |
| GEN_VERSION_TARGET = '//src/base:version_gen_h' |
| TARGET_TOOLCHAIN = '//gn/standalone/toolchain:gcc_like_host' |
| HOST_TOOLCHAIN = '//gn/standalone/toolchain:gcc_like_host' |
| LINKER_UNIT_TYPES = ('executable', 'shared_library', 'static_library') |
| |
| # TODO(primiano): investigate these, they require further componentization. |
| ODR_VIOLATION_IGNORE_TARGETS = { |
| '//test/cts:perfetto_cts_deps', |
| '//:perfetto_integrationtests', |
| } |
| |
| |
| def _check_command_output(cmd, cwd): |
| try: |
| output = subprocess.check_output(cmd, stderr=subprocess.STDOUT, cwd=cwd) |
| except subprocess.CalledProcessError as e: |
| print( |
| 'Command "{}" failed in {}:'.format(' '.join(cmd), cwd), |
| file=sys.stderr) |
| print(e.output.decode(), file=sys.stderr) |
| sys.exit(1) |
| else: |
| return output.decode() |
| |
| |
| def repo_root(): |
| """Returns an absolute path to the repository root.""" |
| return os.path.join( |
| os.path.realpath(os.path.dirname(__file__)), os.path.pardir) |
| |
| |
| def _tool_path(name): |
| return os.path.join(repo_root(), 'tools', name) |
| |
| |
| def prepare_out_directory(gn_args, name, root=repo_root()): |
| """Creates the JSON build description by running GN. |
| |
| Returns (path, desc) where |path| is the location of the output directory |
| and |desc| is the JSON build description. |
| """ |
| out = os.path.join(root, 'out', name) |
| try: |
| os.makedirs(out) |
| except OSError as e: |
| if e.errno != errno.EEXIST: |
| raise |
| _check_command_output([_tool_path('gn'), 'gen', out, |
| '--args=%s' % gn_args], |
| cwd=repo_root()) |
| return out |
| |
| |
| def load_build_description(out): |
| """Creates the JSON build description by running GN.""" |
| desc = _check_command_output([ |
| _tool_path('gn'), 'desc', out, '--format=json', '--all-toolchains', '//*' |
| ], |
| cwd=repo_root()) |
| return json.loads(desc) |
| |
| |
| def create_build_description(gn_args, root=repo_root()): |
| """Prepares a GN out directory and loads the build description from it. |
| |
| The temporary out directory is automatically deleted. |
| """ |
| out = prepare_out_directory(gn_args, 'tmp.gn_utils', root=root) |
| try: |
| return load_build_description(out) |
| finally: |
| shutil.rmtree(out) |
| |
| |
| def build_targets(out, targets, quiet=False): |
| """Runs ninja to build a list of GN targets in the given out directory. |
| |
| Compiling these targets is required so that we can include any generated |
| source files in the amalgamated result. |
| """ |
| targets = [t.replace('//', '') for t in targets] |
| with open(os.devnull, 'w') as devnull: |
| stdout = devnull if quiet else None |
| subprocess.check_call( |
| [_tool_path('ninja')] + targets, cwd=out, stdout=stdout) |
| |
| |
| def compute_source_dependencies(out): |
| """For each source file, computes a set of headers it depends on.""" |
| ninja_deps = _check_command_output([_tool_path('ninja'), '-t', 'deps'], |
| cwd=out) |
| deps = {} |
| current_source = None |
| for line in ninja_deps.split('\n'): |
| filename = os.path.relpath(os.path.join(out, line.strip()), repo_root()) |
| if not line or line[0] != ' ': |
| current_source = None |
| continue |
| elif not current_source: |
| # We're assuming the source file is always listed before the |
| # headers. |
| assert os.path.splitext(line)[1] in ['.c', '.cc', '.cpp', '.S'] |
| current_source = filename |
| deps[current_source] = [] |
| else: |
| assert current_source |
| deps[current_source].append(filename) |
| return deps |
| |
| |
| def label_to_path(label): |
| """Turn a GN output label (e.g., //some_dir/file.cc) into a path.""" |
| assert label.startswith('//') |
| return label[2:] |
| |
| |
| def label_without_toolchain(label): |
| """Strips the toolchain from a GN label. |
| |
| Return a GN label (e.g //buildtools:protobuf(//gn/standalone/toolchain: |
| gcc_like_host) without the parenthesised toolchain part. |
| """ |
| return label.split('(')[0] |
| |
| |
| def label_to_target_name_with_path(label): |
| """ |
| Turn a GN label into a target name involving the full path. |
| e.g., //src/perfetto:tests -> src_perfetto_tests |
| """ |
| name = re.sub(r'^//:?', '', label) |
| name = re.sub(r'[^a-zA-Z0-9_]', '_', name) |
| return name |
| |
| |
| def gen_buildflags(gn_args, target_file): |
| """Generates the perfetto_build_flags.h for the given config. |
| |
| target_file: the path, relative to the repo root, where the generated |
| buildflag header will be copied into. |
| """ |
| tmp_out = prepare_out_directory(gn_args, 'tmp.gen_buildflags') |
| build_targets(tmp_out, [BUILDFLAGS_TARGET], quiet=True) |
| src = os.path.join(tmp_out, 'gen', 'build_config', 'perfetto_build_flags.h') |
| shutil.copy(src, os.path.join(repo_root(), target_file)) |
| shutil.rmtree(tmp_out) |
| |
| |
| def check_or_commit_generated_files(tmp_files, check): |
| """Checks that gen files are unchanged or renames them to the final location |
| |
| Takes in input a list of 'xxx.swp' files that have been written. |
| If check == False, it renames xxx.swp -> xxx. |
| If check == True, it just checks that the contents of 'xxx.swp' == 'xxx'. |
| Returns 0 if no diff was detected, 1 otherwise (to be used as exit code). |
| """ |
| res = 0 |
| for tmp_file in tmp_files: |
| assert (tmp_file.endswith('.swp')) |
| target_file = os.path.relpath(tmp_file[:-4]) |
| if check: |
| if not filecmp.cmp(tmp_file, target_file): |
| sys.stderr.write('%s needs to be regenerated\n' % target_file) |
| res = 1 |
| os.unlink(tmp_file) |
| else: |
| os.rename(tmp_file, target_file) |
| return res |
| |
| |
| class ODRChecker(object): |
| """Detects ODR violations in linker units |
| |
| When we turn GN source sets into Soong & Bazel file groups, there is the risk |
| to create ODR violations by including the same file group into different |
| linker unit (this is because other build systems don't have a concept |
| equivalent to GN's source_set). This class navigates the transitive |
| dependencies (mostly static libraries) of a target and detects if multiple |
| paths end up including the same file group. This is to avoid situations like: |
| |
| traced.exe -> base(file group) |
| traced.exe -> libperfetto(static lib) -> base(file group) |
| """ |
| |
| def __init__(self, gn, target_name): |
| self.gn = gn |
| self.root = gn.get_target(target_name) |
| self.source_sets = collections.defaultdict(set) |
| self.deps_visited = set() |
| self.source_set_hdr_only = {} |
| |
| self._visit(target_name) |
| num_violations = 0 |
| if target_name in ODR_VIOLATION_IGNORE_TARGETS: |
| return |
| for sset, paths in self.source_sets.items(): |
| if self.is_header_only(sset): |
| continue |
| if len(paths) != 1: |
| num_violations += 1 |
| print( |
| 'ODR violation in target %s, multiple paths include %s:\n %s' % |
| (target_name, sset, '\n '.join(paths)), |
| file=sys.stderr) |
| if num_violations > 0: |
| raise Exception('%d ODR violations detected. Build generation aborted' % |
| num_violations) |
| |
| def _visit(self, target_name, parent_path=''): |
| target = self.gn.get_target(target_name) |
| path = ((parent_path + ' > ') if parent_path else '') + target_name |
| if not target: |
| raise Exception('Cannot find target %s' % target_name) |
| for ssdep in target.source_set_deps: |
| name_and_path = '%s (via %s)' % (target_name, path) |
| self.source_sets[ssdep].add(name_and_path) |
| deps = set(target.deps).union(target.proto_deps) - self.deps_visited |
| for dep_name in deps: |
| dep = self.gn.get_target(dep_name) |
| if dep.type == 'executable': |
| continue # Execs are strong boundaries and don't cause ODR violations. |
| # static_library dependencies should reset the path. It doesn't matter if |
| # we get to a source file via: |
| # source_set1 > static_lib > source.cc OR |
| # source_set1 > source_set2 > static_lib > source.cc |
| # This is NOT an ODR violation because source.cc is linked from the same |
| # static library |
| next_parent_path = path if dep.type != 'static_library' else '' |
| self.deps_visited.add(dep_name) |
| self._visit(dep_name, next_parent_path) |
| |
| def is_header_only(self, source_set_name): |
| cached = self.source_set_hdr_only.get(source_set_name) |
| if cached is not None: |
| return cached |
| target = self.gn.get_target(source_set_name) |
| if target.type != 'source_set': |
| raise TypeError('%s is not a source_set' % source_set_name) |
| res = all(src.endswith('.h') for src in target.sources) |
| self.source_set_hdr_only[source_set_name] = res |
| return res |
| |
| |
| class GnParser(object): |
| """A parser with some cleverness for GN json desc files |
| |
| The main goals of this parser are: |
| 1) Deal with the fact that other build systems don't have an equivalent |
| notion to GN's source_set. Conversely to Bazel's and Soong's filegroups, |
| GN source_sets expect that dependencies, cflags and other source_set |
| properties propagate up to the linker unit (static_library, executable or |
| shared_library). This parser simulates the same behavior: when a |
| source_set is encountered, some of its variables (cflags and such) are |
| copied up to the dependent targets. This is to allow gen_xxx to create |
| one filegroup for each source_set and then squash all the other flags |
| onto the linker unit. |
| 2) Detect and special-case protobuf targets, figuring out the protoc-plugin |
| being used. |
| """ |
| |
| class Target(object): |
| """Reperesents A GN target. |
| |
| Maked properties are propagated up the dependency chain when a |
| source_set dependency is encountered. |
| """ |
| |
| def __init__(self, name, type): |
| self.name = name # e.g. //src/ipc:ipc |
| |
| VALID_TYPES = ('static_library', 'shared_library', 'executable', 'group', |
| 'action', 'source_set', 'proto_library') |
| assert (type in VALID_TYPES) |
| self.type = type |
| self.testonly = False |
| self.toolchain = None |
| |
| # These are valid only for type == proto_library. |
| # This is typically: 'proto', 'protozero', 'ipc'. |
| self.proto_plugin = None |
| self.proto_paths = set() |
| |
| self.sources = set() |
| # TODO(primiano): consider whether the public section should be part of |
| # bubbled-up sources. |
| self.public_headers = set() # 'public' |
| |
| # These are valid only for type == 'action' |
| self.inputs = set() |
| self.outputs = set() |
| self.script = None |
| self.args = [] |
| |
| # These variables are propagated up when encountering a dependency |
| # on a source_set target. |
| self.cflags = set() |
| self.defines = set() |
| self.deps = set() |
| self.libs = set() |
| self.include_dirs = set() |
| self.ldflags = set() |
| self.source_set_deps = set() # Transitive set of source_set deps. |
| self.proto_deps = set() # Transitive set of protobuf deps. |
| |
| # Deps on //gn:xxx have this flag set to True. These dependencies |
| # are special because they pull third_party code from buildtools/. |
| # We don't want to keep recursing into //buildtools in generators, |
| # this flag is used to stop the recursion and create an empty |
| # placeholder target once we hit //gn:protoc or similar. |
| self.is_third_party_dep_ = False |
| |
| def __lt__(self, other): |
| if isinstance(other, self.__class__): |
| return self.name < other.name |
| raise TypeError( |
| '\'<\' not supported between instances of \'%s\' and \'%s\'' % |
| (type(self).__name__, type(other).__name__)) |
| |
| def __repr__(self): |
| return json.dumps({ |
| k: (list(sorted(v)) if isinstance(v, set) else v) |
| for (k, v) in iteritems(self.__dict__) |
| }, |
| indent=4, |
| sort_keys=True) |
| |
| def update(self, other): |
| for key in ('cflags', 'defines', 'deps', 'include_dirs', 'ldflags', |
| 'source_set_deps', 'proto_deps', 'libs', 'proto_paths'): |
| self.__dict__[key].update(other.__dict__.get(key, [])) |
| |
| def __init__(self, gn_desc): |
| self.gn_desc_ = gn_desc |
| self.all_targets = {} |
| self.linker_units = {} # Executables, shared or static libraries. |
| self.source_sets = {} |
| self.actions = {} |
| self.proto_libs = {} |
| |
| def get_target(self, gn_target_name): |
| """Returns a Target object from the fully qualified GN target name. |
| |
| It bubbles up variables from source_set dependencies as described in the |
| class-level comments. |
| """ |
| target = self.all_targets.get(gn_target_name) |
| if target is not None: |
| return target # Target already processed. |
| |
| desc = self.gn_desc_[gn_target_name] |
| target = GnParser.Target(gn_target_name, desc['type']) |
| target.testonly = desc.get('testonly', False) |
| target.toolchain = desc.get('toolchain', None) |
| self.all_targets[gn_target_name] = target |
| |
| # We should never have GN targets directly depend on buidtools. They |
| # should hop via //gn:xxx, so we can give generators an opportunity to |
| # override them. |
| assert (not gn_target_name.startswith('//buildtools')) |
| |
| # Don't descend further into third_party targets. Genrators are supposed |
| # to either ignore them or route to other externally-provided targets. |
| if gn_target_name.startswith('//gn'): |
| target.is_third_party_dep_ = True |
| return target |
| |
| proto_target_type, proto_desc = self.get_proto_target_type_(target) |
| if proto_target_type is not None: |
| self.proto_libs[target.name] = target |
| target.type = 'proto_library' |
| target.proto_plugin = proto_target_type |
| target.proto_paths.update(self.get_proto_paths(proto_desc)) |
| target.sources.update(proto_desc.get('sources', [])) |
| assert (all(x.endswith('.proto') for x in target.sources)) |
| elif target.type == 'source_set': |
| self.source_sets[gn_target_name] = target |
| target.sources.update(desc.get('sources', [])) |
| elif target.type in LINKER_UNIT_TYPES: |
| self.linker_units[gn_target_name] = target |
| target.sources.update(desc.get('sources', [])) |
| elif target.type == 'action': |
| self.actions[gn_target_name] = target |
| target.inputs.update(desc.get('inputs', [])) |
| target.sources.update(desc.get('sources', [])) |
| outs = [re.sub('^//out/.+?/gen/', '', x) for x in desc['outputs']] |
| target.outputs.update(outs) |
| target.script = desc['script'] |
| # Args are typically relative to the root build dir (../../xxx) |
| # because root build dir is typically out/xxx/). |
| target.args = [re.sub('^../../', '//', x) for x in desc['args']] |
| |
| # Default for 'public' is //* - all headers in 'sources' are public. |
| # TODO(primiano): if a 'public' section is specified (even if empty), then |
| # the rest of 'sources' is considered inaccessible by gn. Consider |
| # emulating that, so that generated build files don't end up with overly |
| # accessible headers. |
| public_headers = [x for x in desc.get('public', []) if x != '*'] |
| target.public_headers.update(public_headers) |
| |
| target.cflags.update(desc.get('cflags', []) + desc.get('cflags_cc', [])) |
| target.libs.update(desc.get('libs', [])) |
| target.ldflags.update(desc.get('ldflags', [])) |
| target.defines.update(desc.get('defines', [])) |
| target.include_dirs.update(desc.get('include_dirs', [])) |
| |
| # Recurse in dependencies. |
| for dep_name in desc.get('deps', []): |
| dep = self.get_target(dep_name) |
| if dep.is_third_party_dep_: |
| target.deps.add(dep_name) |
| elif dep.type == 'proto_library': |
| target.proto_deps.add(dep_name) |
| target.proto_paths.update(dep.proto_paths) |
| |
| # Don't bubble deps for action targets |
| if target.type != 'action': |
| target.proto_deps.update(dep.proto_deps) # Bubble up deps. |
| elif dep.type == 'source_set': |
| target.source_set_deps.add(dep_name) |
| target.update(dep) # Bubble up source set's cflags/ldflags etc. |
| elif dep.type == 'group': |
| target.update(dep) # Bubble up groups's cflags/ldflags etc. |
| elif dep.type == 'action': |
| if proto_target_type is None: |
| target.deps.add(dep_name) |
| elif dep.type in LINKER_UNIT_TYPES: |
| target.deps.add(dep_name) |
| |
| return target |
| |
| def get_proto_paths(self, proto_desc): |
| # import_dirs in metadata will be available for source_set targets. |
| metadata = proto_desc.get('metadata', {}) |
| import_dirs = metadata.get('import_dirs', []) |
| if import_dirs: |
| return import_dirs |
| |
| # For all non-source-set targets, we need to parse the command line |
| # of the protoc invocation. |
| proto_paths = [] |
| args = proto_desc.get('args', []) |
| for i, arg in enumerate(args): |
| if arg != '--proto_path': |
| continue |
| proto_paths.append(re.sub('^../../', '//', args[i + 1])) |
| return proto_paths |
| |
| def get_proto_target_type_(self, target): |
| """ Checks if the target is a proto library and return the plugin. |
| |
| Returns: |
| (None, None): if the target is not a proto library. |
| (plugin, proto_desc) where |plugin| is 'proto' in the default (lite) |
| case or 'protozero' or 'ipc' or 'descriptor'; |proto_desc| is the GN |
| json desc of the target with the .proto sources (_gen target for |
| non-descriptor types or the target itself for descriptor type). |
| """ |
| parts = target.name.split('(', 1) |
| name = parts[0] |
| toolchain = '(' + parts[1] if len(parts) > 1 else '' |
| |
| # Descriptor targets don't have a _gen target; instead we look for the |
| # characteristic flag in the args of the target itself. |
| desc = self.gn_desc_.get(target.name) |
| if '--descriptor_set_out' in desc.get('args', []): |
| return 'descriptor', desc |
| |
| # Source set proto targets have a non-empty proto_library_sources in the |
| # metadata of the descirption. |
| metadata = desc.get('metadata', {}) |
| if 'proto_library_sources' in metadata: |
| return 'source_set', desc |
| |
| # In all other cases, we want to look at the _gen target as that has the |
| # important information. |
| gen_desc = self.gn_desc_.get('%s_gen%s' % (name, toolchain)) |
| if gen_desc is None or gen_desc['type'] != 'action': |
| return None, None |
| args = gen_desc.get('args', []) |
| if '/protoc' not in args[0]: |
| return None, None |
| plugin = 'proto' |
| for arg in (arg for arg in args if arg.startswith('--plugin=')): |
| # |arg| at this point looks like: |
| # --plugin=protoc-gen-plugin=gcc_like_host/protozero_plugin |
| # or |
| # --plugin=protoc-gen-plugin=protozero_plugin |
| plugin = arg.split('=')[-1].split('/')[-1].replace('_plugin', '') |
| return plugin, gen_desc |
