Sami Kyostila | 3c88a1d | 2019-05-22 18:29:42 +0100 | [diff] [blame] | 1 | # Copyright (C) 2019 The Android Open Source Project |
| 2 | # |
| 3 | # Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | # you may not use this file except in compliance with the License. |
| 5 | # You may obtain a copy of the License at |
| 6 | # |
| 7 | # http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | # |
| 9 | # Unless required by applicable law or agreed to in writing, software |
| 10 | # distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | # See the License for the specific language governing permissions and |
| 13 | # limitations under the License. |
| 14 | |
| 15 | # A collection of utilities for extracting build rule information from GN |
| 16 | # projects. |
| 17 | |
| 18 | from __future__ import print_function |
| 19 | import errno |
| 20 | import json |
| 21 | import os |
| 22 | import re |
| 23 | import shutil |
| 24 | import subprocess |
| 25 | import sys |
| 26 | |
| 27 | |
| 28 | def _check_command_output(cmd, cwd): |
| 29 | try: |
| 30 | output = subprocess.check_output( |
| 31 | cmd, stderr=subprocess.STDOUT, cwd=cwd) |
| 32 | except subprocess.CalledProcessError as e: |
| 33 | print('Command "{}" failed in {}:'.format(' '.join(cmd), cwd), |
| 34 | file=sys.stderr) |
| 35 | print(e.output, file=sys.stderr) |
| 36 | sys.exit(1) |
| 37 | else: |
| 38 | return output |
| 39 | |
| 40 | |
| 41 | def repo_root(): |
| 42 | """Returns an absolute path to the repository root.""" |
| 43 | return os.path.join( |
| 44 | os.path.realpath(os.path.dirname(__file__)), os.path.pardir) |
| 45 | |
| 46 | |
| 47 | def _tool_path(name): |
| 48 | return os.path.join(repo_root(), 'tools', name) |
| 49 | |
| 50 | |
| 51 | def prepare_out_directory(gn_args, name, root=repo_root()): |
| 52 | """Creates the JSON build description by running GN. |
| 53 | |
| 54 | Returns (path, desc) where |path| is the location of the output directory |
| 55 | and |desc| is the JSON build description. |
| 56 | """ |
| 57 | out = os.path.join(root, 'out', name) |
| 58 | try: |
| 59 | os.makedirs(out) |
| 60 | except OSError as e: |
| 61 | if e.errno != errno.EEXIST: |
| 62 | raise |
| 63 | _check_command_output( |
| 64 | [_tool_path('gn'), 'gen', out, '--args=%s' % gn_args], cwd=repo_root()) |
| 65 | return out |
| 66 | |
| 67 | |
| 68 | def load_build_description(out): |
| 69 | """Creates the JSON build description by running GN.""" |
| 70 | desc = _check_command_output( |
| 71 | [_tool_path('gn'), 'desc', out, '--format=json', |
| 72 | '--all-toolchains', '//*'], |
| 73 | cwd=repo_root()) |
| 74 | return json.loads(desc) |
| 75 | |
| 76 | |
| 77 | def create_build_description(gn_args, root=repo_root()): |
| 78 | """Prepares a GN out directory and loads the build description from it. |
| 79 | |
| 80 | The temporary out directory is automatically deleted. |
| 81 | """ |
| 82 | out = prepare_out_directory(gn_args, 'tmp.gn_utils', root=root) |
| 83 | try: |
| 84 | return load_build_description(out) |
| 85 | finally: |
| 86 | shutil.rmtree(out) |
| 87 | |
| 88 | |
| 89 | def build_targets(out, targets): |
| 90 | """Runs ninja to build a list of GN targets in the given out directory. |
| 91 | |
| 92 | Compiling these targets is required so that we can include any generated |
| 93 | source files in the amalgamated result. |
| 94 | """ |
| 95 | targets = [t.replace('//', '') for t in targets] |
| 96 | subprocess.check_call([_tool_path('ninja')] + targets, cwd=out) |
| 97 | |
| 98 | |
| 99 | def compute_source_dependencies(out): |
| 100 | """For each source file, computes a set of headers it depends on.""" |
| 101 | ninja_deps = _check_command_output( |
| 102 | [_tool_path('ninja'), '-t', 'deps'], cwd=out) |
| 103 | deps = {} |
| 104 | current_source = None |
| 105 | for line in ninja_deps.split('\n'): |
| 106 | filename = os.path.relpath(os.path.join(out, line.strip())) |
| 107 | if not line or line[0] != ' ': |
| 108 | current_source = None |
| 109 | continue |
| 110 | elif not current_source: |
| 111 | # We're assuming the source file is always listed before the |
| 112 | # headers. |
| 113 | assert os.path.splitext(line)[1] in ['.c', '.cc', '.cpp', '.S'] |
| 114 | current_source = filename |
| 115 | deps[current_source] = [] |
| 116 | else: |
| 117 | assert current_source |
| 118 | deps[current_source].append(filename) |
| 119 | return deps |
| 120 | |
| 121 | |
| 122 | def label_to_path(label): |
| 123 | """Turn a GN output label (e.g., //some_dir/file.cc) into a path.""" |
| 124 | assert label.startswith('//') |
| 125 | return label[2:] |
| 126 | |
| 127 | |
| 128 | def label_without_toolchain(label): |
| 129 | """Strips the toolchain from a GN label. |
| 130 | |
| 131 | Return a GN label (e.g //buildtools:protobuf(//gn/standalone/toolchain: |
| 132 | gcc_like_host) without the parenthesised toolchain part. |
| 133 | """ |
| 134 | return label.split('(')[0] |
| 135 | |
| 136 | |
| 137 | def label_to_target_name_with_path(label): |
| 138 | """ |
| 139 | Turn a GN label into a target name involving the full path. |
| 140 | e.g., //src/perfetto:tests -> src_perfetto_tests |
| 141 | """ |
| 142 | name = re.sub(r'^//:?', '', label) |
| 143 | name = re.sub(r'[^a-zA-Z0-9_]', '_', name) |
| 144 | return name |