David 'Digit' Turner | 5dee3e8 | 2019-06-24 14:31:06 +0000 | [diff] [blame] | 1 | # Copyright 2019 The Dawn Authors |
| 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 | # Template to help invoking code generators based on generator_lib.py |
| 16 | # Internal use only, this should only be called from templates implementing |
| 17 | # generator-specific actions. |
| 18 | # |
| 19 | # Variables: |
| 20 | # script: Path to generator script. |
| 21 | # |
| 22 | # args: List of extra command-line arguments passed to the generator. |
| 23 | # |
| 24 | # outputs: List of expected outputs, generation will fail if there is a |
| 25 | # mistmatch. |
| 26 | # |
Corentin Wallez | a9a84df | 2019-09-19 23:30:42 +0000 | [diff] [blame] | 27 | # deps: additional deps for the code generation targets. |
| 28 | # |
David 'Digit' Turner | 5dee3e8 | 2019-06-24 14:31:06 +0000 | [diff] [blame] | 29 | # generator_lib_dir: directory where generator_lib.py is located. |
| 30 | # |
| 31 | # custom_gen_dir: Optional custom target gen dir. Defaults to $target_gen_dir |
| 32 | # but allows output files to not depend on the location of the BUILD.gn |
| 33 | # that generates them. |
| 34 | # |
| 35 | # template_dir: Optional template root directory. Defaults to |
| 36 | # "${generator_lib_dir}/templates". |
| 37 | # |
| 38 | # jinja2_path: Optional Jinja2 installation path. |
| 39 | # |
Corentin Wallez | 05623df | 2019-09-18 23:19:31 +0000 | [diff] [blame] | 40 | # allowed_output_dirs: Optional list of directories that are the only |
| 41 | # directories in which files of `outputs` are allowed to be (and not |
| 42 | # in children directories). Generation will fail if an output isn't |
| 43 | # in a directory in the list. |
| 44 | # |
David 'Digit' Turner | 5dee3e8 | 2019-06-24 14:31:06 +0000 | [diff] [blame] | 45 | # root_dir: Optional root source dir for Python dependencies |
| 46 | # computation. Defaults to "${generator_lib_dir}/..". Any dependency |
| 47 | # outside of this directory is considered a system file and will be |
| 48 | # omitted. |
| 49 | # |
| 50 | template("generator_lib_action") { |
| 51 | _generator_args = [] |
| 52 | if (defined(invoker.args)) { |
| 53 | _generator_args += invoker.args |
| 54 | } |
| 55 | |
| 56 | assert(defined(invoker.generator_lib_dir), |
| 57 | "generator_lib_dir must be defined before calling this action!") |
| 58 | |
| 59 | _template_dir = "${invoker.generator_lib_dir}/templates" |
| 60 | if (defined(invoker.template_dir)) { |
| 61 | _template_dir = invoker.template_dir |
| 62 | } |
| 63 | _generator_args += [ |
| 64 | "--template-dir", |
| 65 | rebase_path(_template_dir), |
| 66 | ] |
| 67 | |
| 68 | if (defined(invoker.root_dir)) { |
| 69 | _generator_args += [ |
| 70 | "--root-dir", |
| 71 | rebase_path(_root_dir, root_build_dir), |
| 72 | ] |
| 73 | } |
| 74 | |
| 75 | if (defined(invoker.jinja2_path)) { |
| 76 | _generator_args += [ |
| 77 | "--jinja2-path", |
| 78 | rebase_path(invoker.jinja2_path), |
| 79 | ] |
| 80 | } |
| 81 | |
| 82 | # Chooses either the default gen_dir or the custom one required by the |
| 83 | # invoker. This allows moving the definition of code generators in different |
| 84 | # BUILD.gn files without changing the location of generated file. Without |
| 85 | # this generated headers could cause issues when old headers aren't removed. |
| 86 | _gen_dir = target_gen_dir |
| 87 | if (defined(invoker.custom_gen_dir)) { |
| 88 | _gen_dir = invoker.custom_gen_dir |
| 89 | } |
| 90 | |
| 91 | # For build parallelism GN wants to know the exact inputs and outputs of |
| 92 | # action targets like we use for our code generator. We avoid asking the |
| 93 | # generator about its inputs by using the "depfile" feature of GN/Ninja. |
| 94 | # |
| 95 | # A ninja limitation is that the depfile is a subset of Makefile that can |
| 96 | # contain a single target, so we output a single "JSON-tarball" instead. |
| 97 | _json_tarball = "${_gen_dir}/${target_name}.json_tarball" |
| 98 | _json_tarball_target = "${target_name}__json_tarball" |
| 99 | _json_tarball_depfile = "${_json_tarball}.d" |
| 100 | |
| 101 | _generator_args += [ |
| 102 | "--output-json-tarball", |
| 103 | rebase_path(_json_tarball, root_build_dir), |
| 104 | "--depfile", |
| 105 | rebase_path(_json_tarball_depfile, root_build_dir), |
| 106 | ] |
| 107 | |
| 108 | # After the JSON tarball is created we need an action target to extract it |
| 109 | # with a list of its outputs. The invoker provided a list of expected |
| 110 | # outputs. To make sure the list is in sync between the generator and the |
| 111 | # build files, we write it to a file and ask the generator to assert it is |
| 112 | # correct. |
| 113 | _expected_outputs_file = "${_gen_dir}/${target_name}.expected_outputs" |
| 114 | write_file(_expected_outputs_file, invoker.outputs) |
| 115 | |
| 116 | _generator_args += [ |
| 117 | "--expected-outputs-file", |
| 118 | rebase_path(_expected_outputs_file, root_build_dir), |
| 119 | ] |
| 120 | |
Corentin Wallez | 05623df | 2019-09-18 23:19:31 +0000 | [diff] [blame] | 121 | # Check that all of the outputs are in a directory that's allowed. This is |
| 122 | # useful to keep the list of directories in sink with other parts of the |
| 123 | # build. |
| 124 | if (defined(invoker.allowed_output_dirs)) { |
| 125 | _allowed_output_dirs_file = "${_gen_dir}/${target_name}.allowed_output_dirs" |
| 126 | write_file(_allowed_output_dirs_file, invoker.allowed_output_dirs) |
| 127 | |
| 128 | _generator_args += [ |
| 129 | "--allowed-output-dirs-file", |
| 130 | rebase_path(_allowed_output_dirs_file, root_build_dir), |
| 131 | ] |
| 132 | } |
| 133 | |
David 'Digit' Turner | 5dee3e8 | 2019-06-24 14:31:06 +0000 | [diff] [blame] | 134 | # The code generator invocation that will write the JSON tarball, check the |
| 135 | # outputs are what's expected and write a depfile for Ninja. |
| 136 | action(_json_tarball_target) { |
| 137 | script = invoker.script |
Kai Ninomiya | 01aeca2 | 2020-07-15 19:51:17 +0000 | [diff] [blame] | 138 | outputs = [ _json_tarball ] |
David 'Digit' Turner | 5dee3e8 | 2019-06-24 14:31:06 +0000 | [diff] [blame] | 139 | depfile = _json_tarball_depfile |
| 140 | args = _generator_args |
Corentin Wallez | a9a84df | 2019-09-19 23:30:42 +0000 | [diff] [blame] | 141 | if (defined(invoker.deps)) { |
| 142 | deps = invoker.deps |
| 143 | } |
David 'Digit' Turner | 5dee3e8 | 2019-06-24 14:31:06 +0000 | [diff] [blame] | 144 | } |
| 145 | |
| 146 | # Extract the JSON tarball into the gen_dir |
| 147 | action(target_name) { |
| 148 | script = "${invoker.generator_lib_dir}/extract_json.py" |
| 149 | args = [ |
| 150 | rebase_path(_json_tarball, root_build_dir), |
| 151 | rebase_path(_gen_dir, root_build_dir), |
| 152 | ] |
| 153 | |
Kai Ninomiya | 01aeca2 | 2020-07-15 19:51:17 +0000 | [diff] [blame] | 154 | deps = [ ":${_json_tarball_target}" ] |
| 155 | inputs = [ _json_tarball ] |
David 'Digit' Turner | 5dee3e8 | 2019-06-24 14:31:06 +0000 | [diff] [blame] | 156 | |
| 157 | # The expected output list is relative to the gen_dir but action |
| 158 | # target outputs are from the root dir so we need to rebase them. |
| 159 | outputs = [] |
| 160 | foreach(source, invoker.outputs) { |
| 161 | outputs += [ "${_gen_dir}/${source}" ] |
| 162 | } |
| 163 | } |
| 164 | } |