137 lines
4.7 KiB
Plaintext
137 lines
4.7 KiB
Plaintext
# Copyright 2019 The Dawn Authors
|
|
#
|
|
# 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.
|
|
|
|
import("../scripts/dawn_overrides_with_defaults.gni")
|
|
|
|
###############################################################################
|
|
# Template to wrap the Dawn code generator
|
|
###############################################################################
|
|
|
|
# Template to help with invocation of the Dawn code generator, looks like this:
|
|
#
|
|
# dawn_generator("my_target_gen") {
|
|
# # Which generator target to output
|
|
# target = "my_target"
|
|
# # The list of expected outputs, generation fails if there's a mismatch
|
|
# outputs = [
|
|
# "MyTarget.cpp",
|
|
# "MyTarget.h",
|
|
# ]
|
|
#
|
|
# # Optional, use a custom generated file directory.
|
|
# custom_gen_dir = "${target_gen_dir}/.."
|
|
# }
|
|
#
|
|
# Using the generated files is done like so:
|
|
#
|
|
# shared_library("my_target") {
|
|
# deps = [ ":my_target_gen "]
|
|
# sources = get_target_outputs(":my_target_gen")
|
|
# }
|
|
#
|
|
template("dawn_generator") {
|
|
# The base arguments for the generator: from this dawn.json, generate this
|
|
# target using templates in this directory.
|
|
generator_args = [
|
|
"--dawn-json",
|
|
rebase_path("${dawn_root}/dawn.json", root_build_dir),
|
|
"--wire-json",
|
|
rebase_path("${dawn_root}/dawn_wire.json", root_build_dir),
|
|
"--template-dir",
|
|
rebase_path("${dawn_root}/generator/templates", root_build_dir),
|
|
"--targets",
|
|
invoker.target,
|
|
]
|
|
|
|
# Use the Jinja2 version pulled from the DEPS file. We do it so we don't
|
|
# have version problems, and users don't have to install Jinja2.
|
|
jinja2_python_path = rebase_path("${dawn_jinja2_dir}/..")
|
|
generator_args += [
|
|
"--extra-python-path",
|
|
jinja2_python_path,
|
|
]
|
|
|
|
# Chooses either the default gen_dir or the custom one required by the
|
|
# invoker. This allows moving the definition of code generators in different
|
|
# BUILD.gn files without changing the location of generated file. Without
|
|
# this generated headers could cause issues when old headers aren't removed.
|
|
gen_dir = target_gen_dir
|
|
if (defined(invoker.custom_gen_dir)) {
|
|
gen_dir = invoker.custom_gen_dir
|
|
}
|
|
|
|
# For build parallelism GN wants to know the exact inputs and outputs of
|
|
# action targets like we use for our code generator. We avoid asking the
|
|
# generator about its inputs by using the "depfile" feature of GN/Ninja.
|
|
#
|
|
# A ninja limitation is that the depfile is a subset of Makefile that can
|
|
# contain a single target, so we output a single "JSON-tarball" instead.
|
|
json_tarball = "${gen_dir}/${target_name}.json_tarball"
|
|
json_tarball_depfile = "${json_tarball}.d"
|
|
|
|
generator_args += [
|
|
"--output-json-tarball",
|
|
rebase_path(json_tarball, root_build_dir),
|
|
"--depfile",
|
|
rebase_path(json_tarball_depfile, root_build_dir),
|
|
]
|
|
|
|
# After the JSON tarball is created we need an action target to extract it
|
|
# with a list of its outputs. The invoker provided a list of expected
|
|
# outputs. To make sure the list is in sync between the generator and the
|
|
# build files, we write it to a file and ask the generator to assert it is
|
|
# correct.
|
|
expected_outputs_file = "${gen_dir}/${target_name}.expected_outputs"
|
|
write_file(expected_outputs_file, invoker.outputs)
|
|
|
|
generator_args += [
|
|
"--expected-outputs-file",
|
|
rebase_path(expected_outputs_file, root_build_dir),
|
|
]
|
|
|
|
# The code generator invocation that will write the JSON tarball, check the
|
|
# outputs are what's expected and write a depfile for Ninja.
|
|
action("${target_name}_json_tarball") {
|
|
script = "${dawn_root}/generator/main.py"
|
|
outputs = [
|
|
json_tarball,
|
|
]
|
|
depfile = json_tarball_depfile
|
|
args = generator_args
|
|
}
|
|
|
|
# Extract the JSON tarball into the gen_dir
|
|
action("${target_name}") {
|
|
script = "${dawn_root}/generator/extract_json.py"
|
|
args = [
|
|
rebase_path(json_tarball, root_build_dir),
|
|
rebase_path(gen_dir, root_build_dir),
|
|
]
|
|
|
|
deps = [
|
|
":${target_name}_json_tarball",
|
|
]
|
|
inputs = [
|
|
json_tarball,
|
|
]
|
|
|
|
# The expected output list is relative to the gen_dir but action
|
|
# target outputs are from the root dir so we need to rebase them.
|
|
outputs = []
|
|
foreach(source, invoker.outputs) {
|
|
outputs += [ "${gen_dir}/${source}" ]
|
|
}
|
|
}
|
|
}
|