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# Copyright 2014 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
# Compile a protocol buffer.
#
# Protobuf parameters:
#
# proto_in_dir (optional)
# Specifies the path relative to the current BUILD.gn file where
# proto files are located and the directory structure of
# this proto library starts.
#
# This option can be calculated automatically but it will raise an
# assertion error if any nested directories are found.
#
# proto_out_dir (optional)
# Specifies the path suffix that output files are generated under.
# This path will be appended to |root_gen_dir|, but for python stubs
# it will be appended to |root_build_dir|/pyproto.
#
# generate_python (optional, default true)
# Generate Python protobuf stubs.
#
# generate_cc (optional, default true)
# Generate C++ protobuf stubs.
#
# cc_generator_options (optional)
# List of extra flags passed to the protocol compiler. If you need to
# add an EXPORT macro to a protobuf's C++ header, set the
# 'cc_generator_options' variable with the value:
# 'dllexport_decl=FOO_EXPORT:' (note trailing colon).
#
# It is likely you also need to #include a file for the above EXPORT
# macro to work (see cc_include) and set
# component_build_force_source_set = true.
#
# cc_include (optional)
# String listing an extra include that should be passed.
# Example: cc_include = "foo/bar.h"
#
# generator_plugin_label (optional)
# GN label for plugin executable which generates custom cc stubs.
# Don't specify a toolchain, host toolchain is assumed.
#
# generator_plugin_script (optional)
# Path to plugin script. Mutually exclusive with |generator_plugin_label|.
#
# generator_plugin_script_deps (optional)
# List of additional files required for generator plugin script.
#
# generator_plugin_suffix[es] (required if using a plugin)
# Suffix (before extension) for generated .cc and .h files
# or list of suffixes for all files (with extensions).
#
# generator_plugin_options (optional)
# Extra flags passed to the plugin. See cc_generator_options.
#
# deps (optional)
# Additional dependencies.
#
# use_protobuf_full (optional)
# If adding protobuf library would be required, adds protobuf_full to deps
# instead of protobuf_lite.
#
# import_dirs (optional)
# A list of extra import directories to be passed to protoc compiler. The
# default case is just proto_in_dir.
# WARNING: This options should not be used in Chrome code until
# http://crbug.com/691451 is resolved.
#
# Parameters for compiling the generated code:
#
# component_build_force_source_set (Default=false)
# When set true the generated code will be compiled as a source set in
# the component build. This does not affect static builds. If you are
# exporting symbols from a component, this is required to prevent those
# symbols from being stripped. If you're not using dllexports in
# cc_generator_options, it's usually best to leave this false.
#
# defines (optional)
# Defines to supply to the source set that compiles the generated source
# code.
#
# extra_configs (optional)
# A list of config labels that will be appended to the configs applying
# to the source set.
#
# Example:
# proto_library("mylib") {
# sources = [
# "foo.proto",
# ]
# }
template("proto_library") {
assert(defined(invoker.sources), "Need sources for proto_library")
proto_sources = invoker.sources
# Don't apply OS-specific sources filtering to the assignments later on.
# Platform files should have gotten filtered out in the sources assignment
# when this template was invoked. If they weren't, it was on purpose and
# this template shouldn't re-apply the filter.
set_sources_assignment_filter([])
if (host_os == "win") {
host_executable_suffix = ".exe"
} else {
host_executable_suffix = ""
}
if (defined(invoker.generate_cc)) {
generate_cc = invoker.generate_cc
} else {
generate_cc = true
}
if (defined(invoker.generate_python)) {
generate_python = invoker.generate_python
} else {
generate_python = true
}
if (defined(invoker.generator_plugin_label)) {
# Straightforward way to get the name of executable doesn't work because
# |root_out_dir| and |root_build_dir| may differ in cross-compilation and
# also Windows executables have .exe at the end.
plugin_host_label = invoker.generator_plugin_label + "($host_toolchain)"
plugin_path =
get_label_info(plugin_host_label, "root_out_dir") + "/" +
get_label_info(plugin_host_label, "name") + host_executable_suffix
generate_with_plugin = true
} else if (defined(invoker.generator_plugin_script)) {
plugin_path = invoker.generator_plugin_script
generate_with_plugin = true
} else {
generate_with_plugin = false
}
if (generate_with_plugin) {
if (defined(invoker.generator_plugin_suffix)) {
generator_plugin_suffixes = [
"${invoker.generator_plugin_suffix}.h",
"${invoker.generator_plugin_suffix}.cc",
]
} else {
generator_plugin_suffixes = invoker.generator_plugin_suffixes
}
}
if (defined(invoker.proto_in_dir)) {
proto_in_dir = invoker.proto_in_dir
has_nested_dirs = false
foreach(proto_source, proto_sources) {
if (get_path_info(proto_source, "dir") != proto_in_dir) {
has_nested_dirs = true
}
}
} else {
proto_in_dir = get_path_info(proto_sources[0], "dir")
has_nested_dirs = false
# Sanity check, |proto_in_dir| should be defined to allow sub-directories.
foreach(proto_source, proto_sources) {
assert(get_path_info(proto_source, "dir") == proto_in_dir,
"Please define |proto_in_dir| to allow nested directories.")
}
}
# Avoid absolute path because of the assumption that |proto_in_dir| is
# relative to the directory of current BUILD.gn file.
proto_in_dir = rebase_path(proto_in_dir, ".")
if (defined(invoker.proto_out_dir)) {
proto_out_dir = invoker.proto_out_dir
} else {
# Absolute path to the directory of current BUILD.gn file excluding "//".
proto_out_dir = rebase_path(".", "//")
if (proto_in_dir != ".") {
proto_out_dir += "/$proto_in_dir"
}
}
# We need both absolute path to use in GN statements and a relative one
# to pass to external script.
if (generate_cc || generate_with_plugin) {
cc_out_dir = "$root_gen_dir/" + proto_out_dir
rel_cc_out_dir = rebase_path(cc_out_dir, root_build_dir)
}
if (generate_python) {
py_out_dir = "$root_out_dir/pyproto/" + proto_out_dir
rel_py_out_dir = rebase_path(py_out_dir, root_build_dir)
}
protos = rebase_path(invoker.sources, proto_in_dir)
protogens = []
# List output files.
foreach(proto, protos) {
proto_dir = get_path_info(proto, "dir")
proto_name = get_path_info(proto, "name")
proto_path = proto_dir + "/" + proto_name
if (generate_cc) {
protogens += [
"$cc_out_dir/$proto_path.pb.h",
"$cc_out_dir/$proto_path.pb.cc",
]
}
if (generate_python) {
protogens += [ "$py_out_dir/${proto_path}_pb2.py" ]
}
if (generate_with_plugin) {
foreach(suffix, generator_plugin_suffixes) {
protogens += [ "$cc_out_dir/${proto_path}${suffix}" ]
}
}
}
action_name = "${target_name}_gen"
source_set_name = target_name
# Generate protobuf stubs.
action(action_name) {
visibility = [ ":$source_set_name" ]
script = "//tools/protoc_wrapper/protoc_wrapper.py"
sources = proto_sources
outputs = get_path_info(protogens, "abspath")
args = protos
protoc_label = "//third_party/protobuf:protoc($host_toolchain)"
protoc_path = get_label_info(protoc_label, "root_out_dir") + "/protoc" +
host_executable_suffix
args += [
# Wrapper should never pick a system protoc.
# Path should be rebased because |root_build_dir| for current toolchain
# may be different from |root_out_dir| of protoc built on host toolchain.
"--protoc",
"./" + rebase_path(protoc_path, root_build_dir),
"--proto-in-dir",
rebase_path(proto_in_dir, root_build_dir),
]
if (generate_cc) {
args += [
"--cc-out-dir",
rel_cc_out_dir,
]
if (defined(invoker.cc_generator_options)) {
args += [
"--cc-options",
invoker.cc_generator_options,
]
}
if (defined(invoker.cc_include)) {
args += [
"--include",
invoker.cc_include,
]
}
}
if (generate_python) {
args += [
"--py-out-dir",
rel_py_out_dir,
]
}
if (generate_with_plugin) {
args += [
"--plugin",
rebase_path(plugin_path, root_build_dir),
"--plugin-out-dir",
rel_cc_out_dir,
]
if (defined(invoker.generator_plugin_options)) {
args += [
"--plugin-options",
invoker.generator_plugin_options,
]
}
}
if (defined(invoker.import_dirs)) {
foreach(path, invoker.import_dirs) {
args += ["--import-dir=" + rebase_path(path, root_build_dir)]
}
}
# System protoc is not used so it's necessary to build a chromium one.
inputs = [
protoc_path,
]
deps = [
protoc_label,
]
if (generate_with_plugin) {
inputs += [ plugin_path ]
if (defined(invoker.generator_plugin_script_deps)) {
# Additional scripts for plugin.
inputs += invoker.generator_plugin_script_deps
}
if (defined(plugin_host_label)) {
# Action depends on native generator plugin but for host toolchain only.
deps += [ plugin_host_label ]
}
}
if (defined(invoker.deps)) {
# The deps may have steps that have to run before running protoc.
deps += invoker.deps
}
}
# Option to disable building a library in component build.
if (defined(invoker.component_build_force_source_set) &&
invoker.component_build_force_source_set && is_component_build) {
link_target_type = "source_set"
} else {
link_target_type = "static_library"
}
# Generated files may include other generated headers. These includes always
# use relative paths starting at |cc_out_dir|.
# However there is no necessity to add an additional directory, if all protos
# are located in the same directory which is in the search path by default.
if (has_nested_dirs) {
config_name = "${target_name}_config"
config(config_name) {
include_dirs = [ cc_out_dir ]
}
}
# Build generated protobuf stubs as libary or source set.
target(link_target_type, target_name) {
forward_variables_from(invoker,
[
"defines",
"testonly",
"visibility",
])
sources = get_target_outputs(":$action_name")
if (defined(invoker.extra_configs)) {
configs += invoker.extra_configs
}
public_configs = [ "//third_party/protobuf:using_proto" ]
if (generate_cc || generate_with_plugin) {
# Not necessary if all protos are located in the same directory.
if (has_nested_dirs) {
# It's not enough to set |include_dirs| for target since public imports
# expose corresponding includes to header files as well.
public_configs += [ ":$config_name" ]
}
# If using built-in cc generator, the resulting headers reference headers
# within protobuf_lite. Hence, dependencies require those headers too.
# If using generator plugin, extra deps should be resolved by the invoker.
if (generate_cc) {
if (defined(invoker.use_protobuf_full) &&
invoker.use_protobuf_full == true) {
public_deps = [
"//third_party/protobuf:protobuf_full",
]
} else {
public_deps = [
"//third_party/protobuf:protobuf_lite",
]
}
}
}
deps = [
":$action_name",
]
# This will link any libraries in the deps (the use of invoker.deps in the
# action won't link it).
if (defined(invoker.deps)) {
deps += invoker.deps
}
}
}