naiveproxy/src/build/rust/cargo_crate.gni
2022-05-29 18:11:59 +08:00

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# Copyright 2021 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.
import("//build/config/rust.gni")
import("//build/rust/rust_target.gni")
# This template allows for building Cargo crates within gn.
#
# It is intended for use with pre-existing (third party) code and
# is none too efficient. (It will stall the build pipeline whilst
# it runs build scripts to work out what flags are needed). First
# party code should directly use first-class gn targets, such as
# //build/rust/rust_static_library.gni or similar.
#
# Because it's intended for third-party code, it automatically
# defaults to //build/config/compiler:no_chromium_code which
# suppresses some warnings. If you *do* use this for first party
# code, you should remove that config and add the equivalent
# //build/config/compiler:chromium_code config.
#
# Arguments:
# sources
# crate_root
# epoch
# deps
# features
# build_native_rust_unit_tests
# edition
# crate_name
# All just as in rust_static_library.gni
# library_configs/executable_configs
# All just as in rust_target.gni
#
# dev_deps
# Same meaning as test_deps in rust_static_library.gni, but called
# dev_deps to match Cargo.toml better.
#
# build_root (optional)
# Filename of build.rs build script.
#
# build_deps (optional)
# Build script dependencies
#
# build_sources (optional)
# List of sources for build script. Must be specified if
# build_root is specified.
#
# build_script_outputs (optional)
# List of .rs files generated by the build script, if any.
# Fine to leave undefined even if you have a build script.
# This doesn't directly correspond to any Cargo variable,
# but unfortunately is necessary for gn to build its dependency
# trees automatically.
# Many build scripts just output --cfg directives, in which case
# no source code is generated and this can remain empty.
#
# build_script_inputs (optional)
# If the build script reads any files generated by build_deps,
# as opposed to merely linking against them, add a list of such
# files here. Again, this doesn't correspond to a Cargo variable
# but is necessary for gn.
#
# crate_type "bin", "proc-macro" or "rlib" (optional)
# Whether to build an executable. The default is "rlib".
# At present others are not supported.
#
# cargo_pkg_authors
# cargo_pkg_version
# cargo_pkg_name
# cargo_pkg_description
# Strings as found within 'version' and similar fields within Cargo.toml.
# Converted to environment variables passed to rustc, in case the crate
# uses clap `crate_version!` or `crate_authors!` macros (fairly common in
# command line tool help)
template("cargo_crate") {
orig_target_name = target_name
_crate_name = orig_target_name
if (defined(invoker.crate_name)) {
_crate_name = invoker.crate_name
}
# Executables need to have unique names. Work out a prefix.
if (defined(invoker.build_root)) {
_epochlabel = "vunknown"
if (defined(invoker.epoch)) {
_tempepoch = string_replace(invoker.epoch, ".", "_")
_epochlabel = "v${_tempepoch}"
}
build_script_name =
"${_crate_name}_${target_name}_${_epochlabel}_build_script"
}
_rustenv = []
if (defined(invoker.rustenv)) {
_rustenv = invoker.rustenv
}
if (defined(invoker.cargo_pkg_authors)) {
_rustenv += [ string_join("=",
[
"CARGO_PKG_AUTHORS",
invoker.cargo_pkg_authors,
]) ]
}
if (defined(invoker.cargo_pkg_version)) {
_rustenv += [ string_join("=",
[
"CARGO_PKG_VERSION",
invoker.cargo_pkg_version,
]) ]
}
if (defined(invoker.cargo_pkg_name)) {
_rustenv += [ string_join("=",
[
"CARGO_PKG_NAME",
invoker.cargo_pkg_name,
]) ]
}
if (defined(invoker.cargo_pkg_description)) {
_rustenv += [ string_join("=",
[
"CARGO_PKG_DESCRIPTION",
invoker.cargo_pkg_description,
]) ]
}
# The main target, either a Rust source set or an executable
rust_target(target_name) {
# Work out what we're building
crate_type = "rlib"
if (defined(invoker.crate_type)) {
crate_type = invoker.crate_type
}
if (!defined(rustflags)) {
rustflags = []
}
rustenv = _rustenv
if (crate_type == "bin") {
target_type = "executable"
assert(!defined(invoker.epoch))
} else if (crate_type == "proc-macro") {
target_type = "rust_proc_macro"
} else {
assert(crate_type == "rlib")
target_type = "rust_library"
}
if (!defined(build_native_rust_unit_tests)) {
build_native_rust_unit_tests = true
}
# We may generate multiple build rules for the same Cargo crate, as they may
# have multiple build configurations: for use from deps, build-deps or
# dev-deps. But that would try to build multiple crates with the same name,
# colliding on the libcratename.rlib outputs. So we specify an output_dir
# for Cargo crates which includes the GN target name to disambiguate them.
output_dir = "${target_out_dir}/${orig_target_name}"
# The unit tests for each target, if generated, should be unique as well,
# and needs to be unique within the name of the binary itself.
unit_test_target = "${_crate_name}_${orig_target_name}_unittests"
forward_variables_from(invoker,
"*",
[
"build_root",
"build_deps",
"build_sources",
"build_script_inputs",
"build_script_outputs",
"output_dir",
"unit_test_target",
"target_type",
"visibility",
"testonly",
"configs",
])
if (defined(invoker.build_root)) {
# Uh-oh, we have a build script
if (!defined(deps)) {
deps = []
}
if (!defined(sources)) {
sources = []
}
if (defined(invoker.dev_deps)) {
test_deps = invoker.dev_deps
}
# Re-compute the directory the build script used as its `--out-dir`. This
# logic needs to match that in `action("${build_script_name}_output")`.
_build_script_target_out_dir =
get_label_info(":${build_script_name}_output", "target_out_dir")
_build_script_out_dir = "$_build_script_target_out_dir/$orig_target_name"
# This... is a bit weird. We generate a file called cargo_flags.rs which
# does not actually contain Rust code, but instead some flags to add
# to the rustc command line. We need it to end in a .rs extension so that
# we can include it in the 'sources' line and thus have dependency
# calculation done correctly. data_deps won't work because targets don't
# require them to be present until runtime.
flags_file = "$_build_script_out_dir/cargo_flags.rs"
rustflags += [ "@" + rebase_path(flags_file, root_build_dir) ]
sources += [ flags_file ]
if (defined(invoker.build_script_outputs)) {
# Build scripts may output arbitrary files. They are usually included in
# the main Rust target using include! or include_str! and therefore the
# filename may be .rs or may be arbitrary. We want to educate ninja
# about the dependency either way.
foreach(extra_source,
filter_include(invoker.build_script_outputs, [ "*.rs" ])) {
sources += [ "$_build_script_out_dir/$extra_source" ]
}
inputs = []
foreach(extra_source,
filter_exclude(invoker.build_script_outputs, [ "*.rs" ])) {
inputs += [ "$_build_script_out_dir/$extra_source" ]
}
}
deps += [ ":${build_script_name}_output" ]
} else {
not_needed([ "orig_target_name" ])
}
}
if (defined(invoker.build_root)) {
# Extra targets required to make build script work
action("${build_script_name}_output") {
script = rebase_path("//build/rust/run_build_script.py")
build_script_target = ":${build_script_name}($host_toolchain)"
deps = [ build_script_target ]
_build_script_exe_dir =
get_label_info(build_script_target, "root_out_dir")
build_script = "$_build_script_exe_dir/${build_script_name}"
if (is_win) {
build_script = "${build_script}.exe"
}
_build_script_out_dir = "$target_out_dir/$orig_target_name"
flags_file = "$_build_script_out_dir/cargo_flags.rs"
inputs = [ build_script ]
outputs = [ flags_file ]
args = [
"--build-script",
rebase_path(build_script, root_build_dir),
"--output",
rebase_path(flags_file, root_build_dir),
"--rust-prefix",
rebase_path("${rust_sysroot}/bin"),
"--out-dir",
rebase_path(_build_script_out_dir, root_build_dir),
"--src-dir",
rebase_path(get_path_info(invoker.build_root, "dir"), root_build_dir),
]
if (defined(rust_abi_target) && rust_abi_target != "") {
args += [
"--target",
rust_abi_target,
]
}
if (defined(invoker.features)) {
args += [ "--features" ]
args += invoker.features
}
if (defined(invoker.build_script_outputs)) {
args += [ "--generated-files" ]
args += invoker.build_script_outputs
foreach(generated_file, invoker.build_script_outputs) {
outputs += [ "$_build_script_out_dir/$generated_file" ]
}
}
if (_rustenv != []) {
args += [ "--env" ]
args += _rustenv
}
if (defined(invoker.build_script_inputs)) {
inputs += invoker.build_script_inputs
}
}
if (current_toolchain == host_toolchain) {
rust_target(build_script_name) {
target_type = "executable"
sources = invoker.build_sources
crate_root = invoker.build_root
if (defined(invoker.build_deps)) {
deps = invoker.build_deps
}
forward_variables_from(invoker,
[
"features",
"edition",
"rustflags",
])
executable_configs -= [ "//build/config/compiler:chromium_code" ]
executable_configs += [ "//build/config/compiler:no_chromium_code" ]
}
} else {
not_needed(invoker,
[
"build_sources",
"build_deps",
"build_root",
"build_script_inputs",
"build_script_outputs",
])
}
}
}
set_defaults("cargo_crate") {
library_configs = default_compiler_configs
library_configs -= [ "//build/config/compiler:chromium_code" ]
library_configs += [ "//build/config/compiler:no_chromium_code" ]
executable_configs = default_executable_configs
executable_configs -= [ "//build/config/compiler:chromium_code" ]
executable_configs += [ "//build/config/compiler:no_chromium_code" ]
}