# Copyright 2022 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
import("//build/config/clang/clang.gni")
import("//build/config/rust.gni")
import("//build/config/sysroot.gni")
import("//build/rust/rust_bindgen_generator.gni")
import("//build/rust/rust_static_library.gni")
if (is_win) {
import("//build/toolchain/win/win_toolchain_data.gni")
}
_bindgen_path = "${rust_bindgen_root}/bin/bindgen"
if (host_os == "win") {
_bindgen_path = "${_bindgen_path}.exe"
}
# On Windows, the libclang.dll is beside the bindgen.exe, otherwise it is in
# ../lib.
_libclang_path = rust_bindgen_root
if (!use_chromium_rust_toolchain &&
(current_cpu == "ppc64" || current_cpu == "s390x")) {
_libclang_path = rust_sysroot_absolute + "/lib64"
} else if (host_os == "win") {
_libclang_path += "/bin"
} else {
_libclang_path += "/lib"
}
# Template to build Rust/C bindings with bindgen.
#
# This template expands to a rust_static_library that exports the
# bindings generated from bindgen at the root of the library.
#
# Parameters:
#
# header:
# The .h file to generate bindings for.
#
# deps: (optional)
# C targets on which the headers depend in order to build successfully.
#
# configs: (optional)
# C compilation targets determine the correct list of -D and -I flags based
# on their dependencies and any configs applied. The same applies here. Set
# any configs here as if this were a C target.
#
# cpp: (optional)
# Use C++ mode to consume the header instead of C mode (the default).
#
# bindgen_flags: (optional)
# The additional bindgen flags which are passed to the executable. A `--` will
# be prepended to each flag. So use `bindgen_flags = [ "foo" ]` to pass
# `--foo` to bindgen.
#
# wrap_static_fns: (optional)
# If set to true, enables binding `static` and `static inline` functions in
# the header. Setting this causes the template to emit a source_set target
# named "${target_name}_static_fns", which must be incorporated into the
# build. Additionally, `get_target_outputs` will return both the Rust file and
# a generated C file, but callers can rely on the Rust file being first.
#
# crate_name: (optional)
# If set, then specified the name of the auto-generated crate, so that it
# doesn't need to be imported using `chromium::import!` macro. This should
# be used sparingly - typically only in low-level, foundational libraries
# that cannot depend on Chromium prelude (such as `//build/rust/allocator`).
#
# For a small, self-contained example please see:
# * C header: //build/rust/tests/bindgen_test
# * C++ header: //build/rust/tests/bindgen_cpp_test
template("rust_bindgen") {
_rust_bindgen_generator_target_name = target_name + "_generator"
_wrap_static_fns = false
if (defined(invoker.wrap_static_fns) && invoker.wrap_static_fns) {
_wrap_static_fns = true
}
if (defined(invoker.crate_name)) {
_crate_name = invoker.crate_name
}
rust_bindgen_generator(_rust_bindgen_generator_target_name) {
forward_variables_from(invoker,
"*",
[
"library_name",
"output_name",
] + TESTONLY_AND_VISIBILITY)
if (defined(invoker.testonly)) {
testonly = invoker.testonly
}
# This will allow the rust_static_library to depend on the
# `rust_bindgen_generator` through visibility.
library_name = target_name
# We know the library that is going to consume this rust_bindgen and we're
# sure that only a single bindgen is there. So rename the bindings to avoid
# passing envflags. envflags are usually problematic for Cronet as Soong
# does not support it (b/181221467).
#
# Because of the above, we can hard-code "bindings" name in:
# * `output_name` (below)
# * `_output_bindings_rs` (above)
# * `mod bindings;` (in `//build/rust/bindings.rs`)
output_name = "bindings"
}
# Calculate `_generated_bindings_rs`.
_bindgen_outputs = get_target_outputs(":$_rust_bindgen_generator_target_name")
_bindgen_rs_outputs = filter_include(_bindgen_outputs, [ "*.rs" ])
assert(len(_bindgen_rs_outputs) == 1)
_generated_bindings_rs = _bindgen_rs_outputs[0]
rust_static_library(target_name) {
forward_variables_from(invoker, TESTONLY_AND_VISIBILITY + [ "crate_name" ])
if (defined(_crate_name)) {
crate_name = _crate_name
}
crate_root = _generated_bindings_rs
sources = [ crate_root ]
allow_unsafe = true
deps = [ ":$_rust_bindgen_generator_target_name" ]
if (defined(invoker.deps)) {
deps += invoker.deps
}
if (_wrap_static_fns) {
# Add a dependency on the static_fns library for simplicity if
# it's declared.
deps += [ ":${_rust_bindgen_generator_target_name}_static_fns" ]
}
rustflags = [
# Don't warn about unused code in the generated bindings.
"-Adead_code",
# Don't warn about C/C++-style names.
"-Anon_snake_case",
"-Anon_camel_case_types",
"-Anon_upper_case_globals",
]
# The generated crate doesn't need these dependencies.
# And avoiding them avoids dependency cycles.
no_allocator_crate = true
no_chromium_prelude = true
no_clippy = true
}
}