| # Copyright 2021 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/rust.gni") |
| import("//build/rust/rust_unit_test.gni") |
| |
| # The //build directory is re-used for non-Chromium products. We do not support |
| # cxx bindings in such contexts, because //third_party may be missing. |
| if (build_with_chromium) { |
| import("//third_party/rust/cxx/chromium_integration/rust_cxx.gni") |
| } |
| |
| # Creates a Rust target (rlib, executable, proc macro etc.) with ability to |
| # understand some handy variables such as "edition" and "features" and also to |
| # build any associated unit tests. |
| # |
| # Normally, you should not use this directly. Use either |
| # - cargo_crate.gni - for 3p crates only |
| # - rust_static_library.gni - for 1p Rust code |
| # |
| # Because the common use of this is rust_static_library, all the documentation |
| # for the supported options is given in rust_static_library.gni. Please refer |
| # over there. |
| # |
| # If you're using rust_target directly, you will also need to specify: |
| # target_type executable, rust_library etc. per GN norms |
| # |
| # There is one area where this differs from `rust_static_library`: configs. |
| # Here, you must specify `executable_configs` or `library_configs` depending on |
| # the type of thing you're generating. This is so that different defaults can |
| # be provided. |
| |
| template("rust_target") { |
| _target_name = target_name |
| |
| # NOTE: TargetName=>CrateName mangling algorithm should be updated |
| # simultaneously in 3 places: here, //build/rust/rust_static_library.gni, |
| # //build/rust/chromium_prelude/import_attribute.rs |
| if (defined(invoker.crate_name)) { |
| _crate_name = invoker.crate_name |
| } else { |
| # Not using `get_label_info(..., "label_no_toolchain")` to consistently |
| # use `//foo/bar:baz` instead of the alternative shorter `//foo/bar` form. |
| _dir = get_label_info(":${_target_name}", "dir") |
| _dir = string_replace(_dir, "//", "") |
| _crate_name = "${_dir}:${_target_name}" |
| |
| # The `string_replace` calls below replicate the escaping algorithm |
| # from the `escape_non_identifier_chars` function in |
| # //build/rust/chromium_prelude/import_attribute.rs. Note that the |
| # ordering of `match` branches within the Rust function doesn't matter, |
| # but the ordering of `string_replace` calls *does* matter - the escape |
| # character `_` needs to be handled first to meet the injectivity |
| # requirement (otherwise we would get `/` => `_s` => `_us` and the same |
| # result for `_s` => `_us`). |
| _crate_name = string_replace(_crate_name, "_", "_u") |
| _crate_name = string_replace(_crate_name, "/", "_s") |
| _crate_name = string_replace(_crate_name, ":", "_c") |
| _crate_name = string_replace(_crate_name, "-", "_d") |
| } |
| _generate_crate_root = |
| defined(invoker.generate_crate_root) && invoker.generate_crate_root |
| |
| # Only one of `crate_root` or `generate_crate_root` can be specified, or |
| # neither. |
| assert(!defined(invoker.crate_root) || !_generate_crate_root) |
| |
| # This is where the OUT_DIR environment variable points to when running a |
| # build script and when compiling the build target, for consuming generated |
| # files. |
| _env_out_dir = "$target_gen_dir/$_target_name" |
| |
| _allow_unsafe = false |
| if (defined(invoker.allow_unsafe)) { |
| _allow_unsafe = invoker.allow_unsafe |
| } |
| |
| if (_generate_crate_root) { |
| generated_file("${_target_name}_crate_root") { |
| outputs = [ "${target_gen_dir}/${target_name}.rs" ] |
| contents = [ |
| "// Generated crate root for ${_target_name}.", |
| "// @generated", |
| "", |
| ] |
| foreach(rs, invoker.sources) { |
| rs_path_from_root = rebase_path(rs, target_gen_dir) |
| contents += [ "#[path = \"${rs_path_from_root}\"]" ] |
| |
| # Drop the file extension from the module name. |
| rs_modname = string_replace(rs, ".rs", "") |
| |
| # Replace invalid "/" chars in the source file path. |
| rs_modname = string_replace(rs_modname, "/", "_") |
| |
| # Since source files are specified relative to the BUILD.gn they may |
| # also have ".." path components. |
| rs_modname = string_replace(rs_modname, "..", "dotdot") |
| contents += [ |
| "mod ${rs_modname};", |
| "", |
| ] |
| } |
| } |
| _generated_crate_root = get_target_outputs(":${_target_name}_crate_root") |
| _crate_root = _generated_crate_root[0] |
| } else if (defined(invoker.crate_root)) { |
| _crate_root = invoker.crate_root |
| } else if (invoker.target_type == "executable") { |
| _crate_root = "src/main.rs" |
| } else { |
| _crate_root = "src/lib.rs" |
| } |
| |
| _testonly = false |
| if (defined(invoker.testonly)) { |
| _testonly = invoker.testonly |
| } |
| if (defined(invoker.visibility)) { |
| _visibility = invoker.visibility |
| } |
| |
| _rustflags = [] |
| if (defined(invoker.rustflags)) { |
| _rustflags += invoker.rustflags |
| } |
| if (defined(invoker.features)) { |
| foreach(i, invoker.features) { |
| _rustflags += [ "--cfg=feature=\"${i}\"" ] |
| } |
| } |
| _edition = "2021" |
| if (defined(invoker.edition)) { |
| _edition = invoker.edition |
| } |
| |
| assert(!defined(configs)) |
| _configs = [ "//build/rust:edition_${_edition}" ] |
| _test_configs = [] |
| if (invoker.target_type == "executable") { |
| _configs += invoker.executable_configs |
| } else if (invoker.target_type == "rust_proc_macro") { |
| _configs += invoker.proc_macro_configs |
| _test_configs += [ "//build/rust:proc_macro_extern" ] |
| } else if (invoker.target_type == "shared_library") { |
| _configs += invoker.shared_library_configs |
| } else { |
| _configs += invoker.library_configs |
| } |
| |
| if (invoker.target_type == "rust_proc_macro") { |
| _main_target_suffix = "__proc_macro" |
| } else if (invoker.target_type == "shared_library") { |
| _main_target_suffix = "__proc_macro" |
| } else { |
| _main_target_suffix = "" |
| } |
| |
| _deps = [] |
| if (defined(invoker.deps)) { |
| _deps += invoker.deps |
| } |
| _public_deps = [] |
| if (defined(invoker.public_deps)) { |
| _public_deps += invoker.public_deps |
| } |
| if (defined(invoker.aliased_deps)) { |
| _aliased_deps = invoker.aliased_deps |
| } else { |
| _aliased_deps = { |
| } |
| } |
| |
| _build_unit_tests = false |
| if (defined(invoker.build_native_rust_unit_tests)) { |
| _build_unit_tests = |
| invoker.build_native_rust_unit_tests && can_build_rust_unit_tests |
| } |
| |
| # Declares that the Rust crate generates bindings between C++ and Rust via the |
| # Cxx crate. It may generate C++ headers and/or use the cxx crate macros to |
| # generate Rust code internally, depending on what bindings are declared. If |
| # set, it's a set of rust files that include Cxx bindings declarations. |
| _cxx_bindings = [] |
| assert(!defined(invoker.cxx_bindings) || enable_cxx, |
| "cxx bindings are not supported when building rust targets " + |
| "outside the Chromium build.") |
| if (defined(invoker.cxx_bindings)) { |
| _cxx_bindings = invoker.cxx_bindings |
| } |
| _rustenv = [ "OUT_DIR=" + |
| rebase_path(_env_out_dir, get_path_info(_crate_root, "dir")) ] |
| if (defined(invoker.rustenv)) { |
| _rustenv += invoker.rustenv |
| } |
| |
| # We require that all source files are listed, even though this is |
| # not a requirement for rustc. The reason is to ensure that tools |
| # such as `gn deps` give the correct answer, and thus we trigger |
| # the right test suites etc. on code change. |
| # TODO(crbug.com/40200431) - verify this is correct |
| assert(defined(invoker.sources), "sources must be listed") |
| |
| if (invoker.target_type == "rust_proc_macro" && |
| !toolchain_for_rust_host_build_tools) { |
| # Redirect to the proc macro toolchain, which uses prebuilt stdlib libraries |
| # that are not built with panic=abort. |
| group(_target_name) { |
| testonly = _testonly |
| if (defined(_visibility)) { |
| visibility = _visibility |
| } |
| public_deps = |
| [ ":${_target_name}${_main_target_suffix}($rust_macro_toolchain)" ] |
| } |
| |
| not_needed(invoker, "*") |
| not_needed([ |
| "_aliased_deps", |
| "_allow_unsafe", |
| "_build_unit_tests", |
| "_crate_root", |
| "_crate_name", |
| "_cxx_bindings", |
| "_deps", |
| "_rustc_metadata", |
| "_out_dir", |
| "_public_deps", |
| "_rustenv", |
| "_rustflags", |
| "_support_use_from_cpp", |
| "_testonly", |
| ]) |
| } else { |
| # These are dependencies that must be included into the C++ target that |
| # depends on this Rust one, and into the Rust target itself, respectively. |
| # |
| # For an rlib or exe, it's enough to add all these as dependencies of the |
| # Rust target alone, and they will get included into the final link step. |
| # |
| # But when then Rust target is a shared library, the C++ target needs to |
| # link the C++ thunks that are used to call the cxx bridge functions. And |
| # Cxx library itself needs to be in both. |
| _cxx_generated_deps_for_cpp = [] |
| _cxx_generated_deps_for_rust = [] |
| if (_cxx_bindings != []) { |
| _cxx_generated_deps_for_cpp += [ |
| # The Cxx-generated thunks, which have the public C++ names and bounce |
| # over to the Rust code. |
| ":${_target_name}_cxx_generated", |
| |
| # Additionally, C++ bindings generated by Cxx can include C++ types |
| # that come from the Cxx library, such as `rust::Str`. The header and |
| # implementation of these types are provided in the cxx_cppdeps target. |
| # The C++ targets depending on this Rust target need the headers, while |
| # the Rust target needs the implementation. |
| "//build/rust:cxx_cppdeps", |
| ] |
| _cxx_generated_deps_for_rust = [ |
| # The implementation of the Cxx library needs to be in the Rust target. |
| "//build/rust:cxx_cppdeps", |
| ] |
| } |
| |
| # Proc macros and shared libraries have a group for the target name and |
| # redirect to a suffixed target for the actual library. |
| if (_main_target_suffix != "") { |
| group(_target_name) { |
| testonly = _testonly |
| if (defined(_visibility)) { |
| visibility = _visibility |
| } |
| public_deps = [ ":${_target_name}${_main_target_suffix}" ] |
| public_deps += _cxx_generated_deps_for_cpp |
| } |
| } |
| |
| _rustc_metadata = "" |
| if (defined(invoker.rustc_metadata)) { |
| _rustc_metadata = invoker.rustc_metadata |
| } |
| |
| _rust_deps = _deps |
| _rust_aliased_deps = _aliased_deps |
| _rust_public_deps = _public_deps |
| _cxx_deps = _deps |
| |
| # Include the `chromium` crate in all first-party code. Third-party code |
| # (and the `chromium` crate itself) opts out by setting |
| # `no_chromium_prelude`. |
| if (!defined(invoker.no_chromium_prelude) || !invoker.no_chromium_prelude) { |
| if (enable_chromium_prelude) { |
| _rust_deps += [ "//build/rust/chromium_prelude" ] |
| } |
| } |
| |
| if (_cxx_bindings != []) { |
| # The Rust target (and unit tests) need the Cxx crate when using it to |
| # generate bindings. |
| _rust_deps += [ "//build/rust:cxx_rustdeps" ] |
| } |
| |
| if (!defined(invoker.no_std) || !invoker.no_std) { |
| _rust_deps += [ "//build/rust/std" ] |
| } |
| |
| if (_build_unit_tests) { |
| _unit_test_target = "${_target_name}_unittests" |
| if (defined(invoker.unit_test_target)) { |
| _unit_test_target = invoker.unit_test_target |
| } |
| |
| rust_unit_test(_unit_test_target) { |
| testonly = true |
| crate_name = _unit_test_target |
| crate_root = _crate_root |
| sources = invoker.sources + [ crate_root ] |
| rustflags = _rustflags |
| env_out_dir = _env_out_dir |
| if (defined(invoker.unit_test_output_dir)) { |
| output_dir = invoker.unit_test_output_dir |
| } |
| deps = _rust_deps + _public_deps |
| aliased_deps = _rust_aliased_deps |
| public_deps = [ ":${_target_name}" ] |
| if (defined(invoker.test_deps)) { |
| deps += invoker.test_deps |
| } |
| inputs = [] |
| if (defined(invoker.inputs)) { |
| inputs += invoker.inputs |
| } |
| if (defined(invoker.test_inputs)) { |
| inputs += invoker.test_inputs |
| } |
| if (defined(invoker.executable_configs)) { |
| configs = [] |
| configs += invoker.executable_configs |
| } |
| configs += _test_configs |
| rustenv = _rustenv |
| |
| if (!_allow_unsafe) { |
| configs += [ "//build/rust:forbid_unsafe" ] |
| } |
| } |
| } else { |
| not_needed([ |
| "_crate_root", |
| "_crate_name", |
| "_rustc_metadata", |
| "_test_configs", |
| ]) |
| not_needed(invoker, [ "executable_configs" ]) |
| } |
| |
| target(invoker.target_type, "${_target_name}${_main_target_suffix}") { |
| forward_variables_from(invoker, |
| "*", |
| TESTONLY_AND_VISIBILITY + [ |
| "features", |
| "deps", |
| "aliased_deps", |
| "public_deps", |
| "rustflags", |
| "rustenv", |
| "configs", |
| "unit_test_output_dir", |
| "unit_test_target", |
| "test_inputs", |
| ]) |
| |
| if (_main_target_suffix != "") { |
| # There's a group that depends on this target, and dependencies must |
| # be through that group. |
| visibility = [ ":$_target_name" ] |
| not_needed([ "_visibility" ]) |
| } else if (defined(_visibility)) { |
| visibility = _visibility |
| } |
| |
| testonly = _testonly |
| crate_name = _crate_name |
| crate_root = _crate_root |
| configs = [] |
| configs = _configs |
| deps = _rust_deps + _cxx_generated_deps_for_rust |
| aliased_deps = _rust_aliased_deps |
| public_deps = _rust_public_deps |
| if (_main_target_suffix == "") { |
| # When these are not provided by a wrapper group target, they are added |
| # to the Rust target itself. |
| public_deps += _cxx_generated_deps_for_cpp |
| } |
| rustflags = _rustflags |
| if (_rustc_metadata != "") { |
| rustflags += [ "-Cmetadata=${_rustc_metadata}" ] |
| } |
| rustenv = _rustenv |
| |
| if (_generate_crate_root) { |
| deps += [ ":${_target_name}_crate_root" ] |
| sources += [ _crate_root ] |
| } |
| |
| if (!defined(output_name)) { |
| # Note that file names of libraries must start with the crate name in |
| # order for the compiler to find transitive dependencies in the |
| # directory search paths (since they are not all explicitly specified). |
| # |
| # For bin targets, we expect the target name to be unique, and the name |
| # of the exe should not add magic stuff to it. And bin crates can not be |
| # transitive dependencies. |
| if (invoker.target_type == "executable") { |
| output_name = _target_name |
| } else { |
| # TODO(danakj): Since the crate name includes the whole path for 1p |
| # libraries, we could move the output_dir to `root_out_dir` here for |
| # them, which would make for shorter file paths. But we need to not |
| # do the same for 3p crates or those with a `crate_name` set |
| # explicitly. |
| output_name = _crate_name |
| } |
| } |
| |
| if (!_allow_unsafe) { |
| configs += [ "//build/rust:forbid_unsafe" ] |
| } |
| } |
| |
| if (_cxx_bindings != []) { |
| rust_cxx("${_target_name}_cxx_generated") { |
| testonly = _testonly |
| visibility = [ ":${_target_name}" ] |
| if (defined(_visibility)) { |
| visibility += _visibility |
| } |
| sources = _cxx_bindings |
| deps = _cxx_deps + _public_deps |
| configs = _configs |
| |
| if (is_component_build) { |
| # In a component_build the cxx bindings may be linked into a shared |
| # library at any point up the dependency tree, so always export. |
| export_symbols = true |
| } else if (invoker.target_type == "shared_library") { |
| export_symbols = true |
| } else { |
| export_symbols = false |
| } |
| } |
| } else { |
| not_needed([ "_cxx_deps" ]) |
| } |
| } |
| } |
