build/icu/icu_rust_crates.gni

# Copyright 2023 The Fuchsia 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("config.gni")  # icu_flavors

# Apparently, defaults are set per rule name, regardless of what the rule may
# expand to.
set_defaults("icu_rust_library") {
  configs = default_common_binary_configs
}

template("icu_group") {
  foreach(icu_flavor, icu_flavors) {
    group("${target_name}.icu_${icu_flavor.name}_${icu_flavor.commit_id}") {
      forward_variables_from(invoker,
                             "*",
                             [
                               "visibility",
                               "testonly",
                               "public_deps",
                             ])
      forward_variables_from(invoker,
                             [
                               "visibility",
                               "testonly",
                             ])

      if (defined(invoker.public_deps)) {
        public_deps = []
      }
      foreach(public_dep, invoker.public_deps) {
        # Public deps for icu_group are all assumed to be ICU targets, so we can
        # just fix them up unconditionally.
        public_deps +=
            [ "${public_dep}.icu_${icu_flavor.name}_${icu_flavor.commit_id}" ]
      }
      public_deps += invoker.public_deps
      public_deps -= invoker.public_deps
    }
  }

  group(target_name) {
    forward_variables_from(invoker,
                           "*",
                           [
                             "visibility",
                             "testonly",
                           ])
    forward_variables_from(invoker,
                           [
                             "visibility",
                             "testonly",
                           ])
  }
}

# An ICU-aware rust-library, for use in //third_party/rust_crates.
template("icu_rust_library") {
  _main_target_name = target_name
  if (defined(invoker.name)) {
    _main_target_name = name
  }
  foreach(icu_flavor, icu_flavors) {
    rust_library(
        "${target_name}.icu_${icu_flavor.name}_${icu_flavor.commit_id}") {
      # The `rust_library` template uses the `crate_name` parameter to set
      # the crate name (in contrast to e.g. `rustc_library` which uses
      # `name`).
      crate_name = _main_target_name
      forward_variables_from(invoker,
                             "*",
                             [
                               "visibility",
                               "testonly",
                               "target_name",  # Workaround for
                                               # https://fxbug.dev/42083609.
                             ])
      forward_variables_from(invoker,
                             [
                               "visibility",
                               "testonly",
                             ])

      # For some reason using `.icu...` in the output names causes a compile
      # error which disappears if the same compilation is run multiple times.
      # For now, we keep `_icu_...` here.
      if (defined(output_name)) {
        output_name = "${invoker.output_name}_icu_${icu_flavor.name}_${icu_flavor.commit_id}"
      } else {
        output_name =
            "${target_name}_icu_${icu_flavor.name}_${icu_flavor.commit_id}"
      }

      # Ensure that each ICU-flavored rust artifact gets placed in a directory
      # with like rust artifacts. This ensures no crates from other flavors get
      # mixed in at link time.
      output_dir = "${target_out_dir}/icu_rust_crates_flavored_outdir." +
                   "${icu_flavor.name}_${icu_flavor.commit_id}"

      # Add the appropriate ICU rust configuration.
      configs += [ "//src/lib/icu:version" ]
      configs -= [ "//src/lib/icu:version" ]
      configs += [ "//src/lib/icu:version_${icu_flavor.name}" ]

      if (defined(deps)) {
        deps_copy = deps
        deps = []

        # ":rust_icu_*" deps are the only ones that need to be flavored.
        foreach(dep, deps_copy) {
          if (string_replace(dep, "rust_icu_", "") != dep) {
            deps += [ "${dep}.icu_${icu_flavor.name}_${icu_flavor.commit_id}" ]
          } else {
            deps += [ dep ]
          }
        }
      }
    }
  }

  rust_library(target_name) {
    forward_variables_from(invoker,
                           "*",
                           [
                             "visibility",
                             "testonly",
                           ])
    forward_variables_from(invoker,
                           [
                             "visibility",
                             "testonly",
                           ])
    output_name = invoker.output_name

    # See the comment on `output_dir` above.
    output_dir = "${target_out_dir}/icu_rust_crates_unflavored_outdir"
  }
}