build/icu/icu_source_set.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, icu_fixup_deps

# An ICU-aware source_set.
#
# Args:
#
#   - icu_deps: list(label): the target labels that need to be fixed up for
#     ICU product assembly.  Otherwise the same as deps.
#   - icu_public_deps: list(label): Same as above, but for public_deps
#
# All other args are forwarded verbatim from the invoker.
template("icu_source_set") {
  foreach(icu_flavor, icu_flavors) {
    # While we could make do with shorter target labels, we're using a per-ICU
    # commit ID so that we could possibly use targets from different builds.
    source_set(
        "${target_name}.icu_${icu_flavor.name}_${icu_flavor.commit_id}") {
      # Do not forward variables which the template does not support. In addition,
      # treat "visibility" and "testonly" as special.
      forward_variables_from(invoker,
                             "*",
                             [
                               "visibility",
                               "testonly",
                               "icu_deps",
                               "icu_public_deps",
                               "target_name",  # Workaround for
                                               # https://fxbug.dev/42083609.
                             ])
      forward_variables_from(invoker,
                             [
                               "visibility",
                               "testonly",
                             ])

      # Ensure that we preserve the toolchain when adding dependencies.
      _flavored_icu_deps = [
        get_label_info("//third_party/icu/${icu_flavor.name}:icu",
                       "label_with_toolchain"),
        get_label_info("//third_party/icu/${icu_flavor.name}:icudata",
                       "label_with_toolchain"),
      ]
      not_needed([
                   "icu_flavor",
                   "_flavored_icu_deps",
                 ])

      if (defined(invoker.icu_deps)) {
        if (!defined(deps)) {
          deps = []
        }

        # Replace the ICU dependencies with a direct dependency on a flavored
        # version of the same dependency.
        deps += icu_fixup_deps + _flavored_icu_deps
        deps -= icu_fixup_deps

        foreach(icu_dep, invoker.icu_deps) {
          # Fully resolve labels like "//foo/bar" to "//foo/bar:bar", so that
          # ICU fixup doesn't change the leaf directory name.
          _relabel = get_label_info(icu_dep, "label_no_toolchain")
          deps +=
              # TODO(fmil): Should this refer to the toolchain?
              [ "${_relabel}.icu_${icu_flavor.name}_${icu_flavor.commit_id}(${current_toolchain})" ]
        }
      }

      # Similar to above, but for public_deps.
      if (defined(invoker.icu_public_deps)) {
        if (!defined(public_deps)) {
          public_deps = []
        }
        public_deps += icu_fixup_deps + _flavored_icu_deps
        public_deps -= icu_fixup_deps

        foreach(icu_public_dep, invoker.icu_public_deps) {
          _relabel = get_label_info(icu_public_dep, "label_no_toolchain")
          public_deps += [ "${_relabel}.icu_${icu_flavor.name}_${icu_flavor.commit_id}(${current_toolchain})" ]
        }
      }
    }
  }

  # The original source set, with the original target name.
  source_set(target_name) {
    # Do not forward variables that this template does not support.
    forward_variables_from(invoker,
                           "*",
                           [
                             "visibility",
                             "testonly",
                             "icu_deps",
                             "icu_public_deps",
                           ])
    forward_variables_from(invoker,
                           [
                             "visibility",
                             "testonly",
                           ])

    if (defined(invoker.icu_deps)) {
      if (!defined(deps)) {
        deps = []
      }
      deps += invoker.icu_deps
    }
    if (defined(invoker.icu_public_deps)) {
      if (!defined(public_deps)) {
        public_deps = []
      }
      public_deps += invoker.icu_public_deps
    }
  }
}