third_party/emboss/build_defs.gni

# Copyright 2022 The Pigweed Authors
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may not
# use this file except in compliance with the License. You may obtain a copy of
# the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations under
# the License.

import("//build_overrides/pigweed.gni")

import("$dir_pw_third_party/emboss/emboss.gni")

template("emboss_cc_library") {
  assert(defined(invoker.source), "Need source arg for emboss_cc_library")
  assert(
      "$dir_pw_third_party_emboss" != "",
      "\$dir_pw_third_party_emboss must be set to the path of your Emboss installation")
  source = get_path_info(invoker.source, "file")

  # The --output-path arg to the embossc script only specifies the
  # prefix of the path at which the generated header is placed. To this
  # prefix, the script appends the entire path of the input Emboss source,
  # which is provided as rebase_path(source, root_build_dir).

  # rebase_path(source, root_build_dir) will always start with a number
  # of updirs (e.g. "../../../").

  # In order for the compiled header path in the embossc script to resolve
  # to $target_gen_dir as we desire, we must provide an --output-path arg
  # that resolves to $target_gen_dir after rebase_path(source, root_build_dir)
  # is appended to it. To achieve this, we specify output-path to be
  # $root_gen_dir followed by a number of fake directories needed to cancel
  # out these starting updirs.
  compiled_header_path = "$target_gen_dir/" + source + ".h"
  path_sep = "/"
  elements = string_split(rebase_path(source, root_build_dir), path_sep)
  updirs = filter_include(elements, [ ".." ])

  fakedirs = []
  foreach(element, updirs) {
    fakedirs += [ "fake" ]
  }
  output_path = root_gen_dir + path_sep + string_join(path_sep, fakedirs)

  action(target_name + "_header") {
    script = "$dir_pw_third_party/emboss/embossc_runner.py"
    args = [
      rebase_path("$dir_pw_third_party_emboss/embossc", root_build_dir),
      "--generate",
      "cc",
      "--output-path",
      rebase_path(output_path, root_build_dir),
      rebase_path(source, root_build_dir),
    ]
    inputs = [
      source,
      "$dir_pw_third_party_emboss/embossc",
      "$dir_pw_third_party_emboss/compiler/back_end/__init__.py",
      "$dir_pw_third_party_emboss/compiler/back_end/cpp/__init__.py",
      "$dir_pw_third_party_emboss/compiler/back_end/cpp/emboss_codegen_cpp.py",
      "$dir_pw_third_party_emboss/compiler/back_end/cpp/generated_code_templates",
      "$dir_pw_third_party_emboss/compiler/back_end/cpp/header_generator.py",
      "$dir_pw_third_party_emboss/compiler/back_end/util/__init__.py",
      "$dir_pw_third_party_emboss/compiler/back_end/util/code_template.py",
      "$dir_pw_third_party_emboss/compiler/front_end/__init__.py",
      "$dir_pw_third_party_emboss/compiler/front_end/attribute_checker.py",
      "$dir_pw_third_party_emboss/compiler/front_end/attributes.py",
      "$dir_pw_third_party_emboss/compiler/front_end/constraints.py",
      "$dir_pw_third_party_emboss/compiler/front_end/dependency_checker.py",
      "$dir_pw_third_party_emboss/compiler/front_end/emboss_front_end.py",
      "$dir_pw_third_party_emboss/compiler/front_end/error_examples",
      "$dir_pw_third_party_emboss/compiler/front_end/expression_bounds.py",
      "$dir_pw_third_party_emboss/compiler/front_end/glue.py",
      "$dir_pw_third_party_emboss/compiler/front_end/lr1.py",
      "$dir_pw_third_party_emboss/compiler/front_end/module_ir.py",
      "$dir_pw_third_party_emboss/compiler/front_end/parser.py",
      "$dir_pw_third_party_emboss/compiler/front_end/prelude.emb",
      "$dir_pw_third_party_emboss/compiler/front_end/reserved_words",
      "$dir_pw_third_party_emboss/compiler/front_end/symbol_resolver.py",
      "$dir_pw_third_party_emboss/compiler/front_end/synthetics.py",
      "$dir_pw_third_party_emboss/compiler/front_end/tokenizer.py",
      "$dir_pw_third_party_emboss/compiler/front_end/type_check.py",
      "$dir_pw_third_party_emboss/compiler/front_end/write_inference.py",
      "$dir_pw_third_party_emboss/compiler/util/error.py",
      "$dir_pw_third_party_emboss/compiler/util/expression_parser.py",
      "$dir_pw_third_party_emboss/compiler/util/ir_pb2.py",
      "$dir_pw_third_party_emboss/compiler/util/ir_util.py",
      "$dir_pw_third_party_emboss/compiler/util/name_conversion.py",
      "$dir_pw_third_party_emboss/compiler/util/parser_types.py",
      "$dir_pw_third_party_emboss/compiler/util/simple_memoizer.py",
      "$dir_pw_third_party_emboss/compiler/util/traverse_ir.py",
    ]
    outputs = [ compiled_header_path ]
  }

  config("emboss_config") {
    include_dirs = [
      "$dir_pw_third_party_emboss",
      root_gen_dir,
    ]
  }

  source_set(target_name) {
    sources = [ compiled_header_path ]
    deps = [ "$dir_pw_third_party/emboss:cpp_utils" ]
    public_deps = [ ":" + target_name + "_header" ]
    public_configs = [ ":emboss_config" ]
  }
}