# Copyright 2019 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("$dir_pw_build/python_script.gni")

# Creates a target which runs a size report diff on a set of executables.
#
# Args:
#   base: The default base executable target to run the diff against. May be
#     omitted if all binaries provide their own base.
#   binaries: List of executables to compare in the diff.
#     Each binary in the list is a scope containing up to three variables:
#       label: Descriptive name for the executable. Required.
#       target: Build target for the executable. Required.
#       base: Optional base diff target. Overrides global base argument.
#   source_filter: Optional regex to filter data source names in Bloaty.
#   title: Optional title string to display with the size report.
#   full_report: Optional boolean flag indicating whether to produce a full
#     symbol size breakdown or a summary.
#
# Example:
#   pw_size_report("foo_bloat") {
#     base = ":foo_base"
#     binaries = [
#       {
#         target = ":foo_static"
#         label = "Static"
#       },
#       {
#         target = ":foo_dynamic"
#         label = "Dynamic"
#       },
#     ]
#     title = "static vs. dynamic foo"
#   }
#
template("pw_size_report") {
  _bloaty_config = pw_executable_config.bloaty_config_file

  if (defined(invoker.base)) {
    _global_base = invoker.base
    _all_target_dependencies = [ _global_base ]
  } else {
    _all_target_dependencies = []
  }

  if (defined(invoker.title)) {
    _title = invoker.title
  } else {
    _title = target_name
  }

  # This template creates an action which invokes a Python script to run a size
  # report on each of the provided targets. Each of the targets is listed as a
  # dependency of the action so that the report gets updated when anything is
  # changed. Most of the code below builds the command-line arguments to pass
  # each of the targets into the script.

  _binary_paths = []
  _binary_labels = []

  # Process each of the binaries, resolving their full output paths and building
  # them into a list of command-line arguments to the bloat script.
  foreach(binary, invoker.binaries) {
    assert(defined(binary.label) && defined(binary.target),
           "Size report binaries must define 'label' and 'target' variables")

    _all_target_dependencies += [ binary.target ]

    _target_dir = get_label_info(binary.target, "target_out_dir")
    _target_name = get_label_info(binary.target, "name")
    _binary_path = get_path_info(_target_dir, "abspath") + ":$_target_name"

    # If the binary defines its own base, use that instead of the global base.
    if (defined(binary.base)) {
      _binary_base = binary.base
      _all_target_dependencies += [ _binary_base ]
    } else if (defined(_global_base)) {
      _binary_base = _global_base
    } else {
      assert(false, "pw_size_report requires a 'base' file")
    }

    _base_dir = get_label_info(_binary_base, "target_out_dir")
    _base_name = get_label_info(_binary_base, "name")
    _binary_path += ";" + get_path_info(_base_dir, "abspath") + ":$_base_name"

    _binary_paths += [ _binary_path ]
    _binary_labels += [ binary.label ]
  }

  _bloat_script_args = [
    "--bloaty-config",
    get_path_info(_bloaty_config, "abspath"),
    "--out-dir",
    target_gen_dir,
    "--target",
    target_name,
    "--title",
    _title,
    "--labels",
    string_join(";", _binary_labels),
  ]

  if (defined(invoker.full_report) && invoker.full_report) {
    _bloat_script_args += [ "--full" ]
  }

  if (defined(invoker.source_filter)) {
    _bloat_script_args += [
      "--source-filter",
      invoker.source_filter,
    ]
  }

  _doc_rst_output = "$target_gen_dir/${target_name}.rst"

  # Create an action which runs the size report script on the provided targets.
  pw_python_script(target_name) {
    metadata = {
      pw_doc_sources = rebase_path([ _doc_rst_output ], root_build_dir)
    }
    script = "$dir_pw_bloat/py/bloat.py"
    inputs = [
      _bloaty_config,
      "$dir_pw_bloat/py/binary_diff.py",
      "$dir_pw_bloat/py/bloat_output.py",
    ]
    outputs = [
      "$target_gen_dir/${target_name}.txt",
      _doc_rst_output,
    ]
    deps = _all_target_dependencies
    args = _bloat_script_args + _binary_paths
  }
}