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# Copyright 2021 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("$dir_pw_build/python_action.gni")
import("$dir_pw_build/target_types.gni")
# Turns binary blobs into a C++ source_set library of hard-coded byte arrays.
# The byte arrays are constant initialized and are safe to access at any time,
# including before main().
#
# blobs A list of scopes, where each scope corresponds to a binary
# blob to be transformed from file to byte array. This is a
# required field. Blob fields include:
#
# symbol_name [required]: The C++ symbol for the byte array.
#
# file_path [required]: The file path for the binary blob.
#
# linker_section [optional]: If present, places the byte array
# in the specified linker section.
#
# alignas [optional]: If present, the byte array is aligned as
# specified. The value of this argument is used verbatim
# in an alignas() specifier for the blob byte array.
#
# out_header The header file to generate. Users will include this file
# exactly as it is written here to reference the byte arrays.
#
# namespace The C++ namespace in which to place the generated blobs.
#
template("pw_cc_blob_library") {
assert(defined(invoker.blobs), "pw_cc_blob_library requires 'blobs'")
assert(defined(invoker.out_header),
"pw_cc_blob_library requires an 'out_header'")
assert(defined(invoker.namespace),
"pw_cc_blob_library requires a 'namespace'")
_blobs = []
_blob_files = []
foreach(blob, invoker.blobs) {
assert(defined(blob.symbol_name), "Each 'blob' requires a 'symbol_name'")
assert(defined(blob.file_path), "Each 'blob' requires a 'file_path'")
_blob_files += [ blob.file_path ]
blob.file_path = rebase_path(blob.file_path, root_build_dir)
_blobs += [ blob ]
}
_out_dir = "$target_gen_dir/$target_name"
_blob_json_file = "$_out_dir/blobs.json"
write_file(_blob_json_file, _blobs, "json")
_header = "$_out_dir/public/${invoker.out_header}"
_source = "$_out_dir/" + get_path_info(invoker.out_header, "name") + ".cc"
pw_python_action("$target_name._gen") {
forward_variables_from(invoker,
[
"deps",
"public_deps",
])
module = "pw_build.generate_cc_blob_library"
python_deps = [ "$dir_pw_build/py" ]
args = [
"--blob-file",
rebase_path(_blob_json_file, root_build_dir),
"--namespace=${invoker.namespace}",
"--header-include=${invoker.out_header}",
"--out-header",
rebase_path(_header, root_build_dir),
"--out-source",
rebase_path(_source, root_build_dir),
]
inputs = [ _blob_json_file ] + _blob_files
outputs = [
_header,
_source,
]
}
config("$target_name._include_path") {
include_dirs = [ "$_out_dir/public" ]
visibility = [ ":*" ]
}
pw_source_set(target_name) {
public = [ _header ]
sources = [ _source ]
public_configs = [ ":$target_name._include_path" ]
deps = [
":$target_name._gen",
dir_pw_preprocessor,
]
forward_variables_from(invoker, [ "visibility" ])
}
}