blob: d1e727fbf02f28ab0af899fdef9d4b5dc58702d8 [file] [log] [blame]
// 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.
#include "pw_build_info/build_id.h"
#include <cstdint>
#include <cstring>
#include <span>
#include "pw_preprocessor/compiler.h"
extern "C" const uint8_t gnu_build_id_begin;
namespace pw::build_info {
namespace {
PW_PACKED(struct) ElfNoteInfo {
uint32_t name_size;
uint32_t descriptor_size;
uint32_t type;
};
} // namespace
// Reading more than a uint8_t from gnu_build_id_begin triggers compiler
// warnings that must be silenced.
PW_MODIFY_DIAGNOSTICS_PUSH();
PW_MODIFY_DIAGNOSTIC(ignored, "-Warray-bounds");
PW_MODIFY_DIAGNOSTIC_GCC(ignored, "-Wstringop-overflow");
std::span<const std::byte> BuildId() {
// Read the sizes at the beginning of the note section.
ElfNoteInfo build_id_note_sizes;
memcpy(
&build_id_note_sizes, &gnu_build_id_begin, sizeof(build_id_note_sizes));
// Skip the "name" entry of the note section, and return a span to the
// descriptor.
return std::as_bytes(std::span(&gnu_build_id_begin +
sizeof(build_id_note_sizes) +
build_id_note_sizes.name_size,
build_id_note_sizes.descriptor_size));
}
PW_MODIFY_DIAGNOSTICS_POP();
} // namespace pw::build_info