| // 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 "pw_preprocessor/compiler.h" |
| #include "pw_span/span.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"); |
| |
| 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 as_bytes(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 |