58 lines
1.8 KiB
C++
58 lines
1.8 KiB
C++
// Copyright 2021 The Pigweed Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License"); you may not
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// use this file except in compliance with the License. You may obtain a copy of
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// the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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// License for the specific language governing permissions and limitations under
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// the License.
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#include "pw_build_info/build_id.h"
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#include <cstdint>
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#include <cstring>
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#include <span>
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#include "pw_preprocessor/compiler.h"
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extern "C" const uint8_t gnu_build_id_begin;
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namespace pw::build_info {
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namespace {
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PW_PACKED(struct) ElfNoteInfo {
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uint32_t name_size;
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uint32_t descriptor_size;
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uint32_t type;
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};
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} // namespace
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// Reading more than a uint8_t from gnu_build_id_begin triggers compiler
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// warnings that must be silenced.
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PW_MODIFY_DIAGNOSTICS_PUSH();
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PW_MODIFY_DIAGNOSTIC(ignored, "-Warray-bounds");
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PW_MODIFY_DIAGNOSTIC_GCC(ignored, "-Wstringop-overflow");
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std::span<const std::byte> BuildId() {
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// Read the sizes at the beginning of the note section.
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ElfNoteInfo build_id_note_sizes;
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memcpy(
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&build_id_note_sizes, &gnu_build_id_begin, sizeof(build_id_note_sizes));
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// Skip the "name" entry of the note section, and return a span to the
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// descriptor.
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return std::as_bytes(std::span(&gnu_build_id_begin +
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sizeof(build_id_note_sizes) +
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build_id_note_sizes.name_size,
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build_id_note_sizes.descriptor_size));
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}
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PW_MODIFY_DIAGNOSTICS_POP();
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} // namespace pw::build_info
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