| // Copyright 2021 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef SRC_LIB_UNWINDER_MEMORY_H_ |
| #define SRC_LIB_UNWINDER_MEMORY_H_ |
| |
| #include <cstdint> |
| #include <cstring> |
| #include <map> |
| |
| #include "src/lib/unwinder/error.h" |
| |
| namespace unwinder { |
| |
| // Abstract representation of a readable memory space. |
| class Memory { |
| public: |
| virtual ~Memory() = default; |
| virtual Error ReadBytes(uint64_t addr, uint64_t size, void* dst) = 0; |
| |
| template <class Type> |
| [[nodiscard]] Error Read(uint64_t addr, Type& res) { |
| return ReadBytes(addr, sizeof(res), &res); |
| } |
| |
| // Read an object and advance the addr by the read size. Do not advance if failed. |
| template <class Type> |
| [[nodiscard]] Error ReadAndAdvance(uint64_t& addr, Type& res) { |
| if (auto err = Read(addr, res); err.has_err()) { |
| return err; |
| } |
| addr += sizeof(res); |
| return Success(); |
| } |
| |
| [[nodiscard]] Error ReadSLEB128AndAdvance(uint64_t& addr, int64_t& res); |
| [[nodiscard]] Error ReadULEB128AndAdvance(uint64_t& addr, uint64_t& res); |
| |
| // Read the data in DWARF encoding. data_rel_base is only used in .eh_frame_hdr. |
| [[nodiscard]] Error ReadEncodedAndAdvance(uint64_t& addr, uint64_t& res, uint8_t enc, |
| uint64_t data_rel_base = 0); |
| [[nodiscard]] Error ReadEncoded(uint64_t addr, uint64_t& res, uint8_t enc, |
| uint64_t data_rel_base = 0) { |
| return ReadEncodedAndAdvance(addr, res, enc, data_rel_base); |
| } |
| }; |
| |
| class LocalMemory : public Memory { |
| public: |
| Error ReadBytes(uint64_t addr, uint64_t size, void* dst) override { |
| memcpy(dst, reinterpret_cast<void*>(addr), size); // NOLINT(performance-no-int-to-ptr) |
| return Success(); |
| } |
| }; |
| |
| // A memory that fails any reads. |
| class UnavailableMemory : public Memory { |
| public: |
| Error ReadBytes(uint64_t addr, uint64_t size, void* dst) override { |
| return Error("Unavailable memory"); |
| } |
| }; |
| |
| } // namespace unwinder |
| |
| #endif // SRC_LIB_UNWINDER_MEMORY_H_ |