| //===-- DIERef.h ------------------------------------------------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLDB_SOURCE_PLUGINS_SYMBOLFILE_DWARF_DIEREF_H |
| #define LLDB_SOURCE_PLUGINS_SYMBOLFILE_DWARF_DIEREF_H |
| |
| #include "lldb/Core/dwarf.h" |
| #include "lldb/Utility/LLDBAssert.h" |
| #include <cassert> |
| #include <optional> |
| |
| namespace lldb_private::plugin { |
| namespace dwarf { |
| /// Identifies a DWARF debug info entry within a given Module. It contains three |
| /// "coordinates": |
| /// - file_index: identifies the separate stand alone debug info file |
| /// that is referred to by the main debug info file. This will be the |
| /// index of a DWO file for fission, or the .o file on mac when not |
| /// using a dSYM file. If this field is not set, then this references |
| /// a DIE inside the original object file. |
| /// - section: identifies the section of the debug info entry in the given file: |
| /// debug_info or debug_types. |
| /// - die_offset: The offset of the debug info entry as an absolute offset from |
| /// the beginning of the section specified in the section field. |
| class DIERef { |
| public: |
| enum Section : uint8_t { DebugInfo, DebugTypes }; |
| DIERef(std::optional<uint32_t> file_index, Section section, |
| dw_offset_t die_offset) |
| : m_die_offset(die_offset), m_file_index(file_index.value_or(0)), |
| m_file_index_valid(file_index ? true : false), m_section(section) { |
| assert(this->file_index() == file_index && "File Index is out of range?"); |
| } |
| |
| explicit DIERef(lldb::user_id_t uid) { |
| m_die_offset = uid & k_die_offset_mask; |
| m_file_index_valid = (uid & k_file_index_valid_bit) != 0; |
| m_file_index = m_file_index_valid |
| ? (uid >> k_die_offset_bit_size) & k_file_index_mask |
| : 0; |
| m_section = |
| (uid & k_section_bit) != 0 ? Section::DebugTypes : Section::DebugInfo; |
| } |
| |
| lldb::user_id_t get_id() const { |
| if (m_die_offset == k_die_offset_mask) |
| return LLDB_INVALID_UID; |
| |
| return lldb::user_id_t(file_index().value_or(0)) << k_die_offset_bit_size | |
| die_offset() | (m_file_index_valid ? k_file_index_valid_bit : 0) | |
| (section() == Section::DebugTypes ? k_section_bit : 0); |
| } |
| |
| std::optional<uint32_t> file_index() const { |
| if (m_file_index_valid) |
| return m_file_index; |
| return std::nullopt; |
| } |
| |
| Section section() const { return static_cast<Section>(m_section); } |
| |
| dw_offset_t die_offset() const { return m_die_offset; } |
| |
| bool operator<(DIERef other) const { |
| if (m_file_index_valid != other.m_file_index_valid) |
| return m_file_index_valid < other.m_file_index_valid; |
| if (m_file_index_valid && (m_file_index != other.m_file_index)) |
| return m_file_index < other.m_file_index; |
| if (m_section != other.m_section) |
| return m_section < other.m_section; |
| return m_die_offset < other.m_die_offset; |
| } |
| |
| bool operator==(const DIERef &rhs) const { |
| return file_index() == rhs.file_index() && m_section == rhs.m_section && |
| m_die_offset == rhs.m_die_offset; |
| } |
| |
| bool operator!=(const DIERef &rhs) const { return !(*this == rhs); } |
| |
| /// Decode a serialized version of this object from data. |
| /// |
| /// \param data |
| /// The decoder object that references the serialized data. |
| /// |
| /// \param offset_ptr |
| /// A pointer that contains the offset from which the data will be decoded |
| /// from that gets updated as data gets decoded. |
| /// |
| /// \return |
| /// Returns a valid DIERef if decoding succeeded, std::nullopt if there was |
| /// unsufficient or invalid values that were decoded. |
| static std::optional<DIERef> Decode(const DataExtractor &data, |
| lldb::offset_t *offset_ptr); |
| |
| /// Encode this object into a data encoder object. |
| /// |
| /// This allows this object to be serialized to disk. |
| /// |
| /// \param encoder |
| /// A data encoder object that serialized bytes will be encoded into. |
| /// |
| void Encode(DataEncoder &encoder) const; |
| |
| static constexpr uint64_t k_die_offset_bit_size = DW_DIE_OFFSET_MAX_BITSIZE; |
| static constexpr uint64_t k_file_index_bit_size = |
| 64 - DW_DIE_OFFSET_MAX_BITSIZE - /* size of control bits */ 2; |
| |
| static constexpr uint64_t k_file_index_valid_bit = |
| (1ull << (k_file_index_bit_size + k_die_offset_bit_size)); |
| static constexpr uint64_t k_section_bit = |
| (1ull << (k_file_index_bit_size + k_die_offset_bit_size + 1)); |
| static constexpr uint64_t |
| k_file_index_mask = (~0ull) >> (64 - k_file_index_bit_size); // 0x3fffff; |
| static constexpr uint64_t k_die_offset_mask = (~0ull) >> |
| (64 - k_die_offset_bit_size); |
| |
| private: |
| // Allow 2TB of .debug_info/.debug_types offset |
| dw_offset_t m_die_offset : k_die_offset_bit_size; |
| // Used for DWO index or for .o file index on mac |
| dw_offset_t m_file_index : k_file_index_bit_size; |
| // Set to 1 if m_file_index is a DWO number |
| dw_offset_t m_file_index_valid : 1; |
| // Set to 0 for .debug_info 1 for .debug_types, |
| dw_offset_t m_section : 1; |
| }; |
| static_assert(sizeof(DIERef) == 8); |
| |
| typedef std::vector<DIERef> DIEArray; |
| } // namespace dwarf |
| } // namespace lldb_private::plugin |
| |
| namespace llvm { |
| template <> struct format_provider<lldb_private::plugin::dwarf::DIERef> { |
| static void format(const lldb_private::plugin::dwarf::DIERef &ref, |
| raw_ostream &OS, StringRef Style); |
| }; |
| } // namespace llvm |
| |
| #endif // LLDB_SOURCE_PLUGINS_SYMBOLFILE_DWARF_DIEREF_H |