1 //===-- DIERef.h ------------------------------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLDB_SOURCE_PLUGINS_SYMBOLFILE_DWARF_DIEREF_H 10 #define LLDB_SOURCE_PLUGINS_SYMBOLFILE_DWARF_DIEREF_H 11 12 #include "lldb/Core/dwarf.h" 13 #include "llvm/Support/FormatProviders.h" 14 #include <cassert> 15 #include <optional> 16 #include <vector> 17 18 /// Identifies a DWARF debug info entry within a given Module. It contains three 19 /// "coordinates": 20 /// - dwo_num: identifies the dwo file in the Module. If this field is not set, 21 /// the DIERef references the main file. 22 /// - section: identifies the section of the debug info entry in the given file: 23 /// debug_info or debug_types. 24 /// - die_offset: The offset of the debug info entry as an absolute offset from 25 /// the beginning of the section specified in the section field. 26 class DIERef { 27 public: 28 enum Section : uint8_t { DebugInfo, DebugTypes }; 29 30 DIERef(std::optional<uint32_t> dwo_num, Section section, 31 dw_offset_t die_offset) 32 : m_dwo_num(dwo_num.value_or(0)), m_dwo_num_valid(bool(dwo_num)), 33 m_section(section), m_die_offset(die_offset) { 34 assert(this->dwo_num() == dwo_num && "Dwo number out of range?"); 35 } 36 37 std::optional<uint32_t> dwo_num() const { 38 if (m_dwo_num_valid) 39 return m_dwo_num; 40 return std::nullopt; 41 } 42 43 Section section() const { return static_cast<Section>(m_section); } 44 45 dw_offset_t die_offset() const { return m_die_offset; } 46 47 bool operator<(DIERef other) const { 48 if (m_dwo_num_valid != other.m_dwo_num_valid) 49 return m_dwo_num_valid < other.m_dwo_num_valid; 50 if (m_dwo_num_valid && (m_dwo_num != other.m_dwo_num)) 51 return m_dwo_num < other.m_dwo_num; 52 if (m_section != other.m_section) 53 return m_section < other.m_section; 54 return m_die_offset < other.m_die_offset; 55 } 56 57 bool operator==(const DIERef &rhs) const { 58 return dwo_num() == rhs.dwo_num() && m_section == rhs.m_section && 59 m_die_offset == rhs.m_die_offset; 60 } 61 62 bool operator!=(const DIERef &rhs) const { return !(*this == rhs); } 63 64 /// Decode a serialized version of this object from data. 65 /// 66 /// \param data 67 /// The decoder object that references the serialized data. 68 /// 69 /// \param offset_ptr 70 /// A pointer that contains the offset from which the data will be decoded 71 /// from that gets updated as data gets decoded. 72 /// 73 /// \return 74 /// Returns a valid DIERef if decoding succeeded, std::nullopt if there was 75 /// unsufficient or invalid values that were decoded. 76 static std::optional<DIERef> Decode(const lldb_private::DataExtractor &data, 77 lldb::offset_t *offset_ptr); 78 79 /// Encode this object into a data encoder object. 80 /// 81 /// This allows this object to be serialized to disk. 82 /// 83 /// \param encoder 84 /// A data encoder object that serialized bytes will be encoded into. 85 /// 86 void Encode(lldb_private::DataEncoder &encoder) const; 87 88 private: 89 uint32_t m_dwo_num : 30; 90 uint32_t m_dwo_num_valid : 1; 91 uint32_t m_section : 1; 92 dw_offset_t m_die_offset; 93 }; 94 static_assert(sizeof(DIERef) == 8); 95 96 typedef std::vector<DIERef> DIEArray; 97 98 namespace llvm { 99 template<> struct format_provider<DIERef> { 100 static void format(const DIERef &ref, raw_ostream &OS, StringRef Style); 101 }; 102 } // namespace llvm 103 104 #endif // LLDB_SOURCE_PLUGINS_SYMBOLFILE_DWARF_DIEREF_H 105