1 //===-- SymbolFileDWARFDwp.cpp ----------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "SymbolFileDWARFDwp.h"
11 
12 #include "lldb/Core/Section.h"
13 #include "lldb/Symbol/ObjectFile.h"
14 
15 #include "SymbolFileDWARFDwoDwp.h"
16 
17 static llvm::DWARFSectionKind
18 lldbSectTypeToLlvmSectionKind(lldb::SectionType type) {
19   switch (type) {
20   case lldb::eSectionTypeDWARFDebugInfo:
21     return llvm::DW_SECT_INFO;
22   // case lldb::eSectionTypeDWARFDebugTypes:
23   //   return llvm::DW_SECT_TYPES;
24   case lldb::eSectionTypeDWARFDebugAbbrev:
25     return llvm::DW_SECT_ABBREV;
26   case lldb::eSectionTypeDWARFDebugLine:
27     return llvm::DW_SECT_LINE;
28   case lldb::eSectionTypeDWARFDebugLoc:
29     return llvm::DW_SECT_LOC;
30   case lldb::eSectionTypeDWARFDebugStrOffsets:
31     return llvm::DW_SECT_STR_OFFSETS;
32   // case lldb::eSectionTypeDWARFDebugMacinfo:
33   //   return llvm::DW_SECT_MACINFO;
34   case lldb::eSectionTypeDWARFDebugMacro:
35     return llvm::DW_SECT_MACRO;
36   default:
37     // Note: 0 is an invalid dwarf section kind.
38     return llvm::DWARFSectionKind(0);
39   }
40 }
41 
42 std::unique_ptr<SymbolFileDWARFDwp>
43 SymbolFileDWARFDwp::Create(lldb::ModuleSP module_sp,
44                            const lldb_private::FileSpec &file_spec) {
45   const lldb::offset_t file_offset = 0;
46   lldb::DataBufferSP file_data_sp;
47   lldb::offset_t file_data_offset = 0;
48   lldb::ObjectFileSP obj_file = lldb_private::ObjectFile::FindPlugin(
49       module_sp, &file_spec, file_offset,
50       lldb_private::FileSystem::Instance().GetByteSize(file_spec), file_data_sp,
51       file_data_offset);
52   if (obj_file == nullptr)
53     return nullptr;
54 
55   std::unique_ptr<SymbolFileDWARFDwp> dwp_symfile(
56       new SymbolFileDWARFDwp(module_sp, obj_file));
57 
58   lldb_private::DWARFDataExtractor debug_cu_index;
59   if (!dwp_symfile->LoadRawSectionData(lldb::eSectionTypeDWARFDebugCuIndex,
60                                        debug_cu_index))
61     return nullptr;
62 
63   llvm::DataExtractor llvm_debug_cu_index(
64       llvm::StringRef(debug_cu_index.PeekCStr(0), debug_cu_index.GetByteSize()),
65       debug_cu_index.GetByteOrder() == lldb::eByteOrderLittle,
66       debug_cu_index.GetAddressByteSize());
67   if (!dwp_symfile->m_debug_cu_index.parse(llvm_debug_cu_index))
68     return nullptr;
69   dwp_symfile->InitDebugCUIndexMap();
70   return dwp_symfile;
71 }
72 
73 void SymbolFileDWARFDwp::InitDebugCUIndexMap() {
74   m_debug_cu_index_map.clear();
75   for (const auto &entry : m_debug_cu_index.getRows())
76     m_debug_cu_index_map.emplace(entry.getSignature(), &entry);
77 }
78 
79 SymbolFileDWARFDwp::SymbolFileDWARFDwp(lldb::ModuleSP module_sp,
80                                        lldb::ObjectFileSP obj_file)
81     : m_obj_file(std::move(obj_file)), m_debug_cu_index(llvm::DW_SECT_INFO)
82 {}
83 
84 std::unique_ptr<SymbolFileDWARFDwo>
85 SymbolFileDWARFDwp::GetSymbolFileForDwoId(DWARFUnit *dwarf_cu,
86                                           uint64_t dwo_id) {
87   return std::unique_ptr<SymbolFileDWARFDwo>(
88       new SymbolFileDWARFDwoDwp(this, m_obj_file, dwarf_cu, dwo_id));
89 }
90 
91 bool SymbolFileDWARFDwp::LoadSectionData(
92     uint64_t dwo_id, lldb::SectionType sect_type,
93     lldb_private::DWARFDataExtractor &data) {
94   lldb_private::DWARFDataExtractor section_data;
95   if (!LoadRawSectionData(sect_type, section_data))
96     return false;
97 
98   auto it = m_debug_cu_index_map.find(dwo_id);
99   if (it == m_debug_cu_index_map.end())
100     return false;
101 
102   auto *offsets =
103       it->second->getOffset(lldbSectTypeToLlvmSectionKind(sect_type));
104   if (offsets) {
105     data.SetData(section_data, offsets->Offset, offsets->Length);
106   } else {
107     data.SetData(section_data, 0, section_data.GetByteSize());
108   }
109   return true;
110 }
111 
112 bool SymbolFileDWARFDwp::LoadRawSectionData(
113     lldb::SectionType sect_type, lldb_private::DWARFDataExtractor &data) {
114   std::lock_guard<std::mutex> lock(m_sections_mutex);
115 
116   auto it = m_sections.find(sect_type);
117   if (it != m_sections.end()) {
118     if (it->second.GetByteSize() == 0)
119       return false;
120 
121     data = it->second;
122     return true;
123   }
124 
125   const lldb_private::SectionList *section_list =
126       m_obj_file->GetSectionList(false /* update_module_section_list */);
127   if (section_list) {
128     lldb::SectionSP section_sp(
129         section_list->FindSectionByType(sect_type, true));
130     if (section_sp) {
131       if (m_obj_file->ReadSectionData(section_sp.get(), data) != 0) {
132         m_sections[sect_type] = data;
133         return true;
134       }
135     }
136   }
137   m_sections[sect_type].Clear();
138   return false;
139 }
140