1 //===-- DWARFDebugInfo.cpp ------------------------------------------------===//
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 #include "SymbolFileDWARF.h"
10
11 #include <algorithm>
12 #include <set>
13
14 #include "lldb/Host/PosixApi.h"
15 #include "lldb/Symbol/ObjectFile.h"
16 #include "lldb/Utility/RegularExpression.h"
17 #include "lldb/Utility/Stream.h"
18 #include "llvm/Support/Casting.h"
19
20 #include "DWARFCompileUnit.h"
21 #include "DWARFContext.h"
22 #include "DWARFDebugAranges.h"
23 #include "DWARFDebugInfo.h"
24 #include "DWARFDebugInfoEntry.h"
25 #include "DWARFFormValue.h"
26 #include "DWARFTypeUnit.h"
27
28 using namespace lldb;
29 using namespace lldb_private;
30 using namespace std;
31
32 // Constructor
DWARFDebugInfo(SymbolFileDWARF & dwarf,lldb_private::DWARFContext & context)33 DWARFDebugInfo::DWARFDebugInfo(SymbolFileDWARF &dwarf,
34 lldb_private::DWARFContext &context)
35 : m_dwarf(dwarf), m_context(context), m_units(), m_cu_aranges_up() {}
36
GetCompileUnitAranges()37 llvm::Expected<DWARFDebugAranges &> DWARFDebugInfo::GetCompileUnitAranges() {
38 if (m_cu_aranges_up)
39 return *m_cu_aranges_up;
40
41 m_cu_aranges_up = std::make_unique<DWARFDebugAranges>();
42 const DWARFDataExtractor &debug_aranges_data =
43 m_context.getOrLoadArangesData();
44 if (llvm::Error error = m_cu_aranges_up->extract(debug_aranges_data))
45 return std::move(error);
46
47 // Make a list of all CUs represented by the arange data in the file.
48 std::set<dw_offset_t> cus_with_data;
49 for (size_t n = 0; n < m_cu_aranges_up->GetNumRanges(); n++) {
50 dw_offset_t offset = m_cu_aranges_up->OffsetAtIndex(n);
51 if (offset != DW_INVALID_OFFSET)
52 cus_with_data.insert(offset);
53 }
54
55 // Manually build arange data for everything that wasn't in the
56 // .debug_aranges table.
57 const size_t num_units = GetNumUnits();
58 for (size_t idx = 0; idx < num_units; ++idx) {
59 DWARFUnit *cu = GetUnitAtIndex(idx);
60
61 dw_offset_t offset = cu->GetOffset();
62 if (cus_with_data.find(offset) == cus_with_data.end())
63 cu->BuildAddressRangeTable(m_cu_aranges_up.get());
64 }
65
66 const bool minimize = true;
67 m_cu_aranges_up->Sort(minimize);
68 return *m_cu_aranges_up;
69 }
70
ParseUnitsFor(DIERef::Section section)71 void DWARFDebugInfo::ParseUnitsFor(DIERef::Section section) {
72 DWARFDataExtractor data = section == DIERef::Section::DebugTypes
73 ? m_context.getOrLoadDebugTypesData()
74 : m_context.getOrLoadDebugInfoData();
75 const llvm::DWARFUnitIndex *index = nullptr;
76 if (m_context.isDwo())
77 index = &llvm::getDWARFUnitIndex(m_context.GetAsLLVM(),
78 section == DIERef::Section::DebugTypes
79 ? llvm::DW_SECT_EXT_TYPES
80 : llvm::DW_SECT_INFO);
81 lldb::offset_t offset = 0;
82 while (data.ValidOffset(offset)) {
83 llvm::Expected<DWARFUnitSP> unit_sp = DWARFUnit::extract(
84 m_dwarf, m_units.size(), data, section, &offset, index);
85
86 if (!unit_sp) {
87 // FIXME: Propagate this error up.
88 llvm::consumeError(unit_sp.takeError());
89 return;
90 }
91
92 // If it didn't return an error, then it should be returning a valid Unit.
93 assert(*unit_sp);
94 m_units.push_back(*unit_sp);
95 offset = (*unit_sp)->GetNextUnitOffset();
96
97 if (auto *type_unit = llvm::dyn_cast<DWARFTypeUnit>(unit_sp->get())) {
98 m_type_hash_to_unit_index.emplace_back(type_unit->GetTypeHash(),
99 unit_sp.get()->GetID());
100 }
101 }
102 }
103
ParseUnitHeadersIfNeeded()104 void DWARFDebugInfo::ParseUnitHeadersIfNeeded() {
105 llvm::call_once(m_units_once_flag, [&] {
106 ParseUnitsFor(DIERef::Section::DebugInfo);
107 ParseUnitsFor(DIERef::Section::DebugTypes);
108 llvm::sort(m_type_hash_to_unit_index, llvm::less_first());
109 });
110 }
111
GetNumUnits()112 size_t DWARFDebugInfo::GetNumUnits() {
113 ParseUnitHeadersIfNeeded();
114 return m_units.size();
115 }
116
GetUnitAtIndex(size_t idx)117 DWARFUnit *DWARFDebugInfo::GetUnitAtIndex(size_t idx) {
118 DWARFUnit *cu = nullptr;
119 if (idx < GetNumUnits())
120 cu = m_units[idx].get();
121 return cu;
122 }
123
FindUnitIndex(DIERef::Section section,dw_offset_t offset)124 uint32_t DWARFDebugInfo::FindUnitIndex(DIERef::Section section,
125 dw_offset_t offset) {
126 ParseUnitHeadersIfNeeded();
127
128 // llvm::lower_bound is not used as for DIE offsets it would still return
129 // index +1 and GetOffset() returning index itself would be a special case.
130 auto pos = llvm::upper_bound(
131 m_units, std::make_pair(section, offset),
132 [](const std::pair<DIERef::Section, dw_offset_t> &lhs,
133 const DWARFUnitSP &rhs) {
134 return lhs < std::make_pair(rhs->GetDebugSection(), rhs->GetOffset());
135 });
136 uint32_t idx = std::distance(m_units.begin(), pos);
137 if (idx == 0)
138 return DW_INVALID_OFFSET;
139 return idx - 1;
140 }
141
GetUnitAtOffset(DIERef::Section section,dw_offset_t cu_offset,uint32_t * idx_ptr)142 DWARFUnit *DWARFDebugInfo::GetUnitAtOffset(DIERef::Section section,
143 dw_offset_t cu_offset,
144 uint32_t *idx_ptr) {
145 uint32_t idx = FindUnitIndex(section, cu_offset);
146 DWARFUnit *result = GetUnitAtIndex(idx);
147 if (result && result->GetOffset() != cu_offset) {
148 result = nullptr;
149 idx = DW_INVALID_INDEX;
150 }
151 if (idx_ptr)
152 *idx_ptr = idx;
153 return result;
154 }
155
GetUnit(const DIERef & die_ref)156 DWARFUnit *DWARFDebugInfo::GetUnit(const DIERef &die_ref) {
157 return GetUnitContainingDIEOffset(die_ref.section(), die_ref.die_offset());
158 }
159
160 DWARFUnit *
GetUnitContainingDIEOffset(DIERef::Section section,dw_offset_t die_offset)161 DWARFDebugInfo::GetUnitContainingDIEOffset(DIERef::Section section,
162 dw_offset_t die_offset) {
163 uint32_t idx = FindUnitIndex(section, die_offset);
164 DWARFUnit *result = GetUnitAtIndex(idx);
165 if (result && !result->ContainsDIEOffset(die_offset))
166 return nullptr;
167 return result;
168 }
169
GetTypeUnitForHash(uint64_t hash)170 DWARFTypeUnit *DWARFDebugInfo::GetTypeUnitForHash(uint64_t hash) {
171 auto pos = llvm::lower_bound(m_type_hash_to_unit_index,
172 std::make_pair(hash, 0u), llvm::less_first());
173 if (pos == m_type_hash_to_unit_index.end() || pos->first != hash)
174 return nullptr;
175 return llvm::cast<DWARFTypeUnit>(GetUnitAtIndex(pos->second));
176 }
177
ContainsTypeUnits()178 bool DWARFDebugInfo::ContainsTypeUnits() {
179 ParseUnitHeadersIfNeeded();
180 return !m_type_hash_to_unit_index.empty();
181 }
182
183 DWARFDIE
GetDIEForDIEOffset(DIERef::Section section,dw_offset_t die_offset)184 DWARFDebugInfo::GetDIEForDIEOffset(DIERef::Section section,
185 dw_offset_t die_offset) {
186 DWARFUnit *cu = GetUnitContainingDIEOffset(section, die_offset);
187 if (cu)
188 return cu->GetDIE(die_offset);
189 return DWARFDIE();
190 }
191
192 // GetDIE()
193 //
194 // Get the DIE (Debug Information Entry) with the specified offset.
195 DWARFDIE
GetDIE(const DIERef & die_ref)196 DWARFDebugInfo::GetDIE(const DIERef &die_ref) {
197 DWARFUnit *cu = GetUnit(die_ref);
198 if (cu)
199 return cu->GetNonSkeletonUnit().GetDIE(die_ref.die_offset());
200 return DWARFDIE(); // Not found
201 }
202