1 //===-- PdbIndex.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 "PdbIndex.h"
10 #include "PdbUtil.h"
11
12 #include "llvm/DebugInfo/CodeView/SymbolDeserializer.h"
13 #include "llvm/DebugInfo/PDB/Native/DbiStream.h"
14 #include "llvm/DebugInfo/PDB/Native/GlobalsStream.h"
15 #include "llvm/DebugInfo/PDB/Native/ISectionContribVisitor.h"
16 #include "llvm/DebugInfo/PDB/Native/PDBFile.h"
17 #include "llvm/DebugInfo/PDB/Native/PublicsStream.h"
18 #include "llvm/DebugInfo/PDB/Native/SymbolStream.h"
19 #include "llvm/DebugInfo/PDB/Native/TpiStream.h"
20 #include "llvm/Object/COFF.h"
21 #include "llvm/Support/Error.h"
22
23 #include "lldb/Utility/LLDBAssert.h"
24 #include "lldb/lldb-defines.h"
25
26 using namespace lldb_private;
27 using namespace lldb_private::npdb;
28 using namespace llvm::codeview;
29 using namespace llvm::pdb;
30
PdbIndex()31 PdbIndex::PdbIndex() : m_cus(*this), m_va_to_modi(m_allocator) {}
32
33 #define ASSIGN_PTR_OR_RETURN(result_ptr, expr) \
34 { \
35 auto expected_result = expr; \
36 if (!expected_result) \
37 return expected_result.takeError(); \
38 result_ptr = &expected_result.get(); \
39 }
40
41 llvm::Expected<std::unique_ptr<PdbIndex>>
create(llvm::pdb::PDBFile * file)42 PdbIndex::create(llvm::pdb::PDBFile *file) {
43 lldbassert(file);
44
45 std::unique_ptr<PdbIndex> result(new PdbIndex());
46 ASSIGN_PTR_OR_RETURN(result->m_dbi, file->getPDBDbiStream());
47 ASSIGN_PTR_OR_RETURN(result->m_tpi, file->getPDBTpiStream());
48 ASSIGN_PTR_OR_RETURN(result->m_ipi, file->getPDBIpiStream());
49 ASSIGN_PTR_OR_RETURN(result->m_info, file->getPDBInfoStream());
50 ASSIGN_PTR_OR_RETURN(result->m_publics, file->getPDBPublicsStream());
51 ASSIGN_PTR_OR_RETURN(result->m_globals, file->getPDBGlobalsStream());
52 ASSIGN_PTR_OR_RETURN(result->m_symrecords, file->getPDBSymbolStream());
53
54 result->m_tpi->buildHashMap();
55
56 result->m_file = file;
57
58 return std::move(result);
59 }
60
MakeVirtualAddress(uint16_t segment,uint32_t offset) const61 lldb::addr_t PdbIndex::MakeVirtualAddress(uint16_t segment,
62 uint32_t offset) const {
63 uint32_t max_section = dbi().getSectionHeaders().size();
64 // Segment indices are 1-based.
65 // If this is an absolute symbol, it's indicated by the magic section index
66 // |max_section+1|. In this case, the offset is meaningless, so just return.
67 if (segment == 0 || segment > max_section)
68 return LLDB_INVALID_ADDRESS;
69
70 const llvm::object::coff_section &cs = dbi().getSectionHeaders()[segment - 1];
71 return m_load_address + static_cast<lldb::addr_t>(cs.VirtualAddress) +
72 static_cast<lldb::addr_t>(offset);
73 }
74
75 llvm::Optional<uint16_t>
GetModuleIndexForAddr(uint16_t segment,uint32_t offset) const76 PdbIndex::GetModuleIndexForAddr(uint16_t segment, uint32_t offset) const {
77 return GetModuleIndexForVa(MakeVirtualAddress(segment, offset));
78 }
79
GetModuleIndexForVa(lldb::addr_t va) const80 llvm::Optional<uint16_t> PdbIndex::GetModuleIndexForVa(lldb::addr_t va) const {
81 auto iter = m_va_to_modi.find(va);
82 if (iter == m_va_to_modi.end())
83 return llvm::None;
84
85 return iter.value();
86 }
87
ParseSectionContribs()88 void PdbIndex::ParseSectionContribs() {
89 class Visitor : public ISectionContribVisitor {
90 PdbIndex &m_ctx;
91 llvm::IntervalMap<uint64_t, uint16_t> &m_imap;
92
93 public:
94 Visitor(PdbIndex &ctx, llvm::IntervalMap<uint64_t, uint16_t> &imap)
95 : m_ctx(ctx), m_imap(imap) {}
96
97 void visit(const SectionContrib &C) override {
98 if (C.Size == 0)
99 return;
100
101 uint64_t va = m_ctx.MakeVirtualAddress(C.ISect, C.Off);
102 if (va == LLDB_INVALID_ADDRESS)
103 return;
104 uint64_t end = va + C.Size;
105 // IntervalMap's start and end represent a closed range, not a half-open
106 // range, so we have to subtract 1.
107 m_imap.insert(va, end - 1, C.Imod);
108 }
109 void visit(const SectionContrib2 &C) override { visit(C.Base); }
110 };
111 Visitor v(*this, m_va_to_modi);
112 dbi().visitSectionContributions(v);
113 }
114
BuildAddrToSymbolMap(CompilandIndexItem & cci)115 void PdbIndex::BuildAddrToSymbolMap(CompilandIndexItem &cci) {
116 lldbassert(cci.m_symbols_by_va.empty() &&
117 "Addr to symbol map is already built!");
118 uint16_t modi = cci.m_id.modi;
119 const CVSymbolArray &syms = cci.m_debug_stream.getSymbolArray();
120 for (auto iter = syms.begin(); iter != syms.end(); ++iter) {
121 if (!SymbolHasAddress(*iter))
122 continue;
123
124 SegmentOffset so = GetSegmentAndOffset(*iter);
125 lldb::addr_t va = MakeVirtualAddress(so.segment, so.offset);
126 if (va == LLDB_INVALID_ADDRESS)
127 continue;
128
129 PdbCompilandSymId cu_sym_id(modi, iter.offset());
130
131 // It's rare, but we could have multiple symbols with the same address
132 // because of identical comdat folding. Right now, the first one will win.
133 cci.m_symbols_by_va.insert(std::make_pair(va, PdbSymUid(cu_sym_id)));
134 }
135 }
136
FindSymbolsByVa(lldb::addr_t va)137 std::vector<SymbolAndUid> PdbIndex::FindSymbolsByVa(lldb::addr_t va) {
138 std::vector<SymbolAndUid> result;
139
140 llvm::Optional<uint16_t> modi = GetModuleIndexForVa(va);
141 if (!modi)
142 return result;
143
144 CompilandIndexItem &cci = compilands().GetOrCreateCompiland(*modi);
145 if (cci.m_symbols_by_va.empty())
146 BuildAddrToSymbolMap(cci);
147
148 // The map is sorted by starting address of the symbol. So for example
149 // we could (in theory) have this situation
150 //
151 // [------------------]
152 // [----------]
153 // [-----------]
154 // [-------------]
155 // [----]
156 // [-----]
157 // ^ Address we're searching for
158 // In order to find this, we use the upper_bound of the key value which would
159 // be the first symbol whose starting address is higher than the element we're
160 // searching for.
161
162 auto ub = cci.m_symbols_by_va.upper_bound(va);
163
164 for (auto iter = cci.m_symbols_by_va.begin(); iter != ub; ++iter) {
165 PdbCompilandSymId cu_sym_id = iter->second.asCompilandSym();
166 CVSymbol sym = ReadSymbolRecord(cu_sym_id);
167
168 SegmentOffsetLength sol;
169 if (SymbolIsCode(sym))
170 sol = GetSegmentOffsetAndLength(sym);
171 else
172 sol.so = GetSegmentAndOffset(sym);
173
174 lldb::addr_t start = MakeVirtualAddress(sol.so.segment, sol.so.offset);
175 if (start == LLDB_INVALID_ADDRESS)
176 continue;
177
178 lldb::addr_t end = start + sol.length;
179 if (va >= start && va < end)
180 result.push_back({std::move(sym), iter->second});
181 }
182
183 return result;
184 }
185
ReadSymbolRecord(PdbCompilandSymId cu_sym) const186 CVSymbol PdbIndex::ReadSymbolRecord(PdbCompilandSymId cu_sym) const {
187 const CompilandIndexItem *cci = compilands().GetCompiland(cu_sym.modi);
188 auto iter = cci->m_debug_stream.getSymbolArray().at(cu_sym.offset);
189 lldbassert(iter != cci->m_debug_stream.getSymbolArray().end());
190 return *iter;
191 }
192
ReadSymbolRecord(PdbGlobalSymId global) const193 CVSymbol PdbIndex::ReadSymbolRecord(PdbGlobalSymId global) const {
194 return symrecords().readRecord(global.offset);
195 }
196