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PdbIndex.cpp
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1 //===-- PdbIndex.cpp --------------------------------------------*- 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 #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 
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 
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>>
42 PdbIndex::create(std::unique_ptr<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 = std::move(file);
57 
58  return std::move(result);
59 }
60 
62  uint32_t offset) const {
63  // Segment indices are 1-based.
64  lldbassert(segment > 0);
65 
66  uint32_t max_section = dbi().getSectionHeaders().size();
67  lldbassert(segment <= max_section + 1);
68 
69  // If this is an absolute symbol, it's indicated by the magic section index
70  // |max_section+1|. In this case, the offset is meaningless, so just return.
71  if (segment == max_section + 1)
72  return LLDB_INVALID_ADDRESS;
73 
74  const llvm::object::coff_section &cs = dbi().getSectionHeaders()[segment - 1];
75  return m_load_address + static_cast<lldb::addr_t>(cs.VirtualAddress) +
76  static_cast<lldb::addr_t>(offset);
77 }
78 
80  return MakeVirtualAddress(so.segment, so.offset);
81 }
82 
83 llvm::Optional<uint16_t>
85  return GetModuleIndexForVa(MakeVirtualAddress(segment, offset));
86 }
87 
88 llvm::Optional<uint16_t> PdbIndex::GetModuleIndexForVa(lldb::addr_t va) const {
89  auto iter = m_va_to_modi.find(va);
90  if (iter == m_va_to_modi.end())
91  return llvm::None;
92 
93  return iter.value();
94 }
95 
97  class Visitor : public ISectionContribVisitor {
98  PdbIndex &m_ctx;
99  llvm::IntervalMap<uint64_t, uint16_t> &m_imap;
100 
101  public:
102  Visitor(PdbIndex &ctx, llvm::IntervalMap<uint64_t, uint16_t> &imap)
103  : m_ctx(ctx), m_imap(imap) {}
104 
105  void visit(const SectionContrib &C) override {
106  if (C.Size == 0)
107  return;
108 
109  uint64_t va = m_ctx.MakeVirtualAddress(C.ISect, C.Off);
110  uint64_t end = va + C.Size;
111  // IntervalMap's start and end represent a closed range, not a half-open
112  // range, so we have to subtract 1.
113  m_imap.insert(va, end - 1, C.Imod);
114  }
115  void visit(const SectionContrib2 &C) override { visit(C.Base); }
116  };
117  Visitor v(*this, m_va_to_modi);
118  dbi().visitSectionContributions(v);
119 }
120 
121 void PdbIndex::BuildAddrToSymbolMap(CompilandIndexItem &cci) {
122  lldbassert(cci.m_symbols_by_va.empty() &&
123  "Addr to symbol map is already built!");
124  uint16_t modi = cci.m_id.modi;
125  const CVSymbolArray &syms = cci.m_debug_stream.getSymbolArray();
126  for (auto iter = syms.begin(); iter != syms.end(); ++iter) {
127  if (!SymbolHasAddress(*iter))
128  continue;
129 
132 
133  PdbCompilandSymId cu_sym_id(modi, iter.offset());
134 
135  // It's rare, but we could have multiple symbols with the same address
136  // because of identical comdat folding. Right now, the first one will win.
137  cci.m_symbols_by_va.insert(std::make_pair(va, PdbSymUid(cu_sym_id)));
138  }
139 }
140 
141 std::vector<SymbolAndUid> PdbIndex::FindSymbolsByVa(lldb::addr_t va) {
142  std::vector<SymbolAndUid> result;
143 
144  llvm::Optional<uint16_t> modi = GetModuleIndexForVa(va);
145  if (!modi)
146  return result;
147 
149  if (cci.m_symbols_by_va.empty())
150  BuildAddrToSymbolMap(cci);
151 
152  // The map is sorted by starting address of the symbol. So for example
153  // we could (in theory) have this situation
154  //
155  // [------------------]
156  // [----------]
157  // [-----------]
158  // [-------------]
159  // [----]
160  // [-----]
161  // ^ Address we're searching for
162  // In order to find this, we use the upper_bound of the key value which would
163  // be the first symbol whose starting address is higher than the element we're
164  // searching for.
165 
166  auto ub = cci.m_symbols_by_va.upper_bound(va);
167 
168  for (auto iter = cci.m_symbols_by_va.begin(); iter != ub; ++iter) {
169  PdbCompilandSymId cu_sym_id = iter->second.asCompilandSym();
170  CVSymbol sym = ReadSymbolRecord(cu_sym_id);
171 
173  if (SymbolIsCode(sym))
174  sol = GetSegmentOffsetAndLength(sym);
175  else
176  sol.so = GetSegmentAndOffset(sym);
177 
178  lldb::addr_t start = MakeVirtualAddress(sol.so);
179  lldb::addr_t end = start + sol.length;
180  if (va >= start && va < end)
181  result.push_back({std::move(sym), iter->second});
182  }
183 
184  return result;
185 }
186 
188  const CompilandIndexItem *cci = compilands().GetCompiland(cu_sym.modi);
189  auto iter = cci->m_debug_stream.getSymbolArray().at(cu_sym.offset);
190  lldbassert(iter != cci->m_debug_stream.getSymbolArray().end());
191  return *iter;
192 }
193 
195  return symrecords().readRecord(global.offset);
196 }
Represents a single compile unit.
SegmentOffsetLength GetSegmentOffsetAndLength(const llvm::codeview::CVSymbol &sym)
Enumerations for broadcasting.
Definition: SBLaunchInfo.h:14
static llvm::Expected< std::unique_ptr< PdbIndex > > create(std::unique_ptr< llvm::pdb::PDBFile >)
Definition: PdbIndex.cpp:42
SegmentOffset GetSegmentAndOffset(const llvm::codeview::CVSymbol &sym)
llvm::pdb::ModuleDebugStreamRef m_debug_stream
#define lldbassert(x)
Definition: LLDBAssert.h:15
bool SymbolIsCode(const llvm::codeview::CVSymbol &sym)
PdbIndex - Lazy access to the important parts of a PDB file.
Definition: PdbIndex.h:48
llvm::codeview::CVSymbol ReadSymbolRecord(PdbCompilandSymId cu_sym) const
Definition: PdbIndex.cpp:187
std::vector< SymbolAndUid > FindSymbolsByVa(lldb::addr_t va)
Definition: PdbIndex.cpp:141
CompilandIndexItem & GetOrCreateCompiland(uint16_t modi)
llvm::Optional< uint16_t > GetModuleIndexForAddr(uint16_t segment, uint32_t offset) const
Definition: PdbIndex.cpp:84
#define LLDB_INVALID_ADDRESS
Invalid value definitions.
Definition: lldb-defines.h:85
llvm::Optional< uint16_t > GetModuleIndexForVa(lldb::addr_t va) const
Definition: PdbIndex.cpp:88
lldb::addr_t MakeVirtualAddress(uint16_t segment, uint32_t offset) const
Definition: PdbIndex.cpp:61
bool SymbolHasAddress(const llvm::codeview::CVSymbol &sym)
uint64_t addr_t
Definition: lldb-types.h:83
const CompilandIndexItem * GetCompiland(uint16_t modi) const
llvm::pdb::DbiStream & dbi()
Definition: PdbIndex.h:123
CompileUnitIndex & compilands()
Definition: PdbIndex.h:144
std::map< lldb::addr_t, PdbSymUid > m_symbols_by_va
llvm::pdb::SymbolStream & symrecords()
Definition: PdbIndex.h:141
#define ASSIGN_PTR_OR_RETURN(result_ptr, expr)
Definition: PdbIndex.cpp:33