contrib/llvm-project/lldb/source/Plugins/SymbolFile/NativePDB/PdbIndex.cpp

   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
  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
  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
  61 lldb::addr_t PdbIndex::MakeVirtualAddress(uint16_t segment,
  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
  79 lldb::addr_t PdbIndex::MakeVirtualAddress(const SegmentOffset &so) const {
  80   return MakeVirtualAddress(so.segment, so.offset);
  81 }
  82
  83 llvm::Optional<uint16_t>
  84 PdbIndex::GetModuleIndexForAddr(uint16_t segment, uint32_t offset) const {
  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
  96 void PdbIndex::ParseSectionContribs() {
  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
 130     SegmentOffset so = GetSegmentAndOffset(*iter);
 131     lldb::addr_t va = MakeVirtualAddress(so);
 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
 148   CompilandIndexItem &cci = compilands().GetOrCreateCompiland(*modi);
 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
 172     SegmentOffsetLength sol;
 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
 187 CVSymbol PdbIndex::ReadSymbolRecord(PdbCompilandSymId cu_sym) const {
 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
 194 CVSymbol PdbIndex::ReadSymbolRecord(PdbGlobalSymId global) const {
 195   return symrecords().readRecord(global.offset);
 196 }