include/llvm/DebugInfo/PDB/Native/SymbolCache.h

   1 //==- SymbolCache.h - Cache of native symbols and ids ------------*- 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 #ifndef LLVM_DEBUGINFO_PDB_NATIVE_SYMBOLCACHE_H
  10 #define LLVM_DEBUGINFO_PDB_NATIVE_SYMBOLCACHE_H
  11
  12 #include "llvm/ADT/DenseMap.h"
  13 #include "llvm/DebugInfo/CodeView/TypeDeserializer.h"
  14 #include "llvm/DebugInfo/CodeView/TypeIndex.h"
  15 #include "llvm/DebugInfo/CodeView/TypeRecord.h"
  16 #include "llvm/DebugInfo/PDB/Native/NativeRawSymbol.h"
  17 #include "llvm/Support/Allocator.h"
  18
  19 #include <memory>
  20 #include <vector>
  21
  22 namespace llvm {
  23 namespace pdb {
  24 class DbiStream;
  25 class PDBFile;
  26
  27 class SymbolCache {
  28   NativeSession &Session;
  29   DbiStream *Dbi = nullptr;
  30
  31   /// Cache of all stable symbols, indexed by SymIndexId.  Just because a
  32   /// symbol has been parsed does not imply that it will be stable and have
  33   /// an Id.  Id allocation is an implementation, with the only guarantee
  34   /// being that once an Id is allocated, the symbol can be assumed to be
  35   /// cached.
  36   std::vector<std::unique_ptr<NativeRawSymbol>> Cache;
  37
  38   /// For type records from the TPI stream which have been paresd and cached,
  39   /// stores a mapping to SymIndexId of the cached symbol.
  40   DenseMap<codeview::TypeIndex, SymIndexId> TypeIndexToSymbolId;
  41
  42   /// For field list members which have been parsed and cached, stores a mapping
  43   /// from (IndexOfClass, MemberIndex) to the corresponding SymIndexId of the
  44   /// cached symbol.
  45   DenseMap<std::pair<codeview::TypeIndex, uint32_t>, SymIndexId>
  46       FieldListMembersToSymbolId;
  47
  48   /// List of SymIndexIds for each compiland, indexed by compiland index as they
  49   /// appear in the PDB file.
  50   std::vector<SymIndexId> Compilands;
  51
  52   /// Map from global symbol offset to SymIndexId.
  53   DenseMap<uint32_t, SymIndexId> GlobalOffsetToSymbolId;
  54
  55   SymIndexId createSymbolPlaceholder() {
  56     SymIndexId Id = Cache.size();
  57     Cache.push_back(nullptr);
  58     return Id;
  59   }
  60
  61   template <typename ConcreteSymbolT, typename CVRecordT, typename... Args>
  62   SymIndexId createSymbolForType(codeview::TypeIndex TI, codeview::CVType CVT,
  63                                  Args &&... ConstructorArgs) {
  64     CVRecordT Record;
  65     if (auto EC =
  66             codeview::TypeDeserializer::deserializeAs<CVRecordT>(CVT, Record)) {
  67       consumeError(std::move(EC));
  68       return 0;
  69     }
  70
  71     return createSymbol<ConcreteSymbolT>(
  72         TI, std::move(Record), std::forward<Args>(ConstructorArgs)...);
  73   }
  74
  75   SymIndexId createSymbolForModifiedType(codeview::TypeIndex ModifierTI,
  76                                          codeview::CVType CVT);
  77
  78   SymIndexId createSimpleType(codeview::TypeIndex TI,
  79                               codeview::ModifierOptions Mods);
  80
  81 public:
  82   SymbolCache(NativeSession &Session, DbiStream *Dbi);
  83
  84   template <typename ConcreteSymbolT, typename... Args>
  85   SymIndexId createSymbol(Args &&... ConstructorArgs) {
  86     SymIndexId Id = Cache.size();
  87
  88     // Initial construction must not access the cache, since it must be done
  89     // atomically.
  90     auto Result = std::make_unique<ConcreteSymbolT>(
  91         Session, Id, std::forward<Args>(ConstructorArgs)...);
  92     Result->SymbolId = Id;
  93
  94     NativeRawSymbol *NRS = static_cast<NativeRawSymbol *>(Result.get());
  95     Cache.push_back(std::move(Result));
  96
  97     // After the item is in the cache, we can do further initialization which
  98     // is then allowed to access the cache.
  99     NRS->initialize();
 100     return Id;
 101   }
 102
 103   std::unique_ptr<IPDBEnumSymbols>
 104   createTypeEnumerator(codeview::TypeLeafKind Kind);
 105
 106   std::unique_ptr<IPDBEnumSymbols>
 107   createTypeEnumerator(std::vector<codeview::TypeLeafKind> Kinds);
 108
 109   std::unique_ptr<IPDBEnumSymbols>
 110   createGlobalsEnumerator(codeview::SymbolKind Kind);
 111
 112   SymIndexId findSymbolByTypeIndex(codeview::TypeIndex TI);
 113
 114   template <typename ConcreteSymbolT, typename... Args>
 115   SymIndexId getOrCreateFieldListMember(codeview::TypeIndex FieldListTI,
 116                                         uint32_t Index,
 117                                         Args &&... ConstructorArgs) {
 118     SymIndexId SymId = Cache.size();
 119     std::pair<codeview::TypeIndex, uint32_t> Key{FieldListTI, Index};
 120     auto Result = FieldListMembersToSymbolId.try_emplace(Key, SymId);
 121     if (Result.second)
 122       SymId =
 123           createSymbol<ConcreteSymbolT>(std::forward<Args>(ConstructorArgs)...);
 124     else
 125       SymId = Result.first->second;
 126     return SymId;
 127   }
 128
 129   SymIndexId getOrCreateGlobalSymbolByOffset(uint32_t Offset);
 130
 131   std::unique_ptr<PDBSymbolCompiland> getOrCreateCompiland(uint32_t Index);
 132   uint32_t getNumCompilands() const;
 133
 134   std::unique_ptr<PDBSymbol> getSymbolById(SymIndexId SymbolId) const;
 135
 136   NativeRawSymbol &getNativeSymbolById(SymIndexId SymbolId) const;
 137
 138   template <typename ConcreteT>
 139   ConcreteT &getNativeSymbolById(SymIndexId SymbolId) const {
 140     return static_cast<ConcreteT &>(getNativeSymbolById(SymbolId));
 141   }
 142 };
 143
 144 } // namespace pdb
 145 } // namespace llvm
 146
 147 #endif