1 files changed, 148 insertions, 0 deletions
diff --git a/include/llvm/DebugInfo/PDB/Native/SymbolCache.h b/include/llvm/DebugInfo/PDB/Native/SymbolCache.h
new file mode 100644
index 000000000000..08e1d41e6ee9
--- /dev/null
+++ b/include/llvm/DebugInfo/PDB/Native/SymbolCache.h
@@ -0,0 +1,148 @@
+//==- SymbolCache.h - Cache of native symbols and ids ------------*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEBUGINFO_PDB_NATIVE_SYMBOLCACHE_H
+#define LLVM_DEBUGINFO_PDB_NATIVE_SYMBOLCACHE_H
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/DebugInfo/CodeView/TypeDeserializer.h"
+#include "llvm/DebugInfo/CodeView/TypeIndex.h"
+#include "llvm/DebugInfo/CodeView/TypeRecord.h"
+#include "llvm/DebugInfo/PDB/Native/NativeRawSymbol.h"
+#include "llvm/Support/Allocator.h"
+
+#include <memory>
+#include <vector>
+
+namespace llvm {
+namespace pdb {
+class DbiStream;
+class PDBFile;
+
+class SymbolCache {
+  NativeSession &Session;
+  DbiStream *Dbi = nullptr;
+
+  /// Cache of all stable symbols, indexed by SymIndexId.  Just because a
+  /// symbol has been parsed does not imply that it will be stable and have
+  /// an Id.  Id allocation is an implementation, with the only guarantee
+  /// being that once an Id is allocated, the symbol can be assumed to be
+  /// cached.
+  std::vector<std::unique_ptr<NativeRawSymbol>> Cache;
+
+  /// For type records from the TPI stream which have been paresd and cached,
+  /// stores a mapping to SymIndexId of the cached symbol.
+  DenseMap<codeview::TypeIndex, SymIndexId> TypeIndexToSymbolId;
+
+  /// For field list members which have been parsed and cached, stores a mapping
+  /// from (IndexOfClass, MemberIndex) to the corresponding SymIndexId of the
+  /// cached symbol.
+  DenseMap<std::pair<codeview::TypeIndex, uint32_t>, SymIndexId>
+      FieldListMembersToSymbolId;
+
+  /// List of SymIndexIds for each compiland, indexed by compiland index as they
+  /// appear in the PDB file.
+  std::vector<SymIndexId> Compilands;
+
+  /// Map from global symbol offset to SymIndexId.
+  DenseMap<uint32_t, SymIndexId> GlobalOffsetToSymbolId;
+
+  SymIndexId createSymbolPlaceholder() {
+    SymIndexId Id = Cache.size();
+    Cache.push_back(nullptr);
+    return Id;
+  }
+
+  template <typename ConcreteSymbolT, typename CVRecordT, typename... Args>
+  SymIndexId createSymbolForType(codeview::TypeIndex TI, codeview::CVType CVT,
+                                 Args &&... ConstructorArgs) {
+    CVRecordT Record;
+    if (auto EC =
+            codeview::TypeDeserializer::deserializeAs<CVRecordT>(CVT, Record)) {
+      consumeError(std::move(EC));
+      return 0;
+    }
+
+    return createSymbol<ConcreteSymbolT>(
+        TI, std::move(Record), std::forward<Args>(ConstructorArgs)...);
+  }
+
+  SymIndexId createSymbolForModifiedType(codeview::TypeIndex ModifierTI,
+                                         codeview::CVType CVT);
+
+  SymIndexId createSimpleType(codeview::TypeIndex TI,
+                              codeview::ModifierOptions Mods);
+
+public:
+  SymbolCache(NativeSession &Session, DbiStream *Dbi);
+
+  template <typename ConcreteSymbolT, typename... Args>
+  SymIndexId createSymbol(Args &&... ConstructorArgs) {
+    SymIndexId Id = Cache.size();
+
+    // Initial construction must not access the cache, since it must be done
+    // atomically.
+    auto Result = llvm::make_unique<ConcreteSymbolT>(
+        Session, Id, std::forward<Args>(ConstructorArgs)...);
+    Result->SymbolId = Id;
+
+    NativeRawSymbol *NRS = static_cast<NativeRawSymbol *>(Result.get());
+    Cache.push_back(std::move(Result));
+
+    // After the item is in the cache, we can do further initialization which
+    // is then allowed to access the cache.
+    NRS->initialize();
+    return Id;
+  }
+
+  std::unique_ptr<IPDBEnumSymbols>
+  createTypeEnumerator(codeview::TypeLeafKind Kind);
+
+  std::unique_ptr<IPDBEnumSymbols>
+  createTypeEnumerator(std::vector<codeview::TypeLeafKind> Kinds);
+
+  std::unique_ptr<IPDBEnumSymbols>
+  createGlobalsEnumerator(codeview::SymbolKind Kind);
+
+  SymIndexId findSymbolByTypeIndex(codeview::TypeIndex TI);
+
+  template <typename ConcreteSymbolT, typename... Args>
+  SymIndexId getOrCreateFieldListMember(codeview::TypeIndex FieldListTI,
+                                        uint32_t Index,
+                                        Args &&... ConstructorArgs) {
+    SymIndexId SymId = Cache.size();
+    std::pair<codeview::TypeIndex, uint32_t> Key{FieldListTI, Index};
+    auto Result = FieldListMembersToSymbolId.try_emplace(Key, SymId);
+    if (Result.second)
+      SymId =
+          createSymbol<ConcreteSymbolT>(std::forward<Args>(ConstructorArgs)...);
+    else
+      SymId = Result.first->second;
+    return SymId;
+  }
+
+  SymIndexId getOrCreateGlobalSymbolByOffset(uint32_t Offset);
+
+  std::unique_ptr<PDBSymbolCompiland> getOrCreateCompiland(uint32_t Index);
+  uint32_t getNumCompilands() const;
+
+  std::unique_ptr<PDBSymbol> getSymbolById(SymIndexId SymbolId) const;
+
+  NativeRawSymbol &getNativeSymbolById(SymIndexId SymbolId) const;
+
+  template <typename ConcreteT>
+  ConcreteT &getNativeSymbolById(SymIndexId SymbolId) const {
+    return static_cast<ConcreteT &>(getNativeSymbolById(SymbolId));
+  }
+};
+
+} // namespace pdb
+} // namespace llvm
+
+#endif