Revert "[PDB] Merge types in parallel when using ghashing"

This reverts commit 49b3459.

Author: rnk

lld/COFF/DebugTypes.cpp

@@ -10,37 +10,32 @@
 #define LLD_COFF_DEBUGTYPES_H
 
 #include "lld/Common/LLVM.h"
-#include "llvm/ADT/BitVector.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/DebugInfo/CodeView/TypeIndexDiscovery.h"
-#include "llvm/DebugInfo/CodeView/TypeRecord.h"
+#include "llvm/DebugInfo/CodeView/TypeIndex.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/MemoryBuffer.h"
 
 namespace llvm {
 namespace codeview {
-struct GloballyHashedType;
+class PrecompRecord;
+class TypeServer2Record;
 } // namespace codeview
 namespace pdb {
 class NativeSession;
-class TpiStream;
 }
 } // namespace llvm
 
 namespace lld {
 namespace coff {
 
-using llvm::codeview::GloballyHashedType;
 using llvm::codeview::TypeIndex;
 
 class ObjFile;
 class PDBInputFile;
 class TypeMerger;
-struct GHashState;
 
 class TpiSource {
 public:
-  enum TpiKind : uint8_t { Regular, PCH, UsingPCH, PDB, PDBIpi, UsingPDB };
+  enum TpiKind { Regular, PCH, UsingPCH, PDB, PDBIpi, UsingPDB };
 
   TpiSource(TpiKind k, ObjFile *f);
   virtual ~TpiSource();
@@ -58,97 +53,21 @@ class TpiSource {
   /// caller-provided ObjectIndexMap.
   virtual Error mergeDebugT(TypeMerger *m);
 
-  /// Load global hashes, either by hashing types directly, or by loading them
-  /// from LLVM's .debug$H section.
-  virtual void loadGHashes();
-
-  /// Use global hashes to merge type information.
-  virtual void remapTpiWithGHashes(GHashState *g);
-
-  // Remap a type index in place.
-  bool remapTypeIndex(TypeIndex &ti, llvm::codeview::TiRefKind refKind) const;
-
-protected:
-  void remapRecord(MutableArrayRef<uint8_t> rec,
-                   ArrayRef<llvm::codeview::TiReference> typeRefs);
-
-  void mergeTypeRecord(llvm::codeview::CVType ty);
-
-  // Merge the type records listed in uniqueTypes. beginIndex is the TypeIndex
-  // of the first record in this source, typically 0x1000. When PCHs are
-  // involved, it may start higher.
-  void mergeUniqueTypeRecords(
-      ArrayRef<uint8_t> debugTypes,
-      TypeIndex beginIndex = TypeIndex(TypeIndex::FirstNonSimpleIndex));
-
-  // Use the ghash table to construct a map from source type index to
-  // destination PDB type index. Usable for either TPI or IPI.
-  void fillMapFromGHashes(GHashState *m,
-                          llvm::SmallVectorImpl<TypeIndex> &indexMap);
-
-  // Copies ghashes from a vector into an array. These are long lived, so it's
-  // worth the time to copy these into an appropriately sized vector to reduce
-  // memory usage.
-  void assignGHashesFromVector(std::vector<GloballyHashedType> &&hashVec);
-
-  // Walk over file->debugTypes and fill in the isItemIndex bit vector.
-  void fillIsItemIndexFromDebugT();
-
-public:
-  bool remapTypesInSymbolRecord(MutableArrayRef<uint8_t> rec);
-
-  void remapTypesInTypeRecord(MutableArrayRef<uint8_t> rec);
-
   /// Is this a dependent file that needs to be processed first, before other
   /// OBJs?
   virtual bool isDependency() const { return false; }
 
-  /// Returns true if this type record should be omitted from the PDB, even if
-  /// it is unique. This prevents a record from being added to the input ghash
-  /// table.
-  bool shouldOmitFromPdb(uint32_t ghashIdx) {
-    return ghashIdx == endPrecompGHashIdx;
-  }
-
-  /// All sources of type information in the program.
-  static std::vector<TpiSource *> instances;
-
-  /// Dependency type sources, such as type servers or PCH object files. These
-  /// must be processed before objects that rely on them. Set by
-  /// TpiSources::sortDependencies.
-  static ArrayRef<TpiSource *> dependencySources;
-
-  /// Object file sources. These must be processed after dependencySources.
-  static ArrayRef<TpiSource *> objectSources;
-
-  /// Sorts the dependencies and reassigns TpiSource indices.
-  static void sortDependencies();
+  static void forEachSource(llvm::function_ref<void(TpiSource *)> fn);
 
   static uint32_t countTypeServerPDBs();
   static uint32_t countPrecompObjs();
 
-  /// Free heap allocated ghashes.
-  static void clearGHashes();
-
   /// Clear global data structures for TpiSources.
   static void clear();
 
   const TpiKind kind;
-  bool ownedGHashes = true;
-  uint32_t tpiSrcIdx = 0;
-
-protected:
-  /// The ghash index (zero based, not 0x1000-based) of the LF_ENDPRECOMP record
-  /// in this object, if one exists. This is the all ones value otherwise. It is
-  /// recorded here so that it can be omitted from the final ghash table.
-  uint32_t endPrecompGHashIdx = ~0U;
-
-public:
   ObjFile *file;
 
-  /// An error encountered during type merging, if any.
-  Error typeMergingError = Error::success();
-
   // Storage for tpiMap or ipiMap, depending on the kind of source.
   llvm::SmallVector<TypeIndex, 0> indexMapStorage;
 
@@ -157,31 +76,6 @@ class TpiSource {
   // objects.
   llvm::ArrayRef<TypeIndex> tpiMap;
   llvm::ArrayRef<TypeIndex> ipiMap;
-
-  /// Array of global type hashes, indexed by TypeIndex. May be calculated on
-  /// demand, or present in input object files.
-  llvm::ArrayRef<llvm::codeview::GloballyHashedType> ghashes;
-
-  /// When ghashing is used, record the mapping from LF_[M]FUNC_ID to function
-  /// type index here. Both indices are PDB indices, not object type indexes.
-  llvm::DenseMap<TypeIndex, TypeIndex> funcIdToType;
-
-  /// Indicates if a type record is an item index or a type index.
-  llvm::BitVector isItemIndex;
-
-  /// A list of all "unique" type indices which must be merged into the final
-  /// PDB. GHash type deduplication produces this list, and it should be
-  /// considerably smaller than the input.
-  std::vector<uint32_t> uniqueTypes;
-
-  struct MergedInfo {
-    std::vector<uint8_t> recs;
-    std::vector<uint16_t> recSizes;
-    std::vector<uint32_t> recHashes;
-  };
-
-  MergedInfo mergedTpi;
-  MergedInfo mergedIpi;
 };
 
 TpiSource *makeTpiSource(ObjFile *file);

lld/COFF/DebugTypes.h

@@ -69,13 +69,13 @@ bool link(ArrayRef<const char *> args, bool canExitEarly, raw_ostream &stdoutOS,
   lld::stderrOS = &stderrOS;
 
   errorHandler().cleanupCallback = []() {
-    TpiSource::clear();
     freeArena();
     ObjFile::instances.clear();
     PDBInputFile::instances.clear();
     ImportFile::instances.clear();
     BitcodeFile::instances.clear();
     memset(MergeChunk::instances, 0, sizeof(MergeChunk::instances));
+    TpiSource::clear();
     OutputSection::clear();
   };