lld/COFF/TypeMerger.h

   1 //===- TypeMerger.h ---------------------------------------------*- 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 LLD_COFF_TYPEMERGER_H
  10 #define LLD_COFF_TYPEMERGER_H
  11
  12 #include "Config.h"
  13 #include "DebugTypes.h"
  14 #include "lld/Common/Timer.h"
  15 #include "llvm/DebugInfo/CodeView/MergingTypeTableBuilder.h"
  16 #include "llvm/DebugInfo/CodeView/TypeHashing.h"
  17 #include "llvm/Support/Allocator.h"
  18 #include <atomic>
  19
  20 namespace lld {
  21 namespace coff {
  22
  23 using llvm::codeview::GloballyHashedType;
  24 using llvm::codeview::TypeIndex;
  25
  26 struct GHashState;
  27
  28 class TypeMerger {
  29 public:
  30   TypeMerger(COFFLinkerContext &ctx, llvm::BumpPtrAllocator &alloc);
  31
  32   ~TypeMerger();
  33
  34   /// Get the type table or the global type table if /DEBUG:GHASH is enabled.
  35   inline llvm::codeview::TypeCollection &getTypeTable() {
  36     assert(!config->debugGHashes);
  37     return typeTable;
  38   }
  39
  40   /// Get the ID table or the global ID table if /DEBUG:GHASH is enabled.
  41   inline llvm::codeview::TypeCollection &getIDTable() {
  42     assert(!config->debugGHashes);
  43     return idTable;
  44   }
  45
  46   /// Use global hashes to eliminate duplicate types and identify unique type
  47   /// indices in each TpiSource.
  48   void mergeTypesWithGHash();
  49
  50   /// Map from PDB function id type indexes to PDB function type indexes.
  51   /// Populated after mergeTypesWithGHash.
  52   llvm::DenseMap<TypeIndex, TypeIndex> funcIdToType;
  53
  54   /// Type records that will go into the PDB TPI stream.
  55   llvm::codeview::MergingTypeTableBuilder typeTable;
  56
  57   /// Item records that will go into the PDB IPI stream.
  58   llvm::codeview::MergingTypeTableBuilder idTable;
  59
  60   // When showSummary is enabled, these are histograms of TPI and IPI records
  61   // keyed by type index.
  62   SmallVector<uint32_t, 0> tpiCounts;
  63   SmallVector<uint32_t, 0> ipiCounts;
  64
  65   /// Dependency type sources, such as type servers or PCH object files. These
  66   /// must be processed before objects that rely on them. Set by
  67   /// sortDependencies.
  68   ArrayRef<TpiSource *> dependencySources;
  69
  70   /// Object file sources. These must be processed after dependencySources.
  71   ArrayRef<TpiSource *> objectSources;
  72
  73   /// Sorts the dependencies and reassigns TpiSource indices.
  74   void sortDependencies();
  75
  76 private:
  77   void clearGHashes();
  78
  79   COFFLinkerContext &ctx;
  80 };
  81
  82 } // namespace coff
  83 } // namespace lld
  84
  85 #endif