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
86