lld/COFF/DebugTypes.h

   1 //===- DebugTypes.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_DEBUGTYPES_H
  10 #define LLD_COFF_DEBUGTYPES_H
  11
  12 #include "lld/Common/LLVM.h"
  13 #include "llvm/ADT/BitVector.h"
  14 #include "llvm/ADT/DenseMap.h"
  15 #include "llvm/DebugInfo/CodeView/TypeIndexDiscovery.h"
  16 #include "llvm/DebugInfo/CodeView/TypeRecord.h"
  17 #include "llvm/Support/Error.h"
  18 #include "llvm/Support/MemoryBuffer.h"
  19
  20 namespace llvm::codeview {
  21 struct GloballyHashedType;
  22 }
  23 namespace llvm::pdb {
  24 class NativeSession;
  25 class TpiStream;
  26 }
  27
  28 namespace lld::coff {
  29
  30 using llvm::codeview::GloballyHashedType;
  31 using llvm::codeview::TypeIndex;
  32
  33 class ObjFile;
  34 class PDBInputFile;
  35 class TypeMerger;
  36 struct GHashState;
  37 class COFFLinkerContext;
  38
  39 class TpiSource {
  40 public:
  41   enum TpiKind : uint8_t { Regular, PCH, UsingPCH, PDB, PDBIpi, UsingPDB };
  42
  43   TpiSource(COFFLinkerContext &ctx, TpiKind k, ObjFile *f);
  44   virtual ~TpiSource();
  45
  46   /// Produce a mapping from the type and item indices used in the object
  47   /// file to those in the destination PDB.
  48   ///
  49   /// If the object file uses a type server PDB (compiled with /Zi), merge TPI
  50   /// and IPI from the type server PDB and return a map for it. Each unique type
  51   /// server PDB is merged at most once, so this may return an existing index
  52   /// mapping.
  53   ///
  54   /// If the object does not use a type server PDB (compiled with /Z7), we merge
  55   /// all the type and item records from the .debug$S stream and fill in the
  56   /// caller-provided ObjectIndexMap.
  57   virtual Error mergeDebugT(TypeMerger *m);
  58
  59   /// Load global hashes, either by hashing types directly, or by loading them
  60   /// from LLVM's .debug$H section.
  61   virtual void loadGHashes();
  62
  63   /// Use global hashes to merge type information.
  64   virtual void remapTpiWithGHashes(GHashState *g);
  65
  66   // Remap a type index in place.
  67   bool remapTypeIndex(TypeIndex &ti, llvm::codeview::TiRefKind refKind) const;
  68
  69 protected:
  70   void remapRecord(MutableArrayRef<uint8_t> rec,
  71                    ArrayRef<llvm::codeview::TiReference> typeRefs);
  72
  73   void mergeTypeRecord(TypeIndex curIndex, llvm::codeview::CVType ty);
  74
  75   // Merge the type records listed in uniqueTypes. beginIndex is the TypeIndex
  76   // of the first record in this source, typically 0x1000. When PCHs are
  77   // involved, it may start higher.
  78   void mergeUniqueTypeRecords(
  79       ArrayRef<uint8_t> debugTypes,
  80       TypeIndex beginIndex = TypeIndex(TypeIndex::FirstNonSimpleIndex));
  81
  82   // Use the ghash table to construct a map from source type index to
  83   // destination PDB type index. Usable for either TPI or IPI.
  84   void fillMapFromGHashes(GHashState *m);
  85
  86   // Copies ghashes from a vector into an array. These are long lived, so it's
  87   // worth the time to copy these into an appropriately sized vector to reduce
  88   // memory usage.
  89   void assignGHashesFromVector(std::vector<GloballyHashedType> &&hashVec);
  90
  91   // Walk over file->debugTypes and fill in the isItemIndex bit vector.
  92   void fillIsItemIndexFromDebugT();
  93
  94   COFFLinkerContext &ctx;
  95
  96 public:
  97   bool remapTypesInSymbolRecord(MutableArrayRef<uint8_t> rec);
  98
  99   void remapTypesInTypeRecord(MutableArrayRef<uint8_t> rec);
 100
 101   /// Is this a dependent file that needs to be processed first, before other
 102   /// OBJs?
 103   virtual bool isDependency() const { return false; }
 104
 105   /// Returns true if this type record should be omitted from the PDB, even if
 106   /// it is unique. This prevents a record from being added to the input ghash
 107   /// table.
 108   bool shouldOmitFromPdb(uint32_t ghashIdx) {
 109     return ghashIdx == endPrecompIdx;
 110   }
 111
 112   const TpiKind kind;
 113   bool ownedGHashes = true;
 114   uint32_t tpiSrcIdx = 0;
 115
 116   /// The index (zero based, not 0x1000-based) of the LF_ENDPRECOMP record in
 117   /// this object, if one exists. This is the all ones value otherwise. It is
 118   /// recorded here for validation, and so that it can be omitted from the final
 119   /// ghash table.
 120   uint32_t endPrecompIdx = ~0U;
 121
 122 public:
 123   ObjFile *file;
 124
 125   /// An error encountered during type merging, if any.
 126   Error typeMergingError = Error::success();
 127
 128   // Storage for tpiMap or ipiMap, depending on the kind of source.
 129   llvm::SmallVector<TypeIndex, 0> indexMapStorage;
 130
 131   // Source type index to PDB type index mapping for type and item records.
 132   // These mappings will be the same for /Z7 objects, and distinct for /Zi
 133   // objects.
 134   llvm::ArrayRef<TypeIndex> tpiMap;
 135   llvm::ArrayRef<TypeIndex> ipiMap;
 136
 137   /// Array of global type hashes, indexed by TypeIndex. May be calculated on
 138   /// demand, or present in input object files.
 139   llvm::ArrayRef<llvm::codeview::GloballyHashedType> ghashes;
 140
 141   /// When ghashing is used, record the mapping from LF_[M]FUNC_ID to function
 142   /// type index here. Both indices are PDB indices, not object type indexes.
 143   std::vector<std::pair<TypeIndex, TypeIndex>> funcIdToType;
 144
 145   /// Indicates if a type record is an item index or a type index.
 146   llvm::BitVector isItemIndex;
 147
 148   /// A list of all "unique" type indices which must be merged into the final
 149   /// PDB. GHash type deduplication produces this list, and it should be
 150   /// considerably smaller than the input.
 151   std::vector<uint32_t> uniqueTypes;
 152
 153   struct MergedInfo {
 154     std::vector<uint8_t> recs;
 155     std::vector<uint16_t> recSizes;
 156     std::vector<uint32_t> recHashes;
 157   };
 158
 159   MergedInfo mergedTpi;
 160   MergedInfo mergedIpi;
 161
 162   uint64_t nbTypeRecords = 0;
 163   uint64_t nbTypeRecordsBytes = 0;
 164 };
 165
 166 TpiSource *makeTpiSource(COFFLinkerContext &ctx, ObjFile *f);
 167 TpiSource *makeTypeServerSource(COFFLinkerContext &ctx,
 168                                 PDBInputFile *pdbInputFile);
 169 TpiSource *makeUseTypeServerSource(COFFLinkerContext &ctx, ObjFile *file,
 170                                    llvm::codeview::TypeServer2Record ts);
 171 TpiSource *makePrecompSource(COFFLinkerContext &ctx, ObjFile *file);
 172 TpiSource *makeUsePrecompSource(COFFLinkerContext &ctx, ObjFile *file,
 173                                 llvm::codeview::PrecompRecord ts);
 174
 175 } // namespace lld::coff
 176
 177 #endif