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 {
  21 namespace codeview {
  22 struct GloballyHashedType;
  23 } // namespace codeview
  24 namespace pdb {
  25 class NativeSession;
  26 class TpiStream;
  27 }
  28 } // namespace llvm
  29
  30 namespace lld {
  31 namespace coff {
  32
  33 using llvm::codeview::GloballyHashedType;
  34 using llvm::codeview::TypeIndex;
  35
  36 class ObjFile;
  37 class PDBInputFile;
  38 class TypeMerger;
  39 struct GHashState;
  40
  41 class TpiSource {
  42 public:
  43   enum TpiKind : uint8_t { Regular, PCH, UsingPCH, PDB, PDBIpi, UsingPDB };
  44
  45   TpiSource(TpiKind k, ObjFile *f);
  46   virtual ~TpiSource();
  47
  48   /// Produce a mapping from the type and item indices used in the object
  49   /// file to those in the destination PDB.
  50   ///
  51   /// If the object file uses a type server PDB (compiled with /Zi), merge TPI
  52   /// and IPI from the type server PDB and return a map for it. Each unique type
  53   /// server PDB is merged at most once, so this may return an existing index
  54   /// mapping.
  55   ///
  56   /// If the object does not use a type server PDB (compiled with /Z7), we merge
  57   /// all the type and item records from the .debug$S stream and fill in the
  58   /// caller-provided ObjectIndexMap.
  59   virtual Error mergeDebugT(TypeMerger *m);
  60
  61   /// Load global hashes, either by hashing types directly, or by loading them
  62   /// from LLVM's .debug$H section.
  63   virtual void loadGHashes();
  64
  65   /// Use global hashes to merge type information.
  66   virtual void remapTpiWithGHashes(GHashState *g);
  67
  68   // Remap a type index in place.
  69   bool remapTypeIndex(TypeIndex &ti, llvm::codeview::TiRefKind refKind) const;
  70
  71 protected:
  72   void remapRecord(MutableArrayRef<uint8_t> rec,
  73                    ArrayRef<llvm::codeview::TiReference> typeRefs);
  74
  75   void mergeTypeRecord(TypeIndex curIndex, llvm::codeview::CVType ty);
  76
  77   // Merge the type records listed in uniqueTypes. beginIndex is the TypeIndex
  78   // of the first record in this source, typically 0x1000. When PCHs are
  79   // involved, it may start higher.
  80   void mergeUniqueTypeRecords(
  81       ArrayRef<uint8_t> debugTypes,
  82       TypeIndex beginIndex = TypeIndex(TypeIndex::FirstNonSimpleIndex));
  83
  84   // Use the ghash table to construct a map from source type index to
  85   // destination PDB type index. Usable for either TPI or IPI.
  86   void fillMapFromGHashes(GHashState *m);
  87
  88   // Copies ghashes from a vector into an array. These are long lived, so it's
  89   // worth the time to copy these into an appropriately sized vector to reduce
  90   // memory usage.
  91   void assignGHashesFromVector(std::vector<GloballyHashedType> &&hashVec);
  92
  93   // Walk over file->debugTypes and fill in the isItemIndex bit vector.
  94   void fillIsItemIndexFromDebugT();
  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 == endPrecompGHashIdx;
 110   }
 111
 112   /// All sources of type information in the program.
 113   static std::vector<TpiSource *> instances;
 114
 115   /// Dependency type sources, such as type servers or PCH object files. These
 116   /// must be processed before objects that rely on them. Set by
 117   /// TpiSources::sortDependencies.
 118   static ArrayRef<TpiSource *> dependencySources;
 119
 120   /// Object file sources. These must be processed after dependencySources.
 121   static ArrayRef<TpiSource *> objectSources;
 122
 123   /// Sorts the dependencies and reassigns TpiSource indices.
 124   static void sortDependencies();
 125
 126   static uint32_t countTypeServerPDBs();
 127   static uint32_t countPrecompObjs();
 128
 129   /// Free heap allocated ghashes.
 130   static void clearGHashes();
 131
 132   /// Clear global data structures for TpiSources.
 133   static void clear();
 134
 135   const TpiKind kind;
 136   bool ownedGHashes = true;
 137   uint32_t tpiSrcIdx = 0;
 138
 139 protected:
 140   /// The ghash index (zero based, not 0x1000-based) of the LF_ENDPRECOMP record
 141   /// in this object, if one exists. This is the all ones value otherwise. It is
 142   /// recorded here so that it can be omitted from the final ghash table.
 143   uint32_t endPrecompGHashIdx = ~0U;
 144
 145 public:
 146   ObjFile *file;
 147
 148   /// An error encountered during type merging, if any.
 149   Error typeMergingError = Error::success();
 150
 151   // Storage for tpiMap or ipiMap, depending on the kind of source.
 152   llvm::SmallVector<TypeIndex, 0> indexMapStorage;
 153
 154   // Source type index to PDB type index mapping for type and item records.
 155   // These mappings will be the same for /Z7 objects, and distinct for /Zi
 156   // objects.
 157   llvm::ArrayRef<TypeIndex> tpiMap;
 158   llvm::ArrayRef<TypeIndex> ipiMap;
 159
 160   /// Array of global type hashes, indexed by TypeIndex. May be calculated on
 161   /// demand, or present in input object files.
 162   llvm::ArrayRef<llvm::codeview::GloballyHashedType> ghashes;
 163
 164   /// When ghashing is used, record the mapping from LF_[M]FUNC_ID to function
 165   /// type index here. Both indices are PDB indices, not object type indexes.
 166   std::vector<std::pair<TypeIndex, TypeIndex>> funcIdToType;
 167
 168   /// Indicates if a type record is an item index or a type index.
 169   llvm::BitVector isItemIndex;
 170
 171   /// A list of all "unique" type indices which must be merged into the final
 172   /// PDB. GHash type deduplication produces this list, and it should be
 173   /// considerably smaller than the input.
 174   std::vector<uint32_t> uniqueTypes;
 175
 176   struct MergedInfo {
 177     std::vector<uint8_t> recs;
 178     std::vector<uint16_t> recSizes;
 179     std::vector<uint32_t> recHashes;
 180   };
 181
 182   MergedInfo mergedTpi;
 183   MergedInfo mergedIpi;
 184
 185   uint64_t nbTypeRecords = 0;
 186   uint64_t nbTypeRecordsBytes = 0;
 187 };
 188
 189 TpiSource *makeTpiSource(ObjFile *file);
 190 TpiSource *makeTypeServerSource(PDBInputFile *pdbInputFile);
 191 TpiSource *makeUseTypeServerSource(ObjFile *file,
 192                                    llvm::codeview::TypeServer2Record ts);
 193 TpiSource *makePrecompSource(ObjFile *file);
 194 TpiSource *makeUsePrecompSource(ObjFile *file,
 195                                 llvm::codeview::PrecompRecord ts);
 196
 197 } // namespace coff
 198 } // namespace lld
 199
 200 #endif