lib/DebugInfo/CodeView/MergingTypeTableBuilder.cpp

   1 //===- MergingTypeTableBuilder.cpp ----------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "llvm/DebugInfo/CodeView/MergingTypeTableBuilder.h"
  11 #include "llvm/ADT/ArrayRef.h"
  12 #include "llvm/ADT/DenseSet.h"
  13 #include "llvm/ADT/STLExtras.h"
  14 #include "llvm/DebugInfo/CodeView/CodeView.h"
  15 #include "llvm/DebugInfo/CodeView/ContinuationRecordBuilder.h"
  16 #include "llvm/DebugInfo/CodeView/RecordSerialization.h"
  17 #include "llvm/DebugInfo/CodeView/TypeIndex.h"
  18 #include "llvm/Support/Allocator.h"
  19 #include "llvm/Support/BinaryByteStream.h"
  20 #include "llvm/Support/BinaryStreamWriter.h"
  21 #include "llvm/Support/Endian.h"
  22 #include "llvm/Support/Error.h"
  23 #include <algorithm>
  24 #include <cassert>
  25 #include <cstdint>
  26 #include <cstring>
  27
  28 using namespace llvm;
  29 using namespace llvm::codeview;
  30
  31 TypeIndex MergingTypeTableBuilder::nextTypeIndex() const {
  32   return TypeIndex::fromArrayIndex(SeenRecords.size());
  33 }
  34
  35 MergingTypeTableBuilder::MergingTypeTableBuilder(BumpPtrAllocator &Storage)
  36     : RecordStorage(Storage) {
  37   SeenRecords.reserve(4096);
  38 }
  39
  40 MergingTypeTableBuilder::~MergingTypeTableBuilder() = default;
  41
  42 Optional<TypeIndex> MergingTypeTableBuilder::getFirst() {
  43   if (empty())
  44     return None;
  45
  46   return TypeIndex(TypeIndex::FirstNonSimpleIndex);
  47 }
  48
  49 Optional<TypeIndex> MergingTypeTableBuilder::getNext(TypeIndex Prev) {
  50   if (++Prev == nextTypeIndex())
  51     return None;
  52   return Prev;
  53 }
  54
  55 CVType MergingTypeTableBuilder::getType(TypeIndex Index) {
  56   CVType Type;
  57   Type.RecordData = SeenRecords[Index.toArrayIndex()];
  58   const RecordPrefix *P =
  59       reinterpret_cast<const RecordPrefix *>(Type.RecordData.data());
  60   Type.Type = static_cast<TypeLeafKind>(uint16_t(P->RecordKind));
  61   return Type;
  62 }
  63
  64 StringRef MergingTypeTableBuilder::getTypeName(TypeIndex Index) {
  65   llvm_unreachable("Method not implemented");
  66 }
  67
  68 bool MergingTypeTableBuilder::contains(TypeIndex Index) {
  69   if (Index.isSimple() || Index.isNoneType())
  70     return false;
  71
  72   return Index.toArrayIndex() < SeenRecords.size();
  73 }
  74
  75 uint32_t MergingTypeTableBuilder::size() { return SeenRecords.size(); }
  76
  77 uint32_t MergingTypeTableBuilder::capacity() { return SeenRecords.size(); }
  78
  79 ArrayRef<ArrayRef<uint8_t>> MergingTypeTableBuilder::records() const {
  80   return SeenRecords;
  81 }
  82
  83 void MergingTypeTableBuilder::reset() {
  84   HashedRecords.clear();
  85   SeenRecords.clear();
  86 }
  87
  88 static inline ArrayRef<uint8_t> stabilize(BumpPtrAllocator &Alloc,
  89                                           ArrayRef<uint8_t> Data) {
  90   uint8_t *Stable = Alloc.Allocate<uint8_t>(Data.size());
  91   memcpy(Stable, Data.data(), Data.size());
  92   return makeArrayRef(Stable, Data.size());
  93 }
  94
  95 TypeIndex MergingTypeTableBuilder::insertRecordAs(hash_code Hash,
  96                                                   ArrayRef<uint8_t> &Record) {
  97   assert(Record.size() < UINT32_MAX && "Record too big");
  98   assert(Record.size() % 4 == 0 && "Record is not aligned to 4 bytes!");
  99
 100   LocallyHashedType WeakHash{Hash, Record};
 101   auto Result = HashedRecords.try_emplace(WeakHash, nextTypeIndex());
 102
 103   if (Result.second) {
 104     ArrayRef<uint8_t> RecordData = stabilize(RecordStorage, Record);
 105     Result.first->first.RecordData = RecordData;
 106     SeenRecords.push_back(RecordData);
 107   }
 108
 109   // Update the caller's copy of Record to point a stable copy.
 110   TypeIndex ActualTI = Result.first->second;
 111   Record = SeenRecords[ActualTI.toArrayIndex()];
 112   return ActualTI;
 113 }
 114
 115 TypeIndex
 116 MergingTypeTableBuilder::insertRecordBytes(ArrayRef<uint8_t> &Record) {
 117   return insertRecordAs(hash_value(Record), Record);
 118 }
 119
 120 TypeIndex
 121 MergingTypeTableBuilder::insertRecord(ContinuationRecordBuilder &Builder) {
 122   TypeIndex TI;
 123   auto Fragments = Builder.end(nextTypeIndex());
 124   assert(!Fragments.empty());
 125   for (auto C : Fragments)
 126     TI = insertRecordBytes(C.RecordData);
 127   return TI;
 128 }