lib/DebugInfo/CodeView/LazyRandomTypeCollection.cpp

   1 //===- LazyRandomTypeCollection.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/LazyRandomTypeCollection.h"
  11 #include "llvm/ADT/ArrayRef.h"
  12 #include "llvm/ADT/None.h"
  13 #include "llvm/ADT/StringExtras.h"
  14 #include "llvm/ADT/StringRef.h"
  15 #include "llvm/DebugInfo/CodeView/CodeViewError.h"
  16 #include "llvm/DebugInfo/CodeView/RecordName.h"
  17 #include "llvm/DebugInfo/CodeView/TypeRecord.h"
  18 #include "llvm/Support/BinaryStreamReader.h"
  19 #include "llvm/Support/Endian.h"
  20 #include "llvm/Support/Error.h"
  21 #include <algorithm>
  22 #include <cassert>
  23 #include <cstdint>
  24 #include <iterator>
  25
  26 using namespace llvm;
  27 using namespace llvm::codeview;
  28
  29 static void error(Error &&EC) {
  30   assert(!static_cast<bool>(EC));
  31   if (EC)
  32     consumeError(std::move(EC));
  33 }
  34
  35 LazyRandomTypeCollection::LazyRandomTypeCollection(uint32_t RecordCountHint)
  36     : LazyRandomTypeCollection(CVTypeArray(), RecordCountHint,
  37                                PartialOffsetArray()) {}
  38
  39 LazyRandomTypeCollection::LazyRandomTypeCollection(
  40     const CVTypeArray &Types, uint32_t RecordCountHint,
  41     PartialOffsetArray PartialOffsets)
  42     : NameStorage(Allocator), Types(Types), PartialOffsets(PartialOffsets) {
  43   Records.resize(RecordCountHint);
  44 }
  45
  46 LazyRandomTypeCollection::LazyRandomTypeCollection(ArrayRef<uint8_t> Data,
  47                                                    uint32_t RecordCountHint)
  48     : LazyRandomTypeCollection(RecordCountHint) {
  49 }
  50
  51 LazyRandomTypeCollection::LazyRandomTypeCollection(StringRef Data,
  52                                                    uint32_t RecordCountHint)
  53     : LazyRandomTypeCollection(
  54           makeArrayRef(Data.bytes_begin(), Data.bytes_end()), RecordCountHint) {
  55 }
  56
  57 LazyRandomTypeCollection::LazyRandomTypeCollection(const CVTypeArray &Types,
  58                                                    uint32_t NumRecords)
  59     : LazyRandomTypeCollection(Types, NumRecords, PartialOffsetArray()) {}
  60
  61 void LazyRandomTypeCollection::reset(BinaryStreamReader &Reader,
  62                                      uint32_t RecordCountHint) {
  63   Count = 0;
  64   PartialOffsets = PartialOffsetArray();
  65
  66   error(Reader.readArray(Types, Reader.bytesRemaining()));
  67
  68   // Clear and then resize, to make sure existing data gets destroyed.
  69   Records.clear();
  70   Records.resize(RecordCountHint);
  71 }
  72
  73 void LazyRandomTypeCollection::reset(StringRef Data, uint32_t RecordCountHint) {
  74   BinaryStreamReader Reader(Data, support::little);
  75   reset(Reader, RecordCountHint);
  76 }
  77
  78 void LazyRandomTypeCollection::reset(ArrayRef<uint8_t> Data,
  79                                      uint32_t RecordCountHint) {
  80   BinaryStreamReader Reader(Data, support::little);
  81   reset(Reader, RecordCountHint);
  82 }
  83
  84 uint32_t LazyRandomTypeCollection::getOffsetOfType(TypeIndex Index) {
  85   error(ensureTypeExists(Index));
  86   assert(contains(Index));
  87
  88   return Records[Index.toArrayIndex()].Offset;
  89 }
  90
  91 CVType LazyRandomTypeCollection::getType(TypeIndex Index) {
  92   auto EC = ensureTypeExists(Index);
  93   error(std::move(EC));
  94   assert(contains(Index));
  95
  96   return Records[Index.toArrayIndex()].Type;
  97 }
  98
  99 Optional<CVType> LazyRandomTypeCollection::tryGetType(TypeIndex Index) {
 100   if (auto EC = ensureTypeExists(Index)) {
 101     consumeError(std::move(EC));
 102     return None;
 103   }
 104
 105   assert(contains(Index));
 106   return Records[Index.toArrayIndex()].Type;
 107 }
 108
 109 StringRef LazyRandomTypeCollection::getTypeName(TypeIndex Index) {
 110   if (Index.isNoneType() || Index.isSimple())
 111     return TypeIndex::simpleTypeName(Index);
 112
 113   // Try to make sure the type exists.  Even if it doesn't though, it may be
 114   // because we're dumping a symbol stream with no corresponding type stream
 115   // present, in which case we still want to be able to print <unknown UDT>
 116   // for the type names.
 117   if (auto EC = ensureTypeExists(Index)) {
 118     consumeError(std::move(EC));
 119     return "<unknown UDT>";
 120   }
 121
 122   uint32_t I = Index.toArrayIndex();
 123   ensureCapacityFor(Index);
 124   if (Records[I].Name.data() == nullptr) {
 125     StringRef Result = NameStorage.save(computeTypeName(*this, Index));
 126     Records[I].Name = Result;
 127   }
 128   return Records[I].Name;
 129 }
 130
 131 bool LazyRandomTypeCollection::contains(TypeIndex Index) {
 132   if (Index.isSimple() || Index.isNoneType())
 133     return false;
 134
 135   if (Records.size() <= Index.toArrayIndex())
 136     return false;
 137   if (!Records[Index.toArrayIndex()].Type.valid())
 138     return false;
 139   return true;
 140 }
 141
 142 uint32_t LazyRandomTypeCollection::size() { return Count; }
 143
 144 uint32_t LazyRandomTypeCollection::capacity() { return Records.size(); }
 145
 146 Error LazyRandomTypeCollection::ensureTypeExists(TypeIndex TI) {
 147   if (contains(TI))
 148     return Error::success();
 149
 150   return visitRangeForType(TI);
 151 }
 152
 153 void LazyRandomTypeCollection::ensureCapacityFor(TypeIndex Index) {
 154   uint32_t MinSize = Index.toArrayIndex() + 1;
 155
 156   if (MinSize <= capacity())
 157     return;
 158
 159   uint32_t NewCapacity = MinSize * 3 / 2;
 160
 161   assert(NewCapacity > capacity());
 162   Records.resize(NewCapacity);
 163 }
 164
 165 Error LazyRandomTypeCollection::visitRangeForType(TypeIndex TI) {
 166   if (PartialOffsets.empty())
 167     return fullScanForType(TI);
 168
 169   auto Next = std::upper_bound(PartialOffsets.begin(), PartialOffsets.end(), TI,
 170                                [](TypeIndex Value, const TypeIndexOffset &IO) {
 171                                  return Value < IO.Type;
 172                                });
 173
 174   assert(Next != PartialOffsets.begin());
 175   auto Prev = std::prev(Next);
 176
 177   TypeIndex TIB = Prev->Type;
 178   if (contains(TIB)) {
 179     // They've asked us to fetch a type index, but the entry we found in the
 180     // partial offsets array has already been visited.  Since we visit an entire
 181     // block every time, that means this record should have been previously
 182     // discovered.  Ultimately, this means this is a request for a non-existant
 183     // type index.
 184     return make_error<CodeViewError>("Invalid type index");
 185   }
 186
 187   TypeIndex TIE;
 188   if (Next == PartialOffsets.end()) {
 189     TIE = TypeIndex::fromArrayIndex(capacity());
 190   } else {
 191     TIE = Next->Type;
 192   }
 193
 194   visitRange(TIB, Prev->Offset, TIE);
 195   return Error::success();
 196 }
 197
 198 Optional<TypeIndex> LazyRandomTypeCollection::getFirst() {
 199   TypeIndex TI = TypeIndex::fromArrayIndex(0);
 200   if (auto EC = ensureTypeExists(TI)) {
 201     consumeError(std::move(EC));
 202     return None;
 203   }
 204   return TI;
 205 }
 206
 207 Optional<TypeIndex> LazyRandomTypeCollection::getNext(TypeIndex Prev) {
 208   // We can't be sure how long this type stream is, given that the initial count
 209   // given to the constructor is just a hint.  So just try to make sure the next
 210   // record exists, and if anything goes wrong, we must be at the end.
 211   if (auto EC = ensureTypeExists(Prev + 1)) {
 212     consumeError(std::move(EC));
 213     return None;
 214   }
 215
 216   return Prev + 1;
 217 }
 218
 219 Error LazyRandomTypeCollection::fullScanForType(TypeIndex TI) {
 220   assert(PartialOffsets.empty());
 221
 222   TypeIndex CurrentTI = TypeIndex::fromArrayIndex(0);
 223   auto Begin = Types.begin();
 224
 225   if (Count > 0) {
 226     // In the case of type streams which we don't know the number of records of,
 227     // it's possible to search for a type index triggering a full scan, but then
 228     // later additional records are added since we didn't know how many there
 229     // would be until we did a full visitation, then you try to access the new
 230     // type triggering another full scan.  To avoid this, we assume that if the
 231     // database has some records, this must be what's going on.  We can also
 232     // assume that this index must be larger than the largest type index we've
 233     // visited, so we start from there and scan forward.
 234     uint32_t Offset = Records[LargestTypeIndex.toArrayIndex()].Offset;
 235     CurrentTI = LargestTypeIndex + 1;
 236     Begin = Types.at(Offset);
 237     ++Begin;
 238   }
 239
 240   auto End = Types.end();
 241   while (Begin != End) {
 242     ensureCapacityFor(CurrentTI);
 243     LargestTypeIndex = std::max(LargestTypeIndex, CurrentTI);
 244     auto Idx = CurrentTI.toArrayIndex();
 245     Records[Idx].Type = *Begin;
 246     Records[Idx].Offset = Begin.offset();
 247     ++Count;
 248     ++Begin;
 249     ++CurrentTI;
 250   }
 251   if (CurrentTI <= TI) {
 252     return make_error<CodeViewError>("Type Index does not exist!");
 253   }
 254   return Error::success();
 255 }
 256
 257 void LazyRandomTypeCollection::visitRange(TypeIndex Begin, uint32_t BeginOffset,
 258                                           TypeIndex End) {
 259   auto RI = Types.at(BeginOffset);
 260   assert(RI != Types.end());
 261
 262   ensureCapacityFor(End);
 263   while (Begin != End) {
 264     LargestTypeIndex = std::max(LargestTypeIndex, Begin);
 265     auto Idx = Begin.toArrayIndex();
 266     Records[Idx].Type = *RI;
 267     Records[Idx].Offset = RI.offset();
 268     ++Count;
 269     ++Begin;
 270     ++RI;
 271   }
 272 }