llvm/tools/llvm-pdbutil/ExplainOutputStyle.cpp

   1 //===- ExplainOutputStyle.cpp --------------------------------- *- 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 #include "ExplainOutputStyle.h"
  10
  11 #include "StreamUtil.h"
  12 #include "llvm-pdbutil.h"
  13
  14 #include "llvm/DebugInfo/CodeView/Formatters.h"
  15 #include "llvm/DebugInfo/CodeView/LazyRandomTypeCollection.h"
  16 #include "llvm/DebugInfo/MSF/MappedBlockStream.h"
  17 #include "llvm/DebugInfo/PDB/Native/DbiStream.h"
  18 #include "llvm/DebugInfo/PDB/Native/FormatUtil.h"
  19 #include "llvm/DebugInfo/PDB/Native/InfoStream.h"
  20 #include "llvm/DebugInfo/PDB/Native/InputFile.h"
  21 #include "llvm/DebugInfo/PDB/Native/NativeSession.h"
  22 #include "llvm/DebugInfo/PDB/Native/PDBFile.h"
  23 #include "llvm/DebugInfo/PDB/Native/RawTypes.h"
  24 #include "llvm/Object/COFF.h"
  25 #include "llvm/Support/BinaryByteStream.h"
  26 #include "llvm/Support/BinaryStreamArray.h"
  27 #include "llvm/Support/Error.h"
  28
  29 using namespace llvm;
  30 using namespace llvm::codeview;
  31 using namespace llvm::msf;
  32 using namespace llvm::pdb;
  33
  34 ExplainOutputStyle::ExplainOutputStyle(InputFile &File, uint64_t FileOffset)
  35     : File(File), FileOffset(FileOffset), P(2, false, outs(), opts::Filters) {}
  36
  37 Error ExplainOutputStyle::dump() {
  38   P.formatLine("Explaining file offset {0} of file '{1}'.", FileOffset,
  39                File.getFilePath());
  40
  41   if (File.isPdb())
  42     return explainPdbFile();
  43
  44   return explainBinaryFile();
  45 }
  46
  47 Error ExplainOutputStyle::explainPdbFile() {
  48   bool IsAllocated = explainPdbBlockStatus();
  49   if (!IsAllocated)
  50     return Error::success();
  51
  52   AutoIndent Indent(P);
  53   if (isPdbSuperBlock())
  54     explainPdbSuperBlockOffset();
  55   else if (isPdbFpmBlock())
  56     explainPdbFpmBlockOffset();
  57   else if (isPdbBlockMapBlock())
  58     explainPdbBlockMapOffset();
  59   else if (isPdbStreamDirectoryBlock())
  60     explainPdbStreamDirectoryOffset();
  61   else if (auto Index = getPdbBlockStreamIndex())
  62     explainPdbStreamOffset(*Index);
  63   else
  64     explainPdbUnknownBlock();
  65   return Error::success();
  66 }
  67
  68 Error ExplainOutputStyle::explainBinaryFile() {
  69   std::unique_ptr<BinaryByteStream> Stream =
  70       std::make_unique<BinaryByteStream>(File.unknown().getBuffer(),
  71                                           llvm::support::little);
  72   switch (opts::explain::InputType) {
  73   case opts::explain::InputFileType::DBIStream: {
  74     DbiStream Dbi(std::move(Stream));
  75     if (auto EC = Dbi.reload(nullptr))
  76       return EC;
  77     explainStreamOffset(Dbi, FileOffset);
  78     break;
  79   }
  80   case opts::explain::InputFileType::PDBStream: {
  81     InfoStream Info(std::move(Stream));
  82     if (auto EC = Info.reload())
  83       return EC;
  84     explainStreamOffset(Info, FileOffset);
  85     break;
  86   }
  87   default:
  88     llvm_unreachable("Invalid input file type!");
  89   }
  90   return Error::success();
  91 }
  92
  93 uint32_t ExplainOutputStyle::pdbBlockIndex() const {
  94   return FileOffset / File.pdb().getBlockSize();
  95 }
  96
  97 uint32_t ExplainOutputStyle::pdbBlockOffset() const {
  98   uint64_t BlockStart = pdbBlockIndex() * File.pdb().getBlockSize();
  99   assert(FileOffset >= BlockStart);
 100   return FileOffset - BlockStart;
 101 }
 102
 103 bool ExplainOutputStyle::isPdbSuperBlock() const {
 104   return pdbBlockIndex() == 0;
 105 }
 106
 107 bool ExplainOutputStyle::isPdbFpm1() const {
 108   return ((pdbBlockIndex() - 1) % File.pdb().getBlockSize() == 0);
 109 }
 110 bool ExplainOutputStyle::isPdbFpm2() const {
 111   return ((pdbBlockIndex() - 2) % File.pdb().getBlockSize() == 0);
 112 }
 113
 114 bool ExplainOutputStyle::isPdbFpmBlock() const {
 115   return isPdbFpm1() || isPdbFpm2();
 116 }
 117
 118 bool ExplainOutputStyle::isPdbBlockMapBlock() const {
 119   return pdbBlockIndex() == File.pdb().getBlockMapIndex();
 120 }
 121
 122 bool ExplainOutputStyle::isPdbStreamDirectoryBlock() const {
 123   const auto &Layout = File.pdb().getMsfLayout();
 124   return llvm::is_contained(Layout.DirectoryBlocks, pdbBlockIndex());
 125 }
 126
 127 std::optional<uint32_t> ExplainOutputStyle::getPdbBlockStreamIndex() const {
 128   const auto &Layout = File.pdb().getMsfLayout();
 129   for (const auto &Entry : enumerate(Layout.StreamMap)) {
 130     if (!llvm::is_contained(Entry.value(), pdbBlockIndex()))
 131       continue;
 132     return Entry.index();
 133   }
 134   return std::nullopt;
 135 }
 136
 137 bool ExplainOutputStyle::explainPdbBlockStatus() {
 138   if (FileOffset >= File.pdb().getFileSize()) {
 139     P.formatLine("Address {0} is not in the file (file size = {1}).",
 140                  FileOffset, File.pdb().getFileSize());
 141     return false;
 142   }
 143   P.formatLine("Block:Offset = {2:X-}:{1:X-4}.", FileOffset, pdbBlockOffset(),
 144                pdbBlockIndex());
 145
 146   bool IsFree = File.pdb().getMsfLayout().FreePageMap[pdbBlockIndex()];
 147   P.formatLine("Address is in block {0} ({1}allocated).", pdbBlockIndex(),
 148                IsFree ? "un" : "");
 149   return !IsFree;
 150 }
 151
 152 #define endof(Class, Field) (offsetof(Class, Field) + sizeof(Class::Field))
 153
 154 void ExplainOutputStyle::explainPdbSuperBlockOffset() {
 155   P.formatLine("This corresponds to offset {0} of the MSF super block, ",
 156                pdbBlockOffset());
 157   if (pdbBlockOffset() < endof(SuperBlock, MagicBytes))
 158     P.printLine("which is part of the MSF file magic.");
 159   else if (pdbBlockOffset() < endof(SuperBlock, BlockSize)) {
 160     P.printLine("which contains the block size of the file.");
 161     P.formatLine("The current value is {0}.",
 162                  uint32_t(File.pdb().getMsfLayout().SB->BlockSize));
 163   } else if (pdbBlockOffset() < endof(SuperBlock, FreeBlockMapBlock)) {
 164     P.printLine("which contains the index of the FPM block (e.g. 1 or 2).");
 165     P.formatLine("The current value is {0}.",
 166                  uint32_t(File.pdb().getMsfLayout().SB->FreeBlockMapBlock));
 167   } else if (pdbBlockOffset() < endof(SuperBlock, NumBlocks)) {
 168     P.printLine("which contains the number of blocks in the file.");
 169     P.formatLine("The current value is {0}.",
 170                  uint32_t(File.pdb().getMsfLayout().SB->NumBlocks));
 171   } else if (pdbBlockOffset() < endof(SuperBlock, NumDirectoryBytes)) {
 172     P.printLine("which contains the number of bytes in the stream directory.");
 173     P.formatLine("The current value is {0}.",
 174                  uint32_t(File.pdb().getMsfLayout().SB->NumDirectoryBytes));
 175   } else if (pdbBlockOffset() < endof(SuperBlock, Unknown1)) {
 176     P.printLine("whose purpose is unknown.");
 177     P.formatLine("The current value is {0}.",
 178                  uint32_t(File.pdb().getMsfLayout().SB->Unknown1));
 179   } else if (pdbBlockOffset() < endof(SuperBlock, BlockMapAddr)) {
 180     P.printLine("which contains the file offset of the block map.");
 181     P.formatLine("The current value is {0}.",
 182                  uint32_t(File.pdb().getMsfLayout().SB->BlockMapAddr));
 183   } else {
 184     assert(pdbBlockOffset() > sizeof(SuperBlock));
 185     P.printLine(
 186         "which is outside the range of valid data for the super block.");
 187   }
 188 }
 189
 190 static std::string toBinaryString(uint8_t Byte) {
 191   char Result[9] = {0};
 192   for (int I = 0; I < 8; ++I) {
 193     char C = (Byte & 1) ? '1' : '0';
 194     Result[I] = C;
 195     Byte >>= 1;
 196   }
 197   return std::string(Result);
 198 }
 199
 200 void ExplainOutputStyle::explainPdbFpmBlockOffset() {
 201   const MSFLayout &Layout = File.pdb().getMsfLayout();
 202   uint32_t MainFpm = Layout.mainFpmBlock();
 203   uint32_t AltFpm = Layout.alternateFpmBlock();
 204
 205   assert(isPdbFpmBlock());
 206   uint32_t Fpm = isPdbFpm1() ? 1 : 2;
 207   uint32_t FpmChunk = pdbBlockIndex() / File.pdb().getBlockSize();
 208   assert((Fpm == MainFpm) || (Fpm == AltFpm));
 209   (void)AltFpm;
 210   bool IsMain = (Fpm == MainFpm);
 211   P.formatLine("Address is in FPM{0} ({1} FPM)", Fpm, IsMain ? "Main" : "Alt");
 212   uint32_t DescribedBlockStart =
 213       8 * (FpmChunk * File.pdb().getBlockSize() + pdbBlockOffset());
 214   if (DescribedBlockStart > File.pdb().getBlockCount()) {
 215     P.printLine("Address is in extraneous FPM space.");
 216     return;
 217   }
 218
 219   P.formatLine("Address describes the allocation status of blocks [{0},{1})",
 220                DescribedBlockStart, DescribedBlockStart + 8);
 221   ArrayRef<uint8_t> Bytes;
 222   cantFail(File.pdb().getMsfBuffer().readBytes(FileOffset, 1, Bytes));
 223   P.formatLine("Status = {0} (Note: 0 = allocated, 1 = free)",
 224                toBinaryString(Bytes[0]));
 225 }
 226
 227 void ExplainOutputStyle::explainPdbBlockMapOffset() {
 228   uint64_t BlockMapOffset = File.pdb().getBlockMapOffset();
 229   uint32_t OffsetInBlock = FileOffset - BlockMapOffset;
 230   P.formatLine("Address is at offset {0} of the directory block list",
 231                OffsetInBlock);
 232 }
 233
 234 static uint32_t getOffsetInStream(ArrayRef<support::ulittle32_t> StreamBlocks,
 235                                   uint64_t FileOffset, uint32_t BlockSize) {
 236   uint32_t BlockIndex = FileOffset / BlockSize;
 237   uint32_t OffsetInBlock = FileOffset - BlockIndex * BlockSize;
 238
 239   auto Iter = llvm::find(StreamBlocks, BlockIndex);
 240   assert(Iter != StreamBlocks.end());
 241   uint32_t StreamBlockIndex = std::distance(StreamBlocks.begin(), Iter);
 242   return StreamBlockIndex * BlockSize + OffsetInBlock;
 243 }
 244
 245 void ExplainOutputStyle::explainPdbStreamOffset(uint32_t Stream) {
 246   SmallVector<StreamInfo, 12> Streams;
 247   discoverStreamPurposes(File.pdb(), Streams);
 248
 249   assert(Stream <= Streams.size());
 250   const StreamInfo &S = Streams[Stream];
 251   const auto &Layout = File.pdb().getStreamLayout(Stream);
 252   uint32_t StreamOff =
 253       getOffsetInStream(Layout.Blocks, FileOffset, File.pdb().getBlockSize());
 254   P.formatLine("Address is at offset {0}/{1} of Stream {2} ({3}){4}.",
 255                StreamOff, Layout.Length, Stream, S.getLongName(),
 256                (StreamOff > Layout.Length) ? " in unused space" : "");
 257   switch (S.getPurpose()) {
 258   case StreamPurpose::DBI: {
 259     DbiStream &Dbi = cantFail(File.pdb().getPDBDbiStream());
 260     explainStreamOffset(Dbi, StreamOff);
 261     break;
 262   }
 263   case StreamPurpose::PDB: {
 264     InfoStream &Info = cantFail(File.pdb().getPDBInfoStream());
 265     explainStreamOffset(Info, StreamOff);
 266     break;
 267   }
 268   case StreamPurpose::IPI:
 269   case StreamPurpose::TPI:
 270   case StreamPurpose::ModuleStream:
 271   case StreamPurpose::NamedStream:
 272   default:
 273     break;
 274   }
 275 }
 276
 277 void ExplainOutputStyle::explainPdbStreamDirectoryOffset() {
 278   auto DirectoryBlocks = File.pdb().getDirectoryBlockArray();
 279   const auto &Layout = File.pdb().getMsfLayout();
 280   uint32_t StreamOff =
 281       getOffsetInStream(DirectoryBlocks, FileOffset, File.pdb().getBlockSize());
 282   P.formatLine("Address is at offset {0}/{1} of Stream Directory{2}.",
 283                StreamOff, uint32_t(Layout.SB->NumDirectoryBytes),
 284                uint32_t(StreamOff > Layout.SB->NumDirectoryBytes)
 285                    ? " in unused space"
 286                    : "");
 287 }
 288
 289 void ExplainOutputStyle::explainPdbUnknownBlock() {
 290   P.formatLine("Address has unknown purpose.");
 291 }
 292
 293 template <typename T>
 294 static void printStructField(LinePrinter &P, StringRef Label, T Value) {
 295   P.formatLine("which contains {0}.", Label);
 296   P.formatLine("The current value is {0}.", Value);
 297 }
 298
 299 static void explainDbiHeaderOffset(LinePrinter &P, DbiStream &Dbi,
 300                                    uint32_t Offset) {
 301   const DbiStreamHeader *Header = Dbi.getHeader();
 302   assert(Header != nullptr);
 303
 304   if (Offset < endof(DbiStreamHeader, VersionSignature))
 305     printStructField(P, "the DBI Stream Version Signature",
 306                      int32_t(Header->VersionSignature));
 307   else if (Offset < endof(DbiStreamHeader, VersionHeader))
 308     printStructField(P, "the DBI Stream Version Header",
 309                      uint32_t(Header->VersionHeader));
 310   else if (Offset < endof(DbiStreamHeader, Age))
 311     printStructField(P, "the age of the DBI Stream", uint32_t(Header->Age));
 312   else if (Offset < endof(DbiStreamHeader, GlobalSymbolStreamIndex))
 313     printStructField(P, "the index of the Global Symbol Stream",
 314                      uint16_t(Header->GlobalSymbolStreamIndex));
 315   else if (Offset < endof(DbiStreamHeader, BuildNumber))
 316     printStructField(P, "the build number", uint16_t(Header->BuildNumber));
 317   else if (Offset < endof(DbiStreamHeader, PublicSymbolStreamIndex))
 318     printStructField(P, "the index of the Public Symbol Stream",
 319                      uint16_t(Header->PublicSymbolStreamIndex));
 320   else if (Offset < endof(DbiStreamHeader, PdbDllVersion))
 321     printStructField(P, "the version of mspdb.dll",
 322                      uint16_t(Header->PdbDllVersion));
 323   else if (Offset < endof(DbiStreamHeader, SymRecordStreamIndex))
 324     printStructField(P, "the index of the Symbol Record Stream",
 325                      uint16_t(Header->SymRecordStreamIndex));
 326   else if (Offset < endof(DbiStreamHeader, PdbDllRbld))
 327     printStructField(P, "the rbld of mspdb.dll", uint16_t(Header->PdbDllRbld));
 328   else if (Offset < endof(DbiStreamHeader, ModiSubstreamSize))
 329     printStructField(P, "the size of the Module Info Substream",
 330                      int32_t(Header->ModiSubstreamSize));
 331   else if (Offset < endof(DbiStreamHeader, SecContrSubstreamSize))
 332     printStructField(P, "the size of the Section Contribution Substream",
 333                      int32_t(Header->SecContrSubstreamSize));
 334   else if (Offset < endof(DbiStreamHeader, SectionMapSize))
 335     printStructField(P, "the size of the Section Map Substream",
 336                      int32_t(Header->SectionMapSize));
 337   else if (Offset < endof(DbiStreamHeader, FileInfoSize))
 338     printStructField(P, "the size of the File Info Substream",
 339                      int32_t(Header->FileInfoSize));
 340   else if (Offset < endof(DbiStreamHeader, TypeServerSize))
 341     printStructField(P, "the size of the Type Server Map",
 342                      int32_t(Header->TypeServerSize));
 343   else if (Offset < endof(DbiStreamHeader, MFCTypeServerIndex))
 344     printStructField(P, "the index of the MFC Type Server stream",
 345                      uint32_t(Header->MFCTypeServerIndex));
 346   else if (Offset < endof(DbiStreamHeader, OptionalDbgHdrSize))
 347     printStructField(P, "the size of the Optional Debug Stream array",
 348                      int32_t(Header->OptionalDbgHdrSize));
 349   else if (Offset < endof(DbiStreamHeader, ECSubstreamSize))
 350     printStructField(P, "the size of the Edit & Continue Substream",
 351                      int32_t(Header->ECSubstreamSize));
 352   else if (Offset < endof(DbiStreamHeader, Flags))
 353     printStructField(P, "the DBI Stream flags", uint16_t(Header->Flags));
 354   else if (Offset < endof(DbiStreamHeader, MachineType))
 355     printStructField(P, "the machine type", uint16_t(Header->MachineType));
 356   else if (Offset < endof(DbiStreamHeader, Reserved))
 357     printStructField(P, "reserved data", uint32_t(Header->Reserved));
 358 }
 359
 360 static void explainDbiModiSubstreamOffset(LinePrinter &P, DbiStream &Dbi,
 361                                           uint32_t Offset) {
 362   VarStreamArray<DbiModuleDescriptor> ModuleDescriptors;
 363   BinaryStreamRef ModiSubstreamData = Dbi.getModiSubstreamData().StreamData;
 364   BinaryStreamReader Reader(ModiSubstreamData);
 365
 366   cantFail(Reader.readArray(ModuleDescriptors, ModiSubstreamData.getLength()));
 367   auto Prev = ModuleDescriptors.begin();
 368   assert(Prev.offset() == 0);
 369   auto Current = Prev;
 370   uint32_t Index = 0;
 371   while (true) {
 372     Prev = Current;
 373     ++Current;
 374     if (Current == ModuleDescriptors.end() || Offset < Current.offset())
 375       break;
 376     ++Index;
 377   }
 378
 379   const DbiModuleDescriptor &Descriptor = *Prev;
 380   P.formatLine("which contains the descriptor for module {0} ({1}).", Index,
 381                Descriptor.getModuleName());
 382 }
 383
 384 template <typename T>
 385 static void dontExplain(LinePrinter &Printer, T &Stream, uint32_t Offset) {}
 386
 387 template <typename T, typename SubstreamRangeT>
 388 static void explainSubstreamOffset(LinePrinter &P, uint32_t OffsetInStream,
 389                                    T &Stream,
 390                                    const SubstreamRangeT &Substreams) {
 391   uint32_t SubOffset = OffsetInStream;
 392   for (const auto &Entry : Substreams) {
 393     if (Entry.Size <= 0)
 394       continue;
 395     uint32_t S = static_cast<uint32_t>(Entry.Size);
 396     if (SubOffset < S) {
 397       P.formatLine("address is at offset {0}/{1} of the {2}.", SubOffset, S,
 398                    Entry.Label);
 399       Entry.Explain(P, Stream, SubOffset);
 400       return;
 401     }
 402     SubOffset -= S;
 403   }
 404 }
 405
 406 void ExplainOutputStyle::explainStreamOffset(DbiStream &Dbi,
 407                                              uint32_t OffsetInStream) {
 408   P.printLine("Within the DBI stream:");
 409   AutoIndent Indent(P);
 410   const DbiStreamHeader *Header = Dbi.getHeader();
 411   assert(Header != nullptr);
 412
 413   struct SubstreamInfo {
 414     int32_t Size;
 415     StringRef Label;
 416     void (*Explain)(LinePrinter &, DbiStream &, uint32_t);
 417   } Substreams[] = {
 418       {sizeof(DbiStreamHeader), "DBI Stream Header", explainDbiHeaderOffset},
 419       {int32_t(Header->ModiSubstreamSize), "Module Info Substream",
 420        explainDbiModiSubstreamOffset},
 421       {int32_t(Header->SecContrSubstreamSize), "Section Contribution Substream",
 422        dontExplain<DbiStream>},
 423       {int32_t(Header->SectionMapSize), "Section Map", dontExplain<DbiStream>},
 424       {int32_t(Header->FileInfoSize), "File Info Substream",
 425        dontExplain<DbiStream>},
 426       {int32_t(Header->TypeServerSize), "Type Server Map Substream",
 427        dontExplain<DbiStream>},
 428       {int32_t(Header->ECSubstreamSize), "Edit & Continue Substream",
 429        dontExplain<DbiStream>},
 430       {int32_t(Header->OptionalDbgHdrSize), "Optional Debug Stream Array",
 431        dontExplain<DbiStream>},
 432   };
 433
 434   explainSubstreamOffset(P, OffsetInStream, Dbi, Substreams);
 435 }
 436
 437 static void explainPdbStreamHeaderOffset(LinePrinter &P, InfoStream &Info,
 438                                          uint32_t Offset) {
 439   const InfoStreamHeader *Header = Info.getHeader();
 440   assert(Header != nullptr);
 441
 442   if (Offset < endof(InfoStreamHeader, Version))
 443     printStructField(P, "the PDB Stream Version Signature",
 444                      uint32_t(Header->Version));
 445   else if (Offset < endof(InfoStreamHeader, Signature))
 446     printStructField(P, "the signature of the PDB Stream",
 447                      uint32_t(Header->Signature));
 448   else if (Offset < endof(InfoStreamHeader, Age))
 449     printStructField(P, "the age of the PDB", uint32_t(Header->Age));
 450   else if (Offset < endof(InfoStreamHeader, Guid))
 451     printStructField(P, "the guid of the PDB", fmt_guid(Header->Guid.Guid));
 452 }
 453
 454 void ExplainOutputStyle::explainStreamOffset(InfoStream &Info,
 455                                              uint32_t OffsetInStream) {
 456   P.printLine("Within the PDB stream:");
 457   AutoIndent Indent(P);
 458
 459   struct SubstreamInfo {
 460     uint32_t Size;
 461     StringRef Label;
 462     void (*Explain)(LinePrinter &, InfoStream &, uint32_t);
 463   } Substreams[] = {{sizeof(InfoStreamHeader), "PDB Stream Header",
 464                      explainPdbStreamHeaderOffset},
 465                     {Info.getNamedStreamMapByteSize(), "Named Stream Map",
 466                      dontExplain<InfoStream>},
 467                     {Info.getStreamSize(), "PDB Feature Signatures",
 468                      dontExplain<InfoStream>}};
 469
 470   explainSubstreamOffset(P, OffsetInStream, Info, Substreams);
 471 }