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