1 //===- DbiStreamBuilder.cpp - PDB Dbi Stream Creation -----------*- 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 "llvm/DebugInfo/PDB/Native/DbiStreamBuilder.h"
10 
11 #include "llvm/ADT/ArrayRef.h"
12 #include "llvm/BinaryFormat/COFF.h"
13 #include "llvm/DebugInfo/CodeView/DebugFrameDataSubsection.h"
14 #include "llvm/DebugInfo/MSF/MSFBuilder.h"
15 #include "llvm/DebugInfo/MSF/MappedBlockStream.h"
16 #include "llvm/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.h"
17 #include "llvm/DebugInfo/PDB/Native/DbiStream.h"
18 #include "llvm/DebugInfo/PDB/Native/RawError.h"
19 #include "llvm/Object/COFF.h"
20 #include "llvm/Support/BinaryStreamWriter.h"
21 #include "llvm/Support/Parallel.h"
22 
23 using namespace llvm;
24 using namespace llvm::codeview;
25 using namespace llvm::msf;
26 using namespace llvm::pdb;
27 
28 DbiStreamBuilder::DbiStreamBuilder(msf::MSFBuilder &Msf)
29     : Msf(Msf), Allocator(Msf.getAllocator()), Age(1), BuildNumber(0),
30       PdbDllVersion(0), PdbDllRbld(0), Flags(0), MachineType(PDB_Machine::x86),
31       Header(nullptr) {}
32 
33 DbiStreamBuilder::~DbiStreamBuilder() {}
34 
35 void DbiStreamBuilder::setVersionHeader(PdbRaw_DbiVer V) { VerHeader = V; }
36 
37 void DbiStreamBuilder::setAge(uint32_t A) { Age = A; }
38 
39 void DbiStreamBuilder::setBuildNumber(uint16_t B) { BuildNumber = B; }
40 
41 void DbiStreamBuilder::setBuildNumber(uint8_t Major, uint8_t Minor) {
42   BuildNumber = (uint16_t(Major) << DbiBuildNo::BuildMajorShift) &
43                 DbiBuildNo::BuildMajorMask;
44   BuildNumber |= (uint16_t(Minor) << DbiBuildNo::BuildMinorShift) &
45                  DbiBuildNo::BuildMinorMask;
46   BuildNumber |= DbiBuildNo::NewVersionFormatMask;
47 }
48 
49 void DbiStreamBuilder::setPdbDllVersion(uint16_t V) { PdbDllVersion = V; }
50 
51 void DbiStreamBuilder::setPdbDllRbld(uint16_t R) { PdbDllRbld = R; }
52 
53 void DbiStreamBuilder::setFlags(uint16_t F) { Flags = F; }
54 
55 void DbiStreamBuilder::setMachineType(PDB_Machine M) { MachineType = M; }
56 
57 void DbiStreamBuilder::setMachineType(COFF::MachineTypes M) {
58   // These enums are mirrors of each other, so we can just cast the value.
59   MachineType = static_cast<pdb::PDB_Machine>(static_cast<unsigned>(M));
60 }
61 
62 void DbiStreamBuilder::setGlobalsStreamIndex(uint32_t Index) {
63   GlobalsStreamIndex = Index;
64 }
65 
66 void DbiStreamBuilder::setSymbolRecordStreamIndex(uint32_t Index) {
67   SymRecordStreamIndex = Index;
68 }
69 
70 void DbiStreamBuilder::setPublicsStreamIndex(uint32_t Index) {
71   PublicsStreamIndex = Index;
72 }
73 
74 void DbiStreamBuilder::addNewFpoData(const codeview::FrameData &FD) {
75   if (!NewFpoData.hasValue())
76     NewFpoData.emplace(false);
77 
78   NewFpoData->addFrameData(FD);
79 }
80 
81 void DbiStreamBuilder::addOldFpoData(const object::FpoData &FD) {
82   OldFpoData.push_back(FD);
83 }
84 
85 Error DbiStreamBuilder::addDbgStream(pdb::DbgHeaderType Type,
86                                      ArrayRef<uint8_t> Data) {
87   assert(Type != DbgHeaderType::NewFPO &&
88          "NewFPO data should be written via addFrameData()!");
89 
90   DbgStreams[(int)Type].emplace();
91   DbgStreams[(int)Type]->Size = Data.size();
92   DbgStreams[(int)Type]->WriteFn = [Data](BinaryStreamWriter &Writer) {
93     return Writer.writeArray(Data);
94   };
95   return Error::success();
96 }
97 
98 uint32_t DbiStreamBuilder::addECName(StringRef Name) {
99   return ECNamesBuilder.insert(Name);
100 }
101 
102 uint32_t DbiStreamBuilder::calculateSerializedLength() const {
103   // For now we only support serializing the header.
104   return sizeof(DbiStreamHeader) + calculateFileInfoSubstreamSize() +
105          calculateModiSubstreamSize() + calculateSectionContribsStreamSize() +
106          calculateSectionMapStreamSize() + calculateDbgStreamsSize() +
107          ECNamesBuilder.calculateSerializedSize();
108 }
109 
110 Expected<DbiModuleDescriptorBuilder &>
111 DbiStreamBuilder::addModuleInfo(StringRef ModuleName) {
112   uint32_t Index = ModiList.size();
113   ModiList.push_back(
114       std::make_unique<DbiModuleDescriptorBuilder>(ModuleName, Index, Msf));
115   return *ModiList.back();
116 }
117 
118 Error DbiStreamBuilder::addModuleSourceFile(DbiModuleDescriptorBuilder &Module,
119                                             StringRef File) {
120   uint32_t Index = SourceFileNames.size();
121   SourceFileNames.insert(std::make_pair(File, Index));
122   Module.addSourceFile(File);
123   return Error::success();
124 }
125 
126 Expected<uint32_t> DbiStreamBuilder::getSourceFileNameIndex(StringRef File) {
127   auto NameIter = SourceFileNames.find(File);
128   if (NameIter == SourceFileNames.end())
129     return make_error<RawError>(raw_error_code::no_entry,
130                                 "The specified source file was not found");
131   return NameIter->getValue();
132 }
133 
134 uint32_t DbiStreamBuilder::calculateModiSubstreamSize() const {
135   uint32_t Size = 0;
136   for (const auto &M : ModiList)
137     Size += M->calculateSerializedLength();
138   return Size;
139 }
140 
141 uint32_t DbiStreamBuilder::calculateSectionContribsStreamSize() const {
142   if (SectionContribs.empty())
143     return 0;
144   return sizeof(enum PdbRaw_DbiSecContribVer) +
145          sizeof(SectionContribs[0]) * SectionContribs.size();
146 }
147 
148 uint32_t DbiStreamBuilder::calculateSectionMapStreamSize() const {
149   if (SectionMap.empty())
150     return 0;
151   return sizeof(SecMapHeader) + sizeof(SecMapEntry) * SectionMap.size();
152 }
153 
154 uint32_t DbiStreamBuilder::calculateNamesOffset() const {
155   uint32_t Offset = 0;
156   Offset += sizeof(ulittle16_t);                         // NumModules
157   Offset += sizeof(ulittle16_t);                         // NumSourceFiles
158   Offset += ModiList.size() * sizeof(ulittle16_t);       // ModIndices
159   Offset += ModiList.size() * sizeof(ulittle16_t);       // ModFileCounts
160   uint32_t NumFileInfos = 0;
161   for (const auto &M : ModiList)
162     NumFileInfos += M->source_files().size();
163   Offset += NumFileInfos * sizeof(ulittle32_t); // FileNameOffsets
164   return Offset;
165 }
166 
167 uint32_t DbiStreamBuilder::calculateFileInfoSubstreamSize() const {
168   uint32_t Size = calculateNamesOffset();
169   Size += calculateNamesBufferSize();
170   return alignTo(Size, sizeof(uint32_t));
171 }
172 
173 uint32_t DbiStreamBuilder::calculateNamesBufferSize() const {
174   uint32_t Size = 0;
175   for (const auto &F : SourceFileNames) {
176     Size += F.getKeyLength() + 1; // Names[I];
177   }
178   return Size;
179 }
180 
181 uint32_t DbiStreamBuilder::calculateDbgStreamsSize() const {
182   return DbgStreams.size() * sizeof(uint16_t);
183 }
184 
185 Error DbiStreamBuilder::generateFileInfoSubstream() {
186   uint32_t Size = calculateFileInfoSubstreamSize();
187   auto Data = Allocator.Allocate<uint8_t>(Size);
188   uint32_t NamesOffset = calculateNamesOffset();
189 
190   FileInfoBuffer = MutableBinaryByteStream(MutableArrayRef<uint8_t>(Data, Size),
191                                            llvm::support::little);
192 
193   WritableBinaryStreamRef MetadataBuffer =
194       WritableBinaryStreamRef(FileInfoBuffer).keep_front(NamesOffset);
195   BinaryStreamWriter MetadataWriter(MetadataBuffer);
196 
197   uint16_t ModiCount = std::min<uint32_t>(UINT16_MAX, ModiList.size());
198   uint16_t FileCount = std::min<uint32_t>(UINT16_MAX, SourceFileNames.size());
199   if (auto EC = MetadataWriter.writeInteger(ModiCount)) // NumModules
200     return EC;
201   if (auto EC = MetadataWriter.writeInteger(FileCount)) // NumSourceFiles
202     return EC;
203   for (uint16_t I = 0; I < ModiCount; ++I) {
204     if (auto EC = MetadataWriter.writeInteger(I)) // Mod Indices
205       return EC;
206   }
207   for (const auto &MI : ModiList) {
208     FileCount = static_cast<uint16_t>(MI->source_files().size());
209     if (auto EC = MetadataWriter.writeInteger(FileCount)) // Mod File Counts
210       return EC;
211   }
212 
213   // Before writing the FileNameOffsets array, write the NamesBuffer array.
214   // A side effect of this is that this will actually compute the various
215   // file name offsets, so we can then go back and write the FileNameOffsets
216   // array to the other substream.
217   NamesBuffer = WritableBinaryStreamRef(FileInfoBuffer).drop_front(NamesOffset);
218   BinaryStreamWriter NameBufferWriter(NamesBuffer);
219   for (auto &Name : SourceFileNames) {
220     Name.second = NameBufferWriter.getOffset();
221     if (auto EC = NameBufferWriter.writeCString(Name.getKey()))
222       return EC;
223   }
224 
225   for (const auto &MI : ModiList) {
226     for (StringRef Name : MI->source_files()) {
227       auto Result = SourceFileNames.find(Name);
228       if (Result == SourceFileNames.end())
229         return make_error<RawError>(raw_error_code::no_entry,
230                                     "The source file was not found.");
231       if (auto EC = MetadataWriter.writeInteger(Result->second))
232         return EC;
233     }
234   }
235 
236   if (auto EC = NameBufferWriter.padToAlignment(sizeof(uint32_t)))
237     return EC;
238 
239   if (NameBufferWriter.bytesRemaining() > 0)
240     return make_error<RawError>(raw_error_code::invalid_format,
241                                 "The names buffer contained unexpected data.");
242 
243   if (MetadataWriter.bytesRemaining() > sizeof(uint32_t))
244     return make_error<RawError>(
245         raw_error_code::invalid_format,
246         "The metadata buffer contained unexpected data.");
247 
248   return Error::success();
249 }
250 
251 Error DbiStreamBuilder::finalize() {
252   if (Header)
253     return Error::success();
254 
255   for (auto &MI : ModiList)
256     MI->finalize();
257 
258   if (auto EC = generateFileInfoSubstream())
259     return EC;
260 
261   DbiStreamHeader *H = Allocator.Allocate<DbiStreamHeader>();
262   ::memset(H, 0, sizeof(DbiStreamHeader));
263   H->VersionHeader = *VerHeader;
264   H->VersionSignature = -1;
265   H->Age = Age;
266   H->BuildNumber = BuildNumber;
267   H->Flags = Flags;
268   H->PdbDllRbld = PdbDllRbld;
269   H->PdbDllVersion = PdbDllVersion;
270   H->MachineType = static_cast<uint16_t>(MachineType);
271 
272   H->ECSubstreamSize = ECNamesBuilder.calculateSerializedSize();
273   H->FileInfoSize = FileInfoBuffer.getLength();
274   H->ModiSubstreamSize = calculateModiSubstreamSize();
275   H->OptionalDbgHdrSize = DbgStreams.size() * sizeof(uint16_t);
276   H->SecContrSubstreamSize = calculateSectionContribsStreamSize();
277   H->SectionMapSize = calculateSectionMapStreamSize();
278   H->TypeServerSize = 0;
279   H->SymRecordStreamIndex = SymRecordStreamIndex;
280   H->PublicSymbolStreamIndex = PublicsStreamIndex;
281   H->MFCTypeServerIndex = 0; // Not sure what this is, but link.exe writes 0.
282   H->GlobalSymbolStreamIndex = GlobalsStreamIndex;
283 
284   Header = H;
285   return Error::success();
286 }
287 
288 Error DbiStreamBuilder::finalizeMsfLayout() {
289   if (NewFpoData.hasValue()) {
290     DbgStreams[(int)DbgHeaderType::NewFPO].emplace();
291     DbgStreams[(int)DbgHeaderType::NewFPO]->Size =
292         NewFpoData->calculateSerializedSize();
293     DbgStreams[(int)DbgHeaderType::NewFPO]->WriteFn =
294         [this](BinaryStreamWriter &Writer) {
295           return NewFpoData->commit(Writer);
296         };
297   }
298 
299   if (!OldFpoData.empty()) {
300     DbgStreams[(int)DbgHeaderType::FPO].emplace();
301     DbgStreams[(int)DbgHeaderType::FPO]->Size =
302         sizeof(object::FpoData) * OldFpoData.size();
303     DbgStreams[(int)DbgHeaderType::FPO]->WriteFn =
304         [this](BinaryStreamWriter &Writer) {
305           return Writer.writeArray(makeArrayRef(OldFpoData));
306         };
307   }
308 
309   for (auto &S : DbgStreams) {
310     if (!S.hasValue())
311       continue;
312     auto ExpectedIndex = Msf.addStream(S->Size);
313     if (!ExpectedIndex)
314       return ExpectedIndex.takeError();
315     S->StreamNumber = *ExpectedIndex;
316   }
317 
318   for (auto &MI : ModiList) {
319     if (auto EC = MI->finalizeMsfLayout())
320       return EC;
321   }
322 
323   uint32_t Length = calculateSerializedLength();
324   if (auto EC = Msf.setStreamSize(StreamDBI, Length))
325     return EC;
326   return Error::success();
327 }
328 
329 static uint16_t toSecMapFlags(uint32_t Flags) {
330   uint16_t Ret = 0;
331   if (Flags & COFF::IMAGE_SCN_MEM_READ)
332     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Read);
333   if (Flags & COFF::IMAGE_SCN_MEM_WRITE)
334     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Write);
335   if (Flags & COFF::IMAGE_SCN_MEM_EXECUTE)
336     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Execute);
337   if (!(Flags & COFF::IMAGE_SCN_MEM_16BIT))
338     Ret |= static_cast<uint16_t>(OMFSegDescFlags::AddressIs32Bit);
339 
340   // This seems always 1.
341   Ret |= static_cast<uint16_t>(OMFSegDescFlags::IsSelector);
342 
343   return Ret;
344 }
345 
346 // Populate the Section Map from COFF section headers.
347 //
348 // A Section Map seem to be a copy of a COFF section list in other format.
349 // I don't know why a PDB file contains both a COFF section header and
350 // a Section Map, but it seems it must be present in a PDB.
351 void DbiStreamBuilder::createSectionMap(
352     ArrayRef<llvm::object::coff_section> SecHdrs) {
353   int Idx = 0;
354 
355   auto Add = [&]() -> SecMapEntry & {
356     SectionMap.emplace_back();
357     auto &Entry = SectionMap.back();
358     memset(&Entry, 0, sizeof(Entry));
359 
360     Entry.Frame = Idx + 1;
361 
362     // We don't know the meaning of these fields yet.
363     Entry.SecName = UINT16_MAX;
364     Entry.ClassName = UINT16_MAX;
365 
366     return Entry;
367   };
368 
369   for (auto &Hdr : SecHdrs) {
370     auto &Entry = Add();
371     Entry.Flags = toSecMapFlags(Hdr.Characteristics);
372     Entry.SecByteLength = Hdr.VirtualSize;
373     ++Idx;
374   }
375 
376   // The last entry is for absolute symbols.
377   auto &Entry = Add();
378   Entry.Flags = static_cast<uint16_t>(OMFSegDescFlags::AddressIs32Bit) |
379                 static_cast<uint16_t>(OMFSegDescFlags::IsAbsoluteAddress);
380   Entry.SecByteLength = UINT32_MAX;
381 }
382 
383 Error DbiStreamBuilder::commit(const msf::MSFLayout &Layout,
384                                WritableBinaryStreamRef MsfBuffer) {
385   if (auto EC = finalize())
386     return EC;
387 
388   auto DbiS = WritableMappedBlockStream::createIndexedStream(
389       Layout, MsfBuffer, StreamDBI, Allocator);
390 
391   BinaryStreamWriter Writer(*DbiS);
392   if (auto EC = Writer.writeObject(*Header))
393     return EC;
394 
395   for (auto &M : ModiList) {
396     if (auto EC = M->commit(Writer))
397       return EC;
398   }
399 
400   // Commit symbol streams. This is a lot of data, so do it in parallel.
401   if (auto EC = parallelForEachError(
402           ModiList, [&](std::unique_ptr<DbiModuleDescriptorBuilder> &M) {
403             return M->commitSymbolStream(Layout, MsfBuffer);
404           }))
405     return EC;
406 
407   if (!SectionContribs.empty()) {
408     if (auto EC = Writer.writeEnum(DbiSecContribVer60))
409       return EC;
410     if (auto EC = Writer.writeArray(makeArrayRef(SectionContribs)))
411       return EC;
412   }
413 
414   if (!SectionMap.empty()) {
415     ulittle16_t Size = static_cast<ulittle16_t>(SectionMap.size());
416     SecMapHeader SMHeader = {Size, Size};
417     if (auto EC = Writer.writeObject(SMHeader))
418       return EC;
419     if (auto EC = Writer.writeArray(makeArrayRef(SectionMap)))
420       return EC;
421   }
422 
423   if (auto EC = Writer.writeStreamRef(FileInfoBuffer))
424     return EC;
425 
426   if (auto EC = ECNamesBuilder.commit(Writer))
427     return EC;
428 
429   for (auto &Stream : DbgStreams) {
430     uint16_t StreamNumber = kInvalidStreamIndex;
431     if (Stream.hasValue())
432       StreamNumber = Stream->StreamNumber;
433     if (auto EC = Writer.writeInteger(StreamNumber))
434       return EC;
435   }
436 
437   for (auto &Stream : DbgStreams) {
438     if (!Stream.hasValue())
439       continue;
440     assert(Stream->StreamNumber != kInvalidStreamIndex);
441 
442     auto WritableStream = WritableMappedBlockStream::createIndexedStream(
443         Layout, MsfBuffer, Stream->StreamNumber, Allocator);
444     BinaryStreamWriter DbgStreamWriter(*WritableStream);
445 
446     if (auto EC = Stream->WriteFn(DbgStreamWriter))
447       return EC;
448   }
449 
450   if (Writer.bytesRemaining() > 0)
451     return make_error<RawError>(raw_error_code::invalid_format,
452                                 "Unexpected bytes found in DBI Stream");
453   return Error::success();
454 }
455