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