1 //===- DbiStreamBuilder.cpp - PDB Dbi Stream Creation -----------*- C++ -*-===//
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/PDB/Native/DbiStreamBuilder.h"
11 
12 #include "llvm/ADT/ArrayRef.h"
13 #include "llvm/DebugInfo/MSF/MSFBuilder.h"
14 #include "llvm/DebugInfo/MSF/MappedBlockStream.h"
15 #include "llvm/DebugInfo/MSF/StreamWriter.h"
16 #include "llvm/DebugInfo/PDB/Native/DbiStream.h"
17 #include "llvm/DebugInfo/PDB/Native/RawError.h"
18 #include "llvm/Object/COFF.h"
19 #include "llvm/Support/COFF.h"
20 
21 using namespace llvm;
22 using namespace llvm::codeview;
23 using namespace llvm::msf;
24 using namespace llvm::pdb;
25 
26 namespace {
27 class ModiSubstreamBuilder {};
28 }
29 
30 DbiStreamBuilder::DbiStreamBuilder(msf::MSFBuilder &Msf)
31     : Msf(Msf), Allocator(Msf.getAllocator()), Age(1), BuildNumber(0),
32       PdbDllVersion(0), PdbDllRbld(0), Flags(0), MachineType(PDB_Machine::x86),
33       Header(nullptr), DbgStreams((int)DbgHeaderType::Max) {}
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::setPdbDllVersion(uint16_t V) { PdbDllVersion = V; }
42 
43 void DbiStreamBuilder::setPdbDllRbld(uint16_t R) { PdbDllRbld = R; }
44 
45 void DbiStreamBuilder::setFlags(uint16_t F) { Flags = F; }
46 
47 void DbiStreamBuilder::setMachineType(PDB_Machine M) { MachineType = M; }
48 
49 void DbiStreamBuilder::setSectionContribs(ArrayRef<SectionContrib> Arr) {
50   SectionContribs = Arr;
51 }
52 
53 void DbiStreamBuilder::setSectionMap(ArrayRef<SecMapEntry> SecMap) {
54   SectionMap = SecMap;
55 }
56 
57 Error DbiStreamBuilder::addDbgStream(pdb::DbgHeaderType Type,
58                                      ArrayRef<uint8_t> Data) {
59   if (DbgStreams[(int)Type].StreamNumber)
60     return make_error<RawError>(raw_error_code::duplicate_entry,
61                                 "The specified stream type already exists");
62   auto ExpectedIndex = Msf.addStream(Data.size());
63   if (!ExpectedIndex)
64     return ExpectedIndex.takeError();
65   uint32_t Index = std::move(*ExpectedIndex);
66   DbgStreams[(int)Type].Data = Data;
67   DbgStreams[(int)Type].StreamNumber = Index;
68   return Error::success();
69 }
70 
71 uint32_t DbiStreamBuilder::calculateSerializedLength() const {
72   // For now we only support serializing the header.
73   return sizeof(DbiStreamHeader) + calculateFileInfoSubstreamSize() +
74          calculateModiSubstreamSize() + calculateSectionContribsStreamSize() +
75          calculateSectionMapStreamSize() + calculateDbgStreamsSize();
76 }
77 
78 Error DbiStreamBuilder::addModuleInfo(StringRef ObjFile, StringRef Module) {
79   auto Entry = llvm::make_unique<ModuleInfo>();
80   ModuleInfo *M = Entry.get();
81   Entry->Mod = Module;
82   Entry->Obj = ObjFile;
83   auto Result = ModuleInfos.insert(std::make_pair(Module, std::move(Entry)));
84   if (!Result.second)
85     return make_error<RawError>(raw_error_code::duplicate_entry,
86                                 "The specified module already exists");
87   ModuleInfoList.push_back(M);
88   return Error::success();
89 }
90 
91 Error DbiStreamBuilder::addModuleSourceFile(StringRef Module, StringRef File) {
92   auto ModIter = ModuleInfos.find(Module);
93   if (ModIter == ModuleInfos.end())
94     return make_error<RawError>(raw_error_code::no_entry,
95                                 "The specified module was not found");
96   uint32_t Index = SourceFileNames.size();
97   SourceFileNames.insert(std::make_pair(File, Index));
98   auto &ModEntry = *ModIter;
99   ModEntry.second->SourceFiles.push_back(File);
100   return Error::success();
101 }
102 
103 uint32_t DbiStreamBuilder::calculateModiSubstreamSize() const {
104   uint32_t Size = 0;
105   for (const auto &M : ModuleInfoList) {
106     Size += sizeof(ModuleInfoHeader);
107     Size += M->Mod.size() + 1;
108     Size += M->Obj.size() + 1;
109   }
110   return alignTo(Size, sizeof(uint32_t));
111 }
112 
113 uint32_t DbiStreamBuilder::calculateSectionContribsStreamSize() const {
114   if (SectionContribs.empty())
115     return 0;
116   return sizeof(enum PdbRaw_DbiSecContribVer) +
117          sizeof(SectionContribs[0]) * SectionContribs.size();
118 }
119 
120 uint32_t DbiStreamBuilder::calculateSectionMapStreamSize() const {
121   if (SectionMap.empty())
122     return 0;
123   return sizeof(SecMapHeader) + sizeof(SecMapEntry) * SectionMap.size();
124 }
125 
126 uint32_t DbiStreamBuilder::calculateFileInfoSubstreamSize() const {
127   uint32_t Size = 0;
128   Size += sizeof(ulittle16_t);                         // NumModules
129   Size += sizeof(ulittle16_t);                         // NumSourceFiles
130   Size += ModuleInfoList.size() * sizeof(ulittle16_t); // ModIndices
131   Size += ModuleInfoList.size() * sizeof(ulittle16_t); // ModFileCounts
132   uint32_t NumFileInfos = 0;
133   for (const auto &M : ModuleInfoList)
134     NumFileInfos += M->SourceFiles.size();
135   Size += NumFileInfos * sizeof(ulittle32_t); // FileNameOffsets
136   Size += calculateNamesBufferSize();
137   return alignTo(Size, sizeof(uint32_t));
138 }
139 
140 uint32_t DbiStreamBuilder::calculateNamesBufferSize() const {
141   uint32_t Size = 0;
142   for (const auto &F : SourceFileNames) {
143     Size += F.getKeyLength() + 1; // Names[I];
144   }
145   return Size;
146 }
147 
148 uint32_t DbiStreamBuilder::calculateDbgStreamsSize() const {
149   return DbgStreams.size() * sizeof(uint16_t);
150 }
151 
152 Error DbiStreamBuilder::generateModiSubstream() {
153   uint32_t Size = calculateModiSubstreamSize();
154   auto Data = Allocator.Allocate<uint8_t>(Size);
155 
156   ModInfoBuffer = MutableByteStream(MutableArrayRef<uint8_t>(Data, Size));
157 
158   StreamWriter ModiWriter(ModInfoBuffer);
159   for (const auto &M : ModuleInfoList) {
160     ModuleInfoHeader Layout = {};
161     Layout.ModDiStream = kInvalidStreamIndex;
162     Layout.NumFiles = M->SourceFiles.size();
163     if (auto EC = ModiWriter.writeObject(Layout))
164       return EC;
165     if (auto EC = ModiWriter.writeZeroString(M->Mod))
166       return EC;
167     if (auto EC = ModiWriter.writeZeroString(M->Obj))
168       return EC;
169   }
170   if (ModiWriter.bytesRemaining() > sizeof(uint32_t))
171     return make_error<RawError>(raw_error_code::invalid_format,
172                                 "Unexpected bytes in Modi Stream Data");
173   return Error::success();
174 }
175 
176 Error DbiStreamBuilder::generateFileInfoSubstream() {
177   uint32_t Size = calculateFileInfoSubstreamSize();
178   uint32_t NameSize = calculateNamesBufferSize();
179   auto Data = Allocator.Allocate<uint8_t>(Size);
180   uint32_t NamesOffset = Size - NameSize;
181 
182   FileInfoBuffer = MutableByteStream(MutableArrayRef<uint8_t>(Data, Size));
183 
184   WritableStreamRef MetadataBuffer =
185       WritableStreamRef(FileInfoBuffer).keep_front(NamesOffset);
186   StreamWriter MetadataWriter(MetadataBuffer);
187 
188   uint16_t ModiCount = std::min<uint32_t>(UINT16_MAX, ModuleInfos.size());
189   uint16_t FileCount = std::min<uint32_t>(UINT16_MAX, SourceFileNames.size());
190   if (auto EC = MetadataWriter.writeInteger(
191           ModiCount, llvm::support::little)) // NumModules
192     return EC;
193   if (auto EC = MetadataWriter.writeInteger(
194           FileCount, llvm::support::little)) // NumSourceFiles
195     return EC;
196   for (uint16_t I = 0; I < ModiCount; ++I) {
197     if (auto EC = MetadataWriter.writeInteger(
198             I, llvm::support::little)) // Mod Indices
199       return EC;
200   }
201   for (const auto MI : ModuleInfoList) {
202     FileCount = static_cast<uint16_t>(MI->SourceFiles.size());
203     if (auto EC = MetadataWriter.writeInteger(
204             FileCount, llvm::support::little)) // Mod File Counts
205       return EC;
206   }
207 
208   // Before writing the FileNameOffsets array, write the NamesBuffer array.
209   // A side effect of this is that this will actually compute the various
210   // file name offsets, so we can then go back and write the FileNameOffsets
211   // array to the other substream.
212   NamesBuffer = WritableStreamRef(FileInfoBuffer).drop_front(NamesOffset);
213   StreamWriter NameBufferWriter(NamesBuffer);
214   for (auto &Name : SourceFileNames) {
215     Name.second = NameBufferWriter.getOffset();
216     if (auto EC = NameBufferWriter.writeZeroString(Name.getKey()))
217       return EC;
218   }
219 
220   for (const auto MI : ModuleInfoList) {
221     for (StringRef Name : MI->SourceFiles) {
222       auto Result = SourceFileNames.find(Name);
223       if (Result == SourceFileNames.end())
224         return make_error<RawError>(raw_error_code::no_entry,
225                                     "The source file was not found.");
226       if (auto EC = MetadataWriter.writeInteger(Result->second,
227                                                 llvm::support::little))
228         return EC;
229     }
230   }
231 
232   if (NameBufferWriter.bytesRemaining() > 0)
233     return make_error<RawError>(raw_error_code::invalid_format,
234                                 "The names buffer contained unexpected data.");
235 
236   if (MetadataWriter.bytesRemaining() > sizeof(uint32_t))
237     return make_error<RawError>(
238         raw_error_code::invalid_format,
239         "The metadata buffer contained unexpected data.");
240 
241   return Error::success();
242 }
243 
244 Error DbiStreamBuilder::finalize() {
245   if (Header)
246     return Error::success();
247 
248   DbiStreamHeader *H = Allocator.Allocate<DbiStreamHeader>();
249 
250   if (auto EC = generateModiSubstream())
251     return EC;
252   if (auto EC = generateFileInfoSubstream())
253     return EC;
254 
255   H->VersionHeader = *VerHeader;
256   H->VersionSignature = -1;
257   H->Age = Age;
258   H->BuildNumber = BuildNumber;
259   H->Flags = Flags;
260   H->PdbDllRbld = PdbDllRbld;
261   H->PdbDllVersion = PdbDllVersion;
262   H->MachineType = static_cast<uint16_t>(MachineType);
263 
264   H->ECSubstreamSize = 0;
265   H->FileInfoSize = FileInfoBuffer.getLength();
266   H->ModiSubstreamSize = ModInfoBuffer.getLength();
267   H->OptionalDbgHdrSize = DbgStreams.size() * sizeof(uint16_t);
268   H->SecContrSubstreamSize = calculateSectionContribsStreamSize();
269   H->SectionMapSize = calculateSectionMapStreamSize();
270   H->TypeServerSize = 0;
271   H->SymRecordStreamIndex = kInvalidStreamIndex;
272   H->PublicSymbolStreamIndex = kInvalidStreamIndex;
273   H->MFCTypeServerIndex = kInvalidStreamIndex;
274   H->GlobalSymbolStreamIndex = kInvalidStreamIndex;
275 
276   Header = H;
277   return Error::success();
278 }
279 
280 Error DbiStreamBuilder::finalizeMsfLayout() {
281   uint32_t Length = calculateSerializedLength();
282   if (auto EC = Msf.setStreamSize(StreamDBI, Length))
283     return EC;
284   return Error::success();
285 }
286 
287 static uint16_t toSecMapFlags(uint32_t Flags) {
288   uint16_t Ret = 0;
289   if (Flags & COFF::IMAGE_SCN_MEM_READ)
290     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Read);
291   if (Flags & COFF::IMAGE_SCN_MEM_WRITE)
292     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Write);
293   if (Flags & COFF::IMAGE_SCN_MEM_EXECUTE)
294     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Execute);
295   if (Flags & COFF::IMAGE_SCN_MEM_EXECUTE)
296     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Execute);
297   if (!(Flags & COFF::IMAGE_SCN_MEM_16BIT))
298     Ret |= static_cast<uint16_t>(OMFSegDescFlags::AddressIs32Bit);
299 
300   // This seems always 1.
301   Ret |= static_cast<uint16_t>(OMFSegDescFlags::IsSelector);
302 
303   return Ret;
304 }
305 
306 // A utility function to create Section Contributions
307 // for a given input sections.
308 std::vector<SectionContrib> DbiStreamBuilder::createSectionContribs(
309     ArrayRef<object::coff_section> SecHdrs) {
310   std::vector<SectionContrib> Ret;
311 
312   // Create a SectionContrib for each input section.
313   for (auto &Sec : SecHdrs) {
314     Ret.emplace_back();
315     auto &Entry = Ret.back();
316     memset(&Entry, 0, sizeof(Entry));
317 
318     Entry.Off = Sec.PointerToRawData;
319     Entry.Size = Sec.SizeOfRawData;
320     Entry.Characteristics = Sec.Characteristics;
321   }
322   return Ret;
323 }
324 
325 // A utility function to create a Section Map for a given list of COFF sections.
326 //
327 // A Section Map seem to be a copy of a COFF section list in other format.
328 // I don't know why a PDB file contains both a COFF section header and
329 // a Section Map, but it seems it must be present in a PDB.
330 std::vector<SecMapEntry> DbiStreamBuilder::createSectionMap(
331     ArrayRef<llvm::object::coff_section> SecHdrs) {
332   std::vector<SecMapEntry> Ret;
333   int Idx = 0;
334 
335   auto Add = [&]() -> SecMapEntry & {
336     Ret.emplace_back();
337     auto &Entry = Ret.back();
338     memset(&Entry, 0, sizeof(Entry));
339 
340     Entry.Frame = Idx + 1;
341 
342     // We don't know the meaning of these fields yet.
343     Entry.SecName = UINT16_MAX;
344     Entry.ClassName = UINT16_MAX;
345 
346     return Entry;
347   };
348 
349   for (auto &Hdr : SecHdrs) {
350     auto &Entry = Add();
351     Entry.Flags = toSecMapFlags(Hdr.Characteristics);
352     Entry.SecByteLength = Hdr.VirtualSize;
353     ++Idx;
354   }
355 
356   // The last entry is for absolute symbols.
357   auto &Entry = Add();
358   Entry.Flags = static_cast<uint16_t>(OMFSegDescFlags::AddressIs32Bit) |
359                 static_cast<uint16_t>(OMFSegDescFlags::IsAbsoluteAddress);
360   Entry.SecByteLength = UINT32_MAX;
361 
362   return Ret;
363 }
364 
365 Error DbiStreamBuilder::commit(const msf::MSFLayout &Layout,
366                                const msf::WritableStream &Buffer) {
367   if (auto EC = finalize())
368     return EC;
369 
370   auto InfoS =
371       WritableMappedBlockStream::createIndexedStream(Layout, Buffer, StreamDBI);
372 
373   StreamWriter Writer(*InfoS);
374   if (auto EC = Writer.writeObject(*Header))
375     return EC;
376 
377   if (auto EC = Writer.writeStreamRef(ModInfoBuffer))
378     return EC;
379 
380   if (!SectionContribs.empty()) {
381     if (auto EC = Writer.writeEnum(DbiSecContribVer60, llvm::support::little))
382       return EC;
383     if (auto EC = Writer.writeArray(SectionContribs))
384       return EC;
385   }
386 
387   if (!SectionMap.empty()) {
388     ulittle16_t Size = static_cast<ulittle16_t>(SectionMap.size());
389     SecMapHeader SMHeader = {Size, Size};
390     if (auto EC = Writer.writeObject(SMHeader))
391       return EC;
392     if (auto EC = Writer.writeArray(SectionMap))
393       return EC;
394   }
395 
396   if (auto EC = Writer.writeStreamRef(FileInfoBuffer))
397     return EC;
398 
399   for (auto &Stream : DbgStreams)
400     if (auto EC =
401             Writer.writeInteger(Stream.StreamNumber, llvm::support::little))
402       return EC;
403 
404   for (auto &Stream : DbgStreams) {
405     if (Stream.StreamNumber == kInvalidStreamIndex)
406       continue;
407     auto WritableStream = WritableMappedBlockStream::createIndexedStream(
408         Layout, Buffer, Stream.StreamNumber);
409     StreamWriter DbgStreamWriter(*WritableStream);
410     if (auto EC = DbgStreamWriter.writeArray(Stream.Data))
411       return EC;
412   }
413 
414   if (Writer.bytesRemaining() > 0)
415     return make_error<RawError>(raw_error_code::invalid_format,
416                                 "Unexpected bytes found in DBI Stream");
417   return Error::success();
418 }
419