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/BinaryFormat/COFF.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 
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), DbgStreams((int)DbgHeaderType::Max) {}
31 
32 DbiStreamBuilder::~DbiStreamBuilder() {}
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::setPdbDllVersion(uint16_t V) { PdbDllVersion = V; }
41 
42 void DbiStreamBuilder::setPdbDllRbld(uint16_t R) { PdbDllRbld = R; }
43 
44 void DbiStreamBuilder::setFlags(uint16_t F) { Flags = F; }
45 
46 void DbiStreamBuilder::setMachineType(PDB_Machine M) { MachineType = M; }
47 
48 void DbiStreamBuilder::setSectionMap(ArrayRef<SecMapEntry> SecMap) {
49   SectionMap = SecMap;
50 }
51 
52 Error DbiStreamBuilder::addDbgStream(pdb::DbgHeaderType Type,
53                                      ArrayRef<uint8_t> Data) {
54   if (DbgStreams[(int)Type].StreamNumber)
55     return make_error<RawError>(raw_error_code::duplicate_entry,
56                                 "The specified stream type already exists");
57   auto ExpectedIndex = Msf.addStream(Data.size());
58   if (!ExpectedIndex)
59     return ExpectedIndex.takeError();
60   uint32_t Index = std::move(*ExpectedIndex);
61   DbgStreams[(int)Type].Data = Data;
62   DbgStreams[(int)Type].StreamNumber = Index;
63   return Error::success();
64 }
65 
66 uint32_t DbiStreamBuilder::calculateSerializedLength() const {
67   // For now we only support serializing the header.
68   return sizeof(DbiStreamHeader) + calculateFileInfoSubstreamSize() +
69          calculateModiSubstreamSize() + calculateSectionContribsStreamSize() +
70          calculateSectionMapStreamSize() + calculateDbgStreamsSize();
71 }
72 
73 Expected<DbiModuleDescriptorBuilder &>
74 DbiStreamBuilder::addModuleInfo(StringRef ModuleName) {
75   uint32_t Index = ModiList.size();
76   auto MIB =
77       llvm::make_unique<DbiModuleDescriptorBuilder>(ModuleName, Index, Msf);
78   auto M = MIB.get();
79   auto Result = ModiMap.insert(std::make_pair(ModuleName, std::move(MIB)));
80 
81   if (!Result.second)
82     return make_error<RawError>(raw_error_code::duplicate_entry,
83                                 "The specified module already exists");
84   ModiList.push_back(M);
85   return *M;
86 }
87 
88 Error DbiStreamBuilder::addModuleSourceFile(StringRef Module, StringRef File) {
89   auto ModIter = ModiMap.find(Module);
90   if (ModIter == ModiMap.end())
91     return make_error<RawError>(raw_error_code::no_entry,
92                                 "The specified module was not found");
93   uint32_t Index = SourceFileNames.size();
94   SourceFileNames.insert(std::make_pair(File, Index));
95   auto &ModEntry = *ModIter;
96   ModEntry.second->addSourceFile(File);
97   return Error::success();
98 }
99 
100 Expected<uint32_t> DbiStreamBuilder::getSourceFileNameIndex(StringRef File) {
101   auto NameIter = SourceFileNames.find(File);
102   if (NameIter == SourceFileNames.end())
103     return make_error<RawError>(raw_error_code::no_entry,
104                                 "The specified source file was not found");
105   return NameIter->getValue();
106 }
107 
108 uint32_t DbiStreamBuilder::calculateModiSubstreamSize() const {
109   uint32_t Size = 0;
110   for (const auto &M : ModiList)
111     Size += M->calculateSerializedLength();
112   return Size;
113 }
114 
115 uint32_t DbiStreamBuilder::calculateSectionContribsStreamSize() const {
116   if (SectionContribs.empty())
117     return 0;
118   return sizeof(enum PdbRaw_DbiSecContribVer) +
119          sizeof(SectionContribs[0]) * SectionContribs.size();
120 }
121 
122 uint32_t DbiStreamBuilder::calculateSectionMapStreamSize() const {
123   if (SectionMap.empty())
124     return 0;
125   return sizeof(SecMapHeader) + sizeof(SecMapEntry) * SectionMap.size();
126 }
127 
128 uint32_t DbiStreamBuilder::calculateNamesOffset() const {
129   uint32_t Offset = 0;
130   Offset += sizeof(ulittle16_t);                         // NumModules
131   Offset += sizeof(ulittle16_t);                         // NumSourceFiles
132   Offset += ModiList.size() * sizeof(ulittle16_t);       // ModIndices
133   Offset += ModiList.size() * sizeof(ulittle16_t);       // ModFileCounts
134   uint32_t NumFileInfos = 0;
135   for (const auto &M : ModiList)
136     NumFileInfos += M->source_files().size();
137   Offset += NumFileInfos * sizeof(ulittle32_t); // FileNameOffsets
138   return Offset;
139 }
140 
141 uint32_t DbiStreamBuilder::calculateFileInfoSubstreamSize() const {
142   uint32_t Size = calculateNamesOffset();
143   Size += calculateNamesBufferSize();
144   return alignTo(Size, sizeof(uint32_t));
145 }
146 
147 uint32_t DbiStreamBuilder::calculateNamesBufferSize() const {
148   uint32_t Size = 0;
149   for (const auto &F : SourceFileNames) {
150     Size += F.getKeyLength() + 1; // Names[I];
151   }
152   return Size;
153 }
154 
155 uint32_t DbiStreamBuilder::calculateDbgStreamsSize() const {
156   return DbgStreams.size() * sizeof(uint16_t);
157 }
158 
159 Error DbiStreamBuilder::generateFileInfoSubstream() {
160   uint32_t Size = calculateFileInfoSubstreamSize();
161   auto Data = Allocator.Allocate<uint8_t>(Size);
162   uint32_t NamesOffset = calculateNamesOffset();
163 
164   FileInfoBuffer = MutableBinaryByteStream(MutableArrayRef<uint8_t>(Data, Size),
165                                            llvm::support::little);
166 
167   WritableBinaryStreamRef MetadataBuffer =
168       WritableBinaryStreamRef(FileInfoBuffer).keep_front(NamesOffset);
169   BinaryStreamWriter MetadataWriter(MetadataBuffer);
170 
171   uint16_t ModiCount = std::min<uint32_t>(UINT16_MAX, ModiList.size());
172   uint16_t FileCount = std::min<uint32_t>(UINT16_MAX, SourceFileNames.size());
173   if (auto EC = MetadataWriter.writeInteger(ModiCount)) // NumModules
174     return EC;
175   if (auto EC = MetadataWriter.writeInteger(FileCount)) // NumSourceFiles
176     return EC;
177   for (uint16_t I = 0; I < ModiCount; ++I) {
178     if (auto EC = MetadataWriter.writeInteger(I)) // Mod Indices
179       return EC;
180   }
181   for (const auto &MI : ModiList) {
182     FileCount = static_cast<uint16_t>(MI->source_files().size());
183     if (auto EC = MetadataWriter.writeInteger(FileCount)) // Mod File Counts
184       return EC;
185   }
186 
187   // Before writing the FileNameOffsets array, write the NamesBuffer array.
188   // A side effect of this is that this will actually compute the various
189   // file name offsets, so we can then go back and write the FileNameOffsets
190   // array to the other substream.
191   NamesBuffer = WritableBinaryStreamRef(FileInfoBuffer).drop_front(NamesOffset);
192   BinaryStreamWriter NameBufferWriter(NamesBuffer);
193   for (auto &Name : SourceFileNames) {
194     Name.second = NameBufferWriter.getOffset();
195     if (auto EC = NameBufferWriter.writeCString(Name.getKey()))
196       return EC;
197   }
198 
199   for (const auto &MI : ModiList) {
200     for (StringRef Name : MI->source_files()) {
201       auto Result = SourceFileNames.find(Name);
202       if (Result == SourceFileNames.end())
203         return make_error<RawError>(raw_error_code::no_entry,
204                                     "The source file was not found.");
205       if (auto EC = MetadataWriter.writeInteger(Result->second))
206         return EC;
207     }
208   }
209 
210   if (auto EC = NameBufferWriter.padToAlignment(sizeof(uint32_t)))
211     return EC;
212 
213   if (NameBufferWriter.bytesRemaining() > 0)
214     return make_error<RawError>(raw_error_code::invalid_format,
215                                 "The names buffer contained unexpected data.");
216 
217   if (MetadataWriter.bytesRemaining() > sizeof(uint32_t))
218     return make_error<RawError>(
219         raw_error_code::invalid_format,
220         "The metadata buffer contained unexpected data.");
221 
222   return Error::success();
223 }
224 
225 Error DbiStreamBuilder::finalize() {
226   if (Header)
227     return Error::success();
228 
229   for (auto &MI : ModiList)
230     MI->finalize();
231 
232   if (auto EC = generateFileInfoSubstream())
233     return EC;
234 
235   DbiStreamHeader *H = Allocator.Allocate<DbiStreamHeader>();
236   H->VersionHeader = *VerHeader;
237   H->VersionSignature = -1;
238   H->Age = Age;
239   H->BuildNumber = BuildNumber;
240   H->Flags = Flags;
241   H->PdbDllRbld = PdbDllRbld;
242   H->PdbDllVersion = PdbDllVersion;
243   H->MachineType = static_cast<uint16_t>(MachineType);
244 
245   H->ECSubstreamSize = 0;
246   H->FileInfoSize = FileInfoBuffer.getLength();
247   H->ModiSubstreamSize = calculateModiSubstreamSize();
248   H->OptionalDbgHdrSize = DbgStreams.size() * sizeof(uint16_t);
249   H->SecContrSubstreamSize = calculateSectionContribsStreamSize();
250   H->SectionMapSize = calculateSectionMapStreamSize();
251   H->TypeServerSize = 0;
252   H->SymRecordStreamIndex = kInvalidStreamIndex;
253   H->PublicSymbolStreamIndex = kInvalidStreamIndex;
254   H->MFCTypeServerIndex = kInvalidStreamIndex;
255   H->GlobalSymbolStreamIndex = kInvalidStreamIndex;
256 
257   Header = H;
258   return Error::success();
259 }
260 
261 Error DbiStreamBuilder::finalizeMsfLayout() {
262   for (auto &MI : ModiList) {
263     if (auto EC = MI->finalizeMsfLayout())
264       return EC;
265   }
266 
267   uint32_t Length = calculateSerializedLength();
268   if (auto EC = Msf.setStreamSize(StreamDBI, Length))
269     return EC;
270   return Error::success();
271 }
272 
273 static uint16_t toSecMapFlags(uint32_t Flags) {
274   uint16_t Ret = 0;
275   if (Flags & COFF::IMAGE_SCN_MEM_READ)
276     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Read);
277   if (Flags & COFF::IMAGE_SCN_MEM_WRITE)
278     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Write);
279   if (Flags & COFF::IMAGE_SCN_MEM_EXECUTE)
280     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Execute);
281   if (Flags & COFF::IMAGE_SCN_MEM_EXECUTE)
282     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Execute);
283   if (!(Flags & COFF::IMAGE_SCN_MEM_16BIT))
284     Ret |= static_cast<uint16_t>(OMFSegDescFlags::AddressIs32Bit);
285 
286   // This seems always 1.
287   Ret |= static_cast<uint16_t>(OMFSegDescFlags::IsSelector);
288 
289   return Ret;
290 }
291 
292 void DbiStreamBuilder::addSectionContrib(DbiModuleDescriptorBuilder *ModuleDbi,
293                                          const object::coff_section *SecHdr) {
294   SectionContrib SC;
295   memset(&SC, 0, sizeof(SC));
296   SC.ISect = (uint16_t)~0U; // This represents nil.
297   SC.Off = SecHdr->PointerToRawData;
298   SC.Size = SecHdr->SizeOfRawData;
299   SC.Characteristics = SecHdr->Characteristics;
300   // Use the module index in the module dbi stream or nil (-1).
301   SC.Imod = ModuleDbi ? ModuleDbi->getModuleIndex() : (uint16_t)~0U;
302   SectionContribs.emplace_back(SC);
303 }
304 
305 // A utility function to create a Section Map for a given list of COFF sections.
306 //
307 // A Section Map seem to be a copy of a COFF section list in other format.
308 // I don't know why a PDB file contains both a COFF section header and
309 // a Section Map, but it seems it must be present in a PDB.
310 std::vector<SecMapEntry> DbiStreamBuilder::createSectionMap(
311     ArrayRef<llvm::object::coff_section> SecHdrs) {
312   std::vector<SecMapEntry> Ret;
313   int Idx = 0;
314 
315   auto Add = [&]() -> SecMapEntry & {
316     Ret.emplace_back();
317     auto &Entry = Ret.back();
318     memset(&Entry, 0, sizeof(Entry));
319 
320     Entry.Frame = Idx + 1;
321 
322     // We don't know the meaning of these fields yet.
323     Entry.SecName = UINT16_MAX;
324     Entry.ClassName = UINT16_MAX;
325 
326     return Entry;
327   };
328 
329   for (auto &Hdr : SecHdrs) {
330     auto &Entry = Add();
331     Entry.Flags = toSecMapFlags(Hdr.Characteristics);
332     Entry.SecByteLength = Hdr.VirtualSize;
333     ++Idx;
334   }
335 
336   // The last entry is for absolute symbols.
337   auto &Entry = Add();
338   Entry.Flags = static_cast<uint16_t>(OMFSegDescFlags::AddressIs32Bit) |
339                 static_cast<uint16_t>(OMFSegDescFlags::IsAbsoluteAddress);
340   Entry.SecByteLength = UINT32_MAX;
341 
342   return Ret;
343 }
344 
345 Error DbiStreamBuilder::commit(const msf::MSFLayout &Layout,
346                                WritableBinaryStreamRef MsfBuffer) {
347   if (auto EC = finalize())
348     return EC;
349 
350   auto DbiS = WritableMappedBlockStream::createIndexedStream(
351       Layout, MsfBuffer, StreamDBI, Allocator);
352 
353   BinaryStreamWriter Writer(*DbiS);
354   if (auto EC = Writer.writeObject(*Header))
355     return EC;
356 
357   for (auto &M : ModiList) {
358     if (auto EC = M->commit(Writer, Layout, MsfBuffer))
359       return EC;
360   }
361 
362   if (!SectionContribs.empty()) {
363     if (auto EC = Writer.writeEnum(DbiSecContribVer60))
364       return EC;
365     if (auto EC = Writer.writeArray(makeArrayRef(SectionContribs)))
366       return EC;
367   }
368 
369   if (!SectionMap.empty()) {
370     ulittle16_t Size = static_cast<ulittle16_t>(SectionMap.size());
371     SecMapHeader SMHeader = {Size, Size};
372     if (auto EC = Writer.writeObject(SMHeader))
373       return EC;
374     if (auto EC = Writer.writeArray(SectionMap))
375       return EC;
376   }
377 
378   if (auto EC = Writer.writeStreamRef(FileInfoBuffer))
379     return EC;
380 
381   for (auto &Stream : DbgStreams)
382     if (auto EC = Writer.writeInteger(Stream.StreamNumber))
383       return EC;
384 
385   for (auto &Stream : DbgStreams) {
386     if (Stream.StreamNumber == kInvalidStreamIndex)
387       continue;
388     auto WritableStream = WritableMappedBlockStream::createIndexedStream(
389         Layout, MsfBuffer, Stream.StreamNumber, Allocator);
390     BinaryStreamWriter DbgStreamWriter(*WritableStream);
391     if (auto EC = DbgStreamWriter.writeArray(Stream.Data))
392       return EC;
393   }
394 
395   if (Writer.bytesRemaining() > 0)
396     return make_error<RawError>(raw_error_code::invalid_format,
397                                 "Unexpected bytes found in DBI Stream");
398   return Error::success();
399 }
400