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