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 void DbiStreamBuilder::setSymbolRecordStreamIndex(uint32_t Index) {
53   SymRecordStreamIndex = Index;
54 }
55 
56 void DbiStreamBuilder::setPublicsStreamIndex(uint32_t Index) {
57   PublicsStreamIndex = Index;
58 }
59 
60 Error DbiStreamBuilder::addDbgStream(pdb::DbgHeaderType Type,
61                                      ArrayRef<uint8_t> Data) {
62   if (DbgStreams[(int)Type].StreamNumber != kInvalidStreamIndex)
63     return make_error<RawError>(raw_error_code::duplicate_entry,
64                                 "The specified stream type already exists");
65   auto ExpectedIndex = Msf.addStream(Data.size());
66   if (!ExpectedIndex)
67     return ExpectedIndex.takeError();
68   uint32_t Index = std::move(*ExpectedIndex);
69   DbgStreams[(int)Type].Data = Data;
70   DbgStreams[(int)Type].StreamNumber = Index;
71   return Error::success();
72 }
73 
74 uint32_t DbiStreamBuilder::addECName(StringRef Name) {
75   return ECNamesBuilder.insert(Name);
76 }
77 
78 uint32_t DbiStreamBuilder::calculateSerializedLength() const {
79   // For now we only support serializing the header.
80   return sizeof(DbiStreamHeader) + calculateFileInfoSubstreamSize() +
81          calculateModiSubstreamSize() + calculateSectionContribsStreamSize() +
82          calculateSectionMapStreamSize() + calculateDbgStreamsSize() +
83          ECNamesBuilder.calculateSerializedSize();
84 }
85 
86 Expected<DbiModuleDescriptorBuilder &>
87 DbiStreamBuilder::addModuleInfo(StringRef ModuleName) {
88   uint32_t Index = ModiList.size();
89   auto MIB =
90       llvm::make_unique<DbiModuleDescriptorBuilder>(ModuleName, Index, Msf);
91   auto M = MIB.get();
92   auto Result = ModiMap.insert(std::make_pair(ModuleName, std::move(MIB)));
93 
94   if (!Result.second)
95     return make_error<RawError>(raw_error_code::duplicate_entry,
96                                 "The specified module already exists");
97   ModiList.push_back(M);
98   return *M;
99 }
100 
101 Error DbiStreamBuilder::addModuleSourceFile(StringRef Module, StringRef File) {
102   auto ModIter = ModiMap.find(Module);
103   if (ModIter == ModiMap.end())
104     return make_error<RawError>(raw_error_code::no_entry,
105                                 "The specified module was not found");
106   return addModuleSourceFile(*ModIter->second, File);
107 }
108 
109 Error DbiStreamBuilder::addModuleSourceFile(DbiModuleDescriptorBuilder &Module,
110                                             StringRef File) {
111   uint32_t Index = SourceFileNames.size();
112   SourceFileNames.insert(std::make_pair(File, Index));
113   Module.addSourceFile(File);
114   return Error::success();
115 }
116 
117 Expected<uint32_t> DbiStreamBuilder::getSourceFileNameIndex(StringRef File) {
118   auto NameIter = SourceFileNames.find(File);
119   if (NameIter == SourceFileNames.end())
120     return make_error<RawError>(raw_error_code::no_entry,
121                                 "The specified source file was not found");
122   return NameIter->getValue();
123 }
124 
125 uint32_t DbiStreamBuilder::calculateModiSubstreamSize() const {
126   uint32_t Size = 0;
127   for (const auto &M : ModiList)
128     Size += M->calculateSerializedLength();
129   return Size;
130 }
131 
132 uint32_t DbiStreamBuilder::calculateSectionContribsStreamSize() const {
133   if (SectionContribs.empty())
134     return 0;
135   return sizeof(enum PdbRaw_DbiSecContribVer) +
136          sizeof(SectionContribs[0]) * SectionContribs.size();
137 }
138 
139 uint32_t DbiStreamBuilder::calculateSectionMapStreamSize() const {
140   if (SectionMap.empty())
141     return 0;
142   return sizeof(SecMapHeader) + sizeof(SecMapEntry) * SectionMap.size();
143 }
144 
145 uint32_t DbiStreamBuilder::calculateNamesOffset() const {
146   uint32_t Offset = 0;
147   Offset += sizeof(ulittle16_t);                         // NumModules
148   Offset += sizeof(ulittle16_t);                         // NumSourceFiles
149   Offset += ModiList.size() * sizeof(ulittle16_t);       // ModIndices
150   Offset += ModiList.size() * sizeof(ulittle16_t);       // ModFileCounts
151   uint32_t NumFileInfos = 0;
152   for (const auto &M : ModiList)
153     NumFileInfos += M->source_files().size();
154   Offset += NumFileInfos * sizeof(ulittle32_t); // FileNameOffsets
155   return Offset;
156 }
157 
158 uint32_t DbiStreamBuilder::calculateFileInfoSubstreamSize() const {
159   uint32_t Size = calculateNamesOffset();
160   Size += calculateNamesBufferSize();
161   return alignTo(Size, sizeof(uint32_t));
162 }
163 
164 uint32_t DbiStreamBuilder::calculateNamesBufferSize() const {
165   uint32_t Size = 0;
166   for (const auto &F : SourceFileNames) {
167     Size += F.getKeyLength() + 1; // Names[I];
168   }
169   return Size;
170 }
171 
172 uint32_t DbiStreamBuilder::calculateDbgStreamsSize() const {
173   return DbgStreams.size() * sizeof(uint16_t);
174 }
175 
176 Error DbiStreamBuilder::generateFileInfoSubstream() {
177   uint32_t Size = calculateFileInfoSubstreamSize();
178   auto Data = Allocator.Allocate<uint8_t>(Size);
179   uint32_t NamesOffset = calculateNamesOffset();
180 
181   FileInfoBuffer = MutableBinaryByteStream(MutableArrayRef<uint8_t>(Data, Size),
182                                            llvm::support::little);
183 
184   WritableBinaryStreamRef MetadataBuffer =
185       WritableBinaryStreamRef(FileInfoBuffer).keep_front(NamesOffset);
186   BinaryStreamWriter MetadataWriter(MetadataBuffer);
187 
188   uint16_t ModiCount = std::min<uint32_t>(UINT16_MAX, ModiList.size());
189   uint16_t FileCount = std::min<uint32_t>(UINT16_MAX, SourceFileNames.size());
190   if (auto EC = MetadataWriter.writeInteger(ModiCount)) // NumModules
191     return EC;
192   if (auto EC = MetadataWriter.writeInteger(FileCount)) // NumSourceFiles
193     return EC;
194   for (uint16_t I = 0; I < ModiCount; ++I) {
195     if (auto EC = MetadataWriter.writeInteger(I)) // Mod Indices
196       return EC;
197   }
198   for (const auto &MI : ModiList) {
199     FileCount = static_cast<uint16_t>(MI->source_files().size());
200     if (auto EC = MetadataWriter.writeInteger(FileCount)) // Mod File Counts
201       return EC;
202   }
203 
204   // Before writing the FileNameOffsets array, write the NamesBuffer array.
205   // A side effect of this is that this will actually compute the various
206   // file name offsets, so we can then go back and write the FileNameOffsets
207   // array to the other substream.
208   NamesBuffer = WritableBinaryStreamRef(FileInfoBuffer).drop_front(NamesOffset);
209   BinaryStreamWriter NameBufferWriter(NamesBuffer);
210   for (auto &Name : SourceFileNames) {
211     Name.second = NameBufferWriter.getOffset();
212     if (auto EC = NameBufferWriter.writeCString(Name.getKey()))
213       return EC;
214   }
215 
216   for (const auto &MI : ModiList) {
217     for (StringRef Name : MI->source_files()) {
218       auto Result = SourceFileNames.find(Name);
219       if (Result == SourceFileNames.end())
220         return make_error<RawError>(raw_error_code::no_entry,
221                                     "The source file was not found.");
222       if (auto EC = MetadataWriter.writeInteger(Result->second))
223         return EC;
224     }
225   }
226 
227   if (auto EC = NameBufferWriter.padToAlignment(sizeof(uint32_t)))
228     return EC;
229 
230   if (NameBufferWriter.bytesRemaining() > 0)
231     return make_error<RawError>(raw_error_code::invalid_format,
232                                 "The names buffer contained unexpected data.");
233 
234   if (MetadataWriter.bytesRemaining() > sizeof(uint32_t))
235     return make_error<RawError>(
236         raw_error_code::invalid_format,
237         "The metadata buffer contained unexpected data.");
238 
239   return Error::success();
240 }
241 
242 Error DbiStreamBuilder::finalize() {
243   if (Header)
244     return Error::success();
245 
246   for (auto &MI : ModiList)
247     MI->finalize();
248 
249   if (auto EC = generateFileInfoSubstream())
250     return EC;
251 
252   DbiStreamHeader *H = Allocator.Allocate<DbiStreamHeader>();
253   ::memset(H, 0, sizeof(DbiStreamHeader));
254   H->VersionHeader = *VerHeader;
255   H->VersionSignature = -1;
256   H->Age = Age;
257   H->BuildNumber = BuildNumber;
258   H->Flags = Flags;
259   H->PdbDllRbld = PdbDllRbld;
260   H->PdbDllVersion = PdbDllVersion;
261   H->MachineType = static_cast<uint16_t>(MachineType);
262 
263   H->ECSubstreamSize = ECNamesBuilder.calculateSerializedSize();
264   H->FileInfoSize = FileInfoBuffer.getLength();
265   H->ModiSubstreamSize = calculateModiSubstreamSize();
266   H->OptionalDbgHdrSize = DbgStreams.size() * sizeof(uint16_t);
267   H->SecContrSubstreamSize = calculateSectionContribsStreamSize();
268   H->SectionMapSize = calculateSectionMapStreamSize();
269   H->TypeServerSize = 0;
270   H->SymRecordStreamIndex = SymRecordStreamIndex;
271   H->PublicSymbolStreamIndex = PublicsStreamIndex;
272   H->MFCTypeServerIndex = kInvalidStreamIndex;
273   H->GlobalSymbolStreamIndex = kInvalidStreamIndex;
274 
275   Header = H;
276   return Error::success();
277 }
278 
279 Error DbiStreamBuilder::finalizeMsfLayout() {
280   for (auto &MI : ModiList) {
281     if (auto EC = MI->finalizeMsfLayout())
282       return EC;
283   }
284 
285   uint32_t Length = calculateSerializedLength();
286   if (auto EC = Msf.setStreamSize(StreamDBI, Length))
287     return EC;
288   return Error::success();
289 }
290 
291 static uint16_t toSecMapFlags(uint32_t Flags) {
292   uint16_t Ret = 0;
293   if (Flags & COFF::IMAGE_SCN_MEM_READ)
294     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Read);
295   if (Flags & COFF::IMAGE_SCN_MEM_WRITE)
296     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Write);
297   if (Flags & COFF::IMAGE_SCN_MEM_EXECUTE)
298     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Execute);
299   if (Flags & COFF::IMAGE_SCN_MEM_EXECUTE)
300     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Execute);
301   if (!(Flags & COFF::IMAGE_SCN_MEM_16BIT))
302     Ret |= static_cast<uint16_t>(OMFSegDescFlags::AddressIs32Bit);
303 
304   // This seems always 1.
305   Ret |= static_cast<uint16_t>(OMFSegDescFlags::IsSelector);
306 
307   return Ret;
308 }
309 
310 void DbiStreamBuilder::addSectionContrib(DbiModuleDescriptorBuilder *ModuleDbi,
311                                          const object::coff_section *SecHdr) {
312   SectionContrib SC;
313   memset(&SC, 0, sizeof(SC));
314   SC.ISect = (uint16_t)~0U; // This represents nil.
315   SC.Off = SecHdr->PointerToRawData;
316   SC.Size = SecHdr->SizeOfRawData;
317   SC.Characteristics = SecHdr->Characteristics;
318   // Use the module index in the module dbi stream or nil (-1).
319   SC.Imod = ModuleDbi ? ModuleDbi->getModuleIndex() : (uint16_t)~0U;
320   SectionContribs.emplace_back(SC);
321 }
322 
323 // A utility function to create a Section Map for a given list of COFF sections.
324 //
325 // A Section Map seem to be a copy of a COFF section list in other format.
326 // I don't know why a PDB file contains both a COFF section header and
327 // a Section Map, but it seems it must be present in a PDB.
328 std::vector<SecMapEntry> DbiStreamBuilder::createSectionMap(
329     ArrayRef<llvm::object::coff_section> SecHdrs) {
330   std::vector<SecMapEntry> Ret;
331   int Idx = 0;
332 
333   auto Add = [&]() -> SecMapEntry & {
334     Ret.emplace_back();
335     auto &Entry = Ret.back();
336     memset(&Entry, 0, sizeof(Entry));
337 
338     Entry.Frame = Idx + 1;
339 
340     // We don't know the meaning of these fields yet.
341     Entry.SecName = UINT16_MAX;
342     Entry.ClassName = UINT16_MAX;
343 
344     return Entry;
345   };
346 
347   for (auto &Hdr : SecHdrs) {
348     auto &Entry = Add();
349     Entry.Flags = toSecMapFlags(Hdr.Characteristics);
350     Entry.SecByteLength = Hdr.VirtualSize;
351     ++Idx;
352   }
353 
354   // The last entry is for absolute symbols.
355   auto &Entry = Add();
356   Entry.Flags = static_cast<uint16_t>(OMFSegDescFlags::AddressIs32Bit) |
357                 static_cast<uint16_t>(OMFSegDescFlags::IsAbsoluteAddress);
358   Entry.SecByteLength = UINT32_MAX;
359 
360   return Ret;
361 }
362 
363 Error DbiStreamBuilder::commit(const msf::MSFLayout &Layout,
364                                WritableBinaryStreamRef MsfBuffer) {
365   if (auto EC = finalize())
366     return EC;
367 
368   auto DbiS = WritableMappedBlockStream::createIndexedStream(
369       Layout, MsfBuffer, StreamDBI, Allocator);
370 
371   BinaryStreamWriter Writer(*DbiS);
372   if (auto EC = Writer.writeObject(*Header))
373     return EC;
374 
375   for (auto &M : ModiList) {
376     if (auto EC = M->commit(Writer, Layout, MsfBuffer))
377       return EC;
378   }
379 
380   if (!SectionContribs.empty()) {
381     if (auto EC = Writer.writeEnum(DbiSecContribVer60))
382       return EC;
383     if (auto EC = Writer.writeArray(makeArrayRef(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   if (auto EC = ECNamesBuilder.commit(Writer))
400     return EC;
401 
402   for (auto &Stream : DbgStreams)
403     if (auto EC = Writer.writeInteger(Stream.StreamNumber))
404       return EC;
405 
406   for (auto &Stream : DbgStreams) {
407     if (Stream.StreamNumber == kInvalidStreamIndex)
408       continue;
409     auto WritableStream = WritableMappedBlockStream::createIndexedStream(
410         Layout, MsfBuffer, Stream.StreamNumber, Allocator);
411     BinaryStreamWriter DbgStreamWriter(*WritableStream);
412     if (auto EC = DbgStreamWriter.writeArray(Stream.Data))
413       return EC;
414   }
415 
416   if (Writer.bytesRemaining() > 0)
417     return make_error<RawError>(raw_error_code::invalid_format,
418                                 "Unexpected bytes found in DBI Stream");
419   return Error::success();
420 }
421