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::setGlobalsStreamIndex(uint32_t Index) {
53   GlobalsStreamIndex = Index;
54 }
55 
56 void DbiStreamBuilder::setSymbolRecordStreamIndex(uint32_t Index) {
57   SymRecordStreamIndex = Index;
58 }
59 
60 void DbiStreamBuilder::setPublicsStreamIndex(uint32_t Index) {
61   PublicsStreamIndex = Index;
62 }
63 
64 Error DbiStreamBuilder::addDbgStream(pdb::DbgHeaderType Type,
65                                      ArrayRef<uint8_t> Data) {
66   if (DbgStreams[(int)Type].StreamNumber != kInvalidStreamIndex)
67     return make_error<RawError>(raw_error_code::duplicate_entry,
68                                 "The specified stream type already exists");
69   auto ExpectedIndex = Msf.addStream(Data.size());
70   if (!ExpectedIndex)
71     return ExpectedIndex.takeError();
72   uint32_t Index = std::move(*ExpectedIndex);
73   DbgStreams[(int)Type].Data = Data;
74   DbgStreams[(int)Type].StreamNumber = Index;
75   return Error::success();
76 }
77 
78 uint32_t DbiStreamBuilder::addECName(StringRef Name) {
79   return ECNamesBuilder.insert(Name);
80 }
81 
82 uint32_t DbiStreamBuilder::calculateSerializedLength() const {
83   // For now we only support serializing the header.
84   return sizeof(DbiStreamHeader) + calculateFileInfoSubstreamSize() +
85          calculateModiSubstreamSize() + calculateSectionContribsStreamSize() +
86          calculateSectionMapStreamSize() + calculateDbgStreamsSize() +
87          ECNamesBuilder.calculateSerializedSize();
88 }
89 
90 Expected<DbiModuleDescriptorBuilder &>
91 DbiStreamBuilder::addModuleInfo(StringRef ModuleName) {
92   uint32_t Index = ModiList.size();
93   ModiList.push_back(
94       llvm::make_unique<DbiModuleDescriptorBuilder>(ModuleName, Index, Msf));
95   return *ModiList.back();
96 }
97 
98 Error DbiStreamBuilder::addModuleSourceFile(DbiModuleDescriptorBuilder &Module,
99                                             StringRef File) {
100   uint32_t Index = SourceFileNames.size();
101   SourceFileNames.insert(std::make_pair(File, Index));
102   Module.addSourceFile(File);
103   return Error::success();
104 }
105 
106 Expected<uint32_t> DbiStreamBuilder::getSourceFileNameIndex(StringRef File) {
107   auto NameIter = SourceFileNames.find(File);
108   if (NameIter == SourceFileNames.end())
109     return make_error<RawError>(raw_error_code::no_entry,
110                                 "The specified source file was not found");
111   return NameIter->getValue();
112 }
113 
114 uint32_t DbiStreamBuilder::calculateModiSubstreamSize() const {
115   uint32_t Size = 0;
116   for (const auto &M : ModiList)
117     Size += M->calculateSerializedLength();
118   return Size;
119 }
120 
121 uint32_t DbiStreamBuilder::calculateSectionContribsStreamSize() const {
122   if (SectionContribs.empty())
123     return 0;
124   return sizeof(enum PdbRaw_DbiSecContribVer) +
125          sizeof(SectionContribs[0]) * SectionContribs.size();
126 }
127 
128 uint32_t DbiStreamBuilder::calculateSectionMapStreamSize() const {
129   if (SectionMap.empty())
130     return 0;
131   return sizeof(SecMapHeader) + sizeof(SecMapEntry) * SectionMap.size();
132 }
133 
134 uint32_t DbiStreamBuilder::calculateNamesOffset() const {
135   uint32_t Offset = 0;
136   Offset += sizeof(ulittle16_t);                         // NumModules
137   Offset += sizeof(ulittle16_t);                         // NumSourceFiles
138   Offset += ModiList.size() * sizeof(ulittle16_t);       // ModIndices
139   Offset += ModiList.size() * sizeof(ulittle16_t);       // ModFileCounts
140   uint32_t NumFileInfos = 0;
141   for (const auto &M : ModiList)
142     NumFileInfos += M->source_files().size();
143   Offset += NumFileInfos * sizeof(ulittle32_t); // FileNameOffsets
144   return Offset;
145 }
146 
147 uint32_t DbiStreamBuilder::calculateFileInfoSubstreamSize() const {
148   uint32_t Size = calculateNamesOffset();
149   Size += calculateNamesBufferSize();
150   return alignTo(Size, sizeof(uint32_t));
151 }
152 
153 uint32_t DbiStreamBuilder::calculateNamesBufferSize() const {
154   uint32_t Size = 0;
155   for (const auto &F : SourceFileNames) {
156     Size += F.getKeyLength() + 1; // Names[I];
157   }
158   return Size;
159 }
160 
161 uint32_t DbiStreamBuilder::calculateDbgStreamsSize() const {
162   return DbgStreams.size() * sizeof(uint16_t);
163 }
164 
165 Error DbiStreamBuilder::generateFileInfoSubstream() {
166   uint32_t Size = calculateFileInfoSubstreamSize();
167   auto Data = Allocator.Allocate<uint8_t>(Size);
168   uint32_t NamesOffset = calculateNamesOffset();
169 
170   FileInfoBuffer = MutableBinaryByteStream(MutableArrayRef<uint8_t>(Data, Size),
171                                            llvm::support::little);
172 
173   WritableBinaryStreamRef MetadataBuffer =
174       WritableBinaryStreamRef(FileInfoBuffer).keep_front(NamesOffset);
175   BinaryStreamWriter MetadataWriter(MetadataBuffer);
176 
177   uint16_t ModiCount = std::min<uint32_t>(UINT16_MAX, ModiList.size());
178   uint16_t FileCount = std::min<uint32_t>(UINT16_MAX, SourceFileNames.size());
179   if (auto EC = MetadataWriter.writeInteger(ModiCount)) // NumModules
180     return EC;
181   if (auto EC = MetadataWriter.writeInteger(FileCount)) // NumSourceFiles
182     return EC;
183   for (uint16_t I = 0; I < ModiCount; ++I) {
184     if (auto EC = MetadataWriter.writeInteger(I)) // Mod Indices
185       return EC;
186   }
187   for (const auto &MI : ModiList) {
188     FileCount = static_cast<uint16_t>(MI->source_files().size());
189     if (auto EC = MetadataWriter.writeInteger(FileCount)) // Mod File Counts
190       return EC;
191   }
192 
193   // Before writing the FileNameOffsets array, write the NamesBuffer array.
194   // A side effect of this is that this will actually compute the various
195   // file name offsets, so we can then go back and write the FileNameOffsets
196   // array to the other substream.
197   NamesBuffer = WritableBinaryStreamRef(FileInfoBuffer).drop_front(NamesOffset);
198   BinaryStreamWriter NameBufferWriter(NamesBuffer);
199   for (auto &Name : SourceFileNames) {
200     Name.second = NameBufferWriter.getOffset();
201     if (auto EC = NameBufferWriter.writeCString(Name.getKey()))
202       return EC;
203   }
204 
205   for (const auto &MI : ModiList) {
206     for (StringRef Name : MI->source_files()) {
207       auto Result = SourceFileNames.find(Name);
208       if (Result == SourceFileNames.end())
209         return make_error<RawError>(raw_error_code::no_entry,
210                                     "The source file was not found.");
211       if (auto EC = MetadataWriter.writeInteger(Result->second))
212         return EC;
213     }
214   }
215 
216   if (auto EC = NameBufferWriter.padToAlignment(sizeof(uint32_t)))
217     return EC;
218 
219   if (NameBufferWriter.bytesRemaining() > 0)
220     return make_error<RawError>(raw_error_code::invalid_format,
221                                 "The names buffer contained unexpected data.");
222 
223   if (MetadataWriter.bytesRemaining() > sizeof(uint32_t))
224     return make_error<RawError>(
225         raw_error_code::invalid_format,
226         "The metadata buffer contained unexpected data.");
227 
228   return Error::success();
229 }
230 
231 Error DbiStreamBuilder::finalize() {
232   if (Header)
233     return Error::success();
234 
235   for (auto &MI : ModiList)
236     MI->finalize();
237 
238   if (auto EC = generateFileInfoSubstream())
239     return EC;
240 
241   DbiStreamHeader *H = Allocator.Allocate<DbiStreamHeader>();
242   ::memset(H, 0, sizeof(DbiStreamHeader));
243   H->VersionHeader = *VerHeader;
244   H->VersionSignature = -1;
245   H->Age = Age;
246   H->BuildNumber = BuildNumber;
247   H->Flags = Flags;
248   H->PdbDllRbld = PdbDllRbld;
249   H->PdbDllVersion = PdbDllVersion;
250   H->MachineType = static_cast<uint16_t>(MachineType);
251 
252   H->ECSubstreamSize = ECNamesBuilder.calculateSerializedSize();
253   H->FileInfoSize = FileInfoBuffer.getLength();
254   H->ModiSubstreamSize = calculateModiSubstreamSize();
255   H->OptionalDbgHdrSize = DbgStreams.size() * sizeof(uint16_t);
256   H->SecContrSubstreamSize = calculateSectionContribsStreamSize();
257   H->SectionMapSize = calculateSectionMapStreamSize();
258   H->TypeServerSize = 0;
259   H->SymRecordStreamIndex = SymRecordStreamIndex;
260   H->PublicSymbolStreamIndex = PublicsStreamIndex;
261   H->MFCTypeServerIndex = kInvalidStreamIndex;
262   H->GlobalSymbolStreamIndex = GlobalsStreamIndex;
263 
264   Header = H;
265   return Error::success();
266 }
267 
268 Error DbiStreamBuilder::finalizeMsfLayout() {
269   for (auto &MI : ModiList) {
270     if (auto EC = MI->finalizeMsfLayout())
271       return EC;
272   }
273 
274   uint32_t Length = calculateSerializedLength();
275   if (auto EC = Msf.setStreamSize(StreamDBI, Length))
276     return EC;
277   return Error::success();
278 }
279 
280 static uint16_t toSecMapFlags(uint32_t Flags) {
281   uint16_t Ret = 0;
282   if (Flags & COFF::IMAGE_SCN_MEM_READ)
283     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Read);
284   if (Flags & COFF::IMAGE_SCN_MEM_WRITE)
285     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Write);
286   if (Flags & COFF::IMAGE_SCN_MEM_EXECUTE)
287     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Execute);
288   if (Flags & COFF::IMAGE_SCN_MEM_EXECUTE)
289     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Execute);
290   if (!(Flags & COFF::IMAGE_SCN_MEM_16BIT))
291     Ret |= static_cast<uint16_t>(OMFSegDescFlags::AddressIs32Bit);
292 
293   // This seems always 1.
294   Ret |= static_cast<uint16_t>(OMFSegDescFlags::IsSelector);
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(
345       Layout, MsfBuffer, StreamDBI, Allocator);
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(makeArrayRef(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   if (auto EC = ECNamesBuilder.commit(Writer))
376     return EC;
377 
378   for (auto &Stream : DbgStreams)
379     if (auto EC = Writer.writeInteger(Stream.StreamNumber))
380       return EC;
381 
382   for (auto &Stream : DbgStreams) {
383     if (Stream.StreamNumber == kInvalidStreamIndex)
384       continue;
385     auto WritableStream = WritableMappedBlockStream::createIndexedStream(
386         Layout, MsfBuffer, Stream.StreamNumber, Allocator);
387     BinaryStreamWriter DbgStreamWriter(*WritableStream);
388     if (auto EC = DbgStreamWriter.writeArray(Stream.Data))
389       return EC;
390   }
391 
392   if (Writer.bytesRemaining() > 0)
393     return make_error<RawError>(raw_error_code::invalid_format,
394                                 "Unexpected bytes found in DBI Stream");
395   return Error::success();
396 }
397