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