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/MSF/StreamWriter.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/COFF.h"
20 
21 using namespace llvm;
22 using namespace llvm::codeview;
23 using namespace llvm::msf;
24 using namespace llvm::pdb;
25 
26 namespace {
27 class ModiSubstreamBuilder {};
28 }
29 
30 DbiStreamBuilder::DbiStreamBuilder(msf::MSFBuilder &Msf)
31     : Msf(Msf), Allocator(Msf.getAllocator()), Age(1), BuildNumber(0),
32       PdbDllVersion(0), PdbDllRbld(0), Flags(0), MachineType(PDB_Machine::x86),
33       Header(nullptr), DbgStreams((int)DbgHeaderType::Max) {}
34 
35 void DbiStreamBuilder::setVersionHeader(PdbRaw_DbiVer V) { VerHeader = V; }
36 
37 void DbiStreamBuilder::setAge(uint32_t A) { Age = A; }
38 
39 void DbiStreamBuilder::setBuildNumber(uint16_t B) { BuildNumber = B; }
40 
41 void DbiStreamBuilder::setPdbDllVersion(uint16_t V) { PdbDllVersion = V; }
42 
43 void DbiStreamBuilder::setPdbDllRbld(uint16_t R) { PdbDllRbld = R; }
44 
45 void DbiStreamBuilder::setFlags(uint16_t F) { Flags = F; }
46 
47 void DbiStreamBuilder::setMachineType(PDB_Machine M) { MachineType = M; }
48 
49 void DbiStreamBuilder::setSectionContribs(ArrayRef<SectionContrib> Arr) {
50   SectionContribs = Arr;
51 }
52 
53 void DbiStreamBuilder::setSectionMap(ArrayRef<SecMapEntry> SecMap) {
54   SectionMap = SecMap;
55 }
56 
57 Error DbiStreamBuilder::addDbgStream(pdb::DbgHeaderType Type,
58                                      ArrayRef<uint8_t> Data) {
59   if (DbgStreams[(int)Type].StreamNumber)
60     return make_error<RawError>(raw_error_code::duplicate_entry,
61                                 "The specified stream type already exists");
62   auto ExpectedIndex = Msf.addStream(Data.size());
63   if (!ExpectedIndex)
64     return ExpectedIndex.takeError();
65   uint32_t Index = std::move(*ExpectedIndex);
66   DbgStreams[(int)Type].Data = Data;
67   DbgStreams[(int)Type].StreamNumber = Index;
68   return Error::success();
69 }
70 
71 uint32_t DbiStreamBuilder::calculateSerializedLength() const {
72   // For now we only support serializing the header.
73   return sizeof(DbiStreamHeader) + calculateFileInfoSubstreamSize() +
74          calculateModiSubstreamSize() + calculateSectionContribsStreamSize() +
75          calculateSectionMapStreamSize() + calculateDbgStreamsSize();
76 }
77 
78 Error DbiStreamBuilder::addModuleInfo(StringRef ObjFile, StringRef Module) {
79   auto Entry = llvm::make_unique<ModuleInfo>();
80   ModuleInfo *M = Entry.get();
81   Entry->Mod = Module;
82   Entry->Obj = ObjFile;
83   auto Result = ModuleInfos.insert(std::make_pair(Module, std::move(Entry)));
84   if (!Result.second)
85     return make_error<RawError>(raw_error_code::duplicate_entry,
86                                 "The specified module already exists");
87   ModuleInfoList.push_back(M);
88   return Error::success();
89 }
90 
91 Error DbiStreamBuilder::addModuleSourceFile(StringRef Module, StringRef File) {
92   auto ModIter = ModuleInfos.find(Module);
93   if (ModIter == ModuleInfos.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->SourceFiles.push_back(File);
100   return Error::success();
101 }
102 
103 uint32_t DbiStreamBuilder::calculateModiSubstreamSize() const {
104   uint32_t Size = 0;
105   for (const auto &M : ModuleInfoList) {
106     Size += sizeof(ModuleInfoHeader);
107     Size += M->Mod.size() + 1;
108     Size += M->Obj.size() + 1;
109   }
110   return alignTo(Size, sizeof(uint32_t));
111 }
112 
113 uint32_t DbiStreamBuilder::calculateSectionContribsStreamSize() const {
114   if (SectionContribs.empty())
115     return 0;
116   return sizeof(enum PdbRaw_DbiSecContribVer) +
117          sizeof(SectionContribs[0]) * SectionContribs.size();
118 }
119 
120 uint32_t DbiStreamBuilder::calculateSectionMapStreamSize() const {
121   if (SectionMap.empty())
122     return 0;
123   return sizeof(SecMapHeader) + sizeof(SecMapEntry) * SectionMap.size();
124 }
125 
126 uint32_t DbiStreamBuilder::calculateFileInfoSubstreamSize() const {
127   uint32_t Size = 0;
128   Size += sizeof(ulittle16_t);                         // NumModules
129   Size += sizeof(ulittle16_t);                         // NumSourceFiles
130   Size += ModuleInfoList.size() * sizeof(ulittle16_t); // ModIndices
131   Size += ModuleInfoList.size() * sizeof(ulittle16_t); // ModFileCounts
132   uint32_t NumFileInfos = 0;
133   for (const auto &M : ModuleInfoList)
134     NumFileInfos += M->SourceFiles.size();
135   Size += NumFileInfos * sizeof(ulittle32_t); // FileNameOffsets
136   Size += calculateNamesBufferSize();
137   return alignTo(Size, sizeof(uint32_t));
138 }
139 
140 uint32_t DbiStreamBuilder::calculateNamesBufferSize() const {
141   uint32_t Size = 0;
142   for (const auto &F : SourceFileNames) {
143     Size += F.getKeyLength() + 1; // Names[I];
144   }
145   return Size;
146 }
147 
148 uint32_t DbiStreamBuilder::calculateDbgStreamsSize() const {
149   return DbgStreams.size() * sizeof(uint16_t);
150 }
151 
152 Error DbiStreamBuilder::generateModiSubstream() {
153   uint32_t Size = calculateModiSubstreamSize();
154   auto Data = Allocator.Allocate<uint8_t>(Size);
155 
156   ModInfoBuffer = MutableByteStream(MutableArrayRef<uint8_t>(Data, Size));
157 
158   StreamWriter ModiWriter(ModInfoBuffer);
159   for (const auto &M : ModuleInfoList) {
160     ModuleInfoHeader Layout = {};
161     Layout.ModDiStream = kInvalidStreamIndex;
162     Layout.NumFiles = M->SourceFiles.size();
163     if (auto EC = ModiWriter.writeObject(Layout))
164       return EC;
165     if (auto EC = ModiWriter.writeZeroString(M->Mod))
166       return EC;
167     if (auto EC = ModiWriter.writeZeroString(M->Obj))
168       return EC;
169   }
170   if (ModiWriter.bytesRemaining() > sizeof(uint32_t))
171     return make_error<RawError>(raw_error_code::invalid_format,
172                                 "Unexpected bytes in Modi Stream Data");
173   return Error::success();
174 }
175 
176 Error DbiStreamBuilder::generateFileInfoSubstream() {
177   uint32_t Size = calculateFileInfoSubstreamSize();
178   uint32_t NameSize = calculateNamesBufferSize();
179   auto Data = Allocator.Allocate<uint8_t>(Size);
180   uint32_t NamesOffset = Size - NameSize;
181 
182   FileInfoBuffer = MutableByteStream(MutableArrayRef<uint8_t>(Data, Size));
183 
184   WritableStreamRef MetadataBuffer =
185       WritableStreamRef(FileInfoBuffer).keep_front(NamesOffset);
186   StreamWriter MetadataWriter(MetadataBuffer);
187 
188   uint16_t ModiCount = std::min<uint32_t>(UINT16_MAX, ModuleInfos.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 : ModuleInfoList) {
199     FileCount = static_cast<uint16_t>(MI->SourceFiles.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 = WritableStreamRef(FileInfoBuffer).drop_front(NamesOffset);
209   StreamWriter NameBufferWriter(NamesBuffer);
210   for (auto &Name : SourceFileNames) {
211     Name.second = NameBufferWriter.getOffset();
212     if (auto EC = NameBufferWriter.writeZeroString(Name.getKey()))
213       return EC;
214   }
215 
216   for (const auto MI : ModuleInfoList) {
217     for (StringRef Name : MI->SourceFiles) {
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 (NameBufferWriter.bytesRemaining() > 0)
228     return make_error<RawError>(raw_error_code::invalid_format,
229                                 "The names buffer contained unexpected data.");
230 
231   if (MetadataWriter.bytesRemaining() > sizeof(uint32_t))
232     return make_error<RawError>(
233         raw_error_code::invalid_format,
234         "The metadata buffer contained unexpected data.");
235 
236   return Error::success();
237 }
238 
239 Error DbiStreamBuilder::finalize() {
240   if (Header)
241     return Error::success();
242 
243   DbiStreamHeader *H = Allocator.Allocate<DbiStreamHeader>();
244 
245   if (auto EC = generateModiSubstream())
246     return EC;
247   if (auto EC = generateFileInfoSubstream())
248     return EC;
249 
250   H->VersionHeader = *VerHeader;
251   H->VersionSignature = -1;
252   H->Age = Age;
253   H->BuildNumber = BuildNumber;
254   H->Flags = Flags;
255   H->PdbDllRbld = PdbDllRbld;
256   H->PdbDllVersion = PdbDllVersion;
257   H->MachineType = static_cast<uint16_t>(MachineType);
258 
259   H->ECSubstreamSize = 0;
260   H->FileInfoSize = FileInfoBuffer.getLength();
261   H->ModiSubstreamSize = ModInfoBuffer.getLength();
262   H->OptionalDbgHdrSize = DbgStreams.size() * sizeof(uint16_t);
263   H->SecContrSubstreamSize = calculateSectionContribsStreamSize();
264   H->SectionMapSize = calculateSectionMapStreamSize();
265   H->TypeServerSize = 0;
266   H->SymRecordStreamIndex = kInvalidStreamIndex;
267   H->PublicSymbolStreamIndex = kInvalidStreamIndex;
268   H->MFCTypeServerIndex = kInvalidStreamIndex;
269   H->GlobalSymbolStreamIndex = kInvalidStreamIndex;
270 
271   Header = H;
272   return Error::success();
273 }
274 
275 Error DbiStreamBuilder::finalizeMsfLayout() {
276   uint32_t Length = calculateSerializedLength();
277   if (auto EC = Msf.setStreamSize(StreamDBI, Length))
278     return EC;
279   return Error::success();
280 }
281 
282 static uint16_t toSecMapFlags(uint32_t Flags) {
283   uint16_t Ret = 0;
284   if (Flags & COFF::IMAGE_SCN_MEM_READ)
285     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Read);
286   if (Flags & COFF::IMAGE_SCN_MEM_WRITE)
287     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Write);
288   if (Flags & COFF::IMAGE_SCN_MEM_EXECUTE)
289     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Execute);
290   if (Flags & COFF::IMAGE_SCN_MEM_EXECUTE)
291     Ret |= static_cast<uint16_t>(OMFSegDescFlags::Execute);
292   if (!(Flags & COFF::IMAGE_SCN_MEM_16BIT))
293     Ret |= static_cast<uint16_t>(OMFSegDescFlags::AddressIs32Bit);
294 
295   // This seems always 1.
296   Ret |= static_cast<uint16_t>(OMFSegDescFlags::IsSelector);
297 
298   return Ret;
299 }
300 
301 // A utility function to create Section Contributions
302 // for a given input sections.
303 std::vector<SectionContrib> DbiStreamBuilder::createSectionContribs(
304     ArrayRef<object::coff_section> SecHdrs) {
305   std::vector<SectionContrib> Ret;
306 
307   // Create a SectionContrib for each input section.
308   for (auto &Sec : SecHdrs) {
309     Ret.emplace_back();
310     auto &Entry = Ret.back();
311     memset(&Entry, 0, sizeof(Entry));
312 
313     Entry.Off = Sec.PointerToRawData;
314     Entry.Size = Sec.SizeOfRawData;
315     Entry.Characteristics = Sec.Characteristics;
316   }
317   return Ret;
318 }
319 
320 // A utility function to create a Section Map for a given list of COFF sections.
321 //
322 // A Section Map seem to be a copy of a COFF section list in other format.
323 // I don't know why a PDB file contains both a COFF section header and
324 // a Section Map, but it seems it must be present in a PDB.
325 std::vector<SecMapEntry> DbiStreamBuilder::createSectionMap(
326     ArrayRef<llvm::object::coff_section> SecHdrs) {
327   std::vector<SecMapEntry> Ret;
328   int Idx = 0;
329 
330   auto Add = [&]() -> SecMapEntry & {
331     Ret.emplace_back();
332     auto &Entry = Ret.back();
333     memset(&Entry, 0, sizeof(Entry));
334 
335     Entry.Frame = Idx + 1;
336 
337     // We don't know the meaning of these fields yet.
338     Entry.SecName = UINT16_MAX;
339     Entry.ClassName = UINT16_MAX;
340 
341     return Entry;
342   };
343 
344   for (auto &Hdr : SecHdrs) {
345     auto &Entry = Add();
346     Entry.Flags = toSecMapFlags(Hdr.Characteristics);
347     Entry.SecByteLength = Hdr.VirtualSize;
348     ++Idx;
349   }
350 
351   // The last entry is for absolute symbols.
352   auto &Entry = Add();
353   Entry.Flags = static_cast<uint16_t>(OMFSegDescFlags::AddressIs32Bit) |
354                 static_cast<uint16_t>(OMFSegDescFlags::IsAbsoluteAddress);
355   Entry.SecByteLength = UINT32_MAX;
356 
357   return Ret;
358 }
359 
360 Error DbiStreamBuilder::commit(const msf::MSFLayout &Layout,
361                                const msf::WritableStream &Buffer) {
362   if (auto EC = finalize())
363     return EC;
364 
365   auto InfoS =
366       WritableMappedBlockStream::createIndexedStream(Layout, Buffer, StreamDBI);
367 
368   StreamWriter Writer(*InfoS);
369   if (auto EC = Writer.writeObject(*Header))
370     return EC;
371 
372   if (auto EC = Writer.writeStreamRef(ModInfoBuffer))
373     return EC;
374 
375   if (!SectionContribs.empty()) {
376     if (auto EC = Writer.writeEnum(DbiSecContribVer60))
377       return EC;
378     if (auto EC = Writer.writeArray(SectionContribs))
379       return EC;
380   }
381 
382   if (!SectionMap.empty()) {
383     ulittle16_t Size = static_cast<ulittle16_t>(SectionMap.size());
384     SecMapHeader SMHeader = {Size, Size};
385     if (auto EC = Writer.writeObject(SMHeader))
386       return EC;
387     if (auto EC = Writer.writeArray(SectionMap))
388       return EC;
389   }
390 
391   if (auto EC = Writer.writeStreamRef(FileInfoBuffer))
392     return EC;
393 
394   for (auto &Stream : DbgStreams)
395     if (auto EC = Writer.writeInteger(Stream.StreamNumber))
396       return EC;
397 
398   for (auto &Stream : DbgStreams) {
399     if (Stream.StreamNumber == kInvalidStreamIndex)
400       continue;
401     auto WritableStream = WritableMappedBlockStream::createIndexedStream(
402         Layout, Buffer, Stream.StreamNumber);
403     StreamWriter DbgStreamWriter(*WritableStream);
404     if (auto EC = DbgStreamWriter.writeArray(Stream.Data))
405       return EC;
406   }
407 
408   if (Writer.bytesRemaining() > 0)
409     return make_error<RawError>(raw_error_code::invalid_format,
410                                 "Unexpected bytes found in DBI Stream");
411   return Error::success();
412 }
413