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1 //===- DbiModuleDescriptorBuilder.cpp - PDB Mod Info 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/DbiModuleDescriptorBuilder.h"
11 
12 #include "llvm/ADT/ArrayRef.h"
13 #include "llvm/BinaryFormat/COFF.h"
14 #include "llvm/DebugInfo/CodeView/DebugSubsectionRecord.h"
15 #include "llvm/DebugInfo/MSF/MSFBuilder.h"
16 #include "llvm/DebugInfo/MSF/MSFCommon.h"
17 #include "llvm/DebugInfo/MSF/MappedBlockStream.h"
18 #include "llvm/DebugInfo/PDB/Native/DbiModuleDescriptor.h"
19 #include "llvm/DebugInfo/PDB/Native/GSIStreamBuilder.h"
20 #include "llvm/DebugInfo/PDB/Native/RawConstants.h"
21 #include "llvm/DebugInfo/PDB/Native/RawError.h"
22 #include "llvm/Support/BinaryItemStream.h"
23 #include "llvm/Support/BinaryStreamWriter.h"
24 
25 using namespace llvm;
26 using namespace llvm::codeview;
27 using namespace llvm::msf;
28 using namespace llvm::pdb;
29 
calculateDiSymbolStreamSize(uint32_t SymbolByteSize,uint32_t C13Size)30 static uint32_t calculateDiSymbolStreamSize(uint32_t SymbolByteSize,
31                                             uint32_t C13Size) {
32   uint32_t Size = sizeof(uint32_t);   // Signature
33   Size += alignTo(SymbolByteSize, 4); // Symbol Data
34   Size += 0;                          // TODO: Layout.C11Bytes
35   Size += C13Size;                    // C13 Debug Info Size
36   Size += sizeof(uint32_t);           // GlobalRefs substream size (always 0)
37   Size += 0;                          // GlobalRefs substream bytes
38   return Size;
39 }
40 
DbiModuleDescriptorBuilder(StringRef ModuleName,uint32_t ModIndex,msf::MSFBuilder & Msf)41 DbiModuleDescriptorBuilder::DbiModuleDescriptorBuilder(StringRef ModuleName,
42                                                        uint32_t ModIndex,
43                                                        msf::MSFBuilder &Msf)
44     : MSF(Msf), ModuleName(ModuleName) {
45   ::memset(&Layout, 0, sizeof(Layout));
46   Layout.Mod = ModIndex;
47 }
48 
~DbiModuleDescriptorBuilder()49 DbiModuleDescriptorBuilder::~DbiModuleDescriptorBuilder() {}
50 
getStreamIndex() const51 uint16_t DbiModuleDescriptorBuilder::getStreamIndex() const {
52   return Layout.ModDiStream;
53 }
54 
setObjFileName(StringRef Name)55 void DbiModuleDescriptorBuilder::setObjFileName(StringRef Name) {
56   ObjFileName = Name;
57 }
58 
setPdbFilePathNI(uint32_t NI)59 void DbiModuleDescriptorBuilder::setPdbFilePathNI(uint32_t NI) {
60   PdbFilePathNI = NI;
61 }
62 
setFirstSectionContrib(const SectionContrib & SC)63 void DbiModuleDescriptorBuilder::setFirstSectionContrib(
64     const SectionContrib &SC) {
65   Layout.SC = SC;
66 }
67 
addSymbol(CVSymbol Symbol)68 void DbiModuleDescriptorBuilder::addSymbol(CVSymbol Symbol) {
69   Symbols.push_back(Symbol);
70   // Symbols written to a PDB file are required to be 4 byte aligned.  The same
71   // is not true of object files.
72   assert(Symbol.length() % alignOf(CodeViewContainer::Pdb) == 0 &&
73          "Invalid Symbol alignment!");
74   SymbolByteSize += Symbol.length();
75 }
76 
addSourceFile(StringRef Path)77 void DbiModuleDescriptorBuilder::addSourceFile(StringRef Path) {
78   SourceFiles.push_back(Path);
79 }
80 
calculateC13DebugInfoSize() const81 uint32_t DbiModuleDescriptorBuilder::calculateC13DebugInfoSize() const {
82   uint32_t Result = 0;
83   for (const auto &Builder : C13Builders) {
84     assert(Builder && "Empty C13 Fragment Builder!");
85     Result += Builder->calculateSerializedLength();
86   }
87   return Result;
88 }
89 
calculateSerializedLength() const90 uint32_t DbiModuleDescriptorBuilder::calculateSerializedLength() const {
91   uint32_t L = sizeof(Layout);
92   uint32_t M = ModuleName.size() + 1;
93   uint32_t O = ObjFileName.size() + 1;
94   return alignTo(L + M + O, sizeof(uint32_t));
95 }
96 
finalize()97 void DbiModuleDescriptorBuilder::finalize() {
98   Layout.SC.Imod = Layout.Mod;
99   Layout.FileNameOffs = 0; // TODO: Fix this
100   Layout.Flags = 0;        // TODO: Fix this
101   Layout.C11Bytes = 0;
102   Layout.C13Bytes = calculateC13DebugInfoSize();
103   (void)Layout.Mod;         // Set in constructor
104   (void)Layout.ModDiStream; // Set in finalizeMsfLayout
105   Layout.NumFiles = SourceFiles.size();
106   Layout.PdbFilePathNI = PdbFilePathNI;
107   Layout.SrcFileNameNI = 0;
108 
109   // This value includes both the signature field as well as the record bytes
110   // from the symbol stream.
111   Layout.SymBytes = SymbolByteSize + sizeof(uint32_t);
112 }
113 
finalizeMsfLayout()114 Error DbiModuleDescriptorBuilder::finalizeMsfLayout() {
115   this->Layout.ModDiStream = kInvalidStreamIndex;
116   uint32_t C13Size = calculateC13DebugInfoSize();
117   auto ExpectedSN =
118       MSF.addStream(calculateDiSymbolStreamSize(SymbolByteSize, C13Size));
119   if (!ExpectedSN)
120     return ExpectedSN.takeError();
121   Layout.ModDiStream = *ExpectedSN;
122   return Error::success();
123 }
124 
commit(BinaryStreamWriter & ModiWriter,const msf::MSFLayout & MsfLayout,WritableBinaryStreamRef MsfBuffer)125 Error DbiModuleDescriptorBuilder::commit(BinaryStreamWriter &ModiWriter,
126                                          const msf::MSFLayout &MsfLayout,
127                                          WritableBinaryStreamRef MsfBuffer) {
128   // We write the Modi record to the `ModiWriter`, but we additionally write its
129   // symbol stream to a brand new stream.
130   if (auto EC = ModiWriter.writeObject(Layout))
131     return EC;
132   if (auto EC = ModiWriter.writeCString(ModuleName))
133     return EC;
134   if (auto EC = ModiWriter.writeCString(ObjFileName))
135     return EC;
136   if (auto EC = ModiWriter.padToAlignment(sizeof(uint32_t)))
137     return EC;
138 
139   if (Layout.ModDiStream != kInvalidStreamIndex) {
140     auto NS = WritableMappedBlockStream::createIndexedStream(
141         MsfLayout, MsfBuffer, Layout.ModDiStream, MSF.getAllocator());
142     WritableBinaryStreamRef Ref(*NS);
143     BinaryStreamWriter SymbolWriter(Ref);
144     // Write the symbols.
145     if (auto EC =
146             SymbolWriter.writeInteger<uint32_t>(COFF::DEBUG_SECTION_MAGIC))
147       return EC;
148     BinaryItemStream<CVSymbol> Records(llvm::support::endianness::little);
149     Records.setItems(Symbols);
150     BinaryStreamRef RecordsRef(Records);
151     if (auto EC = SymbolWriter.writeStreamRef(RecordsRef))
152       return EC;
153     if (auto EC = SymbolWriter.padToAlignment(4))
154       return EC;
155     // TODO: Write C11 Line data
156     assert(SymbolWriter.getOffset() % alignOf(CodeViewContainer::Pdb) == 0 &&
157            "Invalid debug section alignment!");
158     for (const auto &Builder : C13Builders) {
159       assert(Builder && "Empty C13 Fragment Builder!");
160       if (auto EC = Builder->commit(SymbolWriter))
161         return EC;
162     }
163 
164     // TODO: Figure out what GlobalRefs substream actually is and populate it.
165     if (auto EC = SymbolWriter.writeInteger<uint32_t>(0))
166       return EC;
167     if (SymbolWriter.bytesRemaining() > 0)
168       return make_error<RawError>(raw_error_code::stream_too_long);
169   }
170   return Error::success();
171 }
172 
addDebugSubsection(std::shared_ptr<DebugSubsection> Subsection)173 void DbiModuleDescriptorBuilder::addDebugSubsection(
174     std::shared_ptr<DebugSubsection> Subsection) {
175   assert(Subsection);
176   C13Builders.push_back(llvm::make_unique<DebugSubsectionRecordBuilder>(
177       std::move(Subsection), CodeViewContainer::Pdb));
178 }
179 
addDebugSubsection(const DebugSubsectionRecord & SubsectionContents)180 void DbiModuleDescriptorBuilder::addDebugSubsection(
181     const DebugSubsectionRecord &SubsectionContents) {
182   C13Builders.push_back(llvm::make_unique<DebugSubsectionRecordBuilder>(
183       SubsectionContents, CodeViewContainer::Pdb));
184 }
185