xref: /llvm-project/llvm/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp (revision 297b6eb20df59d7c5d593b6f04fd4ea9d0e77e29)
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/RawConstants.h"
20 #include "llvm/DebugInfo/PDB/Native/RawError.h"
21 #include "llvm/Support/BinaryItemStream.h"
22 #include "llvm/Support/BinaryStreamWriter.h"
23 
24 using namespace llvm;
25 using namespace llvm::codeview;
26 using namespace llvm::msf;
27 using namespace llvm::pdb;
28 
29 namespace llvm {
30 template <> struct BinaryItemTraits<CVSymbol> {
31   static size_t length(const CVSymbol &Item) { return Item.RecordData.size(); }
32 
33   static ArrayRef<uint8_t> bytes(const CVSymbol &Item) {
34     return Item.RecordData;
35   }
36 };
37 }
38 
39 static uint32_t calculateDiSymbolStreamSize(uint32_t SymbolByteSize,
40                                             uint32_t C13Size) {
41   uint32_t Size = sizeof(uint32_t);   // Signature
42   Size += alignTo(SymbolByteSize, 4); // Symbol Data
43   Size += 0;                          // TODO: Layout.C11Bytes
44   Size += C13Size;                    // C13 Debug Info Size
45   Size += sizeof(uint32_t);           // GlobalRefs substream size (always 0)
46   Size += 0;                          // GlobalRefs substream bytes
47   return Size;
48 }
49 
50 DbiModuleDescriptorBuilder::DbiModuleDescriptorBuilder(StringRef ModuleName,
51                                                        uint32_t ModIndex,
52                                                        msf::MSFBuilder &Msf)
53     : MSF(Msf), ModuleName(ModuleName) {
54   ::memset(&Layout, 0, sizeof(Layout));
55   Layout.Mod = ModIndex;
56 }
57 
58 DbiModuleDescriptorBuilder::~DbiModuleDescriptorBuilder() {}
59 
60 uint16_t DbiModuleDescriptorBuilder::getStreamIndex() const {
61   return Layout.ModDiStream;
62 }
63 
64 void DbiModuleDescriptorBuilder::setObjFileName(StringRef Name) {
65   ObjFileName = Name;
66 }
67 
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 
77 void DbiModuleDescriptorBuilder::addSourceFile(StringRef Path) {
78   SourceFiles.push_back(Path);
79 }
80 
81 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 
90 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 
97 template <typename T> struct Foo {
98   explicit Foo(T &&Answer) : Answer(Answer) {}
99 
100   T Answer;
101 };
102 
103 template <typename T> Foo<T> makeFoo(T &&t) { return Foo<T>(std::move(t)); }
104 
105 void DbiModuleDescriptorBuilder::finalize() {
106   Layout.SC.ModuleIndex = Layout.Mod;
107   Layout.FileNameOffs = 0; // TODO: Fix this
108   Layout.Flags = 0;        // TODO: Fix this
109   Layout.C11Bytes = 0;
110   Layout.C13Bytes = calculateC13DebugInfoSize();
111   (void)Layout.Mod;         // Set in constructor
112   (void)Layout.ModDiStream; // Set in finalizeMsfLayout
113   Layout.NumFiles = SourceFiles.size();
114   Layout.PdbFilePathNI = 0;
115   Layout.SrcFileNameNI = 0;
116 
117   // This value includes both the signature field as well as the record bytes
118   // from the symbol stream.
119   Layout.SymBytes = SymbolByteSize + sizeof(uint32_t);
120 }
121 
122 Error DbiModuleDescriptorBuilder::finalizeMsfLayout() {
123   this->Layout.ModDiStream = kInvalidStreamIndex;
124   uint32_t C13Size = calculateC13DebugInfoSize();
125   auto ExpectedSN =
126       MSF.addStream(calculateDiSymbolStreamSize(SymbolByteSize, C13Size));
127   if (!ExpectedSN)
128     return ExpectedSN.takeError();
129   Layout.ModDiStream = *ExpectedSN;
130   return Error::success();
131 }
132 
133 Error DbiModuleDescriptorBuilder::commit(BinaryStreamWriter &ModiWriter,
134                                          const msf::MSFLayout &MsfLayout,
135                                          WritableBinaryStreamRef MsfBuffer) {
136   // We write the Modi record to the `ModiWriter`, but we additionally write its
137   // symbol stream to a brand new stream.
138   if (auto EC = ModiWriter.writeObject(Layout))
139     return EC;
140   if (auto EC = ModiWriter.writeCString(ModuleName))
141     return EC;
142   if (auto EC = ModiWriter.writeCString(ObjFileName))
143     return EC;
144   if (auto EC = ModiWriter.padToAlignment(sizeof(uint32_t)))
145     return EC;
146 
147   if (Layout.ModDiStream != kInvalidStreamIndex) {
148     auto NS = WritableMappedBlockStream::createIndexedStream(
149         MsfLayout, MsfBuffer, Layout.ModDiStream, MSF.getAllocator());
150     WritableBinaryStreamRef Ref(*NS);
151     BinaryStreamWriter SymbolWriter(Ref);
152     // Write the symbols.
153     if (auto EC =
154             SymbolWriter.writeInteger<uint32_t>(COFF::DEBUG_SECTION_MAGIC))
155       return EC;
156     BinaryItemStream<CVSymbol> Records(llvm::support::endianness::little);
157     Records.setItems(Symbols);
158     BinaryStreamRef RecordsRef(Records);
159     if (auto EC = SymbolWriter.writeStreamRef(RecordsRef))
160       return EC;
161     if (auto EC = SymbolWriter.padToAlignment(4))
162       return EC;
163     // TODO: Write C11 Line data
164     assert(SymbolWriter.getOffset() % alignOf(CodeViewContainer::Pdb) == 0 &&
165            "Invalid debug section alignment!");
166     for (const auto &Builder : C13Builders) {
167       assert(Builder && "Empty C13 Fragment Builder!");
168       if (auto EC = Builder->commit(SymbolWriter))
169         return EC;
170     }
171 
172     // TODO: Figure out what GlobalRefs substream actually is and populate it.
173     if (auto EC = SymbolWriter.writeInteger<uint32_t>(0))
174       return EC;
175     if (SymbolWriter.bytesRemaining() > 0)
176       return make_error<RawError>(raw_error_code::stream_too_long);
177   }
178   return Error::success();
179 }
180 
181 void DbiModuleDescriptorBuilder::addDebugSubsection(
182     std::shared_ptr<DebugSubsection> Subsection) {
183   assert(Subsection);
184   C13Builders.push_back(llvm::make_unique<DebugSubsectionRecordBuilder>(
185       std::move(Subsection), CodeViewContainer::Pdb));
186 }
187 
188 void DbiModuleDescriptorBuilder::addDebugSubsection(
189     const DebugSubsectionRecord &SubsectionContents) {
190   C13Builders.push_back(llvm::make_unique<DebugSubsectionRecordBuilder>(
191       SubsectionContents, CodeViewContainer::Pdb));
192 }
193