xref: /llvm-project/llvm/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp (revision eacdf04fdda7c6156b4e063cfce28f643493f76e)
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/PublicsStreamBuilder.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 
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 
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 
49 DbiModuleDescriptorBuilder::~DbiModuleDescriptorBuilder() {}
50 
51 uint16_t DbiModuleDescriptorBuilder::getStreamIndex() const {
52   return Layout.ModDiStream;
53 }
54 
55 void DbiModuleDescriptorBuilder::setObjFileName(StringRef Name) {
56   ObjFileName = Name;
57 }
58 
59 void DbiModuleDescriptorBuilder::setPdbFilePathNI(uint32_t NI) {
60   PdbFilePathNI = NI;
61 }
62 
63 void DbiModuleDescriptorBuilder::addSymbol(CVSymbol Symbol) {
64   Symbols.push_back(Symbol);
65   // Symbols written to a PDB file are required to be 4 byte aligned.  The same
66   // is not true of object files.
67   assert(Symbol.length() % alignOf(CodeViewContainer::Pdb) == 0 &&
68          "Invalid Symbol alignment!");
69   SymbolByteSize += Symbol.length();
70 }
71 
72 void DbiModuleDescriptorBuilder::addSourceFile(StringRef Path) {
73   SourceFiles.push_back(Path);
74 }
75 
76 uint32_t DbiModuleDescriptorBuilder::calculateC13DebugInfoSize() const {
77   uint32_t Result = 0;
78   for (const auto &Builder : C13Builders) {
79     assert(Builder && "Empty C13 Fragment Builder!");
80     Result += Builder->calculateSerializedLength();
81   }
82   return Result;
83 }
84 
85 uint32_t DbiModuleDescriptorBuilder::calculateSerializedLength() const {
86   uint32_t L = sizeof(Layout);
87   uint32_t M = ModuleName.size() + 1;
88   uint32_t O = ObjFileName.size() + 1;
89   return alignTo(L + M + O, sizeof(uint32_t));
90 }
91 
92 template <typename T> struct Foo {
93   explicit Foo(T &&Answer) : Answer(Answer) {}
94 
95   T Answer;
96 };
97 
98 template <typename T> Foo<T> makeFoo(T &&t) { return Foo<T>(std::move(t)); }
99 
100 void DbiModuleDescriptorBuilder::finalize() {
101   Layout.SC.ModuleIndex = Layout.Mod;
102   Layout.FileNameOffs = 0; // TODO: Fix this
103   Layout.Flags = 0;        // TODO: Fix this
104   Layout.C11Bytes = 0;
105   Layout.C13Bytes = calculateC13DebugInfoSize();
106   (void)Layout.Mod;         // Set in constructor
107   (void)Layout.ModDiStream; // Set in finalizeMsfLayout
108   Layout.NumFiles = SourceFiles.size();
109   Layout.PdbFilePathNI = PdbFilePathNI;
110   Layout.SrcFileNameNI = 0;
111 
112   // This value includes both the signature field as well as the record bytes
113   // from the symbol stream.
114   Layout.SymBytes = SymbolByteSize + sizeof(uint32_t);
115 }
116 
117 Error DbiModuleDescriptorBuilder::finalizeMsfLayout() {
118   this->Layout.ModDiStream = kInvalidStreamIndex;
119   uint32_t C13Size = calculateC13DebugInfoSize();
120   auto ExpectedSN =
121       MSF.addStream(calculateDiSymbolStreamSize(SymbolByteSize, C13Size));
122   if (!ExpectedSN)
123     return ExpectedSN.takeError();
124   Layout.ModDiStream = *ExpectedSN;
125   return Error::success();
126 }
127 
128 Error DbiModuleDescriptorBuilder::commit(BinaryStreamWriter &ModiWriter,
129                                          const msf::MSFLayout &MsfLayout,
130                                          WritableBinaryStreamRef MsfBuffer) {
131   // We write the Modi record to the `ModiWriter`, but we additionally write its
132   // symbol stream to a brand new stream.
133   if (auto EC = ModiWriter.writeObject(Layout))
134     return EC;
135   if (auto EC = ModiWriter.writeCString(ModuleName))
136     return EC;
137   if (auto EC = ModiWriter.writeCString(ObjFileName))
138     return EC;
139   if (auto EC = ModiWriter.padToAlignment(sizeof(uint32_t)))
140     return EC;
141 
142   if (Layout.ModDiStream != kInvalidStreamIndex) {
143     auto NS = WritableMappedBlockStream::createIndexedStream(
144         MsfLayout, MsfBuffer, Layout.ModDiStream, MSF.getAllocator());
145     WritableBinaryStreamRef Ref(*NS);
146     BinaryStreamWriter SymbolWriter(Ref);
147     // Write the symbols.
148     if (auto EC =
149             SymbolWriter.writeInteger<uint32_t>(COFF::DEBUG_SECTION_MAGIC))
150       return EC;
151     BinaryItemStream<CVSymbol> Records(llvm::support::endianness::little);
152     Records.setItems(Symbols);
153     BinaryStreamRef RecordsRef(Records);
154     if (auto EC = SymbolWriter.writeStreamRef(RecordsRef))
155       return EC;
156     if (auto EC = SymbolWriter.padToAlignment(4))
157       return EC;
158     // TODO: Write C11 Line data
159     assert(SymbolWriter.getOffset() % alignOf(CodeViewContainer::Pdb) == 0 &&
160            "Invalid debug section alignment!");
161     for (const auto &Builder : C13Builders) {
162       assert(Builder && "Empty C13 Fragment Builder!");
163       if (auto EC = Builder->commit(SymbolWriter))
164         return EC;
165     }
166 
167     // TODO: Figure out what GlobalRefs substream actually is and populate it.
168     if (auto EC = SymbolWriter.writeInteger<uint32_t>(0))
169       return EC;
170     if (SymbolWriter.bytesRemaining() > 0)
171       return make_error<RawError>(raw_error_code::stream_too_long);
172   }
173   return Error::success();
174 }
175 
176 void DbiModuleDescriptorBuilder::addDebugSubsection(
177     std::shared_ptr<DebugSubsection> Subsection) {
178   assert(Subsection);
179   C13Builders.push_back(llvm::make_unique<DebugSubsectionRecordBuilder>(
180       std::move(Subsection), CodeViewContainer::Pdb));
181 }
182 
183 void DbiModuleDescriptorBuilder::addDebugSubsection(
184     const DebugSubsectionRecord &SubsectionContents) {
185   C13Builders.push_back(llvm::make_unique<DebugSubsectionRecordBuilder>(
186       SubsectionContents, CodeViewContainer::Pdb));
187 }
188