PDB.cpp revision 314564 
1//===- PDB.cpp ------------------------------------------------------------===//
2//
3//                             The LLVM Linker
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 "PDB.h"
11#include "Chunks.h"
12#include "Config.h"
13#include "Error.h"
14#include "SymbolTable.h"
15#include "Symbols.h"
16#include "llvm/DebugInfo/CodeView/CVDebugRecord.h"
17#include "llvm/DebugInfo/CodeView/CVTypeDumper.h"
18#include "llvm/DebugInfo/CodeView/SymbolDumper.h"
19#include "llvm/DebugInfo/CodeView/TypeDatabase.h"
20#include "llvm/DebugInfo/CodeView/TypeDumpVisitor.h"
21#include "llvm/DebugInfo/CodeView/TypeStreamMerger.h"
22#include "llvm/DebugInfo/CodeView/TypeTableBuilder.h"
23#include "llvm/DebugInfo/MSF/ByteStream.h"
24#include "llvm/DebugInfo/MSF/MSFBuilder.h"
25#include "llvm/DebugInfo/MSF/MSFCommon.h"
26#include "llvm/DebugInfo/PDB/Raw/DbiStream.h"
27#include "llvm/DebugInfo/PDB/Raw/DbiStreamBuilder.h"
28#include "llvm/DebugInfo/PDB/Raw/InfoStream.h"
29#include "llvm/DebugInfo/PDB/Raw/InfoStreamBuilder.h"
30#include "llvm/DebugInfo/PDB/Raw/PDBFile.h"
31#include "llvm/DebugInfo/PDB/Raw/PDBFileBuilder.h"
32#include "llvm/DebugInfo/PDB/Raw/TpiStream.h"
33#include "llvm/DebugInfo/PDB/Raw/TpiStreamBuilder.h"
34#include "llvm/Object/COFF.h"
35#include "llvm/Support/Endian.h"
36#include "llvm/Support/FileOutputBuffer.h"
37#include "llvm/Support/ScopedPrinter.h"
38#include <memory>
39
40using namespace lld;
41using namespace lld::coff;
42using namespace llvm;
43using namespace llvm::codeview;
44using namespace llvm::support;
45using namespace llvm::support::endian;
46
47using llvm::object::coff_section;
48
49static ExitOnError ExitOnErr;
50
51// Returns a list of all SectionChunks.
52static std::vector<coff_section> getInputSections(SymbolTable *Symtab) {
53  std::vector<coff_section> V;
54  for (Chunk *C : Symtab->getChunks())
55    if (auto *SC = dyn_cast<SectionChunk>(C))
56      V.push_back(*SC->Header);
57  return V;
58}
59
60static SectionChunk *findByName(std::vector<SectionChunk *> &Sections,
61                                StringRef Name) {
62  for (SectionChunk *C : Sections)
63    if (C->getSectionName() == Name)
64      return C;
65  return nullptr;
66}
67
68static ArrayRef<uint8_t> getDebugSection(ObjectFile *File, StringRef SecName) {
69  SectionChunk *Sec = findByName(File->getDebugChunks(), SecName);
70  if (!Sec)
71    return {};
72
73  // First 4 bytes are section magic.
74  ArrayRef<uint8_t> Data = Sec->getContents();
75  if (Data.size() < 4)
76    fatal(SecName + " too short");
77  if (read32le(Data.data()) != COFF::DEBUG_SECTION_MAGIC)
78    fatal(SecName + " has an invalid magic");
79  return Data.slice(4);
80}
81
82// Merge .debug$T sections and returns it.
83static std::vector<uint8_t> mergeDebugT(SymbolTable *Symtab) {
84  ScopedPrinter W(outs());
85
86  // Visit all .debug$T sections to add them to Builder.
87  codeview::TypeTableBuilder Builder(BAlloc);
88  for (ObjectFile *File : Symtab->ObjectFiles) {
89    ArrayRef<uint8_t> Data = getDebugSection(File, ".debug$T");
90    if (Data.empty())
91      continue;
92
93    msf::ByteStream Stream(Data);
94    codeview::CVTypeArray Types;
95    msf::StreamReader Reader(Stream);
96    if (auto EC = Reader.readArray(Types, Reader.getLength()))
97      fatal(EC, "Reader::readArray failed");
98    if (!codeview::mergeTypeStreams(Builder, Types))
99      fatal("codeview::mergeTypeStreams failed");
100  }
101
102  // Construct section contents.
103  std::vector<uint8_t> V;
104  Builder.ForEachRecord([&](TypeIndex TI, ArrayRef<uint8_t> Rec) {
105    V.insert(V.end(), Rec.begin(), Rec.end());
106  });
107  return V;
108}
109
110static void dumpDebugT(ScopedPrinter &W, ObjectFile *File) {
111  ListScope LS(W, "DebugT");
112  ArrayRef<uint8_t> Data = getDebugSection(File, ".debug$T");
113  if (Data.empty())
114    return;
115
116  TypeDatabase TDB;
117  TypeDumpVisitor TDV(TDB, &W, false);
118  CVTypeDumper TypeDumper(TDB);
119  if (auto EC = TypeDumper.dump(Data, TDV))
120    fatal(EC, "CVTypeDumper::dump failed");
121}
122
123static void dumpDebugS(ScopedPrinter &W, ObjectFile *File) {
124  ListScope LS(W, "DebugS");
125  ArrayRef<uint8_t> Data = getDebugSection(File, ".debug$S");
126  if (Data.empty())
127    return;
128
129  msf::ByteStream Stream(Data);
130  CVSymbolArray Symbols;
131  msf::StreamReader Reader(Stream);
132  if (auto EC = Reader.readArray(Symbols, Reader.getLength()))
133    fatal(EC, "StreamReader.readArray<CVSymbolArray> failed");
134
135  TypeDatabase TDB;
136  CVSymbolDumper SymbolDumper(W, TDB, nullptr, false);
137  if (auto EC = SymbolDumper.dump(Symbols))
138    fatal(EC, "CVSymbolDumper::dump failed");
139}
140
141// Dump CodeView debug info. This is for debugging.
142static void dumpCodeView(SymbolTable *Symtab) {
143  ScopedPrinter W(outs());
144
145  for (ObjectFile *File : Symtab->ObjectFiles) {
146    dumpDebugT(W, File);
147    dumpDebugS(W, File);
148  }
149}
150
151static void addTypeInfo(pdb::TpiStreamBuilder &TpiBuilder,
152                        ArrayRef<uint8_t> Data) {
153  msf::ByteStream Stream(Data);
154  codeview::CVTypeArray Records;
155  msf::StreamReader Reader(Stream);
156  if (auto EC = Reader.readArray(Records, Reader.getLength()))
157    fatal(EC, "Reader.readArray failed");
158  for (const codeview::CVType &Rec : Records)
159    TpiBuilder.addTypeRecord(Rec);
160}
161
162// Creates a PDB file.
163void coff::createPDB(StringRef Path, SymbolTable *Symtab,
164                     ArrayRef<uint8_t> SectionTable,
165                     const llvm::codeview::DebugInfo *DI) {
166  if (Config->DumpPdb)
167    dumpCodeView(Symtab);
168
169  BumpPtrAllocator Alloc;
170  pdb::PDBFileBuilder Builder(Alloc);
171  ExitOnErr(Builder.initialize(4096)); // 4096 is blocksize
172
173  // Create streams in MSF for predefined streams, namely
174  // PDB, TPI, DBI and IPI.
175  for (int I = 0; I < (int)pdb::kSpecialStreamCount; ++I)
176    ExitOnErr(Builder.getMsfBuilder().addStream(0));
177
178  // Add an Info stream.
179  auto &InfoBuilder = Builder.getInfoBuilder();
180  InfoBuilder.setAge(DI->PDB70.Age);
181  InfoBuilder.setGuid(
182      *reinterpret_cast<const pdb::PDB_UniqueId *>(&DI->PDB70.Signature));
183  // Should be the current time, but set 0 for reproducibilty.
184  InfoBuilder.setSignature(0);
185  InfoBuilder.setVersion(pdb::PdbRaw_ImplVer::PdbImplVC70);
186
187  // Add an empty DPI stream.
188  auto &DbiBuilder = Builder.getDbiBuilder();
189  DbiBuilder.setVersionHeader(pdb::PdbDbiV110);
190
191  // Add an empty TPI stream.
192  auto &TpiBuilder = Builder.getTpiBuilder();
193  TpiBuilder.setVersionHeader(pdb::PdbTpiV80);
194  std::vector<uint8_t> TpiData;
195  if (Config->DebugPdb) {
196    TpiData = mergeDebugT(Symtab);
197    addTypeInfo(TpiBuilder, TpiData);
198  }
199
200  // Add an empty IPI stream.
201  auto &IpiBuilder = Builder.getIpiBuilder();
202  IpiBuilder.setVersionHeader(pdb::PdbTpiV80);
203
204  // Add Section Contributions.
205  std::vector<pdb::SectionContrib> Contribs =
206      pdb::DbiStreamBuilder::createSectionContribs(getInputSections(Symtab));
207  DbiBuilder.setSectionContribs(Contribs);
208
209  // Add Section Map stream.
210  ArrayRef<object::coff_section> Sections = {
211      (const object::coff_section *)SectionTable.data(),
212      SectionTable.size() / sizeof(object::coff_section)};
213  std::vector<pdb::SecMapEntry> SectionMap =
214      pdb::DbiStreamBuilder::createSectionMap(Sections);
215  DbiBuilder.setSectionMap(SectionMap);
216
217  ExitOnErr(DbiBuilder.addModuleInfo("", "* Linker *"));
218
219  // Add COFF section header stream.
220  ExitOnErr(
221      DbiBuilder.addDbgStream(pdb::DbgHeaderType::SectionHdr, SectionTable));
222
223  // Write to a file.
224  ExitOnErr(Builder.commit(Path));
225}
226