COFF: PDB: Allow multiple modules with the same name.

[pcc]

Summary

It is possible for two modules to have the same name if they are
archive members with the same name, or if we are doing LTO (in which
case all modules will have the name "lto.tmp").

[zturner]

Seems like this agrees with what MS does, which is a bit surprising, but looks correct in any case.

lld/test/COFF/pdb-same-name.test

+# RUN: rm -rf %t1 %t2
+# RUN: mkdir %t1 %t2
+# RUN: yaml2obj < %p/Inputs/pdb1.yaml > %t1/foo.obj
+# RUN: llvm-ar cru %t1/foo.lib %t1/foo.obj
+# RUN: yaml2obj < %p/Inputs/pdb2.yaml > %t2/foo.obj
+# RUN: llvm-ar cru %t2/foo.lib %t2/foo.obj
+
+# RUN: rm -f %t.dll %t.pdb
+# RUN: lld-link /debug /pdb:%t.pdb /dll /out:%t.dll /entry:main /nodefaultlib \
+# RUN:   %t1/foo.lib %t2/foo.lib
+
+# RUN: llvm-pdbutil dump -modules %t.pdb | FileCheck -check-prefix RAW %s
+
+RAW:                               Modules
+RAW-NEXT: ============================================================
+RAW-NEXT:   Mod 0000 | `foo.obj`:
+RAW-NEXT:              Obj: `{{.*}}1\foo.lib`:
+RAW-NEXT:              debug stream: 9, # files: 1, has ec info: false
+RAW-NEXT:              pdb file ni: 0 ``, src file ni: 0 ``
+RAW-NEXT:   Mod 0001 | `foo.obj`:
+RAW-NEXT:              Obj: `{{.*}}2\foo.lib`:
+RAW-NEXT:              debug stream: 10, # files: 1, has ec info: false
+RAW-NEXT:              pdb file ni: 0 ``, src file ni: 0 ``

llvm/include/llvm/DebugInfo/PDB/Native/DbiStreamBuilder.h

public:
 
   uint32_t calculateSerializedLength() const;
 
   void setGlobalsStreamIndex(uint32_t Index);
   void setPublicsStreamIndex(uint32_t Index);
   void setSymbolRecordStreamIndex(uint32_t Index);
 
   Expected<DbiModuleDescriptorBuilder &> addModuleInfo(StringRef ModuleName);
-  Error addModuleSourceFile(StringRef Module, StringRef File);
   Error addModuleSourceFile(DbiModuleDescriptorBuilder &Module, StringRef File);
   Expected<uint32_t> getSourceFileNameIndex(StringRef FileName);
 
   Error finalizeMsfLayout();
 
   Error commit(const msf::MSFLayout &Layout, WritableBinaryStreamRef MsfBuffer);
 
   void addSectionContrib(const SectionContrib &SC) {
private:
   uint16_t Flags;
   PDB_Machine MachineType;
   uint32_t GlobalsStreamIndex = kInvalidStreamIndex;
   uint32_t PublicsStreamIndex = kInvalidStreamIndex;
   uint32_t SymRecordStreamIndex = kInvalidStreamIndex;
 
   const DbiStreamHeader *Header;
 
-  StringMap<std::unique_ptr<DbiModuleDescriptorBuilder>> ModiMap;
-  std::vector<DbiModuleDescriptorBuilder *> ModiList;
+  std::vector<std::unique_ptr<DbiModuleDescriptorBuilder>> ModiList;
 
   StringMap<uint32_t> SourceFileNames;
 
   PDBStringTableBuilder ECNamesBuilder;
   WritableBinaryStreamRef NamesBuffer;
   MutableBinaryByteStream FileInfoBuffer;
   std::vector<SectionContrib> SectionContribs;
   ArrayRef<SecMapEntry> SectionMap;
   llvm::SmallVector<DebugStream, (int)DbgHeaderType::Max> DbgStreams;
 };
 }
 }
 
 #endif

llvm/lib/DebugInfo/PDB/Native/DbiStreamBuilder.cpp

return sizeof(DbiStreamHeader) + calculateFileInfoSubstreamSize() +
          calculateModiSubstreamSize() + calculateSectionContribsStreamSize() +
          calculateSectionMapStreamSize() + calculateDbgStreamsSize() +
          ECNamesBuilder.calculateSerializedSize();
 }
 
 Expected<DbiModuleDescriptorBuilder &>
 DbiStreamBuilder::addModuleInfo(StringRef ModuleName) {
   uint32_t Index = ModiList.size();
-  auto MIB =
-      llvm::make_unique<DbiModuleDescriptorBuilder>(ModuleName, Index, Msf);
-  auto M = MIB.get();
-  auto Result = ModiMap.insert(std::make_pair(ModuleName, std::move(MIB)));
-
-  if (!Result.second)
-    return make_error<RawError>(raw_error_code::duplicate_entry,
-                                "The specified module already exists");
-  ModiList.push_back(M);
-  return *M;
-}
-
-Error DbiStreamBuilder::addModuleSourceFile(StringRef Module, StringRef File) {
-  auto ModIter = ModiMap.find(Module);
-  if (ModIter == ModiMap.end())
-    return make_error<RawError>(raw_error_code::no_entry,
-                                "The specified module was not found");
-  return addModuleSourceFile(*ModIter->second, File);
+  ModiList.push_back(
+      llvm::make_unique<DbiModuleDescriptorBuilder>(ModuleName, Index, Msf));
+  return *ModiList.back();
 }
 
 Error DbiStreamBuilder::addModuleSourceFile(DbiModuleDescriptorBuilder &Module,
                                             StringRef File) {
   uint32_t Index = SourceFileNames.size();
   SourceFileNames.insert(std::make_pair(File, Index));
   Module.addSourceFile(File);
   return Error::success();

llvm/tools/llvm-pdbutil/llvm-pdbutil.cpp

static void yamlToPdb(StringRef Path) {
   DbiBuilder.setPdbDllRbld(Dbi.PdbDllRbld);
   DbiBuilder.setPdbDllVersion(Dbi.PdbDllVersion);
   DbiBuilder.setVersionHeader(Dbi.VerHeader);
   for (const auto &MI : Dbi.ModInfos) {
     auto &ModiBuilder = ExitOnErr(DbiBuilder.addModuleInfo(MI.Mod));
     ModiBuilder.setObjFileName(MI.Obj);
 
     for (auto S : MI.SourceFiles)
-      ExitOnErr(DbiBuilder.addModuleSourceFile(MI.Mod, S));
+      ExitOnErr(DbiBuilder.addModuleSourceFile(ModiBuilder, S));
     if (MI.Modi.hasValue()) {
       const auto &ModiStream = *MI.Modi;
       for (auto Symbol : ModiStream.Symbols) {
         ModiBuilder.addSymbol(
             Symbol.toCodeViewSymbol(Allocator, CodeViewContainer::Pdb));
       }
     }