Remove InputFiles::LogName.

[ruiu]

Summary

LogName member was added to construct input file names for logging
only once. This patch does this in a different way. Now toString
caches its results.

lld/ELF/InputFiles.h

ArrayRef<InputSectionBase *> getSections() const {
     return Sections;
   }
 
   // Filename of .a which contained this file. If this file was
   // not in an archive file, it is the empty string. We use this
   // string for creating error messages.
   StringRef ArchiveName;
 
-  // Filename used for logging. It is either in the form of "foo.o" or
-  // "bar.a(foo.o)".
-  std::string LogName;
-
   // If this is an architecture-specific file, the following members
   // have ELF type (i.e. ELF{32,64}{LE,BE}) and target machine type.
   ELFKind EKind = ELFNoneKind;
   uint16_t EMachine = llvm::ELF::EM_NONE;
   uint8_t OSABI = 0;
 
+  // Cache for toString(). Only toString() should use this member.
+  mutable std::string ToStringCache;
+
 protected:
   InputFile(Kind K, MemoryBufferRef M);
   std::vector<InputSectionBase *> Sections;
 
 private:
   const Kind FileKind;
 };
 

lld/ELF/InputFiles.cpp

 using namespace llvm::object;
 using namespace llvm::sys::fs;
 
 using namespace lld;
 using namespace lld::elf;
 
 TarWriter *elf::Tar;
 
-InputFile::InputFile(Kind K, MemoryBufferRef M)
-    : MB(M), LogName(M.getBufferIdentifier()), FileKind(K) {}
+InputFile::InputFile(Kind K, MemoryBufferRef M) : MB(M), FileKind(K) {}
 
 namespace {
 // In ELF object file all section addresses are zero. If we have multiple
 // .text sections (when using -ffunction-section or comdat group) then
 // LLVM DWARF parser will not be able to parse .debug_line correctly, unless
 // we assign each section some unique address. This callback method assigns
 // each section an address equal to its offset in ELF object file.
 class ObjectInfo : public LoadedObjectInfo {
Optional<MemoryBufferRef> elf::readFile(StringRef Path) {
 
   if (Tar)
     Tar->append(relativeToRoot(Path), MBRef.getBuffer());
   return MBRef;
 }
 
 template <class ELFT> void elf::ObjectFile<ELFT>::initializeDwarfLine() {
   std::unique_ptr<object::ObjectFile> Obj =
-      check(object::ObjectFile::createObjectFile(this->MB), this->LogName);
+      check(object::ObjectFile::createObjectFile(this->MB), toString(this));
 
   ObjectInfo ObjInfo;
   DWARFContextInMemory Dwarf(*Obj, &ObjInfo);
   DwarfLine.reset(new DWARFDebugLine(&Dwarf.getLineSection().Relocs));
   DataExtractor LineData(Dwarf.getLineSection().Data, Config->IsLE,
                          Config->Wordsize);
 
   // The second parameter is offset in .debug_line section
std::string elf::ObjectFile<ELFT>::getLineInfo(InputSectionBase *S,
                                                uint64_t Offset) {
   if (Optional<DILineInfo> Info = getDILineInfo(S, Offset))
     return Info->FileName + ":" + std::to_string(Info->Line);
   return "";
 }
 
 // Returns "(internal)", "foo.a(bar.o)" or "baz.o".
 std::string lld::toString(const InputFile *F) {
-  return F ? F->LogName : "(internal)";
+  if (!F)
+    return "(internal)";
+
+  if (F->ToStringCache.empty()) {
+    if (F->ArchiveName.empty())
+      F->ToStringCache = F->getName();
+    else
+      F->ToStringCache = (F->ArchiveName + "(" + F->getName() + ")").str();
+  }
+  return F->ToStringCache;
 }
 
 template <class ELFT> static ELFKind getELFKind() {
   if (ELFT::TargetEndianness == support::little)
     return ELFT::Is64Bits ? ELF64LEKind : ELF32LEKind;
   return ELFT::Is64Bits ? ELF64BEKind : ELF32BEKind;
 }
 
 template <class ELFT>
 ELFFileBase<ELFT>::ELFFileBase(Kind K, MemoryBufferRef MB) : InputFile(K, MB) {
   EKind = getELFKind<ELFT>();
   EMachine = getObj().getHeader()->e_machine;
   OSABI = getObj().getHeader()->e_ident[llvm::ELF::EI_OSABI];
 }
 
 template <class ELFT>
 typename ELFT::SymRange ELFFileBase<ELFT>::getGlobalSymbols() {
   return makeArrayRef(Symbols.begin() + FirstNonLocal, Symbols.end());
 }
 
 template <class ELFT>
 uint32_t ELFFileBase<ELFT>::getSectionIndex(const Elf_Sym &Sym) const {
   return check(getObj().getSectionIndex(&Sym, Symbols, SymtabSHNDX),
-               this->LogName);
+               toString(this));
 }
 
 template <class ELFT>
 void ELFFileBase<ELFT>::initSymtab(ArrayRef<Elf_Shdr> Sections,
                                    const Elf_Shdr *Symtab) {
   FirstNonLocal = Symtab->sh_info;
-  Symbols = check(getObj().symbols(Symtab), this->LogName);
+  Symbols = check(getObj().symbols(Symtab), toString(this));
   if (FirstNonLocal == 0 || FirstNonLocal > Symbols.size())
     fatal(toString(this) + ": invalid sh_info in symbol table");
 
-  StringTable =
-      check(getObj().getStringTableForSymtab(*Symtab, Sections), this->LogName);
+  StringTable = check(getObj().getStringTableForSymtab(*Symtab, Sections),
+                      toString(this));
 }
 
 template <class ELFT>
 elf::ObjectFile<ELFT>::ObjectFile(MemoryBufferRef M)
     : ELFFileBase<ELFT>(Base::ObjectKind, M) {}
 
 template <class ELFT>
 ArrayRef<SymbolBody *> elf::ObjectFile<ELFT>::getNonLocalSymbols() {

 // returns a group name.
 template <class ELFT>
 StringRef
 elf::ObjectFile<ELFT>::getShtGroupSignature(ArrayRef<Elf_Shdr> Sections,
                                             const Elf_Shdr &Sec) {
   if (this->Symbols.empty())
     this->initSymtab(
         Sections,
-        check(object::getSection<ELFT>(Sections, Sec.sh_link), this->LogName));
-  const Elf_Sym *Sym =
-      check(object::getSymbol<ELFT>(this->Symbols, Sec.sh_info), this->LogName);
-  return check(Sym->getName(this->StringTable), this->LogName);
+        check(object::getSection<ELFT>(Sections, Sec.sh_link), toString(this)));
+  const Elf_Sym *Sym = check(
+      object::getSymbol<ELFT>(this->Symbols, Sec.sh_info), toString(this));
+  return check(Sym->getName(this->StringTable), toString(this));
 }
 
 template <class ELFT>
 ArrayRef<typename elf::ObjectFile<ELFT>::Elf_Word>
 elf::ObjectFile<ELFT>::getShtGroupEntries(const Elf_Shdr &Sec) {
   const ELFFile<ELFT> &Obj = this->getObj();
   ArrayRef<Elf_Word> Entries = check(
-      Obj.template getSectionContentsAsArray<Elf_Word>(&Sec), this->LogName);
+      Obj.template getSectionContentsAsArray<Elf_Word>(&Sec), toString(this));
   if (Entries.empty() || Entries[0] != GRP_COMDAT)
     fatal(toString(this) + ": unsupported SHT_GROUP format");
   return Entries.slice(1);
 }
 
 template <class ELFT>
 bool elf::ObjectFile<ELFT>::shouldMerge(const Elf_Shdr &Sec) {
   // We don't merge sections if -O0 (default is -O1). This makes sometimes
bool elf::ObjectFile<ELFT>::shouldMerge(const Elf_Shdr &Sec) {
 
   return Sec.sh_addralign <= EntSize;
 }
 
 template <class ELFT>
 void elf::ObjectFile<ELFT>::initializeSections(
     DenseSet<CachedHashStringRef> &ComdatGroups) {
   ArrayRef<Elf_Shdr> ObjSections =
-      check(this->getObj().sections(), this->LogName);
+      check(this->getObj().sections(), toString(this));
   const ELFFile<ELFT> &Obj = this->getObj();
   uint64_t Size = ObjSections.size();
   this->Sections.resize(Size);
   unsigned I = -1;
   StringRef SectionStringTable =
-      check(Obj.getSectionStringTable(ObjSections), this->LogName);
+      check(Obj.getSectionStringTable(ObjSections), toString(this));
   for (const Elf_Shdr &Sec : ObjSections) {
     ++I;
     if (this->Sections[I] == &InputSection::Discarded)
       continue;
 
     // SHF_EXCLUDE'ed sections are discarded by the linker. However,
     // if -r is given, we'll let the final link discard such sections.
     // This is compatible with GNU.
case SHT_GROUP:
         this->Sections[SecIndex] = &InputSection::Discarded;
       }
       break;
     case SHT_SYMTAB:
       this->initSymtab(ObjSections, &Sec);
       break;
     case SHT_SYMTAB_SHNDX:
       this->SymtabSHNDX =
-          check(Obj.getSHNDXTable(Sec, ObjSections), this->LogName);
+          check(Obj.getSHNDXTable(Sec, ObjSections), toString(this));
       break;
     case SHT_STRTAB:
     case SHT_NULL:
       break;
     default:
       this->Sections[I] = createInputSection(Sec, SectionStringTable);
     }
 
InputSectionBase *elf::ObjectFile<ELFT>::getRelocTarget(const Elf_Shdr &Sec) {
   return Target;
 }
 
 template <class ELFT>
 InputSectionBase *
 elf::ObjectFile<ELFT>::createInputSection(const Elf_Shdr &Sec,
                                           StringRef SectionStringTable) {
   StringRef Name = check(
-      this->getObj().getSectionName(&Sec, SectionStringTable), this->LogName);
+      this->getObj().getSectionName(&Sec, SectionStringTable), toString(this));
 
   switch (Sec.sh_type) {
   case SHT_ARM_ATTRIBUTES:
     // FIXME: ARM meta-data section. Retain the first attribute section
     // we see. The eglibc ARM dynamic loaders require the presence of an
     // attribute section for dlopen to work.
     // In a full implementation we would merge all attribute sections.
     if (In<ELFT>::ARMAttributes == nullptr) {
if (Target->FirstRelocation)
             ": multiple relocation sections to one section are not supported");
     if (isa<MergeInputSection>(Target))
       fatal(toString(this) +
             ": relocations pointing to SHF_MERGE are not supported");
 
     size_t NumRelocations;
     if (Sec.sh_type == SHT_RELA) {
       ArrayRef<Elf_Rela> Rels =
-          check(this->getObj().relas(&Sec), this->LogName);
+          check(this->getObj().relas(&Sec), toString(this));
       Target->FirstRelocation = Rels.begin();
       NumRelocations = Rels.size();
       Target->AreRelocsRela = true;
     } else {
-      ArrayRef<Elf_Rel> Rels = check(this->getObj().rels(&Sec), this->LogName);
+      ArrayRef<Elf_Rel> Rels = check(this->getObj().rels(&Sec), toString(this));
       Target->FirstRelocation = Rels.begin();
       NumRelocations = Rels.size();
       Target->AreRelocsRela = false;
     }
     assert(isUInt<31>(NumRelocations));
     Target->NumRelocations = NumRelocations;
 
     // Relocation sections processed by the linker are usually removed
SymbolBody *elf::ObjectFile<ELFT>::createSymbolBody(const Elf_Sym *Sym) {
 
   uint8_t StOther = Sym->st_other;
   uint8_t Type = Sym->getType();
   uint64_t Value = Sym->st_value;
   uint64_t Size = Sym->st_size;
 
   if (Binding == STB_LOCAL) {
     if (Sym->getType() == STT_FILE)
-      SourceFile = check(Sym->getName(this->StringTable), this->LogName);
+      SourceFile = check(Sym->getName(this->StringTable), toString(this));
 
     if (this->StringTable.size() <= Sym->st_name)
       fatal(toString(this) + ": invalid symbol name offset");
 
     StringRefZ Name = this->StringTable.data() + Sym->st_name;
     if (Sym->st_shndx == SHN_UNDEF)
       return make<Undefined>(Name, /*IsLocal=*/true, StOther, Type, this);
 
     return make<DefinedRegular>(Name, /*IsLocal=*/true, StOther, Type, Value,
                                 Size, Sec, this);
   }
 
-  StringRef Name = check(Sym->getName(this->StringTable), this->LogName);
+  StringRef Name = check(Sym->getName(this->StringTable), toString(this));
 
   switch (Sym->st_shndx) {
   case SHN_UNDEF:
     return elf::Symtab<ELFT>::X
         ->addUndefined(Name, /*IsLocal=*/false, Binding, StOther, Type,
                        /*CanOmitFromDynSym=*/false, this)
         ->body();
   case SHN_COMMON:
template <class ELFT> void ArchiveFile::parse() {
   if (File->symbols().begin() == File->symbols().end())
     Config->ArchiveWithoutSymbolsSeen = true;
 }
 
 // Returns a buffer pointing to a member file containing a given symbol.
 std::pair<MemoryBufferRef, uint64_t>
 ArchiveFile::getMember(const Archive::Symbol *Sym) {
   Archive::Child C =
-      check(Sym->getMember(), this->LogName +
+      check(Sym->getMember(), toString(this) +
                                   ": could not get the member for symbol " +
                                   Sym->getName());
 
   if (!Seen.insert(C.getChildOffset()).second)
     return {MemoryBufferRef(), 0};
 
   MemoryBufferRef Ret =
       check(C.getMemoryBufferRef(),
-            this->LogName +
+            toString(this) +
                 ": could not get the buffer for the member defining symbol " +
                 Sym->getName());
 
   if (C.getParent()->isThin() && Tar)
-    Tar->append(relativeToRoot(check(C.getFullName(), this->LogName)),
+    Tar->append(relativeToRoot(check(C.getFullName(), toString(this))),
                 Ret.getBuffer());
   if (C.getParent()->isThin())
     return {Ret, 0};
   return {Ret, C.getChildOffset()};
 }
 
 template <class ELFT>
 SharedFile<ELFT>::SharedFile(MemoryBufferRef M)
     : ELFFileBase<ELFT>(Base::SharedKind, M), AsNeeded(Config->AsNeeded) {}
 
 template <class ELFT>
 const typename ELFT::Shdr *
 SharedFile<ELFT>::getSection(const Elf_Sym &Sym) const {
   return check(
       this->getObj().getSection(&Sym, this->Symbols, this->SymtabSHNDX),
-      this->LogName);
+      toString(this));
 }
 
 // Partially parse the shared object file so that we can call
 // getSoName on this object.
 template <class ELFT> void SharedFile<ELFT>::parseSoName() {
   const Elf_Shdr *DynamicSec = nullptr;
 
   const ELFFile<ELFT> Obj = this->getObj();
-  ArrayRef<Elf_Shdr> Sections = check(Obj.sections(), this->LogName);
+  ArrayRef<Elf_Shdr> Sections = check(Obj.sections(), toString(this));
   for (const Elf_Shdr &Sec : Sections) {
     switch (Sec.sh_type) {
     default:
       continue;
     case SHT_DYNSYM:
       this->initSymtab(Sections, &Sec);
       break;
     case SHT_DYNAMIC:
       DynamicSec = &Sec;
       break;
     case SHT_SYMTAB_SHNDX:
       this->SymtabSHNDX =
-          check(Obj.getSHNDXTable(Sec, Sections), this->LogName);
+          check(Obj.getSHNDXTable(Sec, Sections), toString(this));
       break;
     case SHT_GNU_versym:
       this->VersymSec = &Sec;
       break;
     case SHT_GNU_verdef:
       this->VerdefSec = &Sec;
       break;
     }
   }
 
   if (this->VersymSec && this->Symbols.empty())
     error("SHT_GNU_versym should be associated with symbol table");
 
   // DSOs are identified by soname, and they usually contain
   // DT_SONAME tag in their header. But if they are missing,
   // filenames are used as default sonames.
   SoName = sys::path::filename(this->getName());
 
   if (!DynamicSec)
     return;
 
   ArrayRef<Elf_Dyn> Arr =
       check(Obj.template getSectionContentsAsArray<Elf_Dyn>(DynamicSec),
-            this->LogName);
+            toString(this));
   for (const Elf_Dyn &Dyn : Arr) {
     if (Dyn.d_tag == DT_SONAME) {
       uint64_t Val = Dyn.getVal();
       if (Val >= this->StringTable.size())
         fatal(toString(this) + ": invalid DT_SONAME entry");
       SoName = StringRef(this->StringTable.data() + Val);
       return;
     }
for (const Elf_Sym &Sym : Syms) {
     unsigned VersymIndex = 0;
     if (Versym) {
       VersymIndex = Versym->vs_index;
       ++Versym;
     }
     bool Hidden = VersymIndex & VERSYM_HIDDEN;
     VersymIndex = VersymIndex & ~VERSYM_HIDDEN;
 
-    StringRef Name = check(Sym.getName(this->StringTable), this->LogName);
+    StringRef Name = check(Sym.getName(this->StringTable), toString(this));
     if (Sym.isUndefined()) {
       Undefs.push_back(Name);
       continue;
     }
 
     // Ignore local symbols.
     if (Versym && VersymIndex == VER_NDX_LOCAL)
       continue;
void BitcodeFile::parse(DenseSet<CachedHashStringRef> &ComdatGroups) {
   // ThinLTO uses the MemoryBufferRef identifier to access its internal
   // data structures and if two archives define two members with the same name,
   // this causes a collision which result in only one of the objects being
   // taken into consideration at LTO time (which very likely causes undefined
   // symbols later in the link stage).
   MemoryBufferRef MBRef(MB.getBuffer(),
                         Saver.save(ArchiveName + MB.getBufferIdentifier() +
                                    utostr(OffsetInArchive)));
-  Obj = check(lto::InputFile::create(MBRef), this->LogName);
+  Obj = check(lto::InputFile::create(MBRef), toString(this));
 
   std::vector<bool> KeptComdats;
   for (StringRef S : Obj->getComdatTable())
     KeptComdats.push_back(ComdatGroups.insert(CachedHashStringRef(S)).second);
 
   for (const lto::InputFile::Symbol &ObjSym : Obj->symbols())
     Symbols.push_back(createBitcodeSymbol<ELFT>(KeptComdats, ObjSym, this));
 }
static bool isBitcode(MemoryBufferRef MB) {
   return identify_magic(MB.getBuffer()) == file_magic::bitcode;
 }
 
 InputFile *elf::createObjectFile(MemoryBufferRef MB, StringRef ArchiveName,
                                  uint64_t OffsetInArchive) {
   InputFile *F = isBitcode(MB) ? make<BitcodeFile>(MB, OffsetInArchive)
                                : createELFFile<ObjectFile>(MB);
   F->ArchiveName = ArchiveName;
-  if (!ArchiveName.empty())
-    F->LogName = (ArchiveName + "(" + F->LogName + ")").str();
   return F;
 }
 
 InputFile *elf::createSharedFile(MemoryBufferRef MB) {
   return createELFFile<SharedFile>(MB);
 }
 
 MemoryBufferRef LazyObjectFile::getBuffer() {

 }
 
 template <class ELFT> std::vector<StringRef> LazyObjectFile::getElfSymbols() {
   typedef typename ELFT::Shdr Elf_Shdr;
   typedef typename ELFT::Sym Elf_Sym;
   typedef typename ELFT::SymRange Elf_Sym_Range;
 
   const ELFFile<ELFT> Obj(this->MB.getBuffer());
-  ArrayRef<Elf_Shdr> Sections = check(Obj.sections(), this->LogName);
+  ArrayRef<Elf_Shdr> Sections = check(Obj.sections(), toString(this));
   for (const Elf_Shdr &Sec : Sections) {
     if (Sec.sh_type != SHT_SYMTAB)
       continue;
 
-    Elf_Sym_Range Syms = check(Obj.symbols(&Sec), this->LogName);
+    Elf_Sym_Range Syms = check(Obj.symbols(&Sec), toString(this));
     uint32_t FirstNonLocal = Sec.sh_info;
     StringRef StringTable =
-        check(Obj.getStringTableForSymtab(Sec, Sections), this->LogName);
+        check(Obj.getStringTableForSymtab(Sec, Sections), toString(this));
     std::vector<StringRef> V;
 
     for (const Elf_Sym &Sym : Syms.slice(FirstNonLocal))
       if (Sym.st_shndx != SHN_UNDEF)
-        V.push_back(check(Sym.getName(StringTable), this->LogName));
+        V.push_back(check(Sym.getName(StringTable), toString(this)));
     return V;
   }
   return {};
 }
 
 std::vector<StringRef> LazyObjectFile::getBitcodeSymbols() {
   std::unique_ptr<lto::InputFile> Obj =
-      check(lto::InputFile::create(this->MB), this->LogName);
+      check(lto::InputFile::create(this->MB), toString(this));
   std::vector<StringRef> V;
   for (const lto::InputFile::Symbol &Sym : Obj->symbols())
     if (!Sym.isUndefined())
       V.push_back(Saver.save(Sym.getName()));
   return V;
 }
 
 // Returns a vector of globally-visible defined symbol names.