From 9cf32a0f1d22c5ece8a581e98166ddac8a6e61a7 Mon Sep 17 00:00:00 2001
From: Peter Collingbourne <peter@pcc.me.uk>
Date: Fri, 3 Nov 2017 21:30:06 +0000
Subject: [PATCH] Revert r317046, "Object: Move some code from ELF.h into
 ELF.cpp."

This change resulted in a measured 1.5-2% perf regression linking
chrome.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317371 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Object/ELF.h | 263 ++++++++++++++++++++++++++++++++++++++
 lib/Object/ELF.cpp        | 263 --------------------------------------
 2 files changed, 263 insertions(+), 263 deletions(-)

diff --git a/include/llvm/Object/ELF.h b/include/llvm/Object/ELF.h
index 92fb46e8e935..c24b6310465e 100644
--- a/include/llvm/Object/ELF.h
+++ b/include/llvm/Object/ELF.h
@@ -204,6 +204,46 @@ getExtendedSymbolTableIndex(const typename ELFT::Sym *Sym,
   return ShndxTable[Index];
 }
 
+template <class ELFT>
+Expected<uint32_t>
+ELFFile<ELFT>::getSectionIndex(const Elf_Sym *Sym, Elf_Sym_Range Syms,
+                               ArrayRef<Elf_Word> ShndxTable) const {
+  uint32_t Index = Sym->st_shndx;
+  if (Index == ELF::SHN_XINDEX) {
+    auto ErrorOrIndex = getExtendedSymbolTableIndex<ELFT>(
+        Sym, Syms.begin(), ShndxTable);
+    if (!ErrorOrIndex)
+      return ErrorOrIndex.takeError();
+    return *ErrorOrIndex;
+  }
+  if (Index == ELF::SHN_UNDEF || Index >= ELF::SHN_LORESERVE)
+    return 0;
+  return Index;
+}
+
+template <class ELFT>
+Expected<const typename ELFT::Shdr *>
+ELFFile<ELFT>::getSection(const Elf_Sym *Sym, const Elf_Shdr *SymTab,
+                          ArrayRef<Elf_Word> ShndxTable) const {
+  auto SymsOrErr = symbols(SymTab);
+  if (!SymsOrErr)
+    return SymsOrErr.takeError();
+  return getSection(Sym, *SymsOrErr, ShndxTable);
+}
+
+template <class ELFT>
+Expected<const typename ELFT::Shdr *>
+ELFFile<ELFT>::getSection(const Elf_Sym *Sym, Elf_Sym_Range Symbols,
+                          ArrayRef<Elf_Word> ShndxTable) const {
+  auto IndexOrErr = getSectionIndex(Sym, Symbols, ShndxTable);
+  if (!IndexOrErr)
+    return IndexOrErr.takeError();
+  uint32_t Index = *IndexOrErr;
+  if (Index == 0)
+    return nullptr;
+  return getSection(Index);
+}
+
 template <class ELFT>
 inline Expected<const typename ELFT::Sym *>
 getSymbol(typename ELFT::SymRange Symbols, uint32_t Index) {
@@ -212,6 +252,15 @@ getSymbol(typename ELFT::SymRange Symbols, uint32_t Index) {
   return &Symbols[Index];
 }
 
+template <class ELFT>
+Expected<const typename ELFT::Sym *>
+ELFFile<ELFT>::getSymbol(const Elf_Shdr *Sec, uint32_t Index) const {
+  auto SymtabOrErr = symbols(Sec);
+  if (!SymtabOrErr)
+    return SymtabOrErr.takeError();
+  return object::getSymbol<ELFT>(*SymtabOrErr, Index);
+}
+
 template <class ELFT>
 template <typename T>
 Expected<ArrayRef<T>>
@@ -232,6 +281,119 @@ ELFFile<ELFT>::getSectionContentsAsArray(const Elf_Shdr *Sec) const {
   return makeArrayRef(Start, Size / sizeof(T));
 }
 
+template <class ELFT>
+Expected<ArrayRef<uint8_t>>
+ELFFile<ELFT>::getSectionContents(const Elf_Shdr *Sec) const {
+  return getSectionContentsAsArray<uint8_t>(Sec);
+}
+
+template <class ELFT>
+StringRef ELFFile<ELFT>::getRelocationTypeName(uint32_t Type) const {
+  return getELFRelocationTypeName(getHeader()->e_machine, Type);
+}
+
+template <class ELFT>
+void ELFFile<ELFT>::getRelocationTypeName(uint32_t Type,
+                                          SmallVectorImpl<char> &Result) const {
+  if (!isMipsELF64()) {
+    StringRef Name = getRelocationTypeName(Type);
+    Result.append(Name.begin(), Name.end());
+  } else {
+    // The Mips N64 ABI allows up to three operations to be specified per
+    // relocation record. Unfortunately there's no easy way to test for the
+    // presence of N64 ELFs as they have no special flag that identifies them
+    // as being N64. We can safely assume at the moment that all Mips
+    // ELFCLASS64 ELFs are N64. New Mips64 ABIs should provide enough
+    // information to disambiguate between old vs new ABIs.
+    uint8_t Type1 = (Type >> 0) & 0xFF;
+    uint8_t Type2 = (Type >> 8) & 0xFF;
+    uint8_t Type3 = (Type >> 16) & 0xFF;
+
+    // Concat all three relocation type names.
+    StringRef Name = getRelocationTypeName(Type1);
+    Result.append(Name.begin(), Name.end());
+
+    Name = getRelocationTypeName(Type2);
+    Result.append(1, '/');
+    Result.append(Name.begin(), Name.end());
+
+    Name = getRelocationTypeName(Type3);
+    Result.append(1, '/');
+    Result.append(Name.begin(), Name.end());
+  }
+}
+
+template <class ELFT>
+Expected<const typename ELFT::Sym *>
+ELFFile<ELFT>::getRelocationSymbol(const Elf_Rel *Rel,
+                                   const Elf_Shdr *SymTab) const {
+  uint32_t Index = Rel->getSymbol(isMips64EL());
+  if (Index == 0)
+    return nullptr;
+  return getEntry<Elf_Sym>(SymTab, Index);
+}
+
+template <class ELFT>
+Expected<StringRef>
+ELFFile<ELFT>::getSectionStringTable(Elf_Shdr_Range Sections) const {
+  uint32_t Index = getHeader()->e_shstrndx;
+  if (Index == ELF::SHN_XINDEX)
+    Index = Sections[0].sh_link;
+
+  if (!Index) // no section string table.
+    return "";
+  if (Index >= Sections.size())
+    return createError("invalid section index");
+  return getStringTable(&Sections[Index]);
+}
+
+template <class ELFT> ELFFile<ELFT>::ELFFile(StringRef Object) : Buf(Object) {}
+
+template <class ELFT>
+Expected<ELFFile<ELFT>> ELFFile<ELFT>::create(StringRef Object) {
+  if (sizeof(Elf_Ehdr) > Object.size())
+    return createError("Invalid buffer");
+  return ELFFile(Object);
+}
+
+template <class ELFT>
+Expected<typename ELFT::ShdrRange> ELFFile<ELFT>::sections() const {
+  const uintX_t SectionTableOffset = getHeader()->e_shoff;
+  if (SectionTableOffset == 0)
+    return ArrayRef<Elf_Shdr>();
+
+  if (getHeader()->e_shentsize != sizeof(Elf_Shdr))
+    return createError(
+        "invalid section header entry size (e_shentsize) in ELF header");
+
+  const uint64_t FileSize = Buf.size();
+
+  if (SectionTableOffset + sizeof(Elf_Shdr) > FileSize)
+    return createError("section header table goes past the end of the file");
+
+  // Invalid address alignment of section headers
+  if (SectionTableOffset & (alignof(Elf_Shdr) - 1))
+    return createError("invalid alignment of section headers");
+
+  const Elf_Shdr *First =
+      reinterpret_cast<const Elf_Shdr *>(base() + SectionTableOffset);
+
+  uintX_t NumSections = getHeader()->e_shnum;
+  if (NumSections == 0)
+    NumSections = First->sh_size;
+
+  if (NumSections > UINT64_MAX / sizeof(Elf_Shdr))
+    return createError("section table goes past the end of file");
+
+  const uint64_t SectionTableSize = NumSections * sizeof(Elf_Shdr);
+
+  // Section table goes past end of file!
+  if (SectionTableOffset + SectionTableSize > FileSize)
+    return createError("section table goes past the end of file");
+
+  return makeArrayRef(First, NumSections);
+}
+
 template <class ELFT>
 template <typename T>
 Expected<const T *> ELFFile<ELFT>::getEntry(uint32_t Section,
@@ -254,6 +416,107 @@ Expected<const T *> ELFFile<ELFT>::getEntry(const Elf_Shdr *Section,
   return reinterpret_cast<const T *>(base() + Pos);
 }
 
+template <class ELFT>
+Expected<const typename ELFT::Shdr *>
+ELFFile<ELFT>::getSection(uint32_t Index) const {
+  auto TableOrErr = sections();
+  if (!TableOrErr)
+    return TableOrErr.takeError();
+  return object::getSection<ELFT>(*TableOrErr, Index);
+}
+
+template <class ELFT>
+Expected<StringRef>
+ELFFile<ELFT>::getStringTable(const Elf_Shdr *Section) const {
+  if (Section->sh_type != ELF::SHT_STRTAB)
+    return createError("invalid sh_type for string table, expected SHT_STRTAB");
+  auto V = getSectionContentsAsArray<char>(Section);
+  if (!V)
+    return V.takeError();
+  ArrayRef<char> Data = *V;
+  if (Data.empty())
+    return createError("empty string table");
+  if (Data.back() != '\0')
+    return createError("string table non-null terminated");
+  return StringRef(Data.begin(), Data.size());
+}
+
+template <class ELFT>
+Expected<ArrayRef<typename ELFT::Word>>
+ELFFile<ELFT>::getSHNDXTable(const Elf_Shdr &Section) const {
+  auto SectionsOrErr = sections();
+  if (!SectionsOrErr)
+    return SectionsOrErr.takeError();
+  return getSHNDXTable(Section, *SectionsOrErr);
+}
+
+template <class ELFT>
+Expected<ArrayRef<typename ELFT::Word>>
+ELFFile<ELFT>::getSHNDXTable(const Elf_Shdr &Section,
+                             Elf_Shdr_Range Sections) const {
+  assert(Section.sh_type == ELF::SHT_SYMTAB_SHNDX);
+  auto VOrErr = getSectionContentsAsArray<Elf_Word>(&Section);
+  if (!VOrErr)
+    return VOrErr.takeError();
+  ArrayRef<Elf_Word> V = *VOrErr;
+  auto SymTableOrErr = object::getSection<ELFT>(Sections, Section.sh_link);
+  if (!SymTableOrErr)
+    return SymTableOrErr.takeError();
+  const Elf_Shdr &SymTable = **SymTableOrErr;
+  if (SymTable.sh_type != ELF::SHT_SYMTAB &&
+      SymTable.sh_type != ELF::SHT_DYNSYM)
+    return createError("invalid sh_type");
+  if (V.size() != (SymTable.sh_size / sizeof(Elf_Sym)))
+    return createError("invalid section contents size");
+  return V;
+}
+
+template <class ELFT>
+Expected<StringRef>
+ELFFile<ELFT>::getStringTableForSymtab(const Elf_Shdr &Sec) const {
+  auto SectionsOrErr = sections();
+  if (!SectionsOrErr)
+    return SectionsOrErr.takeError();
+  return getStringTableForSymtab(Sec, *SectionsOrErr);
+}
+
+template <class ELFT>
+Expected<StringRef>
+ELFFile<ELFT>::getStringTableForSymtab(const Elf_Shdr &Sec,
+                                       Elf_Shdr_Range Sections) const {
+
+  if (Sec.sh_type != ELF::SHT_SYMTAB && Sec.sh_type != ELF::SHT_DYNSYM)
+    return createError(
+        "invalid sh_type for symbol table, expected SHT_SYMTAB or SHT_DYNSYM");
+  auto SectionOrErr = object::getSection<ELFT>(Sections, Sec.sh_link);
+  if (!SectionOrErr)
+    return SectionOrErr.takeError();
+  return getStringTable(*SectionOrErr);
+}
+
+template <class ELFT>
+Expected<StringRef>
+ELFFile<ELFT>::getSectionName(const Elf_Shdr *Section) const {
+  auto SectionsOrErr = sections();
+  if (!SectionsOrErr)
+    return SectionsOrErr.takeError();
+  auto Table = getSectionStringTable(*SectionsOrErr);
+  if (!Table)
+    return Table.takeError();
+  return getSectionName(Section, *Table);
+}
+
+template <class ELFT>
+Expected<StringRef> ELFFile<ELFT>::getSectionName(const Elf_Shdr *Section,
+                                                  StringRef DotShstrtab) const {
+  uint32_t Offset = Section->sh_name;
+  if (Offset == 0)
+    return StringRef();
+  if (Offset >= DotShstrtab.size())
+    return createError("invalid string offset");
+  return StringRef(DotShstrtab.data() + Offset);
+}
+
 /// This function returns the hash value for a symbol in the .dynsym section
 /// Name of the API remains consistent as specified in the libelf
 /// REF : http://www.sco.com/developers/gabi/latest/ch5.dynamic.html#hash
diff --git a/lib/Object/ELF.cpp b/lib/Object/ELF.cpp
index ef8c844a66f1..c72a1258c1ee 100644
--- a/lib/Object/ELF.cpp
+++ b/lib/Object/ELF.cpp
@@ -214,269 +214,6 @@ StringRef llvm::object::getELFSectionTypeName(uint32_t Machine, unsigned Type) {
   }
 }
 
-template <class ELFT>
-Expected<uint32_t>
-ELFFile<ELFT>::getSectionIndex(const Elf_Sym *Sym, Elf_Sym_Range Syms,
-                               ArrayRef<Elf_Word> ShndxTable) const {
-  uint32_t Index = Sym->st_shndx;
-  if (Index == ELF::SHN_XINDEX) {
-    auto ErrorOrIndex = getExtendedSymbolTableIndex<ELFT>(
-        Sym, Syms.begin(), ShndxTable);
-    if (!ErrorOrIndex)
-      return ErrorOrIndex.takeError();
-    return *ErrorOrIndex;
-  }
-  if (Index == ELF::SHN_UNDEF || Index >= ELF::SHN_LORESERVE)
-    return 0;
-  return Index;
-}
-
-template <class ELFT>
-Expected<const typename ELFT::Shdr *>
-ELFFile<ELFT>::getSection(const Elf_Sym *Sym, const Elf_Shdr *SymTab,
-                          ArrayRef<Elf_Word> ShndxTable) const {
-  auto SymsOrErr = symbols(SymTab);
-  if (!SymsOrErr)
-    return SymsOrErr.takeError();
-  return getSection(Sym, *SymsOrErr, ShndxTable);
-}
-
-template <class ELFT>
-Expected<const typename ELFT::Shdr *>
-ELFFile<ELFT>::getSection(const Elf_Sym *Sym, Elf_Sym_Range Symbols,
-                          ArrayRef<Elf_Word> ShndxTable) const {
-  auto IndexOrErr = getSectionIndex(Sym, Symbols, ShndxTable);
-  if (!IndexOrErr)
-    return IndexOrErr.takeError();
-  uint32_t Index = *IndexOrErr;
-  if (Index == 0)
-    return nullptr;
-  return getSection(Index);
-}
-
-template <class ELFT>
-Expected<const typename ELFT::Sym *>
-ELFFile<ELFT>::getSymbol(const Elf_Shdr *Sec, uint32_t Index) const {
-  auto SymtabOrErr = symbols(Sec);
-  if (!SymtabOrErr)
-    return SymtabOrErr.takeError();
-  return object::getSymbol<ELFT>(*SymtabOrErr, Index);
-}
-
-template <class ELFT>
-Expected<ArrayRef<uint8_t>>
-ELFFile<ELFT>::getSectionContents(const Elf_Shdr *Sec) const {
-  return getSectionContentsAsArray<uint8_t>(Sec);
-}
-
-template <class ELFT>
-StringRef ELFFile<ELFT>::getRelocationTypeName(uint32_t Type) const {
-  return getELFRelocationTypeName(getHeader()->e_machine, Type);
-}
-
-template <class ELFT>
-void ELFFile<ELFT>::getRelocationTypeName(uint32_t Type,
-                                          SmallVectorImpl<char> &Result) const {
-  if (!isMipsELF64()) {
-    StringRef Name = getRelocationTypeName(Type);
-    Result.append(Name.begin(), Name.end());
-  } else {
-    // The Mips N64 ABI allows up to three operations to be specified per
-    // relocation record. Unfortunately there's no easy way to test for the
-    // presence of N64 ELFs as they have no special flag that identifies them
-    // as being N64. We can safely assume at the moment that all Mips
-    // ELFCLASS64 ELFs are N64. New Mips64 ABIs should provide enough
-    // information to disambiguate between old vs new ABIs.
-    uint8_t Type1 = (Type >> 0) & 0xFF;
-    uint8_t Type2 = (Type >> 8) & 0xFF;
-    uint8_t Type3 = (Type >> 16) & 0xFF;
-
-    // Concat all three relocation type names.
-    StringRef Name = getRelocationTypeName(Type1);
-    Result.append(Name.begin(), Name.end());
-
-    Name = getRelocationTypeName(Type2);
-    Result.append(1, '/');
-    Result.append(Name.begin(), Name.end());
-
-    Name = getRelocationTypeName(Type3);
-    Result.append(1, '/');
-    Result.append(Name.begin(), Name.end());
-  }
-}
-
-template <class ELFT>
-Expected<const typename ELFT::Sym *>
-ELFFile<ELFT>::getRelocationSymbol(const Elf_Rel *Rel,
-                                   const Elf_Shdr *SymTab) const {
-  uint32_t Index = Rel->getSymbol(isMips64EL());
-  if (Index == 0)
-    return nullptr;
-  return getEntry<Elf_Sym>(SymTab, Index);
-}
-
-template <class ELFT>
-Expected<StringRef>
-ELFFile<ELFT>::getSectionStringTable(Elf_Shdr_Range Sections) const {
-  uint32_t Index = getHeader()->e_shstrndx;
-  if (Index == ELF::SHN_XINDEX)
-    Index = Sections[0].sh_link;
-
-  if (!Index) // no section string table.
-    return "";
-  if (Index >= Sections.size())
-    return createError("invalid section index");
-  return getStringTable(&Sections[Index]);
-}
-
-template <class ELFT> ELFFile<ELFT>::ELFFile(StringRef Object) : Buf(Object) {}
-
-template <class ELFT>
-Expected<ELFFile<ELFT>> ELFFile<ELFT>::create(StringRef Object) {
-  if (sizeof(Elf_Ehdr) > Object.size())
-    return createError("Invalid buffer");
-  return ELFFile(Object);
-}
-
-template <class ELFT>
-Expected<typename ELFT::ShdrRange> ELFFile<ELFT>::sections() const {
-  const uintX_t SectionTableOffset = getHeader()->e_shoff;
-  if (SectionTableOffset == 0)
-    return ArrayRef<Elf_Shdr>();
-
-  if (getHeader()->e_shentsize != sizeof(Elf_Shdr))
-    return createError(
-        "invalid section header entry size (e_shentsize) in ELF header");
-
-  const uint64_t FileSize = Buf.size();
-
-  if (SectionTableOffset + sizeof(Elf_Shdr) > FileSize)
-    return createError("section header table goes past the end of the file");
-
-  // Invalid address alignment of section headers
-  if (SectionTableOffset & (alignof(Elf_Shdr) - 1))
-    return createError("invalid alignment of section headers");
-
-  const Elf_Shdr *First =
-      reinterpret_cast<const Elf_Shdr *>(base() + SectionTableOffset);
-
-  uintX_t NumSections = getHeader()->e_shnum;
-  if (NumSections == 0)
-    NumSections = First->sh_size;
-
-  if (NumSections > UINT64_MAX / sizeof(Elf_Shdr))
-    return createError("section table goes past the end of file");
-
-  const uint64_t SectionTableSize = NumSections * sizeof(Elf_Shdr);
-
-  // Section table goes past end of file!
-  if (SectionTableOffset + SectionTableSize > FileSize)
-    return createError("section table goes past the end of file");
-
-  return makeArrayRef(First, NumSections);
-}
-
-template <class ELFT>
-Expected<const typename ELFT::Shdr *>
-ELFFile<ELFT>::getSection(uint32_t Index) const {
-  auto TableOrErr = sections();
-  if (!TableOrErr)
-    return TableOrErr.takeError();
-  return object::getSection<ELFT>(*TableOrErr, Index);
-}
-
-template <class ELFT>
-Expected<StringRef>
-ELFFile<ELFT>::getStringTable(const Elf_Shdr *Section) const {
-  if (Section->sh_type != ELF::SHT_STRTAB)
-    return createError("invalid sh_type for string table, expected SHT_STRTAB");
-  auto V = getSectionContentsAsArray<char>(Section);
-  if (!V)
-    return V.takeError();
-  ArrayRef<char> Data = *V;
-  if (Data.empty())
-    return createError("empty string table");
-  if (Data.back() != '\0')
-    return createError("string table non-null terminated");
-  return StringRef(Data.begin(), Data.size());
-}
-
-template <class ELFT>
-Expected<ArrayRef<typename ELFT::Word>>
-ELFFile<ELFT>::getSHNDXTable(const Elf_Shdr &Section) const {
-  auto SectionsOrErr = sections();
-  if (!SectionsOrErr)
-    return SectionsOrErr.takeError();
-  return getSHNDXTable(Section, *SectionsOrErr);
-}
-
-template <class ELFT>
-Expected<ArrayRef<typename ELFT::Word>>
-ELFFile<ELFT>::getSHNDXTable(const Elf_Shdr &Section,
-                             Elf_Shdr_Range Sections) const {
-  assert(Section.sh_type == ELF::SHT_SYMTAB_SHNDX);
-  auto VOrErr = getSectionContentsAsArray<Elf_Word>(&Section);
-  if (!VOrErr)
-    return VOrErr.takeError();
-  ArrayRef<Elf_Word> V = *VOrErr;
-  auto SymTableOrErr = object::getSection<ELFT>(Sections, Section.sh_link);
-  if (!SymTableOrErr)
-    return SymTableOrErr.takeError();
-  const Elf_Shdr &SymTable = **SymTableOrErr;
-  if (SymTable.sh_type != ELF::SHT_SYMTAB &&
-      SymTable.sh_type != ELF::SHT_DYNSYM)
-    return createError("invalid sh_type");
-  if (V.size() != (SymTable.sh_size / sizeof(Elf_Sym)))
-    return createError("invalid section contents size");
-  return V;
-}
-
-template <class ELFT>
-Expected<StringRef>
-ELFFile<ELFT>::getStringTableForSymtab(const Elf_Shdr &Sec) const {
-  auto SectionsOrErr = sections();
-  if (!SectionsOrErr)
-    return SectionsOrErr.takeError();
-  return getStringTableForSymtab(Sec, *SectionsOrErr);
-}
-
-template <class ELFT>
-Expected<StringRef>
-ELFFile<ELFT>::getStringTableForSymtab(const Elf_Shdr &Sec,
-                                       Elf_Shdr_Range Sections) const {
-
-  if (Sec.sh_type != ELF::SHT_SYMTAB && Sec.sh_type != ELF::SHT_DYNSYM)
-    return createError(
-        "invalid sh_type for symbol table, expected SHT_SYMTAB or SHT_DYNSYM");
-  auto SectionOrErr = object::getSection<ELFT>(Sections, Sec.sh_link);
-  if (!SectionOrErr)
-    return SectionOrErr.takeError();
-  return getStringTable(*SectionOrErr);
-}
-
-template <class ELFT>
-Expected<StringRef>
-ELFFile<ELFT>::getSectionName(const Elf_Shdr *Section) const {
-  auto SectionsOrErr = sections();
-  if (!SectionsOrErr)
-    return SectionsOrErr.takeError();
-  auto Table = getSectionStringTable(*SectionsOrErr);
-  if (!Table)
-    return Table.takeError();
-  return getSectionName(Section, *Table);
-}
-
-template <class ELFT>
-Expected<StringRef> ELFFile<ELFT>::getSectionName(const Elf_Shdr *Section,
-                                                  StringRef DotShstrtab) const {
-  uint32_t Offset = Section->sh_name;
-  if (Offset == 0)
-    return StringRef();
-  if (Offset >= DotShstrtab.size())
-    return createError("invalid string offset");
-  return StringRef(DotShstrtab.data() + Offset);
-}
-
 template <class ELFT>
 Expected<std::vector<typename ELFT::Rela>>
 ELFFile<ELFT>::android_relas(const Elf_Shdr *Sec) const {