/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h

Bug Summary

File:	include/llvm/Support/Error.h
Warning:	line 201, column 5 Potential leak of memory pointed to by 'Payload._M_t._M_head_impl'

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name Object.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-8/lib/clang/8.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/llvm-objcopy -I /build/llvm-toolchain-snapshot-8~svn345461/tools/llvm-objcopy -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn345461/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/include/clang/8.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-8/lib/clang/8.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/llvm-objcopy -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-10-27-211344-32123-1 -x c++ /build/llvm-toolchain-snapshot-8~svn345461/tools/llvm-objcopy/Object.cpp -faddrsig

/build/llvm-toolchain-snapshot-8~svn345461/tools/llvm-objcopy/Object.cpp

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1//===- Object.cpp ---------------------------------------------------------===//
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//===----------------------------------------------------------------------===//

10#include "Object.h"
11#include "llvm-objcopy.h"
12#include "llvm/ADT/ArrayRef.h"
13#include "llvm/ADT/STLExtras.h"
14#include "llvm/ADT/StringRef.h"
15#include "llvm/ADT/Twine.h"
16#include "llvm/ADT/iterator_range.h"
17#include "llvm/BinaryFormat/ELF.h"
18#include "llvm/MC/MCTargetOptions.h"
19#include "llvm/Object/ELFObjectFile.h"
20#include "llvm/Support/Compression.h"
21#include "llvm/Support/ErrorHandling.h"
22#include "llvm/Support/FileOutputBuffer.h"
23#include "llvm/Support/Path.h"
24#include <algorithm>
25#include <cstddef>
26#include <cstdint>
27#include <iterator>
28#include <utility>
29#include <vector>

31namespace llvm {
32namespace objcopy {
33namespace elf {

35using namespace object;
36using namespace ELF;

38template <class ELFT> void ELFWriter<ELFT>::writePhdr(const Segment &Seg) {
uint8_t *B = Buf.getBufferStart();
B += Obj.ProgramHdrSegment.Offset + Seg.Index * sizeof(Elf_Phdr);
Elf_Phdr &Phdr = *reinterpret_cast<Elf_Phdr *>(B);
Phdr.p_type = Seg.Type;
Phdr.p_flags = Seg.Flags;
Phdr.p_offset = Seg.Offset;
Phdr.p_vaddr = Seg.VAddr;
Phdr.p_paddr = Seg.PAddr;
Phdr.p_filesz = Seg.FileSize;
Phdr.p_memsz = Seg.MemSize;
Phdr.p_align = Seg.Align;
50}

52void SectionBase::removeSectionReferences(const SectionBase *Sec) {}
53void SectionBase::removeSymbols(function_ref<bool(const Symbol &)> ToRemove) {}
54void SectionBase::initialize(SectionTableRef SecTable) {}
55void SectionBase::finalize() {}
56void SectionBase::markSymbols() {}

58template <class ELFT> void ELFWriter<ELFT>::writeShdr(const SectionBase &Sec) {
uint8_t *B = Buf.getBufferStart();
B += Sec.HeaderOffset;
Elf_Shdr &Shdr = *reinterpret_cast<Elf_Shdr *>(B);
Shdr.sh_name = Sec.NameIndex;
Shdr.sh_type = Sec.Type;
Shdr.sh_flags = Sec.Flags;
Shdr.sh_addr = Sec.Addr;
Shdr.sh_offset = Sec.Offset;
Shdr.sh_size = Sec.Size;
Shdr.sh_link = Sec.Link;
Shdr.sh_info = Sec.Info;
Shdr.sh_addralign = Sec.Align;
Shdr.sh_entsize = Sec.EntrySize;
72}

74SectionVisitor::~SectionVisitor() {}

76void BinarySectionWriter::visit(const SectionIndexSection &Sec) {
error("Cannot write symbol section index table '" + Sec.Name + "' ");
78}

80void BinarySectionWriter::visit(const SymbolTableSection &Sec) {
error("Cannot write symbol table '" + Sec.Name + "' out to binary");
82}

84void BinarySectionWriter::visit(const RelocationSection &Sec) {
error("Cannot write relocation section '" + Sec.Name + "' out to binary");
86}

88void BinarySectionWriter::visit(const GnuDebugLinkSection &Sec) {
error("Cannot write '" + Sec.Name + "' out to binary");
90}

92void BinarySectionWriter::visit(const GroupSection &Sec) {
error("Cannot write '" + Sec.Name + "' out to binary");
94}

96void SectionWriter::visit(const Section &Sec) {
if (Sec.Type == SHT_NOBITS)
  return;
uint8_t *Buf = Out.getBufferStart() + Sec.Offset;
std::copy(std::begin(Sec.Contents), std::end(Sec.Contents), Buf);
101}

103void Section::accept(SectionVisitor &Visitor) const { Visitor.visit(*this); }

105void SectionWriter::visit(const OwnedDataSection &Sec) {
uint8_t *Buf = Out.getBufferStart() + Sec.Offset;
std::copy(std::begin(Sec.Data), std::end(Sec.Data), Buf);
108}

110static const std::vector<uint8_t> ZlibGnuMagic = {'Z', 'L', 'I', 'B'};

112static bool isDataGnuCompressed(ArrayRef<uint8_t> Data) {
return Data.size() > ZlibGnuMagic.size() &&
       std::equal(ZlibGnuMagic.begin(), ZlibGnuMagic.end(), Data.data());
115}

117template <class ELFT>
118static std::tuple<uint64_t, uint64_t>
119getDecompressedSizeAndAlignment(ArrayRef<uint8_t> Data) {
const bool IsGnuDebug = isDataGnuCompressed(Data);
const uint64_t DecompressedSize =
    IsGnuDebug
        ? support::endian::read64be(reinterpret_cast<const uint64_t *>(
              Data.data() + ZlibGnuMagic.size()))
        : reinterpret_cast<const Elf_Chdr_Impl<ELFT> *>(Data.data())->ch_size;
const uint64_t DecompressedAlign =
    IsGnuDebug ? 1
               : reinterpret_cast<const Elf_Chdr_Impl<ELFT> *>(Data.data())
                     ->ch_addralign;

return std::make_tuple(DecompressedSize, DecompressedAlign);
132}

134template <class ELFT>
135void ELFSectionWriter<ELFT>::visit(const DecompressedSection &Sec) {
uint8_t *Buf = Out.getBufferStart() + Sec.Offset;

if (!zlib::isAvailable()) {
  std::copy(Sec.OriginalData.begin(), Sec.OriginalData.end(), Buf);
  return;
}

const size_t DataOffset = isDataGnuCompressed(Sec.OriginalData)
                              ? (ZlibGnuMagic.size() + sizeof(Sec.Size))
                              : sizeof(Elf_Chdr_Impl<ELFT>);

StringRef CompressedContent(
    reinterpret_cast<const char *>(Sec.OriginalData.data()) + DataOffset,
    Sec.OriginalData.size() - DataOffset);

SmallVector<char, 128> DecompressedContent;
if (Error E = zlib::uncompress(CompressedContent, DecompressedContent,
                               static_cast<size_t>(Sec.Size)))
  reportError(Sec.Name, std::move(E));

std::copy(DecompressedContent.begin(), DecompressedContent.end(), Buf);
157}

159void BinarySectionWriter::visit(const DecompressedSection &Sec) {
error("Cannot write compressed section '" + Sec.Name + "' ");
161}

163void DecompressedSection::accept(SectionVisitor &Visitor) const {
Visitor.visit(*this);
165}

167void OwnedDataSection::accept(SectionVisitor &Visitor) const {
Visitor.visit(*this);
169}

171void BinarySectionWriter::visit(const CompressedSection &Sec) {
error("Cannot write compressed section '" + Sec.Name + "' ");
173}

175template <class ELFT>
176void ELFSectionWriter<ELFT>::visit(const CompressedSection &Sec) {
uint8_t *Buf = Out.getBufferStart();
Buf += Sec.Offset;

if (Sec.CompressionType == DebugCompressionType::None) {
  std::copy(Sec.OriginalData.begin(), Sec.OriginalData.end(), Buf);
  return;
}

if (Sec.CompressionType == DebugCompressionType::GNU) {
  const char *Magic = "ZLIB";
  memcpy(Buf, Magic, strlen(Magic));
  Buf += strlen(Magic);
  const uint64_t DecompressedSize =
      support::endian::read64be(&Sec.DecompressedSize);
  memcpy(Buf, &DecompressedSize, sizeof(DecompressedSize));
  Buf += sizeof(DecompressedSize);
} else {
  Elf_Chdr_Impl<ELFT> Chdr;
  Chdr.ch_type = ELF::ELFCOMPRESS_ZLIB;
  Chdr.ch_size = Sec.DecompressedSize;
  Chdr.ch_addralign = Sec.DecompressedAlign;
  memcpy(Buf, &Chdr, sizeof(Chdr));
  Buf += sizeof(Chdr);
}

std::copy(Sec.CompressedData.begin(), Sec.CompressedData.end(), Buf);
203}

205CompressedSection::CompressedSection(const SectionBase &Sec,
                                   DebugCompressionType CompressionType)
  : SectionBase(Sec), CompressionType(CompressionType),
    DecompressedSize(Sec.OriginalData.size()), DecompressedAlign(Sec.Align) {

if (!zlib::isAvailable()) {
  CompressionType = DebugCompressionType::None;
  return;
}

if (Error E = zlib::compress(
        StringRef(reinterpret_cast<const char *>(OriginalData.data()),
                  OriginalData.size()),
        CompressedData))
  reportError(Name, std::move(E));

size_t ChdrSize;
if (CompressionType == DebugCompressionType::GNU) {
  Name = ".z" + Sec.Name.substr(1);
  ChdrSize = sizeof("ZLIB") - 1 + sizeof(uint64_t);
} else {
  Flags |= ELF::SHF_COMPRESSED;
  ChdrSize =
      std::max(std::max(sizeof(object::Elf_Chdr_Impl<object::ELF64LE>),
                        sizeof(object::Elf_Chdr_Impl<object::ELF64BE>)),
               std::max(sizeof(object::Elf_Chdr_Impl<object::ELF32LE>),
                        sizeof(object::Elf_Chdr_Impl<object::ELF32BE>)));
}
Size = ChdrSize + CompressedData.size();
Align = 8;
235}

237CompressedSection::CompressedSection(ArrayRef<uint8_t> CompressedData,
                                   uint64_t DecompressedSize,
                                   uint64_t DecompressedAlign)
  : CompressionType(DebugCompressionType::None),
    DecompressedSize(DecompressedSize), DecompressedAlign(DecompressedAlign) {
OriginalData = CompressedData;
243}

245void CompressedSection::accept(SectionVisitor &Visitor) const {
Visitor.visit(*this);
247}

249void StringTableSection::addString(StringRef Name) {
StrTabBuilder.add(Name);
Size = StrTabBuilder.getSize();
252}

254uint32_t StringTableSection::findIndex(StringRef Name) const {
return StrTabBuilder.getOffset(Name);
256}

258void StringTableSection::finalize() { StrTabBuilder.finalize(); }

260void SectionWriter::visit(const StringTableSection &Sec) {
Sec.StrTabBuilder.write(Out.getBufferStart() + Sec.Offset);
262}

264void StringTableSection::accept(SectionVisitor &Visitor) const {
Visitor.visit(*this);
266}

268template <class ELFT>
269void ELFSectionWriter<ELFT>::visit(const SectionIndexSection &Sec) {
uint8_t *Buf = Out.getBufferStart() + Sec.Offset;
auto *IndexesBuffer = reinterpret_cast<Elf_Word *>(Buf);
std::copy(std::begin(Sec.Indexes), std::end(Sec.Indexes), IndexesBuffer);
273}

275void SectionIndexSection::initialize(SectionTableRef SecTable) {
Size = 0;
setSymTab(SecTable.getSectionOfType<SymbolTableSection>(
    Link,
    "Link field value " + Twine(Link) + " in section " + Name + " is invalid",
    "Link field value " + Twine(Link) + " in section " + Name +
        " is not a symbol table"));
Symbols->setShndxTable(this);
283}

285void SectionIndexSection::finalize() { Link = Symbols->Index; }

287void SectionIndexSection::accept(SectionVisitor &Visitor) const {
Visitor.visit(*this);
289}

291static bool isValidReservedSectionIndex(uint16_t Index, uint16_t Machine) {
switch (Index) {
case SHN_ABS:
case SHN_COMMON:
  return true;
}
if (Machine == EM_HEXAGON) {
  switch (Index) {
  case SHN_HEXAGON_SCOMMON:
  case SHN_HEXAGON_SCOMMON_2:
  case SHN_HEXAGON_SCOMMON_4:
  case SHN_HEXAGON_SCOMMON_8:
    return true;
  }
}
return false;
307}

309// Large indexes force us to clarify exactly what this function should do. This
310// function should return the value that will appear in st_shndx when written
311// out.
312uint16_t Symbol::getShndx() const {
if (DefinedIn != nullptr) {
  if (DefinedIn->Index >= SHN_LORESERVE)
    return SHN_XINDEX;
  return DefinedIn->Index;
}
switch (ShndxType) {
// This means that we don't have a defined section but we do need to
// output a legitimate section index.
case SYMBOL_SIMPLE_INDEX:
  return SHN_UNDEF;
case SYMBOL_ABS:
case SYMBOL_COMMON:
case SYMBOL_HEXAGON_SCOMMON:
case SYMBOL_HEXAGON_SCOMMON_2:
case SYMBOL_HEXAGON_SCOMMON_4:
case SYMBOL_HEXAGON_SCOMMON_8:
case SYMBOL_XINDEX:
  return static_cast<uint16_t>(ShndxType);
}
llvm_unreachable("Symbol with invalid ShndxType encountered")::llvm::llvm_unreachable_internal("Symbol with invalid ShndxType encountered"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/llvm-objcopy/Object.cpp"
, 332);
333}

335void SymbolTableSection::assignIndices() {
uint32_t Index = 0;
for (auto &Sym : Symbols)
  Sym->Index = Index++;
339}

341void SymbolTableSection::addSymbol(Twine Name, uint8_t Bind, uint8_t Type,
                                 SectionBase *DefinedIn, uint64_t Value,
                                 uint8_t Visibility, uint16_t Shndx,
                                 uint64_t Size) {
Symbol Sym;
Sym.Name = Name.str();
Sym.Binding = Bind;
Sym.Type = Type;
Sym.DefinedIn = DefinedIn;
if (DefinedIn != nullptr)
  DefinedIn->HasSymbol = true;
if (DefinedIn == nullptr) {
  if (Shndx >= SHN_LORESERVE)
    Sym.ShndxType = static_cast<SymbolShndxType>(Shndx);
  else
    Sym.ShndxType = SYMBOL_SIMPLE_INDEX;
}
Sym.Value = Value;
Sym.Visibility = Visibility;
Sym.Size = Size;
Sym.Index = Symbols.size();
Symbols.emplace_back(llvm::make_unique<Symbol>(Sym));
Size += this->EntrySize;
364}

366void SymbolTableSection::removeSectionReferences(const SectionBase *Sec) {
if (SectionIndexTable == Sec)
  SectionIndexTable = nullptr;
if (SymbolNames == Sec) {
  error("String table " + SymbolNames->Name +
        " cannot be removed because it is referenced by the symbol table " +
        this->Name);
}
removeSymbols([Sec](const Symbol &Sym) { return Sym.DefinedIn == Sec; });
375}

377void SymbolTableSection::updateSymbols(function_ref<void(Symbol &)> Callable) {
std::for_each(std::begin(Symbols) + 1, std::end(Symbols),
              [Callable](SymPtr &Sym) { Callable(*Sym); });
std::stable_partition(
    std::begin(Symbols), std::end(Symbols),
    [](const SymPtr &Sym) { return Sym->Binding == STB_LOCAL; });
assignIndices();
384}

386void SymbolTableSection::removeSymbols(
  function_ref<bool(const Symbol &)> ToRemove) {
Symbols.erase(
    std::remove_if(std::begin(Symbols) + 1, std::end(Symbols),
                   [ToRemove](const SymPtr &Sym) { return ToRemove(*Sym); }),
    std::end(Symbols));
Size = Symbols.size() * EntrySize;
assignIndices();
394}

396void SymbolTableSection::initialize(SectionTableRef SecTable) {
Size = 0;
setStrTab(SecTable.getSectionOfType<StringTableSection>(
    Link,
    "Symbol table has link index of " + Twine(Link) +
        " which is not a valid index",
    "Symbol table has link index of " + Twine(Link) +
        " which is not a string table"));
404}

406void SymbolTableSection::finalize() {
// Make sure SymbolNames is finalized before getting name indexes.
SymbolNames->finalize();

uint32_t MaxLocalIndex = 0;
for (auto &Sym : Symbols) {
  Sym->NameIndex = SymbolNames->findIndex(Sym->Name);
  if (Sym->Binding == STB_LOCAL)
    MaxLocalIndex = std::max(MaxLocalIndex, Sym->Index);
}
// Now we need to set the Link and Info fields.
Link = SymbolNames->Index;
Info = MaxLocalIndex + 1;
419}

421void SymbolTableSection::prepareForLayout() {
// Add all potential section indexes before file layout so that the section
// index section has the approprite size.
if (SectionIndexTable != nullptr) {
  for (const auto &Sym : Symbols) {
    if (Sym->DefinedIn != nullptr && Sym->DefinedIn->Index >= SHN_LORESERVE)
      SectionIndexTable->addIndex(Sym->DefinedIn->Index);
    else
      SectionIndexTable->addIndex(SHN_UNDEF);
  }
}
// Add all of our strings to SymbolNames so that SymbolNames has the right
// size before layout is decided.
for (auto &Sym : Symbols)
  SymbolNames->addString(Sym->Name);
436}

438const Symbol *SymbolTableSection::getSymbolByIndex(uint32_t Index) const {
if (Symbols.size() <= Index)
  error("Invalid symbol index: " + Twine(Index));
return Symbols[Index].get();
442}

444Symbol *SymbolTableSection::getSymbolByIndex(uint32_t Index) {
return const_cast<Symbol *>(
    static_cast<const SymbolTableSection *>(this)->getSymbolByIndex(Index));
447}

449template <class ELFT>
450void ELFSectionWriter<ELFT>::visit(const SymbolTableSection &Sec) {
uint8_t *Buf = Out.getBufferStart();
Buf += Sec.Offset;
Elf_Sym *Sym = reinterpret_cast<Elf_Sym *>(Buf);
// Loop though symbols setting each entry of the symbol table.
for (auto &Symbol : Sec.Symbols) {
  Sym->st_name = Symbol->NameIndex;
  Sym->st_value = Symbol->Value;
  Sym->st_size = Symbol->Size;
  Sym->st_other = Symbol->Visibility;
  Sym->setBinding(Symbol->Binding);
  Sym->setType(Symbol->Type);
  Sym->st_shndx = Symbol->getShndx();
  ++Sym;
}
465}

467void SymbolTableSection::accept(SectionVisitor &Visitor) const {
Visitor.visit(*this);
469}

471template <class SymTabType>
472void RelocSectionWithSymtabBase<SymTabType>::removeSectionReferences(
  const SectionBase *Sec) {
if (Symbols == Sec) {
  error("Symbol table " + Symbols->Name +
        " cannot be removed because it is "
        "referenced by the relocation "
        "section " +
        this->Name);
}
481}

483template <class SymTabType>
484void RelocSectionWithSymtabBase<SymTabType>::initialize(
  SectionTableRef SecTable) {
if (Link != SHN_UNDEF)
  setSymTab(SecTable.getSectionOfType<SymTabType>(
      Link,
      "Link field value " + Twine(Link) + " in section " + Name +
          " is invalid",
      "Link field value " + Twine(Link) + " in section " + Name +
          " is not a symbol table"));

if (Info != SHN_UNDEF)
  setSection(SecTable.getSection(Info, "Info field value " + Twine(Info) +
                                           " in section " + Name +
                                           " is invalid"));
else
  setSection(nullptr);
500}

502template <class SymTabType>
503void RelocSectionWithSymtabBase<SymTabType>::finalize() {
this->Link = Symbols ? Symbols->Index : 0;

if (SecToApplyRel != nullptr)
  this->Info = SecToApplyRel->Index;
508}

510template <class ELFT>
511static void setAddend(Elf_Rel_Impl<ELFT, false> &Rel, uint64_t Addend) {}

513template <class ELFT>
514static void setAddend(Elf_Rel_Impl<ELFT, true> &Rela, uint64_t Addend) {
Rela.r_addend = Addend;
516}

518template <class RelRange, class T>
519static void writeRel(const RelRange &Relocations, T *Buf) {
for (const auto &Reloc : Relocations) {
  Buf->r_offset = Reloc.Offset;
  setAddend(*Buf, Reloc.Addend);
  Buf->setSymbolAndType(Reloc.RelocSymbol->Index, Reloc.Type, false);
  ++Buf;
}
526}

528template <class ELFT>
529void ELFSectionWriter<ELFT>::visit(const RelocationSection &Sec) {
uint8_t *Buf = Out.getBufferStart() + Sec.Offset;
if (Sec.Type == SHT_REL)
  writeRel(Sec.Relocations, reinterpret_cast<Elf_Rel *>(Buf));
else
  writeRel(Sec.Relocations, reinterpret_cast<Elf_Rela *>(Buf));
535}

537void RelocationSection::accept(SectionVisitor &Visitor) const {
Visitor.visit(*this);
539}

541void RelocationSection::removeSymbols(
  function_ref<bool(const Symbol &)> ToRemove) {
for (const Relocation &Reloc : Relocations)
  if (ToRemove(*Reloc.RelocSymbol))
    error("not stripping symbol '" + Reloc.RelocSymbol->Name +
          "' because it is named in a relocation");
547}

549void RelocationSection::markSymbols() {
for (const Relocation &Reloc : Relocations)
  Reloc.RelocSymbol->Referenced = true;
552}

554void SectionWriter::visit(const DynamicRelocationSection &Sec) {
std::copy(std::begin(Sec.Contents), std::end(Sec.Contents),
          Out.getBufferStart() + Sec.Offset);
557}

559void DynamicRelocationSection::accept(SectionVisitor &Visitor) const {
Visitor.visit(*this);
561}

563void Section::removeSectionReferences(const SectionBase *Sec) {
if (LinkSection == Sec) {
  error("Section " + LinkSection->Name +
        " cannot be removed because it is "
        "referenced by the section " +
        this->Name);
}
570}

572void GroupSection::finalize() {
this->Info = Sym->Index;
this->Link = SymTab->Index;
575}

577void GroupSection::removeSymbols(function_ref<bool(const Symbol &)> ToRemove) {
if (ToRemove(*Sym)) {
  error("Symbol " + Sym->Name +
        " cannot be removed because it is "
        "referenced by the section " +
        this->Name + "[" + Twine(this->Index) + "]");
}
584}

586void GroupSection::markSymbols() {
if (Sym)
  Sym->Referenced = true;
589}

591void Section::initialize(SectionTableRef SecTable) {
if (Link != ELF::SHN_UNDEF) {
  LinkSection =
      SecTable.getSection(Link, "Link field value " + Twine(Link) +
                                    " in section " + Name + " is invalid");
  if (LinkSection->Type == ELF::SHT_SYMTAB)
    LinkSection = nullptr;
}
599}

601void Section::finalize() { this->Link = LinkSection ? LinkSection->Index : 0; }

603void GnuDebugLinkSection::init(StringRef File, StringRef Data) {
FileName = sys::path::filename(File);
// The format for the .gnu_debuglink starts with the file name and is
// followed by a null terminator and then the CRC32 of the file. The CRC32
// should be 4 byte aligned. So we add the FileName size, a 1 for the null
// byte, and then finally push the size to alignment and add 4.
Size = alignTo(FileName.size() + 1, 4) + 4;
// The CRC32 will only be aligned if we align the whole section.
Align = 4;
Type = ELF::SHT_PROGBITS;
Name = ".gnu_debuglink";
// For sections not found in segments, OriginalOffset is only used to
// establish the order that sections should go in. By using the maximum
// possible offset we cause this section to wind up at the end.
OriginalOffset = std::numeric_limits<uint64_t>::max();
JamCRC crc;
crc.update(ArrayRef<char>(Data.data(), Data.size()));
// The CRC32 value needs to be complemented because the JamCRC dosn't
// finalize the CRC32 value. It also dosn't negate the initial CRC32 value
// but it starts by default at 0xFFFFFFFF which is the complement of zero.
CRC32 = ~crc.getCRC();
624}

626GnuDebugLinkSection::GnuDebugLinkSection(StringRef File) : FileName(File) {
// Read in the file to compute the CRC of it.
auto DebugOrErr = MemoryBuffer::getFile(File);
if (!DebugOrErr)
  error("'" + File + "': " + DebugOrErr.getError().message());
auto Debug = std::move(*DebugOrErr);
init(File, Debug->getBuffer());
633}

635template <class ELFT>
636void ELFSectionWriter<ELFT>::visit(const GnuDebugLinkSection &Sec) {
auto Buf = Out.getBufferStart() + Sec.Offset;
char *File = reinterpret_cast<char *>(Buf);
Elf_Word *CRC =
    reinterpret_cast<Elf_Word *>(Buf + Sec.Size - sizeof(Elf_Word));
*CRC = Sec.CRC32;
std::copy(std::begin(Sec.FileName), std::end(Sec.FileName), File);
643}

645void GnuDebugLinkSection::accept(SectionVisitor &Visitor) const {
Visitor.visit(*this);
647}

649template <class ELFT>
650void ELFSectionWriter<ELFT>::visit(const GroupSection &Sec) {
ELF::Elf32_Word *Buf =
    reinterpret_cast<ELF::Elf32_Word *>(Out.getBufferStart() + Sec.Offset);
*Buf++ = Sec.FlagWord;
for (const auto *S : Sec.GroupMembers)
  support::endian::write32<ELFT::TargetEndianness>(Buf++, S->Index);
656}

658void GroupSection::accept(SectionVisitor &Visitor) const {
Visitor.visit(*this);
660}

662// Returns true IFF a section is wholly inside the range of a segment
663static bool sectionWithinSegment(const SectionBase &Section,
                               const Segment &Segment) {
// If a section is empty it should be treated like it has a size of 1. This is
// to clarify the case when an empty section lies on a boundary between two
// segments and ensures that the section "belongs" to the second segment and
// not the first.
uint64_t SecSize = Section.Size ? Section.Size : 1;
return Segment.Offset <= Section.OriginalOffset &&
       Segment.Offset + Segment.FileSize >= Section.OriginalOffset + SecSize;
672}

674// Returns true IFF a segment's original offset is inside of another segment's
675// range.
676static bool segmentOverlapsSegment(const Segment &Child,
                                 const Segment &Parent) {

return Parent.OriginalOffset <= Child.OriginalOffset &&
       Parent.OriginalOffset + Parent.FileSize > Child.OriginalOffset;
681}

683static bool compareSegmentsByOffset(const Segment *A, const Segment *B) {
// Any segment without a parent segment should come before a segment
// that has a parent segment.
if (A->OriginalOffset < B->OriginalOffset)
  return true;
if (A->OriginalOffset > B->OriginalOffset)
  return false;
return A->Index < B->Index;
691}

693static bool compareSegmentsByPAddr(const Segment *A, const Segment *B) {
if (A->PAddr < B->PAddr)
  return true;
if (A->PAddr > B->PAddr)
  return false;
return A->Index < B->Index;
699}

701template <class ELFT> void BinaryELFBuilder<ELFT>::initFileHeader() {
Obj->Flags = 0x0;
Obj->Type = ET_REL;
Obj->Entry = 0x0;
Obj->Machine = EMachine;
Obj->Version = 1;
707}

709template <class ELFT> void BinaryELFBuilder<ELFT>::initHeaderSegment() {
Obj->ElfHdrSegment.Index = 0;
711}

713template <class ELFT> StringTableSection *BinaryELFBuilder<ELFT>::addStrTab() {
auto &StrTab = Obj->addSection<StringTableSection>();
StrTab.Name = ".strtab";

Obj->SectionNames = &StrTab;
return &StrTab;
719}

721template <class ELFT>
722SymbolTableSection *
723BinaryELFBuilder<ELFT>::addSymTab(StringTableSection *StrTab) {
auto &SymTab = Obj->addSection<SymbolTableSection>();

SymTab.Name = ".symtab";
SymTab.Link = StrTab->Index;
// TODO: Factor out dependence on ElfType here.
SymTab.EntrySize = sizeof(Elf_Sym);

// The symbol table always needs a null symbol
SymTab.addSymbol("", 0, 0, nullptr, 0, 0, 0, 0);

Obj->SymbolTable = &SymTab;
return &SymTab;
736}

738template <class ELFT>
739void BinaryELFBuilder<ELFT>::addData(SymbolTableSection *SymTab) {
auto Data = ArrayRef<uint8_t>(
    reinterpret_cast<const uint8_t *>(MemBuf->getBufferStart()),
    MemBuf->getBufferSize());
auto &DataSection = Obj->addSection<Section>(Data);
DataSection.Name = ".data";
DataSection.Type = ELF::SHT_PROGBITS;
DataSection.Size = Data.size();
DataSection.Flags = ELF::SHF_ALLOC | ELF::SHF_WRITE;

std::string SanitizedFilename = MemBuf->getBufferIdentifier().str();
std::replace_if(std::begin(SanitizedFilename), std::end(SanitizedFilename),
                [](char c) { return !isalnum(c); }, '_');
Twine Prefix = Twine("_binary_") + SanitizedFilename;

SymTab->addSymbol(Prefix + "_start", STB_GLOBAL, STT_NOTYPE, &DataSection,
                  /*Value=*/0, STV_DEFAULT, 0, 0);
SymTab->addSymbol(Prefix + "_end", STB_GLOBAL, STT_NOTYPE, &DataSection,
                  /*Value=*/DataSection.Size, STV_DEFAULT, 0, 0);
SymTab->addSymbol(Prefix + "_size", STB_GLOBAL, STT_NOTYPE, nullptr,
                  /*Value=*/DataSection.Size, STV_DEFAULT, SHN_ABS, 0);
760}

762template <class ELFT> void BinaryELFBuilder<ELFT>::initSections() {
for (auto &Section : Obj->sections()) {
  Section.initialize(Obj->sections());
}
766}

768template <class ELFT> std::unique_ptr<Object> BinaryELFBuilder<ELFT>::build() {
initFileHeader();
initHeaderSegment();
StringTableSection *StrTab = addStrTab();
SymbolTableSection *SymTab = addSymTab(StrTab);
initSections();
addData(SymTab);

return std::move(Obj);
777}

779template <class ELFT> void ELFBuilder<ELFT>::setParentSegment(Segment &Child) {
for (auto &Parent : Obj.segments()) {
  // Every segment will overlap with itself but we don't want a segment to
  // be it's own parent so we avoid that situation.
  if (&Child != &Parent && segmentOverlapsSegment(Child, Parent)) {
    // We want a canonical "most parental" segment but this requires
    // inspecting the ParentSegment.
    if (compareSegmentsByOffset(&Parent, &Child))
      if (Child.ParentSegment == nullptr ||
          compareSegmentsByOffset(&Parent, Child.ParentSegment)) {
        Child.ParentSegment = &Parent;
      }
  }
}
793}

795template <class ELFT> void ELFBuilder<ELFT>::readProgramHeaders() {
uint32_t Index = 0;
for (const auto &Phdr : unwrapOrError(ElfFile.program_headers())) {
  ArrayRef<uint8_t> Data{ElfFile.base() + Phdr.p_offset,
                         (size_t)Phdr.p_filesz};
  Segment &Seg = Obj.addSegment(Data);
  Seg.Type = Phdr.p_type;
  Seg.Flags = Phdr.p_flags;
  Seg.OriginalOffset = Phdr.p_offset;
  Seg.Offset = Phdr.p_offset;
  Seg.VAddr = Phdr.p_vaddr;
  Seg.PAddr = Phdr.p_paddr;
  Seg.FileSize = Phdr.p_filesz;
  Seg.MemSize = Phdr.p_memsz;
  Seg.Align = Phdr.p_align;
  Seg.Index = Index++;
  for (auto &Section : Obj.sections()) {
    if (sectionWithinSegment(Section, Seg)) {
      Seg.addSection(&Section);
      if (!Section.ParentSegment ||
          Section.ParentSegment->Offset > Seg.Offset) {
        Section.ParentSegment = &Seg;
      }
    }
  }
}

auto &ElfHdr = Obj.ElfHdrSegment;
ElfHdr.Index = Index++;

const auto &Ehdr = *ElfFile.getHeader();
auto &PrHdr = Obj.ProgramHdrSegment;
PrHdr.Type = PT_PHDR;
PrHdr.Flags = 0;
// The spec requires us to have p_vaddr % p_align == p_offset % p_align.
// Whereas this works automatically for ElfHdr, here OriginalOffset is
// always non-zero and to ensure the equation we assign the same value to
// VAddr as well.
PrHdr.OriginalOffset = PrHdr.Offset = PrHdr.VAddr = Ehdr.e_phoff;
PrHdr.PAddr = 0;
PrHdr.FileSize = PrHdr.MemSize = Ehdr.e_phentsize * Ehdr.e_phnum;
// The spec requires us to naturally align all the fields.
PrHdr.Align = sizeof(Elf_Addr);
PrHdr.Index = Index++;

// Now we do an O(n^2) loop through the segments in order to match up
// segments.
for (auto &Child : Obj.segments())
  setParentSegment(Child);
setParentSegment(ElfHdr);
setParentSegment(PrHdr);
846}

848template <class ELFT>
849void ELFBuilder<ELFT>::initGroupSection(GroupSection *GroupSec) {
auto SecTable = Obj.sections();
auto SymTab = SecTable.template getSectionOfType<SymbolTableSection>(
    GroupSec->Link,
    "Link field value " + Twine(GroupSec->Link) + " in section " +
        GroupSec->Name + " is invalid",
    "Link field value " + Twine(GroupSec->Link) + " in section " +
        GroupSec->Name + " is not a symbol table");
auto Sym = SymTab->getSymbolByIndex(GroupSec->Info);
if (!Sym)
  error("Info field value " + Twine(GroupSec->Info) + " in section " +
        GroupSec->Name + " is not a valid symbol index");
GroupSec->setSymTab(SymTab);
GroupSec->setSymbol(Sym);
if (GroupSec->Contents.size() % sizeof(ELF::Elf32_Word) ||
    GroupSec->Contents.empty())
  error("The content of the section " + GroupSec->Name + " is malformed");
const ELF::Elf32_Word *Word =
    reinterpret_cast<const ELF::Elf32_Word *>(GroupSec->Contents.data());
const ELF::Elf32_Word *End =
    Word + GroupSec->Contents.size() / sizeof(ELF::Elf32_Word);
GroupSec->setFlagWord(*Word++);
for (; Word != End; ++Word) {
  uint32_t Index = support::endian::read32<ELFT::TargetEndianness>(Word);
  GroupSec->addMember(SecTable.getSection(
      Index, "Group member index " + Twine(Index) + " in section " +
                 GroupSec->Name + " is invalid"));
}
877}

879template <class ELFT>
880void ELFBuilder<ELFT>::initSymbolTable(SymbolTableSection *SymTab) {
const Elf_Shdr &Shdr = *unwrapOrError(ElfFile.getSection(SymTab->Index));
StringRef StrTabData = unwrapOrError(ElfFile.getStringTableForSymtab(Shdr));
1
Calling 'ELFFile::getStringTableForSymtab'→
ArrayRef<Elf_Word> ShndxData;

auto Symbols = unwrapOrError(ElfFile.symbols(&Shdr));
for (const auto &Sym : Symbols) {
  SectionBase *DefSection = nullptr;
  StringRef Name = unwrapOrError(Sym.getName(StrTabData));

  if (Sym.st_shndx == SHN_XINDEX) {
    if (SymTab->getShndxTable() == nullptr)
      error("Symbol '" + Name +
            "' has index SHN_XINDEX but no SHT_SYMTAB_SHNDX section exists.");
    if (ShndxData.data() == nullptr) {
      const Elf_Shdr &ShndxSec =
          *unwrapOrError(ElfFile.getSection(SymTab->getShndxTable()->Index));
      ShndxData = unwrapOrError(
          ElfFile.template getSectionContentsAsArray<Elf_Word>(&ShndxSec));
      if (ShndxData.size() != Symbols.size())
        error("Symbol section index table does not have the same number of "
              "entries as the symbol table.");
    }
    Elf_Word Index = ShndxData[&Sym - Symbols.begin()];
    DefSection = Obj.sections().getSection(
        Index,
        "Symbol '" + Name + "' has invalid section index " + Twine(Index));
  } else if (Sym.st_shndx >= SHN_LORESERVE) {
    if (!isValidReservedSectionIndex(Sym.st_shndx, Obj.Machine)) {
      error(
          "Symbol '" + Name +
          "' has unsupported value greater than or equal to SHN_LORESERVE: " +
          Twine(Sym.st_shndx));
    }
  } else if (Sym.st_shndx != SHN_UNDEF) {
    DefSection = Obj.sections().getSection(
        Sym.st_shndx, "Symbol '" + Name +
                          "' is defined has invalid section index " +
                          Twine(Sym.st_shndx));
  }

  SymTab->addSymbol(Name, Sym.getBinding(), Sym.getType(), DefSection,
                    Sym.getValue(), Sym.st_other, Sym.st_shndx, Sym.st_size);
}
924}

926template <class ELFT>
927static void getAddend(uint64_t &ToSet, const Elf_Rel_Impl<ELFT, false> &Rel) {}

929template <class ELFT>
930static void getAddend(uint64_t &ToSet, const Elf_Rel_Impl<ELFT, true> &Rela) {
ToSet = Rela.r_addend;
932}

934template <class T>
935static void initRelocations(RelocationSection *Relocs,
                          SymbolTableSection *SymbolTable, T RelRange) {
for (const auto &Rel : RelRange) {
  Relocation ToAdd;
  ToAdd.Offset = Rel.r_offset;
  getAddend(ToAdd.Addend, Rel);
  ToAdd.Type = Rel.getType(false);
  ToAdd.RelocSymbol = SymbolTable->getSymbolByIndex(Rel.getSymbol(false));
  Relocs->addRelocation(ToAdd);
}
945}

947SectionBase *SectionTableRef::getSection(uint32_t Index, Twine ErrMsg) {
if (Index == SHN_UNDEF || Index > Sections.size())
  error(ErrMsg);
return Sections[Index - 1].get();
951}

953template <class T>
954T *SectionTableRef::getSectionOfType(uint32_t Index, Twine IndexErrMsg,
                                   Twine TypeErrMsg) {
if (T *Sec = dyn_cast<T>(getSection(Index, IndexErrMsg)))
  return Sec;
error(TypeErrMsg);
959}

961template <class ELFT>
962SectionBase &ELFBuilder<ELFT>::makeSection(const Elf_Shdr &Shdr) {
ArrayRef<uint8_t> Data;
switch (Shdr.sh_type) {
case SHT_REL:
case SHT_RELA:
  if (Shdr.sh_flags & SHF_ALLOC) {
    Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
    return Obj.addSection<DynamicRelocationSection>(Data);
  }
  return Obj.addSection<RelocationSection>();
case SHT_STRTAB:
  // If a string table is allocated we don't want to mess with it. That would
  // mean altering the memory image. There are no special link types or
  // anything so we can just use a Section.
  if (Shdr.sh_flags & SHF_ALLOC) {
    Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
    return Obj.addSection<Section>(Data);
  }
  return Obj.addSection<StringTableSection>();
case SHT_HASH:
case SHT_GNU_HASH:
  // Hash tables should refer to SHT_DYNSYM which we're not going to change.
  // Because of this we don't need to mess with the hash tables either.
  Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
  return Obj.addSection<Section>(Data);
case SHT_GROUP:
  Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
  return Obj.addSection<GroupSection>(Data);
case SHT_DYNSYM:
  Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
  return Obj.addSection<DynamicSymbolTableSection>(Data);
case SHT_DYNAMIC:
  Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
  return Obj.addSection<DynamicSection>(Data);
case SHT_SYMTAB: {
  auto &SymTab = Obj.addSection<SymbolTableSection>();
  Obj.SymbolTable = &SymTab;
  return SymTab;
}
case SHT_SYMTAB_SHNDX: {
  auto &ShndxSection = Obj.addSection<SectionIndexSection>();
  Obj.SectionIndexTable = &ShndxSection;
  return ShndxSection;
}
case SHT_NOBITS:
  return Obj.addSection<Section>(Data);
default: {
  Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));

  if (isDataGnuCompressed(Data) || (Shdr.sh_flags & ELF::SHF_COMPRESSED)) {
    uint64_t DecompressedSize, DecompressedAlign;
    std::tie(DecompressedSize, DecompressedAlign) =
        getDecompressedSizeAndAlignment<ELFT>(Data);
    return Obj.addSection<CompressedSection>(Data, DecompressedSize,
                                             DecompressedAlign);
  }

  return Obj.addSection<Section>(Data);
}
}
1022}

1024template <class ELFT> void ELFBuilder<ELFT>::readSectionHeaders() {
uint32_t Index = 0;
for (const auto &Shdr : unwrapOrError(ElfFile.sections())) {
  if (Index == 0) {
    ++Index;
    continue;
  }
  auto &Sec = makeSection(Shdr);
  Sec.Name = unwrapOrError(ElfFile.getSectionName(&Shdr));
  Sec.Type = Shdr.sh_type;
  Sec.Flags = Shdr.sh_flags;
  Sec.Addr = Shdr.sh_addr;
  Sec.Offset = Shdr.sh_offset;
  Sec.OriginalOffset = Shdr.sh_offset;
  Sec.Size = Shdr.sh_size;
  Sec.Link = Shdr.sh_link;
  Sec.Info = Shdr.sh_info;
  Sec.Align = Shdr.sh_addralign;
  Sec.EntrySize = Shdr.sh_entsize;
  Sec.Index = Index++;
  Sec.OriginalData =
      ArrayRef<uint8_t>(ElfFile.base() + Shdr.sh_offset,
                        (Shdr.sh_type == SHT_NOBITS) ? 0 : Shdr.sh_size);
}

// If a section index table exists we'll need to initialize it before we
// initialize the symbol table because the symbol table might need to
// reference it.
if (Obj.SectionIndexTable)
  Obj.SectionIndexTable->initialize(Obj.sections());

// Now that all of the sections have been added we can fill out some extra
// details about symbol tables. We need the symbol table filled out before
// any relocations.
if (Obj.SymbolTable) {
  Obj.SymbolTable->initialize(Obj.sections());
  initSymbolTable(Obj.SymbolTable);
}

// Now that all sections and symbols have been added we can add
// relocations that reference symbols and set the link and info fields for
// relocation sections.
for (auto &Section : Obj.sections()) {
  if (&Section == Obj.SymbolTable)
    continue;
  Section.initialize(Obj.sections());
  if (auto RelSec = dyn_cast<RelocationSection>(&Section)) {
    auto Shdr = unwrapOrError(ElfFile.sections()).begin() + RelSec->Index;
    if (RelSec->Type == SHT_REL)
      initRelocations(RelSec, Obj.SymbolTable,
                      unwrapOrError(ElfFile.rels(Shdr)));
    else
      initRelocations(RelSec, Obj.SymbolTable,
                      unwrapOrError(ElfFile.relas(Shdr)));
  } else if (auto GroupSec = dyn_cast<GroupSection>(&Section)) {
    initGroupSection(GroupSec);
  }
}
1082}

1084template <class ELFT> void ELFBuilder<ELFT>::build() {
const auto &Ehdr = *ElfFile.getHeader();

Obj.Type = Ehdr.e_type;
Obj.Machine = Ehdr.e_machine;
Obj.Version = Ehdr.e_version;
Obj.Entry = Ehdr.e_entry;
Obj.Flags = Ehdr.e_flags;

readSectionHeaders();
readProgramHeaders();

uint32_t ShstrIndex = Ehdr.e_shstrndx;
if (ShstrIndex == SHN_XINDEX)
  ShstrIndex = unwrapOrError(ElfFile.getSection(0))->sh_link;

Obj.SectionNames =
    Obj.sections().template getSectionOfType<StringTableSection>(
        ShstrIndex,
        "e_shstrndx field value " + Twine(Ehdr.e_shstrndx) +
            " in elf header " + " is invalid",
        "e_shstrndx field value " + Twine(Ehdr.e_shstrndx) +
            " in elf header " + " is not a string table");
1107}

1109// A generic size function which computes sizes of any random access range.
1110template <class R> size_t size(R &&Range) {
return static_cast<size_t>(std::end(Range) - std::begin(Range));
1112}

1114Writer::~Writer() {}

1116Reader::~Reader() {}

1118std::unique_ptr<Object> BinaryReader::create() const {
if (MInfo.Is64Bit)
  return MInfo.IsLittleEndian
             ? BinaryELFBuilder<ELF64LE>(MInfo.EMachine, MemBuf).build()
             : BinaryELFBuilder<ELF64BE>(MInfo.EMachine, MemBuf).build();
else
  return MInfo.IsLittleEndian
             ? BinaryELFBuilder<ELF32LE>(MInfo.EMachine, MemBuf).build()
             : BinaryELFBuilder<ELF32BE>(MInfo.EMachine, MemBuf).build();
1127}

1129std::unique_ptr<Object> ELFReader::create() const {
auto Obj = llvm::make_unique<Object>();
if (auto *o = dyn_cast<ELFObjectFile<ELF32LE>>(Bin)) {
  ELFBuilder<ELF32LE> Builder(*o, *Obj);
  Builder.build();
  return Obj;
} else if (auto *o = dyn_cast<ELFObjectFile<ELF64LE>>(Bin)) {
  ELFBuilder<ELF64LE> Builder(*o, *Obj);
  Builder.build();
  return Obj;
} else if (auto *o = dyn_cast<ELFObjectFile<ELF32BE>>(Bin)) {
  ELFBuilder<ELF32BE> Builder(*o, *Obj);
  Builder.build();
  return Obj;
} else if (auto *o = dyn_cast<ELFObjectFile<ELF64BE>>(Bin)) {
  ELFBuilder<ELF64BE> Builder(*o, *Obj);
  Builder.build();
  return Obj;
}
error("Invalid file type");
1149}

1151template <class ELFT> void ELFWriter<ELFT>::writeEhdr() {
uint8_t *B = Buf.getBufferStart();
Elf_Ehdr &Ehdr = *reinterpret_cast<Elf_Ehdr *>(B);
std::fill(Ehdr.e_ident, Ehdr.e_ident + 16, 0);
Ehdr.e_ident[EI_MAG0] = 0x7f;
Ehdr.e_ident[EI_MAG1] = 'E';
Ehdr.e_ident[EI_MAG2] = 'L';
Ehdr.e_ident[EI_MAG3] = 'F';
Ehdr.e_ident[EI_CLASS] = ELFT::Is64Bits ? ELFCLASS64 : ELFCLASS32;
Ehdr.e_ident[EI_DATA] =
    ELFT::TargetEndianness == support::big ? ELFDATA2MSB : ELFDATA2LSB;
Ehdr.e_ident[EI_VERSION] = EV_CURRENT;
Ehdr.e_ident[EI_OSABI] = ELFOSABI_NONE;
Ehdr.e_ident[EI_ABIVERSION] = 0;

Ehdr.e_type = Obj.Type;
Ehdr.e_machine = Obj.Machine;
Ehdr.e_version = Obj.Version;
Ehdr.e_entry = Obj.Entry;
// We have to use the fully-qualified name llvm::size
// since some compilers complain on ambiguous resolution.
Ehdr.e_phnum = llvm::size(Obj.segments());
Ehdr.e_phoff = (Ehdr.e_phnum != 0) ? Obj.ProgramHdrSegment.Offset : 0;
Ehdr.e_phentsize = (Ehdr.e_phnum != 0) ? sizeof(Elf_Phdr) : 0;
Ehdr.e_flags = Obj.Flags;
Ehdr.e_ehsize = sizeof(Elf_Ehdr);
if (WriteSectionHeaders && size(Obj.sections()) != 0) {
  Ehdr.e_shentsize = sizeof(Elf_Shdr);
  Ehdr.e_shoff = Obj.SHOffset;
  // """
  // If the number of sections is greater than or equal to
  // SHN_LORESERVE (0xff00), this member has the value zero and the actual
  // number of section header table entries is contained in the sh_size field
  // of the section header at index 0.
  // """
  auto Shnum = size(Obj.sections()) + 1;
  if (Shnum >= SHN_LORESERVE)
    Ehdr.e_shnum = 0;
  else
    Ehdr.e_shnum = Shnum;
  // """
  // If the section name string table section index is greater than or equal
  // to SHN_LORESERVE (0xff00), this member has the value SHN_XINDEX (0xffff)
  // and the actual index of the section name string table section is
  // contained in the sh_link field of the section header at index 0.
  // """
  if (Obj.SectionNames->Index >= SHN_LORESERVE)
    Ehdr.e_shstrndx = SHN_XINDEX;
  else
    Ehdr.e_shstrndx = Obj.SectionNames->Index;
} else {
  Ehdr.e_shentsize = 0;
  Ehdr.e_shoff = 0;
  Ehdr.e_shnum = 0;
  Ehdr.e_shstrndx = 0;
}
1207}

1209template <class ELFT> void ELFWriter<ELFT>::writePhdrs() {
for (auto &Seg : Obj.segments())
  writePhdr(Seg);
1212}

1214template <class ELFT> void ELFWriter<ELFT>::writeShdrs() {
uint8_t *B = Buf.getBufferStart() + Obj.SHOffset;
// This reference serves to write the dummy section header at the begining
// of the file. It is not used for anything else
Elf_Shdr &Shdr = *reinterpret_cast<Elf_Shdr *>(B);
Shdr.sh_name = 0;
Shdr.sh_type = SHT_NULL;
Shdr.sh_flags = 0;
Shdr.sh_addr = 0;
Shdr.sh_offset = 0;
// See writeEhdr for why we do this.
uint64_t Shnum = size(Obj.sections()) + 1;
if (Shnum >= SHN_LORESERVE)
  Shdr.sh_size = Shnum;
else
  Shdr.sh_size = 0;
// See writeEhdr for why we do this.
if (Obj.SectionNames != nullptr && Obj.SectionNames->Index >= SHN_LORESERVE)
  Shdr.sh_link = Obj.SectionNames->Index;
else
  Shdr.sh_link = 0;
Shdr.sh_info = 0;
Shdr.sh_addralign = 0;
Shdr.sh_entsize = 0;

for (auto &Sec : Obj.sections())
  writeShdr(Sec);
1241}

1243template <class ELFT> void ELFWriter<ELFT>::writeSectionData() {
for (auto &Sec : Obj.sections())
  Sec.accept(*SecWriter);
1246}

1248void Object::removeSections(std::function<bool(const SectionBase &)> ToRemove) {

auto Iter = std::stable_partition(
    std::begin(Sections), std::end(Sections), [=](const SecPtr &Sec) {
      if (ToRemove(*Sec))
        return false;
      if (auto RelSec = dyn_cast<RelocationSectionBase>(Sec.get())) {
        if (auto ToRelSec = RelSec->getSection())
          return !ToRemove(*ToRelSec);
      }
      return true;
    });
if (SymbolTable != nullptr && ToRemove(*SymbolTable))
  SymbolTable = nullptr;
if (SectionNames != nullptr && ToRemove(*SectionNames))
  SectionNames = nullptr;
if (SectionIndexTable != nullptr && ToRemove(*SectionIndexTable))
  SectionIndexTable = nullptr;
// Now make sure there are no remaining references to the sections that will
// be removed. Sometimes it is impossible to remove a reference so we emit
// an error here instead.
for (auto &RemoveSec : make_range(Iter, std::end(Sections))) {
  for (auto &Segment : Segments)
    Segment->removeSection(RemoveSec.get());
  for (auto &KeepSec : make_range(std::begin(Sections), Iter))
    KeepSec->removeSectionReferences(RemoveSec.get());
}
// Now finally get rid of them all togethor.
Sections.erase(Iter, std::end(Sections));
1277}

1279void Object::removeSymbols(function_ref<bool(const Symbol &)> ToRemove) {
if (!SymbolTable)
  return;

for (const SecPtr &Sec : Sections)
  Sec->removeSymbols(ToRemove);
1285}

1287void Object::sortSections() {
// Put all sections in offset order. Maintain the ordering as closely as
// possible while meeting that demand however.
auto CompareSections = [](const SecPtr &A, const SecPtr &B) {
  return A->OriginalOffset < B->OriginalOffset;
};
std::stable_sort(std::begin(this->Sections), std::end(this->Sections),
                 CompareSections);
1295}

1297static uint64_t alignToAddr(uint64_t Offset, uint64_t Addr, uint64_t Align) {
// Calculate Diff such that (Offset + Diff) & -Align == Addr & -Align.
if (Align == 0)
  Align = 1;
auto Diff =
    static_cast<int64_t>(Addr % Align) - static_cast<int64_t>(Offset % Align);
// We only want to add to Offset, however, so if Diff < 0 we can add Align and
// (Offset + Diff) & -Align == Addr & -Align will still hold.
if (Diff < 0)
  Diff += Align;
return Offset + Diff;
1308}

1310// Orders segments such that if x = y->ParentSegment then y comes before x.
1311static void OrderSegments(std::vector<Segment *> &Segments) {
std::stable_sort(std::begin(Segments), std::end(Segments),
                 compareSegmentsByOffset);
1314}

1316// This function finds a consistent layout for a list of segments starting from
1317// an Offset. It assumes that Segments have been sorted by OrderSegments and
1318// returns an Offset one past the end of the last segment.
1319static uint64_t LayoutSegments(std::vector<Segment *> &Segments,
                             uint64_t Offset) {
assert(std::is_sorted(std::begin(Segments), std::end(Segments),((std::is_sorted(std::begin(Segments), std::end(Segments), compareSegmentsByOffset
)) ? static_cast<void> (0) : __assert_fail ("std::is_sorted(std::begin(Segments), std::end(Segments), compareSegmentsByOffset)"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/llvm-objcopy/Object.cpp"
, 1322, __PRETTY_FUNCTION__))
                      compareSegmentsByOffset))((std::is_sorted(std::begin(Segments), std::end(Segments), compareSegmentsByOffset
)) ? static_cast<void> (0) : __assert_fail ("std::is_sorted(std::begin(Segments), std::end(Segments), compareSegmentsByOffset)"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/llvm-objcopy/Object.cpp"
, 1322, __PRETTY_FUNCTION__));
// The only way a segment should move is if a section was between two
// segments and that section was removed. If that section isn't in a segment
// then it's acceptable, but not ideal, to simply move it to after the
// segments. So we can simply layout segments one after the other accounting
// for alignment.
for (auto &Segment : Segments) {
  // We assume that segments have been ordered by OriginalOffset and Index
  // such that a parent segment will always come before a child segment in
  // OrderedSegments. This means that the Offset of the ParentSegment should
  // already be set and we can set our offset relative to it.
  if (Segment->ParentSegment != nullptr) {
    auto Parent = Segment->ParentSegment;
    Segment->Offset =
        Parent->Offset + Segment->OriginalOffset - Parent->OriginalOffset;
  } else {
    Offset = alignToAddr(Offset, Segment->VAddr, Segment->Align);
    Segment->Offset = Offset;
  }
  Offset = std::max(Offset, Segment->Offset + Segment->FileSize);
}
return Offset;
1344}

1346// This function finds a consistent layout for a list of sections. It assumes
1347// that the ->ParentSegment of each section has already been laid out. The
1348// supplied starting Offset is used for the starting offset of any section that
1349// does not have a ParentSegment. It returns either the offset given if all
1350// sections had a ParentSegment or an offset one past the last section if there
1351// was a section that didn't have a ParentSegment.
1352template <class Range>
1353static uint64_t LayoutSections(Range Sections, uint64_t Offset) {
// Now the offset of every segment has been set we can assign the offsets
// of each section. For sections that are covered by a segment we should use
// the segment's original offset and the section's original offset to compute
// the offset from the start of the segment. Using the offset from the start
// of the segment we can assign a new offset to the section. For sections not
// covered by segments we can just bump Offset to the next valid location.
uint32_t Index = 1;
for (auto &Section : Sections) {
  Section.Index = Index++;
  if (Section.ParentSegment != nullptr) {
    auto Segment = *Section.ParentSegment;
    Section.Offset =
        Segment.Offset + (Section.OriginalOffset - Segment.OriginalOffset);
  } else {
    Offset = alignTo(Offset, Section.Align == 0 ? 1 : Section.Align);
    Section.Offset = Offset;
    if (Section.Type != SHT_NOBITS)
      Offset += Section.Size;
  }
}
return Offset;
1375}

1377template <class ELFT> void ELFWriter<ELFT>::initEhdrSegment() {
auto &ElfHdr = Obj.ElfHdrSegment;
ElfHdr.Type = PT_PHDR;
ElfHdr.Flags = 0;
ElfHdr.OriginalOffset = ElfHdr.Offset = 0;
ElfHdr.VAddr = 0;
ElfHdr.PAddr = 0;
ElfHdr.FileSize = ElfHdr.MemSize = sizeof(Elf_Ehdr);
ElfHdr.Align = 0;
1386}

1388template <class ELFT> void ELFWriter<ELFT>::assignOffsets() {
// We need a temporary list of segments that has a special order to it
// so that we know that anytime ->ParentSegment is set that segment has
// already had its offset properly set.
std::vector<Segment *> OrderedSegments;
for (auto &Segment : Obj.segments())
  OrderedSegments.push_back(&Segment);
OrderedSegments.push_back(&Obj.ElfHdrSegment);
OrderedSegments.push_back(&Obj.ProgramHdrSegment);
OrderSegments(OrderedSegments);
// Offset is used as the start offset of the first segment to be laid out.
// Since the ELF Header (ElfHdrSegment) must be at the start of the file,
// we start at offset 0.
uint64_t Offset = 0;
Offset = LayoutSegments(OrderedSegments, Offset);
Offset = LayoutSections(Obj.sections(), Offset);
// If we need to write the section header table out then we need to align the
// Offset so that SHOffset is valid.
if (WriteSectionHeaders)
  Offset = alignTo(Offset, sizeof(Elf_Addr));
Obj.SHOffset = Offset;
1409}

1411template <class ELFT> size_t ELFWriter<ELFT>::totalSize() const {
// We already have the section header offset so we can calculate the total
// size by just adding up the size of each section header.
auto NullSectionSize = WriteSectionHeaders ? sizeof(Elf_Shdr) : 0;
return Obj.SHOffset + size(Obj.sections()) * sizeof(Elf_Shdr) +
       NullSectionSize;
1417}

1419template <class ELFT> void ELFWriter<ELFT>::write() {
writeEhdr();
writePhdrs();
writeSectionData();
if (WriteSectionHeaders)
  writeShdrs();
if (auto E = Buf.commit())
  reportError(Buf.getName(), errorToErrorCode(std::move(E)));
1427}

1429template <class ELFT> void ELFWriter<ELFT>::finalize() {
// It could happen that SectionNames has been removed and yet the user wants
// a section header table output. We need to throw an error if a user tries
// to do that.
if (Obj.SectionNames == nullptr && WriteSectionHeaders)
  error("Cannot write section header table because section header string "
        "table was removed.");

Obj.sortSections();

// We need to assign indexes before we perform layout because we need to know
// if we need large indexes or not. We can assign indexes first and check as
// we go to see if we will actully need large indexes.
bool NeedsLargeIndexes = false;
if (size(Obj.sections()) >= SHN_LORESERVE) {
  auto Sections = Obj.sections();
  NeedsLargeIndexes =
      std::any_of(Sections.begin() + SHN_LORESERVE, Sections.end(),
                  [](const SectionBase &Sec) { return Sec.HasSymbol; });
  // TODO: handle case where only one section needs the large index table but
  // only needs it because the large index table hasn't been removed yet.
}

if (NeedsLargeIndexes) {
  // This means we definitely need to have a section index table but if we
  // already have one then we should use it instead of making a new one.
  if (Obj.SymbolTable != nullptr && Obj.SectionIndexTable == nullptr) {
    // Addition of a section to the end does not invalidate the indexes of
    // other sections and assigns the correct index to the new section.
    auto &Shndx = Obj.addSection<SectionIndexSection>();
    Obj.SymbolTable->setShndxTable(&Shndx);
    Shndx.setSymTab(Obj.SymbolTable);
  }
} else {
  // Since we don't need SectionIndexTable we should remove it and all
  // references to it.
  if (Obj.SectionIndexTable != nullptr) {
    Obj.removeSections([this](const SectionBase &Sec) {
      return &Sec == Obj.SectionIndexTable;
    });
  }
}

// Make sure we add the names of all the sections. Importantly this must be
// done after we decide to add or remove SectionIndexes.
if (Obj.SectionNames != nullptr)
  for (const auto &Section : Obj.sections()) {
    Obj.SectionNames->addString(Section.Name);
  }

initEhdrSegment();
// Before we can prepare for layout the indexes need to be finalized.
uint64_t Index = 0;
for (auto &Sec : Obj.sections())
  Sec.Index = Index++;

// The symbol table does not update all other sections on update. For
// instance, symbol names are not added as new symbols are added. This means
// that some sections, like .strtab, don't yet have their final size.
if (Obj.SymbolTable != nullptr)
  Obj.SymbolTable->prepareForLayout();

assignOffsets();

// Finalize SectionNames first so that we can assign name indexes.
if (Obj.SectionNames != nullptr)
  Obj.SectionNames->finalize();
// Finally now that all offsets and indexes have been set we can finalize any
// remaining issues.
uint64_t Offset = Obj.SHOffset + sizeof(Elf_Shdr);
for (auto &Section : Obj.sections()) {
  Section.HeaderOffset = Offset;
  Offset += sizeof(Elf_Shdr);
  if (WriteSectionHeaders)
    Section.NameIndex = Obj.SectionNames->findIndex(Section.Name);
  Section.finalize();
}

Buf.allocate(totalSize());
SecWriter = llvm::make_unique<ELFSectionWriter<ELFT>>(Buf);
1509}

1511void BinaryWriter::write() {
for (auto &Section : Obj.sections()) {
  if ((Section.Flags & SHF_ALLOC) == 0)
    continue;
  Section.accept(*SecWriter);
}
if (auto E = Buf.commit())
  reportError(Buf.getName(), errorToErrorCode(std::move(E)));
1519}

1521void BinaryWriter::finalize() {
// TODO: Create a filter range to construct OrderedSegments from so that this
// code can be deduped with assignOffsets above. This should also solve the
// todo below for LayoutSections.
// We need a temporary list of segments that has a special order to it
// so that we know that anytime ->ParentSegment is set that segment has
// already had it's offset properly set. We only want to consider the segments
// that will affect layout of allocated sections so we only add those.
std::vector<Segment *> OrderedSegments;
for (auto &Section : Obj.sections()) {
  if ((Section.Flags & SHF_ALLOC) != 0 && Section.ParentSegment != nullptr) {
    OrderedSegments.push_back(Section.ParentSegment);
  }
}

// For binary output, we're going to use physical addresses instead of
// virtual addresses, since a binary output is used for cases like ROM
// loading and physical addresses are intended for ROM loading.
// However, if no segment has a physical address, we'll fallback to using
// virtual addresses for all.
if (std::all_of(std::begin(OrderedSegments), std::end(OrderedSegments),
                [](const Segment *Segment) { return Segment->PAddr == 0; }))
  for (const auto &Segment : OrderedSegments)
    Segment->PAddr = Segment->VAddr;

std::stable_sort(std::begin(OrderedSegments), std::end(OrderedSegments),
                 compareSegmentsByPAddr);

// Because we add a ParentSegment for each section we might have duplicate
// segments in OrderedSegments. If there were duplicates then LayoutSegments
// would do very strange things.
auto End =
    std::unique(std::begin(OrderedSegments), std::end(OrderedSegments));
OrderedSegments.erase(End, std::end(OrderedSegments));

uint64_t Offset = 0;

// Modify the first segment so that there is no gap at the start. This allows
// our layout algorithm to proceed as expected while not out writing out the
// gap at the start.
if (!OrderedSegments.empty()) {
  auto Seg = OrderedSegments[0];
  auto Sec = Seg->firstSection();
  auto Diff = Sec->OriginalOffset - Seg->OriginalOffset;
  Seg->OriginalOffset += Diff;
  // The size needs to be shrunk as well.
  Seg->FileSize -= Diff;
  // The PAddr needs to be increased to remove the gap before the first
  // section.
  Seg->PAddr += Diff;
  uint64_t LowestPAddr = Seg->PAddr;
  for (auto &Segment : OrderedSegments) {
    Segment->Offset = Segment->PAddr - LowestPAddr;
    Offset = std::max(Offset, Segment->Offset + Segment->FileSize);
  }
}

// TODO: generalize LayoutSections to take a range. Pass a special range
// constructed from an iterator that skips values for which a predicate does
// not hold. Then pass such a range to LayoutSections instead of constructing
// AllocatedSections here.
std::vector<SectionBase *> AllocatedSections;
for (auto &Section : Obj.sections()) {
  if ((Section.Flags & SHF_ALLOC) == 0)
    continue;
  AllocatedSections.push_back(&Section);
}
LayoutSections(make_pointee_range(AllocatedSections), Offset);

// Now that every section has been laid out we just need to compute the total
// file size. This might not be the same as the offset returned by
// LayoutSections, because we want to truncate the last segment to the end of
// its last section, to match GNU objcopy's behaviour.
TotalSize = 0;
for (const auto &Section : AllocatedSections) {
  if (Section->Type != SHT_NOBITS)
    TotalSize = std::max(TotalSize, Section->Offset + Section->Size);
}

Buf.allocate(TotalSize);
SecWriter = llvm::make_unique<BinarySectionWriter>(Buf);
1602}

1604template class BinaryELFBuilder<ELF64LE>;
1605template class BinaryELFBuilder<ELF64BE>;
1606template class BinaryELFBuilder<ELF32LE>;
1607template class BinaryELFBuilder<ELF32BE>;

1609template class ELFBuilder<ELF64LE>;
1610template class ELFBuilder<ELF64BE>;
1611template class ELFBuilder<ELF32LE>;
1612template class ELFBuilder<ELF32BE>;

1614template class ELFWriter<ELF64LE>;
1615template class ELFWriter<ELF64BE>;
1616template class ELFWriter<ELF32LE>;
1617template class ELFWriter<ELF32BE>;

1619} // end namespace elf
1620} // end namespace objcopy
1621} // end namespace llvm

←

/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Object/ELF.h

→

1//===- ELF.h - ELF object file implementation -------------------*- 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// This file declares the ELFFile template class.
11//
12//===----------------------------------------------------------------------===//

14#ifndef LLVM_OBJECT_ELF_H
15#define LLVM_OBJECT_ELF_H

17#include "llvm/ADT/ArrayRef.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/ADT/StringRef.h"
20#include "llvm/BinaryFormat/ELF.h"
21#include "llvm/Object/ELFTypes.h"
22#include "llvm/Object/Error.h"
23#include "llvm/Support/Endian.h"
24#include "llvm/Support/Error.h"
25#include <cassert>
26#include <cstddef>
27#include <cstdint>
28#include <limits>
29#include <utility>

31namespace llvm {
32namespace object {

34StringRef getELFRelocationTypeName(uint32_t Machine, uint32_t Type);
35uint32_t getELFRelrRelocationType(uint32_t Machine);
36StringRef getELFSectionTypeName(uint32_t Machine, uint32_t Type);

38// Subclasses of ELFFile may need this for template instantiation
39inline std::pair<unsigned char, unsigned char>
40getElfArchType(StringRef Object) {
if (Object.size() < ELF::EI_NIDENT)
  return std::make_pair((uint8_t)ELF::ELFCLASSNONE,
                        (uint8_t)ELF::ELFDATANONE);
return std::make_pair((uint8_t)Object[ELF::EI_CLASS],
                      (uint8_t)Object[ELF::EI_DATA]);
46}

48static inline Error createError(StringRef Err) {
return make_error<StringError>(Err, object_error::parse_failed);
9
←
Calling 'make_error<llvm::StringError, llvm::StringRef &, llvm::object::object_error>'→
50}

52template <class ELFT>
53class ELFFile {
54public:
LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)using Elf_Addr = typename ELFT::Addr; using Elf_Off = typename
 ELFT::Off; using Elf_Half = typename ELFT::Half; using Elf_Word
 = typename ELFT::Word; using Elf_Sword = typename ELFT::Sword
; using Elf_Xword = typename ELFT::Xword; using Elf_Sxword = typename
 ELFT::Sxword;
using uintX_t = typename ELFT::uint;
using Elf_Ehdr = typename ELFT::Ehdr;
using Elf_Shdr = typename ELFT::Shdr;
using Elf_Sym = typename ELFT::Sym;
using Elf_Dyn = typename ELFT::Dyn;
using Elf_Phdr = typename ELFT::Phdr;
using Elf_Rel = typename ELFT::Rel;
using Elf_Rela = typename ELFT::Rela;
using Elf_Relr = typename ELFT::Relr;
using Elf_Verdef = typename ELFT::Verdef;
using Elf_Verdaux = typename ELFT::Verdaux;
using Elf_Verneed = typename ELFT::Verneed;
using Elf_Vernaux = typename ELFT::Vernaux;
using Elf_Versym = typename ELFT::Versym;
using Elf_Hash = typename ELFT::Hash;
using Elf_GnuHash = typename ELFT::GnuHash;
using Elf_Nhdr = typename ELFT::Nhdr;
using Elf_Note = typename ELFT::Note;
using Elf_Note_Iterator = typename ELFT::NoteIterator;
using Elf_Dyn_Range = typename ELFT::DynRange;
using Elf_Shdr_Range = typename ELFT::ShdrRange;
using Elf_Sym_Range = typename ELFT::SymRange;
using Elf_Rel_Range = typename ELFT::RelRange;
using Elf_Rela_Range = typename ELFT::RelaRange;
using Elf_Relr_Range = typename ELFT::RelrRange;
using Elf_Phdr_Range = typename ELFT::PhdrRange;

const uint8_t *base() const {
  return reinterpret_cast<const uint8_t *>(Buf.data());
}

size_t getBufSize() const { return Buf.size(); }

89private:
StringRef Buf;

ELFFile(StringRef Object);

94public:
const Elf_Ehdr *getHeader() const {
  return reinterpret_cast<const Elf_Ehdr *>(base());
}

template <typename T>
Expected<const T *> getEntry(uint32_t Section, uint32_t Entry) const;
template <typename T>
Expected<const T *> getEntry(const Elf_Shdr *Section, uint32_t Entry) const;

Expected<StringRef> getStringTable(const Elf_Shdr *Section) const;
Expected<StringRef> getStringTableForSymtab(const Elf_Shdr &Section) const;
Expected<StringRef> getStringTableForSymtab(const Elf_Shdr &Section,
                                            Elf_Shdr_Range Sections) const;

Expected<ArrayRef<Elf_Word>> getSHNDXTable(const Elf_Shdr &Section) const;
Expected<ArrayRef<Elf_Word>> getSHNDXTable(const Elf_Shdr &Section,
                                           Elf_Shdr_Range Sections) const;

StringRef getRelocationTypeName(uint32_t Type) const;
void getRelocationTypeName(uint32_t Type,
                           SmallVectorImpl<char> &Result) const;
uint32_t getRelrRelocationType() const;

const char *getDynamicTagAsString(unsigned Arch, uint64_t Type) const;
const char *getDynamicTagAsString(uint64_t Type) const;

/// Get the symbol for a given relocation.
Expected<const Elf_Sym *> getRelocationSymbol(const Elf_Rel *Rel,
                                              const Elf_Shdr *SymTab) const;

static Expected<ELFFile> create(StringRef Object);

bool isMipsELF64() const {
  return getHeader()->e_machine == ELF::EM_MIPS &&
         getHeader()->getFileClass() == ELF::ELFCLASS64;
}

bool isMips64EL() const {
  return isMipsELF64() &&
         getHeader()->getDataEncoding() == ELF::ELFDATA2LSB;
}

Expected<Elf_Shdr_Range> sections() const;

Expected<Elf_Dyn_Range> dynamicEntries() const;

Expected<const uint8_t *> toMappedAddr(uint64_t VAddr) const;

Expected<Elf_Sym_Range> symbols(const Elf_Shdr *Sec) const {
  if (!Sec)
    return makeArrayRef<Elf_Sym>(nullptr, nullptr);
  return getSectionContentsAsArray<Elf_Sym>(Sec);
}

Expected<Elf_Rela_Range> relas(const Elf_Shdr *Sec) const {
  return getSectionContentsAsArray<Elf_Rela>(Sec);
}

Expected<Elf_Rel_Range> rels(const Elf_Shdr *Sec) const {
  return getSectionContentsAsArray<Elf_Rel>(Sec);
}

Expected<Elf_Relr_Range> relrs(const Elf_Shdr *Sec) const {
  return getSectionContentsAsArray<Elf_Relr>(Sec);
}

Expected<std::vector<Elf_Rela>> decode_relrs(Elf_Relr_Range relrs) const;

Expected<std::vector<Elf_Rela>> android_relas(const Elf_Shdr *Sec) const;

/// Iterate over program header table.
Expected<Elf_Phdr_Range> program_headers() const {
  if (getHeader()->e_phnum && getHeader()->e_phentsize != sizeof(Elf_Phdr))
    return createError("invalid e_phentsize");
  if (getHeader()->e_phoff +
          (getHeader()->e_phnum * getHeader()->e_phentsize) >
      getBufSize())
    return createError("program headers longer than binary");
  auto *Begin =
      reinterpret_cast<const Elf_Phdr *>(base() + getHeader()->e_phoff);
  return makeArrayRef(Begin, Begin + getHeader()->e_phnum);
}

/// Get an iterator over notes in a program header.
///
/// The program header must be of type \c PT_NOTE.
///
/// \param Phdr the program header to iterate over.
/// \param Err [out] an error to support fallible iteration, which should
///  be checked after iteration ends.
Elf_Note_Iterator notes_begin(const Elf_Phdr &Phdr, Error &Err) const {
  if (Phdr.p_type != ELF::PT_NOTE) {
    Err = createError("attempt to iterate notes of non-note program header");
    return Elf_Note_Iterator(Err);
  }
  if (Phdr.p_offset + Phdr.p_filesz > getBufSize()) {
    Err = createError("invalid program header offset/size");
    return Elf_Note_Iterator(Err);
  }
  return Elf_Note_Iterator(base() + Phdr.p_offset, Phdr.p_filesz, Err);
}

/// Get an iterator over notes in a section.
///
/// The section must be of type \c SHT_NOTE.
///
/// \param Shdr the section to iterate over.
/// \param Err [out] an error to support fallible iteration, which should
///  be checked after iteration ends.
Elf_Note_Iterator notes_begin(const Elf_Shdr &Shdr, Error &Err) const {
  if (Shdr.sh_type != ELF::SHT_NOTE) {
    Err = createError("attempt to iterate notes of non-note section");
    return Elf_Note_Iterator(Err);
  }
  if (Shdr.sh_offset + Shdr.sh_size > getBufSize()) {
    Err = createError("invalid section offset/size");
    return Elf_Note_Iterator(Err);
  }
  return Elf_Note_Iterator(base() + Shdr.sh_offset, Shdr.sh_size, Err);
}

/// Get the end iterator for notes.
Elf_Note_Iterator notes_end() const {
  return Elf_Note_Iterator();
}

/// Get an iterator range over notes of a program header.
///
/// The program header must be of type \c PT_NOTE.
///
/// \param Phdr the program header to iterate over.
/// \param Err [out] an error to support fallible iteration, which should
///  be checked after iteration ends.
iterator_range<Elf_Note_Iterator> notes(const Elf_Phdr &Phdr,
                                        Error &Err) const {
  return make_range(notes_begin(Phdr, Err), notes_end());
}

/// Get an iterator range over notes of a section.
///
/// The section must be of type \c SHT_NOTE.
///
/// \param Shdr the section to iterate over.
/// \param Err [out] an error to support fallible iteration, which should
///  be checked after iteration ends.
iterator_range<Elf_Note_Iterator> notes(const Elf_Shdr &Shdr,
                                        Error &Err) const {
  return make_range(notes_begin(Shdr, Err), notes_end());
}

Expected<StringRef> getSectionStringTable(Elf_Shdr_Range Sections) const;
Expected<uint32_t> getSectionIndex(const Elf_Sym *Sym, Elf_Sym_Range Syms,
                                   ArrayRef<Elf_Word> ShndxTable) const;
Expected<const Elf_Shdr *> getSection(const Elf_Sym *Sym,
                                      const Elf_Shdr *SymTab,
                                      ArrayRef<Elf_Word> ShndxTable) const;
Expected<const Elf_Shdr *> getSection(const Elf_Sym *Sym,
                                      Elf_Sym_Range Symtab,
                                      ArrayRef<Elf_Word> ShndxTable) const;
Expected<const Elf_Shdr *> getSection(uint32_t Index) const;
Expected<const Elf_Shdr *> getSection(const StringRef SectionName) const;

Expected<const Elf_Sym *> getSymbol(const Elf_Shdr *Sec,
                                    uint32_t Index) const;

Expected<StringRef> getSectionName(const Elf_Shdr *Section) const;
Expected<StringRef> getSectionName(const Elf_Shdr *Section,
                                   StringRef DotShstrtab) const;
template <typename T>
Expected<ArrayRef<T>> getSectionContentsAsArray(const Elf_Shdr *Sec) const;
Expected<ArrayRef<uint8_t>> getSectionContents(const Elf_Shdr *Sec) const;
266};

268using ELF32LEFile = ELFFile<ELF32LE>;
269using ELF64LEFile = ELFFile<ELF64LE>;
270using ELF32BEFile = ELFFile<ELF32BE>;
271using ELF64BEFile = ELFFile<ELF64BE>;

273template <class ELFT>
274inline Expected<const typename ELFT::Shdr *>
275getSection(typename ELFT::ShdrRange Sections, uint32_t Index) {
if (Index >= Sections.size())
6
←
Assuming the condition is true→
7
←
Taking true branch→
  return createError("invalid section index");
8
←
Calling 'createError'→
return &Sections[Index];
279}

281template <class ELFT>
282inline Expected<uint32_t>
283getExtendedSymbolTableIndex(const typename ELFT::Sym *Sym,
                          const typename ELFT::Sym *FirstSym,
                          ArrayRef<typename ELFT::Word> ShndxTable) {
assert(Sym->st_shndx == ELF::SHN_XINDEX)((Sym->st_shndx == ELF::SHN_XINDEX) ? static_cast<void>
 (0) : __assert_fail ("Sym->st_shndx == ELF::SHN_XINDEX", "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Object/ELF.h"
, 286, __PRETTY_FUNCTION__));
unsigned Index = Sym - FirstSym;
if (Index >= ShndxTable.size())
  return createError("index past the end of the symbol table");

// The size of the table was checked in getSHNDXTable.
return ShndxTable[Index];
293}

295template <class ELFT>
296Expected<uint32_t>
297ELFFile<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;
310}

312template <class ELFT>
313Expected<const typename ELFT::Shdr *>
314ELFFile<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);
320}

322template <class ELFT>
323Expected<const typename ELFT::Shdr *>
324ELFFile<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);
333}

335template <class ELFT>
336inline Expected<const typename ELFT::Sym *>
337getSymbol(typename ELFT::SymRange Symbols, uint32_t Index) {
if (Index >= Symbols.size())
  return createError("invalid symbol index");
return &Symbols[Index];
341}

343template <class ELFT>
344Expected<const typename ELFT::Sym *>
345ELFFile<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);
350}

352template <class ELFT>
353template <typename T>
354Expected<ArrayRef<T>>
355ELFFile<ELFT>::getSectionContentsAsArray(const Elf_Shdr *Sec) const {
if (Sec->sh_entsize != sizeof(T) && sizeof(T) != 1)
  return createError("invalid sh_entsize");

uintX_t Offset = Sec->sh_offset;
uintX_t Size = Sec->sh_size;

if (Size % sizeof(T))
  return createError("size is not a multiple of sh_entsize");
if ((std::numeric_limits<uintX_t>::max() - Offset < Size) ||
    Offset + Size > Buf.size())
  return createError("invalid section offset");

if (Offset % alignof(T))
  return createError("unaligned data");

const T *Start = reinterpret_cast<const T *>(base() + Offset);
return makeArrayRef(Start, Size / sizeof(T));
373}

375template <class ELFT>
376Expected<ArrayRef<uint8_t>>
377ELFFile<ELFT>::getSectionContents(const Elf_Shdr *Sec) const {
return getSectionContentsAsArray<uint8_t>(Sec);
379}

381template <class ELFT>
382StringRef ELFFile<ELFT>::getRelocationTypeName(uint32_t Type) const {
return getELFRelocationTypeName(getHeader()->e_machine, Type);
384}

386template <class ELFT>
387void 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());
}
415}

417template <class ELFT>
418uint32_t ELFFile<ELFT>::getRelrRelocationType() const {
return getELFRelrRelocationType(getHeader()->e_machine);
420}

422template <class ELFT>
423Expected<const typename ELFT::Sym *>
424ELFFile<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);
430}

432template <class ELFT>
433Expected<StringRef>
434ELFFile<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]);
444}

446template <class ELFT> ELFFile<ELFT>::ELFFile(StringRef Object) : Buf(Object) {}

448template <class ELFT>
449Expected<ELFFile<ELFT>> ELFFile<ELFT>::create(StringRef Object) {
if (sizeof(Elf_Ehdr) > Object.size())
  return createError("Invalid buffer");
return ELFFile(Object);
453}

455template <class ELFT>
456Expected<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(18446744073709551615UL) / 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);
491}

493template <class ELFT>
494template <typename T>
495Expected<const T *> ELFFile<ELFT>::getEntry(uint32_t Section,
                                          uint32_t Entry) const {
auto SecOrErr = getSection(Section);
if (!SecOrErr)
  return SecOrErr.takeError();
return getEntry<T>(*SecOrErr, Entry);
501}

503template <class ELFT>
504template <typename T>
505Expected<const T *> ELFFile<ELFT>::getEntry(const Elf_Shdr *Section,
                                          uint32_t Entry) const {
if (sizeof(T) != Section->sh_entsize)
  return createError("invalid sh_entsize");
size_t Pos = Section->sh_offset + Entry * sizeof(T);
if (Pos + sizeof(T) > Buf.size())
  return createError("invalid section offset");
return reinterpret_cast<const T *>(base() + Pos);
513}

515template <class ELFT>
516Expected<const typename ELFT::Shdr *>
517ELFFile<ELFT>::getSection(uint32_t Index) const {
auto TableOrErr = sections();
if (!TableOrErr)
  return TableOrErr.takeError();
return object::getSection<ELFT>(*TableOrErr, Index);
522}

524template <class ELFT>
525Expected<const typename ELFT::Shdr *>
526ELFFile<ELFT>::getSection(const StringRef SectionName) const {
auto TableOrErr = sections();
if (!TableOrErr)
  return TableOrErr.takeError();
for (auto &Sec : *TableOrErr) {
  auto SecNameOrErr = getSectionName(&Sec);
  if (!SecNameOrErr)
    return SecNameOrErr.takeError();
  if (*SecNameOrErr == SectionName)
    return &Sec;
}
return createError("invalid section name");
538}

540template <class ELFT>
541Expected<StringRef>
542ELFFile<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());
554}

556template <class ELFT>
557Expected<ArrayRef<typename ELFT::Word>>
558ELFFile<ELFT>::getSHNDXTable(const Elf_Shdr &Section) const {
auto SectionsOrErr = sections();
if (!SectionsOrErr)
  return SectionsOrErr.takeError();
return getSHNDXTable(Section, *SectionsOrErr);
563}

565template <class ELFT>
566Expected<ArrayRef<typename ELFT::Word>>
567ELFFile<ELFT>::getSHNDXTable(const Elf_Shdr &Section,
                           Elf_Shdr_Range Sections) const {
assert(Section.sh_type == ELF::SHT_SYMTAB_SHNDX)((Section.sh_type == ELF::SHT_SYMTAB_SHNDX) ? static_cast<
void> (0) : __assert_fail ("Section.sh_type == ELF::SHT_SYMTAB_SHNDX"
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Object/ELF.h"
, 569, __PRETTY_FUNCTION__));
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;
584}

586template <class ELFT>
587Expected<StringRef>
588ELFFile<ELFT>::getStringTableForSymtab(const Elf_Shdr &Sec) const {
auto SectionsOrErr = sections();
if (!SectionsOrErr)
2
←
Taking false branch→
  return SectionsOrErr.takeError();
return getStringTableForSymtab(Sec, *SectionsOrErr);
3
←
Calling 'ELFFile::getStringTableForSymtab'→
593}

595template <class ELFT>
596Expected<StringRef>
597ELFFile<ELFT>::getStringTableForSymtab(const Elf_Shdr &Sec,
                                     Elf_Shdr_Range Sections) const {

if (Sec.sh_type != ELF::SHT_SYMTAB && Sec.sh_type != ELF::SHT_DYNSYM)
4
←
Assuming the condition is false→
  return createError(
      "invalid sh_type for symbol table, expected SHT_SYMTAB or SHT_DYNSYM");
auto SectionOrErr = object::getSection<ELFT>(Sections, Sec.sh_link);
5
←
Calling 'getSection<llvm::object::ELFType<llvm::support::big, false>>'→
if (!SectionOrErr)
  return SectionOrErr.takeError();
return getStringTable(*SectionOrErr);
607}

609template <class ELFT>
610Expected<StringRef>
611ELFFile<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);
619}

621template <class ELFT>
622Expected<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);
630}

632/// This function returns the hash value for a symbol in the .dynsym section
633/// Name of the API remains consistent as specified in the libelf
634/// REF : http://www.sco.com/developers/gabi/latest/ch5.dynamic.html#hash
635inline unsigned hashSysV(StringRef SymbolName) {
unsigned h = 0, g;
for (char C : SymbolName) {
  h = (h << 4) + C;
  g = h & 0xf0000000L;
  if (g != 0)
    h ^= g >> 24;
  h &= ~g;
}
return h;
645}

647} // end namespace object
648} // end namespace llvm

650#endif // LLVM_OBJECT_ELF_H

←

/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h

→

1//===- llvm/Support/Error.h - Recoverable error handling --------*- 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// This file defines an API used to report recoverable errors.
11//
12//===----------------------------------------------------------------------===//
13 
14#ifndef LLVM_SUPPORT_ERROR_H
15#define LLVM_SUPPORT_ERROR_H
16 
17#include "llvm-c/Error.h"
18#include "llvm/ADT/STLExtras.h"
19#include "llvm/ADT/SmallVector.h"
20#include "llvm/ADT/StringExtras.h"
21#include "llvm/ADT/Twine.h"
22#include "llvm/Config/abi-breaking.h"
23#include "llvm/Support/AlignOf.h"
24#include "llvm/Support/Compiler.h"
25#include "llvm/Support/Debug.h"
26#include "llvm/Support/ErrorHandling.h"
27#include "llvm/Support/ErrorOr.h"
28#include "llvm/Support/Format.h"
29#include "llvm/Support/raw_ostream.h"
30#include <algorithm>
31#include <cassert>
32#include <cstdint>
33#include <cstdlib>
34#include <functional>
35#include <memory>
36#include <new>
37#include <string>
38#include <system_error>
39#include <type_traits>
40#include <utility>
41#include <vector>
42 
43namespace llvm {
44 
45class ErrorSuccess;
46 
47/// Base class for error info classes. Do not extend this directly: Extend
48/// the ErrorInfo template subclass instead.
49class ErrorInfoBase {
50public:
51  virtual ~ErrorInfoBase() = default;
52 
53  /// Print an error message to an output stream.
54  virtual void log(raw_ostream &OS) const = 0;
55 
56  /// Return the error message as a string.
57  virtual std::string message() const {
58    std::string Msg;
59    raw_string_ostream OS(Msg);
60    log(OS);
61    return OS.str();
62  }
63 
64  /// Convert this error to a std::error_code.
65  ///
66  /// This is a temporary crutch to enable interaction with code still
67  /// using std::error_code. It will be removed in the future.
68  virtual std::error_code convertToErrorCode() const = 0;
69 
70  // Returns the class ID for this type.
71  static const void *classID() { return &ID; }
72 
73  // Returns the class ID for the dynamic type of this ErrorInfoBase instance.
74  virtual const void *dynamicClassID() const = 0;
75 
76  // Check whether this instance is a subclass of the class identified by
77  // ClassID.
78  virtual bool isA(const void *const ClassID) const {
79    return ClassID == classID();
80  }
81 
82  // Check whether this instance is a subclass of ErrorInfoT.
83  template <typename ErrorInfoT> bool isA() const {
84    return isA(ErrorInfoT::classID());
85  }
86 
87private:
88  virtual void anchor();
89 
90  static char ID;
91};
92 
93/// Lightweight error class with error context and mandatory checking.
94///
95/// Instances of this class wrap a ErrorInfoBase pointer. Failure states
96/// are represented by setting the pointer to a ErrorInfoBase subclass
97/// instance containing information describing the failure. Success is
98/// represented by a null pointer value.
99///
100/// Instances of Error also contains a 'Checked' flag, which must be set
101/// before the destructor is called, otherwise the destructor will trigger a
102/// runtime error. This enforces at runtime the requirement that all Error
103/// instances be checked or returned to the caller.
104///
105/// There are two ways to set the checked flag, depending on what state the
106/// Error instance is in. For Error instances indicating success, it
107/// is sufficient to invoke the boolean conversion operator. E.g.:
108///
109///   @code{.cpp}
110///   Error foo(<...>);
111///
112///   if (auto E = foo(<...>))
113///     return E; // <- Return E if it is in the error state.
114///   // We have verified that E was in the success state. It can now be safely
115///   // destroyed.
116///   @endcode
117///
118/// A success value *can not* be dropped. For example, just calling 'foo(<...>)'
119/// without testing the return value will raise a runtime error, even if foo
120/// returns success.
121///
122/// For Error instances representing failure, you must use either the
123/// handleErrors or handleAllErrors function with a typed handler. E.g.:
124///
125///   @code{.cpp}
126///   class MyErrorInfo : public ErrorInfo<MyErrorInfo> {
127///     // Custom error info.
128///   };
129///
130///   Error foo(<...>) { return make_error<MyErrorInfo>(...); }
131///
132///   auto E = foo(<...>); // <- foo returns failure with MyErrorInfo.
133///   auto NewE =
134///     handleErrors(E,
135///       [](const MyErrorInfo &M) {
136///         // Deal with the error.
137///       },
138///       [](std::unique_ptr<OtherError> M) -> Error {
139///         if (canHandle(*M)) {
140///           // handle error.
141///           return Error::success();
142///         }
143///         // Couldn't handle this error instance. Pass it up the stack.
144///         return Error(std::move(M));
145///       );
146///   // Note - we must check or return NewE in case any of the handlers
147///   // returned a new error.
148///   @endcode
149///
150/// The handleAllErrors function is identical to handleErrors, except
151/// that it has a void return type, and requires all errors to be handled and
152/// no new errors be returned. It prevents errors (assuming they can all be
153/// handled) from having to be bubbled all the way to the top-level.
154///
155/// *All* Error instances must be checked before destruction, even if
156/// they're moved-assigned or constructed from Success values that have already
157/// been checked. This enforces checking through all levels of the call stack.
158class LLVM_NODISCARD[[clang::warn_unused_result]] Error {
159  // Both ErrorList and FileError need to be able to yank ErrorInfoBase
160  // pointers out of this class to add to the error list.
161  friend class ErrorList;
162  friend class FileError;
163 
164  // handleErrors needs to be able to set the Checked flag.
165  template <typename... HandlerTs>
166  friend Error handleErrors(Error E, HandlerTs &&... Handlers);
167 
168  // Expected<T> needs to be able to steal the payload when constructed from an
169  // error.
170  template <typename T> friend class Expected;
171 
172  // wrap needs to be able to steal the payload.
173  friend LLVMErrorRef wrap(Error);
174 
175protected:
176  /// Create a success value. Prefer using 'Error::success()' for readability
177  Error() {
178    setPtr(nullptr);
179    setChecked(false);
180  }
181 
182public:
183  /// Create a success value.
184  static ErrorSuccess success();
185 
186  // Errors are not copy-constructable.
187  Error(const Error &Other) = delete;
188 
189  /// Move-construct an error value. The newly constructed error is considered
190  /// unchecked, even if the source error had been checked. The original error
191  /// becomes a checked Success value, regardless of its original state.
192  Error(Error &&Other) {
193    setChecked(true);
194    *this = std::move(Other);
195  }
196 
197  /// Create an error value. Prefer using the 'make_error' function, but
198  /// this constructor can be useful when "re-throwing" errors from handlers.
199  Error(std::unique_ptr<ErrorInfoBase> Payload) {
200    setPtr(Payload.release());
201    setChecked(false);
14
←
Potential leak of memory pointed to by 'Payload._M_t._M_head_impl'
202  }
203 
204  // Errors are not copy-assignable.
205  Error &operator=(const Error &Other) = delete;
206 
207  /// Move-assign an error value. The current error must represent success, you
208  /// you cannot overwrite an unhandled error. The current error is then
209  /// considered unchecked. The source error becomes a checked success value,
210  /// regardless of its original state.
211  Error &operator=(Error &&Other) {
212    // Don't allow overwriting of unchecked values.
213    assertIsChecked();
214    setPtr(Other.getPtr());
215 
216    // This Error is unchecked, even if the source error was checked.
217    setChecked(false);
218 
219    // Null out Other's payload and set its checked bit.
220    Other.setPtr(nullptr);
221    Other.setChecked(true);
222 
223    return *this;
224  }
225 
226  /// Destroy a Error. Fails with a call to abort() if the error is
227  /// unchecked.
228  ~Error() {
229    assertIsChecked();
230    delete getPtr();
231  }
232 
233  /// Bool conversion. Returns true if this Error is in a failure state,
234  /// and false if it is in an accept state. If the error is in a Success state
235  /// it will be considered checked.
236  explicit operator bool() {
237    setChecked(getPtr() == nullptr);
238    return getPtr() != nullptr;
239  }
240 
241  /// Check whether one error is a subclass of another.
242  template <typename ErrT> bool isA() const {
243    return getPtr() && getPtr()->isA(ErrT::classID());
244  }
245 
246  /// Returns the dynamic class id of this error, or null if this is a success
247  /// value.
248  const void* dynamicClassID() const {
249    if (!getPtr())
250      return nullptr;
251    return getPtr()->dynamicClassID();
252  }
253 
254private:
255#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
256  // assertIsChecked() happens very frequently, but under normal circumstances
257  // is supposed to be a no-op.  So we want it to be inlined, but having a bunch
258  // of debug prints can cause the function to be too large for inlining.  So
259  // it's important that we define this function out of line so that it can't be
260  // inlined.
261  LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
262  void fatalUncheckedError() const;
263#endif
264 
265  void assertIsChecked() {
266#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
267    if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false))
268      fatalUncheckedError();
269#endif
270  }
271 
272  ErrorInfoBase *getPtr() const {
273    return reinterpret_cast<ErrorInfoBase*>(
274             reinterpret_cast<uintptr_t>(Payload) &
275             ~static_cast<uintptr_t>(0x1));
276  }
277 
278  void setPtr(ErrorInfoBase *EI) {
279#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
280    Payload = reinterpret_cast<ErrorInfoBase*>(
281                (reinterpret_cast<uintptr_t>(EI) &
282                 ~static_cast<uintptr_t>(0x1)) |
283                (reinterpret_cast<uintptr_t>(Payload) & 0x1));
284#else
285    Payload = EI;
286#endif
287  }
288 
289  bool getChecked() const {
290#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
291    return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0;
292#else
293    return true;
294#endif
295  }
296 
297  void setChecked(bool V) {
298    Payload = reinterpret_cast<ErrorInfoBase*>(
299                (reinterpret_cast<uintptr_t>(Payload) &
300                  ~static_cast<uintptr_t>(0x1)) |
301                  (V ? 0 : 1));
302  }
303 
304  std::unique_ptr<ErrorInfoBase> takePayload() {
305    std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
306    setPtr(nullptr);
307    setChecked(true);
308    return Tmp;
309  }
310 
311  friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
312    if (auto P = E.getPtr())
313      P->log(OS);
314    else
315      OS << "success";
316    return OS;
317  }
318 
319  ErrorInfoBase *Payload = nullptr;
320};
321 
322/// Subclass of Error for the sole purpose of identifying the success path in
323/// the type system. This allows to catch invalid conversion to Expected<T> at
324/// compile time.
325class ErrorSuccess final : public Error {};
326 
327inline ErrorSuccess Error::success() { return ErrorSuccess(); }
328 
329/// Make a Error instance representing failure using the given error info
330/// type.
331template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
332  return Error(llvm::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
10
←
Calling 'make_unique<llvm::StringError, llvm::StringRef &, llvm::object::object_error>'→
12
←
Returned allocated memory→
13
←
Calling constructor for 'Error'→
333}
334 
335/// Base class for user error types. Users should declare their error types
336/// like:
337///
338/// class MyError : public ErrorInfo<MyError> {
339///   ....
340/// };
341///
342/// This class provides an implementation of the ErrorInfoBase::kind
343/// method, which is used by the Error RTTI system.
344template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
345class ErrorInfo : public ParentErrT {
346public:
347  using ParentErrT::ParentErrT; // inherit constructors
348 
349  static const void *classID() { return &ThisErrT::ID; }
350 
351  const void *dynamicClassID() const override { return &ThisErrT::ID; }
352 
353  bool isA(const void *const ClassID) const override {
354    return ClassID == classID() || ParentErrT::isA(ClassID);
355  }
356};
357 
358/// Special ErrorInfo subclass representing a list of ErrorInfos.
359/// Instances of this class are constructed by joinError.
360class ErrorList final : public ErrorInfo<ErrorList> {
361  // handleErrors needs to be able to iterate the payload list of an
362  // ErrorList.
363  template <typename... HandlerTs>
364  friend Error handleErrors(Error E, HandlerTs &&... Handlers);
365 
366  // joinErrors is implemented in terms of join.
367  friend Error joinErrors(Error, Error);
368 
369public:
370  void log(raw_ostream &OS) const override {
371    OS << "Multiple errors:\n";
372    for (auto &ErrPayload : Payloads) {
373      ErrPayload->log(OS);
374      OS << "\n";
375    }
376  }
377 
378  std::error_code convertToErrorCode() const override;
379 
380  // Used by ErrorInfo::classID.
381  static char ID;
382 
383private:
384  ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
385            std::unique_ptr<ErrorInfoBase> Payload2) {
386    assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 387, __PRETTY_FUNCTION__))
387           "ErrorList constructor payloads should be singleton errors")((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 387, __PRETTY_FUNCTION__));
388    Payloads.push_back(std::move(Payload1));
389    Payloads.push_back(std::move(Payload2));
390  }
391 
392  static Error join(Error E1, Error E2) {
393    if (!E1)
394      return E2;
395    if (!E2)
396      return E1;
397    if (E1.isA<ErrorList>()) {
398      auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
399      if (E2.isA<ErrorList>()) {
400        auto E2Payload = E2.takePayload();
401        auto &E2List = static_cast<ErrorList &>(*E2Payload);
402        for (auto &Payload : E2List.Payloads)
403          E1List.Payloads.push_back(std::move(Payload));
404      } else
405        E1List.Payloads.push_back(E2.takePayload());
406 
407      return E1;
408    }
409    if (E2.isA<ErrorList>()) {
410      auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
411      E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
412      return E2;
413    }
414    return Error(std::unique_ptr<ErrorList>(
415        new ErrorList(E1.takePayload(), E2.takePayload())));
416  }
417 
418  std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
419};
420 
421/// Concatenate errors. The resulting Error is unchecked, and contains the
422/// ErrorInfo(s), if any, contained in E1, followed by the
423/// ErrorInfo(s), if any, contained in E2.
424inline Error joinErrors(Error E1, Error E2) {
425  return ErrorList::join(std::move(E1), std::move(E2));
426}
427 
428/// Tagged union holding either a T or a Error.
429///
430/// This class parallels ErrorOr, but replaces error_code with Error. Since
431/// Error cannot be copied, this class replaces getError() with
432/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
433/// error class type.
434template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
435  template <class T1> friend class ExpectedAsOutParameter;
436  template <class OtherT> friend class Expected;
437 
438  static const bool isRef = std::is_reference<T>::value;
439 
440  using wrap = std::reference_wrapper<typename std::remove_reference<T>::type>;
441 
442  using error_type = std::unique_ptr<ErrorInfoBase>;
443 
444public:
445  using storage_type = typename std::conditional<isRef, wrap, T>::type;
446  using value_type = T;
447 
448private:
449  using reference = typename std::remove_reference<T>::type &;
450  using const_reference = const typename std::remove_reference<T>::type &;
451  using pointer = typename std::remove_reference<T>::type *;
452  using const_pointer = const typename std::remove_reference<T>::type *;
453 
454public:
455  /// Create an Expected<T> error value from the given Error.
456  Expected(Error Err)
457      : HasError(true)
458#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
459        // Expected is unchecked upon construction in Debug builds.
460        , Unchecked(true)
461#endif
462  {
463    assert(Err && "Cannot create Expected<T> from Error success value.")((Err && "Cannot create Expected<T> from Error success value."
) ? static_cast<void> (0) : __assert_fail ("Err && \"Cannot create Expected<T> from Error success value.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 463, __PRETTY_FUNCTION__));
464    new (getErrorStorage()) error_type(Err.takePayload());
465  }
466 
467  /// Forbid to convert from Error::success() implicitly, this avoids having
468  /// Expected<T> foo() { return Error::success(); } which compiles otherwise
469  /// but triggers the assertion above.
470  Expected(ErrorSuccess) = delete;
471 
472  /// Create an Expected<T> success value from the given OtherT value, which
473  /// must be convertible to T.
474  template <typename OtherT>
475  Expected(OtherT &&Val,
476           typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
477               * = nullptr)
478      : HasError(false)
479#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
480        // Expected is unchecked upon construction in Debug builds.
481        , Unchecked(true)
482#endif
483  {
484    new (getStorage()) storage_type(std::forward<OtherT>(Val));
485  }
486 
487  /// Move construct an Expected<T> value.
488  Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
489 
490  /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
491  /// must be convertible to T.
492  template <class OtherT>
493  Expected(Expected<OtherT> &&Other,
494           typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
495               * = nullptr) {
496    moveConstruct(std::move(Other));
497  }
498 
499  /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
500  /// isn't convertible to T.
501  template <class OtherT>
502  explicit Expected(
503      Expected<OtherT> &&Other,
504      typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * =
505          nullptr) {
506    moveConstruct(std::move(Other));
507  }
508 
509  /// Move-assign from another Expected<T>.
510  Expected &operator=(Expected &&Other) {
511    moveAssign(std::move(Other));
512    return *this;
513  }
514 
515  /// Destroy an Expected<T>.
516  ~Expected() {
517    assertIsChecked();
518    if (!HasError)
519      getStorage()->~storage_type();
520    else
521      getErrorStorage()->~error_type();
522  }
523 
524  /// Return false if there is an error.
525  explicit operator bool() {
526#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
527    Unchecked = HasError;
528#endif
529    return !HasError;
530  }
531 
532  /// Returns a reference to the stored T value.
533  reference get() {
534    assertIsChecked();
535    return *getStorage();
536  }
537 
538  /// Returns a const reference to the stored T value.
539  const_reference get() const {
540    assertIsChecked();
541    return const_cast<Expected<T> *>(this)->get();
542  }
543 
544  /// Check that this Expected<T> is an error of type ErrT.
545  template <typename ErrT> bool errorIsA() const {
546    return HasError && (*getErrorStorage())->template isA<ErrT>();
547  }
548 
549  /// Take ownership of the stored error.
550  /// After calling this the Expected<T> is in an indeterminate state that can
551  /// only be safely destructed. No further calls (beside the destructor) should
552  /// be made on the Expected<T> vaule.
553  Error takeError() {
554#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
555    Unchecked = false;
556#endif
557    return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
558  }
559 
560  /// Returns a pointer to the stored T value.
561  pointer operator->() {
562    assertIsChecked();
563    return toPointer(getStorage());
564  }
565 
566  /// Returns a const pointer to the stored T value.
567  const_pointer operator->() const {
568    assertIsChecked();
569    return toPointer(getStorage());
570  }
571 
572  /// Returns a reference to the stored T value.
573  reference operator*() {
574    assertIsChecked();
575    return *getStorage();
576  }
577 
578  /// Returns a const reference to the stored T value.
579  const_reference operator*() const {
580    assertIsChecked();
581    return *getStorage();
582  }
583 
584private:
585  template <class T1>
586  static bool compareThisIfSameType(const T1 &a, const T1 &b) {
587    return &a == &b;
588  }
589 
590  template <class T1, class T2>
591  static bool compareThisIfSameType(const T1 &a, const T2 &b) {
592    return false;
593  }
594 
595  template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
596    HasError = Other.HasError;
597#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
598    Unchecked = true;
599    Other.Unchecked = false;
600#endif
601 
602    if (!HasError)
603      new (getStorage()) storage_type(std::move(*Other.getStorage()));
604    else
605      new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
606  }
607 
608  template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
609    assertIsChecked();
610 
611    if (compareThisIfSameType(*this, Other))
612      return;
613 
614    this->~Expected();
615    new (this) Expected(std::move(Other));
616  }
617 
618  pointer toPointer(pointer Val) { return Val; }
619 
620  const_pointer toPointer(const_pointer Val) const { return Val; }
621 
622  pointer toPointer(wrap *Val) { return &Val->get(); }
623 
624  const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
625 
626  storage_type *getStorage() {
627    assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 627, __PRETTY_FUNCTION__));
628    return reinterpret_cast<storage_type *>(TStorage.buffer);
629  }
630 
631  const storage_type *getStorage() const {
632    assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 632, __PRETTY_FUNCTION__));
633    return reinterpret_cast<const storage_type *>(TStorage.buffer);
634  }
635 
636  error_type *getErrorStorage() {
637    assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 637, __PRETTY_FUNCTION__));
638    return reinterpret_cast<error_type *>(ErrorStorage.buffer);
639  }
640 
641  const error_type *getErrorStorage() const {
642    assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 642, __PRETTY_FUNCTION__));
643    return reinterpret_cast<const error_type *>(ErrorStorage.buffer);
644  }
645 
646  // Used by ExpectedAsOutParameter to reset the checked flag.
647  void setUnchecked() {
648#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
649    Unchecked = true;
650#endif
651  }
652 
653#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
654  LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
655  LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline))
656  void fatalUncheckedExpected() const {
657    dbgs() << "Expected<T> must be checked before access or destruction.\n";
658    if (HasError) {
659      dbgs() << "Unchecked Expected<T> contained error:\n";
660      (*getErrorStorage())->log(dbgs());
661    } else
662      dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
663                "values in success mode must still be checked prior to being "
664                "destroyed).\n";
665    abort();
666  }
667#endif
668 
669  void assertIsChecked() {
670#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
671    if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
672      fatalUncheckedExpected();
673#endif
674  }
675 
676  union {
677    AlignedCharArrayUnion<storage_type> TStorage;
678    AlignedCharArrayUnion<error_type> ErrorStorage;
679  };
680  bool HasError : 1;
681#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
682  bool Unchecked : 1;
683#endif
684};
685 
686/// Report a serious error, calling any installed error handler. See
687/// ErrorHandling.h.
688LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void report_fatal_error(Error Err,
689                                                bool gen_crash_diag = true);
690 
691/// Report a fatal error if Err is a failure value.
692///
693/// This function can be used to wrap calls to fallible functions ONLY when it
694/// is known that the Error will always be a success value. E.g.
695///
696///   @code{.cpp}
697///   // foo only attempts the fallible operation if DoFallibleOperation is
698///   // true. If DoFallibleOperation is false then foo always returns
699///   // Error::success().
700///   Error foo(bool DoFallibleOperation);
701///
702///   cantFail(foo(false));
703///   @endcode
704inline void cantFail(Error Err, const char *Msg = nullptr) {
705  if (Err) {
706    if (!Msg)
707      Msg = "Failure value returned from cantFail wrapped call";
708    llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 708);
709  }
710}
711 
712/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
713/// returns the contained value.
714///
715/// This function can be used to wrap calls to fallible functions ONLY when it
716/// is known that the Error will always be a success value. E.g.
717///
718///   @code{.cpp}
719///   // foo only attempts the fallible operation if DoFallibleOperation is
720///   // true. If DoFallibleOperation is false then foo always returns an int.
721///   Expected<int> foo(bool DoFallibleOperation);
722///
723///   int X = cantFail(foo(false));
724///   @endcode
725template <typename T>
726T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
727  if (ValOrErr)
728    return std::move(*ValOrErr);
729  else {
730    if (!Msg)
731      Msg = "Failure value returned from cantFail wrapped call";
732    llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 732);
733  }
734}
735 
736/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
737/// returns the contained reference.
738///
739/// This function can be used to wrap calls to fallible functions ONLY when it
740/// is known that the Error will always be a success value. E.g.
741///
742///   @code{.cpp}
743///   // foo only attempts the fallible operation if DoFallibleOperation is
744///   // true. If DoFallibleOperation is false then foo always returns a Bar&.
745///   Expected<Bar&> foo(bool DoFallibleOperation);
746///
747///   Bar &X = cantFail(foo(false));
748///   @endcode
749template <typename T>
750T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
751  if (ValOrErr)
752    return *ValOrErr;
753  else {
754    if (!Msg)
755      Msg = "Failure value returned from cantFail wrapped call";
756    llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 756);
757  }
758}
759 
760/// Helper for testing applicability of, and applying, handlers for
761/// ErrorInfo types.
762template <typename HandlerT>
763class ErrorHandlerTraits
764    : public ErrorHandlerTraits<decltype(
765          &std::remove_reference<HandlerT>::type::operator())> {};
766 
767// Specialization functions of the form 'Error (const ErrT&)'.
768template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
769public:
770  static bool appliesTo(const ErrorInfoBase &E) {
771    return E.template isA<ErrT>();
772  }
773 
774  template <typename HandlerT>
775  static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
776    assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 776, __PRETTY_FUNCTION__));
777    return H(static_cast<ErrT &>(*E));
778  }
779};
780 
781// Specialization functions of the form 'void (const ErrT&)'.
782template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
783public:
784  static bool appliesTo(const ErrorInfoBase &E) {
785    return E.template isA<ErrT>();
786  }
787 
788  template <typename HandlerT>
789  static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
790    assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 790, __PRETTY_FUNCTION__));
791    H(static_cast<ErrT &>(*E));
792    return Error::success();
793  }
794};
795 
796/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
797template <typename ErrT>
798class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
799public:
800  static bool appliesTo(const ErrorInfoBase &E) {
801    return E.template isA<ErrT>();
802  }
803 
804  template <typename HandlerT>
805  static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
806    assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 806, __PRETTY_FUNCTION__));
807    std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
808    return H(std::move(SubE));
809  }
810};
811 
812/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
813template <typename ErrT>
814class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
815public:
816  static bool appliesTo(const ErrorInfoBase &E) {
817    return E.template isA<ErrT>();
818  }
819 
820  template <typename HandlerT>
821  static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
822    assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 822, __PRETTY_FUNCTION__));
823    std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
824    H(std::move(SubE));
825    return Error::success();
826  }
827};
828 
829// Specialization for member functions of the form 'RetT (const ErrT&)'.
830template <typename C, typename RetT, typename ErrT>
831class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
832    : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
833 
834// Specialization for member functions of the form 'RetT (const ErrT&) const'.
835template <typename C, typename RetT, typename ErrT>
836class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
837    : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
838 
839// Specialization for member functions of the form 'RetT (const ErrT&)'.
840template <typename C, typename RetT, typename ErrT>
841class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
842    : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
843 
844// Specialization for member functions of the form 'RetT (const ErrT&) const'.
845template <typename C, typename RetT, typename ErrT>
846class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
847    : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
848 
849/// Specialization for member functions of the form
850/// 'RetT (std::unique_ptr<ErrT>)'.
851template <typename C, typename RetT, typename ErrT>
852class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
853    : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
854 
855/// Specialization for member functions of the form
856/// 'RetT (std::unique_ptr<ErrT>) const'.
857template <typename C, typename RetT, typename ErrT>
858class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
859    : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
860 
861inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
862  return Error(std::move(Payload));
863}
864 
865template <typename HandlerT, typename... HandlerTs>
866Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
867                      HandlerT &&Handler, HandlerTs &&... Handlers) {
868  if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
869    return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
870                                               std::move(Payload));
871  return handleErrorImpl(std::move(Payload),
872                         std::forward<HandlerTs>(Handlers)...);
873}
874 
875/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
876/// unhandled errors (or Errors returned by handlers) are re-concatenated and
877/// returned.
878/// Because this function returns an error, its result must also be checked
879/// or returned. If you intend to handle all errors use handleAllErrors
880/// (which returns void, and will abort() on unhandled errors) instead.
881template <typename... HandlerTs>
882Error handleErrors(Error E, HandlerTs &&... Hs) {
883  if (!E)
884    return Error::success();
885 
886  std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
887 
888  if (Payload->isA<ErrorList>()) {
889    ErrorList &List = static_cast<ErrorList &>(*Payload);
890    Error R;
891    for (auto &P : List.Payloads)
892      R = ErrorList::join(
893          std::move(R),
894          handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
895    return R;
896  }
897 
898  return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
899}
900 
901/// Behaves the same as handleErrors, except that by contract all errors
902/// *must* be handled by the given handlers (i.e. there must be no remaining
903/// errors after running the handlers, or llvm_unreachable is called).
904template <typename... HandlerTs>
905void handleAllErrors(Error E, HandlerTs &&... Handlers) {
906  cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
907}
908 
909/// Check that E is a non-error, then drop it.
910/// If E is an error, llvm_unreachable will be called.
911inline void handleAllErrors(Error E) {
912  cantFail(std::move(E));
913}
914 
915/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
916///
917/// If the incoming value is a success value it is returned unmodified. If it
918/// is a failure value then it the contained error is passed to handleErrors.
919/// If handleErrors is able to handle the error then the RecoveryPath functor
920/// is called to supply the final result. If handleErrors is not able to
921/// handle all errors then the unhandled errors are returned.
922///
923/// This utility enables the follow pattern:
924///
925///   @code{.cpp}
926///   enum FooStrategy { Aggressive, Conservative };
927///   Expected<Foo> foo(FooStrategy S);
928///
929///   auto ResultOrErr =
930///     handleExpected(
931///       foo(Aggressive),
932///       []() { return foo(Conservative); },
933///       [](AggressiveStrategyError&) {
934///         // Implicitly conusme this - we'll recover by using a conservative
935///         // strategy.
936///       });
937///
938///   @endcode
939template <typename T, typename RecoveryFtor, typename... HandlerTs>
940Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
941                           HandlerTs &&... Handlers) {
942  if (ValOrErr)
943    return ValOrErr;
944 
945  if (auto Err = handleErrors(ValOrErr.takeError(),
946                              std::forward<HandlerTs>(Handlers)...))
947    return std::move(Err);
948 
949  return RecoveryPath();
950}
951 
952/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
953/// will be printed before the first one is logged. A newline will be printed
954/// after each error.
955///
956/// This is useful in the base level of your program to allow clean termination
957/// (allowing clean deallocation of resources, etc.), while reporting error
958/// information to the user.
959void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner);
960 
961/// Write all error messages (if any) in E to a string. The newline character
962/// is used to separate error messages.
963inline std::string toString(Error E) {
964  SmallVector<std::string, 2> Errors;
965  handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
966    Errors.push_back(EI.message());
967  });
968  return join(Errors.begin(), Errors.end(), "\n");
969}
970 
971/// Consume a Error without doing anything. This method should be used
972/// only where an error can be considered a reasonable and expected return
973/// value.
974///
975/// Uses of this method are potentially indicative of design problems: If it's
976/// legitimate to do nothing while processing an "error", the error-producer
977/// might be more clearly refactored to return an Optional<T>.
978inline void consumeError(Error Err) {
979  handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
980}
981 
982/// Helper for converting an Error to a bool.
983///
984/// This method returns true if Err is in an error state, or false if it is
985/// in a success state.  Puts Err in a checked state in both cases (unlike
986/// Error::operator bool(), which only does this for success states).
987inline bool errorToBool(Error Err) {
988  bool IsError = static_cast<bool>(Err);
989  if (IsError)
990    consumeError(std::move(Err));
991  return IsError;
992}
993 
994/// Helper for Errors used as out-parameters.
995///
996/// This helper is for use with the Error-as-out-parameter idiom, where an error
997/// is passed to a function or method by reference, rather than being returned.
998/// In such cases it is helpful to set the checked bit on entry to the function
999/// so that the error can be written to (unchecked Errors abort on assignment)
1000/// and clear the checked bit on exit so that clients cannot accidentally forget
1001/// to check the result. This helper performs these actions automatically using
1002/// RAII:
1003///
1004///   @code{.cpp}
1005///   Result foo(Error &Err) {
1006///     ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1007///     // <body of foo>
1008///     // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1009///   }
1010///   @endcode
1011///
1012/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1013/// used with optional Errors (Error pointers that are allowed to be null). If
1014/// ErrorAsOutParameter took an Error reference, an instance would have to be
1015/// created inside every condition that verified that Error was non-null. By
1016/// taking an Error pointer we can just create one instance at the top of the
1017/// function.
1018class ErrorAsOutParameter {
1019public:
1020  ErrorAsOutParameter(Error *Err) : Err(Err) {
1021    // Raise the checked bit if Err is success.
1022    if (Err)
1023      (void)!!*Err;
1024  }
1025 
1026  ~ErrorAsOutParameter() {
1027    // Clear the checked bit.
1028    if (Err && !*Err)
1029      *Err = Error::success();
1030  }
1031 
1032private:
1033  Error *Err;
1034};
1035 
1036/// Helper for Expected<T>s used as out-parameters.
1037///
1038/// See ErrorAsOutParameter.
1039template <typename T>
1040class ExpectedAsOutParameter {
1041public:
1042  ExpectedAsOutParameter(Expected<T> *ValOrErr)
1043    : ValOrErr(ValOrErr) {
1044    if (ValOrErr)
1045      (void)!!*ValOrErr;
1046  }
1047 
1048  ~ExpectedAsOutParameter() {
1049    if (ValOrErr)
1050      ValOrErr->setUnchecked();
1051  }
1052 
1053private:
1054  Expected<T> *ValOrErr;
1055};
1056 
1057/// This class wraps a std::error_code in a Error.
1058///
1059/// This is useful if you're writing an interface that returns a Error
1060/// (or Expected) and you want to call code that still returns
1061/// std::error_codes.
1062class ECError : public ErrorInfo<ECError> {
1063  friend Error errorCodeToError(std::error_code);
1064 
1065public:
1066  void setErrorCode(std::error_code EC) { this->EC = EC; }
1067  std::error_code convertToErrorCode() const override { return EC; }
1068  void log(raw_ostream &OS) const override { OS << EC.message(); }
1069 
1070  // Used by ErrorInfo::classID.
1071  static char ID;
1072 
1073protected:
1074  ECError() = default;
1075  ECError(std::error_code EC) : EC(EC) {}
1076 
1077  std::error_code EC;
1078};
1079 
1080/// The value returned by this function can be returned from convertToErrorCode
1081/// for Error values where no sensible translation to std::error_code exists.
1082/// It should only be used in this situation, and should never be used where a
1083/// sensible conversion to std::error_code is available, as attempts to convert
1084/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1085///error to try to convert such a value).
1086std::error_code inconvertibleErrorCode();
1087 
1088/// Helper for converting an std::error_code to a Error.
1089Error errorCodeToError(std::error_code EC);
1090 
1091/// Helper for converting an ECError to a std::error_code.
1092///
1093/// This method requires that Err be Error() or an ECError, otherwise it
1094/// will trigger a call to abort().
1095std::error_code errorToErrorCode(Error Err);
1096 
1097/// Convert an ErrorOr<T> to an Expected<T>.
1098template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1099  if (auto EC = EO.getError())
1100    return errorCodeToError(EC);
1101  return std::move(*EO);
1102}
1103 
1104/// Convert an Expected<T> to an ErrorOr<T>.
1105template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1106  if (auto Err = E.takeError())
1107    return errorToErrorCode(std::move(Err));
1108  return std::move(*E);
1109}
1110 
1111/// This class wraps a string in an Error.
1112///
1113/// StringError is useful in cases where the client is not expected to be able
1114/// to consume the specific error message programmatically (for example, if the
1115/// error message is to be presented to the user).
1116///
1117/// StringError can also be used when additional information is to be printed
1118/// along with a error_code message. Depending on the constructor called, this
1119/// class can either display:
1120///    1. the error_code message (ECError behavior)
1121///    2. a string
1122///    3. the error_code message and a string
1123///
1124/// These behaviors are useful when subtyping is required; for example, when a
1125/// specific library needs an explicit error type. In the example below,
1126/// PDBError is derived from StringError:
1127///
1128///   @code{.cpp}
1129///   Expected<int> foo() {
1130///      return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1131///                                        "Additional information");
1132///   }
1133///   @endcode
1134///
1135class StringError : public ErrorInfo<StringError> {
1136public:
1137  static char ID;
1138 
1139  // Prints EC + S and converts to EC
1140  StringError(std::error_code EC, const Twine &S = Twine());
1141 
1142  // Prints S and converts to EC
1143  StringError(const Twine &S, std::error_code EC);
1144 
1145  void log(raw_ostream &OS) const override;
1146  std::error_code convertToErrorCode() const override;
1147 
1148  const std::string &getMessage() const { return Msg; }
1149 
1150private:
1151  std::string Msg;
1152  std::error_code EC;
1153  const bool PrintMsgOnly = false;
1154};
1155 
1156/// Create formatted StringError object.
1157template <typename... Ts>
1158Error createStringError(std::error_code EC, char const *Fmt,
1159                        const Ts &... Vals) {
1160  std::string Buffer;
1161  raw_string_ostream Stream(Buffer);
1162  Stream << format(Fmt, Vals...);
1163  return make_error<StringError>(Stream.str(), EC);
1164}
1165 
1166Error createStringError(std::error_code EC, char const *Msg);
1167 
1168/// This class wraps a filename and another Error.
1169///
1170/// In some cases, an error needs to live along a 'source' name, in order to
1171/// show more detailed information to the user.
1172class FileError final : public ErrorInfo<FileError> {
1173 
1174  friend Error createFileError(std::string, Error);
1175 
1176public:
1177  void log(raw_ostream &OS) const override {
1178    assert(Err && !FileName.empty() && "Trying to log after takeError().")((Err && !FileName.empty() && "Trying to log after takeError()."
) ? static_cast<void> (0) : __assert_fail ("Err && !FileName.empty() && \"Trying to log after takeError().\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1178, __PRETTY_FUNCTION__));
1179    OS << "'" << FileName << "': ";
1180    Err->log(OS);
1181  }
1182 
1183  Error takeError() { return Error(std::move(Err)); }
1184 
1185  std::error_code convertToErrorCode() const override;
1186 
1187  // Used by ErrorInfo::classID.
1188  static char ID;
1189 
1190private:
1191  FileError(std::string F, std::unique_ptr<ErrorInfoBase> E) {
1192    assert(E && "Cannot create FileError from Error success value.")((E && "Cannot create FileError from Error success value."
) ? static_cast<void> (0) : __assert_fail ("E && \"Cannot create FileError from Error success value.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1192, __PRETTY_FUNCTION__));
1193    assert(!F.empty() &&((!F.empty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.empty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1194, __PRETTY_FUNCTION__))
1194           "The file name provided to FileError must not be empty.")((!F.empty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.empty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1194, __PRETTY_FUNCTION__));
1195    FileName = F;
1196    Err = std::move(E);
1197  }
1198 
1199  static Error build(std::string F, Error E) {
1200    return Error(std::unique_ptr<FileError>(new FileError(F, E.takePayload())));
1201  }
1202 
1203  std::string FileName;
1204  std::unique_ptr<ErrorInfoBase> Err;
1205};
1206 
1207/// Concatenate a source file path and/or name with an Error. The resulting
1208/// Error is unchecked.
1209inline Error createFileError(std::string F, Error E) {
1210  return FileError::build(F, std::move(E));
1211}
1212 
1213Error createFileError(std::string F, ErrorSuccess) = delete;
1214 
1215/// Helper for check-and-exit error handling.
1216///
1217/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1218///
1219class ExitOnError {
1220public:
1221  /// Create an error on exit helper.
1222  ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1223      : Banner(std::move(Banner)),
1224        GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1225 
1226  /// Set the banner string for any errors caught by operator().
1227  void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1228 
1229  /// Set the exit-code mapper function.
1230  void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1231    this->GetExitCode = std::move(GetExitCode);
1232  }
1233 
1234  /// Check Err. If it's in a failure state log the error(s) and exit.
1235  void operator()(Error Err) const { checkError(std::move(Err)); }
1236 
1237  /// Check E. If it's in a success state then return the contained value. If
1238  /// it's in a failure state log the error(s) and exit.
1239  template <typename T> T operator()(Expected<T> &&E) const {
1240    checkError(E.takeError());
1241    return std::move(*E);
1242  }
1243 
1244  /// Check E. If it's in a success state then return the contained reference. If
1245  /// it's in a failure state log the error(s) and exit.
1246  template <typename T> T& operator()(Expected<T&> &&E) const {
1247    checkError(E.takeError());
1248    return *E;
1249  }
1250 
1251private:
1252  void checkError(Error Err) const {
1253    if (Err) {
1254      int ExitCode = GetExitCode(Err);
1255      logAllUnhandledErrors(std::move(Err), errs(), Banner);
1256      exit(ExitCode);
1257    }
1258  }
1259 
1260  std::string Banner;
1261  std::function<int(const Error &)> GetExitCode;
1262};
1263 
1264/// Conversion from Error to LLVMErrorRef for C error bindings.
1265inline LLVMErrorRef wrap(Error Err) {
1266  return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1267}
1268 
1269/// Conversion from LLVMErrorRef to Error for C error bindings.
1270inline Error unwrap(LLVMErrorRef ErrRef) {
1271  return Error(std::unique_ptr<ErrorInfoBase>(
1272      reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1273}
1274 
1275} // end namespace llvm
1276 
1277#endif // LLVM_SUPPORT_ERROR_H

←

/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h

1//===- llvm/ADT/STLExtras.h - Useful STL related functions ------*- 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// This file contains some templates that are useful if you are working with the
11// STL at all.
12//
13// No library is required when using these functions.
14//
15//===----------------------------------------------------------------------===//
16 
17#ifndef LLVM_ADT_STLEXTRAS_H
18#define LLVM_ADT_STLEXTRAS_H
19 
20#include "llvm/ADT/Optional.h"
21#include "llvm/ADT/SmallVector.h"
22#include "llvm/ADT/iterator.h"
23#include "llvm/ADT/iterator_range.h"
24#include "llvm/Config/abi-breaking.h"
25#include "llvm/Support/ErrorHandling.h"
26#include <algorithm>
27#include <cassert>
28#include <cstddef>
29#include <cstdint>
30#include <cstdlib>
31#include <functional>
32#include <initializer_list>
33#include <iterator>
34#include <limits>
35#include <memory>
36#include <tuple>
37#include <type_traits>
38#include <utility>
39 
40#ifdef EXPENSIVE_CHECKS
41#include <random> // for std::mt19937
42#endif
43 
44namespace llvm {
45 
46// Only used by compiler if both template types are the same.  Useful when
47// using SFINAE to test for the existence of member functions.
48template <typename T, T> struct SameType;
49 
50namespace detail {
51 
52template <typename RangeT>
53using IterOfRange = decltype(std::begin(std::declval<RangeT &>()));
54 
55template <typename RangeT>
56using ValueOfRange = typename std::remove_reference<decltype(
57    *std::begin(std::declval<RangeT &>()))>::type;
58 
59} // end namespace detail
60 
61//===----------------------------------------------------------------------===//
62//     Extra additions to <type_traits>
63//===----------------------------------------------------------------------===//
64 
65template <typename T>
66struct negation : std::integral_constant<bool, !bool(T::value)> {};
67 
68template <typename...> struct conjunction : std::true_type {};
69template <typename B1> struct conjunction<B1> : B1 {};
70template <typename B1, typename... Bn>
71struct conjunction<B1, Bn...>
72    : std::conditional<bool(B1::value), conjunction<Bn...>, B1>::type {};
73 
74//===----------------------------------------------------------------------===//
75//     Extra additions to <functional>
76//===----------------------------------------------------------------------===//
77 
78template <class Ty> struct identity {
79  using argument_type = Ty;
80 
81  Ty &operator()(Ty &self) const {
82    return self;
83  }
84  const Ty &operator()(const Ty &self) const {
85    return self;
86  }
87};
88 
89template <class Ty> struct less_ptr {
90  bool operator()(const Ty* left, const Ty* right) const {
91    return *left < *right;
92  }
93};
94 
95template <class Ty> struct greater_ptr {
96  bool operator()(const Ty* left, const Ty* right) const {
97    return *right < *left;
98  }
99};
100 
101/// An efficient, type-erasing, non-owning reference to a callable. This is
102/// intended for use as the type of a function parameter that is not used
103/// after the function in question returns.
104///
105/// This class does not own the callable, so it is not in general safe to store
106/// a function_ref.
107template<typename Fn> class function_ref;
108 
109template<typename Ret, typename ...Params>
110class function_ref<Ret(Params...)> {
111  Ret (*callback)(intptr_t callable, Params ...params) = nullptr;
112  intptr_t callable;
113 
114  template<typename Callable>
115  static Ret callback_fn(intptr_t callable, Params ...params) {
116    return (*reinterpret_cast<Callable*>(callable))(
117        std::forward<Params>(params)...);
118  }
119 
120public:
121  function_ref() = default;
122  function_ref(std::nullptr_t) {}
123 
124  template <typename Callable>
125  function_ref(Callable &&callable,
126               typename std::enable_if<
127                   !std::is_same<typename std::remove_reference<Callable>::type,
128                                 function_ref>::value>::type * = nullptr)
129      : callback(callback_fn<typename std::remove_reference<Callable>::type>),
130        callable(reinterpret_cast<intptr_t>(&callable)) {}
131 
132  Ret operator()(Params ...params) const {
133    return callback(callable, std::forward<Params>(params)...);
134  }
135 
136  operator bool() const { return callback; }
137};
138 
139// deleter - Very very very simple method that is used to invoke operator
140// delete on something.  It is used like this:
141//
142//   for_each(V.begin(), B.end(), deleter<Interval>);
143template <class T>
144inline void deleter(T *Ptr) {
145  delete Ptr;
146}
147 
148//===----------------------------------------------------------------------===//
149//     Extra additions to <iterator>
150//===----------------------------------------------------------------------===//
151 
152namespace adl_detail {
153 
154using std::begin;
155 
156template <typename ContainerTy>
157auto adl_begin(ContainerTy &&container)
158    -> decltype(begin(std::forward<ContainerTy>(container))) {
159  return begin(std::forward<ContainerTy>(container));
160}
161 
162using std::end;
163 
164template <typename ContainerTy>
165auto adl_end(ContainerTy &&container)
166    -> decltype(end(std::forward<ContainerTy>(container))) {
167  return end(std::forward<ContainerTy>(container));
168}
169 
170using std::swap;
171 
172template <typename T>
173void adl_swap(T &&lhs, T &&rhs) noexcept(noexcept(swap(std::declval<T>(),
174                                                       std::declval<T>()))) {
175  swap(std::forward<T>(lhs), std::forward<T>(rhs));
176}
177 
178} // end namespace adl_detail
179 
180template <typename ContainerTy>
181auto adl_begin(ContainerTy &&container)
182    -> decltype(adl_detail::adl_begin(std::forward<ContainerTy>(container))) {
183  return adl_detail::adl_begin(std::forward<ContainerTy>(container));
184}
185 
186template <typename ContainerTy>
187auto adl_end(ContainerTy &&container)
188    -> decltype(adl_detail::adl_end(std::forward<ContainerTy>(container))) {
189  return adl_detail::adl_end(std::forward<ContainerTy>(container));
190}
191 
192template <typename T>
193void adl_swap(T &&lhs, T &&rhs) noexcept(
194    noexcept(adl_detail::adl_swap(std::declval<T>(), std::declval<T>()))) {
195  adl_detail::adl_swap(std::forward<T>(lhs), std::forward<T>(rhs));
196}
197 
198// mapped_iterator - This is a simple iterator adapter that causes a function to
199// be applied whenever operator* is invoked on the iterator.
200 
201template <typename ItTy, typename FuncTy,
202          typename FuncReturnTy =
203            decltype(std::declval<FuncTy>()(*std::declval<ItTy>()))>
204class mapped_iterator
205    : public iterator_adaptor_base<
206             mapped_iterator<ItTy, FuncTy>, ItTy,
207             typename std::iterator_traits<ItTy>::iterator_category,
208             typename std::remove_reference<FuncReturnTy>::type> {
209public:
210  mapped_iterator(ItTy U, FuncTy F)
211    : mapped_iterator::iterator_adaptor_base(std::move(U)), F(std::move(F)) {}
212 
213  ItTy getCurrent() { return this->I; }
214 
215  FuncReturnTy operator*() { return F(*this->I); }
216 
217private:
218  FuncTy F;
219};
220 
221// map_iterator - Provide a convenient way to create mapped_iterators, just like
222// make_pair is useful for creating pairs...
223template <class ItTy, class FuncTy>
224inline mapped_iterator<ItTy, FuncTy> map_iterator(ItTy I, FuncTy F) {
225  return mapped_iterator<ItTy, FuncTy>(std::move(I), std::move(F));
226}
227 
228/// Helper to determine if type T has a member called rbegin().
229template <typename Ty> class has_rbegin_impl {
230  using yes = char[1];
231  using no = char[2];
232 
233  template <typename Inner>
234  static yes& test(Inner *I, decltype(I->rbegin()) * = nullptr);
235 
236  template <typename>
237  static no& test(...);
238 
239public:
240  static const bool value = sizeof(test<Ty>(nullptr)) == sizeof(yes);
241};
242 
243/// Metafunction to determine if T& or T has a member called rbegin().
244template <typename Ty>
245struct has_rbegin : has_rbegin_impl<typename std::remove_reference<Ty>::type> {
246};
247 
248// Returns an iterator_range over the given container which iterates in reverse.
249// Note that the container must have rbegin()/rend() methods for this to work.
250template <typename ContainerTy>
251auto reverse(ContainerTy &&C,
252             typename std::enable_if<has_rbegin<ContainerTy>::value>::type * =
253                 nullptr) -> decltype(make_range(C.rbegin(), C.rend())) {
254  return make_range(C.rbegin(), C.rend());
255}
256 
257// Returns a std::reverse_iterator wrapped around the given iterator.
258template <typename IteratorTy>
259std::reverse_iterator<IteratorTy> make_reverse_iterator(IteratorTy It) {
260  return std::reverse_iterator<IteratorTy>(It);
261}
262 
263// Returns an iterator_range over the given container which iterates in reverse.
264// Note that the container must have begin()/end() methods which return
265// bidirectional iterators for this to work.
266template <typename ContainerTy>
267auto reverse(
268    ContainerTy &&C,
269    typename std::enable_if<!has_rbegin<ContainerTy>::value>::type * = nullptr)
270    -> decltype(make_range(llvm::make_reverse_iterator(std::end(C)),
271                           llvm::make_reverse_iterator(std::begin(C)))) {
272  return make_range(llvm::make_reverse_iterator(std::end(C)),
273                    llvm::make_reverse_iterator(std::begin(C)));
274}
275 
276/// An iterator adaptor that filters the elements of given inner iterators.
277///
278/// The predicate parameter should be a callable object that accepts the wrapped
279/// iterator's reference type and returns a bool. When incrementing or
280/// decrementing the iterator, it will call the predicate on each element and
281/// skip any where it returns false.
282///
283/// \code
284///   int A[] = { 1, 2, 3, 4 };
285///   auto R = make_filter_range(A, [](int N) { return N % 2 == 1; });
286///   // R contains { 1, 3 }.
287/// \endcode
288///
289/// Note: filter_iterator_base implements support for forward iteration.
290/// filter_iterator_impl exists to provide support for bidirectional iteration,
291/// conditional on whether the wrapped iterator supports it.
292template <typename WrappedIteratorT, typename PredicateT, typename IterTag>
293class filter_iterator_base
294    : public iterator_adaptor_base<
295          filter_iterator_base<WrappedIteratorT, PredicateT, IterTag>,
296          WrappedIteratorT,
297          typename std::common_type<
298              IterTag, typename std::iterator_traits<
299                           WrappedIteratorT>::iterator_category>::type> {
300  using BaseT = iterator_adaptor_base<
301      filter_iterator_base<WrappedIteratorT, PredicateT, IterTag>,
302      WrappedIteratorT,
303      typename std::common_type<
304          IterTag, typename std::iterator_traits<
305                       WrappedIteratorT>::iterator_category>::type>;
306 
307protected:
308  WrappedIteratorT End;
309  PredicateT Pred;
310 
311  void findNextValid() {
312    while (this->I != End && !Pred(*this->I))
313      BaseT::operator++();
314  }
315 
316  // Construct the iterator. The begin iterator needs to know where the end
317  // is, so that it can properly stop when it gets there. The end iterator only
318  // needs the predicate to support bidirectional iteration.
319  filter_iterator_base(WrappedIteratorT Begin, WrappedIteratorT End,
320                       PredicateT Pred)
321      : BaseT(Begin), End(End), Pred(Pred) {
322    findNextValid();
323  }
324 
325public:
326  using BaseT::operator++;
327 
328  filter_iterator_base &operator++() {
329    BaseT::operator++();
330    findNextValid();
331    return *this;
332  }
333};
334 
335/// Specialization of filter_iterator_base for forward iteration only.
336template <typename WrappedIteratorT, typename PredicateT,
337          typename IterTag = std::forward_iterator_tag>
338class filter_iterator_impl
339    : public filter_iterator_base<WrappedIteratorT, PredicateT, IterTag> {
340  using BaseT = filter_iterator_base<WrappedIteratorT, PredicateT, IterTag>;
341 
342public:
343  filter_iterator_impl(WrappedIteratorT Begin, WrappedIteratorT End,
344                       PredicateT Pred)
345      : BaseT(Begin, End, Pred) {}
346};
347 
348/// Specialization of filter_iterator_base for bidirectional iteration.
349template <typename WrappedIteratorT, typename PredicateT>
350class filter_iterator_impl<WrappedIteratorT, PredicateT,
351                           std::bidirectional_iterator_tag>
352    : public filter_iterator_base<WrappedIteratorT, PredicateT,
353                                  std::bidirectional_iterator_tag> {
354  using BaseT = filter_iterator_base<WrappedIteratorT, PredicateT,
355                                     std::bidirectional_iterator_tag>;
356  void findPrevValid() {
357    while (!this->Pred(*this->I))
358      BaseT::operator--();
359  }
360 
361public:
362  using BaseT::operator--;
363 
364  filter_iterator_impl(WrappedIteratorT Begin, WrappedIteratorT End,
365                       PredicateT Pred)
366      : BaseT(Begin, End, Pred) {}
367 
368  filter_iterator_impl &operator--() {
369    BaseT::operator--();
370    findPrevValid();
371    return *this;
372  }
373};
374 
375namespace detail {
376 
377template <bool is_bidirectional> struct fwd_or_bidi_tag_impl {
378  using type = std::forward_iterator_tag;
379};
380 
381template <> struct fwd_or_bidi_tag_impl<true> {
382  using type = std::bidirectional_iterator_tag;
383};
384 
385/// Helper which sets its type member to forward_iterator_tag if the category
386/// of \p IterT does not derive from bidirectional_iterator_tag, and to
387/// bidirectional_iterator_tag otherwise.
388template <typename IterT> struct fwd_or_bidi_tag {
389  using type = typename fwd_or_bidi_tag_impl<std::is_base_of<
390      std::bidirectional_iterator_tag,
391      typename std::iterator_traits<IterT>::iterator_category>::value>::type;
392};
393 
394} // namespace detail
395 
396/// Defines filter_iterator to a suitable specialization of
397/// filter_iterator_impl, based on the underlying iterator's category.
398template <typename WrappedIteratorT, typename PredicateT>
399using filter_iterator = filter_iterator_impl<
400    WrappedIteratorT, PredicateT,
401    typename detail::fwd_or_bidi_tag<WrappedIteratorT>::type>;
402 
403/// Convenience function that takes a range of elements and a predicate,
404/// and return a new filter_iterator range.
405///
406/// FIXME: Currently if RangeT && is a rvalue reference to a temporary, the
407/// lifetime of that temporary is not kept by the returned range object, and the
408/// temporary is going to be dropped on the floor after the make_iterator_range
409/// full expression that contains this function call.
410template <typename RangeT, typename PredicateT>
411iterator_range<filter_iterator<detail::IterOfRange<RangeT>, PredicateT>>
412make_filter_range(RangeT &&Range, PredicateT Pred) {
413  using FilterIteratorT =
414      filter_iterator<detail::IterOfRange<RangeT>, PredicateT>;
415  return make_range(
416      FilterIteratorT(std::begin(std::forward<RangeT>(Range)),
417                      std::end(std::forward<RangeT>(Range)), Pred),
418      FilterIteratorT(std::end(std::forward<RangeT>(Range)),
419                      std::end(std::forward<RangeT>(Range)), Pred));
420}
421 
422/// A pseudo-iterator adaptor that is designed to implement "early increment"
423/// style loops.
424///
425/// This is *not a normal iterator* and should almost never be used directly. It
426/// is intended primarily to be used with range based for loops and some range
427/// algorithms.
428///
429/// The iterator isn't quite an `OutputIterator` or an `InputIterator` but
430/// somewhere between them. The constraints of these iterators are:
431///
432/// - On construction or after being incremented, it is comparable and
433///   dereferencable. It is *not* incrementable.
434/// - After being dereferenced, it is neither comparable nor dereferencable, it
435///   is only incrementable.
436///
437/// This means you can only dereference the iterator once, and you can only
438/// increment it once between dereferences.
439template <typename WrappedIteratorT>
440class early_inc_iterator_impl
441    : public iterator_adaptor_base<early_inc_iterator_impl<WrappedIteratorT>,
442                                   WrappedIteratorT, std::input_iterator_tag> {
443  using BaseT =
444      iterator_adaptor_base<early_inc_iterator_impl<WrappedIteratorT>,
445                            WrappedIteratorT, std::input_iterator_tag>;
446 
447  using PointerT = typename std::iterator_traits<WrappedIteratorT>::pointer;
448 
449protected:
450#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
451  bool IsEarlyIncremented = false;
452#endif
453 
454public:
455  early_inc_iterator_impl(WrappedIteratorT I) : BaseT(I) {}
456 
457  using BaseT::operator*;
458  typename BaseT::reference operator*() {
459#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
460    assert(!IsEarlyIncremented && "Cannot dereference twice!")((!IsEarlyIncremented && "Cannot dereference twice!")
 ? static_cast<void> (0) : __assert_fail ("!IsEarlyIncremented && \"Cannot dereference twice!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h"
, 460, __PRETTY_FUNCTION__));
461    IsEarlyIncremented = true;
462#endif
463    return *(this->I)++;
464  }
465 
466  using BaseT::operator++;
467  early_inc_iterator_impl &operator++() {
468#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
469    assert(IsEarlyIncremented && "Cannot increment before dereferencing!")((IsEarlyIncremented && "Cannot increment before dereferencing!"
) ? static_cast<void> (0) : __assert_fail ("IsEarlyIncremented && \"Cannot increment before dereferencing!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h"
, 469, __PRETTY_FUNCTION__));
470    IsEarlyIncremented = false;
471#endif
472    return *this;
473  }
474 
475  using BaseT::operator==;
476  bool operator==(const early_inc_iterator_impl &RHS) const {
477#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
478    assert(!IsEarlyIncremented && "Cannot compare after dereferencing!")((!IsEarlyIncremented && "Cannot compare after dereferencing!"
) ? static_cast<void> (0) : __assert_fail ("!IsEarlyIncremented && \"Cannot compare after dereferencing!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h"
, 478, __PRETTY_FUNCTION__));
479#endif
480    return BaseT::operator==(RHS);
481  }
482};
483 
484/// Make a range that does early increment to allow mutation of the underlying
485/// range without disrupting iteration.
486///
487/// The underlying iterator will be incremented immediately after it is
488/// dereferenced, allowing deletion of the current node or insertion of nodes to
489/// not disrupt iteration provided they do not invalidate the *next* iterator --
490/// the current iterator can be invalidated.
491///
492/// This requires a very exact pattern of use that is only really suitable to
493/// range based for loops and other range algorithms that explicitly guarantee
494/// to dereference exactly once each element, and to increment exactly once each
495/// element.
496template <typename RangeT>
497iterator_range<early_inc_iterator_impl<detail::IterOfRange<RangeT>>>
498make_early_inc_range(RangeT &&Range) {
499  using EarlyIncIteratorT =
500      early_inc_iterator_impl<detail::IterOfRange<RangeT>>;
501  return make_range(EarlyIncIteratorT(std::begin(std::forward<RangeT>(Range))),
502                    EarlyIncIteratorT(std::end(std::forward<RangeT>(Range))));
503}
504 
505// forward declarations required by zip_shortest/zip_first
506template <typename R, typename UnaryPredicate>
507bool all_of(R &&range, UnaryPredicate P);
508 
509template <size_t... I> struct index_sequence;
510 
511template <class... Ts> struct index_sequence_for;
512 
513namespace detail {
514 
515using std::declval;
516 
517// We have to alias this since inlining the actual type at the usage site
518// in the parameter list of iterator_facade_base<> below ICEs MSVC 2017.
519template<typename... Iters> struct ZipTupleType {
520  using type = std::tuple<decltype(*declval<Iters>())...>;
521};
522 
523template <typename ZipType, typename... Iters>
524using zip_traits = iterator_facade_base<
525    ZipType, typename std::common_type<std::bidirectional_iterator_tag,
526                                       typename std::iterator_traits<
527                                           Iters>::iterator_category...>::type,
528    // ^ TODO: Implement random access methods.
529    typename ZipTupleType<Iters...>::type,
530    typename std::iterator_traits<typename std::tuple_element<
531        0, std::tuple<Iters...>>::type>::difference_type,
532    // ^ FIXME: This follows boost::make_zip_iterator's assumption that all
533    // inner iterators have the same difference_type. It would fail if, for
534    // instance, the second field's difference_type were non-numeric while the
535    // first is.
536    typename ZipTupleType<Iters...>::type *,
537    typename ZipTupleType<Iters...>::type>;
538 
539template <typename ZipType, typename... Iters>
540struct zip_common : public zip_traits<ZipType, Iters...> {
541  using Base = zip_traits<ZipType, Iters...>;
542  using value_type = typename Base::value_type;
543 
544  std::tuple<Iters...> iterators;
545 
546protected:
547  template <size_t... Ns> value_type deref(index_sequence<Ns...>) const {
548    return value_type(*std::get<Ns>(iterators)...);
549  }
550 
551  template <size_t... Ns>
552  decltype(iterators) tup_inc(index_sequence<Ns...>) const {
553    return std::tuple<Iters...>(std::next(std::get<Ns>(iterators))...);
554  }
555 
556  template <size_t... Ns>
557  decltype(iterators) tup_dec(index_sequence<Ns...>) const {
558    return std::tuple<Iters...>(std::prev(std::get<Ns>(iterators))...);
559  }
560 
561public:
562  zip_common(Iters &&... ts) : iterators(std::forward<Iters>(ts)...) {}
563 
564  value_type operator*() { return deref(index_sequence_for<Iters...>{}); }
565 
566  const value_type operator*() const {
567    return deref(index_sequence_for<Iters...>{});
568  }
569 
570  ZipType &operator++() {
571    iterators = tup_inc(index_sequence_for<Iters...>{});
572    return *reinterpret_cast<ZipType *>(this);
573  }
574 
575  ZipType &operator--() {
576    static_assert(Base::IsBidirectional,
577                  "All inner iterators must be at least bidirectional.");
578    iterators = tup_dec(index_sequence_for<Iters...>{});
579    return *reinterpret_cast<ZipType *>(this);
580  }
581};
582 
583template <typename... Iters>
584struct zip_first : public zip_common<zip_first<Iters...>, Iters...> {
585  using Base = zip_common<zip_first<Iters...>, Iters...>;
586 
587  bool operator==(const zip_first<Iters...> &other) const {
588    return std::get<0>(this->iterators) == std::get<0>(other.iterators);
589  }
590 
591  zip_first(Iters &&... ts) : Base(std::forward<Iters>(ts)...) {}
592};
593 
594template <typename... Iters>
595class zip_shortest : public zip_common<zip_shortest<Iters...>, Iters...> {
596  template <size_t... Ns>
597  bool test(const zip_shortest<Iters...> &other, index_sequence<Ns...>) const {
598    return all_of(std::initializer_list<bool>{std::get<Ns>(this->iterators) !=
599                                              std::get<Ns>(other.iterators)...},
600                  identity<bool>{});
601  }
602 
603public:
604  using Base = zip_common<zip_shortest<Iters...>, Iters...>;
605 
606  zip_shortest(Iters &&... ts) : Base(std::forward<Iters>(ts)...) {}
607 
608  bool operator==(const zip_shortest<Iters...> &other) const {
609    return !test(other, index_sequence_for<Iters...>{});
610  }
611};
612 
613template <template <typename...> class ItType, typename... Args> class zippy {
614public:
615  using iterator = ItType<decltype(std::begin(std::declval<Args>()))...>;
616  using iterator_category = typename iterator::iterator_category;
617  using value_type = typename iterator::value_type;
618  using difference_type = typename iterator::difference_type;
619  using pointer = typename iterator::pointer;
620  using reference = typename iterator::reference;
621 
622private:
623  std::tuple<Args...> ts;
624 
625  template <size_t... Ns> iterator begin_impl(index_sequence<Ns...>) const {
626    return iterator(std::begin(std::get<Ns>(ts))...);
627  }
628  template <size_t... Ns> iterator end_impl(index_sequence<Ns...>) const {
629    return iterator(std::end(std::get<Ns>(ts))...);
630  }
631 
632public:
633  zippy(Args &&... ts_) : ts(std::forward<Args>(ts_)...) {}
634 
635  iterator begin() const { return begin_impl(index_sequence_for<Args...>{}); }
636  iterator end() const { return end_impl(index_sequence_for<Args...>{}); }
637};
638 
639} // end namespace detail
640 
641/// zip iterator for two or more iteratable types.
642template <typename T, typename U, typename... Args>
643detail::zippy<detail::zip_shortest, T, U, Args...> zip(T &&t, U &&u,
644                                                       Args &&... args) {
645  return detail::zippy<detail::zip_shortest, T, U, Args...>(
646      std::forward<T>(t), std::forward<U>(u), std::forward<Args>(args)...);
647}
648 
649/// zip iterator that, for the sake of efficiency, assumes the first iteratee to
650/// be the shortest.
651template <typename T, typename U, typename... Args>
652detail::zippy<detail::zip_first, T, U, Args...> zip_first(T &&t, U &&u,
653                                                          Args &&... args) {
654  return detail::zippy<detail::zip_first, T, U, Args...>(
655      std::forward<T>(t), std::forward<U>(u), std::forward<Args>(args)...);
656}
657 
658/// Iterator wrapper that concatenates sequences together.
659///
660/// This can concatenate different iterators, even with different types, into
661/// a single iterator provided the value types of all the concatenated
662/// iterators expose `reference` and `pointer` types that can be converted to
663/// `ValueT &` and `ValueT *` respectively. It doesn't support more
664/// interesting/customized pointer or reference types.
665///
666/// Currently this only supports forward or higher iterator categories as
667/// inputs and always exposes a forward iterator interface.
668template <typename ValueT, typename... IterTs>
669class concat_iterator
670    : public iterator_facade_base<concat_iterator<ValueT, IterTs...>,
671                                  std::forward_iterator_tag, ValueT> {
672  using BaseT = typename concat_iterator::iterator_facade_base;
673 
674  /// We store both the current and end iterators for each concatenated
675  /// sequence in a tuple of pairs.
676  ///
677  /// Note that something like iterator_range seems nice at first here, but the
678  /// range properties are of little benefit and end up getting in the way
679  /// because we need to do mutation on the current iterators.
680  std::tuple<IterTs...> Begins;
681  std::tuple<IterTs...> Ends;
682 
683  /// Attempts to increment a specific iterator.
684  ///
685  /// Returns true if it was able to increment the iterator. Returns false if
686  /// the iterator is already at the end iterator.
687  template <size_t Index> bool incrementHelper() {
688    auto &Begin = std::get<Index>(Begins);
689    auto &End = std::get<Index>(Ends);
690    if (Begin == End)
691      return false;
692 
693    ++Begin;
694    return true;
695  }
696 
697  /// Increments the first non-end iterator.
698  ///
699  /// It is an error to call this with all iterators at the end.
700  template <size_t... Ns> void increment(index_sequence<Ns...>) {
701    // Build a sequence of functions to increment each iterator if possible.
702    bool (concat_iterator::*IncrementHelperFns[])() = {
703        &concat_iterator::incrementHelper<Ns>...};
704 
705    // Loop over them, and stop as soon as we succeed at incrementing one.
706    for (auto &IncrementHelperFn : IncrementHelperFns)
707      if ((this->*IncrementHelperFn)())
708        return;
709 
710    llvm_unreachable("Attempted to increment an end concat iterator!")::llvm::llvm_unreachable_internal("Attempted to increment an end concat iterator!"
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h"
, 710);
711  }
712 
713  /// Returns null if the specified iterator is at the end. Otherwise,
714  /// dereferences the iterator and returns the address of the resulting
715  /// reference.
716  template <size_t Index> ValueT *getHelper() const {
717    auto &Begin = std::get<Index>(Begins);
718    auto &End = std::get<Index>(Ends);
719    if (Begin == End)
720      return nullptr;
721 
722    return &*Begin;
723  }
724 
725  /// Finds the first non-end iterator, dereferences, and returns the resulting
726  /// reference.
727  ///
728  /// It is an error to call this with all iterators at the end.
729  template <size_t... Ns> ValueT &get(index_sequence<Ns...>) const {
730    // Build a sequence of functions to get from iterator if possible.
731    ValueT *(concat_iterator::*GetHelperFns[])() const = {
732        &concat_iterator::getHelper<Ns>...};
733 
734    // Loop over them, and return the first result we find.
735    for (auto &GetHelperFn : GetHelperFns)
736      if (ValueT *P = (this->*GetHelperFn)())
737        return *P;
738 
739    llvm_unreachable("Attempted to get a pointer from an end concat iterator!")::llvm::llvm_unreachable_internal("Attempted to get a pointer from an end concat iterator!"
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h"
, 739);
740  }
741 
742public:
743  /// Constructs an iterator from a squence of ranges.
744  ///
745  /// We need the full range to know how to switch between each of the
746  /// iterators.
747  template <typename... RangeTs>
748  explicit concat_iterator(RangeTs &&... Ranges)
749      : Begins(std::begin(Ranges)...), Ends(std::end(Ranges)...) {}
750 
751  using BaseT::operator++;
752 
753  concat_iterator &operator++() {
754    increment(index_sequence_for<IterTs...>());
755    return *this;
756  }
757 
758  ValueT &operator*() const { return get(index_sequence_for<IterTs...>()); }
759 
760  bool operator==(const concat_iterator &RHS) const {
761    return Begins == RHS.Begins && Ends == RHS.Ends;
762  }
763};
764 
765namespace detail {
766 
767/// Helper to store a sequence of ranges being concatenated and access them.
768///
769/// This is designed to facilitate providing actual storage when temporaries
770/// are passed into the constructor such that we can use it as part of range
771/// based for loops.
772template <typename ValueT, typename... RangeTs> class concat_range {
773public:
774  using iterator =
775      concat_iterator<ValueT,
776                      decltype(std::begin(std::declval<RangeTs &>()))...>;
777 
778private:
779  std::tuple<RangeTs...> Ranges;
780 
781  template <size_t... Ns> iterator begin_impl(index_sequence<Ns...>) {
782    return iterator(std::get<Ns>(Ranges)...);
783  }
784  template <size_t... Ns> iterator end_impl(index_sequence<Ns...>) {
785    return iterator(make_range(std::end(std::get<Ns>(Ranges)),
786                               std::end(std::get<Ns>(Ranges)))...);
787  }
788 
789public:
790  concat_range(RangeTs &&... Ranges)
791      : Ranges(std::forward<RangeTs>(Ranges)...) {}
792 
793  iterator begin() { return begin_impl(index_sequence_for<RangeTs...>{}); }
794  iterator end() { return end_impl(index_sequence_for<RangeTs...>{}); }
795};
796 
797} // end namespace detail
798 
799/// Concatenated range across two or more ranges.
800///
801/// The desired value type must be explicitly specified.
802template <typename ValueT, typename... RangeTs>
803detail::concat_range<ValueT, RangeTs...> concat(RangeTs &&... Ranges) {
804  static_assert(sizeof...(RangeTs) > 1,
805                "Need more than one range to concatenate!");
806  return detail::concat_range<ValueT, RangeTs...>(
807      std::forward<RangeTs>(Ranges)...);
808}
809 
810//===----------------------------------------------------------------------===//
811//     Extra additions to <utility>
812//===----------------------------------------------------------------------===//
813 
814/// Function object to check whether the first component of a std::pair
815/// compares less than the first component of another std::pair.
816struct less_first {
817  template <typename T> bool operator()(const T &lhs, const T &rhs) const {
818    return lhs.first < rhs.first;
819  }
820};
821 
822/// Function object to check whether the second component of a std::pair
823/// compares less than the second component of another std::pair.
824struct less_second {
825  template <typename T> bool operator()(const T &lhs, const T &rhs) const {
826    return lhs.second < rhs.second;
827  }
828};
829 
830/// \brief Function object to apply a binary function to the first component of
831/// a std::pair.
832template<typename FuncTy>
833struct on_first {
834  FuncTy func;
835 
836  template <typename T>
837  auto operator()(const T &lhs, const T &rhs) const
838      -> decltype(func(lhs.first, rhs.first)) {
839    return func(lhs.first, rhs.first);
840  }
841};
842 
843// A subset of N3658. More stuff can be added as-needed.
844 
845/// Represents a compile-time sequence of integers.
846template <class T, T... I> struct integer_sequence {
847  using value_type = T;
848 
849  static constexpr size_t size() { return sizeof...(I); }
850};
851 
852/// Alias for the common case of a sequence of size_ts.
853template <size_t... I>
854struct index_sequence : integer_sequence<std::size_t, I...> {};
855 
856template <std::size_t N, std::size_t... I>
857struct build_index_impl : build_index_impl<N - 1, N - 1, I...> {};
858template <std::size_t... I>
859struct build_index_impl<0, I...> : index_sequence<I...> {};
860 
861/// Creates a compile-time integer sequence for a parameter pack.
862template <class... Ts>
863struct index_sequence_for : build_index_impl<sizeof...(Ts)> {};
864 
865/// Utility type to build an inheritance chain that makes it easy to rank
866/// overload candidates.
867template <int N> struct rank : rank<N - 1> {};
868template <> struct rank<0> {};
869 
870/// traits class for checking whether type T is one of any of the given
871/// types in the variadic list.
872template <typename T, typename... Ts> struct is_one_of {
873  static const bool value = false;
874};
875 
876template <typename T, typename U, typename... Ts>
877struct is_one_of<T, U, Ts...> {
878  static const bool value =
879      std::is_same<T, U>::value || is_one_of<T, Ts...>::value;
880};
881 
882/// traits class for checking whether type T is a base class for all
883///  the given types in the variadic list.
884template <typename T, typename... Ts> struct are_base_of {
885  static const bool value = true;
886};
887 
888template <typename T, typename U, typename... Ts>
889struct are_base_of<T, U, Ts...> {
890  static const bool value =
891      std::is_base_of<T, U>::value && are_base_of<T, Ts...>::value;
892};
893 
894//===----------------------------------------------------------------------===//
895//     Extra additions for arrays
896//===----------------------------------------------------------------------===//
897 
898/// Find the length of an array.
899template <class T, std::size_t N>
900constexpr inline size_t array_lengthof(T (&)[N]) {
901  return N;
902}
903 
904/// Adapt std::less<T> for array_pod_sort.
905template<typename T>
906inline int array_pod_sort_comparator(const void *P1, const void *P2) {
907  if (std::less<T>()(*reinterpret_cast<const T*>(P1),
908                     *reinterpret_cast<const T*>(P2)))
909    return -1;
910  if (std::less<T>()(*reinterpret_cast<const T*>(P2),
911                     *reinterpret_cast<const T*>(P1)))
912    return 1;
913  return 0;
914}
915 
916/// get_array_pod_sort_comparator - This is an internal helper function used to
917/// get type deduction of T right.
918template<typename T>
919inline int (*get_array_pod_sort_comparator(const T &))
920             (const void*, const void*) {
921  return array_pod_sort_comparator<T>;
922}
923 
924/// array_pod_sort - This sorts an array with the specified start and end
925/// extent.  This is just like std::sort, except that it calls qsort instead of
926/// using an inlined template.  qsort is slightly slower than std::sort, but
927/// most sorts are not performance critical in LLVM and std::sort has to be
928/// template instantiated for each type, leading to significant measured code
929/// bloat.  This function should generally be used instead of std::sort where
930/// possible.
931///
932/// This function assumes that you have simple POD-like types that can be
933/// compared with std::less and can be moved with memcpy.  If this isn't true,
934/// you should use std::sort.
935///
936/// NOTE: If qsort_r were portable, we could allow a custom comparator and
937/// default to std::less.
938template<class IteratorTy>
939inline void array_pod_sort(IteratorTy Start, IteratorTy End) {
940  // Don't inefficiently call qsort with one element or trigger undefined
941  // behavior with an empty sequence.
942  auto NElts = End - Start;
943  if (NElts <= 1) return;
944#ifdef EXPENSIVE_CHECKS
945  std::mt19937 Generator(std::random_device{}());
946  std::shuffle(Start, End, Generator);
947#endif
948  qsort(&*Start, NElts, sizeof(*Start), get_array_pod_sort_comparator(*Start));
949}
950 
951template <class IteratorTy>
952inline void array_pod_sort(
953    IteratorTy Start, IteratorTy End,
954    int (*Compare)(
955        const typename std::iterator_traits<IteratorTy>::value_type *,
956        const typename std::iterator_traits<IteratorTy>::value_type *)) {
957  // Don't inefficiently call qsort with one element or trigger undefined
958  // behavior with an empty sequence.
959  auto NElts = End - Start;
960  if (NElts <= 1) return;
961#ifdef EXPENSIVE_CHECKS
962  std::mt19937 Generator(std::random_device{}());
963  std::shuffle(Start, End, Generator);
964#endif
965  qsort(&*Start, NElts, sizeof(*Start),
966        reinterpret_cast<int (*)(const void *, const void *)>(Compare));
967}
968 
969// Provide wrappers to std::sort which shuffle the elements before sorting
970// to help uncover non-deterministic behavior (PR35135).
971template <typename IteratorTy>
972inline void sort(IteratorTy Start, IteratorTy End) {
973#ifdef EXPENSIVE_CHECKS
974  std::mt19937 Generator(std::random_device{}());
975  std::shuffle(Start, End, Generator);
976#endif
977  std::sort(Start, End);
978}
979 
980template <typename Container> inline void sort(Container &&C) {
981  llvm::sort(adl_begin(C), adl_end(C));
982}
983 
984template <typename IteratorTy, typename Compare>
985inline void sort(IteratorTy Start, IteratorTy End, Compare Comp) {
986#ifdef EXPENSIVE_CHECKS
987  std::mt19937 Generator(std::random_device{}());
988  std::shuffle(Start, End, Generator);
989#endif
990  std::sort(Start, End, Comp);
991}
992 
993template <typename Container, typename Compare>
994inline void sort(Container &&C, Compare Comp) {
995  llvm::sort(adl_begin(C), adl_end(C), Comp);
996}
997 
998//===----------------------------------------------------------------------===//
999//     Extra additions to <algorithm>
1000//===----------------------------------------------------------------------===//
1001 
1002/// For a container of pointers, deletes the pointers and then clears the
1003/// container.
1004template<typename Container>
1005void DeleteContainerPointers(Container &C) {
1006  for (auto V : C)
1007    delete V;
1008  C.clear();
1009}
1010 
1011/// In a container of pairs (usually a map) whose second element is a pointer,
1012/// deletes the second elements and then clears the container.
1013template<typename Container>
1014void DeleteContainerSeconds(Container &C) {
1015  for (auto &V : C)
1016    delete V.second;
1017  C.clear();
1018}
1019 
1020/// Get the size of a range. This is a wrapper function around std::distance
1021/// which is only enabled when the operation is O(1).
1022template <typename R>
1023auto size(R &&Range, typename std::enable_if<
1024                         std::is_same<typename std::iterator_traits<decltype(
1025                                          Range.begin())>::iterator_category,
1026                                      std::random_access_iterator_tag>::value,
1027                         void>::type * = nullptr)
1028    -> decltype(std::distance(Range.begin(), Range.end())) {
1029  return std::distance(Range.begin(), Range.end());
1030}
1031 
1032/// Provide wrappers to std::for_each which take ranges instead of having to
1033/// pass begin/end explicitly.
1034template <typename R, typename UnaryPredicate>
1035UnaryPredicate for_each(R &&Range, UnaryPredicate P) {
1036  return std::for_each(adl_begin(Range), adl_end(Range), P);
1037}
1038 
1039/// Provide wrappers to std::all_of which take ranges instead of having to pass
1040/// begin/end explicitly.
1041template <typename R, typename UnaryPredicate>
1042bool all_of(R &&Range, UnaryPredicate P) {
1043  return std::all_of(adl_begin(Range), adl_end(Range), P);
1044}
1045 
1046/// Provide wrappers to std::any_of which take ranges instead of having to pass
1047/// begin/end explicitly.
1048template <typename R, typename UnaryPredicate>
1049bool any_of(R &&Range, UnaryPredicate P) {
1050  return std::any_of(adl_begin(Range), adl_end(Range), P);
1051}
1052 
1053/// Provide wrappers to std::none_of which take ranges instead of having to pass
1054/// begin/end explicitly.
1055template <typename R, typename UnaryPredicate>
1056bool none_of(R &&Range, UnaryPredicate P) {
1057  return std::none_of(adl_begin(Range), adl_end(Range), P);
1058}
1059 
1060/// Provide wrappers to std::find which take ranges instead of having to pass
1061/// begin/end explicitly.
1062template <typename R, typename T>
1063auto find(R &&Range, const T &Val) -> decltype(adl_begin(Range)) {
1064  return std::find(adl_begin(Range), adl_end(Range), Val);
1065}
1066 
1067/// Provide wrappers to std::find_if which take ranges instead of having to pass
1068/// begin/end explicitly.
1069template <typename R, typename UnaryPredicate>
1070auto find_if(R &&Range, UnaryPredicate P) -> decltype(adl_begin(Range)) {
1071  return std::find_if(adl_begin(Range), adl_end(Range), P);
1072}
1073 
1074template <typename R, typename UnaryPredicate>
1075auto find_if_not(R &&Range, UnaryPredicate P) -> decltype(adl_begin(Range)) {
1076  return std::find_if_not(adl_begin(Range), adl_end(Range), P);
1077}
1078 
1079/// Provide wrappers to std::remove_if which take ranges instead of having to
1080/// pass begin/end explicitly.
1081template <typename R, typename UnaryPredicate>
1082auto remove_if(R &&Range, UnaryPredicate P) -> decltype(adl_begin(Range)) {
1083  return std::remove_if(adl_begin(Range), adl_end(Range), P);
1084}
1085 
1086/// Provide wrappers to std::copy_if which take ranges instead of having to
1087/// pass begin/end explicitly.
1088template <typename R, typename OutputIt, typename UnaryPredicate>
1089OutputIt copy_if(R &&Range, OutputIt Out, UnaryPredicate P) {
1090  return std::copy_if(adl_begin(Range), adl_end(Range), Out, P);
1091}
1092 
1093template <typename R, typename OutputIt>
1094OutputIt copy(R &&Range, OutputIt Out) {
1095  return std::copy(adl_begin(Range), adl_end(Range), Out);
1096}
1097 
1098/// Wrapper function around std::find to detect if an element exists
1099/// in a container.
1100template <typename R, typename E>
1101bool is_contained(R &&Range, const E &Element) {
1102  return std::find(adl_begin(Range), adl_end(Range), Element) != adl_end(Range);
1103}
1104 
1105/// Wrapper function around std::count to count the number of times an element
1106/// \p Element occurs in the given range \p Range.
1107template <typename R, typename E>
1108auto count(R &&Range, const E &Element) ->
1109    typename std::iterator_traits<decltype(adl_begin(Range))>::difference_type {
1110  return std::count(adl_begin(Range), adl_end(Range), Element);
1111}
1112 
1113/// Wrapper function around std::count_if to count the number of times an
1114/// element satisfying a given predicate occurs in a range.
1115template <typename R, typename UnaryPredicate>
1116auto count_if(R &&Range, UnaryPredicate P) ->
1117    typename std::iterator_traits<decltype(adl_begin(Range))>::difference_type {
1118  return std::count_if(adl_begin(Range), adl_end(Range), P);
1119}
1120 
1121/// Wrapper function around std::transform to apply a function to a range and
1122/// store the result elsewhere.
1123template <typename R, typename OutputIt, typename UnaryPredicate>
1124OutputIt transform(R &&Range, OutputIt d_first, UnaryPredicate P) {
1125  return std::transform(adl_begin(Range), adl_end(Range), d_first, P);
1126}
1127 
1128/// Provide wrappers to std::partition which take ranges instead of having to
1129/// pass begin/end explicitly.
1130template <typename R, typename UnaryPredicate>
1131auto partition(R &&Range, UnaryPredicate P) -> decltype(adl_begin(Range)) {
1132  return std::partition(adl_begin(Range), adl_end(Range), P);
1133}
1134 
1135/// Provide wrappers to std::lower_bound which take ranges instead of having to
1136/// pass begin/end explicitly.
1137template <typename R, typename ForwardIt>
1138auto lower_bound(R &&Range, ForwardIt I) -> decltype(adl_begin(Range)) {
1139  return std::lower_bound(adl_begin(Range), adl_end(Range), I);
1140}
1141 
1142template <typename R, typename ForwardIt, typename Compare>
1143auto lower_bound(R &&Range, ForwardIt I, Compare C)
1144    -> decltype(adl_begin(Range)) {
1145  return std::lower_bound(adl_begin(Range), adl_end(Range), I, C);
1146}
1147 
1148/// Provide wrappers to std::upper_bound which take ranges instead of having to
1149/// pass begin/end explicitly.
1150template <typename R, typename ForwardIt>
1151auto upper_bound(R &&Range, ForwardIt I) -> decltype(adl_begin(Range)) {
1152  return std::upper_bound(adl_begin(Range), adl_end(Range), I);
1153}
1154 
1155template <typename R, typename ForwardIt, typename Compare>
1156auto upper_bound(R &&Range, ForwardIt I, Compare C)
1157    -> decltype(adl_begin(Range)) {
1158  return std::upper_bound(adl_begin(Range), adl_end(Range), I, C);
1159}
1160/// Wrapper function around std::equal to detect if all elements
1161/// in a container are same.
1162template <typename R>
1163bool is_splat(R &&Range) {
1164  size_t range_size = size(Range);
1165  return range_size != 0 && (range_size == 1 ||
1166         std::equal(adl_begin(Range) + 1, adl_end(Range), adl_begin(Range)));
1167}
1168 
1169/// Given a range of type R, iterate the entire range and return a
1170/// SmallVector with elements of the vector.  This is useful, for example,
1171/// when you want to iterate a range and then sort the results.
1172template <unsigned Size, typename R>
1173SmallVector<typename std::remove_const<detail::ValueOfRange<R>>::type, Size>
1174to_vector(R &&Range) {
1175  return {adl_begin(Range), adl_end(Range)};
1176}
1177 
1178/// Provide a container algorithm similar to C++ Library Fundamentals v2's
1179/// `erase_if` which is equivalent to:
1180///
1181///   C.erase(remove_if(C, pred), C.end());
1182///
1183/// This version works for any container with an erase method call accepting
1184/// two iterators.
1185template <typename Container, typename UnaryPredicate>
1186void erase_if(Container &C, UnaryPredicate P) {
1187  C.erase(remove_if(C, P), C.end());
1188}
1189 
1190//===----------------------------------------------------------------------===//
1191//     Extra additions to <memory>
1192//===----------------------------------------------------------------------===//
1193 
1194// Implement make_unique according to N3656.
1195 
1196/// Constructs a `new T()` with the given args and returns a
1197///        `unique_ptr<T>` which owns the object.
1198///
1199/// Example:
1200///
1201///     auto p = make_unique<int>();
1202///     auto p = make_unique<std::tuple<int, int>>(0, 1);
1203template <class T, class... Args>
1204typename std::enable_if<!std::is_array<T>::value, std::unique_ptr<T>>::type
1205make_unique(Args &&... args) {
1206  return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
11
←
Memory is allocated→
1207}
1208 
1209/// Constructs a `new T[n]` with the given args and returns a
1210///        `unique_ptr<T[]>` which owns the object.
1211///
1212/// \param n size of the new array.
1213///
1214/// Example:
1215///
1216///     auto p = make_unique<int[]>(2); // value-initializes the array with 0's.
1217template <class T>
1218typename std::enable_if<std::is_array<T>::value && std::extent<T>::value == 0,
1219                        std::unique_ptr<T>>::type
1220make_unique(size_t n) {
1221  return std::unique_ptr<T>(new typename std::remove_extent<T>::type[n]());
1222}
1223 
1224/// This function isn't used and is only here to provide better compile errors.
1225template <class T, class... Args>
1226typename std::enable_if<std::extent<T>::value != 0>::type
1227make_unique(Args &&...) = delete;
1228 
1229struct FreeDeleter {
1230  void operator()(void* v) {
1231    ::free(v);
1232  }
1233};
1234 
1235template<typename First, typename Second>
1236struct pair_hash {
1237  size_t operator()(const std::pair<First, Second> &P) const {
1238    return std::hash<First>()(P.first) * 31 + std::hash<Second>()(P.second);
1239  }
1240};
1241 
1242/// A functor like C++14's std::less<void> in its absence.
1243struct less {
1244  template <typename A, typename B> bool operator()(A &&a, B &&b) const {
1245    return std::forward<A>(a) < std::forward<B>(b);
1246  }
1247};
1248 
1249/// A functor like C++14's std::equal<void> in its absence.
1250struct equal {
1251  template <typename A, typename B> bool operator()(A &&a, B &&b) const {
1252    return std::forward<A>(a) == std::forward<B>(b);
1253  }
1254};
1255 
1256/// Binary functor that adapts to any other binary functor after dereferencing
1257/// operands.
1258template <typename T> struct deref {
1259  T func;
1260 
1261  // Could be further improved to cope with non-derivable functors and
1262  // non-binary functors (should be a variadic template member function
1263  // operator()).
1264  template <typename A, typename B>
1265  auto operator()(A &lhs, B &rhs) const -> decltype(func(*lhs, *rhs)) {
1266    assert(lhs)((lhs) ? static_cast<void> (0) : __assert_fail ("lhs", "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h"
, 1266, __PRETTY_FUNCTION__));
1267    assert(rhs)((rhs) ? static_cast<void> (0) : __assert_fail ("rhs", "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h"
, 1267, __PRETTY_FUNCTION__));
1268    return func(*lhs, *rhs);
1269  }
1270};
1271 
1272namespace detail {
1273 
1274template <typename R> class enumerator_iter;
1275 
1276template <typename R> struct result_pair {
1277  friend class enumerator_iter<R>;
1278 
1279  result_pair() = default;
1280  result_pair(std::size_t Index, IterOfRange<R> Iter)
1281      : Index(Index), Iter(Iter) {}
1282 
1283  result_pair<R> &operator=(const result_pair<R> &Other) {
1284    Index = Other.Index;
1285    Iter = Other.Iter;
1286    return *this;
1287  }
1288 
1289  std::size_t index() const { return Index; }
1290  const ValueOfRange<R> &value() const { return *Iter; }
1291  ValueOfRange<R> &value() { return *Iter; }
1292 
1293private:
1294  std::size_t Index = std::numeric_limits<std::size_t>::max();
1295  IterOfRange<R> Iter;
1296};
1297 
1298template <typename R>
1299class enumerator_iter
1300    : public iterator_facade_base<
1301          enumerator_iter<R>, std::forward_iterator_tag, result_pair<R>,
1302          typename std::iterator_traits<IterOfRange<R>>::difference_type,
1303          typename std::iterator_traits<IterOfRange<R>>::pointer,
1304          typename std::iterator_traits<IterOfRange<R>>::reference> {
1305  using result_type = result_pair<R>;
1306 
1307public:
1308  explicit enumerator_iter(IterOfRange<R> EndIter)
1309      : Result(std::numeric_limits<size_t>::max(), EndIter) {}
1310 
1311  enumerator_iter(std::size_t Index, IterOfRange<R> Iter)
1312      : Result(Index, Iter) {}
1313 
1314  result_type &operator*() { return Result; }
1315  const result_type &operator*() const { return Result; }
1316 
1317  enumerator_iter<R> &operator++() {
1318    assert(Result.Index != std::numeric_limits<size_t>::max())((Result.Index != std::numeric_limits<size_t>::max()) ?
 static_cast<void> (0) : __assert_fail ("Result.Index != std::numeric_limits<size_t>::max()"
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/STLExtras.h"
, 1318, __PRETTY_FUNCTION__));
1319    ++Result.Iter;
1320    ++Result.Index;
1321    return *this;
1322  }
1323 
1324  bool operator==(const enumerator_iter<R> &RHS) const {
1325    // Don't compare indices here, only iterators.  It's possible for an end
1326    // iterator to have different indices depending on whether it was created
1327    // by calling std::end() versus incrementing a valid iterator.
1328    return Result.Iter == RHS.Result.Iter;
1329  }
1330 
1331  enumerator_iter<R> &operator=(const enumerator_iter<R> &Other) {
1332    Result = Other.Result;
1333    return *this;
1334  }
1335 
1336private:
1337  result_type Result;
1338};
1339 
1340template <typename R> class enumerator {
1341public:
1342  explicit enumerator(R &&Range) : TheRange(std::forward<R>(Range)) {}
1343 
1344  enumerator_iter<R> begin() {
1345    return enumerator_iter<R>(0, std::begin(TheRange));
1346  }
1347 
1348  enumerator_iter<R> end() {
1349    return enumerator_iter<R>(std::end(TheRange));
1350  }
1351 
1352private:
1353  R TheRange;
1354};
1355 
1356} // end namespace detail
1357 
1358/// Given an input range, returns a new range whose values are are pair (A,B)
1359/// such that A is the 0-based index of the item in the sequence, and B is
1360/// the value from the original sequence.  Example:
1361///
1362/// std::vector<char> Items = {'A', 'B', 'C', 'D'};
1363/// for (auto X : enumerate(Items)) {
1364///   printf("Item %d - %c\n", X.index(), X.value());
1365/// }
1366///
1367/// Output:
1368///   Item 0 - A
1369///   Item 1 - B
1370///   Item 2 - C
1371///   Item 3 - D
1372///
1373template <typename R> detail::enumerator<R> enumerate(R &&TheRange) {
1374  return detail::enumerator<R>(std::forward<R>(TheRange));
1375}
1376 
1377namespace detail {
1378 
1379template <typename F, typename Tuple, std::size_t... I>
1380auto apply_tuple_impl(F &&f, Tuple &&t, index_sequence<I...>)
1381    -> decltype(std::forward<F>(f)(std::get<I>(std::forward<Tuple>(t))...)) {
1382  return std::forward<F>(f)(std::get<I>(std::forward<Tuple>(t))...);
1383}
1384 
1385} // end namespace detail
1386 
1387/// Given an input tuple (a1, a2, ..., an), pass the arguments of the
1388/// tuple variadically to f as if by calling f(a1, a2, ..., an) and
1389/// return the result.
1390template <typename F, typename Tuple>
1391auto apply_tuple(F &&f, Tuple &&t) -> decltype(detail::apply_tuple_impl(
1392    std::forward<F>(f), std::forward<Tuple>(t),
1393    build_index_impl<
1394        std::tuple_size<typename std::decay<Tuple>::type>::value>{})) {
1395  using Indices = build_index_impl<
1396      std::tuple_size<typename std::decay<Tuple>::type>::value>;
1397 
1398  return detail::apply_tuple_impl(std::forward<F>(f), std::forward<Tuple>(t),
1399                                  Indices{});
1400}
1401 
1402} // end namespace llvm
1403 
1404#endif // LLVM_ADT_STLEXTRAS_H