/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 MachONormalizedFileToAtoms.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/lld/lib/ReaderWriter/MachO -I /build/llvm-toolchain-snapshot-8~svn345461/tools/lld/lib/ReaderWriter/MachO -I /build/llvm-toolchain-snapshot-8~svn345461/tools/lld/include -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/lld/include -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn345461/include -I /build/llvm-toolchain-snapshot-8~svn345461/tools/lld/lib/ReaderWriter/MachO/. -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/lld/lib/ReaderWriter/MachO -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/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp -faddrsig

/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp

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1//===- lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp --------------===//
2//
3//                             The LLVM Linker
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//

10///
11/// \file Converts from in-memory normalized mach-o to in-memory Atoms.
12///
13///                  +------------+
14///                  | normalized |
15///                  +------------+
16///                        |
17///                        |
18///                        v
19///                    +-------+
20///                    | Atoms |
21///                    +-------+

23#include "ArchHandler.h"
24#include "Atoms.h"
25#include "File.h"
26#include "MachONormalizedFile.h"
27#include "MachONormalizedFileBinaryUtils.h"
28#include "lld/Common/LLVM.h"
29#include "lld/Core/Error.h"
30#include "llvm/BinaryFormat/Dwarf.h"
31#include "llvm/BinaryFormat/MachO.h"
32#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
33#include "llvm/Support/DataExtractor.h"
34#include "llvm/Support/Debug.h"
35#include "llvm/Support/Error.h"
36#include "llvm/Support/Format.h"
37#include "llvm/Support/LEB128.h"
38#include "llvm/Support/raw_ostream.h"

40using namespace llvm::MachO;
41using namespace lld::mach_o::normalized;

43#define DEBUG_TYPE"normalized-file-to-atoms" "normalized-file-to-atoms"

45namespace lld {
46namespace mach_o {


49namespace { // anonymous


52#define ENTRY(seg, sect, type, atomType) \
{seg, sect, type, DefinedAtom::atomType }

55struct MachORelocatableSectionToAtomType {
StringRef                 segmentName;
StringRef                 sectionName;
SectionType               sectionType;
DefinedAtom::ContentType  atomType;
60};

62const MachORelocatableSectionToAtomType sectsToAtomType[] = {
ENTRY("__TEXT", "__text",           S_REGULAR,          typeCode),
ENTRY("__TEXT", "__text",           S_REGULAR,          typeResolver),
ENTRY("__TEXT", "__cstring",        S_CSTRING_LITERALS, typeCString),
ENTRY("",       "",                 S_CSTRING_LITERALS, typeCString),
ENTRY("__TEXT", "__ustring",        S_REGULAR,          typeUTF16String),
ENTRY("__TEXT", "__const",          S_REGULAR,          typeConstant),
ENTRY("__TEXT", "__const_coal",     S_COALESCED,        typeConstant),
ENTRY("__TEXT", "__eh_frame",       S_COALESCED,        typeCFI),
ENTRY("__TEXT", "__eh_frame",       S_REGULAR,          typeCFI),
ENTRY("__TEXT", "__literal4",       S_4BYTE_LITERALS,   typeLiteral4),
ENTRY("__TEXT", "__literal8",       S_8BYTE_LITERALS,   typeLiteral8),
ENTRY("__TEXT", "__literal16",      S_16BYTE_LITERALS,  typeLiteral16),
ENTRY("__TEXT", "__gcc_except_tab", S_REGULAR,          typeLSDA),
ENTRY("__DATA", "__data",           S_REGULAR,          typeData),
ENTRY("__DATA", "__datacoal_nt",    S_COALESCED,        typeData),
ENTRY("__DATA", "__const",          S_REGULAR,          typeConstData),
ENTRY("__DATA", "__cfstring",       S_REGULAR,          typeCFString),
ENTRY("__DATA", "__mod_init_func",  S_MOD_INIT_FUNC_POINTERS,
                                                        typeInitializerPtr),
ENTRY("__DATA", "__mod_term_func",  S_MOD_TERM_FUNC_POINTERS,
                                                        typeTerminatorPtr),
ENTRY("__DATA", "__got",            S_NON_LAZY_SYMBOL_POINTERS,
                                                        typeGOT),
ENTRY("__DATA", "__bss",            S_ZEROFILL,         typeZeroFill),
ENTRY("",       "",                 S_NON_LAZY_SYMBOL_POINTERS,
                                                        typeGOT),
ENTRY("__DATA", "__interposing",    S_INTERPOSING,      typeInterposingTuples),
ENTRY("__DATA", "__thread_vars",    S_THREAD_LOCAL_VARIABLES,
                                                        typeThunkTLV),
ENTRY("__DATA", "__thread_data", S_THREAD_LOCAL_REGULAR, typeTLVInitialData),
ENTRY("__DATA", "__thread_bss",     S_THREAD_LOCAL_ZEROFILL,
                                                      typeTLVInitialZeroFill),
ENTRY("__DATA", "__objc_imageinfo", S_REGULAR,          typeObjCImageInfo),
ENTRY("__DATA", "__objc_catlist",   S_REGULAR,          typeObjC2CategoryList),
ENTRY("",       "",                 S_INTERPOSING,      typeInterposingTuples),
ENTRY("__LD",   "__compact_unwind", S_REGULAR,
                                                       typeCompactUnwindInfo),
ENTRY("",       "",                 S_REGULAR,          typeUnknown)
101};
102#undef ENTRY


105/// Figures out ContentType of a mach-o section.
106DefinedAtom::ContentType atomTypeFromSection(const Section &section,
                                           bool &customSectionName) {
// First look for match of name and type. Empty names in table are wildcards.
customSectionName = false;
for (const MachORelocatableSectionToAtomType *p = sectsToAtomType ;
                               p->atomType != DefinedAtom::typeUnknown; ++p) {
  if (p->sectionType != section.type)
    continue;
  if (!p->segmentName.equals(section.segmentName) && !p->segmentName.empty())
    continue;
  if (!p->sectionName.equals(section.sectionName) && !p->sectionName.empty())
    continue;
  customSectionName = p->segmentName.empty() && p->sectionName.empty();
  return p->atomType;
}
// Look for code denoted by section attributes
if (section.attributes & S_ATTR_PURE_INSTRUCTIONS)
  return DefinedAtom::typeCode;

return DefinedAtom::typeUnknown;
126}

128enum AtomizeModel {
atomizeAtSymbols,
atomizeFixedSize,
atomizePointerSize,
atomizeUTF8,
atomizeUTF16,
atomizeCFI,
atomizeCU,
atomizeCFString
137};

139/// Returns info on how to atomize a section of the specified ContentType.
140void sectionParseInfo(DefinedAtom::ContentType atomType,
                    unsigned int &sizeMultiple,
                    DefinedAtom::Scope &scope,
                    DefinedAtom::Merge &merge,
                    AtomizeModel &atomizeModel) {
struct ParseInfo {
  DefinedAtom::ContentType  atomType;
  unsigned int              sizeMultiple;
  DefinedAtom::Scope        scope;
  DefinedAtom::Merge        merge;
  AtomizeModel              atomizeModel;
};

#define ENTRY(type, size, scope, merge, model) \
  {DefinedAtom::type, size, DefinedAtom::scope, DefinedAtom::merge, model }

static const ParseInfo parseInfo[] = {
  ENTRY(typeCode,              1, scopeGlobal,          mergeNo,
                                                          atomizeAtSymbols),
  ENTRY(typeData,              1, scopeGlobal,          mergeNo,
                                                          atomizeAtSymbols),
  ENTRY(typeConstData,         1, scopeGlobal,          mergeNo,
                                                          atomizeAtSymbols),
  ENTRY(typeZeroFill,          1, scopeGlobal,          mergeNo,
                                                          atomizeAtSymbols),
  ENTRY(typeConstant,          1, scopeGlobal,          mergeNo,
                                                          atomizeAtSymbols),
  ENTRY(typeCString,           1, scopeLinkageUnit,     mergeByContent,
                                                          atomizeUTF8),
  ENTRY(typeUTF16String,       1, scopeLinkageUnit,     mergeByContent,
                                                          atomizeUTF16),
  ENTRY(typeCFI,               4, scopeTranslationUnit, mergeNo,
                                                          atomizeCFI),
  ENTRY(typeLiteral4,          4, scopeLinkageUnit,     mergeByContent,
                                                          atomizeFixedSize),
  ENTRY(typeLiteral8,          8, scopeLinkageUnit,     mergeByContent,
                                                          atomizeFixedSize),
  ENTRY(typeLiteral16,        16, scopeLinkageUnit,     mergeByContent,
                                                          atomizeFixedSize),
  ENTRY(typeCFString,          4, scopeLinkageUnit,     mergeByContent,
                                                          atomizeCFString),
  ENTRY(typeInitializerPtr,    4, scopeTranslationUnit, mergeNo,
                                                          atomizePointerSize),
  ENTRY(typeTerminatorPtr,     4, scopeTranslationUnit, mergeNo,
                                                          atomizePointerSize),
  ENTRY(typeCompactUnwindInfo, 4, scopeTranslationUnit, mergeNo,
                                                          atomizeCU),
  ENTRY(typeGOT,               4, scopeLinkageUnit,     mergeByContent,
                                                          atomizePointerSize),
  ENTRY(typeObjC2CategoryList, 4, scopeTranslationUnit, mergeByContent,
                                                          atomizePointerSize),
  ENTRY(typeUnknown,           1, scopeGlobal,          mergeNo,
                                                          atomizeAtSymbols)
};
#undef ENTRY
const int tableLen = sizeof(parseInfo) / sizeof(ParseInfo);
for (int i=0; i < tableLen; ++i) {
  if (parseInfo[i].atomType == atomType) {
    sizeMultiple = parseInfo[i].sizeMultiple;
    scope        = parseInfo[i].scope;
    merge        = parseInfo[i].merge;
    atomizeModel = parseInfo[i].atomizeModel;
    return;
  }
}

// Unknown type is atomized by symbols.
sizeMultiple = 1;
scope = DefinedAtom::scopeGlobal;
merge = DefinedAtom::mergeNo;
atomizeModel = atomizeAtSymbols;
211}


214Atom::Scope atomScope(uint8_t scope) {
switch (scope) {
case N_EXT:
  return Atom::scopeGlobal;
case N_PEXT:
case N_PEXT | N_EXT:
  return Atom::scopeLinkageUnit;
case 0:
  return Atom::scopeTranslationUnit;
}
llvm_unreachable("unknown scope value!")::llvm::llvm_unreachable_internal("unknown scope value!", "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp"
, 224);
225}

227void appendSymbolsInSection(const std::vector<Symbol> &inSymbols,
                          uint32_t sectionIndex,
                          SmallVector<const Symbol *, 64> &outSyms) {
for (const Symbol &sym : inSymbols) {
  // Only look at definition symbols.
  if ((sym.type & N_TYPE) != N_SECT)
    continue;
  if (sym.sect != sectionIndex)
    continue;
  outSyms.push_back(&sym);
}
238}

240void atomFromSymbol(DefinedAtom::ContentType atomType, const Section &section,
                  MachOFile &file, uint64_t symbolAddr, StringRef symbolName,
                  uint16_t symbolDescFlags, Atom::Scope symbolScope,
                  uint64_t nextSymbolAddr, bool scatterable, bool copyRefs) {
// Mach-O symbol table does have size in it. Instead the size is the
// difference between this and the next symbol.
uint64_t size = nextSymbolAddr - symbolAddr;
uint64_t offset = symbolAddr - section.address;
bool noDeadStrip = (symbolDescFlags & N_NO_DEAD_STRIP) || !scatterable;
if (isZeroFillSection(section.type)) {
  file.addZeroFillDefinedAtom(symbolName, symbolScope, offset, size,
                              noDeadStrip, copyRefs, &section);
} else {
  DefinedAtom::Merge merge = (symbolDescFlags & N_WEAK_DEF)
                            ? DefinedAtom::mergeAsWeak : DefinedAtom::mergeNo;
  bool thumb = (symbolDescFlags & N_ARM_THUMB_DEF);
  if (atomType == DefinedAtom::typeUnknown) {
    // Mach-O needs a segment and section name.  Concatentate those two
    // with a / separator (e.g. "seg/sect") to fit into the lld model
    // of just a section name.
    std::string segSectName = section.segmentName.str()
                              + "/" + section.sectionName.str();
    file.addDefinedAtomInCustomSection(symbolName, symbolScope, atomType,
                                       merge, thumb, noDeadStrip, offset,
                                       size, segSectName, true, &section);
  } else {
    if ((atomType == lld::DefinedAtom::typeCode) &&
        (symbolDescFlags & N_SYMBOL_RESOLVER)) {
      atomType = lld::DefinedAtom::typeResolver;
    }
    file.addDefinedAtom(symbolName, symbolScope, atomType, merge,
                        offset, size, thumb, noDeadStrip, copyRefs, &section);
  }
}
274}

276llvm::Error processSymboledSection(DefinedAtom::ContentType atomType,
                                 const Section &section,
                                 const NormalizedFile &normalizedFile,
                                 MachOFile &file, bool scatterable,
                                 bool copyRefs) {
// Find section's index.
uint32_t sectIndex = 1;
for (auto &sect : normalizedFile.sections) {
  if (&sect == &section)
    break;
  ++sectIndex;
}

// Find all symbols in this section.
SmallVector<const Symbol *, 64> symbols;
appendSymbolsInSection(normalizedFile.globalSymbols, sectIndex, symbols);
appendSymbolsInSection(normalizedFile.localSymbols,  sectIndex, symbols);

// Sort symbols.
std::sort(symbols.begin(), symbols.end(),
          [](const Symbol *lhs, const Symbol *rhs) -> bool {
            if (lhs == rhs)
              return false;
            // First by address.
            uint64_t lhsAddr = lhs->value;
            uint64_t rhsAddr = rhs->value;
            if (lhsAddr != rhsAddr)
              return lhsAddr < rhsAddr;
             // If same address, one is an alias so sort by scope.
            Atom::Scope lScope = atomScope(lhs->scope);
            Atom::Scope rScope = atomScope(rhs->scope);
            if (lScope != rScope)
              return lScope < rScope;
            // If same address and scope, see if one might be better as
            // the alias.
            bool lPrivate = (lhs->name.front() == 'l');
            bool rPrivate = (rhs->name.front() == 'l');
            if (lPrivate != rPrivate)
              return lPrivate;
            // If same address and scope, sort by name.
            return lhs->name < rhs->name;
          });

// Debug logging of symbols.
//for (const Symbol *sym : symbols)
//  llvm::errs() << "  sym: "
//    << llvm::format("0x%08llx ", (uint64_t)sym->value)
//    << ", " << sym->name << "\n";

// If section has no symbols and no content, there are no atoms.
if (symbols.empty() && section.content.empty())
  return llvm::Error::success();

if (symbols.empty()) {
  // Section has no symbols, put all content in one anoymous atom.
  atomFromSymbol(atomType, section, file, section.address, StringRef(),
                0, Atom::scopeTranslationUnit,
                section.address + section.content.size(),
                scatterable, copyRefs);
}
else if (symbols.front()->value != section.address) {
  // Section has anonymous content before first symbol.
  atomFromSymbol(atomType, section, file, section.address, StringRef(),
                 0, Atom::scopeTranslationUnit, symbols.front()->value,
                 scatterable, copyRefs);
}

const Symbol *lastSym = nullptr;
for (const Symbol *sym : symbols) {
  if (lastSym != nullptr) {
    // Ignore any assembler added "ltmpNNN" symbol at start of section
    // if there is another symbol at the start.
    if ((lastSym->value != sym->value)
        || lastSym->value != section.address
        || !lastSym->name.startswith("ltmp")) {
      atomFromSymbol(atomType, section, file, lastSym->value, lastSym->name,
                     lastSym->desc, atomScope(lastSym->scope), sym->value,
                     scatterable, copyRefs);
    }
  }
  lastSym = sym;
}
if (lastSym != nullptr) {
  atomFromSymbol(atomType, section, file, lastSym->value, lastSym->name,
                 lastSym->desc, atomScope(lastSym->scope),
                 section.address + section.content.size(),
                 scatterable, copyRefs);
}

// If object built without .subsections_via_symbols, add reference chain.
if (!scatterable) {
  MachODefinedAtom *prevAtom = nullptr;
  file.eachAtomInSection(section,
                         [&](MachODefinedAtom *atom, uint64_t offset)->void {
    if (prevAtom)
      prevAtom->addReference(Reference::KindNamespace::all,
                             Reference::KindArch::all,
                             Reference::kindLayoutAfter, 0, atom, 0);
    prevAtom = atom;
  });
}

return llvm::Error::success();
379}

381llvm::Error processSection(DefinedAtom::ContentType atomType,
                         const Section &section,
                         bool customSectionName,
                         const NormalizedFile &normalizedFile,
                         MachOFile &file, bool scatterable,
                         bool copyRefs) {
const bool is64 = MachOLinkingContext::is64Bit(normalizedFile.arch);
const bool isBig = MachOLinkingContext::isBigEndian(normalizedFile.arch);

// Get info on how to atomize section.
unsigned int       sizeMultiple;
DefinedAtom::Scope scope;
DefinedAtom::Merge merge;
AtomizeModel       atomizeModel;
sectionParseInfo(atomType, sizeMultiple, scope, merge, atomizeModel);

// Validate section size.
if ((section.content.size() % sizeMultiple) != 0)
  return llvm::make_error<GenericError>(Twine("Section ")
                                        + section.segmentName
                                        + "/" + section.sectionName
                                        + " has size ("
                                        + Twine(section.content.size())
                                        + ") which is not a multiple of "
                                        + Twine(sizeMultiple));

if (atomizeModel == atomizeAtSymbols) {
  // Break section up into atoms each with a fixed size.
  return processSymboledSection(atomType, section, normalizedFile, file,
                                scatterable, copyRefs);
} else {
  unsigned int size;
  for (unsigned int offset = 0, e = section.content.size(); offset != e;) {
    switch (atomizeModel) {
    case atomizeFixedSize:
      // Break section up into atoms each with a fixed size.
      size = sizeMultiple;
      break;
    case atomizePointerSize:
      // Break section up into atoms each the size of a pointer.
      size = is64 ? 8 : 4;
      break;
    case atomizeUTF8:
      // Break section up into zero terminated c-strings.
      size = 0;
      for (unsigned int i = offset; i < e; ++i) {
        if (section.content[i] == 0) {
          size = i + 1 - offset;
          break;
        }
      }
      break;
    case atomizeUTF16:
      // Break section up into zero terminated UTF16 strings.
      size = 0;
      for (unsigned int i = offset; i < e; i += 2) {
        if ((section.content[i] == 0) && (section.content[i + 1] == 0)) {
          size = i + 2 - offset;
          break;
        }
      }
      break;
    case atomizeCFI:
      // Break section up into dwarf unwind CFIs (FDE or CIE).
      size = read32(&section.content[offset], isBig) + 4;
      if (offset+size > section.content.size()) {
        return llvm::make_error<GenericError>(Twine("Section ")
                                              + section.segmentName
                                              + "/" + section.sectionName
                                              + " is malformed.  Size of CFI "
                                              "starting at offset ("
                                              + Twine(offset)
                                              + ") is past end of section.");
      }
      break;
    case atomizeCU:
      // Break section up into compact unwind entries.
      size = is64 ? 32 : 20;
      break;
    case atomizeCFString:
      // Break section up into NS/CFString objects.
      size = is64 ? 32 : 16;
      break;
    case atomizeAtSymbols:
      break;
    }
    if (size == 0) {
      return llvm::make_error<GenericError>(Twine("Section ")
                                            + section.segmentName
                                            + "/" + section.sectionName
                                            + " is malformed.  The last atom "
                                            "is not zero terminated.");
    }
    if (customSectionName) {
      // Mach-O needs a segment and section name.  Concatentate those two
      // with a / separator (e.g. "seg/sect") to fit into the lld model
      // of just a section name.
      std::string segSectName = section.segmentName.str()
                                + "/" + section.sectionName.str();
      file.addDefinedAtomInCustomSection(StringRef(), scope, atomType,
                                         merge, false, false, offset,
                                         size, segSectName, true, &section);
    } else {
      file.addDefinedAtom(StringRef(), scope, atomType, merge, offset, size,
                          false, false, copyRefs, &section);
    }
    offset += size;
  }
}
return llvm::Error::success();
491}

493const Section* findSectionCoveringAddress(const NormalizedFile &normalizedFile,
                                        uint64_t address) {
for (const Section &s : normalizedFile.sections) {
  uint64_t sAddr = s.address;
  if ((sAddr <= address) && (address < sAddr+s.content.size())) {
    return &s;
  }
}
return nullptr;
502}

504const MachODefinedAtom *
505findAtomCoveringAddress(const NormalizedFile &normalizedFile, MachOFile &file,
                      uint64_t addr, Reference::Addend &addend) {
const Section *sect = nullptr;
sect = findSectionCoveringAddress(normalizedFile, addr);
if (!sect)
  return nullptr;

uint32_t offsetInTarget;
uint64_t offsetInSect = addr - sect->address;
auto atom =
    file.findAtomCoveringAddress(*sect, offsetInSect, &offsetInTarget);
addend = offsetInTarget;
return atom;
518}

520// Walks all relocations for a section in a normalized .o file and
521// creates corresponding lld::Reference objects.
522llvm::Error convertRelocs(const Section &section,
                        const NormalizedFile &normalizedFile,
                        bool scatterable,
                        MachOFile &file,
                        ArchHandler &handler) {
// Utility function for ArchHandler to find atom by its address.
auto atomByAddr = [&] (uint32_t sectIndex, uint64_t addr,
                       const lld::Atom **atom, Reference::Addend *addend)
                       -> llvm::Error {
  if (sectIndex > normalizedFile.sections.size())
    return llvm::make_error<GenericError>(Twine("out of range section "
                                   "index (") + Twine(sectIndex) + ")");
  const Section *sect = nullptr;
  if (sectIndex == 0) {
    sect = findSectionCoveringAddress(normalizedFile, addr);
    if (!sect)
      return llvm::make_error<GenericError>(Twine("address (" + Twine(addr)
                                     + ") is not in any section"));
  } else {
    sect = &normalizedFile.sections[sectIndex-1];
  }
  uint32_t offsetInTarget;
  uint64_t offsetInSect = addr - sect->address;
  *atom = file.findAtomCoveringAddress(*sect, offsetInSect, &offsetInTarget);
  *addend = offsetInTarget;
  return llvm::Error::success();
};

// Utility function for ArchHandler to find atom by its symbol index.
auto atomBySymbol = [&] (uint32_t symbolIndex, const lld::Atom **result)
                         -> llvm::Error {
  // Find symbol from index.
  const Symbol *sym = nullptr;
  uint32_t numStabs  = normalizedFile.stabsSymbols.size();
  uint32_t numLocal  = normalizedFile.localSymbols.size();
  uint32_t numGlobal = normalizedFile.globalSymbols.size();
  uint32_t numUndef  = normalizedFile.undefinedSymbols.size();
  assert(symbolIndex >= numStabs && "Searched for stab via atomBySymbol?")((symbolIndex >= numStabs && "Searched for stab via atomBySymbol?"
) ? static_cast<void> (0) : __assert_fail ("symbolIndex >= numStabs && \"Searched for stab via atomBySymbol?\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp"
, 559, __PRETTY_FUNCTION__));
  if (symbolIndex < numStabs+numLocal) {
    sym = &normalizedFile.localSymbols[symbolIndex-numStabs];
  } else if (symbolIndex < numStabs+numLocal+numGlobal) {
    sym = &normalizedFile.globalSymbols[symbolIndex-numStabs-numLocal];
  } else if (symbolIndex < numStabs+numLocal+numGlobal+numUndef) {
    sym = &normalizedFile.undefinedSymbols[symbolIndex-numStabs-numLocal-
                                           numGlobal];
  } else {
    return llvm::make_error<GenericError>(Twine("symbol index (")
                                   + Twine(symbolIndex) + ") out of range");
  }

  // Find atom from symbol.
  if ((sym->type & N_TYPE) == N_SECT) {
    if (sym->sect > normalizedFile.sections.size())
      return llvm::make_error<GenericError>(Twine("symbol section index (")
                                      + Twine(sym->sect) + ") out of range ");
    const Section &symSection = normalizedFile.sections[sym->sect-1];
    uint64_t targetOffsetInSect = sym->value - symSection.address;
    MachODefinedAtom *target = file.findAtomCoveringAddress(symSection,
                                                          targetOffsetInSect);
    if (target) {
      *result = target;
      return llvm::Error::success();
    }
    return llvm::make_error<GenericError>("no atom found for defined symbol");
  } else if ((sym->type & N_TYPE) == N_UNDF) {
    const lld::Atom *target = file.findUndefAtom(sym->name);
    if (target) {
      *result = target;
      return llvm::Error::success();
    }
    return llvm::make_error<GenericError>("no undefined atom found for sym");
  } else {
    // Search undefs
    return llvm::make_error<GenericError>("no atom found for symbol");
  }
};

const bool isBig = MachOLinkingContext::isBigEndian(normalizedFile.arch);
// Use old-school iterator so that paired relocations can be grouped.
for (auto it=section.relocations.begin(), e=section.relocations.end();
                                                              it != e; ++it) {
  const Relocation &reloc = *it;
  // Find atom this relocation is in.
  if (reloc.offset > section.content.size())
    return llvm::make_error<GenericError>(
                                  Twine("r_address (") + Twine(reloc.offset)
                                  + ") is larger than section size ("
                                  + Twine(section.content.size()) + ")");
  uint32_t offsetInAtom;
  MachODefinedAtom *inAtom = file.findAtomCoveringAddress(section,
                                                          reloc.offset,
                                                          &offsetInAtom);
  assert(inAtom && "r_address in range, should have found atom")((inAtom && "r_address in range, should have found atom"
) ? static_cast<void> (0) : __assert_fail ("inAtom && \"r_address in range, should have found atom\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp"
, 614, __PRETTY_FUNCTION__));
  uint64_t fixupAddress = section.address + reloc.offset;

  const lld::Atom *target = nullptr;
  Reference::Addend addend = 0;
  Reference::KindValue kind;
  if (handler.isPairedReloc(reloc)) {
    // Handle paired relocations together.
    const Relocation &reloc2 = *++it;
    auto relocErr = handler.getPairReferenceInfo(
        reloc, reloc2, inAtom, offsetInAtom, fixupAddress, isBig, scatterable,
        atomByAddr, atomBySymbol, &kind, &target, &addend);
    if (relocErr) {
      return handleErrors(std::move(relocErr),
                          [&](std::unique_ptr<GenericError> GE) {
        return llvm::make_error<GenericError>(
          Twine("bad relocation (") + GE->getMessage()
           + ") in section "
           + section.segmentName + "/" + section.sectionName
           + " (r1_address=" + Twine::utohexstr(reloc.offset)
           + ", r1_type=" + Twine(reloc.type)
           + ", r1_extern=" + Twine(reloc.isExtern)
           + ", r1_length=" + Twine((int)reloc.length)
           + ", r1_pcrel=" + Twine(reloc.pcRel)
           + (!reloc.scattered ? (Twine(", r1_symbolnum=")
                                  + Twine(reloc.symbol))
                               : (Twine(", r1_scattered=1, r1_value=")
                                  + Twine(reloc.value)))
           + ")"
           + ", (r2_address=" + Twine::utohexstr(reloc2.offset)
           + ", r2_type=" + Twine(reloc2.type)
           + ", r2_extern=" + Twine(reloc2.isExtern)
           + ", r2_length=" + Twine((int)reloc2.length)
           + ", r2_pcrel=" + Twine(reloc2.pcRel)
           + (!reloc2.scattered ? (Twine(", r2_symbolnum=")
                                   + Twine(reloc2.symbol))
                                : (Twine(", r2_scattered=1, r2_value=")
                                   + Twine(reloc2.value)))
           + ")" );
        });
    }
  }
  else {
    // Use ArchHandler to convert relocation record into information
    // needed to instantiate an lld::Reference object.
    auto relocErr = handler.getReferenceInfo(
        reloc, inAtom, offsetInAtom, fixupAddress, isBig, atomByAddr,
        atomBySymbol, &kind, &target, &addend);
    if (relocErr) {
      return handleErrors(std::move(relocErr),
                          [&](std::unique_ptr<GenericError> GE) {
        return llvm::make_error<GenericError>(
3
←
Calling 'make_error<lld::GenericError, llvm::Twine>'→
          Twine("bad relocation (") + GE->getMessage()
           + ") in section "
           + section.segmentName + "/" + section.sectionName
           + " (r_address=" + Twine::utohexstr(reloc.offset)
           + ", r_type=" + Twine(reloc.type)
           + ", r_extern=" + Twine(reloc.isExtern)
           + ", r_length=" + Twine((int)reloc.length)
           + ", r_pcrel=" + Twine(reloc.pcRel)
           + (!reloc.scattered ? (Twine(", r_symbolnum=") + Twine(reloc.symbol))
1
Assuming the condition is true→
2
←
'?' condition is true→
                               : (Twine(", r_scattered=1, r_value=")
                                  + Twine(reloc.value)))
           + ")" );
        });
    }
  }
  // Instantiate an lld::Reference object and add to its atom.
  inAtom->addReference(Reference::KindNamespace::mach_o,
                       handler.kindArch(),
                       kind, offsetInAtom, target, addend);
}

return llvm::Error::success();
688}

690bool isDebugInfoSection(const Section &section) {
if ((section.attributes & S_ATTR_DEBUG) == 0)
  return false;
return section.segmentName.equals("__DWARF");
694}

696static const Atom* findDefinedAtomByName(MachOFile &file, Twine name) {
std::string strName = name.str();
for (auto *atom : file.defined())
  if (atom->name() == strName)
    return atom;
return nullptr;
702}

704static StringRef copyDebugString(StringRef str, BumpPtrAllocator &alloc) {
char *strCopy = alloc.Allocate<char>(str.size() + 1);
memcpy(strCopy, str.data(), str.size());
strCopy[str.size()] = '\0';
return strCopy;
709}

711llvm::Error parseStabs(MachOFile &file,
                     const NormalizedFile &normalizedFile,
                     bool copyRefs) {

if (normalizedFile.stabsSymbols.empty())
  return llvm::Error::success();

// FIXME: Kill this off when we can move to sane yaml parsing.
std::unique_ptr<BumpPtrAllocator> allocator;
if (copyRefs)
  allocator = llvm::make_unique<BumpPtrAllocator>();

enum { start, inBeginEnd } state = start;

const Atom *currentAtom = nullptr;
uint64_t currentAtomAddress = 0;
StabsDebugInfo::StabsList stabsList;
for (const auto &stabSym : normalizedFile.stabsSymbols) {
  Stab stab(nullptr, stabSym.type, stabSym.sect, stabSym.desc,
            stabSym.value, stabSym.name);
  switch (state) {
  case start:
    switch (static_cast<StabType>(stabSym.type)) {
    case N_BNSYM:
      state = inBeginEnd;
      currentAtomAddress = stabSym.value;
      Reference::Addend addend;
      currentAtom = findAtomCoveringAddress(normalizedFile, file,
                                            currentAtomAddress, addend);
      if (addend != 0)
        return llvm::make_error<GenericError>(
                 "Non-zero addend for BNSYM '" + stabSym.name + "' in " +
                 file.path());
      if (currentAtom)
        stab.atom = currentAtom;
      else {
        // FIXME: ld64 just issues a warning here - should we match that?
        return llvm::make_error<GenericError>(
                 "can't find atom for stabs BNSYM at " +
                 Twine::utohexstr(stabSym.value) + " in " + file.path());
      }
      break;
    case N_SO:
    case N_OSO:
      // Not associated with an atom, just copy.
      if (copyRefs)
        stab.str = copyDebugString(stabSym.name, *allocator);
      else
        stab.str = stabSym.name;
      break;
    case N_GSYM: {
      auto colonIdx = stabSym.name.find(':');
      if (colonIdx != StringRef::npos) {
        StringRef name = stabSym.name.substr(0, colonIdx);
        currentAtom = findDefinedAtomByName(file, "_" + name);
        stab.atom = currentAtom;
        if (copyRefs)
          stab.str = copyDebugString(stabSym.name, *allocator);
        else
          stab.str = stabSym.name;
      } else {
        currentAtom = findDefinedAtomByName(file, stabSym.name);
        stab.atom = currentAtom;
        if (copyRefs)
          stab.str = copyDebugString(stabSym.name, *allocator);
        else
          stab.str = stabSym.name;
      }
      if (stab.atom == nullptr)
        return llvm::make_error<GenericError>(
                 "can't find atom for N_GSYM stabs" + stabSym.name +
                 " in " + file.path());
      break;
    }
    case N_FUN:
      return llvm::make_error<GenericError>(
               "old-style N_FUN stab '" + stabSym.name + "' unsupported");
    default:
      return llvm::make_error<GenericError>(
               "unrecognized stab symbol '" + stabSym.name + "'");
    }
    break;
  case inBeginEnd:
    stab.atom = currentAtom;
    switch (static_cast<StabType>(stabSym.type)) {
    case N_ENSYM:
      state = start;
      currentAtom = nullptr;
      break;
    case N_FUN:
      // Just copy the string.
      if (copyRefs)
        stab.str = copyDebugString(stabSym.name, *allocator);
      else
        stab.str = stabSym.name;
      break;
    default:
      return llvm::make_error<GenericError>(
               "unrecognized stab symbol '" + stabSym.name + "'");
    }
  }
  llvm::dbgs() << "Adding to stabsList: " << stab << "\n";
  stabsList.push_back(stab);
}

file.setDebugInfo(llvm::make_unique<StabsDebugInfo>(std::move(stabsList)));

// FIXME: Kill this off when we fix YAML memory ownership.
file.debugInfo()->setAllocator(std::move(allocator));

return llvm::Error::success();
822}

824static llvm::DataExtractor
825dataExtractorFromSection(const NormalizedFile &normalizedFile,
                       const Section &S) {
const bool is64 = MachOLinkingContext::is64Bit(normalizedFile.arch);
const bool isBig = MachOLinkingContext::isBigEndian(normalizedFile.arch);
StringRef SecData(reinterpret_cast<const char*>(S.content.data()),
                  S.content.size());
return llvm::DataExtractor(SecData, !isBig, is64 ? 8 : 4);
832}

834// FIXME: Cribbed from llvm-dwp -- should share "lightweight CU DIE
835//        inspection" code if possible.
836static uint32_t getCUAbbrevOffset(llvm::DataExtractor abbrevData,
                                uint64_t abbrCode) {
uint64_t curCode;
uint32_t offset = 0;
while ((curCode = abbrevData.getULEB128(&offset)) != abbrCode) {
  // Tag
  abbrevData.getULEB128(&offset);
  // DW_CHILDREN
  abbrevData.getU8(&offset);
  // Attributes
  while (abbrevData.getULEB128(&offset) | abbrevData.getULEB128(&offset))
    ;
}
return offset;
850}

852// FIXME: Cribbed from llvm-dwp -- should share "lightweight CU DIE
853//        inspection" code if possible.
854static Expected<const char *>
855getIndexedString(const NormalizedFile &normalizedFile,
               llvm::dwarf::Form form, llvm::DataExtractor infoData,
               uint32_t &infoOffset, const Section &stringsSection) {
if (form == llvm::dwarf::DW_FORM_string)
 return infoData.getCStr(&infoOffset);
if (form != llvm::dwarf::DW_FORM_strp)
  return llvm::make_error<GenericError>(
      "string field encoded without DW_FORM_strp");
uint32_t stringOffset = infoData.getU32(&infoOffset);
llvm::DataExtractor stringsData =
  dataExtractorFromSection(normalizedFile, stringsSection);
return stringsData.getCStr(&stringOffset);
867}

869// FIXME: Cribbed from llvm-dwp -- should share "lightweight CU DIE
870//        inspection" code if possible.
871static llvm::Expected<TranslationUnitSource>
872readCompUnit(const NormalizedFile &normalizedFile,
           const Section &info,
           const Section &abbrev,
           const Section &strings,
           StringRef path) {
// FIXME: Cribbed from llvm-dwp -- should share "lightweight CU DIE
//        inspection" code if possible.
uint32_t offset = 0;
llvm::dwarf::DwarfFormat Format = llvm::dwarf::DwarfFormat::DWARF32;
auto infoData = dataExtractorFromSection(normalizedFile, info);
uint32_t length = infoData.getU32(&offset);
if (length == 0xffffffff) {
  Format = llvm::dwarf::DwarfFormat::DWARF64;
  infoData.getU64(&offset);
}
else if (length > 0xffffff00)
  return llvm::make_error<GenericError>("Malformed DWARF in " + path);

uint16_t version = infoData.getU16(&offset);

if (version < 2 || version > 4)
  return llvm::make_error<GenericError>("Unsupported DWARF version in " +
                                        path);

infoData.getU32(&offset); // Abbrev offset (should be zero)
uint8_t addrSize = infoData.getU8(&offset);

uint32_t abbrCode = infoData.getULEB128(&offset);
auto abbrevData = dataExtractorFromSection(normalizedFile, abbrev);
uint32_t abbrevOffset = getCUAbbrevOffset(abbrevData, abbrCode);
uint64_t tag = abbrevData.getULEB128(&abbrevOffset);
if (tag != llvm::dwarf::DW_TAG_compile_unit)
  return llvm::make_error<GenericError>("top level DIE is not a compile unit");
// DW_CHILDREN
abbrevData.getU8(&abbrevOffset);
uint32_t name;
llvm::dwarf::Form form;
llvm::dwarf::FormParams formParams = {version, addrSize, Format};
TranslationUnitSource tu;
while ((name = abbrevData.getULEB128(&abbrevOffset)) |
       (form = static_cast<llvm::dwarf::Form>(
           abbrevData.getULEB128(&abbrevOffset))) &&
       (name != 0 || form != 0)) {
  switch (name) {
  case llvm::dwarf::DW_AT_name: {
    if (auto eName = getIndexedString(normalizedFile, form, infoData, offset,
                                      strings))
        tu.name = *eName;
    else
      return eName.takeError();
    break;
  }
  case llvm::dwarf::DW_AT_comp_dir: {
    if (auto eName = getIndexedString(normalizedFile, form, infoData, offset,
                                      strings))
      tu.path = *eName;
    else
      return eName.takeError();
    break;
  }
  default:
    llvm::DWARFFormValue::skipValue(form, infoData, &offset, formParams);
  }
}
return tu;
937}

939llvm::Error parseDebugInfo(MachOFile &file,
                         const NormalizedFile &normalizedFile, bool copyRefs) {

// Find the interesting debug info sections.
const Section *debugInfo = nullptr;
const Section *debugAbbrev = nullptr;
const Section *debugStrings = nullptr;

for (auto &s : normalizedFile.sections) {
  if (s.segmentName == "__DWARF") {
    if (s.sectionName == "__debug_info")
      debugInfo = &s;
    else if (s.sectionName == "__debug_abbrev")
      debugAbbrev = &s;
    else if (s.sectionName == "__debug_str")
      debugStrings = &s;
  }
}

if (!debugInfo)
  return parseStabs(file, normalizedFile, copyRefs);

if (debugInfo->content.size() == 0)
  return llvm::Error::success();

if (debugInfo->content.size() < 12)
  return llvm::make_error<GenericError>("Malformed __debug_info section in " +
                                        file.path() + ": too small");

if (!debugAbbrev)
  return llvm::make_error<GenericError>("Missing __dwarf_abbrev section in " +
                                        file.path());

if (auto tuOrErr = readCompUnit(normalizedFile, *debugInfo, *debugAbbrev,
                                *debugStrings, file.path())) {
  // FIXME: Kill of allocator and code under 'copyRefs' when we fix YAML
  //        memory ownership.
  std::unique_ptr<BumpPtrAllocator> allocator;
  if (copyRefs) {
    allocator = llvm::make_unique<BumpPtrAllocator>();
    tuOrErr->name = copyDebugString(tuOrErr->name, *allocator);
    tuOrErr->path = copyDebugString(tuOrErr->path, *allocator);
  }
  file.setDebugInfo(llvm::make_unique<DwarfDebugInfo>(std::move(*tuOrErr)));
  if (copyRefs)
    file.debugInfo()->setAllocator(std::move(allocator));
} else
  return tuOrErr.takeError();

return llvm::Error::success();
989}

991static int64_t readSPtr(bool is64, bool isBig, const uint8_t *addr) {
if (is64)
  return read64(addr, isBig);

int32_t res = read32(addr, isBig);
return res;
997}

999/// --- Augmentation String Processing ---

1001struct CIEInfo {
bool _augmentationDataPresent = false;
bool _mayHaveEH = false;
uint32_t _offsetOfLSDA = ~0U;
uint32_t _offsetOfPersonality = ~0U;
uint32_t _offsetOfFDEPointerEncoding = ~0U;
uint32_t _augmentationDataLength = ~0U;
1008};

1010typedef llvm::DenseMap<const MachODefinedAtom*, CIEInfo> CIEInfoMap;

1012static llvm::Error processAugmentationString(const uint8_t *augStr,
                                           CIEInfo &cieInfo,
                                           unsigned &len) {

if (augStr[0] == '\0') {
  len = 1;
  return llvm::Error::success();
}

if (augStr[0] != 'z')
  return llvm::make_error<GenericError>("expected 'z' at start of "
                                        "augmentation string");

cieInfo._augmentationDataPresent = true;
uint64_t idx = 1;

uint32_t offsetInAugmentationData = 0;
while (augStr[idx] != '\0') {
  if (augStr[idx] == 'L') {
    cieInfo._offsetOfLSDA = offsetInAugmentationData;
    // This adds a single byte to the augmentation data.
    ++offsetInAugmentationData;
    ++idx;
    continue;
  }
  if (augStr[idx] == 'P') {
    cieInfo._offsetOfPersonality = offsetInAugmentationData;
    // This adds a single byte to the augmentation data for the encoding,
    // then a number of bytes for the pointer data.
    // FIXME: We are assuming 4 is correct here for the pointer size as we
    // always currently use delta32ToGOT.
    offsetInAugmentationData += 5;
    ++idx;
    continue;
  }
  if (augStr[idx] == 'R') {
    cieInfo._offsetOfFDEPointerEncoding = offsetInAugmentationData;
    // This adds a single byte to the augmentation data.
    ++offsetInAugmentationData;
    ++idx;
    continue;
  }
  if (augStr[idx] == 'e') {
    if (augStr[idx + 1] != 'h')
      return llvm::make_error<GenericError>("expected 'eh' in "
                                            "augmentation string");
    cieInfo._mayHaveEH = true;
    idx += 2;
    continue;
  }
  ++idx;
}

cieInfo._augmentationDataLength = offsetInAugmentationData;

len = idx + 1;
return llvm::Error::success();
1069}

1071static llvm::Error processCIE(const NormalizedFile &normalizedFile,
                            MachOFile &file,
                            mach_o::ArchHandler &handler,
                            const Section *ehFrameSection,
                            MachODefinedAtom *atom,
                            uint64_t offset,
                            CIEInfoMap &cieInfos) {
const bool isBig = MachOLinkingContext::isBigEndian(normalizedFile.arch);
const uint8_t *frameData = atom->rawContent().data();

CIEInfo cieInfo;

uint32_t size = read32(frameData, isBig);
uint64_t cieIDField = size == 0xffffffffU
                        ? sizeof(uint32_t) + sizeof(uint64_t)
                        : sizeof(uint32_t);
uint64_t versionField = cieIDField + sizeof(uint32_t);
uint64_t augmentationStringField = versionField + sizeof(uint8_t);

unsigned augmentationStringLength = 0;
if (auto err = processAugmentationString(frameData + augmentationStringField,
                                         cieInfo, augmentationStringLength))
  return err;

if (cieInfo._offsetOfPersonality != ~0U) {
  // If we have augmentation data for the personality function, then we may
  // need to implicitly generate its relocation.

  // Parse the EH Data field which is pointer sized.
  uint64_t EHDataField = augmentationStringField + augmentationStringLength;
  const bool is64 = MachOLinkingContext::is64Bit(normalizedFile.arch);
  unsigned EHDataFieldSize = (cieInfo._mayHaveEH ? (is64 ? 8 : 4) : 0);

  // Parse Code Align Factor which is a ULEB128.
  uint64_t CodeAlignField = EHDataField + EHDataFieldSize;
  unsigned lengthFieldSize = 0;
  llvm::decodeULEB128(frameData + CodeAlignField, &lengthFieldSize);

  // Parse Data Align Factor which is a SLEB128.
  uint64_t DataAlignField = CodeAlignField + lengthFieldSize;
  llvm::decodeSLEB128(frameData + DataAlignField, &lengthFieldSize);

  // Parse Return Address Register which is a byte.
  uint64_t ReturnAddressField = DataAlignField + lengthFieldSize;

  // Parse the augmentation length which is a ULEB128.
  uint64_t AugmentationLengthField = ReturnAddressField + 1;
  uint64_t AugmentationLength =
    llvm::decodeULEB128(frameData + AugmentationLengthField,
                        &lengthFieldSize);

  if (AugmentationLength != cieInfo._augmentationDataLength)
    return llvm::make_error<GenericError>("CIE augmentation data length "
                                          "mismatch");

  // Get the start address of the augmentation data.
  uint64_t AugmentationDataField = AugmentationLengthField + lengthFieldSize;

  // Parse the personality function from the augmentation data.
  uint64_t PersonalityField =
    AugmentationDataField + cieInfo._offsetOfPersonality;

  // Parse the personality encoding.
  // FIXME: Verify that this is a 32-bit pcrel offset.
  uint64_t PersonalityFunctionField = PersonalityField + 1;

  if (atom->begin() != atom->end()) {
    // If we have an explicit relocation, then make sure it matches this
    // offset as this is where we'd expect it to be applied to.
    DefinedAtom::reference_iterator CurrentRef = atom->begin();
    if (CurrentRef->offsetInAtom() != PersonalityFunctionField)
      return llvm::make_error<GenericError>("CIE personality reloc at "
                                            "wrong offset");

    if (++CurrentRef != atom->end())
      return llvm::make_error<GenericError>("CIE contains too many relocs");
  } else {
    // Implicitly generate the personality function reloc.  It's assumed to
    // be a delta32 offset to a GOT entry.
    // FIXME: Parse the encoding and check this.
    int32_t funcDelta = read32(frameData + PersonalityFunctionField, isBig);
    uint64_t funcAddress = ehFrameSection->address + offset +
                           PersonalityFunctionField;
    funcAddress += funcDelta;

    const MachODefinedAtom *func = nullptr;
    Reference::Addend addend;
    func = findAtomCoveringAddress(normalizedFile, file, funcAddress,
                                   addend);
    atom->addReference(Reference::KindNamespace::mach_o, handler.kindArch(),
                       handler.unwindRefToPersonalityFunctionKind(),
                       PersonalityFunctionField, func, addend);
  }
} else if (atom->begin() != atom->end()) {
  // Otherwise, we expect there to be no relocations in this atom as the only
  // relocation would have been to the personality function.
  return llvm::make_error<GenericError>("unexpected relocation in CIE");
}


cieInfos[atom] = std::move(cieInfo);

return llvm::Error::success();
1174}

1176static llvm::Error processFDE(const NormalizedFile &normalizedFile,
                            MachOFile &file,
                            mach_o::ArchHandler &handler,
                            const Section *ehFrameSection,
                            MachODefinedAtom *atom,
                            uint64_t offset,
                            const CIEInfoMap &cieInfos) {

const bool isBig = MachOLinkingContext::isBigEndian(normalizedFile.arch);
const bool is64 = MachOLinkingContext::is64Bit(normalizedFile.arch);

// Compiler wasn't lazy and actually told us what it meant.
// Unfortunately, the compiler may not have generated references for all of
// [cie, func, lsda] and so we still need to parse the FDE and add references
// for any the compiler didn't generate.
if (atom->begin() != atom->end())
  atom->sortReferences();

DefinedAtom::reference_iterator CurrentRef = atom->begin();

// This helper returns the reference (if one exists) at the offset we are
// currently processing.  It automatically increments the ref iterator if we
// do return a ref, and throws an error if we pass over a ref without
// comsuming it.
auto currentRefGetter = [&CurrentRef,
                         &atom](uint64_t Offset)->const Reference* {
  // If there are no more refs found, then we are done.
  if (CurrentRef == atom->end())
    return nullptr;

  const Reference *Ref = *CurrentRef;

  // If we haven't reached the offset for this reference, then return that
  // we don't yet have a reference to process.
  if (Offset < Ref->offsetInAtom())
    return nullptr;

  // If the offset is equal, then we want to process this ref.
  if (Offset == Ref->offsetInAtom()) {
    ++CurrentRef;
    return Ref;
  }

  // The current ref is at an offset which is earlier than the current
  // offset, then we failed to consume it when we should have.  In this case
  // throw an error.
  llvm::report_fatal_error("Skipped reference when processing FDE");
};

// Helper to either get the reference at this current location, and verify
// that it is of the expected type, or add a reference of that type.
// Returns the reference target.
auto verifyOrAddReference = [&](uint64_t targetAddress,
                                Reference::KindValue refKind,
                                uint64_t refAddress,
                                bool allowsAddend)->const Atom* {
  if (auto *ref = currentRefGetter(refAddress)) {
    // The compiler already emitted a relocation for the CIE ref.  This should
    // have been converted to the correct type of reference in
    // get[Pair]ReferenceInfo().
    assert(ref->kindValue() == refKind &&((ref->kindValue() == refKind && "Incorrect EHFrame reference kind"
) ? static_cast<void> (0) : __assert_fail ("ref->kindValue() == refKind && \"Incorrect EHFrame reference kind\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp"
, 1237, __PRETTY_FUNCTION__))
           "Incorrect EHFrame reference kind")((ref->kindValue() == refKind && "Incorrect EHFrame reference kind"
) ? static_cast<void> (0) : __assert_fail ("ref->kindValue() == refKind && \"Incorrect EHFrame reference kind\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp"
, 1237, __PRETTY_FUNCTION__));
    return ref->target();
  }
  Reference::Addend addend;
  auto *target = findAtomCoveringAddress(normalizedFile, file,
                                         targetAddress, addend);
  atom->addReference(Reference::KindNamespace::mach_o, handler.kindArch(),
                     refKind, refAddress, target, addend);

  if (!allowsAddend)
    assert(!addend && "EHFrame reference cannot have addend")((!addend && "EHFrame reference cannot have addend") ?
 static_cast<void> (0) : __assert_fail ("!addend && \"EHFrame reference cannot have addend\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp"
, 1247, __PRETTY_FUNCTION__));
  return target;
};

const uint8_t *startFrameData = atom->rawContent().data();
const uint8_t *frameData = startFrameData;

uint32_t size = read32(frameData, isBig);
uint64_t cieFieldInFDE = size == 0xffffffffU
  ? sizeof(uint32_t) + sizeof(uint64_t)
  : sizeof(uint32_t);

// Linker needs to fixup a reference from the FDE to its parent CIE (a
// 32-bit byte offset backwards in the __eh_frame section).
uint32_t cieDelta = read32(frameData + cieFieldInFDE, isBig);
uint64_t cieAddress = ehFrameSection->address + offset + cieFieldInFDE;
cieAddress -= cieDelta;

auto *cieRefTarget = verifyOrAddReference(cieAddress,
                                          handler.unwindRefToCIEKind(),
                                          cieFieldInFDE, false);
const MachODefinedAtom *cie = dyn_cast<MachODefinedAtom>(cieRefTarget);
assert(cie && cie->contentType() == DefinedAtom::typeCFI &&((cie && cie->contentType() == DefinedAtom::typeCFI
 && "FDE's CIE field does not point at the start of a CIE."
) ? static_cast<void> (0) : __assert_fail ("cie && cie->contentType() == DefinedAtom::typeCFI && \"FDE's CIE field does not point at the start of a CIE.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp"
, 1270, __PRETTY_FUNCTION__))
       "FDE's CIE field does not point at the start of a CIE.")((cie && cie->contentType() == DefinedAtom::typeCFI
 && "FDE's CIE field does not point at the start of a CIE."
) ? static_cast<void> (0) : __assert_fail ("cie && cie->contentType() == DefinedAtom::typeCFI && \"FDE's CIE field does not point at the start of a CIE.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp"
, 1270, __PRETTY_FUNCTION__));

const CIEInfo &cieInfo = cieInfos.find(cie)->second;

// Linker needs to fixup reference from the FDE to the function it's
// describing. FIXME: there are actually different ways to do this, and the
// particular method used is specified in the CIE's augmentation fields
// (hopefully)
uint64_t rangeFieldInFDE = cieFieldInFDE + sizeof(uint32_t);

int64_t functionFromFDE = readSPtr(is64, isBig,
                                   frameData + rangeFieldInFDE);
uint64_t rangeStart = ehFrameSection->address + offset + rangeFieldInFDE;
rangeStart += functionFromFDE;

verifyOrAddReference(rangeStart,
                     handler.unwindRefToFunctionKind(),
                     rangeFieldInFDE, true);

// Handle the augmentation data if there is any.
if (cieInfo._augmentationDataPresent) {
  // First process the augmentation data length field.
  uint64_t augmentationDataLengthFieldInFDE =
    rangeFieldInFDE + 2 * (is64 ? sizeof(uint64_t) : sizeof(uint32_t));
  unsigned lengthFieldSize = 0;
  uint64_t augmentationDataLength =
    llvm::decodeULEB128(frameData + augmentationDataLengthFieldInFDE,
                        &lengthFieldSize);

  if (cieInfo._offsetOfLSDA != ~0U && augmentationDataLength > 0) {

    // Look at the augmentation data field.
    uint64_t augmentationDataFieldInFDE =
      augmentationDataLengthFieldInFDE + lengthFieldSize;

    int64_t lsdaFromFDE = readSPtr(is64, isBig,
                                   frameData + augmentationDataFieldInFDE);
    uint64_t lsdaStart =
      ehFrameSection->address + offset + augmentationDataFieldInFDE +
      lsdaFromFDE;

    verifyOrAddReference(lsdaStart,
                         handler.unwindRefToFunctionKind(),
                         augmentationDataFieldInFDE, true);
  }
}

return llvm::Error::success();
1318}

1320llvm::Error addEHFrameReferences(const NormalizedFile &normalizedFile,
                               MachOFile &file,
                               mach_o::ArchHandler &handler) {

const Section *ehFrameSection = nullptr;
for (auto &section : normalizedFile.sections)
  if (section.segmentName == "__TEXT" &&
      section.sectionName == "__eh_frame") {
    ehFrameSection = &section;
    break;
  }

// No __eh_frame so nothing to do.
if (!ehFrameSection)
  return llvm::Error::success();

llvm::Error ehFrameErr = llvm::Error::success();
CIEInfoMap cieInfos;

file.eachAtomInSection(*ehFrameSection,
                       [&](MachODefinedAtom *atom, uint64_t offset) -> void {
  assert(atom->contentType() == DefinedAtom::typeCFI)((atom->contentType() == DefinedAtom::typeCFI) ? static_cast
<void> (0) : __assert_fail ("atom->contentType() == DefinedAtom::typeCFI"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp"
, 1341, __PRETTY_FUNCTION__));

  // Bail out if we've encountered an error.
  if (ehFrameErr)
    return;

  const bool isBig = MachOLinkingContext::isBigEndian(normalizedFile.arch);
  if (ArchHandler::isDwarfCIE(isBig, atom))
    ehFrameErr = processCIE(normalizedFile, file, handler, ehFrameSection,
                            atom, offset, cieInfos);
  else
    ehFrameErr = processFDE(normalizedFile, file, handler, ehFrameSection,
                            atom, offset, cieInfos);
});

return ehFrameErr;
1357}

1359llvm::Error parseObjCImageInfo(const Section &sect,
                             const NormalizedFile &normalizedFile,
                             MachOFile &file) {

//	struct objc_image_info  {
//		uint32_t	version;	// initially 0
//		uint32_t	flags;
//	};

ArrayRef<uint8_t> content = sect.content;
if (content.size() != 8)
  return llvm::make_error<GenericError>(sect.segmentName + "/" +
                                        sect.sectionName +
                                        " in file " + file.path() +
                                        " should be 8 bytes in size");

const bool isBig = MachOLinkingContext::isBigEndian(normalizedFile.arch);
uint32_t version = read32(content.data(), isBig);
if (version)
  return llvm::make_error<GenericError>(sect.segmentName + "/" +
                                        sect.sectionName +
                                        " in file " + file.path() +
                                        " should have version=0");

uint32_t flags = read32(content.data() + 4, isBig);
if (flags & (MachOLinkingContext::objc_supports_gc |
             MachOLinkingContext::objc_gc_only))
  return llvm::make_error<GenericError>(sect.segmentName + "/" +
                                        sect.sectionName +
                                        " in file " + file.path() +
                                        " uses GC.  This is not supported");

if (flags & MachOLinkingContext::objc_retainReleaseForSimulator)
  file.setObjcConstraint(MachOLinkingContext::objc_retainReleaseForSimulator);
else
  file.setObjcConstraint(MachOLinkingContext::objc_retainRelease);

file.setSwiftVersion((flags >> 8) & 0xFF);

return llvm::Error::success();
1399}

1401/// Converts normalized mach-o file into an lld::File and lld::Atoms.
1402llvm::Expected<std::unique_ptr<lld::File>>
1403objectToAtoms(const NormalizedFile &normalizedFile, StringRef path,
            bool copyRefs) {
std::unique_ptr<MachOFile> file(new MachOFile(path));
if (auto ec = normalizedObjectToAtoms(file.get(), normalizedFile, copyRefs))
  return std::move(ec);
return std::unique_ptr<File>(std::move(file));
1409}

1411llvm::Expected<std::unique_ptr<lld::File>>
1412dylibToAtoms(const NormalizedFile &normalizedFile, StringRef path,
           bool copyRefs) {
// Instantiate SharedLibraryFile object.
std::unique_ptr<MachODylibFile> file(new MachODylibFile(path));
if (auto ec = normalizedDylibToAtoms(file.get(), normalizedFile, copyRefs))
  return std::move(ec);
return std::unique_ptr<File>(std::move(file));
1419}

1421} // anonymous namespace

1423namespace normalized {

1425static bool isObjCImageInfo(const Section &sect) {
return (sect.segmentName == "__OBJC" && sect.sectionName == "__image_info") ||
  (sect.segmentName == "__DATA" && sect.sectionName == "__objc_imageinfo");
1428}

1430llvm::Error
1431normalizedObjectToAtoms(MachOFile *file,
                      const NormalizedFile &normalizedFile,
                      bool copyRefs) {
LLVM_DEBUG(llvm::dbgs() << "******** Normalizing file to atoms: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("normalized-file-to-atoms")) { llvm::dbgs() << "******** Normalizing file to atoms: "
 << file->path() << "\n"; } } while (false)
                        << file->path() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("normalized-file-to-atoms")) { llvm::dbgs() << "******** Normalizing file to atoms: "
 << file->path() << "\n"; } } while (false);
bool scatterable = ((normalizedFile.flags & MH_SUBSECTIONS_VIA_SYMBOLS) != 0);

// Create atoms from each section.
for (auto &sect : normalizedFile.sections) {

  // If this is a debug-info section parse it specially.
  if (isDebugInfoSection(sect))
    continue;

  // If the file contains an objc_image_info struct, then we should parse the
  // ObjC flags and Swift version.
  if (isObjCImageInfo(sect)) {
    if (auto ec = parseObjCImageInfo(sect, normalizedFile, *file))
      return ec;
    // We then skip adding atoms for this section as we use the ObjCPass to
    // re-emit this data after it has been aggregated for all files.
    continue;
  }

  bool customSectionName;
  DefinedAtom::ContentType atomType = atomTypeFromSection(sect,
                                                          customSectionName);
  if (auto ec =  processSection(atomType, sect, customSectionName,
                                normalizedFile, *file, scatterable, copyRefs))
    return ec;
}
// Create atoms from undefined symbols.
for (auto &sym : normalizedFile.undefinedSymbols) {
  // Undefinded symbols with n_value != 0 are actually tentative definitions.
  if (sym.value == Hex64(0)) {
    file->addUndefinedAtom(sym.name, copyRefs);
  } else {
    file->addTentativeDefAtom(sym.name, atomScope(sym.scope), sym.value,
                              DefinedAtom::Alignment(1 << (sym.desc >> 8)),
                              copyRefs);
  }
}

// Convert mach-o relocations to References
std::unique_ptr<mach_o::ArchHandler> handler
                                   = ArchHandler::create(normalizedFile.arch);
for (auto &sect : normalizedFile.sections) {
  if (isDebugInfoSection(sect))
    continue;
  if (llvm::Error ec = convertRelocs(sect, normalizedFile, scatterable,
                                     *file, *handler))
    return ec;
}

// Add additional arch-specific References
file->eachDefinedAtom([&](MachODefinedAtom* atom) -> void {
  handler->addAdditionalReferences(*atom);
});

// Each __eh_frame section needs references to both __text (the function we're
// providing unwind info for) and itself (FDE -> CIE). These aren't
// represented in the relocations on some architectures, so we have to add
// them back in manually there.
if (auto ec = addEHFrameReferences(normalizedFile, *file, *handler))
  return ec;

// Process mach-o data-in-code regions array. That information is encoded in
// atoms as References at each transition point.
unsigned nextIndex = 0;
for (const DataInCode &entry : normalizedFile.dataInCode) {
  ++nextIndex;
  const Section* s = findSectionCoveringAddress(normalizedFile, entry.offset);
  if (!s) {
    return llvm::make_error<GenericError>(Twine("LC_DATA_IN_CODE address ("
                                                + Twine(entry.offset)
                                                + ") is not in any section"));
  }
  uint64_t offsetInSect = entry.offset - s->address;
  uint32_t offsetInAtom;
  MachODefinedAtom *atom = file->findAtomCoveringAddress(*s, offsetInSect,
                                                         &offsetInAtom);
  if (offsetInAtom + entry.length > atom->size()) {
    return llvm::make_error<GenericError>(Twine("LC_DATA_IN_CODE entry "
                                                "(offset="
                                                + Twine(entry.offset)
                                                + ", length="
                                                + Twine(entry.length)
                                                + ") crosses atom boundary."));
  }
  // Add reference that marks start of data-in-code.
  atom->addReference(Reference::KindNamespace::mach_o, handler->kindArch(),
                     handler->dataInCodeTransitionStart(*atom),
                     offsetInAtom, atom, entry.kind);

  // Peek at next entry, if it starts where this one ends, skip ending ref.
  if (nextIndex < normalizedFile.dataInCode.size()) {
    const DataInCode &nextEntry = normalizedFile.dataInCode[nextIndex];
    if (nextEntry.offset == (entry.offset + entry.length))
      continue;
  }

  // If data goes to end of function, skip ending ref.
  if ((offsetInAtom + entry.length) == atom->size())
    continue;

  // Add reference that marks end of data-in-code.
  atom->addReference(Reference::KindNamespace::mach_o, handler->kindArch(),
                     handler->dataInCodeTransitionEnd(*atom),
                     offsetInAtom+entry.length, atom, 0);
}

// Cache some attributes on the file for use later.
file->setFlags(normalizedFile.flags);
file->setArch(normalizedFile.arch);
file->setOS(normalizedFile.os);
file->setMinVersion(normalizedFile.minOSverson);
file->setMinVersionLoadCommandKind(normalizedFile.minOSVersionKind);

// Sort references in each atom to their canonical order.
for (const DefinedAtom* defAtom : file->defined()) {
  reinterpret_cast<const SimpleDefinedAtom*>(defAtom)->sortReferences();
}

if (auto err = parseDebugInfo(*file, normalizedFile, copyRefs))
  return err;

return llvm::Error::success();
1558}

1560llvm::Error
1561normalizedDylibToAtoms(MachODylibFile *file,
                     const NormalizedFile &normalizedFile,
                     bool copyRefs) {
file->setInstallName(normalizedFile.installName);
file->setCompatVersion(normalizedFile.compatVersion);
file->setCurrentVersion(normalizedFile.currentVersion);

// Tell MachODylibFile object about all symbols it exports.
if (!normalizedFile.exportInfo.empty()) {
  // If exports trie exists, use it instead of traditional symbol table.
  for (const Export &exp : normalizedFile.exportInfo) {
    bool weakDef = (exp.flags & EXPORT_SYMBOL_FLAGS_WEAK_DEFINITION);
    // StringRefs from export iterator are ephemeral, so force copy.
    file->addExportedSymbol(exp.name, weakDef, true);
  }
} else {
  for (auto &sym : normalizedFile.globalSymbols) {
    assert((sym.scope & N_EXT) && "only expect external symbols here")(((sym.scope & N_EXT) && "only expect external symbols here"
) ? static_cast<void> (0) : __assert_fail ("(sym.scope & N_EXT) && \"only expect external symbols here\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp"
, 1578, __PRETTY_FUNCTION__));
    bool weakDef = (sym.desc & N_WEAK_DEF);
    file->addExportedSymbol(sym.name, weakDef, copyRefs);
  }
}
// Tell MachODylibFile object about all dylibs it re-exports.
for (const DependentDylib &dep : normalizedFile.dependentDylibs) {
  if (dep.kind == llvm::MachO::LC_REEXPORT_DYLIB)
    file->addReExportedDylib(dep.path);
}
return llvm::Error::success();
1589}

1591void relocatableSectionInfoForContentType(DefinedAtom::ContentType atomType,
                                        StringRef &segmentName,
                                        StringRef &sectionName,
                                        SectionType &sectionType,
                                        SectionAttr &sectionAttrs,
                                        bool &relocsToDefinedCanBeImplicit) {

for (const MachORelocatableSectionToAtomType *p = sectsToAtomType ;
                               p->atomType != DefinedAtom::typeUnknown; ++p) {
  if (p->atomType != atomType)
    continue;
  // Wild carded entries are ignored for reverse lookups.
  if (p->segmentName.empty() || p->sectionName.empty())
    continue;
  segmentName = p->segmentName;
  sectionName = p->sectionName;
  sectionType = p->sectionType;
  sectionAttrs = 0;
  relocsToDefinedCanBeImplicit = false;
  if (atomType == DefinedAtom::typeCode)
    sectionAttrs = S_ATTR_PURE_INSTRUCTIONS;
  if (atomType == DefinedAtom::typeCFI)
    relocsToDefinedCanBeImplicit = true;
  return;
}
llvm_unreachable("content type not yet supported")::llvm::llvm_unreachable_internal("content type not yet supported"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp"
, 1616);
1617}

1619llvm::Expected<std::unique_ptr<lld::File>>
1620normalizedToAtoms(const NormalizedFile &normalizedFile, StringRef path,
                bool copyRefs) {
switch (normalizedFile.fileType) {
case MH_DYLIB:
case MH_DYLIB_STUB:
  return dylibToAtoms(normalizedFile, path, copyRefs);
case MH_OBJECT:
  return objectToAtoms(normalizedFile, path, copyRefs);
default:
  llvm_unreachable("unhandled MachO file type!")::llvm::llvm_unreachable_internal("unhandled MachO file type!"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp"
, 1629);
}
1631}

1633} // namespace normalized
1634} // namespace mach_o
1635} // namespace lld

←

/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);
8
←
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)...));
4
←
Calling 'make_unique<lld::GenericError, llvm::Twine>'→
6
←
Returned allocated memory→
7
←
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)...));
5
←
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