text: //===- lib/MC/MCSymbol.cpp - MCSymbol implementation ----------------------===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  
  #include "llvm/MC/MCSymbol.h"
  #include "llvm/MC/MCAsmInfo.h"
  #include "llvm/MC/MCContext.h"
  #include "llvm/MC/MCExpr.h"
  #include "llvm/Support/Debug.h"
  #include "llvm/Support/ErrorHandling.h"
  #include "llvm/Support/raw_ostream.h"
  using namespace llvm;
  
  // Only the address of this fragment is ever actually used.
  static MCDummyFragment SentinelFragment(nullptr);
  
  // Sentinel value for the absolute pseudo fragment.
  MCFragment *MCSymbol::AbsolutePseudoFragment = &SentinelFragment;
  
  void *MCSymbol::operator new(size_t s, const StringMapEntry<bool> *Name,
                               MCContext &Ctx) {
    // We may need more space for a Name to account for alignment.  So allocate
    // space for the storage type and not the name pointer.
    size_t Size = s + (Name ? sizeof(NameEntryStorageTy) : 0);
  
    // For safety, ensure that the alignment of a pointer is enough for an
    // MCSymbol.  This also ensures we don't need padding between the name and
    // symbol.
    static_assert((unsigned)AlignOf<MCSymbol>::Alignment <=
                  AlignOf<NameEntryStorageTy>::Alignment,
                  "Bad alignment of MCSymbol");
    void *Storage = Ctx.allocate(Size, alignOf<NameEntryStorageTy>());
    NameEntryStorageTy *Start = static_cast<NameEntryStorageTy*>(Storage);
    NameEntryStorageTy *End = Start + (Name ? 1 : 0);
    return End;
  }
  
  void MCSymbol::setVariableValue(const MCExpr *Value) {
    assert(!IsUsed && "Cannot set a variable that has already been used.");
    assert(Value && "Invalid variable value!");
    assert((SymbolContents == SymContentsUnset ||
            SymbolContents == SymContentsVariable) &&
           "Cannot give common/offset symbol a variable value");
    this->Value = Value;
    SymbolContents = SymContentsVariable;
    setUndefined();
  }
  
  void MCSymbol::print(raw_ostream &OS, const MCAsmInfo *MAI) const {
    // The name for this MCSymbol is required to be a valid target name.  However,
    // some targets support quoting names with funny characters.  If the name
    // contains a funny character, then print it quoted.
    StringRef Name = getName();
    if (!MAI || MAI->isValidUnquotedName(Name)) {
      OS << Name;
      return;
    }
  
    if (MAI && !MAI->supportsNameQuoting())
      report_fatal_error("Symbol name with unsupported characters");
  
    OS << '"';
    for (char C : Name) {
      if (C == '\n')
        OS << "\\n";
      else if (C == '"')
        OS << "\\\"";
      else
        OS << C;
    }
    OS << '"';
  }
  
  #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
  LLVM_DUMP_METHOD void MCSymbol::dump() const { dbgs() << *this; }
  #endif
  