--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/include/llvm/MC/MCSymbol.h	Thu Dec 12 13:56:28 2013 +0900
@@ -0,0 +1,165 @@
+//===- MCSymbol.h - Machine Code Symbols ------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the declaration of the MCSymbol class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_MC_MCSYMBOL_H
+#define LLVM_MC_MCSYMBOL_H
+
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Compiler.h"
+
+namespace llvm {
+  class MCExpr;
+  class MCSection;
+  class MCContext;
+  class raw_ostream;
+
+  /// MCSymbol - Instances of this class represent a symbol name in the MC file,
+  /// and MCSymbols are created and unique'd by the MCContext class.  MCSymbols
+  /// should only be constructed with valid names for the object file.
+  ///
+  /// If the symbol is defined/emitted into the current translation unit, the
+  /// Section member is set to indicate what section it lives in.  Otherwise, if
+  /// it is a reference to an external entity, it has a null section.
+  class MCSymbol {
+    // Special sentinal value for the absolute pseudo section.
+    //
+    // FIXME: Use a PointerInt wrapper for this?
+    static const MCSection *AbsolutePseudoSection;
+
+    /// Name - The name of the symbol.  The referred-to string data is actually
+    /// held by the StringMap that lives in MCContext.
+    StringRef Name;
+
+    /// Section - The section the symbol is defined in. This is null for
+    /// undefined symbols, and the special AbsolutePseudoSection value for
+    /// absolute symbols.
+    const MCSection *Section;
+
+    /// Value - If non-null, the value for a variable symbol.
+    const MCExpr *Value;
+
+    /// IsTemporary - True if this is an assembler temporary label, which
+    /// typically does not survive in the .o file's symbol table.  Usually
+    /// "Lfoo" or ".foo".
+    unsigned IsTemporary : 1;
+
+    /// IsUsed - True if this symbol has been used.
+    mutable unsigned IsUsed : 1;
+
+  private:  // MCContext creates and uniques these.
+    friend class MCExpr;
+    friend class MCContext;
+    MCSymbol(StringRef name, bool isTemporary)
+      : Name(name), Section(0), Value(0),
+        IsTemporary(isTemporary), IsUsed(false) {}
+
+    MCSymbol(const MCSymbol&) LLVM_DELETED_FUNCTION;
+    void operator=(const MCSymbol&) LLVM_DELETED_FUNCTION;
+  public:
+    /// getName - Get the symbol name.
+    StringRef getName() const { return Name; }
+
+    /// @name Accessors
+    /// @{
+
+    /// isTemporary - Check if this is an assembler temporary symbol.
+    bool isTemporary() const { return IsTemporary; }
+
+    /// isUsed - Check if this is used.
+    bool isUsed() const { return IsUsed; }
+    void setUsed(bool Value) const { IsUsed = Value; }
+
+    /// @}
+    /// @name Associated Sections
+    /// @{
+
+    /// isDefined - Check if this symbol is defined (i.e., it has an address).
+    ///
+    /// Defined symbols are either absolute or in some section.
+    bool isDefined() const {
+      return Section != 0;
+    }
+
+    /// isInSection - Check if this symbol is defined in some section (i.e., it
+    /// is defined but not absolute).
+    bool isInSection() const {
+      return isDefined() && !isAbsolute();
+    }
+
+    /// isUndefined - Check if this symbol undefined (i.e., implicitly defined).
+    bool isUndefined() const {
+      return !isDefined();
+    }
+
+    /// isAbsolute - Check if this is an absolute symbol.
+    bool isAbsolute() const {
+      return Section == AbsolutePseudoSection;
+    }
+
+    /// getSection - Get the section associated with a defined, non-absolute
+    /// symbol.
+    const MCSection &getSection() const {
+      assert(isInSection() && "Invalid accessor!");
+      return *Section;
+    }
+
+    /// setSection - Mark the symbol as defined in the section \p S.
+    void setSection(const MCSection &S) { Section = &S; }
+
+    /// setUndefined - Mark the symbol as undefined.
+    void setUndefined() {
+      Section = 0;
+    }
+
+    /// setAbsolute - Mark the symbol as absolute.
+    void setAbsolute() { Section = AbsolutePseudoSection; }
+
+    /// @}
+    /// @name Variable Symbols
+    /// @{
+
+    /// isVariable - Check if this is a variable symbol.
+    bool isVariable() const {
+      return Value != 0;
+    }
+
+    /// getVariableValue() - Get the value for variable symbols.
+    const MCExpr *getVariableValue() const {
+      assert(isVariable() && "Invalid accessor!");
+      IsUsed = true;
+      return Value;
+    }
+
+    // AliasedSymbol() - If this is an alias (a = b), return the symbol
+    // we ultimately point to. For a non alias, this just returns the symbol
+    // itself.
+    const MCSymbol &AliasedSymbol() const;
+
+    void setVariableValue(const MCExpr *Value);
+
+    /// @}
+
+    /// print - Print the value to the stream \p OS.
+    void print(raw_ostream &OS) const;
+
+    /// dump - Print the value to stderr.
+    void dump() const;
+  };
+
+  inline raw_ostream &operator<<(raw_ostream &OS, const MCSymbol &Sym) {
+    Sym.print(OS);
+    return OS;
+  }
+} // end namespace llvm
+
+#endif