[mips] Add assembler support for '.set mipsX'.

[oota-llvm.git] / include / llvm / MC / MCSymbol.h

diff --git a/include/llvm/MC/MCSymbol.h b/include/llvm/MC/MCSymbol.h
index 122e897a92df3aa90168a8e0f49e263705e9b60f..0b3c3ceb210f28b12e1162926e21232e8f569b61 100644 (file)
--- a/include/llvm/MC/MCSymbol.h
+++ b/include/llvm/MC/MCSymbol.h
@@ -14,61 +14,94 @@
 #ifndef LLVM_MC_MCSYMBOL_H
 #define LLVM_MC_MCSYMBOL_H
 
-#include <string>
 #include "llvm/ADT/StringRef.h"
-#include "llvm/Support/DataTypes.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.
+  /// 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.  
-  /// 
+  /// 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.
-    std::string Name;
+    /// 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(const StringRef &_Name, bool _IsTemporary) 
-      : Name(_Name), Section(0), IsTemporary(_IsTemporary) {}
-    
-    MCSymbol(const MCSymbol&);       // DO NOT IMPLEMENT
-    void operator=(const MCSymbol&); // DO NOT IMPLEMENT
+    MCSymbol(StringRef name, bool isTemporary)
+      : Name(name), Section(nullptr), Value(nullptr),
+        IsTemporary(isTemporary), IsUsed(false) {}
+
+    MCSymbol(const MCSymbol&) LLVM_DELETED_FUNCTION;
+    void operator=(const MCSymbol&) LLVM_DELETED_FUNCTION;
   public:
     /// getName - Get the symbol name.
-    const std::string &getName() const { return Name; }
+    StringRef getName() const { return Name; }
 
-    /// @name Symbol Type
+    /// @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 != nullptr;
+    }
+
+    /// 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 Section == 0;
+      return !isDefined();
     }
 
-    /// isAbsolute - Check if this this is an absolute symbol.
+    /// isAbsolute - Check if this is an absolute symbol.
     bool isAbsolute() const {
       return Section == AbsolutePseudoSection;
     }
@@ -76,30 +109,57 @@ namespace llvm {
     /// getSection - Get the section associated with a defined, non-absolute
     /// symbol.
     const MCSection &getSection() const {
-      assert(!isUndefined() && !isAbsolute() && "Invalid accessor!");
+      assert(isInSection() && "Invalid accessor!");
       return *Section;
     }
 
-    /// setSection - Mark the symbol as defined in the section \arg S.
+    /// 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;
+      Section = nullptr;
     }
 
     /// 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 != nullptr;
+    }
+
+    /// 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 \arg OS.
+    /// 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