Added support in MC for Directional Local Labels.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103989 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCContext.h

@@ -20,6 +20,7 @@ namespace llvm {
   class MCExpr;
   class MCSection;
   class MCSymbol;
+  class MCLabel;
   class StringRef;
   class Twine;
   class MCSectionMachO;
@@ -43,6 +44,15 @@ namespace llvm {
     /// NextUniqueID - The next ID to dole out to an unnamed assembler temporary
     /// symbol.
     unsigned NextUniqueID;
+
+    /// Instances of directional local labels.
+    DenseMap<unsigned, MCLabel *> Instances;
+    /// NextInstance() creates the next instance of the directional local label
+    /// for the LocalLabelVal and adds it to the map if needed.
+    unsigned NextInstance(int64_t LocalLabelVal);
+    /// GetInstance() gets the current instance of the directional local label
+    /// for the LocalLabelVal and adds it to the map if needed.
+    unsigned GetInstance(int64_t LocalLabelVal);
     
     /// Allocator - Allocator object used for creating machine code objects.
     ///
@@ -64,6 +74,14 @@ namespace llvm {
     /// with a unique but unspecified name.
     MCSymbol *CreateTempSymbol();
 
+    /// CreateDirectionalLocalSymbol - Create the defintion of a directional
+    /// local symbol for numbered label (used for "1:" defintions).
+    MCSymbol *CreateDirectionalLocalSymbol(int64_t LocalLabelVal);
+
+    /// GetDirectionalLocalSymbol - Create and return a directional local
+    /// symbol for numbered label (used for "1b" or 1f" references).
+    MCSymbol *GetDirectionalLocalSymbol(int64_t LocalLabelVal, int bORf);
+
     /// GetOrCreateSymbol - Lookup the symbol inside with the specified
     /// @p Name.  If it exists, return it.  If not, create a forward
     /// reference and return it.

include/llvm/MC/MCLabel.h

@@ -0,0 +1,56 @@
+//===- MCLabel.h - Machine Code Directional Local Labels --------*- 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 MCLabel class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_MC_MCLABEL_H
+#define LLVM_MC_MCLABEL_H
+
+namespace llvm {
+  class MCContext;
+  class raw_ostream;
+
+  /// MCLabel - Instances of this class represent a label name in the MC file,
+  /// and MCLabel are created and unique'd by the MCContext class.  MCLabel
+  /// should only be constructed for valid instances in the object file.
+  class MCLabel {
+    // Instance - the instance number of this Directional Local Label
+    unsigned Instance;
+
+  private:  // MCContext creates and uniques these.
+    friend class MCContext;
+    MCLabel(unsigned instance)
+      : Instance(instance) {}
+
+    MCLabel(const MCLabel&);       // DO NOT IMPLEMENT
+    void operator=(const MCLabel&); // DO NOT IMPLEMENT
+  public:
+    /// getInstance - Get the current instance of this Directional Local Label.
+    unsigned getInstance() const { return Instance; }
+
+    /// incInstance - Increment the current instance of this Directional Local
+    /// Label.
+    unsigned incInstance() { return ++Instance; }
+
+    /// print - Print the value to the stream \arg OS.
+    void print(raw_ostream &OS) const;
+
+    /// dump - Print the value to stderr.
+    void dump() const;
+  };
+
+  inline raw_ostream &operator<<(raw_ostream &OS, const MCLabel &Label) {
+    Label.print(OS);
+    return OS;
+  }
+} // end namespace llvm
+
+#endif