llvm-mc: Add dummy MCStreamer implementation, (eventually) for use in profiling.
 - Currently unused.

 - A few other random comment fixes lumped in.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78960 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCNullStreamer.cpp b/lib/MC/MCNullStreamer.cpp
new file mode 100644
index 0000000..3ac79cb
--- /dev/null
+++ b/lib/MC/MCNullStreamer.cpp
@@ -0,0 +1,72 @@
+//===- lib/MC/MCNullStreamer.cpp - Dummy Streamer 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/MCStreamer.h"
+
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCSectionMachO.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/MC/MCValue.h"
+
+using namespace llvm;
+
+namespace {
+
+  class MCNullStreamer : public MCStreamer {
+  public:
+    MCNullStreamer(MCContext &Context) : MCStreamer(Context) {}
+
+    /// @name MCStreamer Interface
+    /// @{
+
+    virtual void SwitchSection(MCSection *Section) {}
+
+    virtual void EmitLabel(MCSymbol *Symbol) {}
+
+    virtual void EmitAssemblerFlag(AssemblerFlag Flag) {}
+
+    virtual void EmitAssignment(MCSymbol *Symbol, const MCValue &Value,
+                                bool MakeAbsolute = false) {}
+
+    virtual void EmitSymbolAttribute(MCSymbol *Symbol, SymbolAttr Attribute) {}
+
+    virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
+
+    virtual void EmitLocalSymbol(MCSymbol *Symbol, const MCValue &Value) {}
+
+    virtual void EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,
+                                  unsigned Pow2Alignment, bool IsLocal) {}
+
+    virtual void EmitZerofill(MCSection *Section, MCSymbol *Symbol = NULL,
+                              unsigned Size = 0, unsigned Pow2Alignment = 0) {}
+
+    virtual void EmitBytes(const StringRef &Data) {}
+
+    virtual void EmitValue(const MCValue &Value, unsigned Size) {}
+
+    virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
+                                      unsigned ValueSize = 1,
+                                      unsigned MaxBytesToEmit = 0) {}
+
+    virtual void EmitValueToOffset(const MCValue &Offset, 
+                                   unsigned char Value = 0) {}
+    
+    virtual void EmitInstruction(const MCInst &Inst) {}
+
+    virtual void Finish() {}
+    
+    /// @}
+  };
+
+}
+    
+MCStreamer *llvm::createNullStreamer(MCContext &Context) {
+  return new MCNullStreamer(Context);
+}