diff --git a/include/llvm/Assembly/AsmAnnotationWriter.h b/include/llvm/Assembly/AsmAnnotationWriter.h
new file mode 100644
index 00000000000..192cb3de0b2
--- /dev/null
+++ b/include/llvm/Assembly/AsmAnnotationWriter.h
@@ -0,0 +1,40 @@
+//===-- AsmAnnotationWriter.h - Itf for annotation .ll files - --*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// Clients of the assembly writer can use this interface to add their own
+// special-purpose annotations to LLVM assembly language printouts.  Note that
+// the assembly parser won't be able to parse these, in general, so
+// implementations are advised to print stuff as LLVM comments.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ASSEMBLY_ASMANNOTATIONWRITER_H
+#define LLVM_ASSEMBLY_ASMANNOTATIONWRITER_H
+
+#include <iosfwd>
+class Function;
+class BasicBlock;
+class Instruction;
+
+struct AssemblyAnnotationWriter {
+  
+  // emitFunctionAnnot - This may be implemented to emit a string right before
+  // the start of a function.
+  virtual void emitFunctionAnnot(const Function *F, std::ostream &OS) {}
+
+  // emitBasicBlockAnnot - This may be implemented to emit a string right after
+  // the basic block label, but before the first instruction in the block.
+  virtual void emitBasicBlockAnnot(const BasicBlock *BB, std::ostream &OS) {}
+
+  // emitInstructionAnnot - This may be implemented to emit a string right
+  // before an instruction is emitted.
+  virtual void emitInstructionAnnot(const Instruction *I, std::ostream &OS) {}
+};
+
+#endif