subclassed MCAsmStreamer

include/llvm/Support/TargetRegistry.h

Index: include/llvm/Support/TargetRegistry.h
diff --git a/include/llvm/Support/TargetRegistry.h b/include/llvm/Support/TargetRegistry.h
index 9b11826e3609390e87baec018179e889dcaef177..232e209dd1a2ae2a3c6569c64423ce2a66f46088 100644
--- a/include/llvm/Support/TargetRegistry.h
+++ b/include/llvm/Support/TargetRegistry.h
@@ -147,6 +147,11 @@ namespace llvm {
                                               raw_pwrite_stream &OS,
                                               MCCodeEmitter *Emitter,
                                               bool RelaxAll);
+    typedef MCStreamer *(*NaClAsmStreamerCtorTy)(MCContext &Context,
+						 std::unique_ptr<formatted_raw_ostream> OS,
+						 bool isVerboseAsm, bool useDwarfDirectory,
+						 MCInstPrinter *IP, MCCodeEmitter *CE,
+						 MCAsmBackend *MAB, bool ShowInst);
     typedef MCTargetStreamer *(*NullTargetStreamerCtorTy)(MCStreamer &S);
     typedef MCTargetStreamer *(*AsmTargetStreamerCtorTy)(
         MCStreamer &S, formatted_raw_ostream &OS, MCInstPrinter *InstPrint,
@@ -234,6 +239,9 @@ namespace llvm {
     MachOStreamerCtorTy MachOStreamerCtorFn;
     ELFStreamerCtorTy ELFStreamerCtorFn;
 
+    // Construction functions for NaCl asm streamer, if registered.
+    NaClAsmStreamerCtorTy NaClAsmStreamerCtorFn;
+
     /// Construction function for this target's null TargetStreamer, if
     /// registered (default = nullptr).
     NullTargetStreamerCtorTy NullTargetStreamerCtorFn;
@@ -486,6 +494,22 @@ namespace llvm {
       return S;
     }
 
+    MCStreamer *createNaClAsmStreamer(MCContext &Ctx,
+                                  std::unique_ptr<formatted_raw_ostream> OS,
+                                  bool IsVerboseAsm, bool UseDwarfDirectory,
+                                  MCInstPrinter *InstPrint, MCCodeEmitter *CE,
+                                  MCAsmBackend *TAB, bool ShowInst) const {
+      if (NaClAsmStreamerCtorFn) {
+	formatted_raw_ostream &OSRef = *OS;
+	MCStreamer *S = NaClAsmStreamerCtorFn(Ctx, std::move(OS), IsVerboseAsm,
+					      UseDwarfDirectory, InstPrint, CE,
+					      TAB, ShowInst);
+	createAsmTargetStreamer(*S, OSRef, InstPrint, IsVerboseAsm);
+	return S;
+      }
+      return nullptr;
+    }
+
     MCTargetStreamer *createAsmTargetStreamer(MCStreamer &S,
                                               formatted_raw_ostream &OS,
                                               MCInstPrinter *InstPrint,
@@ -825,6 +849,10 @@ namespace llvm {
       T.ELFStreamerCtorFn = Fn;
     }
 
+    static void RegisterNaClAsmStreamer(Target &T, Target::NaClAsmStreamerCtorTy Fn) {
+      T.NaClAsmStreamerCtorFn = Fn;
+    }
+
     static void
     RegisterNullTargetStreamer(Target &T, Target::NullTargetStreamerCtorTy Fn) {
       T.NullTargetStreamerCtorFn = Fn;