SystemZ: Register null target streamer

[arsenm]

Summary

Fixes at least one null dereference.

[uweigand]

LGTM, thanks!

[arsenm]

5baa4b8e1164b3635ef9220104159988f4ee836a

llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCTargetDesc.cpp

createAsmTargetStreamer(MCStreamer &S,
   return new SystemZTargetAsmStreamer(S, OS);
 }
 
 static MCTargetStreamer *
 createObjectTargetStreamer(MCStreamer &S, const MCSubtargetInfo &STI) {
   return new SystemZTargetELFStreamer(S);
 }
 
+static MCTargetStreamer *
+createNullTargetStreamer(MCStreamer &S) {
+  return new SystemZTargetStreamer(S);
+}
+
 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeSystemZTargetMC() {
   // Register the MCAsmInfo.
   TargetRegistry::RegisterMCAsmInfo(getTheSystemZTarget(),
                                     createSystemZMCAsmInfo);
 
   // Register the MCCodeEmitter.
   TargetRegistry::RegisterMCCodeEmitter(getTheSystemZTarget(),
                                         createSystemZMCCodeEmitter);
extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeSystemZTargetMC() {
 
   // Register the asm streamer.
   TargetRegistry::RegisterAsmTargetStreamer(getTheSystemZTarget(),
                                             createAsmTargetStreamer);
 
   // Register the obj streamer
   TargetRegistry::RegisterObjectTargetStreamer(getTheSystemZTarget(),
                                                createObjectTargetStreamer);
+
+  // Register the null streamer
+  TargetRegistry::RegisterNullTargetStreamer(getTheSystemZTarget(),
+                                             createNullTargetStreamer);
 }

llvm/lib/Target/SystemZ/SystemZTargetStreamer.h

bool operator()(const MCInstSTIPair &MCI_STI_A,
       return false;
     }
   };
   typedef std::map<MCInstSTIPair, MCSymbol *, CmpMCInst> EXRLT2SymMap;
   EXRLT2SymMap EXRLTargets2Sym;
 
   void emitConstantPools() override;
 
-  virtual void emitMachine(StringRef CPU) = 0;
+  virtual void emitMachine(StringRef CPU) {};
 };
 
 } // end namespace llvm
 
 #endif // LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZTARGETSTREAMER_H

llvm/test/CodeGen/SystemZ/memcpy-01.ll

 ; Test memcpy using MVC.
 ;
 ; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+; RUN: llc -mtriple=s390x-linux-gnu -filetype=null %s
 
 declare void @llvm.memcpy.p0.p0.i32(ptr nocapture, ptr nocapture, i32, i1) nounwind
 declare void @llvm.memcpy.p0.p0.i64(ptr nocapture, ptr nocapture, i64, i1) nounwind
 declare void @foo(ptr, ptr)
 
 ; Test a no-op move, i32 version.
 define void @f1(ptr %dest, ptr %src) {
 ; CHECK-LABEL: f1: