AArch64: Register null MCTargetStreamer

[arsenm]

Summary

Fixes crashes with clang -emit-codegen-only

[arsenm]

Test

[paquette]

LGTM

[MaskRay]

llvm/test/CodeGen/AArch64/null-mctargetstreamer.ll

1

6

delete blank line

[arsenm]

95176b890052206991a4b33756d165b142d4664e

llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp

if (const auto *Sign = mdconst::extract_or_null<ConstantInt>(
           M.getModuleFlag("sign-return-address")))
     if (Sign->getZExtValue())
       Flags |= ELF::GNU_PROPERTY_AARCH64_FEATURE_1_PAC;
 
   if (Flags == 0)
     return;
 
   // Emit a .note.gnu.property section with the flags.
-  if (auto *TS = static_cast<AArch64TargetStreamer *>(
-          OutStreamer->getTargetStreamer()))
-    TS->emitNoteSection(Flags);
+  auto *TS =
+      static_cast<AArch64TargetStreamer *>(OutStreamer->getTargetStreamer());
 }
 
 void AArch64AsmPrinter::emitFunctionHeaderComment() {
   const AArch64FunctionInfo *FI = MF->getInfo<AArch64FunctionInfo>();
   Optional<std::string> OutlinerString = FI->getOutliningStyle();
   if (OutlinerString != None)
     OutStreamer->getCommentOS() << ' ' << OutlinerString;
 }

llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCTargetDesc.cpp

for (Target *T : {&getTheAArch64leTarget(), &getTheAArch64beTarget(),
 
     // Register the obj target streamer.
     TargetRegistry::RegisterObjectTargetStreamer(
         *T, createAArch64ObjectTargetStreamer);
 
     // Register the asm streamer.
     TargetRegistry::RegisterAsmTargetStreamer(*T,
                                               createAArch64AsmTargetStreamer);
+    // Register the null streamer.
+    TargetRegistry::RegisterNullTargetStreamer(*T,
+                                               createAArch64NullTargetStreamer);
+
     // Register the MCInstPrinter.
     TargetRegistry::RegisterMCInstPrinter(*T, createAArch64MCInstPrinter);
   }
 
   // Register the asm backend.
   for (Target *T : {&getTheAArch64leTarget(), &getTheAArch64_32Target(),
                     &getTheARM64Target(), &getTheARM64_32Target()})
     TargetRegistry::RegisterMCAsmBackend(*T, createAArch64leAsmBackend);
   TargetRegistry::RegisterMCAsmBackend(getTheAArch64beTarget(),
                                        createAArch64beAsmBackend);
 }

llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h

 
 private:
   void emitARM64WinUnwindCode(unsigned UnwindCode, int Reg, int Offset);
 };
 
 MCTargetStreamer *
 createAArch64ObjectTargetStreamer(MCStreamer &S, const MCSubtargetInfo &STI);
 
+MCTargetStreamer *createAArch64NullTargetStreamer(MCStreamer &S);
+
 } // end namespace llvm
 
 #endif

llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp

llvm::createAArch64ObjectTargetStreamer(MCStreamer &S,
                                         const MCSubtargetInfo &STI) {
   const Triple &TT = STI.getTargetTriple();
   if (TT.isOSBinFormatELF())
     return new AArch64TargetELFStreamer(S);
   if (TT.isOSBinFormatCOFF())
     return new AArch64TargetWinCOFFStreamer(S);
   return nullptr;
 }
+
+MCTargetStreamer *llvm::createAArch64NullTargetStreamer(MCStreamer &S) {
+  return new AArch64TargetStreamer(S);
+}

llvm/test/CodeGen/AArch64/null-mctargetstreamer.ll

+; RUN: llc -mtriple=aarch64-unknown-unknown -filetype=null < %s
+
+define dso_local aarch64_vector_pcs void @foo() {
+  ret void
+}
+