From 0ebab8bae4215000ec73c0233f929466fc05a038 Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault@amd.com>
Date: Sat, 29 Oct 2022 12:17:23 -0700
Subject: [PATCH] PPC: Implement null target streamer

---
 .../PowerPC/MCTargetDesc/PPCMCTargetDesc.cpp   |  7 +++++++
 llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp      | 18 ++++++------------
 llvm/lib/Target/PowerPC/PPCTargetStreamer.h    |  8 ++++----
 3 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.cpp b/llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.cpp
index 9b37c862dbd0b..10e352923c1a9 100644
--- a/llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.cpp
+++ b/llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.cpp
@@ -352,6 +352,10 @@ static MCTargetStreamer *createAsmTargetStreamer(MCStreamer &S,
   return new PPCTargetAsmStreamer(S, OS);
 }
 
+static MCTargetStreamer *createNullTargetStreamer(MCStreamer &S) {
+  return new PPCTargetStreamer(S);
+}
+
 static MCTargetStreamer *
 createObjectTargetStreamer(MCStreamer &S, const MCSubtargetInfo &STI) {
   const Triple &TT = STI.getTargetTriple();
@@ -432,6 +436,9 @@ extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializePowerPCTargetMC() {
     // Register the asm target streamer.
     TargetRegistry::RegisterAsmTargetStreamer(*T, createAsmTargetStreamer);
 
+    // Register the null target streamer.
+    TargetRegistry::RegisterNullTargetStreamer(*T, createNullTargetStreamer);
+
     // Register the MCInstPrinter.
     TargetRegistry::RegisterMCInstPrinter(*T, createPPCMCInstPrinter);
   }
diff --git a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
index 955f8cd44e8d2..30e96cff9e2c3 100644
--- a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -1572,9 +1572,7 @@ void PPCLinuxAsmPrinter::emitStartOfAsmFile(Module &M) {
   if (static_cast<const PPCTargetMachine &>(TM).isELFv2ABI()) {
     PPCTargetStreamer *TS =
       static_cast<PPCTargetStreamer *>(OutStreamer->getTargetStreamer());
-
-    if (TS)
-      TS->emitAbiVersion(2);
+    TS->emitAbiVersion(2);
   }
 
   if (static_cast<const PPCTargetMachine &>(TM).isPPC64() ||
@@ -1700,7 +1698,7 @@ void PPCLinuxAsmPrinter::emitEndOfAsmFile(Module &M) {
       MCSymbol *const TOCEntryLabel = TOCMapPair.second;
 
       OutStreamer->emitLabel(TOCEntryLabel);
-      if (isPPC64 && TS != nullptr)
+      if (isPPC64)
         TS->emitTCEntry(*TOCEntryTarget, TOCMapPair.first.second);
       else
         OutStreamer->emitSymbolValue(TOCEntryTarget, 4);
@@ -1806,9 +1804,7 @@ void PPCLinuxAsmPrinter::emitFunctionBodyStart() {
 
     PPCTargetStreamer *TS =
       static_cast<PPCTargetStreamer *>(OutStreamer->getTargetStreamer());
-
-    if (TS)
-      TS->emitLocalEntry(cast<MCSymbolELF>(CurrentFnSym), LocalOffsetExp);
+    TS->emitLocalEntry(cast<MCSymbolELF>(CurrentFnSym), LocalOffsetExp);
   } else if (Subtarget->isUsingPCRelativeCalls()) {
     // When generating the entry point for a function we have a few scenarios
     // based on whether or not that function uses R2 and whether or not that
@@ -1835,9 +1831,8 @@ void PPCLinuxAsmPrinter::emitFunctionBodyStart() {
         MF->hasInlineAsm() || (!PPCFI->usesTOCBasePtr() && UsesX2OrR2)) {
       PPCTargetStreamer *TS =
           static_cast<PPCTargetStreamer *>(OutStreamer->getTargetStreamer());
-      if (TS)
-        TS->emitLocalEntry(cast<MCSymbolELF>(CurrentFnSym),
-                           MCConstantExpr::create(1, OutContext));
+      TS->emitLocalEntry(cast<MCSymbolELF>(CurrentFnSym),
+                         MCConstantExpr::create(1, OutContext));
     }
   }
 }
@@ -2568,8 +2563,7 @@ void PPCAIXAsmPrinter::emitEndOfAsmFile(Module &M) {
     OutStreamer->switchSection(TCEntry);
 
     OutStreamer->emitLabel(I.second);
-    if (TS != nullptr)
-      TS->emitTCEntry(*I.first.first, I.first.second);
+    TS->emitTCEntry(*I.first.first, I.first.second);
   }
 
   for (const auto *GV : TOCDataGlobalVars)
diff --git a/llvm/lib/Target/PowerPC/PPCTargetStreamer.h b/llvm/lib/Target/PowerPC/PPCTargetStreamer.h
index e3fc6285494c5..daf5b93ff21f0 100644
--- a/llvm/lib/Target/PowerPC/PPCTargetStreamer.h
+++ b/llvm/lib/Target/PowerPC/PPCTargetStreamer.h
@@ -25,10 +25,10 @@ class PPCTargetStreamer : public MCTargetStreamer {
   ~PPCTargetStreamer() override;
 
   virtual void emitTCEntry(const MCSymbol &S,
-                           MCSymbolRefExpr::VariantKind Kind) = 0;
-  virtual void emitMachine(StringRef CPU) = 0;
-  virtual void emitAbiVersion(int AbiVersion) = 0;
-  virtual void emitLocalEntry(MCSymbolELF *S, const MCExpr *LocalOffset) = 0;
+                           MCSymbolRefExpr::VariantKind Kind){};
+  virtual void emitMachine(StringRef CPU){};
+  virtual void emitAbiVersion(int AbiVersion){};
+  virtual void emitLocalEntry(MCSymbolELF *S, const MCExpr *LocalOffset){};
 };
 
 } // end namespace llvm