Make getTargetStreamer return a possibly null pointer.

This will allow it to be called from target independent parts of the main
streamer that don't know if there is a registered target streamer or not. This
in turn will allow targets to perform extra actions at specified points in the
interface: add extra flags for some labels, extra work during finalization, etc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199174 91177308-0d34-0410-b5e6-96231b3b80d8

Author: espindola

include/llvm/MC/MCStreamer.h

@@ -171,9 +171,8 @@ class MCStreamer {
 
   MCContext &getContext() const { return Context; }
 
-  MCTargetStreamer &getTargetStreamer() {
-    assert(TargetStreamer);
-    return *TargetStreamer;
+  MCTargetStreamer *getTargetStreamer() {
+    return TargetStreamer.get();
   }
 
   unsigned getNumFrameInfos() { return FrameInfos.size(); }

lib/CodeGen/AsmPrinter/ARMException.cpp

@@ -48,7 +48,7 @@ ARMException::ARMException(AsmPrinter *A)
 ARMException::~ARMException() {}
 
 ARMTargetStreamer &ARMException::getTargetStreamer() {
-  MCTargetStreamer &TS = Asm->OutStreamer.getTargetStreamer();
+  MCTargetStreamer &TS = *Asm->OutStreamer.getTargetStreamer();
   return static_cast<ARMTargetStreamer &>(TS);
 }
 

lib/Target/ARM/ARMAsmPrinter.cpp

@@ -616,7 +616,7 @@ static ARMBuildAttrs::CPUArch getArchForCPU(StringRef CPU,
 }
 
 void ARMAsmPrinter::emitAttributes() {
-  MCTargetStreamer &TS = OutStreamer.getTargetStreamer();
+  MCTargetStreamer &TS = *OutStreamer.getTargetStreamer();
   ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
 
   ATS.switchVendor("aeabi");
@@ -983,7 +983,7 @@ void ARMAsmPrinter::EmitUnwindingInstruction(const MachineInstr *MI) {
   assert(MI->getFlag(MachineInstr::FrameSetup) &&
       "Only instruction which are involved into frame setup code are allowed");
 
-  MCTargetStreamer &TS = OutStreamer.getTargetStreamer();
+  MCTargetStreamer &TS = *OutStreamer.getTargetStreamer();
   ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
   const MachineFunction &MF = *MI->getParent()->getParent();
   const TargetRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();

lib/Target/ARM/AsmParser/ARMAsmParser.cpp

@@ -192,7 +192,7 @@ class ARMAsmParser : public MCTargetAsmParser {
   }
 
   ARMTargetStreamer &getTargetStreamer() {
-    MCTargetStreamer &TS = getParser().getStreamer().getTargetStreamer();
+    MCTargetStreamer &TS = *getParser().getStreamer().getTargetStreamer();
     return static_cast<ARMTargetStreamer &>(TS);
   }
 

lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp

@@ -925,7 +925,7 @@ void ARMTargetELFStreamer::emitInst(uint32_t Inst, char Suffix) {
 }
 
 void ARMELFStreamer::FinishImpl() {
-  MCTargetStreamer &TS = getTargetStreamer();
+  MCTargetStreamer &TS = *getTargetStreamer();
   ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
   ATS.finishAttributeSection();
 

lib/Target/Mips/AsmParser/MipsAsmParser.cpp

@@ -57,7 +57,7 @@ namespace {
 class MipsAsmParser : public MCTargetAsmParser {
 
   MipsTargetStreamer &getTargetStreamer() {
-    MCTargetStreamer &TS = Parser.getStreamer().getTargetStreamer();
+    MCTargetStreamer &TS = *Parser.getStreamer().getTargetStreamer();
     return static_cast<MipsTargetStreamer &>(TS);
   }
 

lib/Target/Mips/MipsAsmPrinter.cpp

@@ -46,7 +46,7 @@
 using namespace llvm;
 
 MipsTargetStreamer &MipsAsmPrinter::getTargetStreamer() {
-  return static_cast<MipsTargetStreamer &>(OutStreamer.getTargetStreamer());
+  return static_cast<MipsTargetStreamer &>(*OutStreamer.getTargetStreamer());
 }
 
 bool MipsAsmPrinter::runOnMachineFunction(MachineFunction &MF) {

lib/Target/PowerPC/PPCAsmPrinter.cpp

@@ -769,7 +769,7 @@ bool PPCLinuxAsmPrinter::doFinalization(Module &M) {
   bool isPPC64 = TD->getPointerSizeInBits() == 64;
 
   PPCTargetStreamer &TS =
-      static_cast<PPCTargetStreamer &>(OutStreamer.getTargetStreamer());
+      static_cast<PPCTargetStreamer &>(*OutStreamer.getTargetStreamer());
 
   if (isPPC64 && !TOC.empty()) {
     const MCSectionELF *Section = OutStreamer.getContext().getELFSection(".toc",

lib/Target/Sparc/SparcAsmPrinter.cpp

@@ -37,7 +37,8 @@ using namespace llvm;
 namespace {
   class SparcAsmPrinter : public AsmPrinter {
     SparcTargetStreamer &getTargetStreamer() {
-      return static_cast<SparcTargetStreamer&>(OutStreamer.getTargetStreamer());
+      return static_cast<SparcTargetStreamer &>(
+          *OutStreamer.getTargetStreamer());
     }
   public:
     explicit SparcAsmPrinter(TargetMachine &TM, MCStreamer &Streamer)