MCContext/TargetMachine: Take MCRegisterInfo and MCSubtargetInfo by reference. NFC (llvm#195032)

Both MCRegisterInfo and MCSubtargetInfo are non-null at every callsite
that matters (only nullable in unit tests like
`llvm/unittests/CodeGen/MFCommon.inc`), mirroring the recent `const
MCAsmInfo &` cleanup.

* TargetMachine::getMCRegisterInfo and getMCSubtargetInfo return
  references.
* MCContext's constructor takes const MCRegisterInfo & and
  const MCSubtargetInfo &.

Author: MaskRay

bolt/include/bolt/Core/BinaryContext.h

@@ -1545,8 +1545,7 @@ class BinaryContext {
   /// won't be used in the main code emitter.
   IndependentCodeEmitter createIndependentMCCodeEmitter() const {
     IndependentCodeEmitter MCEInstance;
-    MCEInstance.LocalCtx.reset(
-        new MCContext(*TheTriple, *AsmInfo, MRI.get(), STI.get()));
+    MCEInstance.LocalCtx.reset(new MCContext(*TheTriple, *AsmInfo, *MRI, *STI));
     MCEInstance.LocalMOFI.reset(
         TheTarget->createMCObjectFileInfo(*MCEInstance.LocalCtx,
                                           /*PIC=*/!HasFixedLoadAddress));

bolt/lib/Core/BinaryContext.cpp

@@ -255,7 +255,7 @@ Expected<std::unique_ptr<BinaryContext>> BinaryContext::createBinaryContext(
         Twine("BOLT-ERROR: no instruction info for target ", TripleName));
 
   std::unique_ptr<MCContext> Ctx(
-      new MCContext(TheTriple, *AsmInfo, MRI.get(), STI.get()));
+      new MCContext(TheTriple, *AsmInfo, *MRI, *STI));
   std::unique_ptr<MCObjectFileInfo> MOFI(
       TheTarget->createMCObjectFileInfo(*Ctx, IsPIC));
   Ctx->setObjectFileInfo(MOFI.get());

clang/lib/Parse/ParseStmtAsm.cpp

@@ -566,7 +566,7 @@ StmtResult Parser::ParseMicrosoftAsmStatement(SourceLocation AsmLoc) {
   }
 
   llvm::SourceMgr TempSrcMgr;
-  llvm::MCContext Ctx(TheTriple, *MAI, MRI.get(), STI.get(), &TempSrcMgr);
+  llvm::MCContext Ctx(TheTriple, *MAI, *MRI, *STI, &TempSrcMgr);
   std::unique_ptr<llvm::MCObjectFileInfo> MOFI(
       TheTarget->createMCObjectFileInfo(Ctx, /*PIC=*/false));
   Ctx.setObjectFileInfo(MOFI.get());

clang/tools/driver/cc1_main.cpp

@@ -144,9 +144,9 @@ static int PrintSupportedExtensions(std::string TargetStr) {
   std::unique_ptr<llvm::TargetMachine> TheTargetMachine(
       TheTarget->createTargetMachine(Triple, "", "", Options, std::nullopt));
   const llvm::Triple &MachineTriple = TheTargetMachine->getTargetTriple();
-  const llvm::MCSubtargetInfo *MCInfo = TheTargetMachine->getMCSubtargetInfo();
+  const llvm::MCSubtargetInfo &MCInfo = TheTargetMachine->getMCSubtargetInfo();
   const llvm::ArrayRef<llvm::SubtargetFeatureKV> Features =
-    MCInfo->getAllProcessorFeatures();
+      MCInfo.getAllProcessorFeatures();
 
   llvm::StringMap<llvm::StringRef> DescMap;
   for (const llvm::SubtargetFeatureKV &feature : Features)
@@ -187,13 +187,13 @@ static int PrintEnabledExtensions(const TargetOptions& TargetOpts) {
       TheTarget->createTargetMachine(Triple, TargetOpts.CPU, FeaturesStr,
                                      BackendOptions, std::nullopt));
   const llvm::Triple &MachineTriple = TheTargetMachine->getTargetTriple();
-  const llvm::MCSubtargetInfo *MCInfo = TheTargetMachine->getMCSubtargetInfo();
+  const llvm::MCSubtargetInfo &MCInfo = TheTargetMachine->getMCSubtargetInfo();
 
   // Extract the feature names that are enabled for the given target.
   // We do that by capturing the key from the set of SubtargetFeatureKV entries
   // provided by MCSubtargetInfo, which match the '-target-feature' values.
   const std::vector<llvm::SubtargetFeatureKV> Features =
-    MCInfo->getEnabledProcessorFeatures();
+      MCInfo.getEnabledProcessorFeatures();
   std::set<llvm::StringRef> EnabledFeatureNames;
   for (const llvm::SubtargetFeatureKV &feature : Features)
     EnabledFeatureNames.insert(feature.Key);

clang/tools/driver/cc1as_main.cpp

@@ -506,7 +506,7 @@ static bool ExecuteAssemblerImpl(AssemblerInvocation &Opts,
            << Opts.CPU << FS.empty() << FS;
   }
 
-  MCContext Ctx(Triple(Opts.Triple), *MAI, MRI.get(), STI.get(), &SrcMgr);
+  MCContext Ctx(Triple(Opts.Triple), *MAI, *MRI, *STI, &SrcMgr);
 
   bool PIC = false;
   if (Opts.RelocationModel == "static") {

lldb/source/Plugins/Disassembler/LLVMC/DisassemblerLLVMC.cpp

@@ -1283,9 +1283,8 @@ DisassemblerLLVMC::MCDisasmInstance::Create(const char *triple_name,
   if (!asm_info_up)
     return Instance();
 
-  std::unique_ptr<llvm::MCContext> context_up(
-      new llvm::MCContext(llvm::Triple(triple), *asm_info_up, reg_info_up.get(),
-                          subtarget_info_up.get()));
+  std::unique_ptr<llvm::MCContext> context_up(new llvm::MCContext(
+      llvm::Triple(triple), *asm_info_up, *reg_info_up, *subtarget_info_up));
   if (!context_up)
     return Instance();
 

lldb/source/Plugins/Instruction/MIPS/EmulateInstructionMIPS.cpp

@@ -157,8 +157,8 @@ EmulateInstructionMIPS::EmulateInstructionMIPS(
   m_subtype_info.reset(target->createMCSubtargetInfo(triple, cpu, features));
   assert(m_asm_info.get() && m_subtype_info.get());
 
-  m_context = std::make_unique<llvm::MCContext>(
-      triple, *m_asm_info, m_reg_info.get(), m_subtype_info.get());
+  m_context = std::make_unique<llvm::MCContext>(triple, *m_asm_info,
+                                                *m_reg_info, *m_subtype_info);
   assert(m_context.get());
 
   m_disasm.reset(target->createMCDisassembler(*m_subtype_info, *m_context));

lldb/source/Plugins/Instruction/MIPS64/EmulateInstructionMIPS64.cpp

@@ -161,8 +161,8 @@ EmulateInstructionMIPS64::EmulateInstructionMIPS64(
   m_subtype_info.reset(target->createMCSubtargetInfo(triple, cpu, features));
   assert(m_asm_info.get() && m_subtype_info.get());
 
-  m_context = std::make_unique<llvm::MCContext>(
-      triple, *m_asm_info, m_reg_info.get(), m_subtype_info.get());
+  m_context = std::make_unique<llvm::MCContext>(triple, *m_asm_info,
+                                                *m_reg_info, *m_subtype_info);
   assert(m_context.get());
 
   m_disasm.reset(target->createMCDisassembler(*m_subtype_info, *m_context));

llvm/include/llvm/MC/MCContext.h

@@ -377,8 +377,8 @@ class MCContext {
 
 public:
   LLVM_ABI explicit MCContext(const Triple &TheTriple, const MCAsmInfo &MAI,
-                              const MCRegisterInfo *MRI,
-                              const MCSubtargetInfo *MSTI,
+                              const MCRegisterInfo &MRI,
+                              const MCSubtargetInfo &MSTI,
                               const SourceMgr *Mgr = nullptr,
                               bool DoAutoReset = true,
                               StringRef Swift5ReflSegmentName = {});

llvm/include/llvm/Target/TargetMachine.h

@@ -239,9 +239,9 @@ class LLVM_ABI TargetMachine {
   /// Return target specific asm information.
   const MCAsmInfo &getMCAsmInfo() const { return *AsmInfo; }
 
-  const MCRegisterInfo *getMCRegisterInfo() const { return MRI.get(); }
+  const MCRegisterInfo &getMCRegisterInfo() const { return *MRI; }
   const MCInstrInfo *getMCInstrInfo() const { return MII.get(); }
-  const MCSubtargetInfo *getMCSubtargetInfo() const { return STI.get(); }
+  const MCSubtargetInfo &getMCSubtargetInfo() const { return *STI; }
 
   /// Return the ExceptionHandling to use, considering TargetOptions and the
   /// Triple's default.