MCSymbolXCOFF: Migrate away from classof

The object file format specific derived classes are used in context
where the type is statically known. We don't use isa/dyn_cast and we
want to eliminate MCSymbol::Kind in the base class.

Author: MaskRay

llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp

@@ -2371,9 +2371,10 @@ bool TargetLoweringObjectFileXCOFF::ShouldSetSSPCanaryBitInTB(
 
 MCSymbol *
 TargetLoweringObjectFileXCOFF::getEHInfoTableSymbol(const MachineFunction *MF) {
-  MCSymbol *EHInfoSym = MF->getContext().getOrCreateSymbol(
-      "__ehinfo." + Twine(MF->getFunctionNumber()));
-  cast<MCSymbolXCOFF>(EHInfoSym)->setEHInfo();
+  auto *EHInfoSym =
+      static_cast<MCSymbolXCOFF *>(MF->getContext().getOrCreateSymbol(
+          "__ehinfo." + Twine(MF->getFunctionNumber())));
+  EHInfoSym->setEHInfo();
   return EHInfoSym;
 }
 
@@ -2511,7 +2512,8 @@ MCSection *TargetLoweringObjectFileXCOFF::SelectSectionForGlobal(
 
   if (Kind.isText()) {
     if (TM.getFunctionSections()) {
-      return cast<MCSymbolXCOFF>(getFunctionEntryPointSymbol(GO, TM))
+      return static_cast<const MCSymbolXCOFF *>(
+                 getFunctionEntryPointSymbol(GO, TM))
           ->getRepresentedCsect();
     }
     return TextSection;
@@ -2714,7 +2716,7 @@ MCSection *TargetLoweringObjectFileXCOFF::getSectionForTOCEntry(
     const MCSymbol *Sym, const TargetMachine &TM) const {
   const XCOFF::StorageMappingClass SMC = [](const MCSymbol *Sym,
                                             const TargetMachine &TM) {
-    const MCSymbolXCOFF *XSym = cast<MCSymbolXCOFF>(Sym);
+    auto *XSym = static_cast<const MCSymbolXCOFF *>(Sym);
 
     // The "_$TLSML" symbol for TLS local-dynamic mode requires XMC_TC,
     // otherwise the AIX assembler will complain.
@@ -2738,8 +2740,8 @@ MCSection *TargetLoweringObjectFileXCOFF::getSectionForTOCEntry(
   }(Sym, TM);
 
   return getContext().getXCOFFSection(
-      cast<MCSymbolXCOFF>(Sym)->getSymbolTableName(), SectionKind::getData(),
-      XCOFF::CsectProperties(SMC, XCOFF::XTY_SD));
+      static_cast<const MCSymbolXCOFF *>(Sym)->getSymbolTableName(),
+      SectionKind::getData(), XCOFF::CsectProperties(SMC, XCOFF::XTY_SD));
 }
 
 MCSection *TargetLoweringObjectFileXCOFF::getSectionForLSDA(

llvm/lib/MC/MCAsmStreamer.cpp

@@ -897,14 +897,14 @@ void MCAsmStreamer::emitXCOFFLocalCommonSymbol(MCSymbol *LabelSym,
 
   // Print symbol's rename (original name contains invalid character(s)) if
   // there is one.
-  MCSymbolXCOFF *XSym = cast<MCSymbolXCOFF>(CsectSym);
+  auto *XSym = static_cast<MCSymbolXCOFF *>(CsectSym);
   if (XSym->hasRename())
     emitXCOFFRenameDirective(XSym, XSym->getSymbolTableName());
 }
 
 void MCAsmStreamer::emitXCOFFSymbolLinkageWithVisibility(
     MCSymbol *Symbol, MCSymbolAttr Linkage, MCSymbolAttr Visibility) {
-
+  auto &Sym = static_cast<MCSymbolXCOFF &>(*Symbol);
   switch (Linkage) {
   case MCSA_Global:
     OS << MAI->getGlobalDirective();
@@ -944,9 +944,8 @@ void MCAsmStreamer::emitXCOFFSymbolLinkageWithVisibility(
 
   // Print symbol's rename (original name contains invalid character(s)) if
   // there is one.
-  if (cast<MCSymbolXCOFF>(Symbol)->hasRename())
-    emitXCOFFRenameDirective(Symbol,
-                             cast<MCSymbolXCOFF>(Symbol)->getSymbolTableName());
+  if (Sym.hasRename())
+    emitXCOFFRenameDirective(&Sym, Sym.getSymbolTableName());
 }
 
 void MCAsmStreamer::emitXCOFFRenameDirective(const MCSymbol *Name,

llvm/lib/MC/MCContext.cpp

@@ -889,9 +889,9 @@ MCSectionXCOFF *MCContext::getXCOFFSection(
   MCSymbolXCOFF *QualName = nullptr;
   // Debug section don't have storage class attribute.
   if (IsDwarfSec)
-    QualName = cast<MCSymbolXCOFF>(getOrCreateSymbol(CachedName));
+    QualName = static_cast<MCSymbolXCOFF *>(getOrCreateSymbol(CachedName));
   else
-    QualName = cast<MCSymbolXCOFF>(getOrCreateSymbol(
+    QualName = static_cast<MCSymbolXCOFF *>(getOrCreateSymbol(
         CachedName + "[" +
         XCOFF::getMappingClassString(CsectProp->MappingClass) + "]"));
 

llvm/lib/MC/MCXCOFFStreamer.cpp

@@ -52,7 +52,7 @@ void MCXCOFFStreamer::changeSection(MCSection *Section, uint32_t Subsection) {
 
 bool MCXCOFFStreamer::emitSymbolAttribute(MCSymbol *Sym,
                                           MCSymbolAttr Attribute) {
-  auto *Symbol = cast<MCSymbolXCOFF>(Sym);
+  auto *Symbol = static_cast<MCSymbolXCOFF *>(Sym);
   getAssembler().registerSymbol(*Symbol);
 
   switch (Attribute) {
@@ -129,15 +129,14 @@ void MCXCOFFStreamer::emitXCOFFCInfoSym(StringRef Name, StringRef Metadata) {
 
 void MCXCOFFStreamer::emitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                        Align ByteAlignment) {
+  auto *Sym = static_cast<MCSymbolXCOFF *>(Symbol);
   getAssembler().registerSymbol(*Symbol);
-  Symbol->setExternal(cast<MCSymbolXCOFF>(Symbol)->getStorageClass() !=
-                      XCOFF::C_HIDEXT);
+  Symbol->setExternal(Sym->getStorageClass() != XCOFF::C_HIDEXT);
   Symbol->setCommon(Size, ByteAlignment);
 
   // Default csect align is 4, but common symbols have explicit alignment values
   // and we should honor it.
-  cast<MCSymbolXCOFF>(Symbol)->getRepresentedCsect()->setAlignment(
-      ByteAlignment);
+  Sym->getRepresentedCsect()->setAlignment(ByteAlignment);
 
   // Emit the alignment and storage for the variable to the section.
   emitValueToAlignment(ByteAlignment);

llvm/lib/MC/XCOFFObjectWriter.cpp

@@ -591,7 +591,7 @@ void XCOFFWriter::executePostLayoutBinding() {
     if (S.isTemporary())
       continue;
 
-    const MCSymbolXCOFF *XSym = cast<MCSymbolXCOFF>(&S);
+    auto *XSym = static_cast<const MCSymbolXCOFF *>(&S);
     const MCSectionXCOFF *ContainingCsect = getContainingCsect(XSym);
 
     if (ContainingCsect->isDwarfSect())

llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp

@@ -2767,7 +2767,7 @@ void PPCAIXAsmPrinter::emitGlobalVariableHelper(const GlobalVariable *GV) {
   if (GV->hasComdat())
     report_fatal_error("COMDAT not yet supported by AIX.");
 
-  MCSymbolXCOFF *GVSym = cast<MCSymbolXCOFF>(getSymbol(GV));
+  auto *GVSym = static_cast<MCSymbolXCOFF *>(getSymbol(GV));
 
   if (GV->isDeclarationForLinker()) {
     emitLinkage(GV, GVSym);
@@ -2860,7 +2860,7 @@ void PPCAIXAsmPrinter::emitFunctionDescriptor() {
   MCSectionSubPair Current = OutStreamer->getCurrentSection();
   // Emit function descriptor.
   OutStreamer->switchSection(
-      cast<MCSymbolXCOFF>(CurrentFnDescSym)->getRepresentedCsect());
+      static_cast<MCSymbolXCOFF *>(CurrentFnDescSym)->getRepresentedCsect());
 
   // Emit aliasing label for function descriptor csect.
   for (const GlobalAlias *Alias : GOAliasMap[&MF->getFunction()])
@@ -2995,7 +2995,8 @@ void PPCAIXAsmPrinter::emitEndOfAsmFile(Module &M) {
       SmallString<128> Name;
       StringRef Prefix = ".";
       Name += Prefix;
-      Name += cast<MCSymbolXCOFF>(I.first.first)->getSymbolTableName();
+      Name += static_cast<const MCSymbolXCOFF *>(I.first.first)
+                  ->getSymbolTableName();
       MCSymbol *S = OutContext.getOrCreateSymbol(Name);
       TCEntry = static_cast<MCSectionXCOFF *>(
           getObjFileLowering().getSectionForTOCEntry(S, TM));
@@ -3191,8 +3192,8 @@ void PPCAIXAsmPrinter::emitInstruction(const MachineInstr *MI) {
   case PPC::BL_NOP: {
     const MachineOperand &MO = MI->getOperand(0);
     if (MO.isSymbol()) {
-      MCSymbolXCOFF *S =
-          cast<MCSymbolXCOFF>(OutContext.getOrCreateSymbol(MO.getSymbolName()));
+      auto *S = static_cast<MCSymbolXCOFF *>(
+          OutContext.getOrCreateSymbol(MO.getSymbolName()));
       ExtSymSDNodeSymbols.insert(S);
     }
   } break;

llvm/lib/Target/PowerPC/PPCISelLowering.cpp

@@ -5540,8 +5540,8 @@ static SDValue transformCallee(const SDValue &Callee, SelectionDAG &DAG,
   const auto getAIXFuncEntryPointSymbolSDNode = [&](const GlobalValue *GV) {
     const TargetMachine &TM = Subtarget.getTargetMachine();
     const TargetLoweringObjectFile *TLOF = TM.getObjFileLowering();
-    MCSymbolXCOFF *S =
-        cast<MCSymbolXCOFF>(TLOF->getFunctionEntryPointSymbol(GV, TM));
+    auto *S =
+        static_cast<MCSymbolXCOFF *>(TLOF->getFunctionEntryPointSymbol(GV, TM));
 
     MVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout());
     return DAG.getMCSymbol(S, PtrVT);