MCSectionWasm: Remove classof

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

Author: MaskRay

llvm/include/llvm/MC/MCSectionWasm.h

@@ -89,7 +89,6 @@ class MCSectionWasm final : public MCSection {
     assert(isWasmData());
     IsPassive = V;
   }
-  static bool classof(const MCSection *S) { return S->getVariant() == SV_Wasm; }
 };
 
 } // end namespace llvm

llvm/lib/MC/MCParser/WasmAsmParser.cpp

@@ -252,7 +252,7 @@ class WasmAsmParser : public MCAsmParserExtension {
     if (TypeName == "function") {
       WasmSym->setType(wasm::WASM_SYMBOL_TYPE_FUNCTION);
       auto *Current =
-          cast<MCSectionWasm>(getStreamer().getCurrentSectionOnly());
+          static_cast<MCSectionWasm *>(getStreamer().getCurrentSectionOnly());
       if (Current->getGroup())
         WasmSym->setComdat(true);
     } else if (TypeName == "global")

llvm/lib/MC/MCWasmStreamer.cpp

@@ -58,7 +58,7 @@ void MCWasmStreamer::emitLabelAtPos(MCSymbol *S, SMLoc Loc, MCFragment &F,
 
 void MCWasmStreamer::changeSection(MCSection *Section, uint32_t Subsection) {
   MCAssembler &Asm = getAssembler();
-  auto *SectionWasm = cast<MCSectionWasm>(Section);
+  auto *SectionWasm = static_cast<const MCSectionWasm *>(Section);
   const MCSymbol *Grp = SectionWasm->getGroup();
   if (Grp)
     Asm.registerSymbol(*Grp);

llvm/lib/MC/WasmObjectWriter.cpp

@@ -480,7 +480,7 @@ void WasmObjectWriter::recordRelocation(const MCFragment &F,
   // The WebAssembly backend should never generate FKF_IsPCRel fixups
   assert(!Fixup.isPCRel());
 
-  const auto &FixupSection = cast<MCSectionWasm>(*F.getParent());
+  const auto &FixupSection = static_cast<MCSectionWasm &>(*F.getParent());
   uint64_t C = Target.getConstant();
   uint64_t FixupOffset = Asm->getFragmentOffset(F) + Fixup.getOffset();
   MCContext &Ctx = getContext();

llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp

@@ -900,7 +900,8 @@ class WebAssemblyAsmParser final : public MCTargetAsmParser {
 
   bool checkDataSection() {
     if (CurrentState != DataSection) {
-      auto *WS = cast<MCSectionWasm>(getStreamer().getCurrentSectionOnly());
+      auto *WS = static_cast<const MCSectionWasm *>(
+          getStreamer().getCurrentSectionOnly());
       if (WS && WS->isText())
         return error("data directive must occur in a data segment: ",
                      Lexer.getTok());
@@ -1218,7 +1219,8 @@ class WebAssemblyAsmParser final : public MCTargetAsmParser {
 
   void doBeforeLabelEmit(MCSymbol *Symbol, SMLoc IDLoc) override {
     // Code below only applies to labels in text sections.
-    auto *CWS = cast<MCSectionWasm>(getStreamer().getCurrentSectionOnly());
+    auto *CWS = static_cast<const MCSectionWasm *>(
+        getStreamer().getCurrentSectionOnly());
     if (!CWS->isText())
       return;