[MC] Move MCAssembler::isSymbolLinkerVisible to MCSymbolMachO

Author: MaskRay

llvm/include/llvm/MC/MCAssembler.h

@@ -256,12 +256,6 @@ class MCAssembler {
   // If this symbol is equivalent to A + Constant, return A.
   const MCSymbol *getBaseSymbol(const MCSymbol &Symbol) const;
 
-  /// Check whether a particular symbol is visible to the linker and is required
-  /// in the symbol table, or whether it can be discarded by the assembler. This
-  /// also effects whether the assembler treats the label as potentially
-  /// defining a separate atom.
-  bool isSymbolLinkerVisible(const MCSymbol &SD) const;
-
   /// Emit the section contents to \p OS.
   void writeSectionData(raw_ostream &OS, const MCSection *Section) const;
 

llvm/include/llvm/MC/MCSymbolMachO.h

@@ -109,6 +109,18 @@ class MCSymbolMachO : public MCSymbol {
     setFlags(Value & SF_DescFlagsMask);
   }
 
+  // Check whether a particular symbol is visible to the linker and is required
+  // in the symbol table, or whether it can be discarded by the assembler. This
+  // also effects whether the assembler treats the label as potentially defining
+  // a separate atom.
+  bool isSymbolLinkerVisible() const {
+    // Non-temporary labels should always be visible to the linker.
+    if (!isTemporary())
+      return true;
+
+    return isUsedInReloc();
+  }
+
   /// Get the encoded value of the flags as they will be emitted in to
   /// the MachO binary
   uint16_t getEncodedFlags(bool EncodeAsAltEntry) const {

llvm/lib/MC/MCAssembler.cpp

@@ -160,17 +160,6 @@ bool MCAssembler::isThumbFunc(const MCSymbol *Symbol) const {
   return true;
 }
 
-bool MCAssembler::isSymbolLinkerVisible(const MCSymbol &Symbol) const {
-  // Non-temporary labels should always be visible to the linker.
-  if (!Symbol.isTemporary())
-    return true;
-
-  if (Symbol.isUsedInReloc())
-    return true;
-
-  return false;
-}
-
 bool MCAssembler::evaluateFixup(const MCFixup &Fixup, const MCFragment *DF,
                                 MCValue &Target, const MCSubtargetInfo *STI,
                                 uint64_t &Value, bool &WasForced) const {

llvm/lib/MC/MCMachOStreamer.cpp

@@ -198,7 +198,7 @@ void MCMachOStreamer::emitEHSymAttributes(const MCSymbol *Symbol,
 void MCMachOStreamer::emitLabel(MCSymbol *Symbol, SMLoc Loc) {
   // We have to create a new fragment if this is an atom defining symbol,
   // fragments cannot span atoms.
-  if (getAssembler().isSymbolLinkerVisible(*Symbol))
+  if (cast<MCSymbolMachO>(Symbol)->isSymbolLinkerVisible())
     insert(getContext().allocFragment<MCDataFragment>());
 
   MCObjectStreamer::emitLabel(Symbol, Loc);
@@ -507,8 +507,9 @@ void MCMachOStreamer::finishImpl() {
   // defining symbols.
   DenseMap<const MCFragment *, const MCSymbol *> DefiningSymbolMap;
   for (const MCSymbol &Symbol : getAssembler().symbols()) {
-    if (getAssembler().isSymbolLinkerVisible(Symbol) && Symbol.isInSection() &&
-        !Symbol.isVariable() && !cast<MCSymbolMachO>(Symbol).isAltEntry()) {
+    auto &Sym = cast<MCSymbolMachO>(Symbol);
+    if (Sym.isSymbolLinkerVisible() && Sym.isInSection() && !Sym.isVariable() &&
+        !Sym.isAltEntry()) {
       // An atom defining symbol should never be internal to a fragment.
       assert(Symbol.getOffset() == 0 &&
              "Invalid offset in atom defining symbol!");

llvm/lib/MC/MachObjectWriter.cpp

@@ -582,7 +582,7 @@ void MachObjectWriter::computeSymbolTable(
 
   // Build the string table.
   for (const MCSymbol &Symbol : Asm.symbols()) {
-    if (!Asm.isSymbolLinkerVisible(Symbol))
+    if (!cast<MCSymbolMachO>(Symbol).isSymbolLinkerVisible())
       continue;
 
     StringTable.add(Symbol.getName());
@@ -596,7 +596,7 @@ void MachObjectWriter::computeSymbolTable(
   // important for letting us diff .o files.
   for (const MCSymbol &Symbol : Asm.symbols()) {
     // Ignore non-linker visible symbols.
-    if (!Asm.isSymbolLinkerVisible(Symbol))
+    if (!cast<MCSymbolMachO>(Symbol).isSymbolLinkerVisible())
       continue;
 
     if (!Symbol.isExternal() && !Symbol.isUndefined())
@@ -622,7 +622,7 @@ void MachObjectWriter::computeSymbolTable(
   // Now add the data for local symbols.
   for (const MCSymbol &Symbol : Asm.symbols()) {
     // Ignore non-linker visible symbols.
-    if (!Asm.isSymbolLinkerVisible(Symbol))
+    if (!cast<MCSymbolMachO>(Symbol).isSymbolLinkerVisible())
       continue;
 
     if (Symbol.isExternal() || Symbol.isUndefined())