Create a MCSymbolELF.

This create a MCSymbolELF class and moves SymbolSize since only ELF
needs a size expression.

This reduces the size of MCSymbol from 56 to 48 bytes.

llvm-svn: 238801

8 files changed, 32 insertions, 28 deletions

diff --git a/llvm/lib/MC/ELFObjectWriter.cpp b/llvm/lib/MC/ELFObjectWriter.cpp
index 50b848aec27..927180c48dd 100644
--- a/llvm/lib/MC/ELFObjectWriter.cpp
+++ b/llvm/lib/MC/ELFObjectWriter.cpp
@@ -27,6 +27,7 @@
 #include "llvm/MC/MCFixupKindInfo.h"
 #include "llvm/MC/MCObjectWriter.h"
 #include "llvm/MC/MCSectionELF.h"
+#include "llvm/MC/MCSymbolELF.h"
 #include "llvm/MC/MCValue.h"
 #include "llvm/MC/StringTableBuilder.h"
 #include "llvm/Support/Compression.h"
@@ -79,7 +80,7 @@ class ELFObjectWriter : public MCObjectWriter {
 
     /// Helper struct for containing some precomputed information on symbols.
     struct ELFSymbolData {
-      const MCSymbol *Symbol;
+      const MCSymbolELF *Symbol;
       uint32_t SectionIndex;
       StringRef Name;
 
@@ -451,7 +452,8 @@ void ELFObjectWriter::writeSymbol(SymbolTableWriter &Writer,
   assert((!Symbol.getFragment() ||
           (Symbol.getFragment()->getParent() == &Symbol.getSection())) &&
          "The symbol's section doesn't match the fragment's symbol");
-  const MCSymbol *Base = Layout.getBaseSymbol(Symbol);
+  const MCSymbolELF *Base =
+      cast_or_null<MCSymbolELF>(Layout.getBaseSymbol(Symbol));
 
   // This has to be in sync with when computeSymbolTable uses SHN_ABS or
   // SHN_COMMON.
@@ -810,7 +812,7 @@ void ELFObjectWriter::computeSymbolTable(
       continue;
 
     ELFSymbolData MSD;
-    MSD.Symbol = &Symbol;
+    MSD.Symbol = cast<MCSymbolELF>(&Symbol);
 
     // Undefined symbols are global, but this is the first place we
     // are able to set it.
diff --git a/llvm/lib/MC/MCAsmStreamer.cpp b/llvm/lib/MC/MCAsmStreamer.cpp
index 8a5624bc333..92997d05258 100644
--- a/llvm/lib/MC/MCAsmStreamer.cpp
+++ b/llvm/lib/MC/MCAsmStreamer.cpp
@@ -24,7 +24,7 @@
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/MC/MCSectionCOFF.h"
 #include "llvm/MC/MCSectionMachO.h"
-#include "llvm/MC/MCSymbol.h"
+#include "llvm/MC/MCSymbolELF.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Format.h"
@@ -139,7 +139,7 @@ public:
   void EmitCOFFSafeSEH(MCSymbol const *Symbol) override;
   void EmitCOFFSectionIndex(MCSymbol const *Symbol) override;
   void EmitCOFFSecRel32(MCSymbol const *Symbol) override;
-  void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) override;
+  void emitELFSize(MCSymbolELF *Symbol, const MCExpr *Value) override;
   void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                         unsigned ByteAlignment) override;
 
@@ -502,7 +502,7 @@ void MCAsmStreamer::EmitCOFFSecRel32(MCSymbol const *Symbol) {
   EmitEOL();
 }
 
-void MCAsmStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
+void MCAsmStreamer::emitELFSize(MCSymbolELF *Symbol, const MCExpr *Value) {
   assert(MAI->hasDotTypeDotSizeDirective());
   OS << "\t.size\t" << *Symbol << ", " << *Value << '\n';
 }
diff --git a/llvm/lib/MC/MCContext.cpp b/llvm/lib/MC/MCContext.cpp
index 5756da3c6a2..4bb39d3f883 100644
--- a/llvm/lib/MC/MCContext.cpp
+++ b/llvm/lib/MC/MCContext.cpp
@@ -20,7 +20,7 @@
 #include "llvm/MC/MCSectionELF.h"
 #include "llvm/MC/MCSectionMachO.h"
 #include "llvm/MC/MCStreamer.h"
-#include "llvm/MC/MCSymbol.h"
+#include "llvm/MC/MCSymbolELF.h"
 #include "llvm/Support/ELF.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FileSystem.h"
@@ -119,8 +119,8 @@ MCSymbol *MCContext::getOrCreateSymbol(const Twine &Name) {
   return Sym;
 }
 
-MCSymbol *MCContext::getOrCreateSectionSymbol(const MCSectionELF &Section) {
-  MCSymbol *&Sym = SectionSymbols[&Section];
+MCSymbolELF *MCContext::getOrCreateSectionSymbol(const MCSectionELF &Section) {
+  MCSymbolELF *&Sym = SectionSymbols[&Section];
   if (Sym)
     return Sym;
 
@@ -128,12 +128,12 @@ MCSymbol *MCContext::getOrCreateSectionSymbol(const MCSectionELF &Section) {
 
   MCSymbol *&OldSym = Symbols[Name];
   if (OldSym && OldSym->isUndefined()) {
-    Sym = OldSym;
-    return OldSym;
+    Sym = cast<MCSymbolELF>(OldSym);
+    return Sym;
   }
 
   auto NameIter = UsedNames.insert(std::make_pair(Name, true)).first;
-  Sym = new (*this) MCSymbol(&*NameIter, /*isTemporary*/ false);
+  Sym = new (*this) MCSymbolELF(&*NameIter, /*isTemporary*/ false);
 
   if (!OldSym)
     OldSym = Sym;
@@ -157,6 +157,14 @@ MCSymbol *MCContext::getOrCreateLSDASymbol(StringRef FuncName) {
                            FuncName);
 }
 
+MCSymbol *MCContext::createSymbolImpl(const StringMapEntry<bool> *Name,
+                                      bool IsTemporary) {
+  bool IsELF = MOFI && MOFI->getObjectFileType() == MCObjectFileInfo::IsELF;
+  if (IsELF)
+    return new (*this) MCSymbolELF(Name, IsTemporary);
+  return new (*this) MCSymbol(false, Name, IsTemporary);
+}
+
 MCSymbol *MCContext::CreateSymbol(StringRef Name, bool AlwaysAddSuffix) {
   // Determine whether this is an assembler temporary or normal label, if used.
   bool IsTemporary = false;
@@ -164,7 +172,7 @@ MCSymbol *MCContext::CreateSymbol(StringRef Name, bool AlwaysAddSuffix) {
     IsTemporary = Name.startswith(MAI->getPrivateGlobalPrefix());
 
   if (IsTemporary && AlwaysAddSuffix && !UseNamesOnTempLabels)
-    return new (*this) MCSymbol(nullptr, true);
+    return createSymbolImpl(nullptr, true);
 
   SmallString<128> NewName = Name;
   bool AddSuffix = AlwaysAddSuffix;
@@ -178,8 +186,7 @@ MCSymbol *MCContext::CreateSymbol(StringRef Name, bool AlwaysAddSuffix) {
     if (NameEntry.second) {
       // Ok, we found a name. Have the MCSymbol object itself refer to the copy
       // of the string that is embedded in the UsedNames entry.
-      MCSymbol *Result = new (*this) MCSymbol(&*NameEntry.first, IsTemporary);
-      return Result;
+      return createSymbolImpl(&*NameEntry.first, IsTemporary);
     }
     assert(IsTemporary && "Cannot rename non-temporary symbols");
     AddSuffix = true;
diff --git a/llvm/lib/MC/MCELFStreamer.cpp b/llvm/lib/MC/MCELFStreamer.cpp
index 6a04fa0f794..01c8e2825e9 100644
--- a/llvm/lib/MC/MCELFStreamer.cpp
+++ b/llvm/lib/MC/MCELFStreamer.cpp
@@ -28,6 +28,7 @@
 #include "llvm/MC/MCObjectStreamer.h"
 #include "llvm/MC/MCSection.h"
 #include "llvm/MC/MCSectionELF.h"
+#include "llvm/MC/MCSymbolELF.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/MC/MCValue.h"
 #include "llvm/Support/Debug.h"
@@ -333,10 +334,11 @@ void MCELFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
     Symbol->setCommon(Size, ByteAlignment);
   }
 
-  Symbol->setSize(MCConstantExpr::create(Size, getContext()));
+  cast<MCSymbolELF>(Symbol)
+      ->setSize(MCConstantExpr::create(Size, getContext()));
 }
 
-void MCELFStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
+void MCELFStreamer::emitELFSize(MCSymbolELF *Symbol, const MCExpr *Value) {
   Symbol->setSize(Value);
 }
 
diff --git a/llvm/lib/MC/MCMachOStreamer.cpp b/llvm/lib/MC/MCMachOStreamer.cpp
index ff4b391789f..dfa7d24edae 100644
--- a/llvm/lib/MC/MCMachOStreamer.cpp
+++ b/llvm/lib/MC/MCMachOStreamer.cpp
@@ -93,9 +93,6 @@ public:
   void EndCOFFSymbolDef() override {
     llvm_unreachable("macho doesn't support this directive");
   }
-  void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) override {
-    llvm_unreachable("macho doesn't support this directive");
-  }
   void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                              unsigned ByteAlignment) override;
   void EmitZerofill(MCSection *Section, MCSymbol *Symbol = nullptr,
diff --git a/llvm/lib/MC/MCParser/ELFAsmParser.cpp b/llvm/lib/MC/MCParser/ELFAsmParser.cpp
index 590e362740a..e3585bd2763 100644
--- a/llvm/lib/MC/MCParser/ELFAsmParser.cpp
+++ b/llvm/lib/MC/MCParser/ELFAsmParser.cpp
@@ -16,7 +16,7 @@
 #include "llvm/MC/MCParser/MCAsmLexer.h"
 #include "llvm/MC/MCSectionELF.h"
 #include "llvm/MC/MCStreamer.h"
-#include "llvm/MC/MCSymbol.h"
+#include "llvm/MC/MCSymbolELF.h"
 #include "llvm/Support/ELF.h"
 using namespace llvm;
 
@@ -209,7 +209,7 @@ bool ELFAsmParser::ParseDirectiveSize(StringRef, SMLoc) {
   StringRef Name;
   if (getParser().parseIdentifier(Name))
     return TokError("expected identifier in directive");
-  MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
+  MCSymbolELF *Sym = cast<MCSymbolELF>(getContext().getOrCreateSymbol(Name));
 
   if (getLexer().isNot(AsmToken::Comma))
     return TokError("unexpected token in directive");
@@ -222,7 +222,7 @@ bool ELFAsmParser::ParseDirectiveSize(StringRef, SMLoc) {
   if (getLexer().isNot(AsmToken::EndOfStatement))
     return TokError("unexpected token in directive");
 
-  getStreamer().EmitELFSize(Sym, Expr);
+  getStreamer().emitELFSize(Sym, Expr);
   return false;
 }
 
diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index 426bf90afcf..011969a3da0 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -646,7 +646,7 @@ void MCStreamer::EndCOFFSymbolDef() {}
 void MCStreamer::EmitFileDirective(StringRef Filename) {}
 void MCStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {}
 void MCStreamer::EmitCOFFSymbolType(int Type) {}
-void MCStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
+void MCStreamer::emitELFSize(MCSymbolELF *Symbol, const MCExpr *Value) {}
 void MCStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                        unsigned ByteAlignment) {}
 void MCStreamer::EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol,
diff --git a/llvm/lib/MC/WinCOFFStreamer.cpp b/llvm/lib/MC/WinCOFFStreamer.cpp
index f007b5ee7c8..c53a1a6a529 100644
--- a/llvm/lib/MC/WinCOFFStreamer.cpp
+++ b/llvm/lib/MC/WinCOFFStreamer.cpp
@@ -195,10 +195,6 @@ void MCWinCOFFStreamer::EmitCOFFSecRel32(MCSymbol const *Symbol) {
   DF->getContents().resize(DF->getContents().size() + 4, 0);
 }
 
-void MCWinCOFFStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
-  llvm_unreachable("not supported");
-}
-
 void MCWinCOFFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                          unsigned ByteAlignment) {
   assert((!Symbol->isInSection() ||