From: Peter Collingbourne <peter@pcc.me.uk>
Date: Sat, 8 Apr 2017 23:35:49 +0000 (+0000)
Subject: MC: Remove unused virtual function MCObjectWriter::isWeak. NFC.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b06c394fe3fb9af6359a35cd60c15f22909360c6;p=llvm

MC: Remove unused virtual function MCObjectWriter::isWeak. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299817 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/MC/MCObjectWriter.h b/include/llvm/MC/MCObjectWriter.h
index 32d4d1f357e..86bcbb6861d 100644
--- a/include/llvm/MC/MCObjectWriter.h
+++ b/include/llvm/MC/MCObjectWriter.h
@@ -109,11 +109,6 @@ public:
                                                       bool InSet,
                                                       bool IsPCRel) const;
 
-  /// True if this symbol (which is a variable) is weak. This is not
-  /// just STB_WEAK, but more generally whether or not we can evaluate
-  /// past it.
-  virtual bool isWeak(const MCSymbol &Sym) const;
-
   /// Write the object file.
   ///
   /// This routine is called by the assembler after layout and relaxation is
diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp
index b6f21ba26b6..ee9c25cda94 100644
--- a/lib/MC/ELFObjectWriter.cpp
+++ b/lib/MC/ELFObjectWriter.cpp
@@ -248,8 +248,6 @@ public:
                                               const MCFragment &FB, bool InSet,
                                               bool IsPCRel) const override;
 
-  bool isWeak(const MCSymbol &Sym) const override;
-
   void writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) override;
   void writeSection(const SectionIndexMapTy &SectionIndexMap,
                     uint32_t GroupSymbolIndex, uint64_t Offset, uint64_t Size,
@@ -1359,34 +1357,13 @@ bool ELFObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(
   const auto &SymA = cast<MCSymbolELF>(SA);
   if (IsPCRel) {
     assert(!InSet);
-    if (::isWeak(SymA))
+    if (isWeak(SymA))
       return false;
   }
   return MCObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(Asm, SymA, FB,
                                                                 InSet, IsPCRel);
 }
 
-bool ELFObjectWriter::isWeak(const MCSymbol &S) const {
-  const auto &Sym = cast<MCSymbolELF>(S);
-  if (::isWeak(Sym))
-    return true;
-
-  // It is invalid to replace a reference to a global in a comdat
-  // with a reference to a local since out of comdat references
-  // to a local are forbidden.
-  // We could try to return false for more cases, like the reference
-  // being in the same comdat or Sym being an alias to another global,
-  // but it is not clear if it is worth the effort.
-  if (Sym.getBinding() != ELF::STB_GLOBAL)
-    return false;
-
-  if (!Sym.isInSection())
-    return false;
-
-  const auto &Sec = cast<MCSectionELF>(Sym.getSection());
-  return Sec.getGroup();
-}
-
 MCObjectWriter *llvm::createELFObjectWriter(MCELFObjectTargetWriter *MOTW,
                                             raw_pwrite_stream &OS,
                                             bool IsLittleEndian) {
diff --git a/lib/MC/MCObjectWriter.cpp b/lib/MC/MCObjectWriter.cpp
index 26ed5855e3d..478b4e84e74 100644
--- a/lib/MC/MCObjectWriter.cpp
+++ b/lib/MC/MCObjectWriter.cpp
@@ -51,5 +51,3 @@ bool MCObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(
   // On ELF and COFF  A - B is absolute if A and B are in the same section.
   return &SecA == &SecB;
 }
-
-bool MCObjectWriter::isWeak(const MCSymbol &) const { return false; }
diff --git a/lib/MC/WinCOFFObjectWriter.cpp b/lib/MC/WinCOFFObjectWriter.cpp
index e1fde90af7d..da8fe73f823 100644
--- a/lib/MC/WinCOFFObjectWriter.cpp
+++ b/lib/MC/WinCOFFObjectWriter.cpp
@@ -194,8 +194,6 @@ public:
                                               const MCFragment &FB, bool InSet,
                                               bool IsPCRel) const override;
 
-  bool isWeak(const MCSymbol &Sym) const override;
-
   void recordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
                         const MCFragment *Fragment, const MCFixup &Fixup,
                         MCValue Target, bool &IsPCRel,
@@ -709,23 +707,6 @@ bool WinCOFFObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(
                                                                 InSet, IsPCRel);
 }
 
-bool WinCOFFObjectWriter::isWeak(const MCSymbol &Sym) const {
-  if (!Sym.isExternal())
-    return false;
-
-  if (!Sym.isInSection())
-    return false;
-
-  const auto &Sec = cast<MCSectionCOFF>(Sym.getSection());
-  if (!Sec.getCOMDATSymbol())
-    return false;
-
-  // It looks like for COFF it is invalid to replace a reference to a global
-  // in a comdat with a reference to a local.
-  // FIXME: Add a specification reference if available.
-  return true;
-}
-
 void WinCOFFObjectWriter::recordRelocation(
     MCAssembler &Asm, const MCAsmLayout &Layout, const MCFragment *Fragment,
     const MCFixup &Fixup, MCValue Target, bool &IsPCRel, uint64_t &FixedValue) {