Fix Whitespace.

[oota-llvm.git] / lib / MC / ELFObjectWriter.cpp

diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp
index 72a6cbd5ef44171b4ac04031cacef4740dc6cb90..8a8d68e55a8b526991f61e54470f21d5a90af602 100644 (file)
--- a/lib/MC/ELFObjectWriter.cpp
+++ b/lib/MC/ELFObjectWriter.cpp
@@ -58,6 +58,14 @@ static void SetBinding(MCSymbolData &SD, unsigned Binding) {
   SD.setFlags(OtherFlags | (Binding << ELF_STB_Shift));
 }
 
+static unsigned GetVisibility(MCSymbolData &SD) {
+  unsigned Visibility =
+    (SD.getFlags() & (0xf << ELF_STV_Shift)) >> ELF_STV_Shift;
+  assert(Visibility == ELF::STV_DEFAULT || Visibility == ELF::STV_INTERNAL ||
+         Visibility == ELF::STV_HIDDEN || Visibility == ELF::STV_PROTECTED);
+  return Visibility;
+}
+
 static bool isFixupKindX86PCRel(unsigned Kind) {
   switch (Kind) {
   default:
@@ -429,9 +437,23 @@ static uint64_t SymbolValue(MCSymbolData &Data, const MCAsmLayout &Layout) {
 
 void ELFObjectWriterImpl::WriteSymbol(MCDataFragment *F, ELFSymbolData &MSD,
                                       const MCAsmLayout &Layout) {
-  MCSymbolData &Data = *MSD.SymbolData;
-  uint8_t Info = (Data.getFlags() & 0xff);
-  uint8_t Other = ((Data.getFlags() & 0xf00) >> ELF_STV_Shift);
+  MCSymbolData &OrigData = *MSD.SymbolData;
+  MCSymbolData *AliasData = NULL;
+  if (OrigData.Symbol->isVariable()) {
+    const MCExpr *Value = OrigData.getSymbol().getVariableValue();
+    assert (Value->getKind() == MCExpr::SymbolRef && "Unimplemented");
+    const MCSymbolRefExpr *Ref = static_cast<const MCSymbolRefExpr*>(Value);
+    AliasData = &Layout.getAssembler().getSymbolData(Ref->getSymbol());
+  }
+  MCSymbolData &Data = AliasData ? *AliasData : OrigData;
+
+  uint8_t Binding = GetBinding(OrigData);
+  uint8_t Visibility = GetVisibility(OrigData);
+  uint8_t Type = GetType(Data);
+
+  uint8_t Info = (Binding << ELF_STB_Shift) | (Type << ELF_STT_Shift);
+  uint8_t Other = Visibility;
+
   uint64_t Value = SymbolValue(Data, Layout);
   uint64_t Size = 0;
   const MCExpr *ESize;
@@ -445,12 +467,22 @@ void ELFObjectWriterImpl::WriteSymbol(MCDataFragment *F, ELFSymbolData &MSD,
       const MCBinaryExpr *BE = static_cast<const MCBinaryExpr *>(ESize);
 
       if (BE->EvaluateAsRelocatable(Res, &Layout)) {
-        MCSymbolData &A =
-          Layout.getAssembler().getSymbolData(Res.getSymA()->getSymbol());
-        MCSymbolData &B =
-          Layout.getAssembler().getSymbolData(Res.getSymB()->getSymbol());
+        uint64_t AddressA = 0;
+        uint64_t AddressB = 0;
+        const MCSymbol &SymA = Res.getSymA()->getSymbol();
+        const MCSymbol &SymB = Res.getSymB()->getSymbol();
+
+        if (SymA.isDefined()) {
+          MCSymbolData &A = Layout.getAssembler().getSymbolData(SymA);
+          AddressA = Layout.getSymbolAddress(&A);
+        }
+
+        if (SymB.isDefined()) {
+          MCSymbolData &B = Layout.getAssembler().getSymbolData(SymB);
+          AddressB = Layout.getSymbolAddress(&B);
+        }
 
-        Size = Layout.getSymbolAddress(&A) - Layout.getSymbolAddress(&B);
+        Size = AddressA - AddressB;
       }
     } else if (ESize->getKind() == MCExpr::Constant) {
       Size = static_cast<const MCConstantExpr *>(ESize)->getValue();
@@ -502,8 +534,9 @@ void ELFObjectWriterImpl::WriteSymbolTable(MCDataFragment *F,
   for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i) {
     ELFSymbolData &MSD = ExternalSymbolData[i];
     MCSymbolData &Data = *MSD.SymbolData;
-    assert((Data.getFlags() & ELF_STB_Global) &&
-           "External symbol requires STB_GLOBAL flag");
+    assert(((Data.getFlags() & ELF_STB_Global) ||
+            (Data.getFlags() & ELF_STB_Weak)) &&
+           "External symbol requires STB_GLOBAL or STB_WEAK flag");
     WriteSymbol(F, MSD, Layout);
     if (GetBinding(Data) == ELF::STB_LOCAL)
       LastLocalSymbolIndex++;
@@ -519,7 +552,8 @@ void ELFObjectWriterImpl::WriteSymbolTable(MCDataFragment *F,
 }
 
 static bool ShouldRelocOnSymbol(const MCSymbolData &SD,
-                                const MCValue &Target) {
+                                const MCValue &Target,
+                                const MCFragment &F) {
   const MCSymbol &Symbol = SD.getSymbol();
   if (Symbol.isUndefined())
     return true;
@@ -527,10 +561,18 @@ static bool ShouldRelocOnSymbol(const MCSymbolData &SD,
   const MCSectionELF &Section =
     static_cast<const MCSectionELF&>(Symbol.getSection());
 
+  if (SD.isExternal())
+    return true;
+
   if (Section.getFlags() & MCSectionELF::SHF_MERGE)
     return Target.getConstant() != 0;
 
-  if (SD.isExternal())
+  MCSymbolRefExpr::VariantKind Kind = Target.getSymA()->getKind();
+  const MCSectionELF &Sec2 =
+    static_cast<const MCSectionELF&>(F.getParent()->getSection());
+
+  if (&Sec2 != &Section &&
+      (Kind == MCSymbolRefExpr::VK_PLT || Kind == MCSymbolRefExpr::VK_GOTPCREL))
     return true;
 
   return false;
@@ -577,7 +619,7 @@ void ELFObjectWriterImpl::RecordRelocation(const MCAssembler &Asm,
       return;
     }
 
-    bool RelocOnSymbol = ShouldRelocOnSymbol(SD, Target);
+    bool RelocOnSymbol = ShouldRelocOnSymbol(SD, Target, *Fragment);
     if (!RelocOnSymbol) {
       Index = F->getParent()->getOrdinal();
 
@@ -629,6 +671,9 @@ void ELFObjectWriterImpl::RecordRelocation(const MCAssembler &Asm,
         case MCSymbolRefExpr::VK_GOT:
           Type = ELF::R_X86_64_GOT32;
           break;
+        case llvm::MCSymbolRefExpr::VK_GOTPCREL:
+          Type = ELF::R_X86_64_GOTPCREL;
+          break;
         default:
           llvm_unreachable("Unimplemented");
         }
@@ -726,7 +771,7 @@ void ELFObjectWriterImpl::ComputeSymbolTable(MCAssembler &Asm) {
 
   // Build section lookup table.
   NumRegularSections = Asm.size();
-  DenseMap<const MCSection*, uint8_t> SectionIndexMap;
+  DenseMap<const MCSection*, uint32_t> SectionIndexMap;
   unsigned Index = 1;
   for (MCAssembler::iterator it = Asm.begin(),
          ie = Asm.end(); it != ie; ++it, ++Index)
@@ -797,9 +842,20 @@ void ELFObjectWriterImpl::ComputeSymbolTable(MCAssembler &Asm) {
     MSD.SymbolData = it;
     MSD.StringIndex = Entry;
 
+    // FIXME: There is duplicated code with the local case.
     if (it->isCommon()) {
       MSD.SectionIndex = ELF::SHN_COMMON;
       ExternalSymbolData.push_back(MSD);
+    } else if (Symbol.isVariable()) {
+      const MCExpr *Value = Symbol.getVariableValue();
+      assert (Value->getKind() == MCExpr::SymbolRef && "Unimplemented");
+      const MCSymbolRefExpr *Ref = static_cast<const MCSymbolRefExpr*>(Value);
+      const MCSymbol &RefSymbol = Ref->getSymbol();
+      if (RefSymbol.isDefined()) {
+        MSD.SectionIndex = SectionIndexMap.lookup(&RefSymbol.getSection());
+        assert(MSD.SectionIndex && "Invalid section index!");
+        ExternalSymbolData.push_back(MSD);
+      }
     } else if (Symbol.isUndefined()) {
       MSD.SectionIndex = ELF::SHN_UNDEF;
       // FIXME: Undefined symbols are global, but this is the first place we
@@ -1072,7 +1128,7 @@ void ELFObjectWriterImpl::WriteObject(MCAssembler &Asm,
   // ... then all of the sections ...
   DenseMap<const MCSection*, uint64_t> SectionOffsetMap;
 
-  DenseMap<const MCSection*, uint8_t> SectionIndexMap;
+  DenseMap<const MCSection*, uint32_t> SectionIndexMap;
 
   unsigned Index = 1;
   for (MCAssembler::const_iterator it = Asm.begin(),