#include "llvm/MC/MCStreamer.h"
+#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSymbol.h"
+#include "llvm/MC/MCValue.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/ErrorHandling.h"
namespace {
+static void SetBinding(MCSymbolData &SD, unsigned Binding) {
+ assert(Binding == ELF::STB_LOCAL || Binding == ELF::STB_GLOBAL ||
+ Binding == ELF::STB_WEAK);
+ uint32_t OtherFlags = SD.getFlags() & ~(0xf << ELF_STB_Shift);
+ SD.setFlags(OtherFlags | (Binding << ELF_STB_Shift));
+}
+
+static unsigned GetBinding(const MCSymbolData &SD) {
+ uint32_t Binding = (SD.getFlags() & (0xf << ELF_STB_Shift)) >> ELF_STB_Shift;
+ assert(Binding == ELF::STB_LOCAL || Binding == ELF::STB_GLOBAL ||
+ Binding == ELF::STB_WEAK);
+ return Binding;
+}
+
+static void SetType(MCSymbolData &SD, unsigned Type) {
+ assert(Type == ELF::STT_NOTYPE || Type == ELF::STT_OBJECT ||
+ Type == ELF::STT_FUNC || Type == ELF::STT_SECTION ||
+ Type == ELF::STT_FILE || Type == ELF::STT_COMMON ||
+ Type == ELF::STT_TLS);
+
+ uint32_t OtherFlags = SD.getFlags() & ~(0xf << ELF_STT_Shift);
+ SD.setFlags(OtherFlags | (Type << ELF_STT_Shift));
+}
+
+static void SetVisibility(MCSymbolData &SD, unsigned Visibility) {
+ assert(Visibility == ELF::STV_DEFAULT || Visibility == ELF::STV_INTERNAL ||
+ Visibility == ELF::STV_HIDDEN || Visibility == ELF::STV_PROTECTED);
+
+ uint32_t OtherFlags = SD.getFlags() & ~(0xf << ELF_STV_Shift);
+ SD.setFlags(OtherFlags | (Visibility << ELF_STV_Shift));
+}
+
class MCELFStreamer : public MCObjectStreamer {
- void EmitInstToFragment(const MCInst &Inst);
- void EmitInstToData(const MCInst &Inst);
public:
MCELFStreamer(MCContext &Context, TargetAsmBackend &TAB,
raw_ostream &OS, MCCodeEmitter *Emitter)
- : MCObjectStreamer(Context, TAB, OS, Emitter) {}
+ : MCObjectStreamer(Context, TAB, OS, Emitter, false) {}
~MCELFStreamer() {}
/// @name MCStreamer Interface
/// @{
+ virtual void InitSections();
virtual void EmitLabel(MCSymbol *Symbol);
virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
+ virtual void EmitThumbFunc(MCSymbol *Func);
virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
+ virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol);
+ virtual void SwitchSection(const MCSection *Section);
virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
assert(0 && "ELF doesn't support this directive");
unsigned char Value = 0);
virtual void EmitFileDirective(StringRef Filename);
- virtual void EmitDwarfFileDirective(unsigned FileNo, StringRef Filename) {
- DEBUG(dbgs() << "FIXME: MCELFStreamer:EmitDwarfFileDirective not implemented\n");
- }
- virtual void EmitInstruction(const MCInst &Inst);
virtual void Finish();
+private:
+ virtual void EmitInstToFragment(const MCInst &Inst);
+ virtual void EmitInstToData(const MCInst &Inst);
+
+ struct LocalCommon {
+ MCSymbolData *SD;
+ uint64_t Size;
+ unsigned ByteAlignment;
+ };
+ std::vector<LocalCommon> LocalCommons;
+
+ SmallPtrSet<MCSymbol *, 16> BindingExplicitlySet;
/// @}
+ void SetSection(StringRef Section, unsigned Type, unsigned Flags,
+ SectionKind Kind) {
+ SwitchSection(getContext().getELFSection(Section, Type, Flags, Kind));
+ }
+
+ void SetSectionData() {
+ SetSection(".data", MCSectionELF::SHT_PROGBITS,
+ MCSectionELF::SHF_WRITE |MCSectionELF::SHF_ALLOC,
+ SectionKind::getDataRel());
+ EmitCodeAlignment(4, 0);
+ }
+ void SetSectionText() {
+ SetSection(".text", MCSectionELF::SHT_PROGBITS,
+ MCSectionELF::SHF_EXECINSTR |
+ MCSectionELF::SHF_ALLOC, SectionKind::getText());
+ EmitCodeAlignment(4, 0);
+ }
+ void SetSectionBss() {
+ SetSection(".bss", MCSectionELF::SHT_NOBITS,
+ MCSectionELF::SHF_WRITE |
+ MCSectionELF::SHF_ALLOC, SectionKind::getBSS());
+ EmitCodeAlignment(4, 0);
+ }
};
} // end anonymous namespace.
+void MCELFStreamer::InitSections() {
+ // This emulates the same behavior of GNU as. This makes it easier
+ // to compare the output as the major sections are in the same order.
+ SetSectionText();
+ SetSectionData();
+ SetSectionBss();
+ SetSectionText();
+}
+
void MCELFStreamer::EmitLabel(MCSymbol *Symbol) {
assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
+ Symbol->setSection(*CurSection);
+
+ MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
+
+ const MCSectionELF &Section =
+ static_cast<const MCSectionELF&>(Symbol->getSection());
+ if (Section.getFlags() & MCSectionELF::SHF_TLS)
+ SetType(SD, ELF::STT_TLS);
+
// FIXME: This is wasteful, we don't necessarily need to create a data
// fragment. Instead, we should mark the symbol as pointing into the data
// fragment if it exists, otherwise we should just queue the label and set its
// fragment pointer when we emit the next fragment.
MCDataFragment *F = getOrCreateDataFragment();
- MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
+
assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
SD.setFragment(F);
SD.setOffset(F->getContents().size());
-
- Symbol->setSection(*CurSection);
}
void MCELFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
switch (Flag) {
+ case MCAF_SyntaxUnified: return; // no-op here.
+ case MCAF_Code16: return; // no-op here.
+ case MCAF_Code32: return; // no-op here.
case MCAF_SubsectionsViaSymbols:
getAssembler().setSubsectionsViaSymbols(true);
return;
assert(0 && "invalid assembler flag!");
}
+void MCELFStreamer::EmitThumbFunc(MCSymbol *Func) {
+ // FIXME: Anything needed here to flag the function as thumb?
+}
+
void MCELFStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
// TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
// MCObjectStreamer.
Symbol->setVariableValue(AddValueSymbols(Value));
}
+void MCELFStreamer::SwitchSection(const MCSection *Section) {
+ const MCSymbol *Grp = static_cast<const MCSectionELF *>(Section)->getGroup();
+ if (Grp)
+ getAssembler().getOrCreateSymbolData(*Grp);
+ this->MCObjectStreamer::SwitchSection(Section);
+}
+
+void MCELFStreamer::EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {
+ getAssembler().getOrCreateSymbolData(*Symbol);
+ MCSymbolData &AliasSD = getAssembler().getOrCreateSymbolData(*Alias);
+ AliasSD.setFlags(AliasSD.getFlags() | ELF_Other_Weakref);
+ const MCExpr *Value = MCSymbolRefExpr::Create(Symbol, getContext());
+ Alias->setVariableValue(Value);
+}
+
void MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
MCSymbolAttr Attribute) {
// Indirect symbols are handled differently, to match how 'as' handles
assert(0 && "Invalid symbol attribute for ELF!");
break;
+ case MCSA_ELF_TypeGnuUniqueObject:
+ // Ignore for now.
+ break;
+
case MCSA_Global:
- SD.setFlags(SD.getFlags() | ELF_STB_Global);
+ SetBinding(SD, ELF::STB_GLOBAL);
SD.setExternal(true);
+ BindingExplicitlySet.insert(Symbol);
break;
case MCSA_WeakReference:
case MCSA_Weak:
- SD.setFlags(SD.getFlags() | ELF_STB_Weak);
+ SetBinding(SD, ELF::STB_WEAK);
+ SD.setExternal(true);
+ BindingExplicitlySet.insert(Symbol);
break;
case MCSA_Local:
- SD.setFlags(SD.getFlags() | ELF_STB_Local);
+ SetBinding(SD, ELF::STB_LOCAL);
+ SD.setExternal(false);
+ BindingExplicitlySet.insert(Symbol);
break;
case MCSA_ELF_TypeFunction:
- SD.setFlags(SD.getFlags() | ELF_STT_Func);
+ SetType(SD, ELF::STT_FUNC);
break;
case MCSA_ELF_TypeObject:
- SD.setFlags(SD.getFlags() | ELF_STT_Object);
+ SetType(SD, ELF::STT_OBJECT);
break;
case MCSA_ELF_TypeTLS:
- SD.setFlags(SD.getFlags() | ELF_STT_Tls);
+ SetType(SD, ELF::STT_TLS);
break;
case MCSA_ELF_TypeCommon:
- SD.setFlags(SD.getFlags() | ELF_STT_Common);
+ SetType(SD, ELF::STT_COMMON);
break;
case MCSA_ELF_TypeNoType:
- SD.setFlags(SD.getFlags() | ELF_STT_Notype);
+ SetType(SD, ELF::STT_NOTYPE);
break;
case MCSA_Protected:
- SD.setFlags(SD.getFlags() | ELF_STV_Protected);
+ SetVisibility(SD, ELF::STV_PROTECTED);
break;
case MCSA_Hidden:
- SD.setFlags(SD.getFlags() | ELF_STV_Hidden);
+ SetVisibility(SD, ELF::STV_HIDDEN);
break;
case MCSA_Internal:
- SD.setFlags(SD.getFlags() | ELF_STV_Internal);
+ SetVisibility(SD, ELF::STV_INTERNAL);
break;
}
}
unsigned ByteAlignment) {
MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
- if ((SD.getFlags() & (0xf << ELF_STB_Shift)) == ELF_STB_Local) {
+ if (!BindingExplicitlySet.count(Symbol)) {
+ SetBinding(SD, ELF::STB_GLOBAL);
+ SD.setExternal(true);
+ }
+
+ SetType(SD, ELF::STT_OBJECT);
+
+ if (GetBinding(SD) == ELF_STB_Local) {
const MCSection *Section = getAssembler().getContext().getELFSection(".bss",
MCSectionELF::SHT_NOBITS,
MCSectionELF::SHF_WRITE |
MCSectionELF::SHF_ALLOC,
SectionKind::getBSS());
-
- MCSectionData &SectData = getAssembler().getOrCreateSectionData(*Section);
- MCFragment *F = new MCFillFragment(0, 0, Size, &SectData);
- SD.setFragment(F);
Symbol->setSection(*Section);
- SD.setSize(MCConstantExpr::Create(Size, getContext()));
- }
- SD.setFlags(SD.getFlags() | ELF_STB_Global);
- SD.setExternal(true);
+ struct LocalCommon L = {&SD, Size, ByteAlignment};
+ LocalCommons.push_back(L);
+ } else {
+ SD.setCommon(Size, ByteAlignment);
+ }
- SD.setCommon(Size, ByteAlignment);
+ SD.setSize(MCConstantExpr::Create(Size, getContext()));
}
void MCELFStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
DF->getContents().append(Code.begin(), Code.end());
}
-void MCELFStreamer::EmitInstruction(const MCInst &Inst) {
- // Scan for values.
- for (unsigned i = 0; i != Inst.getNumOperands(); ++i)
- if (Inst.getOperand(i).isExpr())
- AddValueSymbols(Inst.getOperand(i).getExpr());
+void MCELFStreamer::Finish() {
+ // FIXME: duplicated code with the MachO streamer.
+ // Dump out the dwarf file & directory tables and line tables.
+ if (getContext().hasDwarfFiles()) {
+ const MCSection *DwarfLineSection =
+ getContext().getELFSection(".debug_line", 0, 0,
+ SectionKind::getDataRelLocal());
+ MCSectionData &DLS =
+ getAssembler().getOrCreateSectionData(*DwarfLineSection);
+ int PointerSize = getAssembler().getBackend().getPointerSize();
+ MCDwarfFileTable::Emit(this, DwarfLineSection, &DLS, PointerSize);
+ }
- getCurrentSectionData()->setHasInstructions(true);
+ for (std::vector<LocalCommon>::const_iterator i = LocalCommons.begin(),
+ e = LocalCommons.end();
+ i != e; ++i) {
+ MCSymbolData *SD = i->SD;
+ uint64_t Size = i->Size;
+ unsigned ByteAlignment = i->ByteAlignment;
+ const MCSymbol &Symbol = SD->getSymbol();
+ const MCSection &Section = Symbol.getSection();
- // If this instruction doesn't need relaxation, just emit it as data.
- if (!getAssembler().getBackend().MayNeedRelaxation(Inst)) {
- EmitInstToData(Inst);
- return;
- }
+ MCSectionData &SectData = getAssembler().getOrCreateSectionData(Section);
+ new MCAlignFragment(ByteAlignment, 0, 1, ByteAlignment, &SectData);
- // Otherwise, if we are relaxing everything, relax the instruction as much as
- // possible and emit it as data.
- if (getAssembler().getRelaxAll()) {
- MCInst Relaxed;
- getAssembler().getBackend().RelaxInstruction(Inst, Relaxed);
- while (getAssembler().getBackend().MayNeedRelaxation(Relaxed))
- getAssembler().getBackend().RelaxInstruction(Relaxed, Relaxed);
- EmitInstToData(Relaxed);
- return;
- }
+ MCFragment *F = new MCFillFragment(0, 0, Size, &SectData);
+ SD->setFragment(F);
- // Otherwise emit to a separate fragment.
- EmitInstToFragment(Inst);
-}
+ // Update the maximum alignment of the section if necessary.
+ if (ByteAlignment > SectData.getAlignment())
+ SectData.setAlignment(ByteAlignment);
+ }
-void MCELFStreamer::Finish() {
- getAssembler().Finish();
+ this->MCObjectStreamer::Finish();
}
MCStreamer *llvm::createELFStreamer(MCContext &Context, TargetAsmBackend &TAB,
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