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-rw-r--r--contrib/llvm/lib/MC/MCMachOStreamer.cpp493
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diff --git a/contrib/llvm/lib/MC/MCMachOStreamer.cpp b/contrib/llvm/lib/MC/MCMachOStreamer.cpp
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+++ b/contrib/llvm/lib/MC/MCMachOStreamer.cpp
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+//===- lib/MC/MCMachOStreamer.cpp - Mach-O Object Output ------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/MC/MCStreamer.h"
+
+#include "llvm/MC/MCAssembler.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCCodeEmitter.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCObjectStreamer.h"
+#include "llvm/MC/MCSection.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/MC/MCMachOSymbolFlags.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetAsmBackend.h"
+
+using namespace llvm;
+
+namespace {
+
+class MCMachOStreamer : public MCObjectStreamer {
+private:
+ MCFragment *getCurrentFragment() const {
+ assert(getCurrentSectionData() && "No current section!");
+
+ if (!getCurrentSectionData()->empty())
+ return &getCurrentSectionData()->getFragmentList().back();
+
+ return 0;
+ }
+
+ /// Get a data fragment to write into, creating a new one if the current
+ /// fragment is not a data fragment.
+ MCDataFragment *getOrCreateDataFragment() const {
+ MCDataFragment *F = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
+ if (!F)
+ F = new MCDataFragment(getCurrentSectionData());
+ return F;
+ }
+
+ void EmitInstToFragment(const MCInst &Inst);
+ void EmitInstToData(const MCInst &Inst);
+
+public:
+ MCMachOStreamer(MCContext &Context, TargetAsmBackend &TAB,
+ raw_ostream &OS, MCCodeEmitter *Emitter)
+ : MCObjectStreamer(Context, TAB, OS, Emitter) {}
+
+ const MCExpr *AddValueSymbols(const MCExpr *Value) {
+ switch (Value->getKind()) {
+ case MCExpr::Target: assert(0 && "Can't handle target exprs yet!");
+ case MCExpr::Constant:
+ break;
+
+ case MCExpr::Binary: {
+ const MCBinaryExpr *BE = cast<MCBinaryExpr>(Value);
+ AddValueSymbols(BE->getLHS());
+ AddValueSymbols(BE->getRHS());
+ break;
+ }
+
+ case MCExpr::SymbolRef:
+ getAssembler().getOrCreateSymbolData(
+ cast<MCSymbolRefExpr>(Value)->getSymbol());
+ break;
+
+ case MCExpr::Unary:
+ AddValueSymbols(cast<MCUnaryExpr>(Value)->getSubExpr());
+ break;
+ }
+
+ return Value;
+ }
+
+ /// @name MCStreamer Interface
+ /// @{
+
+ virtual void EmitLabel(MCSymbol *Symbol);
+ virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
+ virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
+ virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
+ virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
+ virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
+ unsigned ByteAlignment);
+ virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {
+ assert(0 && "macho doesn't support this directive");
+ }
+ virtual void EmitCOFFSymbolStorageClass(int StorageClass) {
+ assert(0 && "macho doesn't support this directive");
+ }
+ virtual void EmitCOFFSymbolType(int Type) {
+ assert(0 && "macho doesn't support this directive");
+ }
+ virtual void EndCOFFSymbolDef() {
+ assert(0 && "macho doesn't support this directive");
+ }
+ virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
+ assert(0 && "macho doesn't support this directive");
+ }
+ virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {
+ assert(0 && "macho doesn't support this directive");
+ }
+ virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
+ unsigned Size = 0, unsigned ByteAlignment = 0);
+ virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
+ uint64_t Size, unsigned ByteAlignment = 0);
+ virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
+ virtual void EmitValue(const MCExpr *Value, unsigned Size,unsigned AddrSpace);
+ virtual void EmitGPRel32Value(const MCExpr *Value) {
+ assert(0 && "macho doesn't support this directive");
+ }
+ virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
+ unsigned ValueSize = 1,
+ unsigned MaxBytesToEmit = 0);
+ virtual void EmitCodeAlignment(unsigned ByteAlignment,
+ unsigned MaxBytesToEmit = 0);
+ virtual void EmitValueToOffset(const MCExpr *Offset,
+ unsigned char Value = 0);
+
+ virtual void EmitFileDirective(StringRef Filename) {
+ report_fatal_error("unsupported directive: '.file'");
+ }
+ virtual void EmitDwarfFileDirective(unsigned FileNo, StringRef Filename) {
+ report_fatal_error("unsupported directive: '.file'");
+ }
+
+ virtual void EmitInstruction(const MCInst &Inst);
+
+ virtual void Finish();
+
+ /// @}
+};
+
+} // end anonymous namespace.
+
+void MCMachOStreamer::EmitLabel(MCSymbol *Symbol) {
+ assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
+ assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
+ assert(CurSection && "Cannot emit before setting section!");
+
+ Symbol->setSection(*CurSection);
+
+ MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
+
+ // We have to create a new fragment if this is an atom defining symbol,
+ // fragments cannot span atoms.
+ if (getAssembler().isSymbolLinkerVisible(SD.getSymbol()))
+ new MCDataFragment(getCurrentSectionData());
+
+ // 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();
+ assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
+ SD.setFragment(F);
+ SD.setOffset(F->getContents().size());
+
+ // This causes the reference type flag to be cleared. Darwin 'as' was "trying"
+ // to clear the weak reference and weak definition bits too, but the
+ // implementation was buggy. For now we just try to match 'as', for
+ // diffability.
+ //
+ // FIXME: Cleanup this code, these bits should be emitted based on semantic
+ // properties, not on the order of definition, etc.
+ SD.setFlags(SD.getFlags() & ~SF_ReferenceTypeMask);
+}
+
+void MCMachOStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
+ switch (Flag) {
+ case MCAF_SubsectionsViaSymbols:
+ getAssembler().setSubsectionsViaSymbols(true);
+ return;
+ }
+
+ assert(0 && "invalid assembler flag!");
+}
+
+void MCMachOStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
+ // FIXME: Lift context changes into super class.
+ getAssembler().getOrCreateSymbolData(*Symbol);
+ Symbol->setVariableValue(AddValueSymbols(Value));
+}
+
+void MCMachOStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
+ MCSymbolAttr Attribute) {
+ // Indirect symbols are handled differently, to match how 'as' handles
+ // them. This makes writing matching .o files easier.
+ if (Attribute == MCSA_IndirectSymbol) {
+ // Note that we intentionally cannot use the symbol data here; this is
+ // important for matching the string table that 'as' generates.
+ IndirectSymbolData ISD;
+ ISD.Symbol = Symbol;
+ ISD.SectionData = getCurrentSectionData();
+ getAssembler().getIndirectSymbols().push_back(ISD);
+ return;
+ }
+
+ // Adding a symbol attribute always introduces the symbol, note that an
+ // important side effect of calling getOrCreateSymbolData here is to register
+ // the symbol with the assembler.
+ MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
+
+ // The implementation of symbol attributes is designed to match 'as', but it
+ // leaves much to desired. It doesn't really make sense to arbitrarily add and
+ // remove flags, but 'as' allows this (in particular, see .desc).
+ //
+ // In the future it might be worth trying to make these operations more well
+ // defined.
+ switch (Attribute) {
+ case MCSA_Invalid:
+ case MCSA_ELF_TypeFunction:
+ case MCSA_ELF_TypeIndFunction:
+ case MCSA_ELF_TypeObject:
+ case MCSA_ELF_TypeTLS:
+ case MCSA_ELF_TypeCommon:
+ case MCSA_ELF_TypeNoType:
+ case MCSA_IndirectSymbol:
+ case MCSA_Hidden:
+ case MCSA_Internal:
+ case MCSA_Protected:
+ case MCSA_Weak:
+ case MCSA_Local:
+ assert(0 && "Invalid symbol attribute for Mach-O!");
+ break;
+
+ case MCSA_Global:
+ SD.setExternal(true);
+ // This effectively clears the undefined lazy bit, in Darwin 'as', although
+ // it isn't very consistent because it implements this as part of symbol
+ // lookup.
+ //
+ // FIXME: Cleanup this code, these bits should be emitted based on semantic
+ // properties, not on the order of definition, etc.
+ SD.setFlags(SD.getFlags() & ~SF_ReferenceTypeUndefinedLazy);
+ break;
+
+ case MCSA_LazyReference:
+ // FIXME: This requires -dynamic.
+ SD.setFlags(SD.getFlags() | SF_NoDeadStrip);
+ if (Symbol->isUndefined())
+ SD.setFlags(SD.getFlags() | SF_ReferenceTypeUndefinedLazy);
+ break;
+
+ // Since .reference sets the no dead strip bit, it is equivalent to
+ // .no_dead_strip in practice.
+ case MCSA_Reference:
+ case MCSA_NoDeadStrip:
+ SD.setFlags(SD.getFlags() | SF_NoDeadStrip);
+ break;
+
+ case MCSA_PrivateExtern:
+ SD.setExternal(true);
+ SD.setPrivateExtern(true);
+ break;
+
+ case MCSA_WeakReference:
+ // FIXME: This requires -dynamic.
+ if (Symbol->isUndefined())
+ SD.setFlags(SD.getFlags() | SF_WeakReference);
+ break;
+
+ case MCSA_WeakDefinition:
+ // FIXME: 'as' enforces that this is defined and global. The manual claims
+ // it has to be in a coalesced section, but this isn't enforced.
+ SD.setFlags(SD.getFlags() | SF_WeakDefinition);
+ break;
+
+ case MCSA_WeakDefAutoPrivate:
+ SD.setFlags(SD.getFlags() | SF_WeakDefinition | SF_WeakReference);
+ break;
+ }
+}
+
+void MCMachOStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
+ // Encode the 'desc' value into the lowest implementation defined bits.
+ assert(DescValue == (DescValue & SF_DescFlagsMask) &&
+ "Invalid .desc value!");
+ getAssembler().getOrCreateSymbolData(*Symbol).setFlags(
+ DescValue & SF_DescFlagsMask);
+}
+
+void MCMachOStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
+ unsigned ByteAlignment) {
+ // FIXME: Darwin 'as' does appear to allow redef of a .comm by itself.
+ assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
+
+ MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
+ SD.setExternal(true);
+ SD.setCommon(Size, ByteAlignment);
+}
+
+void MCMachOStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
+ unsigned Size, unsigned ByteAlignment) {
+ MCSectionData &SectData = getAssembler().getOrCreateSectionData(*Section);
+
+ // The symbol may not be present, which only creates the section.
+ if (!Symbol)
+ return;
+
+ // FIXME: Assert that this section has the zerofill type.
+
+ assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
+
+ MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
+
+ // Emit an align fragment if necessary.
+ if (ByteAlignment != 1)
+ new MCAlignFragment(ByteAlignment, 0, 0, ByteAlignment, &SectData);
+
+ MCFragment *F = new MCFillFragment(0, 0, Size, &SectData);
+ SD.setFragment(F);
+
+ Symbol->setSection(*Section);
+
+ // Update the maximum alignment on the zero fill section if necessary.
+ if (ByteAlignment > SectData.getAlignment())
+ SectData.setAlignment(ByteAlignment);
+}
+
+// This should always be called with the thread local bss section. Like the
+// .zerofill directive this doesn't actually switch sections on us.
+void MCMachOStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
+ uint64_t Size, unsigned ByteAlignment) {
+ EmitZerofill(Section, Symbol, Size, ByteAlignment);
+ return;
+}
+
+void MCMachOStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
+ getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
+}
+
+void MCMachOStreamer::EmitValue(const MCExpr *Value, unsigned Size,
+ unsigned AddrSpace) {
+ MCDataFragment *DF = getOrCreateDataFragment();
+
+ // Avoid fixups when possible.
+ int64_t AbsValue;
+ if (AddValueSymbols(Value)->EvaluateAsAbsolute(AbsValue)) {
+ // FIXME: Endianness assumption.
+ for (unsigned i = 0; i != Size; ++i)
+ DF->getContents().push_back(uint8_t(AbsValue >> (i * 8)));
+ } else {
+ DF->addFixup(MCFixup::Create(DF->getContents().size(),
+ AddValueSymbols(Value),
+ MCFixup::getKindForSize(Size)));
+ DF->getContents().resize(DF->getContents().size() + Size, 0);
+ }
+}
+
+void MCMachOStreamer::EmitValueToAlignment(unsigned ByteAlignment,
+ int64_t Value, unsigned ValueSize,
+ unsigned MaxBytesToEmit) {
+ if (MaxBytesToEmit == 0)
+ MaxBytesToEmit = ByteAlignment;
+ new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
+ getCurrentSectionData());
+
+ // Update the maximum alignment on the current section if necessary.
+ if (ByteAlignment > getCurrentSectionData()->getAlignment())
+ getCurrentSectionData()->setAlignment(ByteAlignment);
+}
+
+void MCMachOStreamer::EmitCodeAlignment(unsigned ByteAlignment,
+ unsigned MaxBytesToEmit) {
+ if (MaxBytesToEmit == 0)
+ MaxBytesToEmit = ByteAlignment;
+ MCAlignFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit,
+ getCurrentSectionData());
+ F->setEmitNops(true);
+
+ // Update the maximum alignment on the current section if necessary.
+ if (ByteAlignment > getCurrentSectionData()->getAlignment())
+ getCurrentSectionData()->setAlignment(ByteAlignment);
+}
+
+void MCMachOStreamer::EmitValueToOffset(const MCExpr *Offset,
+ unsigned char Value) {
+ new MCOrgFragment(*Offset, Value, getCurrentSectionData());
+}
+
+void MCMachOStreamer::EmitInstToFragment(const MCInst &Inst) {
+ MCInstFragment *IF = new MCInstFragment(Inst, getCurrentSectionData());
+
+ // Add the fixups and data.
+ //
+ // FIXME: Revisit this design decision when relaxation is done, we may be
+ // able to get away with not storing any extra data in the MCInst.
+ SmallVector<MCFixup, 4> Fixups;
+ SmallString<256> Code;
+ raw_svector_ostream VecOS(Code);
+ getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
+ VecOS.flush();
+
+ IF->getCode() = Code;
+ IF->getFixups() = Fixups;
+}
+
+void MCMachOStreamer::EmitInstToData(const MCInst &Inst) {
+ MCDataFragment *DF = getOrCreateDataFragment();
+
+ SmallVector<MCFixup, 4> Fixups;
+ SmallString<256> Code;
+ raw_svector_ostream VecOS(Code);
+ getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
+ VecOS.flush();
+
+ // Add the fixups and data.
+ for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
+ Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
+ DF->addFixup(Fixups[i]);
+ }
+ DF->getContents().append(Code.begin(), Code.end());
+}
+
+void MCMachOStreamer::EmitInstruction(const MCInst &Inst) {
+ // Scan for values.
+ for (unsigned i = Inst.getNumOperands(); i--; )
+ if (Inst.getOperand(i).isExpr())
+ AddValueSymbols(Inst.getOperand(i).getExpr());
+
+ getCurrentSectionData()->setHasInstructions(true);
+
+ // If this instruction doesn't need relaxation, just emit it as data.
+ if (!getAssembler().getBackend().MayNeedRelaxation(Inst)) {
+ EmitInstToData(Inst);
+ return;
+ }
+
+ // 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;
+ }
+
+ // Otherwise emit to a separate fragment.
+ EmitInstToFragment(Inst);
+}
+
+void MCMachOStreamer::Finish() {
+ // We have to set the fragment atom associations so we can relax properly for
+ // Mach-O.
+
+ // First, scan the symbol table to build a lookup table from fragments to
+ // defining symbols.
+ DenseMap<const MCFragment*, MCSymbolData*> DefiningSymbolMap;
+ for (MCAssembler::symbol_iterator it = getAssembler().symbol_begin(),
+ ie = getAssembler().symbol_end(); it != ie; ++it) {
+ if (getAssembler().isSymbolLinkerVisible(it->getSymbol()) &&
+ it->getFragment()) {
+ // An atom defining symbol should never be internal to a fragment.
+ assert(it->getOffset() == 0 && "Invalid offset in atom defining symbol!");
+ DefiningSymbolMap[it->getFragment()] = it;
+ }
+ }
+
+ // Set the fragment atom associations by tracking the last seen atom defining
+ // symbol.
+ for (MCAssembler::iterator it = getAssembler().begin(),
+ ie = getAssembler().end(); it != ie; ++it) {
+ MCSymbolData *CurrentAtom = 0;
+ for (MCSectionData::iterator it2 = it->begin(),
+ ie2 = it->end(); it2 != ie2; ++it2) {
+ if (MCSymbolData *SD = DefiningSymbolMap.lookup(it2))
+ CurrentAtom = SD;
+ it2->setAtom(CurrentAtom);
+ }
+ }
+
+ this->MCObjectStreamer::Finish();
+}
+
+MCStreamer *llvm::createMachOStreamer(MCContext &Context, TargetAsmBackend &TAB,
+ raw_ostream &OS, MCCodeEmitter *CE,
+ bool RelaxAll) {
+ MCMachOStreamer *S = new MCMachOStreamer(Context, TAB, OS, CE);
+ if (RelaxAll)
+ S->getAssembler().setRelaxAll(true);
+ return S;
+}
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