#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/MC/MCSectionMachO.h"
+#include "llvm/MC/MCDwarf.h"
#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetAsmBackend.h"
+
using namespace llvm;
namespace {
-class MCMachOStreamer : public MCStreamer {
- /// SymbolFlags - We store the value for the 'desc' symbol field in the lowest
- /// 16 bits of the implementation defined flags.
- enum SymbolFlags { // See <mach-o/nlist.h>.
- SF_DescFlagsMask = 0xFFFF,
-
- // Reference type flags.
- SF_ReferenceTypeMask = 0x0007,
- SF_ReferenceTypeUndefinedNonLazy = 0x0000,
- SF_ReferenceTypeUndefinedLazy = 0x0001,
- SF_ReferenceTypeDefined = 0x0002,
- SF_ReferenceTypePrivateDefined = 0x0003,
- SF_ReferenceTypePrivateUndefinedNonLazy = 0x0004,
- SF_ReferenceTypePrivateUndefinedLazy = 0x0005,
-
- // Other 'desc' flags.
- SF_NoDeadStrip = 0x0020,
- SF_WeakReference = 0x0040,
- SF_WeakDefinition = 0x0080
- };
-
+class MCMachOStreamer : public MCObjectStreamer {
private:
- MCAssembler Assembler;
-
- MCSectionData *CurSectionData;
-
- DenseMap<const MCSection*, MCSectionData*> SectionMap;
-
- DenseMap<const MCSymbol*, MCSymbolData*> SymbolMap;
-
-private:
- MCFragment *getCurrentFragment() const {
- assert(CurSectionData && "No current section!");
-
- if (!CurSectionData->empty())
- return &CurSectionData->getFragmentList().back();
-
- return 0;
- }
-
- MCSymbolData &getSymbolData(MCSymbol &Symbol) {
- MCSymbolData *&Entry = SymbolMap[&Symbol];
-
- if (!Entry)
- Entry = new MCSymbolData(Symbol, 0, 0, &Assembler);
-
- return *Entry;
- }
+ void EmitInstToFragment(const MCInst &Inst);
+ void EmitInstToData(const MCInst &Inst);
+ // FIXME: These will likely moved to a better place.
+ void MakeLineEntryForSection(const MCSection *Section);
+ const MCExpr * MakeStartMinusEndExpr(MCSymbol *Start, MCSymbol *End,
+ int IntVal);
+ void EmitDwarfFileTable(void);
public:
- MCMachOStreamer(MCContext &Context, raw_ostream &_OS)
- : MCStreamer(Context), Assembler(_OS), CurSectionData(0) {}
- ~MCMachOStreamer() {}
+ MCMachOStreamer(MCContext &Context, TargetAsmBackend &TAB,
+ raw_ostream &OS, MCCodeEmitter *Emitter)
+ : MCObjectStreamer(Context, TAB, OS, Emitter) {}
/// @name MCStreamer Interface
/// @{
- virtual void SwitchSection(const MCSection *Section);
-
virtual void EmitLabel(MCSymbol *Symbol);
-
- virtual void EmitAssemblerFlag(AssemblerFlag Flag);
-
- virtual void EmitAssignment(MCSymbol *Symbol, const MCValue &Value,
- bool MakeAbsolute = false);
-
- virtual void EmitSymbolAttribute(MCSymbol *Symbol, SymbolAttr Attribute);
-
+ 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 EmitLocalSymbol(MCSymbol *Symbol, const MCValue &Value);
-
- virtual void EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,
- unsigned Pow2Alignment, bool IsLocal);
-
- virtual void EmitZerofill(MCSection *Section, MCSymbol *Symbol = NULL,
- unsigned Size = 0, unsigned Pow2Alignment = 0);
-
- virtual void EmitBytes(const StringRef &Data);
-
- virtual void EmitValue(const MCValue &Value, unsigned Size);
-
+ 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 EmitValueToOffset(const MCValue &Offset,
+ virtual void EmitCodeAlignment(unsigned ByteAlignment,
+ unsigned MaxBytesToEmit = 0);
+ virtual void EmitValueToOffset(const MCExpr *Offset,
unsigned char Value = 0);
+ virtual void EmitFileDirective(StringRef Filename) {
+ // FIXME: Just ignore the .file; it isn't important enough to fail the
+ // entire assembly.
+
+ //report_fatal_error("unsupported directive: '.file'");
+ }
+ virtual void EmitDwarfFileDirective(unsigned FileNo, StringRef Filename) {
+ // FIXME: Just ignore the .file; it isn't important enough to fail the
+ // entire assembly.
+
+ //report_fatal_error("unsupported directive: '.file'");
+ }
+
virtual void EmitInstruction(const MCInst &Inst);
virtual void Finish();
} // end anonymous namespace.
-void MCMachOStreamer::SwitchSection(const MCSection *Section) {
- assert(Section && "Cannot switch to a null section!");
-
- // If already in this section, then this is a noop.
- if (Section == CurSection) return;
-
- CurSection = Section;
- MCSectionData *&Entry = SectionMap[Section];
-
- if (!Entry)
- Entry = new MCSectionData(*Section, &Assembler);
-
- CurSectionData = Entry;
-}
-
void MCMachOStreamer::EmitLabel(MCSymbol *Symbol) {
+ // TODO: This is almost exactly the same as WinCOFFStreamer. Consider merging
+ // into MCObjectStreamer.
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);
- MCDataFragment *F = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
- if (!F)
- F = new MCDataFragment(CurSectionData);
+ // 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());
- MCSymbolData &SD = getSymbolData(*Symbol);
+ // 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 and weak reference flags to be cleared.
- SD.setFlags(SD.getFlags() & ~(SF_WeakReference | SF_ReferenceTypeMask));
-
- Symbol->setSection(*CurSection);
+ // 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(AssemblerFlag Flag) {
- llvm_unreachable("FIXME: Not yet implemented!");
-}
+void MCMachOStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
+ switch (Flag) {
+ case MCAF_SubsectionsViaSymbols:
+ getAssembler().setSubsectionsViaSymbols(true);
+ return;
+ }
-void MCMachOStreamer::EmitAssignment(MCSymbol *Symbol,
- const MCValue &Value,
- bool MakeAbsolute) {
- // Only absolute symbols can be redefined.
- assert((Symbol->isUndefined() || Symbol->isAbsolute()) &&
- "Cannot define a symbol twice!");
+ assert(0 && "invalid assembler flag!");
+}
- llvm_unreachable("FIXME: Not yet implemented!");
+void MCMachOStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
+ // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
+ // MCObjectStreamer.
+ // FIXME: Lift context changes into super class.
+ getAssembler().getOrCreateSymbolData(*Symbol);
+ Symbol->setVariableValue(AddValueSymbols(Value));
}
void MCMachOStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
- SymbolAttr Attribute) {
+ 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 getSymbolData here is to register the
- // symbol with the assembler.
- MCSymbolData &SD = getSymbolData(*Symbol);
+ // 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
// In the future it might be worth trying to make these operations more well
// defined.
switch (Attribute) {
- case MCStreamer::Hidden:
- case MCStreamer::Internal:
- case MCStreamer::Protected:
- case MCStreamer::Weak:
+ 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 MCStreamer::Global:
- getSymbolData(*Symbol).setExternal(true);
+ 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 MCStreamer::LazyReference:
+ case MCSA_LazyReference:
// FIXME: This requires -dynamic.
SD.setFlags(SD.getFlags() | SF_NoDeadStrip);
if (Symbol->isUndefined())
SD.setFlags(SD.getFlags() | SF_ReferenceTypeUndefinedLazy);
break;
- case MCStreamer::IndirectSymbol:
- llvm_unreachable("FIXME: Not yet implemented!");
- break;
-
// Since .reference sets the no dead strip bit, it is equivalent to
// .no_dead_strip in practice.
- case MCStreamer::Reference:
- case MCStreamer::NoDeadStrip:
+ case MCSA_Reference:
+ case MCSA_NoDeadStrip:
SD.setFlags(SD.getFlags() | SF_NoDeadStrip);
break;
- case MCStreamer::PrivateExtern:
+ case MCSA_PrivateExtern:
SD.setExternal(true);
SD.setPrivateExtern(true);
break;
- case MCStreamer::WeakReference:
+ case MCSA_WeakReference:
// FIXME: This requires -dynamic.
if (Symbol->isUndefined())
SD.setFlags(SD.getFlags() | SF_WeakReference);
break;
- case MCStreamer::WeakDefinition:
+ 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) &&
+ assert(DescValue == (DescValue & SF_DescFlagsMask) &&
"Invalid .desc value!");
- getSymbolData(*Symbol).setFlags(DescValue & SF_DescFlagsMask);
+ getAssembler().getOrCreateSymbolData(*Symbol).setFlags(
+ DescValue & SF_DescFlagsMask);
}
-void MCMachOStreamer::EmitLocalSymbol(MCSymbol *Symbol, const MCValue &Value) {
- llvm_unreachable("FIXME: Not yet implemented!");
+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::EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,
- unsigned Pow2Alignment,
- bool IsLocal) {
- llvm_unreachable("FIXME: Not yet implemented!");
+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);
}
-void MCMachOStreamer::EmitZerofill(MCSection *Section, MCSymbol *Symbol,
- unsigned Size, unsigned Pow2Alignment) {
- llvm_unreachable("FIXME: Not yet implemented!");
+// 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(const StringRef &Data) {
- MCDataFragment *DF = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
- if (!DF)
- DF = new MCDataFragment(CurSectionData);
- DF->getContents().append(Data.begin(), Data.end());
+void MCMachOStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
+ // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
+ // MCObjectStreamer.
+ getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
}
-void MCMachOStreamer::EmitValue(const MCValue &Value, unsigned Size) {
- new MCFillFragment(Value, Size, 1, CurSectionData);
+void MCMachOStreamer::EmitValue(const MCExpr *Value, unsigned Size,
+ unsigned AddrSpace) {
+ // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
+ // MCObjectStreamer.
+ 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) {
+ // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
+ // MCObjectStreamer.
if (MaxBytesToEmit == 0)
MaxBytesToEmit = ByteAlignment;
new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
- CurSectionData);
+ 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) {
+ // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
+ // MCObjectStreamer.
+ 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 > CurSectionData->getAlignment())
- CurSectionData->setAlignment(ByteAlignment);
+ if (ByteAlignment > getCurrentSectionData()->getAlignment())
+ getCurrentSectionData()->setAlignment(ByteAlignment);
}
-void MCMachOStreamer::EmitValueToOffset(const MCValue &Offset,
+void MCMachOStreamer::EmitValueToOffset(const MCExpr *Offset,
unsigned char Value) {
- new MCOrgFragment(Offset, Value, CurSectionData);
+ 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) {
- llvm_unreachable("FIXME: Not yet implemented!");
+ // Scan for values.
+ for (unsigned i = Inst.getNumOperands(); i--; )
+ if (Inst.getOperand(i).isExpr())
+ AddValueSymbols(Inst.getOperand(i).getExpr());
+
+ getCurrentSectionData()->setHasInstructions(true);
+
+ // Now that a machine instruction has been assembled into this section, make
+ // a line entry for any .loc directive that has been seen.
+ MakeLineEntryForSection(getCurrentSection());
+
+ // 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);
+}
+
+//
+// This is called when an instruction is assembled into the specified section
+// and if there is information from the last .loc directive that has yet to have
+// a line entry made for it is made.
+//
+void MCMachOStreamer::MakeLineEntryForSection(const MCSection *Section) {
+ if (!getContext().getDwarfLocSeen())
+ return;
+
+ // Create a symbol at in the current section for use in the line entry.
+ MCSymbol *LineSym = getContext().CreateTempSymbol();
+ // Set the value of the symbol to use for the MCLineEntry.
+ EmitLabel(LineSym);
+
+ // Get the current .loc info saved in the context.
+ const MCDwarfLoc &DwarfLoc = getContext().getCurrentDwarfLoc();
+
+ // Create a (local) line entry with the symbol and the current .loc info.
+ MCLineEntry LineEntry(LineSym, DwarfLoc);
+
+ // clear DwarfLocSeen saying the current .loc info is now used.
+ getContext().clearDwarfLocSeen();
+
+ // Get the MCLineSection for this section, if one does not exist for this
+ // section create it.
+ DenseMap<const MCSection *, MCLineSection *> &MCLineSections =
+ getContext().getMCLineSections();
+ MCLineSection *LineSection = MCLineSections[Section];
+ if (!LineSection) {
+ // Create a new MCLineSection. This will be deleted after the dwarf line
+ // table is created using it by iterating through the MCLineSections
+ // DenseMap.
+ LineSection = new MCLineSection;
+ // Save a pointer to the new LineSection into the MCLineSections DenseMap.
+ MCLineSections[Section] = LineSection;
+ }
+
+ // Add the line entry to this section's entries.
+ LineSection->addLineEntry(LineEntry);
+}
+
+//
+// This helper routine returns an expression of End - Start + IntVal for use
+// by EmitDwarfFileTable() below.
+//
+const MCExpr * MCMachOStreamer::MakeStartMinusEndExpr(MCSymbol *Start,
+ MCSymbol *End,
+ int IntVal) {
+ MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None;
+ const MCExpr *Res =
+ MCSymbolRefExpr::Create(End, Variant, getContext());
+ const MCExpr *RHS =
+ MCSymbolRefExpr::Create(Start, Variant, getContext());
+ const MCExpr *Res1 =
+ MCBinaryExpr::Create(MCBinaryExpr::Sub, Res, RHS,getContext());
+ const MCExpr *Res2 =
+ MCConstantExpr::Create(IntVal, getContext());
+ const MCExpr *Res3 =
+ MCBinaryExpr::Create(MCBinaryExpr::Sub, Res1, Res2, getContext());
+ return Res3;
+}
+
+//
+// This emits the Dwarf file (and eventually the line) table.
+//
+void MCMachOStreamer::EmitDwarfFileTable(void) {
+ // For now make sure we don't put out the Dwarf file table if no .file
+ // directives were seen.
+ const std::vector<MCDwarfFile *> &MCDwarfFiles =
+ getContext().getMCDwarfFiles();
+ if (MCDwarfFiles.size() == 0)
+ return;
+
+ // This is the Mach-O section, for ELF it is the .debug_line section.
+ SwitchSection(getContext().getMachOSection("__DWARF", "__debug_line",
+ MCSectionMachO::S_ATTR_DEBUG,
+ 0, SectionKind::getDataRelLocal()));
+
+ // Create a symbol at the beginning of this section.
+ MCSymbol *LineStartSym = getContext().CreateTempSymbol();
+ // Set the value of the symbol, as we are at the start of the section.
+ EmitLabel(LineStartSym);
+
+ // Create a symbol for the end of the section (to be set when we get there).
+ MCSymbol *LineEndSym = getContext().CreateTempSymbol();
+
+ // The first 4 bytes is the total length of the information for this
+ // compilation unit (not including these 4 bytes for the length).
+ EmitValue(MakeStartMinusEndExpr(LineStartSym, LineEndSym, 4), 4, 0);
+
+ // Next 2 bytes is the Version, which is Dwarf 2.
+ EmitIntValue(2, 2);
+
+ // Create a symbol for the end of the prologue (to be set when we get there).
+ MCSymbol *ProEndSym = getContext().CreateTempSymbol(); // Lprologue_end
+
+ // Length of the prologue, is the next 4 bytes. Which is the start of the
+ // section to the end of the prologue. Not including the 4 bytes for the
+ // total length, the 2 bytes for the version, and these 4 bytes for the
+ // length of the prologue.
+ EmitValue(MakeStartMinusEndExpr(LineStartSym, ProEndSym, (4 + 2 + 4)), 4, 0);
+
+ // Parameters of the state machine, are next.
+ // Define the architecture-dependent minimum instruction length (in
+ // bytes). This value should be rather too small than too big. */
+ // DWARF2_LINE_MIN_INSN_LENGTH
+ EmitIntValue(1, 1);
+ // Flag that indicates the initial value of the is_stmt_start flag.
+ // DWARF2_LINE_DEFAULT_IS_STMT
+ EmitIntValue(1, 1);
+ // Minimum line offset in a special line info. opcode. This value
+ // was chosen to give a reasonable range of values. */
+ // DWARF2_LINE_BASE
+ EmitIntValue(-5, 1);
+ // Range of line offsets in a special line info. opcode.
+ // DWARF2_LINE_RANGE
+ EmitIntValue(14, 1);
+ // First special line opcode - leave room for the standard opcodes.
+ // DWARF2_LINE_OPCODE_BASE
+ EmitIntValue(13, 1);
+
+ // Standard opcode lengths
+ EmitIntValue(0, 1); // length of DW_LNS_copy
+ EmitIntValue(1, 1); // length of DW_LNS_advance_pc
+ EmitIntValue(1, 1); // length of DW_LNS_advance_line
+ EmitIntValue(1, 1); // length of DW_LNS_set_file
+ EmitIntValue(1, 1); // length of DW_LNS_set_column
+ EmitIntValue(0, 1); // length of DW_LNS_negate_stmt
+ EmitIntValue(0, 1); // length of DW_LNS_set_basic_block
+ EmitIntValue(0, 1); // length of DW_LNS_const_add_pc
+ EmitIntValue(1, 1); // length of DW_LNS_fixed_advance_pc
+ EmitIntValue(0, 1); // length of DW_LNS_set_prologue_end
+ EmitIntValue(0, 1); // length of DW_LNS_set_epilogue_begin
+ EmitIntValue(1, 1); // DW_LNS_set_isa
+
+ // Put out the directory and file tables.
+
+ // First the directory table.
+ const std::vector<StringRef> &MCDwarfDirs =
+ getContext().getMCDwarfDirs();
+ for (unsigned i = 0; i < MCDwarfDirs.size(); i++) {
+ EmitBytes(MCDwarfDirs[i], 0); // the DirectoryName
+ EmitBytes(StringRef("\0", 1), 0); // the null termination of the string
+ }
+ EmitIntValue(0, 1); // Terminate the directory list
+
+ // Second the file table.
+ for (unsigned i = 1; i < MCDwarfFiles.size(); i++) {
+ EmitBytes(MCDwarfFiles[i]->getName(), 0); // FileName
+ EmitBytes(StringRef("\0", 1), 0); // the null termination of the string
+ // FIXME the Directory number should be a .uleb128 not a .byte
+ EmitIntValue(MCDwarfFiles[i]->getDirIndex(), 1);
+ EmitIntValue(0, 1); // last modification timestamp (always 0)
+ EmitIntValue(0, 1); // filesize (always 0)
+ }
+ EmitIntValue(0, 1); // Terminate the file list
+
+ // This is the end of the prologue, so set the value of the symbol at the
+ // end of the prologue (that was used in a previous expression).
+ EmitLabel(ProEndSym);
+
+ // TODO: This is the point where the line tables would be emitted.
+
+ // Delete the MCLineSections that were created in
+ // MCMachOStreamer::MakeLineEntryForSection() and used to emit the line
+ // tables.
+ DenseMap<const MCSection *, MCLineSection *> &MCLineSections =
+ getContext().getMCLineSections();
+ for (DenseMap<const MCSection *, MCLineSection *>::iterator it =
+ MCLineSections.begin(), ie = MCLineSections.end(); it != ie; ++it) {
+ delete it->second;
+ }
+
+ // If there are no line tables emited then we emit:
+ // The following DW_LNE_set_address sequence to set the address to zero
+ // TODO test for 32-bit or 64-bit output
+ // This is the sequence for 32-bit code
+ EmitIntValue(0, 1);
+ EmitIntValue(5, 1);
+ EmitIntValue(2, 1);
+ EmitIntValue(0, 1);
+ EmitIntValue(0, 1);
+ EmitIntValue(0, 1);
+ EmitIntValue(0, 1);
+
+ // Lastly emit the DW_LNE_end_sequence which consists of 3 bytes '00 01 01'
+ // (00 is the code for extended opcodes, followed by a ULEB128 length of the
+ // extended opcode (01), and the DW_LNE_end_sequence (01).
+ EmitIntValue(0, 1); // DW_LNS_extended_op
+ EmitIntValue(1, 1); // ULEB128 length of the extended opcode
+ EmitIntValue(1, 1); // DW_LNE_end_sequence
+
+ // This is the end of the section, so set the value of the symbol at the end
+ // of this section (that was used in a previous expression).
+ EmitLabel(LineEndSym);
}
void MCMachOStreamer::Finish() {
- Assembler.Finish();
+ // Dump out the dwarf file and directory tables (soon to include line table)
+ EmitDwarfFileTable();
+
+ // 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, raw_ostream &OS) {
- return new MCMachOStreamer(Context, OS);
+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;
}
projects / oota-llvm.git / blobdiff