summaryrefslogtreecommitdiffstats
path: root/contrib/llvm/lib/MC/MCMachOStreamer.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'contrib/llvm/lib/MC/MCMachOStreamer.cpp')
-rw-r--r--contrib/llvm/lib/MC/MCMachOStreamer.cpp436
1 files changed, 436 insertions, 0 deletions
diff --git a/contrib/llvm/lib/MC/MCMachOStreamer.cpp b/contrib/llvm/lib/MC/MCMachOStreamer.cpp
new file mode 100644
index 0000000..7d08d0e
--- /dev/null
+++ b/contrib/llvm/lib/MC/MCMachOStreamer.cpp
@@ -0,0 +1,436 @@
+//
+// 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/MCAsmBackend.h"
+#include "llvm/MC/MCAssembler.h"
+#include "llvm/MC/MCCodeEmitter.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDwarf.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCMachOSymbolFlags.h"
+#include "llvm/MC/MCObjectStreamer.h"
+#include "llvm/MC/MCSection.h"
+#include "llvm/MC/MCSectionMachO.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/Support/Dwarf.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+namespace {
+
+class MCMachOStreamer : public MCObjectStreamer {
+private:
+ virtual void EmitInstToData(const MCInst &Inst);
+
+ void EmitDataRegion(DataRegionData::KindTy Kind);
+ void EmitDataRegionEnd();
+public:
+ MCMachOStreamer(MCContext &Context, MCAsmBackend &MAB, raw_ostream &OS,
+ MCCodeEmitter *Emitter)
+ : MCObjectStreamer(SK_MachOStreamer, Context, MAB, OS, Emitter) {}
+
+ /// @name MCStreamer Interface
+ /// @{
+
+ virtual void InitSections();
+ virtual void InitToTextSection();
+ virtual void EmitLabel(MCSymbol *Symbol);
+ virtual void EmitDebugLabel(MCSymbol *Symbol);
+ virtual void EmitEHSymAttributes(const MCSymbol *Symbol,
+ MCSymbol *EHSymbol);
+ virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
+ virtual void EmitLinkerOptions(ArrayRef<std::string> Options);
+ virtual void EmitDataRegion(MCDataRegionType Kind);
+ virtual void EmitThumbFunc(MCSymbol *Func);
+ 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) {
+ llvm_unreachable("macho doesn't support this directive");
+ }
+ virtual void EmitCOFFSymbolStorageClass(int StorageClass) {
+ llvm_unreachable("macho doesn't support this directive");
+ }
+ virtual void EmitCOFFSymbolType(int Type) {
+ llvm_unreachable("macho doesn't support this directive");
+ }
+ virtual void EndCOFFSymbolDef() {
+ llvm_unreachable("macho doesn't support this directive");
+ }
+ virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
+ llvm_unreachable("macho doesn't support this directive");
+ }
+ virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
+ unsigned ByteAlignment);
+ virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
+ uint64_t Size = 0, unsigned ByteAlignment = 0);
+ virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
+ uint64_t Size, unsigned ByteAlignment = 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 FinishImpl();
+
+ /// @}
+
+ static bool classof(const MCStreamer *S) {
+ return S->getKind() == SK_MachOStreamer;
+ }
+};
+
+} // end anonymous namespace.
+
+void MCMachOStreamer::InitSections() {
+ InitToTextSection();
+}
+
+void MCMachOStreamer::InitToTextSection() {
+ SwitchSection(getContext().getMachOSection(
+ "__TEXT", "__text",
+ MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS, 0,
+ SectionKind::getText()));
+}
+
+void MCMachOStreamer::EmitEHSymAttributes(const MCSymbol *Symbol,
+ MCSymbol *EHSymbol) {
+ MCSymbolData &SD =
+ getAssembler().getOrCreateSymbolData(*Symbol);
+ if (SD.isExternal())
+ EmitSymbolAttribute(EHSymbol, MCSA_Global);
+ if (SD.getFlags() & SF_WeakDefinition)
+ EmitSymbolAttribute(EHSymbol, MCSA_WeakDefinition);
+ if (SD.isPrivateExtern())
+ EmitSymbolAttribute(EHSymbol, MCSA_PrivateExtern);
+}
+
+void MCMachOStreamer::EmitLabel(MCSymbol *Symbol) {
+ assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
+
+ // isSymbolLinkerVisible uses the section.
+ Symbol->setSection(*getCurrentSection());
+ // We have to create a new fragment if this is an atom defining symbol,
+ // fragments cannot span atoms.
+ if (getAssembler().isSymbolLinkerVisible(*Symbol))
+ new MCDataFragment(getCurrentSectionData());
+
+ MCObjectStreamer::EmitLabel(Symbol);
+
+ MCSymbolData &SD = getAssembler().getSymbolData(*Symbol);
+ // 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::EmitDebugLabel(MCSymbol *Symbol) {
+ EmitLabel(Symbol);
+}
+void MCMachOStreamer::EmitDataRegion(DataRegionData::KindTy Kind) {
+ if (!getAssembler().getBackend().hasDataInCodeSupport())
+ return;
+ // Create a temporary label to mark the start of the data region.
+ MCSymbol *Start = getContext().CreateTempSymbol();
+ EmitLabel(Start);
+ // Record the region for the object writer to use.
+ DataRegionData Data = { Kind, Start, NULL };
+ std::vector<DataRegionData> &Regions = getAssembler().getDataRegions();
+ Regions.push_back(Data);
+}
+
+void MCMachOStreamer::EmitDataRegionEnd() {
+ if (!getAssembler().getBackend().hasDataInCodeSupport())
+ return;
+ std::vector<DataRegionData> &Regions = getAssembler().getDataRegions();
+ assert(Regions.size() && "Mismatched .end_data_region!");
+ DataRegionData &Data = Regions.back();
+ assert(Data.End == NULL && "Mismatched .end_data_region!");
+ // Create a temporary label to mark the end of the data region.
+ Data.End = getContext().CreateTempSymbol();
+ EmitLabel(Data.End);
+}
+
+void MCMachOStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
+ // Let the target do whatever target specific stuff it needs to do.
+ getAssembler().getBackend().handleAssemblerFlag(Flag);
+ // Do any generic stuff we need to do.
+ switch (Flag) {
+ case MCAF_SyntaxUnified: return; // no-op here.
+ case MCAF_Code16: return; // Change parsing mode; no-op here.
+ case MCAF_Code32: return; // Change parsing mode; no-op here.
+ case MCAF_Code64: return; // Change parsing mode; no-op here.
+ case MCAF_SubsectionsViaSymbols:
+ getAssembler().setSubsectionsViaSymbols(true);
+ return;
+ }
+}
+
+void MCMachOStreamer::EmitLinkerOptions(ArrayRef<std::string> Options) {
+ getAssembler().getLinkerOptions().push_back(Options);
+}
+
+void MCMachOStreamer::EmitDataRegion(MCDataRegionType Kind) {
+ switch (Kind) {
+ case MCDR_DataRegion:
+ EmitDataRegion(DataRegionData::Data);
+ return;
+ case MCDR_DataRegionJT8:
+ EmitDataRegion(DataRegionData::JumpTable8);
+ return;
+ case MCDR_DataRegionJT16:
+ EmitDataRegion(DataRegionData::JumpTable16);
+ return;
+ case MCDR_DataRegionJT32:
+ EmitDataRegion(DataRegionData::JumpTable32);
+ return;
+ case MCDR_DataRegionEnd:
+ EmitDataRegionEnd();
+ return;
+ }
+}
+
+void MCMachOStreamer::EmitThumbFunc(MCSymbol *Symbol) {
+ // Remember that the function is a thumb function. Fixup and relocation
+ // values will need adjusted.
+ getAssembler().setIsThumbFunc(Symbol);
+
+ // Mark the thumb bit on the symbol.
+ MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
+ SD.setFlags(SD.getFlags() | SF_ThumbFunc);
+}
+
+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_ELF_TypeGnuUniqueObject:
+ case MCSA_Hidden:
+ case MCSA_IndirectSymbol:
+ case MCSA_Internal:
+ case MCSA_Protected:
+ case MCSA_Weak:
+ case MCSA_Local:
+ llvm_unreachable("Invalid symbol attribute for Mach-O!");
+
+ 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_SymbolResolver:
+ SD.setFlags(SD.getFlags() | SF_SymbolResolver);
+ 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::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
+ unsigned ByteAlignment) {
+ // '.lcomm' is equivalent to '.zerofill'.
+ return EmitZerofill(getContext().getMachOSection("__DATA", "__bss",
+ MCSectionMachO::S_ZEROFILL,
+ 0, SectionKind::getBSS()),
+ Symbol, Size, ByteAlignment);
+}
+
+void MCMachOStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
+ uint64_t 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::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->getFixups().push_back(Fixups[i]);
+ }
+ DF->getContents().append(Code.begin(), Code.end());
+}
+
+void MCMachOStreamer::FinishImpl() {
+ EmitFrames(true);
+
+ // 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::FinishImpl();
+}
+
+MCStreamer *llvm::createMachOStreamer(MCContext &Context, MCAsmBackend &MAB,
+ raw_ostream &OS, MCCodeEmitter *CE,
+ bool RelaxAll) {
+ MCMachOStreamer *S = new MCMachOStreamer(Context, MAB, OS, CE);
+ if (RelaxAll)
+ S->getAssembler().setRelaxAll(true);
+ return S;
+}
OpenPOWER on IntegriCloud