From cd749a9c07f1de2fb8affde90537efa4bc3e7c54 Mon Sep 17 00:00:00 2001
From: rdivacky <rdivacky@FreeBSD.org>
Date: Wed, 14 Oct 2009 17:57:32 +0000
Subject: Update llvm to r84119.
---
lib/MC/MCMachOStreamer.cpp | 379 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 379 insertions(+)
create mode 100644 lib/MC/MCMachOStreamer.cpp
(limited to 'lib/MC/MCMachOStreamer.cpp')
diff --git a/lib/MC/MCMachOStreamer.cpp b/lib/MC/MCMachOStreamer.cpp
new file mode 100644
index 0000000..e04bd1f
--- /dev/null
+++ b/lib/MC/MCMachOStreamer.cpp
@@ -0,0 +1,379 @@
+//===- 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/MCSection.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/MC/MCValue.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.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
+ };
+
+private:
+ MCAssembler Assembler;
+
+ MCCodeEmitter *Emitter;
+
+ 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;
+ }
+
+ MCSectionData &getSectionData(const MCSection &Section) {
+ MCSectionData *&Entry = SectionMap[&Section];
+
+ if (!Entry)
+ Entry = new MCSectionData(Section, &Assembler);
+
+ return *Entry;
+ }
+
+ MCSymbolData &getSymbolData(const MCSymbol &Symbol) {
+ MCSymbolData *&Entry = SymbolMap[&Symbol];
+
+ if (!Entry)
+ Entry = new MCSymbolData(Symbol, 0, 0, &Assembler);
+
+ return *Entry;
+ }
+
+public:
+ MCMachOStreamer(MCContext &Context, raw_ostream &_OS, MCCodeEmitter *_Emitter)
+ : MCStreamer(Context), Assembler(Context, _OS), Emitter(_Emitter),
+ CurSectionData(0) {}
+ ~MCMachOStreamer() {}
+
+ const MCExpr *AddValueSymbols(const MCExpr *Value) {
+ switch (Value->getKind()) {
+ case MCExpr::Constant:
+ break;
+
+ case MCExpr::Binary: {
+ const MCBinaryExpr *BE = cast<MCBinaryExpr>(Value);
+ AddValueSymbols(BE->getLHS());
+ AddValueSymbols(BE->getRHS());
+ break;
+ }
+
+ case MCExpr::SymbolRef:
+ getSymbolData(cast<MCSymbolRefExpr>(Value)->getSymbol());
+ break;
+
+ case MCExpr::Unary:
+ AddValueSymbols(cast<MCUnaryExpr>(Value)->getSubExpr());
+ break;
+ }
+
+ return Value;
+ }
+
+ /// @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 MCExpr *Value);
+
+ virtual void EmitSymbolAttribute(MCSymbol *Symbol, SymbolAttr Attribute);
+
+ virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
+
+ virtual void EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,
+ unsigned ByteAlignment);
+
+ virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
+ unsigned Size = 0, unsigned ByteAlignment = 0);
+
+ virtual void EmitBytes(const StringRef &Data);
+
+ virtual void EmitValue(const MCExpr *Value, unsigned Size);
+
+ virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
+ unsigned ValueSize = 1,
+ unsigned MaxBytesToEmit = 0);
+
+ virtual void EmitValueToOffset(const MCExpr *Offset,
+ unsigned char Value = 0);
+
+ 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;
+ CurSectionData = &getSectionData(*Section);
+}
+
+void MCMachOStreamer::EmitLabel(MCSymbol *Symbol) {
+ assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
+
+ // FIXME: We should also use offsets into Fill fragments.
+ MCDataFragment *F = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
+ if (!F)
+ F = new MCDataFragment(CurSectionData);
+
+ MCSymbolData &SD = getSymbolData(*Symbol);
+ 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);
+}
+
+void MCMachOStreamer::EmitAssemblerFlag(AssemblerFlag Flag) {
+ switch (Flag) {
+ case SubsectionsViaSymbols:
+ Assembler.setSubsectionsViaSymbols(true);
+ return;
+ }
+
+ assert(0 && "invalid assembler flag!");
+}
+
+void MCMachOStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
+ // Only absolute symbols can be redefined.
+ assert((Symbol->isUndefined() || Symbol->isAbsolute()) &&
+ "Cannot define a symbol twice!");
+
+ llvm_unreachable("FIXME: Not yet implemented!");
+}
+
+void MCMachOStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
+ SymbolAttr Attribute) {
+ // Indirect symbols are handled differently, to match how 'as' handles
+ // them. This makes writing matching .o files easier.
+ if (Attribute == MCStreamer::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 = CurSectionData;
+ Assembler.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);
+
+ // 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 MCStreamer::IndirectSymbol:
+ case MCStreamer::Hidden:
+ case MCStreamer::Internal:
+ case MCStreamer::Protected:
+ case MCStreamer::Weak:
+ assert(0 && "Invalid symbol attribute for Mach-O!");
+ break;
+
+ case MCStreamer::Global:
+ SD.setExternal(true);
+ break;
+
+ case MCStreamer::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 MCStreamer::Reference:
+ case MCStreamer::NoDeadStrip:
+ SD.setFlags(SD.getFlags() | SF_NoDeadStrip);
+ break;
+
+ case MCStreamer::PrivateExtern:
+ SD.setExternal(true);
+ SD.setPrivateExtern(true);
+ break;
+
+ case MCStreamer::WeakReference:
+ // FIXME: This requires -dynamic.
+ if (Symbol->isUndefined())
+ SD.setFlags(SD.getFlags() | SF_WeakReference);
+ break;
+
+ case MCStreamer::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;
+ }
+}
+
+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!");
+ getSymbolData(*Symbol).setFlags(DescValue & SF_DescFlagsMask);
+}
+
+void MCMachOStreamer::EmitCommonSymbol(MCSymbol *Symbol, unsigned 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 = getSymbolData(*Symbol);
+ SD.setExternal(true);
+ SD.setCommon(Size, ByteAlignment);
+}
+
+void MCMachOStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
+ unsigned Size, unsigned ByteAlignment) {
+ MCSectionData &SectData = getSectionData(*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 = getSymbolData(*Symbol);
+
+ MCFragment *F = new MCZeroFillFragment(Size, ByteAlignment, &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::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::EmitValue(const MCExpr *Value, unsigned Size) {
+ MCValue RelocValue;
+
+ if (!AddValueSymbols(Value)->EvaluateAsRelocatable(getContext(), RelocValue))
+ return llvm_report_error("expected relocatable expression");
+
+ new MCFillFragment(RelocValue, Size, 1, CurSectionData);
+}
+
+void MCMachOStreamer::EmitValueToAlignment(unsigned ByteAlignment,
+ int64_t Value, unsigned ValueSize,
+ unsigned MaxBytesToEmit) {
+ if (MaxBytesToEmit == 0)
+ MaxBytesToEmit = ByteAlignment;
+ new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
+ CurSectionData);
+
+ // Update the maximum alignment on the current section if necessary.
+ if (ByteAlignment > CurSectionData->getAlignment())
+ CurSectionData->setAlignment(ByteAlignment);
+}
+
+void MCMachOStreamer::EmitValueToOffset(const MCExpr *Offset,
+ unsigned char Value) {
+ MCValue RelocOffset;
+
+ if (!AddValueSymbols(Offset)->EvaluateAsRelocatable(getContext(),
+ RelocOffset))
+ return llvm_report_error("expected relocatable expression");
+
+ new MCOrgFragment(RelocOffset, Value, CurSectionData);
+}
+
+void MCMachOStreamer::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());
+
+ if (!Emitter)
+ llvm_unreachable("no code emitter available!");
+
+ // FIXME: Relocations!
+ SmallString<256> Code;
+ raw_svector_ostream VecOS(Code);
+ Emitter->EncodeInstruction(Inst, VecOS);
+ EmitBytes(VecOS.str());
+}
+
+void MCMachOStreamer::Finish() {
+ Assembler.Finish();
+}
+
+MCStreamer *llvm::createMachOStreamer(MCContext &Context, raw_ostream &OS,
+ MCCodeEmitter *CE) {
+ return new MCMachOStreamer(Context, OS, CE);
+}
--
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