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The ELF implementation now creates text, data and bss to match the gnu as behavior. The text streamer still has the old MachO specific behavior since the testsuite checks that it will error when a directive is given before a setting the current section for example. A nice benefit is that -n is not required anymore when producing ELF files. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114027 91177308-0d34-0410-b5e6-96231b3b80d8
687 lines
26 KiB
C++
687 lines
26 KiB
C++
//===- lib/MC/MCMachOStreamer.cpp - Mach-O Object Output ------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/MC/MCStreamer.h"
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#include "llvm/MC/MCAssembler.h"
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#include "llvm/MC/MCContext.h"
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#include "llvm/MC/MCCodeEmitter.h"
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#include "llvm/MC/MCExpr.h"
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#include "llvm/MC/MCInst.h"
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#include "llvm/MC/MCObjectStreamer.h"
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#include "llvm/MC/MCSection.h"
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#include "llvm/MC/MCSymbol.h"
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#include "llvm/MC/MCMachOSymbolFlags.h"
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#include "llvm/MC/MCSectionMachO.h"
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#include "llvm/MC/MCDwarf.h"
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#include "llvm/Support/ErrorHandling.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/Target/TargetAsmBackend.h"
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using namespace llvm;
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namespace {
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class MCMachOStreamer : public MCObjectStreamer {
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private:
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void EmitInstToFragment(const MCInst &Inst);
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void EmitInstToData(const MCInst &Inst);
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// FIXME: These will likely moved to a better place.
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void MakeLineEntryForSection(const MCSection *Section);
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const MCExpr * MakeStartMinusEndExpr(MCSymbol *Start, MCSymbol *End,
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int IntVal);
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void EmitDwarfFileTable(void);
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public:
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MCMachOStreamer(MCContext &Context, TargetAsmBackend &TAB,
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raw_ostream &OS, MCCodeEmitter *Emitter)
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: MCObjectStreamer(Context, TAB, OS, Emitter) {}
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/// @name MCStreamer Interface
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/// @{
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virtual void InitSections();
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virtual void EmitLabel(MCSymbol *Symbol);
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virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
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virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
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virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
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virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
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virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
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unsigned ByteAlignment);
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virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {
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assert(0 && "macho doesn't support this directive");
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}
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virtual void EmitCOFFSymbolStorageClass(int StorageClass) {
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assert(0 && "macho doesn't support this directive");
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}
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virtual void EmitCOFFSymbolType(int Type) {
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assert(0 && "macho doesn't support this directive");
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}
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virtual void EndCOFFSymbolDef() {
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assert(0 && "macho doesn't support this directive");
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}
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virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
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assert(0 && "macho doesn't support this directive");
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}
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virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {
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assert(0 && "macho doesn't support this directive");
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}
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virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
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unsigned Size = 0, unsigned ByteAlignment = 0);
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virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
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uint64_t Size, unsigned ByteAlignment = 0);
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virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
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virtual void EmitValue(const MCExpr *Value, unsigned Size,unsigned AddrSpace);
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virtual void EmitGPRel32Value(const MCExpr *Value) {
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assert(0 && "macho doesn't support this directive");
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}
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virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
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unsigned ValueSize = 1,
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unsigned MaxBytesToEmit = 0);
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virtual void EmitCodeAlignment(unsigned ByteAlignment,
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unsigned MaxBytesToEmit = 0);
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virtual void EmitValueToOffset(const MCExpr *Offset,
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unsigned char Value = 0);
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virtual void EmitFileDirective(StringRef Filename) {
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// FIXME: Just ignore the .file; it isn't important enough to fail the
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// entire assembly.
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//report_fatal_error("unsupported directive: '.file'");
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}
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virtual void EmitDwarfFileDirective(unsigned FileNo, StringRef Filename) {
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// FIXME: Just ignore the .file; it isn't important enough to fail the
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// entire assembly.
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//report_fatal_error("unsupported directive: '.file'");
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}
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virtual void EmitInstruction(const MCInst &Inst);
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virtual void Finish();
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/// @}
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};
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} // end anonymous namespace.
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void MCMachOStreamer::InitSections() {
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SwitchSection(getContext().getMachOSection("__TEXT", "__text",
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MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
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0, SectionKind::getText()));
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}
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void MCMachOStreamer::EmitLabel(MCSymbol *Symbol) {
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// TODO: This is almost exactly the same as WinCOFFStreamer. Consider merging
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// into MCObjectStreamer.
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assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
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assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
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assert(CurSection && "Cannot emit before setting section!");
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Symbol->setSection(*CurSection);
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MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
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// We have to create a new fragment if this is an atom defining symbol,
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// fragments cannot span atoms.
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if (getAssembler().isSymbolLinkerVisible(SD.getSymbol()))
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new MCDataFragment(getCurrentSectionData());
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// FIXME: This is wasteful, we don't necessarily need to create a data
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// fragment. Instead, we should mark the symbol as pointing into the data
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// fragment if it exists, otherwise we should just queue the label and set its
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// fragment pointer when we emit the next fragment.
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MCDataFragment *F = getOrCreateDataFragment();
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assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
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SD.setFragment(F);
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SD.setOffset(F->getContents().size());
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// This causes the reference type flag to be cleared. Darwin 'as' was "trying"
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// to clear the weak reference and weak definition bits too, but the
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// implementation was buggy. For now we just try to match 'as', for
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// diffability.
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//
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// FIXME: Cleanup this code, these bits should be emitted based on semantic
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// properties, not on the order of definition, etc.
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SD.setFlags(SD.getFlags() & ~SF_ReferenceTypeMask);
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}
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void MCMachOStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
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switch (Flag) {
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case MCAF_SubsectionsViaSymbols:
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getAssembler().setSubsectionsViaSymbols(true);
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return;
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}
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assert(0 && "invalid assembler flag!");
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}
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void MCMachOStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
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// TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
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// MCObjectStreamer.
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// FIXME: Lift context changes into super class.
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getAssembler().getOrCreateSymbolData(*Symbol);
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Symbol->setVariableValue(AddValueSymbols(Value));
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}
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void MCMachOStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
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MCSymbolAttr Attribute) {
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// Indirect symbols are handled differently, to match how 'as' handles
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// them. This makes writing matching .o files easier.
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if (Attribute == MCSA_IndirectSymbol) {
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// Note that we intentionally cannot use the symbol data here; this is
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// important for matching the string table that 'as' generates.
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IndirectSymbolData ISD;
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ISD.Symbol = Symbol;
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ISD.SectionData = getCurrentSectionData();
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getAssembler().getIndirectSymbols().push_back(ISD);
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return;
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}
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// Adding a symbol attribute always introduces the symbol, note that an
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// important side effect of calling getOrCreateSymbolData here is to register
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// the symbol with the assembler.
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MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
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// The implementation of symbol attributes is designed to match 'as', but it
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// leaves much to desired. It doesn't really make sense to arbitrarily add and
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// remove flags, but 'as' allows this (in particular, see .desc).
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//
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// In the future it might be worth trying to make these operations more well
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// defined.
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switch (Attribute) {
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case MCSA_Invalid:
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case MCSA_ELF_TypeFunction:
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case MCSA_ELF_TypeIndFunction:
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case MCSA_ELF_TypeObject:
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case MCSA_ELF_TypeTLS:
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case MCSA_ELF_TypeCommon:
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case MCSA_ELF_TypeNoType:
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case MCSA_IndirectSymbol:
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case MCSA_Hidden:
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case MCSA_Internal:
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case MCSA_Protected:
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case MCSA_Weak:
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case MCSA_Local:
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assert(0 && "Invalid symbol attribute for Mach-O!");
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break;
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case MCSA_Global:
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SD.setExternal(true);
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// This effectively clears the undefined lazy bit, in Darwin 'as', although
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// it isn't very consistent because it implements this as part of symbol
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// lookup.
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//
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// FIXME: Cleanup this code, these bits should be emitted based on semantic
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// properties, not on the order of definition, etc.
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SD.setFlags(SD.getFlags() & ~SF_ReferenceTypeUndefinedLazy);
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break;
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case MCSA_LazyReference:
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// FIXME: This requires -dynamic.
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SD.setFlags(SD.getFlags() | SF_NoDeadStrip);
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if (Symbol->isUndefined())
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SD.setFlags(SD.getFlags() | SF_ReferenceTypeUndefinedLazy);
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break;
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// Since .reference sets the no dead strip bit, it is equivalent to
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// .no_dead_strip in practice.
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case MCSA_Reference:
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case MCSA_NoDeadStrip:
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SD.setFlags(SD.getFlags() | SF_NoDeadStrip);
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break;
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case MCSA_PrivateExtern:
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SD.setExternal(true);
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SD.setPrivateExtern(true);
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break;
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case MCSA_WeakReference:
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// FIXME: This requires -dynamic.
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if (Symbol->isUndefined())
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SD.setFlags(SD.getFlags() | SF_WeakReference);
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break;
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case MCSA_WeakDefinition:
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// FIXME: 'as' enforces that this is defined and global. The manual claims
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// it has to be in a coalesced section, but this isn't enforced.
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SD.setFlags(SD.getFlags() | SF_WeakDefinition);
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break;
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case MCSA_WeakDefAutoPrivate:
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SD.setFlags(SD.getFlags() | SF_WeakDefinition | SF_WeakReference);
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break;
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}
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}
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void MCMachOStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
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// Encode the 'desc' value into the lowest implementation defined bits.
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assert(DescValue == (DescValue & SF_DescFlagsMask) &&
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"Invalid .desc value!");
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getAssembler().getOrCreateSymbolData(*Symbol).setFlags(
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DescValue & SF_DescFlagsMask);
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}
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void MCMachOStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
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unsigned ByteAlignment) {
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// FIXME: Darwin 'as' does appear to allow redef of a .comm by itself.
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assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
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MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
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SD.setExternal(true);
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SD.setCommon(Size, ByteAlignment);
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}
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void MCMachOStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
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unsigned Size, unsigned ByteAlignment) {
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MCSectionData &SectData = getAssembler().getOrCreateSectionData(*Section);
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// The symbol may not be present, which only creates the section.
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if (!Symbol)
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return;
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// FIXME: Assert that this section has the zerofill type.
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assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
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MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
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// Emit an align fragment if necessary.
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if (ByteAlignment != 1)
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new MCAlignFragment(ByteAlignment, 0, 0, ByteAlignment, &SectData);
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MCFragment *F = new MCFillFragment(0, 0, Size, &SectData);
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SD.setFragment(F);
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Symbol->setSection(*Section);
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// Update the maximum alignment on the zero fill section if necessary.
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if (ByteAlignment > SectData.getAlignment())
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SectData.setAlignment(ByteAlignment);
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}
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// This should always be called with the thread local bss section. Like the
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// .zerofill directive this doesn't actually switch sections on us.
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void MCMachOStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
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uint64_t Size, unsigned ByteAlignment) {
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EmitZerofill(Section, Symbol, Size, ByteAlignment);
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return;
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}
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void MCMachOStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
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// TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
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// MCObjectStreamer.
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getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
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}
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void MCMachOStreamer::EmitValue(const MCExpr *Value, unsigned Size,
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unsigned AddrSpace) {
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// TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
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// MCObjectStreamer.
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MCDataFragment *DF = getOrCreateDataFragment();
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// Avoid fixups when possible.
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int64_t AbsValue;
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if (AddValueSymbols(Value)->EvaluateAsAbsolute(AbsValue)) {
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// FIXME: Endianness assumption.
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for (unsigned i = 0; i != Size; ++i)
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DF->getContents().push_back(uint8_t(AbsValue >> (i * 8)));
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} else {
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DF->addFixup(MCFixup::Create(DF->getContents().size(),
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AddValueSymbols(Value),
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MCFixup::getKindForSize(Size)));
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DF->getContents().resize(DF->getContents().size() + Size, 0);
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}
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}
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void MCMachOStreamer::EmitValueToAlignment(unsigned ByteAlignment,
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int64_t Value, unsigned ValueSize,
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unsigned MaxBytesToEmit) {
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// TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
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// MCObjectStreamer.
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if (MaxBytesToEmit == 0)
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MaxBytesToEmit = ByteAlignment;
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new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
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getCurrentSectionData());
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// Update the maximum alignment on the current section if necessary.
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if (ByteAlignment > getCurrentSectionData()->getAlignment())
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getCurrentSectionData()->setAlignment(ByteAlignment);
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}
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void MCMachOStreamer::EmitCodeAlignment(unsigned ByteAlignment,
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unsigned MaxBytesToEmit) {
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// TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
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// MCObjectStreamer.
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if (MaxBytesToEmit == 0)
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MaxBytesToEmit = ByteAlignment;
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MCAlignFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit,
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getCurrentSectionData());
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F->setEmitNops(true);
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// Update the maximum alignment on the current section if necessary.
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if (ByteAlignment > getCurrentSectionData()->getAlignment())
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getCurrentSectionData()->setAlignment(ByteAlignment);
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}
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void MCMachOStreamer::EmitValueToOffset(const MCExpr *Offset,
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unsigned char Value) {
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new MCOrgFragment(*Offset, Value, getCurrentSectionData());
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}
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void MCMachOStreamer::EmitInstToFragment(const MCInst &Inst) {
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MCInstFragment *IF = new MCInstFragment(Inst, getCurrentSectionData());
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// Add the fixups and data.
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//
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// FIXME: Revisit this design decision when relaxation is done, we may be
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// able to get away with not storing any extra data in the MCInst.
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SmallVector<MCFixup, 4> Fixups;
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SmallString<256> Code;
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raw_svector_ostream VecOS(Code);
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getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
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VecOS.flush();
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IF->getCode() = Code;
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IF->getFixups() = Fixups;
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}
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void MCMachOStreamer::EmitInstToData(const MCInst &Inst) {
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MCDataFragment *DF = getOrCreateDataFragment();
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SmallVector<MCFixup, 4> Fixups;
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SmallString<256> Code;
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raw_svector_ostream VecOS(Code);
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getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
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VecOS.flush();
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// Add the fixups and data.
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for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
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Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
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DF->addFixup(Fixups[i]);
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}
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DF->getContents().append(Code.begin(), Code.end());
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}
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void MCMachOStreamer::EmitInstruction(const MCInst &Inst) {
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// Scan for values.
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for (unsigned i = Inst.getNumOperands(); i--; )
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if (Inst.getOperand(i).isExpr())
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AddValueSymbols(Inst.getOperand(i).getExpr());
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getCurrentSectionData()->setHasInstructions(true);
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// Now that a machine instruction has been assembled into this section, make
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// a line entry for any .loc directive that has been seen.
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MakeLineEntryForSection(getCurrentSection());
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// If this instruction doesn't need relaxation, just emit it as data.
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if (!getAssembler().getBackend().MayNeedRelaxation(Inst)) {
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EmitInstToData(Inst);
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return;
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}
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// Otherwise, if we are relaxing everything, relax the instruction as much as
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// possible and emit it as data.
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if (getAssembler().getRelaxAll()) {
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MCInst Relaxed;
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getAssembler().getBackend().RelaxInstruction(Inst, Relaxed);
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while (getAssembler().getBackend().MayNeedRelaxation(Relaxed))
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getAssembler().getBackend().RelaxInstruction(Relaxed, Relaxed);
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EmitInstToData(Relaxed);
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return;
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}
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// Otherwise emit to a separate fragment.
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EmitInstToFragment(Inst);
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}
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//
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// This is called when an instruction is assembled into the specified section
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// and if there is information from the last .loc directive that has yet to have
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// a line entry made for it is made.
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//
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void MCMachOStreamer::MakeLineEntryForSection(const MCSection *Section) {
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if (!getContext().getDwarfLocSeen())
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return;
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// Create a symbol at in the current section for use in the line entry.
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MCSymbol *LineSym = getContext().CreateTempSymbol();
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// Set the value of the symbol to use for the MCLineEntry.
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EmitLabel(LineSym);
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// Get the current .loc info saved in the context.
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const MCDwarfLoc &DwarfLoc = getContext().getCurrentDwarfLoc();
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// Create a (local) line entry with the symbol and the current .loc info.
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MCLineEntry LineEntry(LineSym, DwarfLoc);
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// clear DwarfLocSeen saying the current .loc info is now used.
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getContext().clearDwarfLocSeen();
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|
|
// 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(uint64_t(-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() {
|
|
// 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, 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;
|
|
}
|