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//===- lib/MC/MCObjectStreamer.cpp - Object File MCStreamer Interface -----===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCObjectStreamer.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/Target/TargetAsmBackend.h"
using namespace llvm;
MCObjectStreamer::MCObjectStreamer(MCContext &Context, TargetAsmBackend &TAB,
raw_ostream &_OS, MCCodeEmitter *_Emitter,
bool _PadSectionToAlignment)
: MCStreamer(Context), Assembler(new MCAssembler(Context, TAB,
*_Emitter,
_PadSectionToAlignment,
_OS)),
CurSectionData(0)
{
}
MCObjectStreamer::~MCObjectStreamer() {
delete &Assembler->getBackend();
delete &Assembler->getEmitter();
delete Assembler;
}
MCFragment *MCObjectStreamer::getCurrentFragment() const {
assert(getCurrentSectionData() && "No current section!");
if (!getCurrentSectionData()->empty())
return &getCurrentSectionData()->getFragmentList().back();
return 0;
}
MCDataFragment *MCObjectStreamer::getOrCreateDataFragment() const {
MCDataFragment *F = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
if (!F)
F = new MCDataFragment(getCurrentSectionData());
return F;
}
const MCExpr *MCObjectStreamer::AddValueSymbols(const MCExpr *Value) {
switch (Value->getKind()) {
case MCExpr::Target: llvm_unreachable("Can't handle target exprs yet!");
case MCExpr::Constant:
break;
case MCExpr::Binary: {
const MCBinaryExpr *BE = cast<MCBinaryExpr>(Value);
AddValueSymbols(BE->getLHS());
AddValueSymbols(BE->getRHS());
break;
}
case MCExpr::SymbolRef:
Assembler->getOrCreateSymbolData(cast<MCSymbolRefExpr>(Value)->getSymbol());
break;
case MCExpr::Unary:
AddValueSymbols(cast<MCUnaryExpr>(Value)->getSubExpr());
break;
}
return Value;
}
void MCObjectStreamer::EmitULEB128Value(const MCExpr *Value,
unsigned AddrSpace) {
new MCLEBFragment(*Value, false, getCurrentSectionData());
}
void MCObjectStreamer::EmitSLEB128Value(const MCExpr *Value,
unsigned AddrSpace) {
new MCLEBFragment(*Value, true, getCurrentSectionData());
}
void MCObjectStreamer::EmitWeakReference(MCSymbol *Alias,
const MCSymbol *Symbol) {
report_fatal_error("This file format doesn't support weak aliases.");
}
void MCObjectStreamer::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;
PrevSection = CurSection;
CurSection = Section;
CurSectionData = &getAssembler().getOrCreateSectionData(*Section);
}
void MCObjectStreamer::EmitInstruction(const MCInst &Inst) {
// Scan for values.
for (unsigned i = Inst.getNumOperands(); i--; )
if (Inst.getOperand(i).isExpr())
AddValueSymbols(Inst.getOperand(i).getExpr());
getCurrentSectionData()->setHasInstructions(true);
// Now that a machine instruction has been assembled into this section, make
// a line entry for any .loc directive that has been seen.
MCLineEntry::Make(this, 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);
}
void MCObjectStreamer::Finish() {
getAssembler().Finish();
}
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