//===----------------------------------------------------------------------===//
#include "llvm/MC/MCObjectStreamer.h"
+#include "llvm/ADT/STLExtras.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCObjectWriter.h"
+#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm;
MCObjectStreamer::MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB,
raw_ostream &OS, MCCodeEmitter *Emitter_)
- : MCStreamer(Context),
- Assembler(new MCAssembler(Context, TAB,
- *Emitter_, *TAB.createObjectWriter(OS),
- OS)),
- CurSectionData(0)
-{
-}
+ : MCStreamer(Context),
+ Assembler(new MCAssembler(Context, TAB, *Emitter_,
+ *TAB.createObjectWriter(OS), OS)),
+ CurSectionData(nullptr), EmitEHFrame(true), EmitDebugFrame(false) {}
MCObjectStreamer::MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB,
raw_ostream &OS, MCCodeEmitter *Emitter_,
MCAssembler *_Assembler)
- : MCStreamer(Context), Assembler(_Assembler), CurSectionData(0)
-{
-}
+ : MCStreamer(Context), Assembler(_Assembler), CurSectionData(nullptr),
+ EmitEHFrame(true), EmitDebugFrame(false) {}
MCObjectStreamer::~MCObjectStreamer() {
delete &Assembler->getBackend();
delete Assembler;
}
+void MCObjectStreamer::flushPendingLabels(MCFragment *F) {
+ if (PendingLabels.size()) {
+ if (!F) {
+ F = new MCDataFragment();
+ CurSectionData->getFragmentList().insert(CurInsertionPoint, F);
+ F->setParent(CurSectionData);
+ }
+ for (MCSymbolData *SD : PendingLabels) {
+ SD->setFragment(F);
+ SD->setOffset(0);
+ }
+ PendingLabels.clear();
+ }
+}
+
+void MCObjectStreamer::reset() {
+ if (Assembler)
+ Assembler->reset();
+ CurSectionData = nullptr;
+ CurInsertionPoint = MCSectionData::iterator();
+ EmitEHFrame = true;
+ EmitDebugFrame = false;
+ PendingLabels.clear();
+ MCStreamer::reset();
+}
+
+void MCObjectStreamer::EmitFrames(MCAsmBackend *MAB) {
+ if (!getNumFrameInfos())
+ return;
+
+ if (EmitEHFrame)
+ MCDwarfFrameEmitter::Emit(*this, MAB, true);
+
+ if (EmitDebugFrame)
+ MCDwarfFrameEmitter::Emit(*this, MAB, false);
+}
+
MCFragment *MCObjectStreamer::getCurrentFragment() const {
assert(getCurrentSectionData() && "No current section!");
- if (!getCurrentSectionData()->empty())
- return &getCurrentSectionData()->getFragmentList().back();
+ if (CurInsertionPoint != getCurrentSectionData()->getFragmentList().begin())
+ return std::prev(CurInsertionPoint);
- return 0;
+ return nullptr;
}
-MCDataFragment *MCObjectStreamer::getOrCreateDataFragment() const {
+MCDataFragment *MCObjectStreamer::getOrCreateDataFragment() {
MCDataFragment *F = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
- if (!F)
- F = new MCDataFragment(getCurrentSectionData());
+ // When bundling is enabled, we don't want to add data to a fragment that
+ // already has instructions (see MCELFStreamer::EmitInstToData for details)
+ if (!F || (Assembler->isBundlingEnabled() && F->hasInstructions())) {
+ F = new MCDataFragment();
+ insert(F);
+ }
return F;
}
-const MCExpr *MCObjectStreamer::AddValueSymbols(const MCExpr *Value) {
- switch (Value->getKind()) {
- case MCExpr::Target:
- cast<MCTargetExpr>(Value)->AddValueSymbols(Assembler);
- break;
-
- 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;
- }
+void MCObjectStreamer::visitUsedSymbol(const MCSymbol &Sym) {
+ Assembler->getOrCreateSymbolData(Sym);
+}
- return Value;
+void MCObjectStreamer::EmitCFISections(bool EH, bool Debug) {
+ MCStreamer::EmitCFISections(EH, Debug);
+ EmitEHFrame = EH;
+ EmitDebugFrame = Debug;
}
void MCObjectStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
- unsigned AddrSpace) {
- assert(AddrSpace == 0 && "Address space must be 0!");
+ const SMLoc &Loc) {
+ MCStreamer::EmitValueImpl(Value, Size, Loc);
MCDataFragment *DF = getOrCreateDataFragment();
+ MCLineEntry::Make(this, getCurrentSection().first);
+
// Avoid fixups when possible.
int64_t AbsValue;
- if (AddValueSymbols(Value)->EvaluateAsAbsolute(AbsValue, getAssembler())) {
- EmitIntValue(AbsValue, Size, AddrSpace);
+ if (Value->EvaluateAsAbsolute(AbsValue, getAssembler())) {
+ EmitIntValue(AbsValue, Size);
return;
}
- DF->addFixup(MCFixup::Create(DF->getContents().size(),
- Value,
- MCFixup::getKindForSize(Size, false)));
+ DF->getFixups().push_back(
+ MCFixup::Create(DF->getContents().size(), Value,
+ MCFixup::getKindForSize(Size, false), Loc));
DF->getContents().resize(DF->getContents().size() + Size, 0);
}
void MCObjectStreamer::EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) {
- RecordProcStart(Frame);
+ // We need to create a local symbol to avoid relocations.
+ Frame.Begin = getContext().CreateTempSymbol();
+ EmitLabel(Frame.Begin);
}
void MCObjectStreamer::EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
- RecordProcEnd(Frame);
+ Frame.End = getContext().CreateTempSymbol();
+ EmitLabel(Frame.End);
}
void MCObjectStreamer::EmitLabel(MCSymbol *Symbol) {
MCStreamer::EmitLabel(Symbol);
MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*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());
+
+ // If there is a current fragment, mark the symbol as pointing into it.
+ // Otherwise queue the label and set its fragment pointer when we emit the
+ // next fragment.
+ if (auto *F = dyn_cast_or_null<MCDataFragment>(getCurrentFragment())) {
+ SD.setFragment(F);
+ SD.setOffset(F->getContents().size());
+ } else {
+ PendingLabels.push_back(&SD);
+ }
}
void MCObjectStreamer::EmitULEB128Value(const MCExpr *Value) {
EmitULEB128IntValue(IntValue);
return;
}
- Value = ForceExpAbs(Value);
- new MCLEBFragment(*Value, false, getCurrentSectionData());
+ insert(new MCLEBFragment(*Value, false));
}
void MCObjectStreamer::EmitSLEB128Value(const MCExpr *Value) {
EmitSLEB128IntValue(IntValue);
return;
}
- Value = ForceExpAbs(Value);
- new MCLEBFragment(*Value, true, getCurrentSectionData());
+ insert(new MCLEBFragment(*Value, true));
}
void MCObjectStreamer::EmitWeakReference(MCSymbol *Alias,
report_fatal_error("This file format doesn't support weak aliases.");
}
-void MCObjectStreamer::ChangeSection(const MCSection *Section) {
+void MCObjectStreamer::ChangeSection(const MCSection *Section,
+ const MCExpr *Subsection) {
assert(Section && "Cannot switch to a null section!");
+ flushPendingLabels(nullptr);
CurSectionData = &getAssembler().getOrCreateSectionData(*Section);
+
+ int64_t IntSubsection = 0;
+ if (Subsection &&
+ !Subsection->EvaluateAsAbsolute(IntSubsection, getAssembler()))
+ report_fatal_error("Cannot evaluate subsection number");
+ if (IntSubsection < 0 || IntSubsection > 8192)
+ report_fatal_error("Subsection number out of range");
+ CurInsertionPoint =
+ CurSectionData->getSubsectionInsertionPoint(unsigned(IntSubsection));
+}
+
+void MCObjectStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
+ getAssembler().getOrCreateSymbolData(*Symbol);
+ MCStreamer::EmitAssignment(Symbol, Value);
}
-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());
+void MCObjectStreamer::EmitInstruction(const MCInst &Inst,
+ const MCSubtargetInfo &STI) {
+ MCStreamer::EmitInstruction(Inst, STI);
- getCurrentSectionData()->setHasInstructions(true);
+ MCSectionData *SD = getCurrentSectionData();
+ SD->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());
+ MCLineEntry::Make(this, getCurrentSection().first);
// If this instruction doesn't need relaxation, just emit it as data.
- if (!getAssembler().getBackend().mayNeedRelaxation(Inst)) {
- EmitInstToData(Inst);
+ MCAssembler &Assembler = getAssembler();
+ if (!Assembler.getBackend().mayNeedRelaxation(Inst)) {
+ EmitInstToData(Inst, STI);
return;
}
- // Otherwise, if we are relaxing everything, relax the instruction as much as
- // possible and emit it as data.
- if (getAssembler().getRelaxAll()) {
+ // Otherwise, relax and emit it as data if either:
+ // - The RelaxAll flag was passed
+ // - Bundling is enabled and this instruction is inside a bundle-locked
+ // group. We want to emit all such instructions into the same data
+ // fragment.
+ if (Assembler.getRelaxAll() ||
+ (Assembler.isBundlingEnabled() && SD->isBundleLocked())) {
MCInst Relaxed;
getAssembler().getBackend().relaxInstruction(Inst, Relaxed);
while (getAssembler().getBackend().mayNeedRelaxation(Relaxed))
getAssembler().getBackend().relaxInstruction(Relaxed, Relaxed);
- EmitInstToData(Relaxed);
+ EmitInstToData(Relaxed, STI);
return;
}
// Otherwise emit to a separate fragment.
- EmitInstToFragment(Inst);
+ EmitInstToFragment(Inst, STI);
}
-void MCObjectStreamer::EmitInstToFragment(const MCInst &Inst) {
- MCInstFragment *IF = new MCInstFragment(Inst, getCurrentSectionData());
+void MCObjectStreamer::EmitInstToFragment(const MCInst &Inst,
+ const MCSubtargetInfo &STI) {
+ // Always create a new, separate fragment here, because its size can change
+ // during relaxation.
+ MCRelaxableFragment *IF = new MCRelaxableFragment(Inst, STI);
+ insert(IF);
SmallString<128> Code;
raw_svector_ostream VecOS(Code);
- getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, IF->getFixups());
+ getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, IF->getFixups(),
+ STI);
VecOS.flush();
- IF->getCode().append(Code.begin(), Code.end());
+ IF->getContents().append(Code.begin(), Code.end());
+}
+
+#ifndef NDEBUG
+static const char *const BundlingNotImplementedMsg =
+ "Aligned bundling is not implemented for this object format";
+#endif
+
+void MCObjectStreamer::EmitBundleAlignMode(unsigned AlignPow2) {
+ llvm_unreachable(BundlingNotImplementedMsg);
+}
+
+void MCObjectStreamer::EmitBundleLock(bool AlignToEnd) {
+ llvm_unreachable(BundlingNotImplementedMsg);
+}
+
+void MCObjectStreamer::EmitBundleUnlock() {
+ llvm_unreachable(BundlingNotImplementedMsg);
+}
+
+void MCObjectStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
+ unsigned Column, unsigned Flags,
+ unsigned Isa,
+ unsigned Discriminator,
+ StringRef FileName) {
+ // In case we see two .loc directives in a row, make sure the
+ // first one gets a line entry.
+ MCLineEntry::Make(this, getCurrentSection().first);
+
+ this->MCStreamer::EmitDwarfLocDirective(FileNo, Line, Column, Flags,
+ Isa, Discriminator, FileName);
+}
+
+static const MCExpr *buildSymbolDiff(MCObjectStreamer &OS, const MCSymbol *A,
+ const MCSymbol *B) {
+ MCContext &Context = OS.getContext();
+ MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None;
+ const MCExpr *ARef = MCSymbolRefExpr::Create(A, Variant, Context);
+ const MCExpr *BRef = MCSymbolRefExpr::Create(B, Variant, Context);
+ const MCExpr *AddrDelta =
+ MCBinaryExpr::Create(MCBinaryExpr::Sub, ARef, BRef, Context);
+ return AddrDelta;
+}
+
+static void emitDwarfSetLineAddr(MCObjectStreamer &OS, int64_t LineDelta,
+ const MCSymbol *Label, int PointerSize) {
+ // emit the sequence to set the address
+ OS.EmitIntValue(dwarf::DW_LNS_extended_op, 1);
+ OS.EmitULEB128IntValue(PointerSize + 1);
+ OS.EmitIntValue(dwarf::DW_LNE_set_address, 1);
+ OS.EmitSymbolValue(Label, PointerSize);
+
+ // emit the sequence for the LineDelta (from 1) and a zero address delta.
+ MCDwarfLineAddr::Emit(&OS, LineDelta, 0);
}
void MCObjectStreamer::EmitDwarfAdvanceLineAddr(int64_t LineDelta,
const MCSymbol *Label,
unsigned PointerSize) {
if (!LastLabel) {
- EmitDwarfSetLineAddr(LineDelta, Label, PointerSize);
+ emitDwarfSetLineAddr(*this, LineDelta, Label, PointerSize);
return;
}
- const MCExpr *AddrDelta = BuildSymbolDiff(getContext(), Label, LastLabel);
+ const MCExpr *AddrDelta = buildSymbolDiff(*this, Label, LastLabel);
int64_t Res;
if (AddrDelta->EvaluateAsAbsolute(Res, getAssembler())) {
MCDwarfLineAddr::Emit(this, LineDelta, Res);
return;
}
- AddrDelta = ForceExpAbs(AddrDelta);
- new MCDwarfLineAddrFragment(LineDelta, *AddrDelta, getCurrentSectionData());
+ insert(new MCDwarfLineAddrFragment(LineDelta, *AddrDelta));
}
void MCObjectStreamer::EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
const MCSymbol *Label) {
- const MCExpr *AddrDelta = BuildSymbolDiff(getContext(), Label, LastLabel);
+ const MCExpr *AddrDelta = buildSymbolDiff(*this, Label, LastLabel);
int64_t Res;
if (AddrDelta->EvaluateAsAbsolute(Res, getAssembler())) {
MCDwarfFrameEmitter::EmitAdvanceLoc(*this, Res);
return;
}
- AddrDelta = ForceExpAbs(AddrDelta);
- new MCDwarfCallFrameFragment(*AddrDelta, getCurrentSectionData());
+ insert(new MCDwarfCallFrameFragment(*AddrDelta));
+}
+
+void MCObjectStreamer::EmitBytes(StringRef Data) {
+ MCLineEntry::Make(this, getCurrentSection().first);
+ getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
+}
+
+void MCObjectStreamer::EmitValueToAlignment(unsigned ByteAlignment,
+ int64_t Value,
+ unsigned ValueSize,
+ unsigned MaxBytesToEmit) {
+ if (MaxBytesToEmit == 0)
+ MaxBytesToEmit = ByteAlignment;
+ insert(new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit));
+
+ // Update the maximum alignment on the current section if necessary.
+ if (ByteAlignment > getCurrentSectionData()->getAlignment())
+ getCurrentSectionData()->setAlignment(ByteAlignment);
+}
+
+void MCObjectStreamer::EmitCodeAlignment(unsigned ByteAlignment,
+ unsigned MaxBytesToEmit) {
+ EmitValueToAlignment(ByteAlignment, 0, 1, MaxBytesToEmit);
+ cast<MCAlignFragment>(getCurrentFragment())->setEmitNops(true);
}
bool MCObjectStreamer::EmitValueToOffset(const MCExpr *Offset,
unsigned char Value) {
int64_t Res;
if (Offset->EvaluateAsAbsolute(Res, getAssembler())) {
- new MCOrgFragment(*Offset, Value, getCurrentSectionData());
+ insert(new MCOrgFragment(*Offset, Value));
return false;
}
if (!Delta->EvaluateAsAbsolute(Res, getAssembler()))
return true;
- EmitFill(Res, Value, 0);
+ EmitFill(Res, Value);
return false;
}
void MCObjectStreamer::EmitGPRel32Value(const MCExpr *Value) {
MCDataFragment *DF = getOrCreateDataFragment();
- DF->addFixup(MCFixup::Create(DF->getContents().size(),
- Value,
- FK_GPRel_4));
+ DF->getFixups().push_back(MCFixup::Create(DF->getContents().size(),
+ Value, FK_GPRel_4));
DF->getContents().resize(DF->getContents().size() + 4, 0);
}
-void MCObjectStreamer::FinishImpl() {
- // Dump out the dwarf file & directory tables and line tables.
- const MCSymbol *LineSectionSymbol = NULL;
- if (getContext().hasDwarfFiles())
- LineSectionSymbol = MCDwarfFileTable::Emit(this);
+// Associate GPRel32 fixup with data and resize data area
+void MCObjectStreamer::EmitGPRel64Value(const MCExpr *Value) {
+ MCDataFragment *DF = getOrCreateDataFragment();
+
+ DF->getFixups().push_back(MCFixup::Create(DF->getContents().size(),
+ Value, FK_GPRel_4));
+ DF->getContents().resize(DF->getContents().size() + 8, 0);
+}
+void MCObjectStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue) {
+ // FIXME: A MCFillFragment would be more memory efficient but MCExpr has
+ // problems evaluating expressions across multiple fragments.
+ getOrCreateDataFragment()->getContents().append(NumBytes, FillValue);
+}
+
+void MCObjectStreamer::EmitZeros(uint64_t NumBytes) {
+ const MCSection *Sec = getCurrentSection().first;
+ assert(Sec && "need a section");
+ unsigned ItemSize = Sec->isVirtualSection() ? 0 : 1;
+ insert(new MCFillFragment(0, ItemSize, NumBytes));
+}
+
+void MCObjectStreamer::FinishImpl() {
// If we are generating dwarf for assembly source files dump out the sections.
if (getContext().getGenDwarfForAssembly())
- MCGenDwarfInfo::Emit(this, LineSectionSymbol);
+ MCGenDwarfInfo::Emit(this);
+
+ // Dump out the dwarf file & directory tables and line tables.
+ MCDwarfLineTable::Emit(this);
+ flushPendingLabels(nullptr);
getAssembler().Finish();
}