1 //===- lib/MC/MCStreamer.cpp - Streaming Machine Code Output --------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "llvm/MC/MCStreamer.h"
11 #include "llvm/ADT/SmallString.h"
12 #include "llvm/ADT/Twine.h"
13 #include "llvm/MC/MCAsmBackend.h"
14 #include "llvm/MC/MCAsmInfo.h"
15 #include "llvm/MC/MCContext.h"
16 #include "llvm/MC/MCExpr.h"
17 #include "llvm/MC/MCObjectFileInfo.h"
18 #include "llvm/MC/MCObjectWriter.h"
19 #include "llvm/MC/MCSection.h"
20 #include "llvm/MC/MCSymbol.h"
21 #include "llvm/MC/MCWin64EH.h"
22 #include "llvm/Support/ErrorHandling.h"
23 #include "llvm/Support/LEB128.h"
24 #include "llvm/Support/raw_ostream.h"
28 // Pin the vtables to this file.
29 MCTargetStreamer::~MCTargetStreamer() {}
31 MCTargetStreamer::MCTargetStreamer(MCStreamer &S) : Streamer(S) {
32 S.setTargetStreamer(this);
35 void MCTargetStreamer::emitLabel(MCSymbol *Symbol) {}
37 void MCTargetStreamer::finish() {}
39 void MCTargetStreamer::emitAssignment(MCSymbol *Symbol, const MCExpr *Value) {}
41 MCStreamer::MCStreamer(MCContext &Ctx)
42 : Context(Ctx), CurrentWinFrameInfo(nullptr) {
43 SectionStack.push_back(std::pair<MCSectionSubPair, MCSectionSubPair>());
46 MCStreamer::~MCStreamer() {
47 for (unsigned i = 0; i < getNumWinFrameInfos(); ++i)
48 delete WinFrameInfos[i];
51 void MCStreamer::reset() {
52 DwarfFrameInfos.clear();
53 for (unsigned i = 0; i < getNumWinFrameInfos(); ++i)
54 delete WinFrameInfos[i];
55 WinFrameInfos.clear();
56 CurrentWinFrameInfo = nullptr;
57 SymbolOrdering.clear();
59 SectionStack.push_back(std::pair<MCSectionSubPair, MCSectionSubPair>());
62 raw_ostream &MCStreamer::GetCommentOS() {
63 // By default, discard comments.
67 void MCStreamer::emitRawComment(const Twine &T, bool TabPrefix) {}
69 void MCStreamer::generateCompactUnwindEncodings(MCAsmBackend *MAB) {
70 for (auto &FI : DwarfFrameInfos)
71 FI.CompactUnwindEncoding =
72 (MAB ? MAB->generateCompactUnwindEncoding(FI.Instructions) : 0);
75 /// EmitIntValue - Special case of EmitValue that avoids the client having to
76 /// pass in a MCExpr for constant integers.
77 void MCStreamer::EmitIntValue(uint64_t Value, unsigned Size) {
78 assert(1 <= Size && Size <= 8 && "Invalid size");
79 assert((isUIntN(8 * Size, Value) || isIntN(8 * Size, Value)) &&
82 const bool isLittleEndian = Context.getAsmInfo()->isLittleEndian();
83 for (unsigned i = 0; i != Size; ++i) {
84 unsigned index = isLittleEndian ? i : (Size - i - 1);
85 buf[i] = uint8_t(Value >> (index * 8));
87 EmitBytes(StringRef(buf, Size));
90 /// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
91 /// client having to pass in a MCExpr for constant integers.
92 void MCStreamer::EmitULEB128IntValue(uint64_t Value, unsigned Padding) {
94 raw_svector_ostream OSE(Tmp);
95 encodeULEB128(Value, OSE, Padding);
99 /// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
100 /// client having to pass in a MCExpr for constant integers.
101 void MCStreamer::EmitSLEB128IntValue(int64_t Value) {
102 SmallString<128> Tmp;
103 raw_svector_ostream OSE(Tmp);
104 encodeSLEB128(Value, OSE);
105 EmitBytes(OSE.str());
108 void MCStreamer::EmitValue(const MCExpr *Value, unsigned Size,
110 EmitValueImpl(Value, Size, Loc);
113 void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
114 bool IsSectionRelative) {
115 assert((!IsSectionRelative || Size == 4) &&
116 "SectionRelative value requires 4-bytes");
118 if (!IsSectionRelative)
119 EmitValueImpl(MCSymbolRefExpr::Create(Sym, getContext()), Size);
121 EmitCOFFSecRel32(Sym);
124 void MCStreamer::EmitGPRel64Value(const MCExpr *Value) {
125 report_fatal_error("unsupported directive in streamer");
128 void MCStreamer::EmitGPRel32Value(const MCExpr *Value) {
129 report_fatal_error("unsupported directive in streamer");
132 /// EmitFill - Emit NumBytes bytes worth of the value specified by
133 /// FillValue. This implements directives such as '.space'.
134 void MCStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue) {
135 const MCExpr *E = MCConstantExpr::Create(FillValue, getContext());
136 for (uint64_t i = 0, e = NumBytes; i != e; ++i)
140 /// The implementation in this class just redirects to EmitFill.
141 void MCStreamer::EmitZeros(uint64_t NumBytes) {
142 EmitFill(NumBytes, 0);
145 unsigned MCStreamer::EmitDwarfFileDirective(unsigned FileNo,
147 StringRef Filename, unsigned CUID) {
148 return getContext().GetDwarfFile(Directory, Filename, FileNo, CUID);
151 void MCStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
152 unsigned Column, unsigned Flags,
154 unsigned Discriminator,
155 StringRef FileName) {
156 getContext().setCurrentDwarfLoc(FileNo, Line, Column, Flags, Isa,
160 MCSymbol *MCStreamer::getDwarfLineTableSymbol(unsigned CUID) {
161 MCDwarfLineTable &Table = getContext().getMCDwarfLineTable(CUID);
162 if (!Table.getLabel()) {
163 StringRef Prefix = Context.getAsmInfo()->getPrivateGlobalPrefix();
165 Context.GetOrCreateSymbol(Prefix + "line_table_start" + Twine(CUID)));
167 return Table.getLabel();
170 MCDwarfFrameInfo *MCStreamer::getCurrentDwarfFrameInfo() {
171 if (DwarfFrameInfos.empty())
173 return &DwarfFrameInfos.back();
176 void MCStreamer::EnsureValidDwarfFrame() {
177 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
178 if (!CurFrame || CurFrame->End)
179 report_fatal_error("No open frame");
182 void MCStreamer::EmitEHSymAttributes(const MCSymbol *Symbol,
183 MCSymbol *EHSymbol) {
186 void MCStreamer::InitSections(bool NoExecStack) {
187 SwitchSection(getContext().getObjectFileInfo()->getTextSection());
190 void MCStreamer::AssignSection(MCSymbol *Symbol, const MCSection *Section) {
192 Symbol->setSection(*Section);
194 Symbol->setUndefined();
196 // As we emit symbols into a section, track the order so that they can
197 // be sorted upon later. Zero is reserved to mean 'unemitted'.
198 SymbolOrdering[Symbol] = 1 + SymbolOrdering.size();
201 void MCStreamer::EmitLabel(MCSymbol *Symbol) {
202 assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
203 assert(getCurrentSection().first && "Cannot emit before setting section!");
204 AssignSection(Symbol, getCurrentSection().first);
206 MCTargetStreamer *TS = getTargetStreamer();
208 TS->emitLabel(Symbol);
211 void MCStreamer::EmitCFISections(bool EH, bool Debug) {
215 void MCStreamer::EmitCFIStartProc(bool IsSimple) {
216 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
217 if (CurFrame && !CurFrame->End)
218 report_fatal_error("Starting a frame before finishing the previous one!");
220 MCDwarfFrameInfo Frame;
221 Frame.IsSimple = IsSimple;
222 EmitCFIStartProcImpl(Frame);
224 const MCAsmInfo* MAI = Context.getAsmInfo();
226 for (const MCCFIInstruction& Inst : MAI->getInitialFrameState()) {
227 if (Inst.getOperation() == MCCFIInstruction::OpDefCfa ||
228 Inst.getOperation() == MCCFIInstruction::OpDefCfaRegister) {
229 Frame.CurrentCfaRegister = Inst.getRegister();
234 DwarfFrameInfos.push_back(Frame);
237 void MCStreamer::EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) {
240 void MCStreamer::EmitCFIEndProc() {
241 EnsureValidDwarfFrame();
242 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
243 EmitCFIEndProcImpl(*CurFrame);
246 void MCStreamer::EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
247 // Put a dummy non-null value in Frame.End to mark that this frame has been
249 Frame.End = (MCSymbol *) 1;
252 MCSymbol *MCStreamer::EmitCFICommon() {
253 EnsureValidDwarfFrame();
254 MCSymbol *Label = getContext().CreateTempSymbol();
259 void MCStreamer::EmitCFIDefCfa(int64_t Register, int64_t Offset) {
260 MCSymbol *Label = EmitCFICommon();
261 MCCFIInstruction Instruction =
262 MCCFIInstruction::createDefCfa(Label, Register, Offset);
263 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
264 CurFrame->Instructions.push_back(Instruction);
265 CurFrame->CurrentCfaRegister = static_cast<unsigned>(Register);
268 void MCStreamer::EmitCFIDefCfaOffset(int64_t Offset) {
269 MCSymbol *Label = EmitCFICommon();
270 MCCFIInstruction Instruction =
271 MCCFIInstruction::createDefCfaOffset(Label, Offset);
272 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
273 CurFrame->Instructions.push_back(Instruction);
276 void MCStreamer::EmitCFIAdjustCfaOffset(int64_t Adjustment) {
277 MCSymbol *Label = EmitCFICommon();
278 MCCFIInstruction Instruction =
279 MCCFIInstruction::createAdjustCfaOffset(Label, Adjustment);
280 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
281 CurFrame->Instructions.push_back(Instruction);
284 void MCStreamer::EmitCFIDefCfaRegister(int64_t Register) {
285 MCSymbol *Label = EmitCFICommon();
286 MCCFIInstruction Instruction =
287 MCCFIInstruction::createDefCfaRegister(Label, Register);
288 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
289 CurFrame->Instructions.push_back(Instruction);
290 CurFrame->CurrentCfaRegister = static_cast<unsigned>(Register);
293 void MCStreamer::EmitCFIOffset(int64_t Register, int64_t Offset) {
294 MCSymbol *Label = EmitCFICommon();
295 MCCFIInstruction Instruction =
296 MCCFIInstruction::createOffset(Label, Register, Offset);
297 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
298 CurFrame->Instructions.push_back(Instruction);
301 void MCStreamer::EmitCFIRelOffset(int64_t Register, int64_t Offset) {
302 MCSymbol *Label = EmitCFICommon();
303 MCCFIInstruction Instruction =
304 MCCFIInstruction::createRelOffset(Label, Register, Offset);
305 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
306 CurFrame->Instructions.push_back(Instruction);
309 void MCStreamer::EmitCFIPersonality(const MCSymbol *Sym,
311 EnsureValidDwarfFrame();
312 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
313 CurFrame->Personality = Sym;
314 CurFrame->PersonalityEncoding = Encoding;
317 void MCStreamer::EmitCFILsda(const MCSymbol *Sym, unsigned Encoding) {
318 EnsureValidDwarfFrame();
319 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
320 CurFrame->Lsda = Sym;
321 CurFrame->LsdaEncoding = Encoding;
324 void MCStreamer::EmitCFIRememberState() {
325 MCSymbol *Label = EmitCFICommon();
326 MCCFIInstruction Instruction = MCCFIInstruction::createRememberState(Label);
327 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
328 CurFrame->Instructions.push_back(Instruction);
331 void MCStreamer::EmitCFIRestoreState() {
332 // FIXME: Error if there is no matching cfi_remember_state.
333 MCSymbol *Label = EmitCFICommon();
334 MCCFIInstruction Instruction = MCCFIInstruction::createRestoreState(Label);
335 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
336 CurFrame->Instructions.push_back(Instruction);
339 void MCStreamer::EmitCFISameValue(int64_t Register) {
340 MCSymbol *Label = EmitCFICommon();
341 MCCFIInstruction Instruction =
342 MCCFIInstruction::createSameValue(Label, Register);
343 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
344 CurFrame->Instructions.push_back(Instruction);
347 void MCStreamer::EmitCFIRestore(int64_t Register) {
348 MCSymbol *Label = EmitCFICommon();
349 MCCFIInstruction Instruction =
350 MCCFIInstruction::createRestore(Label, Register);
351 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
352 CurFrame->Instructions.push_back(Instruction);
355 void MCStreamer::EmitCFIEscape(StringRef Values) {
356 MCSymbol *Label = EmitCFICommon();
357 MCCFIInstruction Instruction = MCCFIInstruction::createEscape(Label, Values);
358 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
359 CurFrame->Instructions.push_back(Instruction);
362 void MCStreamer::EmitCFISignalFrame() {
363 EnsureValidDwarfFrame();
364 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
365 CurFrame->IsSignalFrame = true;
368 void MCStreamer::EmitCFIUndefined(int64_t Register) {
369 MCSymbol *Label = EmitCFICommon();
370 MCCFIInstruction Instruction =
371 MCCFIInstruction::createUndefined(Label, Register);
372 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
373 CurFrame->Instructions.push_back(Instruction);
376 void MCStreamer::EmitCFIRegister(int64_t Register1, int64_t Register2) {
377 MCSymbol *Label = EmitCFICommon();
378 MCCFIInstruction Instruction =
379 MCCFIInstruction::createRegister(Label, Register1, Register2);
380 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
381 CurFrame->Instructions.push_back(Instruction);
384 void MCStreamer::EmitCFIWindowSave() {
385 MCSymbol *Label = EmitCFICommon();
386 MCCFIInstruction Instruction =
387 MCCFIInstruction::createWindowSave(Label);
388 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
389 CurFrame->Instructions.push_back(Instruction);
392 void MCStreamer::EnsureValidWinFrameInfo() {
393 if (!CurrentWinFrameInfo || CurrentWinFrameInfo->End)
394 report_fatal_error("No open Win64 EH frame function!");
397 void MCStreamer::EmitWinCFIStartProc(const MCSymbol *Symbol) {
398 if (CurrentWinFrameInfo && !CurrentWinFrameInfo->End)
399 report_fatal_error("Starting a function before ending the previous one!");
401 MCSymbol *StartProc = getContext().CreateTempSymbol();
402 EmitLabel(StartProc);
404 WinFrameInfos.push_back(new WinEH::FrameInfo(Symbol, StartProc));
405 CurrentWinFrameInfo = WinFrameInfos.back();
408 void MCStreamer::EmitWinCFIEndProc() {
409 EnsureValidWinFrameInfo();
410 if (CurrentWinFrameInfo->ChainedParent)
411 report_fatal_error("Not all chained regions terminated!");
413 MCSymbol *Label = getContext().CreateTempSymbol();
415 CurrentWinFrameInfo->End = Label;
418 void MCStreamer::EmitWinCFIStartChained() {
419 EnsureValidWinFrameInfo();
421 MCSymbol *StartProc = getContext().CreateTempSymbol();
422 EmitLabel(StartProc);
424 WinFrameInfos.push_back(new WinEH::FrameInfo(CurrentWinFrameInfo->Function,
425 StartProc, CurrentWinFrameInfo));
426 CurrentWinFrameInfo = WinFrameInfos.back();
429 void MCStreamer::EmitWinCFIEndChained() {
430 EnsureValidWinFrameInfo();
431 if (!CurrentWinFrameInfo->ChainedParent)
432 report_fatal_error("End of a chained region outside a chained region!");
434 MCSymbol *Label = getContext().CreateTempSymbol();
437 CurrentWinFrameInfo->End = Label;
438 CurrentWinFrameInfo =
439 const_cast<WinEH::FrameInfo *>(CurrentWinFrameInfo->ChainedParent);
442 void MCStreamer::EmitWinEHHandler(const MCSymbol *Sym, bool Unwind,
444 EnsureValidWinFrameInfo();
445 if (CurrentWinFrameInfo->ChainedParent)
446 report_fatal_error("Chained unwind areas can't have handlers!");
447 CurrentWinFrameInfo->ExceptionHandler = Sym;
448 if (!Except && !Unwind)
449 report_fatal_error("Don't know what kind of handler this is!");
451 CurrentWinFrameInfo->HandlesUnwind = true;
453 CurrentWinFrameInfo->HandlesExceptions = true;
456 void MCStreamer::EmitWinEHHandlerData() {
457 EnsureValidWinFrameInfo();
458 if (CurrentWinFrameInfo->ChainedParent)
459 report_fatal_error("Chained unwind areas can't have handlers!");
462 void MCStreamer::EmitWinCFIPushReg(unsigned Register) {
463 EnsureValidWinFrameInfo();
465 MCSymbol *Label = getContext().CreateTempSymbol();
468 WinEH::Instruction Inst = Win64EH::Instruction::PushNonVol(Label, Register);
469 CurrentWinFrameInfo->Instructions.push_back(Inst);
472 void MCStreamer::EmitWinCFISetFrame(unsigned Register, unsigned Offset) {
473 EnsureValidWinFrameInfo();
474 if (CurrentWinFrameInfo->LastFrameInst >= 0)
475 report_fatal_error("Frame register and offset already specified!");
477 report_fatal_error("Misaligned frame pointer offset!");
479 report_fatal_error("Frame offset must be less than or equal to 240!");
481 MCSymbol *Label = getContext().CreateTempSymbol();
484 WinEH::Instruction Inst =
485 Win64EH::Instruction::SetFPReg(Label, Register, Offset);
486 CurrentWinFrameInfo->LastFrameInst = CurrentWinFrameInfo->Instructions.size();
487 CurrentWinFrameInfo->Instructions.push_back(Inst);
490 void MCStreamer::EmitWinCFIAllocStack(unsigned Size) {
491 EnsureValidWinFrameInfo();
493 report_fatal_error("Allocation size must be non-zero!");
495 report_fatal_error("Misaligned stack allocation!");
497 MCSymbol *Label = getContext().CreateTempSymbol();
500 WinEH::Instruction Inst = Win64EH::Instruction::Alloc(Label, Size);
501 CurrentWinFrameInfo->Instructions.push_back(Inst);
504 void MCStreamer::EmitWinCFISaveReg(unsigned Register, unsigned Offset) {
505 EnsureValidWinFrameInfo();
507 report_fatal_error("Misaligned saved register offset!");
509 MCSymbol *Label = getContext().CreateTempSymbol();
512 WinEH::Instruction Inst =
513 Win64EH::Instruction::SaveNonVol(Label, Register, Offset);
514 CurrentWinFrameInfo->Instructions.push_back(Inst);
517 void MCStreamer::EmitWinCFISaveXMM(unsigned Register, unsigned Offset) {
518 EnsureValidWinFrameInfo();
520 report_fatal_error("Misaligned saved vector register offset!");
522 MCSymbol *Label = getContext().CreateTempSymbol();
525 WinEH::Instruction Inst =
526 Win64EH::Instruction::SaveXMM(Label, Register, Offset);
527 CurrentWinFrameInfo->Instructions.push_back(Inst);
530 void MCStreamer::EmitWinCFIPushFrame(bool Code) {
531 EnsureValidWinFrameInfo();
532 if (CurrentWinFrameInfo->Instructions.size() > 0)
533 report_fatal_error("If present, PushMachFrame must be the first UOP");
535 MCSymbol *Label = getContext().CreateTempSymbol();
538 WinEH::Instruction Inst = Win64EH::Instruction::PushMachFrame(Label, Code);
539 CurrentWinFrameInfo->Instructions.push_back(Inst);
542 void MCStreamer::EmitWinCFIEndProlog() {
543 EnsureValidWinFrameInfo();
545 MCSymbol *Label = getContext().CreateTempSymbol();
548 CurrentWinFrameInfo->PrologEnd = Label;
551 void MCStreamer::EmitCOFFSectionIndex(MCSymbol const *Symbol) {
554 void MCStreamer::EmitCOFFSecRel32(MCSymbol const *Symbol) {
557 /// EmitRawText - If this file is backed by an assembly streamer, this dumps
558 /// the specified string in the output .s file. This capability is
559 /// indicated by the hasRawTextSupport() predicate.
560 void MCStreamer::EmitRawTextImpl(StringRef String) {
561 errs() << "EmitRawText called on an MCStreamer that doesn't support it, "
562 " something must not be fully mc'ized\n";
566 void MCStreamer::EmitRawText(const Twine &T) {
567 SmallString<128> Str;
568 EmitRawTextImpl(T.toStringRef(Str));
571 void MCStreamer::EmitWindowsUnwindTables() {
574 void MCStreamer::Finish() {
575 if (!DwarfFrameInfos.empty() && !DwarfFrameInfos.back().End)
576 report_fatal_error("Unfinished frame!");
578 MCTargetStreamer *TS = getTargetStreamer();
585 void MCStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
586 visitUsedExpr(*Value);
587 Symbol->setVariableValue(Value);
589 MCTargetStreamer *TS = getTargetStreamer();
591 TS->emitAssignment(Symbol, Value);
594 void MCStreamer::visitUsedSymbol(const MCSymbol &Sym) {
597 void MCStreamer::visitUsedExpr(const MCExpr &Expr) {
598 switch (Expr.getKind()) {
600 cast<MCTargetExpr>(Expr).visitUsedExpr(*this);
603 case MCExpr::Constant:
606 case MCExpr::Binary: {
607 const MCBinaryExpr &BE = cast<MCBinaryExpr>(Expr);
608 visitUsedExpr(*BE.getLHS());
609 visitUsedExpr(*BE.getRHS());
613 case MCExpr::SymbolRef:
614 visitUsedSymbol(cast<MCSymbolRefExpr>(Expr).getSymbol());
618 visitUsedExpr(*cast<MCUnaryExpr>(Expr).getSubExpr());
623 void MCStreamer::EmitInstruction(const MCInst &Inst,
624 const MCSubtargetInfo &STI) {
626 for (unsigned i = Inst.getNumOperands(); i--;)
627 if (Inst.getOperand(i).isExpr())
628 visitUsedExpr(*Inst.getOperand(i).getExpr());
631 void MCStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {}
632 void MCStreamer::EmitThumbFunc(MCSymbol *Func) {}
633 void MCStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
634 void MCStreamer::BeginCOFFSymbolDef(const MCSymbol *Symbol) {}
635 void MCStreamer::EndCOFFSymbolDef() {}
636 void MCStreamer::EmitFileDirective(StringRef Filename) {}
637 void MCStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {}
638 void MCStreamer::EmitCOFFSymbolType(int Type) {}
639 void MCStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
640 void MCStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
641 unsigned ByteAlignment) {}
642 void MCStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
643 uint64_t Size, unsigned ByteAlignment) {}
644 void MCStreamer::ChangeSection(const MCSection *, const MCExpr *) {}
645 void MCStreamer::EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {}
646 void MCStreamer::EmitBytes(StringRef Data) {}
647 void MCStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
649 visitUsedExpr(*Value);
651 void MCStreamer::EmitULEB128Value(const MCExpr *Value) {}
652 void MCStreamer::EmitSLEB128Value(const MCExpr *Value) {}
653 void MCStreamer::EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
655 unsigned MaxBytesToEmit) {}
656 void MCStreamer::EmitCodeAlignment(unsigned ByteAlignment,
657 unsigned MaxBytesToEmit) {}
658 bool MCStreamer::EmitValueToOffset(const MCExpr *Offset, unsigned char Value) {
661 void MCStreamer::EmitBundleAlignMode(unsigned AlignPow2) {}
662 void MCStreamer::EmitBundleLock(bool AlignToEnd) {}
663 void MCStreamer::FinishImpl() {}
664 void MCStreamer::EmitBundleUnlock() {}
666 void MCStreamer::SwitchSection(const MCSection *Section,
667 const MCExpr *Subsection) {
668 assert(Section && "Cannot switch to a null section!");
669 MCSectionSubPair curSection = SectionStack.back().first;
670 SectionStack.back().second = curSection;
671 if (MCSectionSubPair(Section, Subsection) != curSection) {
672 SectionStack.back().first = MCSectionSubPair(Section, Subsection);
673 assert(!Section->hasEnded() && "Section already ended");
674 ChangeSection(Section, Subsection);
675 MCSymbol *Sym = Section->getBeginSymbol();
676 if (Sym && !Sym->isInSection())
681 MCSymbol *MCStreamer::endSection(const MCSection *Section) {
682 // TODO: keep track of the last subsection so that this symbol appears in the
684 MCSymbol *Sym = Section->getEndSymbol(Context);
685 if (Sym->isInSection())
688 SwitchSection(Section);