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/MCInst.h"
18 #include "llvm/MC/MCInstPrinter.h"
19 #include "llvm/MC/MCObjectFileInfo.h"
20 #include "llvm/MC/MCObjectWriter.h"
21 #include "llvm/MC/MCSection.h"
22 #include "llvm/MC/MCSymbol.h"
23 #include "llvm/MC/MCWin64EH.h"
24 #include "llvm/Support/ErrorHandling.h"
25 #include "llvm/Support/LEB128.h"
26 #include "llvm/Support/raw_ostream.h"
30 // Pin the vtables to this file.
31 MCTargetStreamer::~MCTargetStreamer() {}
33 MCTargetStreamer::MCTargetStreamer(MCStreamer &S) : Streamer(S) {
34 S.setTargetStreamer(this);
37 void MCTargetStreamer::emitLabel(MCSymbol *Symbol) {}
39 void MCTargetStreamer::finish() {}
41 void MCTargetStreamer::emitAssignment(MCSymbol *Symbol, const MCExpr *Value) {}
43 MCStreamer::MCStreamer(MCContext &Ctx)
44 : Context(Ctx), CurrentWinFrameInfo(nullptr) {
45 SectionStack.push_back(std::pair<MCSectionSubPair, MCSectionSubPair>());
48 MCStreamer::~MCStreamer() {
49 for (unsigned i = 0; i < getNumWinFrameInfos(); ++i)
50 delete WinFrameInfos[i];
53 void MCStreamer::reset() {
54 DwarfFrameInfos.clear();
55 for (unsigned i = 0; i < getNumWinFrameInfos(); ++i)
56 delete WinFrameInfos[i];
57 WinFrameInfos.clear();
58 CurrentWinFrameInfo = nullptr;
59 SymbolOrdering.clear();
61 SectionStack.push_back(std::pair<MCSectionSubPair, MCSectionSubPair>());
64 raw_ostream &MCStreamer::GetCommentOS() {
65 // By default, discard comments.
69 void MCStreamer::emitRawComment(const Twine &T, bool TabPrefix) {}
71 void MCStreamer::generateCompactUnwindEncodings(MCAsmBackend *MAB) {
72 for (auto &FI : DwarfFrameInfos)
73 FI.CompactUnwindEncoding =
74 (MAB ? MAB->generateCompactUnwindEncoding(FI.Instructions) : 0);
77 /// EmitIntValue - Special case of EmitValue that avoids the client having to
78 /// pass in a MCExpr for constant integers.
79 void MCStreamer::EmitIntValue(uint64_t Value, unsigned Size) {
80 assert(1 <= Size && Size <= 8 && "Invalid size");
81 assert((isUIntN(8 * Size, Value) || isIntN(8 * Size, Value)) &&
84 const bool isLittleEndian = Context.getAsmInfo()->isLittleEndian();
85 for (unsigned i = 0; i != Size; ++i) {
86 unsigned index = isLittleEndian ? i : (Size - i - 1);
87 buf[i] = uint8_t(Value >> (index * 8));
89 EmitBytes(StringRef(buf, Size));
92 /// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
93 /// client having to pass in a MCExpr for constant integers.
94 void MCStreamer::EmitULEB128IntValue(uint64_t Value, unsigned Padding) {
96 raw_svector_ostream OSE(Tmp);
97 encodeULEB128(Value, OSE, Padding);
101 /// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
102 /// client having to pass in a MCExpr for constant integers.
103 void MCStreamer::EmitSLEB128IntValue(int64_t Value) {
104 SmallString<128> Tmp;
105 raw_svector_ostream OSE(Tmp);
106 encodeSLEB128(Value, OSE);
107 EmitBytes(OSE.str());
110 void MCStreamer::EmitValue(const MCExpr *Value, unsigned Size, SMLoc Loc) {
111 EmitValueImpl(Value, Size, Loc);
114 void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
115 bool IsSectionRelative) {
116 assert((!IsSectionRelative || Size == 4) &&
117 "SectionRelative value requires 4-bytes");
119 if (!IsSectionRelative)
120 EmitValueImpl(MCSymbolRefExpr::create(Sym, getContext()), Size);
122 EmitCOFFSecRel32(Sym);
125 void MCStreamer::EmitGPRel64Value(const MCExpr *Value) {
126 report_fatal_error("unsupported directive in streamer");
129 void MCStreamer::EmitGPRel32Value(const MCExpr *Value) {
130 report_fatal_error("unsupported directive in streamer");
133 /// EmitFill - Emit NumBytes bytes worth of the value specified by
134 /// FillValue. This implements directives such as '.space'.
135 void MCStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue) {
136 const MCExpr *E = MCConstantExpr::create(FillValue, getContext());
137 for (uint64_t i = 0, e = NumBytes; i != e; ++i)
141 /// The implementation in this class just redirects to EmitFill.
142 void MCStreamer::EmitZeros(uint64_t NumBytes) {
143 EmitFill(NumBytes, 0);
146 unsigned MCStreamer::EmitDwarfFileDirective(unsigned FileNo,
148 StringRef Filename, unsigned CUID) {
149 return getContext().getDwarfFile(Directory, Filename, FileNo, CUID);
152 void MCStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
153 unsigned Column, unsigned Flags,
155 unsigned Discriminator,
156 StringRef FileName) {
157 getContext().setCurrentDwarfLoc(FileNo, Line, Column, Flags, Isa,
161 MCSymbol *MCStreamer::getDwarfLineTableSymbol(unsigned CUID) {
162 MCDwarfLineTable &Table = getContext().getMCDwarfLineTable(CUID);
163 if (!Table.getLabel()) {
164 StringRef Prefix = Context.getAsmInfo()->getPrivateGlobalPrefix();
166 Context.getOrCreateSymbol(Prefix + "line_table_start" + Twine(CUID)));
168 return Table.getLabel();
171 MCDwarfFrameInfo *MCStreamer::getCurrentDwarfFrameInfo() {
172 if (DwarfFrameInfos.empty())
174 return &DwarfFrameInfos.back();
177 void MCStreamer::EnsureValidDwarfFrame() {
178 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
179 if (!CurFrame || CurFrame->End)
180 report_fatal_error("No open frame");
183 void MCStreamer::EmitEHSymAttributes(const MCSymbol *Symbol,
184 MCSymbol *EHSymbol) {
187 void MCStreamer::InitSections(bool NoExecStack) {
188 SwitchSection(getContext().getObjectFileInfo()->getTextSection());
191 void MCStreamer::AssignFragment(MCSymbol *Symbol, MCFragment *Fragment) {
193 Symbol->setFragment(Fragment);
195 // As we emit symbols into a section, track the order so that they can
196 // be sorted upon later. Zero is reserved to mean 'unemitted'.
197 SymbolOrdering[Symbol] = 1 + SymbolOrdering.size();
200 void MCStreamer::EmitLabel(MCSymbol *Symbol) {
201 assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
202 assert(getCurrentSection().first && "Cannot emit before setting section!");
203 assert(!Symbol->getFragment() && "Unexpected fragment on symbol data!");
204 Symbol->setFragment(&getCurrentSectionOnly()->getDummyFragment());
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::EmitCFIGnuArgsSize(int64_t Size) {
363 MCSymbol *Label = EmitCFICommon();
364 MCCFIInstruction Instruction =
365 MCCFIInstruction::createGnuArgsSize(Label, Size);
366 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
367 CurFrame->Instructions.push_back(Instruction);
370 void MCStreamer::EmitCFISignalFrame() {
371 EnsureValidDwarfFrame();
372 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
373 CurFrame->IsSignalFrame = true;
376 void MCStreamer::EmitCFIUndefined(int64_t Register) {
377 MCSymbol *Label = EmitCFICommon();
378 MCCFIInstruction Instruction =
379 MCCFIInstruction::createUndefined(Label, Register);
380 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
381 CurFrame->Instructions.push_back(Instruction);
384 void MCStreamer::EmitCFIRegister(int64_t Register1, int64_t Register2) {
385 MCSymbol *Label = EmitCFICommon();
386 MCCFIInstruction Instruction =
387 MCCFIInstruction::createRegister(Label, Register1, Register2);
388 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
389 CurFrame->Instructions.push_back(Instruction);
392 void MCStreamer::EmitCFIWindowSave() {
393 MCSymbol *Label = EmitCFICommon();
394 MCCFIInstruction Instruction =
395 MCCFIInstruction::createWindowSave(Label);
396 MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
397 CurFrame->Instructions.push_back(Instruction);
400 void MCStreamer::EnsureValidWinFrameInfo() {
401 const MCAsmInfo *MAI = Context.getAsmInfo();
402 if (!MAI->usesWindowsCFI())
403 report_fatal_error(".seh_* directives are not supported on this target");
404 if (!CurrentWinFrameInfo || CurrentWinFrameInfo->End)
405 report_fatal_error("No open Win64 EH frame function!");
408 void MCStreamer::EmitWinCFIStartProc(const MCSymbol *Symbol) {
409 const MCAsmInfo *MAI = Context.getAsmInfo();
410 if (!MAI->usesWindowsCFI())
411 report_fatal_error(".seh_* directives are not supported on this target");
412 if (CurrentWinFrameInfo && !CurrentWinFrameInfo->End)
413 report_fatal_error("Starting a function before ending the previous one!");
415 MCSymbol *StartProc = getContext().createTempSymbol();
416 EmitLabel(StartProc);
418 WinFrameInfos.push_back(new WinEH::FrameInfo(Symbol, StartProc));
419 CurrentWinFrameInfo = WinFrameInfos.back();
422 void MCStreamer::EmitWinCFIEndProc() {
423 EnsureValidWinFrameInfo();
424 if (CurrentWinFrameInfo->ChainedParent)
425 report_fatal_error("Not all chained regions terminated!");
427 MCSymbol *Label = getContext().createTempSymbol();
429 CurrentWinFrameInfo->End = Label;
432 void MCStreamer::EmitWinCFIStartChained() {
433 EnsureValidWinFrameInfo();
435 MCSymbol *StartProc = getContext().createTempSymbol();
436 EmitLabel(StartProc);
438 WinFrameInfos.push_back(new WinEH::FrameInfo(CurrentWinFrameInfo->Function,
439 StartProc, CurrentWinFrameInfo));
440 CurrentWinFrameInfo = WinFrameInfos.back();
443 void MCStreamer::EmitWinCFIEndChained() {
444 EnsureValidWinFrameInfo();
445 if (!CurrentWinFrameInfo->ChainedParent)
446 report_fatal_error("End of a chained region outside a chained region!");
448 MCSymbol *Label = getContext().createTempSymbol();
451 CurrentWinFrameInfo->End = Label;
452 CurrentWinFrameInfo =
453 const_cast<WinEH::FrameInfo *>(CurrentWinFrameInfo->ChainedParent);
456 void MCStreamer::EmitWinEHHandler(const MCSymbol *Sym, bool Unwind,
458 EnsureValidWinFrameInfo();
459 if (CurrentWinFrameInfo->ChainedParent)
460 report_fatal_error("Chained unwind areas can't have handlers!");
461 CurrentWinFrameInfo->ExceptionHandler = Sym;
462 if (!Except && !Unwind)
463 report_fatal_error("Don't know what kind of handler this is!");
465 CurrentWinFrameInfo->HandlesUnwind = true;
467 CurrentWinFrameInfo->HandlesExceptions = true;
470 void MCStreamer::EmitWinEHHandlerData() {
471 EnsureValidWinFrameInfo();
472 if (CurrentWinFrameInfo->ChainedParent)
473 report_fatal_error("Chained unwind areas can't have handlers!");
476 void MCStreamer::EmitSyntaxDirective() {}
478 void MCStreamer::EmitWinCFIPushReg(unsigned Register) {
479 EnsureValidWinFrameInfo();
481 MCSymbol *Label = getContext().createTempSymbol();
484 WinEH::Instruction Inst = Win64EH::Instruction::PushNonVol(Label, Register);
485 CurrentWinFrameInfo->Instructions.push_back(Inst);
488 void MCStreamer::EmitWinCFISetFrame(unsigned Register, unsigned Offset) {
489 EnsureValidWinFrameInfo();
490 if (CurrentWinFrameInfo->LastFrameInst >= 0)
491 report_fatal_error("Frame register and offset already specified!");
493 report_fatal_error("Misaligned frame pointer offset!");
495 report_fatal_error("Frame offset must be less than or equal to 240!");
497 MCSymbol *Label = getContext().createTempSymbol();
500 WinEH::Instruction Inst =
501 Win64EH::Instruction::SetFPReg(Label, Register, Offset);
502 CurrentWinFrameInfo->LastFrameInst = CurrentWinFrameInfo->Instructions.size();
503 CurrentWinFrameInfo->Instructions.push_back(Inst);
506 void MCStreamer::EmitWinCFIAllocStack(unsigned Size) {
507 EnsureValidWinFrameInfo();
509 report_fatal_error("Allocation size must be non-zero!");
511 report_fatal_error("Misaligned stack allocation!");
513 MCSymbol *Label = getContext().createTempSymbol();
516 WinEH::Instruction Inst = Win64EH::Instruction::Alloc(Label, Size);
517 CurrentWinFrameInfo->Instructions.push_back(Inst);
520 void MCStreamer::EmitWinCFISaveReg(unsigned Register, unsigned Offset) {
521 EnsureValidWinFrameInfo();
523 report_fatal_error("Misaligned saved register offset!");
525 MCSymbol *Label = getContext().createTempSymbol();
528 WinEH::Instruction Inst =
529 Win64EH::Instruction::SaveNonVol(Label, Register, Offset);
530 CurrentWinFrameInfo->Instructions.push_back(Inst);
533 void MCStreamer::EmitWinCFISaveXMM(unsigned Register, unsigned Offset) {
534 EnsureValidWinFrameInfo();
536 report_fatal_error("Misaligned saved vector register offset!");
538 MCSymbol *Label = getContext().createTempSymbol();
541 WinEH::Instruction Inst =
542 Win64EH::Instruction::SaveXMM(Label, Register, Offset);
543 CurrentWinFrameInfo->Instructions.push_back(Inst);
546 void MCStreamer::EmitWinCFIPushFrame(bool Code) {
547 EnsureValidWinFrameInfo();
548 if (CurrentWinFrameInfo->Instructions.size() > 0)
549 report_fatal_error("If present, PushMachFrame must be the first UOP");
551 MCSymbol *Label = getContext().createTempSymbol();
554 WinEH::Instruction Inst = Win64EH::Instruction::PushMachFrame(Label, Code);
555 CurrentWinFrameInfo->Instructions.push_back(Inst);
558 void MCStreamer::EmitWinCFIEndProlog() {
559 EnsureValidWinFrameInfo();
561 MCSymbol *Label = getContext().createTempSymbol();
564 CurrentWinFrameInfo->PrologEnd = Label;
567 void MCStreamer::EmitCOFFSafeSEH(MCSymbol const *Symbol) {
570 void MCStreamer::EmitCOFFSectionIndex(MCSymbol const *Symbol) {
573 void MCStreamer::EmitCOFFSecRel32(MCSymbol const *Symbol) {
576 /// EmitRawText - If this file is backed by an assembly streamer, this dumps
577 /// the specified string in the output .s file. This capability is
578 /// indicated by the hasRawTextSupport() predicate.
579 void MCStreamer::EmitRawTextImpl(StringRef String) {
580 errs() << "EmitRawText called on an MCStreamer that doesn't support it, "
581 " something must not be fully mc'ized\n";
585 void MCStreamer::EmitRawText(const Twine &T) {
586 SmallString<128> Str;
587 EmitRawTextImpl(T.toStringRef(Str));
590 void MCStreamer::EmitWindowsUnwindTables() {
593 void MCStreamer::Finish() {
594 if (!DwarfFrameInfos.empty() && !DwarfFrameInfos.back().End)
595 report_fatal_error("Unfinished frame!");
597 MCTargetStreamer *TS = getTargetStreamer();
604 void MCStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
605 visitUsedExpr(*Value);
606 Symbol->setVariableValue(Value);
608 MCTargetStreamer *TS = getTargetStreamer();
610 TS->emitAssignment(Symbol, Value);
613 void MCTargetStreamer::prettyPrintAsm(MCInstPrinter &InstPrinter, raw_ostream &OS,
614 const MCInst &Inst, const MCSubtargetInfo &STI) {
615 InstPrinter.printInst(&Inst, OS, "", STI);
618 void MCStreamer::visitUsedSymbol(const MCSymbol &Sym) {
621 void MCStreamer::visitUsedExpr(const MCExpr &Expr) {
622 switch (Expr.getKind()) {
624 cast<MCTargetExpr>(Expr).visitUsedExpr(*this);
627 case MCExpr::Constant:
630 case MCExpr::Binary: {
631 const MCBinaryExpr &BE = cast<MCBinaryExpr>(Expr);
632 visitUsedExpr(*BE.getLHS());
633 visitUsedExpr(*BE.getRHS());
637 case MCExpr::SymbolRef:
638 visitUsedSymbol(cast<MCSymbolRefExpr>(Expr).getSymbol());
642 visitUsedExpr(*cast<MCUnaryExpr>(Expr).getSubExpr());
647 void MCStreamer::EmitInstruction(const MCInst &Inst,
648 const MCSubtargetInfo &STI) {
650 for (unsigned i = Inst.getNumOperands(); i--;)
651 if (Inst.getOperand(i).isExpr())
652 visitUsedExpr(*Inst.getOperand(i).getExpr());
655 void MCStreamer::emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo,
657 // Get the Hi-Lo expression.
659 MCBinaryExpr::createSub(MCSymbolRefExpr::create(Hi, Context),
660 MCSymbolRefExpr::create(Lo, Context), Context);
662 const MCAsmInfo *MAI = Context.getAsmInfo();
663 if (!MAI->doesSetDirectiveSuppressesReloc()) {
664 EmitValue(Diff, Size);
668 // Otherwise, emit with .set (aka assignment).
669 MCSymbol *SetLabel = Context.createTempSymbol("set", true);
670 EmitAssignment(SetLabel, Diff);
671 EmitSymbolValue(SetLabel, Size);
674 void MCStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {}
675 void MCStreamer::EmitThumbFunc(MCSymbol *Func) {}
676 void MCStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
677 void MCStreamer::BeginCOFFSymbolDef(const MCSymbol *Symbol) {}
678 void MCStreamer::EndCOFFSymbolDef() {}
679 void MCStreamer::EmitFileDirective(StringRef Filename) {}
680 void MCStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {}
681 void MCStreamer::EmitCOFFSymbolType(int Type) {}
682 void MCStreamer::emitELFSize(MCSymbolELF *Symbol, const MCExpr *Value) {}
683 void MCStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
684 unsigned ByteAlignment) {}
685 void MCStreamer::EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol,
686 uint64_t Size, unsigned ByteAlignment) {}
687 void MCStreamer::ChangeSection(MCSection *, const MCExpr *) {}
688 void MCStreamer::EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {}
689 void MCStreamer::EmitBytes(StringRef Data) {}
690 void MCStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size, SMLoc Loc) {
691 visitUsedExpr(*Value);
693 void MCStreamer::EmitULEB128Value(const MCExpr *Value) {}
694 void MCStreamer::EmitSLEB128Value(const MCExpr *Value) {}
695 void MCStreamer::EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
697 unsigned MaxBytesToEmit) {}
698 void MCStreamer::EmitCodeAlignment(unsigned ByteAlignment,
699 unsigned MaxBytesToEmit) {}
700 bool MCStreamer::EmitValueToOffset(const MCExpr *Offset, unsigned char Value) {
703 void MCStreamer::EmitBundleAlignMode(unsigned AlignPow2) {}
704 void MCStreamer::EmitBundleLock(bool AlignToEnd) {}
705 void MCStreamer::FinishImpl() {}
706 void MCStreamer::EmitBundleUnlock() {}
708 void MCStreamer::SwitchSection(MCSection *Section, const MCExpr *Subsection) {
709 assert(Section && "Cannot switch to a null section!");
710 MCSectionSubPair curSection = SectionStack.back().first;
711 SectionStack.back().second = curSection;
712 if (MCSectionSubPair(Section, Subsection) != curSection) {
713 ChangeSection(Section, Subsection);
714 SectionStack.back().first = MCSectionSubPair(Section, Subsection);
715 assert(!Section->hasEnded() && "Section already ended");
716 MCSymbol *Sym = Section->getBeginSymbol();
717 if (Sym && !Sym->isInSection())
722 MCSymbol *MCStreamer::endSection(MCSection *Section) {
723 // TODO: keep track of the last subsection so that this symbol appears in the
725 MCSymbol *Sym = Section->getEndSymbol(Context);
726 if (Sym->isInSection())
729 SwitchSection(Section);