MCStreamer.cpp revision 276479 
1//===- lib/MC/MCStreamer.cpp - Streaming Machine Code Output --------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
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/MCSymbol.h"
20#include "llvm/MC/MCWin64EH.h"
21#include "llvm/Support/ErrorHandling.h"
22#include "llvm/Support/LEB128.h"
23#include "llvm/Support/raw_ostream.h"
24#include <cstdlib>
25using namespace llvm;
26
27// Pin the vtables to this file.
28MCTargetStreamer::~MCTargetStreamer() {}
29
30MCTargetStreamer::MCTargetStreamer(MCStreamer &S) : Streamer(S) {
31  S.setTargetStreamer(this);
32}
33
34void MCTargetStreamer::emitLabel(MCSymbol *Symbol) {}
35
36void MCTargetStreamer::finish() {}
37
38void MCTargetStreamer::emitAssignment(MCSymbol *Symbol, const MCExpr *Value) {}
39
40MCStreamer::MCStreamer(MCContext &Ctx)
41    : Context(Ctx), CurrentWinFrameInfo(nullptr) {
42  SectionStack.push_back(std::pair<MCSectionSubPair, MCSectionSubPair>());
43}
44
45MCStreamer::~MCStreamer() {
46  for (unsigned i = 0; i < getNumWinFrameInfos(); ++i)
47    delete WinFrameInfos[i];
48}
49
50void MCStreamer::reset() {
51  for (unsigned i = 0; i < getNumWinFrameInfos(); ++i)
52    delete WinFrameInfos[i];
53  WinFrameInfos.clear();
54  CurrentWinFrameInfo = nullptr;
55  SectionStack.clear();
56  SectionStack.push_back(std::pair<MCSectionSubPair, MCSectionSubPair>());
57}
58
59const MCExpr *MCStreamer::BuildSymbolDiff(MCContext &Context,
60                                          const MCSymbol *A,
61                                          const MCSymbol *B) {
62  MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None;
63  const MCExpr *ARef =
64    MCSymbolRefExpr::Create(A, Variant, Context);
65  const MCExpr *BRef =
66    MCSymbolRefExpr::Create(B, Variant, Context);
67  const MCExpr *AddrDelta =
68    MCBinaryExpr::Create(MCBinaryExpr::Sub, ARef, BRef, Context);
69  return AddrDelta;
70}
71
72const MCExpr *MCStreamer::ForceExpAbs(const MCExpr* Expr) {
73  assert(!isa<MCSymbolRefExpr>(Expr));
74  if (Context.getAsmInfo()->hasAggressiveSymbolFolding())
75    return Expr;
76
77  MCSymbol *ABS = Context.CreateTempSymbol();
78  EmitAssignment(ABS, Expr);
79  return MCSymbolRefExpr::Create(ABS, Context);
80}
81
82raw_ostream &MCStreamer::GetCommentOS() {
83  // By default, discard comments.
84  return nulls();
85}
86
87void MCStreamer::emitRawComment(const Twine &T, bool TabPrefix) {}
88
89void MCStreamer::generateCompactUnwindEncodings(MCAsmBackend *MAB) {
90  for (auto &FI : DwarfFrameInfos)
91    FI.CompactUnwindEncoding =
92        (MAB ? MAB->generateCompactUnwindEncoding(FI.Instructions) : 0);
93}
94
95void MCStreamer::EmitDwarfSetLineAddr(int64_t LineDelta,
96                                      const MCSymbol *Label, int PointerSize) {
97  // emit the sequence to set the address
98  EmitIntValue(dwarf::DW_LNS_extended_op, 1);
99  EmitULEB128IntValue(PointerSize + 1);
100  EmitIntValue(dwarf::DW_LNE_set_address, 1);
101  EmitSymbolValue(Label, PointerSize);
102
103  // emit the sequence for the LineDelta (from 1) and a zero address delta.
104  MCDwarfLineAddr::Emit(this, LineDelta, 0);
105}
106
107/// EmitIntValue - Special case of EmitValue that avoids the client having to
108/// pass in a MCExpr for constant integers.
109void MCStreamer::EmitIntValue(uint64_t Value, unsigned Size) {
110  assert(Size <= 8 && "Invalid size");
111  assert((isUIntN(8 * Size, Value) || isIntN(8 * Size, Value)) &&
112         "Invalid size");
113  char buf[8];
114  const bool isLittleEndian = Context.getAsmInfo()->isLittleEndian();
115  for (unsigned i = 0; i != Size; ++i) {
116    unsigned index = isLittleEndian ? i : (Size - i - 1);
117    buf[i] = uint8_t(Value >> (index * 8));
118  }
119  EmitBytes(StringRef(buf, Size));
120}
121
122/// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
123/// client having to pass in a MCExpr for constant integers.
124void MCStreamer::EmitULEB128IntValue(uint64_t Value, unsigned Padding) {
125  SmallString<128> Tmp;
126  raw_svector_ostream OSE(Tmp);
127  encodeULEB128(Value, OSE, Padding);
128  EmitBytes(OSE.str());
129}
130
131/// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
132/// client having to pass in a MCExpr for constant integers.
133void MCStreamer::EmitSLEB128IntValue(int64_t Value) {
134  SmallString<128> Tmp;
135  raw_svector_ostream OSE(Tmp);
136  encodeSLEB128(Value, OSE);
137  EmitBytes(OSE.str());
138}
139
140void MCStreamer::EmitAbsValue(const MCExpr *Value, unsigned Size) {
141  const MCExpr *ABS = ForceExpAbs(Value);
142  EmitValue(ABS, Size);
143}
144
145
146void MCStreamer::EmitValue(const MCExpr *Value, unsigned Size,
147                           const SMLoc &Loc) {
148  EmitValueImpl(Value, Size, Loc);
149}
150
151void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
152                                 bool IsSectionRelative) {
153  assert((!IsSectionRelative || Size == 4) &&
154         "SectionRelative value requires 4-bytes");
155
156  if (!IsSectionRelative)
157    EmitValueImpl(MCSymbolRefExpr::Create(Sym, getContext()), Size);
158  else
159    EmitCOFFSecRel32(Sym);
160}
161
162void MCStreamer::EmitGPRel64Value(const MCExpr *Value) {
163  report_fatal_error("unsupported directive in streamer");
164}
165
166void MCStreamer::EmitGPRel32Value(const MCExpr *Value) {
167  report_fatal_error("unsupported directive in streamer");
168}
169
170/// EmitFill - Emit NumBytes bytes worth of the value specified by
171/// FillValue.  This implements directives such as '.space'.
172void MCStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue) {
173  const MCExpr *E = MCConstantExpr::Create(FillValue, getContext());
174  for (uint64_t i = 0, e = NumBytes; i != e; ++i)
175    EmitValue(E, 1);
176}
177
178/// The implementation in this class just redirects to EmitFill.
179void MCStreamer::EmitZeros(uint64_t NumBytes) {
180  EmitFill(NumBytes, 0);
181}
182
183unsigned MCStreamer::EmitDwarfFileDirective(unsigned FileNo,
184                                            StringRef Directory,
185                                            StringRef Filename, unsigned CUID) {
186  return getContext().GetDwarfFile(Directory, Filename, FileNo, CUID);
187}
188
189void MCStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
190                                       unsigned Column, unsigned Flags,
191                                       unsigned Isa,
192                                       unsigned Discriminator,
193                                       StringRef FileName) {
194  getContext().setCurrentDwarfLoc(FileNo, Line, Column, Flags, Isa,
195                                  Discriminator);
196}
197
198MCSymbol *MCStreamer::getDwarfLineTableSymbol(unsigned CUID) {
199  MCDwarfLineTable &Table = getContext().getMCDwarfLineTable(CUID);
200  if (!Table.getLabel()) {
201    StringRef Prefix = Context.getAsmInfo()->getPrivateGlobalPrefix();
202    Table.setLabel(
203        Context.GetOrCreateSymbol(Prefix + "line_table_start" + Twine(CUID)));
204  }
205  return Table.getLabel();
206}
207
208MCDwarfFrameInfo *MCStreamer::getCurrentDwarfFrameInfo() {
209  if (DwarfFrameInfos.empty())
210    return nullptr;
211  return &DwarfFrameInfos.back();
212}
213
214void MCStreamer::EnsureValidDwarfFrame() {
215  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
216  if (!CurFrame || CurFrame->End)
217    report_fatal_error("No open frame");
218}
219
220void MCStreamer::EmitEHSymAttributes(const MCSymbol *Symbol,
221                                     MCSymbol *EHSymbol) {
222}
223
224void MCStreamer::InitSections() {
225  SwitchSection(getContext().getObjectFileInfo()->getTextSection());
226}
227
228void MCStreamer::AssignSection(MCSymbol *Symbol, const MCSection *Section) {
229  if (Section)
230    Symbol->setSection(*Section);
231  else
232    Symbol->setUndefined();
233
234  // As we emit symbols into a section, track the order so that they can
235  // be sorted upon later. Zero is reserved to mean 'unemitted'.
236  SymbolOrdering[Symbol] = 1 + SymbolOrdering.size();
237}
238
239void MCStreamer::EmitLabel(MCSymbol *Symbol) {
240  assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
241  assert(getCurrentSection().first && "Cannot emit before setting section!");
242  AssignSection(Symbol, getCurrentSection().first);
243
244  MCTargetStreamer *TS = getTargetStreamer();
245  if (TS)
246    TS->emitLabel(Symbol);
247}
248
249void MCStreamer::EmitCompactUnwindEncoding(uint32_t CompactUnwindEncoding) {
250  EnsureValidDwarfFrame();
251  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
252  CurFrame->CompactUnwindEncoding = CompactUnwindEncoding;
253}
254
255void MCStreamer::EmitCFISections(bool EH, bool Debug) {
256  assert(EH || Debug);
257}
258
259void MCStreamer::EmitCFIStartProc(bool IsSimple) {
260  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
261  if (CurFrame && !CurFrame->End)
262    report_fatal_error("Starting a frame before finishing the previous one!");
263
264  MCDwarfFrameInfo Frame;
265  Frame.IsSimple = IsSimple;
266  EmitCFIStartProcImpl(Frame);
267
268  DwarfFrameInfos.push_back(Frame);
269}
270
271void MCStreamer::EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) {
272}
273
274void MCStreamer::EmitCFIEndProc() {
275  EnsureValidDwarfFrame();
276  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
277  EmitCFIEndProcImpl(*CurFrame);
278}
279
280void MCStreamer::EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
281  // Put a dummy non-null value in Frame.End to mark that this frame has been
282  // closed.
283  Frame.End = (MCSymbol *) 1;
284}
285
286MCSymbol *MCStreamer::EmitCFICommon() {
287  EnsureValidDwarfFrame();
288  MCSymbol *Label = getContext().CreateTempSymbol();
289  EmitLabel(Label);
290  return Label;
291}
292
293void MCStreamer::EmitCFIDefCfa(int64_t Register, int64_t Offset) {
294  MCSymbol *Label = EmitCFICommon();
295  MCCFIInstruction Instruction =
296    MCCFIInstruction::createDefCfa(Label, Register, Offset);
297  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
298  CurFrame->Instructions.push_back(Instruction);
299}
300
301void MCStreamer::EmitCFIDefCfaOffset(int64_t Offset) {
302  MCSymbol *Label = EmitCFICommon();
303  MCCFIInstruction Instruction =
304    MCCFIInstruction::createDefCfaOffset(Label, Offset);
305  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
306  CurFrame->Instructions.push_back(Instruction);
307}
308
309void MCStreamer::EmitCFIAdjustCfaOffset(int64_t Adjustment) {
310  MCSymbol *Label = EmitCFICommon();
311  MCCFIInstruction Instruction =
312    MCCFIInstruction::createAdjustCfaOffset(Label, Adjustment);
313  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
314  CurFrame->Instructions.push_back(Instruction);
315}
316
317void MCStreamer::EmitCFIDefCfaRegister(int64_t Register) {
318  MCSymbol *Label = EmitCFICommon();
319  MCCFIInstruction Instruction =
320    MCCFIInstruction::createDefCfaRegister(Label, Register);
321  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
322  CurFrame->Instructions.push_back(Instruction);
323}
324
325void MCStreamer::EmitCFIOffset(int64_t Register, int64_t Offset) {
326  MCSymbol *Label = EmitCFICommon();
327  MCCFIInstruction Instruction =
328    MCCFIInstruction::createOffset(Label, Register, Offset);
329  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
330  CurFrame->Instructions.push_back(Instruction);
331}
332
333void MCStreamer::EmitCFIRelOffset(int64_t Register, int64_t Offset) {
334  MCSymbol *Label = EmitCFICommon();
335  MCCFIInstruction Instruction =
336    MCCFIInstruction::createRelOffset(Label, Register, Offset);
337  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
338  CurFrame->Instructions.push_back(Instruction);
339}
340
341void MCStreamer::EmitCFIPersonality(const MCSymbol *Sym,
342                                    unsigned Encoding) {
343  EnsureValidDwarfFrame();
344  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
345  CurFrame->Personality = Sym;
346  CurFrame->PersonalityEncoding = Encoding;
347}
348
349void MCStreamer::EmitCFILsda(const MCSymbol *Sym, unsigned Encoding) {
350  EnsureValidDwarfFrame();
351  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
352  CurFrame->Lsda = Sym;
353  CurFrame->LsdaEncoding = Encoding;
354}
355
356void MCStreamer::EmitCFIRememberState() {
357  MCSymbol *Label = EmitCFICommon();
358  MCCFIInstruction Instruction = MCCFIInstruction::createRememberState(Label);
359  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
360  CurFrame->Instructions.push_back(Instruction);
361}
362
363void MCStreamer::EmitCFIRestoreState() {
364  // FIXME: Error if there is no matching cfi_remember_state.
365  MCSymbol *Label = EmitCFICommon();
366  MCCFIInstruction Instruction = MCCFIInstruction::createRestoreState(Label);
367  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
368  CurFrame->Instructions.push_back(Instruction);
369}
370
371void MCStreamer::EmitCFISameValue(int64_t Register) {
372  MCSymbol *Label = EmitCFICommon();
373  MCCFIInstruction Instruction =
374    MCCFIInstruction::createSameValue(Label, Register);
375  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
376  CurFrame->Instructions.push_back(Instruction);
377}
378
379void MCStreamer::EmitCFIRestore(int64_t Register) {
380  MCSymbol *Label = EmitCFICommon();
381  MCCFIInstruction Instruction =
382    MCCFIInstruction::createRestore(Label, Register);
383  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
384  CurFrame->Instructions.push_back(Instruction);
385}
386
387void MCStreamer::EmitCFIEscape(StringRef Values) {
388  MCSymbol *Label = EmitCFICommon();
389  MCCFIInstruction Instruction = MCCFIInstruction::createEscape(Label, Values);
390  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
391  CurFrame->Instructions.push_back(Instruction);
392}
393
394void MCStreamer::EmitCFISignalFrame() {
395  EnsureValidDwarfFrame();
396  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
397  CurFrame->IsSignalFrame = true;
398}
399
400void MCStreamer::EmitCFIUndefined(int64_t Register) {
401  MCSymbol *Label = EmitCFICommon();
402  MCCFIInstruction Instruction =
403    MCCFIInstruction::createUndefined(Label, Register);
404  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
405  CurFrame->Instructions.push_back(Instruction);
406}
407
408void MCStreamer::EmitCFIRegister(int64_t Register1, int64_t Register2) {
409  MCSymbol *Label = EmitCFICommon();
410  MCCFIInstruction Instruction =
411    MCCFIInstruction::createRegister(Label, Register1, Register2);
412  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
413  CurFrame->Instructions.push_back(Instruction);
414}
415
416void MCStreamer::EmitCFIWindowSave() {
417  MCSymbol *Label = EmitCFICommon();
418  MCCFIInstruction Instruction =
419    MCCFIInstruction::createWindowSave(Label);
420  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
421  CurFrame->Instructions.push_back(Instruction);
422}
423
424void MCStreamer::EnsureValidWinFrameInfo() {
425  if (!CurrentWinFrameInfo || CurrentWinFrameInfo->End)
426    report_fatal_error("No open Win64 EH frame function!");
427}
428
429void MCStreamer::EmitWinCFIStartProc(const MCSymbol *Symbol) {
430  if (CurrentWinFrameInfo && !CurrentWinFrameInfo->End)
431    report_fatal_error("Starting a function before ending the previous one!");
432  MCWinFrameInfo *Frame = new MCWinFrameInfo;
433  Frame->Begin = getContext().CreateTempSymbol();
434  Frame->Function = Symbol;
435  EmitLabel(Frame->Begin);
436  WinFrameInfos.push_back(Frame);
437  CurrentWinFrameInfo = WinFrameInfos.back();
438}
439
440void MCStreamer::EmitWinCFIEndProc() {
441  EnsureValidWinFrameInfo();
442  if (CurrentWinFrameInfo->ChainedParent)
443    report_fatal_error("Not all chained regions terminated!");
444  CurrentWinFrameInfo->End = getContext().CreateTempSymbol();
445  EmitLabel(CurrentWinFrameInfo->End);
446}
447
448void MCStreamer::EmitWinCFIStartChained() {
449  EnsureValidWinFrameInfo();
450  MCWinFrameInfo *Frame = new MCWinFrameInfo;
451  Frame->Begin = getContext().CreateTempSymbol();
452  Frame->Function = CurrentWinFrameInfo->Function;
453  Frame->ChainedParent = CurrentWinFrameInfo;
454  EmitLabel(Frame->Begin);
455  WinFrameInfos.push_back(Frame);
456  CurrentWinFrameInfo = WinFrameInfos.back();
457}
458
459void MCStreamer::EmitWinCFIEndChained() {
460  EnsureValidWinFrameInfo();
461  if (!CurrentWinFrameInfo->ChainedParent)
462    report_fatal_error("End of a chained region outside a chained region!");
463  CurrentWinFrameInfo->End = getContext().CreateTempSymbol();
464  EmitLabel(CurrentWinFrameInfo->End);
465  CurrentWinFrameInfo = CurrentWinFrameInfo->ChainedParent;
466}
467
468void MCStreamer::EmitWinEHHandler(const MCSymbol *Sym, bool Unwind,
469                                  bool Except) {
470  EnsureValidWinFrameInfo();
471  if (CurrentWinFrameInfo->ChainedParent)
472    report_fatal_error("Chained unwind areas can't have handlers!");
473  CurrentWinFrameInfo->ExceptionHandler = Sym;
474  if (!Except && !Unwind)
475    report_fatal_error("Don't know what kind of handler this is!");
476  if (Unwind)
477    CurrentWinFrameInfo->HandlesUnwind = true;
478  if (Except)
479    CurrentWinFrameInfo->HandlesExceptions = true;
480}
481
482void MCStreamer::EmitWinEHHandlerData() {
483  EnsureValidWinFrameInfo();
484  if (CurrentWinFrameInfo->ChainedParent)
485    report_fatal_error("Chained unwind areas can't have handlers!");
486}
487
488void MCStreamer::EmitWinCFIPushReg(unsigned Register) {
489  EnsureValidWinFrameInfo();
490
491  MCSymbol *Label = getContext().CreateTempSymbol();
492  EmitLabel(Label);
493
494  WinEH::Instruction Inst = Win64EH::Instruction::PushNonVol(Label, Register);
495  CurrentWinFrameInfo->Instructions.push_back(Inst);
496}
497
498void MCStreamer::EmitWinCFISetFrame(unsigned Register, unsigned Offset) {
499  EnsureValidWinFrameInfo();
500  if (CurrentWinFrameInfo->LastFrameInst >= 0)
501    report_fatal_error("Frame register and offset already specified!");
502  if (Offset & 0x0F)
503    report_fatal_error("Misaligned frame pointer offset!");
504  if (Offset > 240)
505    report_fatal_error("Frame offset must be less than or equal to 240!");
506
507  MCSymbol *Label = getContext().CreateTempSymbol();
508  EmitLabel(Label);
509
510  WinEH::Instruction Inst =
511      Win64EH::Instruction::SetFPReg(Label, Register, Offset);
512  CurrentWinFrameInfo->LastFrameInst = CurrentWinFrameInfo->Instructions.size();
513  CurrentWinFrameInfo->Instructions.push_back(Inst);
514}
515
516void MCStreamer::EmitWinCFIAllocStack(unsigned Size) {
517  EnsureValidWinFrameInfo();
518  if (Size == 0)
519    report_fatal_error("Allocation size must be non-zero!");
520  if (Size & 7)
521    report_fatal_error("Misaligned stack allocation!");
522
523  MCSymbol *Label = getContext().CreateTempSymbol();
524  EmitLabel(Label);
525
526  WinEH::Instruction Inst = Win64EH::Instruction::Alloc(Label, Size);
527  CurrentWinFrameInfo->Instructions.push_back(Inst);
528}
529
530void MCStreamer::EmitWinCFISaveReg(unsigned Register, unsigned Offset) {
531  EnsureValidWinFrameInfo();
532  if (Offset & 7)
533    report_fatal_error("Misaligned saved register offset!");
534
535  MCSymbol *Label = getContext().CreateTempSymbol();
536  EmitLabel(Label);
537
538  WinEH::Instruction Inst =
539      Win64EH::Instruction::SaveNonVol(Label, Register, Offset);
540  CurrentWinFrameInfo->Instructions.push_back(Inst);
541}
542
543void MCStreamer::EmitWinCFISaveXMM(unsigned Register, unsigned Offset) {
544  EnsureValidWinFrameInfo();
545  if (Offset & 0x0F)
546    report_fatal_error("Misaligned saved vector register offset!");
547
548  MCSymbol *Label = getContext().CreateTempSymbol();
549  EmitLabel(Label);
550
551  WinEH::Instruction Inst =
552      Win64EH::Instruction::SaveXMM(Label, Register, Offset);
553  CurrentWinFrameInfo->Instructions.push_back(Inst);
554}
555
556void MCStreamer::EmitWinCFIPushFrame(bool Code) {
557  EnsureValidWinFrameInfo();
558  if (CurrentWinFrameInfo->Instructions.size() > 0)
559    report_fatal_error("If present, PushMachFrame must be the first UOP");
560
561  MCSymbol *Label = getContext().CreateTempSymbol();
562  EmitLabel(Label);
563
564  WinEH::Instruction Inst = Win64EH::Instruction::PushMachFrame(Label, Code);
565  CurrentWinFrameInfo->Instructions.push_back(Inst);
566}
567
568void MCStreamer::EmitWinCFIEndProlog() {
569  EnsureValidWinFrameInfo();
570  CurrentWinFrameInfo->PrologEnd = getContext().CreateTempSymbol();
571  EmitLabel(CurrentWinFrameInfo->PrologEnd);
572}
573
574void MCStreamer::EmitCOFFSectionIndex(MCSymbol const *Symbol) {
575}
576
577void MCStreamer::EmitCOFFSecRel32(MCSymbol const *Symbol) {
578}
579
580/// EmitRawText - If this file is backed by an assembly streamer, this dumps
581/// the specified string in the output .s file.  This capability is
582/// indicated by the hasRawTextSupport() predicate.
583void MCStreamer::EmitRawTextImpl(StringRef String) {
584  errs() << "EmitRawText called on an MCStreamer that doesn't support it, "
585  " something must not be fully mc'ized\n";
586  abort();
587}
588
589void MCStreamer::EmitRawText(const Twine &T) {
590  SmallString<128> Str;
591  EmitRawTextImpl(T.toStringRef(Str));
592}
593
594void MCStreamer::EmitWindowsUnwindTables() {
595  if (!getNumWinFrameInfos())
596    return;
597
598  MCWin64EHUnwindEmitter::Emit(*this);
599}
600
601void MCStreamer::Finish() {
602  if (!DwarfFrameInfos.empty() && !DwarfFrameInfos.back().End)
603    report_fatal_error("Unfinished frame!");
604
605  MCTargetStreamer *TS = getTargetStreamer();
606  if (TS)
607    TS->finish();
608
609  FinishImpl();
610}
611
612void MCStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
613  visitUsedExpr(*Value);
614  Symbol->setVariableValue(Value);
615
616  MCTargetStreamer *TS = getTargetStreamer();
617  if (TS)
618    TS->emitAssignment(Symbol, Value);
619}
620
621void MCStreamer::visitUsedSymbol(const MCSymbol &Sym) {
622}
623
624void MCStreamer::visitUsedExpr(const MCExpr &Expr) {
625  switch (Expr.getKind()) {
626  case MCExpr::Target:
627    cast<MCTargetExpr>(Expr).visitUsedExpr(*this);
628    break;
629
630  case MCExpr::Constant:
631    break;
632
633  case MCExpr::Binary: {
634    const MCBinaryExpr &BE = cast<MCBinaryExpr>(Expr);
635    visitUsedExpr(*BE.getLHS());
636    visitUsedExpr(*BE.getRHS());
637    break;
638  }
639
640  case MCExpr::SymbolRef:
641    visitUsedSymbol(cast<MCSymbolRefExpr>(Expr).getSymbol());
642    break;
643
644  case MCExpr::Unary:
645    visitUsedExpr(*cast<MCUnaryExpr>(Expr).getSubExpr());
646    break;
647  }
648}
649
650void MCStreamer::EmitInstruction(const MCInst &Inst,
651                                 const MCSubtargetInfo &STI) {
652  // Scan for values.
653  for (unsigned i = Inst.getNumOperands(); i--;)
654    if (Inst.getOperand(i).isExpr())
655      visitUsedExpr(*Inst.getOperand(i).getExpr());
656}
657
658void MCStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {}
659void MCStreamer::EmitThumbFunc(MCSymbol *Func) {}
660void MCStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
661void MCStreamer::BeginCOFFSymbolDef(const MCSymbol *Symbol) {}
662void MCStreamer::EndCOFFSymbolDef() {}
663void MCStreamer::EmitFileDirective(StringRef Filename) {}
664void MCStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {}
665void MCStreamer::EmitCOFFSymbolType(int Type) {}
666void MCStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
667void MCStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
668                                       unsigned ByteAlignment) {}
669void MCStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
670                                uint64_t Size, unsigned ByteAlignment) {}
671void MCStreamer::ChangeSection(const MCSection *, const MCExpr *) {}
672void MCStreamer::EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {}
673void MCStreamer::EmitBytes(StringRef Data) {}
674void MCStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
675                               const SMLoc &Loc) {
676  visitUsedExpr(*Value);
677}
678void MCStreamer::EmitULEB128Value(const MCExpr *Value) {}
679void MCStreamer::EmitSLEB128Value(const MCExpr *Value) {}
680void MCStreamer::EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
681                                      unsigned ValueSize,
682                                      unsigned MaxBytesToEmit) {}
683void MCStreamer::EmitCodeAlignment(unsigned ByteAlignment,
684                                   unsigned MaxBytesToEmit) {}
685bool MCStreamer::EmitValueToOffset(const MCExpr *Offset, unsigned char Value) {
686  return false;
687}
688void MCStreamer::EmitBundleAlignMode(unsigned AlignPow2) {}
689void MCStreamer::EmitBundleLock(bool AlignToEnd) {}
690void MCStreamer::FinishImpl() {}
691void MCStreamer::EmitBundleUnlock() {}
692