MCStreamer.cpp revision 5fbe5e783ee0c5ae27c17490a752d7e603e84ed2 
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/MCAsmInfo.h"
11#include "llvm/MC/MCContext.h"
12#include "llvm/MC/MCStreamer.h"
13#include "llvm/MC/MCExpr.h"
14#include "llvm/MC/MCObjectWriter.h"
15#include "llvm/MC/MCSymbol.h"
16#include "llvm/Support/ErrorHandling.h"
17#include "llvm/Support/raw_ostream.h"
18#include "llvm/ADT/SmallString.h"
19#include "llvm/ADT/Twine.h"
20#include <cstdlib>
21using namespace llvm;
22
23MCStreamer::MCStreamer(MCContext &Ctx) : Context(Ctx), EmitEHFrame(true),
24                                         EmitDebugFrame(false),
25                                         CurrentW64UnwindInfo(0) {
26  const MCSection *section = NULL;
27  SectionStack.push_back(std::make_pair(section, section));
28}
29
30MCStreamer::~MCStreamer() {
31  for (unsigned i = 0; i < getNumW64UnwindInfos(); ++i)
32    delete W64UnwindInfos[i];
33}
34
35const MCExpr *MCStreamer::BuildSymbolDiff(MCContext &Context,
36                                          const MCSymbol *A,
37                                          const MCSymbol *B) {
38  MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None;
39  const MCExpr *ARef =
40    MCSymbolRefExpr::Create(A, Variant, Context);
41  const MCExpr *BRef =
42    MCSymbolRefExpr::Create(B, Variant, Context);
43  const MCExpr *AddrDelta =
44    MCBinaryExpr::Create(MCBinaryExpr::Sub, ARef, BRef, Context);
45  return AddrDelta;
46}
47
48const MCExpr *MCStreamer::ForceExpAbs(const MCExpr* Expr) {
49  if (Context.getAsmInfo().hasAggressiveSymbolFolding() ||
50      isa<MCSymbolRefExpr>(Expr))
51    return Expr;
52
53  MCSymbol *ABS = Context.CreateTempSymbol();
54  EmitAssignment(ABS, Expr);
55  return MCSymbolRefExpr::Create(ABS, Context);
56}
57
58raw_ostream &MCStreamer::GetCommentOS() {
59  // By default, discard comments.
60  return nulls();
61}
62
63void MCStreamer::EmitDwarfSetLineAddr(int64_t LineDelta,
64                                      const MCSymbol *Label, int PointerSize) {
65  // emit the sequence to set the address
66  EmitIntValue(dwarf::DW_LNS_extended_op, 1);
67  EmitULEB128IntValue(PointerSize + 1);
68  EmitIntValue(dwarf::DW_LNE_set_address, 1);
69  EmitSymbolValue(Label, PointerSize);
70
71  // emit the sequence for the LineDelta (from 1) and a zero address delta.
72  MCDwarfLineAddr::Emit(this, LineDelta, 0);
73}
74
75/// EmitIntValue - Special case of EmitValue that avoids the client having to
76/// pass in a MCExpr for constant integers.
77void MCStreamer::EmitIntValue(uint64_t Value, unsigned Size,
78                              unsigned AddrSpace) {
79  assert(Size <= 8 && "Invalid size");
80  assert((isUIntN(8 * Size, Value) || isIntN(8 * Size, Value)) &&
81         "Invalid size");
82  char buf[8];
83  const bool isLittleEndian = Context.getAsmInfo().isLittleEndian();
84  for (unsigned i = 0; i != Size; ++i) {
85    unsigned index = isLittleEndian ? i : (Size - i - 1);
86    buf[i] = uint8_t(Value >> (index * 8));
87  }
88  EmitBytes(StringRef(buf, Size), AddrSpace);
89}
90
91/// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
92/// client having to pass in a MCExpr for constant integers.
93void MCStreamer::EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace) {
94  SmallString<32> Tmp;
95  raw_svector_ostream OSE(Tmp);
96  MCObjectWriter::EncodeULEB128(Value, OSE);
97  EmitBytes(OSE.str(), AddrSpace);
98}
99
100/// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
101/// client having to pass in a MCExpr for constant integers.
102void MCStreamer::EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace) {
103  SmallString<32> Tmp;
104  raw_svector_ostream OSE(Tmp);
105  MCObjectWriter::EncodeSLEB128(Value, OSE);
106  EmitBytes(OSE.str(), AddrSpace);
107}
108
109void MCStreamer::EmitAbsValue(const MCExpr *Value, unsigned Size,
110                              unsigned AddrSpace) {
111  const MCExpr *ABS = ForceExpAbs(Value);
112  EmitValue(ABS, Size, AddrSpace);
113}
114
115
116void MCStreamer::EmitValue(const MCExpr *Value, unsigned Size,
117                           unsigned AddrSpace) {
118  EmitValueImpl(Value, Size, AddrSpace);
119}
120
121void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
122                                  unsigned AddrSpace) {
123  EmitValueImpl(MCSymbolRefExpr::Create(Sym, getContext()), Size,
124                AddrSpace);
125}
126
127void MCStreamer::EmitGPRel32Value(const MCExpr *Value) {
128  report_fatal_error("unsupported directive in streamer");
129}
130
131/// EmitFill - Emit NumBytes bytes worth of the value specified by
132/// FillValue.  This implements directives such as '.space'.
133void MCStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
134                          unsigned AddrSpace) {
135  const MCExpr *E = MCConstantExpr::Create(FillValue, getContext());
136  for (uint64_t i = 0, e = NumBytes; i != e; ++i)
137    EmitValue(E, 1, AddrSpace);
138}
139
140bool MCStreamer::EmitDwarfFileDirective(unsigned FileNo,
141                                        StringRef Filename) {
142  return getContext().GetDwarfFile(Filename, FileNo) == 0;
143}
144
145void MCStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
146                                       unsigned Column, unsigned Flags,
147                                       unsigned Isa,
148                                       unsigned Discriminator,
149                                       StringRef FileName) {
150  getContext().setCurrentDwarfLoc(FileNo, Line, Column, Flags, Isa,
151                                  Discriminator);
152}
153
154MCDwarfFrameInfo *MCStreamer::getCurrentFrameInfo() {
155  if (FrameInfos.empty())
156    return NULL;
157  return &FrameInfos.back();
158}
159
160void MCStreamer::EnsureValidFrame() {
161  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
162  if (!CurFrame || CurFrame->End)
163    report_fatal_error("No open frame");
164}
165
166void MCStreamer::EmitEHSymAttributes(const MCSymbol *Symbol,
167                                     MCSymbol *EHSymbol) {
168}
169
170void MCStreamer::EmitLabel(MCSymbol *Symbol) {
171  assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
172  assert(getCurrentSection() && "Cannot emit before setting section!");
173  Symbol->setSection(*getCurrentSection());
174  LastSymbol = Symbol;
175}
176
177void MCStreamer::EmitCompactUnwindEncoding(uint32_t CompactUnwindEncoding) {
178  EnsureValidFrame();
179  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
180  CurFrame->CompactUnwindEncoding = CompactUnwindEncoding;
181}
182
183void MCStreamer::EmitCFISections(bool EH, bool Debug) {
184  assert(EH || Debug);
185  EmitEHFrame = EH;
186  EmitDebugFrame = Debug;
187}
188
189void MCStreamer::EmitCFIStartProc() {
190  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
191  if (CurFrame && !CurFrame->End)
192    report_fatal_error("Starting a frame before finishing the previous one!");
193
194  MCDwarfFrameInfo Frame;
195  Frame.Function = LastSymbol;
196
197  // If the function is externally visible, we need to create a local
198  // symbol to avoid relocations.
199  StringRef Prefix = getContext().getAsmInfo().getPrivateGlobalPrefix();
200  if (LastSymbol && LastSymbol->getName().startswith(Prefix)) {
201    Frame.Begin = LastSymbol;
202  } else {
203    Frame.Begin = getContext().CreateTempSymbol();
204    EmitLabel(Frame.Begin);
205  }
206
207  FrameInfos.push_back(Frame);
208}
209
210void MCStreamer::EmitCFIEndProc() {
211  EnsureValidFrame();
212  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
213  CurFrame->End = getContext().CreateTempSymbol();
214  EmitLabel(CurFrame->End);
215}
216
217void MCStreamer::EmitCFIDefCfa(int64_t Register, int64_t Offset) {
218  EnsureValidFrame();
219  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
220  MCSymbol *Label = getContext().CreateTempSymbol();
221  EmitLabel(Label);
222  MachineLocation Dest(MachineLocation::VirtualFP);
223  MachineLocation Source(Register, -Offset);
224  MCCFIInstruction Instruction(Label, Dest, Source);
225  CurFrame->Instructions.push_back(Instruction);
226}
227
228void MCStreamer::EmitCFIDefCfaOffset(int64_t Offset) {
229  EnsureValidFrame();
230  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
231  MCSymbol *Label = getContext().CreateTempSymbol();
232  EmitLabel(Label);
233  MachineLocation Dest(MachineLocation::VirtualFP);
234  MachineLocation Source(MachineLocation::VirtualFP, -Offset);
235  MCCFIInstruction Instruction(Label, Dest, Source);
236  CurFrame->Instructions.push_back(Instruction);
237}
238
239void MCStreamer::EmitCFIAdjustCfaOffset(int64_t Adjustment) {
240  EnsureValidFrame();
241  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
242  MCSymbol *Label = getContext().CreateTempSymbol();
243  EmitLabel(Label);
244  MachineLocation Dest(MachineLocation::VirtualFP);
245  MachineLocation Source(MachineLocation::VirtualFP, Adjustment);
246  MCCFIInstruction Instruction(MCCFIInstruction::RelMove, Label, Dest, Source);
247  CurFrame->Instructions.push_back(Instruction);
248}
249
250void MCStreamer::EmitCFIDefCfaRegister(int64_t Register) {
251  EnsureValidFrame();
252  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
253  MCSymbol *Label = getContext().CreateTempSymbol();
254  EmitLabel(Label);
255  MachineLocation Dest(Register);
256  MachineLocation Source(MachineLocation::VirtualFP);
257  MCCFIInstruction Instruction(Label, Dest, Source);
258  CurFrame->Instructions.push_back(Instruction);
259}
260
261void MCStreamer::EmitCFIOffset(int64_t Register, int64_t Offset) {
262  EnsureValidFrame();
263  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
264  MCSymbol *Label = getContext().CreateTempSymbol();
265  EmitLabel(Label);
266  MachineLocation Dest(Register, Offset);
267  MachineLocation Source(Register, Offset);
268  MCCFIInstruction Instruction(Label, Dest, Source);
269  CurFrame->Instructions.push_back(Instruction);
270}
271
272void MCStreamer::EmitCFIRelOffset(int64_t Register, int64_t Offset) {
273  EnsureValidFrame();
274  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
275  MCSymbol *Label = getContext().CreateTempSymbol();
276  EmitLabel(Label);
277  MachineLocation Dest(Register, Offset);
278  MachineLocation Source(Register, Offset);
279  MCCFIInstruction Instruction(MCCFIInstruction::RelMove, Label, Dest, Source);
280  CurFrame->Instructions.push_back(Instruction);
281}
282
283void MCStreamer::EmitCFIPersonality(const MCSymbol *Sym,
284                                    unsigned Encoding) {
285  EnsureValidFrame();
286  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
287  CurFrame->Personality = Sym;
288  CurFrame->PersonalityEncoding = Encoding;
289}
290
291void MCStreamer::EmitCFILsda(const MCSymbol *Sym, unsigned Encoding) {
292  EnsureValidFrame();
293  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
294  CurFrame->Lsda = Sym;
295  CurFrame->LsdaEncoding = Encoding;
296}
297
298void MCStreamer::EmitCFIRememberState() {
299  EnsureValidFrame();
300  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
301  MCSymbol *Label = getContext().CreateTempSymbol();
302  EmitLabel(Label);
303  MCCFIInstruction Instruction(MCCFIInstruction::Remember, Label);
304  CurFrame->Instructions.push_back(Instruction);
305}
306
307void MCStreamer::EmitCFIRestoreState() {
308  // FIXME: Error if there is no matching cfi_remember_state.
309  EnsureValidFrame();
310  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
311  MCSymbol *Label = getContext().CreateTempSymbol();
312  EmitLabel(Label);
313  MCCFIInstruction Instruction(MCCFIInstruction::Restore, Label);
314  CurFrame->Instructions.push_back(Instruction);
315}
316
317void MCStreamer::EmitCFISameValue(int64_t Register) {
318  EnsureValidFrame();
319  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
320  MCSymbol *Label = getContext().CreateTempSymbol();
321  EmitLabel(Label);
322  MCCFIInstruction Instruction(MCCFIInstruction::SameValue, Label, Register);
323  CurFrame->Instructions.push_back(Instruction);
324}
325
326void MCStreamer::setCurrentW64UnwindInfo(MCWin64EHUnwindInfo *Frame) {
327  W64UnwindInfos.push_back(Frame);
328  CurrentW64UnwindInfo = W64UnwindInfos.back();
329}
330
331void MCStreamer::EnsureValidW64UnwindInfo() {
332  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
333  if (!CurFrame || CurFrame->End)
334    report_fatal_error("No open Win64 EH frame function!");
335}
336
337void MCStreamer::EmitWin64EHStartProc(const MCSymbol *Symbol) {
338  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
339  if (CurFrame && !CurFrame->End)
340    report_fatal_error("Starting a function before ending the previous one!");
341  MCWin64EHUnwindInfo *Frame = new MCWin64EHUnwindInfo;
342  Frame->Begin = getContext().CreateTempSymbol();
343  Frame->Function = Symbol;
344  EmitLabel(Frame->Begin);
345  setCurrentW64UnwindInfo(Frame);
346}
347
348void MCStreamer::EmitWin64EHEndProc() {
349  EnsureValidW64UnwindInfo();
350  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
351  if (CurFrame->ChainedParent)
352    report_fatal_error("Not all chained regions terminated!");
353  CurFrame->End = getContext().CreateTempSymbol();
354  EmitLabel(CurFrame->End);
355}
356
357void MCStreamer::EmitWin64EHStartChained() {
358  EnsureValidW64UnwindInfo();
359  MCWin64EHUnwindInfo *Frame = new MCWin64EHUnwindInfo;
360  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
361  Frame->Begin = getContext().CreateTempSymbol();
362  Frame->Function = CurFrame->Function;
363  Frame->ChainedParent = CurFrame;
364  EmitLabel(Frame->Begin);
365  setCurrentW64UnwindInfo(Frame);
366}
367
368void MCStreamer::EmitWin64EHEndChained() {
369  EnsureValidW64UnwindInfo();
370  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
371  if (!CurFrame->ChainedParent)
372    report_fatal_error("End of a chained region outside a chained region!");
373  CurFrame->End = getContext().CreateTempSymbol();
374  EmitLabel(CurFrame->End);
375  CurrentW64UnwindInfo = CurFrame->ChainedParent;
376}
377
378void MCStreamer::EmitWin64EHHandler(const MCSymbol *Sym, bool Unwind,
379                                    bool Except) {
380  EnsureValidW64UnwindInfo();
381  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
382  if (CurFrame->ChainedParent)
383    report_fatal_error("Chained unwind areas can't have handlers!");
384  CurFrame->ExceptionHandler = Sym;
385  if (!Except && !Unwind)
386    report_fatal_error("Don't know what kind of handler this is!");
387  if (Unwind)
388    CurFrame->HandlesUnwind = true;
389  if (Except)
390    CurFrame->HandlesExceptions = true;
391}
392
393void MCStreamer::EmitWin64EHHandlerData() {
394  EnsureValidW64UnwindInfo();
395  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
396  if (CurFrame->ChainedParent)
397    report_fatal_error("Chained unwind areas can't have handlers!");
398}
399
400void MCStreamer::EmitWin64EHPushReg(unsigned Register) {
401  EnsureValidW64UnwindInfo();
402  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
403  MCSymbol *Label = getContext().CreateTempSymbol();
404  MCWin64EHInstruction Inst(Win64EH::UOP_PushNonVol, Label, Register);
405  EmitLabel(Label);
406  CurFrame->Instructions.push_back(Inst);
407}
408
409void MCStreamer::EmitWin64EHSetFrame(unsigned Register, unsigned Offset) {
410  EnsureValidW64UnwindInfo();
411  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
412  if (CurFrame->LastFrameInst >= 0)
413    report_fatal_error("Frame register and offset already specified!");
414  if (Offset & 0x0F)
415    report_fatal_error("Misaligned frame pointer offset!");
416  MCWin64EHInstruction Inst(Win64EH::UOP_SetFPReg, NULL, Register, Offset);
417  CurFrame->LastFrameInst = CurFrame->Instructions.size();
418  CurFrame->Instructions.push_back(Inst);
419}
420
421void MCStreamer::EmitWin64EHAllocStack(unsigned Size) {
422  EnsureValidW64UnwindInfo();
423  if (Size & 7)
424    report_fatal_error("Misaligned stack allocation!");
425  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
426  MCSymbol *Label = getContext().CreateTempSymbol();
427  MCWin64EHInstruction Inst(Label, Size);
428  EmitLabel(Label);
429  CurFrame->Instructions.push_back(Inst);
430}
431
432void MCStreamer::EmitWin64EHSaveReg(unsigned Register, unsigned Offset) {
433  EnsureValidW64UnwindInfo();
434  if (Offset & 7)
435    report_fatal_error("Misaligned saved register offset!");
436  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
437  MCSymbol *Label = getContext().CreateTempSymbol();
438  MCWin64EHInstruction Inst(
439     Offset > 512*1024-8 ? Win64EH::UOP_SaveNonVolBig : Win64EH::UOP_SaveNonVol,
440                            Label, Register, Offset);
441  EmitLabel(Label);
442  CurFrame->Instructions.push_back(Inst);
443}
444
445void MCStreamer::EmitWin64EHSaveXMM(unsigned Register, unsigned Offset) {
446  EnsureValidW64UnwindInfo();
447  if (Offset & 0x0F)
448    report_fatal_error("Misaligned saved vector register offset!");
449  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
450  MCSymbol *Label = getContext().CreateTempSymbol();
451  MCWin64EHInstruction Inst(
452    Offset > 512*1024-16 ? Win64EH::UOP_SaveXMM128Big : Win64EH::UOP_SaveXMM128,
453                            Label, Register, Offset);
454  EmitLabel(Label);
455  CurFrame->Instructions.push_back(Inst);
456}
457
458void MCStreamer::EmitWin64EHPushFrame(bool Code) {
459  EnsureValidW64UnwindInfo();
460  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
461  if (CurFrame->Instructions.size() > 0)
462    report_fatal_error("If present, PushMachFrame must be the first UOP");
463  MCSymbol *Label = getContext().CreateTempSymbol();
464  MCWin64EHInstruction Inst(Win64EH::UOP_PushMachFrame, Label, Code);
465  EmitLabel(Label);
466  CurFrame->Instructions.push_back(Inst);
467}
468
469void MCStreamer::EmitWin64EHEndProlog() {
470  EnsureValidW64UnwindInfo();
471  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
472  CurFrame->PrologEnd = getContext().CreateTempSymbol();
473  EmitLabel(CurFrame->PrologEnd);
474}
475
476void MCStreamer::EmitFnStart() {
477  errs() << "Not implemented yet\n";
478  abort();
479}
480
481void MCStreamer::EmitFnEnd() {
482  errs() << "Not implemented yet\n";
483  abort();
484}
485
486void MCStreamer::EmitCantUnwind() {
487  errs() << "Not implemented yet\n";
488  abort();
489}
490
491void MCStreamer::EmitHandlerData() {
492  errs() << "Not implemented yet\n";
493  abort();
494}
495
496void MCStreamer::EmitPersonality(const MCSymbol *Personality) {
497  errs() << "Not implemented yet\n";
498  abort();
499}
500
501void MCStreamer::EmitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset) {
502  errs() << "Not implemented yet\n";
503  abort();
504}
505
506void MCStreamer::EmitPad(int64_t Offset) {
507  errs() << "Not implemented yet\n";
508  abort();
509}
510
511void MCStreamer::EmitRegSave(const SmallVectorImpl<unsigned> &RegList, bool) {
512  errs() << "Not implemented yet\n";
513  abort();
514}
515
516/// EmitRawText - If this file is backed by an assembly streamer, this dumps
517/// the specified string in the output .s file.  This capability is
518/// indicated by the hasRawTextSupport() predicate.
519void MCStreamer::EmitRawText(StringRef String) {
520  errs() << "EmitRawText called on an MCStreamer that doesn't support it, "
521  " something must not be fully mc'ized\n";
522  abort();
523}
524
525void MCStreamer::EmitRawText(const Twine &T) {
526  SmallString<128> Str;
527  T.toVector(Str);
528  EmitRawText(Str.str());
529}
530
531void MCStreamer::EmitFrames(bool usingCFI) {
532  if (!getNumFrameInfos())
533    return;
534
535  if (EmitEHFrame)
536    MCDwarfFrameEmitter::Emit(*this, usingCFI, true);
537
538  if (EmitDebugFrame)
539    MCDwarfFrameEmitter::Emit(*this, usingCFI, false);
540}
541
542void MCStreamer::EmitW64Tables() {
543  if (!getNumW64UnwindInfos())
544    return;
545
546  MCWin64EHUnwindEmitter::Emit(*this);
547}
548