MCStreamer.cpp revision c4cbf9b6aa95cf861a5a80bfccf615ff5c53e4ef 
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  // FIXME: Endianness assumption.
84  for (unsigned i = 0; i != Size; ++i)
85    buf[i] = uint8_t(Value >> (i * 8));
86  EmitBytes(StringRef(buf, Size), AddrSpace);
87}
88
89/// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
90/// client having to pass in a MCExpr for constant integers.
91void MCStreamer::EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace) {
92  SmallString<32> Tmp;
93  raw_svector_ostream OSE(Tmp);
94  MCObjectWriter::EncodeULEB128(Value, OSE);
95  EmitBytes(OSE.str(), AddrSpace);
96}
97
98/// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
99/// client having to pass in a MCExpr for constant integers.
100void MCStreamer::EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace) {
101  SmallString<32> Tmp;
102  raw_svector_ostream OSE(Tmp);
103  MCObjectWriter::EncodeSLEB128(Value, OSE);
104  EmitBytes(OSE.str(), AddrSpace);
105}
106
107void MCStreamer::EmitAbsValue(const MCExpr *Value, unsigned Size,
108                              unsigned AddrSpace) {
109  const MCExpr *ABS = ForceExpAbs(Value);
110  EmitValue(ABS, Size, AddrSpace);
111}
112
113
114void MCStreamer::EmitValue(const MCExpr *Value, unsigned Size,
115                           unsigned AddrSpace) {
116  EmitValueImpl(Value, Size, AddrSpace);
117}
118
119void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
120                                  unsigned AddrSpace) {
121  EmitValueImpl(MCSymbolRefExpr::Create(Sym, getContext()), Size,
122                AddrSpace);
123}
124
125void MCStreamer::EmitGPRel32Value(const MCExpr *Value) {
126  report_fatal_error("unsupported directive in streamer");
127}
128
129/// EmitFill - Emit NumBytes bytes worth of the value specified by
130/// FillValue.  This implements directives such as '.space'.
131void MCStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
132                          unsigned AddrSpace) {
133  const MCExpr *E = MCConstantExpr::Create(FillValue, getContext());
134  for (uint64_t i = 0, e = NumBytes; i != e; ++i)
135    EmitValue(E, 1, AddrSpace);
136}
137
138bool MCStreamer::EmitDwarfFileDirective(unsigned FileNo,
139                                        StringRef Filename) {
140  return getContext().GetDwarfFile(Filename, FileNo) == 0;
141}
142
143void MCStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
144                                       unsigned Column, unsigned Flags,
145                                       unsigned Isa,
146                                       unsigned Discriminator,
147                                       StringRef FileName) {
148  getContext().setCurrentDwarfLoc(FileNo, Line, Column, Flags, Isa,
149                                  Discriminator);
150}
151
152MCDwarfFrameInfo *MCStreamer::getCurrentFrameInfo() {
153  if (FrameInfos.empty())
154    return NULL;
155  return &FrameInfos.back();
156}
157
158void MCStreamer::EnsureValidFrame() {
159  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
160  if (!CurFrame || CurFrame->End)
161    report_fatal_error("No open frame");
162}
163
164void MCStreamer::EmitEHSymAttributes(const MCSymbol *Symbol,
165                                     MCSymbol *EHSymbol) {
166}
167
168void MCStreamer::EmitLabel(MCSymbol *Symbol) {
169  assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
170  assert(getCurrentSection() && "Cannot emit before setting section!");
171  Symbol->setSection(*getCurrentSection());
172
173  StringRef Prefix = getContext().getAsmInfo().getPrivateGlobalPrefix();
174  if (!Symbol->getName().startswith(Prefix))
175    LastNonPrivate = Symbol;
176}
177
178void MCStreamer::EmitCFISections(bool EH, bool Debug) {
179  assert(EH || Debug);
180  EmitEHFrame = EH;
181  EmitDebugFrame = Debug;
182}
183
184void MCStreamer::EmitCFIStartProc() {
185  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
186  if (CurFrame && !CurFrame->End)
187    report_fatal_error("Starting a frame before finishing the previous one!");
188  MCDwarfFrameInfo Frame;
189  Frame.Begin = getContext().CreateTempSymbol();
190  Frame.Function = LastNonPrivate;
191  EmitLabel(Frame.Begin);
192  FrameInfos.push_back(Frame);
193}
194
195void MCStreamer::EmitCFIEndProc() {
196  EnsureValidFrame();
197  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
198  CurFrame->End = getContext().CreateTempSymbol();
199  EmitLabel(CurFrame->End);
200}
201
202void MCStreamer::EmitCFIDefCfa(int64_t Register, int64_t Offset) {
203  EnsureValidFrame();
204  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
205  MCSymbol *Label = getContext().CreateTempSymbol();
206  EmitLabel(Label);
207  MachineLocation Dest(MachineLocation::VirtualFP);
208  MachineLocation Source(Register, -Offset);
209  MCCFIInstruction Instruction(Label, Dest, Source);
210  CurFrame->Instructions.push_back(Instruction);
211}
212
213void MCStreamer::EmitCFIDefCfaOffset(int64_t Offset) {
214  EnsureValidFrame();
215  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
216  MCSymbol *Label = getContext().CreateTempSymbol();
217  EmitLabel(Label);
218  MachineLocation Dest(MachineLocation::VirtualFP);
219  MachineLocation Source(MachineLocation::VirtualFP, -Offset);
220  MCCFIInstruction Instruction(Label, Dest, Source);
221  CurFrame->Instructions.push_back(Instruction);
222}
223
224void MCStreamer::EmitCFIAdjustCfaOffset(int64_t Adjustment) {
225  EnsureValidFrame();
226  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
227  MCSymbol *Label = getContext().CreateTempSymbol();
228  EmitLabel(Label);
229  MachineLocation Dest(MachineLocation::VirtualFP);
230  MachineLocation Source(MachineLocation::VirtualFP, Adjustment);
231  MCCFIInstruction Instruction(MCCFIInstruction::RelMove, Label, Dest, Source);
232  CurFrame->Instructions.push_back(Instruction);
233}
234
235void MCStreamer::EmitCFIDefCfaRegister(int64_t Register) {
236  EnsureValidFrame();
237  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
238  MCSymbol *Label = getContext().CreateTempSymbol();
239  EmitLabel(Label);
240  MachineLocation Dest(Register);
241  MachineLocation Source(MachineLocation::VirtualFP);
242  MCCFIInstruction Instruction(Label, Dest, Source);
243  CurFrame->Instructions.push_back(Instruction);
244}
245
246void MCStreamer::EmitCFIOffset(int64_t Register, int64_t Offset) {
247  EnsureValidFrame();
248  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
249  MCSymbol *Label = getContext().CreateTempSymbol();
250  EmitLabel(Label);
251  MachineLocation Dest(Register, Offset);
252  MachineLocation Source(Register, Offset);
253  MCCFIInstruction Instruction(Label, Dest, Source);
254  CurFrame->Instructions.push_back(Instruction);
255}
256
257void MCStreamer::EmitCFIRelOffset(int64_t Register, int64_t Offset) {
258  EnsureValidFrame();
259  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
260  MCSymbol *Label = getContext().CreateTempSymbol();
261  EmitLabel(Label);
262  MachineLocation Dest(Register, Offset);
263  MachineLocation Source(Register, Offset);
264  MCCFIInstruction Instruction(MCCFIInstruction::RelMove, Label, Dest, Source);
265  CurFrame->Instructions.push_back(Instruction);
266}
267
268void MCStreamer::EmitCFIPersonality(const MCSymbol *Sym,
269                                    unsigned Encoding) {
270  EnsureValidFrame();
271  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
272  CurFrame->Personality = Sym;
273  CurFrame->PersonalityEncoding = Encoding;
274}
275
276void MCStreamer::EmitCFILsda(const MCSymbol *Sym, unsigned Encoding) {
277  EnsureValidFrame();
278  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
279  CurFrame->Lsda = Sym;
280  CurFrame->LsdaEncoding = Encoding;
281}
282
283void MCStreamer::EmitCFIRememberState() {
284  EnsureValidFrame();
285  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
286  MCSymbol *Label = getContext().CreateTempSymbol();
287  EmitLabel(Label);
288  MCCFIInstruction Instruction(MCCFIInstruction::Remember, Label);
289  CurFrame->Instructions.push_back(Instruction);
290}
291
292void MCStreamer::EmitCFIRestoreState() {
293  // FIXME: Error if there is no matching cfi_remember_state.
294  EnsureValidFrame();
295  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
296  MCSymbol *Label = getContext().CreateTempSymbol();
297  EmitLabel(Label);
298  MCCFIInstruction Instruction(MCCFIInstruction::Restore, Label);
299  CurFrame->Instructions.push_back(Instruction);
300}
301
302void MCStreamer::EmitCFISameValue(int64_t Register) {
303  EnsureValidFrame();
304  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
305  MCSymbol *Label = getContext().CreateTempSymbol();
306  EmitLabel(Label);
307  MCCFIInstruction Instruction(MCCFIInstruction::SameValue, Label, Register);
308  CurFrame->Instructions.push_back(Instruction);
309}
310
311void MCStreamer::setCurrentW64UnwindInfo(MCWin64EHUnwindInfo *Frame) {
312  W64UnwindInfos.push_back(Frame);
313  CurrentW64UnwindInfo = W64UnwindInfos.back();
314}
315
316void MCStreamer::EnsureValidW64UnwindInfo() {
317  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
318  if (!CurFrame || CurFrame->End)
319    report_fatal_error("No open Win64 EH frame function!");
320}
321
322void MCStreamer::EmitWin64EHStartProc(const MCSymbol *Symbol) {
323  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
324  if (CurFrame && !CurFrame->End)
325    report_fatal_error("Starting a function before ending the previous one!");
326  MCWin64EHUnwindInfo *Frame = new MCWin64EHUnwindInfo;
327  Frame->Begin = getContext().CreateTempSymbol();
328  Frame->Function = Symbol;
329  EmitLabel(Frame->Begin);
330  setCurrentW64UnwindInfo(Frame);
331}
332
333void MCStreamer::EmitWin64EHEndProc() {
334  EnsureValidW64UnwindInfo();
335  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
336  if (CurFrame->ChainedParent)
337    report_fatal_error("Not all chained regions terminated!");
338  CurFrame->End = getContext().CreateTempSymbol();
339  EmitLabel(CurFrame->End);
340}
341
342void MCStreamer::EmitWin64EHStartChained() {
343  EnsureValidW64UnwindInfo();
344  MCWin64EHUnwindInfo *Frame = new MCWin64EHUnwindInfo;
345  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
346  Frame->Begin = getContext().CreateTempSymbol();
347  Frame->Function = CurFrame->Function;
348  Frame->ChainedParent = CurFrame;
349  EmitLabel(Frame->Begin);
350  setCurrentW64UnwindInfo(Frame);
351}
352
353void MCStreamer::EmitWin64EHEndChained() {
354  EnsureValidW64UnwindInfo();
355  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
356  if (!CurFrame->ChainedParent)
357    report_fatal_error("End of a chained region outside a chained region!");
358  CurFrame->End = getContext().CreateTempSymbol();
359  EmitLabel(CurFrame->End);
360  CurrentW64UnwindInfo = CurFrame->ChainedParent;
361}
362
363void MCStreamer::EmitWin64EHHandler(const MCSymbol *Sym, bool Unwind,
364                                    bool Except) {
365  EnsureValidW64UnwindInfo();
366  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
367  if (CurFrame->ChainedParent)
368    report_fatal_error("Chained unwind areas can't have handlers!");
369  CurFrame->ExceptionHandler = Sym;
370  if (!Except && !Unwind)
371    report_fatal_error("Don't know what kind of handler this is!");
372  if (Unwind)
373    CurFrame->HandlesUnwind = true;
374  if (Except)
375    CurFrame->HandlesExceptions = true;
376}
377
378void MCStreamer::EmitWin64EHHandlerData() {
379  EnsureValidW64UnwindInfo();
380  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
381  if (CurFrame->ChainedParent)
382    report_fatal_error("Chained unwind areas can't have handlers!");
383}
384
385void MCStreamer::EmitWin64EHPushReg(unsigned Register) {
386  EnsureValidW64UnwindInfo();
387  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
388  MCSymbol *Label = getContext().CreateTempSymbol();
389  MCWin64EHInstruction Inst(Win64EH::UOP_PushNonVol, Label, Register);
390  EmitLabel(Label);
391  CurFrame->Instructions.push_back(Inst);
392}
393
394void MCStreamer::EmitWin64EHSetFrame(unsigned Register, unsigned Offset) {
395  EnsureValidW64UnwindInfo();
396  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
397  if (CurFrame->LastFrameInst >= 0)
398    report_fatal_error("Frame register and offset already specified!");
399  if (Offset & 0x0F)
400    report_fatal_error("Misaligned frame pointer offset!");
401  MCWin64EHInstruction Inst(Win64EH::UOP_SetFPReg, NULL, Register, Offset);
402  CurFrame->LastFrameInst = CurFrame->Instructions.size();
403  CurFrame->Instructions.push_back(Inst);
404}
405
406void MCStreamer::EmitWin64EHAllocStack(unsigned Size) {
407  EnsureValidW64UnwindInfo();
408  if (Size & 7)
409    report_fatal_error("Misaligned stack allocation!");
410  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
411  MCSymbol *Label = getContext().CreateTempSymbol();
412  MCWin64EHInstruction Inst(Label, Size);
413  EmitLabel(Label);
414  CurFrame->Instructions.push_back(Inst);
415}
416
417void MCStreamer::EmitWin64EHSaveReg(unsigned Register, unsigned Offset) {
418  EnsureValidW64UnwindInfo();
419  if (Offset & 7)
420    report_fatal_error("Misaligned saved register offset!");
421  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
422  MCSymbol *Label = getContext().CreateTempSymbol();
423  MCWin64EHInstruction Inst(
424     Offset > 512*1024-8 ? Win64EH::UOP_SaveNonVolBig : Win64EH::UOP_SaveNonVol,
425                            Label, Register, Offset);
426  EmitLabel(Label);
427  CurFrame->Instructions.push_back(Inst);
428}
429
430void MCStreamer::EmitWin64EHSaveXMM(unsigned Register, unsigned Offset) {
431  EnsureValidW64UnwindInfo();
432  if (Offset & 0x0F)
433    report_fatal_error("Misaligned saved vector register offset!");
434  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
435  MCSymbol *Label = getContext().CreateTempSymbol();
436  MCWin64EHInstruction Inst(
437    Offset > 512*1024-16 ? Win64EH::UOP_SaveXMM128Big : Win64EH::UOP_SaveXMM128,
438                            Label, Register, Offset);
439  EmitLabel(Label);
440  CurFrame->Instructions.push_back(Inst);
441}
442
443void MCStreamer::EmitWin64EHPushFrame(bool Code) {
444  EnsureValidW64UnwindInfo();
445  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
446  if (CurFrame->Instructions.size() > 0)
447    report_fatal_error("If present, PushMachFrame must be the first UOP");
448  MCSymbol *Label = getContext().CreateTempSymbol();
449  MCWin64EHInstruction Inst(Win64EH::UOP_PushMachFrame, Label, Code);
450  EmitLabel(Label);
451  CurFrame->Instructions.push_back(Inst);
452}
453
454void MCStreamer::EmitWin64EHEndProlog() {
455  EnsureValidW64UnwindInfo();
456  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
457  CurFrame->PrologEnd = getContext().CreateTempSymbol();
458  EmitLabel(CurFrame->PrologEnd);
459}
460
461void MCStreamer::EmitFnStart() {
462  errs() << "Not implemented yet\n";
463  abort();
464}
465
466void MCStreamer::EmitFnEnd() {
467  errs() << "Not implemented yet\n";
468  abort();
469}
470
471void MCStreamer::EmitCantUnwind() {
472  errs() << "Not implemented yet\n";
473  abort();
474}
475
476void MCStreamer::EmitHandlerData() {
477  errs() << "Not implemented yet\n";
478  abort();
479}
480
481void MCStreamer::EmitPersonality(const MCSymbol *Personality) {
482  errs() << "Not implemented yet\n";
483  abort();
484}
485
486void MCStreamer::EmitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset) {
487  errs() << "Not implemented yet\n";
488  abort();
489}
490
491void MCStreamer::EmitPad(int64_t Offset) {
492  errs() << "Not implemented yet\n";
493  abort();
494}
495
496void MCStreamer::EmitRegSave(const SmallVectorImpl<unsigned> &RegList, bool) {
497  errs() << "Not implemented yet\n";
498  abort();
499}
500
501/// EmitRawText - If this file is backed by an assembly streamer, this dumps
502/// the specified string in the output .s file.  This capability is
503/// indicated by the hasRawTextSupport() predicate.
504void MCStreamer::EmitRawText(StringRef String) {
505  errs() << "EmitRawText called on an MCStreamer that doesn't support it, "
506  " something must not be fully mc'ized\n";
507  abort();
508}
509
510void MCStreamer::EmitRawText(const Twine &T) {
511  SmallString<128> Str;
512  T.toVector(Str);
513  EmitRawText(Str.str());
514}
515
516void MCStreamer::EmitFrames(bool usingCFI) {
517  if (!getNumFrameInfos())
518    return;
519
520  if (EmitEHFrame)
521    MCDwarfFrameEmitter::Emit(*this, usingCFI, true);
522
523  if (EmitDebugFrame)
524    MCDwarfFrameEmitter::Emit(*this, usingCFI, false);
525}
526
527void MCStreamer::EmitW64Tables() {
528  if (!getNumW64UnwindInfos())
529    return;
530
531  MCWin64EHUnwindEmitter::Emit(*this);
532}
533