MCStreamer.cpp revision 81f3830f2ed0b26e8bd7ae62e127db427f9f350d 
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  const MCSection *section = NULL;
26  SectionStack.push_back(std::make_pair(section, section));
27}
28
29MCStreamer::~MCStreamer() {
30}
31
32const MCExpr *MCStreamer::BuildSymbolDiff(MCContext &Context,
33                                          const MCSymbol *A,
34                                          const MCSymbol *B) {
35  MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None;
36  const MCExpr *ARef =
37    MCSymbolRefExpr::Create(A, Variant, Context);
38  const MCExpr *BRef =
39    MCSymbolRefExpr::Create(B, Variant, Context);
40  const MCExpr *AddrDelta =
41    MCBinaryExpr::Create(MCBinaryExpr::Sub, ARef, BRef, Context);
42  return AddrDelta;
43}
44
45const MCExpr *MCStreamer::ForceExpAbs(const MCExpr* Expr) {
46  if (Context.getAsmInfo().hasAggressiveSymbolFolding() ||
47      isa<MCSymbolRefExpr>(Expr))
48    return Expr;
49
50  MCSymbol *ABS = Context.CreateTempSymbol();
51  EmitAssignment(ABS, Expr);
52  return MCSymbolRefExpr::Create(ABS, Context);
53}
54
55raw_ostream &MCStreamer::GetCommentOS() {
56  // By default, discard comments.
57  return nulls();
58}
59
60void MCStreamer::EmitDwarfSetLineAddr(int64_t LineDelta,
61                                      const MCSymbol *Label, int PointerSize) {
62  // emit the sequence to set the address
63  EmitIntValue(dwarf::DW_LNS_extended_op, 1);
64  EmitULEB128IntValue(PointerSize + 1);
65  EmitIntValue(dwarf::DW_LNE_set_address, 1);
66  EmitSymbolValue(Label, PointerSize);
67
68  // emit the sequence for the LineDelta (from 1) and a zero address delta.
69  MCDwarfLineAddr::Emit(this, LineDelta, 0);
70}
71
72/// EmitIntValue - Special case of EmitValue that avoids the client having to
73/// pass in a MCExpr for constant integers.
74void MCStreamer::EmitIntValue(uint64_t Value, unsigned Size,
75                              unsigned AddrSpace) {
76  assert(Size <= 8 && "Invalid size");
77  assert((isUIntN(8 * Size, Value) || isIntN(8 * Size, Value)) &&
78         "Invalid size");
79  char buf[8];
80  // FIXME: Endianness assumption.
81  for (unsigned i = 0; i != Size; ++i)
82    buf[i] = uint8_t(Value >> (i * 8));
83  EmitBytes(StringRef(buf, Size), AddrSpace);
84}
85
86/// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
87/// client having to pass in a MCExpr for constant integers.
88void MCStreamer::EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace) {
89  SmallString<32> Tmp;
90  raw_svector_ostream OSE(Tmp);
91  MCObjectWriter::EncodeULEB128(Value, OSE);
92  EmitBytes(OSE.str(), AddrSpace);
93}
94
95/// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
96/// client having to pass in a MCExpr for constant integers.
97void MCStreamer::EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace) {
98  SmallString<32> Tmp;
99  raw_svector_ostream OSE(Tmp);
100  MCObjectWriter::EncodeSLEB128(Value, OSE);
101  EmitBytes(OSE.str(), AddrSpace);
102}
103
104void MCStreamer::EmitAbsValue(const MCExpr *Value, unsigned Size,
105                              unsigned AddrSpace) {
106  const MCExpr *ABS = ForceExpAbs(Value);
107  EmitValue(ABS, Size, AddrSpace);
108}
109
110
111void MCStreamer::EmitValue(const MCExpr *Value, unsigned Size,
112                           unsigned AddrSpace) {
113  EmitValueImpl(Value, Size, AddrSpace);
114}
115
116void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
117                                  unsigned AddrSpace) {
118  EmitValueImpl(MCSymbolRefExpr::Create(Sym, getContext()), Size,
119                AddrSpace);
120}
121
122void MCStreamer::EmitGPRel32Value(const MCExpr *Value) {
123  report_fatal_error("unsupported directive in streamer");
124}
125
126/// EmitFill - Emit NumBytes bytes worth of the value specified by
127/// FillValue.  This implements directives such as '.space'.
128void MCStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
129                          unsigned AddrSpace) {
130  const MCExpr *E = MCConstantExpr::Create(FillValue, getContext());
131  for (uint64_t i = 0, e = NumBytes; i != e; ++i)
132    EmitValue(E, 1, AddrSpace);
133}
134
135bool MCStreamer::EmitDwarfFileDirective(unsigned FileNo,
136                                        StringRef Filename) {
137  return getContext().GetDwarfFile(Filename, FileNo) == 0;
138}
139
140void MCStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
141                                       unsigned Column, unsigned Flags,
142                                       unsigned Isa,
143                                       unsigned Discriminator,
144                                       StringRef FileName) {
145  getContext().setCurrentDwarfLoc(FileNo, Line, Column, Flags, Isa,
146                                  Discriminator);
147}
148
149MCDwarfFrameInfo *MCStreamer::getCurrentFrameInfo() {
150  if (FrameInfos.empty())
151    return NULL;
152  return &FrameInfos.back();
153}
154
155void MCStreamer::EnsureValidFrame() {
156  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
157  if (!CurFrame || CurFrame->End)
158    report_fatal_error("No open frame");
159}
160
161void MCStreamer::EmitEHSymAttributes(const MCSymbol *Symbol,
162                                     MCSymbol *EHSymbol) {
163}
164
165void MCStreamer::EmitLabel(MCSymbol *Symbol) {
166  assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
167  assert(getCurrentSection() && "Cannot emit before setting section!");
168  Symbol->setSection(*getCurrentSection());
169
170  StringRef Prefix = getContext().getAsmInfo().getPrivateGlobalPrefix();
171  if (!Symbol->getName().startswith(Prefix))
172    LastNonPrivate = Symbol;
173}
174
175void MCStreamer::EmitCFISections(bool EH, bool Debug) {
176  assert(EH || Debug);
177  EmitEHFrame = EH;
178  EmitDebugFrame = Debug;
179}
180
181void MCStreamer::EmitCFIStartProc() {
182  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
183  if (CurFrame && !CurFrame->End)
184    report_fatal_error("Starting a frame before finishing the previous one!");
185  MCDwarfFrameInfo Frame;
186  Frame.Begin = getContext().CreateTempSymbol();
187  Frame.Function = LastNonPrivate;
188  EmitLabel(Frame.Begin);
189  FrameInfos.push_back(Frame);
190}
191
192void MCStreamer::EmitCFIEndProc() {
193  EnsureValidFrame();
194  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
195  CurFrame->End = getContext().CreateTempSymbol();
196  EmitLabel(CurFrame->End);
197}
198
199void MCStreamer::EmitCFIDefCfa(int64_t Register, int64_t Offset) {
200  EnsureValidFrame();
201  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
202  MCSymbol *Label = getContext().CreateTempSymbol();
203  EmitLabel(Label);
204  MachineLocation Dest(MachineLocation::VirtualFP);
205  MachineLocation Source(Register, -Offset);
206  MCCFIInstruction Instruction(Label, Dest, Source);
207  CurFrame->Instructions.push_back(Instruction);
208}
209
210void MCStreamer::EmitCFIDefCfaOffset(int64_t Offset) {
211  EnsureValidFrame();
212  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
213  MCSymbol *Label = getContext().CreateTempSymbol();
214  EmitLabel(Label);
215  MachineLocation Dest(MachineLocation::VirtualFP);
216  MachineLocation Source(MachineLocation::VirtualFP, -Offset);
217  MCCFIInstruction Instruction(Label, Dest, Source);
218  CurFrame->Instructions.push_back(Instruction);
219}
220
221void MCStreamer::EmitCFIAdjustCfaOffset(int64_t Adjustment) {
222  EnsureValidFrame();
223  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
224  MCSymbol *Label = getContext().CreateTempSymbol();
225  EmitLabel(Label);
226  MachineLocation Dest(MachineLocation::VirtualFP);
227  MachineLocation Source(MachineLocation::VirtualFP, Adjustment);
228  MCCFIInstruction Instruction(MCCFIInstruction::RelMove, Label, Dest, Source);
229  CurFrame->Instructions.push_back(Instruction);
230}
231
232void MCStreamer::EmitCFIDefCfaRegister(int64_t Register) {
233  EnsureValidFrame();
234  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
235  MCSymbol *Label = getContext().CreateTempSymbol();
236  EmitLabel(Label);
237  MachineLocation Dest(Register);
238  MachineLocation Source(MachineLocation::VirtualFP);
239  MCCFIInstruction Instruction(Label, Dest, Source);
240  CurFrame->Instructions.push_back(Instruction);
241}
242
243void MCStreamer::EmitCFIOffset(int64_t Register, int64_t Offset) {
244  EnsureValidFrame();
245  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
246  MCSymbol *Label = getContext().CreateTempSymbol();
247  EmitLabel(Label);
248  MachineLocation Dest(Register, Offset);
249  MachineLocation Source(Register, Offset);
250  MCCFIInstruction Instruction(Label, Dest, Source);
251  CurFrame->Instructions.push_back(Instruction);
252}
253
254void MCStreamer::EmitCFIRelOffset(int64_t Register, int64_t Offset) {
255  EnsureValidFrame();
256  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
257  MCSymbol *Label = getContext().CreateTempSymbol();
258  EmitLabel(Label);
259  MachineLocation Dest(Register, Offset);
260  MachineLocation Source(Register, Offset);
261  MCCFIInstruction Instruction(MCCFIInstruction::RelMove, Label, Dest, Source);
262  CurFrame->Instructions.push_back(Instruction);
263}
264
265void MCStreamer::EmitCFIPersonality(const MCSymbol *Sym,
266                                    unsigned Encoding) {
267  EnsureValidFrame();
268  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
269  CurFrame->Personality = Sym;
270  CurFrame->PersonalityEncoding = Encoding;
271}
272
273void MCStreamer::EmitCFILsda(const MCSymbol *Sym, unsigned Encoding) {
274  EnsureValidFrame();
275  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
276  CurFrame->Lsda = Sym;
277  CurFrame->LsdaEncoding = Encoding;
278}
279
280void MCStreamer::EmitCFIRememberState() {
281  EnsureValidFrame();
282  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
283  MCSymbol *Label = getContext().CreateTempSymbol();
284  EmitLabel(Label);
285  MCCFIInstruction Instruction(MCCFIInstruction::Remember, Label);
286  CurFrame->Instructions.push_back(Instruction);
287}
288
289void MCStreamer::EmitCFIRestoreState() {
290  // FIXME: Error if there is no matching cfi_remember_state.
291  EnsureValidFrame();
292  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
293  MCSymbol *Label = getContext().CreateTempSymbol();
294  EmitLabel(Label);
295  MCCFIInstruction Instruction(MCCFIInstruction::Restore, Label);
296  CurFrame->Instructions.push_back(Instruction);
297}
298
299void MCStreamer::EmitCFISameValue(int64_t Register) {
300  EnsureValidFrame();
301  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
302  MCSymbol *Label = getContext().CreateTempSymbol();
303  EmitLabel(Label);
304  MCCFIInstruction Instruction(MCCFIInstruction::SameValue, Label, Register);
305  CurFrame->Instructions.push_back(Instruction);
306}
307
308void MCStreamer::setCurrentW64UnwindInfo(MCWin64EHUnwindInfo *Frame) {
309  W64UnwindInfos.push_back(*Frame);
310  CurrentW64UnwindInfo = &W64UnwindInfos.back();
311}
312
313void MCStreamer::EnsureValidW64UnwindInfo() {
314  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
315  if (!CurFrame || CurFrame->End)
316    report_fatal_error("No open Win64 EH frame function!");
317}
318
319void MCStreamer::EmitWin64EHStartProc(MCSymbol *Symbol) {
320  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
321  if (CurFrame && !CurFrame->End)
322    report_fatal_error("Starting a function before ending the previous one!");
323  MCWin64EHUnwindInfo Frame;
324  Frame.Begin = getContext().CreateTempSymbol();
325  Frame.Function = Symbol;
326  EmitLabel(Frame.Begin);
327  setCurrentW64UnwindInfo(&Frame);
328}
329
330void MCStreamer::EmitWin64EHEndProc() {
331  EnsureValidW64UnwindInfo();
332  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
333  if (CurFrame->ChainedParent)
334    report_fatal_error("Not all chained regions terminated!");
335  CurFrame->End = getContext().CreateTempSymbol();
336  EmitLabel(CurFrame->End);
337}
338
339void MCStreamer::EmitWin64EHStartChained() {
340  EnsureValidW64UnwindInfo();
341  MCWin64EHUnwindInfo Frame;
342  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
343  Frame.Begin = getContext().CreateTempSymbol();
344  Frame.Function = CurFrame->Function;
345  Frame.ChainedParent = CurFrame;
346  EmitLabel(Frame.Begin);
347  setCurrentW64UnwindInfo(&Frame);
348}
349
350void MCStreamer::EmitWin64EHEndChained() {
351  EnsureValidW64UnwindInfo();
352  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
353  if (!CurFrame->ChainedParent)
354    report_fatal_error("End of a chained region outside a chained region!");
355  CurFrame->End = getContext().CreateTempSymbol();
356  EmitLabel(CurFrame->End);
357  CurrentW64UnwindInfo = CurFrame->ChainedParent;
358}
359
360void MCStreamer::EmitWin64EHHandler(const MCSymbol *Sym, bool Unwind,
361                                    bool Except) {
362  EnsureValidW64UnwindInfo();
363  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
364  if (CurFrame->ChainedParent)
365    report_fatal_error("Chained unwind areas can't have handlers!");
366  CurFrame->ExceptionHandler = Sym;
367  if (!Except && !Unwind)
368    report_fatal_error("Don't know what kind of handler this is!");
369  if (Unwind)
370    CurFrame->HandlesUnwind = true;
371  if (Except)
372    CurFrame->HandlesExceptions = true;
373}
374
375void MCStreamer::EmitWin64EHHandlerData() {
376  EnsureValidW64UnwindInfo();
377  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
378  if (CurFrame->ChainedParent)
379    report_fatal_error("Chained unwind areas can't have handlers!");
380}
381
382void MCStreamer::EmitWin64EHPushReg(unsigned Register) {
383  EnsureValidW64UnwindInfo();
384  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
385  MCWin64EHInstruction Inst(Win64EH::UOP_PushNonVol, Register);
386  CurFrame->Instructions.push_back(Inst);
387}
388
389void MCStreamer::EmitWin64EHSetFrame(unsigned Register, unsigned Offset) {
390  EnsureValidW64UnwindInfo();
391  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
392  MCWin64EHInstruction Inst(Win64EH::UOP_SetFPReg, Register, Offset);
393  CurFrame->LastFrameInst = CurFrame->Instructions.size();
394  CurFrame->Instructions.push_back(Inst);
395}
396
397void MCStreamer::EmitWin64EHAllocStack(unsigned Size) {
398  EnsureValidW64UnwindInfo();
399  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
400  MCWin64EHInstruction Inst(Size);
401  CurFrame->Instructions.push_back(Inst);
402}
403
404void MCStreamer::EmitWin64EHSaveReg(unsigned Register, unsigned Offset) {
405  EnsureValidW64UnwindInfo();
406  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
407  MCWin64EHInstruction Inst(
408         Offset > 0xFFFF ? Win64EH::UOP_SaveNonVol : Win64EH::UOP_SaveNonVolBig,
409                            Register, Offset);
410  CurFrame->Instructions.push_back(Inst);
411}
412
413void MCStreamer::EmitWin64EHSaveXMM(unsigned Register, unsigned Offset) {
414  EnsureValidW64UnwindInfo();
415  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
416  MCWin64EHInstruction Inst(
417         Offset > 0xFFFF ? Win64EH::UOP_SaveXMM128 : Win64EH::UOP_SaveXMM128Big,
418                            Register, Offset);
419  CurFrame->Instructions.push_back(Inst);
420}
421
422void MCStreamer::EmitWin64EHPushFrame(bool Code) {
423  EnsureValidW64UnwindInfo();
424  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
425  MCWin64EHInstruction Inst(Win64EH::UOP_PushMachFrame, Code);
426  CurFrame->Instructions.push_back(Inst);
427}
428
429void MCStreamer::EmitWin64EHEndProlog() {
430  EnsureValidW64UnwindInfo();
431  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
432  CurFrame->PrologEnd = getContext().CreateTempSymbol();
433  EmitLabel(CurFrame->PrologEnd);
434}
435
436void MCStreamer::EmitFnStart() {
437  errs() << "Not implemented yet\n";
438  abort();
439}
440
441void MCStreamer::EmitFnEnd() {
442  errs() << "Not implemented yet\n";
443  abort();
444}
445
446void MCStreamer::EmitCantUnwind() {
447  errs() << "Not implemented yet\n";
448  abort();
449}
450
451void MCStreamer::EmitHandlerData() {
452  errs() << "Not implemented yet\n";
453  abort();
454}
455
456void MCStreamer::EmitPersonality(const MCSymbol *Personality) {
457  errs() << "Not implemented yet\n";
458  abort();
459}
460
461void MCStreamer::EmitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset) {
462  errs() << "Not implemented yet\n";
463  abort();
464}
465
466void MCStreamer::EmitPad(int64_t Offset) {
467  errs() << "Not implemented yet\n";
468  abort();
469}
470
471void MCStreamer::EmitRegSave(const SmallVectorImpl<unsigned> &RegList, bool) {
472  errs() << "Not implemented yet\n";
473  abort();
474}
475
476/// EmitRawText - If this file is backed by an assembly streamer, this dumps
477/// the specified string in the output .s file.  This capability is
478/// indicated by the hasRawTextSupport() predicate.
479void MCStreamer::EmitRawText(StringRef String) {
480  errs() << "EmitRawText called on an MCStreamer that doesn't support it, "
481  " something must not be fully mc'ized\n";
482  abort();
483}
484
485void MCStreamer::EmitRawText(const Twine &T) {
486  SmallString<128> Str;
487  T.toVector(Str);
488  EmitRawText(Str.str());
489}
490
491void MCStreamer::EmitFrames(bool usingCFI) {
492  if (!getNumFrameInfos())
493    return;
494
495  if (EmitEHFrame)
496    MCDwarfFrameEmitter::Emit(*this, usingCFI, true);
497
498  if (EmitDebugFrame)
499    MCDwarfFrameEmitter::Emit(*this, usingCFI, false);
500}
501