MCStreamer.cpp revision a6f2678f08299f053feb58337fc4322131d99bf4 
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    return Expr;
48
49  MCSymbol *ABS = Context.CreateTempSymbol();
50  EmitAssignment(ABS, Expr);
51  return MCSymbolRefExpr::Create(ABS, Context);
52}
53
54raw_ostream &MCStreamer::GetCommentOS() {
55  // By default, discard comments.
56  return nulls();
57}
58
59void MCStreamer::EmitDwarfSetLineAddr(int64_t LineDelta,
60                                      const MCSymbol *Label, int PointerSize) {
61  // emit the sequence to set the address
62  EmitIntValue(dwarf::DW_LNS_extended_op, 1);
63  EmitULEB128IntValue(PointerSize + 1);
64  EmitIntValue(dwarf::DW_LNE_set_address, 1);
65  EmitSymbolValue(Label, PointerSize);
66
67  // emit the sequence for the LineDelta (from 1) and a zero address delta.
68  MCDwarfLineAddr::Emit(this, LineDelta, 0);
69}
70
71/// EmitIntValue - Special case of EmitValue that avoids the client having to
72/// pass in a MCExpr for constant integers.
73void MCStreamer::EmitIntValue(uint64_t Value, unsigned Size,
74                              unsigned AddrSpace) {
75  assert(Size <= 8 && "Invalid size");
76  assert((isUIntN(8 * Size, Value) || isIntN(8 * Size, Value)) &&
77         "Invalid size");
78  char buf[8];
79  // FIXME: Endianness assumption.
80  for (unsigned i = 0; i != Size; ++i)
81    buf[i] = uint8_t(Value >> (i * 8));
82  EmitBytes(StringRef(buf, Size), AddrSpace);
83}
84
85/// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
86/// client having to pass in a MCExpr for constant integers.
87void MCStreamer::EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace) {
88  SmallString<32> Tmp;
89  raw_svector_ostream OSE(Tmp);
90  MCObjectWriter::EncodeULEB128(Value, OSE);
91  EmitBytes(OSE.str(), AddrSpace);
92}
93
94/// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
95/// client having to pass in a MCExpr for constant integers.
96void MCStreamer::EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace) {
97  SmallString<32> Tmp;
98  raw_svector_ostream OSE(Tmp);
99  MCObjectWriter::EncodeSLEB128(Value, OSE);
100  EmitBytes(OSE.str(), AddrSpace);
101}
102
103void MCStreamer::EmitAbsValue(const MCExpr *Value, unsigned Size,
104                              unsigned AddrSpace) {
105  const MCExpr *ABS = ForceExpAbs(Value);
106  EmitValue(ABS, Size, AddrSpace);
107}
108
109
110void MCStreamer::EmitValue(const MCExpr *Value, unsigned Size,
111                           unsigned AddrSpace) {
112  EmitValueImpl(Value, Size, AddrSpace);
113}
114
115void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
116                                  unsigned AddrSpace) {
117  EmitValueImpl(MCSymbolRefExpr::Create(Sym, getContext()), Size,
118                AddrSpace);
119}
120
121void MCStreamer::EmitGPRel32Value(const MCExpr *Value) {
122  report_fatal_error("unsupported directive in streamer");
123}
124
125/// EmitFill - Emit NumBytes bytes worth of the value specified by
126/// FillValue.  This implements directives such as '.space'.
127void MCStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
128                          unsigned AddrSpace) {
129  const MCExpr *E = MCConstantExpr::Create(FillValue, getContext());
130  for (uint64_t i = 0, e = NumBytes; i != e; ++i)
131    EmitValue(E, 1, AddrSpace);
132}
133
134bool MCStreamer::EmitDwarfFileDirective(unsigned FileNo,
135                                        StringRef Filename) {
136  return getContext().GetDwarfFile(Filename, FileNo) == 0;
137}
138
139void MCStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
140                                       unsigned Column, unsigned Flags,
141                                       unsigned Isa,
142                                       unsigned Discriminator,
143                                       StringRef FileName) {
144  getContext().setCurrentDwarfLoc(FileNo, Line, Column, Flags, Isa,
145                                  Discriminator);
146}
147
148MCDwarfFrameInfo *MCStreamer::getCurrentFrameInfo() {
149  if (FrameInfos.empty())
150    return NULL;
151  return &FrameInfos.back();
152}
153
154void MCStreamer::EnsureValidFrame() {
155  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
156  if (!CurFrame || CurFrame->End)
157    report_fatal_error("No open frame");
158}
159
160void MCStreamer::EmitEHSymAttributes(const MCSymbol *Symbol,
161                                     MCSymbol *EHSymbol) {
162}
163
164void MCStreamer::EmitLabel(MCSymbol *Symbol) {
165  assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
166  assert(getCurrentSection() && "Cannot emit before setting section!");
167  Symbol->setSection(*getCurrentSection());
168
169  StringRef Prefix = getContext().getAsmInfo().getPrivateGlobalPrefix();
170  if (!Symbol->getName().startswith(Prefix))
171    LastNonPrivate = Symbol;
172}
173
174void MCStreamer::EmitCFISections(bool EH, bool Debug) {
175  assert(EH || Debug);
176  EmitEHFrame = EH;
177  EmitDebugFrame = Debug;
178}
179
180void MCStreamer::EmitCFIStartProc() {
181  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
182  if (CurFrame && !CurFrame->End)
183    report_fatal_error("Starting a frame before finishing the previous one!");
184  MCDwarfFrameInfo Frame;
185  Frame.Begin = getContext().CreateTempSymbol();
186  Frame.Function = LastNonPrivate;
187  EmitLabel(Frame.Begin);
188  FrameInfos.push_back(Frame);
189}
190
191void MCStreamer::EmitCFIEndProc() {
192  EnsureValidFrame();
193  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
194  CurFrame->End = getContext().CreateTempSymbol();
195  EmitLabel(CurFrame->End);
196}
197
198void MCStreamer::EmitCFIDefCfa(int64_t Register, int64_t Offset) {
199  EnsureValidFrame();
200  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
201  MCSymbol *Label = getContext().CreateTempSymbol();
202  EmitLabel(Label);
203  MachineLocation Dest(MachineLocation::VirtualFP);
204  MachineLocation Source(Register, -Offset);
205  MCCFIInstruction Instruction(Label, Dest, Source);
206  CurFrame->Instructions.push_back(Instruction);
207}
208
209void MCStreamer::EmitCFIDefCfaOffset(int64_t Offset) {
210  EnsureValidFrame();
211  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
212  MCSymbol *Label = getContext().CreateTempSymbol();
213  EmitLabel(Label);
214  MachineLocation Dest(MachineLocation::VirtualFP);
215  MachineLocation Source(MachineLocation::VirtualFP, -Offset);
216  MCCFIInstruction Instruction(Label, Dest, Source);
217  CurFrame->Instructions.push_back(Instruction);
218}
219
220void MCStreamer::EmitCFIAdjustCfaOffset(int64_t Adjustment) {
221  EnsureValidFrame();
222  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
223  MCSymbol *Label = getContext().CreateTempSymbol();
224  EmitLabel(Label);
225  MachineLocation Dest(MachineLocation::VirtualFP);
226  MachineLocation Source(MachineLocation::VirtualFP, Adjustment);
227  MCCFIInstruction Instruction(MCCFIInstruction::RelMove, Label, Dest, Source);
228  CurFrame->Instructions.push_back(Instruction);
229}
230
231void MCStreamer::EmitCFIDefCfaRegister(int64_t Register) {
232  EnsureValidFrame();
233  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
234  MCSymbol *Label = getContext().CreateTempSymbol();
235  EmitLabel(Label);
236  MachineLocation Dest(Register);
237  MachineLocation Source(MachineLocation::VirtualFP);
238  MCCFIInstruction Instruction(Label, Dest, Source);
239  CurFrame->Instructions.push_back(Instruction);
240}
241
242void MCStreamer::EmitCFIOffset(int64_t Register, int64_t Offset) {
243  EnsureValidFrame();
244  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
245  MCSymbol *Label = getContext().CreateTempSymbol();
246  EmitLabel(Label);
247  MachineLocation Dest(Register, Offset);
248  MachineLocation Source(Register, Offset);
249  MCCFIInstruction Instruction(Label, Dest, Source);
250  CurFrame->Instructions.push_back(Instruction);
251}
252
253void MCStreamer::EmitCFIRelOffset(int64_t Register, int64_t Offset) {
254  EnsureValidFrame();
255  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
256  MCSymbol *Label = getContext().CreateTempSymbol();
257  EmitLabel(Label);
258  MachineLocation Dest(Register, Offset);
259  MachineLocation Source(Register, Offset);
260  MCCFIInstruction Instruction(MCCFIInstruction::RelMove, Label, Dest, Source);
261  CurFrame->Instructions.push_back(Instruction);
262}
263
264void MCStreamer::EmitCFIPersonality(const MCSymbol *Sym,
265                                    unsigned Encoding) {
266  EnsureValidFrame();
267  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
268  CurFrame->Personality = Sym;
269  CurFrame->PersonalityEncoding = Encoding;
270}
271
272void MCStreamer::EmitCFILsda(const MCSymbol *Sym, unsigned Encoding) {
273  EnsureValidFrame();
274  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
275  CurFrame->Lsda = Sym;
276  CurFrame->LsdaEncoding = Encoding;
277}
278
279void MCStreamer::EmitCFIRememberState() {
280  EnsureValidFrame();
281  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
282  MCSymbol *Label = getContext().CreateTempSymbol();
283  EmitLabel(Label);
284  MCCFIInstruction Instruction(MCCFIInstruction::Remember, Label);
285  CurFrame->Instructions.push_back(Instruction);
286}
287
288void MCStreamer::EmitCFIRestoreState() {
289  // FIXME: Error if there is no matching cfi_remember_state.
290  EnsureValidFrame();
291  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
292  MCSymbol *Label = getContext().CreateTempSymbol();
293  EmitLabel(Label);
294  MCCFIInstruction Instruction(MCCFIInstruction::Restore, Label);
295  CurFrame->Instructions.push_back(Instruction);
296}
297
298void MCStreamer::EmitCFISameValue(int64_t Register) {
299  EnsureValidFrame();
300  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
301  MCSymbol *Label = getContext().CreateTempSymbol();
302  EmitLabel(Label);
303  MCCFIInstruction Instruction(MCCFIInstruction::SameValue, Label, Register);
304  CurFrame->Instructions.push_back(Instruction);
305}
306
307void MCStreamer::setCurrentW64UnwindInfo(MCWin64EHUnwindInfo *Frame) {
308  W64UnwindInfos.push_back(*Frame);
309  CurrentW64UnwindInfo = &W64UnwindInfos.back();
310}
311
312void MCStreamer::EnsureValidW64UnwindInfo() {
313  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
314  if (!CurFrame || CurFrame->End)
315    report_fatal_error("No open Win64 EH frame function!");
316}
317
318void MCStreamer::EmitWin64EHStartProc(MCSymbol *Symbol) {
319  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
320  if (CurFrame && !CurFrame->End)
321    report_fatal_error("Starting a function before ending the previous one!");
322  MCWin64EHUnwindInfo Frame;
323  Frame.Begin = getContext().CreateTempSymbol();
324  Frame.Function = Symbol;
325  EmitLabel(Frame.Begin);
326  setCurrentW64UnwindInfo(&Frame);
327}
328
329void MCStreamer::EmitWin64EHEndProc() {
330  EnsureValidW64UnwindInfo();
331  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
332  if (CurFrame->ChainedParent)
333    report_fatal_error("Not all chained regions terminated!");
334  CurFrame->End = getContext().CreateTempSymbol();
335  EmitLabel(CurFrame->End);
336}
337
338void MCStreamer::EmitWin64EHStartChained() {
339  EnsureValidW64UnwindInfo();
340  MCWin64EHUnwindInfo Frame;
341  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
342  Frame.Begin = getContext().CreateTempSymbol();
343  Frame.Function = CurFrame->Function;
344  Frame.ChainedParent = CurFrame;
345  EmitLabel(Frame.Begin);
346  setCurrentW64UnwindInfo(&Frame);
347}
348
349void MCStreamer::EmitWin64EHEndChained() {
350  EnsureValidW64UnwindInfo();
351  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
352  if (!CurFrame->ChainedParent)
353    report_fatal_error("End of a chained region outside a chained region!");
354  CurFrame->End = getContext().CreateTempSymbol();
355  EmitLabel(CurFrame->End);
356  CurrentW64UnwindInfo = CurFrame->ChainedParent;
357}
358
359void MCStreamer::EmitWin64EHHandler(const MCSymbol *Sym, bool Unwind,
360                                    bool Except) {
361  EnsureValidW64UnwindInfo();
362  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
363  CurFrame->ExceptionHandler = Sym;
364  if (Unwind)
365    CurFrame->UnwindOnly = true;
366  else if (!Except)
367    report_fatal_error("Don't know what kind of handler this is!");
368}
369
370void MCStreamer::EmitWin64EHHandlerData() {
371  errs() << "Not implemented yet\n";
372  abort();
373}
374
375void MCStreamer::EmitWin64EHPushReg(unsigned Register) {
376  EnsureValidW64UnwindInfo();
377  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
378  MCWin64EHInstruction Inst(Win64EH::UOP_PushNonVol, Register);
379  CurFrame->Instructions.push_back(Inst);
380}
381
382void MCStreamer::EmitWin64EHSetFrame(unsigned Register, unsigned Offset) {
383  EnsureValidW64UnwindInfo();
384  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
385  MCWin64EHInstruction Inst(Win64EH::UOP_SetFPReg, Register, Offset);
386  CurFrame->Instructions.push_back(Inst);
387}
388
389void MCStreamer::EmitWin64EHAllocStack(unsigned Size) {
390  EnsureValidW64UnwindInfo();
391  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
392  MCWin64EHInstruction Inst(Size);
393  CurFrame->Instructions.push_back(Inst);
394}
395
396void MCStreamer::EmitWin64EHSaveReg(unsigned Register, unsigned Offset) {
397  EnsureValidW64UnwindInfo();
398  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
399  MCWin64EHInstruction Inst(
400         Offset > 0xFFFF ? Win64EH::UOP_SaveNonVol : Win64EH::UOP_SaveNonVolBig,
401                            Register, Offset);
402  CurFrame->Instructions.push_back(Inst);
403}
404
405void MCStreamer::EmitWin64EHSaveXMM(unsigned Register, unsigned Offset) {
406  EnsureValidW64UnwindInfo();
407  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
408  MCWin64EHInstruction Inst(
409         Offset > 0xFFFF ? Win64EH::UOP_SaveXMM128 : Win64EH::UOP_SaveXMM128Big,
410                            Register, Offset);
411  CurFrame->Instructions.push_back(Inst);
412}
413
414void MCStreamer::EmitWin64EHPushFrame(bool Code) {
415  EnsureValidW64UnwindInfo();
416  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
417  MCWin64EHInstruction Inst(Win64EH::UOP_PushMachFrame, Code);
418  CurFrame->Instructions.push_back(Inst);
419}
420
421void MCStreamer::EmitWin64EHEndProlog() {
422  EnsureValidW64UnwindInfo();
423  MCWin64EHUnwindInfo *CurFrame = CurrentW64UnwindInfo;
424  CurFrame->PrologEnd = getContext().CreateTempSymbol();
425  EmitLabel(CurFrame->PrologEnd);
426}
427
428void MCStreamer::EmitFnStart() {
429  errs() << "Not implemented yet\n";
430  abort();
431}
432
433void MCStreamer::EmitFnEnd() {
434  errs() << "Not implemented yet\n";
435  abort();
436}
437
438void MCStreamer::EmitCantUnwind() {
439  errs() << "Not implemented yet\n";
440  abort();
441}
442
443void MCStreamer::EmitHandlerData() {
444  errs() << "Not implemented yet\n";
445  abort();
446}
447
448void MCStreamer::EmitPersonality(const MCSymbol *Personality) {
449  errs() << "Not implemented yet\n";
450  abort();
451}
452
453void MCStreamer::EmitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset) {
454  errs() << "Not implemented yet\n";
455  abort();
456}
457
458void MCStreamer::EmitPad(int64_t Offset) {
459  errs() << "Not implemented yet\n";
460  abort();
461}
462
463void MCStreamer::EmitRegSave(const SmallVectorImpl<unsigned> &RegList, bool) {
464  errs() << "Not implemented yet\n";
465  abort();
466}
467
468/// EmitRawText - If this file is backed by an assembly streamer, this dumps
469/// the specified string in the output .s file.  This capability is
470/// indicated by the hasRawTextSupport() predicate.
471void MCStreamer::EmitRawText(StringRef String) {
472  errs() << "EmitRawText called on an MCStreamer that doesn't support it, "
473  " something must not be fully mc'ized\n";
474  abort();
475}
476
477void MCStreamer::EmitRawText(const Twine &T) {
478  SmallString<128> Str;
479  T.toVector(Str);
480  EmitRawText(Str.str());
481}
482
483void MCStreamer::EmitFrames(bool usingCFI) {
484  if (!getNumFrameInfos())
485    return;
486
487  if (EmitEHFrame)
488    MCDwarfFrameEmitter::Emit(*this, usingCFI, true);
489
490  if (EmitDebugFrame)
491    MCDwarfFrameEmitter::Emit(*this, usingCFI, false);
492}
493