MCAsmStreamer.cpp revision e07b75e069969558c3fbb2f5bfb9a652f6ea1d6b 
1//===- lib/MC/MCAsmStreamer.cpp - Text Assembly 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/MC/MCAsmInfo.h"
12#include "llvm/MC/MCCodeEmitter.h"
13#include "llvm/MC/MCContext.h"
14#include "llvm/MC/MCExpr.h"
15#include "llvm/MC/MCInst.h"
16#include "llvm/MC/MCInstPrinter.h"
17#include "llvm/MC/MCSectionMachO.h"
18#include "llvm/MC/MCSymbol.h"
19#include "llvm/ADT/OwningPtr.h"
20#include "llvm/ADT/SmallString.h"
21#include "llvm/ADT/Twine.h"
22#include "llvm/Support/ErrorHandling.h"
23#include "llvm/Support/MathExtras.h"
24#include "llvm/Support/Format.h"
25#include "llvm/Support/FormattedStream.h"
26using namespace llvm;
27
28namespace {
29
30class MCAsmStreamer : public MCStreamer {
31  formatted_raw_ostream &OS;
32  const MCAsmInfo &MAI;
33  OwningPtr<MCInstPrinter> InstPrinter;
34  OwningPtr<MCCodeEmitter> Emitter;
35
36  SmallString<128> CommentToEmit;
37  raw_svector_ostream CommentStream;
38
39  unsigned IsLittleEndian : 1;
40  unsigned IsVerboseAsm : 1;
41  unsigned ShowInst : 1;
42
43public:
44  MCAsmStreamer(MCContext &Context, formatted_raw_ostream &os,
45                bool isLittleEndian, bool isVerboseAsm, MCInstPrinter *printer,
46                MCCodeEmitter *emitter, bool showInst)
47    : MCStreamer(Context), OS(os), MAI(Context.getAsmInfo()),
48      InstPrinter(printer), Emitter(emitter), CommentStream(CommentToEmit),
49      IsLittleEndian(isLittleEndian), IsVerboseAsm(isVerboseAsm),
50      ShowInst(showInst) {
51    if (InstPrinter && IsVerboseAsm)
52      InstPrinter->setCommentStream(CommentStream);
53  }
54  ~MCAsmStreamer() {}
55
56  bool isLittleEndian() const { return IsLittleEndian; }
57
58  inline void EmitEOL() {
59    // If we don't have any comments, just emit a \n.
60    if (!IsVerboseAsm) {
61      OS << '\n';
62      return;
63    }
64    EmitCommentsAndEOL();
65  }
66  void EmitCommentsAndEOL();
67
68  /// isVerboseAsm - Return true if this streamer supports verbose assembly at
69  /// all.
70  virtual bool isVerboseAsm() const { return IsVerboseAsm; }
71
72  /// hasRawTextSupport - We support EmitRawText.
73  virtual bool hasRawTextSupport() const { return true; }
74
75  /// AddComment - Add a comment that can be emitted to the generated .s
76  /// file if applicable as a QoI issue to make the output of the compiler
77  /// more readable.  This only affects the MCAsmStreamer, and only when
78  /// verbose assembly output is enabled.
79  virtual void AddComment(const Twine &T);
80
81  /// AddEncodingComment - Add a comment showing the encoding of an instruction.
82  virtual void AddEncodingComment(const MCInst &Inst);
83
84  /// GetCommentOS - Return a raw_ostream that comments can be written to.
85  /// Unlike AddComment, you are required to terminate comments with \n if you
86  /// use this method.
87  virtual raw_ostream &GetCommentOS() {
88    if (!IsVerboseAsm)
89      return nulls();  // Discard comments unless in verbose asm mode.
90    return CommentStream;
91  }
92
93  /// AddBlankLine - Emit a blank line to a .s file to pretty it up.
94  virtual void AddBlankLine() {
95    EmitEOL();
96  }
97
98  /// @name MCStreamer Interface
99  /// @{
100
101  virtual void SwitchSection(const MCSection *Section);
102
103  virtual void InitSections() {
104    // FIXME, this is MachO specific, but the testsuite
105    // expects this.
106    SwitchSection(getContext().getMachOSection("__TEXT", "__text",
107                         MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
108                         0, SectionKind::getText()));
109  }
110
111  virtual void EmitLabel(MCSymbol *Symbol);
112
113  virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
114
115  virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
116
117  virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
118
119  virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
120  virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol);
121  virtual void EmitCOFFSymbolStorageClass(int StorageClass);
122  virtual void EmitCOFFSymbolType(int Type);
123  virtual void EndCOFFSymbolDef();
124  virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value);
125  virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
126                                unsigned ByteAlignment);
127
128  /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
129  ///
130  /// @param Symbol - The common symbol to emit.
131  /// @param Size - The size of the common symbol.
132  virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size);
133
134  virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
135                            unsigned Size = 0, unsigned ByteAlignment = 0);
136
137  virtual void EmitTBSSSymbol (const MCSection *Section, MCSymbol *Symbol,
138                               uint64_t Size, unsigned ByteAlignment = 0);
139
140  virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
141
142  virtual void EmitValue(const MCExpr *Value, unsigned Size,unsigned AddrSpace);
143  virtual void EmitIntValue(uint64_t Value, unsigned Size, unsigned AddrSpace);
144  virtual void EmitGPRel32Value(const MCExpr *Value);
145
146
147  virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue,
148                        unsigned AddrSpace);
149
150  virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
151                                    unsigned ValueSize = 1,
152                                    unsigned MaxBytesToEmit = 0);
153
154  virtual void EmitCodeAlignment(unsigned ByteAlignment,
155                                 unsigned MaxBytesToEmit = 0);
156
157  virtual void EmitValueToOffset(const MCExpr *Offset,
158                                 unsigned char Value = 0);
159
160  virtual void EmitFileDirective(StringRef Filename);
161  virtual void EmitDwarfFileDirective(unsigned FileNo, StringRef Filename);
162
163  virtual void EmitInstruction(const MCInst &Inst);
164
165  /// EmitRawText - If this file is backed by an assembly streamer, this dumps
166  /// the specified string in the output .s file.  This capability is
167  /// indicated by the hasRawTextSupport() predicate.
168  virtual void EmitRawText(StringRef String);
169
170  virtual void Finish();
171
172  /// @}
173};
174
175} // end anonymous namespace.
176
177/// AddComment - Add a comment that can be emitted to the generated .s
178/// file if applicable as a QoI issue to make the output of the compiler
179/// more readable.  This only affects the MCAsmStreamer, and only when
180/// verbose assembly output is enabled.
181void MCAsmStreamer::AddComment(const Twine &T) {
182  if (!IsVerboseAsm) return;
183
184  // Make sure that CommentStream is flushed.
185  CommentStream.flush();
186
187  T.toVector(CommentToEmit);
188  // Each comment goes on its own line.
189  CommentToEmit.push_back('\n');
190
191  // Tell the comment stream that the vector changed underneath it.
192  CommentStream.resync();
193}
194
195void MCAsmStreamer::EmitCommentsAndEOL() {
196  if (CommentToEmit.empty() && CommentStream.GetNumBytesInBuffer() == 0) {
197    OS << '\n';
198    return;
199  }
200
201  CommentStream.flush();
202  StringRef Comments = CommentToEmit.str();
203
204  assert(Comments.back() == '\n' &&
205         "Comment array not newline terminated");
206  do {
207    // Emit a line of comments.
208    OS.PadToColumn(MAI.getCommentColumn());
209    size_t Position = Comments.find('\n');
210    OS << MAI.getCommentString() << ' ' << Comments.substr(0, Position) << '\n';
211
212    Comments = Comments.substr(Position+1);
213  } while (!Comments.empty());
214
215  CommentToEmit.clear();
216  // Tell the comment stream that the vector changed underneath it.
217  CommentStream.resync();
218}
219
220static inline int64_t truncateToSize(int64_t Value, unsigned Bytes) {
221  assert(Bytes && "Invalid size!");
222  return Value & ((uint64_t) (int64_t) -1 >> (64 - Bytes * 8));
223}
224
225void MCAsmStreamer::SwitchSection(const MCSection *Section) {
226  assert(Section && "Cannot switch to a null section!");
227  if (Section != CurSection) {
228    PrevSection = CurSection;
229    CurSection = Section;
230    Section->PrintSwitchToSection(MAI, OS);
231  }
232}
233
234void MCAsmStreamer::EmitLabel(MCSymbol *Symbol) {
235  assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
236  assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
237  assert(CurSection && "Cannot emit before setting section!");
238
239  OS << *Symbol << MAI.getLabelSuffix();
240  EmitEOL();
241  Symbol->setSection(*CurSection);
242}
243
244void MCAsmStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
245  switch (Flag) {
246  default: assert(0 && "Invalid flag!");
247  case MCAF_SubsectionsViaSymbols: OS << ".subsections_via_symbols"; break;
248  }
249  EmitEOL();
250}
251
252void MCAsmStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
253  OS << *Symbol << " = " << *Value;
254  EmitEOL();
255
256  // FIXME: Lift context changes into super class.
257  Symbol->setVariableValue(Value);
258}
259
260void MCAsmStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
261                                        MCSymbolAttr Attribute) {
262  switch (Attribute) {
263  case MCSA_Invalid: assert(0 && "Invalid symbol attribute");
264  case MCSA_ELF_TypeFunction:    /// .type _foo, STT_FUNC  # aka @function
265  case MCSA_ELF_TypeIndFunction: /// .type _foo, STT_GNU_IFUNC
266  case MCSA_ELF_TypeObject:      /// .type _foo, STT_OBJECT  # aka @object
267  case MCSA_ELF_TypeTLS:         /// .type _foo, STT_TLS     # aka @tls_object
268  case MCSA_ELF_TypeCommon:      /// .type _foo, STT_COMMON  # aka @common
269  case MCSA_ELF_TypeNoType:      /// .type _foo, STT_NOTYPE  # aka @notype
270    assert(MAI.hasDotTypeDotSizeDirective() && "Symbol Attr not supported");
271    OS << "\t.type\t" << *Symbol << ','
272       << ((MAI.getCommentString()[0] != '@') ? '@' : '%');
273    switch (Attribute) {
274    default: assert(0 && "Unknown ELF .type");
275    case MCSA_ELF_TypeFunction:    OS << "function"; break;
276    case MCSA_ELF_TypeIndFunction: OS << "gnu_indirect_function"; break;
277    case MCSA_ELF_TypeObject:      OS << "object"; break;
278    case MCSA_ELF_TypeTLS:         OS << "tls_object"; break;
279    case MCSA_ELF_TypeCommon:      OS << "common"; break;
280    case MCSA_ELF_TypeNoType:      OS << "no_type"; break;
281    }
282    EmitEOL();
283    return;
284  case MCSA_Global: // .globl/.global
285    OS << MAI.getGlobalDirective();
286    break;
287  case MCSA_Hidden:         OS << "\t.hidden\t";          break;
288  case MCSA_IndirectSymbol: OS << "\t.indirect_symbol\t"; break;
289  case MCSA_Internal:       OS << "\t.internal\t";        break;
290  case MCSA_LazyReference:  OS << "\t.lazy_reference\t";  break;
291  case MCSA_Local:          OS << "\t.local\t";           break;
292  case MCSA_NoDeadStrip:    OS << "\t.no_dead_strip\t";   break;
293  case MCSA_PrivateExtern:  OS << "\t.private_extern\t";  break;
294  case MCSA_Protected:      OS << "\t.protected\t";       break;
295  case MCSA_Reference:      OS << "\t.reference\t";       break;
296  case MCSA_Weak:           OS << "\t.weak\t";            break;
297  case MCSA_WeakDefinition: OS << "\t.weak_definition\t"; break;
298      // .weak_reference
299  case MCSA_WeakReference:  OS << MAI.getWeakRefDirective(); break;
300  case MCSA_WeakDefAutoPrivate: OS << "\t.weak_def_can_be_hidden\t"; break;
301  }
302
303  OS << *Symbol;
304  EmitEOL();
305}
306
307void MCAsmStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
308  OS << ".desc" << ' ' << *Symbol << ',' << DescValue;
309  EmitEOL();
310}
311
312void MCAsmStreamer::BeginCOFFSymbolDef(const MCSymbol *Symbol) {
313  OS << "\t.def\t " << *Symbol << ';';
314  EmitEOL();
315}
316
317void MCAsmStreamer::EmitCOFFSymbolStorageClass (int StorageClass) {
318  OS << "\t.scl\t" << StorageClass << ';';
319  EmitEOL();
320}
321
322void MCAsmStreamer::EmitCOFFSymbolType (int Type) {
323  OS << "\t.type\t" << Type << ';';
324  EmitEOL();
325}
326
327void MCAsmStreamer::EndCOFFSymbolDef() {
328  OS << "\t.endef";
329  EmitEOL();
330}
331
332void MCAsmStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
333  assert(MAI.hasDotTypeDotSizeDirective());
334  OS << "\t.size\t" << *Symbol << ", " << *Value << '\n';
335}
336
337void MCAsmStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
338                                     unsigned ByteAlignment) {
339  OS << "\t.comm\t" << *Symbol << ',' << Size;
340  if (ByteAlignment != 0) {
341    if (MAI.getCOMMDirectiveAlignmentIsInBytes())
342      OS << ',' << ByteAlignment;
343    else
344      OS << ',' << Log2_32(ByteAlignment);
345  }
346  EmitEOL();
347}
348
349/// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
350///
351/// @param Symbol - The common symbol to emit.
352/// @param Size - The size of the common symbol.
353void MCAsmStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {
354  assert(MAI.hasLCOMMDirective() && "Doesn't have .lcomm, can't emit it!");
355  OS << "\t.lcomm\t" << *Symbol << ',' << Size;
356  EmitEOL();
357}
358
359void MCAsmStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
360                                 unsigned Size, unsigned ByteAlignment) {
361  // Note: a .zerofill directive does not switch sections.
362  OS << ".zerofill ";
363
364  // This is a mach-o specific directive.
365  const MCSectionMachO *MOSection = ((const MCSectionMachO*)Section);
366  OS << MOSection->getSegmentName() << "," << MOSection->getSectionName();
367
368  if (Symbol != NULL) {
369    OS << ',' << *Symbol << ',' << Size;
370    if (ByteAlignment != 0)
371      OS << ',' << Log2_32(ByteAlignment);
372  }
373  EmitEOL();
374}
375
376// .tbss sym, size, align
377// This depends that the symbol has already been mangled from the original,
378// e.g. _a.
379void MCAsmStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
380                                   uint64_t Size, unsigned ByteAlignment) {
381  assert(Symbol != NULL && "Symbol shouldn't be NULL!");
382  // Instead of using the Section we'll just use the shortcut.
383  // This is a mach-o specific directive and section.
384  OS << ".tbss " << *Symbol << ", " << Size;
385
386  // Output align if we have it.  We default to 1 so don't bother printing
387  // that.
388  if (ByteAlignment > 1) OS << ", " << Log2_32(ByteAlignment);
389
390  EmitEOL();
391}
392
393static inline char toOctal(int X) { return (X&7)+'0'; }
394
395static void PrintQuotedString(StringRef Data, raw_ostream &OS) {
396  OS << '"';
397
398  for (unsigned i = 0, e = Data.size(); i != e; ++i) {
399    unsigned char C = Data[i];
400    if (C == '"' || C == '\\') {
401      OS << '\\' << (char)C;
402      continue;
403    }
404
405    if (isprint((unsigned char)C)) {
406      OS << (char)C;
407      continue;
408    }
409
410    switch (C) {
411      case '\b': OS << "\\b"; break;
412      case '\f': OS << "\\f"; break;
413      case '\n': OS << "\\n"; break;
414      case '\r': OS << "\\r"; break;
415      case '\t': OS << "\\t"; break;
416      default:
417        OS << '\\';
418        OS << toOctal(C >> 6);
419        OS << toOctal(C >> 3);
420        OS << toOctal(C >> 0);
421        break;
422    }
423  }
424
425  OS << '"';
426}
427
428
429void MCAsmStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
430  assert(CurSection && "Cannot emit contents before setting section!");
431  if (Data.empty()) return;
432
433  if (Data.size() == 1) {
434    OS << MAI.getData8bitsDirective(AddrSpace);
435    OS << (unsigned)(unsigned char)Data[0];
436    EmitEOL();
437    return;
438  }
439
440  // If the data ends with 0 and the target supports .asciz, use it, otherwise
441  // use .ascii
442  if (MAI.getAscizDirective() && Data.back() == 0) {
443    OS << MAI.getAscizDirective();
444    Data = Data.substr(0, Data.size()-1);
445  } else {
446    OS << MAI.getAsciiDirective();
447  }
448
449  OS << ' ';
450  PrintQuotedString(Data, OS);
451  EmitEOL();
452}
453
454/// EmitIntValue - Special case of EmitValue that avoids the client having
455/// to pass in a MCExpr for constant integers.
456void MCAsmStreamer::EmitIntValue(uint64_t Value, unsigned Size,
457                                 unsigned AddrSpace) {
458  assert(CurSection && "Cannot emit contents before setting section!");
459  const char *Directive = 0;
460  switch (Size) {
461  default: break;
462  case 1: Directive = MAI.getData8bitsDirective(AddrSpace); break;
463  case 2: Directive = MAI.getData16bitsDirective(AddrSpace); break;
464  case 4: Directive = MAI.getData32bitsDirective(AddrSpace); break;
465  case 8:
466    Directive = MAI.getData64bitsDirective(AddrSpace);
467    // If the target doesn't support 64-bit data, emit as two 32-bit halves.
468    if (Directive) break;
469    if (isLittleEndian()) {
470      EmitIntValue((uint32_t)(Value >> 0 ), 4, AddrSpace);
471      EmitIntValue((uint32_t)(Value >> 32), 4, AddrSpace);
472    } else {
473      EmitIntValue((uint32_t)(Value >> 32), 4, AddrSpace);
474      EmitIntValue((uint32_t)(Value >> 0 ), 4, AddrSpace);
475    }
476    return;
477  }
478
479  assert(Directive && "Invalid size for machine code value!");
480  OS << Directive << truncateToSize(Value, Size);
481  EmitEOL();
482}
483
484void MCAsmStreamer::EmitValue(const MCExpr *Value, unsigned Size,
485                              unsigned AddrSpace) {
486  assert(CurSection && "Cannot emit contents before setting section!");
487  const char *Directive = 0;
488  switch (Size) {
489  default: break;
490  case 1: Directive = MAI.getData8bitsDirective(AddrSpace); break;
491  case 2: Directive = MAI.getData16bitsDirective(AddrSpace); break;
492  case 4: Directive = MAI.getData32bitsDirective(AddrSpace); break;
493  case 8: Directive = MAI.getData64bitsDirective(AddrSpace); break;
494  }
495
496  assert(Directive && "Invalid size for machine code value!");
497  OS << Directive << *Value;
498  EmitEOL();
499}
500
501void MCAsmStreamer::EmitGPRel32Value(const MCExpr *Value) {
502  assert(MAI.getGPRel32Directive() != 0);
503  OS << MAI.getGPRel32Directive() << *Value;
504  EmitEOL();
505}
506
507
508/// EmitFill - Emit NumBytes bytes worth of the value specified by
509/// FillValue.  This implements directives such as '.space'.
510void MCAsmStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
511                             unsigned AddrSpace) {
512  if (NumBytes == 0) return;
513
514  if (AddrSpace == 0)
515    if (const char *ZeroDirective = MAI.getZeroDirective()) {
516      OS << ZeroDirective << NumBytes;
517      if (FillValue != 0)
518        OS << ',' << (int)FillValue;
519      EmitEOL();
520      return;
521    }
522
523  // Emit a byte at a time.
524  MCStreamer::EmitFill(NumBytes, FillValue, AddrSpace);
525}
526
527void MCAsmStreamer::EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
528                                         unsigned ValueSize,
529                                         unsigned MaxBytesToEmit) {
530  // Some assemblers don't support non-power of two alignments, so we always
531  // emit alignments as a power of two if possible.
532  if (isPowerOf2_32(ByteAlignment)) {
533    switch (ValueSize) {
534    default: llvm_unreachable("Invalid size for machine code value!");
535    case 1: OS << MAI.getAlignDirective(); break;
536    // FIXME: use MAI for this!
537    case 2: OS << ".p2alignw "; break;
538    case 4: OS << ".p2alignl "; break;
539    case 8: llvm_unreachable("Unsupported alignment size!");
540    }
541
542    if (MAI.getAlignmentIsInBytes())
543      OS << ByteAlignment;
544    else
545      OS << Log2_32(ByteAlignment);
546
547    if (Value || MaxBytesToEmit) {
548      OS << ", 0x";
549      OS.write_hex(truncateToSize(Value, ValueSize));
550
551      if (MaxBytesToEmit)
552        OS << ", " << MaxBytesToEmit;
553    }
554    EmitEOL();
555    return;
556  }
557
558  // Non-power of two alignment.  This is not widely supported by assemblers.
559  // FIXME: Parameterize this based on MAI.
560  switch (ValueSize) {
561  default: llvm_unreachable("Invalid size for machine code value!");
562  case 1: OS << ".balign";  break;
563  case 2: OS << ".balignw"; break;
564  case 4: OS << ".balignl"; break;
565  case 8: llvm_unreachable("Unsupported alignment size!");
566  }
567
568  OS << ' ' << ByteAlignment;
569  OS << ", " << truncateToSize(Value, ValueSize);
570  if (MaxBytesToEmit)
571    OS << ", " << MaxBytesToEmit;
572  EmitEOL();
573}
574
575void MCAsmStreamer::EmitCodeAlignment(unsigned ByteAlignment,
576                                      unsigned MaxBytesToEmit) {
577  // Emit with a text fill value.
578  EmitValueToAlignment(ByteAlignment, MAI.getTextAlignFillValue(),
579                       1, MaxBytesToEmit);
580}
581
582void MCAsmStreamer::EmitValueToOffset(const MCExpr *Offset,
583                                      unsigned char Value) {
584  // FIXME: Verify that Offset is associated with the current section.
585  OS << ".org " << *Offset << ", " << (unsigned) Value;
586  EmitEOL();
587}
588
589
590void MCAsmStreamer::EmitFileDirective(StringRef Filename) {
591  assert(MAI.hasSingleParameterDotFile());
592  OS << "\t.file\t";
593  PrintQuotedString(Filename, OS);
594  EmitEOL();
595}
596
597void MCAsmStreamer::EmitDwarfFileDirective(unsigned FileNo, StringRef Filename){
598  OS << "\t.file\t" << FileNo << ' ';
599  PrintQuotedString(Filename, OS);
600  EmitEOL();
601}
602
603void MCAsmStreamer::AddEncodingComment(const MCInst &Inst) {
604  raw_ostream &OS = GetCommentOS();
605  SmallString<256> Code;
606  SmallVector<MCFixup, 4> Fixups;
607  raw_svector_ostream VecOS(Code);
608  Emitter->EncodeInstruction(Inst, VecOS, Fixups);
609  VecOS.flush();
610
611  // If we are showing fixups, create symbolic markers in the encoded
612  // representation. We do this by making a per-bit map to the fixup item index,
613  // then trying to display it as nicely as possible.
614  SmallVector<uint8_t, 64> FixupMap;
615  FixupMap.resize(Code.size() * 8);
616  for (unsigned i = 0, e = Code.size() * 8; i != e; ++i)
617    FixupMap[i] = 0;
618
619  for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
620    MCFixup &F = Fixups[i];
621    const MCFixupKindInfo &Info = Emitter->getFixupKindInfo(F.getKind());
622    for (unsigned j = 0; j != Info.TargetSize; ++j) {
623      unsigned Index = F.getOffset() * 8 + Info.TargetOffset + j;
624      assert(Index < Code.size() * 8 && "Invalid offset in fixup!");
625      FixupMap[Index] = 1 + i;
626    }
627  }
628
629  OS << "encoding: [";
630  for (unsigned i = 0, e = Code.size(); i != e; ++i) {
631    if (i)
632      OS << ',';
633
634    // See if all bits are the same map entry.
635    uint8_t MapEntry = FixupMap[i * 8 + 0];
636    for (unsigned j = 1; j != 8; ++j) {
637      if (FixupMap[i * 8 + j] == MapEntry)
638        continue;
639
640      MapEntry = uint8_t(~0U);
641      break;
642    }
643
644    if (MapEntry != uint8_t(~0U)) {
645      if (MapEntry == 0) {
646        OS << format("0x%02x", uint8_t(Code[i]));
647      } else {
648        assert(Code[i] == 0 && "Encoder wrote into fixed up bit!");
649        OS << char('A' + MapEntry - 1);
650      }
651    } else {
652      // Otherwise, write out in binary.
653      OS << "0b";
654      for (unsigned j = 8; j--;) {
655        unsigned Bit = (Code[i] >> j) & 1;
656        if (uint8_t MapEntry = FixupMap[i * 8 + j]) {
657          assert(Bit == 0 && "Encoder wrote into fixed up bit!");
658          OS << char('A' + MapEntry - 1);
659        } else
660          OS << Bit;
661      }
662    }
663  }
664  OS << "]\n";
665
666  for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
667    MCFixup &F = Fixups[i];
668    const MCFixupKindInfo &Info = Emitter->getFixupKindInfo(F.getKind());
669    OS << "  fixup " << char('A' + i) << " - " << "offset: " << F.getOffset()
670       << ", value: " << *F.getValue() << ", kind: " << Info.Name << "\n";
671  }
672}
673
674void MCAsmStreamer::EmitInstruction(const MCInst &Inst) {
675  assert(CurSection && "Cannot emit contents before setting section!");
676
677  // Show the encoding in a comment if we have a code emitter.
678  if (Emitter)
679    AddEncodingComment(Inst);
680
681  // Show the MCInst if enabled.
682  if (ShowInst) {
683    Inst.dump_pretty(GetCommentOS(), &MAI, InstPrinter.get(), "\n ");
684    GetCommentOS() << "\n";
685  }
686
687  // If we have an AsmPrinter, use that to print, otherwise print the MCInst.
688  if (InstPrinter)
689    InstPrinter->printInst(&Inst, OS);
690  else
691    Inst.print(OS, &MAI);
692  EmitEOL();
693}
694
695/// EmitRawText - If this file is backed by an assembly streamer, this dumps
696/// the specified string in the output .s file.  This capability is
697/// indicated by the hasRawTextSupport() predicate.
698void MCAsmStreamer::EmitRawText(StringRef String) {
699  if (!String.empty() && String.back() == '\n')
700    String = String.substr(0, String.size()-1);
701  OS << String;
702  EmitEOL();
703}
704
705void MCAsmStreamer::Finish() {
706}
707
708MCStreamer *llvm::createAsmStreamer(MCContext &Context,
709                                    formatted_raw_ostream &OS,
710                                    bool isLittleEndian,
711                                    bool isVerboseAsm, MCInstPrinter *IP,
712                                    MCCodeEmitter *CE, bool ShowInst) {
713  return new MCAsmStreamer(Context, OS, isLittleEndian, isVerboseAsm,
714                           IP, CE, ShowInst);
715}
716