MCAsmStreamer.cpp revision 212904 
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 EmitLabel(MCSymbol *Symbol);
104
105  virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
106
107  virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
108
109  virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
110
111  virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
112  virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol);
113  virtual void EmitCOFFSymbolStorageClass(int StorageClass);
114  virtual void EmitCOFFSymbolType(int Type);
115  virtual void EndCOFFSymbolDef();
116  virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value);
117  virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
118                                unsigned ByteAlignment);
119
120  /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
121  ///
122  /// @param Symbol - The common symbol to emit.
123  /// @param Size - The size of the common symbol.
124  virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size);
125
126  virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
127                            unsigned Size = 0, unsigned ByteAlignment = 0);
128
129  virtual void EmitTBSSSymbol (const MCSection *Section, MCSymbol *Symbol,
130                               uint64_t Size, unsigned ByteAlignment = 0);
131
132  virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
133
134  virtual void EmitValue(const MCExpr *Value, unsigned Size,unsigned AddrSpace);
135  virtual void EmitIntValue(uint64_t Value, unsigned Size, unsigned AddrSpace);
136  virtual void EmitGPRel32Value(const MCExpr *Value);
137
138
139  virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue,
140                        unsigned AddrSpace);
141
142  virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
143                                    unsigned ValueSize = 1,
144                                    unsigned MaxBytesToEmit = 0);
145
146  virtual void EmitCodeAlignment(unsigned ByteAlignment,
147                                 unsigned MaxBytesToEmit = 0);
148
149  virtual void EmitValueToOffset(const MCExpr *Offset,
150                                 unsigned char Value = 0);
151
152  virtual void EmitFileDirective(StringRef Filename);
153  virtual void EmitDwarfFileDirective(unsigned FileNo, StringRef Filename);
154
155  virtual void EmitInstruction(const MCInst &Inst);
156
157  /// EmitRawText - If this file is backed by a assembly streamer, this dumps
158  /// the specified string in the output .s file.  This capability is
159  /// indicated by the hasRawTextSupport() predicate.
160  virtual void EmitRawText(StringRef String);
161
162  virtual void Finish();
163
164  /// @}
165};
166
167} // end anonymous namespace.
168
169/// AddComment - Add a comment that can be emitted to the generated .s
170/// file if applicable as a QoI issue to make the output of the compiler
171/// more readable.  This only affects the MCAsmStreamer, and only when
172/// verbose assembly output is enabled.
173void MCAsmStreamer::AddComment(const Twine &T) {
174  if (!IsVerboseAsm) return;
175
176  // Make sure that CommentStream is flushed.
177  CommentStream.flush();
178
179  T.toVector(CommentToEmit);
180  // Each comment goes on its own line.
181  CommentToEmit.push_back('\n');
182
183  // Tell the comment stream that the vector changed underneath it.
184  CommentStream.resync();
185}
186
187void MCAsmStreamer::EmitCommentsAndEOL() {
188  if (CommentToEmit.empty() && CommentStream.GetNumBytesInBuffer() == 0) {
189    OS << '\n';
190    return;
191  }
192
193  CommentStream.flush();
194  StringRef Comments = CommentToEmit.str();
195
196  assert(Comments.back() == '\n' &&
197         "Comment array not newline terminated");
198  do {
199    // Emit a line of comments.
200    OS.PadToColumn(MAI.getCommentColumn());
201    size_t Position = Comments.find('\n');
202    OS << MAI.getCommentString() << ' ' << Comments.substr(0, Position) << '\n';
203
204    Comments = Comments.substr(Position+1);
205  } while (!Comments.empty());
206
207  CommentToEmit.clear();
208  // Tell the comment stream that the vector changed underneath it.
209  CommentStream.resync();
210}
211
212static inline int64_t truncateToSize(int64_t Value, unsigned Bytes) {
213  assert(Bytes && "Invalid size!");
214  return Value & ((uint64_t) (int64_t) -1 >> (64 - Bytes * 8));
215}
216
217void MCAsmStreamer::SwitchSection(const MCSection *Section) {
218  assert(Section && "Cannot switch to a null section!");
219  if (Section != CurSection) {
220    PrevSection = CurSection;
221    CurSection = Section;
222    Section->PrintSwitchToSection(MAI, OS);
223  }
224}
225
226void MCAsmStreamer::EmitLabel(MCSymbol *Symbol) {
227  assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
228  assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
229  assert(CurSection && "Cannot emit before setting section!");
230
231  OS << *Symbol << ":";
232  EmitEOL();
233  Symbol->setSection(*CurSection);
234}
235
236void MCAsmStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
237  switch (Flag) {
238  default: assert(0 && "Invalid flag!");
239  case MCAF_SubsectionsViaSymbols: OS << ".subsections_via_symbols"; break;
240  }
241  EmitEOL();
242}
243
244void MCAsmStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
245  OS << *Symbol << " = " << *Value;
246  EmitEOL();
247
248  // FIXME: Lift context changes into super class.
249  Symbol->setVariableValue(Value);
250}
251
252void MCAsmStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
253                                        MCSymbolAttr Attribute) {
254  switch (Attribute) {
255  case MCSA_Invalid: assert(0 && "Invalid symbol attribute");
256  case MCSA_ELF_TypeFunction:    /// .type _foo, STT_FUNC  # aka @function
257  case MCSA_ELF_TypeIndFunction: /// .type _foo, STT_GNU_IFUNC
258  case MCSA_ELF_TypeObject:      /// .type _foo, STT_OBJECT  # aka @object
259  case MCSA_ELF_TypeTLS:         /// .type _foo, STT_TLS     # aka @tls_object
260  case MCSA_ELF_TypeCommon:      /// .type _foo, STT_COMMON  # aka @common
261  case MCSA_ELF_TypeNoType:      /// .type _foo, STT_NOTYPE  # aka @notype
262    assert(MAI.hasDotTypeDotSizeDirective() && "Symbol Attr not supported");
263    OS << "\t.type\t" << *Symbol << ','
264       << ((MAI.getCommentString()[0] != '@') ? '@' : '%');
265    switch (Attribute) {
266    default: assert(0 && "Unknown ELF .type");
267    case MCSA_ELF_TypeFunction:    OS << "function"; break;
268    case MCSA_ELF_TypeIndFunction: OS << "gnu_indirect_function"; break;
269    case MCSA_ELF_TypeObject:      OS << "object"; break;
270    case MCSA_ELF_TypeTLS:         OS << "tls_object"; break;
271    case MCSA_ELF_TypeCommon:      OS << "common"; break;
272    case MCSA_ELF_TypeNoType:      OS << "no_type"; break;
273    }
274    EmitEOL();
275    return;
276  case MCSA_Global: // .globl/.global
277    OS << MAI.getGlobalDirective();
278    break;
279  case MCSA_Hidden:         OS << "\t.hidden\t";          break;
280  case MCSA_IndirectSymbol: OS << "\t.indirect_symbol\t"; break;
281  case MCSA_Internal:       OS << "\t.internal\t";        break;
282  case MCSA_LazyReference:  OS << "\t.lazy_reference\t";  break;
283  case MCSA_Local:          OS << "\t.local\t";           break;
284  case MCSA_NoDeadStrip:    OS << "\t.no_dead_strip\t";   break;
285  case MCSA_PrivateExtern:  OS << "\t.private_extern\t";  break;
286  case MCSA_Protected:      OS << "\t.protected\t";       break;
287  case MCSA_Reference:      OS << "\t.reference\t";       break;
288  case MCSA_Weak:           OS << "\t.weak\t";            break;
289  case MCSA_WeakDefinition: OS << "\t.weak_definition\t"; break;
290      // .weak_reference
291  case MCSA_WeakReference:  OS << MAI.getWeakRefDirective(); break;
292  case MCSA_WeakDefAutoPrivate: OS << "\t.weak_def_can_be_hidden\t"; break;
293  }
294
295  OS << *Symbol;
296  EmitEOL();
297}
298
299void MCAsmStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
300  OS << ".desc" << ' ' << *Symbol << ',' << DescValue;
301  EmitEOL();
302}
303
304void MCAsmStreamer::BeginCOFFSymbolDef(const MCSymbol *Symbol) {
305  OS << "\t.def\t " << *Symbol << ';';
306  EmitEOL();
307}
308
309void MCAsmStreamer::EmitCOFFSymbolStorageClass (int StorageClass) {
310  OS << "\t.scl\t" << StorageClass << ';';
311  EmitEOL();
312}
313
314void MCAsmStreamer::EmitCOFFSymbolType (int Type) {
315  OS << "\t.type\t" << Type << ';';
316  EmitEOL();
317}
318
319void MCAsmStreamer::EndCOFFSymbolDef() {
320  OS << "\t.endef";
321  EmitEOL();
322}
323
324void MCAsmStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
325  assert(MAI.hasDotTypeDotSizeDirective());
326  OS << "\t.size\t" << *Symbol << ", " << *Value << '\n';
327}
328
329void MCAsmStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
330                                     unsigned ByteAlignment) {
331  OS << "\t.comm\t" << *Symbol << ',' << Size;
332  if (ByteAlignment != 0) {
333    if (MAI.getCOMMDirectiveAlignmentIsInBytes())
334      OS << ',' << ByteAlignment;
335    else
336      OS << ',' << Log2_32(ByteAlignment);
337  }
338  EmitEOL();
339}
340
341/// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
342///
343/// @param Symbol - The common symbol to emit.
344/// @param Size - The size of the common symbol.
345void MCAsmStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {
346  assert(MAI.hasLCOMMDirective() && "Doesn't have .lcomm, can't emit it!");
347  OS << "\t.lcomm\t" << *Symbol << ',' << Size;
348  EmitEOL();
349}
350
351void MCAsmStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
352                                 unsigned Size, unsigned ByteAlignment) {
353  // Note: a .zerofill directive does not switch sections.
354  OS << ".zerofill ";
355
356  // This is a mach-o specific directive.
357  const MCSectionMachO *MOSection = ((const MCSectionMachO*)Section);
358  OS << MOSection->getSegmentName() << "," << MOSection->getSectionName();
359
360  if (Symbol != NULL) {
361    OS << ',' << *Symbol << ',' << Size;
362    if (ByteAlignment != 0)
363      OS << ',' << Log2_32(ByteAlignment);
364  }
365  EmitEOL();
366}
367
368// .tbss sym, size, align
369// This depends that the symbol has already been mangled from the original,
370// e.g. _a.
371void MCAsmStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
372                                   uint64_t Size, unsigned ByteAlignment) {
373  assert(Symbol != NULL && "Symbol shouldn't be NULL!");
374  // Instead of using the Section we'll just use the shortcut.
375  // This is a mach-o specific directive and section.
376  OS << ".tbss " << *Symbol << ", " << Size;
377
378  // Output align if we have it.  We default to 1 so don't bother printing
379  // that.
380  if (ByteAlignment > 1) OS << ", " << Log2_32(ByteAlignment);
381
382  EmitEOL();
383}
384
385static inline char toOctal(int X) { return (X&7)+'0'; }
386
387static void PrintQuotedString(StringRef Data, raw_ostream &OS) {
388  OS << '"';
389
390  for (unsigned i = 0, e = Data.size(); i != e; ++i) {
391    unsigned char C = Data[i];
392    if (C == '"' || C == '\\') {
393      OS << '\\' << (char)C;
394      continue;
395    }
396
397    if (isprint((unsigned char)C)) {
398      OS << (char)C;
399      continue;
400    }
401
402    switch (C) {
403      case '\b': OS << "\\b"; break;
404      case '\f': OS << "\\f"; break;
405      case '\n': OS << "\\n"; break;
406      case '\r': OS << "\\r"; break;
407      case '\t': OS << "\\t"; break;
408      default:
409        OS << '\\';
410        OS << toOctal(C >> 6);
411        OS << toOctal(C >> 3);
412        OS << toOctal(C >> 0);
413        break;
414    }
415  }
416
417  OS << '"';
418}
419
420
421void MCAsmStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
422  assert(CurSection && "Cannot emit contents before setting section!");
423  if (Data.empty()) return;
424
425  if (Data.size() == 1) {
426    OS << MAI.getData8bitsDirective(AddrSpace);
427    OS << (unsigned)(unsigned char)Data[0];
428    EmitEOL();
429    return;
430  }
431
432  // If the data ends with 0 and the target supports .asciz, use it, otherwise
433  // use .ascii
434  if (MAI.getAscizDirective() && Data.back() == 0) {
435    OS << MAI.getAscizDirective();
436    Data = Data.substr(0, Data.size()-1);
437  } else {
438    OS << MAI.getAsciiDirective();
439  }
440
441  OS << ' ';
442  PrintQuotedString(Data, OS);
443  EmitEOL();
444}
445
446/// EmitIntValue - Special case of EmitValue that avoids the client having
447/// to pass in a MCExpr for constant integers.
448void MCAsmStreamer::EmitIntValue(uint64_t Value, unsigned Size,
449                                 unsigned AddrSpace) {
450  assert(CurSection && "Cannot emit contents before setting section!");
451  const char *Directive = 0;
452  switch (Size) {
453  default: break;
454  case 1: Directive = MAI.getData8bitsDirective(AddrSpace); break;
455  case 2: Directive = MAI.getData16bitsDirective(AddrSpace); break;
456  case 4: Directive = MAI.getData32bitsDirective(AddrSpace); break;
457  case 8:
458    Directive = MAI.getData64bitsDirective(AddrSpace);
459    // If the target doesn't support 64-bit data, emit as two 32-bit halves.
460    if (Directive) break;
461    if (isLittleEndian()) {
462      EmitIntValue((uint32_t)(Value >> 0 ), 4, AddrSpace);
463      EmitIntValue((uint32_t)(Value >> 32), 4, AddrSpace);
464    } else {
465      EmitIntValue((uint32_t)(Value >> 32), 4, AddrSpace);
466      EmitIntValue((uint32_t)(Value >> 0 ), 4, AddrSpace);
467    }
468    return;
469  }
470
471  assert(Directive && "Invalid size for machine code value!");
472  OS << Directive << truncateToSize(Value, Size);
473  EmitEOL();
474}
475
476void MCAsmStreamer::EmitValue(const MCExpr *Value, unsigned Size,
477                              unsigned AddrSpace) {
478  assert(CurSection && "Cannot emit contents before setting section!");
479  const char *Directive = 0;
480  switch (Size) {
481  default: break;
482  case 1: Directive = MAI.getData8bitsDirective(AddrSpace); break;
483  case 2: Directive = MAI.getData16bitsDirective(AddrSpace); break;
484  case 4: Directive = MAI.getData32bitsDirective(AddrSpace); break;
485  case 8: Directive = MAI.getData64bitsDirective(AddrSpace); break;
486  }
487
488  assert(Directive && "Invalid size for machine code value!");
489  OS << Directive << *Value;
490  EmitEOL();
491}
492
493void MCAsmStreamer::EmitGPRel32Value(const MCExpr *Value) {
494  assert(MAI.getGPRel32Directive() != 0);
495  OS << MAI.getGPRel32Directive() << *Value;
496  EmitEOL();
497}
498
499
500/// EmitFill - Emit NumBytes bytes worth of the value specified by
501/// FillValue.  This implements directives such as '.space'.
502void MCAsmStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
503                             unsigned AddrSpace) {
504  if (NumBytes == 0) return;
505
506  if (AddrSpace == 0)
507    if (const char *ZeroDirective = MAI.getZeroDirective()) {
508      OS << ZeroDirective << NumBytes;
509      if (FillValue != 0)
510        OS << ',' << (int)FillValue;
511      EmitEOL();
512      return;
513    }
514
515  // Emit a byte at a time.
516  MCStreamer::EmitFill(NumBytes, FillValue, AddrSpace);
517}
518
519void MCAsmStreamer::EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
520                                         unsigned ValueSize,
521                                         unsigned MaxBytesToEmit) {
522  // Some assemblers don't support non-power of two alignments, so we always
523  // emit alignments as a power of two if possible.
524  if (isPowerOf2_32(ByteAlignment)) {
525    switch (ValueSize) {
526    default: llvm_unreachable("Invalid size for machine code value!");
527    case 1: OS << MAI.getAlignDirective(); break;
528    // FIXME: use MAI for this!
529    case 2: OS << ".p2alignw "; break;
530    case 4: OS << ".p2alignl "; break;
531    case 8: llvm_unreachable("Unsupported alignment size!");
532    }
533
534    if (MAI.getAlignmentIsInBytes())
535      OS << ByteAlignment;
536    else
537      OS << Log2_32(ByteAlignment);
538
539    if (Value || MaxBytesToEmit) {
540      OS << ", 0x";
541      OS.write_hex(truncateToSize(Value, ValueSize));
542
543      if (MaxBytesToEmit)
544        OS << ", " << MaxBytesToEmit;
545    }
546    EmitEOL();
547    return;
548  }
549
550  // Non-power of two alignment.  This is not widely supported by assemblers.
551  // FIXME: Parameterize this based on MAI.
552  switch (ValueSize) {
553  default: llvm_unreachable("Invalid size for machine code value!");
554  case 1: OS << ".balign";  break;
555  case 2: OS << ".balignw"; break;
556  case 4: OS << ".balignl"; break;
557  case 8: llvm_unreachable("Unsupported alignment size!");
558  }
559
560  OS << ' ' << ByteAlignment;
561  OS << ", " << truncateToSize(Value, ValueSize);
562  if (MaxBytesToEmit)
563    OS << ", " << MaxBytesToEmit;
564  EmitEOL();
565}
566
567void MCAsmStreamer::EmitCodeAlignment(unsigned ByteAlignment,
568                                      unsigned MaxBytesToEmit) {
569  // Emit with a text fill value.
570  EmitValueToAlignment(ByteAlignment, MAI.getTextAlignFillValue(),
571                       1, MaxBytesToEmit);
572}
573
574void MCAsmStreamer::EmitValueToOffset(const MCExpr *Offset,
575                                      unsigned char Value) {
576  // FIXME: Verify that Offset is associated with the current section.
577  OS << ".org " << *Offset << ", " << (unsigned) Value;
578  EmitEOL();
579}
580
581
582void MCAsmStreamer::EmitFileDirective(StringRef Filename) {
583  assert(MAI.hasSingleParameterDotFile());
584  OS << "\t.file\t";
585  PrintQuotedString(Filename, OS);
586  EmitEOL();
587}
588
589void MCAsmStreamer::EmitDwarfFileDirective(unsigned FileNo, StringRef Filename){
590  OS << "\t.file\t" << FileNo << ' ';
591  PrintQuotedString(Filename, OS);
592  EmitEOL();
593}
594
595void MCAsmStreamer::AddEncodingComment(const MCInst &Inst) {
596  raw_ostream &OS = GetCommentOS();
597  SmallString<256> Code;
598  SmallVector<MCFixup, 4> Fixups;
599  raw_svector_ostream VecOS(Code);
600  Emitter->EncodeInstruction(Inst, VecOS, Fixups);
601  VecOS.flush();
602
603  // If we are showing fixups, create symbolic markers in the encoded
604  // representation. We do this by making a per-bit map to the fixup item index,
605  // then trying to display it as nicely as possible.
606  SmallVector<uint8_t, 64> FixupMap;
607  FixupMap.resize(Code.size() * 8);
608  for (unsigned i = 0, e = Code.size() * 8; i != e; ++i)
609    FixupMap[i] = 0;
610
611  for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
612    MCFixup &F = Fixups[i];
613    const MCFixupKindInfo &Info = Emitter->getFixupKindInfo(F.getKind());
614    for (unsigned j = 0; j != Info.TargetSize; ++j) {
615      unsigned Index = F.getOffset() * 8 + Info.TargetOffset + j;
616      assert(Index < Code.size() * 8 && "Invalid offset in fixup!");
617      FixupMap[Index] = 1 + i;
618    }
619  }
620
621  OS << "encoding: [";
622  for (unsigned i = 0, e = Code.size(); i != e; ++i) {
623    if (i)
624      OS << ',';
625
626    // See if all bits are the same map entry.
627    uint8_t MapEntry = FixupMap[i * 8 + 0];
628    for (unsigned j = 1; j != 8; ++j) {
629      if (FixupMap[i * 8 + j] == MapEntry)
630        continue;
631
632      MapEntry = uint8_t(~0U);
633      break;
634    }
635
636    if (MapEntry != uint8_t(~0U)) {
637      if (MapEntry == 0) {
638        OS << format("0x%02x", uint8_t(Code[i]));
639      } else {
640        assert(Code[i] == 0 && "Encoder wrote into fixed up bit!");
641        OS << char('A' + MapEntry - 1);
642      }
643    } else {
644      // Otherwise, write out in binary.
645      OS << "0b";
646      for (unsigned j = 8; j--;) {
647        unsigned Bit = (Code[i] >> j) & 1;
648        if (uint8_t MapEntry = FixupMap[i * 8 + j]) {
649          assert(Bit == 0 && "Encoder wrote into fixed up bit!");
650          OS << char('A' + MapEntry - 1);
651        } else
652          OS << Bit;
653      }
654    }
655  }
656  OS << "]\n";
657
658  for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
659    MCFixup &F = Fixups[i];
660    const MCFixupKindInfo &Info = Emitter->getFixupKindInfo(F.getKind());
661    OS << "  fixup " << char('A' + i) << " - " << "offset: " << F.getOffset()
662       << ", value: " << *F.getValue() << ", kind: " << Info.Name << "\n";
663  }
664}
665
666void MCAsmStreamer::EmitInstruction(const MCInst &Inst) {
667  assert(CurSection && "Cannot emit contents before setting section!");
668
669  // Show the encoding in a comment if we have a code emitter.
670  if (Emitter)
671    AddEncodingComment(Inst);
672
673  // Show the MCInst if enabled.
674  if (ShowInst) {
675    Inst.dump_pretty(GetCommentOS(), &MAI, InstPrinter.get(), "\n ");
676    GetCommentOS() << "\n";
677  }
678
679  // If we have an AsmPrinter, use that to print, otherwise print the MCInst.
680  if (InstPrinter)
681    InstPrinter->printInst(&Inst, OS);
682  else
683    Inst.print(OS, &MAI);
684  EmitEOL();
685}
686
687/// EmitRawText - If this file is backed by a assembly streamer, this dumps
688/// the specified string in the output .s file.  This capability is
689/// indicated by the hasRawTextSupport() predicate.
690void MCAsmStreamer::EmitRawText(StringRef String) {
691  if (!String.empty() && String.back() == '\n')
692    String = String.substr(0, String.size()-1);
693  OS << String;
694  EmitEOL();
695}
696
697void MCAsmStreamer::Finish() {
698}
699
700MCStreamer *llvm::createAsmStreamer(MCContext &Context,
701                                    formatted_raw_ostream &OS,
702                                    bool isLittleEndian,
703                                    bool isVerboseAsm, MCInstPrinter *IP,
704                                    MCCodeEmitter *CE, bool ShowInst) {
705  return new MCAsmStreamer(Context, OS, isLittleEndian, isVerboseAsm,
706                           IP, CE, ShowInst);
707}
708