MCAsmStreamer.cpp revision 738734501635a15d8ed2d1c8d52962ed5f319bd3 
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  virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol);
117
118  virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
119
120  virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
121  virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol);
122  virtual void EmitCOFFSymbolStorageClass(int StorageClass);
123  virtual void EmitCOFFSymbolType(int Type);
124  virtual void EndCOFFSymbolDef();
125  virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value);
126  virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
127                                unsigned ByteAlignment);
128
129  /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
130  ///
131  /// @param Symbol - The common symbol to emit.
132  /// @param Size - The size of the common symbol.
133  virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size);
134
135  virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
136                            unsigned Size = 0, unsigned ByteAlignment = 0);
137
138  virtual void EmitTBSSSymbol (const MCSection *Section, MCSymbol *Symbol,
139                               uint64_t Size, unsigned ByteAlignment = 0);
140
141  virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
142
143  virtual void EmitValue(const MCExpr *Value, unsigned Size,unsigned AddrSpace);
144
145  virtual void EmitIntValue(uint64_t Value, unsigned Size, unsigned AddrSpace);
146
147  virtual void EmitULEB128Value(const MCExpr *Value, unsigned AddrSpace = 0);
148
149  virtual void EmitSLEB128Value(const MCExpr *Value, unsigned AddrSpace = 0);
150
151  virtual void EmitGPRel32Value(const MCExpr *Value);
152
153
154  virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue,
155                        unsigned AddrSpace);
156
157  virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
158                                    unsigned ValueSize = 1,
159                                    unsigned MaxBytesToEmit = 0);
160
161  virtual void EmitCodeAlignment(unsigned ByteAlignment,
162                                 unsigned MaxBytesToEmit = 0);
163
164  virtual void EmitValueToOffset(const MCExpr *Offset,
165                                 unsigned char Value = 0);
166
167  virtual void EmitFileDirective(StringRef Filename);
168  virtual void EmitDwarfFileDirective(unsigned FileNo, StringRef Filename);
169
170  virtual void EmitInstruction(const MCInst &Inst);
171
172  /// EmitRawText - If this file is backed by an assembly streamer, this dumps
173  /// the specified string in the output .s file.  This capability is
174  /// indicated by the hasRawTextSupport() predicate.
175  virtual void EmitRawText(StringRef String);
176
177  virtual void Finish();
178
179  /// @}
180};
181
182} // end anonymous namespace.
183
184/// AddComment - Add a comment that can be emitted to the generated .s
185/// file if applicable as a QoI issue to make the output of the compiler
186/// more readable.  This only affects the MCAsmStreamer, and only when
187/// verbose assembly output is enabled.
188void MCAsmStreamer::AddComment(const Twine &T) {
189  if (!IsVerboseAsm) return;
190
191  // Make sure that CommentStream is flushed.
192  CommentStream.flush();
193
194  T.toVector(CommentToEmit);
195  // Each comment goes on its own line.
196  CommentToEmit.push_back('\n');
197
198  // Tell the comment stream that the vector changed underneath it.
199  CommentStream.resync();
200}
201
202void MCAsmStreamer::EmitCommentsAndEOL() {
203  if (CommentToEmit.empty() && CommentStream.GetNumBytesInBuffer() == 0) {
204    OS << '\n';
205    return;
206  }
207
208  CommentStream.flush();
209  StringRef Comments = CommentToEmit.str();
210
211  assert(Comments.back() == '\n' &&
212         "Comment array not newline terminated");
213  do {
214    // Emit a line of comments.
215    OS.PadToColumn(MAI.getCommentColumn());
216    size_t Position = Comments.find('\n');
217    OS << MAI.getCommentString() << ' ' << Comments.substr(0, Position) << '\n';
218
219    Comments = Comments.substr(Position+1);
220  } while (!Comments.empty());
221
222  CommentToEmit.clear();
223  // Tell the comment stream that the vector changed underneath it.
224  CommentStream.resync();
225}
226
227static inline int64_t truncateToSize(int64_t Value, unsigned Bytes) {
228  assert(Bytes && "Invalid size!");
229  return Value & ((uint64_t) (int64_t) -1 >> (64 - Bytes * 8));
230}
231
232void MCAsmStreamer::SwitchSection(const MCSection *Section) {
233  assert(Section && "Cannot switch to a null section!");
234  if (Section != CurSection) {
235    PrevSection = CurSection;
236    CurSection = Section;
237    Section->PrintSwitchToSection(MAI, OS);
238  }
239}
240
241void MCAsmStreamer::EmitLabel(MCSymbol *Symbol) {
242  assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
243  assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
244  assert(CurSection && "Cannot emit before setting section!");
245
246  OS << *Symbol << MAI.getLabelSuffix();
247  EmitEOL();
248  Symbol->setSection(*CurSection);
249}
250
251void MCAsmStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
252  switch (Flag) {
253  default: assert(0 && "Invalid flag!");
254  case MCAF_SyntaxUnified:         OS << "\t.syntax unified"; break;
255  case MCAF_SubsectionsViaSymbols: OS << ".subsections_via_symbols"; break;
256  }
257  EmitEOL();
258}
259
260void MCAsmStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
261  OS << *Symbol << " = " << *Value;
262  EmitEOL();
263
264  // FIXME: Lift context changes into super class.
265  Symbol->setVariableValue(Value);
266}
267
268void MCAsmStreamer::EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {
269  OS << ".weakref " << *Alias << ", " << *Symbol;
270  EmitEOL();
271}
272
273void MCAsmStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
274                                        MCSymbolAttr Attribute) {
275  switch (Attribute) {
276  case MCSA_Invalid: assert(0 && "Invalid symbol attribute");
277  case MCSA_ELF_TypeFunction:    /// .type _foo, STT_FUNC  # aka @function
278  case MCSA_ELF_TypeIndFunction: /// .type _foo, STT_GNU_IFUNC
279  case MCSA_ELF_TypeObject:      /// .type _foo, STT_OBJECT  # aka @object
280  case MCSA_ELF_TypeTLS:         /// .type _foo, STT_TLS     # aka @tls_object
281  case MCSA_ELF_TypeCommon:      /// .type _foo, STT_COMMON  # aka @common
282  case MCSA_ELF_TypeNoType:      /// .type _foo, STT_NOTYPE  # aka @notype
283    assert(MAI.hasDotTypeDotSizeDirective() && "Symbol Attr not supported");
284    OS << "\t.type\t" << *Symbol << ','
285       << ((MAI.getCommentString()[0] != '@') ? '@' : '%');
286    switch (Attribute) {
287    default: assert(0 && "Unknown ELF .type");
288    case MCSA_ELF_TypeFunction:    OS << "function"; break;
289    case MCSA_ELF_TypeIndFunction: OS << "gnu_indirect_function"; break;
290    case MCSA_ELF_TypeObject:      OS << "object"; break;
291    case MCSA_ELF_TypeTLS:         OS << "tls_object"; break;
292    case MCSA_ELF_TypeCommon:      OS << "common"; break;
293    case MCSA_ELF_TypeNoType:      OS << "no_type"; break;
294    }
295    EmitEOL();
296    return;
297  case MCSA_Global: // .globl/.global
298    OS << MAI.getGlobalDirective();
299    break;
300  case MCSA_Hidden:         OS << "\t.hidden\t";          break;
301  case MCSA_IndirectSymbol: OS << "\t.indirect_symbol\t"; break;
302  case MCSA_Internal:       OS << "\t.internal\t";        break;
303  case MCSA_LazyReference:  OS << "\t.lazy_reference\t";  break;
304  case MCSA_Local:          OS << "\t.local\t";           break;
305  case MCSA_NoDeadStrip:    OS << "\t.no_dead_strip\t";   break;
306  case MCSA_PrivateExtern:  OS << "\t.private_extern\t";  break;
307  case MCSA_Protected:      OS << "\t.protected\t";       break;
308  case MCSA_Reference:      OS << "\t.reference\t";       break;
309  case MCSA_Weak:           OS << "\t.weak\t";            break;
310  case MCSA_WeakDefinition: OS << "\t.weak_definition\t"; break;
311      // .weak_reference
312  case MCSA_WeakReference:  OS << MAI.getWeakRefDirective(); break;
313  case MCSA_WeakDefAutoPrivate: OS << "\t.weak_def_can_be_hidden\t"; break;
314  }
315
316  OS << *Symbol;
317  EmitEOL();
318}
319
320void MCAsmStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
321  OS << ".desc" << ' ' << *Symbol << ',' << DescValue;
322  EmitEOL();
323}
324
325void MCAsmStreamer::BeginCOFFSymbolDef(const MCSymbol *Symbol) {
326  OS << "\t.def\t " << *Symbol << ';';
327  EmitEOL();
328}
329
330void MCAsmStreamer::EmitCOFFSymbolStorageClass (int StorageClass) {
331  OS << "\t.scl\t" << StorageClass << ';';
332  EmitEOL();
333}
334
335void MCAsmStreamer::EmitCOFFSymbolType (int Type) {
336  OS << "\t.type\t" << Type << ';';
337  EmitEOL();
338}
339
340void MCAsmStreamer::EndCOFFSymbolDef() {
341  OS << "\t.endef";
342  EmitEOL();
343}
344
345void MCAsmStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
346  assert(MAI.hasDotTypeDotSizeDirective());
347  OS << "\t.size\t" << *Symbol << ", " << *Value << '\n';
348}
349
350void MCAsmStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
351                                     unsigned ByteAlignment) {
352  OS << "\t.comm\t" << *Symbol << ',' << Size;
353  if (ByteAlignment != 0) {
354    if (MAI.getCOMMDirectiveAlignmentIsInBytes())
355      OS << ',' << ByteAlignment;
356    else
357      OS << ',' << Log2_32(ByteAlignment);
358  }
359  EmitEOL();
360}
361
362/// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
363///
364/// @param Symbol - The common symbol to emit.
365/// @param Size - The size of the common symbol.
366void MCAsmStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {
367  assert(MAI.hasLCOMMDirective() && "Doesn't have .lcomm, can't emit it!");
368  OS << "\t.lcomm\t" << *Symbol << ',' << Size;
369  EmitEOL();
370}
371
372void MCAsmStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
373                                 unsigned Size, unsigned ByteAlignment) {
374  // Note: a .zerofill directive does not switch sections.
375  OS << ".zerofill ";
376
377  // This is a mach-o specific directive.
378  const MCSectionMachO *MOSection = ((const MCSectionMachO*)Section);
379  OS << MOSection->getSegmentName() << "," << MOSection->getSectionName();
380
381  if (Symbol != NULL) {
382    OS << ',' << *Symbol << ',' << Size;
383    if (ByteAlignment != 0)
384      OS << ',' << Log2_32(ByteAlignment);
385  }
386  EmitEOL();
387}
388
389// .tbss sym, size, align
390// This depends that the symbol has already been mangled from the original,
391// e.g. _a.
392void MCAsmStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
393                                   uint64_t Size, unsigned ByteAlignment) {
394  assert(Symbol != NULL && "Symbol shouldn't be NULL!");
395  // Instead of using the Section we'll just use the shortcut.
396  // This is a mach-o specific directive and section.
397  OS << ".tbss " << *Symbol << ", " << Size;
398
399  // Output align if we have it.  We default to 1 so don't bother printing
400  // that.
401  if (ByteAlignment > 1) OS << ", " << Log2_32(ByteAlignment);
402
403  EmitEOL();
404}
405
406static inline char toOctal(int X) { return (X&7)+'0'; }
407
408static void PrintQuotedString(StringRef Data, raw_ostream &OS) {
409  OS << '"';
410
411  for (unsigned i = 0, e = Data.size(); i != e; ++i) {
412    unsigned char C = Data[i];
413    if (C == '"' || C == '\\') {
414      OS << '\\' << (char)C;
415      continue;
416    }
417
418    if (isprint((unsigned char)C)) {
419      OS << (char)C;
420      continue;
421    }
422
423    switch (C) {
424      case '\b': OS << "\\b"; break;
425      case '\f': OS << "\\f"; break;
426      case '\n': OS << "\\n"; break;
427      case '\r': OS << "\\r"; break;
428      case '\t': OS << "\\t"; break;
429      default:
430        OS << '\\';
431        OS << toOctal(C >> 6);
432        OS << toOctal(C >> 3);
433        OS << toOctal(C >> 0);
434        break;
435    }
436  }
437
438  OS << '"';
439}
440
441
442void MCAsmStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
443  assert(CurSection && "Cannot emit contents before setting section!");
444  if (Data.empty()) return;
445
446  if (Data.size() == 1) {
447    OS << MAI.getData8bitsDirective(AddrSpace);
448    OS << (unsigned)(unsigned char)Data[0];
449    EmitEOL();
450    return;
451  }
452
453  // If the data ends with 0 and the target supports .asciz, use it, otherwise
454  // use .ascii
455  if (MAI.getAscizDirective() && Data.back() == 0) {
456    OS << MAI.getAscizDirective();
457    Data = Data.substr(0, Data.size()-1);
458  } else {
459    OS << MAI.getAsciiDirective();
460  }
461
462  OS << ' ';
463  PrintQuotedString(Data, OS);
464  EmitEOL();
465}
466
467/// EmitIntValue - Special case of EmitValue that avoids the client having
468/// to pass in a MCExpr for constant integers.
469void MCAsmStreamer::EmitIntValue(uint64_t Value, unsigned Size,
470                                 unsigned AddrSpace) {
471  assert(CurSection && "Cannot emit contents before setting section!");
472  const char *Directive = 0;
473  switch (Size) {
474  default: break;
475  case 1: Directive = MAI.getData8bitsDirective(AddrSpace); break;
476  case 2: Directive = MAI.getData16bitsDirective(AddrSpace); break;
477  case 4: Directive = MAI.getData32bitsDirective(AddrSpace); break;
478  case 8:
479    Directive = MAI.getData64bitsDirective(AddrSpace);
480    // If the target doesn't support 64-bit data, emit as two 32-bit halves.
481    if (Directive) break;
482    if (isLittleEndian()) {
483      EmitIntValue((uint32_t)(Value >> 0 ), 4, AddrSpace);
484      EmitIntValue((uint32_t)(Value >> 32), 4, AddrSpace);
485    } else {
486      EmitIntValue((uint32_t)(Value >> 32), 4, AddrSpace);
487      EmitIntValue((uint32_t)(Value >> 0 ), 4, AddrSpace);
488    }
489    return;
490  }
491
492  assert(Directive && "Invalid size for machine code value!");
493  OS << Directive << truncateToSize(Value, Size);
494  EmitEOL();
495}
496
497void MCAsmStreamer::EmitValue(const MCExpr *Value, unsigned Size,
498                              unsigned AddrSpace) {
499  assert(CurSection && "Cannot emit contents before setting section!");
500  const char *Directive = 0;
501  switch (Size) {
502  default: break;
503  case 1: Directive = MAI.getData8bitsDirective(AddrSpace); break;
504  case 2: Directive = MAI.getData16bitsDirective(AddrSpace); break;
505  case 4: Directive = MAI.getData32bitsDirective(AddrSpace); break;
506  case 8: Directive = MAI.getData64bitsDirective(AddrSpace); break;
507  }
508
509  assert(Directive && "Invalid size for machine code value!");
510  OS << Directive << *Value;
511  EmitEOL();
512}
513
514void MCAsmStreamer::EmitULEB128Value(const MCExpr *Value, unsigned AddrSpace) {
515  assert(MAI.hasLEB128() && "Cannot print a .uleb");
516  OS << ".uleb128 " << *Value;
517  EmitEOL();
518}
519
520void MCAsmStreamer::EmitSLEB128Value(const MCExpr *Value, unsigned AddrSpace) {
521  assert(MAI.hasLEB128() && "Cannot print a .sleb");
522  OS << ".sleb128 " << *Value;
523  EmitEOL();
524}
525
526void MCAsmStreamer::EmitGPRel32Value(const MCExpr *Value) {
527  assert(MAI.getGPRel32Directive() != 0);
528  OS << MAI.getGPRel32Directive() << *Value;
529  EmitEOL();
530}
531
532
533/// EmitFill - Emit NumBytes bytes worth of the value specified by
534/// FillValue.  This implements directives such as '.space'.
535void MCAsmStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
536                             unsigned AddrSpace) {
537  if (NumBytes == 0) return;
538
539  if (AddrSpace == 0)
540    if (const char *ZeroDirective = MAI.getZeroDirective()) {
541      OS << ZeroDirective << NumBytes;
542      if (FillValue != 0)
543        OS << ',' << (int)FillValue;
544      EmitEOL();
545      return;
546    }
547
548  // Emit a byte at a time.
549  MCStreamer::EmitFill(NumBytes, FillValue, AddrSpace);
550}
551
552void MCAsmStreamer::EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
553                                         unsigned ValueSize,
554                                         unsigned MaxBytesToEmit) {
555  // Some assemblers don't support non-power of two alignments, so we always
556  // emit alignments as a power of two if possible.
557  if (isPowerOf2_32(ByteAlignment)) {
558    switch (ValueSize) {
559    default: llvm_unreachable("Invalid size for machine code value!");
560    case 1: OS << MAI.getAlignDirective(); break;
561    // FIXME: use MAI for this!
562    case 2: OS << ".p2alignw "; break;
563    case 4: OS << ".p2alignl "; break;
564    case 8: llvm_unreachable("Unsupported alignment size!");
565    }
566
567    if (MAI.getAlignmentIsInBytes())
568      OS << ByteAlignment;
569    else
570      OS << Log2_32(ByteAlignment);
571
572    if (Value || MaxBytesToEmit) {
573      OS << ", 0x";
574      OS.write_hex(truncateToSize(Value, ValueSize));
575
576      if (MaxBytesToEmit)
577        OS << ", " << MaxBytesToEmit;
578    }
579    EmitEOL();
580    return;
581  }
582
583  // Non-power of two alignment.  This is not widely supported by assemblers.
584  // FIXME: Parameterize this based on MAI.
585  switch (ValueSize) {
586  default: llvm_unreachable("Invalid size for machine code value!");
587  case 1: OS << ".balign";  break;
588  case 2: OS << ".balignw"; break;
589  case 4: OS << ".balignl"; break;
590  case 8: llvm_unreachable("Unsupported alignment size!");
591  }
592
593  OS << ' ' << ByteAlignment;
594  OS << ", " << truncateToSize(Value, ValueSize);
595  if (MaxBytesToEmit)
596    OS << ", " << MaxBytesToEmit;
597  EmitEOL();
598}
599
600void MCAsmStreamer::EmitCodeAlignment(unsigned ByteAlignment,
601                                      unsigned MaxBytesToEmit) {
602  // Emit with a text fill value.
603  EmitValueToAlignment(ByteAlignment, MAI.getTextAlignFillValue(),
604                       1, MaxBytesToEmit);
605}
606
607void MCAsmStreamer::EmitValueToOffset(const MCExpr *Offset,
608                                      unsigned char Value) {
609  // FIXME: Verify that Offset is associated with the current section.
610  OS << ".org " << *Offset << ", " << (unsigned) Value;
611  EmitEOL();
612}
613
614
615void MCAsmStreamer::EmitFileDirective(StringRef Filename) {
616  assert(MAI.hasSingleParameterDotFile());
617  OS << "\t.file\t";
618  PrintQuotedString(Filename, OS);
619  EmitEOL();
620}
621
622void MCAsmStreamer::EmitDwarfFileDirective(unsigned FileNo, StringRef Filename){
623  OS << "\t.file\t" << FileNo << ' ';
624  PrintQuotedString(Filename, OS);
625  EmitEOL();
626}
627
628void MCAsmStreamer::AddEncodingComment(const MCInst &Inst) {
629  raw_ostream &OS = GetCommentOS();
630  SmallString<256> Code;
631  SmallVector<MCFixup, 4> Fixups;
632  raw_svector_ostream VecOS(Code);
633  Emitter->EncodeInstruction(Inst, VecOS, Fixups);
634  VecOS.flush();
635
636  // If we are showing fixups, create symbolic markers in the encoded
637  // representation. We do this by making a per-bit map to the fixup item index,
638  // then trying to display it as nicely as possible.
639  SmallVector<uint8_t, 64> FixupMap;
640  FixupMap.resize(Code.size() * 8);
641  for (unsigned i = 0, e = Code.size() * 8; i != e; ++i)
642    FixupMap[i] = 0;
643
644  for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
645    MCFixup &F = Fixups[i];
646    const MCFixupKindInfo &Info = Emitter->getFixupKindInfo(F.getKind());
647    for (unsigned j = 0; j != Info.TargetSize; ++j) {
648      unsigned Index = F.getOffset() * 8 + Info.TargetOffset + j;
649      assert(Index < Code.size() * 8 && "Invalid offset in fixup!");
650      FixupMap[Index] = 1 + i;
651    }
652  }
653
654  OS << "encoding: [";
655  for (unsigned i = 0, e = Code.size(); i != e; ++i) {
656    if (i)
657      OS << ',';
658
659    // See if all bits are the same map entry.
660    uint8_t MapEntry = FixupMap[i * 8 + 0];
661    for (unsigned j = 1; j != 8; ++j) {
662      if (FixupMap[i * 8 + j] == MapEntry)
663        continue;
664
665      MapEntry = uint8_t(~0U);
666      break;
667    }
668
669    if (MapEntry != uint8_t(~0U)) {
670      if (MapEntry == 0) {
671        OS << format("0x%02x", uint8_t(Code[i]));
672      } else {
673        assert(Code[i] == 0 && "Encoder wrote into fixed up bit!");
674        OS << char('A' + MapEntry - 1);
675      }
676    } else {
677      // Otherwise, write out in binary.
678      OS << "0b";
679      for (unsigned j = 8; j--;) {
680        unsigned Bit = (Code[i] >> j) & 1;
681        if (uint8_t MapEntry = FixupMap[i * 8 + j]) {
682          assert(Bit == 0 && "Encoder wrote into fixed up bit!");
683          OS << char('A' + MapEntry - 1);
684        } else
685          OS << Bit;
686      }
687    }
688  }
689  OS << "]\n";
690
691  for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
692    MCFixup &F = Fixups[i];
693    const MCFixupKindInfo &Info = Emitter->getFixupKindInfo(F.getKind());
694    OS << "  fixup " << char('A' + i) << " - " << "offset: " << F.getOffset()
695       << ", value: " << *F.getValue() << ", kind: " << Info.Name << "\n";
696  }
697}
698
699void MCAsmStreamer::EmitInstruction(const MCInst &Inst) {
700  assert(CurSection && "Cannot emit contents before setting section!");
701
702  // Show the encoding in a comment if we have a code emitter.
703  if (Emitter)
704    AddEncodingComment(Inst);
705
706  // Show the MCInst if enabled.
707  if (ShowInst) {
708    Inst.dump_pretty(GetCommentOS(), &MAI, InstPrinter.get(), "\n ");
709    GetCommentOS() << "\n";
710  }
711
712  // If we have an AsmPrinter, use that to print, otherwise print the MCInst.
713  if (InstPrinter)
714    InstPrinter->printInst(&Inst, OS);
715  else
716    Inst.print(OS, &MAI);
717  EmitEOL();
718}
719
720/// EmitRawText - If this file is backed by an assembly streamer, this dumps
721/// the specified string in the output .s file.  This capability is
722/// indicated by the hasRawTextSupport() predicate.
723void MCAsmStreamer::EmitRawText(StringRef String) {
724  if (!String.empty() && String.back() == '\n')
725    String = String.substr(0, String.size()-1);
726  OS << String;
727  EmitEOL();
728}
729
730void MCAsmStreamer::Finish() {
731}
732
733MCStreamer *llvm::createAsmStreamer(MCContext &Context,
734                                    formatted_raw_ostream &OS,
735                                    bool isLittleEndian,
736                                    bool isVerboseAsm, MCInstPrinter *IP,
737                                    MCCodeEmitter *CE, bool ShowInst) {
738  return new MCAsmStreamer(Context, OS, isLittleEndian, isVerboseAsm,
739                           IP, CE, ShowInst);
740}
741