MCAsmStreamer.cpp revision 5d4918dbd116b0b5e561c431b1ea527ee1b9302a 
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"
26#include "llvm/Target/TargetLoweringObjectFile.h"
27using namespace llvm;
28
29namespace {
30
31class MCAsmStreamer : public MCStreamer {
32  formatted_raw_ostream &OS;
33  const MCAsmInfo &MAI;
34  OwningPtr<MCInstPrinter> InstPrinter;
35  OwningPtr<MCCodeEmitter> Emitter;
36
37  SmallString<128> CommentToEmit;
38  raw_svector_ostream CommentStream;
39
40  const TargetLoweringObjectFile *TLOF;
41  int PointerSize;
42
43  unsigned IsLittleEndian : 1;
44  unsigned IsVerboseAsm : 1;
45  unsigned ShowInst : 1;
46
47  bool needsSet(const MCExpr *Value);
48
49public:
50  MCAsmStreamer(MCContext &Context, formatted_raw_ostream &os,
51                bool isLittleEndian, bool isVerboseAsm,
52                const TargetLoweringObjectFile *tlof, int pointerSize,
53                MCInstPrinter *printer, MCCodeEmitter *emitter, bool showInst)
54    : MCStreamer(Context), OS(os), MAI(Context.getAsmInfo()),
55      InstPrinter(printer), Emitter(emitter), CommentStream(CommentToEmit),
56      TLOF(tlof), PointerSize(pointerSize),
57      IsLittleEndian(isLittleEndian), IsVerboseAsm(isVerboseAsm),
58      ShowInst(showInst) {
59    if (InstPrinter && IsVerboseAsm)
60      InstPrinter->setCommentStream(CommentStream);
61  }
62  ~MCAsmStreamer() {}
63
64  bool isLittleEndian() const { return IsLittleEndian; }
65
66  inline void EmitEOL() {
67    // If we don't have any comments, just emit a \n.
68    if (!IsVerboseAsm) {
69      OS << '\n';
70      return;
71    }
72    EmitCommentsAndEOL();
73  }
74  void EmitCommentsAndEOL();
75
76  /// isVerboseAsm - Return true if this streamer supports verbose assembly at
77  /// all.
78  virtual bool isVerboseAsm() const { return IsVerboseAsm; }
79
80  /// hasRawTextSupport - We support EmitRawText.
81  virtual bool hasRawTextSupport() const { return true; }
82
83  /// AddComment - Add a comment that can be emitted to the generated .s
84  /// file if applicable as a QoI issue to make the output of the compiler
85  /// more readable.  This only affects the MCAsmStreamer, and only when
86  /// verbose assembly output is enabled.
87  virtual void AddComment(const Twine &T);
88
89  /// AddEncodingComment - Add a comment showing the encoding of an instruction.
90  virtual void AddEncodingComment(const MCInst &Inst);
91
92  /// GetCommentOS - Return a raw_ostream that comments can be written to.
93  /// Unlike AddComment, you are required to terminate comments with \n if you
94  /// use this method.
95  virtual raw_ostream &GetCommentOS() {
96    if (!IsVerboseAsm)
97      return nulls();  // Discard comments unless in verbose asm mode.
98    return CommentStream;
99  }
100
101  /// AddBlankLine - Emit a blank line to a .s file to pretty it up.
102  virtual void AddBlankLine() {
103    EmitEOL();
104  }
105
106  /// @name MCStreamer Interface
107  /// @{
108
109  virtual void SwitchSection(const MCSection *Section);
110
111  virtual void InitSections() {
112    // FIXME, this is MachO specific, but the testsuite
113    // expects this.
114    SwitchSection(getContext().getMachOSection("__TEXT", "__text",
115                         MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
116                         0, SectionKind::getText()));
117  }
118
119  virtual void EmitLabel(MCSymbol *Symbol);
120
121  virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
122  virtual void EmitThumbFunc(MCSymbol *Func);
123
124  virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
125  virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol);
126  virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
127                                        const MCSymbol *LastLabel,
128                                        const MCSymbol *Label);
129
130  virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
131
132  virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
133  virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol);
134  virtual void EmitCOFFSymbolStorageClass(int StorageClass);
135  virtual void EmitCOFFSymbolType(int Type);
136  virtual void EndCOFFSymbolDef();
137  virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value);
138  virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
139                                unsigned ByteAlignment);
140
141  /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
142  ///
143  /// @param Symbol - The common symbol to emit.
144  /// @param Size - The size of the common symbol.
145  virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size);
146
147  virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
148                            unsigned Size = 0, unsigned ByteAlignment = 0);
149
150  virtual void EmitTBSSSymbol (const MCSection *Section, MCSymbol *Symbol,
151                               uint64_t Size, unsigned ByteAlignment = 0);
152
153  virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
154
155  virtual void EmitValue(const MCExpr *Value, unsigned Size,unsigned AddrSpace);
156  virtual void EmitIntValue(uint64_t Value, unsigned Size,
157                            unsigned AddrSpace = 0);
158
159  virtual void EmitULEB128Value(const MCExpr *Value, unsigned AddrSpace = 0);
160
161  virtual void EmitSLEB128Value(const MCExpr *Value, unsigned AddrSpace = 0);
162
163  virtual void EmitGPRel32Value(const MCExpr *Value);
164
165
166  virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue,
167                        unsigned AddrSpace);
168
169  virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
170                                    unsigned ValueSize = 1,
171                                    unsigned MaxBytesToEmit = 0);
172
173  virtual void EmitCodeAlignment(unsigned ByteAlignment,
174                                 unsigned MaxBytesToEmit = 0);
175
176  virtual void EmitValueToOffset(const MCExpr *Offset,
177                                 unsigned char Value = 0);
178
179  virtual void EmitFileDirective(StringRef Filename);
180  virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Filename);
181  virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
182                                     unsigned Column, unsigned Flags,
183                                     unsigned Isa, unsigned Discriminator);
184
185  virtual bool EmitCFIStartProc();
186  virtual bool EmitCFIEndProc();
187  virtual bool EmitCFIDefCfaOffset(int64_t Offset);
188  virtual bool EmitCFIDefCfaRegister(int64_t Register);
189  virtual bool EmitCFIOffset(int64_t Register, int64_t Offset);
190  virtual bool EmitCFIPersonality(const MCSymbol *Sym);
191  virtual bool EmitCFILsda(const MCSymbol *Sym);
192
193  virtual void EmitInstruction(const MCInst &Inst);
194
195  /// EmitRawText - If this file is backed by an assembly streamer, this dumps
196  /// the specified string in the output .s file.  This capability is
197  /// indicated by the hasRawTextSupport() predicate.
198  virtual void EmitRawText(StringRef String);
199
200  virtual void Finish();
201
202  /// @}
203};
204
205} // end anonymous namespace.
206
207/// AddComment - Add a comment that can be emitted to the generated .s
208/// file if applicable as a QoI issue to make the output of the compiler
209/// more readable.  This only affects the MCAsmStreamer, and only when
210/// verbose assembly output is enabled.
211void MCAsmStreamer::AddComment(const Twine &T) {
212  if (!IsVerboseAsm) return;
213
214  // Make sure that CommentStream is flushed.
215  CommentStream.flush();
216
217  T.toVector(CommentToEmit);
218  // Each comment goes on its own line.
219  CommentToEmit.push_back('\n');
220
221  // Tell the comment stream that the vector changed underneath it.
222  CommentStream.resync();
223}
224
225void MCAsmStreamer::EmitCommentsAndEOL() {
226  if (CommentToEmit.empty() && CommentStream.GetNumBytesInBuffer() == 0) {
227    OS << '\n';
228    return;
229  }
230
231  CommentStream.flush();
232  StringRef Comments = CommentToEmit.str();
233
234  assert(Comments.back() == '\n' &&
235         "Comment array not newline terminated");
236  do {
237    // Emit a line of comments.
238    OS.PadToColumn(MAI.getCommentColumn());
239    size_t Position = Comments.find('\n');
240    OS << MAI.getCommentString() << ' ' << Comments.substr(0, Position) << '\n';
241
242    Comments = Comments.substr(Position+1);
243  } while (!Comments.empty());
244
245  CommentToEmit.clear();
246  // Tell the comment stream that the vector changed underneath it.
247  CommentStream.resync();
248}
249
250static inline int64_t truncateToSize(int64_t Value, unsigned Bytes) {
251  assert(Bytes && "Invalid size!");
252  return Value & ((uint64_t) (int64_t) -1 >> (64 - Bytes * 8));
253}
254
255void MCAsmStreamer::SwitchSection(const MCSection *Section) {
256  assert(Section && "Cannot switch to a null section!");
257  if (Section != CurSection) {
258    PrevSection = CurSection;
259    CurSection = Section;
260    Section->PrintSwitchToSection(MAI, OS);
261  }
262}
263
264void MCAsmStreamer::EmitLabel(MCSymbol *Symbol) {
265  assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
266  assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
267  assert(CurSection && "Cannot emit before setting section!");
268
269  OS << *Symbol << MAI.getLabelSuffix();
270  EmitEOL();
271  Symbol->setSection(*CurSection);
272}
273
274void MCAsmStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
275  switch (Flag) {
276  default: assert(0 && "Invalid flag!");
277  case MCAF_SyntaxUnified:         OS << "\t.syntax unified"; break;
278  case MCAF_SubsectionsViaSymbols: OS << ".subsections_via_symbols"; break;
279  case MCAF_Code16:                OS << "\t.code\t16"; break;
280  case MCAF_Code32:                OS << "\t.code\t32"; break;
281  }
282  EmitEOL();
283}
284
285void MCAsmStreamer::EmitThumbFunc(MCSymbol *Func) {
286  // This needs to emit to a temporary string to get properly quoted
287  // MCSymbols when they have spaces in them.
288  OS << "\t.thumb_func";
289  if (Func)
290    OS << '\t' << *Func;
291  EmitEOL();
292}
293
294void MCAsmStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
295  OS << *Symbol << " = " << *Value;
296  EmitEOL();
297
298  // FIXME: Lift context changes into super class.
299  Symbol->setVariableValue(Value);
300}
301
302void MCAsmStreamer::EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {
303  OS << ".weakref " << *Alias << ", " << *Symbol;
304  EmitEOL();
305}
306
307void MCAsmStreamer::EmitDwarfAdvanceLineAddr(int64_t LineDelta,
308                                             const MCSymbol *LastLabel,
309                                             const MCSymbol *Label) {
310  EmitDwarfSetLineAddr(LineDelta, Label, PointerSize);
311}
312
313void MCAsmStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
314                                        MCSymbolAttr Attribute) {
315  switch (Attribute) {
316  case MCSA_Invalid: assert(0 && "Invalid symbol attribute");
317  case MCSA_ELF_TypeFunction:    /// .type _foo, STT_FUNC  # aka @function
318  case MCSA_ELF_TypeIndFunction: /// .type _foo, STT_GNU_IFUNC
319  case MCSA_ELF_TypeObject:      /// .type _foo, STT_OBJECT  # aka @object
320  case MCSA_ELF_TypeTLS:         /// .type _foo, STT_TLS     # aka @tls_object
321  case MCSA_ELF_TypeCommon:      /// .type _foo, STT_COMMON  # aka @common
322  case MCSA_ELF_TypeNoType:      /// .type _foo, STT_NOTYPE  # aka @notype
323  case MCSA_ELF_TypeGnuUniqueObject:  /// .type _foo, @gnu_unique_object
324    assert(MAI.hasDotTypeDotSizeDirective() && "Symbol Attr not supported");
325    OS << "\t.type\t" << *Symbol << ','
326       << ((MAI.getCommentString()[0] != '@') ? '@' : '%');
327    switch (Attribute) {
328    default: assert(0 && "Unknown ELF .type");
329    case MCSA_ELF_TypeFunction:    OS << "function"; break;
330    case MCSA_ELF_TypeIndFunction: OS << "gnu_indirect_function"; break;
331    case MCSA_ELF_TypeObject:      OS << "object"; break;
332    case MCSA_ELF_TypeTLS:         OS << "tls_object"; break;
333    case MCSA_ELF_TypeCommon:      OS << "common"; break;
334    case MCSA_ELF_TypeNoType:      OS << "no_type"; break;
335    case MCSA_ELF_TypeGnuUniqueObject: OS << "gnu_unique_object"; break;
336    }
337    EmitEOL();
338    return;
339  case MCSA_Global: // .globl/.global
340    OS << MAI.getGlobalDirective();
341    break;
342  case MCSA_Hidden:         OS << "\t.hidden\t";          break;
343  case MCSA_IndirectSymbol: OS << "\t.indirect_symbol\t"; break;
344  case MCSA_Internal:       OS << "\t.internal\t";        break;
345  case MCSA_LazyReference:  OS << "\t.lazy_reference\t";  break;
346  case MCSA_Local:          OS << "\t.local\t";           break;
347  case MCSA_NoDeadStrip:    OS << "\t.no_dead_strip\t";   break;
348  case MCSA_SymbolResolver: OS << "\t.symbol_resolver\t"; break;
349  case MCSA_PrivateExtern:  OS << "\t.private_extern\t";  break;
350  case MCSA_Protected:      OS << "\t.protected\t";       break;
351  case MCSA_Reference:      OS << "\t.reference\t";       break;
352  case MCSA_Weak:           OS << "\t.weak\t";            break;
353  case MCSA_WeakDefinition: OS << "\t.weak_definition\t"; break;
354      // .weak_reference
355  case MCSA_WeakReference:  OS << MAI.getWeakRefDirective(); break;
356  case MCSA_WeakDefAutoPrivate: OS << "\t.weak_def_can_be_hidden\t"; break;
357  }
358
359  OS << *Symbol;
360  EmitEOL();
361}
362
363void MCAsmStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
364  OS << ".desc" << ' ' << *Symbol << ',' << DescValue;
365  EmitEOL();
366}
367
368void MCAsmStreamer::BeginCOFFSymbolDef(const MCSymbol *Symbol) {
369  OS << "\t.def\t " << *Symbol << ';';
370  EmitEOL();
371}
372
373void MCAsmStreamer::EmitCOFFSymbolStorageClass (int StorageClass) {
374  OS << "\t.scl\t" << StorageClass << ';';
375  EmitEOL();
376}
377
378void MCAsmStreamer::EmitCOFFSymbolType (int Type) {
379  OS << "\t.type\t" << Type << ';';
380  EmitEOL();
381}
382
383void MCAsmStreamer::EndCOFFSymbolDef() {
384  OS << "\t.endef";
385  EmitEOL();
386}
387
388void MCAsmStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
389  assert(MAI.hasDotTypeDotSizeDirective());
390  OS << "\t.size\t" << *Symbol << ", " << *Value << '\n';
391}
392
393void MCAsmStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
394                                     unsigned ByteAlignment) {
395  OS << "\t.comm\t" << *Symbol << ',' << Size;
396  if (ByteAlignment != 0) {
397    if (MAI.getCOMMDirectiveAlignmentIsInBytes())
398      OS << ',' << ByteAlignment;
399    else
400      OS << ',' << Log2_32(ByteAlignment);
401  }
402  EmitEOL();
403}
404
405/// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
406///
407/// @param Symbol - The common symbol to emit.
408/// @param Size - The size of the common symbol.
409void MCAsmStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {
410  assert(MAI.hasLCOMMDirective() && "Doesn't have .lcomm, can't emit it!");
411  OS << "\t.lcomm\t" << *Symbol << ',' << Size;
412  EmitEOL();
413}
414
415void MCAsmStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
416                                 unsigned Size, unsigned ByteAlignment) {
417  // Note: a .zerofill directive does not switch sections.
418  OS << ".zerofill ";
419
420  // This is a mach-o specific directive.
421  const MCSectionMachO *MOSection = ((const MCSectionMachO*)Section);
422  OS << MOSection->getSegmentName() << "," << MOSection->getSectionName();
423
424  if (Symbol != NULL) {
425    OS << ',' << *Symbol << ',' << Size;
426    if (ByteAlignment != 0)
427      OS << ',' << Log2_32(ByteAlignment);
428  }
429  EmitEOL();
430}
431
432// .tbss sym, size, align
433// This depends that the symbol has already been mangled from the original,
434// e.g. _a.
435void MCAsmStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
436                                   uint64_t Size, unsigned ByteAlignment) {
437  assert(Symbol != NULL && "Symbol shouldn't be NULL!");
438  // Instead of using the Section we'll just use the shortcut.
439  // This is a mach-o specific directive and section.
440  OS << ".tbss " << *Symbol << ", " << Size;
441
442  // Output align if we have it.  We default to 1 so don't bother printing
443  // that.
444  if (ByteAlignment > 1) OS << ", " << Log2_32(ByteAlignment);
445
446  EmitEOL();
447}
448
449static inline char toOctal(int X) { return (X&7)+'0'; }
450
451static void PrintQuotedString(StringRef Data, raw_ostream &OS) {
452  OS << '"';
453
454  for (unsigned i = 0, e = Data.size(); i != e; ++i) {
455    unsigned char C = Data[i];
456    if (C == '"' || C == '\\') {
457      OS << '\\' << (char)C;
458      continue;
459    }
460
461    if (isprint((unsigned char)C)) {
462      OS << (char)C;
463      continue;
464    }
465
466    switch (C) {
467      case '\b': OS << "\\b"; break;
468      case '\f': OS << "\\f"; break;
469      case '\n': OS << "\\n"; break;
470      case '\r': OS << "\\r"; break;
471      case '\t': OS << "\\t"; break;
472      default:
473        OS << '\\';
474        OS << toOctal(C >> 6);
475        OS << toOctal(C >> 3);
476        OS << toOctal(C >> 0);
477        break;
478    }
479  }
480
481  OS << '"';
482}
483
484
485void MCAsmStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
486  assert(CurSection && "Cannot emit contents before setting section!");
487  if (Data.empty()) return;
488
489  if (Data.size() == 1) {
490    OS << MAI.getData8bitsDirective(AddrSpace);
491    OS << (unsigned)(unsigned char)Data[0];
492    EmitEOL();
493    return;
494  }
495
496  // If the data ends with 0 and the target supports .asciz, use it, otherwise
497  // use .ascii
498  if (MAI.getAscizDirective() && Data.back() == 0) {
499    OS << MAI.getAscizDirective();
500    Data = Data.substr(0, Data.size()-1);
501  } else {
502    OS << MAI.getAsciiDirective();
503  }
504
505  OS << ' ';
506  PrintQuotedString(Data, OS);
507  EmitEOL();
508}
509
510void MCAsmStreamer::EmitIntValue(uint64_t Value, unsigned Size,
511                                 unsigned AddrSpace) {
512  EmitValue(MCConstantExpr::Create(Value, getContext()), Size, AddrSpace);
513}
514
515static bool hasSymbolDifference(const MCExpr *Value) {
516  switch (Value->getKind()) {
517  case MCExpr::Target: llvm_unreachable("Can't handle target exprs yet!");
518  case MCExpr::Constant:
519  case MCExpr::SymbolRef:
520    return false;
521  case MCExpr::Unary:
522    return hasSymbolDifference(cast<MCUnaryExpr>(Value)->getSubExpr());
523  case MCExpr::Binary: {
524    const MCBinaryExpr *BE = cast<MCBinaryExpr>(Value);
525    if (BE->getOpcode() == MCBinaryExpr::Sub &&
526	BE->getLHS()->getKind() == MCExpr::SymbolRef &&
527	BE->getRHS()->getKind() == MCExpr::SymbolRef)
528      return true;
529    return hasSymbolDifference(BE->getLHS()) ||
530      hasSymbolDifference(BE->getRHS());
531  }
532  }
533  llvm_unreachable("Switch covers all cases");
534}
535
536bool MCAsmStreamer::needsSet(const MCExpr *Value) {
537  return getContext().getAsmInfo().needsSetToChangeDiffSize() &&
538    hasSymbolDifference(Value);
539}
540
541void MCAsmStreamer::EmitValue(const MCExpr *Value, unsigned Size,
542                              unsigned AddrSpace) {
543  assert(CurSection && "Cannot emit contents before setting section!");
544  const char *Directive = 0;
545  switch (Size) {
546  default: break;
547  case 1: Directive = MAI.getData8bitsDirective(AddrSpace); break;
548  case 2: Directive = MAI.getData16bitsDirective(AddrSpace); break;
549  case 4: Directive = MAI.getData32bitsDirective(AddrSpace); break;
550  case 8:
551    Directive = MAI.getData64bitsDirective(AddrSpace);
552    // If the target doesn't support 64-bit data, emit as two 32-bit halves.
553    if (Directive) break;
554    int64_t IntValue;
555    if (!Value->EvaluateAsAbsolute(IntValue))
556      report_fatal_error("Don't know how to emit this value.");
557    if (isLittleEndian()) {
558      EmitIntValue((uint32_t)(IntValue >> 0 ), 4, AddrSpace);
559      EmitIntValue((uint32_t)(IntValue >> 32), 4, AddrSpace);
560    } else {
561      EmitIntValue((uint32_t)(IntValue >> 32), 4, AddrSpace);
562      EmitIntValue((uint32_t)(IntValue >> 0 ), 4, AddrSpace);
563    }
564    return;
565  }
566
567  assert(Directive && "Invalid size for machine code value!");
568  if (needsSet(Value)) {
569    MCSymbol *SetLabel = getContext().CreateTempSymbol();
570    EmitAssignment(SetLabel, Value);
571    OS << Directive << *SetLabel;
572    EmitEOL();
573    return;
574  }
575
576  OS << Directive << *Value;
577  EmitEOL();
578}
579
580void MCAsmStreamer::EmitULEB128Value(const MCExpr *Value, unsigned AddrSpace) {
581  int64_t IntValue;
582  if (Value->EvaluateAsAbsolute(IntValue)) {
583    EmitULEB128IntValue(IntValue, AddrSpace);
584    return;
585  }
586  assert(MAI.hasLEB128() && "Cannot print a .uleb");
587  OS << ".uleb128 " << *Value;
588  EmitEOL();
589}
590
591void MCAsmStreamer::EmitSLEB128Value(const MCExpr *Value, unsigned AddrSpace) {
592  int64_t IntValue;
593  if (Value->EvaluateAsAbsolute(IntValue)) {
594    EmitSLEB128IntValue(IntValue, AddrSpace);
595    return;
596  }
597  assert(MAI.hasLEB128() && "Cannot print a .sleb");
598  OS << ".sleb128 " << *Value;
599  EmitEOL();
600}
601
602void MCAsmStreamer::EmitGPRel32Value(const MCExpr *Value) {
603  assert(MAI.getGPRel32Directive() != 0);
604  OS << MAI.getGPRel32Directive() << *Value;
605  EmitEOL();
606}
607
608
609/// EmitFill - Emit NumBytes bytes worth of the value specified by
610/// FillValue.  This implements directives such as '.space'.
611void MCAsmStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
612                             unsigned AddrSpace) {
613  if (NumBytes == 0) return;
614
615  if (AddrSpace == 0)
616    if (const char *ZeroDirective = MAI.getZeroDirective()) {
617      OS << ZeroDirective << NumBytes;
618      if (FillValue != 0)
619        OS << ',' << (int)FillValue;
620      EmitEOL();
621      return;
622    }
623
624  // Emit a byte at a time.
625  MCStreamer::EmitFill(NumBytes, FillValue, AddrSpace);
626}
627
628void MCAsmStreamer::EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
629                                         unsigned ValueSize,
630                                         unsigned MaxBytesToEmit) {
631  // Some assemblers don't support non-power of two alignments, so we always
632  // emit alignments as a power of two if possible.
633  if (isPowerOf2_32(ByteAlignment)) {
634    switch (ValueSize) {
635    default: llvm_unreachable("Invalid size for machine code value!");
636    case 1: OS << MAI.getAlignDirective(); break;
637    // FIXME: use MAI for this!
638    case 2: OS << ".p2alignw "; break;
639    case 4: OS << ".p2alignl "; break;
640    case 8: llvm_unreachable("Unsupported alignment size!");
641    }
642
643    if (MAI.getAlignmentIsInBytes())
644      OS << ByteAlignment;
645    else
646      OS << Log2_32(ByteAlignment);
647
648    if (Value || MaxBytesToEmit) {
649      OS << ", 0x";
650      OS.write_hex(truncateToSize(Value, ValueSize));
651
652      if (MaxBytesToEmit)
653        OS << ", " << MaxBytesToEmit;
654    }
655    EmitEOL();
656    return;
657  }
658
659  // Non-power of two alignment.  This is not widely supported by assemblers.
660  // FIXME: Parameterize this based on MAI.
661  switch (ValueSize) {
662  default: llvm_unreachable("Invalid size for machine code value!");
663  case 1: OS << ".balign";  break;
664  case 2: OS << ".balignw"; break;
665  case 4: OS << ".balignl"; break;
666  case 8: llvm_unreachable("Unsupported alignment size!");
667  }
668
669  OS << ' ' << ByteAlignment;
670  OS << ", " << truncateToSize(Value, ValueSize);
671  if (MaxBytesToEmit)
672    OS << ", " << MaxBytesToEmit;
673  EmitEOL();
674}
675
676void MCAsmStreamer::EmitCodeAlignment(unsigned ByteAlignment,
677                                      unsigned MaxBytesToEmit) {
678  // Emit with a text fill value.
679  EmitValueToAlignment(ByteAlignment, MAI.getTextAlignFillValue(),
680                       1, MaxBytesToEmit);
681}
682
683void MCAsmStreamer::EmitValueToOffset(const MCExpr *Offset,
684                                      unsigned char Value) {
685  // FIXME: Verify that Offset is associated with the current section.
686  OS << ".org " << *Offset << ", " << (unsigned) Value;
687  EmitEOL();
688}
689
690
691void MCAsmStreamer::EmitFileDirective(StringRef Filename) {
692  assert(MAI.hasSingleParameterDotFile());
693  OS << "\t.file\t";
694  PrintQuotedString(Filename, OS);
695  EmitEOL();
696}
697
698bool MCAsmStreamer::EmitDwarfFileDirective(unsigned FileNo, StringRef Filename){
699  if (!TLOF) {
700    OS << "\t.file\t" << FileNo << ' ';
701    PrintQuotedString(Filename, OS);
702    EmitEOL();
703  }
704  return this->MCStreamer::EmitDwarfFileDirective(FileNo, Filename);
705}
706
707void MCAsmStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
708                                          unsigned Column, unsigned Flags,
709                                          unsigned Isa,
710                                          unsigned Discriminator) {
711  this->MCStreamer::EmitDwarfLocDirective(FileNo, Line, Column, Flags,
712                                          Isa, Discriminator);
713  if (TLOF)
714    return;
715
716  OS << "\t.loc\t" << FileNo << " " << Line << " " << Column;
717  if (Flags & DWARF2_FLAG_BASIC_BLOCK)
718    OS << " basic_block";
719  if (Flags & DWARF2_FLAG_PROLOGUE_END)
720    OS << " prologue_end";
721  if (Flags & DWARF2_FLAG_EPILOGUE_BEGIN)
722    OS << " epilogue_begin";
723
724  unsigned OldFlags = getContext().getCurrentDwarfLoc().getFlags();
725  if ((Flags & DWARF2_FLAG_IS_STMT) != (OldFlags & DWARF2_FLAG_IS_STMT)) {
726    OS << " is_stmt ";
727
728    if (Flags & DWARF2_FLAG_IS_STMT)
729      OS << "1";
730    else
731      OS << "0";
732  }
733
734  if (Isa)
735    OS << "isa " << Isa;
736  if (Discriminator)
737    OS << "discriminator " << Discriminator;
738  EmitEOL();
739}
740
741bool MCAsmStreamer::EmitCFIStartProc() {
742  if (this->MCStreamer::EmitCFIStartProc())
743    return true;
744
745  OS << ".cfi_startproc";
746  EmitEOL();
747
748  return false;
749}
750
751bool MCAsmStreamer::EmitCFIEndProc() {
752  if (this->MCStreamer::EmitCFIEndProc())
753    return true;
754
755  OS << ".cfi_endproc";
756  EmitEOL();
757
758  return false;
759}
760
761bool MCAsmStreamer::EmitCFIDefCfaOffset(int64_t Offset) {
762  if (this->MCStreamer::EmitCFIDefCfaOffset(Offset))
763    return true;
764
765  OS << ".cfi_def_cfa_offset " << Offset;
766  EmitEOL();
767
768  return false;
769}
770
771bool MCAsmStreamer::EmitCFIDefCfaRegister(int64_t Register) {
772  if (this->MCStreamer::EmitCFIDefCfaRegister(Register))
773    return true;
774
775  OS << ".cfi_def_cfa_register " << Register;
776  EmitEOL();
777
778  return false;
779}
780
781bool MCAsmStreamer::EmitCFIOffset(int64_t Register, int64_t Offset) {
782  if (this->MCStreamer::EmitCFIOffset(Register, Offset))
783    return true;
784
785  OS << ".cfi_offset " << Register << ", " << Offset;
786  EmitEOL();
787
788  return false;
789}
790
791bool MCAsmStreamer::EmitCFIPersonality(const MCSymbol *Sym) {
792  if (this->MCStreamer::EmitCFIPersonality(Sym))
793    return true;
794
795  OS << ".cfi_personality 0, " << *Sym;
796  EmitEOL();
797
798  return false;
799}
800
801bool MCAsmStreamer::EmitCFILsda(const MCSymbol *Sym) {
802  if (this->MCStreamer::EmitCFILsda(Sym))
803    return true;
804
805  OS << ".cfi_lsda 0, " << *Sym;
806  EmitEOL();
807
808  return false;
809}
810
811void MCAsmStreamer::AddEncodingComment(const MCInst &Inst) {
812  raw_ostream &OS = GetCommentOS();
813  SmallString<256> Code;
814  SmallVector<MCFixup, 4> Fixups;
815  raw_svector_ostream VecOS(Code);
816  Emitter->EncodeInstruction(Inst, VecOS, Fixups);
817  VecOS.flush();
818
819  // If we are showing fixups, create symbolic markers in the encoded
820  // representation. We do this by making a per-bit map to the fixup item index,
821  // then trying to display it as nicely as possible.
822  SmallVector<uint8_t, 64> FixupMap;
823  FixupMap.resize(Code.size() * 8);
824  for (unsigned i = 0, e = Code.size() * 8; i != e; ++i)
825    FixupMap[i] = 0;
826
827  for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
828    MCFixup &F = Fixups[i];
829    const MCFixupKindInfo &Info = Emitter->getFixupKindInfo(F.getKind());
830    for (unsigned j = 0; j != Info.TargetSize; ++j) {
831      unsigned Index = F.getOffset() * 8 + Info.TargetOffset + j;
832      assert(Index < Code.size() * 8 && "Invalid offset in fixup!");
833      FixupMap[Index] = 1 + i;
834    }
835  }
836
837  OS << "encoding: [";
838  for (unsigned i = 0, e = Code.size(); i != e; ++i) {
839    if (i)
840      OS << ',';
841
842    // See if all bits are the same map entry.
843    uint8_t MapEntry = FixupMap[i * 8 + 0];
844    for (unsigned j = 1; j != 8; ++j) {
845      if (FixupMap[i * 8 + j] == MapEntry)
846        continue;
847
848      MapEntry = uint8_t(~0U);
849      break;
850    }
851
852    if (MapEntry != uint8_t(~0U)) {
853      if (MapEntry == 0) {
854        OS << format("0x%02x", uint8_t(Code[i]));
855      } else {
856        assert(Code[i] == 0 && "Encoder wrote into fixed up bit!");
857        OS << char('A' + MapEntry - 1);
858      }
859    } else {
860      // Otherwise, write out in binary.
861      OS << "0b";
862      for (unsigned j = 8; j--;) {
863        unsigned Bit = (Code[i] >> j) & 1;
864
865        unsigned FixupBit;
866        if (IsLittleEndian)
867          FixupBit = i * 8 + j;
868        else
869          FixupBit = i * 8 + (7-j);
870
871        if (uint8_t MapEntry = FixupMap[FixupBit]) {
872          assert(Bit == 0 && "Encoder wrote into fixed up bit!");
873          OS << char('A' + MapEntry - 1);
874        } else
875          OS << Bit;
876      }
877    }
878  }
879  OS << "]\n";
880
881  for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
882    MCFixup &F = Fixups[i];
883    const MCFixupKindInfo &Info = Emitter->getFixupKindInfo(F.getKind());
884    OS << "  fixup " << char('A' + i) << " - " << "offset: " << F.getOffset()
885       << ", value: " << *F.getValue() << ", kind: " << Info.Name << "\n";
886  }
887}
888
889void MCAsmStreamer::EmitInstruction(const MCInst &Inst) {
890  assert(CurSection && "Cannot emit contents before setting section!");
891
892  if (TLOF)
893    MCLineEntry::Make(this, getCurrentSection());
894
895  // Show the encoding in a comment if we have a code emitter.
896  if (Emitter)
897    AddEncodingComment(Inst);
898
899  // Show the MCInst if enabled.
900  if (ShowInst) {
901    Inst.dump_pretty(GetCommentOS(), &MAI, InstPrinter.get(), "\n ");
902    GetCommentOS() << "\n";
903  }
904
905  // If we have an AsmPrinter, use that to print, otherwise print the MCInst.
906  if (InstPrinter)
907    InstPrinter->printInst(&Inst, OS);
908  else
909    Inst.print(OS, &MAI);
910  EmitEOL();
911}
912
913/// EmitRawText - If this file is backed by an assembly streamer, this dumps
914/// the specified string in the output .s file.  This capability is
915/// indicated by the hasRawTextSupport() predicate.
916void MCAsmStreamer::EmitRawText(StringRef String) {
917  if (!String.empty() && String.back() == '\n')
918    String = String.substr(0, String.size()-1);
919  OS << String;
920  EmitEOL();
921}
922
923void MCAsmStreamer::Finish() {
924  // Dump out the dwarf file & directory tables and line tables.
925  if (getContext().hasDwarfFiles() && TLOF)
926    MCDwarfFileTable::Emit(this, TLOF->getDwarfLineSection());
927}
928
929MCStreamer *llvm::createAsmStreamer(MCContext &Context,
930                                    formatted_raw_ostream &OS,
931                                    bool isLittleEndian,
932                                    bool isVerboseAsm, MCInstPrinter *IP,
933                                    MCCodeEmitter *CE, bool ShowInst) {
934  return new MCAsmStreamer(Context, OS, isLittleEndian, isVerboseAsm,
935                           NULL, 0, IP, CE, ShowInst);
936}
937
938
939MCStreamer *llvm::createAsmStreamerNoLoc(MCContext &Context,
940                                         formatted_raw_ostream &OS,
941                                         bool isLittleEndian,
942                                         bool isVerboseAsm,
943                                         const TargetLoweringObjectFile *TLOF,
944                                         int PointerSize,
945                                         MCInstPrinter *IP,
946                                         MCCodeEmitter *CE, bool ShowInst) {
947  return new MCAsmStreamer(Context, OS, isLittleEndian, isVerboseAsm,
948                           TLOF, PointerSize, IP, CE, ShowInst);
949}
950