MCAssembler.cpp revision 203954 
1//===- lib/MC/MCAssembler.cpp - Assembler Backend Implementation ----------===//
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#define DEBUG_TYPE "assembler"
11#include "llvm/MC/MCAssembler.h"
12#include "llvm/MC/MCExpr.h"
13#include "llvm/MC/MCSectionMachO.h"
14#include "llvm/MC/MCSymbol.h"
15#include "llvm/MC/MCValue.h"
16#include "llvm/ADT/DenseMap.h"
17#include "llvm/ADT/SmallString.h"
18#include "llvm/ADT/Statistic.h"
19#include "llvm/ADT/StringExtras.h"
20#include "llvm/ADT/StringMap.h"
21#include "llvm/ADT/Twine.h"
22#include "llvm/Support/ErrorHandling.h"
23#include "llvm/Support/MachO.h"
24#include "llvm/Support/raw_ostream.h"
25#include "llvm/Support/Debug.h"
26
27// FIXME: Gross.
28#include "../Target/X86/X86FixupKinds.h"
29
30#include <vector>
31using namespace llvm;
32
33class MachObjectWriter;
34
35STATISTIC(EmittedFragments, "Number of emitted assembler fragments");
36
37// FIXME FIXME FIXME: There are number of places in this file where we convert
38// what is a 64-bit assembler value used for computation into a value in the
39// object file, which may truncate it. We should detect that truncation where
40// invalid and report errors back.
41
42static void WriteFileData(raw_ostream &OS, const MCSectionData &SD,
43                          MachObjectWriter &MOW);
44
45/// isVirtualSection - Check if this is a section which does not actually exist
46/// in the object file.
47static bool isVirtualSection(const MCSection &Section) {
48  // FIXME: Lame.
49  const MCSectionMachO &SMO = static_cast<const MCSectionMachO&>(Section);
50  unsigned Type = SMO.getTypeAndAttributes() & MCSectionMachO::SECTION_TYPE;
51  return (Type == MCSectionMachO::S_ZEROFILL);
52}
53
54static unsigned getFixupKindLog2Size(MCFixupKind Kind) {
55  switch (Kind) {
56  default: llvm_unreachable("invalid fixup kind!");
57  case X86::reloc_pcrel_1byte:
58  case FK_Data_1: return 0;
59  case FK_Data_2: return 1;
60  case X86::reloc_pcrel_4byte:
61  case X86::reloc_riprel_4byte:
62  case FK_Data_4: return 2;
63  case FK_Data_8: return 3;
64  }
65}
66
67static bool isFixupKindPCRel(MCFixupKind Kind) {
68  switch (Kind) {
69  default:
70    return false;
71  case X86::reloc_pcrel_1byte:
72  case X86::reloc_pcrel_4byte:
73  case X86::reloc_riprel_4byte:
74    return true;
75  }
76}
77
78class MachObjectWriter {
79  // See <mach-o/loader.h>.
80  enum {
81    Header_Magic32 = 0xFEEDFACE,
82    Header_Magic64 = 0xFEEDFACF
83  };
84
85  static const unsigned Header32Size = 28;
86  static const unsigned Header64Size = 32;
87  static const unsigned SegmentLoadCommand32Size = 56;
88  static const unsigned Section32Size = 68;
89  static const unsigned SymtabLoadCommandSize = 24;
90  static const unsigned DysymtabLoadCommandSize = 80;
91  static const unsigned Nlist32Size = 12;
92  static const unsigned RelocationInfoSize = 8;
93
94  enum HeaderFileType {
95    HFT_Object = 0x1
96  };
97
98  enum HeaderFlags {
99    HF_SubsectionsViaSymbols = 0x2000
100  };
101
102  enum LoadCommandType {
103    LCT_Segment = 0x1,
104    LCT_Symtab = 0x2,
105    LCT_Dysymtab = 0xb
106  };
107
108  // See <mach-o/nlist.h>.
109  enum SymbolTypeType {
110    STT_Undefined = 0x00,
111    STT_Absolute  = 0x02,
112    STT_Section   = 0x0e
113  };
114
115  enum SymbolTypeFlags {
116    // If any of these bits are set, then the entry is a stab entry number (see
117    // <mach-o/stab.h>. Otherwise the other masks apply.
118    STF_StabsEntryMask = 0xe0,
119
120    STF_TypeMask       = 0x0e,
121    STF_External       = 0x01,
122    STF_PrivateExtern  = 0x10
123  };
124
125  /// IndirectSymbolFlags - Flags for encoding special values in the indirect
126  /// symbol entry.
127  enum IndirectSymbolFlags {
128    ISF_Local    = 0x80000000,
129    ISF_Absolute = 0x40000000
130  };
131
132  /// RelocationFlags - Special flags for addresses.
133  enum RelocationFlags {
134    RF_Scattered = 0x80000000
135  };
136
137  enum RelocationInfoType {
138    RIT_Vanilla             = 0,
139    RIT_Pair                = 1,
140    RIT_Difference          = 2,
141    RIT_PreboundLazyPointer = 3,
142    RIT_LocalDifference     = 4
143  };
144
145  /// MachSymbolData - Helper struct for containing some precomputed information
146  /// on symbols.
147  struct MachSymbolData {
148    MCSymbolData *SymbolData;
149    uint64_t StringIndex;
150    uint8_t SectionIndex;
151
152    // Support lexicographic sorting.
153    bool operator<(const MachSymbolData &RHS) const {
154      const std::string &Name = SymbolData->getSymbol().getName();
155      return Name < RHS.SymbolData->getSymbol().getName();
156    }
157  };
158
159  raw_ostream &OS;
160  bool IsLSB;
161
162public:
163  MachObjectWriter(raw_ostream &_OS, bool _IsLSB = true)
164    : OS(_OS), IsLSB(_IsLSB) {
165  }
166
167  /// @name Helper Methods
168  /// @{
169
170  void Write8(uint8_t Value) {
171    OS << char(Value);
172  }
173
174  void Write16(uint16_t Value) {
175    if (IsLSB) {
176      Write8(uint8_t(Value >> 0));
177      Write8(uint8_t(Value >> 8));
178    } else {
179      Write8(uint8_t(Value >> 8));
180      Write8(uint8_t(Value >> 0));
181    }
182  }
183
184  void Write32(uint32_t Value) {
185    if (IsLSB) {
186      Write16(uint16_t(Value >> 0));
187      Write16(uint16_t(Value >> 16));
188    } else {
189      Write16(uint16_t(Value >> 16));
190      Write16(uint16_t(Value >> 0));
191    }
192  }
193
194  void Write64(uint64_t Value) {
195    if (IsLSB) {
196      Write32(uint32_t(Value >> 0));
197      Write32(uint32_t(Value >> 32));
198    } else {
199      Write32(uint32_t(Value >> 32));
200      Write32(uint32_t(Value >> 0));
201    }
202  }
203
204  void WriteZeros(unsigned N) {
205    const char Zeros[16] = { 0 };
206
207    for (unsigned i = 0, e = N / 16; i != e; ++i)
208      OS << StringRef(Zeros, 16);
209
210    OS << StringRef(Zeros, N % 16);
211  }
212
213  void WriteString(StringRef Str, unsigned ZeroFillSize = 0) {
214    OS << Str;
215    if (ZeroFillSize)
216      WriteZeros(ZeroFillSize - Str.size());
217  }
218
219  /// @}
220
221  void WriteHeader32(unsigned NumLoadCommands, unsigned LoadCommandsSize,
222                     bool SubsectionsViaSymbols) {
223    uint32_t Flags = 0;
224
225    if (SubsectionsViaSymbols)
226      Flags |= HF_SubsectionsViaSymbols;
227
228    // struct mach_header (28 bytes)
229
230    uint64_t Start = OS.tell();
231    (void) Start;
232
233    Write32(Header_Magic32);
234
235    // FIXME: Support cputype.
236    Write32(MachO::CPUTypeI386);
237    // FIXME: Support cpusubtype.
238    Write32(MachO::CPUSubType_I386_ALL);
239    Write32(HFT_Object);
240    Write32(NumLoadCommands);    // Object files have a single load command, the
241                                 // segment.
242    Write32(LoadCommandsSize);
243    Write32(Flags);
244
245    assert(OS.tell() - Start == Header32Size);
246  }
247
248  /// WriteSegmentLoadCommand32 - Write a 32-bit segment load command.
249  ///
250  /// \arg NumSections - The number of sections in this segment.
251  /// \arg SectionDataSize - The total size of the sections.
252  void WriteSegmentLoadCommand32(unsigned NumSections,
253                                 uint64_t VMSize,
254                                 uint64_t SectionDataStartOffset,
255                                 uint64_t SectionDataSize) {
256    // struct segment_command (56 bytes)
257
258    uint64_t Start = OS.tell();
259    (void) Start;
260
261    Write32(LCT_Segment);
262    Write32(SegmentLoadCommand32Size + NumSections * Section32Size);
263
264    WriteString("", 16);
265    Write32(0); // vmaddr
266    Write32(VMSize); // vmsize
267    Write32(SectionDataStartOffset); // file offset
268    Write32(SectionDataSize); // file size
269    Write32(0x7); // maxprot
270    Write32(0x7); // initprot
271    Write32(NumSections);
272    Write32(0); // flags
273
274    assert(OS.tell() - Start == SegmentLoadCommand32Size);
275  }
276
277  void WriteSection32(const MCSectionData &SD, uint64_t FileOffset,
278                      uint64_t RelocationsStart, unsigned NumRelocations) {
279    // The offset is unused for virtual sections.
280    if (isVirtualSection(SD.getSection())) {
281      assert(SD.getFileSize() == 0 && "Invalid file size!");
282      FileOffset = 0;
283    }
284
285    // struct section (68 bytes)
286
287    uint64_t Start = OS.tell();
288    (void) Start;
289
290    // FIXME: cast<> support!
291    const MCSectionMachO &Section =
292      static_cast<const MCSectionMachO&>(SD.getSection());
293    WriteString(Section.getSectionName(), 16);
294    WriteString(Section.getSegmentName(), 16);
295    Write32(SD.getAddress()); // address
296    Write32(SD.getSize()); // size
297    Write32(FileOffset);
298
299    unsigned Flags = Section.getTypeAndAttributes();
300    if (SD.hasInstructions())
301      Flags |= MCSectionMachO::S_ATTR_SOME_INSTRUCTIONS;
302
303    assert(isPowerOf2_32(SD.getAlignment()) && "Invalid alignment!");
304    Write32(Log2_32(SD.getAlignment()));
305    Write32(NumRelocations ? RelocationsStart : 0);
306    Write32(NumRelocations);
307    Write32(Flags);
308    Write32(0); // reserved1
309    Write32(Section.getStubSize()); // reserved2
310
311    assert(OS.tell() - Start == Section32Size);
312  }
313
314  void WriteSymtabLoadCommand(uint32_t SymbolOffset, uint32_t NumSymbols,
315                              uint32_t StringTableOffset,
316                              uint32_t StringTableSize) {
317    // struct symtab_command (24 bytes)
318
319    uint64_t Start = OS.tell();
320    (void) Start;
321
322    Write32(LCT_Symtab);
323    Write32(SymtabLoadCommandSize);
324    Write32(SymbolOffset);
325    Write32(NumSymbols);
326    Write32(StringTableOffset);
327    Write32(StringTableSize);
328
329    assert(OS.tell() - Start == SymtabLoadCommandSize);
330  }
331
332  void WriteDysymtabLoadCommand(uint32_t FirstLocalSymbol,
333                                uint32_t NumLocalSymbols,
334                                uint32_t FirstExternalSymbol,
335                                uint32_t NumExternalSymbols,
336                                uint32_t FirstUndefinedSymbol,
337                                uint32_t NumUndefinedSymbols,
338                                uint32_t IndirectSymbolOffset,
339                                uint32_t NumIndirectSymbols) {
340    // struct dysymtab_command (80 bytes)
341
342    uint64_t Start = OS.tell();
343    (void) Start;
344
345    Write32(LCT_Dysymtab);
346    Write32(DysymtabLoadCommandSize);
347    Write32(FirstLocalSymbol);
348    Write32(NumLocalSymbols);
349    Write32(FirstExternalSymbol);
350    Write32(NumExternalSymbols);
351    Write32(FirstUndefinedSymbol);
352    Write32(NumUndefinedSymbols);
353    Write32(0); // tocoff
354    Write32(0); // ntoc
355    Write32(0); // modtaboff
356    Write32(0); // nmodtab
357    Write32(0); // extrefsymoff
358    Write32(0); // nextrefsyms
359    Write32(IndirectSymbolOffset);
360    Write32(NumIndirectSymbols);
361    Write32(0); // extreloff
362    Write32(0); // nextrel
363    Write32(0); // locreloff
364    Write32(0); // nlocrel
365
366    assert(OS.tell() - Start == DysymtabLoadCommandSize);
367  }
368
369  void WriteNlist32(MachSymbolData &MSD) {
370    MCSymbolData &Data = *MSD.SymbolData;
371    const MCSymbol &Symbol = Data.getSymbol();
372    uint8_t Type = 0;
373    uint16_t Flags = Data.getFlags();
374    uint32_t Address = 0;
375
376    // Set the N_TYPE bits. See <mach-o/nlist.h>.
377    //
378    // FIXME: Are the prebound or indirect fields possible here?
379    if (Symbol.isUndefined())
380      Type = STT_Undefined;
381    else if (Symbol.isAbsolute())
382      Type = STT_Absolute;
383    else
384      Type = STT_Section;
385
386    // FIXME: Set STAB bits.
387
388    if (Data.isPrivateExtern())
389      Type |= STF_PrivateExtern;
390
391    // Set external bit.
392    if (Data.isExternal() || Symbol.isUndefined())
393      Type |= STF_External;
394
395    // Compute the symbol address.
396    if (Symbol.isDefined()) {
397      if (Symbol.isAbsolute()) {
398        llvm_unreachable("FIXME: Not yet implemented!");
399      } else {
400        Address = Data.getFragment()->getAddress() + Data.getOffset();
401      }
402    } else if (Data.isCommon()) {
403      // Common symbols are encoded with the size in the address
404      // field, and their alignment in the flags.
405      Address = Data.getCommonSize();
406
407      // Common alignment is packed into the 'desc' bits.
408      if (unsigned Align = Data.getCommonAlignment()) {
409        unsigned Log2Size = Log2_32(Align);
410        assert((1U << Log2Size) == Align && "Invalid 'common' alignment!");
411        if (Log2Size > 15)
412          llvm_report_error("invalid 'common' alignment '" +
413                            Twine(Align) + "'");
414        // FIXME: Keep this mask with the SymbolFlags enumeration.
415        Flags = (Flags & 0xF0FF) | (Log2Size << 8);
416      }
417    }
418
419    // struct nlist (12 bytes)
420
421    Write32(MSD.StringIndex);
422    Write8(Type);
423    Write8(MSD.SectionIndex);
424
425    // The Mach-O streamer uses the lowest 16-bits of the flags for the 'desc'
426    // value.
427    Write16(Flags);
428    Write32(Address);
429  }
430
431  struct MachRelocationEntry {
432    uint32_t Word0;
433    uint32_t Word1;
434  };
435  void ComputeScatteredRelocationInfo(MCAssembler &Asm, MCFragment &Fragment,
436                                      MCAsmFixup &Fixup,
437                                      const MCValue &Target,
438                             DenseMap<const MCSymbol*,MCSymbolData*> &SymbolMap,
439                                     std::vector<MachRelocationEntry> &Relocs) {
440    uint32_t Address = Fragment.getOffset() + Fixup.Offset;
441    unsigned IsPCRel = 0;
442    unsigned Type = RIT_Vanilla;
443
444    // See <reloc.h>.
445    const MCSymbol *A = Target.getSymA();
446    MCSymbolData *SD = SymbolMap.lookup(A);
447    uint32_t Value = SD->getFragment()->getAddress() + SD->getOffset();
448    uint32_t Value2 = 0;
449
450    if (const MCSymbol *B = Target.getSymB()) {
451      Type = RIT_LocalDifference;
452
453      MCSymbolData *SD = SymbolMap.lookup(B);
454      Value2 = SD->getFragment()->getAddress() + SD->getOffset();
455    }
456
457    unsigned Log2Size = getFixupKindLog2Size(Fixup.Kind);
458
459    // The value which goes in the fixup is current value of the expression.
460    Fixup.FixedValue = Value - Value2 + Target.getConstant();
461    if (isFixupKindPCRel(Fixup.Kind)) {
462      Fixup.FixedValue -= Address + (1 << Log2Size);
463      IsPCRel = 1;
464    }
465
466    MachRelocationEntry MRE;
467    MRE.Word0 = ((Address   <<  0) |
468                 (Type      << 24) |
469                 (Log2Size  << 28) |
470                 (IsPCRel   << 30) |
471                 RF_Scattered);
472    MRE.Word1 = Value;
473    Relocs.push_back(MRE);
474
475    if (Type == RIT_LocalDifference) {
476      Type = RIT_Pair;
477
478      MachRelocationEntry MRE;
479      MRE.Word0 = ((0         <<  0) |
480                   (Type      << 24) |
481                   (Log2Size  << 28) |
482                   (0   << 30) |
483                   RF_Scattered);
484      MRE.Word1 = Value2;
485      Relocs.push_back(MRE);
486    }
487  }
488
489  void ComputeRelocationInfo(MCAssembler &Asm, MCDataFragment &Fragment,
490                             MCAsmFixup &Fixup,
491                             DenseMap<const MCSymbol*,MCSymbolData*> &SymbolMap,
492                             std::vector<MachRelocationEntry> &Relocs) {
493    MCValue Target;
494    if (!Fixup.Value->EvaluateAsRelocatable(Target))
495      llvm_report_error("expected relocatable expression");
496
497    // If this is a difference or a local symbol plus an offset, then we need a
498    // scattered relocation entry.
499    if (Target.getSymB() ||
500        (Target.getSymA() && !Target.getSymA()->isUndefined() &&
501         Target.getConstant()))
502      return ComputeScatteredRelocationInfo(Asm, Fragment, Fixup, Target,
503                                            SymbolMap, Relocs);
504
505    // See <reloc.h>.
506    uint32_t Address = Fragment.getOffset() + Fixup.Offset;
507    uint32_t Value = 0;
508    unsigned Index = 0;
509    unsigned IsPCRel = 0;
510    unsigned IsExtern = 0;
511    unsigned Type = 0;
512
513    if (Target.isAbsolute()) { // constant
514      // SymbolNum of 0 indicates the absolute section.
515      //
516      // FIXME: When is this generated?
517      Type = RIT_Vanilla;
518      Value = 0;
519      llvm_unreachable("FIXME: Not yet implemented!");
520    } else {
521      const MCSymbol *Symbol = Target.getSymA();
522      MCSymbolData *SD = SymbolMap.lookup(Symbol);
523
524      if (Symbol->isUndefined()) {
525        IsExtern = 1;
526        Index = SD->getIndex();
527        Value = 0;
528      } else {
529        // The index is the section ordinal.
530        //
531        // FIXME: O(N)
532        Index = 1;
533        MCAssembler::iterator it = Asm.begin(), ie = Asm.end();
534        for (; it != ie; ++it, ++Index)
535          if (&*it == SD->getFragment()->getParent())
536            break;
537        assert(it != ie && "Unable to find section index!");
538        Value = SD->getFragment()->getAddress() + SD->getOffset();
539      }
540
541      Type = RIT_Vanilla;
542    }
543
544    // The value which goes in the fixup is current value of the expression.
545    Fixup.FixedValue = Value + Target.getConstant();
546
547    unsigned Log2Size = getFixupKindLog2Size(Fixup.Kind);
548
549    if (isFixupKindPCRel(Fixup.Kind)) {
550      Fixup.FixedValue -= Address + (1<<Log2Size);
551      IsPCRel = 1;
552    }
553
554    // struct relocation_info (8 bytes)
555    MachRelocationEntry MRE;
556    MRE.Word0 = Address;
557    MRE.Word1 = ((Index     <<  0) |
558                 (IsPCRel   << 24) |
559                 (Log2Size  << 25) |
560                 (IsExtern  << 27) |
561                 (Type      << 28));
562    Relocs.push_back(MRE);
563  }
564
565  void BindIndirectSymbols(MCAssembler &Asm,
566                           DenseMap<const MCSymbol*,MCSymbolData*> &SymbolMap) {
567    // This is the point where 'as' creates actual symbols for indirect symbols
568    // (in the following two passes). It would be easier for us to do this
569    // sooner when we see the attribute, but that makes getting the order in the
570    // symbol table much more complicated than it is worth.
571    //
572    // FIXME: Revisit this when the dust settles.
573
574    // Bind non lazy symbol pointers first.
575    for (MCAssembler::indirect_symbol_iterator it = Asm.indirect_symbol_begin(),
576           ie = Asm.indirect_symbol_end(); it != ie; ++it) {
577      // FIXME: cast<> support!
578      const MCSectionMachO &Section =
579        static_cast<const MCSectionMachO&>(it->SectionData->getSection());
580
581      unsigned Type =
582        Section.getTypeAndAttributes() & MCSectionMachO::SECTION_TYPE;
583      if (Type != MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS)
584        continue;
585
586      MCSymbolData *&Entry = SymbolMap[it->Symbol];
587      if (!Entry)
588        Entry = new MCSymbolData(*it->Symbol, 0, 0, &Asm);
589    }
590
591    // Then lazy symbol pointers and symbol stubs.
592    for (MCAssembler::indirect_symbol_iterator it = Asm.indirect_symbol_begin(),
593           ie = Asm.indirect_symbol_end(); it != ie; ++it) {
594      // FIXME: cast<> support!
595      const MCSectionMachO &Section =
596        static_cast<const MCSectionMachO&>(it->SectionData->getSection());
597
598      unsigned Type =
599        Section.getTypeAndAttributes() & MCSectionMachO::SECTION_TYPE;
600      if (Type != MCSectionMachO::S_LAZY_SYMBOL_POINTERS &&
601          Type != MCSectionMachO::S_SYMBOL_STUBS)
602        continue;
603
604      MCSymbolData *&Entry = SymbolMap[it->Symbol];
605      if (!Entry) {
606        Entry = new MCSymbolData(*it->Symbol, 0, 0, &Asm);
607
608        // Set the symbol type to undefined lazy, but only on construction.
609        //
610        // FIXME: Do not hardcode.
611        Entry->setFlags(Entry->getFlags() | 0x0001);
612      }
613    }
614  }
615
616  /// ComputeSymbolTable - Compute the symbol table data
617  ///
618  /// \param StringTable [out] - The string table data.
619  /// \param StringIndexMap [out] - Map from symbol names to offsets in the
620  /// string table.
621  void ComputeSymbolTable(MCAssembler &Asm, SmallString<256> &StringTable,
622                          std::vector<MachSymbolData> &LocalSymbolData,
623                          std::vector<MachSymbolData> &ExternalSymbolData,
624                          std::vector<MachSymbolData> &UndefinedSymbolData) {
625    // Build section lookup table.
626    DenseMap<const MCSection*, uint8_t> SectionIndexMap;
627    unsigned Index = 1;
628    for (MCAssembler::iterator it = Asm.begin(),
629           ie = Asm.end(); it != ie; ++it, ++Index)
630      SectionIndexMap[&it->getSection()] = Index;
631    assert(Index <= 256 && "Too many sections!");
632
633    // Index 0 is always the empty string.
634    StringMap<uint64_t> StringIndexMap;
635    StringTable += '\x00';
636
637    // Build the symbol arrays and the string table, but only for non-local
638    // symbols.
639    //
640    // The particular order that we collect the symbols and create the string
641    // table, then sort the symbols is chosen to match 'as'. Even though it
642    // doesn't matter for correctness, this is important for letting us diff .o
643    // files.
644    for (MCAssembler::symbol_iterator it = Asm.symbol_begin(),
645           ie = Asm.symbol_end(); it != ie; ++it) {
646      const MCSymbol &Symbol = it->getSymbol();
647
648      // Ignore assembler temporaries.
649      if (it->getSymbol().isTemporary())
650        continue;
651
652      if (!it->isExternal() && !Symbol.isUndefined())
653        continue;
654
655      uint64_t &Entry = StringIndexMap[Symbol.getName()];
656      if (!Entry) {
657        Entry = StringTable.size();
658        StringTable += Symbol.getName();
659        StringTable += '\x00';
660      }
661
662      MachSymbolData MSD;
663      MSD.SymbolData = it;
664      MSD.StringIndex = Entry;
665
666      if (Symbol.isUndefined()) {
667        MSD.SectionIndex = 0;
668        UndefinedSymbolData.push_back(MSD);
669      } else if (Symbol.isAbsolute()) {
670        MSD.SectionIndex = 0;
671        ExternalSymbolData.push_back(MSD);
672      } else {
673        MSD.SectionIndex = SectionIndexMap.lookup(&Symbol.getSection());
674        assert(MSD.SectionIndex && "Invalid section index!");
675        ExternalSymbolData.push_back(MSD);
676      }
677    }
678
679    // Now add the data for local symbols.
680    for (MCAssembler::symbol_iterator it = Asm.symbol_begin(),
681           ie = Asm.symbol_end(); it != ie; ++it) {
682      const MCSymbol &Symbol = it->getSymbol();
683
684      // Ignore assembler temporaries.
685      if (it->getSymbol().isTemporary())
686        continue;
687
688      if (it->isExternal() || Symbol.isUndefined())
689        continue;
690
691      uint64_t &Entry = StringIndexMap[Symbol.getName()];
692      if (!Entry) {
693        Entry = StringTable.size();
694        StringTable += Symbol.getName();
695        StringTable += '\x00';
696      }
697
698      MachSymbolData MSD;
699      MSD.SymbolData = it;
700      MSD.StringIndex = Entry;
701
702      if (Symbol.isAbsolute()) {
703        MSD.SectionIndex = 0;
704        LocalSymbolData.push_back(MSD);
705      } else {
706        MSD.SectionIndex = SectionIndexMap.lookup(&Symbol.getSection());
707        assert(MSD.SectionIndex && "Invalid section index!");
708        LocalSymbolData.push_back(MSD);
709      }
710    }
711
712    // External and undefined symbols are required to be in lexicographic order.
713    std::sort(ExternalSymbolData.begin(), ExternalSymbolData.end());
714    std::sort(UndefinedSymbolData.begin(), UndefinedSymbolData.end());
715
716    // Set the symbol indices.
717    Index = 0;
718    for (unsigned i = 0, e = LocalSymbolData.size(); i != e; ++i)
719      LocalSymbolData[i].SymbolData->setIndex(Index++);
720    for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i)
721      ExternalSymbolData[i].SymbolData->setIndex(Index++);
722    for (unsigned i = 0, e = UndefinedSymbolData.size(); i != e; ++i)
723      UndefinedSymbolData[i].SymbolData->setIndex(Index++);
724
725    // The string table is padded to a multiple of 4.
726    while (StringTable.size() % 4)
727      StringTable += '\x00';
728  }
729
730  void WriteObject(MCAssembler &Asm) {
731    unsigned NumSections = Asm.size();
732
733    // Compute the symbol -> symbol data map.
734    //
735    // FIXME: This should not be here.
736    DenseMap<const MCSymbol*, MCSymbolData *> SymbolMap;
737    for (MCAssembler::symbol_iterator it = Asm.symbol_begin(),
738           ie = Asm.symbol_end(); it != ie; ++it)
739      SymbolMap[&it->getSymbol()] = it;
740
741    // Create symbol data for any indirect symbols.
742    BindIndirectSymbols(Asm, SymbolMap);
743
744    // Compute symbol table information.
745    SmallString<256> StringTable;
746    std::vector<MachSymbolData> LocalSymbolData;
747    std::vector<MachSymbolData> ExternalSymbolData;
748    std::vector<MachSymbolData> UndefinedSymbolData;
749    unsigned NumSymbols = Asm.symbol_size();
750
751    // No symbol table command is written if there are no symbols.
752    if (NumSymbols)
753      ComputeSymbolTable(Asm, StringTable, LocalSymbolData, ExternalSymbolData,
754                         UndefinedSymbolData);
755
756    // The section data starts after the header, the segment load command (and
757    // section headers) and the symbol table.
758    unsigned NumLoadCommands = 1;
759    uint64_t LoadCommandsSize =
760      SegmentLoadCommand32Size + NumSections * Section32Size;
761
762    // Add the symbol table load command sizes, if used.
763    if (NumSymbols) {
764      NumLoadCommands += 2;
765      LoadCommandsSize += SymtabLoadCommandSize + DysymtabLoadCommandSize;
766    }
767
768    // Compute the total size of the section data, as well as its file size and
769    // vm size.
770    uint64_t SectionDataStart = Header32Size + LoadCommandsSize;
771    uint64_t SectionDataSize = 0;
772    uint64_t SectionDataFileSize = 0;
773    uint64_t VMSize = 0;
774    for (MCAssembler::iterator it = Asm.begin(),
775           ie = Asm.end(); it != ie; ++it) {
776      MCSectionData &SD = *it;
777
778      VMSize = std::max(VMSize, SD.getAddress() + SD.getSize());
779
780      if (isVirtualSection(SD.getSection()))
781        continue;
782
783      SectionDataSize = std::max(SectionDataSize,
784                                 SD.getAddress() + SD.getSize());
785      SectionDataFileSize = std::max(SectionDataFileSize,
786                                     SD.getAddress() + SD.getFileSize());
787    }
788
789    // The section data is padded to 4 bytes.
790    //
791    // FIXME: Is this machine dependent?
792    unsigned SectionDataPadding = OffsetToAlignment(SectionDataFileSize, 4);
793    SectionDataFileSize += SectionDataPadding;
794
795    // Write the prolog, starting with the header and load command...
796    WriteHeader32(NumLoadCommands, LoadCommandsSize,
797                  Asm.getSubsectionsViaSymbols());
798    WriteSegmentLoadCommand32(NumSections, VMSize,
799                              SectionDataStart, SectionDataSize);
800
801    // ... and then the section headers.
802    //
803    // We also compute the section relocations while we do this. Note that
804    // computing relocation info will also update the fixup to have the correct
805    // value; this will overwrite the appropriate data in the fragment when it
806    // is written.
807    std::vector<MachRelocationEntry> RelocInfos;
808    uint64_t RelocTableEnd = SectionDataStart + SectionDataFileSize;
809    for (MCAssembler::iterator it = Asm.begin(),
810           ie = Asm.end(); it != ie; ++it) {
811      MCSectionData &SD = *it;
812
813      // The assembler writes relocations in the reverse order they were seen.
814      //
815      // FIXME: It is probably more complicated than this.
816      unsigned NumRelocsStart = RelocInfos.size();
817      for (MCSectionData::reverse_iterator it2 = SD.rbegin(),
818             ie2 = SD.rend(); it2 != ie2; ++it2)
819        if (MCDataFragment *DF = dyn_cast<MCDataFragment>(&*it2))
820          for (unsigned i = 0, e = DF->fixup_size(); i != e; ++i)
821            ComputeRelocationInfo(Asm, *DF, DF->getFixups()[e - i - 1],
822                                  SymbolMap, RelocInfos);
823
824      unsigned NumRelocs = RelocInfos.size() - NumRelocsStart;
825      uint64_t SectionStart = SectionDataStart + SD.getAddress();
826      WriteSection32(SD, SectionStart, RelocTableEnd, NumRelocs);
827      RelocTableEnd += NumRelocs * RelocationInfoSize;
828    }
829
830    // Write the symbol table load command, if used.
831    if (NumSymbols) {
832      unsigned FirstLocalSymbol = 0;
833      unsigned NumLocalSymbols = LocalSymbolData.size();
834      unsigned FirstExternalSymbol = FirstLocalSymbol + NumLocalSymbols;
835      unsigned NumExternalSymbols = ExternalSymbolData.size();
836      unsigned FirstUndefinedSymbol = FirstExternalSymbol + NumExternalSymbols;
837      unsigned NumUndefinedSymbols = UndefinedSymbolData.size();
838      unsigned NumIndirectSymbols = Asm.indirect_symbol_size();
839      unsigned NumSymTabSymbols =
840        NumLocalSymbols + NumExternalSymbols + NumUndefinedSymbols;
841      uint64_t IndirectSymbolSize = NumIndirectSymbols * 4;
842      uint64_t IndirectSymbolOffset = 0;
843
844      // If used, the indirect symbols are written after the section data.
845      if (NumIndirectSymbols)
846        IndirectSymbolOffset = RelocTableEnd;
847
848      // The symbol table is written after the indirect symbol data.
849      uint64_t SymbolTableOffset = RelocTableEnd + IndirectSymbolSize;
850
851      // The string table is written after symbol table.
852      uint64_t StringTableOffset =
853        SymbolTableOffset + NumSymTabSymbols * Nlist32Size;
854      WriteSymtabLoadCommand(SymbolTableOffset, NumSymTabSymbols,
855                             StringTableOffset, StringTable.size());
856
857      WriteDysymtabLoadCommand(FirstLocalSymbol, NumLocalSymbols,
858                               FirstExternalSymbol, NumExternalSymbols,
859                               FirstUndefinedSymbol, NumUndefinedSymbols,
860                               IndirectSymbolOffset, NumIndirectSymbols);
861    }
862
863    // Write the actual section data.
864    for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it)
865      WriteFileData(OS, *it, *this);
866
867    // Write the extra padding.
868    WriteZeros(SectionDataPadding);
869
870    // Write the relocation entries.
871    for (unsigned i = 0, e = RelocInfos.size(); i != e; ++i) {
872      Write32(RelocInfos[i].Word0);
873      Write32(RelocInfos[i].Word1);
874    }
875
876    // Write the symbol table data, if used.
877    if (NumSymbols) {
878      // Write the indirect symbol entries.
879      for (MCAssembler::indirect_symbol_iterator
880             it = Asm.indirect_symbol_begin(),
881             ie = Asm.indirect_symbol_end(); it != ie; ++it) {
882        // Indirect symbols in the non lazy symbol pointer section have some
883        // special handling.
884        const MCSectionMachO &Section =
885          static_cast<const MCSectionMachO&>(it->SectionData->getSection());
886        unsigned Type =
887          Section.getTypeAndAttributes() & MCSectionMachO::SECTION_TYPE;
888        if (Type == MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS) {
889          // If this symbol is defined and internal, mark it as such.
890          if (it->Symbol->isDefined() &&
891              !SymbolMap.lookup(it->Symbol)->isExternal()) {
892            uint32_t Flags = ISF_Local;
893            if (it->Symbol->isAbsolute())
894              Flags |= ISF_Absolute;
895            Write32(Flags);
896            continue;
897          }
898        }
899
900        Write32(SymbolMap[it->Symbol]->getIndex());
901      }
902
903      // FIXME: Check that offsets match computed ones.
904
905      // Write the symbol table entries.
906      for (unsigned i = 0, e = LocalSymbolData.size(); i != e; ++i)
907        WriteNlist32(LocalSymbolData[i]);
908      for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i)
909        WriteNlist32(ExternalSymbolData[i]);
910      for (unsigned i = 0, e = UndefinedSymbolData.size(); i != e; ++i)
911        WriteNlist32(UndefinedSymbolData[i]);
912
913      // Write the string table.
914      OS << StringTable.str();
915    }
916  }
917
918  void ApplyFixup(const MCAsmFixup &Fixup, MCDataFragment &DF) {
919    unsigned Size = 1 << getFixupKindLog2Size(Fixup.Kind);
920
921    // FIXME: Endianness assumption.
922    assert(Fixup.Offset + Size <= DF.getContents().size() &&
923           "Invalid fixup offset!");
924    for (unsigned i = 0; i != Size; ++i)
925      DF.getContents()[Fixup.Offset + i] = uint8_t(Fixup.FixedValue >> (i * 8));
926  }
927};
928
929/* *** */
930
931MCFragment::MCFragment() : Kind(FragmentType(~0)) {
932}
933
934MCFragment::MCFragment(FragmentType _Kind, MCSectionData *_Parent)
935  : Kind(_Kind),
936    Parent(_Parent),
937    FileSize(~UINT64_C(0))
938{
939  if (Parent)
940    Parent->getFragmentList().push_back(this);
941}
942
943MCFragment::~MCFragment() {
944}
945
946uint64_t MCFragment::getAddress() const {
947  assert(getParent() && "Missing Section!");
948  return getParent()->getAddress() + Offset;
949}
950
951/* *** */
952
953MCSectionData::MCSectionData() : Section(0) {}
954
955MCSectionData::MCSectionData(const MCSection &_Section, MCAssembler *A)
956  : Section(&_Section),
957    Alignment(1),
958    Address(~UINT64_C(0)),
959    Size(~UINT64_C(0)),
960    FileSize(~UINT64_C(0)),
961    HasInstructions(false)
962{
963  if (A)
964    A->getSectionList().push_back(this);
965}
966
967/* *** */
968
969MCSymbolData::MCSymbolData() : Symbol(0) {}
970
971MCSymbolData::MCSymbolData(const MCSymbol &_Symbol, MCFragment *_Fragment,
972                           uint64_t _Offset, MCAssembler *A)
973  : Symbol(&_Symbol), Fragment(_Fragment), Offset(_Offset),
974    IsExternal(false), IsPrivateExtern(false),
975    CommonSize(0), CommonAlign(0), Flags(0), Index(0)
976{
977  if (A)
978    A->getSymbolList().push_back(this);
979}
980
981/* *** */
982
983MCAssembler::MCAssembler(MCContext &_Context, raw_ostream &_OS)
984  : Context(_Context), OS(_OS), SubsectionsViaSymbols(false)
985{
986}
987
988MCAssembler::~MCAssembler() {
989}
990
991void MCAssembler::LayoutSection(MCSectionData &SD) {
992  uint64_t Address = SD.getAddress();
993
994  for (MCSectionData::iterator it = SD.begin(), ie = SD.end(); it != ie; ++it) {
995    MCFragment &F = *it;
996
997    F.setOffset(Address - SD.getAddress());
998
999    // Evaluate fragment size.
1000    switch (F.getKind()) {
1001    case MCFragment::FT_Align: {
1002      MCAlignFragment &AF = cast<MCAlignFragment>(F);
1003
1004      uint64_t Size = OffsetToAlignment(Address, AF.getAlignment());
1005      if (Size > AF.getMaxBytesToEmit())
1006        AF.setFileSize(0);
1007      else
1008        AF.setFileSize(Size);
1009      break;
1010    }
1011
1012    case MCFragment::FT_Data:
1013    case MCFragment::FT_Fill:
1014      F.setFileSize(F.getMaxFileSize());
1015      break;
1016
1017    case MCFragment::FT_Org: {
1018      MCOrgFragment &OF = cast<MCOrgFragment>(F);
1019
1020      MCValue Target;
1021      if (!OF.getOffset().EvaluateAsRelocatable(Target))
1022        llvm_report_error("expected relocatable expression");
1023
1024      if (!Target.isAbsolute())
1025        llvm_unreachable("FIXME: Not yet implemented!");
1026      uint64_t OrgOffset = Target.getConstant();
1027      uint64_t Offset = Address - SD.getAddress();
1028
1029      // FIXME: We need a way to communicate this error.
1030      if (OrgOffset < Offset)
1031        llvm_report_error("invalid .org offset '" + Twine(OrgOffset) +
1032                          "' (at offset '" + Twine(Offset) + "'");
1033
1034      F.setFileSize(OrgOffset - Offset);
1035      break;
1036    }
1037
1038    case MCFragment::FT_ZeroFill: {
1039      MCZeroFillFragment &ZFF = cast<MCZeroFillFragment>(F);
1040
1041      // Align the fragment offset; it is safe to adjust the offset freely since
1042      // this is only in virtual sections.
1043      uint64_t Aligned = RoundUpToAlignment(Address, ZFF.getAlignment());
1044      F.setOffset(Aligned - SD.getAddress());
1045
1046      // FIXME: This is misnamed.
1047      F.setFileSize(ZFF.getSize());
1048      break;
1049    }
1050    }
1051
1052    Address += F.getFileSize();
1053  }
1054
1055  // Set the section sizes.
1056  SD.setSize(Address - SD.getAddress());
1057  if (isVirtualSection(SD.getSection()))
1058    SD.setFileSize(0);
1059  else
1060    SD.setFileSize(Address - SD.getAddress());
1061}
1062
1063/// WriteFileData - Write the \arg F data to the output file.
1064static void WriteFileData(raw_ostream &OS, const MCFragment &F,
1065                          MachObjectWriter &MOW) {
1066  uint64_t Start = OS.tell();
1067  (void) Start;
1068
1069  ++EmittedFragments;
1070
1071  // FIXME: Embed in fragments instead?
1072  switch (F.getKind()) {
1073  case MCFragment::FT_Align: {
1074    MCAlignFragment &AF = cast<MCAlignFragment>(F);
1075    uint64_t Count = AF.getFileSize() / AF.getValueSize();
1076
1077    // FIXME: This error shouldn't actually occur (the front end should emit
1078    // multiple .align directives to enforce the semantics it wants), but is
1079    // severe enough that we want to report it. How to handle this?
1080    if (Count * AF.getValueSize() != AF.getFileSize())
1081      llvm_report_error("undefined .align directive, value size '" +
1082                        Twine(AF.getValueSize()) +
1083                        "' is not a divisor of padding size '" +
1084                        Twine(AF.getFileSize()) + "'");
1085
1086    for (uint64_t i = 0; i != Count; ++i) {
1087      switch (AF.getValueSize()) {
1088      default:
1089        assert(0 && "Invalid size!");
1090      case 1: MOW.Write8 (uint8_t (AF.getValue())); break;
1091      case 2: MOW.Write16(uint16_t(AF.getValue())); break;
1092      case 4: MOW.Write32(uint32_t(AF.getValue())); break;
1093      case 8: MOW.Write64(uint64_t(AF.getValue())); break;
1094      }
1095    }
1096    break;
1097  }
1098
1099  case MCFragment::FT_Data: {
1100    MCDataFragment &DF = cast<MCDataFragment>(F);
1101
1102    // Apply the fixups.
1103    //
1104    // FIXME: Move elsewhere.
1105    for (MCDataFragment::const_fixup_iterator it = DF.fixup_begin(),
1106           ie = DF.fixup_end(); it != ie; ++it)
1107      MOW.ApplyFixup(*it, DF);
1108
1109    OS << cast<MCDataFragment>(F).getContents().str();
1110    break;
1111  }
1112
1113  case MCFragment::FT_Fill: {
1114    MCFillFragment &FF = cast<MCFillFragment>(F);
1115    for (uint64_t i = 0, e = FF.getCount(); i != e; ++i) {
1116      switch (FF.getValueSize()) {
1117      default:
1118        assert(0 && "Invalid size!");
1119      case 1: MOW.Write8 (uint8_t (FF.getValue())); break;
1120      case 2: MOW.Write16(uint16_t(FF.getValue())); break;
1121      case 4: MOW.Write32(uint32_t(FF.getValue())); break;
1122      case 8: MOW.Write64(uint64_t(FF.getValue())); break;
1123      }
1124    }
1125    break;
1126  }
1127
1128  case MCFragment::FT_Org: {
1129    MCOrgFragment &OF = cast<MCOrgFragment>(F);
1130
1131    for (uint64_t i = 0, e = OF.getFileSize(); i != e; ++i)
1132      MOW.Write8(uint8_t(OF.getValue()));
1133
1134    break;
1135  }
1136
1137  case MCFragment::FT_ZeroFill: {
1138    assert(0 && "Invalid zero fill fragment in concrete section!");
1139    break;
1140  }
1141  }
1142
1143  assert(OS.tell() - Start == F.getFileSize());
1144}
1145
1146/// WriteFileData - Write the \arg SD data to the output file.
1147static void WriteFileData(raw_ostream &OS, const MCSectionData &SD,
1148                          MachObjectWriter &MOW) {
1149  // Ignore virtual sections.
1150  if (isVirtualSection(SD.getSection())) {
1151    assert(SD.getFileSize() == 0);
1152    return;
1153  }
1154
1155  uint64_t Start = OS.tell();
1156  (void) Start;
1157
1158  for (MCSectionData::const_iterator it = SD.begin(),
1159         ie = SD.end(); it != ie; ++it)
1160    WriteFileData(OS, *it, MOW);
1161
1162  // Add section padding.
1163  assert(SD.getFileSize() >= SD.getSize() && "Invalid section sizes!");
1164  MOW.WriteZeros(SD.getFileSize() - SD.getSize());
1165
1166  assert(OS.tell() - Start == SD.getFileSize());
1167}
1168
1169void MCAssembler::Finish() {
1170  DEBUG_WITH_TYPE("mc-dump", {
1171      llvm::errs() << "assembler backend - pre-layout\n--\n";
1172      dump(); });
1173
1174  // Layout the concrete sections and fragments.
1175  uint64_t Address = 0;
1176  MCSectionData *Prev = 0;
1177  for (iterator it = begin(), ie = end(); it != ie; ++it) {
1178    MCSectionData &SD = *it;
1179
1180    // Skip virtual sections.
1181    if (isVirtualSection(SD.getSection()))
1182      continue;
1183
1184    // Align this section if necessary by adding padding bytes to the previous
1185    // section.
1186    if (uint64_t Pad = OffsetToAlignment(Address, it->getAlignment())) {
1187      assert(Prev && "Missing prev section!");
1188      Prev->setFileSize(Prev->getFileSize() + Pad);
1189      Address += Pad;
1190    }
1191
1192    // Layout the section fragments and its size.
1193    SD.setAddress(Address);
1194    LayoutSection(SD);
1195    Address += SD.getFileSize();
1196
1197    Prev = &SD;
1198  }
1199
1200  // Layout the virtual sections.
1201  for (iterator it = begin(), ie = end(); it != ie; ++it) {
1202    MCSectionData &SD = *it;
1203
1204    if (!isVirtualSection(SD.getSection()))
1205      continue;
1206
1207    SD.setAddress(Address);
1208    LayoutSection(SD);
1209    Address += SD.getSize();
1210  }
1211
1212  DEBUG_WITH_TYPE("mc-dump", {
1213      llvm::errs() << "assembler backend - post-layout\n--\n";
1214      dump(); });
1215
1216  // Write the object file.
1217  MachObjectWriter MOW(OS);
1218  MOW.WriteObject(*this);
1219
1220  OS.flush();
1221}
1222
1223
1224// Debugging methods
1225
1226namespace llvm {
1227
1228raw_ostream &operator<<(raw_ostream &OS, const MCAsmFixup &AF) {
1229  OS << "<MCAsmFixup" << " Offset:" << AF.Offset << " Value:" << *AF.Value
1230     << " Kind:" << AF.Kind << ">";
1231  return OS;
1232}
1233
1234}
1235
1236void MCFragment::dump() {
1237  raw_ostream &OS = llvm::errs();
1238
1239  OS << "<MCFragment " << (void*) this << " Offset:" << Offset
1240     << " FileSize:" << FileSize;
1241
1242  OS << ">";
1243}
1244
1245void MCAlignFragment::dump() {
1246  raw_ostream &OS = llvm::errs();
1247
1248  OS << "<MCAlignFragment ";
1249  this->MCFragment::dump();
1250  OS << "\n       ";
1251  OS << " Alignment:" << getAlignment()
1252     << " Value:" << getValue() << " ValueSize:" << getValueSize()
1253     << " MaxBytesToEmit:" << getMaxBytesToEmit() << ">";
1254}
1255
1256void MCDataFragment::dump() {
1257  raw_ostream &OS = llvm::errs();
1258
1259  OS << "<MCDataFragment ";
1260  this->MCFragment::dump();
1261  OS << "\n       ";
1262  OS << " Contents:[";
1263  for (unsigned i = 0, e = getContents().size(); i != e; ++i) {
1264    if (i) OS << ",";
1265    OS << hexdigit((Contents[i] >> 4) & 0xF) << hexdigit(Contents[i] & 0xF);
1266  }
1267  OS << "] (" << getContents().size() << " bytes)";
1268
1269  if (!getFixups().empty()) {
1270    OS << ",\n       ";
1271    OS << " Fixups:[";
1272    for (fixup_iterator it = fixup_begin(), ie = fixup_end(); it != ie; ++it) {
1273      if (it != fixup_begin()) OS << ",\n            ";
1274      OS << *it;
1275    }
1276    OS << "]";
1277  }
1278
1279  OS << ">";
1280}
1281
1282void MCFillFragment::dump() {
1283  raw_ostream &OS = llvm::errs();
1284
1285  OS << "<MCFillFragment ";
1286  this->MCFragment::dump();
1287  OS << "\n       ";
1288  OS << " Value:" << getValue() << " ValueSize:" << getValueSize()
1289     << " Count:" << getCount() << ">";
1290}
1291
1292void MCOrgFragment::dump() {
1293  raw_ostream &OS = llvm::errs();
1294
1295  OS << "<MCOrgFragment ";
1296  this->MCFragment::dump();
1297  OS << "\n       ";
1298  OS << " Offset:" << getOffset() << " Value:" << getValue() << ">";
1299}
1300
1301void MCZeroFillFragment::dump() {
1302  raw_ostream &OS = llvm::errs();
1303
1304  OS << "<MCZeroFillFragment ";
1305  this->MCFragment::dump();
1306  OS << "\n       ";
1307  OS << " Size:" << getSize() << " Alignment:" << getAlignment() << ">";
1308}
1309
1310void MCSectionData::dump() {
1311  raw_ostream &OS = llvm::errs();
1312
1313  OS << "<MCSectionData";
1314  OS << " Alignment:" << getAlignment() << " Address:" << Address
1315     << " Size:" << Size << " FileSize:" << FileSize
1316     << " Fragments:[";
1317  for (iterator it = begin(), ie = end(); it != ie; ++it) {
1318    if (it != begin()) OS << ",\n      ";
1319    it->dump();
1320  }
1321  OS << "]>";
1322}
1323
1324void MCSymbolData::dump() {
1325  raw_ostream &OS = llvm::errs();
1326
1327  OS << "<MCSymbolData Symbol:" << getSymbol()
1328     << " Fragment:" << getFragment() << " Offset:" << getOffset()
1329     << " Flags:" << getFlags() << " Index:" << getIndex();
1330  if (isCommon())
1331    OS << " (common, size:" << getCommonSize()
1332       << " align: " << getCommonAlignment() << ")";
1333  if (isExternal())
1334    OS << " (external)";
1335  if (isPrivateExtern())
1336    OS << " (private extern)";
1337  OS << ">";
1338}
1339
1340void MCAssembler::dump() {
1341  raw_ostream &OS = llvm::errs();
1342
1343  OS << "<MCAssembler\n";
1344  OS << "  Sections:[";
1345  for (iterator it = begin(), ie = end(); it != ie; ++it) {
1346    if (it != begin()) OS << ",\n    ";
1347    it->dump();
1348  }
1349  OS << "],\n";
1350  OS << "  Symbols:[";
1351
1352  for (symbol_iterator it = symbol_begin(), ie = symbol_end(); it != ie; ++it) {
1353    if (it != symbol_begin()) OS << ",\n    ";
1354    it->dump();
1355  }
1356  OS << "]>\n";
1357}
1358