MCELFStreamer.cpp revision 97551276c59d4521200d2a4cf312a3fa885f2507 
1//===- lib/MC/MCELFStreamer.cpp - ELF Object 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// This file assembles .s files and emits ELF .o object files.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/MC/MCStreamer.h"
15
16#include "llvm/ADT/SmallPtrSet.h"
17#include "llvm/MC/MCAssembler.h"
18#include "llvm/MC/MCContext.h"
19#include "llvm/MC/MCCodeEmitter.h"
20#include "llvm/MC/MCELFSymbolFlags.h"
21#include "llvm/MC/MCExpr.h"
22#include "llvm/MC/MCInst.h"
23#include "llvm/MC/MCObjectStreamer.h"
24#include "llvm/MC/MCSection.h"
25#include "llvm/MC/MCSectionELF.h"
26#include "llvm/MC/MCSymbol.h"
27#include "llvm/MC/MCValue.h"
28#include "llvm/Support/Debug.h"
29#include "llvm/Support/ELF.h"
30#include "llvm/Support/ErrorHandling.h"
31#include "llvm/Support/raw_ostream.h"
32#include "llvm/Target/TargetAsmBackend.h"
33
34using namespace llvm;
35
36namespace {
37
38static void SetBinding(MCSymbolData &SD, unsigned Binding) {
39  assert(Binding == ELF::STB_LOCAL || Binding == ELF::STB_GLOBAL ||
40         Binding == ELF::STB_WEAK);
41  uint32_t OtherFlags = SD.getFlags() & ~(0xf << ELF_STB_Shift);
42  SD.setFlags(OtherFlags | (Binding << ELF_STB_Shift));
43}
44
45static unsigned GetBinding(const MCSymbolData &SD) {
46  uint32_t Binding = (SD.getFlags() & (0xf << ELF_STB_Shift)) >> ELF_STB_Shift;
47  assert(Binding == ELF::STB_LOCAL || Binding == ELF::STB_GLOBAL ||
48         Binding == ELF::STB_WEAK);
49  return Binding;
50}
51
52static void SetType(MCSymbolData &SD, unsigned Type) {
53  assert(Type == ELF::STT_NOTYPE || Type == ELF::STT_OBJECT ||
54         Type == ELF::STT_FUNC || Type == ELF::STT_SECTION ||
55         Type == ELF::STT_FILE || Type == ELF::STT_COMMON ||
56         Type == ELF::STT_TLS);
57
58  uint32_t OtherFlags = SD.getFlags() & ~(0xf << ELF_STT_Shift);
59  SD.setFlags(OtherFlags | (Type << ELF_STT_Shift));
60}
61
62static void SetVisibility(MCSymbolData &SD, unsigned Visibility) {
63  assert(Visibility == ELF::STV_DEFAULT || Visibility == ELF::STV_INTERNAL ||
64         Visibility == ELF::STV_HIDDEN || Visibility == ELF::STV_PROTECTED);
65
66  uint32_t OtherFlags = SD.getFlags() & ~(0xf << ELF_STV_Shift);
67  SD.setFlags(OtherFlags | (Visibility << ELF_STV_Shift));
68}
69
70class MCELFStreamer : public MCObjectStreamer {
71public:
72  MCELFStreamer(MCContext &Context, TargetAsmBackend &TAB,
73                  raw_ostream &OS, MCCodeEmitter *Emitter)
74    : MCObjectStreamer(Context, TAB, OS, Emitter, false) {}
75
76  ~MCELFStreamer() {}
77
78  /// @name MCStreamer Interface
79  /// @{
80
81  virtual void InitSections();
82  virtual void EmitLabel(MCSymbol *Symbol);
83  virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
84  virtual void EmitThumbFunc(MCSymbol *Func);
85  virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
86  virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol);
87  virtual void SwitchSection(const MCSection *Section);
88  virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
89  virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
90    assert(0 && "ELF doesn't support this directive");
91  }
92  virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
93                                unsigned ByteAlignment);
94  virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {
95    assert(0 && "ELF doesn't support this directive");
96  }
97
98  virtual void EmitCOFFSymbolStorageClass(int StorageClass) {
99    assert(0 && "ELF doesn't support this directive");
100  }
101
102  virtual void EmitCOFFSymbolType(int Type) {
103    assert(0 && "ELF doesn't support this directive");
104  }
105
106  virtual void EndCOFFSymbolDef() {
107    assert(0 && "ELF doesn't support this directive");
108  }
109
110  virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
111     MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
112     SD.setSize(Value);
113  }
114
115  virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {
116    assert(0 && "ELF doesn't support this directive");
117  }
118  virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
119                            unsigned Size = 0, unsigned ByteAlignment = 0) {
120    assert(0 && "ELF doesn't support this directive");
121  }
122  virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
123                              uint64_t Size, unsigned ByteAlignment = 0) {
124    assert(0 && "ELF doesn't support this directive");
125  }
126  virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
127  virtual void EmitValue(const MCExpr *Value, unsigned Size,unsigned AddrSpace);
128  virtual void EmitGPRel32Value(const MCExpr *Value) {
129    assert(0 && "ELF doesn't support this directive");
130  }
131  virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
132                                    unsigned ValueSize = 1,
133                                    unsigned MaxBytesToEmit = 0);
134  virtual void EmitCodeAlignment(unsigned ByteAlignment,
135                                 unsigned MaxBytesToEmit = 0);
136  virtual void EmitValueToOffset(const MCExpr *Offset,
137                                 unsigned char Value = 0);
138
139  virtual void EmitFileDirective(StringRef Filename);
140
141  virtual void Finish();
142
143private:
144  virtual void EmitInstToFragment(const MCInst &Inst);
145  virtual void EmitInstToData(const MCInst &Inst);
146
147  void fixSymbolsInTLSFixups(const MCExpr *expr);
148
149  struct LocalCommon {
150    MCSymbolData *SD;
151    uint64_t Size;
152    unsigned ByteAlignment;
153  };
154  std::vector<LocalCommon> LocalCommons;
155
156  SmallPtrSet<MCSymbol *, 16> BindingExplicitlySet;
157  /// @}
158  void SetSection(StringRef Section, unsigned Type, unsigned Flags,
159                  SectionKind Kind) {
160    SwitchSection(getContext().getELFSection(Section, Type, Flags, Kind));
161  }
162
163  void SetSectionData() {
164    SetSection(".data", MCSectionELF::SHT_PROGBITS,
165               MCSectionELF::SHF_WRITE |MCSectionELF::SHF_ALLOC,
166               SectionKind::getDataRel());
167    EmitCodeAlignment(4, 0);
168  }
169  void SetSectionText() {
170    SetSection(".text", MCSectionELF::SHT_PROGBITS,
171               MCSectionELF::SHF_EXECINSTR |
172               MCSectionELF::SHF_ALLOC, SectionKind::getText());
173    EmitCodeAlignment(4, 0);
174  }
175  void SetSectionBss() {
176    SetSection(".bss", MCSectionELF::SHT_NOBITS,
177               MCSectionELF::SHF_WRITE |
178               MCSectionELF::SHF_ALLOC, SectionKind::getBSS());
179    EmitCodeAlignment(4, 0);
180  }
181};
182
183} // end anonymous namespace.
184
185void MCELFStreamer::InitSections() {
186  // This emulates the same behavior of GNU as. This makes it easier
187  // to compare the output as the major sections are in the same order.
188  SetSectionText();
189  SetSectionData();
190  SetSectionBss();
191  SetSectionText();
192}
193
194void MCELFStreamer::EmitLabel(MCSymbol *Symbol) {
195  assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
196
197  Symbol->setSection(*CurSection);
198
199  MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
200
201  const MCSectionELF &Section =
202    static_cast<const MCSectionELF&>(Symbol->getSection());
203  if (Section.getFlags() & MCSectionELF::SHF_TLS)
204    SetType(SD, ELF::STT_TLS);
205
206  // FIXME: This is wasteful, we don't necessarily need to create a data
207  // fragment. Instead, we should mark the symbol as pointing into the data
208  // fragment if it exists, otherwise we should just queue the label and set its
209  // fragment pointer when we emit the next fragment.
210  MCDataFragment *F = getOrCreateDataFragment();
211
212  assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
213  SD.setFragment(F);
214  SD.setOffset(F->getContents().size());
215}
216
217void MCELFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
218  switch (Flag) {
219  case MCAF_SyntaxUnified: return; // no-op here.
220  case MCAF_Code16: return; // no-op here.
221  case MCAF_Code32: return; // no-op here.
222  case MCAF_SubsectionsViaSymbols:
223    getAssembler().setSubsectionsViaSymbols(true);
224    return;
225  }
226
227  assert(0 && "invalid assembler flag!");
228}
229
230void MCELFStreamer::EmitThumbFunc(MCSymbol *Func) {
231  // FIXME: Anything needed here to flag the function as thumb?
232}
233
234void MCELFStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
235  // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
236  // MCObjectStreamer.
237  // FIXME: Lift context changes into super class.
238  getAssembler().getOrCreateSymbolData(*Symbol);
239  Symbol->setVariableValue(AddValueSymbols(Value));
240}
241
242void MCELFStreamer::SwitchSection(const MCSection *Section) {
243  const MCSymbol *Grp = static_cast<const MCSectionELF *>(Section)->getGroup();
244  if (Grp)
245    getAssembler().getOrCreateSymbolData(*Grp);
246  this->MCObjectStreamer::SwitchSection(Section);
247}
248
249void MCELFStreamer::EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {
250  getAssembler().getOrCreateSymbolData(*Symbol);
251  MCSymbolData &AliasSD = getAssembler().getOrCreateSymbolData(*Alias);
252  AliasSD.setFlags(AliasSD.getFlags() | ELF_Other_Weakref);
253  const MCExpr *Value = MCSymbolRefExpr::Create(Symbol, getContext());
254  Alias->setVariableValue(Value);
255}
256
257void MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
258                                          MCSymbolAttr Attribute) {
259  // Indirect symbols are handled differently, to match how 'as' handles
260  // them. This makes writing matching .o files easier.
261  if (Attribute == MCSA_IndirectSymbol) {
262    // Note that we intentionally cannot use the symbol data here; this is
263    // important for matching the string table that 'as' generates.
264    IndirectSymbolData ISD;
265    ISD.Symbol = Symbol;
266    ISD.SectionData = getCurrentSectionData();
267    getAssembler().getIndirectSymbols().push_back(ISD);
268    return;
269  }
270
271  // Adding a symbol attribute always introduces the symbol, note that an
272  // important side effect of calling getOrCreateSymbolData here is to register
273  // the symbol with the assembler.
274  MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
275
276  // The implementation of symbol attributes is designed to match 'as', but it
277  // leaves much to desired. It doesn't really make sense to arbitrarily add and
278  // remove flags, but 'as' allows this (in particular, see .desc).
279  //
280  // In the future it might be worth trying to make these operations more well
281  // defined.
282  switch (Attribute) {
283  case MCSA_LazyReference:
284  case MCSA_Reference:
285  case MCSA_NoDeadStrip:
286  case MCSA_SymbolResolver:
287  case MCSA_PrivateExtern:
288  case MCSA_WeakDefinition:
289  case MCSA_WeakDefAutoPrivate:
290  case MCSA_Invalid:
291  case MCSA_ELF_TypeIndFunction:
292  case MCSA_IndirectSymbol:
293    assert(0 && "Invalid symbol attribute for ELF!");
294    break;
295
296  case MCSA_ELF_TypeGnuUniqueObject:
297    // Ignore for now.
298    break;
299
300  case MCSA_Global:
301    SetBinding(SD, ELF::STB_GLOBAL);
302    SD.setExternal(true);
303    BindingExplicitlySet.insert(Symbol);
304    break;
305
306  case MCSA_WeakReference:
307  case MCSA_Weak:
308    SetBinding(SD, ELF::STB_WEAK);
309    SD.setExternal(true);
310    BindingExplicitlySet.insert(Symbol);
311    break;
312
313  case MCSA_Local:
314    SetBinding(SD, ELF::STB_LOCAL);
315    SD.setExternal(false);
316    BindingExplicitlySet.insert(Symbol);
317    break;
318
319  case MCSA_ELF_TypeFunction:
320    SetType(SD, ELF::STT_FUNC);
321    break;
322
323  case MCSA_ELF_TypeObject:
324    SetType(SD, ELF::STT_OBJECT);
325    break;
326
327  case MCSA_ELF_TypeTLS:
328    SetType(SD, ELF::STT_TLS);
329    break;
330
331  case MCSA_ELF_TypeCommon:
332    SetType(SD, ELF::STT_COMMON);
333    break;
334
335  case MCSA_ELF_TypeNoType:
336    SetType(SD, ELF::STT_NOTYPE);
337    break;
338
339  case MCSA_Protected:
340    SetVisibility(SD, ELF::STV_PROTECTED);
341    break;
342
343  case MCSA_Hidden:
344    SetVisibility(SD, ELF::STV_HIDDEN);
345    break;
346
347  case MCSA_Internal:
348    SetVisibility(SD, ELF::STV_INTERNAL);
349    break;
350  }
351}
352
353void MCELFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
354                                       unsigned ByteAlignment) {
355  MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
356
357  if (!BindingExplicitlySet.count(Symbol)) {
358    SetBinding(SD, ELF::STB_GLOBAL);
359    SD.setExternal(true);
360  }
361
362  SetType(SD, ELF::STT_OBJECT);
363
364  if (GetBinding(SD) == ELF_STB_Local) {
365    const MCSection *Section = getAssembler().getContext().getELFSection(".bss",
366                                                                    MCSectionELF::SHT_NOBITS,
367                                                                    MCSectionELF::SHF_WRITE |
368                                                                    MCSectionELF::SHF_ALLOC,
369                                                                    SectionKind::getBSS());
370    Symbol->setSection(*Section);
371
372    struct LocalCommon L = {&SD, Size, ByteAlignment};
373    LocalCommons.push_back(L);
374  } else {
375    SD.setCommon(Size, ByteAlignment);
376  }
377
378  SD.setSize(MCConstantExpr::Create(Size, getContext()));
379}
380
381void MCELFStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
382  // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
383  // MCObjectStreamer.
384  getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
385}
386
387void MCELFStreamer::EmitValue(const MCExpr *Value, unsigned Size,
388                                unsigned AddrSpace) {
389  // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
390  // MCObjectStreamer.
391  MCDataFragment *DF = getOrCreateDataFragment();
392
393  // Avoid fixups when possible.
394  int64_t AbsValue;
395  if (AddValueSymbols(Value)->EvaluateAsAbsolute(AbsValue)) {
396    // FIXME: Endianness assumption.
397    for (unsigned i = 0; i != Size; ++i)
398      DF->getContents().push_back(uint8_t(AbsValue >> (i * 8)));
399  } else {
400    DF->addFixup(MCFixup::Create(DF->getContents().size(), AddValueSymbols(Value),
401                                 MCFixup::getKindForSize(Size)));
402    DF->getContents().resize(DF->getContents().size() + Size, 0);
403  }
404}
405
406void MCELFStreamer::EmitValueToAlignment(unsigned ByteAlignment,
407                                           int64_t Value, unsigned ValueSize,
408                                           unsigned MaxBytesToEmit) {
409  // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
410  // MCObjectStreamer.
411  if (MaxBytesToEmit == 0)
412    MaxBytesToEmit = ByteAlignment;
413  new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
414                      getCurrentSectionData());
415
416  // Update the maximum alignment on the current section if necessary.
417  if (ByteAlignment > getCurrentSectionData()->getAlignment())
418    getCurrentSectionData()->setAlignment(ByteAlignment);
419}
420
421void MCELFStreamer::EmitCodeAlignment(unsigned ByteAlignment,
422                                        unsigned MaxBytesToEmit) {
423  // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
424  // MCObjectStreamer.
425  if (MaxBytesToEmit == 0)
426    MaxBytesToEmit = ByteAlignment;
427  MCAlignFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit,
428                                           getCurrentSectionData());
429  F->setEmitNops(true);
430
431  // Update the maximum alignment on the current section if necessary.
432  if (ByteAlignment > getCurrentSectionData()->getAlignment())
433    getCurrentSectionData()->setAlignment(ByteAlignment);
434}
435
436void MCELFStreamer::EmitValueToOffset(const MCExpr *Offset,
437                                        unsigned char Value) {
438  // TODO: This is exactly the same as MCMachOStreamer. Consider merging into
439  // MCObjectStreamer.
440  new MCOrgFragment(*Offset, Value, getCurrentSectionData());
441}
442
443// Add a symbol for the file name of this module. This is the second
444// entry in the module's symbol table (the first being the null symbol).
445void MCELFStreamer::EmitFileDirective(StringRef Filename) {
446  MCSymbol *Symbol = getAssembler().getContext().GetOrCreateSymbol(Filename);
447  Symbol->setSection(*CurSection);
448  Symbol->setAbsolute();
449
450  MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
451
452  SD.setFlags(ELF_STT_File | ELF_STB_Local | ELF_STV_Default);
453}
454
455void  MCELFStreamer::fixSymbolsInTLSFixups(const MCExpr *expr) {
456  switch (expr->getKind()) {
457  case MCExpr::Target: llvm_unreachable("Can't handle target exprs yet!");
458  case MCExpr::Constant:
459    break;
460
461  case MCExpr::Binary: {
462    const MCBinaryExpr *be = cast<MCBinaryExpr>(expr);
463    fixSymbolsInTLSFixups(be->getLHS());
464    fixSymbolsInTLSFixups(be->getRHS());
465    break;
466  }
467
468  case MCExpr::SymbolRef: {
469    const MCSymbolRefExpr &symRef = *cast<MCSymbolRefExpr>(expr);
470    MCSymbolRefExpr::VariantKind kind = symRef.getKind();
471    if (kind != MCSymbolRefExpr::VK_TLSGD &&
472	kind != MCSymbolRefExpr::VK_TLSLD &&
473	kind != MCSymbolRefExpr::VK_TLSLDM &&
474	kind != MCSymbolRefExpr::VK_ARM_TLSGD)
475      return;
476    MCSymbolData &SD = getAssembler().getOrCreateSymbolData(symRef.getSymbol());
477    SetType(SD, ELF::STT_TLS);
478    break;
479  }
480
481  case MCExpr::Unary:
482    fixSymbolsInTLSFixups(cast<MCUnaryExpr>(expr)->getSubExpr());
483    break;
484  }
485}
486
487void MCELFStreamer::EmitInstToFragment(const MCInst &Inst) {
488  MCInstFragment *IF = new MCInstFragment(Inst, getCurrentSectionData());
489
490  // Add the fixups and data.
491  //
492  // FIXME: Revisit this design decision when relaxation is done, we may be
493  // able to get away with not storing any extra data in the MCInst.
494  SmallVector<MCFixup, 4> Fixups;
495  SmallString<256> Code;
496  raw_svector_ostream VecOS(Code);
497  getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
498  VecOS.flush();
499
500  for (unsigned i = 0, e = Fixups.size(); i != e; ++i)
501    fixSymbolsInTLSFixups(Fixups[i].getValue());
502
503  IF->getCode() = Code;
504  IF->getFixups() = Fixups;
505}
506
507void MCELFStreamer::EmitInstToData(const MCInst &Inst) {
508  MCDataFragment *DF = getOrCreateDataFragment();
509
510  SmallVector<MCFixup, 4> Fixups;
511  SmallString<256> Code;
512  raw_svector_ostream VecOS(Code);
513  getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
514  VecOS.flush();
515
516  for (unsigned i = 0, e = Fixups.size(); i != e; ++i)
517    fixSymbolsInTLSFixups(Fixups[i].getValue());
518
519  // Add the fixups and data.
520  for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
521    Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
522    DF->addFixup(Fixups[i]);
523  }
524  DF->getContents().append(Code.begin(), Code.end());
525}
526
527void MCELFStreamer::Finish() {
528  // FIXME: duplicated code with the MachO streamer.
529  // Dump out the dwarf file & directory tables and line tables.
530  if (getContext().hasDwarfFiles()) {
531    const MCSection *DwarfLineSection =
532      getContext().getELFSection(".debug_line", 0, 0,
533                                 SectionKind::getDataRelLocal());
534    MCSectionData &DLS =
535      getAssembler().getOrCreateSectionData(*DwarfLineSection);
536    int PointerSize = getAssembler().getBackend().getPointerSize();
537    MCDwarfFileTable::Emit(this, DwarfLineSection, &DLS, PointerSize);
538  }
539
540  for (std::vector<LocalCommon>::const_iterator i = LocalCommons.begin(),
541                                                e = LocalCommons.end();
542       i != e; ++i) {
543    MCSymbolData *SD = i->SD;
544    uint64_t Size = i->Size;
545    unsigned ByteAlignment = i->ByteAlignment;
546    const MCSymbol &Symbol = SD->getSymbol();
547    const MCSection &Section = Symbol.getSection();
548
549    MCSectionData &SectData = getAssembler().getOrCreateSectionData(Section);
550    new MCAlignFragment(ByteAlignment, 0, 1, ByteAlignment, &SectData);
551
552    MCFragment *F = new MCFillFragment(0, 0, Size, &SectData);
553    SD->setFragment(F);
554
555    // Update the maximum alignment of the section if necessary.
556    if (ByteAlignment > SectData.getAlignment())
557      SectData.setAlignment(ByteAlignment);
558  }
559
560  this->MCObjectStreamer::Finish();
561}
562
563MCStreamer *llvm::createELFStreamer(MCContext &Context, TargetAsmBackend &TAB,
564                                      raw_ostream &OS, MCCodeEmitter *CE,
565                                      bool RelaxAll) {
566  MCELFStreamer *S = new MCELFStreamer(Context, TAB, OS, CE);
567  if (RelaxAll)
568    S->getAssembler().setRelaxAll(true);
569  return S;
570}
571