ARMELFStreamer.cpp revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
1//===- lib/MC/ARMELFStreamer.cpp - ELF Object Output for ARM --------------===//
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 ARM ELF .o object files. Different
11// from generic ELF streamer in emitting mapping symbols ($a, $t and $d) to
12// delimit regions of data and code.
13//
14//===----------------------------------------------------------------------===//
15
16#include "ARMArchName.h"
17#include "ARMFPUName.h"
18#include "ARMRegisterInfo.h"
19#include "ARMUnwindOpAsm.h"
20#include "llvm/ADT/StringExtras.h"
21#include "llvm/ADT/Twine.h"
22#include "llvm/MC/MCAsmBackend.h"
23#include "llvm/MC/MCAsmInfo.h"
24#include "llvm/MC/MCAssembler.h"
25#include "llvm/MC/MCCodeEmitter.h"
26#include "llvm/MC/MCContext.h"
27#include "llvm/MC/MCELF.h"
28#include "llvm/MC/MCELFStreamer.h"
29#include "llvm/MC/MCELFSymbolFlags.h"
30#include "llvm/MC/MCExpr.h"
31#include "llvm/MC/MCInst.h"
32#include "llvm/MC/MCInstPrinter.h"
33#include "llvm/MC/MCObjectFileInfo.h"
34#include "llvm/MC/MCObjectStreamer.h"
35#include "llvm/MC/MCRegisterInfo.h"
36#include "llvm/MC/MCSection.h"
37#include "llvm/MC/MCSectionELF.h"
38#include "llvm/MC/MCStreamer.h"
39#include "llvm/MC/MCSymbol.h"
40#include "llvm/MC/MCValue.h"
41#include "llvm/Support/ARMBuildAttributes.h"
42#include "llvm/Support/ARMEHABI.h"
43#include "llvm/Support/Debug.h"
44#include "llvm/Support/ELF.h"
45#include "llvm/Support/FormattedStream.h"
46#include "llvm/Support/LEB128.h"
47#include "llvm/Support/raw_ostream.h"
48#include <algorithm>
49
50using namespace llvm;
51
52static std::string GetAEABIUnwindPersonalityName(unsigned Index) {
53  assert(Index < ARM::EHABI::NUM_PERSONALITY_INDEX &&
54         "Invalid personality index");
55  return (Twine("__aeabi_unwind_cpp_pr") + Twine(Index)).str();
56}
57
58static const char *GetFPUName(unsigned ID) {
59  switch (ID) {
60  default:
61    llvm_unreachable("Unknown FPU kind");
62    break;
63#define ARM_FPU_NAME(NAME, ID) case ARM::ID: return NAME;
64#include "ARMFPUName.def"
65  }
66  return nullptr;
67}
68
69static const char *GetArchName(unsigned ID) {
70  switch (ID) {
71  default:
72    llvm_unreachable("Unknown ARCH kind");
73    break;
74#define ARM_ARCH_NAME(NAME, ID, DEFAULT_CPU_NAME, DEFAULT_CPU_ARCH) \
75  case ARM::ID: return NAME;
76#define ARM_ARCH_ALIAS(NAME, ID) /* empty */
77#include "ARMArchName.def"
78  }
79  return nullptr;
80}
81
82static const char *GetArchDefaultCPUName(unsigned ID) {
83  switch (ID) {
84  default:
85    llvm_unreachable("Unknown ARCH kind");
86    break;
87#define ARM_ARCH_NAME(NAME, ID, DEFAULT_CPU_NAME, DEFAULT_CPU_ARCH) \
88  case ARM::ID: return DEFAULT_CPU_NAME;
89#define ARM_ARCH_ALIAS(NAME, ID) /* empty */
90#include "ARMArchName.def"
91  }
92  return nullptr;
93}
94
95static unsigned GetArchDefaultCPUArch(unsigned ID) {
96  switch (ID) {
97  default:
98    llvm_unreachable("Unknown ARCH kind");
99    break;
100#define ARM_ARCH_NAME(NAME, ID, DEFAULT_CPU_NAME, DEFAULT_CPU_ARCH) \
101  case ARM::ID: return ARMBuildAttrs::DEFAULT_CPU_ARCH;
102#define ARM_ARCH_ALIAS(NAME, ID) /* empty */
103#include "ARMArchName.def"
104  }
105  return 0;
106}
107
108namespace {
109
110class ARMELFStreamer;
111
112class ARMTargetAsmStreamer : public ARMTargetStreamer {
113  formatted_raw_ostream &OS;
114  MCInstPrinter &InstPrinter;
115  bool IsVerboseAsm;
116
117  void emitFnStart() override;
118  void emitFnEnd() override;
119  void emitCantUnwind() override;
120  void emitPersonality(const MCSymbol *Personality) override;
121  void emitPersonalityIndex(unsigned Index) override;
122  void emitHandlerData() override;
123  void emitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0) override;
124  void emitMovSP(unsigned Reg, int64_t Offset = 0) override;
125  void emitPad(int64_t Offset) override;
126  void emitRegSave(const SmallVectorImpl<unsigned> &RegList,
127                   bool isVector) override;
128  void emitUnwindRaw(int64_t Offset,
129                     const SmallVectorImpl<uint8_t> &Opcodes) override;
130
131  void switchVendor(StringRef Vendor) override;
132  void emitAttribute(unsigned Attribute, unsigned Value) override;
133  void emitTextAttribute(unsigned Attribute, StringRef String) override;
134  void emitIntTextAttribute(unsigned Attribute, unsigned IntValue,
135                            StringRef StrinValue) override;
136  void emitArch(unsigned Arch) override;
137  void emitObjectArch(unsigned Arch) override;
138  void emitFPU(unsigned FPU) override;
139  void emitInst(uint32_t Inst, char Suffix = '\0') override;
140  void finishAttributeSection() override;
141
142  void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE) override;
143  void emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) override;
144
145public:
146  ARMTargetAsmStreamer(MCStreamer &S, formatted_raw_ostream &OS,
147                       MCInstPrinter &InstPrinter, bool VerboseAsm);
148};
149
150ARMTargetAsmStreamer::ARMTargetAsmStreamer(MCStreamer &S,
151                                           formatted_raw_ostream &OS,
152                                           MCInstPrinter &InstPrinter,
153                                           bool VerboseAsm)
154    : ARMTargetStreamer(S), OS(OS), InstPrinter(InstPrinter),
155      IsVerboseAsm(VerboseAsm) {}
156void ARMTargetAsmStreamer::emitFnStart() { OS << "\t.fnstart\n"; }
157void ARMTargetAsmStreamer::emitFnEnd() { OS << "\t.fnend\n"; }
158void ARMTargetAsmStreamer::emitCantUnwind() { OS << "\t.cantunwind\n"; }
159void ARMTargetAsmStreamer::emitPersonality(const MCSymbol *Personality) {
160  OS << "\t.personality " << Personality->getName() << '\n';
161}
162void ARMTargetAsmStreamer::emitPersonalityIndex(unsigned Index) {
163  OS << "\t.personalityindex " << Index << '\n';
164}
165void ARMTargetAsmStreamer::emitHandlerData() { OS << "\t.handlerdata\n"; }
166void ARMTargetAsmStreamer::emitSetFP(unsigned FpReg, unsigned SpReg,
167                                     int64_t Offset) {
168  OS << "\t.setfp\t";
169  InstPrinter.printRegName(OS, FpReg);
170  OS << ", ";
171  InstPrinter.printRegName(OS, SpReg);
172  if (Offset)
173    OS << ", #" << Offset;
174  OS << '\n';
175}
176void ARMTargetAsmStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
177  assert((Reg != ARM::SP && Reg != ARM::PC) &&
178         "the operand of .movsp cannot be either sp or pc");
179
180  OS << "\t.movsp\t";
181  InstPrinter.printRegName(OS, Reg);
182  if (Offset)
183    OS << ", #" << Offset;
184  OS << '\n';
185}
186void ARMTargetAsmStreamer::emitPad(int64_t Offset) {
187  OS << "\t.pad\t#" << Offset << '\n';
188}
189void ARMTargetAsmStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
190                                       bool isVector) {
191  assert(RegList.size() && "RegList should not be empty");
192  if (isVector)
193    OS << "\t.vsave\t{";
194  else
195    OS << "\t.save\t{";
196
197  InstPrinter.printRegName(OS, RegList[0]);
198
199  for (unsigned i = 1, e = RegList.size(); i != e; ++i) {
200    OS << ", ";
201    InstPrinter.printRegName(OS, RegList[i]);
202  }
203
204  OS << "}\n";
205}
206void ARMTargetAsmStreamer::switchVendor(StringRef Vendor) {
207}
208void ARMTargetAsmStreamer::emitAttribute(unsigned Attribute, unsigned Value) {
209  OS << "\t.eabi_attribute\t" << Attribute << ", " << Twine(Value);
210  if (IsVerboseAsm) {
211    StringRef Name = ARMBuildAttrs::AttrTypeAsString(Attribute);
212    if (!Name.empty())
213      OS << "\t@ " << Name;
214  }
215  OS << "\n";
216}
217void ARMTargetAsmStreamer::emitTextAttribute(unsigned Attribute,
218                                             StringRef String) {
219  switch (Attribute) {
220  case ARMBuildAttrs::CPU_name:
221    OS << "\t.cpu\t" << String.lower();
222    break;
223  default:
224    OS << "\t.eabi_attribute\t" << Attribute << ", \"" << String << "\"";
225    if (IsVerboseAsm) {
226      StringRef Name = ARMBuildAttrs::AttrTypeAsString(Attribute);
227      if (!Name.empty())
228        OS << "\t@ " << Name;
229    }
230    break;
231  }
232  OS << "\n";
233}
234void ARMTargetAsmStreamer::emitIntTextAttribute(unsigned Attribute,
235                                                unsigned IntValue,
236                                                StringRef StringValue) {
237  switch (Attribute) {
238  default: llvm_unreachable("unsupported multi-value attribute in asm mode");
239  case ARMBuildAttrs::compatibility:
240    OS << "\t.eabi_attribute\t" << Attribute << ", " << IntValue;
241    if (!StringValue.empty())
242      OS << ", \"" << StringValue << "\"";
243    if (IsVerboseAsm)
244      OS << "\t@ " << ARMBuildAttrs::AttrTypeAsString(Attribute);
245    break;
246  }
247  OS << "\n";
248}
249void ARMTargetAsmStreamer::emitArch(unsigned Arch) {
250  OS << "\t.arch\t" << GetArchName(Arch) << "\n";
251}
252void ARMTargetAsmStreamer::emitObjectArch(unsigned Arch) {
253  OS << "\t.object_arch\t" << GetArchName(Arch) << '\n';
254}
255void ARMTargetAsmStreamer::emitFPU(unsigned FPU) {
256  OS << "\t.fpu\t" << GetFPUName(FPU) << "\n";
257}
258void ARMTargetAsmStreamer::finishAttributeSection() {
259}
260void
261ARMTargetAsmStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
262  OS << "\t.tlsdescseq\t" << S->getSymbol().getName();
263}
264
265void ARMTargetAsmStreamer::emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) {
266  OS << "\t.thumb_set\t" << *Symbol << ", " << *Value << '\n';
267}
268
269void ARMTargetAsmStreamer::emitInst(uint32_t Inst, char Suffix) {
270  OS << "\t.inst";
271  if (Suffix)
272    OS << "." << Suffix;
273  OS << "\t0x" << utohexstr(Inst) << "\n";
274}
275
276void ARMTargetAsmStreamer::emitUnwindRaw(int64_t Offset,
277                                      const SmallVectorImpl<uint8_t> &Opcodes) {
278  OS << "\t.unwind_raw " << Offset;
279  for (SmallVectorImpl<uint8_t>::const_iterator OCI = Opcodes.begin(),
280                                                OCE = Opcodes.end();
281       OCI != OCE; ++OCI)
282    OS << ", 0x" << utohexstr(*OCI);
283  OS << '\n';
284}
285
286class ARMTargetELFStreamer : public ARMTargetStreamer {
287private:
288  // This structure holds all attributes, accounting for
289  // their string/numeric value, so we can later emmit them
290  // in declaration order, keeping all in the same vector
291  struct AttributeItem {
292    enum {
293      HiddenAttribute = 0,
294      NumericAttribute,
295      TextAttribute,
296      NumericAndTextAttributes
297    } Type;
298    unsigned Tag;
299    unsigned IntValue;
300    StringRef StringValue;
301
302    static bool LessTag(const AttributeItem &LHS, const AttributeItem &RHS) {
303      return (LHS.Tag < RHS.Tag);
304    }
305  };
306
307  StringRef CurrentVendor;
308  unsigned FPU;
309  unsigned Arch;
310  unsigned EmittedArch;
311  SmallVector<AttributeItem, 64> Contents;
312
313  const MCSection *AttributeSection;
314
315  AttributeItem *getAttributeItem(unsigned Attribute) {
316    for (size_t i = 0; i < Contents.size(); ++i)
317      if (Contents[i].Tag == Attribute)
318        return &Contents[i];
319    return nullptr;
320  }
321
322  void setAttributeItem(unsigned Attribute, unsigned Value,
323                        bool OverwriteExisting) {
324    // Look for existing attribute item
325    if (AttributeItem *Item = getAttributeItem(Attribute)) {
326      if (!OverwriteExisting)
327        return;
328      Item->Type = AttributeItem::NumericAttribute;
329      Item->IntValue = Value;
330      return;
331    }
332
333    // Create new attribute item
334    AttributeItem Item = {
335      AttributeItem::NumericAttribute,
336      Attribute,
337      Value,
338      StringRef("")
339    };
340    Contents.push_back(Item);
341  }
342
343  void setAttributeItem(unsigned Attribute, StringRef Value,
344                        bool OverwriteExisting) {
345    // Look for existing attribute item
346    if (AttributeItem *Item = getAttributeItem(Attribute)) {
347      if (!OverwriteExisting)
348        return;
349      Item->Type = AttributeItem::TextAttribute;
350      Item->StringValue = Value;
351      return;
352    }
353
354    // Create new attribute item
355    AttributeItem Item = {
356      AttributeItem::TextAttribute,
357      Attribute,
358      0,
359      Value
360    };
361    Contents.push_back(Item);
362  }
363
364  void setAttributeItems(unsigned Attribute, unsigned IntValue,
365                         StringRef StringValue, bool OverwriteExisting) {
366    // Look for existing attribute item
367    if (AttributeItem *Item = getAttributeItem(Attribute)) {
368      if (!OverwriteExisting)
369        return;
370      Item->Type = AttributeItem::NumericAndTextAttributes;
371      Item->IntValue = IntValue;
372      Item->StringValue = StringValue;
373      return;
374    }
375
376    // Create new attribute item
377    AttributeItem Item = {
378      AttributeItem::NumericAndTextAttributes,
379      Attribute,
380      IntValue,
381      StringValue
382    };
383    Contents.push_back(Item);
384  }
385
386  void emitArchDefaultAttributes();
387  void emitFPUDefaultAttributes();
388
389  ARMELFStreamer &getStreamer();
390
391  void emitFnStart() override;
392  void emitFnEnd() override;
393  void emitCantUnwind() override;
394  void emitPersonality(const MCSymbol *Personality) override;
395  void emitPersonalityIndex(unsigned Index) override;
396  void emitHandlerData() override;
397  void emitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0) override;
398  void emitMovSP(unsigned Reg, int64_t Offset = 0) override;
399  void emitPad(int64_t Offset) override;
400  void emitRegSave(const SmallVectorImpl<unsigned> &RegList,
401                   bool isVector) override;
402  void emitUnwindRaw(int64_t Offset,
403                     const SmallVectorImpl<uint8_t> &Opcodes) override;
404
405  void switchVendor(StringRef Vendor) override;
406  void emitAttribute(unsigned Attribute, unsigned Value) override;
407  void emitTextAttribute(unsigned Attribute, StringRef String) override;
408  void emitIntTextAttribute(unsigned Attribute, unsigned IntValue,
409                            StringRef StringValue) override;
410  void emitArch(unsigned Arch) override;
411  void emitObjectArch(unsigned Arch) override;
412  void emitFPU(unsigned FPU) override;
413  void emitInst(uint32_t Inst, char Suffix = '\0') override;
414  void finishAttributeSection() override;
415  void emitLabel(MCSymbol *Symbol) override;
416
417  void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE) override;
418  void emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) override;
419
420  size_t calculateContentSize() const;
421
422public:
423  ARMTargetELFStreamer(MCStreamer &S)
424    : ARMTargetStreamer(S), CurrentVendor("aeabi"), FPU(ARM::INVALID_FPU),
425      Arch(ARM::INVALID_ARCH), EmittedArch(ARM::INVALID_ARCH),
426      AttributeSection(nullptr) {}
427};
428
429/// Extend the generic ELFStreamer class so that it can emit mapping symbols at
430/// the appropriate points in the object files. These symbols are defined in the
431/// ARM ELF ABI: infocenter.arm.com/help/topic/com.arm.../IHI0044D_aaelf.pdf.
432///
433/// In brief: $a, $t or $d should be emitted at the start of each contiguous
434/// region of ARM code, Thumb code or data in a section. In practice, this
435/// emission does not rely on explicit assembler directives but on inherent
436/// properties of the directives doing the emission (e.g. ".byte" is data, "add
437/// r0, r0, r0" an instruction).
438///
439/// As a result this system is orthogonal to the DataRegion infrastructure used
440/// by MachO. Beware!
441class ARMELFStreamer : public MCELFStreamer {
442public:
443  friend class ARMTargetELFStreamer;
444
445  ARMELFStreamer(MCContext &Context, MCAsmBackend &TAB, raw_ostream &OS,
446                 MCCodeEmitter *Emitter, bool IsThumb)
447      : MCELFStreamer(Context, TAB, OS, Emitter), IsThumb(IsThumb),
448        MappingSymbolCounter(0), LastEMS(EMS_None) {
449    Reset();
450  }
451
452  ~ARMELFStreamer() {}
453
454  void FinishImpl() override;
455
456  // ARM exception handling directives
457  void emitFnStart();
458  void emitFnEnd();
459  void emitCantUnwind();
460  void emitPersonality(const MCSymbol *Per);
461  void emitPersonalityIndex(unsigned index);
462  void emitHandlerData();
463  void emitSetFP(unsigned NewFpReg, unsigned NewSpReg, int64_t Offset = 0);
464  void emitMovSP(unsigned Reg, int64_t Offset = 0);
465  void emitPad(int64_t Offset);
466  void emitRegSave(const SmallVectorImpl<unsigned> &RegList, bool isVector);
467  void emitUnwindRaw(int64_t Offset, const SmallVectorImpl<uint8_t> &Opcodes);
468
469  void ChangeSection(const MCSection *Section,
470                     const MCExpr *Subsection) override {
471    // We have to keep track of the mapping symbol state of any sections we
472    // use. Each one should start off as EMS_None, which is provided as the
473    // default constructor by DenseMap::lookup.
474    LastMappingSymbols[getPreviousSection().first] = LastEMS;
475    LastEMS = LastMappingSymbols.lookup(Section);
476
477    MCELFStreamer::ChangeSection(Section, Subsection);
478  }
479
480  /// This function is the one used to emit instruction data into the ELF
481  /// streamer. We override it to add the appropriate mapping symbol if
482  /// necessary.
483  void EmitInstruction(const MCInst& Inst,
484                       const MCSubtargetInfo &STI) override {
485    if (IsThumb)
486      EmitThumbMappingSymbol();
487    else
488      EmitARMMappingSymbol();
489
490    MCELFStreamer::EmitInstruction(Inst, STI);
491  }
492
493  void emitInst(uint32_t Inst, char Suffix) {
494    unsigned Size;
495    char Buffer[4];
496    const bool LittleEndian = getContext().getAsmInfo()->isLittleEndian();
497
498    switch (Suffix) {
499    case '\0':
500      Size = 4;
501
502      assert(!IsThumb);
503      EmitARMMappingSymbol();
504      for (unsigned II = 0, IE = Size; II != IE; II++) {
505        const unsigned I = LittleEndian ? (Size - II - 1) : II;
506        Buffer[Size - II - 1] = uint8_t(Inst >> I * CHAR_BIT);
507      }
508
509      break;
510    case 'n':
511    case 'w':
512      Size = (Suffix == 'n' ? 2 : 4);
513
514      assert(IsThumb);
515      EmitThumbMappingSymbol();
516      for (unsigned II = 0, IE = Size; II != IE; II = II + 2) {
517        const unsigned I0 = LittleEndian ? II + 0 : (Size - II - 1);
518        const unsigned I1 = LittleEndian ? II + 1 : (Size - II - 2);
519        Buffer[Size - II - 2] = uint8_t(Inst >> I0 * CHAR_BIT);
520        Buffer[Size - II - 1] = uint8_t(Inst >> I1 * CHAR_BIT);
521      }
522
523      break;
524    default:
525      llvm_unreachable("Invalid Suffix");
526    }
527
528    MCELFStreamer::EmitBytes(StringRef(Buffer, Size));
529  }
530
531  /// This is one of the functions used to emit data into an ELF section, so the
532  /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
533  /// necessary.
534  void EmitBytes(StringRef Data) override {
535    EmitDataMappingSymbol();
536    MCELFStreamer::EmitBytes(Data);
537  }
538
539  /// This is one of the functions used to emit data into an ELF section, so the
540  /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
541  /// necessary.
542  void EmitValueImpl(const MCExpr *Value, unsigned Size,
543                     const SMLoc &Loc) override {
544    EmitDataMappingSymbol();
545    MCELFStreamer::EmitValueImpl(Value, Size);
546  }
547
548  void EmitAssemblerFlag(MCAssemblerFlag Flag) override {
549    MCELFStreamer::EmitAssemblerFlag(Flag);
550
551    switch (Flag) {
552    case MCAF_SyntaxUnified:
553      return; // no-op here.
554    case MCAF_Code16:
555      IsThumb = true;
556      return; // Change to Thumb mode
557    case MCAF_Code32:
558      IsThumb = false;
559      return; // Change to ARM mode
560    case MCAF_Code64:
561      return;
562    case MCAF_SubsectionsViaSymbols:
563      return;
564    }
565  }
566
567private:
568  enum ElfMappingSymbol {
569    EMS_None,
570    EMS_ARM,
571    EMS_Thumb,
572    EMS_Data
573  };
574
575  void EmitDataMappingSymbol() {
576    if (LastEMS == EMS_Data) return;
577    EmitMappingSymbol("$d");
578    LastEMS = EMS_Data;
579  }
580
581  void EmitThumbMappingSymbol() {
582    if (LastEMS == EMS_Thumb) return;
583    EmitMappingSymbol("$t");
584    LastEMS = EMS_Thumb;
585  }
586
587  void EmitARMMappingSymbol() {
588    if (LastEMS == EMS_ARM) return;
589    EmitMappingSymbol("$a");
590    LastEMS = EMS_ARM;
591  }
592
593  void EmitMappingSymbol(StringRef Name) {
594    MCSymbol *Start = getContext().CreateTempSymbol();
595    EmitLabel(Start);
596
597    MCSymbol *Symbol =
598      getContext().GetOrCreateSymbol(Name + "." +
599                                     Twine(MappingSymbolCounter++));
600
601    MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
602    MCELF::SetType(SD, ELF::STT_NOTYPE);
603    MCELF::SetBinding(SD, ELF::STB_LOCAL);
604    SD.setExternal(false);
605    AssignSection(Symbol, getCurrentSection().first);
606
607    const MCExpr *Value = MCSymbolRefExpr::Create(Start, getContext());
608    Symbol->setVariableValue(Value);
609  }
610
611  void EmitThumbFunc(MCSymbol *Func) override {
612    getAssembler().setIsThumbFunc(Func);
613    EmitSymbolAttribute(Func, MCSA_ELF_TypeFunction);
614  }
615
616  // Helper functions for ARM exception handling directives
617  void Reset();
618
619  void EmitPersonalityFixup(StringRef Name);
620  void FlushPendingOffset();
621  void FlushUnwindOpcodes(bool NoHandlerData);
622
623  void SwitchToEHSection(const char *Prefix, unsigned Type, unsigned Flags,
624                         SectionKind Kind, const MCSymbol &Fn);
625  void SwitchToExTabSection(const MCSymbol &FnStart);
626  void SwitchToExIdxSection(const MCSymbol &FnStart);
627
628  void EmitFixup(const MCExpr *Expr, MCFixupKind Kind);
629
630  bool IsThumb;
631  int64_t MappingSymbolCounter;
632
633  DenseMap<const MCSection *, ElfMappingSymbol> LastMappingSymbols;
634  ElfMappingSymbol LastEMS;
635
636  // ARM Exception Handling Frame Information
637  MCSymbol *ExTab;
638  MCSymbol *FnStart;
639  const MCSymbol *Personality;
640  unsigned PersonalityIndex;
641  unsigned FPReg; // Frame pointer register
642  int64_t FPOffset; // Offset: (final frame pointer) - (initial $sp)
643  int64_t SPOffset; // Offset: (final $sp) - (initial $sp)
644  int64_t PendingOffset; // Offset: (final $sp) - (emitted $sp)
645  bool UsedFP;
646  bool CantUnwind;
647  SmallVector<uint8_t, 64> Opcodes;
648  UnwindOpcodeAssembler UnwindOpAsm;
649};
650} // end anonymous namespace
651
652ARMELFStreamer &ARMTargetELFStreamer::getStreamer() {
653  return static_cast<ARMELFStreamer &>(Streamer);
654}
655
656void ARMTargetELFStreamer::emitFnStart() { getStreamer().emitFnStart(); }
657void ARMTargetELFStreamer::emitFnEnd() { getStreamer().emitFnEnd(); }
658void ARMTargetELFStreamer::emitCantUnwind() { getStreamer().emitCantUnwind(); }
659void ARMTargetELFStreamer::emitPersonality(const MCSymbol *Personality) {
660  getStreamer().emitPersonality(Personality);
661}
662void ARMTargetELFStreamer::emitPersonalityIndex(unsigned Index) {
663  getStreamer().emitPersonalityIndex(Index);
664}
665void ARMTargetELFStreamer::emitHandlerData() {
666  getStreamer().emitHandlerData();
667}
668void ARMTargetELFStreamer::emitSetFP(unsigned FpReg, unsigned SpReg,
669                                     int64_t Offset) {
670  getStreamer().emitSetFP(FpReg, SpReg, Offset);
671}
672void ARMTargetELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
673  getStreamer().emitMovSP(Reg, Offset);
674}
675void ARMTargetELFStreamer::emitPad(int64_t Offset) {
676  getStreamer().emitPad(Offset);
677}
678void ARMTargetELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
679                                       bool isVector) {
680  getStreamer().emitRegSave(RegList, isVector);
681}
682void ARMTargetELFStreamer::emitUnwindRaw(int64_t Offset,
683                                      const SmallVectorImpl<uint8_t> &Opcodes) {
684  getStreamer().emitUnwindRaw(Offset, Opcodes);
685}
686void ARMTargetELFStreamer::switchVendor(StringRef Vendor) {
687  assert(!Vendor.empty() && "Vendor cannot be empty.");
688
689  if (CurrentVendor == Vendor)
690    return;
691
692  if (!CurrentVendor.empty())
693    finishAttributeSection();
694
695  assert(Contents.empty() &&
696         ".ARM.attributes should be flushed before changing vendor");
697  CurrentVendor = Vendor;
698
699}
700void ARMTargetELFStreamer::emitAttribute(unsigned Attribute, unsigned Value) {
701  setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
702}
703void ARMTargetELFStreamer::emitTextAttribute(unsigned Attribute,
704                                             StringRef Value) {
705  setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
706}
707void ARMTargetELFStreamer::emitIntTextAttribute(unsigned Attribute,
708                                                unsigned IntValue,
709                                                StringRef StringValue) {
710  setAttributeItems(Attribute, IntValue, StringValue,
711                    /* OverwriteExisting= */ true);
712}
713void ARMTargetELFStreamer::emitArch(unsigned Value) {
714  Arch = Value;
715}
716void ARMTargetELFStreamer::emitObjectArch(unsigned Value) {
717  EmittedArch = Value;
718}
719void ARMTargetELFStreamer::emitArchDefaultAttributes() {
720  using namespace ARMBuildAttrs;
721
722  setAttributeItem(CPU_name, GetArchDefaultCPUName(Arch), false);
723  if (EmittedArch == ARM::INVALID_ARCH)
724    setAttributeItem(CPU_arch, GetArchDefaultCPUArch(Arch), false);
725  else
726    setAttributeItem(CPU_arch, GetArchDefaultCPUArch(EmittedArch), false);
727
728  switch (Arch) {
729  case ARM::ARMV2:
730  case ARM::ARMV2A:
731  case ARM::ARMV3:
732  case ARM::ARMV3M:
733  case ARM::ARMV4:
734  case ARM::ARMV5:
735    setAttributeItem(ARM_ISA_use, Allowed, false);
736    break;
737
738  case ARM::ARMV4T:
739  case ARM::ARMV5T:
740  case ARM::ARMV5TE:
741  case ARM::ARMV6:
742  case ARM::ARMV6J:
743    setAttributeItem(ARM_ISA_use, Allowed, false);
744    setAttributeItem(THUMB_ISA_use, Allowed, false);
745    break;
746
747  case ARM::ARMV6T2:
748    setAttributeItem(ARM_ISA_use, Allowed, false);
749    setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
750    break;
751
752  case ARM::ARMV6Z:
753  case ARM::ARMV6ZK:
754    setAttributeItem(ARM_ISA_use, Allowed, false);
755    setAttributeItem(THUMB_ISA_use, Allowed, false);
756    setAttributeItem(Virtualization_use, AllowTZ, false);
757    break;
758
759  case ARM::ARMV6M:
760    setAttributeItem(THUMB_ISA_use, Allowed, false);
761    break;
762
763  case ARM::ARMV7:
764    setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
765    break;
766
767  case ARM::ARMV7A:
768    setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
769    setAttributeItem(ARM_ISA_use, Allowed, false);
770    setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
771    break;
772
773  case ARM::ARMV7R:
774    setAttributeItem(CPU_arch_profile, RealTimeProfile, false);
775    setAttributeItem(ARM_ISA_use, Allowed, false);
776    setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
777    break;
778
779  case ARM::ARMV7M:
780    setAttributeItem(CPU_arch_profile, MicroControllerProfile, false);
781    setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
782    break;
783
784  case ARM::ARMV8A:
785    setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
786    setAttributeItem(ARM_ISA_use, Allowed, false);
787    setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
788    setAttributeItem(MPextension_use, Allowed, false);
789    setAttributeItem(Virtualization_use, AllowTZVirtualization, false);
790    break;
791
792  case ARM::IWMMXT:
793    setAttributeItem(ARM_ISA_use, Allowed, false);
794    setAttributeItem(THUMB_ISA_use, Allowed, false);
795    setAttributeItem(WMMX_arch, AllowWMMXv1, false);
796    break;
797
798  case ARM::IWMMXT2:
799    setAttributeItem(ARM_ISA_use, Allowed, false);
800    setAttributeItem(THUMB_ISA_use, Allowed, false);
801    setAttributeItem(WMMX_arch, AllowWMMXv2, false);
802    break;
803
804  default:
805    report_fatal_error("Unknown Arch: " + Twine(Arch));
806    break;
807  }
808}
809void ARMTargetELFStreamer::emitFPU(unsigned Value) {
810  FPU = Value;
811}
812void ARMTargetELFStreamer::emitFPUDefaultAttributes() {
813  switch (FPU) {
814  case ARM::VFP:
815  case ARM::VFPV2:
816    setAttributeItem(ARMBuildAttrs::FP_arch,
817                     ARMBuildAttrs::AllowFPv2,
818                     /* OverwriteExisting= */ false);
819    break;
820
821  case ARM::VFPV3:
822    setAttributeItem(ARMBuildAttrs::FP_arch,
823                     ARMBuildAttrs::AllowFPv3A,
824                     /* OverwriteExisting= */ false);
825    break;
826
827  case ARM::VFPV3_D16:
828    setAttributeItem(ARMBuildAttrs::FP_arch,
829                     ARMBuildAttrs::AllowFPv3B,
830                     /* OverwriteExisting= */ false);
831    break;
832
833  case ARM::VFPV4:
834    setAttributeItem(ARMBuildAttrs::FP_arch,
835                     ARMBuildAttrs::AllowFPv4A,
836                     /* OverwriteExisting= */ false);
837    break;
838
839  case ARM::VFPV4_D16:
840    setAttributeItem(ARMBuildAttrs::FP_arch,
841                     ARMBuildAttrs::AllowFPv4B,
842                     /* OverwriteExisting= */ false);
843    break;
844
845  case ARM::FP_ARMV8:
846    setAttributeItem(ARMBuildAttrs::FP_arch,
847                     ARMBuildAttrs::AllowFPARMv8A,
848                     /* OverwriteExisting= */ false);
849    break;
850
851  case ARM::NEON:
852    setAttributeItem(ARMBuildAttrs::FP_arch,
853                     ARMBuildAttrs::AllowFPv3A,
854                     /* OverwriteExisting= */ false);
855    setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
856                     ARMBuildAttrs::AllowNeon,
857                     /* OverwriteExisting= */ false);
858    break;
859
860  case ARM::NEON_VFPV4:
861    setAttributeItem(ARMBuildAttrs::FP_arch,
862                     ARMBuildAttrs::AllowFPv4A,
863                     /* OverwriteExisting= */ false);
864    setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
865                     ARMBuildAttrs::AllowNeon2,
866                     /* OverwriteExisting= */ false);
867    break;
868
869  case ARM::NEON_FP_ARMV8:
870  case ARM::CRYPTO_NEON_FP_ARMV8:
871    setAttributeItem(ARMBuildAttrs::FP_arch,
872                     ARMBuildAttrs::AllowFPARMv8A,
873                     /* OverwriteExisting= */ false);
874    setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
875                     ARMBuildAttrs::AllowNeonARMv8,
876                     /* OverwriteExisting= */ false);
877    break;
878
879  case ARM::SOFTVFP:
880    break;
881
882  default:
883    report_fatal_error("Unknown FPU: " + Twine(FPU));
884    break;
885  }
886}
887size_t ARMTargetELFStreamer::calculateContentSize() const {
888  size_t Result = 0;
889  for (size_t i = 0; i < Contents.size(); ++i) {
890    AttributeItem item = Contents[i];
891    switch (item.Type) {
892    case AttributeItem::HiddenAttribute:
893      break;
894    case AttributeItem::NumericAttribute:
895      Result += getULEB128Size(item.Tag);
896      Result += getULEB128Size(item.IntValue);
897      break;
898    case AttributeItem::TextAttribute:
899      Result += getULEB128Size(item.Tag);
900      Result += item.StringValue.size() + 1; // string + '\0'
901      break;
902    case AttributeItem::NumericAndTextAttributes:
903      Result += getULEB128Size(item.Tag);
904      Result += getULEB128Size(item.IntValue);
905      Result += item.StringValue.size() + 1; // string + '\0';
906      break;
907    }
908  }
909  return Result;
910}
911void ARMTargetELFStreamer::finishAttributeSection() {
912  // <format-version>
913  // [ <section-length> "vendor-name"
914  // [ <file-tag> <size> <attribute>*
915  //   | <section-tag> <size> <section-number>* 0 <attribute>*
916  //   | <symbol-tag> <size> <symbol-number>* 0 <attribute>*
917  //   ]+
918  // ]*
919
920  if (FPU != ARM::INVALID_FPU)
921    emitFPUDefaultAttributes();
922
923  if (Arch != ARM::INVALID_ARCH)
924    emitArchDefaultAttributes();
925
926  if (Contents.empty())
927    return;
928
929  std::sort(Contents.begin(), Contents.end(), AttributeItem::LessTag);
930
931  ARMELFStreamer &Streamer = getStreamer();
932
933  // Switch to .ARM.attributes section
934  if (AttributeSection) {
935    Streamer.SwitchSection(AttributeSection);
936  } else {
937    AttributeSection =
938      Streamer.getContext().getELFSection(".ARM.attributes",
939                                          ELF::SHT_ARM_ATTRIBUTES,
940                                          0,
941                                          SectionKind::getMetadata());
942    Streamer.SwitchSection(AttributeSection);
943
944    // Format version
945    Streamer.EmitIntValue(0x41, 1);
946  }
947
948  // Vendor size + Vendor name + '\0'
949  const size_t VendorHeaderSize = 4 + CurrentVendor.size() + 1;
950
951  // Tag + Tag Size
952  const size_t TagHeaderSize = 1 + 4;
953
954  const size_t ContentsSize = calculateContentSize();
955
956  Streamer.EmitIntValue(VendorHeaderSize + TagHeaderSize + ContentsSize, 4);
957  Streamer.EmitBytes(CurrentVendor);
958  Streamer.EmitIntValue(0, 1); // '\0'
959
960  Streamer.EmitIntValue(ARMBuildAttrs::File, 1);
961  Streamer.EmitIntValue(TagHeaderSize + ContentsSize, 4);
962
963  // Size should have been accounted for already, now
964  // emit each field as its type (ULEB or String)
965  for (size_t i = 0; i < Contents.size(); ++i) {
966    AttributeItem item = Contents[i];
967    Streamer.EmitULEB128IntValue(item.Tag);
968    switch (item.Type) {
969    default: llvm_unreachable("Invalid attribute type");
970    case AttributeItem::NumericAttribute:
971      Streamer.EmitULEB128IntValue(item.IntValue);
972      break;
973    case AttributeItem::TextAttribute:
974      Streamer.EmitBytes(item.StringValue.upper());
975      Streamer.EmitIntValue(0, 1); // '\0'
976      break;
977    case AttributeItem::NumericAndTextAttributes:
978      Streamer.EmitULEB128IntValue(item.IntValue);
979      Streamer.EmitBytes(item.StringValue.upper());
980      Streamer.EmitIntValue(0, 1); // '\0'
981      break;
982    }
983  }
984
985  Contents.clear();
986  FPU = ARM::INVALID_FPU;
987}
988
989void ARMTargetELFStreamer::emitLabel(MCSymbol *Symbol) {
990  ARMELFStreamer &Streamer = getStreamer();
991  if (!Streamer.IsThumb)
992    return;
993
994  const MCSymbolData &SD = Streamer.getOrCreateSymbolData(Symbol);
995  if (MCELF::GetType(SD) & (ELF::STT_FUNC << ELF_STT_Shift))
996    Streamer.EmitThumbFunc(Symbol);
997}
998
999void
1000ARMTargetELFStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
1001  getStreamer().EmitFixup(S, FK_Data_4);
1002}
1003
1004void ARMTargetELFStreamer::emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) {
1005  if (const MCSymbolRefExpr *SRE = dyn_cast<MCSymbolRefExpr>(Value)) {
1006    const MCSymbol &Sym = SRE->getSymbol();
1007    if (!Sym.isDefined()) {
1008      getStreamer().EmitAssignment(Symbol, Value);
1009      return;
1010    }
1011  }
1012
1013  getStreamer().EmitThumbFunc(Symbol);
1014  getStreamer().EmitAssignment(Symbol, Value);
1015}
1016
1017void ARMTargetELFStreamer::emitInst(uint32_t Inst, char Suffix) {
1018  getStreamer().emitInst(Inst, Suffix);
1019}
1020
1021void ARMELFStreamer::FinishImpl() {
1022  MCTargetStreamer &TS = *getTargetStreamer();
1023  ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
1024  ATS.finishAttributeSection();
1025
1026  MCELFStreamer::FinishImpl();
1027}
1028
1029inline void ARMELFStreamer::SwitchToEHSection(const char *Prefix,
1030                                              unsigned Type,
1031                                              unsigned Flags,
1032                                              SectionKind Kind,
1033                                              const MCSymbol &Fn) {
1034  const MCSectionELF &FnSection =
1035    static_cast<const MCSectionELF &>(Fn.getSection());
1036
1037  // Create the name for new section
1038  StringRef FnSecName(FnSection.getSectionName());
1039  SmallString<128> EHSecName(Prefix);
1040  if (FnSecName != ".text") {
1041    EHSecName += FnSecName;
1042  }
1043
1044  // Get .ARM.extab or .ARM.exidx section
1045  const MCSectionELF *EHSection = nullptr;
1046  if (const MCSymbol *Group = FnSection.getGroup()) {
1047    EHSection = getContext().getELFSection(
1048      EHSecName, Type, Flags | ELF::SHF_GROUP, Kind,
1049      FnSection.getEntrySize(), Group->getName());
1050  } else {
1051    EHSection = getContext().getELFSection(EHSecName, Type, Flags, Kind);
1052  }
1053  assert(EHSection && "Failed to get the required EH section");
1054
1055  // Switch to .ARM.extab or .ARM.exidx section
1056  SwitchSection(EHSection);
1057  EmitCodeAlignment(4);
1058}
1059
1060inline void ARMELFStreamer::SwitchToExTabSection(const MCSymbol &FnStart) {
1061  SwitchToEHSection(".ARM.extab",
1062                    ELF::SHT_PROGBITS,
1063                    ELF::SHF_ALLOC,
1064                    SectionKind::getDataRel(),
1065                    FnStart);
1066}
1067
1068inline void ARMELFStreamer::SwitchToExIdxSection(const MCSymbol &FnStart) {
1069  SwitchToEHSection(".ARM.exidx",
1070                    ELF::SHT_ARM_EXIDX,
1071                    ELF::SHF_ALLOC | ELF::SHF_LINK_ORDER,
1072                    SectionKind::getDataRel(),
1073                    FnStart);
1074}
1075void ARMELFStreamer::EmitFixup(const MCExpr *Expr, MCFixupKind Kind) {
1076  MCDataFragment *Frag = getOrCreateDataFragment();
1077  Frag->getFixups().push_back(MCFixup::Create(Frag->getContents().size(), Expr,
1078                                              Kind));
1079}
1080
1081void ARMELFStreamer::Reset() {
1082  ExTab = nullptr;
1083  FnStart = nullptr;
1084  Personality = nullptr;
1085  PersonalityIndex = ARM::EHABI::NUM_PERSONALITY_INDEX;
1086  FPReg = ARM::SP;
1087  FPOffset = 0;
1088  SPOffset = 0;
1089  PendingOffset = 0;
1090  UsedFP = false;
1091  CantUnwind = false;
1092
1093  Opcodes.clear();
1094  UnwindOpAsm.Reset();
1095}
1096
1097void ARMELFStreamer::emitFnStart() {
1098  assert(FnStart == nullptr);
1099  FnStart = getContext().CreateTempSymbol();
1100  EmitLabel(FnStart);
1101}
1102
1103void ARMELFStreamer::emitFnEnd() {
1104  assert(FnStart && ".fnstart must precedes .fnend");
1105
1106  // Emit unwind opcodes if there is no .handlerdata directive
1107  if (!ExTab && !CantUnwind)
1108    FlushUnwindOpcodes(true);
1109
1110  // Emit the exception index table entry
1111  SwitchToExIdxSection(*FnStart);
1112
1113  if (PersonalityIndex < ARM::EHABI::NUM_PERSONALITY_INDEX)
1114    EmitPersonalityFixup(GetAEABIUnwindPersonalityName(PersonalityIndex));
1115
1116  const MCSymbolRefExpr *FnStartRef =
1117    MCSymbolRefExpr::Create(FnStart,
1118                            MCSymbolRefExpr::VK_ARM_PREL31,
1119                            getContext());
1120
1121  EmitValue(FnStartRef, 4);
1122
1123  if (CantUnwind) {
1124    EmitIntValue(ARM::EHABI::EXIDX_CANTUNWIND, 4);
1125  } else if (ExTab) {
1126    // Emit a reference to the unwind opcodes in the ".ARM.extab" section.
1127    const MCSymbolRefExpr *ExTabEntryRef =
1128      MCSymbolRefExpr::Create(ExTab,
1129                              MCSymbolRefExpr::VK_ARM_PREL31,
1130                              getContext());
1131    EmitValue(ExTabEntryRef, 4);
1132  } else {
1133    // For the __aeabi_unwind_cpp_pr0, we have to emit the unwind opcodes in
1134    // the second word of exception index table entry.  The size of the unwind
1135    // opcodes should always be 4 bytes.
1136    assert(PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0 &&
1137           "Compact model must use __aeabi_unwind_cpp_pr0 as personality");
1138    assert(Opcodes.size() == 4u &&
1139           "Unwind opcode size for __aeabi_unwind_cpp_pr0 must be equal to 4");
1140    uint64_t Intval = Opcodes[0] |
1141                      Opcodes[1] << 8 |
1142                      Opcodes[2] << 16 |
1143                      Opcodes[3] << 24;
1144    EmitIntValue(Intval, Opcodes.size());
1145  }
1146
1147  // Switch to the section containing FnStart
1148  SwitchSection(&FnStart->getSection());
1149
1150  // Clean exception handling frame information
1151  Reset();
1152}
1153
1154void ARMELFStreamer::emitCantUnwind() { CantUnwind = true; }
1155
1156// Add the R_ARM_NONE fixup at the same position
1157void ARMELFStreamer::EmitPersonalityFixup(StringRef Name) {
1158  const MCSymbol *PersonalitySym = getContext().GetOrCreateSymbol(Name);
1159
1160  const MCSymbolRefExpr *PersonalityRef = MCSymbolRefExpr::Create(
1161      PersonalitySym, MCSymbolRefExpr::VK_ARM_NONE, getContext());
1162
1163  AddValueSymbols(PersonalityRef);
1164  MCDataFragment *DF = getOrCreateDataFragment();
1165  DF->getFixups().push_back(MCFixup::Create(DF->getContents().size(),
1166                                            PersonalityRef,
1167                                            MCFixup::getKindForSize(4, false)));
1168}
1169
1170void ARMELFStreamer::FlushPendingOffset() {
1171  if (PendingOffset != 0) {
1172    UnwindOpAsm.EmitSPOffset(-PendingOffset);
1173    PendingOffset = 0;
1174  }
1175}
1176
1177void ARMELFStreamer::FlushUnwindOpcodes(bool NoHandlerData) {
1178  // Emit the unwind opcode to restore $sp.
1179  if (UsedFP) {
1180    const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1181    int64_t LastRegSaveSPOffset = SPOffset - PendingOffset;
1182    UnwindOpAsm.EmitSPOffset(LastRegSaveSPOffset - FPOffset);
1183    UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1184  } else {
1185    FlushPendingOffset();
1186  }
1187
1188  // Finalize the unwind opcode sequence
1189  UnwindOpAsm.Finalize(PersonalityIndex, Opcodes);
1190
1191  // For compact model 0, we have to emit the unwind opcodes in the .ARM.exidx
1192  // section.  Thus, we don't have to create an entry in the .ARM.extab
1193  // section.
1194  if (NoHandlerData && PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0)
1195    return;
1196
1197  // Switch to .ARM.extab section.
1198  SwitchToExTabSection(*FnStart);
1199
1200  // Create .ARM.extab label for offset in .ARM.exidx
1201  assert(!ExTab);
1202  ExTab = getContext().CreateTempSymbol();
1203  EmitLabel(ExTab);
1204
1205  // Emit personality
1206  if (Personality) {
1207    const MCSymbolRefExpr *PersonalityRef =
1208      MCSymbolRefExpr::Create(Personality,
1209                              MCSymbolRefExpr::VK_ARM_PREL31,
1210                              getContext());
1211
1212    EmitValue(PersonalityRef, 4);
1213  }
1214
1215  // Emit unwind opcodes
1216  assert((Opcodes.size() % 4) == 0 &&
1217         "Unwind opcode size for __aeabi_cpp_unwind_pr0 must be multiple of 4");
1218  for (unsigned I = 0; I != Opcodes.size(); I += 4) {
1219    uint64_t Intval = Opcodes[I] |
1220                      Opcodes[I + 1] << 8 |
1221                      Opcodes[I + 2] << 16 |
1222                      Opcodes[I + 3] << 24;
1223    EmitIntValue(Intval, 4);
1224  }
1225
1226  // According to ARM EHABI section 9.2, if the __aeabi_unwind_cpp_pr1() or
1227  // __aeabi_unwind_cpp_pr2() is used, then the handler data must be emitted
1228  // after the unwind opcodes.  The handler data consists of several 32-bit
1229  // words, and should be terminated by zero.
1230  //
1231  // In case that the .handlerdata directive is not specified by the
1232  // programmer, we should emit zero to terminate the handler data.
1233  if (NoHandlerData && !Personality)
1234    EmitIntValue(0, 4);
1235}
1236
1237void ARMELFStreamer::emitHandlerData() { FlushUnwindOpcodes(false); }
1238
1239void ARMELFStreamer::emitPersonality(const MCSymbol *Per) {
1240  Personality = Per;
1241  UnwindOpAsm.setPersonality(Per);
1242}
1243
1244void ARMELFStreamer::emitPersonalityIndex(unsigned Index) {
1245  assert(Index < ARM::EHABI::NUM_PERSONALITY_INDEX && "invalid index");
1246  PersonalityIndex = Index;
1247}
1248
1249void ARMELFStreamer::emitSetFP(unsigned NewFPReg, unsigned NewSPReg,
1250                               int64_t Offset) {
1251  assert((NewSPReg == ARM::SP || NewSPReg == FPReg) &&
1252         "the operand of .setfp directive should be either $sp or $fp");
1253
1254  UsedFP = true;
1255  FPReg = NewFPReg;
1256
1257  if (NewSPReg == ARM::SP)
1258    FPOffset = SPOffset + Offset;
1259  else
1260    FPOffset += Offset;
1261}
1262
1263void ARMELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
1264  assert((Reg != ARM::SP && Reg != ARM::PC) &&
1265         "the operand of .movsp cannot be either sp or pc");
1266  assert(FPReg == ARM::SP && "current FP must be SP");
1267
1268  FlushPendingOffset();
1269
1270  FPReg = Reg;
1271  FPOffset = SPOffset + Offset;
1272
1273  const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1274  UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1275}
1276
1277void ARMELFStreamer::emitPad(int64_t Offset) {
1278  // Track the change of the $sp offset
1279  SPOffset -= Offset;
1280
1281  // To squash multiple .pad directives, we should delay the unwind opcode
1282  // until the .save, .vsave, .handlerdata, or .fnend directives.
1283  PendingOffset -= Offset;
1284}
1285
1286void ARMELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
1287                                 bool IsVector) {
1288  // Collect the registers in the register list
1289  unsigned Count = 0;
1290  uint32_t Mask = 0;
1291  const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1292  for (size_t i = 0; i < RegList.size(); ++i) {
1293    unsigned Reg = MRI->getEncodingValue(RegList[i]);
1294    assert(Reg < (IsVector ? 32U : 16U) && "Register out of range");
1295    unsigned Bit = (1u << Reg);
1296    if ((Mask & Bit) == 0) {
1297      Mask |= Bit;
1298      ++Count;
1299    }
1300  }
1301
1302  // Track the change the $sp offset: For the .save directive, the
1303  // corresponding push instruction will decrease the $sp by (4 * Count).
1304  // For the .vsave directive, the corresponding vpush instruction will
1305  // decrease $sp by (8 * Count).
1306  SPOffset -= Count * (IsVector ? 8 : 4);
1307
1308  // Emit the opcode
1309  FlushPendingOffset();
1310  if (IsVector)
1311    UnwindOpAsm.EmitVFPRegSave(Mask);
1312  else
1313    UnwindOpAsm.EmitRegSave(Mask);
1314}
1315
1316void ARMELFStreamer::emitUnwindRaw(int64_t Offset,
1317                                   const SmallVectorImpl<uint8_t> &Opcodes) {
1318  FlushPendingOffset();
1319  SPOffset = SPOffset - Offset;
1320  UnwindOpAsm.EmitRaw(Opcodes);
1321}
1322
1323namespace llvm {
1324
1325MCStreamer *createMCAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
1326                                bool isVerboseAsm, bool useDwarfDirectory,
1327                                MCInstPrinter *InstPrint, MCCodeEmitter *CE,
1328                                MCAsmBackend *TAB, bool ShowInst) {
1329  MCStreamer *S = llvm::createAsmStreamer(
1330      Ctx, OS, isVerboseAsm, useDwarfDirectory, InstPrint, CE, TAB, ShowInst);
1331  new ARMTargetAsmStreamer(*S, OS, *InstPrint, isVerboseAsm);
1332  return S;
1333}
1334
1335  MCELFStreamer* createARMELFStreamer(MCContext &Context, MCAsmBackend &TAB,
1336                                      raw_ostream &OS, MCCodeEmitter *Emitter,
1337                                      bool RelaxAll, bool NoExecStack,
1338                                      bool IsThumb) {
1339    ARMELFStreamer *S = new ARMELFStreamer(Context, TAB, OS, Emitter, IsThumb);
1340    new ARMTargetELFStreamer(*S);
1341    // FIXME: This should eventually end up somewhere else where more
1342    // intelligent flag decisions can be made. For now we are just maintaining
1343    // the status quo for ARM and setting EF_ARM_EABI_VER5 as the default.
1344    S->getAssembler().setELFHeaderEFlags(ELF::EF_ARM_EABI_VER5);
1345
1346    if (RelaxAll)
1347      S->getAssembler().setRelaxAll(true);
1348    if (NoExecStack)
1349      S->getAssembler().setNoExecStack(true);
1350    return S;
1351  }
1352
1353}
1354
1355
1356