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 "ARMRegisterInfo.h"
17#include "ARMUnwindOpAsm.h"
18#include "llvm/ADT/StringExtras.h"
19#include "llvm/ADT/Twine.h"
20#include "llvm/MC/MCAsmBackend.h"
21#include "llvm/MC/MCAsmInfo.h"
22#include "llvm/MC/MCAssembler.h"
23#include "llvm/MC/MCCodeEmitter.h"
24#include "llvm/MC/MCContext.h"
25#include "llvm/MC/MCELFStreamer.h"
26#include "llvm/MC/MCExpr.h"
27#include "llvm/MC/MCInst.h"
28#include "llvm/MC/MCInstPrinter.h"
29#include "llvm/MC/MCObjectFileInfo.h"
30#include "llvm/MC/MCObjectStreamer.h"
31#include "llvm/MC/MCRegisterInfo.h"
32#include "llvm/MC/MCSection.h"
33#include "llvm/MC/MCSectionELF.h"
34#include "llvm/MC/MCStreamer.h"
35#include "llvm/MC/MCSymbolELF.h"
36#include "llvm/MC/MCValue.h"
37#include "llvm/Support/ARMBuildAttributes.h"
38#include "llvm/Support/ARMEHABI.h"
39#include "llvm/Support/TargetParser.h"
40#include "llvm/Support/Debug.h"
41#include "llvm/Support/ELF.h"
42#include "llvm/Support/FormattedStream.h"
43#include "llvm/Support/LEB128.h"
44#include "llvm/Support/raw_ostream.h"
45#include <algorithm>
46
47using namespace llvm;
48
49static std::string GetAEABIUnwindPersonalityName(unsigned Index) {
50  assert(Index < ARM::EHABI::NUM_PERSONALITY_INDEX &&
51         "Invalid personality index");
52  return (Twine("__aeabi_unwind_cpp_pr") + Twine(Index)).str();
53}
54
55namespace {
56
57class ARMELFStreamer;
58
59class ARMTargetAsmStreamer : public ARMTargetStreamer {
60  formatted_raw_ostream &OS;
61  MCInstPrinter &InstPrinter;
62  bool IsVerboseAsm;
63
64  void emitFnStart() override;
65  void emitFnEnd() override;
66  void emitCantUnwind() override;
67  void emitPersonality(const MCSymbol *Personality) override;
68  void emitPersonalityIndex(unsigned Index) override;
69  void emitHandlerData() override;
70  void emitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0) override;
71  void emitMovSP(unsigned Reg, int64_t Offset = 0) override;
72  void emitPad(int64_t Offset) override;
73  void emitRegSave(const SmallVectorImpl<unsigned> &RegList,
74                   bool isVector) override;
75  void emitUnwindRaw(int64_t Offset,
76                     const SmallVectorImpl<uint8_t> &Opcodes) override;
77
78  void switchVendor(StringRef Vendor) override;
79  void emitAttribute(unsigned Attribute, unsigned Value) override;
80  void emitTextAttribute(unsigned Attribute, StringRef String) override;
81  void emitIntTextAttribute(unsigned Attribute, unsigned IntValue,
82                            StringRef StringValue) override;
83  void emitArch(unsigned Arch) override;
84  void emitArchExtension(unsigned ArchExt) override;
85  void emitObjectArch(unsigned Arch) override;
86  void emitFPU(unsigned FPU) override;
87  void emitInst(uint32_t Inst, char Suffix = '\0') override;
88  void finishAttributeSection() override;
89
90  void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE) override;
91  void emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) override;
92
93public:
94  ARMTargetAsmStreamer(MCStreamer &S, formatted_raw_ostream &OS,
95                       MCInstPrinter &InstPrinter, bool VerboseAsm);
96};
97
98ARMTargetAsmStreamer::ARMTargetAsmStreamer(MCStreamer &S,
99                                           formatted_raw_ostream &OS,
100                                           MCInstPrinter &InstPrinter,
101                                           bool VerboseAsm)
102    : ARMTargetStreamer(S), OS(OS), InstPrinter(InstPrinter),
103      IsVerboseAsm(VerboseAsm) {}
104void ARMTargetAsmStreamer::emitFnStart() { OS << "\t.fnstart\n"; }
105void ARMTargetAsmStreamer::emitFnEnd() { OS << "\t.fnend\n"; }
106void ARMTargetAsmStreamer::emitCantUnwind() { OS << "\t.cantunwind\n"; }
107void ARMTargetAsmStreamer::emitPersonality(const MCSymbol *Personality) {
108  OS << "\t.personality " << Personality->getName() << '\n';
109}
110void ARMTargetAsmStreamer::emitPersonalityIndex(unsigned Index) {
111  OS << "\t.personalityindex " << Index << '\n';
112}
113void ARMTargetAsmStreamer::emitHandlerData() { OS << "\t.handlerdata\n"; }
114void ARMTargetAsmStreamer::emitSetFP(unsigned FpReg, unsigned SpReg,
115                                     int64_t Offset) {
116  OS << "\t.setfp\t";
117  InstPrinter.printRegName(OS, FpReg);
118  OS << ", ";
119  InstPrinter.printRegName(OS, SpReg);
120  if (Offset)
121    OS << ", #" << Offset;
122  OS << '\n';
123}
124void ARMTargetAsmStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
125  assert((Reg != ARM::SP && Reg != ARM::PC) &&
126         "the operand of .movsp cannot be either sp or pc");
127
128  OS << "\t.movsp\t";
129  InstPrinter.printRegName(OS, Reg);
130  if (Offset)
131    OS << ", #" << Offset;
132  OS << '\n';
133}
134void ARMTargetAsmStreamer::emitPad(int64_t Offset) {
135  OS << "\t.pad\t#" << Offset << '\n';
136}
137void ARMTargetAsmStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
138                                       bool isVector) {
139  assert(RegList.size() && "RegList should not be empty");
140  if (isVector)
141    OS << "\t.vsave\t{";
142  else
143    OS << "\t.save\t{";
144
145  InstPrinter.printRegName(OS, RegList[0]);
146
147  for (unsigned i = 1, e = RegList.size(); i != e; ++i) {
148    OS << ", ";
149    InstPrinter.printRegName(OS, RegList[i]);
150  }
151
152  OS << "}\n";
153}
154void ARMTargetAsmStreamer::switchVendor(StringRef Vendor) {
155}
156void ARMTargetAsmStreamer::emitAttribute(unsigned Attribute, unsigned Value) {
157  OS << "\t.eabi_attribute\t" << Attribute << ", " << Twine(Value);
158  if (IsVerboseAsm) {
159    StringRef Name = ARMBuildAttrs::AttrTypeAsString(Attribute);
160    if (!Name.empty())
161      OS << "\t@ " << Name;
162  }
163  OS << "\n";
164}
165void ARMTargetAsmStreamer::emitTextAttribute(unsigned Attribute,
166                                             StringRef String) {
167  switch (Attribute) {
168  case ARMBuildAttrs::CPU_name:
169    OS << "\t.cpu\t" << String.lower();
170    break;
171  default:
172    OS << "\t.eabi_attribute\t" << Attribute << ", \"" << String << "\"";
173    if (IsVerboseAsm) {
174      StringRef Name = ARMBuildAttrs::AttrTypeAsString(Attribute);
175      if (!Name.empty())
176        OS << "\t@ " << Name;
177    }
178    break;
179  }
180  OS << "\n";
181}
182void ARMTargetAsmStreamer::emitIntTextAttribute(unsigned Attribute,
183                                                unsigned IntValue,
184                                                StringRef StringValue) {
185  switch (Attribute) {
186  default: llvm_unreachable("unsupported multi-value attribute in asm mode");
187  case ARMBuildAttrs::compatibility:
188    OS << "\t.eabi_attribute\t" << Attribute << ", " << IntValue;
189    if (!StringValue.empty())
190      OS << ", \"" << StringValue << "\"";
191    if (IsVerboseAsm)
192      OS << "\t@ " << ARMBuildAttrs::AttrTypeAsString(Attribute);
193    break;
194  }
195  OS << "\n";
196}
197void ARMTargetAsmStreamer::emitArch(unsigned Arch) {
198  OS << "\t.arch\t" << ARM::getArchName(Arch) << "\n";
199}
200void ARMTargetAsmStreamer::emitArchExtension(unsigned ArchExt) {
201  OS << "\t.arch_extension\t" << ARM::getArchExtName(ArchExt) << "\n";
202}
203void ARMTargetAsmStreamer::emitObjectArch(unsigned Arch) {
204  OS << "\t.object_arch\t" << ARM::getArchName(Arch) << '\n';
205}
206void ARMTargetAsmStreamer::emitFPU(unsigned FPU) {
207  OS << "\t.fpu\t" << ARM::getFPUName(FPU) << "\n";
208}
209void ARMTargetAsmStreamer::finishAttributeSection() {
210}
211void
212ARMTargetAsmStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
213  OS << "\t.tlsdescseq\t" << S->getSymbol().getName();
214}
215
216void ARMTargetAsmStreamer::emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) {
217  const MCAsmInfo *MAI = Streamer.getContext().getAsmInfo();
218
219  OS << "\t.thumb_set\t";
220  Symbol->print(OS, MAI);
221  OS << ", ";
222  Value->print(OS, MAI);
223  OS << '\n';
224}
225
226void ARMTargetAsmStreamer::emitInst(uint32_t Inst, char Suffix) {
227  OS << "\t.inst";
228  if (Suffix)
229    OS << "." << Suffix;
230  OS << "\t0x" << Twine::utohexstr(Inst) << "\n";
231}
232
233void ARMTargetAsmStreamer::emitUnwindRaw(int64_t Offset,
234                                      const SmallVectorImpl<uint8_t> &Opcodes) {
235  OS << "\t.unwind_raw " << Offset;
236  for (SmallVectorImpl<uint8_t>::const_iterator OCI = Opcodes.begin(),
237                                                OCE = Opcodes.end();
238       OCI != OCE; ++OCI)
239    OS << ", 0x" << Twine::utohexstr(*OCI);
240  OS << '\n';
241}
242
243class ARMTargetELFStreamer : public ARMTargetStreamer {
244private:
245  // This structure holds all attributes, accounting for
246  // their string/numeric value, so we can later emit them
247  // in declaration order, keeping all in the same vector
248  struct AttributeItem {
249    enum {
250      HiddenAttribute = 0,
251      NumericAttribute,
252      TextAttribute,
253      NumericAndTextAttributes
254    } Type;
255    unsigned Tag;
256    unsigned IntValue;
257    std::string StringValue;
258
259    static bool LessTag(const AttributeItem &LHS, const AttributeItem &RHS) {
260      // The conformance tag must be emitted first when serialised
261      // into an object file. Specifically, the addenda to the ARM ABI
262      // states that (2.3.7.4):
263      //
264      // "To simplify recognition by consumers in the common case of
265      // claiming conformity for the whole file, this tag should be
266      // emitted first in a file-scope sub-subsection of the first
267      // public subsection of the attributes section."
268      //
269      // So it is special-cased in this comparison predicate when the
270      // attributes are sorted in finishAttributeSection().
271      return (RHS.Tag != ARMBuildAttrs::conformance) &&
272             ((LHS.Tag == ARMBuildAttrs::conformance) || (LHS.Tag < RHS.Tag));
273    }
274  };
275
276  StringRef CurrentVendor;
277  unsigned FPU;
278  unsigned Arch;
279  unsigned EmittedArch;
280  SmallVector<AttributeItem, 64> Contents;
281
282  MCSection *AttributeSection;
283
284  AttributeItem *getAttributeItem(unsigned Attribute) {
285    for (size_t i = 0; i < Contents.size(); ++i)
286      if (Contents[i].Tag == Attribute)
287        return &Contents[i];
288    return nullptr;
289  }
290
291  void setAttributeItem(unsigned Attribute, unsigned Value,
292                        bool OverwriteExisting) {
293    // Look for existing attribute item
294    if (AttributeItem *Item = getAttributeItem(Attribute)) {
295      if (!OverwriteExisting)
296        return;
297      Item->Type = AttributeItem::NumericAttribute;
298      Item->IntValue = Value;
299      return;
300    }
301
302    // Create new attribute item
303    AttributeItem Item = {
304      AttributeItem::NumericAttribute,
305      Attribute,
306      Value,
307      StringRef("")
308    };
309    Contents.push_back(Item);
310  }
311
312  void setAttributeItem(unsigned Attribute, StringRef Value,
313                        bool OverwriteExisting) {
314    // Look for existing attribute item
315    if (AttributeItem *Item = getAttributeItem(Attribute)) {
316      if (!OverwriteExisting)
317        return;
318      Item->Type = AttributeItem::TextAttribute;
319      Item->StringValue = Value;
320      return;
321    }
322
323    // Create new attribute item
324    AttributeItem Item = {
325      AttributeItem::TextAttribute,
326      Attribute,
327      0,
328      Value
329    };
330    Contents.push_back(Item);
331  }
332
333  void setAttributeItems(unsigned Attribute, unsigned IntValue,
334                         StringRef StringValue, bool OverwriteExisting) {
335    // Look for existing attribute item
336    if (AttributeItem *Item = getAttributeItem(Attribute)) {
337      if (!OverwriteExisting)
338        return;
339      Item->Type = AttributeItem::NumericAndTextAttributes;
340      Item->IntValue = IntValue;
341      Item->StringValue = StringValue;
342      return;
343    }
344
345    // Create new attribute item
346    AttributeItem Item = {
347      AttributeItem::NumericAndTextAttributes,
348      Attribute,
349      IntValue,
350      StringValue
351    };
352    Contents.push_back(Item);
353  }
354
355  void emitArchDefaultAttributes();
356  void emitFPUDefaultAttributes();
357
358  ARMELFStreamer &getStreamer();
359
360  void emitFnStart() override;
361  void emitFnEnd() override;
362  void emitCantUnwind() override;
363  void emitPersonality(const MCSymbol *Personality) override;
364  void emitPersonalityIndex(unsigned Index) override;
365  void emitHandlerData() override;
366  void emitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0) override;
367  void emitMovSP(unsigned Reg, int64_t Offset = 0) override;
368  void emitPad(int64_t Offset) override;
369  void emitRegSave(const SmallVectorImpl<unsigned> &RegList,
370                   bool isVector) override;
371  void emitUnwindRaw(int64_t Offset,
372                     const SmallVectorImpl<uint8_t> &Opcodes) override;
373
374  void switchVendor(StringRef Vendor) override;
375  void emitAttribute(unsigned Attribute, unsigned Value) override;
376  void emitTextAttribute(unsigned Attribute, StringRef String) override;
377  void emitIntTextAttribute(unsigned Attribute, unsigned IntValue,
378                            StringRef StringValue) override;
379  void emitArch(unsigned Arch) override;
380  void emitObjectArch(unsigned Arch) override;
381  void emitFPU(unsigned FPU) override;
382  void emitInst(uint32_t Inst, char Suffix = '\0') override;
383  void finishAttributeSection() override;
384  void emitLabel(MCSymbol *Symbol) override;
385
386  void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE) override;
387  void emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) override;
388
389  size_t calculateContentSize() const;
390
391public:
392  ARMTargetELFStreamer(MCStreamer &S)
393    : ARMTargetStreamer(S), CurrentVendor("aeabi"), FPU(ARM::FK_INVALID),
394      Arch(ARM::AK_INVALID), EmittedArch(ARM::AK_INVALID),
395      AttributeSection(nullptr) {}
396};
397
398/// Extend the generic ELFStreamer class so that it can emit mapping symbols at
399/// the appropriate points in the object files. These symbols are defined in the
400/// ARM ELF ABI: infocenter.arm.com/help/topic/com.arm.../IHI0044D_aaelf.pdf.
401///
402/// In brief: $a, $t or $d should be emitted at the start of each contiguous
403/// region of ARM code, Thumb code or data in a section. In practice, this
404/// emission does not rely on explicit assembler directives but on inherent
405/// properties of the directives doing the emission (e.g. ".byte" is data, "add
406/// r0, r0, r0" an instruction).
407///
408/// As a result this system is orthogonal to the DataRegion infrastructure used
409/// by MachO. Beware!
410class ARMELFStreamer : public MCELFStreamer {
411public:
412  friend class ARMTargetELFStreamer;
413
414  ARMELFStreamer(MCContext &Context, MCAsmBackend &TAB, raw_pwrite_stream &OS,
415                 MCCodeEmitter *Emitter, bool IsThumb)
416      : MCELFStreamer(Context, TAB, OS, Emitter), IsThumb(IsThumb),
417        MappingSymbolCounter(0), LastEMS(EMS_None) {
418    Reset();
419  }
420
421  ~ARMELFStreamer() {}
422
423  void FinishImpl() override;
424
425  // ARM exception handling directives
426  void emitFnStart();
427  void emitFnEnd();
428  void emitCantUnwind();
429  void emitPersonality(const MCSymbol *Per);
430  void emitPersonalityIndex(unsigned index);
431  void emitHandlerData();
432  void emitSetFP(unsigned NewFpReg, unsigned NewSpReg, int64_t Offset = 0);
433  void emitMovSP(unsigned Reg, int64_t Offset = 0);
434  void emitPad(int64_t Offset);
435  void emitRegSave(const SmallVectorImpl<unsigned> &RegList, bool isVector);
436  void emitUnwindRaw(int64_t Offset, const SmallVectorImpl<uint8_t> &Opcodes);
437
438  void ChangeSection(MCSection *Section, const MCExpr *Subsection) override {
439    // We have to keep track of the mapping symbol state of any sections we
440    // use. Each one should start off as EMS_None, which is provided as the
441    // default constructor by DenseMap::lookup.
442    LastMappingSymbols[getPreviousSection().first] = LastEMS;
443    LastEMS = LastMappingSymbols.lookup(Section);
444
445    MCELFStreamer::ChangeSection(Section, Subsection);
446  }
447
448  /// This function is the one used to emit instruction data into the ELF
449  /// streamer. We override it to add the appropriate mapping symbol if
450  /// necessary.
451  void EmitInstruction(const MCInst& Inst,
452                       const MCSubtargetInfo &STI) override {
453    if (IsThumb)
454      EmitThumbMappingSymbol();
455    else
456      EmitARMMappingSymbol();
457
458    MCELFStreamer::EmitInstruction(Inst, STI);
459  }
460
461  void emitInst(uint32_t Inst, char Suffix) {
462    unsigned Size;
463    char Buffer[4];
464    const bool LittleEndian = getContext().getAsmInfo()->isLittleEndian();
465
466    switch (Suffix) {
467    case '\0':
468      Size = 4;
469
470      assert(!IsThumb);
471      EmitARMMappingSymbol();
472      for (unsigned II = 0, IE = Size; II != IE; II++) {
473        const unsigned I = LittleEndian ? (Size - II - 1) : II;
474        Buffer[Size - II - 1] = uint8_t(Inst >> I * CHAR_BIT);
475      }
476
477      break;
478    case 'n':
479    case 'w':
480      Size = (Suffix == 'n' ? 2 : 4);
481
482      assert(IsThumb);
483      EmitThumbMappingSymbol();
484      for (unsigned II = 0, IE = Size; II != IE; II = II + 2) {
485        const unsigned I0 = LittleEndian ? II + 0 : (Size - II - 1);
486        const unsigned I1 = LittleEndian ? II + 1 : (Size - II - 2);
487        Buffer[Size - II - 2] = uint8_t(Inst >> I0 * CHAR_BIT);
488        Buffer[Size - II - 1] = uint8_t(Inst >> I1 * CHAR_BIT);
489      }
490
491      break;
492    default:
493      llvm_unreachable("Invalid Suffix");
494    }
495
496    MCELFStreamer::EmitBytes(StringRef(Buffer, Size));
497  }
498
499  /// This is one of the functions used to emit data into an ELF section, so the
500  /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
501  /// necessary.
502  void EmitBytes(StringRef Data) override {
503    EmitDataMappingSymbol();
504    MCELFStreamer::EmitBytes(Data);
505  }
506
507  /// This is one of the functions used to emit data into an ELF section, so the
508  /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
509  /// necessary.
510  void EmitValueImpl(const MCExpr *Value, unsigned Size, SMLoc Loc) override {
511    if (const MCSymbolRefExpr *SRE = dyn_cast_or_null<MCSymbolRefExpr>(Value))
512      if (SRE->getKind() == MCSymbolRefExpr::VK_ARM_SBREL && !(Size == 4)) {
513        getContext().reportError(Loc, "relocated expression must be 32-bit");
514        return;
515      }
516
517    EmitDataMappingSymbol();
518    MCELFStreamer::EmitValueImpl(Value, Size, Loc);
519  }
520
521  void EmitAssemblerFlag(MCAssemblerFlag Flag) override {
522    MCELFStreamer::EmitAssemblerFlag(Flag);
523
524    switch (Flag) {
525    case MCAF_SyntaxUnified:
526      return; // no-op here.
527    case MCAF_Code16:
528      IsThumb = true;
529      return; // Change to Thumb mode
530    case MCAF_Code32:
531      IsThumb = false;
532      return; // Change to ARM mode
533    case MCAF_Code64:
534      return;
535    case MCAF_SubsectionsViaSymbols:
536      return;
537    }
538  }
539
540private:
541  enum ElfMappingSymbol {
542    EMS_None,
543    EMS_ARM,
544    EMS_Thumb,
545    EMS_Data
546  };
547
548  void EmitDataMappingSymbol() {
549    if (LastEMS == EMS_Data) return;
550    EmitMappingSymbol("$d");
551    LastEMS = EMS_Data;
552  }
553
554  void EmitThumbMappingSymbol() {
555    if (LastEMS == EMS_Thumb) return;
556    EmitMappingSymbol("$t");
557    LastEMS = EMS_Thumb;
558  }
559
560  void EmitARMMappingSymbol() {
561    if (LastEMS == EMS_ARM) return;
562    EmitMappingSymbol("$a");
563    LastEMS = EMS_ARM;
564  }
565
566  void EmitMappingSymbol(StringRef Name) {
567    auto *Symbol = cast<MCSymbolELF>(getContext().getOrCreateSymbol(
568        Name + "." + Twine(MappingSymbolCounter++)));
569    EmitLabel(Symbol);
570
571    Symbol->setType(ELF::STT_NOTYPE);
572    Symbol->setBinding(ELF::STB_LOCAL);
573    Symbol->setExternal(false);
574  }
575
576  void EmitThumbFunc(MCSymbol *Func) override {
577    getAssembler().setIsThumbFunc(Func);
578    EmitSymbolAttribute(Func, MCSA_ELF_TypeFunction);
579  }
580
581  // Helper functions for ARM exception handling directives
582  void Reset();
583
584  void EmitPersonalityFixup(StringRef Name);
585  void FlushPendingOffset();
586  void FlushUnwindOpcodes(bool NoHandlerData);
587
588  void SwitchToEHSection(const char *Prefix, unsigned Type, unsigned Flags,
589                         SectionKind Kind, const MCSymbol &Fn);
590  void SwitchToExTabSection(const MCSymbol &FnStart);
591  void SwitchToExIdxSection(const MCSymbol &FnStart);
592
593  void EmitFixup(const MCExpr *Expr, MCFixupKind Kind);
594
595  bool IsThumb;
596  int64_t MappingSymbolCounter;
597
598  DenseMap<const MCSection *, ElfMappingSymbol> LastMappingSymbols;
599  ElfMappingSymbol LastEMS;
600
601  // ARM Exception Handling Frame Information
602  MCSymbol *ExTab;
603  MCSymbol *FnStart;
604  const MCSymbol *Personality;
605  unsigned PersonalityIndex;
606  unsigned FPReg; // Frame pointer register
607  int64_t FPOffset; // Offset: (final frame pointer) - (initial $sp)
608  int64_t SPOffset; // Offset: (final $sp) - (initial $sp)
609  int64_t PendingOffset; // Offset: (final $sp) - (emitted $sp)
610  bool UsedFP;
611  bool CantUnwind;
612  SmallVector<uint8_t, 64> Opcodes;
613  UnwindOpcodeAssembler UnwindOpAsm;
614};
615} // end anonymous namespace
616
617ARMELFStreamer &ARMTargetELFStreamer::getStreamer() {
618  return static_cast<ARMELFStreamer &>(Streamer);
619}
620
621void ARMTargetELFStreamer::emitFnStart() { getStreamer().emitFnStart(); }
622void ARMTargetELFStreamer::emitFnEnd() { getStreamer().emitFnEnd(); }
623void ARMTargetELFStreamer::emitCantUnwind() { getStreamer().emitCantUnwind(); }
624void ARMTargetELFStreamer::emitPersonality(const MCSymbol *Personality) {
625  getStreamer().emitPersonality(Personality);
626}
627void ARMTargetELFStreamer::emitPersonalityIndex(unsigned Index) {
628  getStreamer().emitPersonalityIndex(Index);
629}
630void ARMTargetELFStreamer::emitHandlerData() {
631  getStreamer().emitHandlerData();
632}
633void ARMTargetELFStreamer::emitSetFP(unsigned FpReg, unsigned SpReg,
634                                     int64_t Offset) {
635  getStreamer().emitSetFP(FpReg, SpReg, Offset);
636}
637void ARMTargetELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
638  getStreamer().emitMovSP(Reg, Offset);
639}
640void ARMTargetELFStreamer::emitPad(int64_t Offset) {
641  getStreamer().emitPad(Offset);
642}
643void ARMTargetELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
644                                       bool isVector) {
645  getStreamer().emitRegSave(RegList, isVector);
646}
647void ARMTargetELFStreamer::emitUnwindRaw(int64_t Offset,
648                                      const SmallVectorImpl<uint8_t> &Opcodes) {
649  getStreamer().emitUnwindRaw(Offset, Opcodes);
650}
651void ARMTargetELFStreamer::switchVendor(StringRef Vendor) {
652  assert(!Vendor.empty() && "Vendor cannot be empty.");
653
654  if (CurrentVendor == Vendor)
655    return;
656
657  if (!CurrentVendor.empty())
658    finishAttributeSection();
659
660  assert(Contents.empty() &&
661         ".ARM.attributes should be flushed before changing vendor");
662  CurrentVendor = Vendor;
663
664}
665void ARMTargetELFStreamer::emitAttribute(unsigned Attribute, unsigned Value) {
666  setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
667}
668void ARMTargetELFStreamer::emitTextAttribute(unsigned Attribute,
669                                             StringRef Value) {
670  setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
671}
672void ARMTargetELFStreamer::emitIntTextAttribute(unsigned Attribute,
673                                                unsigned IntValue,
674                                                StringRef StringValue) {
675  setAttributeItems(Attribute, IntValue, StringValue,
676                    /* OverwriteExisting= */ true);
677}
678void ARMTargetELFStreamer::emitArch(unsigned Value) {
679  Arch = Value;
680}
681void ARMTargetELFStreamer::emitObjectArch(unsigned Value) {
682  EmittedArch = Value;
683}
684void ARMTargetELFStreamer::emitArchDefaultAttributes() {
685  using namespace ARMBuildAttrs;
686
687  setAttributeItem(CPU_name,
688                   ARM::getCPUAttr(Arch),
689                   false);
690
691  if (EmittedArch == ARM::AK_INVALID)
692    setAttributeItem(CPU_arch,
693                     ARM::getArchAttr(Arch),
694                     false);
695  else
696    setAttributeItem(CPU_arch,
697                     ARM::getArchAttr(EmittedArch),
698                     false);
699
700  switch (Arch) {
701  case ARM::AK_ARMV2:
702  case ARM::AK_ARMV2A:
703  case ARM::AK_ARMV3:
704  case ARM::AK_ARMV3M:
705  case ARM::AK_ARMV4:
706    setAttributeItem(ARM_ISA_use, Allowed, false);
707    break;
708
709  case ARM::AK_ARMV4T:
710  case ARM::AK_ARMV5T:
711  case ARM::AK_ARMV5TE:
712  case ARM::AK_ARMV6:
713    setAttributeItem(ARM_ISA_use, Allowed, false);
714    setAttributeItem(THUMB_ISA_use, Allowed, false);
715    break;
716
717  case ARM::AK_ARMV6T2:
718    setAttributeItem(ARM_ISA_use, Allowed, false);
719    setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
720    break;
721
722  case ARM::AK_ARMV6K:
723  case ARM::AK_ARMV6KZ:
724    setAttributeItem(ARM_ISA_use, Allowed, false);
725    setAttributeItem(THUMB_ISA_use, Allowed, false);
726    setAttributeItem(Virtualization_use, AllowTZ, false);
727    break;
728
729  case ARM::AK_ARMV6M:
730    setAttributeItem(THUMB_ISA_use, Allowed, false);
731    break;
732
733  case ARM::AK_ARMV7A:
734    setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
735    setAttributeItem(ARM_ISA_use, Allowed, false);
736    setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
737    break;
738
739  case ARM::AK_ARMV7R:
740    setAttributeItem(CPU_arch_profile, RealTimeProfile, false);
741    setAttributeItem(ARM_ISA_use, Allowed, false);
742    setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
743    break;
744
745  case ARM::AK_ARMV7M:
746    setAttributeItem(CPU_arch_profile, MicroControllerProfile, false);
747    setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
748    break;
749
750  case ARM::AK_ARMV8A:
751  case ARM::AK_ARMV8_1A:
752  case ARM::AK_ARMV8_2A:
753    setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
754    setAttributeItem(ARM_ISA_use, Allowed, false);
755    setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
756    setAttributeItem(MPextension_use, Allowed, false);
757    setAttributeItem(Virtualization_use, AllowTZVirtualization, false);
758    break;
759
760  case ARM::AK_IWMMXT:
761    setAttributeItem(ARM_ISA_use, Allowed, false);
762    setAttributeItem(THUMB_ISA_use, Allowed, false);
763    setAttributeItem(WMMX_arch, AllowWMMXv1, false);
764    break;
765
766  case ARM::AK_IWMMXT2:
767    setAttributeItem(ARM_ISA_use, Allowed, false);
768    setAttributeItem(THUMB_ISA_use, Allowed, false);
769    setAttributeItem(WMMX_arch, AllowWMMXv2, false);
770    break;
771
772  default:
773    report_fatal_error("Unknown Arch: " + Twine(Arch));
774    break;
775  }
776}
777void ARMTargetELFStreamer::emitFPU(unsigned Value) {
778  FPU = Value;
779}
780void ARMTargetELFStreamer::emitFPUDefaultAttributes() {
781  switch (FPU) {
782  case ARM::FK_VFP:
783  case ARM::FK_VFPV2:
784    setAttributeItem(ARMBuildAttrs::FP_arch,
785                     ARMBuildAttrs::AllowFPv2,
786                     /* OverwriteExisting= */ false);
787    break;
788
789  case ARM::FK_VFPV3:
790    setAttributeItem(ARMBuildAttrs::FP_arch,
791                     ARMBuildAttrs::AllowFPv3A,
792                     /* OverwriteExisting= */ false);
793    break;
794
795  case ARM::FK_VFPV3_FP16:
796    setAttributeItem(ARMBuildAttrs::FP_arch,
797                     ARMBuildAttrs::AllowFPv3A,
798                     /* OverwriteExisting= */ false);
799    setAttributeItem(ARMBuildAttrs::FP_HP_extension,
800                     ARMBuildAttrs::AllowHPFP,
801                     /* OverwriteExisting= */ false);
802    break;
803
804  case ARM::FK_VFPV3_D16:
805    setAttributeItem(ARMBuildAttrs::FP_arch,
806                     ARMBuildAttrs::AllowFPv3B,
807                     /* OverwriteExisting= */ false);
808    break;
809
810  case ARM::FK_VFPV3_D16_FP16:
811    setAttributeItem(ARMBuildAttrs::FP_arch,
812                     ARMBuildAttrs::AllowFPv3B,
813                     /* OverwriteExisting= */ false);
814    setAttributeItem(ARMBuildAttrs::FP_HP_extension,
815                     ARMBuildAttrs::AllowHPFP,
816                     /* OverwriteExisting= */ false);
817    break;
818
819  case ARM::FK_VFPV3XD:
820    setAttributeItem(ARMBuildAttrs::FP_arch,
821                     ARMBuildAttrs::AllowFPv3B,
822                     /* OverwriteExisting= */ false);
823    break;
824  case ARM::FK_VFPV3XD_FP16:
825    setAttributeItem(ARMBuildAttrs::FP_arch,
826                     ARMBuildAttrs::AllowFPv3B,
827                     /* OverwriteExisting= */ false);
828    setAttributeItem(ARMBuildAttrs::FP_HP_extension,
829                     ARMBuildAttrs::AllowHPFP,
830                     /* OverwriteExisting= */ false);
831    break;
832
833  case ARM::FK_VFPV4:
834    setAttributeItem(ARMBuildAttrs::FP_arch,
835                     ARMBuildAttrs::AllowFPv4A,
836                     /* OverwriteExisting= */ false);
837    break;
838
839  // ABI_HardFP_use is handled in ARMAsmPrinter, so _SP_D16 is treated the same
840  // as _D16 here.
841  case ARM::FK_FPV4_SP_D16:
842  case ARM::FK_VFPV4_D16:
843    setAttributeItem(ARMBuildAttrs::FP_arch,
844                     ARMBuildAttrs::AllowFPv4B,
845                     /* OverwriteExisting= */ false);
846    break;
847
848  case ARM::FK_FP_ARMV8:
849    setAttributeItem(ARMBuildAttrs::FP_arch,
850                     ARMBuildAttrs::AllowFPARMv8A,
851                     /* OverwriteExisting= */ false);
852    break;
853
854  // FPV5_D16 is identical to FP_ARMV8 except for the number of D registers, so
855  // uses the FP_ARMV8_D16 build attribute.
856  case ARM::FK_FPV5_SP_D16:
857  case ARM::FK_FPV5_D16:
858    setAttributeItem(ARMBuildAttrs::FP_arch,
859                     ARMBuildAttrs::AllowFPARMv8B,
860                     /* OverwriteExisting= */ false);
861    break;
862
863  case ARM::FK_NEON:
864    setAttributeItem(ARMBuildAttrs::FP_arch,
865                     ARMBuildAttrs::AllowFPv3A,
866                     /* OverwriteExisting= */ false);
867    setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
868                     ARMBuildAttrs::AllowNeon,
869                     /* OverwriteExisting= */ false);
870    break;
871
872  case ARM::FK_NEON_FP16:
873    setAttributeItem(ARMBuildAttrs::FP_arch,
874                     ARMBuildAttrs::AllowFPv3A,
875                     /* OverwriteExisting= */ false);
876    setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
877                     ARMBuildAttrs::AllowNeon,
878                     /* OverwriteExisting= */ false);
879    setAttributeItem(ARMBuildAttrs::FP_HP_extension,
880                     ARMBuildAttrs::AllowHPFP,
881                     /* OverwriteExisting= */ false);
882    break;
883
884  case ARM::FK_NEON_VFPV4:
885    setAttributeItem(ARMBuildAttrs::FP_arch,
886                     ARMBuildAttrs::AllowFPv4A,
887                     /* OverwriteExisting= */ false);
888    setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
889                     ARMBuildAttrs::AllowNeon2,
890                     /* OverwriteExisting= */ false);
891    break;
892
893  case ARM::FK_NEON_FP_ARMV8:
894  case ARM::FK_CRYPTO_NEON_FP_ARMV8:
895    setAttributeItem(ARMBuildAttrs::FP_arch,
896                     ARMBuildAttrs::AllowFPARMv8A,
897                     /* OverwriteExisting= */ false);
898    // 'Advanced_SIMD_arch' must be emitted not here, but within
899    // ARMAsmPrinter::emitAttributes(), depending on hasV8Ops() and hasV8_1a()
900    break;
901
902  case ARM::FK_SOFTVFP:
903  case ARM::FK_NONE:
904    break;
905
906  default:
907    report_fatal_error("Unknown FPU: " + Twine(FPU));
908    break;
909  }
910}
911size_t ARMTargetELFStreamer::calculateContentSize() const {
912  size_t Result = 0;
913  for (size_t i = 0; i < Contents.size(); ++i) {
914    AttributeItem item = Contents[i];
915    switch (item.Type) {
916    case AttributeItem::HiddenAttribute:
917      break;
918    case AttributeItem::NumericAttribute:
919      Result += getULEB128Size(item.Tag);
920      Result += getULEB128Size(item.IntValue);
921      break;
922    case AttributeItem::TextAttribute:
923      Result += getULEB128Size(item.Tag);
924      Result += item.StringValue.size() + 1; // string + '\0'
925      break;
926    case AttributeItem::NumericAndTextAttributes:
927      Result += getULEB128Size(item.Tag);
928      Result += getULEB128Size(item.IntValue);
929      Result += item.StringValue.size() + 1; // string + '\0';
930      break;
931    }
932  }
933  return Result;
934}
935void ARMTargetELFStreamer::finishAttributeSection() {
936  // <format-version>
937  // [ <section-length> "vendor-name"
938  // [ <file-tag> <size> <attribute>*
939  //   | <section-tag> <size> <section-number>* 0 <attribute>*
940  //   | <symbol-tag> <size> <symbol-number>* 0 <attribute>*
941  //   ]+
942  // ]*
943
944  if (FPU != ARM::FK_INVALID)
945    emitFPUDefaultAttributes();
946
947  if (Arch != ARM::AK_INVALID)
948    emitArchDefaultAttributes();
949
950  if (Contents.empty())
951    return;
952
953  std::sort(Contents.begin(), Contents.end(), AttributeItem::LessTag);
954
955  ARMELFStreamer &Streamer = getStreamer();
956
957  // Switch to .ARM.attributes section
958  if (AttributeSection) {
959    Streamer.SwitchSection(AttributeSection);
960  } else {
961    AttributeSection = Streamer.getContext().getELFSection(
962        ".ARM.attributes", ELF::SHT_ARM_ATTRIBUTES, 0);
963    Streamer.SwitchSection(AttributeSection);
964
965    // Format version
966    Streamer.EmitIntValue(0x41, 1);
967  }
968
969  // Vendor size + Vendor name + '\0'
970  const size_t VendorHeaderSize = 4 + CurrentVendor.size() + 1;
971
972  // Tag + Tag Size
973  const size_t TagHeaderSize = 1 + 4;
974
975  const size_t ContentsSize = calculateContentSize();
976
977  Streamer.EmitIntValue(VendorHeaderSize + TagHeaderSize + ContentsSize, 4);
978  Streamer.EmitBytes(CurrentVendor);
979  Streamer.EmitIntValue(0, 1); // '\0'
980
981  Streamer.EmitIntValue(ARMBuildAttrs::File, 1);
982  Streamer.EmitIntValue(TagHeaderSize + ContentsSize, 4);
983
984  // Size should have been accounted for already, now
985  // emit each field as its type (ULEB or String)
986  for (size_t i = 0; i < Contents.size(); ++i) {
987    AttributeItem item = Contents[i];
988    Streamer.EmitULEB128IntValue(item.Tag);
989    switch (item.Type) {
990    default: llvm_unreachable("Invalid attribute type");
991    case AttributeItem::NumericAttribute:
992      Streamer.EmitULEB128IntValue(item.IntValue);
993      break;
994    case AttributeItem::TextAttribute:
995      Streamer.EmitBytes(item.StringValue);
996      Streamer.EmitIntValue(0, 1); // '\0'
997      break;
998    case AttributeItem::NumericAndTextAttributes:
999      Streamer.EmitULEB128IntValue(item.IntValue);
1000      Streamer.EmitBytes(item.StringValue);
1001      Streamer.EmitIntValue(0, 1); // '\0'
1002      break;
1003    }
1004  }
1005
1006  Contents.clear();
1007  FPU = ARM::FK_INVALID;
1008}
1009
1010void ARMTargetELFStreamer::emitLabel(MCSymbol *Symbol) {
1011  ARMELFStreamer &Streamer = getStreamer();
1012  if (!Streamer.IsThumb)
1013    return;
1014
1015  Streamer.getAssembler().registerSymbol(*Symbol);
1016  unsigned Type = cast<MCSymbolELF>(Symbol)->getType();
1017  if (Type == ELF::STT_FUNC || Type == ELF::STT_GNU_IFUNC)
1018    Streamer.EmitThumbFunc(Symbol);
1019}
1020
1021void
1022ARMTargetELFStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
1023  getStreamer().EmitFixup(S, FK_Data_4);
1024}
1025
1026void ARMTargetELFStreamer::emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) {
1027  if (const MCSymbolRefExpr *SRE = dyn_cast<MCSymbolRefExpr>(Value)) {
1028    const MCSymbol &Sym = SRE->getSymbol();
1029    if (!Sym.isDefined()) {
1030      getStreamer().EmitAssignment(Symbol, Value);
1031      return;
1032    }
1033  }
1034
1035  getStreamer().EmitThumbFunc(Symbol);
1036  getStreamer().EmitAssignment(Symbol, Value);
1037}
1038
1039void ARMTargetELFStreamer::emitInst(uint32_t Inst, char Suffix) {
1040  getStreamer().emitInst(Inst, Suffix);
1041}
1042
1043void ARMELFStreamer::FinishImpl() {
1044  MCTargetStreamer &TS = *getTargetStreamer();
1045  ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
1046  ATS.finishAttributeSection();
1047
1048  MCELFStreamer::FinishImpl();
1049}
1050
1051inline void ARMELFStreamer::SwitchToEHSection(const char *Prefix,
1052                                              unsigned Type,
1053                                              unsigned Flags,
1054                                              SectionKind Kind,
1055                                              const MCSymbol &Fn) {
1056  const MCSectionELF &FnSection =
1057    static_cast<const MCSectionELF &>(Fn.getSection());
1058
1059  // Create the name for new section
1060  StringRef FnSecName(FnSection.getSectionName());
1061  SmallString<128> EHSecName(Prefix);
1062  if (FnSecName != ".text") {
1063    EHSecName += FnSecName;
1064  }
1065
1066  // Get .ARM.extab or .ARM.exidx section
1067  const MCSymbolELF *Group = FnSection.getGroup();
1068  if (Group)
1069    Flags |= ELF::SHF_GROUP;
1070  MCSectionELF *EHSection =
1071      getContext().getELFSection(EHSecName, Type, Flags, 0, Group,
1072                                 FnSection.getUniqueID(), nullptr, &FnSection);
1073
1074  assert(EHSection && "Failed to get the required EH section");
1075
1076  // Switch to .ARM.extab or .ARM.exidx section
1077  SwitchSection(EHSection);
1078  EmitCodeAlignment(4);
1079}
1080
1081inline void ARMELFStreamer::SwitchToExTabSection(const MCSymbol &FnStart) {
1082  SwitchToEHSection(".ARM.extab", ELF::SHT_PROGBITS, ELF::SHF_ALLOC,
1083                    SectionKind::getData(), FnStart);
1084}
1085
1086inline void ARMELFStreamer::SwitchToExIdxSection(const MCSymbol &FnStart) {
1087  SwitchToEHSection(".ARM.exidx", ELF::SHT_ARM_EXIDX,
1088                    ELF::SHF_ALLOC | ELF::SHF_LINK_ORDER,
1089                    SectionKind::getData(), FnStart);
1090}
1091void ARMELFStreamer::EmitFixup(const MCExpr *Expr, MCFixupKind Kind) {
1092  MCDataFragment *Frag = getOrCreateDataFragment();
1093  Frag->getFixups().push_back(MCFixup::create(Frag->getContents().size(), Expr,
1094                                              Kind));
1095}
1096
1097void ARMELFStreamer::Reset() {
1098  ExTab = nullptr;
1099  FnStart = nullptr;
1100  Personality = nullptr;
1101  PersonalityIndex = ARM::EHABI::NUM_PERSONALITY_INDEX;
1102  FPReg = ARM::SP;
1103  FPOffset = 0;
1104  SPOffset = 0;
1105  PendingOffset = 0;
1106  UsedFP = false;
1107  CantUnwind = false;
1108
1109  Opcodes.clear();
1110  UnwindOpAsm.Reset();
1111}
1112
1113void ARMELFStreamer::emitFnStart() {
1114  assert(FnStart == nullptr);
1115  FnStart = getContext().createTempSymbol();
1116  EmitLabel(FnStart);
1117}
1118
1119void ARMELFStreamer::emitFnEnd() {
1120  assert(FnStart && ".fnstart must precedes .fnend");
1121
1122  // Emit unwind opcodes if there is no .handlerdata directive
1123  if (!ExTab && !CantUnwind)
1124    FlushUnwindOpcodes(true);
1125
1126  // Emit the exception index table entry
1127  SwitchToExIdxSection(*FnStart);
1128
1129  if (PersonalityIndex < ARM::EHABI::NUM_PERSONALITY_INDEX)
1130    EmitPersonalityFixup(GetAEABIUnwindPersonalityName(PersonalityIndex));
1131
1132  const MCSymbolRefExpr *FnStartRef =
1133    MCSymbolRefExpr::create(FnStart,
1134                            MCSymbolRefExpr::VK_ARM_PREL31,
1135                            getContext());
1136
1137  EmitValue(FnStartRef, 4);
1138
1139  if (CantUnwind) {
1140    EmitIntValue(ARM::EHABI::EXIDX_CANTUNWIND, 4);
1141  } else if (ExTab) {
1142    // Emit a reference to the unwind opcodes in the ".ARM.extab" section.
1143    const MCSymbolRefExpr *ExTabEntryRef =
1144      MCSymbolRefExpr::create(ExTab,
1145                              MCSymbolRefExpr::VK_ARM_PREL31,
1146                              getContext());
1147    EmitValue(ExTabEntryRef, 4);
1148  } else {
1149    // For the __aeabi_unwind_cpp_pr0, we have to emit the unwind opcodes in
1150    // the second word of exception index table entry.  The size of the unwind
1151    // opcodes should always be 4 bytes.
1152    assert(PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0 &&
1153           "Compact model must use __aeabi_unwind_cpp_pr0 as personality");
1154    assert(Opcodes.size() == 4u &&
1155           "Unwind opcode size for __aeabi_unwind_cpp_pr0 must be equal to 4");
1156    uint64_t Intval = Opcodes[0] |
1157                      Opcodes[1] << 8 |
1158                      Opcodes[2] << 16 |
1159                      Opcodes[3] << 24;
1160    EmitIntValue(Intval, Opcodes.size());
1161  }
1162
1163  // Switch to the section containing FnStart
1164  SwitchSection(&FnStart->getSection());
1165
1166  // Clean exception handling frame information
1167  Reset();
1168}
1169
1170void ARMELFStreamer::emitCantUnwind() { CantUnwind = true; }
1171
1172// Add the R_ARM_NONE fixup at the same position
1173void ARMELFStreamer::EmitPersonalityFixup(StringRef Name) {
1174  const MCSymbol *PersonalitySym = getContext().getOrCreateSymbol(Name);
1175
1176  const MCSymbolRefExpr *PersonalityRef = MCSymbolRefExpr::create(
1177      PersonalitySym, MCSymbolRefExpr::VK_ARM_NONE, getContext());
1178
1179  visitUsedExpr(*PersonalityRef);
1180  MCDataFragment *DF = getOrCreateDataFragment();
1181  DF->getFixups().push_back(MCFixup::create(DF->getContents().size(),
1182                                            PersonalityRef,
1183                                            MCFixup::getKindForSize(4, false)));
1184}
1185
1186void ARMELFStreamer::FlushPendingOffset() {
1187  if (PendingOffset != 0) {
1188    UnwindOpAsm.EmitSPOffset(-PendingOffset);
1189    PendingOffset = 0;
1190  }
1191}
1192
1193void ARMELFStreamer::FlushUnwindOpcodes(bool NoHandlerData) {
1194  // Emit the unwind opcode to restore $sp.
1195  if (UsedFP) {
1196    const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1197    int64_t LastRegSaveSPOffset = SPOffset - PendingOffset;
1198    UnwindOpAsm.EmitSPOffset(LastRegSaveSPOffset - FPOffset);
1199    UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1200  } else {
1201    FlushPendingOffset();
1202  }
1203
1204  // Finalize the unwind opcode sequence
1205  UnwindOpAsm.Finalize(PersonalityIndex, Opcodes);
1206
1207  // For compact model 0, we have to emit the unwind opcodes in the .ARM.exidx
1208  // section.  Thus, we don't have to create an entry in the .ARM.extab
1209  // section.
1210  if (NoHandlerData && PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0)
1211    return;
1212
1213  // Switch to .ARM.extab section.
1214  SwitchToExTabSection(*FnStart);
1215
1216  // Create .ARM.extab label for offset in .ARM.exidx
1217  assert(!ExTab);
1218  ExTab = getContext().createTempSymbol();
1219  EmitLabel(ExTab);
1220
1221  // Emit personality
1222  if (Personality) {
1223    const MCSymbolRefExpr *PersonalityRef =
1224      MCSymbolRefExpr::create(Personality,
1225                              MCSymbolRefExpr::VK_ARM_PREL31,
1226                              getContext());
1227
1228    EmitValue(PersonalityRef, 4);
1229  }
1230
1231  // Emit unwind opcodes
1232  assert((Opcodes.size() % 4) == 0 &&
1233         "Unwind opcode size for __aeabi_cpp_unwind_pr0 must be multiple of 4");
1234  for (unsigned I = 0; I != Opcodes.size(); I += 4) {
1235    uint64_t Intval = Opcodes[I] |
1236                      Opcodes[I + 1] << 8 |
1237                      Opcodes[I + 2] << 16 |
1238                      Opcodes[I + 3] << 24;
1239    EmitIntValue(Intval, 4);
1240  }
1241
1242  // According to ARM EHABI section 9.2, if the __aeabi_unwind_cpp_pr1() or
1243  // __aeabi_unwind_cpp_pr2() is used, then the handler data must be emitted
1244  // after the unwind opcodes.  The handler data consists of several 32-bit
1245  // words, and should be terminated by zero.
1246  //
1247  // In case that the .handlerdata directive is not specified by the
1248  // programmer, we should emit zero to terminate the handler data.
1249  if (NoHandlerData && !Personality)
1250    EmitIntValue(0, 4);
1251}
1252
1253void ARMELFStreamer::emitHandlerData() { FlushUnwindOpcodes(false); }
1254
1255void ARMELFStreamer::emitPersonality(const MCSymbol *Per) {
1256  Personality = Per;
1257  UnwindOpAsm.setPersonality(Per);
1258}
1259
1260void ARMELFStreamer::emitPersonalityIndex(unsigned Index) {
1261  assert(Index < ARM::EHABI::NUM_PERSONALITY_INDEX && "invalid index");
1262  PersonalityIndex = Index;
1263}
1264
1265void ARMELFStreamer::emitSetFP(unsigned NewFPReg, unsigned NewSPReg,
1266                               int64_t Offset) {
1267  assert((NewSPReg == ARM::SP || NewSPReg == FPReg) &&
1268         "the operand of .setfp directive should be either $sp or $fp");
1269
1270  UsedFP = true;
1271  FPReg = NewFPReg;
1272
1273  if (NewSPReg == ARM::SP)
1274    FPOffset = SPOffset + Offset;
1275  else
1276    FPOffset += Offset;
1277}
1278
1279void ARMELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
1280  assert((Reg != ARM::SP && Reg != ARM::PC) &&
1281         "the operand of .movsp cannot be either sp or pc");
1282  assert(FPReg == ARM::SP && "current FP must be SP");
1283
1284  FlushPendingOffset();
1285
1286  FPReg = Reg;
1287  FPOffset = SPOffset + Offset;
1288
1289  const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1290  UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1291}
1292
1293void ARMELFStreamer::emitPad(int64_t Offset) {
1294  // Track the change of the $sp offset
1295  SPOffset -= Offset;
1296
1297  // To squash multiple .pad directives, we should delay the unwind opcode
1298  // until the .save, .vsave, .handlerdata, or .fnend directives.
1299  PendingOffset -= Offset;
1300}
1301
1302void ARMELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
1303                                 bool IsVector) {
1304  // Collect the registers in the register list
1305  unsigned Count = 0;
1306  uint32_t Mask = 0;
1307  const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1308  for (size_t i = 0; i < RegList.size(); ++i) {
1309    unsigned Reg = MRI->getEncodingValue(RegList[i]);
1310    assert(Reg < (IsVector ? 32U : 16U) && "Register out of range");
1311    unsigned Bit = (1u << Reg);
1312    if ((Mask & Bit) == 0) {
1313      Mask |= Bit;
1314      ++Count;
1315    }
1316  }
1317
1318  // Track the change the $sp offset: For the .save directive, the
1319  // corresponding push instruction will decrease the $sp by (4 * Count).
1320  // For the .vsave directive, the corresponding vpush instruction will
1321  // decrease $sp by (8 * Count).
1322  SPOffset -= Count * (IsVector ? 8 : 4);
1323
1324  // Emit the opcode
1325  FlushPendingOffset();
1326  if (IsVector)
1327    UnwindOpAsm.EmitVFPRegSave(Mask);
1328  else
1329    UnwindOpAsm.EmitRegSave(Mask);
1330}
1331
1332void ARMELFStreamer::emitUnwindRaw(int64_t Offset,
1333                                   const SmallVectorImpl<uint8_t> &Opcodes) {
1334  FlushPendingOffset();
1335  SPOffset = SPOffset - Offset;
1336  UnwindOpAsm.EmitRaw(Opcodes);
1337}
1338
1339namespace llvm {
1340
1341MCTargetStreamer *createARMTargetAsmStreamer(MCStreamer &S,
1342                                             formatted_raw_ostream &OS,
1343                                             MCInstPrinter *InstPrint,
1344                                             bool isVerboseAsm) {
1345  return new ARMTargetAsmStreamer(S, OS, *InstPrint, isVerboseAsm);
1346}
1347
1348MCTargetStreamer *createARMNullTargetStreamer(MCStreamer &S) {
1349  return new ARMTargetStreamer(S);
1350}
1351
1352MCTargetStreamer *createARMObjectTargetStreamer(MCStreamer &S,
1353                                                const MCSubtargetInfo &STI) {
1354  const Triple &TT = STI.getTargetTriple();
1355  if (TT.isOSBinFormatELF())
1356    return new ARMTargetELFStreamer(S);
1357  return new ARMTargetStreamer(S);
1358}
1359
1360MCELFStreamer *createARMELFStreamer(MCContext &Context, MCAsmBackend &TAB,
1361                                    raw_pwrite_stream &OS,
1362                                    MCCodeEmitter *Emitter, bool RelaxAll,
1363                                    bool IsThumb) {
1364    ARMELFStreamer *S = new ARMELFStreamer(Context, TAB, OS, Emitter, IsThumb);
1365    // FIXME: This should eventually end up somewhere else where more
1366    // intelligent flag decisions can be made. For now we are just maintaining
1367    // the status quo for ARM and setting EF_ARM_EABI_VER5 as the default.
1368    S->getAssembler().setELFHeaderEFlags(ELF::EF_ARM_EABI_VER5);
1369
1370    if (RelaxAll)
1371      S->getAssembler().setRelaxAll(true);
1372    return S;
1373  }
1374
1375}
1376
1377
1378