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ARMELFStreamer.cpp
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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/DenseMap.h"
19 #include "llvm/ADT/SmallString.h"
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/ADT/StringRef.h"
22 #include "llvm/ADT/Triple.h"
23 #include "llvm/ADT/Twine.h"
24 #include "llvm/BinaryFormat/ELF.h"
25 #include "llvm/MC/MCAsmBackend.h"
26 #include "llvm/MC/MCAsmInfo.h"
27 #include "llvm/MC/MCAssembler.h"
28 #include "llvm/MC/MCCodeEmitter.h"
29 #include "llvm/MC/MCContext.h"
30 #include "llvm/MC/MCELFStreamer.h"
31 #include "llvm/MC/MCExpr.h"
32 #include "llvm/MC/MCFixup.h"
33 #include "llvm/MC/MCFragment.h"
34 #include "llvm/MC/MCInst.h"
35 #include "llvm/MC/MCInstPrinter.h"
36 #include "llvm/MC/MCRegisterInfo.h"
37 #include "llvm/MC/MCSection.h"
38 #include "llvm/MC/MCSectionELF.h"
39 #include "llvm/MC/MCStreamer.h"
41 #include "llvm/MC/MCSymbol.h"
42 #include "llvm/MC/MCSymbolELF.h"
43 #include "llvm/MC/SectionKind.h"
45 #include "llvm/Support/ARMEHABI.h"
46 #include "llvm/Support/Casting.h"
49 #include "llvm/Support/LEB128.h"
52 #include <algorithm>
53 #include <cassert>
54 #include <climits>
55 #include <cstddef>
56 #include <cstdint>
57 #include <string>
58 
59 using namespace llvm;
60 
61 static std::string GetAEABIUnwindPersonalityName(unsigned Index) {
63  "Invalid personality index");
64  return (Twine("__aeabi_unwind_cpp_pr") + Twine(Index)).str();
65 }
66 
67 namespace {
68 
69 class ARMELFStreamer;
70 
71 class ARMTargetAsmStreamer : public ARMTargetStreamer {
73  MCInstPrinter &InstPrinter;
74  bool IsVerboseAsm;
75 
76  void emitFnStart() override;
77  void emitFnEnd() override;
78  void emitCantUnwind() override;
79  void emitPersonality(const MCSymbol *Personality) override;
80  void emitPersonalityIndex(unsigned Index) override;
81  void emitHandlerData() override;
82  void emitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0) override;
83  void emitMovSP(unsigned Reg, int64_t Offset = 0) override;
84  void emitPad(int64_t Offset) override;
85  void emitRegSave(const SmallVectorImpl<unsigned> &RegList,
86  bool isVector) override;
87  void emitUnwindRaw(int64_t Offset,
88  const SmallVectorImpl<uint8_t> &Opcodes) override;
89 
90  void switchVendor(StringRef Vendor) override;
91  void emitAttribute(unsigned Attribute, unsigned Value) override;
92  void emitTextAttribute(unsigned Attribute, StringRef String) override;
93  void emitIntTextAttribute(unsigned Attribute, unsigned IntValue,
94  StringRef StringValue) override;
95  void emitArch(ARM::ArchKind Arch) override;
96  void emitArchExtension(unsigned ArchExt) override;
97  void emitObjectArch(ARM::ArchKind Arch) override;
98  void emitFPU(unsigned FPU) override;
99  void emitInst(uint32_t Inst, char Suffix = '\0') override;
100  void finishAttributeSection() override;
101 
102  void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE) override;
103  void emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) override;
104 
105 public:
106  ARMTargetAsmStreamer(MCStreamer &S, formatted_raw_ostream &OS,
107  MCInstPrinter &InstPrinter, bool VerboseAsm);
108 };
109 
110 ARMTargetAsmStreamer::ARMTargetAsmStreamer(MCStreamer &S,
112  MCInstPrinter &InstPrinter,
113  bool VerboseAsm)
114  : ARMTargetStreamer(S), OS(OS), InstPrinter(InstPrinter),
115  IsVerboseAsm(VerboseAsm) {}
116 
117 void ARMTargetAsmStreamer::emitFnStart() { OS << "\t.fnstart\n"; }
118 void ARMTargetAsmStreamer::emitFnEnd() { OS << "\t.fnend\n"; }
119 void ARMTargetAsmStreamer::emitCantUnwind() { OS << "\t.cantunwind\n"; }
120 
121 void ARMTargetAsmStreamer::emitPersonality(const MCSymbol *Personality) {
122  OS << "\t.personality " << Personality->getName() << '\n';
123 }
124 
125 void ARMTargetAsmStreamer::emitPersonalityIndex(unsigned Index) {
126  OS << "\t.personalityindex " << Index << '\n';
127 }
128 
129 void ARMTargetAsmStreamer::emitHandlerData() { OS << "\t.handlerdata\n"; }
130 
131 void ARMTargetAsmStreamer::emitSetFP(unsigned FpReg, unsigned SpReg,
132  int64_t Offset) {
133  OS << "\t.setfp\t";
134  InstPrinter.printRegName(OS, FpReg);
135  OS << ", ";
136  InstPrinter.printRegName(OS, SpReg);
137  if (Offset)
138  OS << ", #" << Offset;
139  OS << '\n';
140 }
141 
142 void ARMTargetAsmStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
143  assert((Reg != ARM::SP && Reg != ARM::PC) &&
144  "the operand of .movsp cannot be either sp or pc");
145 
146  OS << "\t.movsp\t";
147  InstPrinter.printRegName(OS, Reg);
148  if (Offset)
149  OS << ", #" << Offset;
150  OS << '\n';
151 }
152 
153 void ARMTargetAsmStreamer::emitPad(int64_t Offset) {
154  OS << "\t.pad\t#" << Offset << '\n';
155 }
156 
157 void ARMTargetAsmStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
158  bool isVector) {
159  assert(RegList.size() && "RegList should not be empty");
160  if (isVector)
161  OS << "\t.vsave\t{";
162  else
163  OS << "\t.save\t{";
164 
165  InstPrinter.printRegName(OS, RegList[0]);
166 
167  for (unsigned i = 1, e = RegList.size(); i != e; ++i) {
168  OS << ", ";
169  InstPrinter.printRegName(OS, RegList[i]);
170  }
171 
172  OS << "}\n";
173 }
174 
175 void ARMTargetAsmStreamer::switchVendor(StringRef Vendor) {}
176 
177 void ARMTargetAsmStreamer::emitAttribute(unsigned Attribute, unsigned Value) {
178  OS << "\t.eabi_attribute\t" << Attribute << ", " << Twine(Value);
179  if (IsVerboseAsm) {
181  if (!Name.empty())
182  OS << "\t@ " << Name;
183  }
184  OS << "\n";
185 }
186 
187 void ARMTargetAsmStreamer::emitTextAttribute(unsigned Attribute,
188  StringRef String) {
189  switch (Attribute) {
191  OS << "\t.cpu\t" << String.lower();
192  break;
193  default:
194  OS << "\t.eabi_attribute\t" << Attribute << ", \"" << String << "\"";
195  if (IsVerboseAsm) {
197  if (!Name.empty())
198  OS << "\t@ " << Name;
199  }
200  break;
201  }
202  OS << "\n";
203 }
204 
205 void ARMTargetAsmStreamer::emitIntTextAttribute(unsigned Attribute,
206  unsigned IntValue,
207  StringRef StringValue) {
208  switch (Attribute) {
209  default: llvm_unreachable("unsupported multi-value attribute in asm mode");
211  OS << "\t.eabi_attribute\t" << Attribute << ", " << IntValue;
212  if (!StringValue.empty())
213  OS << ", \"" << StringValue << "\"";
214  if (IsVerboseAsm)
215  OS << "\t@ " << ARMBuildAttrs::AttrTypeAsString(Attribute);
216  break;
217  }
218  OS << "\n";
219 }
220 
221 void ARMTargetAsmStreamer::emitArch(ARM::ArchKind Arch) {
222  OS << "\t.arch\t" << ARM::getArchName(Arch) << "\n";
223 }
224 
225 void ARMTargetAsmStreamer::emitArchExtension(unsigned ArchExt) {
226  OS << "\t.arch_extension\t" << ARM::getArchExtName(ArchExt) << "\n";
227 }
228 
229 void ARMTargetAsmStreamer::emitObjectArch(ARM::ArchKind Arch) {
230  OS << "\t.object_arch\t" << ARM::getArchName(Arch) << '\n';
231 }
232 
233 void ARMTargetAsmStreamer::emitFPU(unsigned FPU) {
234  OS << "\t.fpu\t" << ARM::getFPUName(FPU) << "\n";
235 }
236 
237 void ARMTargetAsmStreamer::finishAttributeSection() {}
238 
239 void
240 ARMTargetAsmStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
241  OS << "\t.tlsdescseq\t" << S->getSymbol().getName();
242 }
243 
244 void ARMTargetAsmStreamer::emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) {
245  const MCAsmInfo *MAI = Streamer.getContext().getAsmInfo();
246 
247  OS << "\t.thumb_set\t";
248  Symbol->print(OS, MAI);
249  OS << ", ";
250  Value->print(OS, MAI);
251  OS << '\n';
252 }
253 
254 void ARMTargetAsmStreamer::emitInst(uint32_t Inst, char Suffix) {
255  OS << "\t.inst";
256  if (Suffix)
257  OS << "." << Suffix;
258  OS << "\t0x" << Twine::utohexstr(Inst) << "\n";
259 }
260 
261 void ARMTargetAsmStreamer::emitUnwindRaw(int64_t Offset,
262  const SmallVectorImpl<uint8_t> &Opcodes) {
263  OS << "\t.unwind_raw " << Offset;
264  for (SmallVectorImpl<uint8_t>::const_iterator OCI = Opcodes.begin(),
265  OCE = Opcodes.end();
266  OCI != OCE; ++OCI)
267  OS << ", 0x" << Twine::utohexstr(*OCI);
268  OS << '\n';
269 }
270 
271 class ARMTargetELFStreamer : public ARMTargetStreamer {
272 private:
273  // This structure holds all attributes, accounting for
274  // their string/numeric value, so we can later emit them
275  // in declaration order, keeping all in the same vector
276  struct AttributeItem {
277  enum {
278  HiddenAttribute = 0,
279  NumericAttribute,
280  TextAttribute,
281  NumericAndTextAttributes
282  } Type;
283  unsigned Tag;
284  unsigned IntValue;
285  std::string StringValue;
286 
287  static bool LessTag(const AttributeItem &LHS, const AttributeItem &RHS) {
288  // The conformance tag must be emitted first when serialised
289  // into an object file. Specifically, the addenda to the ARM ABI
290  // states that (2.3.7.4):
291  //
292  // "To simplify recognition by consumers in the common case of
293  // claiming conformity for the whole file, this tag should be
294  // emitted first in a file-scope sub-subsection of the first
295  // public subsection of the attributes section."
296  //
297  // So it is special-cased in this comparison predicate when the
298  // attributes are sorted in finishAttributeSection().
299  return (RHS.Tag != ARMBuildAttrs::conformance) &&
300  ((LHS.Tag == ARMBuildAttrs::conformance) || (LHS.Tag < RHS.Tag));
301  }
302  };
303 
304  StringRef CurrentVendor;
305  unsigned FPU = ARM::FK_INVALID;
309 
310  MCSection *AttributeSection = nullptr;
311 
312  AttributeItem *getAttributeItem(unsigned Attribute) {
313  for (size_t i = 0; i < Contents.size(); ++i)
314  if (Contents[i].Tag == Attribute)
315  return &Contents[i];
316  return nullptr;
317  }
318 
319  void setAttributeItem(unsigned Attribute, unsigned Value,
320  bool OverwriteExisting) {
321  // Look for existing attribute item
322  if (AttributeItem *Item = getAttributeItem(Attribute)) {
323  if (!OverwriteExisting)
324  return;
325  Item->Type = AttributeItem::NumericAttribute;
326  Item->IntValue = Value;
327  return;
328  }
329 
330  // Create new attribute item
331  AttributeItem Item = {
332  AttributeItem::NumericAttribute,
333  Attribute,
334  Value,
335  StringRef("")
336  };
337  Contents.push_back(Item);
338  }
339 
340  void setAttributeItem(unsigned Attribute, StringRef Value,
341  bool OverwriteExisting) {
342  // Look for existing attribute item
343  if (AttributeItem *Item = getAttributeItem(Attribute)) {
344  if (!OverwriteExisting)
345  return;
346  Item->Type = AttributeItem::TextAttribute;
347  Item->StringValue = Value;
348  return;
349  }
350 
351  // Create new attribute item
352  AttributeItem Item = {
353  AttributeItem::TextAttribute,
354  Attribute,
355  0,
356  Value
357  };
358  Contents.push_back(Item);
359  }
360 
361  void setAttributeItems(unsigned Attribute, unsigned IntValue,
362  StringRef StringValue, bool OverwriteExisting) {
363  // Look for existing attribute item
364  if (AttributeItem *Item = getAttributeItem(Attribute)) {
365  if (!OverwriteExisting)
366  return;
367  Item->Type = AttributeItem::NumericAndTextAttributes;
368  Item->IntValue = IntValue;
369  Item->StringValue = StringValue;
370  return;
371  }
372 
373  // Create new attribute item
374  AttributeItem Item = {
375  AttributeItem::NumericAndTextAttributes,
376  Attribute,
377  IntValue,
378  StringValue
379  };
380  Contents.push_back(Item);
381  }
382 
383  void emitArchDefaultAttributes();
384  void emitFPUDefaultAttributes();
385 
386  ARMELFStreamer &getStreamer();
387 
388  void emitFnStart() override;
389  void emitFnEnd() override;
390  void emitCantUnwind() override;
391  void emitPersonality(const MCSymbol *Personality) override;
392  void emitPersonalityIndex(unsigned Index) override;
393  void emitHandlerData() override;
394  void emitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0) override;
395  void emitMovSP(unsigned Reg, int64_t Offset = 0) override;
396  void emitPad(int64_t Offset) override;
397  void emitRegSave(const SmallVectorImpl<unsigned> &RegList,
398  bool isVector) override;
399  void emitUnwindRaw(int64_t Offset,
400  const SmallVectorImpl<uint8_t> &Opcodes) override;
401 
402  void switchVendor(StringRef Vendor) override;
403  void emitAttribute(unsigned Attribute, unsigned Value) override;
404  void emitTextAttribute(unsigned Attribute, StringRef String) override;
405  void emitIntTextAttribute(unsigned Attribute, unsigned IntValue,
406  StringRef StringValue) override;
407  void emitArch(ARM::ArchKind Arch) override;
408  void emitObjectArch(ARM::ArchKind Arch) override;
409  void emitFPU(unsigned FPU) override;
410  void emitInst(uint32_t Inst, char Suffix = '\0') override;
411  void finishAttributeSection() override;
412  void emitLabel(MCSymbol *Symbol) override;
413 
414  void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE) override;
415  void emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) override;
416 
417  size_t calculateContentSize() const;
418 
419  // Reset state between object emissions
420  void reset() override;
421 
422 public:
423  ARMTargetELFStreamer(MCStreamer &S)
424  : ARMTargetStreamer(S), CurrentVendor("aeabi") {}
425 };
426 
427 /// Extend the generic ELFStreamer class so that it can emit mapping symbols at
428 /// the appropriate points in the object files. These symbols are defined in the
429 /// ARM ELF ABI: infocenter.arm.com/help/topic/com.arm.../IHI0044D_aaelf.pdf.
430 ///
431 /// In brief: $a, $t or $d should be emitted at the start of each contiguous
432 /// region of ARM code, Thumb code or data in a section. In practice, this
433 /// emission does not rely on explicit assembler directives but on inherent
434 /// properties of the directives doing the emission (e.g. ".byte" is data, "add
435 /// r0, r0, r0" an instruction).
436 ///
437 /// As a result this system is orthogonal to the DataRegion infrastructure used
438 /// by MachO. Beware!
439 class ARMELFStreamer : public MCELFStreamer {
440 public:
441  friend class ARMTargetELFStreamer;
442 
443  ARMELFStreamer(MCContext &Context, std::unique_ptr<MCAsmBackend> TAB,
444  raw_pwrite_stream &OS, std::unique_ptr<MCCodeEmitter> Emitter,
445  bool IsThumb)
446  : MCELFStreamer(Context, std::move(TAB), OS, std::move(Emitter)),
447  IsThumb(IsThumb) {
448  EHReset();
449  }
450 
451  ~ARMELFStreamer() override = default;
452 
453  void FinishImpl() override;
454 
455  // ARM exception handling directives
456  void emitFnStart();
457  void emitFnEnd();
458  void emitCantUnwind();
459  void emitPersonality(const MCSymbol *Per);
460  void emitPersonalityIndex(unsigned index);
461  void emitHandlerData();
462  void emitSetFP(unsigned NewFpReg, unsigned NewSpReg, int64_t Offset = 0);
463  void emitMovSP(unsigned Reg, int64_t Offset = 0);
464  void emitPad(int64_t Offset);
465  void emitRegSave(const SmallVectorImpl<unsigned> &RegList, bool isVector);
466  void emitUnwindRaw(int64_t Offset, const SmallVectorImpl<uint8_t> &Opcodes);
467 
468  void ChangeSection(MCSection *Section, const MCExpr *Subsection) override {
469  LastMappingSymbols[getCurrentSection().first] = std::move(LastEMSInfo);
470  MCELFStreamer::ChangeSection(Section, Subsection);
471  auto LastMappingSymbol = LastMappingSymbols.find(Section);
472  if (LastMappingSymbol != LastMappingSymbols.end()) {
473  LastEMSInfo = std::move(LastMappingSymbol->second);
474  return;
475  }
476  LastEMSInfo.reset(new ElfMappingSymbolInfo(SMLoc(), nullptr, 0));
477  }
478 
479  /// This function is the one used to emit instruction data into the ELF
480  /// streamer. We override it to add the appropriate mapping symbol if
481  /// necessary.
482  void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI,
483  bool) override {
484  if (IsThumb)
485  EmitThumbMappingSymbol();
486  else
487  EmitARMMappingSymbol();
488 
490  }
491 
492  void emitInst(uint32_t Inst, char Suffix) {
493  unsigned Size;
494  char Buffer[4];
495  const bool LittleEndian = getContext().getAsmInfo()->isLittleEndian();
496 
497  switch (Suffix) {
498  case '\0':
499  Size = 4;
500 
501  assert(!IsThumb);
502  EmitARMMappingSymbol();
503  for (unsigned II = 0, IE = Size; II != IE; II++) {
504  const unsigned I = LittleEndian ? (Size - II - 1) : II;
505  Buffer[Size - II - 1] = uint8_t(Inst >> I * CHAR_BIT);
506  }
507 
508  break;
509  case 'n':
510  case 'w':
511  Size = (Suffix == 'n' ? 2 : 4);
512 
513  assert(IsThumb);
514  EmitThumbMappingSymbol();
515  // Thumb wide instructions are emitted as a pair of 16-bit words of the
516  // appropriate endianness.
517  for (unsigned II = 0, IE = Size; II != IE; II = II + 2) {
518  const unsigned I0 = LittleEndian ? II + 0 : II + 1;
519  const unsigned I1 = LittleEndian ? II + 1 : II + 0;
520  Buffer[Size - II - 2] = uint8_t(Inst >> I0 * CHAR_BIT);
521  Buffer[Size - II - 1] = uint8_t(Inst >> I1 * CHAR_BIT);
522  }
523 
524  break;
525  default:
526  llvm_unreachable("Invalid Suffix");
527  }
528 
529  MCELFStreamer::EmitBytes(StringRef(Buffer, Size));
530  }
531 
532  /// This is one of the functions used to emit data into an ELF section, so the
533  /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
534  /// necessary.
535  void EmitBytes(StringRef Data) override {
536  EmitDataMappingSymbol();
538  }
539 
540  void FlushPendingMappingSymbol() {
541  if (!LastEMSInfo->hasInfo())
542  return;
543  ElfMappingSymbolInfo *EMS = LastEMSInfo.get();
544  EmitMappingSymbol("$d", EMS->Loc, EMS->F, EMS->Offset);
545  EMS->resetInfo();
546  }
547 
548  /// This is one of the functions used to emit data into an ELF section, so the
549  /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
550  /// necessary.
551  void EmitValueImpl(const MCExpr *Value, unsigned Size, SMLoc Loc) override {
552  if (const MCSymbolRefExpr *SRE = dyn_cast_or_null<MCSymbolRefExpr>(Value)) {
553  if (SRE->getKind() == MCSymbolRefExpr::VK_ARM_SBREL && !(Size == 4)) {
554  getContext().reportError(Loc, "relocated expression must be 32-bit");
555  return;
556  }
557  getOrCreateDataFragment();
558  }
559 
560  EmitDataMappingSymbol();
561  MCELFStreamer::EmitValueImpl(Value, Size, Loc);
562  }
563 
564  void EmitAssemblerFlag(MCAssemblerFlag Flag) override {
566 
567  switch (Flag) {
568  case MCAF_SyntaxUnified:
569  return; // no-op here.
570  case MCAF_Code16:
571  IsThumb = true;
572  return; // Change to Thumb mode
573  case MCAF_Code32:
574  IsThumb = false;
575  return; // Change to ARM mode
576  case MCAF_Code64:
577  return;
579  return;
580  }
581  }
582 
583 private:
584  enum ElfMappingSymbol {
585  EMS_None,
586  EMS_ARM,
587  EMS_Thumb,
588  EMS_Data
589  };
590 
591  struct ElfMappingSymbolInfo {
592  explicit ElfMappingSymbolInfo(SMLoc Loc, MCFragment *F, uint64_t O)
593  : Loc(Loc), F(F), Offset(O), State(EMS_None) {}
594  void resetInfo() {
595  F = nullptr;
596  Offset = 0;
597  }
598  bool hasInfo() { return F != nullptr; }
599  SMLoc Loc;
600  MCFragment *F;
601  uint64_t Offset;
602  ElfMappingSymbol State;
603  };
604 
605  void EmitDataMappingSymbol() {
606  if (LastEMSInfo->State == EMS_Data)
607  return;
608  else if (LastEMSInfo->State == EMS_None) {
609  // This is a tentative symbol, it won't really be emitted until it's
610  // actually needed.
611  ElfMappingSymbolInfo *EMS = LastEMSInfo.get();
612  auto *DF = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
613  if (!DF)
614  return;
615  EMS->Loc = SMLoc();
616  EMS->F = getCurrentFragment();
617  EMS->Offset = DF->getContents().size();
618  LastEMSInfo->State = EMS_Data;
619  return;
620  }
621  EmitMappingSymbol("$d");
622  LastEMSInfo->State = EMS_Data;
623  }
624 
625  void EmitThumbMappingSymbol() {
626  if (LastEMSInfo->State == EMS_Thumb)
627  return;
628  FlushPendingMappingSymbol();
629  EmitMappingSymbol("$t");
630  LastEMSInfo->State = EMS_Thumb;
631  }
632 
633  void EmitARMMappingSymbol() {
634  if (LastEMSInfo->State == EMS_ARM)
635  return;
636  FlushPendingMappingSymbol();
637  EmitMappingSymbol("$a");
638  LastEMSInfo->State = EMS_ARM;
639  }
640 
641  void EmitMappingSymbol(StringRef Name) {
642  auto *Symbol = cast<MCSymbolELF>(getContext().getOrCreateSymbol(
643  Name + "." + Twine(MappingSymbolCounter++)));
644  EmitLabel(Symbol);
645 
646  Symbol->setType(ELF::STT_NOTYPE);
647  Symbol->setBinding(ELF::STB_LOCAL);
648  Symbol->setExternal(false);
649  }
650 
651  void EmitMappingSymbol(StringRef Name, SMLoc Loc, MCFragment *F,
652  uint64_t Offset) {
653  auto *Symbol = cast<MCSymbolELF>(getContext().getOrCreateSymbol(
654  Name + "." + Twine(MappingSymbolCounter++)));
655  EmitLabel(Symbol, Loc, F);
656  Symbol->setType(ELF::STT_NOTYPE);
657  Symbol->setBinding(ELF::STB_LOCAL);
658  Symbol->setExternal(false);
659  Symbol->setOffset(Offset);
660  }
661 
662  void EmitThumbFunc(MCSymbol *Func) override {
663  getAssembler().setIsThumbFunc(Func);
664  EmitSymbolAttribute(Func, MCSA_ELF_TypeFunction);
665  }
666 
667  // Helper functions for ARM exception handling directives
668  void EHReset();
669 
670  // Reset state between object emissions
671  void reset() override;
672 
673  void EmitPersonalityFixup(StringRef Name);
674  void FlushPendingOffset();
675  void FlushUnwindOpcodes(bool NoHandlerData);
676 
677  void SwitchToEHSection(StringRef Prefix, unsigned Type, unsigned Flags,
678  SectionKind Kind, const MCSymbol &Fn);
679  void SwitchToExTabSection(const MCSymbol &FnStart);
680  void SwitchToExIdxSection(const MCSymbol &FnStart);
681 
682  void EmitFixup(const MCExpr *Expr, MCFixupKind Kind);
683 
684  bool IsThumb;
685  int64_t MappingSymbolCounter = 0;
686 
688  LastMappingSymbols;
689 
690  std::unique_ptr<ElfMappingSymbolInfo> LastEMSInfo;
691 
692  // ARM Exception Handling Frame Information
693  MCSymbol *ExTab;
694  MCSymbol *FnStart;
695  const MCSymbol *Personality;
696  unsigned PersonalityIndex;
697  unsigned FPReg; // Frame pointer register
698  int64_t FPOffset; // Offset: (final frame pointer) - (initial $sp)
699  int64_t SPOffset; // Offset: (final $sp) - (initial $sp)
700  int64_t PendingOffset; // Offset: (final $sp) - (emitted $sp)
701  bool UsedFP;
702  bool CantUnwind;
703  SmallVector<uint8_t, 64> Opcodes;
704  UnwindOpcodeAssembler UnwindOpAsm;
705 };
706 
707 } // end anonymous namespace
708 
709 ARMELFStreamer &ARMTargetELFStreamer::getStreamer() {
710  return static_cast<ARMELFStreamer &>(Streamer);
711 }
712 
713 void ARMTargetELFStreamer::emitFnStart() { getStreamer().emitFnStart(); }
714 void ARMTargetELFStreamer::emitFnEnd() { getStreamer().emitFnEnd(); }
715 void ARMTargetELFStreamer::emitCantUnwind() { getStreamer().emitCantUnwind(); }
716 
717 void ARMTargetELFStreamer::emitPersonality(const MCSymbol *Personality) {
718  getStreamer().emitPersonality(Personality);
719 }
720 
721 void ARMTargetELFStreamer::emitPersonalityIndex(unsigned Index) {
722  getStreamer().emitPersonalityIndex(Index);
723 }
724 
725 void ARMTargetELFStreamer::emitHandlerData() {
726  getStreamer().emitHandlerData();
727 }
728 
729 void ARMTargetELFStreamer::emitSetFP(unsigned FpReg, unsigned SpReg,
730  int64_t Offset) {
731  getStreamer().emitSetFP(FpReg, SpReg, Offset);
732 }
733 
734 void ARMTargetELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
735  getStreamer().emitMovSP(Reg, Offset);
736 }
737 
738 void ARMTargetELFStreamer::emitPad(int64_t Offset) {
739  getStreamer().emitPad(Offset);
740 }
741 
742 void ARMTargetELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
743  bool isVector) {
744  getStreamer().emitRegSave(RegList, isVector);
745 }
746 
747 void ARMTargetELFStreamer::emitUnwindRaw(int64_t Offset,
748  const SmallVectorImpl<uint8_t> &Opcodes) {
749  getStreamer().emitUnwindRaw(Offset, Opcodes);
750 }
751 
752 void ARMTargetELFStreamer::switchVendor(StringRef Vendor) {
753  assert(!Vendor.empty() && "Vendor cannot be empty.");
754 
755  if (CurrentVendor == Vendor)
756  return;
757 
758  if (!CurrentVendor.empty())
759  finishAttributeSection();
760 
761  assert(Contents.empty() &&
762  ".ARM.attributes should be flushed before changing vendor");
763  CurrentVendor = Vendor;
764 
765 }
766 
767 void ARMTargetELFStreamer::emitAttribute(unsigned Attribute, unsigned Value) {
768  setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
769 }
770 
771 void ARMTargetELFStreamer::emitTextAttribute(unsigned Attribute,
772  StringRef Value) {
773  setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
774 }
775 
776 void ARMTargetELFStreamer::emitIntTextAttribute(unsigned Attribute,
777  unsigned IntValue,
778  StringRef StringValue) {
779  setAttributeItems(Attribute, IntValue, StringValue,
780  /* OverwriteExisting= */ true);
781 }
782 
783 void ARMTargetELFStreamer::emitArch(ARM::ArchKind Value) {
784  Arch = Value;
785 }
786 
787 void ARMTargetELFStreamer::emitObjectArch(ARM::ArchKind Value) {
788  EmittedArch = Value;
789 }
790 
791 void ARMTargetELFStreamer::emitArchDefaultAttributes() {
792  using namespace ARMBuildAttrs;
793 
794  setAttributeItem(CPU_name,
795  ARM::getCPUAttr(Arch),
796  false);
797 
798  if (EmittedArch == ARM::ArchKind::INVALID)
799  setAttributeItem(CPU_arch,
800  ARM::getArchAttr(Arch),
801  false);
802  else
803  setAttributeItem(CPU_arch,
804  ARM::getArchAttr(EmittedArch),
805  false);
806 
807  switch (Arch) {
808  case ARM::ArchKind::ARMV2:
809  case ARM::ArchKind::ARMV2A:
810  case ARM::ArchKind::ARMV3:
811  case ARM::ArchKind::ARMV3M:
812  case ARM::ArchKind::ARMV4:
813  setAttributeItem(ARM_ISA_use, Allowed, false);
814  break;
815 
816  case ARM::ArchKind::ARMV4T:
817  case ARM::ArchKind::ARMV5T:
818  case ARM::ArchKind::ARMV5TE:
819  case ARM::ArchKind::ARMV6:
820  setAttributeItem(ARM_ISA_use, Allowed, false);
821  setAttributeItem(THUMB_ISA_use, Allowed, false);
822  break;
823 
824  case ARM::ArchKind::ARMV6T2:
825  setAttributeItem(ARM_ISA_use, Allowed, false);
826  setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
827  break;
828 
829  case ARM::ArchKind::ARMV6K:
830  case ARM::ArchKind::ARMV6KZ:
831  setAttributeItem(ARM_ISA_use, Allowed, false);
832  setAttributeItem(THUMB_ISA_use, Allowed, false);
833  setAttributeItem(Virtualization_use, AllowTZ, false);
834  break;
835 
836  case ARM::ArchKind::ARMV6M:
837  setAttributeItem(THUMB_ISA_use, Allowed, false);
838  break;
839 
840  case ARM::ArchKind::ARMV7A:
841  setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
842  setAttributeItem(ARM_ISA_use, Allowed, false);
843  setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
844  break;
845 
846  case ARM::ArchKind::ARMV7R:
847  setAttributeItem(CPU_arch_profile, RealTimeProfile, false);
848  setAttributeItem(ARM_ISA_use, Allowed, false);
849  setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
850  break;
851 
852  case ARM::ArchKind::ARMV7EM:
853  case ARM::ArchKind::ARMV7M:
854  setAttributeItem(CPU_arch_profile, MicroControllerProfile, false);
855  setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
856  break;
857 
858  case ARM::ArchKind::ARMV8A:
859  case ARM::ArchKind::ARMV8_1A:
860  case ARM::ArchKind::ARMV8_2A:
861  setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
862  setAttributeItem(ARM_ISA_use, Allowed, false);
863  setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
864  setAttributeItem(MPextension_use, Allowed, false);
865  setAttributeItem(Virtualization_use, AllowTZVirtualization, false);
866  break;
867 
868  case ARM::ArchKind::ARMV8MBaseline:
869  case ARM::ArchKind::ARMV8MMainline:
870  setAttributeItem(THUMB_ISA_use, AllowThumbDerived, false);
871  setAttributeItem(CPU_arch_profile, MicroControllerProfile, false);
872  break;
873 
874  case ARM::ArchKind::IWMMXT:
875  setAttributeItem(ARM_ISA_use, Allowed, false);
876  setAttributeItem(THUMB_ISA_use, Allowed, false);
877  setAttributeItem(WMMX_arch, AllowWMMXv1, false);
878  break;
879 
880  case ARM::ArchKind::IWMMXT2:
881  setAttributeItem(ARM_ISA_use, Allowed, false);
882  setAttributeItem(THUMB_ISA_use, Allowed, false);
883  setAttributeItem(WMMX_arch, AllowWMMXv2, false);
884  break;
885 
886  default:
887  report_fatal_error("Unknown Arch: " + Twine(ARM::getArchName(Arch)));
888  break;
889  }
890 }
891 
892 void ARMTargetELFStreamer::emitFPU(unsigned Value) {
893  FPU = Value;
894 }
895 
896 void ARMTargetELFStreamer::emitFPUDefaultAttributes() {
897  switch (FPU) {
898  case ARM::FK_VFP:
899  case ARM::FK_VFPV2:
900  setAttributeItem(ARMBuildAttrs::FP_arch,
902  /* OverwriteExisting= */ false);
903  break;
904 
905  case ARM::FK_VFPV3:
906  setAttributeItem(ARMBuildAttrs::FP_arch,
908  /* OverwriteExisting= */ false);
909  break;
910 
911  case ARM::FK_VFPV3_FP16:
912  setAttributeItem(ARMBuildAttrs::FP_arch,
914  /* OverwriteExisting= */ false);
915  setAttributeItem(ARMBuildAttrs::FP_HP_extension,
917  /* OverwriteExisting= */ false);
918  break;
919 
920  case ARM::FK_VFPV3_D16:
921  setAttributeItem(ARMBuildAttrs::FP_arch,
923  /* OverwriteExisting= */ false);
924  break;
925 
926  case ARM::FK_VFPV3_D16_FP16:
927  setAttributeItem(ARMBuildAttrs::FP_arch,
929  /* OverwriteExisting= */ false);
930  setAttributeItem(ARMBuildAttrs::FP_HP_extension,
932  /* OverwriteExisting= */ false);
933  break;
934 
935  case ARM::FK_VFPV3XD:
936  setAttributeItem(ARMBuildAttrs::FP_arch,
938  /* OverwriteExisting= */ false);
939  break;
940  case ARM::FK_VFPV3XD_FP16:
941  setAttributeItem(ARMBuildAttrs::FP_arch,
943  /* OverwriteExisting= */ false);
944  setAttributeItem(ARMBuildAttrs::FP_HP_extension,
946  /* OverwriteExisting= */ false);
947  break;
948 
949  case ARM::FK_VFPV4:
950  setAttributeItem(ARMBuildAttrs::FP_arch,
952  /* OverwriteExisting= */ false);
953  break;
954 
955  // ABI_HardFP_use is handled in ARMAsmPrinter, so _SP_D16 is treated the same
956  // as _D16 here.
957  case ARM::FK_FPV4_SP_D16:
958  case ARM::FK_VFPV4_D16:
959  setAttributeItem(ARMBuildAttrs::FP_arch,
961  /* OverwriteExisting= */ false);
962  break;
963 
964  case ARM::FK_FP_ARMV8:
965  setAttributeItem(ARMBuildAttrs::FP_arch,
967  /* OverwriteExisting= */ false);
968  break;
969 
970  // FPV5_D16 is identical to FP_ARMV8 except for the number of D registers, so
971  // uses the FP_ARMV8_D16 build attribute.
972  case ARM::FK_FPV5_SP_D16:
973  case ARM::FK_FPV5_D16:
974  setAttributeItem(ARMBuildAttrs::FP_arch,
976  /* OverwriteExisting= */ false);
977  break;
978 
979  case ARM::FK_NEON:
980  setAttributeItem(ARMBuildAttrs::FP_arch,
982  /* OverwriteExisting= */ false);
983  setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
985  /* OverwriteExisting= */ false);
986  break;
987 
988  case ARM::FK_NEON_FP16:
989  setAttributeItem(ARMBuildAttrs::FP_arch,
991  /* OverwriteExisting= */ false);
992  setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
994  /* OverwriteExisting= */ false);
995  setAttributeItem(ARMBuildAttrs::FP_HP_extension,
997  /* OverwriteExisting= */ false);
998  break;
999 
1000  case ARM::FK_NEON_VFPV4:
1001  setAttributeItem(ARMBuildAttrs::FP_arch,
1003  /* OverwriteExisting= */ false);
1004  setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
1006  /* OverwriteExisting= */ false);
1007  break;
1008 
1009  case ARM::FK_NEON_FP_ARMV8:
1010  case ARM::FK_CRYPTO_NEON_FP_ARMV8:
1011  setAttributeItem(ARMBuildAttrs::FP_arch,
1013  /* OverwriteExisting= */ false);
1014  // 'Advanced_SIMD_arch' must be emitted not here, but within
1015  // ARMAsmPrinter::emitAttributes(), depending on hasV8Ops() and hasV8_1a()
1016  break;
1017 
1018  case ARM::FK_SOFTVFP:
1019  case ARM::FK_NONE:
1020  break;
1021 
1022  default:
1023  report_fatal_error("Unknown FPU: " + Twine(FPU));
1024  break;
1025  }
1026 }
1027 
1028 size_t ARMTargetELFStreamer::calculateContentSize() const {
1029  size_t Result = 0;
1030  for (size_t i = 0; i < Contents.size(); ++i) {
1031  AttributeItem item = Contents[i];
1032  switch (item.Type) {
1033  case AttributeItem::HiddenAttribute:
1034  break;
1035  case AttributeItem::NumericAttribute:
1036  Result += getULEB128Size(item.Tag);
1037  Result += getULEB128Size(item.IntValue);
1038  break;
1039  case AttributeItem::TextAttribute:
1040  Result += getULEB128Size(item.Tag);
1041  Result += item.StringValue.size() + 1; // string + '\0'
1042  break;
1043  case AttributeItem::NumericAndTextAttributes:
1044  Result += getULEB128Size(item.Tag);
1045  Result += getULEB128Size(item.IntValue);
1046  Result += item.StringValue.size() + 1; // string + '\0';
1047  break;
1048  }
1049  }
1050  return Result;
1051 }
1052 
1053 void ARMTargetELFStreamer::finishAttributeSection() {
1054  // <format-version>
1055  // [ <section-length> "vendor-name"
1056  // [ <file-tag> <size> <attribute>*
1057  // | <section-tag> <size> <section-number>* 0 <attribute>*
1058  // | <symbol-tag> <size> <symbol-number>* 0 <attribute>*
1059  // ]+
1060  // ]*
1061 
1062  if (FPU != ARM::FK_INVALID)
1063  emitFPUDefaultAttributes();
1064 
1065  if (Arch != ARM::ArchKind::INVALID)
1066  emitArchDefaultAttributes();
1067 
1068  if (Contents.empty())
1069  return;
1070 
1071  std::sort(Contents.begin(), Contents.end(), AttributeItem::LessTag);
1072 
1073  ARMELFStreamer &Streamer = getStreamer();
1074 
1075  // Switch to .ARM.attributes section
1076  if (AttributeSection) {
1077  Streamer.SwitchSection(AttributeSection);
1078  } else {
1079  AttributeSection = Streamer.getContext().getELFSection(
1080  ".ARM.attributes", ELF::SHT_ARM_ATTRIBUTES, 0);
1081  Streamer.SwitchSection(AttributeSection);
1082 
1083  // Format version
1084  Streamer.EmitIntValue(0x41, 1);
1085  }
1086 
1087  // Vendor size + Vendor name + '\0'
1088  const size_t VendorHeaderSize = 4 + CurrentVendor.size() + 1;
1089 
1090  // Tag + Tag Size
1091  const size_t TagHeaderSize = 1 + 4;
1092 
1093  const size_t ContentsSize = calculateContentSize();
1094 
1095  Streamer.EmitIntValue(VendorHeaderSize + TagHeaderSize + ContentsSize, 4);
1096  Streamer.EmitBytes(CurrentVendor);
1097  Streamer.EmitIntValue(0, 1); // '\0'
1098 
1099  Streamer.EmitIntValue(ARMBuildAttrs::File, 1);
1100  Streamer.EmitIntValue(TagHeaderSize + ContentsSize, 4);
1101 
1102  // Size should have been accounted for already, now
1103  // emit each field as its type (ULEB or String)
1104  for (size_t i = 0; i < Contents.size(); ++i) {
1105  AttributeItem item = Contents[i];
1106  Streamer.EmitULEB128IntValue(item.Tag);
1107  switch (item.Type) {
1108  default: llvm_unreachable("Invalid attribute type");
1109  case AttributeItem::NumericAttribute:
1110  Streamer.EmitULEB128IntValue(item.IntValue);
1111  break;
1112  case AttributeItem::TextAttribute:
1113  Streamer.EmitBytes(item.StringValue);
1114  Streamer.EmitIntValue(0, 1); // '\0'
1115  break;
1116  case AttributeItem::NumericAndTextAttributes:
1117  Streamer.EmitULEB128IntValue(item.IntValue);
1118  Streamer.EmitBytes(item.StringValue);
1119  Streamer.EmitIntValue(0, 1); // '\0'
1120  break;
1121  }
1122  }
1123 
1124  Contents.clear();
1125  FPU = ARM::FK_INVALID;
1126 }
1127 
1128 void ARMTargetELFStreamer::emitLabel(MCSymbol *Symbol) {
1129  ARMELFStreamer &Streamer = getStreamer();
1130  if (!Streamer.IsThumb)
1131  return;
1132 
1133  Streamer.getAssembler().registerSymbol(*Symbol);
1134  unsigned Type = cast<MCSymbolELF>(Symbol)->getType();
1135  if (Type == ELF::STT_FUNC || Type == ELF::STT_GNU_IFUNC)
1136  Streamer.EmitThumbFunc(Symbol);
1137 }
1138 
1139 void
1140 ARMTargetELFStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
1141  getStreamer().EmitFixup(S, FK_Data_4);
1142 }
1143 
1144 void ARMTargetELFStreamer::emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) {
1145  if (const MCSymbolRefExpr *SRE = dyn_cast<MCSymbolRefExpr>(Value)) {
1146  const MCSymbol &Sym = SRE->getSymbol();
1147  if (!Sym.isDefined()) {
1148  getStreamer().EmitAssignment(Symbol, Value);
1149  return;
1150  }
1151  }
1152 
1153  getStreamer().EmitThumbFunc(Symbol);
1154  getStreamer().EmitAssignment(Symbol, Value);
1155 }
1156 
1157 void ARMTargetELFStreamer::emitInst(uint32_t Inst, char Suffix) {
1158  getStreamer().emitInst(Inst, Suffix);
1159 }
1160 
1161 void ARMTargetELFStreamer::reset() { AttributeSection = nullptr; }
1162 
1163 void ARMELFStreamer::FinishImpl() {
1164  MCTargetStreamer &TS = *getTargetStreamer();
1165  ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
1166  ATS.finishAttributeSection();
1167 
1169 }
1170 
1171 void ARMELFStreamer::reset() {
1172  MCTargetStreamer &TS = *getTargetStreamer();
1173  ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
1174  ATS.reset();
1175  MappingSymbolCounter = 0;
1177  LastMappingSymbols.clear();
1178  LastEMSInfo.reset();
1179  // MCELFStreamer clear's the assembler's e_flags. However, for
1180  // arm we manually set the ABI version on streamer creation, so
1181  // do the same here
1182  getAssembler().setELFHeaderEFlags(ELF::EF_ARM_EABI_VER5);
1183 }
1184 
1185 inline void ARMELFStreamer::SwitchToEHSection(StringRef Prefix,
1186  unsigned Type,
1187  unsigned Flags,
1188  SectionKind Kind,
1189  const MCSymbol &Fn) {
1190  const MCSectionELF &FnSection =
1191  static_cast<const MCSectionELF &>(Fn.getSection());
1192 
1193  // Create the name for new section
1194  StringRef FnSecName(FnSection.getSectionName());
1195  SmallString<128> EHSecName(Prefix);
1196  if (FnSecName != ".text") {
1197  EHSecName += FnSecName;
1198  }
1199 
1200  // Get .ARM.extab or .ARM.exidx section
1201  const MCSymbolELF *Group = FnSection.getGroup();
1202  if (Group)
1203  Flags |= ELF::SHF_GROUP;
1204  MCSectionELF *EHSection = getContext().getELFSection(
1205  EHSecName, Type, Flags, 0, Group, FnSection.getUniqueID(),
1206  static_cast<const MCSymbolELF *>(&Fn));
1207 
1208  assert(EHSection && "Failed to get the required EH section");
1209 
1210  // Switch to .ARM.extab or .ARM.exidx section
1211  SwitchSection(EHSection);
1212  EmitCodeAlignment(4);
1213 }
1214 
1215 inline void ARMELFStreamer::SwitchToExTabSection(const MCSymbol &FnStart) {
1216  SwitchToEHSection(".ARM.extab", ELF::SHT_PROGBITS, ELF::SHF_ALLOC,
1217  SectionKind::getData(), FnStart);
1218 }
1219 
1220 inline void ARMELFStreamer::SwitchToExIdxSection(const MCSymbol &FnStart) {
1221  SwitchToEHSection(".ARM.exidx", ELF::SHT_ARM_EXIDX,
1223  SectionKind::getData(), FnStart);
1224 }
1225 
1226 void ARMELFStreamer::EmitFixup(const MCExpr *Expr, MCFixupKind Kind) {
1227  MCDataFragment *Frag = getOrCreateDataFragment();
1228  Frag->getFixups().push_back(MCFixup::create(Frag->getContents().size(), Expr,
1229  Kind));
1230 }
1231 
1232 void ARMELFStreamer::EHReset() {
1233  ExTab = nullptr;
1234  FnStart = nullptr;
1235  Personality = nullptr;
1236  PersonalityIndex = ARM::EHABI::NUM_PERSONALITY_INDEX;
1237  FPReg = ARM::SP;
1238  FPOffset = 0;
1239  SPOffset = 0;
1240  PendingOffset = 0;
1241  UsedFP = false;
1242  CantUnwind = false;
1243 
1244  Opcodes.clear();
1245  UnwindOpAsm.Reset();
1246 }
1247 
1248 void ARMELFStreamer::emitFnStart() {
1249  assert(FnStart == nullptr);
1250  FnStart = getContext().createTempSymbol();
1251  EmitLabel(FnStart);
1252 }
1253 
1254 void ARMELFStreamer::emitFnEnd() {
1255  assert(FnStart && ".fnstart must precedes .fnend");
1256 
1257  // Emit unwind opcodes if there is no .handlerdata directive
1258  if (!ExTab && !CantUnwind)
1259  FlushUnwindOpcodes(true);
1260 
1261  // Emit the exception index table entry
1262  SwitchToExIdxSection(*FnStart);
1263 
1264  if (PersonalityIndex < ARM::EHABI::NUM_PERSONALITY_INDEX)
1265  EmitPersonalityFixup(GetAEABIUnwindPersonalityName(PersonalityIndex));
1266 
1267  const MCSymbolRefExpr *FnStartRef =
1268  MCSymbolRefExpr::create(FnStart,
1270  getContext());
1271 
1272  EmitValue(FnStartRef, 4);
1273 
1274  if (CantUnwind) {
1275  EmitIntValue(ARM::EHABI::EXIDX_CANTUNWIND, 4);
1276  } else if (ExTab) {
1277  // Emit a reference to the unwind opcodes in the ".ARM.extab" section.
1278  const MCSymbolRefExpr *ExTabEntryRef =
1281  getContext());
1282  EmitValue(ExTabEntryRef, 4);
1283  } else {
1284  // For the __aeabi_unwind_cpp_pr0, we have to emit the unwind opcodes in
1285  // the second word of exception index table entry. The size of the unwind
1286  // opcodes should always be 4 bytes.
1287  assert(PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0 &&
1288  "Compact model must use __aeabi_unwind_cpp_pr0 as personality");
1289  assert(Opcodes.size() == 4u &&
1290  "Unwind opcode size for __aeabi_unwind_cpp_pr0 must be equal to 4");
1291  uint64_t Intval = Opcodes[0] |
1292  Opcodes[1] << 8 |
1293  Opcodes[2] << 16 |
1294  Opcodes[3] << 24;
1295  EmitIntValue(Intval, Opcodes.size());
1296  }
1297 
1298  // Switch to the section containing FnStart
1299  SwitchSection(&FnStart->getSection());
1300 
1301  // Clean exception handling frame information
1302  EHReset();
1303 }
1304 
1305 void ARMELFStreamer::emitCantUnwind() { CantUnwind = true; }
1306 
1307 // Add the R_ARM_NONE fixup at the same position
1308 void ARMELFStreamer::EmitPersonalityFixup(StringRef Name) {
1309  const MCSymbol *PersonalitySym = getContext().getOrCreateSymbol(Name);
1310 
1311  const MCSymbolRefExpr *PersonalityRef = MCSymbolRefExpr::create(
1312  PersonalitySym, MCSymbolRefExpr::VK_ARM_NONE, getContext());
1313 
1314  visitUsedExpr(*PersonalityRef);
1315  MCDataFragment *DF = getOrCreateDataFragment();
1316  DF->getFixups().push_back(MCFixup::create(DF->getContents().size(),
1317  PersonalityRef,
1318  MCFixup::getKindForSize(4, false)));
1319 }
1320 
1321 void ARMELFStreamer::FlushPendingOffset() {
1322  if (PendingOffset != 0) {
1323  UnwindOpAsm.EmitSPOffset(-PendingOffset);
1324  PendingOffset = 0;
1325  }
1326 }
1327 
1328 void ARMELFStreamer::FlushUnwindOpcodes(bool NoHandlerData) {
1329  // Emit the unwind opcode to restore $sp.
1330  if (UsedFP) {
1331  const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1332  int64_t LastRegSaveSPOffset = SPOffset - PendingOffset;
1333  UnwindOpAsm.EmitSPOffset(LastRegSaveSPOffset - FPOffset);
1334  UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1335  } else {
1336  FlushPendingOffset();
1337  }
1338 
1339  // Finalize the unwind opcode sequence
1340  UnwindOpAsm.Finalize(PersonalityIndex, Opcodes);
1341 
1342  // For compact model 0, we have to emit the unwind opcodes in the .ARM.exidx
1343  // section. Thus, we don't have to create an entry in the .ARM.extab
1344  // section.
1345  if (NoHandlerData && PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0)
1346  return;
1347 
1348  // Switch to .ARM.extab section.
1349  SwitchToExTabSection(*FnStart);
1350 
1351  // Create .ARM.extab label for offset in .ARM.exidx
1352  assert(!ExTab);
1353  ExTab = getContext().createTempSymbol();
1354  EmitLabel(ExTab);
1355 
1356  // Emit personality
1357  if (Personality) {
1358  const MCSymbolRefExpr *PersonalityRef =
1359  MCSymbolRefExpr::create(Personality,
1361  getContext());
1362 
1363  EmitValue(PersonalityRef, 4);
1364  }
1365 
1366  // Emit unwind opcodes
1367  assert((Opcodes.size() % 4) == 0 &&
1368  "Unwind opcode size for __aeabi_cpp_unwind_pr0 must be multiple of 4");
1369  for (unsigned I = 0; I != Opcodes.size(); I += 4) {
1370  uint64_t Intval = Opcodes[I] |
1371  Opcodes[I + 1] << 8 |
1372  Opcodes[I + 2] << 16 |
1373  Opcodes[I + 3] << 24;
1374  EmitIntValue(Intval, 4);
1375  }
1376 
1377  // According to ARM EHABI section 9.2, if the __aeabi_unwind_cpp_pr1() or
1378  // __aeabi_unwind_cpp_pr2() is used, then the handler data must be emitted
1379  // after the unwind opcodes. The handler data consists of several 32-bit
1380  // words, and should be terminated by zero.
1381  //
1382  // In case that the .handlerdata directive is not specified by the
1383  // programmer, we should emit zero to terminate the handler data.
1384  if (NoHandlerData && !Personality)
1385  EmitIntValue(0, 4);
1386 }
1387 
1388 void ARMELFStreamer::emitHandlerData() { FlushUnwindOpcodes(false); }
1389 
1390 void ARMELFStreamer::emitPersonality(const MCSymbol *Per) {
1391  Personality = Per;
1392  UnwindOpAsm.setPersonality(Per);
1393 }
1394 
1395 void ARMELFStreamer::emitPersonalityIndex(unsigned Index) {
1396  assert(Index < ARM::EHABI::NUM_PERSONALITY_INDEX && "invalid index");
1397  PersonalityIndex = Index;
1398 }
1399 
1400 void ARMELFStreamer::emitSetFP(unsigned NewFPReg, unsigned NewSPReg,
1401  int64_t Offset) {
1402  assert((NewSPReg == ARM::SP || NewSPReg == FPReg) &&
1403  "the operand of .setfp directive should be either $sp or $fp");
1404 
1405  UsedFP = true;
1406  FPReg = NewFPReg;
1407 
1408  if (NewSPReg == ARM::SP)
1409  FPOffset = SPOffset + Offset;
1410  else
1411  FPOffset += Offset;
1412 }
1413 
1414 void ARMELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
1415  assert((Reg != ARM::SP && Reg != ARM::PC) &&
1416  "the operand of .movsp cannot be either sp or pc");
1417  assert(FPReg == ARM::SP && "current FP must be SP");
1418 
1419  FlushPendingOffset();
1420 
1421  FPReg = Reg;
1422  FPOffset = SPOffset + Offset;
1423 
1424  const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1425  UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1426 }
1427 
1428 void ARMELFStreamer::emitPad(int64_t Offset) {
1429  // Track the change of the $sp offset
1430  SPOffset -= Offset;
1431 
1432  // To squash multiple .pad directives, we should delay the unwind opcode
1433  // until the .save, .vsave, .handlerdata, or .fnend directives.
1434  PendingOffset -= Offset;
1435 }
1436 
1437 void ARMELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
1438  bool IsVector) {
1439  // Collect the registers in the register list
1440  unsigned Count = 0;
1441  uint32_t Mask = 0;
1442  const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1443  for (size_t i = 0; i < RegList.size(); ++i) {
1444  unsigned Reg = MRI->getEncodingValue(RegList[i]);
1445  assert(Reg < (IsVector ? 32U : 16U) && "Register out of range");
1446  unsigned Bit = (1u << Reg);
1447  if ((Mask & Bit) == 0) {
1448  Mask |= Bit;
1449  ++Count;
1450  }
1451  }
1452 
1453  // Track the change the $sp offset: For the .save directive, the
1454  // corresponding push instruction will decrease the $sp by (4 * Count).
1455  // For the .vsave directive, the corresponding vpush instruction will
1456  // decrease $sp by (8 * Count).
1457  SPOffset -= Count * (IsVector ? 8 : 4);
1458 
1459  // Emit the opcode
1460  FlushPendingOffset();
1461  if (IsVector)
1462  UnwindOpAsm.EmitVFPRegSave(Mask);
1463  else
1464  UnwindOpAsm.EmitRegSave(Mask);
1465 }
1466 
1467 void ARMELFStreamer::emitUnwindRaw(int64_t Offset,
1468  const SmallVectorImpl<uint8_t> &Opcodes) {
1469  FlushPendingOffset();
1470  SPOffset = SPOffset - Offset;
1471  UnwindOpAsm.EmitRaw(Opcodes);
1472 }
1473 
1474 namespace llvm {
1475 
1478  MCInstPrinter *InstPrint,
1479  bool isVerboseAsm) {
1480  return new ARMTargetAsmStreamer(S, OS, *InstPrint, isVerboseAsm);
1481 }
1482 
1484  return new ARMTargetStreamer(S);
1485 }
1486 
1488  const MCSubtargetInfo &STI) {
1489  const Triple &TT = STI.getTargetTriple();
1490  if (TT.isOSBinFormatELF())
1491  return new ARMTargetELFStreamer(S);
1492  return new ARMTargetStreamer(S);
1493 }
1494 
1496  std::unique_ptr<MCAsmBackend> TAB,
1497  raw_pwrite_stream &OS,
1498  std::unique_ptr<MCCodeEmitter> Emitter,
1499  bool RelaxAll, bool IsThumb) {
1500  ARMELFStreamer *S = new ARMELFStreamer(Context, std::move(TAB), OS,
1501  std::move(Emitter), IsThumb);
1502  // FIXME: This should eventually end up somewhere else where more
1503  // intelligent flag decisions can be made. For now we are just maintaining
1504  // the status quo for ARM and setting EF_ARM_EABI_VER5 as the default.
1505  S->getAssembler().setELFHeaderEFlags(ELF::EF_ARM_EABI_VER5);
1506 
1507  if (RelaxAll)
1508  S->getAssembler().setRelaxAll(true);
1509  return S;
1510 }
1511 
1512 } // end namespace llvm
Instances of this class represent a uniqued identifier for a section in the current translation unit...
Definition: MCSection.h:39
static SectionKind getData()
Definition: SectionKind.h:202
void EmitBytes(StringRef Data) override
Emit the bytes in Data into the output.
LLVMContext & Context
static const MCSymbolRefExpr * create(const MCSymbol *Symbol, MCContext &Ctx)
Definition: MCExpr.h:313
LLVM_ATTRIBUTE_NORETURN void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
Definition: Error.cpp:115
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
void reset() override
state management
Definition: MCELFStreamer.h:32
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:42
LLVM_ATTRIBUTE_ALWAYS_INLINE size_type size() const
Definition: SmallVector.h:136
bool isOSBinFormatELF() const
Tests whether the OS uses the ELF binary format.
Definition: Triple.h:588
formatted_raw_ostream - A raw_ostream that wraps another one and keeps track of line and column posit...
Attribute
Attributes.
Definition: Dwarf.h:107
Target specific streamer interface.
Definition: MCStreamer.h:83
virtual void printRegName(raw_ostream &OS, unsigned RegNo) const
Print the assembler register name.
static MCFixupKind getKindForSize(unsigned Size, bool isPCRel)
Return the generic fixup kind for a value with the given size.
Definition: MCFixup.h:102
virtual void finishAttributeSection()
F(f)
StringRef getCPUAttr(ArchKind AK)
StringRef getArchExtName(unsigned ArchExtKind)
StringRef getFPUName(unsigned FPUKind)
virtual void reset()
Reset any state between object emissions, i.e.
const Triple & getTargetTriple() const
getTargetTriple - Return the target triple string.
void setExternal(bool Value) const
Definition: MCSymbol.h:392
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:81
StringRef getArchName(ArchKind AK)
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:36
Reg
All possible values of the reg field in the ModR/M byte.
Represent a reference to a symbol from inside an expression.
Definition: MCExpr.h:165
A four-byte fixup.
Definition: MCFixup.h:26
Context object for machine code objects.
Definition: MCContext.h:63
.code16 (X86) / .code 16 (ARM)
Definition: MCDirectives.h:51
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:133
void EmitValueImpl(const MCExpr *Value, unsigned Size, SMLoc Loc=SMLoc()) override
Emit the expression Value into the output as a native integer of the given Size bytes.
SmallVectorImpl< char > & getContents()
Definition: MCFragment.h:183
MCTargetStreamer * createARMTargetAsmStreamer(MCStreamer &S, formatted_raw_ostream &OS, MCInstPrinter *InstPrint, bool isVerboseAsm)
Instances of this class represent a single low-level machine instruction.
Definition: MCInst.h:159
Flag
These should be considered private to the implementation of the MCInstrDesc class.
Definition: MCInstrDesc.h:121
MCRegisterInfo base class - We assume that the target defines a static array of MCRegisterDesc object...
This class is intended to be used as a base class for asm properties and features specific to the tar...
Definition: MCAsmInfo.h:56
StringRef AttrTypeAsString(unsigned Attr, bool HasTagPrefix=true)
unsigned getUniqueID() const
Definition: MCSectionELF.h:87
void ChangeSection(MCSection *Section, const MCExpr *Subsection) override
Update streamer for a new active section.
MCTargetStreamer * createARMObjectTargetStreamer(MCStreamer &S, const MCSubtargetInfo &STI)
Streaming machine code generation interface.
Definition: MCStreamer.h:183
void print(raw_ostream &OS, const MCAsmInfo *MAI, bool InParens=false) const
Definition: MCExpr.cpp:40
unsigned const MachineRegisterInfo * MRI
const MCSymbolELF * getGroup() const
Definition: MCSectionELF.h:78
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
LLVM_ATTRIBUTE_ALWAYS_INLINE iterator begin()
Definition: SmallVector.h:116
MCFixupKind
Extensible enumeration to represent the type of a fixup.
Definition: MCFixup.h:23
SmallVectorImpl< MCFixup > & getFixups()
Definition: MCFragment.h:208
.subsections_via_symbols (MachO)
Definition: MCDirectives.h:50
SectionKind - This is a simple POD value that classifies the properties of a section.
Definition: SectionKind.h:23
void setOffset(uint64_t Value)
Definition: MCSymbol.h:325
static MCFixup create(uint32_t Offset, const MCExpr *Value, MCFixupKind Kind, SMLoc Loc=SMLoc())
Definition: MCFixup.h:82
static wasm::ValType getType(const TargetRegisterClass *RC)
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
Triple - Helper class for working with autoconf configuration names.
Definition: Triple.h:44
unsigned getULEB128Size(uint64_t Value)
Utility function to get the size of the ULEB128-encoded value.
Definition: LEB128.cpp:20
const MCSymbol & getSymbol() const
Definition: MCExpr.h:326
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:862
bool isVector(MCInstrInfo const &MCII, MCInst const &MCI)
static Twine utohexstr(const uint64_t &Val)
Definition: Twine.h:385
bool isDefined() const
isDefined - Check if this symbol is defined (i.e., it has an address).
Definition: MCSymbol.h:248
.syntax (ARM/ELF)
Definition: MCDirectives.h:49
MCSection & getSection() const
Get the section associated with a defined, non-absolute symbol.
Definition: MCSymbol.h:267
.code32 (X86) / .code 32 (ARM)
Definition: MCDirectives.h:52
.code64 (X86)
Definition: MCDirectives.h:53
LLVM_ATTRIBUTE_ALWAYS_INLINE iterator end()
Definition: SmallVector.h:120
This is an instance of a target assembly language printer that converts an MCInst to valid target ass...
Definition: MCInstPrinter.h:41
uint16_t getEncodingValue(unsigned RegNo) const
Returns the encoding for RegNo.
MCAssemblerFlag
Definition: MCDirectives.h:48
.type _foo, STT_FUNC # aka
Definition: MCDirectives.h:23
#define I(x, y, z)
Definition: MD5.cpp:58
MCSubtargetInfo - Generic base class for all target subtargets.
This represents a section on linux, lots of unix variants and some bare metal systems.
Definition: MCSectionELF.h:28
StringRef getName() const
getName - Get the symbol name.
Definition: MCSymbol.h:203
An abstract base class for streams implementations that also support a pwrite operation.
Definition: raw_ostream.h:337
const unsigned Kind
Fragment for data and encoded instructions.
Definition: MCFragment.h:226
LLVM_NODISCARD std::string lower() const
Definition: StringRef.cpp:108
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
MCTargetStreamer * createARMNullTargetStreamer(MCStreamer &S)
LLVM Value Representation.
Definition: Value.h:73
constexpr char Size[]
Key for Kernel::Arg::Metadata::mSize.
std::underlying_type< E >::type Mask()
Get a bitmask with 1s in all places up to the high-order bit of E&#39;s largest value.
Definition: BitmaskEnum.h:81
void EmitAssemblerFlag(MCAssemblerFlag Flag) override
Note in the output the specified Flag.
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
void sort(Policy policy, RandomAccessIterator Start, RandomAccessIterator End, const Comparator &Comp=Comparator())
Definition: Parallel.h:199
Special entry for the function never unwind.
Definition: ARMEHABI.h:36
static std::string GetAEABIUnwindPersonalityName(unsigned Index)
Represents a location in source code.
Definition: SMLoc.h:24
unsigned getArchAttr(ArchKind AK)
void FinishImpl() override
Streamer specific finalization.
MCELFStreamer * createARMELFStreamer(MCContext &Context, std::unique_ptr< MCAsmBackend > TAB, raw_pwrite_stream &OS, std::unique_ptr< MCCodeEmitter > Emitter, bool RelaxAll, bool IsThumb)
StringRef getSectionName() const
Definition: MCSectionELF.h:73
void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI, bool=false) override
Emit the given Instruction into the current section.
void print(raw_ostream &OS, const MCAsmInfo *MAI) const
print - Print the value to the stream OS.
Definition: MCSymbol.cpp:59