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ARMELFStreamer.cpp
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1 //===- lib/MC/ARMELFStreamer.cpp - ELF Object Output for ARM --------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file assembles .s files and emits ARM ELF .o object files. Different
10 // from generic ELF streamer in emitting mapping symbols ($a, $t and $d) to
11 // delimit regions of data and code.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "ARMRegisterInfo.h"
16 #include "ARMUnwindOpAsm.h"
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/SmallString.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/ADT/StringRef.h"
21 #include "llvm/ADT/Triple.h"
22 #include "llvm/ADT/Twine.h"
23 #include "llvm/BinaryFormat/ELF.h"
24 #include "llvm/MC/MCAsmBackend.h"
25 #include "llvm/MC/MCAsmInfo.h"
26 #include "llvm/MC/MCAssembler.h"
27 #include "llvm/MC/MCCodeEmitter.h"
28 #include "llvm/MC/MCContext.h"
29 #include "llvm/MC/MCELFStreamer.h"
30 #include "llvm/MC/MCExpr.h"
31 #include "llvm/MC/MCFixup.h"
32 #include "llvm/MC/MCFragment.h"
33 #include "llvm/MC/MCInst.h"
34 #include "llvm/MC/MCInstPrinter.h"
35 #include "llvm/MC/MCObjectWriter.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  std::unique_ptr<MCObjectWriter> OW, std::unique_ptr<MCCodeEmitter> Emitter,
445  bool IsThumb)
446  : MCELFStreamer(Context, std::move(TAB), std::move(OW), 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  void emitFill(const MCExpr &NumBytes, uint64_t FillValue,
468  SMLoc Loc) override {
469  EmitDataMappingSymbol();
470  MCObjectStreamer::emitFill(NumBytes, FillValue, Loc);
471  }
472 
473  void ChangeSection(MCSection *Section, const MCExpr *Subsection) override {
474  LastMappingSymbols[getCurrentSection().first] = std::move(LastEMSInfo);
475  MCELFStreamer::ChangeSection(Section, Subsection);
476  auto LastMappingSymbol = LastMappingSymbols.find(Section);
477  if (LastMappingSymbol != LastMappingSymbols.end()) {
478  LastEMSInfo = std::move(LastMappingSymbol->second);
479  return;
480  }
481  LastEMSInfo.reset(new ElfMappingSymbolInfo(SMLoc(), nullptr, 0));
482  }
483 
484  /// This function is the one used to emit instruction data into the ELF
485  /// streamer. We override it to add the appropriate mapping symbol if
486  /// necessary.
487  void EmitInstruction(const MCInst &Inst,
488  const MCSubtargetInfo &STI) override {
489  if (IsThumb)
490  EmitThumbMappingSymbol();
491  else
492  EmitARMMappingSymbol();
493 
495  }
496 
497  void emitInst(uint32_t Inst, char Suffix) {
498  unsigned Size;
499  char Buffer[4];
500  const bool LittleEndian = getContext().getAsmInfo()->isLittleEndian();
501 
502  switch (Suffix) {
503  case '\0':
504  Size = 4;
505 
506  assert(!IsThumb);
507  EmitARMMappingSymbol();
508  for (unsigned II = 0, IE = Size; II != IE; II++) {
509  const unsigned I = LittleEndian ? (Size - II - 1) : II;
510  Buffer[Size - II - 1] = uint8_t(Inst >> I * CHAR_BIT);
511  }
512 
513  break;
514  case 'n':
515  case 'w':
516  Size = (Suffix == 'n' ? 2 : 4);
517 
518  assert(IsThumb);
519  EmitThumbMappingSymbol();
520  // Thumb wide instructions are emitted as a pair of 16-bit words of the
521  // appropriate endianness.
522  for (unsigned II = 0, IE = Size; II != IE; II = II + 2) {
523  const unsigned I0 = LittleEndian ? II + 0 : II + 1;
524  const unsigned I1 = LittleEndian ? II + 1 : II + 0;
525  Buffer[Size - II - 2] = uint8_t(Inst >> I0 * CHAR_BIT);
526  Buffer[Size - II - 1] = uint8_t(Inst >> I1 * CHAR_BIT);
527  }
528 
529  break;
530  default:
531  llvm_unreachable("Invalid Suffix");
532  }
533 
534  MCELFStreamer::EmitBytes(StringRef(Buffer, Size));
535  }
536 
537  /// This is one of the functions used to emit data into an ELF section, so the
538  /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
539  /// necessary.
540  void EmitBytes(StringRef Data) override {
541  EmitDataMappingSymbol();
543  }
544 
545  void FlushPendingMappingSymbol() {
546  if (!LastEMSInfo->hasInfo())
547  return;
548  ElfMappingSymbolInfo *EMS = LastEMSInfo.get();
549  EmitMappingSymbol("$d", EMS->Loc, EMS->F, EMS->Offset);
550  EMS->resetInfo();
551  }
552 
553  /// This is one of the functions used to emit data into an ELF section, so the
554  /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
555  /// necessary.
556  void EmitValueImpl(const MCExpr *Value, unsigned Size, SMLoc Loc) override {
557  if (const MCSymbolRefExpr *SRE = dyn_cast_or_null<MCSymbolRefExpr>(Value)) {
558  if (SRE->getKind() == MCSymbolRefExpr::VK_ARM_SBREL && !(Size == 4)) {
559  getContext().reportError(Loc, "relocated expression must be 32-bit");
560  return;
561  }
562  getOrCreateDataFragment();
563  }
564 
565  EmitDataMappingSymbol();
566  MCELFStreamer::EmitValueImpl(Value, Size, Loc);
567  }
568 
569  void EmitAssemblerFlag(MCAssemblerFlag Flag) override {
571 
572  switch (Flag) {
573  case MCAF_SyntaxUnified:
574  return; // no-op here.
575  case MCAF_Code16:
576  IsThumb = true;
577  return; // Change to Thumb mode
578  case MCAF_Code32:
579  IsThumb = false;
580  return; // Change to ARM mode
581  case MCAF_Code64:
582  return;
584  return;
585  }
586  }
587 
588 private:
589  enum ElfMappingSymbol {
590  EMS_None,
591  EMS_ARM,
592  EMS_Thumb,
593  EMS_Data
594  };
595 
596  struct ElfMappingSymbolInfo {
597  explicit ElfMappingSymbolInfo(SMLoc Loc, MCFragment *F, uint64_t O)
598  : Loc(Loc), F(F), Offset(O), State(EMS_None) {}
599  void resetInfo() {
600  F = nullptr;
601  Offset = 0;
602  }
603  bool hasInfo() { return F != nullptr; }
604  SMLoc Loc;
605  MCFragment *F;
606  uint64_t Offset;
607  ElfMappingSymbol State;
608  };
609 
610  void EmitDataMappingSymbol() {
611  if (LastEMSInfo->State == EMS_Data)
612  return;
613  else if (LastEMSInfo->State == EMS_None) {
614  // This is a tentative symbol, it won't really be emitted until it's
615  // actually needed.
616  ElfMappingSymbolInfo *EMS = LastEMSInfo.get();
617  auto *DF = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
618  if (!DF)
619  return;
620  EMS->Loc = SMLoc();
621  EMS->F = getCurrentFragment();
622  EMS->Offset = DF->getContents().size();
623  LastEMSInfo->State = EMS_Data;
624  return;
625  }
626  EmitMappingSymbol("$d");
627  LastEMSInfo->State = EMS_Data;
628  }
629 
630  void EmitThumbMappingSymbol() {
631  if (LastEMSInfo->State == EMS_Thumb)
632  return;
633  FlushPendingMappingSymbol();
634  EmitMappingSymbol("$t");
635  LastEMSInfo->State = EMS_Thumb;
636  }
637 
638  void EmitARMMappingSymbol() {
639  if (LastEMSInfo->State == EMS_ARM)
640  return;
641  FlushPendingMappingSymbol();
642  EmitMappingSymbol("$a");
643  LastEMSInfo->State = EMS_ARM;
644  }
645 
646  void EmitMappingSymbol(StringRef Name) {
647  auto *Symbol = cast<MCSymbolELF>(getContext().getOrCreateSymbol(
648  Name + "." + Twine(MappingSymbolCounter++)));
649  EmitLabel(Symbol);
650 
651  Symbol->setType(ELF::STT_NOTYPE);
652  Symbol->setBinding(ELF::STB_LOCAL);
653  Symbol->setExternal(false);
654  }
655 
656  void EmitMappingSymbol(StringRef Name, SMLoc Loc, MCFragment *F,
657  uint64_t Offset) {
658  auto *Symbol = cast<MCSymbolELF>(getContext().getOrCreateSymbol(
659  Name + "." + Twine(MappingSymbolCounter++)));
660  EmitLabel(Symbol, Loc, F);
661  Symbol->setType(ELF::STT_NOTYPE);
662  Symbol->setBinding(ELF::STB_LOCAL);
663  Symbol->setExternal(false);
664  Symbol->setOffset(Offset);
665  }
666 
667  void EmitThumbFunc(MCSymbol *Func) override {
668  getAssembler().setIsThumbFunc(Func);
669  EmitSymbolAttribute(Func, MCSA_ELF_TypeFunction);
670  }
671 
672  // Helper functions for ARM exception handling directives
673  void EHReset();
674 
675  // Reset state between object emissions
676  void reset() override;
677 
678  void EmitPersonalityFixup(StringRef Name);
679  void FlushPendingOffset();
680  void FlushUnwindOpcodes(bool NoHandlerData);
681 
682  void SwitchToEHSection(StringRef Prefix, unsigned Type, unsigned Flags,
683  SectionKind Kind, const MCSymbol &Fn);
684  void SwitchToExTabSection(const MCSymbol &FnStart);
685  void SwitchToExIdxSection(const MCSymbol &FnStart);
686 
687  void EmitFixup(const MCExpr *Expr, MCFixupKind Kind);
688 
689  bool IsThumb;
690  int64_t MappingSymbolCounter = 0;
691 
693  LastMappingSymbols;
694 
695  std::unique_ptr<ElfMappingSymbolInfo> LastEMSInfo;
696 
697  // ARM Exception Handling Frame Information
698  MCSymbol *ExTab;
699  MCSymbol *FnStart;
700  const MCSymbol *Personality;
701  unsigned PersonalityIndex;
702  unsigned FPReg; // Frame pointer register
703  int64_t FPOffset; // Offset: (final frame pointer) - (initial $sp)
704  int64_t SPOffset; // Offset: (final $sp) - (initial $sp)
705  int64_t PendingOffset; // Offset: (final $sp) - (emitted $sp)
706  bool UsedFP;
707  bool CantUnwind;
708  SmallVector<uint8_t, 64> Opcodes;
709  UnwindOpcodeAssembler UnwindOpAsm;
710 };
711 
712 } // end anonymous namespace
713 
714 ARMELFStreamer &ARMTargetELFStreamer::getStreamer() {
715  return static_cast<ARMELFStreamer &>(Streamer);
716 }
717 
718 void ARMTargetELFStreamer::emitFnStart() { getStreamer().emitFnStart(); }
719 void ARMTargetELFStreamer::emitFnEnd() { getStreamer().emitFnEnd(); }
720 void ARMTargetELFStreamer::emitCantUnwind() { getStreamer().emitCantUnwind(); }
721 
722 void ARMTargetELFStreamer::emitPersonality(const MCSymbol *Personality) {
723  getStreamer().emitPersonality(Personality);
724 }
725 
726 void ARMTargetELFStreamer::emitPersonalityIndex(unsigned Index) {
727  getStreamer().emitPersonalityIndex(Index);
728 }
729 
730 void ARMTargetELFStreamer::emitHandlerData() {
731  getStreamer().emitHandlerData();
732 }
733 
734 void ARMTargetELFStreamer::emitSetFP(unsigned FpReg, unsigned SpReg,
735  int64_t Offset) {
736  getStreamer().emitSetFP(FpReg, SpReg, Offset);
737 }
738 
739 void ARMTargetELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
740  getStreamer().emitMovSP(Reg, Offset);
741 }
742 
743 void ARMTargetELFStreamer::emitPad(int64_t Offset) {
744  getStreamer().emitPad(Offset);
745 }
746 
747 void ARMTargetELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
748  bool isVector) {
749  getStreamer().emitRegSave(RegList, isVector);
750 }
751 
752 void ARMTargetELFStreamer::emitUnwindRaw(int64_t Offset,
753  const SmallVectorImpl<uint8_t> &Opcodes) {
754  getStreamer().emitUnwindRaw(Offset, Opcodes);
755 }
756 
757 void ARMTargetELFStreamer::switchVendor(StringRef Vendor) {
758  assert(!Vendor.empty() && "Vendor cannot be empty.");
759 
760  if (CurrentVendor == Vendor)
761  return;
762 
763  if (!CurrentVendor.empty())
764  finishAttributeSection();
765 
766  assert(Contents.empty() &&
767  ".ARM.attributes should be flushed before changing vendor");
768  CurrentVendor = Vendor;
769 
770 }
771 
772 void ARMTargetELFStreamer::emitAttribute(unsigned Attribute, unsigned Value) {
773  setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
774 }
775 
776 void ARMTargetELFStreamer::emitTextAttribute(unsigned Attribute,
777  StringRef Value) {
778  setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
779 }
780 
781 void ARMTargetELFStreamer::emitIntTextAttribute(unsigned Attribute,
782  unsigned IntValue,
783  StringRef StringValue) {
784  setAttributeItems(Attribute, IntValue, StringValue,
785  /* OverwriteExisting= */ true);
786 }
787 
788 void ARMTargetELFStreamer::emitArch(ARM::ArchKind Value) {
789  Arch = Value;
790 }
791 
792 void ARMTargetELFStreamer::emitObjectArch(ARM::ArchKind Value) {
793  EmittedArch = Value;
794 }
795 
796 void ARMTargetELFStreamer::emitArchDefaultAttributes() {
797  using namespace ARMBuildAttrs;
798 
799  setAttributeItem(CPU_name,
800  ARM::getCPUAttr(Arch),
801  false);
802 
803  if (EmittedArch == ARM::ArchKind::INVALID)
804  setAttributeItem(CPU_arch,
805  ARM::getArchAttr(Arch),
806  false);
807  else
808  setAttributeItem(CPU_arch,
809  ARM::getArchAttr(EmittedArch),
810  false);
811 
812  switch (Arch) {
813  case ARM::ArchKind::ARMV2:
814  case ARM::ArchKind::ARMV2A:
815  case ARM::ArchKind::ARMV3:
816  case ARM::ArchKind::ARMV3M:
817  case ARM::ArchKind::ARMV4:
818  setAttributeItem(ARM_ISA_use, Allowed, false);
819  break;
820 
821  case ARM::ArchKind::ARMV4T:
822  case ARM::ArchKind::ARMV5T:
823  case ARM::ArchKind::ARMV5TE:
824  case ARM::ArchKind::ARMV6:
825  setAttributeItem(ARM_ISA_use, Allowed, false);
826  setAttributeItem(THUMB_ISA_use, Allowed, false);
827  break;
828 
829  case ARM::ArchKind::ARMV6T2:
830  setAttributeItem(ARM_ISA_use, Allowed, false);
831  setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
832  break;
833 
834  case ARM::ArchKind::ARMV6K:
835  case ARM::ArchKind::ARMV6KZ:
836  setAttributeItem(ARM_ISA_use, Allowed, false);
837  setAttributeItem(THUMB_ISA_use, Allowed, false);
838  setAttributeItem(Virtualization_use, AllowTZ, false);
839  break;
840 
841  case ARM::ArchKind::ARMV6M:
842  setAttributeItem(THUMB_ISA_use, Allowed, false);
843  break;
844 
845  case ARM::ArchKind::ARMV7A:
846  setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
847  setAttributeItem(ARM_ISA_use, Allowed, false);
848  setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
849  break;
850 
851  case ARM::ArchKind::ARMV7R:
852  setAttributeItem(CPU_arch_profile, RealTimeProfile, false);
853  setAttributeItem(ARM_ISA_use, Allowed, false);
854  setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
855  break;
856 
857  case ARM::ArchKind::ARMV7EM:
858  case ARM::ArchKind::ARMV7M:
859  setAttributeItem(CPU_arch_profile, MicroControllerProfile, false);
860  setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
861  break;
862 
863  case ARM::ArchKind::ARMV8A:
864  case ARM::ArchKind::ARMV8_1A:
865  case ARM::ArchKind::ARMV8_2A:
866  case ARM::ArchKind::ARMV8_3A:
867  case ARM::ArchKind::ARMV8_4A:
868  case ARM::ArchKind::ARMV8_5A:
869  setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
870  setAttributeItem(ARM_ISA_use, Allowed, false);
871  setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
872  setAttributeItem(MPextension_use, Allowed, false);
873  setAttributeItem(Virtualization_use, AllowTZVirtualization, false);
874  break;
875 
876  case ARM::ArchKind::ARMV8MBaseline:
877  case ARM::ArchKind::ARMV8MMainline:
878  setAttributeItem(THUMB_ISA_use, AllowThumbDerived, false);
879  setAttributeItem(CPU_arch_profile, MicroControllerProfile, false);
880  break;
881 
882  case ARM::ArchKind::IWMMXT:
883  setAttributeItem(ARM_ISA_use, Allowed, false);
884  setAttributeItem(THUMB_ISA_use, Allowed, false);
885  setAttributeItem(WMMX_arch, AllowWMMXv1, false);
886  break;
887 
888  case ARM::ArchKind::IWMMXT2:
889  setAttributeItem(ARM_ISA_use, Allowed, false);
890  setAttributeItem(THUMB_ISA_use, Allowed, false);
891  setAttributeItem(WMMX_arch, AllowWMMXv2, false);
892  break;
893 
894  default:
895  report_fatal_error("Unknown Arch: " + Twine(ARM::getArchName(Arch)));
896  break;
897  }
898 }
899 
900 void ARMTargetELFStreamer::emitFPU(unsigned Value) {
901  FPU = Value;
902 }
903 
904 void ARMTargetELFStreamer::emitFPUDefaultAttributes() {
905  switch (FPU) {
906  case ARM::FK_VFP:
907  case ARM::FK_VFPV2:
908  setAttributeItem(ARMBuildAttrs::FP_arch,
910  /* OverwriteExisting= */ false);
911  break;
912 
913  case ARM::FK_VFPV3:
914  setAttributeItem(ARMBuildAttrs::FP_arch,
916  /* OverwriteExisting= */ false);
917  break;
918 
919  case ARM::FK_VFPV3_FP16:
920  setAttributeItem(ARMBuildAttrs::FP_arch,
922  /* OverwriteExisting= */ false);
923  setAttributeItem(ARMBuildAttrs::FP_HP_extension,
925  /* OverwriteExisting= */ false);
926  break;
927 
928  case ARM::FK_VFPV3_D16:
929  setAttributeItem(ARMBuildAttrs::FP_arch,
931  /* OverwriteExisting= */ false);
932  break;
933 
934  case ARM::FK_VFPV3_D16_FP16:
935  setAttributeItem(ARMBuildAttrs::FP_arch,
937  /* OverwriteExisting= */ false);
938  setAttributeItem(ARMBuildAttrs::FP_HP_extension,
940  /* OverwriteExisting= */ false);
941  break;
942 
943  case ARM::FK_VFPV3XD:
944  setAttributeItem(ARMBuildAttrs::FP_arch,
946  /* OverwriteExisting= */ false);
947  break;
948  case ARM::FK_VFPV3XD_FP16:
949  setAttributeItem(ARMBuildAttrs::FP_arch,
951  /* OverwriteExisting= */ false);
952  setAttributeItem(ARMBuildAttrs::FP_HP_extension,
954  /* OverwriteExisting= */ false);
955  break;
956 
957  case ARM::FK_VFPV4:
958  setAttributeItem(ARMBuildAttrs::FP_arch,
960  /* OverwriteExisting= */ false);
961  break;
962 
963  // ABI_HardFP_use is handled in ARMAsmPrinter, so _SP_D16 is treated the same
964  // as _D16 here.
965  case ARM::FK_FPV4_SP_D16:
966  case ARM::FK_VFPV4_D16:
967  setAttributeItem(ARMBuildAttrs::FP_arch,
969  /* OverwriteExisting= */ false);
970  break;
971 
972  case ARM::FK_FP_ARMV8:
973  setAttributeItem(ARMBuildAttrs::FP_arch,
975  /* OverwriteExisting= */ false);
976  break;
977 
978  // FPV5_D16 is identical to FP_ARMV8 except for the number of D registers, so
979  // uses the FP_ARMV8_D16 build attribute.
980  case ARM::FK_FPV5_SP_D16:
981  case ARM::FK_FPV5_D16:
982  setAttributeItem(ARMBuildAttrs::FP_arch,
984  /* OverwriteExisting= */ false);
985  break;
986 
987  case ARM::FK_NEON:
988  setAttributeItem(ARMBuildAttrs::FP_arch,
990  /* OverwriteExisting= */ false);
991  setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
993  /* OverwriteExisting= */ false);
994  break;
995 
996  case ARM::FK_NEON_FP16:
997  setAttributeItem(ARMBuildAttrs::FP_arch,
999  /* OverwriteExisting= */ false);
1000  setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
1002  /* OverwriteExisting= */ false);
1003  setAttributeItem(ARMBuildAttrs::FP_HP_extension,
1005  /* OverwriteExisting= */ false);
1006  break;
1007 
1008  case ARM::FK_NEON_VFPV4:
1009  setAttributeItem(ARMBuildAttrs::FP_arch,
1011  /* OverwriteExisting= */ false);
1012  setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
1014  /* OverwriteExisting= */ false);
1015  break;
1016 
1017  case ARM::FK_NEON_FP_ARMV8:
1018  case ARM::FK_CRYPTO_NEON_FP_ARMV8:
1019  setAttributeItem(ARMBuildAttrs::FP_arch,
1021  /* OverwriteExisting= */ false);
1022  // 'Advanced_SIMD_arch' must be emitted not here, but within
1023  // ARMAsmPrinter::emitAttributes(), depending on hasV8Ops() and hasV8_1a()
1024  break;
1025 
1026  case ARM::FK_SOFTVFP:
1027  case ARM::FK_NONE:
1028  break;
1029 
1030  default:
1031  report_fatal_error("Unknown FPU: " + Twine(FPU));
1032  break;
1033  }
1034 }
1035 
1036 size_t ARMTargetELFStreamer::calculateContentSize() const {
1037  size_t Result = 0;
1038  for (size_t i = 0; i < Contents.size(); ++i) {
1039  AttributeItem item = Contents[i];
1040  switch (item.Type) {
1041  case AttributeItem::HiddenAttribute:
1042  break;
1043  case AttributeItem::NumericAttribute:
1044  Result += getULEB128Size(item.Tag);
1045  Result += getULEB128Size(item.IntValue);
1046  break;
1047  case AttributeItem::TextAttribute:
1048  Result += getULEB128Size(item.Tag);
1049  Result += item.StringValue.size() + 1; // string + '\0'
1050  break;
1051  case AttributeItem::NumericAndTextAttributes:
1052  Result += getULEB128Size(item.Tag);
1053  Result += getULEB128Size(item.IntValue);
1054  Result += item.StringValue.size() + 1; // string + '\0';
1055  break;
1056  }
1057  }
1058  return Result;
1059 }
1060 
1061 void ARMTargetELFStreamer::finishAttributeSection() {
1062  // <format-version>
1063  // [ <section-length> "vendor-name"
1064  // [ <file-tag> <size> <attribute>*
1065  // | <section-tag> <size> <section-number>* 0 <attribute>*
1066  // | <symbol-tag> <size> <symbol-number>* 0 <attribute>*
1067  // ]+
1068  // ]*
1069 
1070  if (FPU != ARM::FK_INVALID)
1071  emitFPUDefaultAttributes();
1072 
1073  if (Arch != ARM::ArchKind::INVALID)
1074  emitArchDefaultAttributes();
1075 
1076  if (Contents.empty())
1077  return;
1078 
1079  llvm::sort(Contents, AttributeItem::LessTag);
1080 
1081  ARMELFStreamer &Streamer = getStreamer();
1082 
1083  // Switch to .ARM.attributes section
1084  if (AttributeSection) {
1085  Streamer.SwitchSection(AttributeSection);
1086  } else {
1087  AttributeSection = Streamer.getContext().getELFSection(
1088  ".ARM.attributes", ELF::SHT_ARM_ATTRIBUTES, 0);
1089  Streamer.SwitchSection(AttributeSection);
1090 
1091  // Format version
1092  Streamer.EmitIntValue(0x41, 1);
1093  }
1094 
1095  // Vendor size + Vendor name + '\0'
1096  const size_t VendorHeaderSize = 4 + CurrentVendor.size() + 1;
1097 
1098  // Tag + Tag Size
1099  const size_t TagHeaderSize = 1 + 4;
1100 
1101  const size_t ContentsSize = calculateContentSize();
1102 
1103  Streamer.EmitIntValue(VendorHeaderSize + TagHeaderSize + ContentsSize, 4);
1104  Streamer.EmitBytes(CurrentVendor);
1105  Streamer.EmitIntValue(0, 1); // '\0'
1106 
1107  Streamer.EmitIntValue(ARMBuildAttrs::File, 1);
1108  Streamer.EmitIntValue(TagHeaderSize + ContentsSize, 4);
1109 
1110  // Size should have been accounted for already, now
1111  // emit each field as its type (ULEB or String)
1112  for (size_t i = 0; i < Contents.size(); ++i) {
1113  AttributeItem item = Contents[i];
1114  Streamer.EmitULEB128IntValue(item.Tag);
1115  switch (item.Type) {
1116  default: llvm_unreachable("Invalid attribute type");
1117  case AttributeItem::NumericAttribute:
1118  Streamer.EmitULEB128IntValue(item.IntValue);
1119  break;
1120  case AttributeItem::TextAttribute:
1121  Streamer.EmitBytes(item.StringValue);
1122  Streamer.EmitIntValue(0, 1); // '\0'
1123  break;
1124  case AttributeItem::NumericAndTextAttributes:
1125  Streamer.EmitULEB128IntValue(item.IntValue);
1126  Streamer.EmitBytes(item.StringValue);
1127  Streamer.EmitIntValue(0, 1); // '\0'
1128  break;
1129  }
1130  }
1131 
1132  Contents.clear();
1133  FPU = ARM::FK_INVALID;
1134 }
1135 
1136 void ARMTargetELFStreamer::emitLabel(MCSymbol *Symbol) {
1137  ARMELFStreamer &Streamer = getStreamer();
1138  if (!Streamer.IsThumb)
1139  return;
1140 
1141  Streamer.getAssembler().registerSymbol(*Symbol);
1142  unsigned Type = cast<MCSymbolELF>(Symbol)->getType();
1143  if (Type == ELF::STT_FUNC || Type == ELF::STT_GNU_IFUNC)
1144  Streamer.EmitThumbFunc(Symbol);
1145 }
1146 
1147 void
1148 ARMTargetELFStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
1149  getStreamer().EmitFixup(S, FK_Data_4);
1150 }
1151 
1152 void ARMTargetELFStreamer::emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) {
1153  if (const MCSymbolRefExpr *SRE = dyn_cast<MCSymbolRefExpr>(Value)) {
1154  const MCSymbol &Sym = SRE->getSymbol();
1155  if (!Sym.isDefined()) {
1156  getStreamer().EmitAssignment(Symbol, Value);
1157  return;
1158  }
1159  }
1160 
1161  getStreamer().EmitThumbFunc(Symbol);
1162  getStreamer().EmitAssignment(Symbol, Value);
1163 }
1164 
1165 void ARMTargetELFStreamer::emitInst(uint32_t Inst, char Suffix) {
1166  getStreamer().emitInst(Inst, Suffix);
1167 }
1168 
1169 void ARMTargetELFStreamer::reset() { AttributeSection = nullptr; }
1170 
1171 void ARMELFStreamer::FinishImpl() {
1172  MCTargetStreamer &TS = *getTargetStreamer();
1173  ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
1174  ATS.finishAttributeSection();
1175 
1177 }
1178 
1179 void ARMELFStreamer::reset() {
1180  MCTargetStreamer &TS = *getTargetStreamer();
1181  ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
1182  ATS.reset();
1183  MappingSymbolCounter = 0;
1185  LastMappingSymbols.clear();
1186  LastEMSInfo.reset();
1187  // MCELFStreamer clear's the assembler's e_flags. However, for
1188  // arm we manually set the ABI version on streamer creation, so
1189  // do the same here
1190  getAssembler().setELFHeaderEFlags(ELF::EF_ARM_EABI_VER5);
1191 }
1192 
1193 inline void ARMELFStreamer::SwitchToEHSection(StringRef Prefix,
1194  unsigned Type,
1195  unsigned Flags,
1196  SectionKind Kind,
1197  const MCSymbol &Fn) {
1198  const MCSectionELF &FnSection =
1199  static_cast<const MCSectionELF &>(Fn.getSection());
1200 
1201  // Create the name for new section
1202  StringRef FnSecName(FnSection.getSectionName());
1203  SmallString<128> EHSecName(Prefix);
1204  if (FnSecName != ".text") {
1205  EHSecName += FnSecName;
1206  }
1207 
1208  // Get .ARM.extab or .ARM.exidx section
1209  const MCSymbolELF *Group = FnSection.getGroup();
1210  if (Group)
1211  Flags |= ELF::SHF_GROUP;
1212  MCSectionELF *EHSection = getContext().getELFSection(
1213  EHSecName, Type, Flags, 0, Group, FnSection.getUniqueID(),
1214  static_cast<const MCSymbolELF *>(&Fn));
1215 
1216  assert(EHSection && "Failed to get the required EH section");
1217 
1218  // Switch to .ARM.extab or .ARM.exidx section
1219  SwitchSection(EHSection);
1220  EmitCodeAlignment(4);
1221 }
1222 
1223 inline void ARMELFStreamer::SwitchToExTabSection(const MCSymbol &FnStart) {
1224  SwitchToEHSection(".ARM.extab", ELF::SHT_PROGBITS, ELF::SHF_ALLOC,
1225  SectionKind::getData(), FnStart);
1226 }
1227 
1228 inline void ARMELFStreamer::SwitchToExIdxSection(const MCSymbol &FnStart) {
1229  SwitchToEHSection(".ARM.exidx", ELF::SHT_ARM_EXIDX,
1231  SectionKind::getData(), FnStart);
1232 }
1233 
1234 void ARMELFStreamer::EmitFixup(const MCExpr *Expr, MCFixupKind Kind) {
1235  MCDataFragment *Frag = getOrCreateDataFragment();
1236  Frag->getFixups().push_back(MCFixup::create(Frag->getContents().size(), Expr,
1237  Kind));
1238 }
1239 
1240 void ARMELFStreamer::EHReset() {
1241  ExTab = nullptr;
1242  FnStart = nullptr;
1243  Personality = nullptr;
1244  PersonalityIndex = ARM::EHABI::NUM_PERSONALITY_INDEX;
1245  FPReg = ARM::SP;
1246  FPOffset = 0;
1247  SPOffset = 0;
1248  PendingOffset = 0;
1249  UsedFP = false;
1250  CantUnwind = false;
1251 
1252  Opcodes.clear();
1253  UnwindOpAsm.Reset();
1254 }
1255 
1256 void ARMELFStreamer::emitFnStart() {
1257  assert(FnStart == nullptr);
1258  FnStart = getContext().createTempSymbol();
1259  EmitLabel(FnStart);
1260 }
1261 
1262 void ARMELFStreamer::emitFnEnd() {
1263  assert(FnStart && ".fnstart must precedes .fnend");
1264 
1265  // Emit unwind opcodes if there is no .handlerdata directive
1266  if (!ExTab && !CantUnwind)
1267  FlushUnwindOpcodes(true);
1268 
1269  // Emit the exception index table entry
1270  SwitchToExIdxSection(*FnStart);
1271 
1272  if (PersonalityIndex < ARM::EHABI::NUM_PERSONALITY_INDEX)
1273  EmitPersonalityFixup(GetAEABIUnwindPersonalityName(PersonalityIndex));
1274 
1275  const MCSymbolRefExpr *FnStartRef =
1276  MCSymbolRefExpr::create(FnStart,
1278  getContext());
1279 
1280  EmitValue(FnStartRef, 4);
1281 
1282  if (CantUnwind) {
1283  EmitIntValue(ARM::EHABI::EXIDX_CANTUNWIND, 4);
1284  } else if (ExTab) {
1285  // Emit a reference to the unwind opcodes in the ".ARM.extab" section.
1286  const MCSymbolRefExpr *ExTabEntryRef =
1289  getContext());
1290  EmitValue(ExTabEntryRef, 4);
1291  } else {
1292  // For the __aeabi_unwind_cpp_pr0, we have to emit the unwind opcodes in
1293  // the second word of exception index table entry. The size of the unwind
1294  // opcodes should always be 4 bytes.
1295  assert(PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0 &&
1296  "Compact model must use __aeabi_unwind_cpp_pr0 as personality");
1297  assert(Opcodes.size() == 4u &&
1298  "Unwind opcode size for __aeabi_unwind_cpp_pr0 must be equal to 4");
1299  uint64_t Intval = Opcodes[0] |
1300  Opcodes[1] << 8 |
1301  Opcodes[2] << 16 |
1302  Opcodes[3] << 24;
1303  EmitIntValue(Intval, Opcodes.size());
1304  }
1305 
1306  // Switch to the section containing FnStart
1307  SwitchSection(&FnStart->getSection());
1308 
1309  // Clean exception handling frame information
1310  EHReset();
1311 }
1312 
1313 void ARMELFStreamer::emitCantUnwind() { CantUnwind = true; }
1314 
1315 // Add the R_ARM_NONE fixup at the same position
1316 void ARMELFStreamer::EmitPersonalityFixup(StringRef Name) {
1317  const MCSymbol *PersonalitySym = getContext().getOrCreateSymbol(Name);
1318 
1319  const MCSymbolRefExpr *PersonalityRef = MCSymbolRefExpr::create(
1320  PersonalitySym, MCSymbolRefExpr::VK_ARM_NONE, getContext());
1321 
1322  visitUsedExpr(*PersonalityRef);
1323  MCDataFragment *DF = getOrCreateDataFragment();
1324  DF->getFixups().push_back(MCFixup::create(DF->getContents().size(),
1325  PersonalityRef,
1326  MCFixup::getKindForSize(4, false)));
1327 }
1328 
1329 void ARMELFStreamer::FlushPendingOffset() {
1330  if (PendingOffset != 0) {
1331  UnwindOpAsm.EmitSPOffset(-PendingOffset);
1332  PendingOffset = 0;
1333  }
1334 }
1335 
1336 void ARMELFStreamer::FlushUnwindOpcodes(bool NoHandlerData) {
1337  // Emit the unwind opcode to restore $sp.
1338  if (UsedFP) {
1339  const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1340  int64_t LastRegSaveSPOffset = SPOffset - PendingOffset;
1341  UnwindOpAsm.EmitSPOffset(LastRegSaveSPOffset - FPOffset);
1342  UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1343  } else {
1344  FlushPendingOffset();
1345  }
1346 
1347  // Finalize the unwind opcode sequence
1348  UnwindOpAsm.Finalize(PersonalityIndex, Opcodes);
1349 
1350  // For compact model 0, we have to emit the unwind opcodes in the .ARM.exidx
1351  // section. Thus, we don't have to create an entry in the .ARM.extab
1352  // section.
1353  if (NoHandlerData && PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0)
1354  return;
1355 
1356  // Switch to .ARM.extab section.
1357  SwitchToExTabSection(*FnStart);
1358 
1359  // Create .ARM.extab label for offset in .ARM.exidx
1360  assert(!ExTab);
1361  ExTab = getContext().createTempSymbol();
1362  EmitLabel(ExTab);
1363 
1364  // Emit personality
1365  if (Personality) {
1366  const MCSymbolRefExpr *PersonalityRef =
1367  MCSymbolRefExpr::create(Personality,
1369  getContext());
1370 
1371  EmitValue(PersonalityRef, 4);
1372  }
1373 
1374  // Emit unwind opcodes
1375  assert((Opcodes.size() % 4) == 0 &&
1376  "Unwind opcode size for __aeabi_cpp_unwind_pr0 must be multiple of 4");
1377  for (unsigned I = 0; I != Opcodes.size(); I += 4) {
1378  uint64_t Intval = Opcodes[I] |
1379  Opcodes[I + 1] << 8 |
1380  Opcodes[I + 2] << 16 |
1381  Opcodes[I + 3] << 24;
1382  EmitIntValue(Intval, 4);
1383  }
1384 
1385  // According to ARM EHABI section 9.2, if the __aeabi_unwind_cpp_pr1() or
1386  // __aeabi_unwind_cpp_pr2() is used, then the handler data must be emitted
1387  // after the unwind opcodes. The handler data consists of several 32-bit
1388  // words, and should be terminated by zero.
1389  //
1390  // In case that the .handlerdata directive is not specified by the
1391  // programmer, we should emit zero to terminate the handler data.
1392  if (NoHandlerData && !Personality)
1393  EmitIntValue(0, 4);
1394 }
1395 
1396 void ARMELFStreamer::emitHandlerData() { FlushUnwindOpcodes(false); }
1397 
1398 void ARMELFStreamer::emitPersonality(const MCSymbol *Per) {
1399  Personality = Per;
1400  UnwindOpAsm.setPersonality(Per);
1401 }
1402 
1403 void ARMELFStreamer::emitPersonalityIndex(unsigned Index) {
1404  assert(Index < ARM::EHABI::NUM_PERSONALITY_INDEX && "invalid index");
1405  PersonalityIndex = Index;
1406 }
1407 
1408 void ARMELFStreamer::emitSetFP(unsigned NewFPReg, unsigned NewSPReg,
1409  int64_t Offset) {
1410  assert((NewSPReg == ARM::SP || NewSPReg == FPReg) &&
1411  "the operand of .setfp directive should be either $sp or $fp");
1412 
1413  UsedFP = true;
1414  FPReg = NewFPReg;
1415 
1416  if (NewSPReg == ARM::SP)
1417  FPOffset = SPOffset + Offset;
1418  else
1419  FPOffset += Offset;
1420 }
1421 
1422 void ARMELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
1423  assert((Reg != ARM::SP && Reg != ARM::PC) &&
1424  "the operand of .movsp cannot be either sp or pc");
1425  assert(FPReg == ARM::SP && "current FP must be SP");
1426 
1427  FlushPendingOffset();
1428 
1429  FPReg = Reg;
1430  FPOffset = SPOffset + Offset;
1431 
1432  const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1433  UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1434 }
1435 
1436 void ARMELFStreamer::emitPad(int64_t Offset) {
1437  // Track the change of the $sp offset
1438  SPOffset -= Offset;
1439 
1440  // To squash multiple .pad directives, we should delay the unwind opcode
1441  // until the .save, .vsave, .handlerdata, or .fnend directives.
1442  PendingOffset -= Offset;
1443 }
1444 
1445 void ARMELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
1446  bool IsVector) {
1447  // Collect the registers in the register list
1448  unsigned Count = 0;
1449  uint32_t Mask = 0;
1450  const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1451  for (size_t i = 0; i < RegList.size(); ++i) {
1452  unsigned Reg = MRI->getEncodingValue(RegList[i]);
1453  assert(Reg < (IsVector ? 32U : 16U) && "Register out of range");
1454  unsigned Bit = (1u << Reg);
1455  if ((Mask & Bit) == 0) {
1456  Mask |= Bit;
1457  ++Count;
1458  }
1459  }
1460 
1461  // Track the change the $sp offset: For the .save directive, the
1462  // corresponding push instruction will decrease the $sp by (4 * Count).
1463  // For the .vsave directive, the corresponding vpush instruction will
1464  // decrease $sp by (8 * Count).
1465  SPOffset -= Count * (IsVector ? 8 : 4);
1466 
1467  // Emit the opcode
1468  FlushPendingOffset();
1469  if (IsVector)
1470  UnwindOpAsm.EmitVFPRegSave(Mask);
1471  else
1472  UnwindOpAsm.EmitRegSave(Mask);
1473 }
1474 
1475 void ARMELFStreamer::emitUnwindRaw(int64_t Offset,
1476  const SmallVectorImpl<uint8_t> &Opcodes) {
1477  FlushPendingOffset();
1478  SPOffset = SPOffset - Offset;
1479  UnwindOpAsm.EmitRaw(Opcodes);
1480 }
1481 
1482 namespace llvm {
1483 
1486  MCInstPrinter *InstPrint,
1487  bool isVerboseAsm) {
1488  return new ARMTargetAsmStreamer(S, OS, *InstPrint, isVerboseAsm);
1489 }
1490 
1492  return new ARMTargetStreamer(S);
1493 }
1494 
1496  const MCSubtargetInfo &STI) {
1497  const Triple &TT = STI.getTargetTriple();
1498  if (TT.isOSBinFormatELF())
1499  return new ARMTargetELFStreamer(S);
1500  return new ARMTargetStreamer(S);
1501 }
1502 
1504  std::unique_ptr<MCAsmBackend> TAB,
1505  std::unique_ptr<MCObjectWriter> OW,
1506  std::unique_ptr<MCCodeEmitter> Emitter,
1507  bool RelaxAll, bool IsThumb) {
1508  ARMELFStreamer *S = new ARMELFStreamer(Context, std::move(TAB), std::move(OW),
1509  std::move(Emitter), IsThumb);
1510  // FIXME: This should eventually end up somewhere else where more
1511  // intelligent flag decisions can be made. For now we are just maintaining
1512  // the status quo for ARM and setting EF_ARM_EABI_VER5 as the default.
1513  S->getAssembler().setELFHeaderEFlags(ELF::EF_ARM_EABI_VER5);
1514 
1515  if (RelaxAll)
1516  S->getAssembler().setRelaxAll(true);
1517  return S;
1518 }
1519 
1520 } // end namespace llvm
Instances of this class represent a uniqued identifier for a section in the current translation unit...
Definition: MCSection.h:38
static SectionKind getData()
Definition: SectionKind.h:201
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:321
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:139
This class represents lattice values for constants.
Definition: AllocatorList.h:23
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:41
amdgpu Simplify well known AMD library false FunctionCallee Value const Twine & Name
bool isOSBinFormatELF() const
Tests whether the OS uses the ELF binary format.
Definition: Triple.h:617
formatted_raw_ostream - A raw_ostream that wraps another one and keeps track of line and column posit...
Target specific streamer interface.
Definition: MCStreamer.h:83
unsigned Reg
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:132
virtual void finishAttributeSection()
F(f)
StringRef getCPUAttr(ArchKind AK)
LegalityPredicate isVector(unsigned TypeIdx)
True iff the specified type index is a vector.
virtual void reset()
Reset any state between object emissions, i.e.
const Triple & getTargetTriple() const
void setExternal(bool Value) const
Definition: MCSymbol.h:393
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:80
StringRef getArchName(ArchKind AK)
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:35
Represent a reference to a symbol from inside an expression.
Definition: MCExpr.h:165
LLVM_NODISCARD bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:126
A four-byte fixup.
Definition: MCFixup.h:26
Context object for machine code objects.
Definition: MCContext.h:62
void emitFill(const MCExpr &NumBytes, uint64_t FillValue, SMLoc Loc=SMLoc()) override
Emit Size bytes worth of the value specified by FillValue.
.code16 (X86) / .code 16 (ARM)
Definition: MCDirectives.h:51
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:197
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:158
Flag
These should be considered private to the implementation of the MCInstrDesc class.
Definition: MCInstrDesc.h:117
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:84
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:188
void print(raw_ostream &OS, const MCAsmInfo *MAI, bool InParens=false) const
Definition: MCExpr.cpp:41
unsigned const MachineRegisterInfo * MRI
const MCSymbolELF * getGroup() const
Definition: MCSectionELF.h:75
Special entry for the function never unwind.
Definition: ARMEHABI.h:35
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:45
MCFixupKind
Extensible enumeration to represent the type of a fixup.
Definition: MCFixup.h:22
SmallVectorImpl< MCFixup > & getFixups()
Definition: MCFragment.h:223
.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:22
void setOffset(uint64_t Value)
Definition: MCSymbol.h:326
MCELFStreamer * createARMELFStreamer(MCContext &Context, std::unique_ptr< MCAsmBackend > TAB, std::unique_ptr< MCObjectWriter > OW, std::unique_ptr< MCCodeEmitter > Emitter, bool RelaxAll, bool IsThumb)
static MCFixup create(uint32_t Offset, const MCExpr *Value, MCFixupKind Kind, SMLoc Loc=SMLoc())
Definition: MCFixup.h:90
size_t size() const
Definition: SmallVector.h:52
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:43
unsigned getULEB128Size(uint64_t Value)
Utility function to get the size of the ULEB128-encoded value.
Definition: LEB128.cpp:19
void sort(IteratorTy Start, IteratorTy End)
Definition: STLExtras.h:1115
void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI) override
Emit the given Instruction into the current section.
const MCSymbol & getSymbol() const
Definition: MCExpr.h:334
A no-op fixup.
Definition: MCFixup.h:23
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:841
static Twine utohexstr(const uint64_t &Val)
Definition: Twine.h:387
bool isDefined() const
isDefined - Check if this symbol is defined (i.e., it has an address).
Definition: MCSymbol.h:247
.syntax (ARM/ELF)
Definition: MCDirectives.h:49
MCSection & getSection() const
Get the section associated with a defined, non-absolute symbol.
Definition: MCSymbol.h:266
StringRef getArchExtName(unsigned ArchExtKind)
.code32 (X86) / .code 32 (ARM)
Definition: MCDirectives.h:52
.code64 (X86)
Definition: MCDirectives.h:53
This is an instance of a target assembly language printer that converts an MCInst to valid target ass...
Definition: MCInstPrinter.h:39
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
Generic base class for all target subtargets.
StringRef getFPUName(unsigned FPUKind)
This represents a section on linux, lots of unix variants and some bare metal systems.
Definition: MCSectionELF.h:27
uint32_t Size
Definition: Profile.cpp:46
StringRef getName() const
getName - Get the symbol name.
Definition: MCSymbol.h:202
Fragment for data and encoded instructions.
Definition: MCFragment.h:241
LLVM_NODISCARD std::string lower() const
Definition: StringRef.cpp:107
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
MCTargetStreamer * createARMNullTargetStreamer(MCStreamer &S)
LLVM Value Representation.
Definition: Value.h:72
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:80
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:48
static std::string GetAEABIUnwindPersonalityName(unsigned Index)
Represents a location in source code.
Definition: SMLoc.h:23
unsigned getArchAttr(ArchKind AK)
void FinishImpl() override
Streamer specific finalization.
StringRef getSectionName() const
Definition: MCSectionELF.h:70
void print(raw_ostream &OS, const MCAsmInfo *MAI) const
print - Print the value to the stream OS.
Definition: MCSymbol.cpp:59