e8351063c2e6f3671496cdf05d36d9cd7cf9b4a1
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 //===----------------------------------------------------------------------===//
16 #include "ARMArchName.h"
17 #include "ARMFPUName.h"
18 #include "ARMRegisterInfo.h"
19 #include "ARMUnwindOpAsm.h"
20 #include "llvm/ADT/StringExtras.h"
21 #include "llvm/ADT/Twine.h"
22 #include "llvm/MC/MCAsmBackend.h"
23 #include "llvm/MC/MCAsmInfo.h"
24 #include "llvm/MC/MCAssembler.h"
25 #include "llvm/MC/MCCodeEmitter.h"
26 #include "llvm/MC/MCContext.h"
27 #include "llvm/MC/MCELF.h"
28 #include "llvm/MC/MCELFStreamer.h"
29 #include "llvm/MC/MCELFSymbolFlags.h"
30 #include "llvm/MC/MCExpr.h"
31 #include "llvm/MC/MCInst.h"
32 #include "llvm/MC/MCInstPrinter.h"
33 #include "llvm/MC/MCObjectFileInfo.h"
34 #include "llvm/MC/MCObjectStreamer.h"
35 #include "llvm/MC/MCRegisterInfo.h"
36 #include "llvm/MC/MCSection.h"
37 #include "llvm/MC/MCSectionELF.h"
38 #include "llvm/MC/MCStreamer.h"
39 #include "llvm/MC/MCSymbol.h"
40 #include "llvm/MC/MCValue.h"
41 #include "llvm/Support/ARMBuildAttributes.h"
42 #include "llvm/Support/ARMEHABI.h"
43 #include "llvm/Support/Debug.h"
44 #include "llvm/Support/ELF.h"
45 #include "llvm/Support/FormattedStream.h"
46 #include "llvm/Support/LEB128.h"
47 #include "llvm/Support/raw_ostream.h"
48 #include <algorithm>
50 using namespace llvm;
52 static std::string GetAEABIUnwindPersonalityName(unsigned Index) {
53 assert(Index < ARM::EHABI::NUM_PERSONALITY_INDEX &&
54 "Invalid personality index");
55 return (Twine("__aeabi_unwind_cpp_pr") + Twine(Index)).str();
56 }
58 static const char *GetFPUName(unsigned ID) {
59 switch (ID) {
60 default:
61 llvm_unreachable("Unknown FPU kind");
62 break;
63 #define ARM_FPU_NAME(NAME, ID) case ARM::ID: return NAME;
64 #include "ARMFPUName.def"
65 }
66 return nullptr;
67 }
69 static const char *GetArchName(unsigned ID) {
70 switch (ID) {
71 default:
72 llvm_unreachable("Unknown ARCH kind");
73 break;
74 #define ARM_ARCH_NAME(NAME, ID, DEFAULT_CPU_NAME, DEFAULT_CPU_ARCH) \
75 case ARM::ID: return NAME;
76 #define ARM_ARCH_ALIAS(NAME, ID) /* empty */
77 #include "ARMArchName.def"
78 }
79 return nullptr;
80 }
82 static const char *GetArchDefaultCPUName(unsigned ID) {
83 switch (ID) {
84 default:
85 llvm_unreachable("Unknown ARCH kind");
86 break;
87 #define ARM_ARCH_NAME(NAME, ID, DEFAULT_CPU_NAME, DEFAULT_CPU_ARCH) \
88 case ARM::ID: return DEFAULT_CPU_NAME;
89 #define ARM_ARCH_ALIAS(NAME, ID) /* empty */
90 #include "ARMArchName.def"
91 }
92 return nullptr;
93 }
95 static unsigned GetArchDefaultCPUArch(unsigned ID) {
96 switch (ID) {
97 default:
98 llvm_unreachable("Unknown ARCH kind");
99 break;
100 #define ARM_ARCH_NAME(NAME, ID, DEFAULT_CPU_NAME, DEFAULT_CPU_ARCH) \
101 case ARM::ID: return ARMBuildAttrs::DEFAULT_CPU_ARCH;
102 #define ARM_ARCH_ALIAS(NAME, ID) /* empty */
103 #include "ARMArchName.def"
104 }
105 return 0;
106 }
108 namespace {
110 class ARMELFStreamer;
112 class ARMTargetAsmStreamer : public ARMTargetStreamer {
113 formatted_raw_ostream &OS;
114 MCInstPrinter &InstPrinter;
115 bool IsVerboseAsm;
117 void emitFnStart() override;
118 void emitFnEnd() override;
119 void emitCantUnwind() override;
120 void emitPersonality(const MCSymbol *Personality) override;
121 void emitPersonalityIndex(unsigned Index) override;
122 void emitHandlerData() override;
123 void emitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0) override;
124 void emitMovSP(unsigned Reg, int64_t Offset = 0) override;
125 void emitPad(int64_t Offset) override;
126 void emitRegSave(const SmallVectorImpl<unsigned> &RegList,
127 bool isVector) override;
128 void emitUnwindRaw(int64_t Offset,
129 const SmallVectorImpl<uint8_t> &Opcodes) override;
131 void switchVendor(StringRef Vendor) override;
132 void emitAttribute(unsigned Attribute, unsigned Value) override;
133 void emitTextAttribute(unsigned Attribute, StringRef String) override;
134 void emitIntTextAttribute(unsigned Attribute, unsigned IntValue,
135 StringRef StrinValue) override;
136 void emitArch(unsigned Arch) override;
137 void emitObjectArch(unsigned Arch) override;
138 void emitFPU(unsigned FPU) override;
139 void emitInst(uint32_t Inst, char Suffix = '\0') override;
140 void finishAttributeSection() override;
142 void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE) override;
143 void emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) override;
145 public:
146 ARMTargetAsmStreamer(MCStreamer &S, formatted_raw_ostream &OS,
147 MCInstPrinter &InstPrinter, bool VerboseAsm);
148 };
150 ARMTargetAsmStreamer::ARMTargetAsmStreamer(MCStreamer &S,
151 formatted_raw_ostream &OS,
152 MCInstPrinter &InstPrinter,
153 bool VerboseAsm)
154 : ARMTargetStreamer(S), OS(OS), InstPrinter(InstPrinter),
155 IsVerboseAsm(VerboseAsm) {}
156 void ARMTargetAsmStreamer::emitFnStart() { OS << "\t.fnstart\n"; }
157 void ARMTargetAsmStreamer::emitFnEnd() { OS << "\t.fnend\n"; }
158 void ARMTargetAsmStreamer::emitCantUnwind() { OS << "\t.cantunwind\n"; }
159 void ARMTargetAsmStreamer::emitPersonality(const MCSymbol *Personality) {
160 OS << "\t.personality " << Personality->getName() << '\n';
161 }
162 void ARMTargetAsmStreamer::emitPersonalityIndex(unsigned Index) {
163 OS << "\t.personalityindex " << Index << '\n';
164 }
165 void ARMTargetAsmStreamer::emitHandlerData() { OS << "\t.handlerdata\n"; }
166 void ARMTargetAsmStreamer::emitSetFP(unsigned FpReg, unsigned SpReg,
167 int64_t Offset) {
168 OS << "\t.setfp\t";
169 InstPrinter.printRegName(OS, FpReg);
170 OS << ", ";
171 InstPrinter.printRegName(OS, SpReg);
172 if (Offset)
173 OS << ", #" << Offset;
174 OS << '\n';
175 }
176 void ARMTargetAsmStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
177 assert((Reg != ARM::SP && Reg != ARM::PC) &&
178 "the operand of .movsp cannot be either sp or pc");
180 OS << "\t.movsp\t";
181 InstPrinter.printRegName(OS, Reg);
182 if (Offset)
183 OS << ", #" << Offset;
184 OS << '\n';
185 }
186 void ARMTargetAsmStreamer::emitPad(int64_t Offset) {
187 OS << "\t.pad\t#" << Offset << '\n';
188 }
189 void ARMTargetAsmStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
190 bool isVector) {
191 assert(RegList.size() && "RegList should not be empty");
192 if (isVector)
193 OS << "\t.vsave\t{";
194 else
195 OS << "\t.save\t{";
197 InstPrinter.printRegName(OS, RegList[0]);
199 for (unsigned i = 1, e = RegList.size(); i != e; ++i) {
200 OS << ", ";
201 InstPrinter.printRegName(OS, RegList[i]);
202 }
204 OS << "}\n";
205 }
206 void ARMTargetAsmStreamer::switchVendor(StringRef Vendor) {
207 }
208 void ARMTargetAsmStreamer::emitAttribute(unsigned Attribute, unsigned Value) {
209 OS << "\t.eabi_attribute\t" << Attribute << ", " << Twine(Value);
210 if (IsVerboseAsm) {
211 StringRef Name = ARMBuildAttrs::AttrTypeAsString(Attribute);
212 if (!Name.empty())
213 OS << "\t@ " << Name;
214 }
215 OS << "\n";
216 }
217 void ARMTargetAsmStreamer::emitTextAttribute(unsigned Attribute,
218 StringRef String) {
219 switch (Attribute) {
220 case ARMBuildAttrs::CPU_name:
221 OS << "\t.cpu\t" << String.lower();
222 break;
223 default:
224 OS << "\t.eabi_attribute\t" << Attribute << ", \"" << String << "\"";
225 if (IsVerboseAsm) {
226 StringRef Name = ARMBuildAttrs::AttrTypeAsString(Attribute);
227 if (!Name.empty())
228 OS << "\t@ " << Name;
229 }
230 break;
231 }
232 OS << "\n";
233 }
234 void ARMTargetAsmStreamer::emitIntTextAttribute(unsigned Attribute,
235 unsigned IntValue,
236 StringRef StringValue) {
237 switch (Attribute) {
238 default: llvm_unreachable("unsupported multi-value attribute in asm mode");
239 case ARMBuildAttrs::compatibility:
240 OS << "\t.eabi_attribute\t" << Attribute << ", " << IntValue;
241 if (!StringValue.empty())
242 OS << ", \"" << StringValue << "\"";
243 if (IsVerboseAsm)
244 OS << "\t@ " << ARMBuildAttrs::AttrTypeAsString(Attribute);
245 break;
246 }
247 OS << "\n";
248 }
249 void ARMTargetAsmStreamer::emitArch(unsigned Arch) {
250 OS << "\t.arch\t" << GetArchName(Arch) << "\n";
251 }
252 void ARMTargetAsmStreamer::emitObjectArch(unsigned Arch) {
253 OS << "\t.object_arch\t" << GetArchName(Arch) << '\n';
254 }
255 void ARMTargetAsmStreamer::emitFPU(unsigned FPU) {
256 OS << "\t.fpu\t" << GetFPUName(FPU) << "\n";
257 }
258 void ARMTargetAsmStreamer::finishAttributeSection() {
259 }
260 void
261 ARMTargetAsmStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
262 OS << "\t.tlsdescseq\t" << S->getSymbol().getName();
263 }
265 void ARMTargetAsmStreamer::emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) {
266 OS << "\t.thumb_set\t" << *Symbol << ", " << *Value << '\n';
267 }
269 void ARMTargetAsmStreamer::emitInst(uint32_t Inst, char Suffix) {
270 OS << "\t.inst";
271 if (Suffix)
272 OS << "." << Suffix;
273 OS << "\t0x" << utohexstr(Inst) << "\n";
274 }
276 void ARMTargetAsmStreamer::emitUnwindRaw(int64_t Offset,
277 const SmallVectorImpl<uint8_t> &Opcodes) {
278 OS << "\t.unwind_raw " << Offset;
279 for (SmallVectorImpl<uint8_t>::const_iterator OCI = Opcodes.begin(),
280 OCE = Opcodes.end();
281 OCI != OCE; ++OCI)
282 OS << ", 0x" << utohexstr(*OCI);
283 OS << '\n';
284 }
286 class ARMTargetELFStreamer : public ARMTargetStreamer {
287 private:
288 // This structure holds all attributes, accounting for
289 // their string/numeric value, so we can later emmit them
290 // in declaration order, keeping all in the same vector
291 struct AttributeItem {
292 enum {
293 HiddenAttribute = 0,
294 NumericAttribute,
295 TextAttribute,
296 NumericAndTextAttributes
297 } Type;
298 unsigned Tag;
299 unsigned IntValue;
300 StringRef StringValue;
302 static bool LessTag(const AttributeItem &LHS, const AttributeItem &RHS) {
303 return (LHS.Tag < RHS.Tag);
304 }
305 };
307 StringRef CurrentVendor;
308 unsigned FPU;
309 unsigned Arch;
310 unsigned EmittedArch;
311 SmallVector<AttributeItem, 64> Contents;
313 const MCSection *AttributeSection;
315 AttributeItem *getAttributeItem(unsigned Attribute) {
316 for (size_t i = 0; i < Contents.size(); ++i)
317 if (Contents[i].Tag == Attribute)
318 return &Contents[i];
319 return nullptr;
320 }
322 void setAttributeItem(unsigned Attribute, unsigned Value,
323 bool OverwriteExisting) {
324 // Look for existing attribute item
325 if (AttributeItem *Item = getAttributeItem(Attribute)) {
326 if (!OverwriteExisting)
327 return;
328 Item->Type = AttributeItem::NumericAttribute;
329 Item->IntValue = Value;
330 return;
331 }
333 // Create new attribute item
334 AttributeItem Item = {
335 AttributeItem::NumericAttribute,
336 Attribute,
337 Value,
338 StringRef("")
339 };
340 Contents.push_back(Item);
341 }
343 void setAttributeItem(unsigned Attribute, StringRef Value,
344 bool OverwriteExisting) {
345 // Look for existing attribute item
346 if (AttributeItem *Item = getAttributeItem(Attribute)) {
347 if (!OverwriteExisting)
348 return;
349 Item->Type = AttributeItem::TextAttribute;
350 Item->StringValue = Value;
351 return;
352 }
354 // Create new attribute item
355 AttributeItem Item = {
356 AttributeItem::TextAttribute,
357 Attribute,
358 0,
359 Value
360 };
361 Contents.push_back(Item);
362 }
364 void setAttributeItems(unsigned Attribute, unsigned IntValue,
365 StringRef StringValue, bool OverwriteExisting) {
366 // Look for existing attribute item
367 if (AttributeItem *Item = getAttributeItem(Attribute)) {
368 if (!OverwriteExisting)
369 return;
370 Item->Type = AttributeItem::NumericAndTextAttributes;
371 Item->IntValue = IntValue;
372 Item->StringValue = StringValue;
373 return;
374 }
376 // Create new attribute item
377 AttributeItem Item = {
378 AttributeItem::NumericAndTextAttributes,
379 Attribute,
380 IntValue,
381 StringValue
382 };
383 Contents.push_back(Item);
384 }
386 void emitArchDefaultAttributes();
387 void emitFPUDefaultAttributes();
389 ARMELFStreamer &getStreamer();
391 void emitFnStart() override;
392 void emitFnEnd() override;
393 void emitCantUnwind() override;
394 void emitPersonality(const MCSymbol *Personality) override;
395 void emitPersonalityIndex(unsigned Index) override;
396 void emitHandlerData() override;
397 void emitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0) override;
398 void emitMovSP(unsigned Reg, int64_t Offset = 0) override;
399 void emitPad(int64_t Offset) override;
400 void emitRegSave(const SmallVectorImpl<unsigned> &RegList,
401 bool isVector) override;
402 void emitUnwindRaw(int64_t Offset,
403 const SmallVectorImpl<uint8_t> &Opcodes) override;
405 void switchVendor(StringRef Vendor) override;
406 void emitAttribute(unsigned Attribute, unsigned Value) override;
407 void emitTextAttribute(unsigned Attribute, StringRef String) override;
408 void emitIntTextAttribute(unsigned Attribute, unsigned IntValue,
409 StringRef StringValue) override;
410 void emitArch(unsigned Arch) override;
411 void emitObjectArch(unsigned Arch) override;
412 void emitFPU(unsigned FPU) override;
413 void emitInst(uint32_t Inst, char Suffix = '\0') override;
414 void finishAttributeSection() override;
415 void emitLabel(MCSymbol *Symbol) override;
417 void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE) override;
418 void emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) override;
420 size_t calculateContentSize() const;
422 public:
423 ARMTargetELFStreamer(MCStreamer &S)
424 : ARMTargetStreamer(S), CurrentVendor("aeabi"), FPU(ARM::INVALID_FPU),
425 Arch(ARM::INVALID_ARCH), EmittedArch(ARM::INVALID_ARCH),
426 AttributeSection(nullptr) {}
427 };
429 /// Extend the generic ELFStreamer class so that it can emit mapping symbols at
430 /// the appropriate points in the object files. These symbols are defined in the
431 /// ARM ELF ABI: infocenter.arm.com/help/topic/com.arm.../IHI0044D_aaelf.pdf.
432 ///
433 /// In brief: $a, $t or $d should be emitted at the start of each contiguous
434 /// region of ARM code, Thumb code or data in a section. In practice, this
435 /// emission does not rely on explicit assembler directives but on inherent
436 /// properties of the directives doing the emission (e.g. ".byte" is data, "add
437 /// r0, r0, r0" an instruction).
438 ///
439 /// As a result this system is orthogonal to the DataRegion infrastructure used
440 /// by MachO. Beware!
441 class ARMELFStreamer : public MCELFStreamer {
442 public:
443 friend class ARMTargetELFStreamer;
445 ARMELFStreamer(MCContext &Context, MCAsmBackend &TAB, raw_ostream &OS,
446 MCCodeEmitter *Emitter, bool IsThumb)
447 : MCELFStreamer(Context, TAB, OS, Emitter), IsThumb(IsThumb),
448 MappingSymbolCounter(0), LastEMS(EMS_None) {
449 Reset();
450 }
452 ~ARMELFStreamer() {}
454 void FinishImpl() override;
456 // ARM exception handling directives
457 void emitFnStart();
458 void emitFnEnd();
459 void emitCantUnwind();
460 void emitPersonality(const MCSymbol *Per);
461 void emitPersonalityIndex(unsigned index);
462 void emitHandlerData();
463 void emitSetFP(unsigned NewFpReg, unsigned NewSpReg, int64_t Offset = 0);
464 void emitMovSP(unsigned Reg, int64_t Offset = 0);
465 void emitPad(int64_t Offset);
466 void emitRegSave(const SmallVectorImpl<unsigned> &RegList, bool isVector);
467 void emitUnwindRaw(int64_t Offset, const SmallVectorImpl<uint8_t> &Opcodes);
469 void ChangeSection(const MCSection *Section,
470 const MCExpr *Subsection) override {
471 // We have to keep track of the mapping symbol state of any sections we
472 // use. Each one should start off as EMS_None, which is provided as the
473 // default constructor by DenseMap::lookup.
474 LastMappingSymbols[getPreviousSection().first] = LastEMS;
475 LastEMS = LastMappingSymbols.lookup(Section);
477 MCELFStreamer::ChangeSection(Section, Subsection);
478 }
480 /// This function is the one used to emit instruction data into the ELF
481 /// streamer. We override it to add the appropriate mapping symbol if
482 /// necessary.
483 void EmitInstruction(const MCInst& Inst,
484 const MCSubtargetInfo &STI) override {
485 if (IsThumb)
486 EmitThumbMappingSymbol();
487 else
488 EmitARMMappingSymbol();
490 MCELFStreamer::EmitInstruction(Inst, STI);
491 }
493 void emitInst(uint32_t Inst, char Suffix) {
494 unsigned Size;
495 char Buffer[4];
496 const bool LittleEndian = getContext().getAsmInfo()->isLittleEndian();
498 switch (Suffix) {
499 case '\0':
500 Size = 4;
502 assert(!IsThumb);
503 EmitARMMappingSymbol();
504 for (unsigned II = 0, IE = Size; II != IE; II++) {
505 const unsigned I = LittleEndian ? (Size - II - 1) : II;
506 Buffer[Size - II - 1] = uint8_t(Inst >> I * CHAR_BIT);
507 }
509 break;
510 case 'n':
511 case 'w':
512 Size = (Suffix == 'n' ? 2 : 4);
514 assert(IsThumb);
515 EmitThumbMappingSymbol();
516 for (unsigned II = 0, IE = Size; II != IE; II = II + 2) {
517 const unsigned I0 = LittleEndian ? II + 0 : (Size - II - 1);
518 const unsigned I1 = LittleEndian ? II + 1 : (Size - II - 2);
519 Buffer[Size - II - 2] = uint8_t(Inst >> I0 * CHAR_BIT);
520 Buffer[Size - II - 1] = uint8_t(Inst >> I1 * CHAR_BIT);
521 }
523 break;
524 default:
525 llvm_unreachable("Invalid Suffix");
526 }
528 MCELFStreamer::EmitBytes(StringRef(Buffer, Size));
529 }
531 /// This is one of the functions used to emit data into an ELF section, so the
532 /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
533 /// necessary.
534 void EmitBytes(StringRef Data) override {
535 EmitDataMappingSymbol();
536 MCELFStreamer::EmitBytes(Data);
537 }
539 /// This is one of the functions used to emit data into an ELF section, so the
540 /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
541 /// necessary.
542 void EmitValueImpl(const MCExpr *Value, unsigned Size,
543 const SMLoc &Loc) override {
544 EmitDataMappingSymbol();
545 MCELFStreamer::EmitValueImpl(Value, Size);
546 }
548 void EmitAssemblerFlag(MCAssemblerFlag Flag) override {
549 MCELFStreamer::EmitAssemblerFlag(Flag);
551 switch (Flag) {
552 case MCAF_SyntaxUnified:
553 return; // no-op here.
554 case MCAF_Code16:
555 IsThumb = true;
556 return; // Change to Thumb mode
557 case MCAF_Code32:
558 IsThumb = false;
559 return; // Change to ARM mode
560 case MCAF_Code64:
561 return;
562 case MCAF_SubsectionsViaSymbols:
563 return;
564 }
565 }
567 private:
568 enum ElfMappingSymbol {
569 EMS_None,
570 EMS_ARM,
571 EMS_Thumb,
572 EMS_Data
573 };
575 void EmitDataMappingSymbol() {
576 if (LastEMS == EMS_Data) return;
577 EmitMappingSymbol("$d");
578 LastEMS = EMS_Data;
579 }
581 void EmitThumbMappingSymbol() {
582 if (LastEMS == EMS_Thumb) return;
583 EmitMappingSymbol("$t");
584 LastEMS = EMS_Thumb;
585 }
587 void EmitARMMappingSymbol() {
588 if (LastEMS == EMS_ARM) return;
589 EmitMappingSymbol("$a");
590 LastEMS = EMS_ARM;
591 }
593 void EmitMappingSymbol(StringRef Name) {
594 MCSymbol *Start = getContext().CreateTempSymbol();
595 EmitLabel(Start);
597 MCSymbol *Symbol =
598 getContext().GetOrCreateSymbol(Name + "." +
599 Twine(MappingSymbolCounter++));
601 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
602 MCELF::SetType(SD, ELF::STT_NOTYPE);
603 MCELF::SetBinding(SD, ELF::STB_LOCAL);
604 SD.setExternal(false);
605 AssignSection(Symbol, getCurrentSection().first);
607 const MCExpr *Value = MCSymbolRefExpr::Create(Start, getContext());
608 Symbol->setVariableValue(Value);
609 }
611 void EmitThumbFunc(MCSymbol *Func) override {
612 // FIXME: Anything needed here to flag the function as thumb?
614 getAssembler().setIsThumbFunc(Func);
616 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Func);
617 SD.setFlags(SD.getFlags() | ELF_Other_ThumbFunc);
618 }
620 // Helper functions for ARM exception handling directives
621 void Reset();
623 void EmitPersonalityFixup(StringRef Name);
624 void FlushPendingOffset();
625 void FlushUnwindOpcodes(bool NoHandlerData);
627 void SwitchToEHSection(const char *Prefix, unsigned Type, unsigned Flags,
628 SectionKind Kind, const MCSymbol &Fn);
629 void SwitchToExTabSection(const MCSymbol &FnStart);
630 void SwitchToExIdxSection(const MCSymbol &FnStart);
632 void EmitFixup(const MCExpr *Expr, MCFixupKind Kind);
634 bool IsThumb;
635 int64_t MappingSymbolCounter;
637 DenseMap<const MCSection *, ElfMappingSymbol> LastMappingSymbols;
638 ElfMappingSymbol LastEMS;
640 // ARM Exception Handling Frame Information
641 MCSymbol *ExTab;
642 MCSymbol *FnStart;
643 const MCSymbol *Personality;
644 unsigned PersonalityIndex;
645 unsigned FPReg; // Frame pointer register
646 int64_t FPOffset; // Offset: (final frame pointer) - (initial $sp)
647 int64_t SPOffset; // Offset: (final $sp) - (initial $sp)
648 int64_t PendingOffset; // Offset: (final $sp) - (emitted $sp)
649 bool UsedFP;
650 bool CantUnwind;
651 SmallVector<uint8_t, 64> Opcodes;
652 UnwindOpcodeAssembler UnwindOpAsm;
653 };
654 } // end anonymous namespace
656 ARMELFStreamer &ARMTargetELFStreamer::getStreamer() {
657 return static_cast<ARMELFStreamer &>(Streamer);
658 }
660 void ARMTargetELFStreamer::emitFnStart() { getStreamer().emitFnStart(); }
661 void ARMTargetELFStreamer::emitFnEnd() { getStreamer().emitFnEnd(); }
662 void ARMTargetELFStreamer::emitCantUnwind() { getStreamer().emitCantUnwind(); }
663 void ARMTargetELFStreamer::emitPersonality(const MCSymbol *Personality) {
664 getStreamer().emitPersonality(Personality);
665 }
666 void ARMTargetELFStreamer::emitPersonalityIndex(unsigned Index) {
667 getStreamer().emitPersonalityIndex(Index);
668 }
669 void ARMTargetELFStreamer::emitHandlerData() {
670 getStreamer().emitHandlerData();
671 }
672 void ARMTargetELFStreamer::emitSetFP(unsigned FpReg, unsigned SpReg,
673 int64_t Offset) {
674 getStreamer().emitSetFP(FpReg, SpReg, Offset);
675 }
676 void ARMTargetELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
677 getStreamer().emitMovSP(Reg, Offset);
678 }
679 void ARMTargetELFStreamer::emitPad(int64_t Offset) {
680 getStreamer().emitPad(Offset);
681 }
682 void ARMTargetELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
683 bool isVector) {
684 getStreamer().emitRegSave(RegList, isVector);
685 }
686 void ARMTargetELFStreamer::emitUnwindRaw(int64_t Offset,
687 const SmallVectorImpl<uint8_t> &Opcodes) {
688 getStreamer().emitUnwindRaw(Offset, Opcodes);
689 }
690 void ARMTargetELFStreamer::switchVendor(StringRef Vendor) {
691 assert(!Vendor.empty() && "Vendor cannot be empty.");
693 if (CurrentVendor == Vendor)
694 return;
696 if (!CurrentVendor.empty())
697 finishAttributeSection();
699 assert(Contents.empty() &&
700 ".ARM.attributes should be flushed before changing vendor");
701 CurrentVendor = Vendor;
703 }
704 void ARMTargetELFStreamer::emitAttribute(unsigned Attribute, unsigned Value) {
705 setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
706 }
707 void ARMTargetELFStreamer::emitTextAttribute(unsigned Attribute,
708 StringRef Value) {
709 setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
710 }
711 void ARMTargetELFStreamer::emitIntTextAttribute(unsigned Attribute,
712 unsigned IntValue,
713 StringRef StringValue) {
714 setAttributeItems(Attribute, IntValue, StringValue,
715 /* OverwriteExisting= */ true);
716 }
717 void ARMTargetELFStreamer::emitArch(unsigned Value) {
718 Arch = Value;
719 }
720 void ARMTargetELFStreamer::emitObjectArch(unsigned Value) {
721 EmittedArch = Value;
722 }
723 void ARMTargetELFStreamer::emitArchDefaultAttributes() {
724 using namespace ARMBuildAttrs;
726 setAttributeItem(CPU_name, GetArchDefaultCPUName(Arch), false);
727 if (EmittedArch == ARM::INVALID_ARCH)
728 setAttributeItem(CPU_arch, GetArchDefaultCPUArch(Arch), false);
729 else
730 setAttributeItem(CPU_arch, GetArchDefaultCPUArch(EmittedArch), false);
732 switch (Arch) {
733 case ARM::ARMV2:
734 case ARM::ARMV2A:
735 case ARM::ARMV3:
736 case ARM::ARMV3M:
737 case ARM::ARMV4:
738 case ARM::ARMV5:
739 setAttributeItem(ARM_ISA_use, Allowed, false);
740 break;
742 case ARM::ARMV4T:
743 case ARM::ARMV5T:
744 case ARM::ARMV5TE:
745 case ARM::ARMV6:
746 case ARM::ARMV6J:
747 setAttributeItem(ARM_ISA_use, Allowed, false);
748 setAttributeItem(THUMB_ISA_use, Allowed, false);
749 break;
751 case ARM::ARMV6T2:
752 setAttributeItem(ARM_ISA_use, Allowed, false);
753 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
754 break;
756 case ARM::ARMV6Z:
757 case ARM::ARMV6ZK:
758 setAttributeItem(ARM_ISA_use, Allowed, false);
759 setAttributeItem(THUMB_ISA_use, Allowed, false);
760 setAttributeItem(Virtualization_use, AllowTZ, false);
761 break;
763 case ARM::ARMV6M:
764 setAttributeItem(THUMB_ISA_use, Allowed, false);
765 break;
767 case ARM::ARMV7:
768 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
769 break;
771 case ARM::ARMV7A:
772 setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
773 setAttributeItem(ARM_ISA_use, Allowed, false);
774 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
775 break;
777 case ARM::ARMV7R:
778 setAttributeItem(CPU_arch_profile, RealTimeProfile, false);
779 setAttributeItem(ARM_ISA_use, Allowed, false);
780 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
781 break;
783 case ARM::ARMV7M:
784 setAttributeItem(CPU_arch_profile, MicroControllerProfile, false);
785 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
786 break;
788 case ARM::ARMV8A:
789 setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
790 setAttributeItem(ARM_ISA_use, Allowed, false);
791 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
792 setAttributeItem(MPextension_use, Allowed, false);
793 setAttributeItem(Virtualization_use, AllowTZVirtualization, false);
794 break;
796 case ARM::IWMMXT:
797 setAttributeItem(ARM_ISA_use, Allowed, false);
798 setAttributeItem(THUMB_ISA_use, Allowed, false);
799 setAttributeItem(WMMX_arch, AllowWMMXv1, false);
800 break;
802 case ARM::IWMMXT2:
803 setAttributeItem(ARM_ISA_use, Allowed, false);
804 setAttributeItem(THUMB_ISA_use, Allowed, false);
805 setAttributeItem(WMMX_arch, AllowWMMXv2, false);
806 break;
808 default:
809 report_fatal_error("Unknown Arch: " + Twine(Arch));
810 break;
811 }
812 }
813 void ARMTargetELFStreamer::emitFPU(unsigned Value) {
814 FPU = Value;
815 }
816 void ARMTargetELFStreamer::emitFPUDefaultAttributes() {
817 switch (FPU) {
818 case ARM::VFP:
819 case ARM::VFPV2:
820 setAttributeItem(ARMBuildAttrs::FP_arch,
821 ARMBuildAttrs::AllowFPv2,
822 /* OverwriteExisting= */ false);
823 break;
825 case ARM::VFPV3:
826 setAttributeItem(ARMBuildAttrs::FP_arch,
827 ARMBuildAttrs::AllowFPv3A,
828 /* OverwriteExisting= */ false);
829 break;
831 case ARM::VFPV3_D16:
832 setAttributeItem(ARMBuildAttrs::FP_arch,
833 ARMBuildAttrs::AllowFPv3B,
834 /* OverwriteExisting= */ false);
835 break;
837 case ARM::VFPV4:
838 setAttributeItem(ARMBuildAttrs::FP_arch,
839 ARMBuildAttrs::AllowFPv4A,
840 /* OverwriteExisting= */ false);
841 break;
843 case ARM::VFPV4_D16:
844 setAttributeItem(ARMBuildAttrs::FP_arch,
845 ARMBuildAttrs::AllowFPv4B,
846 /* OverwriteExisting= */ false);
847 break;
849 case ARM::FP_ARMV8:
850 setAttributeItem(ARMBuildAttrs::FP_arch,
851 ARMBuildAttrs::AllowFPARMv8A,
852 /* OverwriteExisting= */ false);
853 break;
855 case ARM::NEON:
856 setAttributeItem(ARMBuildAttrs::FP_arch,
857 ARMBuildAttrs::AllowFPv3A,
858 /* OverwriteExisting= */ false);
859 setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
860 ARMBuildAttrs::AllowNeon,
861 /* OverwriteExisting= */ false);
862 break;
864 case ARM::NEON_VFPV4:
865 setAttributeItem(ARMBuildAttrs::FP_arch,
866 ARMBuildAttrs::AllowFPv4A,
867 /* OverwriteExisting= */ false);
868 setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
869 ARMBuildAttrs::AllowNeon2,
870 /* OverwriteExisting= */ false);
871 break;
873 case ARM::NEON_FP_ARMV8:
874 case ARM::CRYPTO_NEON_FP_ARMV8:
875 setAttributeItem(ARMBuildAttrs::FP_arch,
876 ARMBuildAttrs::AllowFPARMv8A,
877 /* OverwriteExisting= */ false);
878 setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
879 ARMBuildAttrs::AllowNeonARMv8,
880 /* OverwriteExisting= */ false);
881 break;
883 case ARM::SOFTVFP:
884 break;
886 default:
887 report_fatal_error("Unknown FPU: " + Twine(FPU));
888 break;
889 }
890 }
891 size_t ARMTargetELFStreamer::calculateContentSize() const {
892 size_t Result = 0;
893 for (size_t i = 0; i < Contents.size(); ++i) {
894 AttributeItem item = Contents[i];
895 switch (item.Type) {
896 case AttributeItem::HiddenAttribute:
897 break;
898 case AttributeItem::NumericAttribute:
899 Result += getULEB128Size(item.Tag);
900 Result += getULEB128Size(item.IntValue);
901 break;
902 case AttributeItem::TextAttribute:
903 Result += getULEB128Size(item.Tag);
904 Result += item.StringValue.size() + 1; // string + '\0'
905 break;
906 case AttributeItem::NumericAndTextAttributes:
907 Result += getULEB128Size(item.Tag);
908 Result += getULEB128Size(item.IntValue);
909 Result += item.StringValue.size() + 1; // string + '\0';
910 break;
911 }
912 }
913 return Result;
914 }
915 void ARMTargetELFStreamer::finishAttributeSection() {
916 // <format-version>
917 // [ <section-length> "vendor-name"
918 // [ <file-tag> <size> <attribute>*
919 // | <section-tag> <size> <section-number>* 0 <attribute>*
920 // | <symbol-tag> <size> <symbol-number>* 0 <attribute>*
921 // ]+
922 // ]*
924 if (FPU != ARM::INVALID_FPU)
925 emitFPUDefaultAttributes();
927 if (Arch != ARM::INVALID_ARCH)
928 emitArchDefaultAttributes();
930 if (Contents.empty())
931 return;
933 std::sort(Contents.begin(), Contents.end(), AttributeItem::LessTag);
935 ARMELFStreamer &Streamer = getStreamer();
937 // Switch to .ARM.attributes section
938 if (AttributeSection) {
939 Streamer.SwitchSection(AttributeSection);
940 } else {
941 AttributeSection =
942 Streamer.getContext().getELFSection(".ARM.attributes",
943 ELF::SHT_ARM_ATTRIBUTES,
944 0,
945 SectionKind::getMetadata());
946 Streamer.SwitchSection(AttributeSection);
948 // Format version
949 Streamer.EmitIntValue(0x41, 1);
950 }
952 // Vendor size + Vendor name + '\0'
953 const size_t VendorHeaderSize = 4 + CurrentVendor.size() + 1;
955 // Tag + Tag Size
956 const size_t TagHeaderSize = 1 + 4;
958 const size_t ContentsSize = calculateContentSize();
960 Streamer.EmitIntValue(VendorHeaderSize + TagHeaderSize + ContentsSize, 4);
961 Streamer.EmitBytes(CurrentVendor);
962 Streamer.EmitIntValue(0, 1); // '\0'
964 Streamer.EmitIntValue(ARMBuildAttrs::File, 1);
965 Streamer.EmitIntValue(TagHeaderSize + ContentsSize, 4);
967 // Size should have been accounted for already, now
968 // emit each field as its type (ULEB or String)
969 for (size_t i = 0; i < Contents.size(); ++i) {
970 AttributeItem item = Contents[i];
971 Streamer.EmitULEB128IntValue(item.Tag);
972 switch (item.Type) {
973 default: llvm_unreachable("Invalid attribute type");
974 case AttributeItem::NumericAttribute:
975 Streamer.EmitULEB128IntValue(item.IntValue);
976 break;
977 case AttributeItem::TextAttribute:
978 Streamer.EmitBytes(item.StringValue.upper());
979 Streamer.EmitIntValue(0, 1); // '\0'
980 break;
981 case AttributeItem::NumericAndTextAttributes:
982 Streamer.EmitULEB128IntValue(item.IntValue);
983 Streamer.EmitBytes(item.StringValue.upper());
984 Streamer.EmitIntValue(0, 1); // '\0'
985 break;
986 }
987 }
989 Contents.clear();
990 FPU = ARM::INVALID_FPU;
991 }
993 void ARMTargetELFStreamer::emitLabel(MCSymbol *Symbol) {
994 ARMELFStreamer &Streamer = getStreamer();
995 if (!Streamer.IsThumb)
996 return;
998 const MCSymbolData &SD = Streamer.getOrCreateSymbolData(Symbol);
999 if (MCELF::GetType(SD) & (ELF::STT_FUNC << ELF_STT_Shift))
1000 Streamer.EmitThumbFunc(Symbol);
1001 }
1003 void
1004 ARMTargetELFStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
1005 getStreamer().EmitFixup(S, FK_Data_4);
1006 }
1008 void ARMTargetELFStreamer::emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) {
1009 if (const MCSymbolRefExpr *SRE = dyn_cast<MCSymbolRefExpr>(Value)) {
1010 // FIXME: Doing a lookup in here is a hack.
1011 MCSymbol *Sym =
1012 getStreamer().getContext().LookupSymbol(SRE->getSymbol().getName());
1013 if (!Sym->isDefined()) {
1014 getStreamer().EmitSymbolAttribute(Sym, MCSA_Global);
1015 getStreamer().EmitAssignment(Symbol, Value);
1016 return;
1017 }
1018 }
1020 getStreamer().EmitThumbFunc(Symbol);
1021 getStreamer().EmitAssignment(Symbol, Value);
1022 }
1024 void ARMTargetELFStreamer::emitInst(uint32_t Inst, char Suffix) {
1025 getStreamer().emitInst(Inst, Suffix);
1026 }
1028 void ARMELFStreamer::FinishImpl() {
1029 MCTargetStreamer &TS = *getTargetStreamer();
1030 ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
1031 ATS.finishAttributeSection();
1033 MCELFStreamer::FinishImpl();
1034 }
1036 inline void ARMELFStreamer::SwitchToEHSection(const char *Prefix,
1037 unsigned Type,
1038 unsigned Flags,
1039 SectionKind Kind,
1040 const MCSymbol &Fn) {
1041 const MCSectionELF &FnSection =
1042 static_cast<const MCSectionELF &>(Fn.getSection());
1044 // Create the name for new section
1045 StringRef FnSecName(FnSection.getSectionName());
1046 SmallString<128> EHSecName(Prefix);
1047 if (FnSecName != ".text") {
1048 EHSecName += FnSecName;
1049 }
1051 // Get .ARM.extab or .ARM.exidx section
1052 const MCSectionELF *EHSection = nullptr;
1053 if (const MCSymbol *Group = FnSection.getGroup()) {
1054 EHSection = getContext().getELFSection(
1055 EHSecName, Type, Flags | ELF::SHF_GROUP, Kind,
1056 FnSection.getEntrySize(), Group->getName());
1057 } else {
1058 EHSection = getContext().getELFSection(EHSecName, Type, Flags, Kind);
1059 }
1060 assert(EHSection && "Failed to get the required EH section");
1062 // Switch to .ARM.extab or .ARM.exidx section
1063 SwitchSection(EHSection);
1064 EmitCodeAlignment(4);
1065 }
1067 inline void ARMELFStreamer::SwitchToExTabSection(const MCSymbol &FnStart) {
1068 SwitchToEHSection(".ARM.extab",
1069 ELF::SHT_PROGBITS,
1070 ELF::SHF_ALLOC,
1071 SectionKind::getDataRel(),
1072 FnStart);
1073 }
1075 inline void ARMELFStreamer::SwitchToExIdxSection(const MCSymbol &FnStart) {
1076 SwitchToEHSection(".ARM.exidx",
1077 ELF::SHT_ARM_EXIDX,
1078 ELF::SHF_ALLOC | ELF::SHF_LINK_ORDER,
1079 SectionKind::getDataRel(),
1080 FnStart);
1081 }
1082 void ARMELFStreamer::EmitFixup(const MCExpr *Expr, MCFixupKind Kind) {
1083 MCDataFragment *Frag = getOrCreateDataFragment();
1084 Frag->getFixups().push_back(MCFixup::Create(Frag->getContents().size(), Expr,
1085 Kind));
1086 }
1088 void ARMELFStreamer::Reset() {
1089 ExTab = nullptr;
1090 FnStart = nullptr;
1091 Personality = nullptr;
1092 PersonalityIndex = ARM::EHABI::NUM_PERSONALITY_INDEX;
1093 FPReg = ARM::SP;
1094 FPOffset = 0;
1095 SPOffset = 0;
1096 PendingOffset = 0;
1097 UsedFP = false;
1098 CantUnwind = false;
1100 Opcodes.clear();
1101 UnwindOpAsm.Reset();
1102 }
1104 void ARMELFStreamer::emitFnStart() {
1105 assert(FnStart == 0);
1106 FnStart = getContext().CreateTempSymbol();
1107 EmitLabel(FnStart);
1108 }
1110 void ARMELFStreamer::emitFnEnd() {
1111 assert(FnStart && ".fnstart must precedes .fnend");
1113 // Emit unwind opcodes if there is no .handlerdata directive
1114 if (!ExTab && !CantUnwind)
1115 FlushUnwindOpcodes(true);
1117 // Emit the exception index table entry
1118 SwitchToExIdxSection(*FnStart);
1120 if (PersonalityIndex < ARM::EHABI::NUM_PERSONALITY_INDEX)
1121 EmitPersonalityFixup(GetAEABIUnwindPersonalityName(PersonalityIndex));
1123 const MCSymbolRefExpr *FnStartRef =
1124 MCSymbolRefExpr::Create(FnStart,
1125 MCSymbolRefExpr::VK_ARM_PREL31,
1126 getContext());
1128 EmitValue(FnStartRef, 4);
1130 if (CantUnwind) {
1131 EmitIntValue(ARM::EHABI::EXIDX_CANTUNWIND, 4);
1132 } else if (ExTab) {
1133 // Emit a reference to the unwind opcodes in the ".ARM.extab" section.
1134 const MCSymbolRefExpr *ExTabEntryRef =
1135 MCSymbolRefExpr::Create(ExTab,
1136 MCSymbolRefExpr::VK_ARM_PREL31,
1137 getContext());
1138 EmitValue(ExTabEntryRef, 4);
1139 } else {
1140 // For the __aeabi_unwind_cpp_pr0, we have to emit the unwind opcodes in
1141 // the second word of exception index table entry. The size of the unwind
1142 // opcodes should always be 4 bytes.
1143 assert(PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0 &&
1144 "Compact model must use __aeabi_cpp_unwind_pr0 as personality");
1145 assert(Opcodes.size() == 4u &&
1146 "Unwind opcode size for __aeabi_cpp_unwind_pr0 must be equal to 4");
1147 EmitBytes(StringRef(reinterpret_cast<const char*>(Opcodes.data()),
1148 Opcodes.size()));
1149 }
1151 // Switch to the section containing FnStart
1152 SwitchSection(&FnStart->getSection());
1154 // Clean exception handling frame information
1155 Reset();
1156 }
1158 void ARMELFStreamer::emitCantUnwind() { CantUnwind = true; }
1160 // Add the R_ARM_NONE fixup at the same position
1161 void ARMELFStreamer::EmitPersonalityFixup(StringRef Name) {
1162 const MCSymbol *PersonalitySym = getContext().GetOrCreateSymbol(Name);
1164 const MCSymbolRefExpr *PersonalityRef = MCSymbolRefExpr::Create(
1165 PersonalitySym, MCSymbolRefExpr::VK_ARM_NONE, getContext());
1167 AddValueSymbols(PersonalityRef);
1168 MCDataFragment *DF = getOrCreateDataFragment();
1169 DF->getFixups().push_back(MCFixup::Create(DF->getContents().size(),
1170 PersonalityRef,
1171 MCFixup::getKindForSize(4, false)));
1172 }
1174 void ARMELFStreamer::FlushPendingOffset() {
1175 if (PendingOffset != 0) {
1176 UnwindOpAsm.EmitSPOffset(-PendingOffset);
1177 PendingOffset = 0;
1178 }
1179 }
1181 void ARMELFStreamer::FlushUnwindOpcodes(bool NoHandlerData) {
1182 // Emit the unwind opcode to restore $sp.
1183 if (UsedFP) {
1184 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1185 int64_t LastRegSaveSPOffset = SPOffset - PendingOffset;
1186 UnwindOpAsm.EmitSPOffset(LastRegSaveSPOffset - FPOffset);
1187 UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1188 } else {
1189 FlushPendingOffset();
1190 }
1192 // Finalize the unwind opcode sequence
1193 UnwindOpAsm.Finalize(PersonalityIndex, Opcodes);
1195 // For compact model 0, we have to emit the unwind opcodes in the .ARM.exidx
1196 // section. Thus, we don't have to create an entry in the .ARM.extab
1197 // section.
1198 if (NoHandlerData && PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0)
1199 return;
1201 // Switch to .ARM.extab section.
1202 SwitchToExTabSection(*FnStart);
1204 // Create .ARM.extab label for offset in .ARM.exidx
1205 assert(!ExTab);
1206 ExTab = getContext().CreateTempSymbol();
1207 EmitLabel(ExTab);
1209 // Emit personality
1210 if (Personality) {
1211 const MCSymbolRefExpr *PersonalityRef =
1212 MCSymbolRefExpr::Create(Personality,
1213 MCSymbolRefExpr::VK_ARM_PREL31,
1214 getContext());
1216 EmitValue(PersonalityRef, 4);
1217 }
1219 // Emit unwind opcodes
1220 EmitBytes(StringRef(reinterpret_cast<const char *>(Opcodes.data()),
1221 Opcodes.size()));
1223 // According to ARM EHABI section 9.2, if the __aeabi_unwind_cpp_pr1() or
1224 // __aeabi_unwind_cpp_pr2() is used, then the handler data must be emitted
1225 // after the unwind opcodes. The handler data consists of several 32-bit
1226 // words, and should be terminated by zero.
1227 //
1228 // In case that the .handlerdata directive is not specified by the
1229 // programmer, we should emit zero to terminate the handler data.
1230 if (NoHandlerData && !Personality)
1231 EmitIntValue(0, 4);
1232 }
1234 void ARMELFStreamer::emitHandlerData() { FlushUnwindOpcodes(false); }
1236 void ARMELFStreamer::emitPersonality(const MCSymbol *Per) {
1237 Personality = Per;
1238 UnwindOpAsm.setPersonality(Per);
1239 }
1241 void ARMELFStreamer::emitPersonalityIndex(unsigned Index) {
1242 assert(Index < ARM::EHABI::NUM_PERSONALITY_INDEX && "invalid index");
1243 PersonalityIndex = Index;
1244 }
1246 void ARMELFStreamer::emitSetFP(unsigned NewFPReg, unsigned NewSPReg,
1247 int64_t Offset) {
1248 assert((NewSPReg == ARM::SP || NewSPReg == FPReg) &&
1249 "the operand of .setfp directive should be either $sp or $fp");
1251 UsedFP = true;
1252 FPReg = NewFPReg;
1254 if (NewSPReg == ARM::SP)
1255 FPOffset = SPOffset + Offset;
1256 else
1257 FPOffset += Offset;
1258 }
1260 void ARMELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
1261 assert((Reg != ARM::SP && Reg != ARM::PC) &&
1262 "the operand of .movsp cannot be either sp or pc");
1263 assert(FPReg == ARM::SP && "current FP must be SP");
1265 FlushPendingOffset();
1267 FPReg = Reg;
1268 FPOffset = SPOffset + Offset;
1270 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1271 UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1272 }
1274 void ARMELFStreamer::emitPad(int64_t Offset) {
1275 // Track the change of the $sp offset
1276 SPOffset -= Offset;
1278 // To squash multiple .pad directives, we should delay the unwind opcode
1279 // until the .save, .vsave, .handlerdata, or .fnend directives.
1280 PendingOffset -= Offset;
1281 }
1283 void ARMELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
1284 bool IsVector) {
1285 // Collect the registers in the register list
1286 unsigned Count = 0;
1287 uint32_t Mask = 0;
1288 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1289 for (size_t i = 0; i < RegList.size(); ++i) {
1290 unsigned Reg = MRI->getEncodingValue(RegList[i]);
1291 assert(Reg < (IsVector ? 32U : 16U) && "Register out of range");
1292 unsigned Bit = (1u << Reg);
1293 if ((Mask & Bit) == 0) {
1294 Mask |= Bit;
1295 ++Count;
1296 }
1297 }
1299 // Track the change the $sp offset: For the .save directive, the
1300 // corresponding push instruction will decrease the $sp by (4 * Count).
1301 // For the .vsave directive, the corresponding vpush instruction will
1302 // decrease $sp by (8 * Count).
1303 SPOffset -= Count * (IsVector ? 8 : 4);
1305 // Emit the opcode
1306 FlushPendingOffset();
1307 if (IsVector)
1308 UnwindOpAsm.EmitVFPRegSave(Mask);
1309 else
1310 UnwindOpAsm.EmitRegSave(Mask);
1311 }
1313 void ARMELFStreamer::emitUnwindRaw(int64_t Offset,
1314 const SmallVectorImpl<uint8_t> &Opcodes) {
1315 FlushPendingOffset();
1316 SPOffset = SPOffset - Offset;
1317 UnwindOpAsm.EmitRaw(Opcodes);
1318 }
1320 namespace llvm {
1322 MCStreamer *createMCAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
1323 bool isVerboseAsm, bool useCFI,
1324 bool useDwarfDirectory,
1325 MCInstPrinter *InstPrint, MCCodeEmitter *CE,
1326 MCAsmBackend *TAB, bool ShowInst) {
1327 MCStreamer *S =
1328 llvm::createAsmStreamer(Ctx, OS, isVerboseAsm, useCFI, useDwarfDirectory,
1329 InstPrint, CE, TAB, ShowInst);
1330 new ARMTargetAsmStreamer(*S, OS, *InstPrint, isVerboseAsm);
1331 return S;
1332 }
1334 MCELFStreamer* createARMELFStreamer(MCContext &Context, MCAsmBackend &TAB,
1335 raw_ostream &OS, MCCodeEmitter *Emitter,
1336 bool RelaxAll, bool NoExecStack,
1337 bool IsThumb) {
1338 ARMELFStreamer *S = new ARMELFStreamer(Context, TAB, OS, Emitter, IsThumb);
1339 new ARMTargetELFStreamer(*S);
1340 // FIXME: This should eventually end up somewhere else where more
1341 // intelligent flag decisions can be made. For now we are just maintaining
1342 // the status quo for ARM and setting EF_ARM_EABI_VER5 as the default.
1343 S->getAssembler().setELFHeaderEFlags(ELF::EF_ARM_EABI_VER5);
1345 if (RelaxAll)
1346 S->getAssembler().setRelaxAll(true);
1347 if (NoExecStack)
1348 S->getAssembler().setNoExecStack(true);
1349 return S;
1350 }
1352 }