1 //===- lib/MC/ARMELFStreamer.cpp - ELF Object Output for ARM --------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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.
14 //===----------------------------------------------------------------------===//
16 #include "ARMRegisterInfo.h"
17 #include "ARMUnwindOpAsm.h"
18 #include "llvm/ADT/StringExtras.h"
19 #include "llvm/ADT/Twine.h"
20 #include "llvm/MC/MCAsmBackend.h"
21 #include "llvm/MC/MCAsmInfo.h"
22 #include "llvm/MC/MCAssembler.h"
23 #include "llvm/MC/MCCodeEmitter.h"
24 #include "llvm/MC/MCContext.h"
25 #include "llvm/MC/MCELFStreamer.h"
26 #include "llvm/MC/MCExpr.h"
27 #include "llvm/MC/MCInst.h"
28 #include "llvm/MC/MCInstPrinter.h"
29 #include "llvm/MC/MCObjectFileInfo.h"
30 #include "llvm/MC/MCObjectStreamer.h"
31 #include "llvm/MC/MCRegisterInfo.h"
32 #include "llvm/MC/MCSection.h"
33 #include "llvm/MC/MCSectionELF.h"
34 #include "llvm/MC/MCStreamer.h"
35 #include "llvm/MC/MCSymbolELF.h"
36 #include "llvm/MC/MCValue.h"
37 #include "llvm/Support/ARMBuildAttributes.h"
38 #include "llvm/Support/ARMEHABI.h"
39 #include "llvm/Support/TargetParser.h"
40 #include "llvm/Support/Debug.h"
41 #include "llvm/Support/ELF.h"
42 #include "llvm/Support/FormattedStream.h"
43 #include "llvm/Support/LEB128.h"
44 #include "llvm/Support/raw_ostream.h"
49 static std::string GetAEABIUnwindPersonalityName(unsigned Index) {
50 assert(Index < ARM::EHABI::NUM_PERSONALITY_INDEX &&
51 "Invalid personality index");
52 return (Twine("__aeabi_unwind_cpp_pr") + Twine(Index)).str();
59 class ARMTargetAsmStreamer : public ARMTargetStreamer {
60 formatted_raw_ostream &OS;
61 MCInstPrinter &InstPrinter;
64 void emitFnStart() override;
65 void emitFnEnd() override;
66 void emitCantUnwind() override;
67 void emitPersonality(const MCSymbol *Personality) override;
68 void emitPersonalityIndex(unsigned Index) override;
69 void emitHandlerData() override;
70 void emitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0) override;
71 void emitMovSP(unsigned Reg, int64_t Offset = 0) override;
72 void emitPad(int64_t Offset) override;
73 void emitRegSave(const SmallVectorImpl<unsigned> &RegList,
74 bool isVector) override;
75 void emitUnwindRaw(int64_t Offset,
76 const SmallVectorImpl<uint8_t> &Opcodes) override;
78 void switchVendor(StringRef Vendor) override;
79 void emitAttribute(unsigned Attribute, unsigned Value) override;
80 void emitTextAttribute(unsigned Attribute, StringRef String) override;
81 void emitIntTextAttribute(unsigned Attribute, unsigned IntValue,
82 StringRef StrinValue) override;
83 void emitArch(unsigned Arch) override;
84 void emitArchExtension(unsigned ArchExt) override;
85 void emitObjectArch(unsigned Arch) override;
86 void emitFPU(unsigned FPU) override;
87 void emitInst(uint32_t Inst, char Suffix = '\0') override;
88 void finishAttributeSection() override;
90 void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE) override;
91 void emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) override;
94 ARMTargetAsmStreamer(MCStreamer &S, formatted_raw_ostream &OS,
95 MCInstPrinter &InstPrinter, bool VerboseAsm);
98 ARMTargetAsmStreamer::ARMTargetAsmStreamer(MCStreamer &S,
99 formatted_raw_ostream &OS,
100 MCInstPrinter &InstPrinter,
102 : ARMTargetStreamer(S), OS(OS), InstPrinter(InstPrinter),
103 IsVerboseAsm(VerboseAsm) {}
104 void ARMTargetAsmStreamer::emitFnStart() { OS << "\t.fnstart\n"; }
105 void ARMTargetAsmStreamer::emitFnEnd() { OS << "\t.fnend\n"; }
106 void ARMTargetAsmStreamer::emitCantUnwind() { OS << "\t.cantunwind\n"; }
107 void ARMTargetAsmStreamer::emitPersonality(const MCSymbol *Personality) {
108 OS << "\t.personality " << Personality->getName() << '\n';
110 void ARMTargetAsmStreamer::emitPersonalityIndex(unsigned Index) {
111 OS << "\t.personalityindex " << Index << '\n';
113 void ARMTargetAsmStreamer::emitHandlerData() { OS << "\t.handlerdata\n"; }
114 void ARMTargetAsmStreamer::emitSetFP(unsigned FpReg, unsigned SpReg,
117 InstPrinter.printRegName(OS, FpReg);
119 InstPrinter.printRegName(OS, SpReg);
121 OS << ", #" << Offset;
124 void ARMTargetAsmStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
125 assert((Reg != ARM::SP && Reg != ARM::PC) &&
126 "the operand of .movsp cannot be either sp or pc");
129 InstPrinter.printRegName(OS, Reg);
131 OS << ", #" << Offset;
134 void ARMTargetAsmStreamer::emitPad(int64_t Offset) {
135 OS << "\t.pad\t#" << Offset << '\n';
137 void ARMTargetAsmStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
139 assert(RegList.size() && "RegList should not be empty");
145 InstPrinter.printRegName(OS, RegList[0]);
147 for (unsigned i = 1, e = RegList.size(); i != e; ++i) {
149 InstPrinter.printRegName(OS, RegList[i]);
154 void ARMTargetAsmStreamer::switchVendor(StringRef Vendor) {
156 void ARMTargetAsmStreamer::emitAttribute(unsigned Attribute, unsigned Value) {
157 OS << "\t.eabi_attribute\t" << Attribute << ", " << Twine(Value);
159 StringRef Name = ARMBuildAttrs::AttrTypeAsString(Attribute);
161 OS << "\t@ " << Name;
165 void ARMTargetAsmStreamer::emitTextAttribute(unsigned Attribute,
168 case ARMBuildAttrs::CPU_name:
169 OS << "\t.cpu\t" << String.lower();
172 OS << "\t.eabi_attribute\t" << Attribute << ", \"" << String << "\"";
174 StringRef Name = ARMBuildAttrs::AttrTypeAsString(Attribute);
176 OS << "\t@ " << Name;
182 void ARMTargetAsmStreamer::emitIntTextAttribute(unsigned Attribute,
184 StringRef StringValue) {
186 default: llvm_unreachable("unsupported multi-value attribute in asm mode");
187 case ARMBuildAttrs::compatibility:
188 OS << "\t.eabi_attribute\t" << Attribute << ", " << IntValue;
189 if (!StringValue.empty())
190 OS << ", \"" << StringValue << "\"";
192 OS << "\t@ " << ARMBuildAttrs::AttrTypeAsString(Attribute);
197 void ARMTargetAsmStreamer::emitArch(unsigned Arch) {
198 OS << "\t.arch\t" << ARM::getArchName(Arch) << "\n";
200 void ARMTargetAsmStreamer::emitArchExtension(unsigned ArchExt) {
201 OS << "\t.arch_extension\t" << ARM::getArchExtName(ArchExt) << "\n";
203 void ARMTargetAsmStreamer::emitObjectArch(unsigned Arch) {
204 OS << "\t.object_arch\t" << ARM::getArchName(Arch) << '\n';
206 void ARMTargetAsmStreamer::emitFPU(unsigned FPU) {
207 OS << "\t.fpu\t" << ARM::getFPUName(FPU) << "\n";
209 void ARMTargetAsmStreamer::finishAttributeSection() {
212 ARMTargetAsmStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
213 OS << "\t.tlsdescseq\t" << S->getSymbol().getName();
216 void ARMTargetAsmStreamer::emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) {
217 const MCAsmInfo *MAI = Streamer.getContext().getAsmInfo();
219 OS << "\t.thumb_set\t";
220 Symbol->print(OS, MAI);
222 Value->print(OS, MAI);
226 void ARMTargetAsmStreamer::emitInst(uint32_t Inst, char Suffix) {
230 OS << "\t0x" << Twine::utohexstr(Inst) << "\n";
233 void ARMTargetAsmStreamer::emitUnwindRaw(int64_t Offset,
234 const SmallVectorImpl<uint8_t> &Opcodes) {
235 OS << "\t.unwind_raw " << Offset;
236 for (SmallVectorImpl<uint8_t>::const_iterator OCI = Opcodes.begin(),
239 OS << ", 0x" << Twine::utohexstr(*OCI);
243 class ARMTargetELFStreamer : public ARMTargetStreamer {
245 // This structure holds all attributes, accounting for
246 // their string/numeric value, so we can later emmit them
247 // in declaration order, keeping all in the same vector
248 struct AttributeItem {
253 NumericAndTextAttributes
257 StringRef StringValue;
259 static bool LessTag(const AttributeItem &LHS, const AttributeItem &RHS) {
260 // The conformance tag must be emitted first when serialised
261 // into an object file. Specifically, the addenda to the ARM ABI
262 // states that (2.3.7.4):
264 // "To simplify recognition by consumers in the common case of
265 // claiming conformity for the whole file, this tag should be
266 // emitted first in a file-scope sub-subsection of the first
267 // public subsection of the attributes section."
269 // So it is special-cased in this comparison predicate when the
270 // attributes are sorted in finishAttributeSection().
271 return (RHS.Tag != ARMBuildAttrs::conformance) &&
272 ((LHS.Tag == ARMBuildAttrs::conformance) || (LHS.Tag < RHS.Tag));
276 StringRef CurrentVendor;
279 unsigned EmittedArch;
280 SmallVector<AttributeItem, 64> Contents;
282 MCSection *AttributeSection;
284 AttributeItem *getAttributeItem(unsigned Attribute) {
285 for (size_t i = 0; i < Contents.size(); ++i)
286 if (Contents[i].Tag == Attribute)
291 void setAttributeItem(unsigned Attribute, unsigned Value,
292 bool OverwriteExisting) {
293 // Look for existing attribute item
294 if (AttributeItem *Item = getAttributeItem(Attribute)) {
295 if (!OverwriteExisting)
297 Item->Type = AttributeItem::NumericAttribute;
298 Item->IntValue = Value;
302 // Create new attribute item
303 AttributeItem Item = {
304 AttributeItem::NumericAttribute,
309 Contents.push_back(Item);
312 void setAttributeItem(unsigned Attribute, StringRef Value,
313 bool OverwriteExisting) {
314 // Look for existing attribute item
315 if (AttributeItem *Item = getAttributeItem(Attribute)) {
316 if (!OverwriteExisting)
318 Item->Type = AttributeItem::TextAttribute;
319 Item->StringValue = Value;
323 // Create new attribute item
324 AttributeItem Item = {
325 AttributeItem::TextAttribute,
330 Contents.push_back(Item);
333 void setAttributeItems(unsigned Attribute, unsigned IntValue,
334 StringRef StringValue, bool OverwriteExisting) {
335 // Look for existing attribute item
336 if (AttributeItem *Item = getAttributeItem(Attribute)) {
337 if (!OverwriteExisting)
339 Item->Type = AttributeItem::NumericAndTextAttributes;
340 Item->IntValue = IntValue;
341 Item->StringValue = StringValue;
345 // Create new attribute item
346 AttributeItem Item = {
347 AttributeItem::NumericAndTextAttributes,
352 Contents.push_back(Item);
355 void emitArchDefaultAttributes();
356 void emitFPUDefaultAttributes();
358 ARMELFStreamer &getStreamer();
360 void emitFnStart() override;
361 void emitFnEnd() override;
362 void emitCantUnwind() override;
363 void emitPersonality(const MCSymbol *Personality) override;
364 void emitPersonalityIndex(unsigned Index) override;
365 void emitHandlerData() override;
366 void emitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0) override;
367 void emitMovSP(unsigned Reg, int64_t Offset = 0) override;
368 void emitPad(int64_t Offset) override;
369 void emitRegSave(const SmallVectorImpl<unsigned> &RegList,
370 bool isVector) override;
371 void emitUnwindRaw(int64_t Offset,
372 const SmallVectorImpl<uint8_t> &Opcodes) override;
374 void switchVendor(StringRef Vendor) override;
375 void emitAttribute(unsigned Attribute, unsigned Value) override;
376 void emitTextAttribute(unsigned Attribute, StringRef String) override;
377 void emitIntTextAttribute(unsigned Attribute, unsigned IntValue,
378 StringRef StringValue) override;
379 void emitArch(unsigned Arch) override;
380 void emitObjectArch(unsigned Arch) override;
381 void emitFPU(unsigned FPU) override;
382 void emitInst(uint32_t Inst, char Suffix = '\0') override;
383 void finishAttributeSection() override;
384 void emitLabel(MCSymbol *Symbol) override;
386 void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE) override;
387 void emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) override;
389 size_t calculateContentSize() const;
392 ARMTargetELFStreamer(MCStreamer &S)
393 : ARMTargetStreamer(S), CurrentVendor("aeabi"), FPU(ARM::FK_INVALID),
394 Arch(ARM::AK_INVALID), EmittedArch(ARM::AK_INVALID),
395 AttributeSection(nullptr) {}
398 /// Extend the generic ELFStreamer class so that it can emit mapping symbols at
399 /// the appropriate points in the object files. These symbols are defined in the
400 /// ARM ELF ABI: infocenter.arm.com/help/topic/com.arm.../IHI0044D_aaelf.pdf.
402 /// In brief: $a, $t or $d should be emitted at the start of each contiguous
403 /// region of ARM code, Thumb code or data in a section. In practice, this
404 /// emission does not rely on explicit assembler directives but on inherent
405 /// properties of the directives doing the emission (e.g. ".byte" is data, "add
406 /// r0, r0, r0" an instruction).
408 /// As a result this system is orthogonal to the DataRegion infrastructure used
409 /// by MachO. Beware!
410 class ARMELFStreamer : public MCELFStreamer {
412 friend class ARMTargetELFStreamer;
414 ARMELFStreamer(MCContext &Context, MCAsmBackend &TAB, raw_pwrite_stream &OS,
415 MCCodeEmitter *Emitter, bool IsThumb)
416 : MCELFStreamer(Context, TAB, OS, Emitter), IsThumb(IsThumb),
417 MappingSymbolCounter(0), LastEMS(EMS_None) {
423 void FinishImpl() override;
425 // ARM exception handling directives
428 void emitCantUnwind();
429 void emitPersonality(const MCSymbol *Per);
430 void emitPersonalityIndex(unsigned index);
431 void emitHandlerData();
432 void emitSetFP(unsigned NewFpReg, unsigned NewSpReg, int64_t Offset = 0);
433 void emitMovSP(unsigned Reg, int64_t Offset = 0);
434 void emitPad(int64_t Offset);
435 void emitRegSave(const SmallVectorImpl<unsigned> &RegList, bool isVector);
436 void emitUnwindRaw(int64_t Offset, const SmallVectorImpl<uint8_t> &Opcodes);
438 void ChangeSection(MCSection *Section, const MCExpr *Subsection) override {
439 // We have to keep track of the mapping symbol state of any sections we
440 // use. Each one should start off as EMS_None, which is provided as the
441 // default constructor by DenseMap::lookup.
442 LastMappingSymbols[getPreviousSection().first] = LastEMS;
443 LastEMS = LastMappingSymbols.lookup(Section);
445 MCELFStreamer::ChangeSection(Section, Subsection);
448 /// This function is the one used to emit instruction data into the ELF
449 /// streamer. We override it to add the appropriate mapping symbol if
451 void EmitInstruction(const MCInst& Inst,
452 const MCSubtargetInfo &STI) override {
454 EmitThumbMappingSymbol();
456 EmitARMMappingSymbol();
458 MCELFStreamer::EmitInstruction(Inst, STI);
461 void emitInst(uint32_t Inst, char Suffix) {
464 const bool LittleEndian = getContext().getAsmInfo()->isLittleEndian();
471 EmitARMMappingSymbol();
472 for (unsigned II = 0, IE = Size; II != IE; II++) {
473 const unsigned I = LittleEndian ? (Size - II - 1) : II;
474 Buffer[Size - II - 1] = uint8_t(Inst >> I * CHAR_BIT);
480 Size = (Suffix == 'n' ? 2 : 4);
483 EmitThumbMappingSymbol();
484 for (unsigned II = 0, IE = Size; II != IE; II = II + 2) {
485 const unsigned I0 = LittleEndian ? II + 0 : (Size - II - 1);
486 const unsigned I1 = LittleEndian ? II + 1 : (Size - II - 2);
487 Buffer[Size - II - 2] = uint8_t(Inst >> I0 * CHAR_BIT);
488 Buffer[Size - II - 1] = uint8_t(Inst >> I1 * CHAR_BIT);
493 llvm_unreachable("Invalid Suffix");
496 MCELFStreamer::EmitBytes(StringRef(Buffer, Size));
499 /// This is one of the functions used to emit data into an ELF section, so the
500 /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
502 void EmitBytes(StringRef Data) override {
503 EmitDataMappingSymbol();
504 MCELFStreamer::EmitBytes(Data);
507 /// This is one of the functions used to emit data into an ELF section, so the
508 /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
510 void EmitValueImpl(const MCExpr *Value, unsigned Size, SMLoc Loc) override {
511 if (const MCSymbolRefExpr *SRE = dyn_cast_or_null<MCSymbolRefExpr>(Value))
512 if (SRE->getKind() == MCSymbolRefExpr::VK_ARM_SBREL && !(Size == 4)) {
513 getContext().reportError(Loc, "relocated expression must be 32-bit");
517 EmitDataMappingSymbol();
518 MCELFStreamer::EmitValueImpl(Value, Size, Loc);
521 void EmitAssemblerFlag(MCAssemblerFlag Flag) override {
522 MCELFStreamer::EmitAssemblerFlag(Flag);
525 case MCAF_SyntaxUnified:
526 return; // no-op here.
529 return; // Change to Thumb mode
532 return; // Change to ARM mode
535 case MCAF_SubsectionsViaSymbols:
541 enum ElfMappingSymbol {
548 void EmitDataMappingSymbol() {
549 if (LastEMS == EMS_Data) return;
550 EmitMappingSymbol("$d");
554 void EmitThumbMappingSymbol() {
555 if (LastEMS == EMS_Thumb) return;
556 EmitMappingSymbol("$t");
560 void EmitARMMappingSymbol() {
561 if (LastEMS == EMS_ARM) return;
562 EmitMappingSymbol("$a");
566 void EmitMappingSymbol(StringRef Name) {
567 auto *Symbol = cast<MCSymbolELF>(getContext().getOrCreateSymbol(
568 Name + "." + Twine(MappingSymbolCounter++)));
571 Symbol->setType(ELF::STT_NOTYPE);
572 Symbol->setBinding(ELF::STB_LOCAL);
573 Symbol->setExternal(false);
576 void EmitThumbFunc(MCSymbol *Func) override {
577 getAssembler().setIsThumbFunc(Func);
578 EmitSymbolAttribute(Func, MCSA_ELF_TypeFunction);
581 // Helper functions for ARM exception handling directives
584 void EmitPersonalityFixup(StringRef Name);
585 void FlushPendingOffset();
586 void FlushUnwindOpcodes(bool NoHandlerData);
588 void SwitchToEHSection(const char *Prefix, unsigned Type, unsigned Flags,
589 SectionKind Kind, const MCSymbol &Fn);
590 void SwitchToExTabSection(const MCSymbol &FnStart);
591 void SwitchToExIdxSection(const MCSymbol &FnStart);
593 void EmitFixup(const MCExpr *Expr, MCFixupKind Kind);
596 int64_t MappingSymbolCounter;
598 DenseMap<const MCSection *, ElfMappingSymbol> LastMappingSymbols;
599 ElfMappingSymbol LastEMS;
601 // ARM Exception Handling Frame Information
604 const MCSymbol *Personality;
605 unsigned PersonalityIndex;
606 unsigned FPReg; // Frame pointer register
607 int64_t FPOffset; // Offset: (final frame pointer) - (initial $sp)
608 int64_t SPOffset; // Offset: (final $sp) - (initial $sp)
609 int64_t PendingOffset; // Offset: (final $sp) - (emitted $sp)
612 SmallVector<uint8_t, 64> Opcodes;
613 UnwindOpcodeAssembler UnwindOpAsm;
615 } // end anonymous namespace
617 ARMELFStreamer &ARMTargetELFStreamer::getStreamer() {
618 return static_cast<ARMELFStreamer &>(Streamer);
621 void ARMTargetELFStreamer::emitFnStart() { getStreamer().emitFnStart(); }
622 void ARMTargetELFStreamer::emitFnEnd() { getStreamer().emitFnEnd(); }
623 void ARMTargetELFStreamer::emitCantUnwind() { getStreamer().emitCantUnwind(); }
624 void ARMTargetELFStreamer::emitPersonality(const MCSymbol *Personality) {
625 getStreamer().emitPersonality(Personality);
627 void ARMTargetELFStreamer::emitPersonalityIndex(unsigned Index) {
628 getStreamer().emitPersonalityIndex(Index);
630 void ARMTargetELFStreamer::emitHandlerData() {
631 getStreamer().emitHandlerData();
633 void ARMTargetELFStreamer::emitSetFP(unsigned FpReg, unsigned SpReg,
635 getStreamer().emitSetFP(FpReg, SpReg, Offset);
637 void ARMTargetELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
638 getStreamer().emitMovSP(Reg, Offset);
640 void ARMTargetELFStreamer::emitPad(int64_t Offset) {
641 getStreamer().emitPad(Offset);
643 void ARMTargetELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
645 getStreamer().emitRegSave(RegList, isVector);
647 void ARMTargetELFStreamer::emitUnwindRaw(int64_t Offset,
648 const SmallVectorImpl<uint8_t> &Opcodes) {
649 getStreamer().emitUnwindRaw(Offset, Opcodes);
651 void ARMTargetELFStreamer::switchVendor(StringRef Vendor) {
652 assert(!Vendor.empty() && "Vendor cannot be empty.");
654 if (CurrentVendor == Vendor)
657 if (!CurrentVendor.empty())
658 finishAttributeSection();
660 assert(Contents.empty() &&
661 ".ARM.attributes should be flushed before changing vendor");
662 CurrentVendor = Vendor;
665 void ARMTargetELFStreamer::emitAttribute(unsigned Attribute, unsigned Value) {
666 setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
668 void ARMTargetELFStreamer::emitTextAttribute(unsigned Attribute,
670 setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
672 void ARMTargetELFStreamer::emitIntTextAttribute(unsigned Attribute,
674 StringRef StringValue) {
675 setAttributeItems(Attribute, IntValue, StringValue,
676 /* OverwriteExisting= */ true);
678 void ARMTargetELFStreamer::emitArch(unsigned Value) {
681 void ARMTargetELFStreamer::emitObjectArch(unsigned Value) {
684 void ARMTargetELFStreamer::emitArchDefaultAttributes() {
685 using namespace ARMBuildAttrs;
687 setAttributeItem(CPU_name,
688 ARM::getCPUAttr(Arch),
691 if (EmittedArch == ARM::AK_INVALID)
692 setAttributeItem(CPU_arch,
693 ARM::getArchAttr(Arch),
696 setAttributeItem(CPU_arch,
697 ARM::getArchAttr(EmittedArch),
706 setAttributeItem(ARM_ISA_use, Allowed, false);
711 case ARM::AK_ARMV5TE:
714 setAttributeItem(ARM_ISA_use, Allowed, false);
715 setAttributeItem(THUMB_ISA_use, Allowed, false);
718 case ARM::AK_ARMV6T2:
719 setAttributeItem(ARM_ISA_use, Allowed, false);
720 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
724 case ARM::AK_ARMV6KZ:
725 setAttributeItem(ARM_ISA_use, Allowed, false);
726 setAttributeItem(THUMB_ISA_use, Allowed, false);
727 setAttributeItem(Virtualization_use, AllowTZ, false);
731 setAttributeItem(THUMB_ISA_use, Allowed, false);
735 setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
736 setAttributeItem(ARM_ISA_use, Allowed, false);
737 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
741 setAttributeItem(CPU_arch_profile, RealTimeProfile, false);
742 setAttributeItem(ARM_ISA_use, Allowed, false);
743 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
747 setAttributeItem(CPU_arch_profile, MicroControllerProfile, false);
748 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
752 case ARM::AK_ARMV8_1A:
753 setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
754 setAttributeItem(ARM_ISA_use, Allowed, false);
755 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
756 setAttributeItem(MPextension_use, Allowed, false);
757 setAttributeItem(Virtualization_use, AllowTZVirtualization, false);
761 setAttributeItem(ARM_ISA_use, Allowed, false);
762 setAttributeItem(THUMB_ISA_use, Allowed, false);
763 setAttributeItem(WMMX_arch, AllowWMMXv1, false);
766 case ARM::AK_IWMMXT2:
767 setAttributeItem(ARM_ISA_use, Allowed, false);
768 setAttributeItem(THUMB_ISA_use, Allowed, false);
769 setAttributeItem(WMMX_arch, AllowWMMXv2, false);
773 report_fatal_error("Unknown Arch: " + Twine(Arch));
777 void ARMTargetELFStreamer::emitFPU(unsigned Value) {
780 void ARMTargetELFStreamer::emitFPUDefaultAttributes() {
784 setAttributeItem(ARMBuildAttrs::FP_arch,
785 ARMBuildAttrs::AllowFPv2,
786 /* OverwriteExisting= */ false);
790 setAttributeItem(ARMBuildAttrs::FP_arch,
791 ARMBuildAttrs::AllowFPv3A,
792 /* OverwriteExisting= */ false);
795 case ARM::FK_VFPV3_FP16:
796 setAttributeItem(ARMBuildAttrs::FP_arch,
797 ARMBuildAttrs::AllowFPv3A,
798 /* OverwriteExisting= */ false);
799 setAttributeItem(ARMBuildAttrs::FP_HP_extension,
800 ARMBuildAttrs::AllowHPFP,
801 /* OverwriteExisting= */ false);
804 case ARM::FK_VFPV3_D16:
805 setAttributeItem(ARMBuildAttrs::FP_arch,
806 ARMBuildAttrs::AllowFPv3B,
807 /* OverwriteExisting= */ false);
810 case ARM::FK_VFPV3_D16_FP16:
811 setAttributeItem(ARMBuildAttrs::FP_arch,
812 ARMBuildAttrs::AllowFPv3B,
813 /* OverwriteExisting= */ false);
814 setAttributeItem(ARMBuildAttrs::FP_HP_extension,
815 ARMBuildAttrs::AllowHPFP,
816 /* OverwriteExisting= */ false);
819 case ARM::FK_VFPV3XD:
820 setAttributeItem(ARMBuildAttrs::FP_arch,
821 ARMBuildAttrs::AllowFPv3B,
822 /* OverwriteExisting= */ false);
824 case ARM::FK_VFPV3XD_FP16:
825 setAttributeItem(ARMBuildAttrs::FP_arch,
826 ARMBuildAttrs::AllowFPv3B,
827 /* OverwriteExisting= */ false);
828 setAttributeItem(ARMBuildAttrs::FP_HP_extension,
829 ARMBuildAttrs::AllowHPFP,
830 /* OverwriteExisting= */ false);
834 setAttributeItem(ARMBuildAttrs::FP_arch,
835 ARMBuildAttrs::AllowFPv4A,
836 /* OverwriteExisting= */ false);
839 // ABI_HardFP_use is handled in ARMAsmPrinter, so _SP_D16 is treated the same
841 case ARM::FK_FPV4_SP_D16:
842 case ARM::FK_VFPV4_D16:
843 setAttributeItem(ARMBuildAttrs::FP_arch,
844 ARMBuildAttrs::AllowFPv4B,
845 /* OverwriteExisting= */ false);
848 case ARM::FK_FP_ARMV8:
849 setAttributeItem(ARMBuildAttrs::FP_arch,
850 ARMBuildAttrs::AllowFPARMv8A,
851 /* OverwriteExisting= */ false);
854 // FPV5_D16 is identical to FP_ARMV8 except for the number of D registers, so
855 // uses the FP_ARMV8_D16 build attribute.
856 case ARM::FK_FPV5_SP_D16:
857 case ARM::FK_FPV5_D16:
858 setAttributeItem(ARMBuildAttrs::FP_arch,
859 ARMBuildAttrs::AllowFPARMv8B,
860 /* OverwriteExisting= */ false);
864 setAttributeItem(ARMBuildAttrs::FP_arch,
865 ARMBuildAttrs::AllowFPv3A,
866 /* OverwriteExisting= */ false);
867 setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
868 ARMBuildAttrs::AllowNeon,
869 /* OverwriteExisting= */ false);
872 case ARM::FK_NEON_FP16:
873 setAttributeItem(ARMBuildAttrs::FP_arch,
874 ARMBuildAttrs::AllowFPv3A,
875 /* OverwriteExisting= */ false);
876 setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
877 ARMBuildAttrs::AllowNeon,
878 /* OverwriteExisting= */ false);
879 setAttributeItem(ARMBuildAttrs::FP_HP_extension,
880 ARMBuildAttrs::AllowHPFP,
881 /* OverwriteExisting= */ false);
884 case ARM::FK_NEON_VFPV4:
885 setAttributeItem(ARMBuildAttrs::FP_arch,
886 ARMBuildAttrs::AllowFPv4A,
887 /* OverwriteExisting= */ false);
888 setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
889 ARMBuildAttrs::AllowNeon2,
890 /* OverwriteExisting= */ false);
893 case ARM::FK_NEON_FP_ARMV8:
894 case ARM::FK_CRYPTO_NEON_FP_ARMV8:
895 setAttributeItem(ARMBuildAttrs::FP_arch,
896 ARMBuildAttrs::AllowFPARMv8A,
897 /* OverwriteExisting= */ false);
898 // 'Advanced_SIMD_arch' must be emitted not here, but within
899 // ARMAsmPrinter::emitAttributes(), depending on hasV8Ops() and hasV8_1a()
902 case ARM::FK_SOFTVFP:
907 report_fatal_error("Unknown FPU: " + Twine(FPU));
911 size_t ARMTargetELFStreamer::calculateContentSize() const {
913 for (size_t i = 0; i < Contents.size(); ++i) {
914 AttributeItem item = Contents[i];
916 case AttributeItem::HiddenAttribute:
918 case AttributeItem::NumericAttribute:
919 Result += getULEB128Size(item.Tag);
920 Result += getULEB128Size(item.IntValue);
922 case AttributeItem::TextAttribute:
923 Result += getULEB128Size(item.Tag);
924 Result += item.StringValue.size() + 1; // string + '\0'
926 case AttributeItem::NumericAndTextAttributes:
927 Result += getULEB128Size(item.Tag);
928 Result += getULEB128Size(item.IntValue);
929 Result += item.StringValue.size() + 1; // string + '\0';
935 void ARMTargetELFStreamer::finishAttributeSection() {
937 // [ <section-length> "vendor-name"
938 // [ <file-tag> <size> <attribute>*
939 // | <section-tag> <size> <section-number>* 0 <attribute>*
940 // | <symbol-tag> <size> <symbol-number>* 0 <attribute>*
944 if (FPU != ARM::FK_INVALID)
945 emitFPUDefaultAttributes();
947 if (Arch != ARM::AK_INVALID)
948 emitArchDefaultAttributes();
950 if (Contents.empty())
953 std::sort(Contents.begin(), Contents.end(), AttributeItem::LessTag);
955 ARMELFStreamer &Streamer = getStreamer();
957 // Switch to .ARM.attributes section
958 if (AttributeSection) {
959 Streamer.SwitchSection(AttributeSection);
961 AttributeSection = Streamer.getContext().getELFSection(
962 ".ARM.attributes", ELF::SHT_ARM_ATTRIBUTES, 0);
963 Streamer.SwitchSection(AttributeSection);
966 Streamer.EmitIntValue(0x41, 1);
969 // Vendor size + Vendor name + '\0'
970 const size_t VendorHeaderSize = 4 + CurrentVendor.size() + 1;
973 const size_t TagHeaderSize = 1 + 4;
975 const size_t ContentsSize = calculateContentSize();
977 Streamer.EmitIntValue(VendorHeaderSize + TagHeaderSize + ContentsSize, 4);
978 Streamer.EmitBytes(CurrentVendor);
979 Streamer.EmitIntValue(0, 1); // '\0'
981 Streamer.EmitIntValue(ARMBuildAttrs::File, 1);
982 Streamer.EmitIntValue(TagHeaderSize + ContentsSize, 4);
984 // Size should have been accounted for already, now
985 // emit each field as its type (ULEB or String)
986 for (size_t i = 0; i < Contents.size(); ++i) {
987 AttributeItem item = Contents[i];
988 Streamer.EmitULEB128IntValue(item.Tag);
990 default: llvm_unreachable("Invalid attribute type");
991 case AttributeItem::NumericAttribute:
992 Streamer.EmitULEB128IntValue(item.IntValue);
994 case AttributeItem::TextAttribute:
995 Streamer.EmitBytes(item.StringValue);
996 Streamer.EmitIntValue(0, 1); // '\0'
998 case AttributeItem::NumericAndTextAttributes:
999 Streamer.EmitULEB128IntValue(item.IntValue);
1000 Streamer.EmitBytes(item.StringValue);
1001 Streamer.EmitIntValue(0, 1); // '\0'
1007 FPU = ARM::FK_INVALID;
1010 void ARMTargetELFStreamer::emitLabel(MCSymbol *Symbol) {
1011 ARMELFStreamer &Streamer = getStreamer();
1012 if (!Streamer.IsThumb)
1015 Streamer.getAssembler().registerSymbol(*Symbol);
1016 unsigned Type = cast<MCSymbolELF>(Symbol)->getType();
1017 if (Type == ELF::STT_FUNC || Type == ELF::STT_GNU_IFUNC)
1018 Streamer.EmitThumbFunc(Symbol);
1022 ARMTargetELFStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
1023 getStreamer().EmitFixup(S, FK_Data_4);
1026 void ARMTargetELFStreamer::emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) {
1027 if (const MCSymbolRefExpr *SRE = dyn_cast<MCSymbolRefExpr>(Value)) {
1028 const MCSymbol &Sym = SRE->getSymbol();
1029 if (!Sym.isDefined()) {
1030 getStreamer().EmitAssignment(Symbol, Value);
1035 getStreamer().EmitThumbFunc(Symbol);
1036 getStreamer().EmitAssignment(Symbol, Value);
1039 void ARMTargetELFStreamer::emitInst(uint32_t Inst, char Suffix) {
1040 getStreamer().emitInst(Inst, Suffix);
1043 void ARMELFStreamer::FinishImpl() {
1044 MCTargetStreamer &TS = *getTargetStreamer();
1045 ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
1046 ATS.finishAttributeSection();
1048 MCELFStreamer::FinishImpl();
1051 inline void ARMELFStreamer::SwitchToEHSection(const char *Prefix,
1055 const MCSymbol &Fn) {
1056 const MCSectionELF &FnSection =
1057 static_cast<const MCSectionELF &>(Fn.getSection());
1059 // Create the name for new section
1060 StringRef FnSecName(FnSection.getSectionName());
1061 SmallString<128> EHSecName(Prefix);
1062 if (FnSecName != ".text") {
1063 EHSecName += FnSecName;
1066 // Get .ARM.extab or .ARM.exidx section
1067 const MCSymbolELF *Group = FnSection.getGroup();
1069 Flags |= ELF::SHF_GROUP;
1070 MCSectionELF *EHSection =
1071 getContext().getELFSection(EHSecName, Type, Flags, 0, Group,
1072 FnSection.getUniqueID(), nullptr, &FnSection);
1074 assert(EHSection && "Failed to get the required EH section");
1076 // Switch to .ARM.extab or .ARM.exidx section
1077 SwitchSection(EHSection);
1078 EmitCodeAlignment(4);
1081 inline void ARMELFStreamer::SwitchToExTabSection(const MCSymbol &FnStart) {
1082 SwitchToEHSection(".ARM.extab",
1085 SectionKind::getDataRel(),
1089 inline void ARMELFStreamer::SwitchToExIdxSection(const MCSymbol &FnStart) {
1090 SwitchToEHSection(".ARM.exidx",
1092 ELF::SHF_ALLOC | ELF::SHF_LINK_ORDER,
1093 SectionKind::getDataRel(),
1096 void ARMELFStreamer::EmitFixup(const MCExpr *Expr, MCFixupKind Kind) {
1097 MCDataFragment *Frag = getOrCreateDataFragment();
1098 Frag->getFixups().push_back(MCFixup::create(Frag->getContents().size(), Expr,
1102 void ARMELFStreamer::Reset() {
1105 Personality = nullptr;
1106 PersonalityIndex = ARM::EHABI::NUM_PERSONALITY_INDEX;
1115 UnwindOpAsm.Reset();
1118 void ARMELFStreamer::emitFnStart() {
1119 assert(FnStart == nullptr);
1120 FnStart = getContext().createTempSymbol();
1124 void ARMELFStreamer::emitFnEnd() {
1125 assert(FnStart && ".fnstart must precedes .fnend");
1127 // Emit unwind opcodes if there is no .handlerdata directive
1128 if (!ExTab && !CantUnwind)
1129 FlushUnwindOpcodes(true);
1131 // Emit the exception index table entry
1132 SwitchToExIdxSection(*FnStart);
1134 if (PersonalityIndex < ARM::EHABI::NUM_PERSONALITY_INDEX)
1135 EmitPersonalityFixup(GetAEABIUnwindPersonalityName(PersonalityIndex));
1137 const MCSymbolRefExpr *FnStartRef =
1138 MCSymbolRefExpr::create(FnStart,
1139 MCSymbolRefExpr::VK_ARM_PREL31,
1142 EmitValue(FnStartRef, 4);
1145 EmitIntValue(ARM::EHABI::EXIDX_CANTUNWIND, 4);
1147 // Emit a reference to the unwind opcodes in the ".ARM.extab" section.
1148 const MCSymbolRefExpr *ExTabEntryRef =
1149 MCSymbolRefExpr::create(ExTab,
1150 MCSymbolRefExpr::VK_ARM_PREL31,
1152 EmitValue(ExTabEntryRef, 4);
1154 // For the __aeabi_unwind_cpp_pr0, we have to emit the unwind opcodes in
1155 // the second word of exception index table entry. The size of the unwind
1156 // opcodes should always be 4 bytes.
1157 assert(PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0 &&
1158 "Compact model must use __aeabi_unwind_cpp_pr0 as personality");
1159 assert(Opcodes.size() == 4u &&
1160 "Unwind opcode size for __aeabi_unwind_cpp_pr0 must be equal to 4");
1161 uint64_t Intval = Opcodes[0] |
1165 EmitIntValue(Intval, Opcodes.size());
1168 // Switch to the section containing FnStart
1169 SwitchSection(&FnStart->getSection());
1171 // Clean exception handling frame information
1175 void ARMELFStreamer::emitCantUnwind() { CantUnwind = true; }
1177 // Add the R_ARM_NONE fixup at the same position
1178 void ARMELFStreamer::EmitPersonalityFixup(StringRef Name) {
1179 const MCSymbol *PersonalitySym = getContext().getOrCreateSymbol(Name);
1181 const MCSymbolRefExpr *PersonalityRef = MCSymbolRefExpr::create(
1182 PersonalitySym, MCSymbolRefExpr::VK_ARM_NONE, getContext());
1184 visitUsedExpr(*PersonalityRef);
1185 MCDataFragment *DF = getOrCreateDataFragment();
1186 DF->getFixups().push_back(MCFixup::create(DF->getContents().size(),
1188 MCFixup::getKindForSize(4, false)));
1191 void ARMELFStreamer::FlushPendingOffset() {
1192 if (PendingOffset != 0) {
1193 UnwindOpAsm.EmitSPOffset(-PendingOffset);
1198 void ARMELFStreamer::FlushUnwindOpcodes(bool NoHandlerData) {
1199 // Emit the unwind opcode to restore $sp.
1201 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1202 int64_t LastRegSaveSPOffset = SPOffset - PendingOffset;
1203 UnwindOpAsm.EmitSPOffset(LastRegSaveSPOffset - FPOffset);
1204 UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1206 FlushPendingOffset();
1209 // Finalize the unwind opcode sequence
1210 UnwindOpAsm.Finalize(PersonalityIndex, Opcodes);
1212 // For compact model 0, we have to emit the unwind opcodes in the .ARM.exidx
1213 // section. Thus, we don't have to create an entry in the .ARM.extab
1215 if (NoHandlerData && PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0)
1218 // Switch to .ARM.extab section.
1219 SwitchToExTabSection(*FnStart);
1221 // Create .ARM.extab label for offset in .ARM.exidx
1223 ExTab = getContext().createTempSymbol();
1228 const MCSymbolRefExpr *PersonalityRef =
1229 MCSymbolRefExpr::create(Personality,
1230 MCSymbolRefExpr::VK_ARM_PREL31,
1233 EmitValue(PersonalityRef, 4);
1236 // Emit unwind opcodes
1237 assert((Opcodes.size() % 4) == 0 &&
1238 "Unwind opcode size for __aeabi_cpp_unwind_pr0 must be multiple of 4");
1239 for (unsigned I = 0; I != Opcodes.size(); I += 4) {
1240 uint64_t Intval = Opcodes[I] |
1241 Opcodes[I + 1] << 8 |
1242 Opcodes[I + 2] << 16 |
1243 Opcodes[I + 3] << 24;
1244 EmitIntValue(Intval, 4);
1247 // According to ARM EHABI section 9.2, if the __aeabi_unwind_cpp_pr1() or
1248 // __aeabi_unwind_cpp_pr2() is used, then the handler data must be emitted
1249 // after the unwind opcodes. The handler data consists of several 32-bit
1250 // words, and should be terminated by zero.
1252 // In case that the .handlerdata directive is not specified by the
1253 // programmer, we should emit zero to terminate the handler data.
1254 if (NoHandlerData && !Personality)
1258 void ARMELFStreamer::emitHandlerData() { FlushUnwindOpcodes(false); }
1260 void ARMELFStreamer::emitPersonality(const MCSymbol *Per) {
1262 UnwindOpAsm.setPersonality(Per);
1265 void ARMELFStreamer::emitPersonalityIndex(unsigned Index) {
1266 assert(Index < ARM::EHABI::NUM_PERSONALITY_INDEX && "invalid index");
1267 PersonalityIndex = Index;
1270 void ARMELFStreamer::emitSetFP(unsigned NewFPReg, unsigned NewSPReg,
1272 assert((NewSPReg == ARM::SP || NewSPReg == FPReg) &&
1273 "the operand of .setfp directive should be either $sp or $fp");
1278 if (NewSPReg == ARM::SP)
1279 FPOffset = SPOffset + Offset;
1284 void ARMELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
1285 assert((Reg != ARM::SP && Reg != ARM::PC) &&
1286 "the operand of .movsp cannot be either sp or pc");
1287 assert(FPReg == ARM::SP && "current FP must be SP");
1289 FlushPendingOffset();
1292 FPOffset = SPOffset + Offset;
1294 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1295 UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1298 void ARMELFStreamer::emitPad(int64_t Offset) {
1299 // Track the change of the $sp offset
1302 // To squash multiple .pad directives, we should delay the unwind opcode
1303 // until the .save, .vsave, .handlerdata, or .fnend directives.
1304 PendingOffset -= Offset;
1307 void ARMELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
1309 // Collect the registers in the register list
1312 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1313 for (size_t i = 0; i < RegList.size(); ++i) {
1314 unsigned Reg = MRI->getEncodingValue(RegList[i]);
1315 assert(Reg < (IsVector ? 32U : 16U) && "Register out of range");
1316 unsigned Bit = (1u << Reg);
1317 if ((Mask & Bit) == 0) {
1323 // Track the change the $sp offset: For the .save directive, the
1324 // corresponding push instruction will decrease the $sp by (4 * Count).
1325 // For the .vsave directive, the corresponding vpush instruction will
1326 // decrease $sp by (8 * Count).
1327 SPOffset -= Count * (IsVector ? 8 : 4);
1330 FlushPendingOffset();
1332 UnwindOpAsm.EmitVFPRegSave(Mask);
1334 UnwindOpAsm.EmitRegSave(Mask);
1337 void ARMELFStreamer::emitUnwindRaw(int64_t Offset,
1338 const SmallVectorImpl<uint8_t> &Opcodes) {
1339 FlushPendingOffset();
1340 SPOffset = SPOffset - Offset;
1341 UnwindOpAsm.EmitRaw(Opcodes);
1346 MCTargetStreamer *createARMTargetAsmStreamer(MCStreamer &S,
1347 formatted_raw_ostream &OS,
1348 MCInstPrinter *InstPrint,
1349 bool isVerboseAsm) {
1350 return new ARMTargetAsmStreamer(S, OS, *InstPrint, isVerboseAsm);
1353 MCTargetStreamer *createARMNullTargetStreamer(MCStreamer &S) {
1354 return new ARMTargetStreamer(S);
1357 MCTargetStreamer *createARMObjectTargetStreamer(MCStreamer &S,
1358 const MCSubtargetInfo &STI) {
1359 const Triple &TT = STI.getTargetTriple();
1360 if (TT.isOSBinFormatELF())
1361 return new ARMTargetELFStreamer(S);
1362 return new ARMTargetStreamer(S);
1365 MCELFStreamer *createARMELFStreamer(MCContext &Context, MCAsmBackend &TAB,
1366 raw_pwrite_stream &OS,
1367 MCCodeEmitter *Emitter, bool RelaxAll,
1369 ARMELFStreamer *S = new ARMELFStreamer(Context, TAB, OS, Emitter, IsThumb);
1370 // FIXME: This should eventually end up somewhere else where more
1371 // intelligent flag decisions can be made. For now we are just maintaining
1372 // the status quo for ARM and setting EF_ARM_EABI_VER5 as the default.
1373 S->getAssembler().setELFHeaderEFlags(ELF::EF_ARM_EABI_VER5);
1376 S->getAssembler().setRelaxAll(true);