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:
713 setAttributeItem(ARM_ISA_use, Allowed, false);
714 setAttributeItem(THUMB_ISA_use, Allowed, false);
717 case ARM::AK_ARMV6T2:
718 setAttributeItem(ARM_ISA_use, Allowed, false);
719 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
723 case ARM::AK_ARMV6KZ:
724 setAttributeItem(ARM_ISA_use, Allowed, false);
725 setAttributeItem(THUMB_ISA_use, Allowed, false);
726 setAttributeItem(Virtualization_use, AllowTZ, false);
730 setAttributeItem(THUMB_ISA_use, Allowed, false);
734 setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
735 setAttributeItem(ARM_ISA_use, Allowed, false);
736 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
740 setAttributeItem(CPU_arch_profile, RealTimeProfile, false);
741 setAttributeItem(ARM_ISA_use, Allowed, false);
742 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
746 setAttributeItem(CPU_arch_profile, MicroControllerProfile, false);
747 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
751 case ARM::AK_ARMV8_1A:
752 setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
753 setAttributeItem(ARM_ISA_use, Allowed, false);
754 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
755 setAttributeItem(MPextension_use, Allowed, false);
756 setAttributeItem(Virtualization_use, AllowTZVirtualization, false);
760 setAttributeItem(ARM_ISA_use, Allowed, false);
761 setAttributeItem(THUMB_ISA_use, Allowed, false);
762 setAttributeItem(WMMX_arch, AllowWMMXv1, false);
765 case ARM::AK_IWMMXT2:
766 setAttributeItem(ARM_ISA_use, Allowed, false);
767 setAttributeItem(THUMB_ISA_use, Allowed, false);
768 setAttributeItem(WMMX_arch, AllowWMMXv2, false);
772 report_fatal_error("Unknown Arch: " + Twine(Arch));
776 void ARMTargetELFStreamer::emitFPU(unsigned Value) {
779 void ARMTargetELFStreamer::emitFPUDefaultAttributes() {
783 setAttributeItem(ARMBuildAttrs::FP_arch,
784 ARMBuildAttrs::AllowFPv2,
785 /* OverwriteExisting= */ false);
789 setAttributeItem(ARMBuildAttrs::FP_arch,
790 ARMBuildAttrs::AllowFPv3A,
791 /* OverwriteExisting= */ false);
794 case ARM::FK_VFPV3_FP16:
795 setAttributeItem(ARMBuildAttrs::FP_arch,
796 ARMBuildAttrs::AllowFPv3A,
797 /* OverwriteExisting= */ false);
798 setAttributeItem(ARMBuildAttrs::FP_HP_extension,
799 ARMBuildAttrs::AllowHPFP,
800 /* OverwriteExisting= */ false);
803 case ARM::FK_VFPV3_D16:
804 setAttributeItem(ARMBuildAttrs::FP_arch,
805 ARMBuildAttrs::AllowFPv3B,
806 /* OverwriteExisting= */ false);
809 case ARM::FK_VFPV3_D16_FP16:
810 setAttributeItem(ARMBuildAttrs::FP_arch,
811 ARMBuildAttrs::AllowFPv3B,
812 /* OverwriteExisting= */ false);
813 setAttributeItem(ARMBuildAttrs::FP_HP_extension,
814 ARMBuildAttrs::AllowHPFP,
815 /* OverwriteExisting= */ false);
818 case ARM::FK_VFPV3XD:
819 setAttributeItem(ARMBuildAttrs::FP_arch,
820 ARMBuildAttrs::AllowFPv3B,
821 /* OverwriteExisting= */ false);
823 case ARM::FK_VFPV3XD_FP16:
824 setAttributeItem(ARMBuildAttrs::FP_arch,
825 ARMBuildAttrs::AllowFPv3B,
826 /* OverwriteExisting= */ false);
827 setAttributeItem(ARMBuildAttrs::FP_HP_extension,
828 ARMBuildAttrs::AllowHPFP,
829 /* OverwriteExisting= */ false);
833 setAttributeItem(ARMBuildAttrs::FP_arch,
834 ARMBuildAttrs::AllowFPv4A,
835 /* OverwriteExisting= */ false);
838 // ABI_HardFP_use is handled in ARMAsmPrinter, so _SP_D16 is treated the same
840 case ARM::FK_FPV4_SP_D16:
841 case ARM::FK_VFPV4_D16:
842 setAttributeItem(ARMBuildAttrs::FP_arch,
843 ARMBuildAttrs::AllowFPv4B,
844 /* OverwriteExisting= */ false);
847 case ARM::FK_FP_ARMV8:
848 setAttributeItem(ARMBuildAttrs::FP_arch,
849 ARMBuildAttrs::AllowFPARMv8A,
850 /* OverwriteExisting= */ false);
853 // FPV5_D16 is identical to FP_ARMV8 except for the number of D registers, so
854 // uses the FP_ARMV8_D16 build attribute.
855 case ARM::FK_FPV5_SP_D16:
856 case ARM::FK_FPV5_D16:
857 setAttributeItem(ARMBuildAttrs::FP_arch,
858 ARMBuildAttrs::AllowFPARMv8B,
859 /* OverwriteExisting= */ false);
863 setAttributeItem(ARMBuildAttrs::FP_arch,
864 ARMBuildAttrs::AllowFPv3A,
865 /* OverwriteExisting= */ false);
866 setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
867 ARMBuildAttrs::AllowNeon,
868 /* OverwriteExisting= */ false);
871 case ARM::FK_NEON_FP16:
872 setAttributeItem(ARMBuildAttrs::FP_arch,
873 ARMBuildAttrs::AllowFPv3A,
874 /* OverwriteExisting= */ false);
875 setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
876 ARMBuildAttrs::AllowNeon,
877 /* OverwriteExisting= */ false);
878 setAttributeItem(ARMBuildAttrs::FP_HP_extension,
879 ARMBuildAttrs::AllowHPFP,
880 /* OverwriteExisting= */ false);
883 case ARM::FK_NEON_VFPV4:
884 setAttributeItem(ARMBuildAttrs::FP_arch,
885 ARMBuildAttrs::AllowFPv4A,
886 /* OverwriteExisting= */ false);
887 setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
888 ARMBuildAttrs::AllowNeon2,
889 /* OverwriteExisting= */ false);
892 case ARM::FK_NEON_FP_ARMV8:
893 case ARM::FK_CRYPTO_NEON_FP_ARMV8:
894 setAttributeItem(ARMBuildAttrs::FP_arch,
895 ARMBuildAttrs::AllowFPARMv8A,
896 /* OverwriteExisting= */ false);
897 // 'Advanced_SIMD_arch' must be emitted not here, but within
898 // ARMAsmPrinter::emitAttributes(), depending on hasV8Ops() and hasV8_1a()
901 case ARM::FK_SOFTVFP:
906 report_fatal_error("Unknown FPU: " + Twine(FPU));
910 size_t ARMTargetELFStreamer::calculateContentSize() const {
912 for (size_t i = 0; i < Contents.size(); ++i) {
913 AttributeItem item = Contents[i];
915 case AttributeItem::HiddenAttribute:
917 case AttributeItem::NumericAttribute:
918 Result += getULEB128Size(item.Tag);
919 Result += getULEB128Size(item.IntValue);
921 case AttributeItem::TextAttribute:
922 Result += getULEB128Size(item.Tag);
923 Result += item.StringValue.size() + 1; // string + '\0'
925 case AttributeItem::NumericAndTextAttributes:
926 Result += getULEB128Size(item.Tag);
927 Result += getULEB128Size(item.IntValue);
928 Result += item.StringValue.size() + 1; // string + '\0';
934 void ARMTargetELFStreamer::finishAttributeSection() {
936 // [ <section-length> "vendor-name"
937 // [ <file-tag> <size> <attribute>*
938 // | <section-tag> <size> <section-number>* 0 <attribute>*
939 // | <symbol-tag> <size> <symbol-number>* 0 <attribute>*
943 if (FPU != ARM::FK_INVALID)
944 emitFPUDefaultAttributes();
946 if (Arch != ARM::AK_INVALID)
947 emitArchDefaultAttributes();
949 if (Contents.empty())
952 std::sort(Contents.begin(), Contents.end(), AttributeItem::LessTag);
954 ARMELFStreamer &Streamer = getStreamer();
956 // Switch to .ARM.attributes section
957 if (AttributeSection) {
958 Streamer.SwitchSection(AttributeSection);
960 AttributeSection = Streamer.getContext().getELFSection(
961 ".ARM.attributes", ELF::SHT_ARM_ATTRIBUTES, 0);
962 Streamer.SwitchSection(AttributeSection);
965 Streamer.EmitIntValue(0x41, 1);
968 // Vendor size + Vendor name + '\0'
969 const size_t VendorHeaderSize = 4 + CurrentVendor.size() + 1;
972 const size_t TagHeaderSize = 1 + 4;
974 const size_t ContentsSize = calculateContentSize();
976 Streamer.EmitIntValue(VendorHeaderSize + TagHeaderSize + ContentsSize, 4);
977 Streamer.EmitBytes(CurrentVendor);
978 Streamer.EmitIntValue(0, 1); // '\0'
980 Streamer.EmitIntValue(ARMBuildAttrs::File, 1);
981 Streamer.EmitIntValue(TagHeaderSize + ContentsSize, 4);
983 // Size should have been accounted for already, now
984 // emit each field as its type (ULEB or String)
985 for (size_t i = 0; i < Contents.size(); ++i) {
986 AttributeItem item = Contents[i];
987 Streamer.EmitULEB128IntValue(item.Tag);
989 default: llvm_unreachable("Invalid attribute type");
990 case AttributeItem::NumericAttribute:
991 Streamer.EmitULEB128IntValue(item.IntValue);
993 case AttributeItem::TextAttribute:
994 Streamer.EmitBytes(item.StringValue);
995 Streamer.EmitIntValue(0, 1); // '\0'
997 case AttributeItem::NumericAndTextAttributes:
998 Streamer.EmitULEB128IntValue(item.IntValue);
999 Streamer.EmitBytes(item.StringValue);
1000 Streamer.EmitIntValue(0, 1); // '\0'
1006 FPU = ARM::FK_INVALID;
1009 void ARMTargetELFStreamer::emitLabel(MCSymbol *Symbol) {
1010 ARMELFStreamer &Streamer = getStreamer();
1011 if (!Streamer.IsThumb)
1014 Streamer.getAssembler().registerSymbol(*Symbol);
1015 unsigned Type = cast<MCSymbolELF>(Symbol)->getType();
1016 if (Type == ELF::STT_FUNC || Type == ELF::STT_GNU_IFUNC)
1017 Streamer.EmitThumbFunc(Symbol);
1021 ARMTargetELFStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
1022 getStreamer().EmitFixup(S, FK_Data_4);
1025 void ARMTargetELFStreamer::emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) {
1026 if (const MCSymbolRefExpr *SRE = dyn_cast<MCSymbolRefExpr>(Value)) {
1027 const MCSymbol &Sym = SRE->getSymbol();
1028 if (!Sym.isDefined()) {
1029 getStreamer().EmitAssignment(Symbol, Value);
1034 getStreamer().EmitThumbFunc(Symbol);
1035 getStreamer().EmitAssignment(Symbol, Value);
1038 void ARMTargetELFStreamer::emitInst(uint32_t Inst, char Suffix) {
1039 getStreamer().emitInst(Inst, Suffix);
1042 void ARMELFStreamer::FinishImpl() {
1043 MCTargetStreamer &TS = *getTargetStreamer();
1044 ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
1045 ATS.finishAttributeSection();
1047 MCELFStreamer::FinishImpl();
1050 inline void ARMELFStreamer::SwitchToEHSection(const char *Prefix,
1054 const MCSymbol &Fn) {
1055 const MCSectionELF &FnSection =
1056 static_cast<const MCSectionELF &>(Fn.getSection());
1058 // Create the name for new section
1059 StringRef FnSecName(FnSection.getSectionName());
1060 SmallString<128> EHSecName(Prefix);
1061 if (FnSecName != ".text") {
1062 EHSecName += FnSecName;
1065 // Get .ARM.extab or .ARM.exidx section
1066 const MCSymbolELF *Group = FnSection.getGroup();
1068 Flags |= ELF::SHF_GROUP;
1069 MCSectionELF *EHSection =
1070 getContext().getELFSection(EHSecName, Type, Flags, 0, Group,
1071 FnSection.getUniqueID(), nullptr, &FnSection);
1073 assert(EHSection && "Failed to get the required EH section");
1075 // Switch to .ARM.extab or .ARM.exidx section
1076 SwitchSection(EHSection);
1077 EmitCodeAlignment(4);
1080 inline void ARMELFStreamer::SwitchToExTabSection(const MCSymbol &FnStart) {
1081 SwitchToEHSection(".ARM.extab", ELF::SHT_PROGBITS, ELF::SHF_ALLOC,
1082 SectionKind::getData(), FnStart);
1085 inline void ARMELFStreamer::SwitchToExIdxSection(const MCSymbol &FnStart) {
1086 SwitchToEHSection(".ARM.exidx", ELF::SHT_ARM_EXIDX,
1087 ELF::SHF_ALLOC | ELF::SHF_LINK_ORDER,
1088 SectionKind::getData(), FnStart);
1090 void ARMELFStreamer::EmitFixup(const MCExpr *Expr, MCFixupKind Kind) {
1091 MCDataFragment *Frag = getOrCreateDataFragment();
1092 Frag->getFixups().push_back(MCFixup::create(Frag->getContents().size(), Expr,
1096 void ARMELFStreamer::Reset() {
1099 Personality = nullptr;
1100 PersonalityIndex = ARM::EHABI::NUM_PERSONALITY_INDEX;
1109 UnwindOpAsm.Reset();
1112 void ARMELFStreamer::emitFnStart() {
1113 assert(FnStart == nullptr);
1114 FnStart = getContext().createTempSymbol();
1118 void ARMELFStreamer::emitFnEnd() {
1119 assert(FnStart && ".fnstart must precedes .fnend");
1121 // Emit unwind opcodes if there is no .handlerdata directive
1122 if (!ExTab && !CantUnwind)
1123 FlushUnwindOpcodes(true);
1125 // Emit the exception index table entry
1126 SwitchToExIdxSection(*FnStart);
1128 if (PersonalityIndex < ARM::EHABI::NUM_PERSONALITY_INDEX)
1129 EmitPersonalityFixup(GetAEABIUnwindPersonalityName(PersonalityIndex));
1131 const MCSymbolRefExpr *FnStartRef =
1132 MCSymbolRefExpr::create(FnStart,
1133 MCSymbolRefExpr::VK_ARM_PREL31,
1136 EmitValue(FnStartRef, 4);
1139 EmitIntValue(ARM::EHABI::EXIDX_CANTUNWIND, 4);
1141 // Emit a reference to the unwind opcodes in the ".ARM.extab" section.
1142 const MCSymbolRefExpr *ExTabEntryRef =
1143 MCSymbolRefExpr::create(ExTab,
1144 MCSymbolRefExpr::VK_ARM_PREL31,
1146 EmitValue(ExTabEntryRef, 4);
1148 // For the __aeabi_unwind_cpp_pr0, we have to emit the unwind opcodes in
1149 // the second word of exception index table entry. The size of the unwind
1150 // opcodes should always be 4 bytes.
1151 assert(PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0 &&
1152 "Compact model must use __aeabi_unwind_cpp_pr0 as personality");
1153 assert(Opcodes.size() == 4u &&
1154 "Unwind opcode size for __aeabi_unwind_cpp_pr0 must be equal to 4");
1155 uint64_t Intval = Opcodes[0] |
1159 EmitIntValue(Intval, Opcodes.size());
1162 // Switch to the section containing FnStart
1163 SwitchSection(&FnStart->getSection());
1165 // Clean exception handling frame information
1169 void ARMELFStreamer::emitCantUnwind() { CantUnwind = true; }
1171 // Add the R_ARM_NONE fixup at the same position
1172 void ARMELFStreamer::EmitPersonalityFixup(StringRef Name) {
1173 const MCSymbol *PersonalitySym = getContext().getOrCreateSymbol(Name);
1175 const MCSymbolRefExpr *PersonalityRef = MCSymbolRefExpr::create(
1176 PersonalitySym, MCSymbolRefExpr::VK_ARM_NONE, getContext());
1178 visitUsedExpr(*PersonalityRef);
1179 MCDataFragment *DF = getOrCreateDataFragment();
1180 DF->getFixups().push_back(MCFixup::create(DF->getContents().size(),
1182 MCFixup::getKindForSize(4, false)));
1185 void ARMELFStreamer::FlushPendingOffset() {
1186 if (PendingOffset != 0) {
1187 UnwindOpAsm.EmitSPOffset(-PendingOffset);
1192 void ARMELFStreamer::FlushUnwindOpcodes(bool NoHandlerData) {
1193 // Emit the unwind opcode to restore $sp.
1195 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1196 int64_t LastRegSaveSPOffset = SPOffset - PendingOffset;
1197 UnwindOpAsm.EmitSPOffset(LastRegSaveSPOffset - FPOffset);
1198 UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1200 FlushPendingOffset();
1203 // Finalize the unwind opcode sequence
1204 UnwindOpAsm.Finalize(PersonalityIndex, Opcodes);
1206 // For compact model 0, we have to emit the unwind opcodes in the .ARM.exidx
1207 // section. Thus, we don't have to create an entry in the .ARM.extab
1209 if (NoHandlerData && PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0)
1212 // Switch to .ARM.extab section.
1213 SwitchToExTabSection(*FnStart);
1215 // Create .ARM.extab label for offset in .ARM.exidx
1217 ExTab = getContext().createTempSymbol();
1222 const MCSymbolRefExpr *PersonalityRef =
1223 MCSymbolRefExpr::create(Personality,
1224 MCSymbolRefExpr::VK_ARM_PREL31,
1227 EmitValue(PersonalityRef, 4);
1230 // Emit unwind opcodes
1231 assert((Opcodes.size() % 4) == 0 &&
1232 "Unwind opcode size for __aeabi_cpp_unwind_pr0 must be multiple of 4");
1233 for (unsigned I = 0; I != Opcodes.size(); I += 4) {
1234 uint64_t Intval = Opcodes[I] |
1235 Opcodes[I + 1] << 8 |
1236 Opcodes[I + 2] << 16 |
1237 Opcodes[I + 3] << 24;
1238 EmitIntValue(Intval, 4);
1241 // According to ARM EHABI section 9.2, if the __aeabi_unwind_cpp_pr1() or
1242 // __aeabi_unwind_cpp_pr2() is used, then the handler data must be emitted
1243 // after the unwind opcodes. The handler data consists of several 32-bit
1244 // words, and should be terminated by zero.
1246 // In case that the .handlerdata directive is not specified by the
1247 // programmer, we should emit zero to terminate the handler data.
1248 if (NoHandlerData && !Personality)
1252 void ARMELFStreamer::emitHandlerData() { FlushUnwindOpcodes(false); }
1254 void ARMELFStreamer::emitPersonality(const MCSymbol *Per) {
1256 UnwindOpAsm.setPersonality(Per);
1259 void ARMELFStreamer::emitPersonalityIndex(unsigned Index) {
1260 assert(Index < ARM::EHABI::NUM_PERSONALITY_INDEX && "invalid index");
1261 PersonalityIndex = Index;
1264 void ARMELFStreamer::emitSetFP(unsigned NewFPReg, unsigned NewSPReg,
1266 assert((NewSPReg == ARM::SP || NewSPReg == FPReg) &&
1267 "the operand of .setfp directive should be either $sp or $fp");
1272 if (NewSPReg == ARM::SP)
1273 FPOffset = SPOffset + Offset;
1278 void ARMELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
1279 assert((Reg != ARM::SP && Reg != ARM::PC) &&
1280 "the operand of .movsp cannot be either sp or pc");
1281 assert(FPReg == ARM::SP && "current FP must be SP");
1283 FlushPendingOffset();
1286 FPOffset = SPOffset + Offset;
1288 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1289 UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1292 void ARMELFStreamer::emitPad(int64_t Offset) {
1293 // Track the change of the $sp offset
1296 // To squash multiple .pad directives, we should delay the unwind opcode
1297 // until the .save, .vsave, .handlerdata, or .fnend directives.
1298 PendingOffset -= Offset;
1301 void ARMELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
1303 // Collect the registers in the register list
1306 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1307 for (size_t i = 0; i < RegList.size(); ++i) {
1308 unsigned Reg = MRI->getEncodingValue(RegList[i]);
1309 assert(Reg < (IsVector ? 32U : 16U) && "Register out of range");
1310 unsigned Bit = (1u << Reg);
1311 if ((Mask & Bit) == 0) {
1317 // Track the change the $sp offset: For the .save directive, the
1318 // corresponding push instruction will decrease the $sp by (4 * Count).
1319 // For the .vsave directive, the corresponding vpush instruction will
1320 // decrease $sp by (8 * Count).
1321 SPOffset -= Count * (IsVector ? 8 : 4);
1324 FlushPendingOffset();
1326 UnwindOpAsm.EmitVFPRegSave(Mask);
1328 UnwindOpAsm.EmitRegSave(Mask);
1331 void ARMELFStreamer::emitUnwindRaw(int64_t Offset,
1332 const SmallVectorImpl<uint8_t> &Opcodes) {
1333 FlushPendingOffset();
1334 SPOffset = SPOffset - Offset;
1335 UnwindOpAsm.EmitRaw(Opcodes);
1340 MCTargetStreamer *createARMTargetAsmStreamer(MCStreamer &S,
1341 formatted_raw_ostream &OS,
1342 MCInstPrinter *InstPrint,
1343 bool isVerboseAsm) {
1344 return new ARMTargetAsmStreamer(S, OS, *InstPrint, isVerboseAsm);
1347 MCTargetStreamer *createARMNullTargetStreamer(MCStreamer &S) {
1348 return new ARMTargetStreamer(S);
1351 MCTargetStreamer *createARMObjectTargetStreamer(MCStreamer &S,
1352 const MCSubtargetInfo &STI) {
1353 const Triple &TT = STI.getTargetTriple();
1354 if (TT.isOSBinFormatELF())
1355 return new ARMTargetELFStreamer(S);
1356 return new ARMTargetStreamer(S);
1359 MCELFStreamer *createARMELFStreamer(MCContext &Context, MCAsmBackend &TAB,
1360 raw_pwrite_stream &OS,
1361 MCCodeEmitter *Emitter, bool RelaxAll,
1363 ARMELFStreamer *S = new ARMELFStreamer(Context, TAB, OS, Emitter, IsThumb);
1364 // FIXME: This should eventually end up somewhere else where more
1365 // intelligent flag decisions can be made. For now we are just maintaining
1366 // the status quo for ARM and setting EF_ARM_EABI_VER5 as the default.
1367 S->getAssembler().setELFHeaderEFlags(ELF::EF_ARM_EABI_VER5);
1370 S->getAssembler().setRelaxAll(true);