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/MCELF.h"
26 #include "llvm/MC/MCELFStreamer.h"
27 #include "llvm/MC/MCELFSymbolFlags.h"
28 #include "llvm/MC/MCExpr.h"
29 #include "llvm/MC/MCInst.h"
30 #include "llvm/MC/MCInstPrinter.h"
31 #include "llvm/MC/MCObjectFileInfo.h"
32 #include "llvm/MC/MCObjectStreamer.h"
33 #include "llvm/MC/MCRegisterInfo.h"
34 #include "llvm/MC/MCSection.h"
35 #include "llvm/MC/MCSectionELF.h"
36 #include "llvm/MC/MCStreamer.h"
37 #include "llvm/MC/MCSymbol.h"
38 #include "llvm/MC/MCValue.h"
39 #include "llvm/Support/ARMBuildAttributes.h"
40 #include "llvm/Support/ARMEHABI.h"
41 #include "llvm/Support/TargetParser.h"
42 #include "llvm/Support/Debug.h"
43 #include "llvm/Support/ELF.h"
44 #include "llvm/Support/FormattedStream.h"
45 #include "llvm/Support/LEB128.h"
46 #include "llvm/Support/raw_ostream.h"
51 static std::string GetAEABIUnwindPersonalityName(unsigned Index) {
52 assert(Index < ARM::EHABI::NUM_PERSONALITY_INDEX &&
53 "Invalid personality index");
54 return (Twine("__aeabi_unwind_cpp_pr") + Twine(Index)).str();
61 class ARMTargetAsmStreamer : public ARMTargetStreamer {
62 formatted_raw_ostream &OS;
63 MCInstPrinter &InstPrinter;
66 void emitFnStart() override;
67 void emitFnEnd() override;
68 void emitCantUnwind() override;
69 void emitPersonality(const MCSymbol *Personality) override;
70 void emitPersonalityIndex(unsigned Index) override;
71 void emitHandlerData() override;
72 void emitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0) override;
73 void emitMovSP(unsigned Reg, int64_t Offset = 0) override;
74 void emitPad(int64_t Offset) override;
75 void emitRegSave(const SmallVectorImpl<unsigned> &RegList,
76 bool isVector) override;
77 void emitUnwindRaw(int64_t Offset,
78 const SmallVectorImpl<uint8_t> &Opcodes) override;
80 void switchVendor(StringRef Vendor) override;
81 void emitAttribute(unsigned Attribute, unsigned Value) override;
82 void emitTextAttribute(unsigned Attribute, StringRef String) override;
83 void emitIntTextAttribute(unsigned Attribute, unsigned IntValue,
84 StringRef StrinValue) override;
85 void emitArch(unsigned Arch) override;
86 void emitArchExtension(unsigned ArchExt) override;
87 void emitObjectArch(unsigned Arch) override;
88 void emitFPU(unsigned FPU) override;
89 void emitInst(uint32_t Inst, char Suffix = '\0') override;
90 void finishAttributeSection() override;
92 void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE) override;
93 void emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) override;
96 ARMTargetAsmStreamer(MCStreamer &S, formatted_raw_ostream &OS,
97 MCInstPrinter &InstPrinter, bool VerboseAsm);
100 ARMTargetAsmStreamer::ARMTargetAsmStreamer(MCStreamer &S,
101 formatted_raw_ostream &OS,
102 MCInstPrinter &InstPrinter,
104 : ARMTargetStreamer(S), OS(OS), InstPrinter(InstPrinter),
105 IsVerboseAsm(VerboseAsm) {}
106 void ARMTargetAsmStreamer::emitFnStart() { OS << "\t.fnstart\n"; }
107 void ARMTargetAsmStreamer::emitFnEnd() { OS << "\t.fnend\n"; }
108 void ARMTargetAsmStreamer::emitCantUnwind() { OS << "\t.cantunwind\n"; }
109 void ARMTargetAsmStreamer::emitPersonality(const MCSymbol *Personality) {
110 OS << "\t.personality " << Personality->getName() << '\n';
112 void ARMTargetAsmStreamer::emitPersonalityIndex(unsigned Index) {
113 OS << "\t.personalityindex " << Index << '\n';
115 void ARMTargetAsmStreamer::emitHandlerData() { OS << "\t.handlerdata\n"; }
116 void ARMTargetAsmStreamer::emitSetFP(unsigned FpReg, unsigned SpReg,
119 InstPrinter.printRegName(OS, FpReg);
121 InstPrinter.printRegName(OS, SpReg);
123 OS << ", #" << Offset;
126 void ARMTargetAsmStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
127 assert((Reg != ARM::SP && Reg != ARM::PC) &&
128 "the operand of .movsp cannot be either sp or pc");
131 InstPrinter.printRegName(OS, Reg);
133 OS << ", #" << Offset;
136 void ARMTargetAsmStreamer::emitPad(int64_t Offset) {
137 OS << "\t.pad\t#" << Offset << '\n';
139 void ARMTargetAsmStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
141 assert(RegList.size() && "RegList should not be empty");
147 InstPrinter.printRegName(OS, RegList[0]);
149 for (unsigned i = 1, e = RegList.size(); i != e; ++i) {
151 InstPrinter.printRegName(OS, RegList[i]);
156 void ARMTargetAsmStreamer::switchVendor(StringRef Vendor) {
158 void ARMTargetAsmStreamer::emitAttribute(unsigned Attribute, unsigned Value) {
159 OS << "\t.eabi_attribute\t" << Attribute << ", " << Twine(Value);
161 StringRef Name = ARMBuildAttrs::AttrTypeAsString(Attribute);
163 OS << "\t@ " << Name;
167 void ARMTargetAsmStreamer::emitTextAttribute(unsigned Attribute,
170 case ARMBuildAttrs::CPU_name:
171 OS << "\t.cpu\t" << String.lower();
174 OS << "\t.eabi_attribute\t" << Attribute << ", \"" << String << "\"";
176 StringRef Name = ARMBuildAttrs::AttrTypeAsString(Attribute);
178 OS << "\t@ " << Name;
184 void ARMTargetAsmStreamer::emitIntTextAttribute(unsigned Attribute,
186 StringRef StringValue) {
188 default: llvm_unreachable("unsupported multi-value attribute in asm mode");
189 case ARMBuildAttrs::compatibility:
190 OS << "\t.eabi_attribute\t" << Attribute << ", " << IntValue;
191 if (!StringValue.empty())
192 OS << ", \"" << StringValue << "\"";
194 OS << "\t@ " << ARMBuildAttrs::AttrTypeAsString(Attribute);
199 void ARMTargetAsmStreamer::emitArch(unsigned Arch) {
200 OS << "\t.arch\t" << ARMTargetParser::getArchName(Arch) << "\n";
202 void ARMTargetAsmStreamer::emitArchExtension(unsigned ArchExt) {
203 OS << "\t.arch_extension\t" << ARMTargetParser::getArchExtName(ArchExt) << "\n";
205 void ARMTargetAsmStreamer::emitObjectArch(unsigned Arch) {
206 OS << "\t.object_arch\t" << ARMTargetParser::getArchName(Arch) << '\n';
208 void ARMTargetAsmStreamer::emitFPU(unsigned FPU) {
209 OS << "\t.fpu\t" << ARMTargetParser::getFPUName(FPU) << "\n";
211 void ARMTargetAsmStreamer::finishAttributeSection() {
214 ARMTargetAsmStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
215 OS << "\t.tlsdescseq\t" << S->getSymbol().getName();
218 void ARMTargetAsmStreamer::emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) {
219 OS << "\t.thumb_set\t" << *Symbol << ", " << *Value << '\n';
222 void ARMTargetAsmStreamer::emitInst(uint32_t Inst, char Suffix) {
226 OS << "\t0x" << utohexstr(Inst) << "\n";
229 void ARMTargetAsmStreamer::emitUnwindRaw(int64_t Offset,
230 const SmallVectorImpl<uint8_t> &Opcodes) {
231 OS << "\t.unwind_raw " << Offset;
232 for (SmallVectorImpl<uint8_t>::const_iterator OCI = Opcodes.begin(),
235 OS << ", 0x" << utohexstr(*OCI);
239 class ARMTargetELFStreamer : public ARMTargetStreamer {
241 // This structure holds all attributes, accounting for
242 // their string/numeric value, so we can later emmit them
243 // in declaration order, keeping all in the same vector
244 struct AttributeItem {
249 NumericAndTextAttributes
253 StringRef StringValue;
255 static bool LessTag(const AttributeItem &LHS, const AttributeItem &RHS) {
256 // The conformance tag must be emitted first when serialised
257 // into an object file. Specifically, the addenda to the ARM ABI
258 // states that (2.3.7.4):
260 // "To simplify recognition by consumers in the common case of
261 // claiming conformity for the whole file, this tag should be
262 // emitted first in a file-scope sub-subsection of the first
263 // public subsection of the attributes section."
265 // So it is special-cased in this comparison predicate when the
266 // attributes are sorted in finishAttributeSection().
267 return (RHS.Tag != ARMBuildAttrs::conformance) &&
268 ((LHS.Tag == ARMBuildAttrs::conformance) || (LHS.Tag < RHS.Tag));
272 StringRef CurrentVendor;
275 unsigned EmittedArch;
276 SmallVector<AttributeItem, 64> Contents;
278 const MCSection *AttributeSection;
280 AttributeItem *getAttributeItem(unsigned Attribute) {
281 for (size_t i = 0; i < Contents.size(); ++i)
282 if (Contents[i].Tag == Attribute)
287 void setAttributeItem(unsigned Attribute, unsigned Value,
288 bool OverwriteExisting) {
289 // Look for existing attribute item
290 if (AttributeItem *Item = getAttributeItem(Attribute)) {
291 if (!OverwriteExisting)
293 Item->Type = AttributeItem::NumericAttribute;
294 Item->IntValue = Value;
298 // Create new attribute item
299 AttributeItem Item = {
300 AttributeItem::NumericAttribute,
305 Contents.push_back(Item);
308 void setAttributeItem(unsigned Attribute, StringRef Value,
309 bool OverwriteExisting) {
310 // Look for existing attribute item
311 if (AttributeItem *Item = getAttributeItem(Attribute)) {
312 if (!OverwriteExisting)
314 Item->Type = AttributeItem::TextAttribute;
315 Item->StringValue = Value;
319 // Create new attribute item
320 AttributeItem Item = {
321 AttributeItem::TextAttribute,
326 Contents.push_back(Item);
329 void setAttributeItems(unsigned Attribute, unsigned IntValue,
330 StringRef StringValue, bool OverwriteExisting) {
331 // Look for existing attribute item
332 if (AttributeItem *Item = getAttributeItem(Attribute)) {
333 if (!OverwriteExisting)
335 Item->Type = AttributeItem::NumericAndTextAttributes;
336 Item->IntValue = IntValue;
337 Item->StringValue = StringValue;
341 // Create new attribute item
342 AttributeItem Item = {
343 AttributeItem::NumericAndTextAttributes,
348 Contents.push_back(Item);
351 void emitArchDefaultAttributes();
352 void emitFPUDefaultAttributes();
354 ARMELFStreamer &getStreamer();
356 void emitFnStart() override;
357 void emitFnEnd() override;
358 void emitCantUnwind() override;
359 void emitPersonality(const MCSymbol *Personality) override;
360 void emitPersonalityIndex(unsigned Index) override;
361 void emitHandlerData() override;
362 void emitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0) override;
363 void emitMovSP(unsigned Reg, int64_t Offset = 0) override;
364 void emitPad(int64_t Offset) override;
365 void emitRegSave(const SmallVectorImpl<unsigned> &RegList,
366 bool isVector) override;
367 void emitUnwindRaw(int64_t Offset,
368 const SmallVectorImpl<uint8_t> &Opcodes) override;
370 void switchVendor(StringRef Vendor) override;
371 void emitAttribute(unsigned Attribute, unsigned Value) override;
372 void emitTextAttribute(unsigned Attribute, StringRef String) override;
373 void emitIntTextAttribute(unsigned Attribute, unsigned IntValue,
374 StringRef StringValue) override;
375 void emitArch(unsigned Arch) override;
376 void emitObjectArch(unsigned Arch) override;
377 void emitFPU(unsigned FPU) override;
378 void emitInst(uint32_t Inst, char Suffix = '\0') override;
379 void finishAttributeSection() override;
380 void emitLabel(MCSymbol *Symbol) override;
382 void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE) override;
383 void emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) override;
385 size_t calculateContentSize() const;
388 ARMTargetELFStreamer(MCStreamer &S)
389 : ARMTargetStreamer(S), CurrentVendor("aeabi"), FPU(ARM::INVALID_FPU),
390 Arch(ARM::INVALID_ARCH), EmittedArch(ARM::INVALID_ARCH),
391 AttributeSection(nullptr) {}
394 /// Extend the generic ELFStreamer class so that it can emit mapping symbols at
395 /// the appropriate points in the object files. These symbols are defined in the
396 /// ARM ELF ABI: infocenter.arm.com/help/topic/com.arm.../IHI0044D_aaelf.pdf.
398 /// In brief: $a, $t or $d should be emitted at the start of each contiguous
399 /// region of ARM code, Thumb code or data in a section. In practice, this
400 /// emission does not rely on explicit assembler directives but on inherent
401 /// properties of the directives doing the emission (e.g. ".byte" is data, "add
402 /// r0, r0, r0" an instruction).
404 /// As a result this system is orthogonal to the DataRegion infrastructure used
405 /// by MachO. Beware!
406 class ARMELFStreamer : public MCELFStreamer {
408 friend class ARMTargetELFStreamer;
410 ARMELFStreamer(MCContext &Context, MCAsmBackend &TAB, raw_pwrite_stream &OS,
411 MCCodeEmitter *Emitter, bool IsThumb)
412 : MCELFStreamer(Context, TAB, OS, Emitter), IsThumb(IsThumb),
413 MappingSymbolCounter(0), LastEMS(EMS_None) {
419 void FinishImpl() override;
421 // ARM exception handling directives
424 void emitCantUnwind();
425 void emitPersonality(const MCSymbol *Per);
426 void emitPersonalityIndex(unsigned index);
427 void emitHandlerData();
428 void emitSetFP(unsigned NewFpReg, unsigned NewSpReg, int64_t Offset = 0);
429 void emitMovSP(unsigned Reg, int64_t Offset = 0);
430 void emitPad(int64_t Offset);
431 void emitRegSave(const SmallVectorImpl<unsigned> &RegList, bool isVector);
432 void emitUnwindRaw(int64_t Offset, const SmallVectorImpl<uint8_t> &Opcodes);
434 void ChangeSection(const MCSection *Section,
435 const MCExpr *Subsection) override {
436 // We have to keep track of the mapping symbol state of any sections we
437 // use. Each one should start off as EMS_None, which is provided as the
438 // default constructor by DenseMap::lookup.
439 LastMappingSymbols[getPreviousSection().first] = LastEMS;
440 LastEMS = LastMappingSymbols.lookup(Section);
442 MCELFStreamer::ChangeSection(Section, Subsection);
445 /// This function is the one used to emit instruction data into the ELF
446 /// streamer. We override it to add the appropriate mapping symbol if
448 void EmitInstruction(const MCInst& Inst,
449 const MCSubtargetInfo &STI) override {
451 EmitThumbMappingSymbol();
453 EmitARMMappingSymbol();
455 MCELFStreamer::EmitInstruction(Inst, STI);
458 void emitInst(uint32_t Inst, char Suffix) {
461 const bool LittleEndian = getContext().getAsmInfo()->isLittleEndian();
468 EmitARMMappingSymbol();
469 for (unsigned II = 0, IE = Size; II != IE; II++) {
470 const unsigned I = LittleEndian ? (Size - II - 1) : II;
471 Buffer[Size - II - 1] = uint8_t(Inst >> I * CHAR_BIT);
477 Size = (Suffix == 'n' ? 2 : 4);
480 EmitThumbMappingSymbol();
481 for (unsigned II = 0, IE = Size; II != IE; II = II + 2) {
482 const unsigned I0 = LittleEndian ? II + 0 : (Size - II - 1);
483 const unsigned I1 = LittleEndian ? II + 1 : (Size - II - 2);
484 Buffer[Size - II - 2] = uint8_t(Inst >> I0 * CHAR_BIT);
485 Buffer[Size - II - 1] = uint8_t(Inst >> I1 * CHAR_BIT);
490 llvm_unreachable("Invalid Suffix");
493 MCELFStreamer::EmitBytes(StringRef(Buffer, Size));
496 /// This is one of the functions used to emit data into an ELF section, so the
497 /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
499 void EmitBytes(StringRef Data) override {
500 EmitDataMappingSymbol();
501 MCELFStreamer::EmitBytes(Data);
504 /// This is one of the functions used to emit data into an ELF section, so the
505 /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
507 void EmitValueImpl(const MCExpr *Value, unsigned Size,
508 const SMLoc &Loc) override {
509 if (const MCSymbolRefExpr *SRE = dyn_cast_or_null<MCSymbolRefExpr>(Value))
510 if (SRE->getKind() == MCSymbolRefExpr::VK_ARM_SBREL && !(Size == 4))
511 getContext().FatalError(Loc, "relocated expression must be 32-bit");
513 EmitDataMappingSymbol();
514 MCELFStreamer::EmitValueImpl(Value, Size);
517 void EmitAssemblerFlag(MCAssemblerFlag Flag) override {
518 MCELFStreamer::EmitAssemblerFlag(Flag);
521 case MCAF_SyntaxUnified:
522 return; // no-op here.
525 return; // Change to Thumb mode
528 return; // Change to ARM mode
531 case MCAF_SubsectionsViaSymbols:
537 enum ElfMappingSymbol {
544 void EmitDataMappingSymbol() {
545 if (LastEMS == EMS_Data) return;
546 EmitMappingSymbol("$d");
550 void EmitThumbMappingSymbol() {
551 if (LastEMS == EMS_Thumb) return;
552 EmitMappingSymbol("$t");
556 void EmitARMMappingSymbol() {
557 if (LastEMS == EMS_ARM) return;
558 EmitMappingSymbol("$a");
562 void EmitMappingSymbol(StringRef Name) {
563 MCSymbol *Start = getContext().CreateTempSymbol();
567 getContext().GetOrCreateSymbol(Name + "." +
568 Twine(MappingSymbolCounter++));
570 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
571 MCELF::SetType(SD, ELF::STT_NOTYPE);
572 MCELF::SetBinding(SD, ELF::STB_LOCAL);
573 SD.setExternal(false);
574 AssignSection(Symbol, getCurrentSection().first);
576 const MCExpr *Value = MCSymbolRefExpr::Create(Start, getContext());
577 Symbol->setVariableValue(Value);
580 void EmitThumbFunc(MCSymbol *Func) override {
581 getAssembler().setIsThumbFunc(Func);
582 EmitSymbolAttribute(Func, MCSA_ELF_TypeFunction);
585 // Helper functions for ARM exception handling directives
588 void EmitPersonalityFixup(StringRef Name);
589 void FlushPendingOffset();
590 void FlushUnwindOpcodes(bool NoHandlerData);
592 void SwitchToEHSection(const char *Prefix, unsigned Type, unsigned Flags,
593 SectionKind Kind, const MCSymbol &Fn);
594 void SwitchToExTabSection(const MCSymbol &FnStart);
595 void SwitchToExIdxSection(const MCSymbol &FnStart);
597 void EmitFixup(const MCExpr *Expr, MCFixupKind Kind);
600 int64_t MappingSymbolCounter;
602 DenseMap<const MCSection *, ElfMappingSymbol> LastMappingSymbols;
603 ElfMappingSymbol LastEMS;
605 // ARM Exception Handling Frame Information
608 const MCSymbol *Personality;
609 unsigned PersonalityIndex;
610 unsigned FPReg; // Frame pointer register
611 int64_t FPOffset; // Offset: (final frame pointer) - (initial $sp)
612 int64_t SPOffset; // Offset: (final $sp) - (initial $sp)
613 int64_t PendingOffset; // Offset: (final $sp) - (emitted $sp)
616 SmallVector<uint8_t, 64> Opcodes;
617 UnwindOpcodeAssembler UnwindOpAsm;
619 } // end anonymous namespace
621 ARMELFStreamer &ARMTargetELFStreamer::getStreamer() {
622 return static_cast<ARMELFStreamer &>(Streamer);
625 void ARMTargetELFStreamer::emitFnStart() { getStreamer().emitFnStart(); }
626 void ARMTargetELFStreamer::emitFnEnd() { getStreamer().emitFnEnd(); }
627 void ARMTargetELFStreamer::emitCantUnwind() { getStreamer().emitCantUnwind(); }
628 void ARMTargetELFStreamer::emitPersonality(const MCSymbol *Personality) {
629 getStreamer().emitPersonality(Personality);
631 void ARMTargetELFStreamer::emitPersonalityIndex(unsigned Index) {
632 getStreamer().emitPersonalityIndex(Index);
634 void ARMTargetELFStreamer::emitHandlerData() {
635 getStreamer().emitHandlerData();
637 void ARMTargetELFStreamer::emitSetFP(unsigned FpReg, unsigned SpReg,
639 getStreamer().emitSetFP(FpReg, SpReg, Offset);
641 void ARMTargetELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
642 getStreamer().emitMovSP(Reg, Offset);
644 void ARMTargetELFStreamer::emitPad(int64_t Offset) {
645 getStreamer().emitPad(Offset);
647 void ARMTargetELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
649 getStreamer().emitRegSave(RegList, isVector);
651 void ARMTargetELFStreamer::emitUnwindRaw(int64_t Offset,
652 const SmallVectorImpl<uint8_t> &Opcodes) {
653 getStreamer().emitUnwindRaw(Offset, Opcodes);
655 void ARMTargetELFStreamer::switchVendor(StringRef Vendor) {
656 assert(!Vendor.empty() && "Vendor cannot be empty.");
658 if (CurrentVendor == Vendor)
661 if (!CurrentVendor.empty())
662 finishAttributeSection();
664 assert(Contents.empty() &&
665 ".ARM.attributes should be flushed before changing vendor");
666 CurrentVendor = Vendor;
669 void ARMTargetELFStreamer::emitAttribute(unsigned Attribute, unsigned Value) {
670 setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
672 void ARMTargetELFStreamer::emitTextAttribute(unsigned Attribute,
674 setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
676 void ARMTargetELFStreamer::emitIntTextAttribute(unsigned Attribute,
678 StringRef StringValue) {
679 setAttributeItems(Attribute, IntValue, StringValue,
680 /* OverwriteExisting= */ true);
682 void ARMTargetELFStreamer::emitArch(unsigned Value) {
685 void ARMTargetELFStreamer::emitObjectArch(unsigned Value) {
688 void ARMTargetELFStreamer::emitArchDefaultAttributes() {
689 using namespace ARMBuildAttrs;
691 setAttributeItem(CPU_name,
692 ARMTargetParser::getArchDefaultCPUName(Arch),
695 if (EmittedArch == ARM::INVALID_ARCH)
696 setAttributeItem(CPU_arch,
697 ARMTargetParser::getArchDefaultCPUArch(Arch),
700 setAttributeItem(CPU_arch,
701 ARMTargetParser::getArchDefaultCPUArch(EmittedArch),
711 setAttributeItem(ARM_ISA_use, Allowed, false);
719 setAttributeItem(ARM_ISA_use, Allowed, false);
720 setAttributeItem(THUMB_ISA_use, Allowed, false);
724 setAttributeItem(ARM_ISA_use, Allowed, false);
725 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
731 setAttributeItem(ARM_ISA_use, Allowed, false);
732 setAttributeItem(THUMB_ISA_use, Allowed, false);
733 setAttributeItem(Virtualization_use, AllowTZ, false);
737 setAttributeItem(THUMB_ISA_use, Allowed, false);
741 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
745 setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
746 setAttributeItem(ARM_ISA_use, Allowed, false);
747 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
751 setAttributeItem(CPU_arch_profile, RealTimeProfile, false);
752 setAttributeItem(ARM_ISA_use, Allowed, false);
753 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
757 setAttributeItem(CPU_arch_profile, MicroControllerProfile, false);
758 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
763 setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
764 setAttributeItem(ARM_ISA_use, Allowed, false);
765 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
766 setAttributeItem(MPextension_use, Allowed, false);
767 setAttributeItem(Virtualization_use, AllowTZVirtualization, false);
771 setAttributeItem(ARM_ISA_use, Allowed, false);
772 setAttributeItem(THUMB_ISA_use, Allowed, false);
773 setAttributeItem(WMMX_arch, AllowWMMXv1, false);
777 setAttributeItem(ARM_ISA_use, Allowed, false);
778 setAttributeItem(THUMB_ISA_use, Allowed, false);
779 setAttributeItem(WMMX_arch, AllowWMMXv2, false);
783 report_fatal_error("Unknown Arch: " + Twine(Arch));
787 void ARMTargetELFStreamer::emitFPU(unsigned Value) {
790 void ARMTargetELFStreamer::emitFPUDefaultAttributes() {
794 setAttributeItem(ARMBuildAttrs::FP_arch,
795 ARMBuildAttrs::AllowFPv2,
796 /* OverwriteExisting= */ false);
800 setAttributeItem(ARMBuildAttrs::FP_arch,
801 ARMBuildAttrs::AllowFPv3A,
802 /* OverwriteExisting= */ false);
806 setAttributeItem(ARMBuildAttrs::FP_arch,
807 ARMBuildAttrs::AllowFPv3B,
808 /* OverwriteExisting= */ false);
812 setAttributeItem(ARMBuildAttrs::FP_arch,
813 ARMBuildAttrs::AllowFPv4A,
814 /* OverwriteExisting= */ false);
818 setAttributeItem(ARMBuildAttrs::FP_arch,
819 ARMBuildAttrs::AllowFPv4B,
820 /* OverwriteExisting= */ false);
824 setAttributeItem(ARMBuildAttrs::FP_arch,
825 ARMBuildAttrs::AllowFPARMv8A,
826 /* OverwriteExisting= */ false);
829 // FPV5_D16 is identical to FP_ARMV8 except for the number of D registers, so
830 // uses the FP_ARMV8_D16 build attribute.
832 setAttributeItem(ARMBuildAttrs::FP_arch,
833 ARMBuildAttrs::AllowFPARMv8B,
834 /* OverwriteExisting= */ false);
838 setAttributeItem(ARMBuildAttrs::FP_arch,
839 ARMBuildAttrs::AllowFPv3A,
840 /* OverwriteExisting= */ false);
841 setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
842 ARMBuildAttrs::AllowNeon,
843 /* OverwriteExisting= */ false);
846 case ARM::NEON_VFPV4:
847 setAttributeItem(ARMBuildAttrs::FP_arch,
848 ARMBuildAttrs::AllowFPv4A,
849 /* OverwriteExisting= */ false);
850 setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
851 ARMBuildAttrs::AllowNeon2,
852 /* OverwriteExisting= */ false);
855 case ARM::NEON_FP_ARMV8:
856 case ARM::CRYPTO_NEON_FP_ARMV8:
857 setAttributeItem(ARMBuildAttrs::FP_arch,
858 ARMBuildAttrs::AllowFPARMv8A,
859 /* OverwriteExisting= */ false);
860 // 'Advanced_SIMD_arch' must be emitted not here, but within
861 // ARMAsmPrinter::emitAttributes(), depending on hasV8Ops() and hasV8_1a()
868 report_fatal_error("Unknown FPU: " + Twine(FPU));
872 size_t ARMTargetELFStreamer::calculateContentSize() const {
874 for (size_t i = 0; i < Contents.size(); ++i) {
875 AttributeItem item = Contents[i];
877 case AttributeItem::HiddenAttribute:
879 case AttributeItem::NumericAttribute:
880 Result += getULEB128Size(item.Tag);
881 Result += getULEB128Size(item.IntValue);
883 case AttributeItem::TextAttribute:
884 Result += getULEB128Size(item.Tag);
885 Result += item.StringValue.size() + 1; // string + '\0'
887 case AttributeItem::NumericAndTextAttributes:
888 Result += getULEB128Size(item.Tag);
889 Result += getULEB128Size(item.IntValue);
890 Result += item.StringValue.size() + 1; // string + '\0';
896 void ARMTargetELFStreamer::finishAttributeSection() {
898 // [ <section-length> "vendor-name"
899 // [ <file-tag> <size> <attribute>*
900 // | <section-tag> <size> <section-number>* 0 <attribute>*
901 // | <symbol-tag> <size> <symbol-number>* 0 <attribute>*
905 if (FPU != ARM::INVALID_FPU)
906 emitFPUDefaultAttributes();
908 if (Arch != ARM::INVALID_ARCH)
909 emitArchDefaultAttributes();
911 if (Contents.empty())
914 std::sort(Contents.begin(), Contents.end(), AttributeItem::LessTag);
916 ARMELFStreamer &Streamer = getStreamer();
918 // Switch to .ARM.attributes section
919 if (AttributeSection) {
920 Streamer.SwitchSection(AttributeSection);
922 AttributeSection = Streamer.getContext().getELFSection(
923 ".ARM.attributes", ELF::SHT_ARM_ATTRIBUTES, 0);
924 Streamer.SwitchSection(AttributeSection);
927 Streamer.EmitIntValue(0x41, 1);
930 // Vendor size + Vendor name + '\0'
931 const size_t VendorHeaderSize = 4 + CurrentVendor.size() + 1;
934 const size_t TagHeaderSize = 1 + 4;
936 const size_t ContentsSize = calculateContentSize();
938 Streamer.EmitIntValue(VendorHeaderSize + TagHeaderSize + ContentsSize, 4);
939 Streamer.EmitBytes(CurrentVendor);
940 Streamer.EmitIntValue(0, 1); // '\0'
942 Streamer.EmitIntValue(ARMBuildAttrs::File, 1);
943 Streamer.EmitIntValue(TagHeaderSize + ContentsSize, 4);
945 // Size should have been accounted for already, now
946 // emit each field as its type (ULEB or String)
947 for (size_t i = 0; i < Contents.size(); ++i) {
948 AttributeItem item = Contents[i];
949 Streamer.EmitULEB128IntValue(item.Tag);
951 default: llvm_unreachable("Invalid attribute type");
952 case AttributeItem::NumericAttribute:
953 Streamer.EmitULEB128IntValue(item.IntValue);
955 case AttributeItem::TextAttribute:
956 Streamer.EmitBytes(item.StringValue);
957 Streamer.EmitIntValue(0, 1); // '\0'
959 case AttributeItem::NumericAndTextAttributes:
960 Streamer.EmitULEB128IntValue(item.IntValue);
961 Streamer.EmitBytes(item.StringValue);
962 Streamer.EmitIntValue(0, 1); // '\0'
968 FPU = ARM::INVALID_FPU;
971 void ARMTargetELFStreamer::emitLabel(MCSymbol *Symbol) {
972 ARMELFStreamer &Streamer = getStreamer();
973 if (!Streamer.IsThumb)
976 const MCSymbolData &SD = Streamer.getOrCreateSymbolData(Symbol);
977 unsigned Type = MCELF::GetType(SD);
978 if (Type == ELF_STT_Func || Type == ELF_STT_GnuIFunc)
979 Streamer.EmitThumbFunc(Symbol);
983 ARMTargetELFStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
984 getStreamer().EmitFixup(S, FK_Data_4);
987 void ARMTargetELFStreamer::emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) {
988 if (const MCSymbolRefExpr *SRE = dyn_cast<MCSymbolRefExpr>(Value)) {
989 const MCSymbol &Sym = SRE->getSymbol();
990 if (!Sym.isDefined()) {
991 getStreamer().EmitAssignment(Symbol, Value);
996 getStreamer().EmitThumbFunc(Symbol);
997 getStreamer().EmitAssignment(Symbol, Value);
1000 void ARMTargetELFStreamer::emitInst(uint32_t Inst, char Suffix) {
1001 getStreamer().emitInst(Inst, Suffix);
1004 void ARMELFStreamer::FinishImpl() {
1005 MCTargetStreamer &TS = *getTargetStreamer();
1006 ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
1007 ATS.finishAttributeSection();
1009 MCELFStreamer::FinishImpl();
1012 inline void ARMELFStreamer::SwitchToEHSection(const char *Prefix,
1016 const MCSymbol &Fn) {
1017 const MCSectionELF &FnSection =
1018 static_cast<const MCSectionELF &>(Fn.getSection());
1020 // Create the name for new section
1021 StringRef FnSecName(FnSection.getSectionName());
1022 SmallString<128> EHSecName(Prefix);
1023 if (FnSecName != ".text") {
1024 EHSecName += FnSecName;
1027 // Get .ARM.extab or .ARM.exidx section
1028 const MCSymbol *Group = FnSection.getGroup();
1030 Flags |= ELF::SHF_GROUP;
1031 const MCSectionELF *EHSection =
1032 getContext().getELFSection(EHSecName, Type, Flags, 0, Group,
1033 FnSection.getUniqueID(), nullptr, &FnSection);
1035 assert(EHSection && "Failed to get the required EH section");
1037 // Switch to .ARM.extab or .ARM.exidx section
1038 SwitchSection(EHSection);
1039 EmitCodeAlignment(4);
1042 inline void ARMELFStreamer::SwitchToExTabSection(const MCSymbol &FnStart) {
1043 SwitchToEHSection(".ARM.extab",
1046 SectionKind::getDataRel(),
1050 inline void ARMELFStreamer::SwitchToExIdxSection(const MCSymbol &FnStart) {
1051 SwitchToEHSection(".ARM.exidx",
1053 ELF::SHF_ALLOC | ELF::SHF_LINK_ORDER,
1054 SectionKind::getDataRel(),
1057 void ARMELFStreamer::EmitFixup(const MCExpr *Expr, MCFixupKind Kind) {
1058 MCDataFragment *Frag = getOrCreateDataFragment();
1059 Frag->getFixups().push_back(MCFixup::Create(Frag->getContents().size(), Expr,
1063 void ARMELFStreamer::Reset() {
1066 Personality = nullptr;
1067 PersonalityIndex = ARM::EHABI::NUM_PERSONALITY_INDEX;
1076 UnwindOpAsm.Reset();
1079 void ARMELFStreamer::emitFnStart() {
1080 assert(FnStart == nullptr);
1081 FnStart = getContext().CreateTempSymbol();
1085 void ARMELFStreamer::emitFnEnd() {
1086 assert(FnStart && ".fnstart must precedes .fnend");
1088 // Emit unwind opcodes if there is no .handlerdata directive
1089 if (!ExTab && !CantUnwind)
1090 FlushUnwindOpcodes(true);
1092 // Emit the exception index table entry
1093 SwitchToExIdxSection(*FnStart);
1095 if (PersonalityIndex < ARM::EHABI::NUM_PERSONALITY_INDEX)
1096 EmitPersonalityFixup(GetAEABIUnwindPersonalityName(PersonalityIndex));
1098 const MCSymbolRefExpr *FnStartRef =
1099 MCSymbolRefExpr::Create(FnStart,
1100 MCSymbolRefExpr::VK_ARM_PREL31,
1103 EmitValue(FnStartRef, 4);
1106 EmitIntValue(ARM::EHABI::EXIDX_CANTUNWIND, 4);
1108 // Emit a reference to the unwind opcodes in the ".ARM.extab" section.
1109 const MCSymbolRefExpr *ExTabEntryRef =
1110 MCSymbolRefExpr::Create(ExTab,
1111 MCSymbolRefExpr::VK_ARM_PREL31,
1113 EmitValue(ExTabEntryRef, 4);
1115 // For the __aeabi_unwind_cpp_pr0, we have to emit the unwind opcodes in
1116 // the second word of exception index table entry. The size of the unwind
1117 // opcodes should always be 4 bytes.
1118 assert(PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0 &&
1119 "Compact model must use __aeabi_unwind_cpp_pr0 as personality");
1120 assert(Opcodes.size() == 4u &&
1121 "Unwind opcode size for __aeabi_unwind_cpp_pr0 must be equal to 4");
1122 uint64_t Intval = Opcodes[0] |
1126 EmitIntValue(Intval, Opcodes.size());
1129 // Switch to the section containing FnStart
1130 SwitchSection(&FnStart->getSection());
1132 // Clean exception handling frame information
1136 void ARMELFStreamer::emitCantUnwind() { CantUnwind = true; }
1138 // Add the R_ARM_NONE fixup at the same position
1139 void ARMELFStreamer::EmitPersonalityFixup(StringRef Name) {
1140 const MCSymbol *PersonalitySym = getContext().GetOrCreateSymbol(Name);
1142 const MCSymbolRefExpr *PersonalityRef = MCSymbolRefExpr::Create(
1143 PersonalitySym, MCSymbolRefExpr::VK_ARM_NONE, getContext());
1145 visitUsedExpr(*PersonalityRef);
1146 MCDataFragment *DF = getOrCreateDataFragment();
1147 DF->getFixups().push_back(MCFixup::Create(DF->getContents().size(),
1149 MCFixup::getKindForSize(4, false)));
1152 void ARMELFStreamer::FlushPendingOffset() {
1153 if (PendingOffset != 0) {
1154 UnwindOpAsm.EmitSPOffset(-PendingOffset);
1159 void ARMELFStreamer::FlushUnwindOpcodes(bool NoHandlerData) {
1160 // Emit the unwind opcode to restore $sp.
1162 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1163 int64_t LastRegSaveSPOffset = SPOffset - PendingOffset;
1164 UnwindOpAsm.EmitSPOffset(LastRegSaveSPOffset - FPOffset);
1165 UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1167 FlushPendingOffset();
1170 // Finalize the unwind opcode sequence
1171 UnwindOpAsm.Finalize(PersonalityIndex, Opcodes);
1173 // For compact model 0, we have to emit the unwind opcodes in the .ARM.exidx
1174 // section. Thus, we don't have to create an entry in the .ARM.extab
1176 if (NoHandlerData && PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0)
1179 // Switch to .ARM.extab section.
1180 SwitchToExTabSection(*FnStart);
1182 // Create .ARM.extab label for offset in .ARM.exidx
1184 ExTab = getContext().CreateTempSymbol();
1189 const MCSymbolRefExpr *PersonalityRef =
1190 MCSymbolRefExpr::Create(Personality,
1191 MCSymbolRefExpr::VK_ARM_PREL31,
1194 EmitValue(PersonalityRef, 4);
1197 // Emit unwind opcodes
1198 assert((Opcodes.size() % 4) == 0 &&
1199 "Unwind opcode size for __aeabi_cpp_unwind_pr0 must be multiple of 4");
1200 for (unsigned I = 0; I != Opcodes.size(); I += 4) {
1201 uint64_t Intval = Opcodes[I] |
1202 Opcodes[I + 1] << 8 |
1203 Opcodes[I + 2] << 16 |
1204 Opcodes[I + 3] << 24;
1205 EmitIntValue(Intval, 4);
1208 // According to ARM EHABI section 9.2, if the __aeabi_unwind_cpp_pr1() or
1209 // __aeabi_unwind_cpp_pr2() is used, then the handler data must be emitted
1210 // after the unwind opcodes. The handler data consists of several 32-bit
1211 // words, and should be terminated by zero.
1213 // In case that the .handlerdata directive is not specified by the
1214 // programmer, we should emit zero to terminate the handler data.
1215 if (NoHandlerData && !Personality)
1219 void ARMELFStreamer::emitHandlerData() { FlushUnwindOpcodes(false); }
1221 void ARMELFStreamer::emitPersonality(const MCSymbol *Per) {
1223 UnwindOpAsm.setPersonality(Per);
1226 void ARMELFStreamer::emitPersonalityIndex(unsigned Index) {
1227 assert(Index < ARM::EHABI::NUM_PERSONALITY_INDEX && "invalid index");
1228 PersonalityIndex = Index;
1231 void ARMELFStreamer::emitSetFP(unsigned NewFPReg, unsigned NewSPReg,
1233 assert((NewSPReg == ARM::SP || NewSPReg == FPReg) &&
1234 "the operand of .setfp directive should be either $sp or $fp");
1239 if (NewSPReg == ARM::SP)
1240 FPOffset = SPOffset + Offset;
1245 void ARMELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
1246 assert((Reg != ARM::SP && Reg != ARM::PC) &&
1247 "the operand of .movsp cannot be either sp or pc");
1248 assert(FPReg == ARM::SP && "current FP must be SP");
1250 FlushPendingOffset();
1253 FPOffset = SPOffset + Offset;
1255 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1256 UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1259 void ARMELFStreamer::emitPad(int64_t Offset) {
1260 // Track the change of the $sp offset
1263 // To squash multiple .pad directives, we should delay the unwind opcode
1264 // until the .save, .vsave, .handlerdata, or .fnend directives.
1265 PendingOffset -= Offset;
1268 void ARMELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
1270 // Collect the registers in the register list
1273 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1274 for (size_t i = 0; i < RegList.size(); ++i) {
1275 unsigned Reg = MRI->getEncodingValue(RegList[i]);
1276 assert(Reg < (IsVector ? 32U : 16U) && "Register out of range");
1277 unsigned Bit = (1u << Reg);
1278 if ((Mask & Bit) == 0) {
1284 // Track the change the $sp offset: For the .save directive, the
1285 // corresponding push instruction will decrease the $sp by (4 * Count).
1286 // For the .vsave directive, the corresponding vpush instruction will
1287 // decrease $sp by (8 * Count).
1288 SPOffset -= Count * (IsVector ? 8 : 4);
1291 FlushPendingOffset();
1293 UnwindOpAsm.EmitVFPRegSave(Mask);
1295 UnwindOpAsm.EmitRegSave(Mask);
1298 void ARMELFStreamer::emitUnwindRaw(int64_t Offset,
1299 const SmallVectorImpl<uint8_t> &Opcodes) {
1300 FlushPendingOffset();
1301 SPOffset = SPOffset - Offset;
1302 UnwindOpAsm.EmitRaw(Opcodes);
1307 MCTargetStreamer *createARMTargetAsmStreamer(MCStreamer &S,
1308 formatted_raw_ostream &OS,
1309 MCInstPrinter *InstPrint,
1310 bool isVerboseAsm) {
1311 return new ARMTargetAsmStreamer(S, OS, *InstPrint, isVerboseAsm);
1314 MCTargetStreamer *createARMNullTargetStreamer(MCStreamer &S) {
1315 return new ARMTargetStreamer(S);
1318 MCTargetStreamer *createARMObjectTargetStreamer(MCStreamer &S,
1319 const MCSubtargetInfo &STI) {
1320 Triple TT(STI.getTargetTriple());
1321 if (TT.getObjectFormat() == Triple::ELF)
1322 return new ARMTargetELFStreamer(S);
1323 return new ARMTargetStreamer(S);
1326 MCELFStreamer *createARMELFStreamer(MCContext &Context, MCAsmBackend &TAB,
1327 raw_pwrite_stream &OS,
1328 MCCodeEmitter *Emitter, bool RelaxAll,
1330 ARMELFStreamer *S = new ARMELFStreamer(Context, TAB, OS, Emitter, IsThumb);
1331 // FIXME: This should eventually end up somewhere else where more
1332 // intelligent flag decisions can be made. For now we are just maintaining
1333 // the status quo for ARM and setting EF_ARM_EABI_VER5 as the default.
1334 S->getAssembler().setELFHeaderEFlags(ELF::EF_ARM_EABI_VER5);
1337 S->getAssembler().setRelaxAll(true);