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" << ARMTargetParser::getArchName(Arch) << "\n";
200 void ARMTargetAsmStreamer::emitArchExtension(unsigned ArchExt) {
201 OS << "\t.arch_extension\t" << ARMTargetParser::getArchExtName(ArchExt) << "\n";
203 void ARMTargetAsmStreamer::emitObjectArch(unsigned Arch) {
204 OS << "\t.object_arch\t" << ARMTargetParser::getArchName(Arch) << '\n';
206 void ARMTargetAsmStreamer::emitFPU(unsigned FPU) {
207 OS << "\t.fpu\t" << ARMTargetParser::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 ($d) if
510 void EmitValueImpl(const MCExpr *Value, unsigned Size,
511 const SMLoc &Loc) override {
512 if (const MCSymbolRefExpr *SRE = dyn_cast_or_null<MCSymbolRefExpr>(Value))
513 if (SRE->getKind() == MCSymbolRefExpr::VK_ARM_SBREL && !(Size == 4))
514 getContext().reportFatalError(Loc, "relocated expression must be 32-bit");
516 EmitDataMappingSymbol();
517 MCELFStreamer::EmitValueImpl(Value, Size);
520 void EmitAssemblerFlag(MCAssemblerFlag Flag) override {
521 MCELFStreamer::EmitAssemblerFlag(Flag);
524 case MCAF_SyntaxUnified:
525 return; // no-op here.
528 return; // Change to Thumb mode
531 return; // Change to ARM mode
534 case MCAF_SubsectionsViaSymbols:
540 enum ElfMappingSymbol {
547 void EmitDataMappingSymbol() {
548 if (LastEMS == EMS_Data) return;
549 EmitMappingSymbol("$d");
553 void EmitThumbMappingSymbol() {
554 if (LastEMS == EMS_Thumb) return;
555 EmitMappingSymbol("$t");
559 void EmitARMMappingSymbol() {
560 if (LastEMS == EMS_ARM) return;
561 EmitMappingSymbol("$a");
565 void EmitMappingSymbol(StringRef Name) {
566 MCSymbol *Start = getContext().createTempSymbol();
569 auto *Symbol = cast<MCSymbolELF>(getContext().getOrCreateSymbol(
570 Name + "." + Twine(MappingSymbolCounter++)));
572 getAssembler().registerSymbol(*Symbol);
573 Symbol->setType(ELF::STT_NOTYPE);
574 Symbol->setBinding(ELF::STB_LOCAL);
575 Symbol->setExternal(false);
576 AssignSection(Symbol, getCurrentSection().first);
578 const MCExpr *Value = MCSymbolRefExpr::create(Start, getContext());
579 Symbol->setVariableValue(Value);
582 void EmitThumbFunc(MCSymbol *Func) override {
583 getAssembler().setIsThumbFunc(Func);
584 EmitSymbolAttribute(Func, MCSA_ELF_TypeFunction);
587 // Helper functions for ARM exception handling directives
590 void EmitPersonalityFixup(StringRef Name);
591 void FlushPendingOffset();
592 void FlushUnwindOpcodes(bool NoHandlerData);
594 void SwitchToEHSection(const char *Prefix, unsigned Type, unsigned Flags,
595 SectionKind Kind, const MCSymbol &Fn);
596 void SwitchToExTabSection(const MCSymbol &FnStart);
597 void SwitchToExIdxSection(const MCSymbol &FnStart);
599 void EmitFixup(const MCExpr *Expr, MCFixupKind Kind);
602 int64_t MappingSymbolCounter;
604 DenseMap<const MCSection *, ElfMappingSymbol> LastMappingSymbols;
605 ElfMappingSymbol LastEMS;
607 // ARM Exception Handling Frame Information
610 const MCSymbol *Personality;
611 unsigned PersonalityIndex;
612 unsigned FPReg; // Frame pointer register
613 int64_t FPOffset; // Offset: (final frame pointer) - (initial $sp)
614 int64_t SPOffset; // Offset: (final $sp) - (initial $sp)
615 int64_t PendingOffset; // Offset: (final $sp) - (emitted $sp)
618 SmallVector<uint8_t, 64> Opcodes;
619 UnwindOpcodeAssembler UnwindOpAsm;
621 } // end anonymous namespace
623 ARMELFStreamer &ARMTargetELFStreamer::getStreamer() {
624 return static_cast<ARMELFStreamer &>(Streamer);
627 void ARMTargetELFStreamer::emitFnStart() { getStreamer().emitFnStart(); }
628 void ARMTargetELFStreamer::emitFnEnd() { getStreamer().emitFnEnd(); }
629 void ARMTargetELFStreamer::emitCantUnwind() { getStreamer().emitCantUnwind(); }
630 void ARMTargetELFStreamer::emitPersonality(const MCSymbol *Personality) {
631 getStreamer().emitPersonality(Personality);
633 void ARMTargetELFStreamer::emitPersonalityIndex(unsigned Index) {
634 getStreamer().emitPersonalityIndex(Index);
636 void ARMTargetELFStreamer::emitHandlerData() {
637 getStreamer().emitHandlerData();
639 void ARMTargetELFStreamer::emitSetFP(unsigned FpReg, unsigned SpReg,
641 getStreamer().emitSetFP(FpReg, SpReg, Offset);
643 void ARMTargetELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
644 getStreamer().emitMovSP(Reg, Offset);
646 void ARMTargetELFStreamer::emitPad(int64_t Offset) {
647 getStreamer().emitPad(Offset);
649 void ARMTargetELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
651 getStreamer().emitRegSave(RegList, isVector);
653 void ARMTargetELFStreamer::emitUnwindRaw(int64_t Offset,
654 const SmallVectorImpl<uint8_t> &Opcodes) {
655 getStreamer().emitUnwindRaw(Offset, Opcodes);
657 void ARMTargetELFStreamer::switchVendor(StringRef Vendor) {
658 assert(!Vendor.empty() && "Vendor cannot be empty.");
660 if (CurrentVendor == Vendor)
663 if (!CurrentVendor.empty())
664 finishAttributeSection();
666 assert(Contents.empty() &&
667 ".ARM.attributes should be flushed before changing vendor");
668 CurrentVendor = Vendor;
671 void ARMTargetELFStreamer::emitAttribute(unsigned Attribute, unsigned Value) {
672 setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
674 void ARMTargetELFStreamer::emitTextAttribute(unsigned Attribute,
676 setAttributeItem(Attribute, Value, /* OverwriteExisting= */ true);
678 void ARMTargetELFStreamer::emitIntTextAttribute(unsigned Attribute,
680 StringRef StringValue) {
681 setAttributeItems(Attribute, IntValue, StringValue,
682 /* OverwriteExisting= */ true);
684 void ARMTargetELFStreamer::emitArch(unsigned Value) {
687 void ARMTargetELFStreamer::emitObjectArch(unsigned Value) {
690 void ARMTargetELFStreamer::emitArchDefaultAttributes() {
691 using namespace ARMBuildAttrs;
693 setAttributeItem(CPU_name,
694 ARMTargetParser::getCPUAttr(Arch),
697 if (EmittedArch == ARM::AK_INVALID)
698 setAttributeItem(CPU_arch,
699 ARMTargetParser::getArchAttr(Arch),
702 setAttributeItem(CPU_arch,
703 ARMTargetParser::getArchAttr(EmittedArch),
713 setAttributeItem(ARM_ISA_use, Allowed, false);
718 case ARM::AK_ARMV5TE:
721 setAttributeItem(ARM_ISA_use, Allowed, false);
722 setAttributeItem(THUMB_ISA_use, Allowed, false);
725 case ARM::AK_ARMV6T2:
726 setAttributeItem(ARM_ISA_use, Allowed, false);
727 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
732 case ARM::AK_ARMV6ZK:
733 setAttributeItem(ARM_ISA_use, Allowed, false);
734 setAttributeItem(THUMB_ISA_use, Allowed, false);
735 setAttributeItem(Virtualization_use, AllowTZ, false);
739 setAttributeItem(THUMB_ISA_use, Allowed, false);
743 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
747 setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
748 setAttributeItem(ARM_ISA_use, Allowed, false);
749 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
753 setAttributeItem(CPU_arch_profile, RealTimeProfile, false);
754 setAttributeItem(ARM_ISA_use, Allowed, false);
755 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
759 setAttributeItem(CPU_arch_profile, MicroControllerProfile, false);
760 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
764 case ARM::AK_ARMV8_1A:
765 setAttributeItem(CPU_arch_profile, ApplicationProfile, false);
766 setAttributeItem(ARM_ISA_use, Allowed, false);
767 setAttributeItem(THUMB_ISA_use, AllowThumb32, false);
768 setAttributeItem(MPextension_use, Allowed, false);
769 setAttributeItem(Virtualization_use, AllowTZVirtualization, false);
773 setAttributeItem(ARM_ISA_use, Allowed, false);
774 setAttributeItem(THUMB_ISA_use, Allowed, false);
775 setAttributeItem(WMMX_arch, AllowWMMXv1, false);
778 case ARM::AK_IWMMXT2:
779 setAttributeItem(ARM_ISA_use, Allowed, false);
780 setAttributeItem(THUMB_ISA_use, Allowed, false);
781 setAttributeItem(WMMX_arch, AllowWMMXv2, false);
785 report_fatal_error("Unknown Arch: " + Twine(Arch));
789 void ARMTargetELFStreamer::emitFPU(unsigned Value) {
792 void ARMTargetELFStreamer::emitFPUDefaultAttributes() {
796 setAttributeItem(ARMBuildAttrs::FP_arch,
797 ARMBuildAttrs::AllowFPv2,
798 /* OverwriteExisting= */ false);
802 setAttributeItem(ARMBuildAttrs::FP_arch,
803 ARMBuildAttrs::AllowFPv3A,
804 /* OverwriteExisting= */ false);
807 case ARM::FK_VFPV3_D16:
808 setAttributeItem(ARMBuildAttrs::FP_arch,
809 ARMBuildAttrs::AllowFPv3B,
810 /* OverwriteExisting= */ false);
814 setAttributeItem(ARMBuildAttrs::FP_arch,
815 ARMBuildAttrs::AllowFPv4A,
816 /* OverwriteExisting= */ false);
819 // ABI_HardFP_use is handled in ARMAsmPrinter, so _SP_D16 is treated the same
821 case ARM::FK_FPV4_SP_D16:
822 case ARM::FK_VFPV4_D16:
823 setAttributeItem(ARMBuildAttrs::FP_arch,
824 ARMBuildAttrs::AllowFPv4B,
825 /* OverwriteExisting= */ false);
828 case ARM::FK_FP_ARMV8:
829 setAttributeItem(ARMBuildAttrs::FP_arch,
830 ARMBuildAttrs::AllowFPARMv8A,
831 /* OverwriteExisting= */ false);
834 // FPV5_D16 is identical to FP_ARMV8 except for the number of D registers, so
835 // uses the FP_ARMV8_D16 build attribute.
836 case ARM::FK_FPV5_SP_D16:
837 case ARM::FK_FPV5_D16:
838 setAttributeItem(ARMBuildAttrs::FP_arch,
839 ARMBuildAttrs::AllowFPARMv8B,
840 /* OverwriteExisting= */ false);
844 setAttributeItem(ARMBuildAttrs::FP_arch,
845 ARMBuildAttrs::AllowFPv3A,
846 /* OverwriteExisting= */ false);
847 setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
848 ARMBuildAttrs::AllowNeon,
849 /* OverwriteExisting= */ false);
852 case ARM::FK_NEON_VFPV4:
853 setAttributeItem(ARMBuildAttrs::FP_arch,
854 ARMBuildAttrs::AllowFPv4A,
855 /* OverwriteExisting= */ false);
856 setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
857 ARMBuildAttrs::AllowNeon2,
858 /* OverwriteExisting= */ false);
861 case ARM::FK_NEON_FP_ARMV8:
862 case ARM::FK_CRYPTO_NEON_FP_ARMV8:
863 setAttributeItem(ARMBuildAttrs::FP_arch,
864 ARMBuildAttrs::AllowFPARMv8A,
865 /* OverwriteExisting= */ false);
866 // 'Advanced_SIMD_arch' must be emitted not here, but within
867 // ARMAsmPrinter::emitAttributes(), depending on hasV8Ops() and hasV8_1a()
870 case ARM::FK_SOFTVFP:
875 report_fatal_error("Unknown FPU: " + Twine(FPU));
879 size_t ARMTargetELFStreamer::calculateContentSize() const {
881 for (size_t i = 0; i < Contents.size(); ++i) {
882 AttributeItem item = Contents[i];
884 case AttributeItem::HiddenAttribute:
886 case AttributeItem::NumericAttribute:
887 Result += getULEB128Size(item.Tag);
888 Result += getULEB128Size(item.IntValue);
890 case AttributeItem::TextAttribute:
891 Result += getULEB128Size(item.Tag);
892 Result += item.StringValue.size() + 1; // string + '\0'
894 case AttributeItem::NumericAndTextAttributes:
895 Result += getULEB128Size(item.Tag);
896 Result += getULEB128Size(item.IntValue);
897 Result += item.StringValue.size() + 1; // string + '\0';
903 void ARMTargetELFStreamer::finishAttributeSection() {
905 // [ <section-length> "vendor-name"
906 // [ <file-tag> <size> <attribute>*
907 // | <section-tag> <size> <section-number>* 0 <attribute>*
908 // | <symbol-tag> <size> <symbol-number>* 0 <attribute>*
912 if (FPU != ARM::FK_INVALID)
913 emitFPUDefaultAttributes();
915 if (Arch != ARM::AK_INVALID)
916 emitArchDefaultAttributes();
918 if (Contents.empty())
921 std::sort(Contents.begin(), Contents.end(), AttributeItem::LessTag);
923 ARMELFStreamer &Streamer = getStreamer();
925 // Switch to .ARM.attributes section
926 if (AttributeSection) {
927 Streamer.SwitchSection(AttributeSection);
929 AttributeSection = Streamer.getContext().getELFSection(
930 ".ARM.attributes", ELF::SHT_ARM_ATTRIBUTES, 0);
931 Streamer.SwitchSection(AttributeSection);
934 Streamer.EmitIntValue(0x41, 1);
937 // Vendor size + Vendor name + '\0'
938 const size_t VendorHeaderSize = 4 + CurrentVendor.size() + 1;
941 const size_t TagHeaderSize = 1 + 4;
943 const size_t ContentsSize = calculateContentSize();
945 Streamer.EmitIntValue(VendorHeaderSize + TagHeaderSize + ContentsSize, 4);
946 Streamer.EmitBytes(CurrentVendor);
947 Streamer.EmitIntValue(0, 1); // '\0'
949 Streamer.EmitIntValue(ARMBuildAttrs::File, 1);
950 Streamer.EmitIntValue(TagHeaderSize + ContentsSize, 4);
952 // Size should have been accounted for already, now
953 // emit each field as its type (ULEB or String)
954 for (size_t i = 0; i < Contents.size(); ++i) {
955 AttributeItem item = Contents[i];
956 Streamer.EmitULEB128IntValue(item.Tag);
958 default: llvm_unreachable("Invalid attribute type");
959 case AttributeItem::NumericAttribute:
960 Streamer.EmitULEB128IntValue(item.IntValue);
962 case AttributeItem::TextAttribute:
963 Streamer.EmitBytes(item.StringValue);
964 Streamer.EmitIntValue(0, 1); // '\0'
966 case AttributeItem::NumericAndTextAttributes:
967 Streamer.EmitULEB128IntValue(item.IntValue);
968 Streamer.EmitBytes(item.StringValue);
969 Streamer.EmitIntValue(0, 1); // '\0'
975 FPU = ARM::FK_INVALID;
978 void ARMTargetELFStreamer::emitLabel(MCSymbol *Symbol) {
979 ARMELFStreamer &Streamer = getStreamer();
980 if (!Streamer.IsThumb)
983 Streamer.getAssembler().registerSymbol(*Symbol);
984 unsigned Type = cast<MCSymbolELF>(Symbol)->getType();
985 if (Type == ELF::STT_FUNC || Type == ELF::STT_GNU_IFUNC)
986 Streamer.EmitThumbFunc(Symbol);
990 ARMTargetELFStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
991 getStreamer().EmitFixup(S, FK_Data_4);
994 void ARMTargetELFStreamer::emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) {
995 if (const MCSymbolRefExpr *SRE = dyn_cast<MCSymbolRefExpr>(Value)) {
996 const MCSymbol &Sym = SRE->getSymbol();
997 if (!Sym.isDefined()) {
998 getStreamer().EmitAssignment(Symbol, Value);
1003 getStreamer().EmitThumbFunc(Symbol);
1004 getStreamer().EmitAssignment(Symbol, Value);
1007 void ARMTargetELFStreamer::emitInst(uint32_t Inst, char Suffix) {
1008 getStreamer().emitInst(Inst, Suffix);
1011 void ARMELFStreamer::FinishImpl() {
1012 MCTargetStreamer &TS = *getTargetStreamer();
1013 ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
1014 ATS.finishAttributeSection();
1016 MCELFStreamer::FinishImpl();
1019 inline void ARMELFStreamer::SwitchToEHSection(const char *Prefix,
1023 const MCSymbol &Fn) {
1024 const MCSectionELF &FnSection =
1025 static_cast<const MCSectionELF &>(Fn.getSection());
1027 // Create the name for new section
1028 StringRef FnSecName(FnSection.getSectionName());
1029 SmallString<128> EHSecName(Prefix);
1030 if (FnSecName != ".text") {
1031 EHSecName += FnSecName;
1034 // Get .ARM.extab or .ARM.exidx section
1035 const MCSymbolELF *Group = FnSection.getGroup();
1037 Flags |= ELF::SHF_GROUP;
1038 MCSectionELF *EHSection =
1039 getContext().getELFSection(EHSecName, Type, Flags, 0, Group,
1040 FnSection.getUniqueID(), nullptr, &FnSection);
1042 assert(EHSection && "Failed to get the required EH section");
1044 // Switch to .ARM.extab or .ARM.exidx section
1045 SwitchSection(EHSection);
1046 EmitCodeAlignment(4);
1049 inline void ARMELFStreamer::SwitchToExTabSection(const MCSymbol &FnStart) {
1050 SwitchToEHSection(".ARM.extab",
1053 SectionKind::getDataRel(),
1057 inline void ARMELFStreamer::SwitchToExIdxSection(const MCSymbol &FnStart) {
1058 SwitchToEHSection(".ARM.exidx",
1060 ELF::SHF_ALLOC | ELF::SHF_LINK_ORDER,
1061 SectionKind::getDataRel(),
1064 void ARMELFStreamer::EmitFixup(const MCExpr *Expr, MCFixupKind Kind) {
1065 MCDataFragment *Frag = getOrCreateDataFragment();
1066 Frag->getFixups().push_back(MCFixup::create(Frag->getContents().size(), Expr,
1070 void ARMELFStreamer::Reset() {
1073 Personality = nullptr;
1074 PersonalityIndex = ARM::EHABI::NUM_PERSONALITY_INDEX;
1083 UnwindOpAsm.Reset();
1086 void ARMELFStreamer::emitFnStart() {
1087 assert(FnStart == nullptr);
1088 FnStart = getContext().createTempSymbol();
1092 void ARMELFStreamer::emitFnEnd() {
1093 assert(FnStart && ".fnstart must precedes .fnend");
1095 // Emit unwind opcodes if there is no .handlerdata directive
1096 if (!ExTab && !CantUnwind)
1097 FlushUnwindOpcodes(true);
1099 // Emit the exception index table entry
1100 SwitchToExIdxSection(*FnStart);
1102 if (PersonalityIndex < ARM::EHABI::NUM_PERSONALITY_INDEX)
1103 EmitPersonalityFixup(GetAEABIUnwindPersonalityName(PersonalityIndex));
1105 const MCSymbolRefExpr *FnStartRef =
1106 MCSymbolRefExpr::create(FnStart,
1107 MCSymbolRefExpr::VK_ARM_PREL31,
1110 EmitValue(FnStartRef, 4);
1113 EmitIntValue(ARM::EHABI::EXIDX_CANTUNWIND, 4);
1115 // Emit a reference to the unwind opcodes in the ".ARM.extab" section.
1116 const MCSymbolRefExpr *ExTabEntryRef =
1117 MCSymbolRefExpr::create(ExTab,
1118 MCSymbolRefExpr::VK_ARM_PREL31,
1120 EmitValue(ExTabEntryRef, 4);
1122 // For the __aeabi_unwind_cpp_pr0, we have to emit the unwind opcodes in
1123 // the second word of exception index table entry. The size of the unwind
1124 // opcodes should always be 4 bytes.
1125 assert(PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0 &&
1126 "Compact model must use __aeabi_unwind_cpp_pr0 as personality");
1127 assert(Opcodes.size() == 4u &&
1128 "Unwind opcode size for __aeabi_unwind_cpp_pr0 must be equal to 4");
1129 uint64_t Intval = Opcodes[0] |
1133 EmitIntValue(Intval, Opcodes.size());
1136 // Switch to the section containing FnStart
1137 SwitchSection(&FnStart->getSection());
1139 // Clean exception handling frame information
1143 void ARMELFStreamer::emitCantUnwind() { CantUnwind = true; }
1145 // Add the R_ARM_NONE fixup at the same position
1146 void ARMELFStreamer::EmitPersonalityFixup(StringRef Name) {
1147 const MCSymbol *PersonalitySym = getContext().getOrCreateSymbol(Name);
1149 const MCSymbolRefExpr *PersonalityRef = MCSymbolRefExpr::create(
1150 PersonalitySym, MCSymbolRefExpr::VK_ARM_NONE, getContext());
1152 visitUsedExpr(*PersonalityRef);
1153 MCDataFragment *DF = getOrCreateDataFragment();
1154 DF->getFixups().push_back(MCFixup::create(DF->getContents().size(),
1156 MCFixup::getKindForSize(4, false)));
1159 void ARMELFStreamer::FlushPendingOffset() {
1160 if (PendingOffset != 0) {
1161 UnwindOpAsm.EmitSPOffset(-PendingOffset);
1166 void ARMELFStreamer::FlushUnwindOpcodes(bool NoHandlerData) {
1167 // Emit the unwind opcode to restore $sp.
1169 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1170 int64_t LastRegSaveSPOffset = SPOffset - PendingOffset;
1171 UnwindOpAsm.EmitSPOffset(LastRegSaveSPOffset - FPOffset);
1172 UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1174 FlushPendingOffset();
1177 // Finalize the unwind opcode sequence
1178 UnwindOpAsm.Finalize(PersonalityIndex, Opcodes);
1180 // For compact model 0, we have to emit the unwind opcodes in the .ARM.exidx
1181 // section. Thus, we don't have to create an entry in the .ARM.extab
1183 if (NoHandlerData && PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0)
1186 // Switch to .ARM.extab section.
1187 SwitchToExTabSection(*FnStart);
1189 // Create .ARM.extab label for offset in .ARM.exidx
1191 ExTab = getContext().createTempSymbol();
1196 const MCSymbolRefExpr *PersonalityRef =
1197 MCSymbolRefExpr::create(Personality,
1198 MCSymbolRefExpr::VK_ARM_PREL31,
1201 EmitValue(PersonalityRef, 4);
1204 // Emit unwind opcodes
1205 assert((Opcodes.size() % 4) == 0 &&
1206 "Unwind opcode size for __aeabi_cpp_unwind_pr0 must be multiple of 4");
1207 for (unsigned I = 0; I != Opcodes.size(); I += 4) {
1208 uint64_t Intval = Opcodes[I] |
1209 Opcodes[I + 1] << 8 |
1210 Opcodes[I + 2] << 16 |
1211 Opcodes[I + 3] << 24;
1212 EmitIntValue(Intval, 4);
1215 // According to ARM EHABI section 9.2, if the __aeabi_unwind_cpp_pr1() or
1216 // __aeabi_unwind_cpp_pr2() is used, then the handler data must be emitted
1217 // after the unwind opcodes. The handler data consists of several 32-bit
1218 // words, and should be terminated by zero.
1220 // In case that the .handlerdata directive is not specified by the
1221 // programmer, we should emit zero to terminate the handler data.
1222 if (NoHandlerData && !Personality)
1226 void ARMELFStreamer::emitHandlerData() { FlushUnwindOpcodes(false); }
1228 void ARMELFStreamer::emitPersonality(const MCSymbol *Per) {
1230 UnwindOpAsm.setPersonality(Per);
1233 void ARMELFStreamer::emitPersonalityIndex(unsigned Index) {
1234 assert(Index < ARM::EHABI::NUM_PERSONALITY_INDEX && "invalid index");
1235 PersonalityIndex = Index;
1238 void ARMELFStreamer::emitSetFP(unsigned NewFPReg, unsigned NewSPReg,
1240 assert((NewSPReg == ARM::SP || NewSPReg == FPReg) &&
1241 "the operand of .setfp directive should be either $sp or $fp");
1246 if (NewSPReg == ARM::SP)
1247 FPOffset = SPOffset + Offset;
1252 void ARMELFStreamer::emitMovSP(unsigned Reg, int64_t Offset) {
1253 assert((Reg != ARM::SP && Reg != ARM::PC) &&
1254 "the operand of .movsp cannot be either sp or pc");
1255 assert(FPReg == ARM::SP && "current FP must be SP");
1257 FlushPendingOffset();
1260 FPOffset = SPOffset + Offset;
1262 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1263 UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
1266 void ARMELFStreamer::emitPad(int64_t Offset) {
1267 // Track the change of the $sp offset
1270 // To squash multiple .pad directives, we should delay the unwind opcode
1271 // until the .save, .vsave, .handlerdata, or .fnend directives.
1272 PendingOffset -= Offset;
1275 void ARMELFStreamer::emitRegSave(const SmallVectorImpl<unsigned> &RegList,
1277 // Collect the registers in the register list
1280 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1281 for (size_t i = 0; i < RegList.size(); ++i) {
1282 unsigned Reg = MRI->getEncodingValue(RegList[i]);
1283 assert(Reg < (IsVector ? 32U : 16U) && "Register out of range");
1284 unsigned Bit = (1u << Reg);
1285 if ((Mask & Bit) == 0) {
1291 // Track the change the $sp offset: For the .save directive, the
1292 // corresponding push instruction will decrease the $sp by (4 * Count).
1293 // For the .vsave directive, the corresponding vpush instruction will
1294 // decrease $sp by (8 * Count).
1295 SPOffset -= Count * (IsVector ? 8 : 4);
1298 FlushPendingOffset();
1300 UnwindOpAsm.EmitVFPRegSave(Mask);
1302 UnwindOpAsm.EmitRegSave(Mask);
1305 void ARMELFStreamer::emitUnwindRaw(int64_t Offset,
1306 const SmallVectorImpl<uint8_t> &Opcodes) {
1307 FlushPendingOffset();
1308 SPOffset = SPOffset - Offset;
1309 UnwindOpAsm.EmitRaw(Opcodes);
1314 MCTargetStreamer *createARMTargetAsmStreamer(MCStreamer &S,
1315 formatted_raw_ostream &OS,
1316 MCInstPrinter *InstPrint,
1317 bool isVerboseAsm) {
1318 return new ARMTargetAsmStreamer(S, OS, *InstPrint, isVerboseAsm);
1321 MCTargetStreamer *createARMNullTargetStreamer(MCStreamer &S) {
1322 return new ARMTargetStreamer(S);
1325 MCTargetStreamer *createARMObjectTargetStreamer(MCStreamer &S,
1326 const MCSubtargetInfo &STI) {
1327 Triple TT(STI.getTargetTriple());
1328 if (TT.getObjectFormat() == Triple::ELF)
1329 return new ARMTargetELFStreamer(S);
1330 return new ARMTargetStreamer(S);
1333 MCELFStreamer *createARMELFStreamer(MCContext &Context, MCAsmBackend &TAB,
1334 raw_pwrite_stream &OS,
1335 MCCodeEmitter *Emitter, bool RelaxAll,
1337 ARMELFStreamer *S = new ARMELFStreamer(Context, TAB, OS, Emitter, IsThumb);
1338 // FIXME: This should eventually end up somewhere else where more
1339 // intelligent flag decisions can be made. For now we are just maintaining
1340 // the status quo for ARM and setting EF_ARM_EABI_VER5 as the default.
1341 S->getAssembler().setELFHeaderEFlags(ELF::EF_ARM_EABI_VER5);
1344 S->getAssembler().setRelaxAll(true);