1 //===- lib/MC/MCELFStreamer.cpp - ELF Object Output -----------------------===//
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 ELF .o object files.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/MC/MCELFStreamer.h"
15 #include "llvm/ADT/STLExtras.h"
16 #include "llvm/ADT/SmallPtrSet.h"
17 #include "llvm/MC/MCAsmBackend.h"
18 #include "llvm/MC/MCAsmLayout.h"
19 #include "llvm/MC/MCAsmInfo.h"
20 #include "llvm/MC/MCAssembler.h"
21 #include "llvm/MC/MCCodeEmitter.h"
22 #include "llvm/MC/MCContext.h"
23 #include "llvm/MC/MCExpr.h"
24 #include "llvm/MC/MCInst.h"
25 #include "llvm/MC/MCObjectFileInfo.h"
26 #include "llvm/MC/MCObjectStreamer.h"
27 #include "llvm/MC/MCSection.h"
28 #include "llvm/MC/MCSectionELF.h"
29 #include "llvm/MC/MCSymbolELF.h"
30 #include "llvm/MC/MCSymbol.h"
31 #include "llvm/MC/MCValue.h"
32 #include "llvm/Support/Debug.h"
33 #include "llvm/Support/ELF.h"
34 #include "llvm/Support/ErrorHandling.h"
35 #include "llvm/Support/TargetRegistry.h"
36 #include "llvm/Support/raw_ostream.h"
40 bool MCELFStreamer::isBundleLocked() const {
41 return getCurrentSectionOnly()->isBundleLocked();
44 MCELFStreamer::~MCELFStreamer() {
47 void MCELFStreamer::mergeFragment(MCDataFragment *DF,
49 MCAssembler &Assembler = getAssembler();
51 if (Assembler.isBundlingEnabled() && Assembler.getRelaxAll()) {
52 uint64_t FSize = EF->getContents().size();
54 if (FSize > Assembler.getBundleAlignSize())
55 report_fatal_error("Fragment can't be larger than a bundle size");
57 uint64_t RequiredBundlePadding = computeBundlePadding(
58 Assembler, EF, DF->getContents().size(), FSize);
60 if (RequiredBundlePadding > UINT8_MAX)
61 report_fatal_error("Padding cannot exceed 255 bytes");
63 if (RequiredBundlePadding > 0) {
64 SmallString<256> Code;
65 raw_svector_ostream VecOS(Code);
66 MCObjectWriter *OW = Assembler.getBackend().createObjectWriter(VecOS);
68 EF->setBundlePadding(static_cast<uint8_t>(RequiredBundlePadding));
70 Assembler.writeFragmentPadding(*EF, FSize, OW);
73 DF->getContents().append(Code.begin(), Code.end());
77 flushPendingLabels(DF, DF->getContents().size());
79 for (unsigned i = 0, e = EF->getFixups().size(); i != e; ++i) {
80 EF->getFixups()[i].setOffset(EF->getFixups()[i].getOffset() +
81 DF->getContents().size());
82 DF->getFixups().push_back(EF->getFixups()[i]);
84 DF->setHasInstructions(true);
85 DF->getContents().append(EF->getContents().begin(), EF->getContents().end());
88 void MCELFStreamer::InitSections(bool NoExecStack) {
89 // This emulates the same behavior of GNU as. This makes it easier
90 // to compare the output as the major sections are in the same order.
91 MCContext &Ctx = getContext();
92 SwitchSection(Ctx.getObjectFileInfo()->getTextSection());
95 SwitchSection(Ctx.getObjectFileInfo()->getDataSection());
98 SwitchSection(Ctx.getObjectFileInfo()->getBSSSection());
101 SwitchSection(Ctx.getObjectFileInfo()->getTextSection());
104 SwitchSection(Ctx.getAsmInfo()->getNonexecutableStackSection(Ctx));
107 void MCELFStreamer::EmitLabel(MCSymbol *S) {
108 auto *Symbol = cast<MCSymbolELF>(S);
109 assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
111 MCObjectStreamer::EmitLabel(Symbol);
113 const MCSectionELF &Section =
114 static_cast<const MCSectionELF &>(*getCurrentSectionOnly());
115 if (Section.getFlags() & ELF::SHF_TLS)
116 Symbol->setType(ELF::STT_TLS);
119 void MCELFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
120 // Let the target do whatever target specific stuff it needs to do.
121 getAssembler().getBackend().handleAssemblerFlag(Flag);
122 // Do any generic stuff we need to do.
124 case MCAF_SyntaxUnified: return; // no-op here.
125 case MCAF_Code16: return; // Change parsing mode; no-op here.
126 case MCAF_Code32: return; // Change parsing mode; no-op here.
127 case MCAF_Code64: return; // Change parsing mode; no-op here.
128 case MCAF_SubsectionsViaSymbols:
129 getAssembler().setSubsectionsViaSymbols(true);
133 llvm_unreachable("invalid assembler flag!");
136 // If bundle alignment is used and there are any instructions in the section, it
137 // needs to be aligned to at least the bundle size.
138 static void setSectionAlignmentForBundling(const MCAssembler &Assembler,
139 MCSection *Section) {
140 if (Section && Assembler.isBundlingEnabled() && Section->hasInstructions() &&
141 Section->getAlignment() < Assembler.getBundleAlignSize())
142 Section->setAlignment(Assembler.getBundleAlignSize());
145 void MCELFStreamer::ChangeSection(MCSection *Section,
146 const MCExpr *Subsection) {
147 MCSection *CurSection = getCurrentSectionOnly();
148 if (CurSection && isBundleLocked())
149 report_fatal_error("Unterminated .bundle_lock when changing a section");
151 MCAssembler &Asm = getAssembler();
152 // Ensure the previous section gets aligned if necessary.
153 setSectionAlignmentForBundling(Asm, CurSection);
154 auto *SectionELF = static_cast<const MCSectionELF *>(Section);
155 const MCSymbol *Grp = SectionELF->getGroup();
157 Asm.registerSymbol(*Grp);
159 this->MCObjectStreamer::ChangeSection(Section, Subsection);
160 MCContext &Ctx = getContext();
161 auto *Begin = cast_or_null<MCSymbolELF>(Section->getBeginSymbol());
163 Begin = Ctx.getOrCreateSectionSymbol(*SectionELF);
164 Section->setBeginSymbol(Begin);
166 if (Begin->isUndefined()) {
167 Asm.registerSymbol(*Begin);
168 Begin->setType(ELF::STT_SECTION);
172 void MCELFStreamer::EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {
173 getAssembler().registerSymbol(*Symbol);
174 const MCExpr *Value = MCSymbolRefExpr::create(
175 Symbol, MCSymbolRefExpr::VK_WEAKREF, getContext());
176 Alias->setVariableValue(Value);
179 // When GNU as encounters more than one .type declaration for an object it seems
180 // to use a mechanism similar to the one below to decide which type is actually
181 // used in the object file. The greater of T1 and T2 is selected based on the
182 // following ordering:
183 // STT_NOTYPE < STT_OBJECT < STT_FUNC < STT_GNU_IFUNC < STT_TLS < anything else
184 // If neither T1 < T2 nor T2 < T1 according to this ordering, use T2 (the user
186 static unsigned CombineSymbolTypes(unsigned T1, unsigned T2) {
187 for (unsigned Type : {ELF::STT_NOTYPE, ELF::STT_OBJECT, ELF::STT_FUNC,
188 ELF::STT_GNU_IFUNC, ELF::STT_TLS}) {
198 bool MCELFStreamer::EmitSymbolAttribute(MCSymbol *S, MCSymbolAttr Attribute) {
199 auto *Symbol = cast<MCSymbolELF>(S);
200 // Indirect symbols are handled differently, to match how 'as' handles
201 // them. This makes writing matching .o files easier.
202 if (Attribute == MCSA_IndirectSymbol) {
203 // Note that we intentionally cannot use the symbol data here; this is
204 // important for matching the string table that 'as' generates.
205 IndirectSymbolData ISD;
207 ISD.Section = getCurrentSectionOnly();
208 getAssembler().getIndirectSymbols().push_back(ISD);
212 // Adding a symbol attribute always introduces the symbol, note that an
213 // important side effect of calling registerSymbol here is to register
214 // the symbol with the assembler.
215 getAssembler().registerSymbol(*Symbol);
217 // The implementation of symbol attributes is designed to match 'as', but it
218 // leaves much to desired. It doesn't really make sense to arbitrarily add and
219 // remove flags, but 'as' allows this (in particular, see .desc).
221 // In the future it might be worth trying to make these operations more well
224 case MCSA_LazyReference:
226 case MCSA_SymbolResolver:
227 case MCSA_PrivateExtern:
228 case MCSA_WeakDefinition:
229 case MCSA_WeakDefAutoPrivate:
231 case MCSA_IndirectSymbol:
234 case MCSA_NoDeadStrip:
238 case MCSA_ELF_TypeGnuUniqueObject:
239 Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_OBJECT));
240 Symbol->setBinding(ELF::STB_GNU_UNIQUE);
241 Symbol->setExternal(true);
245 Symbol->setBinding(ELF::STB_GLOBAL);
246 Symbol->setExternal(true);
249 case MCSA_WeakReference:
251 Symbol->setBinding(ELF::STB_WEAK);
252 Symbol->setExternal(true);
256 Symbol->setBinding(ELF::STB_LOCAL);
257 Symbol->setExternal(false);
260 case MCSA_ELF_TypeFunction:
261 Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_FUNC));
264 case MCSA_ELF_TypeIndFunction:
265 Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_GNU_IFUNC));
268 case MCSA_ELF_TypeObject:
269 Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_OBJECT));
272 case MCSA_ELF_TypeTLS:
273 Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_TLS));
276 case MCSA_ELF_TypeCommon:
277 // TODO: Emit these as a common symbol.
278 Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_OBJECT));
281 case MCSA_ELF_TypeNoType:
282 Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_NOTYPE));
286 Symbol->setVisibility(ELF::STV_PROTECTED);
290 Symbol->setVisibility(ELF::STV_HIDDEN);
294 Symbol->setVisibility(ELF::STV_INTERNAL);
301 void MCELFStreamer::EmitCommonSymbol(MCSymbol *S, uint64_t Size,
302 unsigned ByteAlignment) {
303 auto *Symbol = cast<MCSymbolELF>(S);
304 getAssembler().registerSymbol(*Symbol);
306 if (!Symbol->isBindingSet()) {
307 Symbol->setBinding(ELF::STB_GLOBAL);
308 Symbol->setExternal(true);
311 Symbol->setType(ELF::STT_OBJECT);
313 if (Symbol->getBinding() == ELF::STB_LOCAL) {
314 struct LocalCommon L = {Symbol, Size, ByteAlignment};
315 LocalCommons.push_back(L);
317 if(Symbol->declareCommon(Size, ByteAlignment))
318 report_fatal_error("Symbol: " + Symbol->getName() +
319 " redeclared as different type");
322 cast<MCSymbolELF>(Symbol)
323 ->setSize(MCConstantExpr::create(Size, getContext()));
326 void MCELFStreamer::emitELFSize(MCSymbolELF *Symbol, const MCExpr *Value) {
327 Symbol->setSize(Value);
330 void MCELFStreamer::EmitLocalCommonSymbol(MCSymbol *S, uint64_t Size,
331 unsigned ByteAlignment) {
332 auto *Symbol = cast<MCSymbolELF>(S);
333 // FIXME: Should this be caught and done earlier?
334 getAssembler().registerSymbol(*Symbol);
335 Symbol->setBinding(ELF::STB_LOCAL);
336 Symbol->setExternal(false);
337 EmitCommonSymbol(Symbol, Size, ByteAlignment);
340 void MCELFStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
342 if (isBundleLocked())
343 report_fatal_error("Emitting values inside a locked bundle is forbidden");
344 fixSymbolsInTLSFixups(Value);
345 MCObjectStreamer::EmitValueImpl(Value, Size, Loc);
348 void MCELFStreamer::EmitValueToAlignment(unsigned ByteAlignment,
351 unsigned MaxBytesToEmit) {
352 if (isBundleLocked())
353 report_fatal_error("Emitting values inside a locked bundle is forbidden");
354 MCObjectStreamer::EmitValueToAlignment(ByteAlignment, Value,
355 ValueSize, MaxBytesToEmit);
358 // Add a symbol for the file name of this module. They start after the
359 // null symbol and don't count as normal symbol, i.e. a non-STT_FILE symbol
360 // with the same name may appear.
361 void MCELFStreamer::EmitFileDirective(StringRef Filename) {
362 getAssembler().addFileName(Filename);
365 void MCELFStreamer::EmitIdent(StringRef IdentString) {
366 MCSection *Comment = getAssembler().getContext().getELFSection(
367 ".comment", ELF::SHT_PROGBITS, ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
369 SwitchSection(Comment);
374 EmitBytes(IdentString);
379 void MCELFStreamer::fixSymbolsInTLSFixups(const MCExpr *expr) {
380 switch (expr->getKind()) {
382 cast<MCTargetExpr>(expr)->fixELFSymbolsInTLSFixups(getAssembler());
384 case MCExpr::Constant:
387 case MCExpr::Binary: {
388 const MCBinaryExpr *be = cast<MCBinaryExpr>(expr);
389 fixSymbolsInTLSFixups(be->getLHS());
390 fixSymbolsInTLSFixups(be->getRHS());
394 case MCExpr::SymbolRef: {
395 const MCSymbolRefExpr &symRef = *cast<MCSymbolRefExpr>(expr);
396 switch (symRef.getKind()) {
399 case MCSymbolRefExpr::VK_GOTTPOFF:
400 case MCSymbolRefExpr::VK_INDNTPOFF:
401 case MCSymbolRefExpr::VK_NTPOFF:
402 case MCSymbolRefExpr::VK_GOTNTPOFF:
403 case MCSymbolRefExpr::VK_TLSGD:
404 case MCSymbolRefExpr::VK_TLSLD:
405 case MCSymbolRefExpr::VK_TLSLDM:
406 case MCSymbolRefExpr::VK_TPOFF:
407 case MCSymbolRefExpr::VK_DTPOFF:
408 case MCSymbolRefExpr::VK_Mips_TLSGD:
409 case MCSymbolRefExpr::VK_Mips_GOTTPREL:
410 case MCSymbolRefExpr::VK_Mips_TPREL_HI:
411 case MCSymbolRefExpr::VK_Mips_TPREL_LO:
412 case MCSymbolRefExpr::VK_PPC_DTPMOD:
413 case MCSymbolRefExpr::VK_PPC_TPREL:
414 case MCSymbolRefExpr::VK_PPC_TPREL_LO:
415 case MCSymbolRefExpr::VK_PPC_TPREL_HI:
416 case MCSymbolRefExpr::VK_PPC_TPREL_HA:
417 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHER:
418 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHERA:
419 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHEST:
420 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHESTA:
421 case MCSymbolRefExpr::VK_PPC_DTPREL:
422 case MCSymbolRefExpr::VK_PPC_DTPREL_LO:
423 case MCSymbolRefExpr::VK_PPC_DTPREL_HI:
424 case MCSymbolRefExpr::VK_PPC_DTPREL_HA:
425 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHER:
426 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHERA:
427 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHEST:
428 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHESTA:
429 case MCSymbolRefExpr::VK_PPC_GOT_TPREL:
430 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO:
431 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HI:
432 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HA:
433 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL:
434 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_LO:
435 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HI:
436 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HA:
437 case MCSymbolRefExpr::VK_PPC_TLS:
438 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD:
439 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_LO:
440 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HI:
441 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HA:
442 case MCSymbolRefExpr::VK_PPC_TLSGD:
443 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD:
444 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO:
445 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HI:
446 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HA:
447 case MCSymbolRefExpr::VK_PPC_TLSLD:
450 getAssembler().registerSymbol(symRef.getSymbol());
451 cast<MCSymbolELF>(symRef.getSymbol()).setType(ELF::STT_TLS);
456 fixSymbolsInTLSFixups(cast<MCUnaryExpr>(expr)->getSubExpr());
461 void MCELFStreamer::EmitInstToFragment(const MCInst &Inst,
462 const MCSubtargetInfo &STI) {
463 this->MCObjectStreamer::EmitInstToFragment(Inst, STI);
464 MCRelaxableFragment &F = *cast<MCRelaxableFragment>(getCurrentFragment());
466 for (unsigned i = 0, e = F.getFixups().size(); i != e; ++i)
467 fixSymbolsInTLSFixups(F.getFixups()[i].getValue());
470 void MCELFStreamer::EmitInstToData(const MCInst &Inst,
471 const MCSubtargetInfo &STI) {
472 MCAssembler &Assembler = getAssembler();
473 SmallVector<MCFixup, 4> Fixups;
474 SmallString<256> Code;
475 raw_svector_ostream VecOS(Code);
476 Assembler.getEmitter().encodeInstruction(Inst, VecOS, Fixups, STI);
478 for (unsigned i = 0, e = Fixups.size(); i != e; ++i)
479 fixSymbolsInTLSFixups(Fixups[i].getValue());
481 // There are several possibilities here:
483 // If bundling is disabled, append the encoded instruction to the current data
484 // fragment (or create a new such fragment if the current fragment is not a
487 // If bundling is enabled:
488 // - If we're not in a bundle-locked group, emit the instruction into a
489 // fragment of its own. If there are no fixups registered for the
490 // instruction, emit a MCCompactEncodedInstFragment. Otherwise, emit a
492 // - If we're in a bundle-locked group, append the instruction to the current
493 // data fragment because we want all the instructions in a group to get into
494 // the same fragment. Be careful not to do that for the first instruction in
495 // the group, though.
498 if (Assembler.isBundlingEnabled()) {
499 MCSection &Sec = *getCurrentSectionOnly();
500 if (Assembler.getRelaxAll() && isBundleLocked())
501 // If the -mc-relax-all flag is used and we are bundle-locked, we re-use
502 // the current bundle group.
503 DF = BundleGroups.back();
504 else if (Assembler.getRelaxAll() && !isBundleLocked())
505 // When not in a bundle-locked group and the -mc-relax-all flag is used,
506 // we create a new temporary fragment which will be later merged into
507 // the current fragment.
508 DF = new MCDataFragment();
509 else if (isBundleLocked() && !Sec.isBundleGroupBeforeFirstInst())
510 // If we are bundle-locked, we re-use the current fragment.
511 // The bundle-locking directive ensures this is a new data fragment.
512 DF = cast<MCDataFragment>(getCurrentFragment());
513 else if (!isBundleLocked() && Fixups.size() == 0) {
514 // Optimize memory usage by emitting the instruction to a
515 // MCCompactEncodedInstFragment when not in a bundle-locked group and
516 // there are no fixups registered.
517 MCCompactEncodedInstFragment *CEIF = new MCCompactEncodedInstFragment();
519 CEIF->getContents().append(Code.begin(), Code.end());
522 DF = new MCDataFragment();
525 if (Sec.getBundleLockState() == MCSection::BundleLockedAlignToEnd) {
526 // If this fragment is for a group marked "align_to_end", set a flag
527 // in the fragment. This can happen after the fragment has already been
528 // created if there are nested bundle_align groups and an inner one
529 // is the one marked align_to_end.
530 DF->setAlignToBundleEnd(true);
533 // We're now emitting an instruction in a bundle group, so this flag has
535 Sec.setBundleGroupBeforeFirstInst(false);
537 DF = getOrCreateDataFragment();
540 // Add the fixups and data.
541 for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
542 Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
543 DF->getFixups().push_back(Fixups[i]);
545 DF->setHasInstructions(true);
546 DF->getContents().append(Code.begin(), Code.end());
548 if (Assembler.isBundlingEnabled() && Assembler.getRelaxAll()) {
549 if (!isBundleLocked()) {
550 mergeFragment(getOrCreateDataFragment(), DF);
556 void MCELFStreamer::EmitBundleAlignMode(unsigned AlignPow2) {
557 assert(AlignPow2 <= 30 && "Invalid bundle alignment");
558 MCAssembler &Assembler = getAssembler();
559 if (AlignPow2 > 0 && (Assembler.getBundleAlignSize() == 0 ||
560 Assembler.getBundleAlignSize() == 1U << AlignPow2))
561 Assembler.setBundleAlignSize(1U << AlignPow2);
563 report_fatal_error(".bundle_align_mode cannot be changed once set");
566 void MCELFStreamer::EmitBundleLock(bool AlignToEnd) {
567 MCSection &Sec = *getCurrentSectionOnly();
571 if (!getAssembler().isBundlingEnabled())
572 report_fatal_error(".bundle_lock forbidden when bundling is disabled");
574 if (!isBundleLocked())
575 Sec.setBundleGroupBeforeFirstInst(true);
577 if (getAssembler().getRelaxAll() && !isBundleLocked()) {
578 // TODO: drop the lock state and set directly in the fragment
579 MCDataFragment *DF = new MCDataFragment();
580 BundleGroups.push_back(DF);
583 Sec.setBundleLockState(AlignToEnd ? MCSection::BundleLockedAlignToEnd
584 : MCSection::BundleLocked);
587 void MCELFStreamer::EmitBundleUnlock() {
588 MCSection &Sec = *getCurrentSectionOnly();
591 if (!getAssembler().isBundlingEnabled())
592 report_fatal_error(".bundle_unlock forbidden when bundling is disabled");
593 else if (!isBundleLocked())
594 report_fatal_error(".bundle_unlock without matching lock");
595 else if (Sec.isBundleGroupBeforeFirstInst())
596 report_fatal_error("Empty bundle-locked group is forbidden");
598 // When the -mc-relax-all flag is used, we emit instructions to fragments
599 // stored on a stack. When the bundle unlock is emitted, we pop a fragment
600 // from the stack a merge it to the one below.
601 if (getAssembler().getRelaxAll()) {
602 assert(!BundleGroups.empty() && "There are no bundle groups");
603 MCDataFragment *DF = BundleGroups.back();
605 // FIXME: Use BundleGroups to track the lock state instead.
606 Sec.setBundleLockState(MCSection::NotBundleLocked);
608 // FIXME: Use more separate fragments for nested groups.
609 if (!isBundleLocked()) {
610 mergeFragment(getOrCreateDataFragment(), DF);
611 BundleGroups.pop_back();
615 if (Sec.getBundleLockState() != MCSection::BundleLockedAlignToEnd)
616 getOrCreateDataFragment()->setAlignToBundleEnd(false);
618 Sec.setBundleLockState(MCSection::NotBundleLocked);
621 void MCELFStreamer::Flush() {
622 for (std::vector<LocalCommon>::const_iterator i = LocalCommons.begin(),
623 e = LocalCommons.end();
625 const MCSymbol &Symbol = *i->Symbol;
626 uint64_t Size = i->Size;
627 unsigned ByteAlignment = i->ByteAlignment;
628 MCSection &Section = *getAssembler().getContext().getELFSection(
629 ".bss", ELF::SHT_NOBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
631 getAssembler().registerSection(Section);
632 new MCAlignFragment(ByteAlignment, 0, 1, ByteAlignment, &Section);
634 MCFragment *F = new MCFillFragment(0, 0, Size, &Section);
635 Symbol.setFragment(F);
637 // Update the maximum alignment of the section if necessary.
638 if (ByteAlignment > Section.getAlignment())
639 Section.setAlignment(ByteAlignment);
642 LocalCommons.clear();
645 void MCELFStreamer::FinishImpl() {
646 // Ensure the last section gets aligned if necessary.
647 MCSection *CurSection = getCurrentSectionOnly();
648 setSectionAlignmentForBundling(getAssembler(), CurSection);
654 this->MCObjectStreamer::FinishImpl();
657 MCStreamer *llvm::createELFStreamer(MCContext &Context, MCAsmBackend &MAB,
658 raw_pwrite_stream &OS, MCCodeEmitter *CE,
660 MCELFStreamer *S = new MCELFStreamer(Context, MAB, OS, CE);
662 S->getAssembler().setRelaxAll(true);
666 void MCELFStreamer::EmitThumbFunc(MCSymbol *Func) {
667 llvm_unreachable("Generic ELF doesn't support this directive");
670 void MCELFStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
671 llvm_unreachable("ELF doesn't support this directive");
674 void MCELFStreamer::BeginCOFFSymbolDef(const MCSymbol *Symbol) {
675 llvm_unreachable("ELF doesn't support this directive");
678 void MCELFStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {
679 llvm_unreachable("ELF doesn't support this directive");
682 void MCELFStreamer::EmitCOFFSymbolType(int Type) {
683 llvm_unreachable("ELF doesn't support this directive");
686 void MCELFStreamer::EndCOFFSymbolDef() {
687 llvm_unreachable("ELF doesn't support this directive");
690 void MCELFStreamer::EmitZerofill(MCSection *Section, MCSymbol *Symbol,
691 uint64_t Size, unsigned ByteAlignment) {
692 llvm_unreachable("ELF doesn't support this directive");
695 void MCELFStreamer::EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol,
696 uint64_t Size, unsigned ByteAlignment) {
697 llvm_unreachable("ELF doesn't support this directive");