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/MCELF.h"
24 #include "llvm/MC/MCELFSymbolFlags.h"
25 #include "llvm/MC/MCExpr.h"
26 #include "llvm/MC/MCInst.h"
27 #include "llvm/MC/MCObjectFileInfo.h"
28 #include "llvm/MC/MCObjectStreamer.h"
29 #include "llvm/MC/MCSection.h"
30 #include "llvm/MC/MCSectionELF.h"
31 #include "llvm/MC/MCSymbol.h"
32 #include "llvm/MC/MCValue.h"
33 #include "llvm/Support/Debug.h"
34 #include "llvm/Support/ELF.h"
35 #include "llvm/Support/ErrorHandling.h"
36 #include "llvm/Support/TargetRegistry.h"
37 #include "llvm/Support/raw_ostream.h"
41 bool MCELFStreamer::isBundleLocked() const {
42 return getCurrentSectionOnly()->isBundleLocked();
45 MCELFStreamer::~MCELFStreamer() {
48 void MCELFStreamer::mergeFragment(MCDataFragment *DF,
49 MCEncodedFragmentWithFixups *EF) {
50 MCAssembler &Assembler = getAssembler();
52 if (Assembler.isBundlingEnabled() && Assembler.getRelaxAll()) {
53 uint64_t FSize = EF->getContents().size();
55 if (FSize > Assembler.getBundleAlignSize())
56 report_fatal_error("Fragment can't be larger than a bundle size");
58 uint64_t RequiredBundlePadding = computeBundlePadding(
59 Assembler, EF, DF->getContents().size(), FSize);
61 if (RequiredBundlePadding > UINT8_MAX)
62 report_fatal_error("Padding cannot exceed 255 bytes");
64 if (RequiredBundlePadding > 0) {
65 SmallString<256> Code;
66 raw_svector_ostream VecOS(Code);
67 MCObjectWriter *OW = Assembler.getBackend().createObjectWriter(VecOS);
69 EF->setBundlePadding(static_cast<uint8_t>(RequiredBundlePadding));
71 Assembler.writeFragmentPadding(*EF, FSize, OW);
75 DF->getContents().append(Code.begin(), Code.end());
79 flushPendingLabels(DF, DF->getContents().size());
81 for (unsigned i = 0, e = EF->getFixups().size(); i != e; ++i) {
82 EF->getFixups()[i].setOffset(EF->getFixups()[i].getOffset() +
83 DF->getContents().size());
84 DF->getFixups().push_back(EF->getFixups()[i]);
86 DF->setHasInstructions(true);
87 DF->getContents().append(EF->getContents().begin(), EF->getContents().end());
90 void MCELFStreamer::InitSections(bool NoExecStack) {
91 // This emulates the same behavior of GNU as. This makes it easier
92 // to compare the output as the major sections are in the same order.
93 MCContext &Ctx = getContext();
94 SwitchSection(Ctx.getObjectFileInfo()->getTextSection());
97 SwitchSection(Ctx.getObjectFileInfo()->getDataSection());
100 SwitchSection(Ctx.getObjectFileInfo()->getBSSSection());
101 EmitCodeAlignment(4);
103 SwitchSection(Ctx.getObjectFileInfo()->getTextSection());
106 SwitchSection(Ctx.getAsmInfo()->getNonexecutableStackSection(Ctx));
109 void MCELFStreamer::EmitLabel(MCSymbol *Symbol) {
110 assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
112 MCObjectStreamer::EmitLabel(Symbol);
114 const MCSectionELF &Section =
115 static_cast<const MCSectionELF&>(Symbol->getSection());
116 if (Section.getFlags() & ELF::SHF_TLS)
117 MCELF::SetType(*Symbol, ELF::STT_TLS);
120 void MCELFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
121 // Let the target do whatever target specific stuff it needs to do.
122 getAssembler().getBackend().handleAssemblerFlag(Flag);
123 // Do any generic stuff we need to do.
125 case MCAF_SyntaxUnified: return; // no-op here.
126 case MCAF_Code16: return; // Change parsing mode; no-op here.
127 case MCAF_Code32: return; // Change parsing mode; no-op here.
128 case MCAF_Code64: return; // Change parsing mode; no-op here.
129 case MCAF_SubsectionsViaSymbols:
130 getAssembler().setSubsectionsViaSymbols(true);
134 llvm_unreachable("invalid assembler flag!");
137 // If bundle aligment is used and there are any instructions in the section, it
138 // needs to be aligned to at least the bundle size.
139 static void setSectionAlignmentForBundling(const MCAssembler &Assembler,
140 MCSection *Section) {
141 if (Section && Assembler.isBundlingEnabled() && Section->hasInstructions() &&
142 Section->getAlignment() < Assembler.getBundleAlignSize())
143 Section->setAlignment(Assembler.getBundleAlignSize());
146 void MCELFStreamer::ChangeSection(MCSection *Section,
147 const MCExpr *Subsection) {
148 MCSection *CurSection = getCurrentSectionOnly();
149 if (CurSection && isBundleLocked())
150 report_fatal_error("Unterminated .bundle_lock when changing a section");
152 MCAssembler &Asm = getAssembler();
153 // Ensure the previous section gets aligned if necessary.
154 setSectionAlignmentForBundling(Asm, CurSection);
155 auto *SectionELF = static_cast<const MCSectionELF *>(Section);
156 const MCSymbol *Grp = SectionELF->getGroup();
158 Asm.registerSymbol(*Grp);
160 this->MCObjectStreamer::ChangeSection(Section, Subsection);
161 MCContext &Ctx = getContext();
162 MCSymbol *Begin = Section->getBeginSymbol();
164 Begin = Ctx.getOrCreateSectionSymbol(*SectionELF);
165 Section->setBeginSymbol(Begin);
167 if (Begin->isUndefined()) {
168 Asm.registerSymbol(*Begin);
169 MCELF::SetType(*Begin, ELF::STT_SECTION);
173 void MCELFStreamer::EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {
174 getAssembler().registerSymbol(*Symbol);
175 const MCExpr *Value = MCSymbolRefExpr::Create(
176 Symbol, MCSymbolRefExpr::VK_WEAKREF, getContext());
177 Alias->setVariableValue(Value);
180 // When GNU as encounters more than one .type declaration for an object it seems
181 // to use a mechanism similar to the one below to decide which type is actually
182 // used in the object file. The greater of T1 and T2 is selected based on the
183 // following ordering:
184 // STT_NOTYPE < STT_OBJECT < STT_FUNC < STT_GNU_IFUNC < STT_TLS < anything else
185 // If neither T1 < T2 nor T2 < T1 according to this ordering, use T2 (the user
187 static unsigned CombineSymbolTypes(unsigned T1, unsigned T2) {
188 for (unsigned Type : {ELF::STT_NOTYPE, ELF::STT_OBJECT, ELF::STT_FUNC,
189 ELF::STT_GNU_IFUNC, ELF::STT_TLS}) {
199 bool MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
200 MCSymbolAttr Attribute) {
201 // Indirect symbols are handled differently, to match how 'as' handles
202 // them. This makes writing matching .o files easier.
203 if (Attribute == MCSA_IndirectSymbol) {
204 // Note that we intentionally cannot use the symbol data here; this is
205 // important for matching the string table that 'as' generates.
206 IndirectSymbolData ISD;
208 ISD.Section = getCurrentSectionOnly();
209 getAssembler().getIndirectSymbols().push_back(ISD);
213 // Adding a symbol attribute always introduces the symbol, note that an
214 // important side effect of calling registerSymbol here is to register
215 // the symbol with the assembler.
216 getAssembler().registerSymbol(*Symbol);
217 MCSymbol &SD = Symbol->getData();
219 // The implementation of symbol attributes is designed to match 'as', but it
220 // leaves much to desired. It doesn't really make sense to arbitrarily add and
221 // remove flags, but 'as' allows this (in particular, see .desc).
223 // In the future it might be worth trying to make these operations more well
226 case MCSA_LazyReference:
228 case MCSA_SymbolResolver:
229 case MCSA_PrivateExtern:
230 case MCSA_WeakDefinition:
231 case MCSA_WeakDefAutoPrivate:
233 case MCSA_IndirectSymbol:
236 case MCSA_NoDeadStrip:
240 case MCSA_ELF_TypeGnuUniqueObject:
242 *Symbol, CombineSymbolTypes(MCELF::GetType(*Symbol), ELF::STT_OBJECT));
243 MCELF::SetBinding(*Symbol, ELF::STB_GNU_UNIQUE);
244 SD.setExternal(true);
245 BindingExplicitlySet.insert(Symbol);
249 MCELF::SetBinding(*Symbol, ELF::STB_GLOBAL);
250 SD.setExternal(true);
251 BindingExplicitlySet.insert(Symbol);
254 case MCSA_WeakReference:
256 MCELF::SetBinding(*Symbol, ELF::STB_WEAK);
257 SD.setExternal(true);
258 BindingExplicitlySet.insert(Symbol);
262 MCELF::SetBinding(*Symbol, ELF::STB_LOCAL);
263 SD.setExternal(false);
264 BindingExplicitlySet.insert(Symbol);
267 case MCSA_ELF_TypeFunction:
268 MCELF::SetType(*Symbol,
269 CombineSymbolTypes(MCELF::GetType(*Symbol), ELF::STT_FUNC));
272 case MCSA_ELF_TypeIndFunction:
273 MCELF::SetType(*Symbol, CombineSymbolTypes(MCELF::GetType(*Symbol),
274 ELF::STT_GNU_IFUNC));
277 case MCSA_ELF_TypeObject:
279 *Symbol, CombineSymbolTypes(MCELF::GetType(*Symbol), ELF::STT_OBJECT));
282 case MCSA_ELF_TypeTLS:
283 MCELF::SetType(*Symbol,
284 CombineSymbolTypes(MCELF::GetType(*Symbol), ELF::STT_TLS));
287 case MCSA_ELF_TypeCommon:
288 // TODO: Emit these as a common symbol.
290 *Symbol, CombineSymbolTypes(MCELF::GetType(*Symbol), ELF::STT_OBJECT));
293 case MCSA_ELF_TypeNoType:
295 *Symbol, CombineSymbolTypes(MCELF::GetType(*Symbol), ELF::STT_NOTYPE));
299 MCELF::SetVisibility(*Symbol, ELF::STV_PROTECTED);
303 MCELF::SetVisibility(*Symbol, ELF::STV_HIDDEN);
307 MCELF::SetVisibility(*Symbol, ELF::STV_INTERNAL);
314 void MCELFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
315 unsigned ByteAlignment) {
316 getAssembler().registerSymbol(*Symbol);
317 MCSymbol &SD = Symbol->getData();
319 if (!BindingExplicitlySet.count(Symbol)) {
320 MCELF::SetBinding(*Symbol, ELF::STB_GLOBAL);
321 SD.setExternal(true);
324 MCELF::SetType(*Symbol, ELF::STT_OBJECT);
326 if (MCELF::GetBinding(*Symbol) == ELF_STB_Local) {
327 MCSection *Section = getAssembler().getContext().getELFSection(
328 ".bss", ELF::SHT_NOBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
330 AssignSection(Symbol, Section);
332 struct LocalCommon L = {Symbol, Size, ByteAlignment};
333 LocalCommons.push_back(L);
335 Symbol->setCommon(Size, ByteAlignment);
338 Symbol->setSize(MCConstantExpr::Create(Size, getContext()));
341 void MCELFStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
342 Symbol->setSize(Value);
345 void MCELFStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
346 unsigned ByteAlignment) {
347 // FIXME: Should this be caught and done earlier?
348 getAssembler().registerSymbol(*Symbol);
349 MCSymbol &SD = Symbol->getData();
350 MCELF::SetBinding(*Symbol, ELF::STB_LOCAL);
351 SD.setExternal(false);
352 BindingExplicitlySet.insert(Symbol);
353 EmitCommonSymbol(Symbol, Size, ByteAlignment);
356 void MCELFStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
358 if (isBundleLocked())
359 report_fatal_error("Emitting values inside a locked bundle is forbidden");
360 fixSymbolsInTLSFixups(Value);
361 MCObjectStreamer::EmitValueImpl(Value, Size, Loc);
364 void MCELFStreamer::EmitValueToAlignment(unsigned ByteAlignment,
367 unsigned MaxBytesToEmit) {
368 if (isBundleLocked())
369 report_fatal_error("Emitting values inside a locked bundle is forbidden");
370 MCObjectStreamer::EmitValueToAlignment(ByteAlignment, Value,
371 ValueSize, MaxBytesToEmit);
374 // Add a symbol for the file name of this module. They start after the
375 // null symbol and don't count as normal symbol, i.e. a non-STT_FILE symbol
376 // with the same name may appear.
377 void MCELFStreamer::EmitFileDirective(StringRef Filename) {
378 getAssembler().addFileName(Filename);
381 void MCELFStreamer::EmitIdent(StringRef IdentString) {
382 MCSection *Comment = getAssembler().getContext().getELFSection(
383 ".comment", ELF::SHT_PROGBITS, ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
385 SwitchSection(Comment);
390 EmitBytes(IdentString);
395 void MCELFStreamer::fixSymbolsInTLSFixups(const MCExpr *expr) {
396 switch (expr->getKind()) {
398 cast<MCTargetExpr>(expr)->fixELFSymbolsInTLSFixups(getAssembler());
400 case MCExpr::Constant:
403 case MCExpr::Binary: {
404 const MCBinaryExpr *be = cast<MCBinaryExpr>(expr);
405 fixSymbolsInTLSFixups(be->getLHS());
406 fixSymbolsInTLSFixups(be->getRHS());
410 case MCExpr::SymbolRef: {
411 const MCSymbolRefExpr &symRef = *cast<MCSymbolRefExpr>(expr);
412 switch (symRef.getKind()) {
415 case MCSymbolRefExpr::VK_GOTTPOFF:
416 case MCSymbolRefExpr::VK_INDNTPOFF:
417 case MCSymbolRefExpr::VK_NTPOFF:
418 case MCSymbolRefExpr::VK_GOTNTPOFF:
419 case MCSymbolRefExpr::VK_TLSGD:
420 case MCSymbolRefExpr::VK_TLSLD:
421 case MCSymbolRefExpr::VK_TLSLDM:
422 case MCSymbolRefExpr::VK_TPOFF:
423 case MCSymbolRefExpr::VK_DTPOFF:
424 case MCSymbolRefExpr::VK_Mips_TLSGD:
425 case MCSymbolRefExpr::VK_Mips_GOTTPREL:
426 case MCSymbolRefExpr::VK_Mips_TPREL_HI:
427 case MCSymbolRefExpr::VK_Mips_TPREL_LO:
428 case MCSymbolRefExpr::VK_PPC_DTPMOD:
429 case MCSymbolRefExpr::VK_PPC_TPREL:
430 case MCSymbolRefExpr::VK_PPC_TPREL_LO:
431 case MCSymbolRefExpr::VK_PPC_TPREL_HI:
432 case MCSymbolRefExpr::VK_PPC_TPREL_HA:
433 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHER:
434 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHERA:
435 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHEST:
436 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHESTA:
437 case MCSymbolRefExpr::VK_PPC_DTPREL:
438 case MCSymbolRefExpr::VK_PPC_DTPREL_LO:
439 case MCSymbolRefExpr::VK_PPC_DTPREL_HI:
440 case MCSymbolRefExpr::VK_PPC_DTPREL_HA:
441 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHER:
442 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHERA:
443 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHEST:
444 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHESTA:
445 case MCSymbolRefExpr::VK_PPC_GOT_TPREL:
446 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO:
447 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HI:
448 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HA:
449 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL:
450 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_LO:
451 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HI:
452 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HA:
453 case MCSymbolRefExpr::VK_PPC_TLS:
454 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD:
455 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_LO:
456 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HI:
457 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HA:
458 case MCSymbolRefExpr::VK_PPC_TLSGD:
459 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD:
460 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO:
461 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HI:
462 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HA:
463 case MCSymbolRefExpr::VK_PPC_TLSLD:
466 getAssembler().registerSymbol(symRef.getSymbol());
467 MCELF::SetType(symRef.getSymbol(), ELF::STT_TLS);
472 fixSymbolsInTLSFixups(cast<MCUnaryExpr>(expr)->getSubExpr());
477 void MCELFStreamer::EmitInstToFragment(const MCInst &Inst,
478 const MCSubtargetInfo &STI) {
479 this->MCObjectStreamer::EmitInstToFragment(Inst, STI);
480 MCRelaxableFragment &F = *cast<MCRelaxableFragment>(getCurrentFragment());
482 for (unsigned i = 0, e = F.getFixups().size(); i != e; ++i)
483 fixSymbolsInTLSFixups(F.getFixups()[i].getValue());
486 void MCELFStreamer::EmitInstToData(const MCInst &Inst,
487 const MCSubtargetInfo &STI) {
488 MCAssembler &Assembler = getAssembler();
489 SmallVector<MCFixup, 4> Fixups;
490 SmallString<256> Code;
491 raw_svector_ostream VecOS(Code);
492 Assembler.getEmitter().encodeInstruction(Inst, VecOS, Fixups, STI);
495 for (unsigned i = 0, e = Fixups.size(); i != e; ++i)
496 fixSymbolsInTLSFixups(Fixups[i].getValue());
498 // There are several possibilities here:
500 // If bundling is disabled, append the encoded instruction to the current data
501 // fragment (or create a new such fragment if the current fragment is not a
504 // If bundling is enabled:
505 // - If we're not in a bundle-locked group, emit the instruction into a
506 // fragment of its own. If there are no fixups registered for the
507 // instruction, emit a MCCompactEncodedInstFragment. Otherwise, emit a
509 // - If we're in a bundle-locked group, append the instruction to the current
510 // data fragment because we want all the instructions in a group to get into
511 // the same fragment. Be careful not to do that for the first instruction in
512 // the group, though.
515 if (Assembler.isBundlingEnabled()) {
516 MCSection &Sec = *getCurrentSectionOnly();
517 if (Assembler.getRelaxAll() && isBundleLocked())
518 // If the -mc-relax-all flag is used and we are bundle-locked, we re-use
519 // the current bundle group.
520 DF = BundleGroups.back();
521 else if (Assembler.getRelaxAll() && !isBundleLocked())
522 // When not in a bundle-locked group and the -mc-relax-all flag is used,
523 // we create a new temporary fragment which will be later merged into
524 // the current fragment.
525 DF = new MCDataFragment();
526 else if (isBundleLocked() && !Sec.isBundleGroupBeforeFirstInst())
527 // If we are bundle-locked, we re-use the current fragment.
528 // The bundle-locking directive ensures this is a new data fragment.
529 DF = cast<MCDataFragment>(getCurrentFragment());
530 else if (!isBundleLocked() && Fixups.size() == 0) {
531 // Optimize memory usage by emitting the instruction to a
532 // MCCompactEncodedInstFragment when not in a bundle-locked group and
533 // there are no fixups registered.
534 MCCompactEncodedInstFragment *CEIF = new MCCompactEncodedInstFragment();
536 CEIF->getContents().append(Code.begin(), Code.end());
539 DF = new MCDataFragment();
542 if (Sec.getBundleLockState() == MCSection::BundleLockedAlignToEnd) {
543 // If this fragment is for a group marked "align_to_end", set a flag
544 // in the fragment. This can happen after the fragment has already been
545 // created if there are nested bundle_align groups and an inner one
546 // is the one marked align_to_end.
547 DF->setAlignToBundleEnd(true);
550 // We're now emitting an instruction in a bundle group, so this flag has
552 Sec.setBundleGroupBeforeFirstInst(false);
554 DF = getOrCreateDataFragment();
557 // Add the fixups and data.
558 for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
559 Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
560 DF->getFixups().push_back(Fixups[i]);
562 DF->setHasInstructions(true);
563 DF->getContents().append(Code.begin(), Code.end());
565 if (Assembler.isBundlingEnabled() && Assembler.getRelaxAll()) {
566 if (!isBundleLocked()) {
567 mergeFragment(getOrCreateDataFragment(), DF);
573 void MCELFStreamer::EmitBundleAlignMode(unsigned AlignPow2) {
574 assert(AlignPow2 <= 30 && "Invalid bundle alignment");
575 MCAssembler &Assembler = getAssembler();
576 if (AlignPow2 > 0 && (Assembler.getBundleAlignSize() == 0 ||
577 Assembler.getBundleAlignSize() == 1U << AlignPow2))
578 Assembler.setBundleAlignSize(1U << AlignPow2);
580 report_fatal_error(".bundle_align_mode cannot be changed once set");
583 void MCELFStreamer::EmitBundleLock(bool AlignToEnd) {
584 MCSection &Sec = *getCurrentSectionOnly();
588 if (!getAssembler().isBundlingEnabled())
589 report_fatal_error(".bundle_lock forbidden when bundling is disabled");
591 if (!isBundleLocked())
592 Sec.setBundleGroupBeforeFirstInst(true);
594 if (getAssembler().getRelaxAll() && !isBundleLocked()) {
595 // TODO: drop the lock state and set directly in the fragment
596 MCDataFragment *DF = new MCDataFragment();
597 BundleGroups.push_back(DF);
600 Sec.setBundleLockState(AlignToEnd ? MCSection::BundleLockedAlignToEnd
601 : MCSection::BundleLocked);
604 void MCELFStreamer::EmitBundleUnlock() {
605 MCSection &Sec = *getCurrentSectionOnly();
608 if (!getAssembler().isBundlingEnabled())
609 report_fatal_error(".bundle_unlock forbidden when bundling is disabled");
610 else if (!isBundleLocked())
611 report_fatal_error(".bundle_unlock without matching lock");
612 else if (Sec.isBundleGroupBeforeFirstInst())
613 report_fatal_error("Empty bundle-locked group is forbidden");
615 // When the -mc-relax-all flag is used, we emit instructions to fragments
616 // stored on a stack. When the bundle unlock is emited, we pop a fragment
617 // from the stack a merge it to the one below.
618 if (getAssembler().getRelaxAll()) {
619 assert(!BundleGroups.empty() && "There are no bundle groups");
620 MCDataFragment *DF = BundleGroups.back();
622 // FIXME: Use BundleGroups to track the lock state instead.
623 Sec.setBundleLockState(MCSection::NotBundleLocked);
625 // FIXME: Use more separate fragments for nested groups.
626 if (!isBundleLocked()) {
627 mergeFragment(getOrCreateDataFragment(), DF);
628 BundleGroups.pop_back();
632 if (Sec.getBundleLockState() != MCSection::BundleLockedAlignToEnd)
633 getOrCreateDataFragment()->setAlignToBundleEnd(false);
635 Sec.setBundleLockState(MCSection::NotBundleLocked);
638 void MCELFStreamer::Flush() {
639 for (std::vector<LocalCommon>::const_iterator i = LocalCommons.begin(),
640 e = LocalCommons.end();
642 const MCSymbol &Symbol = *i->Symbol;
643 uint64_t Size = i->Size;
644 unsigned ByteAlignment = i->ByteAlignment;
645 MCSection &Section = Symbol.getSection();
647 getAssembler().registerSection(Section);
648 new MCAlignFragment(ByteAlignment, 0, 1, ByteAlignment, &Section);
650 MCFragment *F = new MCFillFragment(0, 0, Size, &Section);
651 Symbol.getData().setFragment(F);
653 // Update the maximum alignment of the section if necessary.
654 if (ByteAlignment > Section.getAlignment())
655 Section.setAlignment(ByteAlignment);
658 LocalCommons.clear();
661 void MCELFStreamer::FinishImpl() {
662 // Ensure the last section gets aligned if necessary.
663 MCSection *CurSection = getCurrentSectionOnly();
664 setSectionAlignmentForBundling(getAssembler(), CurSection);
670 this->MCObjectStreamer::FinishImpl();
673 MCStreamer *llvm::createELFStreamer(MCContext &Context, MCAsmBackend &MAB,
674 raw_pwrite_stream &OS, MCCodeEmitter *CE,
676 MCELFStreamer *S = new MCELFStreamer(Context, MAB, OS, CE);
678 S->getAssembler().setRelaxAll(true);
682 void MCELFStreamer::EmitThumbFunc(MCSymbol *Func) {
683 llvm_unreachable("Generic ELF doesn't support this directive");
686 void MCELFStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
687 llvm_unreachable("ELF doesn't support this directive");
690 void MCELFStreamer::BeginCOFFSymbolDef(const MCSymbol *Symbol) {
691 llvm_unreachable("ELF doesn't support this directive");
694 void MCELFStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {
695 llvm_unreachable("ELF doesn't support this directive");
698 void MCELFStreamer::EmitCOFFSymbolType(int Type) {
699 llvm_unreachable("ELF doesn't support this directive");
702 void MCELFStreamer::EndCOFFSymbolDef() {
703 llvm_unreachable("ELF doesn't support this directive");
706 void MCELFStreamer::EmitZerofill(MCSection *Section, MCSymbol *Symbol,
707 uint64_t Size, unsigned ByteAlignment) {
708 llvm_unreachable("ELF doesn't support this directive");
711 void MCELFStreamer::EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol,
712 uint64_t Size, unsigned ByteAlignment) {
713 llvm_unreachable("ELF doesn't support this directive");