1 //===- lib/MC/MCELFStreamer.cpp - ELF Object Output -----------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file assembles .s files and emits ELF .o object files.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "llvm/MC/MCELFStreamer.h"
15 #include "llvm/ADT/SmallPtrSet.h"
16 #include "llvm/ADT/STLExtras.h"
17 #include "llvm/MC/MCAssembler.h"
18 #include "llvm/MC/MCCodeEmitter.h"
19 #include "llvm/MC/MCContext.h"
20 #include "llvm/MC/MCELF.h"
21 #include "llvm/MC/MCELFSymbolFlags.h"
22 #include "llvm/MC/MCExpr.h"
23 #include "llvm/MC/MCInst.h"
24 #include "llvm/MC/MCObjectStreamer.h"
25 #include "llvm/MC/MCSection.h"
26 #include "llvm/MC/MCSectionELF.h"
27 #include "llvm/MC/MCSymbol.h"
28 #include "llvm/MC/MCValue.h"
29 #include "llvm/Support/Debug.h"
30 #include "llvm/Support/ELF.h"
31 #include "llvm/Support/ErrorHandling.h"
32 #include "llvm/Support/raw_ostream.h"
33
34 using namespace llvm;
35
36
SetSection(StringRef Section,unsigned Type,unsigned Flags,SectionKind Kind)37 inline void MCELFStreamer::SetSection(StringRef Section, unsigned Type,
38 unsigned Flags, SectionKind Kind) {
39 SwitchSection(getContext().getELFSection(Section, Type, Flags, Kind));
40 }
41
SetSectionData()42 inline void MCELFStreamer::SetSectionData() {
43 SetSection(".data",
44 ELF::SHT_PROGBITS,
45 ELF::SHF_WRITE | ELF::SHF_ALLOC,
46 SectionKind::getDataRel());
47 EmitCodeAlignment(4, 0);
48 }
49
SetSectionText()50 inline void MCELFStreamer::SetSectionText() {
51 SetSection(".text",
52 ELF::SHT_PROGBITS,
53 ELF::SHF_EXECINSTR | ELF::SHF_ALLOC,
54 SectionKind::getText());
55 EmitCodeAlignment(4, 0);
56 }
57
SetSectionBss()58 inline void MCELFStreamer::SetSectionBss() {
59 SetSection(".bss",
60 ELF::SHT_NOBITS,
61 ELF::SHF_WRITE | ELF::SHF_ALLOC,
62 SectionKind::getBSS());
63 EmitCodeAlignment(4, 0);
64 }
65
~MCELFStreamer()66 MCELFStreamer::~MCELFStreamer() {
67 }
68
InitToTextSection()69 void MCELFStreamer::InitToTextSection() {
70 SetSectionText();
71 }
72
InitSections()73 void MCELFStreamer::InitSections() {
74 // This emulates the same behavior of GNU as. This makes it easier
75 // to compare the output as the major sections are in the same order.
76 SetSectionText();
77 SetSectionData();
78 SetSectionBss();
79 SetSectionText();
80 }
81
EmitLabel(MCSymbol * Symbol)82 void MCELFStreamer::EmitLabel(MCSymbol *Symbol) {
83 assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
84
85 MCObjectStreamer::EmitLabel(Symbol);
86
87 const MCSectionELF &Section =
88 static_cast<const MCSectionELF&>(Symbol->getSection());
89 MCSymbolData &SD = getAssembler().getSymbolData(*Symbol);
90 if (Section.getFlags() & ELF::SHF_TLS)
91 MCELF::SetType(SD, ELF::STT_TLS);
92 }
93
EmitDebugLabel(MCSymbol * Symbol)94 void MCELFStreamer::EmitDebugLabel(MCSymbol *Symbol) {
95 EmitLabel(Symbol);
96 }
97
EmitAssemblerFlag(MCAssemblerFlag Flag)98 void MCELFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
99 switch (Flag) {
100 case MCAF_SyntaxUnified: return; // no-op here.
101 case MCAF_Code16: return; // Change parsing mode; no-op here.
102 case MCAF_Code32: return; // Change parsing mode; no-op here.
103 case MCAF_Code64: return; // Change parsing mode; no-op here.
104 case MCAF_SubsectionsViaSymbols:
105 getAssembler().setSubsectionsViaSymbols(true);
106 return;
107 }
108
109 llvm_unreachable("invalid assembler flag!");
110 }
111
ChangeSection(const MCSection * Section,const MCExpr * Subsection)112 void MCELFStreamer::ChangeSection(const MCSection *Section,
113 const MCExpr *Subsection) {
114 MCSectionData *CurSection = getCurrentSectionData();
115 if (CurSection && CurSection->isBundleLocked())
116 report_fatal_error("Unterminated .bundle_lock when changing a section");
117 const MCSymbol *Grp = static_cast<const MCSectionELF *>(Section)->getGroup();
118 if (Grp)
119 getAssembler().getOrCreateSymbolData(*Grp);
120 this->MCObjectStreamer::ChangeSection(Section, Subsection);
121 }
122
EmitWeakReference(MCSymbol * Alias,const MCSymbol * Symbol)123 void MCELFStreamer::EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {
124 getAssembler().getOrCreateSymbolData(*Symbol);
125 MCSymbolData &AliasSD = getAssembler().getOrCreateSymbolData(*Alias);
126 AliasSD.setFlags(AliasSD.getFlags() | ELF_Other_Weakref);
127 const MCExpr *Value = MCSymbolRefExpr::Create(Symbol, getContext());
128 Alias->setVariableValue(Value);
129 }
130
131 // When GNU as encounters more than one .type declaration for an object it seems
132 // to use a mechanism similar to the one below to decide which type is actually
133 // used in the object file. The greater of T1 and T2 is selected based on the
134 // following ordering:
135 // STT_NOTYPE < STT_OBJECT < STT_FUNC < STT_GNU_IFUNC < STT_TLS < anything else
136 // If neither T1 < T2 nor T2 < T1 according to this ordering, use T2 (the user
137 // provided type).
CombineSymbolTypes(unsigned T1,unsigned T2)138 static unsigned CombineSymbolTypes(unsigned T1, unsigned T2) {
139 unsigned TypeOrdering[] = {ELF::STT_NOTYPE, ELF::STT_OBJECT, ELF::STT_FUNC,
140 ELF::STT_GNU_IFUNC, ELF::STT_TLS};
141 for (unsigned i = 0; i != array_lengthof(TypeOrdering); ++i) {
142 if (T1 == TypeOrdering[i])
143 return T2;
144 if (T2 == TypeOrdering[i])
145 return T1;
146 }
147
148 return T2;
149 }
150
EmitSymbolAttribute(MCSymbol * Symbol,MCSymbolAttr Attribute)151 void MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
152 MCSymbolAttr Attribute) {
153 // Indirect symbols are handled differently, to match how 'as' handles
154 // them. This makes writing matching .o files easier.
155 if (Attribute == MCSA_IndirectSymbol) {
156 // Note that we intentionally cannot use the symbol data here; this is
157 // important for matching the string table that 'as' generates.
158 IndirectSymbolData ISD;
159 ISD.Symbol = Symbol;
160 ISD.SectionData = getCurrentSectionData();
161 getAssembler().getIndirectSymbols().push_back(ISD);
162 return;
163 }
164
165 // Adding a symbol attribute always introduces the symbol, note that an
166 // important side effect of calling getOrCreateSymbolData here is to register
167 // the symbol with the assembler.
168 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
169
170 // The implementation of symbol attributes is designed to match 'as', but it
171 // leaves much to desired. It doesn't really make sense to arbitrarily add and
172 // remove flags, but 'as' allows this (in particular, see .desc).
173 //
174 // In the future it might be worth trying to make these operations more well
175 // defined.
176 switch (Attribute) {
177 case MCSA_LazyReference:
178 case MCSA_Reference:
179 case MCSA_SymbolResolver:
180 case MCSA_PrivateExtern:
181 case MCSA_WeakDefinition:
182 case MCSA_WeakDefAutoPrivate:
183 case MCSA_Invalid:
184 case MCSA_IndirectSymbol:
185 llvm_unreachable("Invalid symbol attribute for ELF!");
186
187 case MCSA_NoDeadStrip:
188 case MCSA_ELF_TypeGnuUniqueObject:
189 // Ignore for now.
190 break;
191
192 case MCSA_Global:
193 MCELF::SetBinding(SD, ELF::STB_GLOBAL);
194 SD.setExternal(true);
195 BindingExplicitlySet.insert(Symbol);
196 break;
197
198 case MCSA_WeakReference:
199 case MCSA_Weak:
200 MCELF::SetBinding(SD, ELF::STB_WEAK);
201 SD.setExternal(true);
202 BindingExplicitlySet.insert(Symbol);
203 break;
204
205 case MCSA_Local:
206 MCELF::SetBinding(SD, ELF::STB_LOCAL);
207 SD.setExternal(false);
208 BindingExplicitlySet.insert(Symbol);
209 break;
210
211 case MCSA_ELF_TypeFunction:
212 MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD),
213 ELF::STT_FUNC));
214 break;
215
216 case MCSA_ELF_TypeIndFunction:
217 MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD),
218 ELF::STT_GNU_IFUNC));
219 break;
220
221 case MCSA_ELF_TypeObject:
222 MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD),
223 ELF::STT_OBJECT));
224 break;
225
226 case MCSA_ELF_TypeTLS:
227 MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD),
228 ELF::STT_TLS));
229 break;
230
231 case MCSA_ELF_TypeCommon:
232 // TODO: Emit these as a common symbol.
233 MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD),
234 ELF::STT_OBJECT));
235 break;
236
237 case MCSA_ELF_TypeNoType:
238 MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD),
239 ELF::STT_NOTYPE));
240 break;
241
242 case MCSA_Protected:
243 MCELF::SetVisibility(SD, ELF::STV_PROTECTED);
244 break;
245
246 case MCSA_Hidden:
247 MCELF::SetVisibility(SD, ELF::STV_HIDDEN);
248 break;
249
250 case MCSA_Internal:
251 MCELF::SetVisibility(SD, ELF::STV_INTERNAL);
252 break;
253 }
254 }
255
EmitCommonSymbol(MCSymbol * Symbol,uint64_t Size,unsigned ByteAlignment)256 void MCELFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
257 unsigned ByteAlignment) {
258 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
259
260 if (!BindingExplicitlySet.count(Symbol)) {
261 MCELF::SetBinding(SD, ELF::STB_GLOBAL);
262 SD.setExternal(true);
263 }
264
265 MCELF::SetType(SD, ELF::STT_OBJECT);
266
267 if (MCELF::GetBinding(SD) == ELF_STB_Local) {
268 const MCSection *Section = getAssembler().getContext().getELFSection(".bss",
269 ELF::SHT_NOBITS,
270 ELF::SHF_WRITE |
271 ELF::SHF_ALLOC,
272 SectionKind::getBSS());
273 Symbol->setSection(*Section);
274
275 struct LocalCommon L = {&SD, Size, ByteAlignment};
276 LocalCommons.push_back(L);
277 } else {
278 SD.setCommon(Size, ByteAlignment);
279 }
280
281 SD.setSize(MCConstantExpr::Create(Size, getContext()));
282 }
283
EmitELFSize(MCSymbol * Symbol,const MCExpr * Value)284 void MCELFStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
285 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
286 SD.setSize(Value);
287 }
288
EmitLocalCommonSymbol(MCSymbol * Symbol,uint64_t Size,unsigned ByteAlignment)289 void MCELFStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
290 unsigned ByteAlignment) {
291 // FIXME: Should this be caught and done earlier?
292 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
293 MCELF::SetBinding(SD, ELF::STB_LOCAL);
294 SD.setExternal(false);
295 BindingExplicitlySet.insert(Symbol);
296 EmitCommonSymbol(Symbol, Size, ByteAlignment);
297 }
298
EmitValueImpl(const MCExpr * Value,unsigned Size)299 void MCELFStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size) {
300 if (getCurrentSectionData()->isBundleLocked())
301 report_fatal_error("Emitting values inside a locked bundle is forbidden");
302 fixSymbolsInTLSFixups(Value);
303 MCObjectStreamer::EmitValueImpl(Value, Size);
304 }
305
EmitValueToAlignment(unsigned ByteAlignment,int64_t Value,unsigned ValueSize,unsigned MaxBytesToEmit)306 void MCELFStreamer::EmitValueToAlignment(unsigned ByteAlignment,
307 int64_t Value,
308 unsigned ValueSize,
309 unsigned MaxBytesToEmit) {
310 if (getCurrentSectionData()->isBundleLocked())
311 report_fatal_error("Emitting values inside a locked bundle is forbidden");
312 MCObjectStreamer::EmitValueToAlignment(ByteAlignment, Value,
313 ValueSize, MaxBytesToEmit);
314 }
315
316
317 // Add a symbol for the file name of this module. This is the second
318 // entry in the module's symbol table (the first being the null symbol).
EmitFileDirective(StringRef Filename)319 void MCELFStreamer::EmitFileDirective(StringRef Filename) {
320 MCSymbol *Symbol = getAssembler().getContext().GetOrCreateSymbol(Filename);
321 Symbol->setSection(*getCurrentSection().first);
322 Symbol->setAbsolute();
323
324 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
325
326 SD.setFlags(ELF_STT_File | ELF_STB_Local | ELF_STV_Default);
327 }
328
fixSymbolsInTLSFixups(const MCExpr * expr)329 void MCELFStreamer::fixSymbolsInTLSFixups(const MCExpr *expr) {
330 switch (expr->getKind()) {
331 case MCExpr::Target:
332 cast<MCTargetExpr>(expr)->fixELFSymbolsInTLSFixups(getAssembler());
333 break;
334 case MCExpr::Constant:
335 break;
336
337 case MCExpr::Binary: {
338 const MCBinaryExpr *be = cast<MCBinaryExpr>(expr);
339 fixSymbolsInTLSFixups(be->getLHS());
340 fixSymbolsInTLSFixups(be->getRHS());
341 break;
342 }
343
344 case MCExpr::SymbolRef: {
345 const MCSymbolRefExpr &symRef = *cast<MCSymbolRefExpr>(expr);
346 switch (symRef.getKind()) {
347 default:
348 return;
349 case MCSymbolRefExpr::VK_GOTTPOFF:
350 case MCSymbolRefExpr::VK_INDNTPOFF:
351 case MCSymbolRefExpr::VK_NTPOFF:
352 case MCSymbolRefExpr::VK_GOTNTPOFF:
353 case MCSymbolRefExpr::VK_TLSGD:
354 case MCSymbolRefExpr::VK_TLSLD:
355 case MCSymbolRefExpr::VK_TLSLDM:
356 case MCSymbolRefExpr::VK_TPOFF:
357 case MCSymbolRefExpr::VK_DTPOFF:
358 case MCSymbolRefExpr::VK_ARM_TLSGD:
359 case MCSymbolRefExpr::VK_ARM_TPOFF:
360 case MCSymbolRefExpr::VK_ARM_GOTTPOFF:
361 case MCSymbolRefExpr::VK_Mips_TLSGD:
362 case MCSymbolRefExpr::VK_Mips_GOTTPREL:
363 case MCSymbolRefExpr::VK_Mips_TPREL_HI:
364 case MCSymbolRefExpr::VK_Mips_TPREL_LO:
365 case MCSymbolRefExpr::VK_PPC_DTPMOD:
366 case MCSymbolRefExpr::VK_PPC_TPREL:
367 case MCSymbolRefExpr::VK_PPC_TPREL_LO:
368 case MCSymbolRefExpr::VK_PPC_TPREL_HI:
369 case MCSymbolRefExpr::VK_PPC_TPREL_HA:
370 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHER:
371 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHERA:
372 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHEST:
373 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHESTA:
374 case MCSymbolRefExpr::VK_PPC_DTPREL:
375 case MCSymbolRefExpr::VK_PPC_DTPREL_LO:
376 case MCSymbolRefExpr::VK_PPC_DTPREL_HI:
377 case MCSymbolRefExpr::VK_PPC_DTPREL_HA:
378 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHER:
379 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHERA:
380 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHEST:
381 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHESTA:
382 case MCSymbolRefExpr::VK_PPC_GOT_TPREL:
383 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO:
384 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HI:
385 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HA:
386 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL:
387 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_LO:
388 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HI:
389 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HA:
390 case MCSymbolRefExpr::VK_PPC_TLS:
391 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD:
392 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_LO:
393 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HI:
394 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HA:
395 case MCSymbolRefExpr::VK_PPC_TLSGD:
396 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD:
397 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO:
398 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HI:
399 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HA:
400 case MCSymbolRefExpr::VK_PPC_TLSLD:
401 break;
402 }
403 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(symRef.getSymbol());
404 MCELF::SetType(SD, ELF::STT_TLS);
405 break;
406 }
407
408 case MCExpr::Unary:
409 fixSymbolsInTLSFixups(cast<MCUnaryExpr>(expr)->getSubExpr());
410 break;
411 }
412 }
413
EmitInstToFragment(const MCInst & Inst)414 void MCELFStreamer::EmitInstToFragment(const MCInst &Inst) {
415 this->MCObjectStreamer::EmitInstToFragment(Inst);
416 MCRelaxableFragment &F = *cast<MCRelaxableFragment>(getCurrentFragment());
417
418 for (unsigned i = 0, e = F.getFixups().size(); i != e; ++i)
419 fixSymbolsInTLSFixups(F.getFixups()[i].getValue());
420 }
421
EmitInstToData(const MCInst & Inst)422 void MCELFStreamer::EmitInstToData(const MCInst &Inst) {
423 MCAssembler &Assembler = getAssembler();
424 SmallVector<MCFixup, 4> Fixups;
425 SmallString<256> Code;
426 raw_svector_ostream VecOS(Code);
427 Assembler.getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
428 VecOS.flush();
429
430 for (unsigned i = 0, e = Fixups.size(); i != e; ++i)
431 fixSymbolsInTLSFixups(Fixups[i].getValue());
432
433 // There are several possibilities here:
434 //
435 // If bundling is disabled, append the encoded instruction to the current data
436 // fragment (or create a new such fragment if the current fragment is not a
437 // data fragment).
438 //
439 // If bundling is enabled:
440 // - If we're not in a bundle-locked group, emit the instruction into a
441 // fragment of its own. If there are no fixups registered for the
442 // instruction, emit a MCCompactEncodedInstFragment. Otherwise, emit a
443 // MCDataFragment.
444 // - If we're in a bundle-locked group, append the instruction to the current
445 // data fragment because we want all the instructions in a group to get into
446 // the same fragment. Be careful not to do that for the first instruction in
447 // the group, though.
448 MCDataFragment *DF;
449
450 if (Assembler.isBundlingEnabled()) {
451 MCSectionData *SD = getCurrentSectionData();
452 if (SD->isBundleLocked() && !SD->isBundleGroupBeforeFirstInst())
453 // If we are bundle-locked, we re-use the current fragment.
454 // The bundle-locking directive ensures this is a new data fragment.
455 DF = cast<MCDataFragment>(getCurrentFragment());
456 else if (!SD->isBundleLocked() && Fixups.size() == 0) {
457 // Optimize memory usage by emitting the instruction to a
458 // MCCompactEncodedInstFragment when not in a bundle-locked group and
459 // there are no fixups registered.
460 MCCompactEncodedInstFragment *CEIF = new MCCompactEncodedInstFragment();
461 insert(CEIF);
462 CEIF->getContents().append(Code.begin(), Code.end());
463 return;
464 } else {
465 DF = new MCDataFragment();
466 insert(DF);
467 if (SD->getBundleLockState() == MCSectionData::BundleLockedAlignToEnd) {
468 // If this is a new fragment created for a bundle-locked group, and the
469 // group was marked as "align_to_end", set a flag in the fragment.
470 DF->setAlignToBundleEnd(true);
471 }
472 }
473
474 // We're now emitting an instruction in a bundle group, so this flag has
475 // to be turned off.
476 SD->setBundleGroupBeforeFirstInst(false);
477 } else {
478 DF = getOrCreateDataFragment();
479 }
480
481 // Add the fixups and data.
482 for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
483 Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
484 DF->getFixups().push_back(Fixups[i]);
485 }
486 DF->setHasInstructions(true);
487 DF->getContents().append(Code.begin(), Code.end());
488 }
489
EmitBundleAlignMode(unsigned AlignPow2)490 void MCELFStreamer::EmitBundleAlignMode(unsigned AlignPow2) {
491 assert(AlignPow2 <= 30 && "Invalid bundle alignment");
492 MCAssembler &Assembler = getAssembler();
493 if (Assembler.getBundleAlignSize() == 0 && AlignPow2 > 0)
494 Assembler.setBundleAlignSize(1 << AlignPow2);
495 else
496 report_fatal_error(".bundle_align_mode should be only set once per file");
497 }
498
EmitBundleLock(bool AlignToEnd)499 void MCELFStreamer::EmitBundleLock(bool AlignToEnd) {
500 MCSectionData *SD = getCurrentSectionData();
501
502 // Sanity checks
503 //
504 if (!getAssembler().isBundlingEnabled())
505 report_fatal_error(".bundle_lock forbidden when bundling is disabled");
506 else if (SD->isBundleLocked())
507 report_fatal_error("Nesting of .bundle_lock is forbidden");
508
509 SD->setBundleLockState(AlignToEnd ? MCSectionData::BundleLockedAlignToEnd :
510 MCSectionData::BundleLocked);
511 SD->setBundleGroupBeforeFirstInst(true);
512 }
513
EmitBundleUnlock()514 void MCELFStreamer::EmitBundleUnlock() {
515 MCSectionData *SD = getCurrentSectionData();
516
517 // Sanity checks
518 if (!getAssembler().isBundlingEnabled())
519 report_fatal_error(".bundle_unlock forbidden when bundling is disabled");
520 else if (!SD->isBundleLocked())
521 report_fatal_error(".bundle_unlock without matching lock");
522 else if (SD->isBundleGroupBeforeFirstInst())
523 report_fatal_error("Empty bundle-locked group is forbidden");
524
525 SD->setBundleLockState(MCSectionData::NotBundleLocked);
526 }
527
FinishImpl()528 void MCELFStreamer::FinishImpl() {
529 EmitFrames(true);
530
531 for (std::vector<LocalCommon>::const_iterator i = LocalCommons.begin(),
532 e = LocalCommons.end();
533 i != e; ++i) {
534 MCSymbolData *SD = i->SD;
535 uint64_t Size = i->Size;
536 unsigned ByteAlignment = i->ByteAlignment;
537 const MCSymbol &Symbol = SD->getSymbol();
538 const MCSection &Section = Symbol.getSection();
539
540 MCSectionData &SectData = getAssembler().getOrCreateSectionData(Section);
541 new MCAlignFragment(ByteAlignment, 0, 1, ByteAlignment, &SectData);
542
543 MCFragment *F = new MCFillFragment(0, 0, Size, &SectData);
544 SD->setFragment(F);
545
546 // Update the maximum alignment of the section if necessary.
547 if (ByteAlignment > SectData.getAlignment())
548 SectData.setAlignment(ByteAlignment);
549 }
550
551 this->MCObjectStreamer::FinishImpl();
552 }
EmitTCEntry(const MCSymbol & S)553 void MCELFStreamer::EmitTCEntry(const MCSymbol &S) {
554 // Creates a R_PPC64_TOC relocation
555 MCObjectStreamer::EmitSymbolValue(&S, 8);
556 }
557
createELFStreamer(MCContext & Context,MCAsmBackend & MAB,raw_ostream & OS,MCCodeEmitter * CE,bool RelaxAll,bool NoExecStack)558 MCStreamer *llvm::createELFStreamer(MCContext &Context, MCAsmBackend &MAB,
559 raw_ostream &OS, MCCodeEmitter *CE,
560 bool RelaxAll, bool NoExecStack) {
561 MCELFStreamer *S = new MCELFStreamer(Context, MAB, OS, CE);
562 if (RelaxAll)
563 S->getAssembler().setRelaxAll(true);
564 if (NoExecStack)
565 S->getAssembler().setNoExecStack(true);
566 return S;
567 }
568
EmitThumbFunc(MCSymbol * Func)569 void MCELFStreamer::EmitThumbFunc(MCSymbol *Func) {
570 llvm_unreachable("Generic ELF doesn't support this directive");
571 }
572
getOrCreateSymbolData(MCSymbol * Symbol)573 MCSymbolData &MCELFStreamer::getOrCreateSymbolData(MCSymbol *Symbol) {
574 return getAssembler().getOrCreateSymbolData(*Symbol);
575 }
576
EmitSymbolDesc(MCSymbol * Symbol,unsigned DescValue)577 void MCELFStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
578 llvm_unreachable("ELF doesn't support this directive");
579 }
580
BeginCOFFSymbolDef(const MCSymbol * Symbol)581 void MCELFStreamer::BeginCOFFSymbolDef(const MCSymbol *Symbol) {
582 llvm_unreachable("ELF doesn't support this directive");
583 }
584
EmitCOFFSymbolStorageClass(int StorageClass)585 void MCELFStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {
586 llvm_unreachable("ELF doesn't support this directive");
587 }
588
EmitCOFFSymbolType(int Type)589 void MCELFStreamer::EmitCOFFSymbolType(int Type) {
590 llvm_unreachable("ELF doesn't support this directive");
591 }
592
EndCOFFSymbolDef()593 void MCELFStreamer::EndCOFFSymbolDef() {
594 llvm_unreachable("ELF doesn't support this directive");
595 }
596
EmitZerofill(const MCSection * Section,MCSymbol * Symbol,uint64_t Size,unsigned ByteAlignment)597 void MCELFStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
598 uint64_t Size, unsigned ByteAlignment) {
599 llvm_unreachable("ELF doesn't support this directive");
600 }
601
EmitTBSSSymbol(const MCSection * Section,MCSymbol * Symbol,uint64_t Size,unsigned ByteAlignment)602 void MCELFStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
603 uint64_t Size, unsigned ByteAlignment) {
604 llvm_unreachable("ELF doesn't support this directive");
605 }
606