Bug Summary

File:lib/MC/MCELFStreamer.cpp
Location:line 638, column 25
Description:Potential leak of memory pointed to by 'F'

Annotated Source Code

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/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"
37
38using namespace llvm;
39
40bool MCELFStreamer::isBundleLocked() const {
41 return getCurrentSectionOnly()->isBundleLocked();
42}
43
44MCELFStreamer::~MCELFStreamer() {
45}
46
47void MCELFStreamer::mergeFragment(MCDataFragment *DF,
48 MCDataFragment *EF) {
49 MCAssembler &Assembler = getAssembler();
50
51 if (Assembler.isBundlingEnabled() && Assembler.getRelaxAll()) {
52 uint64_t FSize = EF->getContents().size();
53
54 if (FSize > Assembler.getBundleAlignSize())
55 report_fatal_error("Fragment can't be larger than a bundle size");
56
57 uint64_t RequiredBundlePadding = computeBundlePadding(
58 Assembler, EF, DF->getContents().size(), FSize);
59
60 if (RequiredBundlePadding > UINT8_MAX(255))
61 report_fatal_error("Padding cannot exceed 255 bytes");
62
63 if (RequiredBundlePadding > 0) {
64 SmallString<256> Code;
65 raw_svector_ostream VecOS(Code);
66 MCObjectWriter *OW = Assembler.getBackend().createObjectWriter(VecOS);
67
68 EF->setBundlePadding(static_cast<uint8_t>(RequiredBundlePadding));
69
70 Assembler.writeFragmentPadding(*EF, FSize, OW);
71 delete OW;
72
73 DF->getContents().append(Code.begin(), Code.end());
74 }
75 }
76
77 flushPendingLabels(DF, DF->getContents().size());
78
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]);
83 }
84 DF->setHasInstructions(true);
85 DF->getContents().append(EF->getContents().begin(), EF->getContents().end());
86}
87
88void 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());
93 EmitCodeAlignment(4);
94
95 SwitchSection(Ctx.getObjectFileInfo()->getDataSection());
96 EmitCodeAlignment(4);
97
98 SwitchSection(Ctx.getObjectFileInfo()->getBSSSection());
99 EmitCodeAlignment(4);
100
101 SwitchSection(Ctx.getObjectFileInfo()->getTextSection());
102
103 if (NoExecStack)
104 SwitchSection(Ctx.getAsmInfo()->getNonexecutableStackSection(Ctx));
105}
106
107void MCELFStreamer::EmitLabel(MCSymbol *S) {
108 auto *Symbol = cast<MCSymbolELF>(S);
109 assert(Symbol->isUndefined() && "Cannot define a symbol twice!")((Symbol->isUndefined() && "Cannot define a symbol twice!"
) ? static_cast<void> (0) : __assert_fail ("Symbol->isUndefined() && \"Cannot define a symbol twice!\""
, "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn251506/lib/MC/MCELFStreamer.cpp"
, 109, __PRETTY_FUNCTION__));
110
111 MCObjectStreamer::EmitLabel(Symbol);
112
113 const MCSectionELF &Section =
114 static_cast<const MCSectionELF &>(*getCurrentSectionOnly());
115 if (Section.getFlags() & ELF::SHF_TLS)
116 Symbol->setType(ELF::STT_TLS);
117}
118
119void 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.
123 switch (Flag) {
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);
130 return;
131 }
132
133 llvm_unreachable("invalid assembler flag!")::llvm::llvm_unreachable_internal("invalid assembler flag!", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn251506/lib/MC/MCELFStreamer.cpp"
, 133);
134}
135
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.
138static 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());
143}
144
145void 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");
150
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();
156 if (Grp)
157 Asm.registerSymbol(*Grp);
158
159 this->MCObjectStreamer::ChangeSection(Section, Subsection);
160 MCContext &Ctx = getContext();
161 auto *Begin = cast_or_null<MCSymbolELF>(Section->getBeginSymbol());
162 if (!Begin) {
163 Begin = Ctx.getOrCreateSectionSymbol(*SectionELF);
164 Section->setBeginSymbol(Begin);
165 }
166 if (Begin->isUndefined()) {
167 Asm.registerSymbol(*Begin);
168 Begin->setType(ELF::STT_SECTION);
169 }
170}
171
172void 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);
177}
178
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
185// provided type).
186static 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}) {
189 if (T1 == Type)
190 return T2;
191 if (T2 == Type)
192 return T1;
193 }
194
195 return T2;
196}
197
198bool 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;
206 ISD.Symbol = Symbol;
207 ISD.Section = getCurrentSectionOnly();
208 getAssembler().getIndirectSymbols().push_back(ISD);
209 return true;
210 }
211
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);
216
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).
220 //
221 // In the future it might be worth trying to make these operations more well
222 // defined.
223 switch (Attribute) {
224 case MCSA_LazyReference:
225 case MCSA_Reference:
226 case MCSA_SymbolResolver:
227 case MCSA_PrivateExtern:
228 case MCSA_WeakDefinition:
229 case MCSA_WeakDefAutoPrivate:
230 case MCSA_Invalid:
231 case MCSA_IndirectSymbol:
232 return false;
233
234 case MCSA_NoDeadStrip:
235 // Ignore for now.
236 break;
237
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);
242 break;
243
244 case MCSA_Global:
245 Symbol->setBinding(ELF::STB_GLOBAL);
246 Symbol->setExternal(true);
247 break;
248
249 case MCSA_WeakReference:
250 case MCSA_Weak:
251 Symbol->setBinding(ELF::STB_WEAK);
252 Symbol->setExternal(true);
253 break;
254
255 case MCSA_Local:
256 Symbol->setBinding(ELF::STB_LOCAL);
257 Symbol->setExternal(false);
258 break;
259
260 case MCSA_ELF_TypeFunction:
261 Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_FUNC));
262 break;
263
264 case MCSA_ELF_TypeIndFunction:
265 Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_GNU_IFUNC));
266 break;
267
268 case MCSA_ELF_TypeObject:
269 Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_OBJECT));
270 break;
271
272 case MCSA_ELF_TypeTLS:
273 Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_TLS));
274 break;
275
276 case MCSA_ELF_TypeCommon:
277 // TODO: Emit these as a common symbol.
278 Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_OBJECT));
279 break;
280
281 case MCSA_ELF_TypeNoType:
282 Symbol->setType(CombineSymbolTypes(Symbol->getType(), ELF::STT_NOTYPE));
283 break;
284
285 case MCSA_Protected:
286 Symbol->setVisibility(ELF::STV_PROTECTED);
287 break;
288
289 case MCSA_Hidden:
290 Symbol->setVisibility(ELF::STV_HIDDEN);
291 break;
292
293 case MCSA_Internal:
294 Symbol->setVisibility(ELF::STV_INTERNAL);
295 break;
296 }
297
298 return true;
299}
300
301void MCELFStreamer::EmitCommonSymbol(MCSymbol *S, uint64_t Size,
302 unsigned ByteAlignment) {
303 auto *Symbol = cast<MCSymbolELF>(S);
304 getAssembler().registerSymbol(*Symbol);
305
306 if (!Symbol->isBindingSet()) {
307 Symbol->setBinding(ELF::STB_GLOBAL);
308 Symbol->setExternal(true);
309 }
310
311 Symbol->setType(ELF::STT_OBJECT);
312
313 if (Symbol->getBinding() == ELF::STB_LOCAL) {
314 struct LocalCommon L = {Symbol, Size, ByteAlignment};
315 LocalCommons.push_back(L);
316 } else {
317 if(Symbol->declareCommon(Size, ByteAlignment))
318 report_fatal_error("Symbol: " + Symbol->getName() +
319 " redeclared as different type");
320 }
321
322 cast<MCSymbolELF>(Symbol)
323 ->setSize(MCConstantExpr::create(Size, getContext()));
324}
325
326void MCELFStreamer::emitELFSize(MCSymbolELF *Symbol, const MCExpr *Value) {
327 Symbol->setSize(Value);
328}
329
330void 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);
338}
339
340void MCELFStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
341 SMLoc Loc) {
342 if (isBundleLocked())
343 report_fatal_error("Emitting values inside a locked bundle is forbidden");
344 fixSymbolsInTLSFixups(Value);
345 MCObjectStreamer::EmitValueImpl(Value, Size, Loc);
346}
347
348void MCELFStreamer::EmitValueToAlignment(unsigned ByteAlignment,
349 int64_t Value,
350 unsigned ValueSize,
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);
356}
357
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.
361void MCELFStreamer::EmitFileDirective(StringRef Filename) {
362 getAssembler().addFileName(Filename);
363}
364
365void MCELFStreamer::EmitIdent(StringRef IdentString) {
366 MCSection *Comment = getAssembler().getContext().getELFSection(
367 ".comment", ELF::SHT_PROGBITS, ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
368 PushSection();
369 SwitchSection(Comment);
370 if (!SeenIdent) {
371 EmitIntValue(0, 1);
372 SeenIdent = true;
373 }
374 EmitBytes(IdentString);
375 EmitIntValue(0, 1);
376 PopSection();
377}
378
379void MCELFStreamer::fixSymbolsInTLSFixups(const MCExpr *expr) {
380 switch (expr->getKind()) {
381 case MCExpr::Target:
382 cast<MCTargetExpr>(expr)->fixELFSymbolsInTLSFixups(getAssembler());
383 break;
384 case MCExpr::Constant:
385 break;
386
387 case MCExpr::Binary: {
388 const MCBinaryExpr *be = cast<MCBinaryExpr>(expr);
389 fixSymbolsInTLSFixups(be->getLHS());
390 fixSymbolsInTLSFixups(be->getRHS());
391 break;
392 }
393
394 case MCExpr::SymbolRef: {
395 const MCSymbolRefExpr &symRef = *cast<MCSymbolRefExpr>(expr);
396 switch (symRef.getKind()) {
397 default:
398 return;
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:
448 break;
449 }
450 getAssembler().registerSymbol(symRef.getSymbol());
451 cast<MCSymbolELF>(symRef.getSymbol()).setType(ELF::STT_TLS);
452 break;
453 }
454
455 case MCExpr::Unary:
456 fixSymbolsInTLSFixups(cast<MCUnaryExpr>(expr)->getSubExpr());
457 break;
458 }
459}
460
461void MCELFStreamer::EmitInstToFragment(const MCInst &Inst,
462 const MCSubtargetInfo &STI) {
463 this->MCObjectStreamer::EmitInstToFragment(Inst, STI);
464 MCRelaxableFragment &F = *cast<MCRelaxableFragment>(getCurrentFragment());
465
466 for (unsigned i = 0, e = F.getFixups().size(); i != e; ++i)
467 fixSymbolsInTLSFixups(F.getFixups()[i].getValue());
468}
469
470void 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);
477
478 for (unsigned i = 0, e = Fixups.size(); i != e; ++i)
479 fixSymbolsInTLSFixups(Fixups[i].getValue());
480
481 // There are several possibilities here:
482 //
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
485 // data fragment).
486 //
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
491 // MCDataFragment.
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.
496 MCDataFragment *DF;
497
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();
518 insert(CEIF);
519 CEIF->getContents().append(Code.begin(), Code.end());
520 return;
521 } else {
522 DF = new MCDataFragment();
523 insert(DF);
524 }
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);
531 }
532
533 // We're now emitting an instruction in a bundle group, so this flag has
534 // to be turned off.
535 Sec.setBundleGroupBeforeFirstInst(false);
536 } else {
537 DF = getOrCreateDataFragment();
538 }
539
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]);
544 }
545 DF->setHasInstructions(true);
546 DF->getContents().append(Code.begin(), Code.end());
547
548 if (Assembler.isBundlingEnabled() && Assembler.getRelaxAll()) {
549 if (!isBundleLocked()) {
550 mergeFragment(getOrCreateDataFragment(), DF);
551 delete DF;
552 }
553 }
554}
555
556void MCELFStreamer::EmitBundleAlignMode(unsigned AlignPow2) {
557 assert(AlignPow2 <= 30 && "Invalid bundle alignment")((AlignPow2 <= 30 && "Invalid bundle alignment") ?
static_cast<void> (0) : __assert_fail ("AlignPow2 <= 30 && \"Invalid bundle alignment\""
, "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn251506/lib/MC/MCELFStreamer.cpp"
, 557, __PRETTY_FUNCTION__));
558 MCAssembler &Assembler = getAssembler();
559 if (AlignPow2 > 0 && (Assembler.getBundleAlignSize() == 0 ||
560 Assembler.getBundleAlignSize() == 1U << AlignPow2))
561 Assembler.setBundleAlignSize(1U << AlignPow2);
562 else
563 report_fatal_error(".bundle_align_mode cannot be changed once set");
564}
565
566void MCELFStreamer::EmitBundleLock(bool AlignToEnd) {
567 MCSection &Sec = *getCurrentSectionOnly();
568
569 // Sanity checks
570 //
571 if (!getAssembler().isBundlingEnabled())
572 report_fatal_error(".bundle_lock forbidden when bundling is disabled");
573
574 if (!isBundleLocked())
575 Sec.setBundleGroupBeforeFirstInst(true);
576
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);
581 }
582
583 Sec.setBundleLockState(AlignToEnd ? MCSection::BundleLockedAlignToEnd
584 : MCSection::BundleLocked);
585}
586
587void MCELFStreamer::EmitBundleUnlock() {
588 MCSection &Sec = *getCurrentSectionOnly();
589
590 // Sanity checks
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");
597
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")((!BundleGroups.empty() && "There are no bundle groups"
) ? static_cast<void> (0) : __assert_fail ("!BundleGroups.empty() && \"There are no bundle groups\""
, "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn251506/lib/MC/MCELFStreamer.cpp"
, 602, __PRETTY_FUNCTION__));
603 MCDataFragment *DF = BundleGroups.back();
604
605 // FIXME: Use BundleGroups to track the lock state instead.
606 Sec.setBundleLockState(MCSection::NotBundleLocked);
607
608 // FIXME: Use more separate fragments for nested groups.
609 if (!isBundleLocked()) {
610 mergeFragment(getOrCreateDataFragment(), DF);
611 BundleGroups.pop_back();
612 delete DF;
613 }
614
615 if (Sec.getBundleLockState() != MCSection::BundleLockedAlignToEnd)
616 getOrCreateDataFragment()->setAlignToBundleEnd(false);
617 } else
618 Sec.setBundleLockState(MCSection::NotBundleLocked);
619}
620
621void MCELFStreamer::Flush() {
622 for (std::vector<LocalCommon>::const_iterator i = LocalCommons.begin(),
2
←
Loop condition is true. Entering loop body
→
623 e = LocalCommons.end();
624 i != e; ++i) {
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);
630
631 getAssembler().registerSection(Section);
632 new MCAlignFragment(ByteAlignment, 0, 1, ByteAlignment, &Section);
633
634 MCFragment *F = new MCFillFragment(0, 0, Size, &Section);
3
←
Memory is allocated
→
635 Symbol.setFragment(F);
636
637 // Update the maximum alignment of the section if necessary.
638 if (ByteAlignment > Section.getAlignment())
4
←
Potential leak of memory pointed to by 'F'
639 Section.setAlignment(ByteAlignment);
640 }
641
642 LocalCommons.clear();
643}
644
645void MCELFStreamer::FinishImpl() {
646 // Ensure the last section gets aligned if necessary.
647 MCSection *CurSection = getCurrentSectionOnly();
648 setSectionAlignmentForBundling(getAssembler(), CurSection);
649
650 EmitFrames(nullptr);
651
652 Flush();
1
Calling 'MCELFStreamer::Flush'
→
653
654 this->MCObjectStreamer::FinishImpl();
655}
656
657MCStreamer *llvm::createELFStreamer(MCContext &Context, MCAsmBackend &MAB,
658 raw_pwrite_stream &OS, MCCodeEmitter *CE,
659 bool RelaxAll) {
660 MCELFStreamer *S = new MCELFStreamer(Context, MAB, OS, CE);
661 if (RelaxAll)
662 S->getAssembler().setRelaxAll(true);
663 return S;
664}
665
666void MCELFStreamer::EmitThumbFunc(MCSymbol *Func) {
667 llvm_unreachable("Generic ELF doesn't support this directive")::llvm::llvm_unreachable_internal("Generic ELF doesn't support this directive"
, "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn251506/lib/MC/MCELFStreamer.cpp"
, 667);
668}
669
670void MCELFStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
671 llvm_unreachable("ELF doesn't support this directive")::llvm::llvm_unreachable_internal("ELF doesn't support this directive"
, "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn251506/lib/MC/MCELFStreamer.cpp"
, 671);
672}
673
674void MCELFStreamer::BeginCOFFSymbolDef(const MCSymbol *Symbol) {
675 llvm_unreachable("ELF doesn't support this directive")::llvm::llvm_unreachable_internal("ELF doesn't support this directive"
, "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn251506/lib/MC/MCELFStreamer.cpp"
, 675);
676}
677
678void MCELFStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {
679 llvm_unreachable("ELF doesn't support this directive")::llvm::llvm_unreachable_internal("ELF doesn't support this directive"
, "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn251506/lib/MC/MCELFStreamer.cpp"
, 679);
680}
681
682void MCELFStreamer::EmitCOFFSymbolType(int Type) {
683 llvm_unreachable("ELF doesn't support this directive")::llvm::llvm_unreachable_internal("ELF doesn't support this directive"
, "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn251506/lib/MC/MCELFStreamer.cpp"
, 683);
684}
685
686void MCELFStreamer::EndCOFFSymbolDef() {
687 llvm_unreachable("ELF doesn't support this directive")::llvm::llvm_unreachable_internal("ELF doesn't support this directive"
, "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn251506/lib/MC/MCELFStreamer.cpp"
, 687);
688}
689
690void MCELFStreamer::EmitZerofill(MCSection *Section, MCSymbol *Symbol,
691 uint64_t Size, unsigned ByteAlignment) {
692 llvm_unreachable("ELF doesn't support this directive")::llvm::llvm_unreachable_internal("ELF doesn't support this directive"
, "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn251506/lib/MC/MCELFStreamer.cpp"
, 692);
693}
694
695void MCELFStreamer::EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol,
696 uint64_t Size, unsigned ByteAlignment) {
697 llvm_unreachable("ELF doesn't support this directive")::llvm::llvm_unreachable_internal("ELF doesn't support this directive"
, "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn251506/lib/MC/MCELFStreamer.cpp"
, 697);
698}