LLVM  4.0.0
ELFAsmParser.cpp
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1 //===- ELFAsmParser.cpp - ELF Assembly Parser -----------------------------===//
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 
11 #include "llvm/ADT/StringSwitch.h"
12 #include "llvm/ADT/Twine.h"
13 #include "llvm/MC/MCAsmInfo.h"
14 #include "llvm/MC/MCContext.h"
15 #include "llvm/MC/MCExpr.h"
17 #include "llvm/MC/MCSectionELF.h"
18 #include "llvm/MC/MCStreamer.h"
19 #include "llvm/MC/MCSymbolELF.h"
20 #include "llvm/Support/ELF.h"
21 using namespace llvm;
22 
23 namespace {
24 
25 class ELFAsmParser : public MCAsmParserExtension {
26  template<bool (ELFAsmParser::*HandlerMethod)(StringRef, SMLoc)>
27  void addDirectiveHandler(StringRef Directive) {
28  MCAsmParser::ExtensionDirectiveHandler Handler = std::make_pair(
29  this, HandleDirective<ELFAsmParser, HandlerMethod>);
30 
31  getParser().addDirectiveHandler(Directive, Handler);
32  }
33 
34  bool ParseSectionSwitch(StringRef Section, unsigned Type, unsigned Flags,
36 
37 public:
38  ELFAsmParser() { BracketExpressionsSupported = true; }
39 
40  void Initialize(MCAsmParser &Parser) override {
41  // Call the base implementation.
43 
44  addDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveData>(".data");
45  addDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveText>(".text");
46  addDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveBSS>(".bss");
47  addDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveRoData>(".rodata");
48  addDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveTData>(".tdata");
49  addDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveTBSS>(".tbss");
50  addDirectiveHandler<
51  &ELFAsmParser::ParseSectionDirectiveDataRel>(".data.rel");
52  addDirectiveHandler<
53  &ELFAsmParser::ParseSectionDirectiveDataRelRo>(".data.rel.ro");
54  addDirectiveHandler<
55  &ELFAsmParser::ParseSectionDirectiveEhFrame>(".eh_frame");
56  addDirectiveHandler<&ELFAsmParser::ParseDirectiveSection>(".section");
57  addDirectiveHandler<
58  &ELFAsmParser::ParseDirectivePushSection>(".pushsection");
59  addDirectiveHandler<&ELFAsmParser::ParseDirectivePopSection>(".popsection");
60  addDirectiveHandler<&ELFAsmParser::ParseDirectiveSize>(".size");
61  addDirectiveHandler<&ELFAsmParser::ParseDirectivePrevious>(".previous");
62  addDirectiveHandler<&ELFAsmParser::ParseDirectiveType>(".type");
63  addDirectiveHandler<&ELFAsmParser::ParseDirectiveIdent>(".ident");
64  addDirectiveHandler<&ELFAsmParser::ParseDirectiveSymver>(".symver");
65  addDirectiveHandler<&ELFAsmParser::ParseDirectiveVersion>(".version");
66  addDirectiveHandler<&ELFAsmParser::ParseDirectiveWeakref>(".weakref");
67  addDirectiveHandler<&ELFAsmParser::ParseDirectiveSymbolAttribute>(".weak");
68  addDirectiveHandler<&ELFAsmParser::ParseDirectiveSymbolAttribute>(".local");
69  addDirectiveHandler<
70  &ELFAsmParser::ParseDirectiveSymbolAttribute>(".protected");
71  addDirectiveHandler<
72  &ELFAsmParser::ParseDirectiveSymbolAttribute>(".internal");
73  addDirectiveHandler<
74  &ELFAsmParser::ParseDirectiveSymbolAttribute>(".hidden");
75  addDirectiveHandler<&ELFAsmParser::ParseDirectiveSubsection>(".subsection");
76  }
77 
78  // FIXME: Part of this logic is duplicated in the MCELFStreamer. What is
79  // the best way for us to get access to it?
80  bool ParseSectionDirectiveData(StringRef, SMLoc) {
81  return ParseSectionSwitch(".data", ELF::SHT_PROGBITS,
84  }
85  bool ParseSectionDirectiveText(StringRef, SMLoc) {
86  return ParseSectionSwitch(".text", ELF::SHT_PROGBITS,
89  }
90  bool ParseSectionDirectiveBSS(StringRef, SMLoc) {
91  return ParseSectionSwitch(".bss", ELF::SHT_NOBITS,
94  }
95  bool ParseSectionDirectiveRoData(StringRef, SMLoc) {
96  return ParseSectionSwitch(".rodata", ELF::SHT_PROGBITS,
99  }
100  bool ParseSectionDirectiveTData(StringRef, SMLoc) {
101  return ParseSectionSwitch(".tdata", ELF::SHT_PROGBITS,
105  }
106  bool ParseSectionDirectiveTBSS(StringRef, SMLoc) {
107  return ParseSectionSwitch(".tbss", ELF::SHT_NOBITS,
111  }
112  bool ParseSectionDirectiveDataRel(StringRef, SMLoc) {
113  return ParseSectionSwitch(".data.rel", ELF::SHT_PROGBITS,
116  }
117  bool ParseSectionDirectiveDataRelRo(StringRef, SMLoc) {
118  return ParseSectionSwitch(".data.rel.ro", ELF::SHT_PROGBITS,
122  }
123  bool ParseSectionDirectiveEhFrame(StringRef, SMLoc) {
124  return ParseSectionSwitch(".eh_frame", ELF::SHT_PROGBITS,
127  }
128  bool ParseDirectivePushSection(StringRef, SMLoc);
129  bool ParseDirectivePopSection(StringRef, SMLoc);
130  bool ParseDirectiveSection(StringRef, SMLoc);
131  bool ParseDirectiveSize(StringRef, SMLoc);
132  bool ParseDirectivePrevious(StringRef, SMLoc);
133  bool ParseDirectiveType(StringRef, SMLoc);
134  bool ParseDirectiveIdent(StringRef, SMLoc);
135  bool ParseDirectiveSymver(StringRef, SMLoc);
136  bool ParseDirectiveVersion(StringRef, SMLoc);
137  bool ParseDirectiveWeakref(StringRef, SMLoc);
138  bool ParseDirectiveSymbolAttribute(StringRef, SMLoc);
139  bool ParseDirectiveSubsection(StringRef, SMLoc);
140 
141 private:
142  bool ParseSectionName(StringRef &SectionName);
143  bool ParseSectionArguments(bool IsPush, SMLoc loc);
144  unsigned parseSunStyleSectionFlags();
145 };
146 
147 }
148 
149 /// ParseDirectiveSymbolAttribute
150 /// ::= { ".local", ".weak", ... } [ identifier ( , identifier )* ]
151 bool ELFAsmParser::ParseDirectiveSymbolAttribute(StringRef Directive, SMLoc) {
152  MCSymbolAttr Attr = StringSwitch<MCSymbolAttr>(Directive)
153  .Case(".weak", MCSA_Weak)
154  .Case(".local", MCSA_Local)
155  .Case(".hidden", MCSA_Hidden)
156  .Case(".internal", MCSA_Internal)
157  .Case(".protected", MCSA_Protected)
159  assert(Attr != MCSA_Invalid && "unexpected symbol attribute directive!");
160  if (getLexer().isNot(AsmToken::EndOfStatement)) {
161  for (;;) {
162  StringRef Name;
163 
164  if (getParser().parseIdentifier(Name))
165  return TokError("expected identifier in directive");
166 
167  MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
168 
169  getStreamer().EmitSymbolAttribute(Sym, Attr);
170 
171  if (getLexer().is(AsmToken::EndOfStatement))
172  break;
173 
174  if (getLexer().isNot(AsmToken::Comma))
175  return TokError("unexpected token in directive");
176  Lex();
177  }
178  }
179 
180  Lex();
181  return false;
182 }
183 
184 bool ELFAsmParser::ParseSectionSwitch(StringRef Section, unsigned Type,
185  unsigned Flags, SectionKind Kind) {
186  const MCExpr *Subsection = nullptr;
187  if (getLexer().isNot(AsmToken::EndOfStatement)) {
188  if (getParser().parseExpression(Subsection))
189  return true;
190  }
191  Lex();
192 
193  getStreamer().SwitchSection(getContext().getELFSection(Section, Type, Flags),
194  Subsection);
195 
196  return false;
197 }
198 
199 bool ELFAsmParser::ParseDirectiveSize(StringRef, SMLoc) {
200  StringRef Name;
201  if (getParser().parseIdentifier(Name))
202  return TokError("expected identifier in directive");
203  MCSymbolELF *Sym = cast<MCSymbolELF>(getContext().getOrCreateSymbol(Name));
204 
205  if (getLexer().isNot(AsmToken::Comma))
206  return TokError("unexpected token in directive");
207  Lex();
208 
209  const MCExpr *Expr;
210  if (getParser().parseExpression(Expr))
211  return true;
212 
213  if (getLexer().isNot(AsmToken::EndOfStatement))
214  return TokError("unexpected token in directive");
215  Lex();
216 
217  getStreamer().emitELFSize(Sym, Expr);
218  return false;
219 }
220 
221 bool ELFAsmParser::ParseSectionName(StringRef &SectionName) {
222  // A section name can contain -, so we cannot just use
223  // parseIdentifier.
224  SMLoc FirstLoc = getLexer().getLoc();
225  unsigned Size = 0;
226 
227  if (getLexer().is(AsmToken::String)) {
228  SectionName = getTok().getIdentifier();
229  Lex();
230  return false;
231  }
232 
233  for (;;) {
234 
235  SMLoc PrevLoc = getLexer().getLoc();
236  if (getLexer().is(AsmToken::Comma) ||
237  getLexer().is(AsmToken::EndOfStatement))
238  break;
239 
240  unsigned CurSize;
241  if (getLexer().is(AsmToken::String)) {
242  CurSize = getTok().getIdentifier().size() + 2;
243  Lex();
244  } else if (getLexer().is(AsmToken::Identifier)) {
245  CurSize = getTok().getIdentifier().size();
246  Lex();
247  } else {
248  CurSize = getTok().getString().size();
249  Lex();
250  }
251  Size += CurSize;
252  SectionName = StringRef(FirstLoc.getPointer(), Size);
253 
254  // Make sure the following token is adjacent.
255  if (PrevLoc.getPointer() + CurSize != getTok().getLoc().getPointer())
256  break;
257  }
258  if (Size == 0)
259  return true;
260 
261  return false;
262 }
263 
264 static unsigned parseSectionFlags(StringRef flagsStr, bool *UseLastGroup) {
265  unsigned flags = 0;
266 
267  // If a valid numerical value is set for the section flag, use it verbatim
268  if (!flagsStr.getAsInteger(0, flags))
269  return flags;
270 
271  for (char i : flagsStr) {
272  switch (i) {
273  case 'a':
274  flags |= ELF::SHF_ALLOC;
275  break;
276  case 'e':
277  flags |= ELF::SHF_EXCLUDE;
278  break;
279  case 'x':
280  flags |= ELF::SHF_EXECINSTR;
281  break;
282  case 'w':
283  flags |= ELF::SHF_WRITE;
284  break;
285  case 'M':
286  flags |= ELF::SHF_MERGE;
287  break;
288  case 'S':
289  flags |= ELF::SHF_STRINGS;
290  break;
291  case 'T':
292  flags |= ELF::SHF_TLS;
293  break;
294  case 'c':
295  flags |= ELF::XCORE_SHF_CP_SECTION;
296  break;
297  case 'd':
298  flags |= ELF::XCORE_SHF_DP_SECTION;
299  break;
300  case 'y':
301  flags |= ELF::SHF_ARM_PURECODE;
302  break;
303  case 'G':
304  flags |= ELF::SHF_GROUP;
305  break;
306  case '?':
307  *UseLastGroup = true;
308  break;
309  default:
310  return -1U;
311  }
312  }
313 
314  return flags;
315 }
316 
317 unsigned ELFAsmParser::parseSunStyleSectionFlags() {
318  unsigned flags = 0;
319  while (getLexer().is(AsmToken::Hash)) {
320  Lex(); // Eat the #.
321 
322  if (!getLexer().is(AsmToken::Identifier))
323  return -1U;
324 
325  StringRef flagId = getTok().getIdentifier();
326  if (flagId == "alloc")
327  flags |= ELF::SHF_ALLOC;
328  else if (flagId == "execinstr")
329  flags |= ELF::SHF_EXECINSTR;
330  else if (flagId == "write")
331  flags |= ELF::SHF_WRITE;
332  else if (flagId == "tls")
333  flags |= ELF::SHF_TLS;
334  else
335  return -1U;
336 
337  Lex(); // Eat the flag.
338 
339  if (!getLexer().is(AsmToken::Comma))
340  break;
341  Lex(); // Eat the comma.
342  }
343  return flags;
344 }
345 
346 
347 bool ELFAsmParser::ParseDirectivePushSection(StringRef s, SMLoc loc) {
348  getStreamer().PushSection();
349 
350  if (ParseSectionArguments(/*IsPush=*/true, loc)) {
351  getStreamer().PopSection();
352  return true;
353  }
354 
355  return false;
356 }
357 
358 bool ELFAsmParser::ParseDirectivePopSection(StringRef, SMLoc) {
359  if (!getStreamer().PopSection())
360  return TokError(".popsection without corresponding .pushsection");
361  return false;
362 }
363 
364 // FIXME: This is a work in progress.
365 bool ELFAsmParser::ParseDirectiveSection(StringRef, SMLoc loc) {
366  return ParseSectionArguments(/*IsPush=*/false, loc);
367 }
368 
369 bool ELFAsmParser::ParseSectionArguments(bool IsPush, SMLoc loc) {
371 
372  if (ParseSectionName(SectionName))
373  return TokError("expected identifier in directive");
374 
375  StringRef TypeName;
376  int64_t Size = 0;
377  StringRef GroupName;
378  unsigned Flags = 0;
379  const MCExpr *Subsection = nullptr;
380  bool UseLastGroup = false;
381  StringRef UniqueStr;
382  int64_t UniqueID = ~0;
383 
384  // Set the defaults first.
385  if (SectionName == ".fini" || SectionName == ".init" ||
386  SectionName == ".rodata")
387  Flags |= ELF::SHF_ALLOC;
388  if (SectionName == ".fini" || SectionName == ".init")
389  Flags |= ELF::SHF_EXECINSTR;
390 
391  if (getLexer().is(AsmToken::Comma)) {
392  Lex();
393 
394  if (IsPush && getLexer().isNot(AsmToken::String)) {
395  if (getParser().parseExpression(Subsection))
396  return true;
397  if (getLexer().isNot(AsmToken::Comma))
398  goto EndStmt;
399  Lex();
400  }
401 
402  unsigned extraFlags;
403 
404  if (getLexer().isNot(AsmToken::String)) {
405  if (!getContext().getAsmInfo()->usesSunStyleELFSectionSwitchSyntax()
406  || getLexer().isNot(AsmToken::Hash))
407  return TokError("expected string in directive");
408  extraFlags = parseSunStyleSectionFlags();
409  } else {
410  StringRef FlagsStr = getTok().getStringContents();
411  Lex();
412  extraFlags = parseSectionFlags(FlagsStr, &UseLastGroup);
413  }
414 
415  if (extraFlags == -1U)
416  return TokError("unknown flag");
417  Flags |= extraFlags;
418 
419  bool Mergeable = Flags & ELF::SHF_MERGE;
420  bool Group = Flags & ELF::SHF_GROUP;
421  if (Group && UseLastGroup)
422  return TokError("Section cannot specifiy a group name while also acting "
423  "as a member of the last group");
424 
425  if (getLexer().isNot(AsmToken::Comma)) {
426  if (Mergeable)
427  return TokError("Mergeable section must specify the type");
428  if (Group)
429  return TokError("Group section must specify the type");
430  } else {
431  Lex();
432  if (getLexer().is(AsmToken::At) || getLexer().is(AsmToken::Percent) ||
433  getLexer().is(AsmToken::String)) {
434  if (!getLexer().is(AsmToken::String))
435  Lex();
436  } else
437  return TokError("expected '@<type>', '%<type>' or \"<type>\"");
438 
439  if (getParser().parseIdentifier(TypeName))
440  return TokError("expected identifier in directive");
441 
442  if (Mergeable) {
443  if (getLexer().isNot(AsmToken::Comma))
444  return TokError("expected the entry size");
445  Lex();
446  if (getParser().parseAbsoluteExpression(Size))
447  return true;
448  if (Size <= 0)
449  return TokError("entry size must be positive");
450  }
451 
452  if (Group) {
453  if (getLexer().isNot(AsmToken::Comma))
454  return TokError("expected group name");
455  Lex();
456  if (getParser().parseIdentifier(GroupName))
457  return true;
458  if (getLexer().is(AsmToken::Comma)) {
459  Lex();
460  StringRef Linkage;
461  if (getParser().parseIdentifier(Linkage))
462  return true;
463  if (Linkage != "comdat")
464  return TokError("Linkage must be 'comdat'");
465  }
466  }
467  if (getLexer().is(AsmToken::Comma)) {
468  Lex();
469  if (getParser().parseIdentifier(UniqueStr))
470  return TokError("expected identifier in directive");
471  if (UniqueStr != "unique")
472  return TokError("expected 'unique'");
473  if (getLexer().isNot(AsmToken::Comma))
474  return TokError("expected commma");
475  Lex();
476  if (getParser().parseAbsoluteExpression(UniqueID))
477  return true;
478  if (UniqueID < 0)
479  return TokError("unique id must be positive");
480  if (!isUInt<32>(UniqueID) || UniqueID == ~0U)
481  return TokError("unique id is too large");
482  }
483  }
484  }
485 
486 EndStmt:
487  if (getLexer().isNot(AsmToken::EndOfStatement))
488  return TokError("unexpected token in directive");
489  Lex();
490 
491  unsigned Type = ELF::SHT_PROGBITS;
492 
493  if (TypeName.empty()) {
494  if (SectionName.startswith(".note"))
495  Type = ELF::SHT_NOTE;
496  else if (SectionName == ".init_array")
497  Type = ELF::SHT_INIT_ARRAY;
498  else if (SectionName == ".fini_array")
499  Type = ELF::SHT_FINI_ARRAY;
500  else if (SectionName == ".preinit_array")
501  Type = ELF::SHT_PREINIT_ARRAY;
502  } else {
503  if (TypeName == "init_array")
504  Type = ELF::SHT_INIT_ARRAY;
505  else if (TypeName == "fini_array")
506  Type = ELF::SHT_FINI_ARRAY;
507  else if (TypeName == "preinit_array")
508  Type = ELF::SHT_PREINIT_ARRAY;
509  else if (TypeName == "nobits")
510  Type = ELF::SHT_NOBITS;
511  else if (TypeName == "progbits")
512  Type = ELF::SHT_PROGBITS;
513  else if (TypeName == "note")
514  Type = ELF::SHT_NOTE;
515  else if (TypeName == "unwind")
516  Type = ELF::SHT_X86_64_UNWIND;
517  else
518  return TokError("unknown section type");
519  }
520 
521  if (UseLastGroup) {
522  MCSectionSubPair CurrentSection = getStreamer().getCurrentSection();
523  if (const MCSectionELF *Section =
524  cast_or_null<MCSectionELF>(CurrentSection.first))
525  if (const MCSymbol *Group = Section->getGroup()) {
526  GroupName = Group->getName();
527  Flags |= ELF::SHF_GROUP;
528  }
529  }
530 
531  MCSection *ELFSection = getContext().getELFSection(SectionName, Type, Flags,
532  Size, GroupName, UniqueID);
533  getStreamer().SwitchSection(ELFSection, Subsection);
534 
535  if (getContext().getGenDwarfForAssembly()) {
536  bool InsertResult = getContext().addGenDwarfSection(ELFSection);
537  if (InsertResult) {
538  if (getContext().getDwarfVersion() <= 2)
539  Warning(loc, "DWARF2 only supports one section per compilation unit");
540 
541  if (!ELFSection->getBeginSymbol()) {
542  MCSymbol *SectionStartSymbol = getContext().createTempSymbol();
543  getStreamer().EmitLabel(SectionStartSymbol);
544  ELFSection->setBeginSymbol(SectionStartSymbol);
545  }
546  }
547  }
548 
549  return false;
550 }
551 
552 bool ELFAsmParser::ParseDirectivePrevious(StringRef DirName, SMLoc) {
553  MCSectionSubPair PreviousSection = getStreamer().getPreviousSection();
554  if (PreviousSection.first == nullptr)
555  return TokError(".previous without corresponding .section");
556  getStreamer().SwitchSection(PreviousSection.first, PreviousSection.second);
557 
558  return false;
559 }
560 
563  .Cases("STT_FUNC", "function", MCSA_ELF_TypeFunction)
564  .Cases("STT_OBJECT", "object", MCSA_ELF_TypeObject)
565  .Cases("STT_TLS", "tls_object", MCSA_ELF_TypeTLS)
566  .Cases("STT_COMMON", "common", MCSA_ELF_TypeCommon)
567  .Cases("STT_NOTYPE", "notype", MCSA_ELF_TypeNoType)
568  .Cases("STT_GNU_IFUNC", "gnu_indirect_function",
570  .Case("gnu_unique_object", MCSA_ELF_TypeGnuUniqueObject)
571  .Default(MCSA_Invalid);
572 }
573 
574 /// ParseDirectiveELFType
575 /// ::= .type identifier , STT_<TYPE_IN_UPPER_CASE>
576 /// ::= .type identifier , #attribute
577 /// ::= .type identifier , @attribute
578 /// ::= .type identifier , %attribute
579 /// ::= .type identifier , "attribute"
580 bool ELFAsmParser::ParseDirectiveType(StringRef, SMLoc) {
581  StringRef Name;
582  if (getParser().parseIdentifier(Name))
583  return TokError("expected identifier in directive");
584 
585  // Handle the identifier as the key symbol.
586  MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
587 
588  // NOTE the comma is optional in all cases. It is only documented as being
589  // optional in the first case, however, GAS will silently treat the comma as
590  // optional in all cases. Furthermore, although the documentation states that
591  // the first form only accepts STT_<TYPE_IN_UPPER_CASE>, in reality, GAS
592  // accepts both the upper case name as well as the lower case aliases.
593  if (getLexer().is(AsmToken::Comma))
594  Lex();
595 
596  if (getLexer().isNot(AsmToken::Identifier) &&
597  getLexer().isNot(AsmToken::Hash) &&
598  getLexer().isNot(AsmToken::Percent) &&
599  getLexer().isNot(AsmToken::String)) {
600  if (!getLexer().getAllowAtInIdentifier())
601  return TokError("expected STT_<TYPE_IN_UPPER_CASE>, '#<type>', "
602  "'%<type>' or \"<type>\"");
603  else if (getLexer().isNot(AsmToken::At))
604  return TokError("expected STT_<TYPE_IN_UPPER_CASE>, '#<type>', '@<type>', "
605  "'%<type>' or \"<type>\"");
606  }
607 
608  if (getLexer().isNot(AsmToken::String) &&
609  getLexer().isNot(AsmToken::Identifier))
610  Lex();
611 
612  SMLoc TypeLoc = getLexer().getLoc();
613 
614  StringRef Type;
615  if (getParser().parseIdentifier(Type))
616  return TokError("expected symbol type in directive");
617 
618  MCSymbolAttr Attr = MCAttrForString(Type);
619  if (Attr == MCSA_Invalid)
620  return Error(TypeLoc, "unsupported attribute in '.type' directive");
621 
622  if (getLexer().isNot(AsmToken::EndOfStatement))
623  return TokError("unexpected token in '.type' directive");
624  Lex();
625 
626  getStreamer().EmitSymbolAttribute(Sym, Attr);
627 
628  return false;
629 }
630 
631 /// ParseDirectiveIdent
632 /// ::= .ident string
633 bool ELFAsmParser::ParseDirectiveIdent(StringRef, SMLoc) {
634  if (getLexer().isNot(AsmToken::String))
635  return TokError("unexpected token in '.ident' directive");
636 
637  StringRef Data = getTok().getIdentifier();
638 
639  Lex();
640 
641  if (getLexer().isNot(AsmToken::EndOfStatement))
642  return TokError("unexpected token in '.ident' directive");
643  Lex();
644 
645  getStreamer().EmitIdent(Data);
646  return false;
647 }
648 
649 /// ParseDirectiveSymver
650 /// ::= .symver foo, bar2@zed
651 bool ELFAsmParser::ParseDirectiveSymver(StringRef, SMLoc) {
652  StringRef Name;
653  if (getParser().parseIdentifier(Name))
654  return TokError("expected identifier in directive");
655 
656  if (getLexer().isNot(AsmToken::Comma))
657  return TokError("expected a comma");
658 
659  // ARM assembly uses @ for a comment...
660  // except when parsing the second parameter of the .symver directive.
661  // Force the next symbol to allow @ in the identifier, which is
662  // required for this directive and then reset it to its initial state.
663  const bool AllowAtInIdentifier = getLexer().getAllowAtInIdentifier();
664  getLexer().setAllowAtInIdentifier(true);
665  Lex();
666  getLexer().setAllowAtInIdentifier(AllowAtInIdentifier);
667 
668  StringRef AliasName;
669  if (getParser().parseIdentifier(AliasName))
670  return TokError("expected identifier in directive");
671 
672  if (AliasName.find('@') == StringRef::npos)
673  return TokError("expected a '@' in the name");
674 
675  MCSymbol *Alias = getContext().getOrCreateSymbol(AliasName);
676  MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
677  const MCExpr *Value = MCSymbolRefExpr::create(Sym, getContext());
678 
679  getStreamer().EmitAssignment(Alias, Value);
680  return false;
681 }
682 
683 /// ParseDirectiveVersion
684 /// ::= .version string
685 bool ELFAsmParser::ParseDirectiveVersion(StringRef, SMLoc) {
686  if (getLexer().isNot(AsmToken::String))
687  return TokError("unexpected token in '.version' directive");
688 
689  StringRef Data = getTok().getIdentifier();
690 
691  Lex();
692 
693  MCSection *Note = getContext().getELFSection(".note", ELF::SHT_NOTE, 0);
694 
695  getStreamer().PushSection();
696  getStreamer().SwitchSection(Note);
697  getStreamer().EmitIntValue(Data.size()+1, 4); // namesz.
698  getStreamer().EmitIntValue(0, 4); // descsz = 0 (no description).
699  getStreamer().EmitIntValue(1, 4); // type = NT_VERSION.
700  getStreamer().EmitBytes(Data); // name.
701  getStreamer().EmitIntValue(0, 1); // terminate the string.
702  getStreamer().EmitValueToAlignment(4); // ensure 4 byte alignment.
703  getStreamer().PopSection();
704  return false;
705 }
706 
707 /// ParseDirectiveWeakref
708 /// ::= .weakref foo, bar
709 bool ELFAsmParser::ParseDirectiveWeakref(StringRef, SMLoc) {
710  // FIXME: Share code with the other alias building directives.
711 
712  StringRef AliasName;
713  if (getParser().parseIdentifier(AliasName))
714  return TokError("expected identifier in directive");
715 
716  if (getLexer().isNot(AsmToken::Comma))
717  return TokError("expected a comma");
718 
719  Lex();
720 
721  StringRef Name;
722  if (getParser().parseIdentifier(Name))
723  return TokError("expected identifier in directive");
724 
725  MCSymbol *Alias = getContext().getOrCreateSymbol(AliasName);
726 
727  MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
728 
729  getStreamer().EmitWeakReference(Alias, Sym);
730  return false;
731 }
732 
733 bool ELFAsmParser::ParseDirectiveSubsection(StringRef, SMLoc) {
734  const MCExpr *Subsection = nullptr;
735  if (getLexer().isNot(AsmToken::EndOfStatement)) {
736  if (getParser().parseExpression(Subsection))
737  return true;
738  }
739 
740  if (getLexer().isNot(AsmToken::EndOfStatement))
741  return TokError("unexpected token in directive");
742 
743  Lex();
744 
745  getStreamer().SubSection(Subsection);
746  return false;
747 }
748 
749 namespace llvm {
750 
752  return new ELFAsmParser;
753 }
754 
755 }
std::enable_if< std::numeric_limits< T >::is_signed, bool >::type getAsInteger(unsigned Radix, T &Result) const
Parse the current string as an integer of the specified radix.
Definition: StringRef.h:494
constexpr bool isUInt< 32 >(uint64_t x)
Definition: MathExtras.h:315
Instances of this class represent a uniqued identifier for a section in the current translation unit...
Definition: MCSection.h:40
static SectionKind getData()
Definition: SectionKind.h:202
static const MCSymbolRefExpr * create(const MCSymbol *Symbol, MCContext &Ctx)
Definition: MCExpr.h:298
const char * getPointer() const
Definition: SMLoc.h:35
size_t i
.type _foo, STT_OBJECT # aka
Definition: MCDirectives.h:25
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:39
Not a valid directive.
Definition: MCDirectives.h:20
Generic assembler parser interface, for use by target specific assembly parsers.
Definition: MCAsmParser.h:66
virtual void Initialize(MCAsmParser &Parser)
Initialize the extension for parsing using the given Parser.
static unsigned parseSectionFlags(StringRef flagsStr, bool *UseLastGroup)
static MCSymbolAttr MCAttrForString(StringRef Type)
.type _foo, STT_NOTYPE # aka
Definition: MCDirectives.h:28
XCORE_SHF_CP_SECTION - All sections with the "c" flag are grouped together by the linker to form the ...
Definition: Support/ELF.h:757
MCAsmParserExtension * createELFAsmParser()
static SectionKind getBSS()
Definition: SectionKind.h:198
struct fuzzer::@269 Flags
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:34
LLVM_ATTRIBUTE_ALWAYS_INLINE R Default(const T &Value) const
Definition: StringSwitch.h:244
.local (ELF)
Definition: MCDirectives.h:35
LLVM_ATTRIBUTE_ALWAYS_INLINE StringSwitch & Case(const char(&S)[N], const T &Value)
Definition: StringSwitch.h:74
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE bool startswith(StringRef Prefix) const
Check if this string starts with the given Prefix.
Definition: StringRef.h:264
.type _foo, STT_GNU_IFUNC
Definition: MCDirectives.h:24
std::pair< MCSection *, const MCExpr * > MCSectionSubPair
Definition: MCStreamer.h:44
.protected (ELF)
Definition: MCDirectives.h:40
uint64_t * Cases
static SectionKind getThreadData()
Definition: SectionKind.h:197
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE size_t size() const
size - Get the string size.
Definition: StringRef.h:135
.hidden (ELF)
Definition: MCDirectives.h:31
A switch()-like statement whose cases are string literals.
Definition: StringSwitch.h:43
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE size_t find(char C, size_t From=0) const
Search for the first character C in the string.
Definition: StringRef.h:295
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:45
XCORE_SHF_DP_SECTION - All sections with the "d" flag are grouped together by the linker to form the ...
Definition: Support/ELF.h:762
SectionKind - This is a simple POD value that classifies the properties of a section.
Definition: SectionKind.h:23
std::pair< MCAsmParserExtension *, DirectiveHandler > ExtensionDirectiveHandler
Definition: MCAsmParser.h:70
static SectionKind getThreadBSS()
Definition: SectionKind.h:196
.type _foo, STT_TLS # aka
Definition: MCDirectives.h:26
static SectionKind getReadOnlyWithRel()
Definition: SectionKind.h:203
MCSymbol * getBeginSymbol()
Definition: MCSection.h:106
MCSymbolAttr
Definition: MCDirectives.h:19
.internal (ELF)
Definition: MCDirectives.h:33
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:130
.type _foo, STT_COMMON # aka
Definition: MCDirectives.h:27
static const size_t npos
Definition: StringRef.h:51
.type _foo, STT_FUNC # aka
Definition: MCDirectives.h:23
This represents a section on linux, lots of unix variants and some bare metal systems.
Definition: MCSectionELF.h:30
const char SectionName[]
Definition: AMDGPUPTNote.h:24
const unsigned Kind
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
Generic interface for extending the MCAsmParser, which is implemented by target and object file assem...
std::string DirName(const std::string &FileName)
LLVM Value Representation.
Definition: Value.h:71
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:47
Represents a location in source code.
Definition: SMLoc.h:24
static SectionKind getReadOnly()
Definition: SectionKind.h:182
static SectionKind getText()
Definition: SectionKind.h:180
void setBeginSymbol(MCSymbol *Sym)
Definition: MCSection.h:110