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
10 #include "llvm/MC/MCParser/MCAsmParserExtension.h"
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"
16 #include "llvm/MC/MCParser/MCAsmLexer.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)>
addDirectiveHandler(StringRef Directive)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,
35 SectionKind Kind);
36
37 public:
ELFAsmParser()38 ELFAsmParser() { BracketExpressionsSupported = true; }
39
Initialize(MCAsmParser & Parser)40 void Initialize(MCAsmParser &Parser) override {
41 // Call the base implementation.
42 this->MCAsmParserExtension::Initialize(Parser);
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?
ParseSectionDirectiveData(StringRef,SMLoc)80 bool ParseSectionDirectiveData(StringRef, SMLoc) {
81 return ParseSectionSwitch(".data", ELF::SHT_PROGBITS,
82 ELF::SHF_WRITE | ELF::SHF_ALLOC,
83 SectionKind::getData());
84 }
ParseSectionDirectiveText(StringRef,SMLoc)85 bool ParseSectionDirectiveText(StringRef, SMLoc) {
86 return ParseSectionSwitch(".text", ELF::SHT_PROGBITS,
87 ELF::SHF_EXECINSTR |
88 ELF::SHF_ALLOC, SectionKind::getText());
89 }
ParseSectionDirectiveBSS(StringRef,SMLoc)90 bool ParseSectionDirectiveBSS(StringRef, SMLoc) {
91 return ParseSectionSwitch(".bss", ELF::SHT_NOBITS,
92 ELF::SHF_WRITE |
93 ELF::SHF_ALLOC, SectionKind::getBSS());
94 }
ParseSectionDirectiveRoData(StringRef,SMLoc)95 bool ParseSectionDirectiveRoData(StringRef, SMLoc) {
96 return ParseSectionSwitch(".rodata", ELF::SHT_PROGBITS,
97 ELF::SHF_ALLOC,
98 SectionKind::getReadOnly());
99 }
ParseSectionDirectiveTData(StringRef,SMLoc)100 bool ParseSectionDirectiveTData(StringRef, SMLoc) {
101 return ParseSectionSwitch(".tdata", ELF::SHT_PROGBITS,
102 ELF::SHF_ALLOC |
103 ELF::SHF_TLS | ELF::SHF_WRITE,
104 SectionKind::getThreadData());
105 }
ParseSectionDirectiveTBSS(StringRef,SMLoc)106 bool ParseSectionDirectiveTBSS(StringRef, SMLoc) {
107 return ParseSectionSwitch(".tbss", ELF::SHT_NOBITS,
108 ELF::SHF_ALLOC |
109 ELF::SHF_TLS | ELF::SHF_WRITE,
110 SectionKind::getThreadBSS());
111 }
ParseSectionDirectiveDataRel(StringRef,SMLoc)112 bool ParseSectionDirectiveDataRel(StringRef, SMLoc) {
113 return ParseSectionSwitch(".data.rel", ELF::SHT_PROGBITS,
114 ELF::SHF_ALLOC | ELF::SHF_WRITE,
115 SectionKind::getData());
116 }
ParseSectionDirectiveDataRelRo(StringRef,SMLoc)117 bool ParseSectionDirectiveDataRelRo(StringRef, SMLoc) {
118 return ParseSectionSwitch(".data.rel.ro", ELF::SHT_PROGBITS,
119 ELF::SHF_ALLOC |
120 ELF::SHF_WRITE,
121 SectionKind::getReadOnlyWithRel());
122 }
ParseSectionDirectiveEhFrame(StringRef,SMLoc)123 bool ParseSectionDirectiveEhFrame(StringRef, SMLoc) {
124 return ParseSectionSwitch(".eh_frame", ELF::SHT_PROGBITS,
125 ELF::SHF_ALLOC | ELF::SHF_WRITE,
126 SectionKind::getData());
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 )* ]
ParseDirectiveSymbolAttribute(StringRef Directive,SMLoc)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)
158 .Default(MCSA_Invalid);
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
ParseSectionSwitch(StringRef Section,unsigned Type,unsigned Flags,SectionKind Kind)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
192 getStreamer().SwitchSection(getContext().getELFSection(Section, Type, Flags),
193 Subsection);
194
195 return false;
196 }
197
ParseDirectiveSize(StringRef,SMLoc)198 bool ELFAsmParser::ParseDirectiveSize(StringRef, SMLoc) {
199 StringRef Name;
200 if (getParser().parseIdentifier(Name))
201 return TokError("expected identifier in directive");
202 MCSymbolELF *Sym = cast<MCSymbolELF>(getContext().getOrCreateSymbol(Name));
203
204 if (getLexer().isNot(AsmToken::Comma))
205 return TokError("unexpected token in directive");
206 Lex();
207
208 const MCExpr *Expr;
209 if (getParser().parseExpression(Expr))
210 return true;
211
212 if (getLexer().isNot(AsmToken::EndOfStatement))
213 return TokError("unexpected token in directive");
214
215 getStreamer().emitELFSize(Sym, Expr);
216 return false;
217 }
218
ParseSectionName(StringRef & SectionName)219 bool ELFAsmParser::ParseSectionName(StringRef &SectionName) {
220 // A section name can contain -, so we cannot just use
221 // parseIdentifier.
222 SMLoc FirstLoc = getLexer().getLoc();
223 unsigned Size = 0;
224
225 if (getLexer().is(AsmToken::String)) {
226 SectionName = getTok().getIdentifier();
227 Lex();
228 return false;
229 }
230
231 for (;;) {
232 unsigned CurSize;
233
234 SMLoc PrevLoc = getLexer().getLoc();
235 if (getLexer().is(AsmToken::Minus)) {
236 CurSize = 1;
237 Lex(); // Consume the "-".
238 } else if (getLexer().is(AsmToken::String)) {
239 CurSize = getTok().getIdentifier().size() + 2;
240 Lex();
241 } else if (getLexer().is(AsmToken::Identifier)) {
242 CurSize = getTok().getIdentifier().size();
243 Lex();
244 } else {
245 break;
246 }
247
248 Size += CurSize;
249 SectionName = StringRef(FirstLoc.getPointer(), Size);
250
251 // Make sure the following token is adjacent.
252 if (PrevLoc.getPointer() + CurSize != getTok().getLoc().getPointer())
253 break;
254 }
255 if (Size == 0)
256 return true;
257
258 return false;
259 }
260
parseSectionFlags(StringRef flagsStr,bool * UseLastGroup)261 static unsigned parseSectionFlags(StringRef flagsStr, bool *UseLastGroup) {
262 unsigned flags = 0;
263
264 for (unsigned i = 0; i < flagsStr.size(); i++) {
265 switch (flagsStr[i]) {
266 case 'a':
267 flags |= ELF::SHF_ALLOC;
268 break;
269 case 'e':
270 flags |= ELF::SHF_EXCLUDE;
271 break;
272 case 'x':
273 flags |= ELF::SHF_EXECINSTR;
274 break;
275 case 'w':
276 flags |= ELF::SHF_WRITE;
277 break;
278 case 'M':
279 flags |= ELF::SHF_MERGE;
280 break;
281 case 'S':
282 flags |= ELF::SHF_STRINGS;
283 break;
284 case 'T':
285 flags |= ELF::SHF_TLS;
286 break;
287 case 'c':
288 flags |= ELF::XCORE_SHF_CP_SECTION;
289 break;
290 case 'd':
291 flags |= ELF::XCORE_SHF_DP_SECTION;
292 break;
293 case 'G':
294 flags |= ELF::SHF_GROUP;
295 break;
296 case '?':
297 *UseLastGroup = true;
298 break;
299 default:
300 return -1U;
301 }
302 }
303
304 return flags;
305 }
306
parseSunStyleSectionFlags()307 unsigned ELFAsmParser::parseSunStyleSectionFlags() {
308 unsigned flags = 0;
309 while (getLexer().is(AsmToken::Hash)) {
310 Lex(); // Eat the #.
311
312 if (!getLexer().is(AsmToken::Identifier))
313 return -1U;
314
315 StringRef flagId = getTok().getIdentifier();
316 if (flagId == "alloc")
317 flags |= ELF::SHF_ALLOC;
318 else if (flagId == "execinstr")
319 flags |= ELF::SHF_EXECINSTR;
320 else if (flagId == "write")
321 flags |= ELF::SHF_WRITE;
322 else if (flagId == "tls")
323 flags |= ELF::SHF_TLS;
324 else
325 return -1U;
326
327 Lex(); // Eat the flag.
328
329 if (!getLexer().is(AsmToken::Comma))
330 break;
331 Lex(); // Eat the comma.
332 }
333 return flags;
334 }
335
336
ParseDirectivePushSection(StringRef s,SMLoc loc)337 bool ELFAsmParser::ParseDirectivePushSection(StringRef s, SMLoc loc) {
338 getStreamer().PushSection();
339
340 if (ParseSectionArguments(/*IsPush=*/true, loc)) {
341 getStreamer().PopSection();
342 return true;
343 }
344
345 return false;
346 }
347
ParseDirectivePopSection(StringRef,SMLoc)348 bool ELFAsmParser::ParseDirectivePopSection(StringRef, SMLoc) {
349 if (!getStreamer().PopSection())
350 return TokError(".popsection without corresponding .pushsection");
351 return false;
352 }
353
354 // FIXME: This is a work in progress.
ParseDirectiveSection(StringRef,SMLoc loc)355 bool ELFAsmParser::ParseDirectiveSection(StringRef, SMLoc loc) {
356 return ParseSectionArguments(/*IsPush=*/false, loc);
357 }
358
ParseSectionArguments(bool IsPush,SMLoc loc)359 bool ELFAsmParser::ParseSectionArguments(bool IsPush, SMLoc loc)
360 {
361 StringRef SectionName;
362
363 if (ParseSectionName(SectionName))
364 return TokError("expected identifier in directive");
365
366 StringRef TypeName;
367 int64_t Size = 0;
368 StringRef GroupName;
369 unsigned Flags = 0;
370 const MCExpr *Subsection = nullptr;
371 bool UseLastGroup = false;
372 StringRef UniqueStr;
373 int64_t UniqueID = ~0;
374
375 // Set the defaults first.
376 if (SectionName == ".fini" || SectionName == ".init" ||
377 SectionName == ".rodata")
378 Flags |= ELF::SHF_ALLOC;
379 if (SectionName == ".fini" || SectionName == ".init")
380 Flags |= ELF::SHF_EXECINSTR;
381
382 if (getLexer().is(AsmToken::Comma)) {
383 Lex();
384
385 if (IsPush && getLexer().isNot(AsmToken::String)) {
386 if (getParser().parseExpression(Subsection))
387 return true;
388 if (getLexer().isNot(AsmToken::Comma))
389 goto EndStmt;
390 Lex();
391 }
392
393 unsigned extraFlags;
394
395 if (getLexer().isNot(AsmToken::String)) {
396 if (!getContext().getAsmInfo()->usesSunStyleELFSectionSwitchSyntax()
397 || getLexer().isNot(AsmToken::Hash))
398 return TokError("expected string in directive");
399 extraFlags = parseSunStyleSectionFlags();
400 } else {
401 bool valid;
402 StringRef FlagsStr = getTok().getStringContents(valid);
403 if (!valid)
404 return true;
405 Lex();
406 extraFlags = parseSectionFlags(FlagsStr, &UseLastGroup);
407 }
408
409 if (extraFlags == -1U)
410 return TokError("unknown flag");
411 Flags |= extraFlags;
412
413 bool Mergeable = Flags & ELF::SHF_MERGE;
414 bool Group = Flags & ELF::SHF_GROUP;
415 if (Group && UseLastGroup)
416 return TokError("Section cannot specifiy a group name while also acting "
417 "as a member of the last group");
418
419 if (getLexer().isNot(AsmToken::Comma)) {
420 if (Mergeable)
421 return TokError("Mergeable section must specify the type");
422 if (Group)
423 return TokError("Group section must specify the type");
424 } else {
425 Lex();
426 if (getLexer().is(AsmToken::At) || getLexer().is(AsmToken::Percent) ||
427 getLexer().is(AsmToken::String)) {
428 if (!getLexer().is(AsmToken::String))
429 Lex();
430 } else
431 return TokError("expected '@<type>', '%<type>' or \"<type>\"");
432
433 if (getParser().parseIdentifier(TypeName))
434 return TokError("expected identifier in directive");
435
436 if (Mergeable) {
437 if (getLexer().isNot(AsmToken::Comma))
438 return TokError("expected the entry size");
439 Lex();
440 if (getParser().parseAbsoluteExpression(Size))
441 return true;
442 if (Size <= 0)
443 return TokError("entry size must be positive");
444 }
445
446 if (Group) {
447 if (getLexer().isNot(AsmToken::Comma))
448 return TokError("expected group name");
449 Lex();
450 if (getParser().parseIdentifier(GroupName))
451 return true;
452 if (getLexer().is(AsmToken::Comma)) {
453 Lex();
454 StringRef Linkage;
455 if (getParser().parseIdentifier(Linkage))
456 return true;
457 if (Linkage != "comdat")
458 return TokError("Linkage must be 'comdat'");
459 }
460 }
461 if (getLexer().is(AsmToken::Comma)) {
462 Lex();
463 if (getParser().parseIdentifier(UniqueStr))
464 return TokError("expected identifier in directive");
465 if (UniqueStr != "unique")
466 return TokError("expected 'unique'");
467 if (getLexer().isNot(AsmToken::Comma))
468 return TokError("expected commma");
469 Lex();
470 if (getParser().parseAbsoluteExpression(UniqueID))
471 return true;
472 if (UniqueID < 0)
473 return TokError("unique id must be positive");
474 if (!isUInt<32>(UniqueID) || UniqueID == ~0U)
475 return TokError("unique id is too large");
476 }
477 }
478 }
479
480 EndStmt:
481 if (getLexer().isNot(AsmToken::EndOfStatement))
482 return TokError("unexpected token in directive");
483
484 unsigned Type = ELF::SHT_PROGBITS;
485
486 if (TypeName.empty()) {
487 if (SectionName.startswith(".note"))
488 Type = ELF::SHT_NOTE;
489 else if (SectionName == ".init_array")
490 Type = ELF::SHT_INIT_ARRAY;
491 else if (SectionName == ".fini_array")
492 Type = ELF::SHT_FINI_ARRAY;
493 else if (SectionName == ".preinit_array")
494 Type = ELF::SHT_PREINIT_ARRAY;
495 } else {
496 if (TypeName == "init_array")
497 Type = ELF::SHT_INIT_ARRAY;
498 else if (TypeName == "fini_array")
499 Type = ELF::SHT_FINI_ARRAY;
500 else if (TypeName == "preinit_array")
501 Type = ELF::SHT_PREINIT_ARRAY;
502 else if (TypeName == "nobits")
503 Type = ELF::SHT_NOBITS;
504 else if (TypeName == "progbits")
505 Type = ELF::SHT_PROGBITS;
506 else if (TypeName == "note")
507 Type = ELF::SHT_NOTE;
508 else if (TypeName == "unwind")
509 Type = ELF::SHT_X86_64_UNWIND;
510 else
511 return TokError("unknown section type");
512 }
513
514 if (UseLastGroup) {
515 MCSectionSubPair CurrentSection = getStreamer().getCurrentSection();
516 if (const MCSectionELF *Section =
517 cast_or_null<MCSectionELF>(CurrentSection.first))
518 if (const MCSymbol *Group = Section->getGroup()) {
519 GroupName = Group->getName();
520 Flags |= ELF::SHF_GROUP;
521 }
522 }
523
524 MCSection *ELFSection = getContext().getELFSection(SectionName, Type, Flags,
525 Size, GroupName, UniqueID);
526 getStreamer().SwitchSection(ELFSection, Subsection);
527
528 if (getContext().getGenDwarfForAssembly()) {
529 bool InsertResult = getContext().addGenDwarfSection(ELFSection);
530 if (InsertResult) {
531 if (getContext().getDwarfVersion() <= 2)
532 Warning(loc, "DWARF2 only supports one section per compilation unit");
533
534 if (!ELFSection->getBeginSymbol()) {
535 MCSymbol *SectionStartSymbol = getContext().createTempSymbol();
536 getStreamer().EmitLabel(SectionStartSymbol);
537 ELFSection->setBeginSymbol(SectionStartSymbol);
538 }
539 }
540 }
541
542 return false;
543 }
544
ParseDirectivePrevious(StringRef DirName,SMLoc)545 bool ELFAsmParser::ParseDirectivePrevious(StringRef DirName, SMLoc) {
546 MCSectionSubPair PreviousSection = getStreamer().getPreviousSection();
547 if (PreviousSection.first == nullptr)
548 return TokError(".previous without corresponding .section");
549 getStreamer().SwitchSection(PreviousSection.first, PreviousSection.second);
550
551 return false;
552 }
553
MCAttrForString(StringRef Type)554 static MCSymbolAttr MCAttrForString(StringRef Type) {
555 return StringSwitch<MCSymbolAttr>(Type)
556 .Cases("STT_FUNC", "function", MCSA_ELF_TypeFunction)
557 .Cases("STT_OBJECT", "object", MCSA_ELF_TypeObject)
558 .Cases("STT_TLS", "tls_object", MCSA_ELF_TypeTLS)
559 .Cases("STT_COMMON", "common", MCSA_ELF_TypeCommon)
560 .Cases("STT_NOTYPE", "notype", MCSA_ELF_TypeNoType)
561 .Cases("STT_GNU_IFUNC", "gnu_indirect_function",
562 MCSA_ELF_TypeIndFunction)
563 .Case("gnu_unique_object", MCSA_ELF_TypeGnuUniqueObject)
564 .Default(MCSA_Invalid);
565 }
566
567 /// ParseDirectiveELFType
568 /// ::= .type identifier , STT_<TYPE_IN_UPPER_CASE>
569 /// ::= .type identifier , #attribute
570 /// ::= .type identifier , @attribute
571 /// ::= .type identifier , %attribute
572 /// ::= .type identifier , "attribute"
ParseDirectiveType(StringRef,SMLoc)573 bool ELFAsmParser::ParseDirectiveType(StringRef, SMLoc) {
574 StringRef Name;
575 if (getParser().parseIdentifier(Name))
576 return TokError("expected identifier in directive");
577
578 // Handle the identifier as the key symbol.
579 MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
580
581 // NOTE the comma is optional in all cases. It is only documented as being
582 // optional in the first case, however, GAS will silently treat the comma as
583 // optional in all cases. Furthermore, although the documentation states that
584 // the first form only accepts STT_<TYPE_IN_UPPER_CASE>, in reality, GAS
585 // accepts both the upper case name as well as the lower case aliases.
586 if (getLexer().is(AsmToken::Comma))
587 Lex();
588
589 if (getLexer().isNot(AsmToken::Identifier) &&
590 getLexer().isNot(AsmToken::Hash) &&
591 getLexer().isNot(AsmToken::Percent) &&
592 getLexer().isNot(AsmToken::String)) {
593 if (!getLexer().getAllowAtInIdentifier())
594 return TokError("expected STT_<TYPE_IN_UPPER_CASE>, '#<type>', "
595 "'%<type>' or \"<type>\"");
596 else if (getLexer().isNot(AsmToken::At))
597 return TokError("expected STT_<TYPE_IN_UPPER_CASE>, '#<type>', '@<type>', "
598 "'%<type>' or \"<type>\"");
599 }
600
601 if (getLexer().isNot(AsmToken::String) &&
602 getLexer().isNot(AsmToken::Identifier))
603 Lex();
604
605 SMLoc TypeLoc = getLexer().getLoc();
606
607 StringRef Type;
608 if (getParser().parseIdentifier(Type))
609 return TokError("expected symbol type in directive");
610
611 MCSymbolAttr Attr = MCAttrForString(Type);
612 if (Attr == MCSA_Invalid)
613 return Error(TypeLoc, "unsupported attribute in '.type' directive");
614
615 if (getLexer().isNot(AsmToken::EndOfStatement))
616 return TokError("unexpected token in '.type' directive");
617 Lex();
618
619 getStreamer().EmitSymbolAttribute(Sym, Attr);
620
621 return false;
622 }
623
624 /// ParseDirectiveIdent
625 /// ::= .ident string
ParseDirectiveIdent(StringRef,SMLoc)626 bool ELFAsmParser::ParseDirectiveIdent(StringRef, SMLoc) {
627 if (getLexer().isNot(AsmToken::String))
628 return TokError("unexpected token in '.ident' directive");
629
630 StringRef Data = getTok().getIdentifier();
631
632 Lex();
633
634 getStreamer().EmitIdent(Data);
635 return false;
636 }
637
638 /// ParseDirectiveSymver
639 /// ::= .symver foo, bar2@zed
ParseDirectiveSymver(StringRef,SMLoc)640 bool ELFAsmParser::ParseDirectiveSymver(StringRef, SMLoc) {
641 StringRef Name;
642 if (getParser().parseIdentifier(Name))
643 return TokError("expected identifier in directive");
644
645 if (getLexer().isNot(AsmToken::Comma))
646 return TokError("expected a comma");
647
648 // ARM assembly uses @ for a comment...
649 // except when parsing the second parameter of the .symver directive.
650 // Force the next symbol to allow @ in the identifier, which is
651 // required for this directive and then reset it to its initial state.
652 const bool AllowAtInIdentifier = getLexer().getAllowAtInIdentifier();
653 getLexer().setAllowAtInIdentifier(true);
654 Lex();
655 getLexer().setAllowAtInIdentifier(AllowAtInIdentifier);
656
657 StringRef AliasName;
658 if (getParser().parseIdentifier(AliasName))
659 return TokError("expected identifier in directive");
660
661 if (AliasName.find('@') == StringRef::npos)
662 return TokError("expected a '@' in the name");
663
664 MCSymbol *Alias = getContext().getOrCreateSymbol(AliasName);
665 MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
666 const MCExpr *Value = MCSymbolRefExpr::create(Sym, getContext());
667
668 getStreamer().EmitAssignment(Alias, Value);
669 return false;
670 }
671
672 /// ParseDirectiveVersion
673 /// ::= .version string
ParseDirectiveVersion(StringRef,SMLoc)674 bool ELFAsmParser::ParseDirectiveVersion(StringRef, SMLoc)
675 {
676 bool Error;
677 if (getLexer().isNot(AsmToken::String))
678 return TokError("unexpected token in '.version' directive");
679
680 StringRef Data = getTok().getIdentifier();
681
682 Lex();
683
684 MCSection *Note = getContext().getELFSection(".note", ELF::SHT_NOTE, 0);
685
686 getStreamer().PushSection();
687 getStreamer().SwitchSection(Note);
688 getStreamer().EmitIntValue(Data.size()+1, 4, Error); // namesz.
689 if (Error)
690 return true;
691 getStreamer().EmitIntValue(0, 4, Error); // descsz = 0 (no description).
692 getStreamer().EmitIntValue(1, 4, Error); // type = NT_VERSION.
693 getStreamer().EmitBytes(Data); // name.
694 getStreamer().EmitIntValue(0, 1, Error); // terminate the string.
695 getStreamer().EmitValueToAlignment(4); // ensure 4 byte alignment.
696 getStreamer().PopSection();
697 return false;
698 }
699
700 /// ParseDirectiveWeakref
701 /// ::= .weakref foo, bar
ParseDirectiveWeakref(StringRef,SMLoc)702 bool ELFAsmParser::ParseDirectiveWeakref(StringRef, SMLoc) {
703 // FIXME: Share code with the other alias building directives.
704
705 StringRef AliasName;
706 if (getParser().parseIdentifier(AliasName))
707 return TokError("expected identifier in directive");
708
709 if (getLexer().isNot(AsmToken::Comma))
710 return TokError("expected a comma");
711
712 Lex();
713
714 StringRef Name;
715 if (getParser().parseIdentifier(Name))
716 return TokError("expected identifier in directive");
717
718 MCSymbol *Alias = getContext().getOrCreateSymbol(AliasName);
719
720 MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
721
722 getStreamer().EmitWeakReference(Alias, Sym);
723 return false;
724 }
725
ParseDirectiveSubsection(StringRef,SMLoc)726 bool ELFAsmParser::ParseDirectiveSubsection(StringRef, SMLoc) {
727 const MCExpr *Subsection = nullptr;
728 if (getLexer().isNot(AsmToken::EndOfStatement)) {
729 if (getParser().parseExpression(Subsection))
730 return true;
731 }
732
733 if (getLexer().isNot(AsmToken::EndOfStatement))
734 return TokError("unexpected token in directive");
735
736 getStreamer().SubSection(Subsection);
737 return false;
738 }
739
740 namespace llvm {
741
createELFAsmParser()742 MCAsmParserExtension *createELFAsmParser() {
743 return new ELFAsmParser;
744 }
745
746 }
747