1 //===- ELFAsmParser.cpp - ELF Assembly Parser -----------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #include "llvm/ADT/StringRef.h"
10 #include "llvm/ADT/StringSwitch.h"
11 #include "llvm/BinaryFormat/ELF.h"
12 #include "llvm/MC/MCAsmInfo.h"
13 #include "llvm/MC/MCContext.h"
14 #include "llvm/MC/MCDirectives.h"
15 #include "llvm/MC/MCExpr.h"
16 #include "llvm/MC/MCParser/MCAsmLexer.h"
17 #include "llvm/MC/MCParser/MCAsmParser.h"
18 #include "llvm/MC/MCParser/MCAsmParserExtension.h"
19 #include "llvm/MC/MCSection.h"
20 #include "llvm/MC/MCSectionELF.h"
21 #include "llvm/MC/MCStreamer.h"
22 #include "llvm/MC/MCSymbol.h"
23 #include "llvm/MC/MCSymbolELF.h"
24 #include "llvm/MC/SectionKind.h"
25 #include "llvm/Support/Casting.h"
26 #include "llvm/Support/MathExtras.h"
27 #include "llvm/Support/SMLoc.h"
28 #include <cassert>
29 #include <cstdint>
30 #include <utility>
31
32 using namespace llvm;
33
34 namespace {
35
36 class ELFAsmParser : public MCAsmParserExtension {
37 template<bool (ELFAsmParser::*HandlerMethod)(StringRef, SMLoc)>
addDirectiveHandler(StringRef Directive)38 void addDirectiveHandler(StringRef Directive) {
39 MCAsmParser::ExtensionDirectiveHandler Handler = std::make_pair(
40 this, HandleDirective<ELFAsmParser, HandlerMethod>);
41
42 getParser().addDirectiveHandler(Directive, Handler);
43 }
44
45 bool ParseSectionSwitch(StringRef Section, unsigned Type, unsigned Flags,
46 SectionKind Kind);
47
48 public:
ELFAsmParser()49 ELFAsmParser() { BracketExpressionsSupported = true; }
50
Initialize(MCAsmParser & Parser)51 void Initialize(MCAsmParser &Parser) override {
52 // Call the base implementation.
53 this->MCAsmParserExtension::Initialize(Parser);
54
55 addDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveData>(".data");
56 addDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveText>(".text");
57 addDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveBSS>(".bss");
58 addDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveRoData>(".rodata");
59 addDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveTData>(".tdata");
60 addDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveTBSS>(".tbss");
61 addDirectiveHandler<
62 &ELFAsmParser::ParseSectionDirectiveDataRel>(".data.rel");
63 addDirectiveHandler<
64 &ELFAsmParser::ParseSectionDirectiveDataRelRo>(".data.rel.ro");
65 addDirectiveHandler<
66 &ELFAsmParser::ParseSectionDirectiveEhFrame>(".eh_frame");
67 addDirectiveHandler<&ELFAsmParser::ParseDirectiveSection>(".section");
68 addDirectiveHandler<
69 &ELFAsmParser::ParseDirectivePushSection>(".pushsection");
70 addDirectiveHandler<&ELFAsmParser::ParseDirectivePopSection>(".popsection");
71 addDirectiveHandler<&ELFAsmParser::ParseDirectiveSize>(".size");
72 addDirectiveHandler<&ELFAsmParser::ParseDirectivePrevious>(".previous");
73 addDirectiveHandler<&ELFAsmParser::ParseDirectiveType>(".type");
74 addDirectiveHandler<&ELFAsmParser::ParseDirectiveIdent>(".ident");
75 addDirectiveHandler<&ELFAsmParser::ParseDirectiveSymver>(".symver");
76 addDirectiveHandler<&ELFAsmParser::ParseDirectiveVersion>(".version");
77 addDirectiveHandler<&ELFAsmParser::ParseDirectiveWeakref>(".weakref");
78 addDirectiveHandler<&ELFAsmParser::ParseDirectiveSymbolAttribute>(".weak");
79 addDirectiveHandler<&ELFAsmParser::ParseDirectiveSymbolAttribute>(".local");
80 addDirectiveHandler<
81 &ELFAsmParser::ParseDirectiveSymbolAttribute>(".protected");
82 addDirectiveHandler<
83 &ELFAsmParser::ParseDirectiveSymbolAttribute>(".internal");
84 addDirectiveHandler<
85 &ELFAsmParser::ParseDirectiveSymbolAttribute>(".hidden");
86 addDirectiveHandler<&ELFAsmParser::ParseDirectiveSubsection>(".subsection");
87 addDirectiveHandler<&ELFAsmParser::ParseDirectiveCGProfile>(".cg_profile");
88 }
89
90 // FIXME: Part of this logic is duplicated in the MCELFStreamer. What is
91 // the best way for us to get access to it?
ParseSectionDirectiveData(StringRef,SMLoc)92 bool ParseSectionDirectiveData(StringRef, SMLoc) {
93 return ParseSectionSwitch(".data", ELF::SHT_PROGBITS,
94 ELF::SHF_WRITE | ELF::SHF_ALLOC,
95 SectionKind::getData());
96 }
ParseSectionDirectiveText(StringRef,SMLoc)97 bool ParseSectionDirectiveText(StringRef, SMLoc) {
98 return ParseSectionSwitch(".text", ELF::SHT_PROGBITS,
99 ELF::SHF_EXECINSTR |
100 ELF::SHF_ALLOC, SectionKind::getText());
101 }
ParseSectionDirectiveBSS(StringRef,SMLoc)102 bool ParseSectionDirectiveBSS(StringRef, SMLoc) {
103 return ParseSectionSwitch(".bss", ELF::SHT_NOBITS,
104 ELF::SHF_WRITE |
105 ELF::SHF_ALLOC, SectionKind::getBSS());
106 }
ParseSectionDirectiveRoData(StringRef,SMLoc)107 bool ParseSectionDirectiveRoData(StringRef, SMLoc) {
108 return ParseSectionSwitch(".rodata", ELF::SHT_PROGBITS,
109 ELF::SHF_ALLOC,
110 SectionKind::getReadOnly());
111 }
ParseSectionDirectiveTData(StringRef,SMLoc)112 bool ParseSectionDirectiveTData(StringRef, SMLoc) {
113 return ParseSectionSwitch(".tdata", ELF::SHT_PROGBITS,
114 ELF::SHF_ALLOC |
115 ELF::SHF_TLS | ELF::SHF_WRITE,
116 SectionKind::getThreadData());
117 }
ParseSectionDirectiveTBSS(StringRef,SMLoc)118 bool ParseSectionDirectiveTBSS(StringRef, SMLoc) {
119 return ParseSectionSwitch(".tbss", ELF::SHT_NOBITS,
120 ELF::SHF_ALLOC |
121 ELF::SHF_TLS | ELF::SHF_WRITE,
122 SectionKind::getThreadBSS());
123 }
ParseSectionDirectiveDataRel(StringRef,SMLoc)124 bool ParseSectionDirectiveDataRel(StringRef, SMLoc) {
125 return ParseSectionSwitch(".data.rel", ELF::SHT_PROGBITS,
126 ELF::SHF_ALLOC | ELF::SHF_WRITE,
127 SectionKind::getData());
128 }
ParseSectionDirectiveDataRelRo(StringRef,SMLoc)129 bool ParseSectionDirectiveDataRelRo(StringRef, SMLoc) {
130 return ParseSectionSwitch(".data.rel.ro", ELF::SHT_PROGBITS,
131 ELF::SHF_ALLOC |
132 ELF::SHF_WRITE,
133 SectionKind::getReadOnlyWithRel());
134 }
ParseSectionDirectiveEhFrame(StringRef,SMLoc)135 bool ParseSectionDirectiveEhFrame(StringRef, SMLoc) {
136 return ParseSectionSwitch(".eh_frame", ELF::SHT_PROGBITS,
137 ELF::SHF_ALLOC | ELF::SHF_WRITE,
138 SectionKind::getData());
139 }
140 bool ParseDirectivePushSection(StringRef, SMLoc);
141 bool ParseDirectivePopSection(StringRef, SMLoc);
142 bool ParseDirectiveSection(StringRef, SMLoc);
143 bool ParseDirectiveSize(StringRef, SMLoc);
144 bool ParseDirectivePrevious(StringRef, SMLoc);
145 bool ParseDirectiveType(StringRef, SMLoc);
146 bool ParseDirectiveIdent(StringRef, SMLoc);
147 bool ParseDirectiveSymver(StringRef, SMLoc);
148 bool ParseDirectiveVersion(StringRef, SMLoc);
149 bool ParseDirectiveWeakref(StringRef, SMLoc);
150 bool ParseDirectiveSymbolAttribute(StringRef, SMLoc);
151 bool ParseDirectiveSubsection(StringRef, SMLoc);
152 bool ParseDirectiveCGProfile(StringRef, SMLoc);
153
154 private:
155 bool ParseSectionName(StringRef &SectionName);
156 bool ParseSectionArguments(bool IsPush, SMLoc loc);
157 unsigned parseSunStyleSectionFlags();
158 bool maybeParseSectionType(StringRef &TypeName);
159 bool parseMergeSize(int64_t &Size);
160 bool parseGroup(StringRef &GroupName);
161 bool parseMetadataSym(MCSymbolELF *&Associated);
162 bool maybeParseUniqueID(int64_t &UniqueID);
163 };
164
165 } // end anonymous namespace
166
167 /// ParseDirectiveSymbolAttribute
168 /// ::= { ".local", ".weak", ... } [ identifier ( , identifier )* ]
ParseDirectiveSymbolAttribute(StringRef Directive,SMLoc)169 bool ELFAsmParser::ParseDirectiveSymbolAttribute(StringRef Directive, SMLoc) {
170 MCSymbolAttr Attr = StringSwitch<MCSymbolAttr>(Directive)
171 .Case(".weak", MCSA_Weak)
172 .Case(".local", MCSA_Local)
173 .Case(".hidden", MCSA_Hidden)
174 .Case(".internal", MCSA_Internal)
175 .Case(".protected", MCSA_Protected)
176 .Default(MCSA_Invalid);
177 assert(Attr != MCSA_Invalid && "unexpected symbol attribute directive!");
178 if (getLexer().isNot(AsmToken::EndOfStatement)) {
179 while (true) {
180 StringRef Name;
181
182 if (getParser().parseIdentifier(Name))
183 return TokError("expected identifier in directive");
184
185 MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
186
187 getStreamer().EmitSymbolAttribute(Sym, Attr);
188
189 if (getLexer().is(AsmToken::EndOfStatement))
190 break;
191
192 if (getLexer().isNot(AsmToken::Comma))
193 return TokError("unexpected token in directive");
194 Lex();
195 }
196 }
197
198 Lex();
199 return false;
200 }
201
ParseSectionSwitch(StringRef Section,unsigned Type,unsigned Flags,SectionKind Kind)202 bool ELFAsmParser::ParseSectionSwitch(StringRef Section, unsigned Type,
203 unsigned Flags, SectionKind Kind) {
204 const MCExpr *Subsection = nullptr;
205 if (getLexer().isNot(AsmToken::EndOfStatement)) {
206 if (getParser().parseExpression(Subsection))
207 return true;
208 }
209 Lex();
210
211 getStreamer().SwitchSection(getContext().getELFSection(Section, Type, Flags),
212 Subsection);
213
214 return false;
215 }
216
ParseDirectiveSize(StringRef,SMLoc)217 bool ELFAsmParser::ParseDirectiveSize(StringRef, SMLoc) {
218 StringRef Name;
219 if (getParser().parseIdentifier(Name))
220 return TokError("expected identifier in directive");
221 MCSymbolELF *Sym = cast<MCSymbolELF>(getContext().getOrCreateSymbol(Name));
222
223 if (getLexer().isNot(AsmToken::Comma))
224 return TokError("unexpected token in directive");
225 Lex();
226
227 const MCExpr *Expr;
228 if (getParser().parseExpression(Expr))
229 return true;
230
231 if (getLexer().isNot(AsmToken::EndOfStatement))
232 return TokError("unexpected token in directive");
233 Lex();
234
235 getStreamer().emitELFSize(Sym, Expr);
236 return false;
237 }
238
ParseSectionName(StringRef & SectionName)239 bool ELFAsmParser::ParseSectionName(StringRef &SectionName) {
240 // A section name can contain -, so we cannot just use
241 // parseIdentifier.
242 SMLoc FirstLoc = getLexer().getLoc();
243 unsigned Size = 0;
244
245 if (getLexer().is(AsmToken::String)) {
246 SectionName = getTok().getIdentifier();
247 Lex();
248 return false;
249 }
250
251 while (!getParser().hasPendingError()) {
252 SMLoc PrevLoc = getLexer().getLoc();
253 if (getLexer().is(AsmToken::Comma) ||
254 getLexer().is(AsmToken::EndOfStatement))
255 break;
256
257 unsigned CurSize;
258 if (getLexer().is(AsmToken::String)) {
259 CurSize = getTok().getIdentifier().size() + 2;
260 Lex();
261 } else if (getLexer().is(AsmToken::Identifier)) {
262 CurSize = getTok().getIdentifier().size();
263 Lex();
264 } else {
265 CurSize = getTok().getString().size();
266 Lex();
267 }
268 Size += CurSize;
269 SectionName = StringRef(FirstLoc.getPointer(), Size);
270
271 // Make sure the following token is adjacent.
272 if (PrevLoc.getPointer() + CurSize != getTok().getLoc().getPointer())
273 break;
274 }
275 if (Size == 0)
276 return true;
277
278 return false;
279 }
280
parseSectionFlags(StringRef flagsStr,bool * UseLastGroup)281 static unsigned parseSectionFlags(StringRef flagsStr, bool *UseLastGroup) {
282 unsigned flags = 0;
283
284 // If a valid numerical value is set for the section flag, use it verbatim
285 if (!flagsStr.getAsInteger(0, flags))
286 return flags;
287
288 for (char i : flagsStr) {
289 switch (i) {
290 case 'a':
291 flags |= ELF::SHF_ALLOC;
292 break;
293 case 'e':
294 flags |= ELF::SHF_EXCLUDE;
295 break;
296 case 'x':
297 flags |= ELF::SHF_EXECINSTR;
298 break;
299 case 'w':
300 flags |= ELF::SHF_WRITE;
301 break;
302 case 'o':
303 flags |= ELF::SHF_LINK_ORDER;
304 break;
305 case 'M':
306 flags |= ELF::SHF_MERGE;
307 break;
308 case 'S':
309 flags |= ELF::SHF_STRINGS;
310 break;
311 case 'T':
312 flags |= ELF::SHF_TLS;
313 break;
314 case 'c':
315 flags |= ELF::XCORE_SHF_CP_SECTION;
316 break;
317 case 'd':
318 flags |= ELF::XCORE_SHF_DP_SECTION;
319 break;
320 case 'y':
321 flags |= ELF::SHF_ARM_PURECODE;
322 break;
323 case 's':
324 flags |= ELF::SHF_HEX_GPREL;
325 break;
326 case 'G':
327 flags |= ELF::SHF_GROUP;
328 break;
329 case '?':
330 *UseLastGroup = true;
331 break;
332 default:
333 return -1U;
334 }
335 }
336
337 return flags;
338 }
339
parseSunStyleSectionFlags()340 unsigned ELFAsmParser::parseSunStyleSectionFlags() {
341 unsigned flags = 0;
342 while (getLexer().is(AsmToken::Hash)) {
343 Lex(); // Eat the #.
344
345 if (!getLexer().is(AsmToken::Identifier))
346 return -1U;
347
348 StringRef flagId = getTok().getIdentifier();
349 if (flagId == "alloc")
350 flags |= ELF::SHF_ALLOC;
351 else if (flagId == "execinstr")
352 flags |= ELF::SHF_EXECINSTR;
353 else if (flagId == "write")
354 flags |= ELF::SHF_WRITE;
355 else if (flagId == "tls")
356 flags |= ELF::SHF_TLS;
357 else
358 return -1U;
359
360 Lex(); // Eat the flag.
361
362 if (!getLexer().is(AsmToken::Comma))
363 break;
364 Lex(); // Eat the comma.
365 }
366 return flags;
367 }
368
369
ParseDirectivePushSection(StringRef s,SMLoc loc)370 bool ELFAsmParser::ParseDirectivePushSection(StringRef s, SMLoc loc) {
371 getStreamer().PushSection();
372
373 if (ParseSectionArguments(/*IsPush=*/true, loc)) {
374 getStreamer().PopSection();
375 return true;
376 }
377
378 return false;
379 }
380
ParseDirectivePopSection(StringRef,SMLoc)381 bool ELFAsmParser::ParseDirectivePopSection(StringRef, SMLoc) {
382 if (!getStreamer().PopSection())
383 return TokError(".popsection without corresponding .pushsection");
384 return false;
385 }
386
ParseDirectiveSection(StringRef,SMLoc loc)387 bool ELFAsmParser::ParseDirectiveSection(StringRef, SMLoc loc) {
388 return ParseSectionArguments(/*IsPush=*/false, loc);
389 }
390
maybeParseSectionType(StringRef & TypeName)391 bool ELFAsmParser::maybeParseSectionType(StringRef &TypeName) {
392 MCAsmLexer &L = getLexer();
393 if (L.isNot(AsmToken::Comma))
394 return false;
395 Lex();
396 if (L.isNot(AsmToken::At) && L.isNot(AsmToken::Percent) &&
397 L.isNot(AsmToken::String)) {
398 if (L.getAllowAtInIdentifier())
399 return TokError("expected '@<type>', '%<type>' or \"<type>\"");
400 else
401 return TokError("expected '%<type>' or \"<type>\"");
402 }
403 if (!L.is(AsmToken::String))
404 Lex();
405 if (L.is(AsmToken::Integer)) {
406 TypeName = getTok().getString();
407 Lex();
408 } else if (getParser().parseIdentifier(TypeName))
409 return TokError("expected identifier in directive");
410 return false;
411 }
412
parseMergeSize(int64_t & Size)413 bool ELFAsmParser::parseMergeSize(int64_t &Size) {
414 if (getLexer().isNot(AsmToken::Comma))
415 return TokError("expected the entry size");
416 Lex();
417 if (getParser().parseAbsoluteExpression(Size))
418 return true;
419 if (Size <= 0)
420 return TokError("entry size must be positive");
421 return false;
422 }
423
parseGroup(StringRef & GroupName)424 bool ELFAsmParser::parseGroup(StringRef &GroupName) {
425 MCAsmLexer &L = getLexer();
426 if (L.isNot(AsmToken::Comma))
427 return TokError("expected group name");
428 Lex();
429 if (L.is(AsmToken::Integer)) {
430 GroupName = getTok().getString();
431 Lex();
432 } else if (getParser().parseIdentifier(GroupName)) {
433 return TokError("invalid group name");
434 }
435 if (L.is(AsmToken::Comma)) {
436 Lex();
437 StringRef Linkage;
438 if (getParser().parseIdentifier(Linkage))
439 return TokError("invalid linkage");
440 if (Linkage != "comdat")
441 return TokError("Linkage must be 'comdat'");
442 }
443 return false;
444 }
445
parseMetadataSym(MCSymbolELF * & Associated)446 bool ELFAsmParser::parseMetadataSym(MCSymbolELF *&Associated) {
447 MCAsmLexer &L = getLexer();
448 if (L.isNot(AsmToken::Comma))
449 return TokError("expected metadata symbol");
450 Lex();
451 StringRef Name;
452 if (getParser().parseIdentifier(Name))
453 return TokError("invalid metadata symbol");
454 Associated = dyn_cast_or_null<MCSymbolELF>(getContext().lookupSymbol(Name));
455 if (!Associated || !Associated->isInSection())
456 return TokError("symbol is not in a section: " + Name);
457 return false;
458 }
459
maybeParseUniqueID(int64_t & UniqueID)460 bool ELFAsmParser::maybeParseUniqueID(int64_t &UniqueID) {
461 MCAsmLexer &L = getLexer();
462 if (L.isNot(AsmToken::Comma))
463 return false;
464 Lex();
465 StringRef UniqueStr;
466 if (getParser().parseIdentifier(UniqueStr))
467 return TokError("expected identifier in directive");
468 if (UniqueStr != "unique")
469 return TokError("expected 'unique'");
470 if (L.isNot(AsmToken::Comma))
471 return TokError("expected commma");
472 Lex();
473 if (getParser().parseAbsoluteExpression(UniqueID))
474 return true;
475 if (UniqueID < 0)
476 return TokError("unique id must be positive");
477 if (!isUInt<32>(UniqueID) || UniqueID == ~0U)
478 return TokError("unique id is too large");
479 return false;
480 }
481
hasPrefix(StringRef SectionName,StringRef Prefix)482 static bool hasPrefix(StringRef SectionName, StringRef Prefix) {
483 return SectionName.startswith(Prefix) || SectionName == Prefix.drop_back();
484 }
485
ParseSectionArguments(bool IsPush,SMLoc loc)486 bool ELFAsmParser::ParseSectionArguments(bool IsPush, SMLoc loc) {
487 StringRef SectionName;
488
489 if (ParseSectionName(SectionName))
490 return TokError("expected identifier in directive");
491
492 StringRef TypeName;
493 int64_t Size = 0;
494 StringRef GroupName;
495 unsigned Flags = 0;
496 const MCExpr *Subsection = nullptr;
497 bool UseLastGroup = false;
498 MCSymbolELF *Associated = nullptr;
499 int64_t UniqueID = ~0;
500
501 // Set the defaults first.
502 if (hasPrefix(SectionName, ".rodata.") || SectionName == ".rodata1")
503 Flags |= ELF::SHF_ALLOC;
504 else if (SectionName == ".fini" || SectionName == ".init" ||
505 hasPrefix(SectionName, ".text."))
506 Flags |= ELF::SHF_ALLOC | ELF::SHF_EXECINSTR;
507 else if (hasPrefix(SectionName, ".data.") || SectionName == ".data1" ||
508 hasPrefix(SectionName, ".bss.") ||
509 hasPrefix(SectionName, ".init_array.") ||
510 hasPrefix(SectionName, ".fini_array.") ||
511 hasPrefix(SectionName, ".preinit_array."))
512 Flags |= ELF::SHF_ALLOC | ELF::SHF_WRITE;
513 else if (hasPrefix(SectionName, ".tdata.") ||
514 hasPrefix(SectionName, ".tbss."))
515 Flags |= ELF::SHF_ALLOC | ELF::SHF_WRITE | ELF::SHF_TLS;
516
517 if (getLexer().is(AsmToken::Comma)) {
518 Lex();
519
520 if (IsPush && getLexer().isNot(AsmToken::String)) {
521 if (getParser().parseExpression(Subsection))
522 return true;
523 if (getLexer().isNot(AsmToken::Comma))
524 goto EndStmt;
525 Lex();
526 }
527
528 unsigned extraFlags;
529
530 if (getLexer().isNot(AsmToken::String)) {
531 if (!getContext().getAsmInfo()->usesSunStyleELFSectionSwitchSyntax()
532 || getLexer().isNot(AsmToken::Hash))
533 return TokError("expected string in directive");
534 extraFlags = parseSunStyleSectionFlags();
535 } else {
536 StringRef FlagsStr = getTok().getStringContents();
537 Lex();
538 extraFlags = parseSectionFlags(FlagsStr, &UseLastGroup);
539 }
540
541 if (extraFlags == -1U)
542 return TokError("unknown flag");
543 Flags |= extraFlags;
544
545 bool Mergeable = Flags & ELF::SHF_MERGE;
546 bool Group = Flags & ELF::SHF_GROUP;
547 if (Group && UseLastGroup)
548 return TokError("Section cannot specifiy a group name while also acting "
549 "as a member of the last group");
550
551 if (maybeParseSectionType(TypeName))
552 return true;
553
554 MCAsmLexer &L = getLexer();
555 if (TypeName.empty()) {
556 if (Mergeable)
557 return TokError("Mergeable section must specify the type");
558 if (Group)
559 return TokError("Group section must specify the type");
560 if (L.isNot(AsmToken::EndOfStatement))
561 return TokError("unexpected token in directive");
562 }
563
564 if (Mergeable)
565 if (parseMergeSize(Size))
566 return true;
567 if (Group)
568 if (parseGroup(GroupName))
569 return true;
570 if (Flags & ELF::SHF_LINK_ORDER)
571 if (parseMetadataSym(Associated))
572 return true;
573 if (maybeParseUniqueID(UniqueID))
574 return true;
575 }
576
577 EndStmt:
578 if (getLexer().isNot(AsmToken::EndOfStatement))
579 return TokError("unexpected token in directive");
580 Lex();
581
582 unsigned Type = ELF::SHT_PROGBITS;
583
584 if (TypeName.empty()) {
585 if (SectionName.startswith(".note"))
586 Type = ELF::SHT_NOTE;
587 else if (hasPrefix(SectionName, ".init_array."))
588 Type = ELF::SHT_INIT_ARRAY;
589 else if (hasPrefix(SectionName, ".bss."))
590 Type = ELF::SHT_NOBITS;
591 else if (hasPrefix(SectionName, ".tbss."))
592 Type = ELF::SHT_NOBITS;
593 else if (hasPrefix(SectionName, ".fini_array."))
594 Type = ELF::SHT_FINI_ARRAY;
595 else if (hasPrefix(SectionName, ".preinit_array."))
596 Type = ELF::SHT_PREINIT_ARRAY;
597 } else {
598 if (TypeName == "init_array")
599 Type = ELF::SHT_INIT_ARRAY;
600 else if (TypeName == "fini_array")
601 Type = ELF::SHT_FINI_ARRAY;
602 else if (TypeName == "preinit_array")
603 Type = ELF::SHT_PREINIT_ARRAY;
604 else if (TypeName == "nobits")
605 Type = ELF::SHT_NOBITS;
606 else if (TypeName == "progbits")
607 Type = ELF::SHT_PROGBITS;
608 else if (TypeName == "note")
609 Type = ELF::SHT_NOTE;
610 else if (TypeName == "unwind")
611 Type = ELF::SHT_X86_64_UNWIND;
612 else if (TypeName == "llvm_odrtab")
613 Type = ELF::SHT_LLVM_ODRTAB;
614 else if (TypeName == "llvm_linker_options")
615 Type = ELF::SHT_LLVM_LINKER_OPTIONS;
616 else if (TypeName == "llvm_call_graph_profile")
617 Type = ELF::SHT_LLVM_CALL_GRAPH_PROFILE;
618 else if (TypeName == "llvm_dependent_libraries")
619 Type = ELF::SHT_LLVM_DEPENDENT_LIBRARIES;
620 else if (TypeName == "llvm_sympart")
621 Type = ELF::SHT_LLVM_SYMPART;
622 else if (TypeName.getAsInteger(0, Type))
623 return TokError("unknown section type");
624 }
625
626 if (UseLastGroup) {
627 MCSectionSubPair CurrentSection = getStreamer().getCurrentSection();
628 if (const MCSectionELF *Section =
629 cast_or_null<MCSectionELF>(CurrentSection.first))
630 if (const MCSymbol *Group = Section->getGroup()) {
631 GroupName = Group->getName();
632 Flags |= ELF::SHF_GROUP;
633 }
634 }
635
636 MCSection *ELFSection =
637 getContext().getELFSection(SectionName, Type, Flags, Size, GroupName,
638 UniqueID, Associated);
639 getStreamer().SwitchSection(ELFSection, Subsection);
640
641 if (getContext().getGenDwarfForAssembly()) {
642 bool InsertResult = getContext().addGenDwarfSection(ELFSection);
643 if (InsertResult) {
644 if (getContext().getDwarfVersion() <= 2)
645 Warning(loc, "DWARF2 only supports one section per compilation unit");
646
647 if (!ELFSection->getBeginSymbol()) {
648 MCSymbol *SectionStartSymbol = getContext().createTempSymbol();
649 getStreamer().EmitLabel(SectionStartSymbol);
650 ELFSection->setBeginSymbol(SectionStartSymbol);
651 }
652 }
653 }
654
655 return false;
656 }
657
ParseDirectivePrevious(StringRef DirName,SMLoc)658 bool ELFAsmParser::ParseDirectivePrevious(StringRef DirName, SMLoc) {
659 MCSectionSubPair PreviousSection = getStreamer().getPreviousSection();
660 if (PreviousSection.first == nullptr)
661 return TokError(".previous without corresponding .section");
662 getStreamer().SwitchSection(PreviousSection.first, PreviousSection.second);
663
664 return false;
665 }
666
MCAttrForString(StringRef Type)667 static MCSymbolAttr MCAttrForString(StringRef Type) {
668 return StringSwitch<MCSymbolAttr>(Type)
669 .Cases("STT_FUNC", "function", MCSA_ELF_TypeFunction)
670 .Cases("STT_OBJECT", "object", MCSA_ELF_TypeObject)
671 .Cases("STT_TLS", "tls_object", MCSA_ELF_TypeTLS)
672 .Cases("STT_COMMON", "common", MCSA_ELF_TypeCommon)
673 .Cases("STT_NOTYPE", "notype", MCSA_ELF_TypeNoType)
674 .Cases("STT_GNU_IFUNC", "gnu_indirect_function",
675 MCSA_ELF_TypeIndFunction)
676 .Case("gnu_unique_object", MCSA_ELF_TypeGnuUniqueObject)
677 .Default(MCSA_Invalid);
678 }
679
680 /// ParseDirectiveELFType
681 /// ::= .type identifier , STT_<TYPE_IN_UPPER_CASE>
682 /// ::= .type identifier , #attribute
683 /// ::= .type identifier , @attribute
684 /// ::= .type identifier , %attribute
685 /// ::= .type identifier , "attribute"
ParseDirectiveType(StringRef,SMLoc)686 bool ELFAsmParser::ParseDirectiveType(StringRef, SMLoc) {
687 StringRef Name;
688 if (getParser().parseIdentifier(Name))
689 return TokError("expected identifier in directive");
690
691 // Handle the identifier as the key symbol.
692 MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
693
694 // NOTE the comma is optional in all cases. It is only documented as being
695 // optional in the first case, however, GAS will silently treat the comma as
696 // optional in all cases. Furthermore, although the documentation states that
697 // the first form only accepts STT_<TYPE_IN_UPPER_CASE>, in reality, GAS
698 // accepts both the upper case name as well as the lower case aliases.
699 if (getLexer().is(AsmToken::Comma))
700 Lex();
701
702 if (getLexer().isNot(AsmToken::Identifier) &&
703 getLexer().isNot(AsmToken::Hash) &&
704 getLexer().isNot(AsmToken::Percent) &&
705 getLexer().isNot(AsmToken::String)) {
706 if (!getLexer().getAllowAtInIdentifier())
707 return TokError("expected STT_<TYPE_IN_UPPER_CASE>, '#<type>', "
708 "'%<type>' or \"<type>\"");
709 else if (getLexer().isNot(AsmToken::At))
710 return TokError("expected STT_<TYPE_IN_UPPER_CASE>, '#<type>', '@<type>', "
711 "'%<type>' or \"<type>\"");
712 }
713
714 if (getLexer().isNot(AsmToken::String) &&
715 getLexer().isNot(AsmToken::Identifier))
716 Lex();
717
718 SMLoc TypeLoc = getLexer().getLoc();
719
720 StringRef Type;
721 if (getParser().parseIdentifier(Type))
722 return TokError("expected symbol type in directive");
723
724 MCSymbolAttr Attr = MCAttrForString(Type);
725 if (Attr == MCSA_Invalid)
726 return Error(TypeLoc, "unsupported attribute in '.type' directive");
727
728 if (getLexer().isNot(AsmToken::EndOfStatement))
729 return TokError("unexpected token in '.type' directive");
730 Lex();
731
732 getStreamer().EmitSymbolAttribute(Sym, Attr);
733
734 return false;
735 }
736
737 /// ParseDirectiveIdent
738 /// ::= .ident string
ParseDirectiveIdent(StringRef,SMLoc)739 bool ELFAsmParser::ParseDirectiveIdent(StringRef, SMLoc) {
740 if (getLexer().isNot(AsmToken::String))
741 return TokError("unexpected token in '.ident' directive");
742
743 StringRef Data = getTok().getIdentifier();
744
745 Lex();
746
747 if (getLexer().isNot(AsmToken::EndOfStatement))
748 return TokError("unexpected token in '.ident' directive");
749 Lex();
750
751 getStreamer().EmitIdent(Data);
752 return false;
753 }
754
755 /// ParseDirectiveSymver
756 /// ::= .symver foo, bar2@zed
ParseDirectiveSymver(StringRef,SMLoc)757 bool ELFAsmParser::ParseDirectiveSymver(StringRef, SMLoc) {
758 StringRef Name;
759 if (getParser().parseIdentifier(Name))
760 return TokError("expected identifier in directive");
761
762 if (getLexer().isNot(AsmToken::Comma))
763 return TokError("expected a comma");
764
765 // ARM assembly uses @ for a comment...
766 // except when parsing the second parameter of the .symver directive.
767 // Force the next symbol to allow @ in the identifier, which is
768 // required for this directive and then reset it to its initial state.
769 const bool AllowAtInIdentifier = getLexer().getAllowAtInIdentifier();
770 getLexer().setAllowAtInIdentifier(true);
771 Lex();
772 getLexer().setAllowAtInIdentifier(AllowAtInIdentifier);
773
774 StringRef AliasName;
775 if (getParser().parseIdentifier(AliasName))
776 return TokError("expected identifier in directive");
777
778 if (AliasName.find('@') == StringRef::npos)
779 return TokError("expected a '@' in the name");
780
781 MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
782 getStreamer().emitELFSymverDirective(AliasName, Sym);
783 return false;
784 }
785
786 /// ParseDirectiveVersion
787 /// ::= .version string
ParseDirectiveVersion(StringRef,SMLoc)788 bool ELFAsmParser::ParseDirectiveVersion(StringRef, SMLoc) {
789 if (getLexer().isNot(AsmToken::String))
790 return TokError("unexpected token in '.version' directive");
791
792 StringRef Data = getTok().getIdentifier();
793
794 Lex();
795
796 MCSection *Note = getContext().getELFSection(".note", ELF::SHT_NOTE, 0);
797
798 getStreamer().PushSection();
799 getStreamer().SwitchSection(Note);
800 getStreamer().EmitIntValue(Data.size()+1, 4); // namesz.
801 getStreamer().EmitIntValue(0, 4); // descsz = 0 (no description).
802 getStreamer().EmitIntValue(1, 4); // type = NT_VERSION.
803 getStreamer().EmitBytes(Data); // name.
804 getStreamer().EmitIntValue(0, 1); // terminate the string.
805 getStreamer().EmitValueToAlignment(4); // ensure 4 byte alignment.
806 getStreamer().PopSection();
807 return false;
808 }
809
810 /// ParseDirectiveWeakref
811 /// ::= .weakref foo, bar
ParseDirectiveWeakref(StringRef,SMLoc)812 bool ELFAsmParser::ParseDirectiveWeakref(StringRef, SMLoc) {
813 // FIXME: Share code with the other alias building directives.
814
815 StringRef AliasName;
816 if (getParser().parseIdentifier(AliasName))
817 return TokError("expected identifier in directive");
818
819 if (getLexer().isNot(AsmToken::Comma))
820 return TokError("expected a comma");
821
822 Lex();
823
824 StringRef Name;
825 if (getParser().parseIdentifier(Name))
826 return TokError("expected identifier in directive");
827
828 MCSymbol *Alias = getContext().getOrCreateSymbol(AliasName);
829
830 MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
831
832 getStreamer().EmitWeakReference(Alias, Sym);
833 return false;
834 }
835
ParseDirectiveSubsection(StringRef,SMLoc)836 bool ELFAsmParser::ParseDirectiveSubsection(StringRef, SMLoc) {
837 const MCExpr *Subsection = nullptr;
838 if (getLexer().isNot(AsmToken::EndOfStatement)) {
839 if (getParser().parseExpression(Subsection))
840 return true;
841 }
842
843 if (getLexer().isNot(AsmToken::EndOfStatement))
844 return TokError("unexpected token in directive");
845
846 Lex();
847
848 getStreamer().SubSection(Subsection);
849 return false;
850 }
851
852 /// ParseDirectiveCGProfile
853 /// ::= .cg_profile identifier, identifier, <number>
ParseDirectiveCGProfile(StringRef,SMLoc)854 bool ELFAsmParser::ParseDirectiveCGProfile(StringRef, SMLoc) {
855 StringRef From;
856 SMLoc FromLoc = getLexer().getLoc();
857 if (getParser().parseIdentifier(From))
858 return TokError("expected identifier in directive");
859
860 if (getLexer().isNot(AsmToken::Comma))
861 return TokError("expected a comma");
862 Lex();
863
864 StringRef To;
865 SMLoc ToLoc = getLexer().getLoc();
866 if (getParser().parseIdentifier(To))
867 return TokError("expected identifier in directive");
868
869 if (getLexer().isNot(AsmToken::Comma))
870 return TokError("expected a comma");
871 Lex();
872
873 int64_t Count;
874 if (getParser().parseIntToken(
875 Count, "expected integer count in '.cg_profile' directive"))
876 return true;
877
878 if (getLexer().isNot(AsmToken::EndOfStatement))
879 return TokError("unexpected token in directive");
880
881 MCSymbol *FromSym = getContext().getOrCreateSymbol(From);
882 MCSymbol *ToSym = getContext().getOrCreateSymbol(To);
883
884 getStreamer().emitCGProfileEntry(
885 MCSymbolRefExpr::create(FromSym, MCSymbolRefExpr::VK_None, getContext(),
886 FromLoc),
887 MCSymbolRefExpr::create(ToSym, MCSymbolRefExpr::VK_None, getContext(),
888 ToLoc),
889 Count);
890 return false;
891 }
892
893 namespace llvm {
894
createELFAsmParser()895 MCAsmParserExtension *createELFAsmParser() {
896 return new ELFAsmParser;
897 }
898
899 } // end namespace llvm
900