1 //===- ELFAsmParser.cpp - ELF Assembly Parser -----------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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"
23 class ELFAsmParser : public MCAsmParserExtension {
24 template<bool (ELFAsmParser::*Handler)(StringRef, SMLoc)>
25 void AddDirectiveHandler(StringRef Directive) {
26 getParser().AddDirectiveHandler(this, Directive,
27 HandleDirective<ELFAsmParser, Handler>);
30 bool ParseSectionSwitch(StringRef Section, unsigned Type,
31 unsigned Flags, SectionKind Kind);
36 virtual void Initialize(MCAsmParser &Parser) {
37 // Call the base implementation.
38 this->MCAsmParserExtension::Initialize(Parser);
40 AddDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveData>(".data");
41 AddDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveText>(".text");
42 AddDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveBSS>(".bss");
43 AddDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveRoData>(".rodata");
44 AddDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveTData>(".tdata");
45 AddDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveTBSS>(".tbss");
46 AddDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveDataRel>(".data.rel");
47 AddDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveDataRelRo>(".data.rel.ro");
48 AddDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveDataRelRoLocal>(".data.rel.ro.local");
49 AddDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveEhFrame>(".eh_frame");
50 AddDirectiveHandler<&ELFAsmParser::ParseDirectiveSection>(".section");
51 AddDirectiveHandler<&ELFAsmParser::ParseDirectiveSize>(".size");
52 AddDirectiveHandler<&ELFAsmParser::ParseDirectivePrevious>(".previous");
53 AddDirectiveHandler<&ELFAsmParser::ParseDirectiveType>(".type");
54 AddDirectiveHandler<&ELFAsmParser::ParseDirectiveIdent>(".ident");
55 AddDirectiveHandler<&ELFAsmParser::ParseDirectiveSymver>(".symver");
58 // FIXME: Part of this logic is duplicated in the MCELFStreamer. What is
59 // the best way for us to get access to it?
60 bool ParseSectionDirectiveData(StringRef, SMLoc) {
61 return ParseSectionSwitch(".data", MCSectionELF::SHT_PROGBITS,
62 MCSectionELF::SHF_WRITE |MCSectionELF::SHF_ALLOC,
63 SectionKind::getDataRel());
65 bool ParseSectionDirectiveText(StringRef, SMLoc) {
66 return ParseSectionSwitch(".text", MCSectionELF::SHT_PROGBITS,
67 MCSectionELF::SHF_EXECINSTR |
68 MCSectionELF::SHF_ALLOC, SectionKind::getText());
70 bool ParseSectionDirectiveBSS(StringRef, SMLoc) {
71 return ParseSectionSwitch(".bss", MCSectionELF::SHT_NOBITS,
72 MCSectionELF::SHF_WRITE |
73 MCSectionELF::SHF_ALLOC, SectionKind::getBSS());
75 bool ParseSectionDirectiveRoData(StringRef, SMLoc) {
76 return ParseSectionSwitch(".rodata", MCSectionELF::SHT_PROGBITS,
77 MCSectionELF::SHF_ALLOC,
78 SectionKind::getReadOnly());
80 bool ParseSectionDirectiveTData(StringRef, SMLoc) {
81 return ParseSectionSwitch(".tdata", MCSectionELF::SHT_PROGBITS,
82 MCSectionELF::SHF_ALLOC |
83 MCSectionELF::SHF_TLS | MCSectionELF::SHF_WRITE,
84 SectionKind::getThreadData());
86 bool ParseSectionDirectiveTBSS(StringRef, SMLoc) {
87 return ParseSectionSwitch(".tbss", MCSectionELF::SHT_NOBITS,
88 MCSectionELF::SHF_ALLOC |
89 MCSectionELF::SHF_TLS | MCSectionELF::SHF_WRITE,
90 SectionKind::getThreadBSS());
92 bool ParseSectionDirectiveDataRel(StringRef, SMLoc) {
93 return ParseSectionSwitch(".data.rel", MCSectionELF::SHT_PROGBITS,
94 MCSectionELF::SHF_ALLOC |
95 MCSectionELF::SHF_WRITE,
96 SectionKind::getDataRel());
98 bool ParseSectionDirectiveDataRelRo(StringRef, SMLoc) {
99 return ParseSectionSwitch(".data.rel.ro", MCSectionELF::SHT_PROGBITS,
100 MCSectionELF::SHF_ALLOC |
101 MCSectionELF::SHF_WRITE,
102 SectionKind::getReadOnlyWithRel());
104 bool ParseSectionDirectiveDataRelRoLocal(StringRef, SMLoc) {
105 return ParseSectionSwitch(".data.rel.ro.local", MCSectionELF::SHT_PROGBITS,
106 MCSectionELF::SHF_ALLOC |
107 MCSectionELF::SHF_WRITE,
108 SectionKind::getReadOnlyWithRelLocal());
110 bool ParseSectionDirectiveEhFrame(StringRef, SMLoc) {
111 return ParseSectionSwitch(".eh_frame", MCSectionELF::SHT_PROGBITS,
112 MCSectionELF::SHF_ALLOC |
113 MCSectionELF::SHF_WRITE,
114 SectionKind::getDataRel());
116 bool ParseDirectiveSection(StringRef, SMLoc);
117 bool ParseDirectiveSize(StringRef, SMLoc);
118 bool ParseDirectivePrevious(StringRef, SMLoc);
119 bool ParseDirectiveType(StringRef, SMLoc);
120 bool ParseDirectiveIdent(StringRef, SMLoc);
121 bool ParseDirectiveSymver(StringRef, SMLoc);
124 bool ParseSectionName(StringRef &SectionName);
129 bool ELFAsmParser::ParseSectionSwitch(StringRef Section, unsigned Type,
130 unsigned Flags, SectionKind Kind) {
131 if (getLexer().isNot(AsmToken::EndOfStatement))
132 return TokError("unexpected token in section switching directive");
135 getStreamer().SwitchSection(getContext().getELFSection(
136 Section, Type, Flags, Kind));
141 bool ELFAsmParser::ParseDirectiveSize(StringRef, SMLoc) {
143 if (getParser().ParseIdentifier(Name))
144 return TokError("expected identifier in directive");
145 MCSymbol *Sym = getContext().GetOrCreateSymbol(Name);;
147 if (getLexer().isNot(AsmToken::Comma))
148 return TokError("unexpected token in directive");
152 if (getParser().ParseExpression(Expr))
155 if (getLexer().isNot(AsmToken::EndOfStatement))
156 return TokError("unexpected token in directive");
158 getStreamer().EmitELFSize(Sym, Expr);
162 bool ELFAsmParser::ParseSectionName(StringRef &SectionName) {
163 // A section name can contain -, so we cannot just use
165 SMLoc FirstLoc = getLexer().getLoc();
172 SMLoc PrevLoc = getLexer().getLoc();
173 if (getLexer().is(AsmToken::Minus)) {
175 Lex(); // Consume the "-".
176 } else if (!getParser().ParseIdentifier(Tmp))
177 CurSize = Tmp.size();
182 SectionName = StringRef(FirstLoc.getPointer(), Size);
184 // Make sure the following token is adjacent.
185 if (PrevLoc.getPointer() + CurSize != getTok().getLoc().getPointer())
194 // FIXME: This is a work in progress.
195 bool ELFAsmParser::ParseDirectiveSection(StringRef, SMLoc) {
196 StringRef SectionName;
198 if (ParseSectionName(SectionName))
199 return TokError("expected identifier in directive");
201 std::string FlagsStr;
204 if (getLexer().is(AsmToken::Comma)) {
207 if (getLexer().isNot(AsmToken::String))
208 return TokError("expected string in directive");
210 FlagsStr = getTok().getStringContents();
213 AsmToken::TokenKind TypeStartToken;
214 if (getContext().getAsmInfo().getCommentString()[0] == '@')
215 TypeStartToken = AsmToken::Percent;
217 TypeStartToken = AsmToken::At;
219 if (getLexer().is(AsmToken::Comma)) {
221 if (getLexer().is(TypeStartToken)) {
223 if (getParser().ParseIdentifier(TypeName))
224 return TokError("expected identifier in directive");
226 if (getLexer().is(AsmToken::Comma)) {
229 if (getParser().ParseAbsoluteExpression(Size))
233 return TokError("section size must be positive");
239 if (getLexer().isNot(AsmToken::EndOfStatement))
240 return TokError("unexpected token in directive");
243 unsigned Type = MCSectionELF::SHT_NULL;
245 // Set the defaults first.
246 if (SectionName == ".fini" || SectionName == ".init") {
247 Type = MCSectionELF::SHT_PROGBITS;
248 Flags |= MCSectionELF::SHF_ALLOC;
249 Flags |= MCSectionELF::SHF_EXECINSTR;
252 for (unsigned i = 0; i < FlagsStr.size(); i++) {
253 switch (FlagsStr[i]) {
255 Flags |= MCSectionELF::SHF_ALLOC;
258 Flags |= MCSectionELF::SHF_EXECINSTR;
261 Flags |= MCSectionELF::SHF_WRITE;
264 Flags |= MCSectionELF::SHF_MERGE;
267 Flags |= MCSectionELF::SHF_STRINGS;
270 Flags |= MCSectionELF::SHF_TLS;
273 Flags |= MCSectionELF::XCORE_SHF_CP_SECTION;
276 Flags |= MCSectionELF::XCORE_SHF_DP_SECTION;
279 return TokError("unknown flag");
283 if (!TypeName.empty()) {
284 if (TypeName == "init_array")
285 Type = MCSectionELF::SHT_INIT_ARRAY;
286 else if (TypeName == "fini_array")
287 Type = MCSectionELF::SHT_FINI_ARRAY;
288 else if (TypeName == "preinit_array")
289 Type = MCSectionELF::SHT_PREINIT_ARRAY;
290 else if (TypeName == "nobits")
291 Type = MCSectionELF::SHT_NOBITS;
292 else if (TypeName == "progbits")
293 Type = MCSectionELF::SHT_PROGBITS;
295 return TokError("unknown section type");
298 SectionKind Kind = (Flags & MCSectionELF::SHF_EXECINSTR)
299 ? SectionKind::getText()
300 : SectionKind::getDataRel();
301 getStreamer().SwitchSection(getContext().getELFSection(SectionName, Type,
307 bool ELFAsmParser::ParseDirectivePrevious(StringRef DirName, SMLoc) {
308 const MCSection *PreviousSection = getStreamer().getPreviousSection();
309 if (PreviousSection != NULL)
310 getStreamer().SwitchSection(PreviousSection);
315 /// ParseDirectiveELFType
316 /// ::= .type identifier , @attribute
317 bool ELFAsmParser::ParseDirectiveType(StringRef, SMLoc) {
319 if (getParser().ParseIdentifier(Name))
320 return TokError("expected identifier in directive");
322 // Handle the identifier as the key symbol.
323 MCSymbol *Sym = getContext().GetOrCreateSymbol(Name);
325 if (getLexer().isNot(AsmToken::Comma))
326 return TokError("unexpected token in '.type' directive");
329 if (getLexer().isNot(AsmToken::At))
330 return TokError("expected '@' before type");
336 TypeLoc = getLexer().getLoc();
337 if (getParser().ParseIdentifier(Type))
338 return TokError("expected symbol type in directive");
340 MCSymbolAttr Attr = StringSwitch<MCSymbolAttr>(Type)
341 .Case("function", MCSA_ELF_TypeFunction)
342 .Case("object", MCSA_ELF_TypeObject)
343 .Case("tls_object", MCSA_ELF_TypeTLS)
344 .Case("common", MCSA_ELF_TypeCommon)
345 .Case("notype", MCSA_ELF_TypeNoType)
346 .Default(MCSA_Invalid);
348 if (Attr == MCSA_Invalid)
349 return Error(TypeLoc, "unsupported attribute in '.type' directive");
351 if (getLexer().isNot(AsmToken::EndOfStatement))
352 return TokError("unexpected token in '.type' directive");
356 getStreamer().EmitSymbolAttribute(Sym, Attr);
361 /// ParseDirectiveIdent
362 /// ::= .ident string
363 bool ELFAsmParser::ParseDirectiveIdent(StringRef, SMLoc) {
364 if (getLexer().isNot(AsmToken::String))
365 return TokError("unexpected token in '.ident' directive");
367 StringRef Data = getTok().getIdentifier();
371 const MCSection *OldSection = getStreamer().getCurrentSection();
372 const MCSection *Comment =
373 getContext().getELFSection(".comment", MCSectionELF::SHT_PROGBITS,
374 MCSectionELF::SHF_MERGE |
375 MCSectionELF::SHF_STRINGS,
376 SectionKind::getReadOnly(),
379 static bool First = true;
381 getStreamer().SwitchSection(Comment);
383 getStreamer().EmitIntValue(0, 1);
385 getStreamer().EmitBytes(Data, 0);
386 getStreamer().EmitIntValue(0, 1);
387 getStreamer().SwitchSection(OldSection);
391 /// ParseDirectiveSymver
392 /// ::= .symver foo, bar2@zed
393 bool ELFAsmParser::ParseDirectiveSymver(StringRef, SMLoc) {
395 if (getParser().ParseIdentifier(Name))
396 return TokError("expected identifier in directive");
398 if (getLexer().isNot(AsmToken::Comma))
399 return TokError("expected a comma");
404 if (getParser().ParseIdentifier(AliasName))
405 return TokError("expected identifier in directive");
407 if (AliasName.find('@') == StringRef::npos)
408 return TokError("expected a '@' in the name");
410 MCSymbol *Alias = getContext().GetOrCreateSymbol(AliasName);
411 MCSymbol *Sym = getContext().GetOrCreateSymbol(Name);
412 const MCExpr *Value = MCSymbolRefExpr::Create(Sym, getContext());
414 getStreamer().EmitAssignment(Alias, Value);
420 MCAsmParserExtension *createELFAsmParser() {
421 return new ELFAsmParser;