| //===- ELFAsmParser.cpp - ELF Assembly Parser -----------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/MC/MCParser/MCAsmParserExtension.h" |
| #include "llvm/ADT/StringSwitch.h" |
| #include "llvm/ADT/Twine.h" |
| #include "llvm/MC/MCAsmInfo.h" |
| #include "llvm/MC/MCContext.h" |
| #include "llvm/MC/MCExpr.h" |
| #include "llvm/MC/MCParser/MCAsmLexer.h" |
| #include "llvm/MC/MCSectionELF.h" |
| #include "llvm/MC/MCStreamer.h" |
| #include "llvm/Support/ELF.h" |
| using namespace llvm; |
| |
| namespace { |
| |
| class ELFAsmParser : public MCAsmParserExtension { |
| template<bool (ELFAsmParser::*Handler)(StringRef, SMLoc)> |
| void AddDirectiveHandler(StringRef Directive) { |
| getParser().AddDirectiveHandler(this, Directive, |
| HandleDirective<ELFAsmParser, Handler>); |
| } |
| |
| bool ParseSectionSwitch(StringRef Section, unsigned Type, |
| unsigned Flags, SectionKind Kind); |
| bool SeenIdent; |
| |
| public: |
| ELFAsmParser() : SeenIdent(false) { |
| BracketExpressionsSupported = true; |
| } |
| |
| virtual void Initialize(MCAsmParser &Parser) { |
| // Call the base implementation. |
| this->MCAsmParserExtension::Initialize(Parser); |
| |
| AddDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveData>(".data"); |
| AddDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveText>(".text"); |
| AddDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveBSS>(".bss"); |
| AddDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveRoData>(".rodata"); |
| AddDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveTData>(".tdata"); |
| AddDirectiveHandler<&ELFAsmParser::ParseSectionDirectiveTBSS>(".tbss"); |
| AddDirectiveHandler< |
| &ELFAsmParser::ParseSectionDirectiveDataRel>(".data.rel"); |
| AddDirectiveHandler< |
| &ELFAsmParser::ParseSectionDirectiveDataRelRo>(".data.rel.ro"); |
| AddDirectiveHandler< |
| &ELFAsmParser::ParseSectionDirectiveDataRelRoLocal>(".data.rel.ro.local"); |
| AddDirectiveHandler< |
| &ELFAsmParser::ParseSectionDirectiveEhFrame>(".eh_frame"); |
| AddDirectiveHandler<&ELFAsmParser::ParseDirectiveSection>(".section"); |
| AddDirectiveHandler< |
| &ELFAsmParser::ParseDirectivePushSection>(".pushsection"); |
| AddDirectiveHandler<&ELFAsmParser::ParseDirectivePopSection>(".popsection"); |
| AddDirectiveHandler<&ELFAsmParser::ParseDirectiveSize>(".size"); |
| AddDirectiveHandler<&ELFAsmParser::ParseDirectivePrevious>(".previous"); |
| AddDirectiveHandler<&ELFAsmParser::ParseDirectiveType>(".type"); |
| AddDirectiveHandler<&ELFAsmParser::ParseDirectiveIdent>(".ident"); |
| AddDirectiveHandler<&ELFAsmParser::ParseDirectiveSymver>(".symver"); |
| AddDirectiveHandler<&ELFAsmParser::ParseDirectiveWeakref>(".weakref"); |
| AddDirectiveHandler<&ELFAsmParser::ParseDirectiveSymbolAttribute>(".weak"); |
| AddDirectiveHandler<&ELFAsmParser::ParseDirectiveSymbolAttribute>(".local"); |
| AddDirectiveHandler< |
| &ELFAsmParser::ParseDirectiveSymbolAttribute>(".protected"); |
| AddDirectiveHandler< |
| &ELFAsmParser::ParseDirectiveSymbolAttribute>(".internal"); |
| AddDirectiveHandler< |
| &ELFAsmParser::ParseDirectiveSymbolAttribute>(".hidden"); |
| } |
| |
| // FIXME: Part of this logic is duplicated in the MCELFStreamer. What is |
| // the best way for us to get access to it? |
| bool ParseSectionDirectiveData(StringRef, SMLoc) { |
| return ParseSectionSwitch(".data", ELF::SHT_PROGBITS, |
| ELF::SHF_WRITE |ELF::SHF_ALLOC, |
| SectionKind::getDataRel()); |
| } |
| bool ParseSectionDirectiveText(StringRef, SMLoc) { |
| return ParseSectionSwitch(".text", ELF::SHT_PROGBITS, |
| ELF::SHF_EXECINSTR | |
| ELF::SHF_ALLOC, SectionKind::getText()); |
| } |
| bool ParseSectionDirectiveBSS(StringRef, SMLoc) { |
| return ParseSectionSwitch(".bss", ELF::SHT_NOBITS, |
| ELF::SHF_WRITE | |
| ELF::SHF_ALLOC, SectionKind::getBSS()); |
| } |
| bool ParseSectionDirectiveRoData(StringRef, SMLoc) { |
| return ParseSectionSwitch(".rodata", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC, |
| SectionKind::getReadOnly()); |
| } |
| bool ParseSectionDirectiveTData(StringRef, SMLoc) { |
| return ParseSectionSwitch(".tdata", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC | |
| ELF::SHF_TLS | ELF::SHF_WRITE, |
| SectionKind::getThreadData()); |
| } |
| bool ParseSectionDirectiveTBSS(StringRef, SMLoc) { |
| return ParseSectionSwitch(".tbss", ELF::SHT_NOBITS, |
| ELF::SHF_ALLOC | |
| ELF::SHF_TLS | ELF::SHF_WRITE, |
| SectionKind::getThreadBSS()); |
| } |
| bool ParseSectionDirectiveDataRel(StringRef, SMLoc) { |
| return ParseSectionSwitch(".data.rel", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC | |
| ELF::SHF_WRITE, |
| SectionKind::getDataRel()); |
| } |
| bool ParseSectionDirectiveDataRelRo(StringRef, SMLoc) { |
| return ParseSectionSwitch(".data.rel.ro", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC | |
| ELF::SHF_WRITE, |
| SectionKind::getReadOnlyWithRel()); |
| } |
| bool ParseSectionDirectiveDataRelRoLocal(StringRef, SMLoc) { |
| return ParseSectionSwitch(".data.rel.ro.local", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC | |
| ELF::SHF_WRITE, |
| SectionKind::getReadOnlyWithRelLocal()); |
| } |
| bool ParseSectionDirectiveEhFrame(StringRef, SMLoc) { |
| return ParseSectionSwitch(".eh_frame", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC | |
| ELF::SHF_WRITE, |
| SectionKind::getDataRel()); |
| } |
| bool ParseDirectivePushSection(StringRef, SMLoc); |
| bool ParseDirectivePopSection(StringRef, SMLoc); |
| bool ParseDirectiveSection(StringRef, SMLoc); |
| bool ParseDirectiveSize(StringRef, SMLoc); |
| bool ParseDirectivePrevious(StringRef, SMLoc); |
| bool ParseDirectiveType(StringRef, SMLoc); |
| bool ParseDirectiveIdent(StringRef, SMLoc); |
| bool ParseDirectiveSymver(StringRef, SMLoc); |
| bool ParseDirectiveWeakref(StringRef, SMLoc); |
| bool ParseDirectiveSymbolAttribute(StringRef, SMLoc); |
| |
| private: |
| bool ParseSectionName(StringRef &SectionName); |
| }; |
| |
| } |
| |
| /// ParseDirectiveSymbolAttribute |
| /// ::= { ".local", ".weak", ... } [ identifier ( , identifier )* ] |
| bool ELFAsmParser::ParseDirectiveSymbolAttribute(StringRef Directive, SMLoc) { |
| MCSymbolAttr Attr = StringSwitch<MCSymbolAttr>(Directive) |
| .Case(".weak", MCSA_Weak) |
| .Case(".local", MCSA_Local) |
| .Case(".hidden", MCSA_Hidden) |
| .Case(".internal", MCSA_Internal) |
| .Case(".protected", MCSA_Protected) |
| .Default(MCSA_Invalid); |
| assert(Attr != MCSA_Invalid && "unexpected symbol attribute directive!"); |
| if (getLexer().isNot(AsmToken::EndOfStatement)) { |
| for (;;) { |
| StringRef Name; |
| |
| if (getParser().ParseIdentifier(Name)) |
| return TokError("expected identifier in directive"); |
| |
| MCSymbol *Sym = getContext().GetOrCreateSymbol(Name); |
| |
| getStreamer().EmitSymbolAttribute(Sym, Attr); |
| |
| if (getLexer().is(AsmToken::EndOfStatement)) |
| break; |
| |
| if (getLexer().isNot(AsmToken::Comma)) |
| return TokError("unexpected token in directive"); |
| Lex(); |
| } |
| } |
| |
| Lex(); |
| return false; |
| } |
| |
| bool ELFAsmParser::ParseSectionSwitch(StringRef Section, unsigned Type, |
| unsigned Flags, SectionKind Kind) { |
| if (getLexer().isNot(AsmToken::EndOfStatement)) |
| return TokError("unexpected token in section switching directive"); |
| Lex(); |
| |
| getStreamer().SwitchSection(getContext().getELFSection( |
| Section, Type, Flags, Kind)); |
| |
| return false; |
| } |
| |
| bool ELFAsmParser::ParseDirectiveSize(StringRef, SMLoc) { |
| StringRef Name; |
| if (getParser().ParseIdentifier(Name)) |
| return TokError("expected identifier in directive"); |
| MCSymbol *Sym = getContext().GetOrCreateSymbol(Name);; |
| |
| if (getLexer().isNot(AsmToken::Comma)) |
| return TokError("unexpected token in directive"); |
| Lex(); |
| |
| const MCExpr *Expr; |
| if (getParser().ParseExpression(Expr)) |
| return true; |
| |
| if (getLexer().isNot(AsmToken::EndOfStatement)) |
| return TokError("unexpected token in directive"); |
| |
| getStreamer().EmitELFSize(Sym, Expr); |
| return false; |
| } |
| |
| bool ELFAsmParser::ParseSectionName(StringRef &SectionName) { |
| // A section name can contain -, so we cannot just use |
| // ParseIdentifier. |
| SMLoc FirstLoc = getLexer().getLoc(); |
| unsigned Size = 0; |
| |
| if (getLexer().is(AsmToken::String)) { |
| SectionName = getTok().getIdentifier(); |
| Lex(); |
| return false; |
| } |
| |
| for (;;) { |
| StringRef Tmp; |
| unsigned CurSize; |
| |
| SMLoc PrevLoc = getLexer().getLoc(); |
| if (getLexer().is(AsmToken::Minus)) { |
| CurSize = 1; |
| Lex(); // Consume the "-". |
| } else if (getLexer().is(AsmToken::String)) { |
| CurSize = getTok().getIdentifier().size() + 2; |
| Lex(); |
| } else if (getLexer().is(AsmToken::Identifier)) { |
| CurSize = getTok().getIdentifier().size(); |
| Lex(); |
| } else { |
| break; |
| } |
| |
| Size += CurSize; |
| SectionName = StringRef(FirstLoc.getPointer(), Size); |
| |
| // Make sure the following token is adjacent. |
| if (PrevLoc.getPointer() + CurSize != getTok().getLoc().getPointer()) |
| break; |
| } |
| if (Size == 0) |
| return true; |
| |
| return false; |
| } |
| |
| static SectionKind computeSectionKind(unsigned Flags) { |
| if (Flags & ELF::SHF_EXECINSTR) |
| return SectionKind::getText(); |
| if (Flags & ELF::SHF_TLS) |
| return SectionKind::getThreadData(); |
| return SectionKind::getDataRel(); |
| } |
| |
| static int parseSectionFlags(StringRef flagsStr) { |
| int flags = 0; |
| |
| for (unsigned i = 0; i < flagsStr.size(); i++) { |
| switch (flagsStr[i]) { |
| case 'a': |
| flags |= ELF::SHF_ALLOC; |
| break; |
| case 'x': |
| flags |= ELF::SHF_EXECINSTR; |
| break; |
| case 'w': |
| flags |= ELF::SHF_WRITE; |
| break; |
| case 'M': |
| flags |= ELF::SHF_MERGE; |
| break; |
| case 'S': |
| flags |= ELF::SHF_STRINGS; |
| break; |
| case 'T': |
| flags |= ELF::SHF_TLS; |
| break; |
| case 'c': |
| flags |= ELF::XCORE_SHF_CP_SECTION; |
| break; |
| case 'd': |
| flags |= ELF::XCORE_SHF_DP_SECTION; |
| break; |
| case 'G': |
| flags |= ELF::SHF_GROUP; |
| break; |
| default: |
| return -1; |
| } |
| } |
| |
| return flags; |
| } |
| |
| bool ELFAsmParser::ParseDirectivePushSection(StringRef s, SMLoc loc) { |
| getStreamer().PushSection(); |
| |
| if (ParseDirectiveSection(s, loc)) { |
| getStreamer().PopSection(); |
| return true; |
| } |
| |
| return false; |
| } |
| |
| bool ELFAsmParser::ParseDirectivePopSection(StringRef, SMLoc) { |
| if (!getStreamer().PopSection()) |
| return TokError(".popsection without corresponding .pushsection"); |
| return false; |
| } |
| |
| // FIXME: This is a work in progress. |
| bool ELFAsmParser::ParseDirectiveSection(StringRef, SMLoc) { |
| StringRef SectionName; |
| |
| if (ParseSectionName(SectionName)) |
| return TokError("expected identifier in directive"); |
| |
| StringRef TypeName; |
| int64_t Size = 0; |
| StringRef GroupName; |
| unsigned Flags = 0; |
| |
| // Set the defaults first. |
| if (SectionName == ".fini" || SectionName == ".init" || |
| SectionName == ".rodata") |
| Flags |= ELF::SHF_ALLOC; |
| if (SectionName == ".fini" || SectionName == ".init") |
| Flags |= ELF::SHF_EXECINSTR; |
| |
| if (getLexer().is(AsmToken::Comma)) { |
| Lex(); |
| |
| if (getLexer().isNot(AsmToken::String)) |
| return TokError("expected string in directive"); |
| |
| StringRef FlagsStr = getTok().getStringContents(); |
| Lex(); |
| |
| int extraFlags = parseSectionFlags(FlagsStr); |
| if (extraFlags < 0) |
| return TokError("unknown flag"); |
| Flags |= extraFlags; |
| |
| bool Mergeable = Flags & ELF::SHF_MERGE; |
| bool Group = Flags & ELF::SHF_GROUP; |
| |
| if (getLexer().isNot(AsmToken::Comma)) { |
| if (Mergeable) |
| return TokError("Mergeable section must specify the type"); |
| if (Group) |
| return TokError("Group section must specify the type"); |
| } else { |
| Lex(); |
| if (getLexer().isNot(AsmToken::Percent) && getLexer().isNot(AsmToken::At)) |
| return TokError("expected '@' or '%' before type"); |
| |
| Lex(); |
| if (getParser().ParseIdentifier(TypeName)) |
| return TokError("expected identifier in directive"); |
| |
| if (Mergeable) { |
| if (getLexer().isNot(AsmToken::Comma)) |
| return TokError("expected the entry size"); |
| Lex(); |
| if (getParser().ParseAbsoluteExpression(Size)) |
| return true; |
| if (Size <= 0) |
| return TokError("entry size must be positive"); |
| } |
| |
| if (Group) { |
| if (getLexer().isNot(AsmToken::Comma)) |
| return TokError("expected group name"); |
| Lex(); |
| if (getParser().ParseIdentifier(GroupName)) |
| return true; |
| if (getLexer().is(AsmToken::Comma)) { |
| Lex(); |
| StringRef Linkage; |
| if (getParser().ParseIdentifier(Linkage)) |
| return true; |
| if (Linkage != "comdat") |
| return TokError("Linkage must be 'comdat'"); |
| } |
| } |
| } |
| } |
| |
| if (getLexer().isNot(AsmToken::EndOfStatement)) |
| return TokError("unexpected token in directive"); |
| |
| unsigned Type = ELF::SHT_PROGBITS; |
| |
| if (!TypeName.empty()) { |
| if (TypeName == "init_array") |
| Type = ELF::SHT_INIT_ARRAY; |
| else if (TypeName == "fini_array") |
| Type = ELF::SHT_FINI_ARRAY; |
| else if (TypeName == "preinit_array") |
| Type = ELF::SHT_PREINIT_ARRAY; |
| else if (TypeName == "nobits") |
| Type = ELF::SHT_NOBITS; |
| else if (TypeName == "progbits") |
| Type = ELF::SHT_PROGBITS; |
| else if (TypeName == "note") |
| Type = ELF::SHT_NOTE; |
| else if (TypeName == "unwind") |
| Type = ELF::SHT_X86_64_UNWIND; |
| else |
| return TokError("unknown section type"); |
| } |
| |
| SectionKind Kind = computeSectionKind(Flags); |
| getStreamer().SwitchSection(getContext().getELFSection(SectionName, Type, |
| Flags, Kind, Size, |
| GroupName)); |
| return false; |
| } |
| |
| bool ELFAsmParser::ParseDirectivePrevious(StringRef DirName, SMLoc) { |
| const MCSection *PreviousSection = getStreamer().getPreviousSection(); |
| if (PreviousSection == NULL) |
| return TokError(".previous without corresponding .section"); |
| getStreamer().SwitchSection(PreviousSection); |
| |
| return false; |
| } |
| |
| /// ParseDirectiveELFType |
| /// ::= .type identifier , @attribute |
| bool ELFAsmParser::ParseDirectiveType(StringRef, SMLoc) { |
| StringRef Name; |
| if (getParser().ParseIdentifier(Name)) |
| return TokError("expected identifier in directive"); |
| |
| // Handle the identifier as the key symbol. |
| MCSymbol *Sym = getContext().GetOrCreateSymbol(Name); |
| |
| if (getLexer().isNot(AsmToken::Comma)) |
| return TokError("unexpected token in '.type' directive"); |
| Lex(); |
| |
| if (getLexer().isNot(AsmToken::Percent) && getLexer().isNot(AsmToken::At)) |
| return TokError("expected '@' or '%' before type"); |
| Lex(); |
| |
| StringRef Type; |
| SMLoc TypeLoc; |
| |
| TypeLoc = getLexer().getLoc(); |
| if (getParser().ParseIdentifier(Type)) |
| return TokError("expected symbol type in directive"); |
| |
| MCSymbolAttr Attr = StringSwitch<MCSymbolAttr>(Type) |
| .Case("function", MCSA_ELF_TypeFunction) |
| .Case("object", MCSA_ELF_TypeObject) |
| .Case("tls_object", MCSA_ELF_TypeTLS) |
| .Case("common", MCSA_ELF_TypeCommon) |
| .Case("notype", MCSA_ELF_TypeNoType) |
| .Case("gnu_unique_object", MCSA_ELF_TypeGnuUniqueObject) |
| .Default(MCSA_Invalid); |
| |
| if (Attr == MCSA_Invalid) |
| return Error(TypeLoc, "unsupported attribute in '.type' directive"); |
| |
| if (getLexer().isNot(AsmToken::EndOfStatement)) |
| return TokError("unexpected token in '.type' directive"); |
| |
| Lex(); |
| |
| getStreamer().EmitSymbolAttribute(Sym, Attr); |
| |
| return false; |
| } |
| |
| /// ParseDirectiveIdent |
| /// ::= .ident string |
| bool ELFAsmParser::ParseDirectiveIdent(StringRef, SMLoc) { |
| if (getLexer().isNot(AsmToken::String)) |
| return TokError("unexpected token in '.ident' directive"); |
| |
| StringRef Data = getTok().getIdentifier(); |
| |
| Lex(); |
| |
| const MCSection *Comment = |
| getContext().getELFSection(".comment", ELF::SHT_PROGBITS, |
| ELF::SHF_MERGE | |
| ELF::SHF_STRINGS, |
| SectionKind::getReadOnly(), |
| 1, ""); |
| |
| getStreamer().PushSection(); |
| getStreamer().SwitchSection(Comment); |
| if (!SeenIdent) { |
| getStreamer().EmitIntValue(0, 1); |
| SeenIdent = true; |
| } |
| getStreamer().EmitBytes(Data, 0); |
| getStreamer().EmitIntValue(0, 1); |
| getStreamer().PopSection(); |
| return false; |
| } |
| |
| /// ParseDirectiveSymver |
| /// ::= .symver foo, bar2@zed |
| bool ELFAsmParser::ParseDirectiveSymver(StringRef, SMLoc) { |
| StringRef Name; |
| if (getParser().ParseIdentifier(Name)) |
| return TokError("expected identifier in directive"); |
| |
| if (getLexer().isNot(AsmToken::Comma)) |
| return TokError("expected a comma"); |
| |
| Lex(); |
| |
| StringRef AliasName; |
| if (getParser().ParseIdentifier(AliasName)) |
| return TokError("expected identifier in directive"); |
| |
| if (AliasName.find('@') == StringRef::npos) |
| return TokError("expected a '@' in the name"); |
| |
| MCSymbol *Alias = getContext().GetOrCreateSymbol(AliasName); |
| MCSymbol *Sym = getContext().GetOrCreateSymbol(Name); |
| const MCExpr *Value = MCSymbolRefExpr::Create(Sym, getContext()); |
| |
| getStreamer().EmitAssignment(Alias, Value); |
| return false; |
| } |
| |
| /// ParseDirectiveWeakref |
| /// ::= .weakref foo, bar |
| bool ELFAsmParser::ParseDirectiveWeakref(StringRef, SMLoc) { |
| // FIXME: Share code with the other alias building directives. |
| |
| StringRef AliasName; |
| if (getParser().ParseIdentifier(AliasName)) |
| return TokError("expected identifier in directive"); |
| |
| if (getLexer().isNot(AsmToken::Comma)) |
| return TokError("expected a comma"); |
| |
| Lex(); |
| |
| StringRef Name; |
| if (getParser().ParseIdentifier(Name)) |
| return TokError("expected identifier in directive"); |
| |
| MCSymbol *Alias = getContext().GetOrCreateSymbol(AliasName); |
| |
| MCSymbol *Sym = getContext().GetOrCreateSymbol(Name); |
| |
| getStreamer().EmitWeakReference(Alias, Sym); |
| return false; |
| } |
| |
| namespace llvm { |
| |
| MCAsmParserExtension *createELFAsmParser() { |
| return new ELFAsmParser; |
| } |
| |
| } |
