llvm-6502/lib/MC/MCParser/ELFAsmParser.cpp
Rafael Espindola 484291c273 Implement .weakref.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117911 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-01 14:28:48 +00:00

481 lines
16 KiB
C++

//===- 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"
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);
public:
ELFAsmParser() {}
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::ParseDirectiveSize>(".size");
AddDirectiveHandler<&ELFAsmParser::ParseDirectivePrevious>(".previous");
AddDirectiveHandler<&ELFAsmParser::ParseDirectiveType>(".type");
AddDirectiveHandler<&ELFAsmParser::ParseDirectiveIdent>(".ident");
AddDirectiveHandler<&ELFAsmParser::ParseDirectiveSymver>(".symver");
AddDirectiveHandler<&ELFAsmParser::ParseDirectiveWeakref>(".weakref");
}
// 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", MCSectionELF::SHT_PROGBITS,
MCSectionELF::SHF_WRITE |MCSectionELF::SHF_ALLOC,
SectionKind::getDataRel());
}
bool ParseSectionDirectiveText(StringRef, SMLoc) {
return ParseSectionSwitch(".text", MCSectionELF::SHT_PROGBITS,
MCSectionELF::SHF_EXECINSTR |
MCSectionELF::SHF_ALLOC, SectionKind::getText());
}
bool ParseSectionDirectiveBSS(StringRef, SMLoc) {
return ParseSectionSwitch(".bss", MCSectionELF::SHT_NOBITS,
MCSectionELF::SHF_WRITE |
MCSectionELF::SHF_ALLOC, SectionKind::getBSS());
}
bool ParseSectionDirectiveRoData(StringRef, SMLoc) {
return ParseSectionSwitch(".rodata", MCSectionELF::SHT_PROGBITS,
MCSectionELF::SHF_ALLOC,
SectionKind::getReadOnly());
}
bool ParseSectionDirectiveTData(StringRef, SMLoc) {
return ParseSectionSwitch(".tdata", MCSectionELF::SHT_PROGBITS,
MCSectionELF::SHF_ALLOC |
MCSectionELF::SHF_TLS | MCSectionELF::SHF_WRITE,
SectionKind::getThreadData());
}
bool ParseSectionDirectiveTBSS(StringRef, SMLoc) {
return ParseSectionSwitch(".tbss", MCSectionELF::SHT_NOBITS,
MCSectionELF::SHF_ALLOC |
MCSectionELF::SHF_TLS | MCSectionELF::SHF_WRITE,
SectionKind::getThreadBSS());
}
bool ParseSectionDirectiveDataRel(StringRef, SMLoc) {
return ParseSectionSwitch(".data.rel", MCSectionELF::SHT_PROGBITS,
MCSectionELF::SHF_ALLOC |
MCSectionELF::SHF_WRITE,
SectionKind::getDataRel());
}
bool ParseSectionDirectiveDataRelRo(StringRef, SMLoc) {
return ParseSectionSwitch(".data.rel.ro", MCSectionELF::SHT_PROGBITS,
MCSectionELF::SHF_ALLOC |
MCSectionELF::SHF_WRITE,
SectionKind::getReadOnlyWithRel());
}
bool ParseSectionDirectiveDataRelRoLocal(StringRef, SMLoc) {
return ParseSectionSwitch(".data.rel.ro.local", MCSectionELF::SHT_PROGBITS,
MCSectionELF::SHF_ALLOC |
MCSectionELF::SHF_WRITE,
SectionKind::getReadOnlyWithRelLocal());
}
bool ParseSectionDirectiveEhFrame(StringRef, SMLoc) {
return ParseSectionSwitch(".eh_frame", MCSectionELF::SHT_PROGBITS,
MCSectionELF::SHF_ALLOC |
MCSectionELF::SHF_WRITE,
SectionKind::getDataRel());
}
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);
private:
bool ParseSectionName(StringRef &SectionName);
};
}
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;
for (;;) {
StringRef Tmp;
unsigned CurSize;
SMLoc PrevLoc = getLexer().getLoc();
if (getLexer().is(AsmToken::Minus)) {
CurSize = 1;
Lex(); // Consume the "-".
} else if (!getParser().ParseIdentifier(Tmp))
CurSize = Tmp.size();
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;
}
// FIXME: This is a work in progress.
bool ELFAsmParser::ParseDirectiveSection(StringRef, SMLoc) {
StringRef SectionName;
if (ParseSectionName(SectionName))
return TokError("expected identifier in directive");
StringRef FlagsStr;
StringRef TypeName;
int64_t Size = 0;
if (getLexer().is(AsmToken::Comma)) {
Lex();
if (getLexer().isNot(AsmToken::String))
return TokError("expected string in directive");
FlagsStr = getTok().getStringContents();
Lex();
AsmToken::TokenKind TypeStartToken;
if (getContext().getAsmInfo().getCommentString()[0] == '@')
TypeStartToken = AsmToken::Percent;
else
TypeStartToken = AsmToken::At;
bool Mergeable = FlagsStr.find('M') != StringRef::npos;
bool Group = FlagsStr.find('G') != StringRef::npos;
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(TypeStartToken))
return TokError("expected the 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();
StringRef GroupName;
if (getParser().ParseIdentifier(GroupName))
return true;
if (getLexer().is(AsmToken::Comma)) {
Lex();
StringRef Linkage;
if (getParser().ParseIdentifier(Linkage))
return true;
if (Linkage != "comdat" && Linkage != ".gnu.linkonce")
return TokError("Linkage must be 'comdat' or '.gnu.linkonce'");
}
}
}
}
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in directive");
unsigned Flags = 0;
unsigned Type = MCSectionELF::SHT_NULL;
// Set the defaults first.
if (SectionName == ".fini" || SectionName == ".init") {
Type = MCSectionELF::SHT_PROGBITS;
Flags |= MCSectionELF::SHF_ALLOC;
Flags |= MCSectionELF::SHF_EXECINSTR;
}
for (unsigned i = 0; i < FlagsStr.size(); i++) {
switch (FlagsStr[i]) {
case 'a':
Flags |= MCSectionELF::SHF_ALLOC;
break;
case 'x':
Flags |= MCSectionELF::SHF_EXECINSTR;
break;
case 'w':
Flags |= MCSectionELF::SHF_WRITE;
break;
case 'M':
Flags |= MCSectionELF::SHF_MERGE;
break;
case 'S':
Flags |= MCSectionELF::SHF_STRINGS;
break;
case 'T':
Flags |= MCSectionELF::SHF_TLS;
break;
case 'c':
Flags |= MCSectionELF::XCORE_SHF_CP_SECTION;
break;
case 'd':
Flags |= MCSectionELF::XCORE_SHF_DP_SECTION;
break;
case 'G':
break;
default:
return TokError("unknown flag");
}
}
if (!TypeName.empty()) {
if (TypeName == "init_array")
Type = MCSectionELF::SHT_INIT_ARRAY;
else if (TypeName == "fini_array")
Type = MCSectionELF::SHT_FINI_ARRAY;
else if (TypeName == "preinit_array")
Type = MCSectionELF::SHT_PREINIT_ARRAY;
else if (TypeName == "nobits")
Type = MCSectionELF::SHT_NOBITS;
else if (TypeName == "progbits")
Type = MCSectionELF::SHT_PROGBITS;
else
return TokError("unknown section type");
}
SectionKind Kind = (Flags & MCSectionELF::SHF_EXECINSTR)
? SectionKind::getText()
: SectionKind::getDataRel();
getStreamer().SwitchSection(getContext().getELFSection(SectionName, Type,
Flags, Kind, false,
Size));
return false;
}
bool ELFAsmParser::ParseDirectivePrevious(StringRef DirName, SMLoc) {
const MCSection *PreviousSection = getStreamer().getPreviousSection();
if (PreviousSection != NULL)
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::At))
return TokError("expected '@' 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)
.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 *OldSection = getStreamer().getCurrentSection();
const MCSection *Comment =
getContext().getELFSection(".comment", MCSectionELF::SHT_PROGBITS,
MCSectionELF::SHF_MERGE |
MCSectionELF::SHF_STRINGS,
SectionKind::getReadOnly(),
false, 1);
static bool First = true;
getStreamer().SwitchSection(Comment);
if (First)
getStreamer().EmitIntValue(0, 1);
First = false;
getStreamer().EmitBytes(Data, 0);
getStreamer().EmitIntValue(0, 1);
getStreamer().SwitchSection(OldSection);
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;
}
}