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llvm-mirror/lib/MC/MCParser/ELFAsmParser.cpp
Nirav Dave 43bf7a6963 [MC] Cleanup Error Handling in AsmParser 
Add parseToken and compatriot functions to stitch error checks in
straight linear code. As part of this fix some erronous handling of
directives where the EndOfStatement token either was not checked or
Lexed on termination.

Reviewers: rnk, majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D22312

llvm-svn: 275795
2016-07-18 15:24:03 +00:00

749 lines
24 KiB
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//===- 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/MC/MCSymbolELF.h"
#include "llvm/Support/ELF.h"
using namespace llvm;
namespace {
class ELFAsmParser : public MCAsmParserExtension {
template<bool (ELFAsmParser::*HandlerMethod)(StringRef, SMLoc)>
void addDirectiveHandler(StringRef Directive) {
MCAsmParser::ExtensionDirectiveHandler Handler = std::make_pair(
this, HandleDirective<ELFAsmParser, HandlerMethod>);
getParser().addDirectiveHandler(Directive, Handler);
}
bool ParseSectionSwitch(StringRef Section, unsigned Type, unsigned Flags,
SectionKind Kind);
public:
ELFAsmParser() { BracketExpressionsSupported = true; }
void Initialize(MCAsmParser &Parser) override {
// 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::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::ParseDirectiveVersion>(".version");
addDirectiveHandler<&ELFAsmParser::ParseDirectiveWeakref>(".weakref");
addDirectiveHandler<&ELFAsmParser::ParseDirectiveSymbolAttribute>(".weak");
addDirectiveHandler<&ELFAsmParser::ParseDirectiveSymbolAttribute>(".local");
addDirectiveHandler<
&ELFAsmParser::ParseDirectiveSymbolAttribute>(".protected");
addDirectiveHandler<
&ELFAsmParser::ParseDirectiveSymbolAttribute>(".internal");
addDirectiveHandler<
&ELFAsmParser::ParseDirectiveSymbolAttribute>(".hidden");
addDirectiveHandler<&ELFAsmParser::ParseDirectiveSubsection>(".subsection");
}
// 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::getData());
}
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::getData());
}
bool ParseSectionDirectiveDataRelRo(StringRef, SMLoc) {
return ParseSectionSwitch(".data.rel.ro", ELF::SHT_PROGBITS,
ELF::SHF_ALLOC |
ELF::SHF_WRITE,
SectionKind::getReadOnlyWithRel());
}
bool ParseSectionDirectiveEhFrame(StringRef, SMLoc) {
return ParseSectionSwitch(".eh_frame", ELF::SHT_PROGBITS,
ELF::SHF_ALLOC | ELF::SHF_WRITE,
SectionKind::getData());
}
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 ParseDirectiveVersion(StringRef, SMLoc);
bool ParseDirectiveWeakref(StringRef, SMLoc);
bool ParseDirectiveSymbolAttribute(StringRef, SMLoc);
bool ParseDirectiveSubsection(StringRef, SMLoc);
private:
bool ParseSectionName(StringRef &SectionName);
bool ParseSectionArguments(bool IsPush, SMLoc loc);
unsigned parseSunStyleSectionFlags();
};
}
/// 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) {
const MCExpr *Subsection = nullptr;
if (getLexer().isNot(AsmToken::EndOfStatement)) {
if (getParser().parseExpression(Subsection))
return true;
}
Lex();
getStreamer().SwitchSection(getContext().getELFSection(Section, Type, Flags),
Subsection);
return false;
}
bool ELFAsmParser::ParseDirectiveSize(StringRef, SMLoc) {
StringRef Name;
if (getParser().parseIdentifier(Name))
return TokError("expected identifier in directive");
MCSymbolELF *Sym = cast<MCSymbolELF>(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");
Lex();
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 (;;) {
SMLoc PrevLoc = getLexer().getLoc();
if (getLexer().is(AsmToken::Comma) ||
getLexer().is(AsmToken::EndOfStatement))
break;
unsigned CurSize;
if (getLexer().is(AsmToken::String)) {
CurSize = getTok().getIdentifier().size() + 2;
Lex();
} else if (getLexer().is(AsmToken::Identifier)) {
CurSize = getTok().getIdentifier().size();
Lex();
} else {
CurSize = getTok().getString().size();
Lex();
}
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 unsigned parseSectionFlags(StringRef flagsStr, bool *UseLastGroup) {
unsigned flags = 0;
for (char i : flagsStr) {
switch (i) {
case 'a':
flags |= ELF::SHF_ALLOC;
break;
case 'e':
flags |= ELF::SHF_EXCLUDE;
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;
case '?':
*UseLastGroup = true;
break;
default:
return -1U;
}
}
return flags;
}
unsigned ELFAsmParser::parseSunStyleSectionFlags() {
unsigned flags = 0;
while (getLexer().is(AsmToken::Hash)) {
Lex(); // Eat the #.
if (!getLexer().is(AsmToken::Identifier))
return -1U;
StringRef flagId = getTok().getIdentifier();
if (flagId == "alloc")
flags |= ELF::SHF_ALLOC;
else if (flagId == "execinstr")
flags |= ELF::SHF_EXECINSTR;
else if (flagId == "write")
flags |= ELF::SHF_WRITE;
else if (flagId == "tls")
flags |= ELF::SHF_TLS;
else
return -1U;
Lex(); // Eat the flag.
if (!getLexer().is(AsmToken::Comma))
break;
Lex(); // Eat the comma.
}
return flags;
}
bool ELFAsmParser::ParseDirectivePushSection(StringRef s, SMLoc loc) {
getStreamer().PushSection();
if (ParseSectionArguments(/*IsPush=*/true, 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 loc) {
return ParseSectionArguments(/*IsPush=*/false, loc);
}
bool ELFAsmParser::ParseSectionArguments(bool IsPush, SMLoc loc) {
StringRef SectionName;
if (ParseSectionName(SectionName))
return TokError("expected identifier in directive");
StringRef TypeName;
int64_t Size = 0;
StringRef GroupName;
unsigned Flags = 0;
const MCExpr *Subsection = nullptr;
bool UseLastGroup = false;
StringRef UniqueStr;
int64_t UniqueID = ~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 (IsPush && getLexer().isNot(AsmToken::String)) {
if (getParser().parseExpression(Subsection))
return true;
if (getLexer().isNot(AsmToken::Comma))
goto EndStmt;
Lex();
}
unsigned extraFlags;
if (getLexer().isNot(AsmToken::String)) {
if (!getContext().getAsmInfo()->usesSunStyleELFSectionSwitchSyntax()
|| getLexer().isNot(AsmToken::Hash))
return TokError("expected string in directive");
extraFlags = parseSunStyleSectionFlags();
} else {
StringRef FlagsStr = getTok().getStringContents();
Lex();
extraFlags = parseSectionFlags(FlagsStr, &UseLastGroup);
}
if (extraFlags == -1U)
return TokError("unknown flag");
Flags |= extraFlags;
bool Mergeable = Flags & ELF::SHF_MERGE;
bool Group = Flags & ELF::SHF_GROUP;
if (Group && UseLastGroup)
return TokError("Section cannot specifiy a group name while also acting "
"as a member of the last 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().is(AsmToken::At) || getLexer().is(AsmToken::Percent) ||
getLexer().is(AsmToken::String)) {
if (!getLexer().is(AsmToken::String))
Lex();
} else
return TokError("expected '@<type>', '%<type>' or \"<type>\"");
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().is(AsmToken::Comma)) {
Lex();
if (getParser().parseIdentifier(UniqueStr))
return TokError("expected identifier in directive");
if (UniqueStr != "unique")
return TokError("expected 'unique'");
if (getLexer().isNot(AsmToken::Comma))
return TokError("expected commma");
Lex();
if (getParser().parseAbsoluteExpression(UniqueID))
return true;
if (UniqueID < 0)
return TokError("unique id must be positive");
if (!isUInt<32>(UniqueID) || UniqueID == ~0U)
return TokError("unique id is too large");
}
}
}
EndStmt:
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in directive");
Lex();
unsigned Type = ELF::SHT_PROGBITS;
if (TypeName.empty()) {
if (SectionName.startswith(".note"))
Type = ELF::SHT_NOTE;
else if (SectionName == ".init_array")
Type = ELF::SHT_INIT_ARRAY;
else if (SectionName == ".fini_array")
Type = ELF::SHT_FINI_ARRAY;
else if (SectionName == ".preinit_array")
Type = ELF::SHT_PREINIT_ARRAY;
} else {
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");
}
if (UseLastGroup) {
MCSectionSubPair CurrentSection = getStreamer().getCurrentSection();
if (const MCSectionELF *Section =
cast_or_null<MCSectionELF>(CurrentSection.first))
if (const MCSymbol *Group = Section->getGroup()) {
GroupName = Group->getName();
Flags |= ELF::SHF_GROUP;
}
}
MCSection *ELFSection = getContext().getELFSection(SectionName, Type, Flags,
Size, GroupName, UniqueID);
getStreamer().SwitchSection(ELFSection, Subsection);
if (getContext().getGenDwarfForAssembly()) {
bool InsertResult = getContext().addGenDwarfSection(ELFSection);
if (InsertResult) {
if (getContext().getDwarfVersion() <= 2)
Warning(loc, "DWARF2 only supports one section per compilation unit");
if (!ELFSection->getBeginSymbol()) {
MCSymbol *SectionStartSymbol = getContext().createTempSymbol();
getStreamer().EmitLabel(SectionStartSymbol);
ELFSection->setBeginSymbol(SectionStartSymbol);
}
}
}
return false;
}
bool ELFAsmParser::ParseDirectivePrevious(StringRef DirName, SMLoc) {
MCSectionSubPair PreviousSection = getStreamer().getPreviousSection();
if (PreviousSection.first == nullptr)
return TokError(".previous without corresponding .section");
getStreamer().SwitchSection(PreviousSection.first, PreviousSection.second);
return false;
}
static MCSymbolAttr MCAttrForString(StringRef Type) {
return StringSwitch<MCSymbolAttr>(Type)
.Cases("STT_FUNC", "function", MCSA_ELF_TypeFunction)
.Cases("STT_OBJECT", "object", MCSA_ELF_TypeObject)
.Cases("STT_TLS", "tls_object", MCSA_ELF_TypeTLS)
.Cases("STT_COMMON", "common", MCSA_ELF_TypeCommon)
.Cases("STT_NOTYPE", "notype", MCSA_ELF_TypeNoType)
.Cases("STT_GNU_IFUNC", "gnu_indirect_function",
MCSA_ELF_TypeIndFunction)
.Case("gnu_unique_object", MCSA_ELF_TypeGnuUniqueObject)
.Default(MCSA_Invalid);
}
/// ParseDirectiveELFType
/// ::= .type identifier , STT_<TYPE_IN_UPPER_CASE>
/// ::= .type identifier , #attribute
/// ::= .type identifier , @attribute
/// ::= .type identifier , %attribute
/// ::= .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);
// NOTE the comma is optional in all cases. It is only documented as being
// optional in the first case, however, GAS will silently treat the comma as
// optional in all cases. Furthermore, although the documentation states that
// the first form only accepts STT_<TYPE_IN_UPPER_CASE>, in reality, GAS
// accepts both the upper case name as well as the lower case aliases.
if (getLexer().is(AsmToken::Comma))
Lex();
if (getLexer().isNot(AsmToken::Identifier) &&
getLexer().isNot(AsmToken::Hash) &&
getLexer().isNot(AsmToken::Percent) &&
getLexer().isNot(AsmToken::String)) {
if (!getLexer().getAllowAtInIdentifier())
return TokError("expected STT_<TYPE_IN_UPPER_CASE>, '#<type>', "
"'%<type>' or \"<type>\"");
else if (getLexer().isNot(AsmToken::At))
return TokError("expected STT_<TYPE_IN_UPPER_CASE>, '#<type>', '@<type>', "
"'%<type>' or \"<type>\"");
}
if (getLexer().isNot(AsmToken::String) &&
getLexer().isNot(AsmToken::Identifier))
Lex();
SMLoc TypeLoc = getLexer().getLoc();
StringRef Type;
if (getParser().parseIdentifier(Type))
return TokError("expected symbol type in directive");
MCSymbolAttr Attr = MCAttrForString(Type);
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();
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in '.ident' directive");
Lex();
getStreamer().EmitIdent(Data);
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");
// ARM assembly uses @ for a comment...
// except when parsing the second parameter of the .symver directive.
// Force the next symbol to allow @ in the identifier, which is
// required for this directive and then reset it to its initial state.
const bool AllowAtInIdentifier = getLexer().getAllowAtInIdentifier();
getLexer().setAllowAtInIdentifier(true);
Lex();
getLexer().setAllowAtInIdentifier(AllowAtInIdentifier);
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;
}
/// ParseDirectiveVersion
/// ::= .version string
bool ELFAsmParser::ParseDirectiveVersion(StringRef, SMLoc) {
if (getLexer().isNot(AsmToken::String))
return TokError("unexpected token in '.version' directive");
StringRef Data = getTok().getIdentifier();
Lex();
MCSection *Note = getContext().getELFSection(".note", ELF::SHT_NOTE, 0);
getStreamer().PushSection();
getStreamer().SwitchSection(Note);
getStreamer().EmitIntValue(Data.size()+1, 4); // namesz.
getStreamer().EmitIntValue(0, 4); // descsz = 0 (no description).
getStreamer().EmitIntValue(1, 4); // type = NT_VERSION.
getStreamer().EmitBytes(Data); // name.
getStreamer().EmitIntValue(0, 1); // terminate the string.
getStreamer().EmitValueToAlignment(4); // ensure 4 byte alignment.
getStreamer().PopSection();
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;
}
bool ELFAsmParser::ParseDirectiveSubsection(StringRef, SMLoc) {
const MCExpr *Subsection = nullptr;
if (getLexer().isNot(AsmToken::EndOfStatement)) {
if (getParser().parseExpression(Subsection))
return true;
}
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in directive");
Lex();
getStreamer().SubSection(Subsection);
return false;
}
namespace llvm {
MCAsmParserExtension *createELFAsmParser() {
return new ELFAsmParser;
}
}
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