DefinedRegular<ELFT> *SymbolTable<ELFT>::addIgnored(StringRef Name,
uint8_t Visibility) {
SymbolBody *S = find(Name);
if (!S || !S->isUndefined())
return nullptr;
return addAbsolute(Name, Visibility);
}
std::vector<SymbolBody *> SymbolTable<ELFT>::findAll(StringRef Pattern) {
std::vector<SymbolBody *> Res;
for (Symbol *Sym : SymVector) {
SymbolBody *B = Sym->body();
if (!B->isUndefined() && globMatch(Pattern, B->getName()))
Res.push_back(B);
}
return Res;
}
// We have a new defined symbol with the specified binding. Return 1 if the new
// symbol should win, -1 if the new symbol should lose, or 0 if both symbols are
// strong defined symbols.
static int compareDefined(Symbol *S, bool WasInserted, uint8_t Binding) {
if (WasInserted)
return 1;
SymbolBody *Body = S->body();
if (Body->isLazy() || Body->isUndefined() || Body->isShared())
return 1;
if (Binding == STB_WEAK)
return -1;
if (S->isWeak())
return 1;
return 0;
}
// Print out a log message for --trace-symbol.
void elf::printTraceSymbol(Symbol *Sym) {
SymbolBody *B = Sym->body();
outs() << getFilename(B->File);
if (B->isUndefined())
outs() << ": reference to ";
else if (B->isCommon())
outs() << ": common definition of ";
else
outs() << ": definition of ";
outs() << B->getName() << "\n";
}
StringMap<std::vector<SymbolBody *>> &SymbolTable<ELFT>::getDemangledSyms() {
if (!DemangledSyms) {
DemangledSyms.emplace();
for (Symbol *Sym : SymVector) {
SymbolBody *B = Sym->body();
if (B->isUndefined())
continue;
if (Optional<std::string> S = demangle(B->getName()))
(*DemangledSyms)[*S].push_back(B);
else
(*DemangledSyms)[B->getName()].push_back(B);
}
}
return *DemangledSyms;
}
template <class ELFT> void LinkerScript<ELFT>::addScriptedSymbols() {
for (const std::unique_ptr<BaseCommand> &Base : Opt.Commands) {
auto *Cmd = dyn_cast<SymbolAssignment>(Base.get());
if (!Cmd || Cmd->Name == ".")
continue;
SymbolBody *B = Symtab<ELFT>::X->find(Cmd->Name);
// The semantic of PROVIDE is that of introducing a symbol only if
// it's not defined and there's at least a reference to it.
if ((!B && !Cmd->Provide) || (B && B->isUndefined()))
Symtab<ELFT>::X->addAbsolute(Cmd->Name,
Cmd->Hidden ? STV_HIDDEN : STV_DEFAULT);
else
// Symbol already exists in symbol table. If it is provided
// then we can't override its value.
Cmd->Ignore = Cmd->Provide;
}
}
std::vector<SymbolBody *>
SymbolTable<ELFT>::findAllByVersion(SymbolVersion Ver) {
std::vector<SymbolBody *> Res;
StringMatcher M(Ver.Name);
if (Ver.IsExternCpp) {
for (auto &P : getDemangledSyms())
if (M.match(P.first()))
Res.insert(Res.end(), P.second.begin(), P.second.end());
return Res;
}
for (Symbol *Sym : SymVector) {
SymbolBody *B = Sym->body();
if (!B->isUndefined() && M.match(B->getName()))
Res.push_back(B);
}
return Res;
}
void Writer<ELFT>::scanRelocs(
InputSectionBase<ELFT> &C,
iterator_range<const Elf_Rel_Impl<ELFT, isRela> *> Rels) {
typedef Elf_Rel_Impl<ELFT, isRela> RelType;
const ObjectFile<ELFT> &File = *C.getFile();
for (const RelType &RI : Rels) {
uint32_t SymIndex = RI.getSymbol(Config->Mips64EL);
SymbolBody *Body = File.getSymbolBody(SymIndex);
uint32_t Type = RI.getType(Config->Mips64EL);
if (Target->isTlsLocalDynamicReloc(Type)) {
if (Target->isTlsOptimized(Type, nullptr))
continue;
if (Out<ELFT>::LocalModuleTlsIndexOffset == uint32_t(-1)) {
Out<ELFT>::LocalModuleTlsIndexOffset =
Out<ELFT>::Got->addLocalModuleTlsIndex();
Out<ELFT>::RelaDyn->addReloc({&C, &RI});
}
continue;
}
// Set "used" bit for --as-needed.
if (Body && Body->isUndefined() && !Body->isWeak())
if (auto *S = dyn_cast<SharedSymbol<ELFT>>(Body->repl()))
S->File->IsUsed = true;
if (Body)
Body = Body->repl();
if (Body && Body->isTLS() && Target->isTlsGlobalDynamicReloc(Type)) {
if (Target->isTlsOptimized(Type, Body))
continue;
if (Body->isInGot())
continue;
Out<ELFT>::Got->addDynTlsEntry(Body);
Out<ELFT>::RelaDyn->addReloc({&C, &RI});
Out<ELFT>::RelaDyn->addReloc({nullptr, nullptr});
Body->setUsedInDynamicReloc();
continue;
}
if (Body && Body->isTLS() && !Target->isTlsDynReloc(Type))
continue;
bool NeedsGot = false;
bool NeedsPlt = false;
if (Body) {
if (auto *E = dyn_cast<SharedSymbol<ELFT>>(Body)) {
if (E->needsCopy())
continue;
if (Target->relocNeedsCopy(Type, *Body))
E->OffsetInBSS = 0;
}
NeedsPlt = Target->relocNeedsPlt(Type, *Body);
if (NeedsPlt) {
if (Body->isInPlt())
continue;
Out<ELFT>::Plt->addEntry(Body);
}
NeedsGot = Target->relocNeedsGot(Type, *Body);
if (NeedsGot) {
if (NeedsPlt && Target->supportsLazyRelocations()) {
Out<ELFT>::GotPlt->addEntry(Body);
} else {
if (Body->isInGot())
continue;
Out<ELFT>::Got->addEntry(Body);
}
}
}
if (Config->EMachine == EM_MIPS && NeedsGot) {
// MIPS ABI has special rules to process GOT entries
// and doesn't require relocation entries for them.
// See "Global Offset Table" in Chapter 5 in the following document
// for detailed description:
// ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf
Body->setUsedInDynamicReloc();
continue;
}
bool CBP = canBePreempted(Body, NeedsGot);
if (!CBP && (!Config->Shared || Target->isRelRelative(Type)))
continue;
if (CBP)
Body->setUsedInDynamicReloc();
if (NeedsPlt && Target->supportsLazyRelocations())
Out<ELFT>::RelaPlt->addReloc({&C, &RI});
else
Out<ELFT>::RelaDyn->addReloc({&C, &RI});
}
}
