void TargetLoweringObjectFileCOFF::emitLinkerFlagsForGlobal(
raw_ostream &OS, const GlobalValue *GV, const Mangler &Mang) const {
if (!GV->hasDLLExportStorageClass() || GV->isDeclaration())
return;
const Triple &TT = getTargetTriple();
if (TT.isKnownWindowsMSVCEnvironment())
OS << " /EXPORT:";
else
OS << " -export:";
if (TT.isWindowsGNUEnvironment() || TT.isWindowsCygwinEnvironment()) {
std::string Flag;
raw_string_ostream FlagOS(Flag);
Mang.getNameWithPrefix(FlagOS, GV, false);
FlagOS.flush();
if (Flag[0] == GV->getParent()->getDataLayout().getGlobalPrefix())
OS << Flag.substr(1);
else
OS << Flag;
} else {
Mang.getNameWithPrefix(OS, GV, false);
}
if (!GV->getValueType()->isFunctionTy()) {
if (TT.isKnownWindowsMSVCEnvironment())
OS << ",DATA";
else
OS << ",data";
}
}
void LTOCodeGenerator::
applyRestriction(GlobalValue &GV,
const ArrayRef<StringRef> &Libcalls,
std::vector<const char*> &MustPreserveList,
SmallPtrSet<GlobalValue*, 8> &AsmUsed,
Mangler &Mangler) {
SmallString<64> Buffer;
Mangler.getNameWithPrefix(Buffer, &GV);
if (GV.isDeclaration())
return;
if (MustPreserveSymbols.count(Buffer))
MustPreserveList.push_back(GV.getName().data());
if (AsmUndefinedRefs.count(Buffer))
AsmUsed.insert(&GV);
// Conservatively append user-supplied runtime library functions to
// llvm.compiler.used. These could be internalized and deleted by
// optimizations like -globalopt, causing problems when later optimizations
// add new library calls (e.g., llvm.memset => memset and printf => puts).
// Leave it to the linker to remove any dead code (e.g. with -dead_strip).
if (isa<Function>(GV) &&
std::binary_search(Libcalls.begin(), Libcalls.end(), GV.getName()))
AsmUsed.insert(&GV);
}
std::string ExecutionEngine::getMangledName(const GlobalValue *GV) {
MutexGuard locked(lock);
Mangler Mang;
SmallString<128> FullName;
Mang.getNameWithPrefix(FullName, GV, false);
return FullName.str();
}
void llvm::emitLinkerFlagsForUsedCOFF(raw_ostream &OS, const GlobalValue *GV,
const Triple &T, Mangler &M) {
if (!T.isKnownWindowsMSVCEnvironment())
return;
OS << " /INCLUDE:";
M.getNameWithPrefix(OS, GV, false);
}
void TargetLoweringObjectFileMachO::getNameWithPrefix(
SmallVectorImpl<char> &OutName, const GlobalValue *GV, Mangler &Mang,
const TargetMachine &TM) const {
SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
const MCSection *TheSection = SectionForGlobal(GV, GVKind, Mang, TM);
bool CannotUsePrivateLabel =
!canUsePrivateLabel(*TM.getMCAsmInfo(), *TheSection);
Mang.getNameWithPrefix(OutName, GV, CannotUsePrivateLabel);
}
void TargetLoweringObjectFileCOFF::getNameWithPrefix(
SmallVectorImpl<char> &OutName, const GlobalValue *GV,
bool CannotUsePrivateLabel, Mangler &Mang, const TargetMachine &TM) const {
if (GV->hasPrivateLinkage() &&
((isa<Function>(GV) && TM.getFunctionSections()) ||
(isa<GlobalVariable>(GV) && TM.getDataSections())))
CannotUsePrivateLabel = true;
Mang.getNameWithPrefix(OutName, GV, CannotUsePrivateLabel);
}
std::string mangle(const GlobalValue *GV) {
std::string MangledName;
{
Mangler Mang;
raw_string_ostream MangledNameStream(MangledName);
Mang.getNameWithPrefix(MangledNameStream, GV, false);
}
return MangledName;
}
void TargetMachine::getNameWithPrefix(SmallVectorImpl<char> &Name,
const GlobalValue *GV, Mangler &Mang,
bool MayAlwaysUsePrivate) const {
if (MayAlwaysUsePrivate || !GV->hasPrivateLinkage()) {
// Simple case: If GV is not private, it is not important to find out if
// private labels are legal in this case or not.
Mang.getNameWithPrefix(Name, GV, false);
return;
}
const TargetLoweringObjectFile *TLOF = getObjFileLowering();
TLOF->getNameWithPrefix(Name, GV, Mang, *this);
}
void LTOCodeGenerator::applyScopeRestrictions() {
if (ScopeRestrictionsDone)
return;
// Declare a callback for the internalize pass that will ask for every
// candidate GlobalValue if it can be internalized or not.
Mangler Mang;
SmallString<64> MangledName;
auto mustPreserveGV = [&](const GlobalValue &GV) -> bool {
// Unnamed globals can't be mangled, but they can't be preserved either.
if (!GV.hasName())
return false;
// Need to mangle the GV as the "MustPreserveSymbols" StringSet is filled
// with the linker supplied name, which on Darwin includes a leading
// underscore.
MangledName.clear();
MangledName.reserve(GV.getName().size() + 1);
Mang.getNameWithPrefix(MangledName, &GV, /*CannotUsePrivateLabel=*/false);
return MustPreserveSymbols.count(MangledName);
};
// Preserve linkonce value on linker request
preserveDiscardableGVs(*MergedModule, mustPreserveGV);
if (!ShouldInternalize)
return;
if (ShouldRestoreGlobalsLinkage) {
// Record the linkage type of non-local symbols so they can be restored
// prior
// to module splitting.
auto RecordLinkage = [&](const GlobalValue &GV) {
if (!GV.hasAvailableExternallyLinkage() && !GV.hasLocalLinkage() &&
GV.hasName())
ExternalSymbols.insert(std::make_pair(GV.getName(), GV.getLinkage()));
};
for (auto &GV : *MergedModule)
RecordLinkage(GV);
for (auto &GV : MergedModule->globals())
RecordLinkage(GV);
for (auto &GV : MergedModule->aliases())
RecordLinkage(GV);
}
// Update the llvm.compiler_used globals to force preserving libcalls and
// symbols referenced from asm
updateCompilerUsed(*MergedModule, *TargetMach, AsmUndefinedRefs);
internalizeModule(*MergedModule, mustPreserveGV);
ScopeRestrictionsDone = true;
}
void LTOCodeGenerator::
applyRestriction(GlobalValue &GV,
std::vector<const char*> &mustPreserveList,
SmallPtrSet<GlobalValue*, 8> &asmUsed,
Mangler &mangler) {
SmallString<64> Buffer;
mangler.getNameWithPrefix(Buffer, &GV, false);
if (GV.isDeclaration())
return;
if (_mustPreserveSymbols.count(Buffer))
mustPreserveList.push_back(GV.getName().data());
if (_asmUndefinedRefs.count(Buffer))
asmUsed.insert(&GV);
}
void TargetMachine::getNameWithPrefix(SmallVectorImpl<char> &Name,
const GlobalValue *GV, Mangler &Mang,
bool MayAlwaysUsePrivate) const {
if (MayAlwaysUsePrivate || !GV->hasPrivateLinkage()) {
// Simple case: If GV is not private, it is not important to find out if
// private labels are legal in this case or not.
Mang.getNameWithPrefix(Name, GV, false);
return;
}
SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, *this);
const TargetLoweringObjectFile *TLOF = getObjFileLowering();
const MCSection *TheSection = TLOF->SectionForGlobal(GV, GVKind, Mang, *this);
bool CannotUsePrivateLabel = !canUsePrivateLabel(*AsmInfo, *TheSection);
TLOF->getNameWithPrefix(Name, GV, CannotUsePrivateLabel, Mang, *this);
}
static MCSymbol *GetSymbolFromOperand(const MachineOperand &MO, AsmPrinter &AP){
const TargetMachine &TM = AP.TM;
Mangler *Mang = AP.Mang;
const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
MCContext &Ctx = AP.OutContext;
bool isDarwin = Triple(TM.getTargetTriple()).isOSDarwin();
SmallString<128> Name;
StringRef Suffix;
if (MO.getTargetFlags() == PPCII::MO_PLT_OR_STUB) {
if (isDarwin)
Suffix = "$stub";
} else if (MO.getTargetFlags() & PPCII::MO_NLP_FLAG)
Suffix = "$non_lazy_ptr";
if (!Suffix.empty())
Name += DL->getPrivateGlobalPrefix();
unsigned PrefixLen = Name.size();
if (!MO.isGlobal()) {
assert(MO.isSymbol() && "Isn't a symbol reference");
Mang->getNameWithPrefix(Name, MO.getSymbolName());
} else {
const GlobalValue *GV = MO.getGlobal();
TM.getNameWithPrefix(Name, GV, *Mang);
}
unsigned OrigLen = Name.size() - PrefixLen;
Name += Suffix;
MCSymbol *Sym = Ctx.GetOrCreateSymbol(Name.str());
StringRef OrigName = StringRef(Name).substr(PrefixLen, OrigLen);
// If the target flags on the operand changes the name of the symbol, do that
// before we return the symbol.
if (MO.getTargetFlags() == PPCII::MO_PLT_OR_STUB && isDarwin) {
MachineModuleInfoImpl::StubValueTy &StubSym =
getMachOMMI(AP).getFnStubEntry(Sym);
if (StubSym.getPointer())
return Sym;
if (MO.isGlobal()) {
StubSym =
MachineModuleInfoImpl::
StubValueTy(AP.getSymbol(MO.getGlobal()),
!MO.getGlobal()->hasInternalLinkage());
} else {
StubSym =
MachineModuleInfoImpl::
StubValueTy(Ctx.GetOrCreateSymbol(OrigName), false);
}
return Sym;
}
// If the symbol reference is actually to a non_lazy_ptr, not to the symbol,
// then add the suffix.
if (MO.getTargetFlags() & PPCII::MO_NLP_FLAG) {
MachineModuleInfoMachO &MachO = getMachOMMI(AP);
MachineModuleInfoImpl::StubValueTy &StubSym =
(MO.getTargetFlags() & PPCII::MO_NLP_HIDDEN_FLAG) ?
MachO.getHiddenGVStubEntry(Sym) : MachO.getGVStubEntry(Sym);
if (!StubSym.getPointer()) {
assert(MO.isGlobal() && "Extern symbol not handled yet");
StubSym = MachineModuleInfoImpl::
StubValueTy(AP.getSymbol(MO.getGlobal()),
!MO.getGlobal()->hasInternalLinkage());
}
return Sym;
}
return Sym;
}
void TargetLoweringObjectFile::getNameWithPrefix(
SmallVectorImpl<char> &OutName, const GlobalValue *GV, Mangler &Mang,
const TargetMachine &TM) const {
Mang.getNameWithPrefix(OutName, GV, /*CannotUsePrivateLabel=*/false);
}
void RecordStreamer::flushSymverDirectives() {
// Mapping from mangled name to GV.
StringMap<const GlobalValue *> MangledNameMap;
// The name in the assembler will be mangled, but the name in the IR
// might not, so we first compute a mapping from mangled name to GV.
Mangler Mang;
SmallString<64> MangledName;
for (const GlobalValue &GV : M.global_values()) {
if (!GV.hasName())
continue;
MangledName.clear();
MangledName.reserve(GV.getName().size() + 1);
Mang.getNameWithPrefix(MangledName, &GV, /*CannotUsePrivateLabel=*/false);
MangledNameMap[MangledName] = &GV;
}
// Walk all the recorded .symver aliases, and set up the binding
// for each alias.
for (auto &Symver : SymverAliasMap) {
const MCSymbol *Aliasee = Symver.first;
MCSymbolAttr Attr = MCSA_Invalid;
bool IsDefined = false;
// First check if the aliasee binding was recorded in the asm.
RecordStreamer::State state = getSymbolState(Aliasee);
switch (state) {
case RecordStreamer::Global:
case RecordStreamer::DefinedGlobal:
Attr = MCSA_Global;
break;
case RecordStreamer::UndefinedWeak:
case RecordStreamer::DefinedWeak:
Attr = MCSA_Weak;
break;
default:
break;
}
switch (state) {
case RecordStreamer::Defined:
case RecordStreamer::DefinedGlobal:
case RecordStreamer::DefinedWeak:
IsDefined = true;
break;
case RecordStreamer::NeverSeen:
case RecordStreamer::Global:
case RecordStreamer::Used:
case RecordStreamer::UndefinedWeak:
break;
}
if (Attr == MCSA_Invalid || !IsDefined) {
const GlobalValue *GV = M.getNamedValue(Aliasee->getName());
if (!GV) {
auto MI = MangledNameMap.find(Aliasee->getName());
if (MI != MangledNameMap.end())
GV = MI->second;
}
if (GV) {
// If we don't have a symbol attribute from assembly, then check if
// the aliasee was defined in the IR.
if (Attr == MCSA_Invalid) {
if (GV->hasExternalLinkage())
Attr = MCSA_Global;
else if (GV->hasLocalLinkage())
Attr = MCSA_Local;
else if (GV->isWeakForLinker())
Attr = MCSA_Weak;
}
IsDefined = IsDefined || !GV->isDeclarationForLinker();
}
}
// Set the detected binding on each alias with this aliasee.
for (auto AliasName : Symver.second) {
std::pair<StringRef, StringRef> Split = AliasName.split("@@@");
SmallString<128> NewName;
if (!Split.second.empty() && !Split.second.startswith("@")) {
// Special processing for "@@@" according
// https://sourceware.org/binutils/docs/as/Symver.html
const char *Separator = IsDefined ? "@@" : "@";
AliasName =
(Split.first + Separator + Split.second).toStringRef(NewName);
}
MCSymbol *Alias = getContext().getOrCreateSymbol(AliasName);
// TODO: Handle "@@@". Depending on SymbolAttribute value it needs to be
// converted into @ or @@.
const MCExpr *Value = MCSymbolRefExpr::create(Aliasee, getContext());
if (IsDefined)
markDefined(*Alias);
// Don't use EmitAssignment override as it always marks alias as defined.
MCStreamer::EmitAssignment(Alias, Value);
if (Attr != MCSA_Invalid)
EmitSymbolAttribute(Alias, Attr);
}
}
}
// Ensure ELF .symver aliases get the same binding as the defined symbol
// they alias with.
static void handleSymverAliases(const Module &M, RecordStreamer &Streamer) {
if (Streamer.symverAliases().empty())
return;
// The name in the assembler will be mangled, but the name in the IR
// might not, so we first compute a mapping from mangled name to GV.
Mangler Mang;
SmallString<64> MangledName;
StringMap<const GlobalValue *> MangledNameMap;
auto GetMangledName = [&](const GlobalValue &GV) {
if (!GV.hasName())
return;
MangledName.clear();
MangledName.reserve(GV.getName().size() + 1);
Mang.getNameWithPrefix(MangledName, &GV, /*CannotUsePrivateLabel=*/false);
MangledNameMap[MangledName] = &GV;
};
for (const Function &F : M)
GetMangledName(F);
for (const GlobalVariable &GV : M.globals())
GetMangledName(GV);
for (const GlobalAlias &GA : M.aliases())
GetMangledName(GA);
// Walk all the recorded .symver aliases, and set up the binding
// for each alias.
for (auto &Symver : Streamer.symverAliases()) {
const MCSymbol *Aliasee = Symver.first;
MCSymbolAttr Attr = MCSA_Invalid;
// First check if the aliasee binding was recorded in the asm.
RecordStreamer::State state = Streamer.getSymbolState(Aliasee);
switch (state) {
case RecordStreamer::Global:
case RecordStreamer::DefinedGlobal:
Attr = MCSA_Global;
break;
case RecordStreamer::UndefinedWeak:
case RecordStreamer::DefinedWeak:
Attr = MCSA_Weak;
break;
default:
break;
}
// If we don't have a symbol attribute from assembly, then check if
// the aliasee was defined in the IR.
if (Attr == MCSA_Invalid) {
const auto *GV = M.getNamedValue(Aliasee->getName());
if (!GV) {
auto MI = MangledNameMap.find(Aliasee->getName());
if (MI != MangledNameMap.end())
GV = MI->second;
else
continue;
}
if (GV->hasExternalLinkage())
Attr = MCSA_Global;
else if (GV->hasLocalLinkage())
Attr = MCSA_Local;
else if (GV->isWeakForLinker())
Attr = MCSA_Weak;
}
if (Attr == MCSA_Invalid)
continue;
// Set the detected binding on each alias with this aliasee.
for (auto &Alias : Symver.second)
Streamer.EmitSymbolAttribute(Alias, Attr);
}
}
