void CodeGenFunction::GenerateThunk(llvm::Function *Fn,
const CGFunctionInfo &FnInfo,
GlobalDecl GD, const ThunkInfo &Thunk) {
const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>();
QualType ResultType = FPT->getResultType();
QualType ThisType = MD->getThisType(getContext());
FunctionArgList FunctionArgs;
// FIXME: It would be nice if more of this code could be shared with
// CodeGenFunction::GenerateCode.
// Create the implicit 'this' parameter declaration.
CurGD = GD;
CGM.getCXXABI().BuildInstanceFunctionParams(*this, ResultType, FunctionArgs);
// Add the rest of the parameters.
for (FunctionDecl::param_const_iterator I = MD->param_begin(),
E = MD->param_end(); I != E; ++I) {
ParmVarDecl *Param = *I;
FunctionArgs.push_back(Param);
}
StartFunction(GlobalDecl(), ResultType, Fn, FnInfo, FunctionArgs,
SourceLocation());
CGM.getCXXABI().EmitInstanceFunctionProlog(*this);
CXXThisValue = CXXABIThisValue;
// Adjust the 'this' pointer if necessary.
llvm::Value *AdjustedThisPtr =
PerformTypeAdjustment(*this, LoadCXXThis(),
Thunk.This.NonVirtual,
Thunk.This.VCallOffsetOffset,
/*IsReturnAdjustment*/false);
CallArgList CallArgs;
// Add our adjusted 'this' pointer.
CallArgs.add(RValue::get(AdjustedThisPtr), ThisType);
// Add the rest of the parameters.
for (FunctionDecl::param_const_iterator I = MD->param_begin(),
E = MD->param_end(); I != E; ++I) {
ParmVarDecl *param = *I;
EmitDelegateCallArg(CallArgs, param);
}
// Get our callee.
llvm::Type *Ty =
CGM.getTypes().GetFunctionType(CGM.getTypes().arrangeGlobalDeclaration(GD));
llvm::Value *Callee = CGM.GetAddrOfFunction(GD, Ty, /*ForVTable=*/true);
#ifndef NDEBUG
const CGFunctionInfo &CallFnInfo =
CGM.getTypes().arrangeCXXMethodCall(CallArgs, FPT,
RequiredArgs::forPrototypePlus(FPT, 1));
assert(CallFnInfo.getRegParm() == FnInfo.getRegParm() &&
CallFnInfo.isNoReturn() == FnInfo.isNoReturn() &&
CallFnInfo.getCallingConvention() == FnInfo.getCallingConvention());
assert(isa<CXXDestructorDecl>(MD) || // ignore dtor return types
similar(CallFnInfo.getReturnInfo(), CallFnInfo.getReturnType(),
FnInfo.getReturnInfo(), FnInfo.getReturnType()));
assert(CallFnInfo.arg_size() == FnInfo.arg_size());
for (unsigned i = 0, e = FnInfo.arg_size(); i != e; ++i)
assert(similar(CallFnInfo.arg_begin()[i].info,
CallFnInfo.arg_begin()[i].type,
FnInfo.arg_begin()[i].info, FnInfo.arg_begin()[i].type));
#endif
// Determine whether we have a return value slot to use.
ReturnValueSlot Slot;
if (!ResultType->isVoidType() &&
FnInfo.getReturnInfo().getKind() == ABIArgInfo::Indirect &&
hasAggregateLLVMType(CurFnInfo->getReturnType()))
Slot = ReturnValueSlot(ReturnValue, ResultType.isVolatileQualified());
// Now emit our call.
RValue RV = EmitCall(FnInfo, Callee, Slot, CallArgs, MD);
if (!Thunk.Return.isEmpty())
RV = PerformReturnAdjustment(*this, ResultType, RV, Thunk);
if (!ResultType->isVoidType() && Slot.isNull())
CGM.getCXXABI().EmitReturnFromThunk(*this, RV, ResultType);
// Disable the final ARC autorelease.
AutoreleaseResult = false;
FinishFunction();
// Set the right linkage.
CGM.setFunctionLinkage(MD, Fn);
// Set the right visibility.
setThunkVisibility(CGM, MD, Thunk, Fn);
}
void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI,
const Decl *TargetDecl,
AttributeListType &PAL,
unsigned &CallingConv) {
unsigned FuncAttrs = 0;
unsigned RetAttrs = 0;
CallingConv = FI.getEffectiveCallingConvention();
if (FI.isNoReturn())
FuncAttrs |= llvm::Attribute::NoReturn;
// FIXME: handle sseregparm someday...
if (TargetDecl) {
if (TargetDecl->hasAttr<NoThrowAttr>())
FuncAttrs |= llvm::Attribute::NoUnwind;
if (TargetDecl->hasAttr<NoReturnAttr>())
FuncAttrs |= llvm::Attribute::NoReturn;
if (TargetDecl->hasAttr<ConstAttr>())
FuncAttrs |= llvm::Attribute::ReadNone;
else if (TargetDecl->hasAttr<PureAttr>())
FuncAttrs |= llvm::Attribute::ReadOnly;
if (TargetDecl->hasAttr<MallocAttr>())
RetAttrs |= llvm::Attribute::NoAlias;
}
if (CodeGenOpts.OptimizeSize)
FuncAttrs |= llvm::Attribute::OptimizeForSize;
if (CodeGenOpts.DisableRedZone)
FuncAttrs |= llvm::Attribute::NoRedZone;
if (CodeGenOpts.NoImplicitFloat)
FuncAttrs |= llvm::Attribute::NoImplicitFloat;
QualType RetTy = FI.getReturnType();
unsigned Index = 1;
const ABIArgInfo &RetAI = FI.getReturnInfo();
switch (RetAI.getKind()) {
case ABIArgInfo::Extend:
if (RetTy->isSignedIntegerType()) {
RetAttrs |= llvm::Attribute::SExt;
} else if (RetTy->isUnsignedIntegerType()) {
RetAttrs |= llvm::Attribute::ZExt;
}
// FALLTHROUGH
case ABIArgInfo::Direct:
break;
case ABIArgInfo::Indirect:
PAL.push_back(llvm::AttributeWithIndex::get(Index,
llvm::Attribute::StructRet |
llvm::Attribute::NoAlias));
++Index;
// sret disables readnone and readonly
FuncAttrs &= ~(llvm::Attribute::ReadOnly |
llvm::Attribute::ReadNone);
break;
case ABIArgInfo::Ignore:
case ABIArgInfo::Coerce:
break;
case ABIArgInfo::Expand:
assert(0 && "Invalid ABI kind for return argument");
}
if (RetAttrs)
PAL.push_back(llvm::AttributeWithIndex::get(0, RetAttrs));
// FIXME: we need to honour command line settings also...
// FIXME: RegParm should be reduced in case of nested functions and/or global
// register variable.
signed RegParm = FI.getRegParm();
unsigned PointerWidth = getContext().Target.getPointerWidth(0);
for (CGFunctionInfo::const_arg_iterator it = FI.arg_begin(),
ie = FI.arg_end(); it != ie; ++it) {
QualType ParamType = it->type;
const ABIArgInfo &AI = it->info;
unsigned Attributes = 0;
// 'restrict' -> 'noalias' is done in EmitFunctionProlog when we
// have the corresponding parameter variable. It doesn't make
// sense to do it here because parameters are so f****d up.
switch (AI.getKind()) {
case ABIArgInfo::Coerce:
break;
case ABIArgInfo::Indirect:
if (AI.getIndirectByVal())
Attributes |= llvm::Attribute::ByVal;
Attributes |=
llvm::Attribute::constructAlignmentFromInt(AI.getIndirectAlign());
// byval disables readnone and readonly.
FuncAttrs &= ~(llvm::Attribute::ReadOnly |
llvm::Attribute::ReadNone);
break;
case ABIArgInfo::Extend:
if (ParamType->isSignedIntegerType()) {
Attributes |= llvm::Attribute::SExt;
} else if (ParamType->isUnsignedIntegerType()) {
Attributes |= llvm::Attribute::ZExt;
}
// FALLS THROUGH
case ABIArgInfo::Direct:
if (RegParm > 0 &&
(ParamType->isIntegerType() || ParamType->isPointerType())) {
RegParm -=
(Context.getTypeSize(ParamType) + PointerWidth - 1) / PointerWidth;
if (RegParm >= 0)
Attributes |= llvm::Attribute::InReg;
}
// FIXME: handle sseregparm someday...
break;
case ABIArgInfo::Ignore:
// Skip increment, no matching LLVM parameter.
continue;
case ABIArgInfo::Expand: {
std::vector<const llvm::Type*> Tys;
// FIXME: This is rather inefficient. Do we ever actually need to do
// anything here? The result should be just reconstructed on the other
// side, so extension should be a non-issue.
getTypes().GetExpandedTypes(ParamType, Tys);
Index += Tys.size();
continue;
}
}
if (Attributes)
PAL.push_back(llvm::AttributeWithIndex::get(Index, Attributes));
++Index;
}
if (FuncAttrs)
PAL.push_back(llvm::AttributeWithIndex::get(~0, FuncAttrs));
}
