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)); }