| //===------- SemaTemplateDeduction.cpp - Template Argument Deduction ------===/ |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| //===----------------------------------------------------------------------===/ |
| // |
| // This file implements C++ template argument deduction. |
| // |
| //===----------------------------------------------------------------------===/ |
| |
| #include "Sema.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/DeclTemplate.h" |
| #include "clang/AST/StmtVisitor.h" |
| #include "clang/AST/Expr.h" |
| #include "clang/AST/ExprCXX.h" |
| #include "clang/Parse/DeclSpec.h" |
| #include "llvm/Support/Compiler.h" |
| |
| namespace clang { |
| /// \brief Various flags that control template argument deduction. |
| /// |
| /// These flags can be bitwise-OR'd together. |
| enum TemplateDeductionFlags { |
| /// \brief No template argument deduction flags, which indicates the |
| /// strictest results for template argument deduction (as used for, e.g., |
| /// matching class template partial specializations). |
| TDF_None = 0, |
| /// \brief Within template argument deduction from a function call, we are |
| /// matching with a parameter type for which the original parameter was |
| /// a reference. |
| TDF_ParamWithReferenceType = 0x1, |
| /// \brief Within template argument deduction from a function call, we |
| /// are matching in a case where we ignore cv-qualifiers. |
| TDF_IgnoreQualifiers = 0x02, |
| /// \brief Within template argument deduction from a function call, |
| /// we are matching in a case where we can perform template argument |
| /// deduction from a template-id of a derived class of the argument type. |
| TDF_DerivedClass = 0x04 |
| }; |
| } |
| |
| using namespace clang; |
| |
| static Sema::TemplateDeductionResult |
| DeduceTemplateArguments(ASTContext &Context, |
| TemplateParameterList *TemplateParams, |
| const TemplateArgument &Param, |
| const TemplateArgument &Arg, |
| Sema::TemplateDeductionInfo &Info, |
| llvm::SmallVectorImpl<TemplateArgument> &Deduced); |
| |
| /// \brief If the given expression is of a form that permits the deduction |
| /// of a non-type template parameter, return the declaration of that |
| /// non-type template parameter. |
| static NonTypeTemplateParmDecl *getDeducedParameterFromExpr(Expr *E) { |
| if (ImplicitCastExpr *IC = dyn_cast<ImplicitCastExpr>(E)) |
| E = IC->getSubExpr(); |
| |
| if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) |
| return dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl()); |
| |
| return 0; |
| } |
| |
| /// \brief Deduce the value of the given non-type template parameter |
| /// from the given constant. |
| static Sema::TemplateDeductionResult |
| DeduceNonTypeTemplateArgument(ASTContext &Context, |
| NonTypeTemplateParmDecl *NTTP, |
| llvm::APSInt Value, |
| Sema::TemplateDeductionInfo &Info, |
| llvm::SmallVectorImpl<TemplateArgument> &Deduced) { |
| assert(NTTP->getDepth() == 0 && |
| "Cannot deduce non-type template argument with depth > 0"); |
| |
| if (Deduced[NTTP->getIndex()].isNull()) { |
| QualType T = NTTP->getType(); |
| |
| // FIXME: Make sure we didn't overflow our data type! |
| unsigned AllowedBits = Context.getTypeSize(T); |
| if (Value.getBitWidth() != AllowedBits) |
| Value.extOrTrunc(AllowedBits); |
| Value.setIsSigned(T->isSignedIntegerType()); |
| |
| Deduced[NTTP->getIndex()] = TemplateArgument(SourceLocation(), Value, T); |
| return Sema::TDK_Success; |
| } |
| |
| assert(Deduced[NTTP->getIndex()].getKind() == TemplateArgument::Integral); |
| |
| // If the template argument was previously deduced to a negative value, |
| // then our deduction fails. |
| const llvm::APSInt *PrevValuePtr = Deduced[NTTP->getIndex()].getAsIntegral(); |
| if (PrevValuePtr->isNegative()) { |
| Info.Param = NTTP; |
| Info.FirstArg = Deduced[NTTP->getIndex()]; |
| Info.SecondArg = TemplateArgument(SourceLocation(), Value, NTTP->getType()); |
| return Sema::TDK_Inconsistent; |
| } |
| |
| llvm::APSInt PrevValue = *PrevValuePtr; |
| if (Value.getBitWidth() > PrevValue.getBitWidth()) |
| PrevValue.zext(Value.getBitWidth()); |
| else if (Value.getBitWidth() < PrevValue.getBitWidth()) |
| Value.zext(PrevValue.getBitWidth()); |
| |
| if (Value != PrevValue) { |
| Info.Param = NTTP; |
| Info.FirstArg = Deduced[NTTP->getIndex()]; |
| Info.SecondArg = TemplateArgument(SourceLocation(), Value, NTTP->getType()); |
| return Sema::TDK_Inconsistent; |
| } |
| |
| return Sema::TDK_Success; |
| } |
| |
| /// \brief Deduce the value of the given non-type template parameter |
| /// from the given type- or value-dependent expression. |
| /// |
| /// \returns true if deduction succeeded, false otherwise. |
| |
| static Sema::TemplateDeductionResult |
| DeduceNonTypeTemplateArgument(ASTContext &Context, |
| NonTypeTemplateParmDecl *NTTP, |
| Expr *Value, |
| Sema::TemplateDeductionInfo &Info, |
| llvm::SmallVectorImpl<TemplateArgument> &Deduced) { |
| assert(NTTP->getDepth() == 0 && |
| "Cannot deduce non-type template argument with depth > 0"); |
| assert((Value->isTypeDependent() || Value->isValueDependent()) && |
| "Expression template argument must be type- or value-dependent."); |
| |
| if (Deduced[NTTP->getIndex()].isNull()) { |
| // FIXME: Clone the Value? |
| Deduced[NTTP->getIndex()] = TemplateArgument(Value); |
| return Sema::TDK_Success; |
| } |
| |
| if (Deduced[NTTP->getIndex()].getKind() == TemplateArgument::Integral) { |
| // Okay, we deduced a constant in one case and a dependent expression |
| // in another case. FIXME: Later, we will check that instantiating the |
| // dependent expression gives us the constant value. |
| return Sema::TDK_Success; |
| } |
| |
| // FIXME: Compare the expressions for equality! |
| return Sema::TDK_Success; |
| } |
| |
| static Sema::TemplateDeductionResult |
| DeduceTemplateArguments(ASTContext &Context, |
| TemplateName Param, |
| TemplateName Arg, |
| Sema::TemplateDeductionInfo &Info, |
| llvm::SmallVectorImpl<TemplateArgument> &Deduced) { |
| // FIXME: Implement template argument deduction for template |
| // template parameters. |
| |
| // FIXME: this routine does not have enough information to produce |
| // good diagnostics. |
| |
| TemplateDecl *ParamDecl = Param.getAsTemplateDecl(); |
| TemplateDecl *ArgDecl = Arg.getAsTemplateDecl(); |
| |
| if (!ParamDecl || !ArgDecl) { |
| // FIXME: fill in Info.Param/Info.FirstArg |
| return Sema::TDK_Inconsistent; |
| } |
| |
| ParamDecl = cast<TemplateDecl>(ParamDecl->getCanonicalDecl()); |
| ArgDecl = cast<TemplateDecl>(ArgDecl->getCanonicalDecl()); |
| if (ParamDecl != ArgDecl) { |
| // FIXME: fill in Info.Param/Info.FirstArg |
| return Sema::TDK_Inconsistent; |
| } |
| |
| return Sema::TDK_Success; |
| } |
| |
| /// \brief Deduce the template arguments by comparing the template parameter |
| /// type (which is a template-id) with the template argument type. |
| /// |
| /// \param Context the AST context in which this deduction occurs. |
| /// |
| /// \param TemplateParams the template parameters that we are deducing |
| /// |
| /// \param Param the parameter type |
| /// |
| /// \param Arg the argument type |
| /// |
| /// \param Info information about the template argument deduction itself |
| /// |
| /// \param Deduced the deduced template arguments |
| /// |
| /// \returns the result of template argument deduction so far. Note that a |
| /// "success" result means that template argument deduction has not yet failed, |
| /// but it may still fail, later, for other reasons. |
| static Sema::TemplateDeductionResult |
| DeduceTemplateArguments(ASTContext &Context, |
| TemplateParameterList *TemplateParams, |
| const TemplateSpecializationType *Param, |
| QualType Arg, |
| Sema::TemplateDeductionInfo &Info, |
| llvm::SmallVectorImpl<TemplateArgument> &Deduced) { |
| assert(Arg->isCanonical() && "Argument type must be canonical"); |
| |
| // Check whether the template argument is a dependent template-id. |
| // FIXME: This is untested code; it can be tested when we implement |
| // partial ordering of class template partial specializations. |
| if (const TemplateSpecializationType *SpecArg |
| = dyn_cast<TemplateSpecializationType>(Arg)) { |
| // Perform template argument deduction for the template name. |
| if (Sema::TemplateDeductionResult Result |
| = DeduceTemplateArguments(Context, |
| Param->getTemplateName(), |
| SpecArg->getTemplateName(), |
| Info, Deduced)) |
| return Result; |
| |
| unsigned NumArgs = Param->getNumArgs(); |
| |
| // FIXME: When one of the template-names refers to a |
| // declaration with default template arguments, do we need to |
| // fill in those default template arguments here? Most likely, |
| // the answer is "yes", but I don't see any references. This |
| // issue may be resolved elsewhere, because we may want to |
| // instantiate default template arguments when we actually write |
| // the template-id. |
| if (SpecArg->getNumArgs() != NumArgs) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| // Perform template argument deduction on each template |
| // argument. |
| for (unsigned I = 0; I != NumArgs; ++I) |
| if (Sema::TemplateDeductionResult Result |
| = DeduceTemplateArguments(Context, TemplateParams, |
| Param->getArg(I), |
| SpecArg->getArg(I), |
| Info, Deduced)) |
| return Result; |
| |
| return Sema::TDK_Success; |
| } |
| |
| // If the argument type is a class template specialization, we |
| // perform template argument deduction using its template |
| // arguments. |
| const RecordType *RecordArg = dyn_cast<RecordType>(Arg); |
| if (!RecordArg) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| ClassTemplateSpecializationDecl *SpecArg |
| = dyn_cast<ClassTemplateSpecializationDecl>(RecordArg->getDecl()); |
| if (!SpecArg) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| // Perform template argument deduction for the template name. |
| if (Sema::TemplateDeductionResult Result |
| = DeduceTemplateArguments(Context, |
| Param->getTemplateName(), |
| TemplateName(SpecArg->getSpecializedTemplate()), |
| Info, Deduced)) |
| return Result; |
| |
| // FIXME: Can the # of arguments in the parameter and the argument |
| // differ due to default arguments? |
| unsigned NumArgs = Param->getNumArgs(); |
| const TemplateArgumentList &ArgArgs = SpecArg->getTemplateArgs(); |
| if (NumArgs != ArgArgs.size()) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| for (unsigned I = 0; I != NumArgs; ++I) |
| if (Sema::TemplateDeductionResult Result |
| = DeduceTemplateArguments(Context, TemplateParams, |
| Param->getArg(I), |
| ArgArgs.get(I), |
| Info, Deduced)) |
| return Result; |
| |
| return Sema::TDK_Success; |
| } |
| |
| /// \brief Returns a completely-unqualified array type, capturing the |
| /// qualifiers in CVRQuals. |
| /// |
| /// \param Context the AST context in which the array type was built. |
| /// |
| /// \param T a canonical type that may be an array type. |
| /// |
| /// \param CVRQuals will receive the set of const/volatile/restrict qualifiers |
| /// that were applied to the element type of the array. |
| /// |
| /// \returns if \p T is an array type, the completely unqualified array type |
| /// that corresponds to T. Otherwise, returns T. |
| static QualType getUnqualifiedArrayType(ASTContext &Context, QualType T, |
| unsigned &CVRQuals) { |
| assert(T->isCanonical() && "Only operates on canonical types"); |
| if (!isa<ArrayType>(T)) { |
| CVRQuals = T.getCVRQualifiers(); |
| return T.getUnqualifiedType(); |
| } |
| |
| if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(T)) { |
| QualType Elt = getUnqualifiedArrayType(Context, CAT->getElementType(), |
| CVRQuals); |
| if (Elt == CAT->getElementType()) |
| return T; |
| |
| return Context.getConstantArrayType(Elt, CAT->getSize(), |
| CAT->getSizeModifier(), 0); |
| } |
| |
| if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(T)) { |
| QualType Elt = getUnqualifiedArrayType(Context, IAT->getElementType(), |
| CVRQuals); |
| if (Elt == IAT->getElementType()) |
| return T; |
| |
| return Context.getIncompleteArrayType(Elt, IAT->getSizeModifier(), 0); |
| } |
| |
| const DependentSizedArrayType *DSAT = cast<DependentSizedArrayType>(T); |
| QualType Elt = getUnqualifiedArrayType(Context, DSAT->getElementType(), |
| CVRQuals); |
| if (Elt == DSAT->getElementType()) |
| return T; |
| |
| // FIXME: Clone expression! |
| return Context.getDependentSizedArrayType(Elt, DSAT->getSizeExpr(), |
| DSAT->getSizeModifier(), 0, |
| SourceRange()); |
| } |
| |
| /// \brief Deduce the template arguments by comparing the parameter type and |
| /// the argument type (C++ [temp.deduct.type]). |
| /// |
| /// \param Context the AST context in which this deduction occurs. |
| /// |
| /// \param TemplateParams the template parameters that we are deducing |
| /// |
| /// \param ParamIn the parameter type |
| /// |
| /// \param ArgIn the argument type |
| /// |
| /// \param Info information about the template argument deduction itself |
| /// |
| /// \param Deduced the deduced template arguments |
| /// |
| /// \param TDF bitwise OR of the TemplateDeductionFlags bits that describe |
| /// how template argument deduction is performed. |
| /// |
| /// \returns the result of template argument deduction so far. Note that a |
| /// "success" result means that template argument deduction has not yet failed, |
| /// but it may still fail, later, for other reasons. |
| static Sema::TemplateDeductionResult |
| DeduceTemplateArguments(ASTContext &Context, |
| TemplateParameterList *TemplateParams, |
| QualType ParamIn, QualType ArgIn, |
| Sema::TemplateDeductionInfo &Info, |
| llvm::SmallVectorImpl<TemplateArgument> &Deduced, |
| unsigned TDF) { |
| // We only want to look at the canonical types, since typedefs and |
| // sugar are not part of template argument deduction. |
| QualType Param = Context.getCanonicalType(ParamIn); |
| QualType Arg = Context.getCanonicalType(ArgIn); |
| |
| // C++0x [temp.deduct.call]p4 bullet 1: |
| // - If the original P is a reference type, the deduced A (i.e., the type |
| // referred to by the reference) can be more cv-qualified than the |
| // transformed A. |
| if (TDF & TDF_ParamWithReferenceType) { |
| unsigned ExtraQualsOnParam |
| = Param.getCVRQualifiers() & ~Arg.getCVRQualifiers(); |
| Param.setCVRQualifiers(Param.getCVRQualifiers() & ~ExtraQualsOnParam); |
| } |
| |
| // If the parameter type is not dependent, there is nothing to deduce. |
| if (!Param->isDependentType()) |
| return Sema::TDK_Success; |
| |
| // C++ [temp.deduct.type]p9: |
| // A template type argument T, a template template argument TT or a |
| // template non-type argument i can be deduced if P and A have one of |
| // the following forms: |
| // |
| // T |
| // cv-list T |
| if (const TemplateTypeParmType *TemplateTypeParm |
| = Param->getAsTemplateTypeParmType()) { |
| unsigned Index = TemplateTypeParm->getIndex(); |
| bool RecanonicalizeArg = false; |
| |
| // If the argument type is an array type, move the qualifiers up to the |
| // top level, so they can be matched with the qualifiers on the parameter. |
| // FIXME: address spaces, ObjC GC qualifiers |
| if (isa<ArrayType>(Arg)) { |
| unsigned CVRQuals = 0; |
| Arg = getUnqualifiedArrayType(Context, Arg, CVRQuals); |
| if (CVRQuals) { |
| Arg = Arg.getWithAdditionalQualifiers(CVRQuals); |
| RecanonicalizeArg = true; |
| } |
| } |
| |
| // The argument type can not be less qualified than the parameter |
| // type. |
| if (Param.isMoreQualifiedThan(Arg) && !(TDF & TDF_IgnoreQualifiers)) { |
| Info.Param = cast<TemplateTypeParmDecl>(TemplateParams->getParam(Index)); |
| Info.FirstArg = Deduced[Index]; |
| Info.SecondArg = TemplateArgument(SourceLocation(), Arg); |
| return Sema::TDK_InconsistentQuals; |
| } |
| |
| assert(TemplateTypeParm->getDepth() == 0 && "Can't deduce with depth > 0"); |
| |
| unsigned Quals = Arg.getCVRQualifiers() & ~Param.getCVRQualifiers(); |
| QualType DeducedType = Arg.getQualifiedType(Quals); |
| if (RecanonicalizeArg) |
| DeducedType = Context.getCanonicalType(DeducedType); |
| |
| if (Deduced[Index].isNull()) |
| Deduced[Index] = TemplateArgument(SourceLocation(), DeducedType); |
| else { |
| // C++ [temp.deduct.type]p2: |
| // [...] If type deduction cannot be done for any P/A pair, or if for |
| // any pair the deduction leads to more than one possible set of |
| // deduced values, or if different pairs yield different deduced |
| // values, or if any template argument remains neither deduced nor |
| // explicitly specified, template argument deduction fails. |
| if (Deduced[Index].getAsType() != DeducedType) { |
| Info.Param |
| = cast<TemplateTypeParmDecl>(TemplateParams->getParam(Index)); |
| Info.FirstArg = Deduced[Index]; |
| Info.SecondArg = TemplateArgument(SourceLocation(), Arg); |
| return Sema::TDK_Inconsistent; |
| } |
| } |
| return Sema::TDK_Success; |
| } |
| |
| // Set up the template argument deduction information for a failure. |
| Info.FirstArg = TemplateArgument(SourceLocation(), ParamIn); |
| Info.SecondArg = TemplateArgument(SourceLocation(), ArgIn); |
| |
| // Check the cv-qualifiers on the parameter and argument types. |
| if (!(TDF & TDF_IgnoreQualifiers)) { |
| if (TDF & TDF_ParamWithReferenceType) { |
| if (Param.isMoreQualifiedThan(Arg)) |
| return Sema::TDK_NonDeducedMismatch; |
| } else { |
| if (Param.getCVRQualifiers() != Arg.getCVRQualifiers()) |
| return Sema::TDK_NonDeducedMismatch; |
| } |
| } |
| |
| switch (Param->getTypeClass()) { |
| // No deduction possible for these types |
| case Type::Builtin: |
| return Sema::TDK_NonDeducedMismatch; |
| |
| // T * |
| case Type::Pointer: { |
| const PointerType *PointerArg = Arg->getAs<PointerType>(); |
| if (!PointerArg) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| unsigned SubTDF = TDF & (TDF_IgnoreQualifiers | TDF_DerivedClass); |
| return DeduceTemplateArguments(Context, TemplateParams, |
| cast<PointerType>(Param)->getPointeeType(), |
| PointerArg->getPointeeType(), |
| Info, Deduced, SubTDF); |
| } |
| |
| // T & |
| case Type::LValueReference: { |
| const LValueReferenceType *ReferenceArg = Arg->getAs<LValueReferenceType>(); |
| if (!ReferenceArg) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| return DeduceTemplateArguments(Context, TemplateParams, |
| cast<LValueReferenceType>(Param)->getPointeeType(), |
| ReferenceArg->getPointeeType(), |
| Info, Deduced, 0); |
| } |
| |
| // T && [C++0x] |
| case Type::RValueReference: { |
| const RValueReferenceType *ReferenceArg = Arg->getAs<RValueReferenceType>(); |
| if (!ReferenceArg) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| return DeduceTemplateArguments(Context, TemplateParams, |
| cast<RValueReferenceType>(Param)->getPointeeType(), |
| ReferenceArg->getPointeeType(), |
| Info, Deduced, 0); |
| } |
| |
| // T [] (implied, but not stated explicitly) |
| case Type::IncompleteArray: { |
| const IncompleteArrayType *IncompleteArrayArg = |
| Context.getAsIncompleteArrayType(Arg); |
| if (!IncompleteArrayArg) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| return DeduceTemplateArguments(Context, TemplateParams, |
| Context.getAsIncompleteArrayType(Param)->getElementType(), |
| IncompleteArrayArg->getElementType(), |
| Info, Deduced, 0); |
| } |
| |
| // T [integer-constant] |
| case Type::ConstantArray: { |
| const ConstantArrayType *ConstantArrayArg = |
| Context.getAsConstantArrayType(Arg); |
| if (!ConstantArrayArg) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| const ConstantArrayType *ConstantArrayParm = |
| Context.getAsConstantArrayType(Param); |
| if (ConstantArrayArg->getSize() != ConstantArrayParm->getSize()) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| return DeduceTemplateArguments(Context, TemplateParams, |
| ConstantArrayParm->getElementType(), |
| ConstantArrayArg->getElementType(), |
| Info, Deduced, 0); |
| } |
| |
| // type [i] |
| case Type::DependentSizedArray: { |
| const ArrayType *ArrayArg = dyn_cast<ArrayType>(Arg); |
| if (!ArrayArg) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| // Check the element type of the arrays |
| const DependentSizedArrayType *DependentArrayParm |
| = cast<DependentSizedArrayType>(Param); |
| if (Sema::TemplateDeductionResult Result |
| = DeduceTemplateArguments(Context, TemplateParams, |
| DependentArrayParm->getElementType(), |
| ArrayArg->getElementType(), |
| Info, Deduced, 0)) |
| return Result; |
| |
| // Determine the array bound is something we can deduce. |
| NonTypeTemplateParmDecl *NTTP |
| = getDeducedParameterFromExpr(DependentArrayParm->getSizeExpr()); |
| if (!NTTP) |
| return Sema::TDK_Success; |
| |
| // We can perform template argument deduction for the given non-type |
| // template parameter. |
| assert(NTTP->getDepth() == 0 && |
| "Cannot deduce non-type template argument at depth > 0"); |
| if (const ConstantArrayType *ConstantArrayArg |
| = dyn_cast<ConstantArrayType>(ArrayArg)) { |
| llvm::APSInt Size(ConstantArrayArg->getSize()); |
| return DeduceNonTypeTemplateArgument(Context, NTTP, Size, |
| Info, Deduced); |
| } |
| if (const DependentSizedArrayType *DependentArrayArg |
| = dyn_cast<DependentSizedArrayType>(ArrayArg)) |
| return DeduceNonTypeTemplateArgument(Context, NTTP, |
| DependentArrayArg->getSizeExpr(), |
| Info, Deduced); |
| |
| // Incomplete type does not match a dependently-sized array type |
| return Sema::TDK_NonDeducedMismatch; |
| } |
| |
| // type(*)(T) |
| // T(*)() |
| // T(*)(T) |
| case Type::FunctionProto: { |
| const FunctionProtoType *FunctionProtoArg = |
| dyn_cast<FunctionProtoType>(Arg); |
| if (!FunctionProtoArg) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| const FunctionProtoType *FunctionProtoParam = |
| cast<FunctionProtoType>(Param); |
| |
| if (FunctionProtoParam->getTypeQuals() != |
| FunctionProtoArg->getTypeQuals()) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| if (FunctionProtoParam->getNumArgs() != FunctionProtoArg->getNumArgs()) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| if (FunctionProtoParam->isVariadic() != FunctionProtoArg->isVariadic()) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| // Check return types. |
| if (Sema::TemplateDeductionResult Result |
| = DeduceTemplateArguments(Context, TemplateParams, |
| FunctionProtoParam->getResultType(), |
| FunctionProtoArg->getResultType(), |
| Info, Deduced, 0)) |
| return Result; |
| |
| for (unsigned I = 0, N = FunctionProtoParam->getNumArgs(); I != N; ++I) { |
| // Check argument types. |
| if (Sema::TemplateDeductionResult Result |
| = DeduceTemplateArguments(Context, TemplateParams, |
| FunctionProtoParam->getArgType(I), |
| FunctionProtoArg->getArgType(I), |
| Info, Deduced, 0)) |
| return Result; |
| } |
| |
| return Sema::TDK_Success; |
| } |
| |
| // template-name<T> (where template-name refers to a class template) |
| // template-name<i> |
| // TT<T> (TODO) |
| // TT<i> (TODO) |
| // TT<> (TODO) |
| case Type::TemplateSpecialization: { |
| const TemplateSpecializationType *SpecParam |
| = cast<TemplateSpecializationType>(Param); |
| |
| // Try to deduce template arguments from the template-id. |
| Sema::TemplateDeductionResult Result |
| = DeduceTemplateArguments(Context, TemplateParams, SpecParam, Arg, |
| Info, Deduced); |
| |
| if (Result && (TDF & TDF_DerivedClass) && |
| Result != Sema::TDK_Inconsistent) { |
| // C++ [temp.deduct.call]p3b3: |
| // If P is a class, and P has the form template-id, then A can be a |
| // derived class of the deduced A. Likewise, if P is a pointer to a |
| // class of the form template-id, A can be a pointer to a derived |
| // class pointed to by the deduced A. |
| // |
| // More importantly: |
| // These alternatives are considered only if type deduction would |
| // otherwise fail. |
| if (const RecordType *RecordT = dyn_cast<RecordType>(Arg)) { |
| // Use data recursion to crawl through the list of base classes. |
| // Visited contains the set of nodes we have already visited, while |
| // ToVisit is our stack of records that we still need to visit. |
| llvm::SmallPtrSet<const RecordType *, 8> Visited; |
| llvm::SmallVector<const RecordType *, 8> ToVisit; |
| ToVisit.push_back(RecordT); |
| bool Successful = false; |
| while (!ToVisit.empty()) { |
| // Retrieve the next class in the inheritance hierarchy. |
| const RecordType *NextT = ToVisit.back(); |
| ToVisit.pop_back(); |
| |
| // If we have already seen this type, skip it. |
| if (!Visited.insert(NextT)) |
| continue; |
| |
| // If this is a base class, try to perform template argument |
| // deduction from it. |
| if (NextT != RecordT) { |
| Sema::TemplateDeductionResult BaseResult |
| = DeduceTemplateArguments(Context, TemplateParams, SpecParam, |
| QualType(NextT, 0), Info, Deduced); |
| |
| // If template argument deduction for this base was successful, |
| // note that we had some success. |
| if (BaseResult == Sema::TDK_Success) |
| Successful = true; |
| // If deduction against this base resulted in an inconsistent |
| // set of deduced template arguments, template argument |
| // deduction fails. |
| else if (BaseResult == Sema::TDK_Inconsistent) |
| return BaseResult; |
| } |
| |
| // Visit base classes |
| CXXRecordDecl *Next = cast<CXXRecordDecl>(NextT->getDecl()); |
| for (CXXRecordDecl::base_class_iterator Base = Next->bases_begin(), |
| BaseEnd = Next->bases_end(); |
| Base != BaseEnd; ++Base) { |
| assert(Base->getType()->isRecordType() && |
| "Base class that isn't a record?"); |
| ToVisit.push_back(Base->getType()->getAs<RecordType>()); |
| } |
| } |
| |
| if (Successful) |
| return Sema::TDK_Success; |
| } |
| |
| } |
| |
| return Result; |
| } |
| |
| // T type::* |
| // T T::* |
| // T (type::*)() |
| // type (T::*)() |
| // type (type::*)(T) |
| // type (T::*)(T) |
| // T (type::*)(T) |
| // T (T::*)() |
| // T (T::*)(T) |
| case Type::MemberPointer: { |
| const MemberPointerType *MemPtrParam = cast<MemberPointerType>(Param); |
| const MemberPointerType *MemPtrArg = dyn_cast<MemberPointerType>(Arg); |
| if (!MemPtrArg) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| if (Sema::TemplateDeductionResult Result |
| = DeduceTemplateArguments(Context, TemplateParams, |
| MemPtrParam->getPointeeType(), |
| MemPtrArg->getPointeeType(), |
| Info, Deduced, |
| TDF & TDF_IgnoreQualifiers)) |
| return Result; |
| |
| return DeduceTemplateArguments(Context, TemplateParams, |
| QualType(MemPtrParam->getClass(), 0), |
| QualType(MemPtrArg->getClass(), 0), |
| Info, Deduced, 0); |
| } |
| |
| // (clang extension) |
| // |
| // type(^)(T) |
| // T(^)() |
| // T(^)(T) |
| case Type::BlockPointer: { |
| const BlockPointerType *BlockPtrParam = cast<BlockPointerType>(Param); |
| const BlockPointerType *BlockPtrArg = dyn_cast<BlockPointerType>(Arg); |
| |
| if (!BlockPtrArg) |
| return Sema::TDK_NonDeducedMismatch; |
| |
| return DeduceTemplateArguments(Context, TemplateParams, |
| BlockPtrParam->getPointeeType(), |
| BlockPtrArg->getPointeeType(), Info, |
| Deduced, 0); |
| } |
| |
| case Type::TypeOfExpr: |
| case Type::TypeOf: |
| case Type::Typename: |
| // No template argument deduction for these types |
| return Sema::TDK_Success; |
| |
| default: |
| break; |
| } |
| |
| // FIXME: Many more cases to go (to go). |
| return Sema::TDK_Success; |
| } |
| |
| static Sema::TemplateDeductionResult |
| DeduceTemplateArguments(ASTContext &Context, |
| TemplateParameterList *TemplateParams, |
| const TemplateArgument &Param, |
| const TemplateArgument &Arg, |
| Sema::TemplateDeductionInfo &Info, |
| llvm::SmallVectorImpl<TemplateArgument> &Deduced) { |
| switch (Param.getKind()) { |
| case TemplateArgument::Null: |
| assert(false && "Null template argument in parameter list"); |
| break; |
| |
| case TemplateArgument::Type: |
| assert(Arg.getKind() == TemplateArgument::Type && "Type/value mismatch"); |
| return DeduceTemplateArguments(Context, TemplateParams, Param.getAsType(), |
| Arg.getAsType(), Info, Deduced, 0); |
| |
| case TemplateArgument::Declaration: |
| // FIXME: Implement this check |
| assert(false && "Unimplemented template argument deduction case"); |
| Info.FirstArg = Param; |
| Info.SecondArg = Arg; |
| return Sema::TDK_NonDeducedMismatch; |
| |
| case TemplateArgument::Integral: |
| if (Arg.getKind() == TemplateArgument::Integral) { |
| // FIXME: Zero extension + sign checking here? |
| if (*Param.getAsIntegral() == *Arg.getAsIntegral()) |
| return Sema::TDK_Success; |
| |
| Info.FirstArg = Param; |
| Info.SecondArg = Arg; |
| return Sema::TDK_NonDeducedMismatch; |
| } |
| |
| if (Arg.getKind() == TemplateArgument::Expression) { |
| Info.FirstArg = Param; |
| Info.SecondArg = Arg; |
| return Sema::TDK_NonDeducedMismatch; |
| } |
| |
| assert(false && "Type/value mismatch"); |
| Info.FirstArg = Param; |
| Info.SecondArg = Arg; |
| return Sema::TDK_NonDeducedMismatch; |
| |
| case TemplateArgument::Expression: { |
| if (NonTypeTemplateParmDecl *NTTP |
| = getDeducedParameterFromExpr(Param.getAsExpr())) { |
| if (Arg.getKind() == TemplateArgument::Integral) |
| // FIXME: Sign problems here |
| return DeduceNonTypeTemplateArgument(Context, NTTP, |
| *Arg.getAsIntegral(), |
| Info, Deduced); |
| if (Arg.getKind() == TemplateArgument::Expression) |
| return DeduceNonTypeTemplateArgument(Context, NTTP, Arg.getAsExpr(), |
| Info, Deduced); |
| |
| assert(false && "Type/value mismatch"); |
| Info.FirstArg = Param; |
| Info.SecondArg = Arg; |
| return Sema::TDK_NonDeducedMismatch; |
| } |
| |
| // Can't deduce anything, but that's okay. |
| return Sema::TDK_Success; |
| } |
| case TemplateArgument::Pack: |
| assert(0 && "FIXME: Implement!"); |
| break; |
| } |
| |
| return Sema::TDK_Success; |
| } |
| |
| static Sema::TemplateDeductionResult |
| DeduceTemplateArguments(ASTContext &Context, |
| TemplateParameterList *TemplateParams, |
| const TemplateArgumentList &ParamList, |
| const TemplateArgumentList &ArgList, |
| Sema::TemplateDeductionInfo &Info, |
| llvm::SmallVectorImpl<TemplateArgument> &Deduced) { |
| assert(ParamList.size() == ArgList.size()); |
| for (unsigned I = 0, N = ParamList.size(); I != N; ++I) { |
| if (Sema::TemplateDeductionResult Result |
| = DeduceTemplateArguments(Context, TemplateParams, |
| ParamList[I], ArgList[I], |
| Info, Deduced)) |
| return Result; |
| } |
| return Sema::TDK_Success; |
| } |
| |
| /// \brief Determine whether two template arguments are the same. |
| static bool isSameTemplateArg(ASTContext &Context, |
| const TemplateArgument &X, |
| const TemplateArgument &Y) { |
| if (X.getKind() != Y.getKind()) |
| return false; |
| |
| switch (X.getKind()) { |
| case TemplateArgument::Null: |
| assert(false && "Comparing NULL template argument"); |
| break; |
| |
| case TemplateArgument::Type: |
| return Context.getCanonicalType(X.getAsType()) == |
| Context.getCanonicalType(Y.getAsType()); |
| |
| case TemplateArgument::Declaration: |
| return X.getAsDecl()->getCanonicalDecl() == |
| Y.getAsDecl()->getCanonicalDecl(); |
| |
| case TemplateArgument::Integral: |
| return *X.getAsIntegral() == *Y.getAsIntegral(); |
| |
| case TemplateArgument::Expression: |
| // FIXME: We assume that all expressions are distinct, but we should |
| // really check their canonical forms. |
| return false; |
| |
| case TemplateArgument::Pack: |
| if (X.pack_size() != Y.pack_size()) |
| return false; |
| |
| for (TemplateArgument::pack_iterator XP = X.pack_begin(), |
| XPEnd = X.pack_end(), |
| YP = Y.pack_begin(); |
| XP != XPEnd; ++XP, ++YP) |
| if (!isSameTemplateArg(Context, *XP, *YP)) |
| return false; |
| |
| return true; |
| } |
| |
| return false; |
| } |
| |
| /// \brief Helper function to build a TemplateParameter when we don't |
| /// know its type statically. |
| static TemplateParameter makeTemplateParameter(Decl *D) { |
| if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(D)) |
| return TemplateParameter(TTP); |
| else if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(D)) |
| return TemplateParameter(NTTP); |
| |
| return TemplateParameter(cast<TemplateTemplateParmDecl>(D)); |
| } |
| |
| /// \brief Perform template argument deduction to determine whether |
| /// the given template arguments match the given class template |
| /// partial specialization per C++ [temp.class.spec.match]. |
| Sema::TemplateDeductionResult |
| Sema::DeduceTemplateArguments(ClassTemplatePartialSpecializationDecl *Partial, |
| const TemplateArgumentList &TemplateArgs, |
| TemplateDeductionInfo &Info) { |
| // C++ [temp.class.spec.match]p2: |
| // A partial specialization matches a given actual template |
| // argument list if the template arguments of the partial |
| // specialization can be deduced from the actual template argument |
| // list (14.8.2). |
| SFINAETrap Trap(*this); |
| llvm::SmallVector<TemplateArgument, 4> Deduced; |
| Deduced.resize(Partial->getTemplateParameters()->size()); |
| if (TemplateDeductionResult Result |
| = ::DeduceTemplateArguments(Context, |
| Partial->getTemplateParameters(), |
| Partial->getTemplateArgs(), |
| TemplateArgs, Info, Deduced)) |
| return Result; |
| |
| InstantiatingTemplate Inst(*this, Partial->getLocation(), Partial, |
| Deduced.data(), Deduced.size()); |
| if (Inst) |
| return TDK_InstantiationDepth; |
| |
| // C++ [temp.deduct.type]p2: |
| // [...] or if any template argument remains neither deduced nor |
| // explicitly specified, template argument deduction fails. |
| TemplateArgumentListBuilder Builder(Partial->getTemplateParameters(), |
| Deduced.size()); |
| for (unsigned I = 0, N = Deduced.size(); I != N; ++I) { |
| if (Deduced[I].isNull()) { |
| Decl *Param |
| = const_cast<Decl *>(Partial->getTemplateParameters()->getParam(I)); |
| if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) |
| Info.Param = TTP; |
| else if (NonTypeTemplateParmDecl *NTTP |
| = dyn_cast<NonTypeTemplateParmDecl>(Param)) |
| Info.Param = NTTP; |
| else |
| Info.Param = cast<TemplateTemplateParmDecl>(Param); |
| return TDK_Incomplete; |
| } |
| |
| Builder.Append(Deduced[I]); |
| } |
| |
| // Form the template argument list from the deduced template arguments. |
| TemplateArgumentList *DeducedArgumentList |
| = new (Context) TemplateArgumentList(Context, Builder, /*TakeArgs=*/true); |
| Info.reset(DeducedArgumentList); |
| |
| // Substitute the deduced template arguments into the template |
| // arguments of the class template partial specialization, and |
| // verify that the instantiated template arguments are both valid |
| // and are equivalent to the template arguments originally provided |
| // to the class template. |
| ClassTemplateDecl *ClassTemplate = Partial->getSpecializedTemplate(); |
| const TemplateArgumentList &PartialTemplateArgs = Partial->getTemplateArgs(); |
| for (unsigned I = 0, N = PartialTemplateArgs.flat_size(); I != N; ++I) { |
| Decl *Param = const_cast<Decl *>( |
| ClassTemplate->getTemplateParameters()->getParam(I)); |
| TemplateArgument InstArg = Instantiate(PartialTemplateArgs[I], |
| *DeducedArgumentList); |
| if (InstArg.isNull()) { |
| Info.Param = makeTemplateParameter(Param); |
| Info.FirstArg = PartialTemplateArgs[I]; |
| return TDK_SubstitutionFailure; |
| } |
| |
| if (InstArg.getKind() == TemplateArgument::Expression) { |
| // When the argument is an expression, check the expression result |
| // against the actual template parameter to get down to the canonical |
| // template argument. |
| Expr *InstExpr = InstArg.getAsExpr(); |
| if (NonTypeTemplateParmDecl *NTTP |
| = dyn_cast<NonTypeTemplateParmDecl>(Param)) { |
| if (CheckTemplateArgument(NTTP, NTTP->getType(), InstExpr, InstArg)) { |
| Info.Param = makeTemplateParameter(Param); |
| Info.FirstArg = PartialTemplateArgs[I]; |
| return TDK_SubstitutionFailure; |
| } |
| } else if (TemplateTemplateParmDecl *TTP |
| = dyn_cast<TemplateTemplateParmDecl>(Param)) { |
| // FIXME: template template arguments should really resolve to decls |
| DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(InstExpr); |
| if (!DRE || CheckTemplateArgument(TTP, DRE)) { |
| Info.Param = makeTemplateParameter(Param); |
| Info.FirstArg = PartialTemplateArgs[I]; |
| return TDK_SubstitutionFailure; |
| } |
| } |
| } |
| |
| if (!isSameTemplateArg(Context, TemplateArgs[I], InstArg)) { |
| Info.Param = makeTemplateParameter(Param); |
| Info.FirstArg = TemplateArgs[I]; |
| Info.SecondArg = InstArg; |
| return TDK_NonDeducedMismatch; |
| } |
| } |
| |
| if (Trap.hasErrorOccurred()) |
| return TDK_SubstitutionFailure; |
| |
| return TDK_Success; |
| } |
| |
| /// \brief Determine whether the given type T is a simple-template-id type. |
| static bool isSimpleTemplateIdType(QualType T) { |
| if (const TemplateSpecializationType *Spec |
| = T->getAsTemplateSpecializationType()) |
| return Spec->getTemplateName().getAsTemplateDecl() != 0; |
| |
| return false; |
| } |
| |
| /// \brief Substitute the explicitly-provided template arguments into the |
| /// given function template according to C++ [temp.arg.explicit]. |
| /// |
| /// \param FunctionTemplate the function template into which the explicit |
| /// template arguments will be substituted. |
| /// |
| /// \param ExplicitTemplateArguments the explicitly-specified template |
| /// arguments. |
| /// |
| /// \param NumExplicitTemplateArguments the number of explicitly-specified |
| /// template arguments in @p ExplicitTemplateArguments. This value may be zero. |
| /// |
| /// \param Deduced the deduced template arguments, which will be populated |
| /// with the converted and checked explicit template arguments. |
| /// |
| /// \param ParamTypes will be populated with the instantiated function |
| /// parameters. |
| /// |
| /// \param FunctionType if non-NULL, the result type of the function template |
| /// will also be instantiated and the pointed-to value will be updated with |
| /// the instantiated function type. |
| /// |
| /// \param Info if substitution fails for any reason, this object will be |
| /// populated with more information about the failure. |
| /// |
| /// \returns TDK_Success if substitution was successful, or some failure |
| /// condition. |
| Sema::TemplateDeductionResult |
| Sema::SubstituteExplicitTemplateArguments( |
| FunctionTemplateDecl *FunctionTemplate, |
| const TemplateArgument *ExplicitTemplateArgs, |
| unsigned NumExplicitTemplateArgs, |
| llvm::SmallVectorImpl<TemplateArgument> &Deduced, |
| llvm::SmallVectorImpl<QualType> &ParamTypes, |
| QualType *FunctionType, |
| TemplateDeductionInfo &Info) { |
| FunctionDecl *Function = FunctionTemplate->getTemplatedDecl(); |
| TemplateParameterList *TemplateParams |
| = FunctionTemplate->getTemplateParameters(); |
| |
| if (NumExplicitTemplateArgs == 0) { |
| // No arguments to substitute; just copy over the parameter types and |
| // fill in the function type. |
| for (FunctionDecl::param_iterator P = Function->param_begin(), |
| PEnd = Function->param_end(); |
| P != PEnd; |
| ++P) |
| ParamTypes.push_back((*P)->getType()); |
| |
| if (FunctionType) |
| *FunctionType = Function->getType(); |
| return TDK_Success; |
| } |
| |
| // Substitution of the explicit template arguments into a function template |
| /// is a SFINAE context. Trap any errors that might occur. |
| SFINAETrap Trap(*this); |
| |
| // C++ [temp.arg.explicit]p3: |
| // Template arguments that are present shall be specified in the |
| // declaration order of their corresponding template-parameters. The |
| // template argument list shall not specify more template-arguments than |
| // there are corresponding template-parameters. |
| TemplateArgumentListBuilder Builder(TemplateParams, |
| NumExplicitTemplateArgs); |
| |
| // Enter a new template instantiation context where we check the |
| // explicitly-specified template arguments against this function template, |
| // and then substitute them into the function parameter types. |
| InstantiatingTemplate Inst(*this, FunctionTemplate->getLocation(), |
| FunctionTemplate, Deduced.data(), Deduced.size(), |
| ActiveTemplateInstantiation::ExplicitTemplateArgumentSubstitution); |
| if (Inst) |
| return TDK_InstantiationDepth; |
| |
| if (CheckTemplateArgumentList(FunctionTemplate, |
| SourceLocation(), SourceLocation(), |
| ExplicitTemplateArgs, |
| NumExplicitTemplateArgs, |
| SourceLocation(), |
| true, |
| Builder) || Trap.hasErrorOccurred()) |
| return TDK_InvalidExplicitArguments; |
| |
| // Form the template argument list from the explicitly-specified |
| // template arguments. |
| TemplateArgumentList *ExplicitArgumentList |
| = new (Context) TemplateArgumentList(Context, Builder, /*TakeArgs=*/true); |
| Info.reset(ExplicitArgumentList); |
| |
| // Instantiate the types of each of the function parameters given the |
| // explicitly-specified template arguments. |
| for (FunctionDecl::param_iterator P = Function->param_begin(), |
| PEnd = Function->param_end(); |
| P != PEnd; |
| ++P) { |
| QualType ParamType = InstantiateType((*P)->getType(), |
| *ExplicitArgumentList, |
| (*P)->getLocation(), |
| (*P)->getDeclName()); |
| if (ParamType.isNull() || Trap.hasErrorOccurred()) |
| return TDK_SubstitutionFailure; |
| |
| ParamTypes.push_back(ParamType); |
| } |
| |
| // If the caller wants a full function type back, instantiate the return |
| // type and form that function type. |
| if (FunctionType) { |
| // FIXME: exception-specifications? |
| const FunctionProtoType *Proto |
| = Function->getType()->getAsFunctionProtoType(); |
| assert(Proto && "Function template does not have a prototype?"); |
| |
| QualType ResultType = InstantiateType(Proto->getResultType(), |
| *ExplicitArgumentList, |
| Function->getTypeSpecStartLoc(), |
| Function->getDeclName()); |
| if (ResultType.isNull() || Trap.hasErrorOccurred()) |
| return TDK_SubstitutionFailure; |
| |
| *FunctionType = BuildFunctionType(ResultType, |
| ParamTypes.data(), ParamTypes.size(), |
| Proto->isVariadic(), |
| Proto->getTypeQuals(), |
| Function->getLocation(), |
| Function->getDeclName()); |
| if (FunctionType->isNull() || Trap.hasErrorOccurred()) |
| return TDK_SubstitutionFailure; |
| } |
| |
| // C++ [temp.arg.explicit]p2: |
| // Trailing template arguments that can be deduced (14.8.2) may be |
| // omitted from the list of explicit template-arguments. If all of the |
| // template arguments can be deduced, they may all be omitted; in this |
| // case, the empty template argument list <> itself may also be omitted. |
| // |
| // Take all of the explicitly-specified arguments and put them into the |
| // set of deduced template arguments. |
| Deduced.reserve(TemplateParams->size()); |
| for (unsigned I = 0, N = ExplicitArgumentList->size(); I != N; ++I) |
| Deduced.push_back(ExplicitArgumentList->get(I)); |
| |
| return TDK_Success; |
| } |
| |
| /// \brief Finish template argument deduction for a function template, |
| /// checking the deduced template arguments for completeness and forming |
| /// the function template specialization. |
| Sema::TemplateDeductionResult |
| Sema::FinishTemplateArgumentDeduction(FunctionTemplateDecl *FunctionTemplate, |
| llvm::SmallVectorImpl<TemplateArgument> &Deduced, |
| FunctionDecl *&Specialization, |
| TemplateDeductionInfo &Info) { |
| TemplateParameterList *TemplateParams |
| = FunctionTemplate->getTemplateParameters(); |
| |
| // C++ [temp.deduct.type]p2: |
| // [...] or if any template argument remains neither deduced nor |
| // explicitly specified, template argument deduction fails. |
| TemplateArgumentListBuilder Builder(TemplateParams, Deduced.size()); |
| for (unsigned I = 0, N = Deduced.size(); I != N; ++I) { |
| if (Deduced[I].isNull()) { |
| Info.Param = makeTemplateParameter( |
| const_cast<Decl *>(TemplateParams->getParam(I))); |
| return TDK_Incomplete; |
| } |
| |
| Builder.Append(Deduced[I]); |
| } |
| |
| // Form the template argument list from the deduced template arguments. |
| TemplateArgumentList *DeducedArgumentList |
| = new (Context) TemplateArgumentList(Context, Builder, /*TakeArgs=*/true); |
| Info.reset(DeducedArgumentList); |
| |
| // Template argument deduction for function templates in a SFINAE context. |
| // Trap any errors that might occur. |
| SFINAETrap Trap(*this); |
| |
| // Enter a new template instantiation context while we instantiate the |
| // actual function declaration. |
| InstantiatingTemplate Inst(*this, FunctionTemplate->getLocation(), |
| FunctionTemplate, Deduced.data(), Deduced.size(), |
| ActiveTemplateInstantiation::DeducedTemplateArgumentSubstitution); |
| if (Inst) |
| return TDK_InstantiationDepth; |
| |
| // Substitute the deduced template arguments into the function template |
| // declaration to produce the function template specialization. |
| Specialization = cast_or_null<FunctionDecl>( |
| InstantiateDecl(FunctionTemplate->getTemplatedDecl(), |
| FunctionTemplate->getDeclContext(), |
| *DeducedArgumentList)); |
| if (!Specialization) |
| return TDK_SubstitutionFailure; |
| |
| // If the template argument list is owned by the function template |
| // specialization, release it. |
| if (Specialization->getTemplateSpecializationArgs() == DeducedArgumentList) |
| Info.take(); |
| |
| // There may have been an error that did not prevent us from constructing a |
| // declaration. Mark the declaration invalid and return with a substitution |
| // failure. |
| if (Trap.hasErrorOccurred()) { |
| Specialization->setInvalidDecl(true); |
| return TDK_SubstitutionFailure; |
| } |
| |
| return TDK_Success; |
| } |
| |
| /// \brief Perform template argument deduction from a function call |
| /// (C++ [temp.deduct.call]). |
| /// |
| /// \param FunctionTemplate the function template for which we are performing |
| /// template argument deduction. |
| /// |
| /// \param HasExplicitTemplateArgs whether any template arguments were |
| /// explicitly specified. |
| /// |
| /// \param ExplicitTemplateArguments when @p HasExplicitTemplateArgs is true, |
| /// the explicitly-specified template arguments. |
| /// |
| /// \param NumExplicitTemplateArguments when @p HasExplicitTemplateArgs is true, |
| /// the number of explicitly-specified template arguments in |
| /// @p ExplicitTemplateArguments. This value may be zero. |
| /// |
| /// \param Args the function call arguments |
| /// |
| /// \param NumArgs the number of arguments in Args |
| /// |
| /// \param Specialization if template argument deduction was successful, |
| /// this will be set to the function template specialization produced by |
| /// template argument deduction. |
| /// |
| /// \param Info the argument will be updated to provide additional information |
| /// about template argument deduction. |
| /// |
| /// \returns the result of template argument deduction. |
| Sema::TemplateDeductionResult |
| Sema::DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate, |
| bool HasExplicitTemplateArgs, |
| const TemplateArgument *ExplicitTemplateArgs, |
| unsigned NumExplicitTemplateArgs, |
| Expr **Args, unsigned NumArgs, |
| FunctionDecl *&Specialization, |
| TemplateDeductionInfo &Info) { |
| FunctionDecl *Function = FunctionTemplate->getTemplatedDecl(); |
| |
| // C++ [temp.deduct.call]p1: |
| // Template argument deduction is done by comparing each function template |
| // parameter type (call it P) with the type of the corresponding argument |
| // of the call (call it A) as described below. |
| unsigned CheckArgs = NumArgs; |
| if (NumArgs < Function->getMinRequiredArguments()) |
| return TDK_TooFewArguments; |
| else if (NumArgs > Function->getNumParams()) { |
| const FunctionProtoType *Proto |
| = Function->getType()->getAsFunctionProtoType(); |
| if (!Proto->isVariadic()) |
| return TDK_TooManyArguments; |
| |
| CheckArgs = Function->getNumParams(); |
| } |
| |
| // The types of the parameters from which we will perform template argument |
| // deduction. |
| TemplateParameterList *TemplateParams |
| = FunctionTemplate->getTemplateParameters(); |
| llvm::SmallVector<TemplateArgument, 4> Deduced; |
| llvm::SmallVector<QualType, 4> ParamTypes; |
| if (NumExplicitTemplateArgs) { |
| TemplateDeductionResult Result = |
| SubstituteExplicitTemplateArguments(FunctionTemplate, |
| ExplicitTemplateArgs, |
| NumExplicitTemplateArgs, |
| Deduced, |
| ParamTypes, |
| 0, |
| Info); |
| if (Result) |
| return Result; |
| } else { |
| // Just fill in the parameter types from the function declaration. |
| for (unsigned I = 0; I != CheckArgs; ++I) |
| ParamTypes.push_back(Function->getParamDecl(I)->getType()); |
| } |
| |
| // Deduce template arguments from the function parameters. |
| Deduced.resize(TemplateParams->size()); |
| for (unsigned I = 0; I != CheckArgs; ++I) { |
| QualType ParamType = ParamTypes[I]; |
| QualType ArgType = Args[I]->getType(); |
| |
| // C++ [temp.deduct.call]p2: |
| // If P is not a reference type: |
| QualType CanonParamType = Context.getCanonicalType(ParamType); |
| bool ParamWasReference = isa<ReferenceType>(CanonParamType); |
| if (!ParamWasReference) { |
| // - If A is an array type, the pointer type produced by the |
| // array-to-pointer standard conversion (4.2) is used in place of |
| // A for type deduction; otherwise, |
| if (ArgType->isArrayType()) |
| ArgType = Context.getArrayDecayedType(ArgType); |
| // - If A is a function type, the pointer type produced by the |
| // function-to-pointer standard conversion (4.3) is used in place |
| // of A for type deduction; otherwise, |
| else if (ArgType->isFunctionType()) |
| ArgType = Context.getPointerType(ArgType); |
| else { |
| // - If A is a cv-qualified type, the top level cv-qualifiers of A’s |
| // type are ignored for type deduction. |
| QualType CanonArgType = Context.getCanonicalType(ArgType); |
| if (CanonArgType.getCVRQualifiers()) |
| ArgType = CanonArgType.getUnqualifiedType(); |
| } |
| } |
| |
| // C++0x [temp.deduct.call]p3: |
| // If P is a cv-qualified type, the top level cv-qualifiers of P’s type |
| // are ignored for type deduction. |
| if (CanonParamType.getCVRQualifiers()) |
| ParamType = CanonParamType.getUnqualifiedType(); |
| if (const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>()) { |
| // [...] If P is a reference type, the type referred to by P is used |
| // for type deduction. |
| ParamType = ParamRefType->getPointeeType(); |
| |
| // [...] If P is of the form T&&, where T is a template parameter, and |
| // the argument is an lvalue, the type A& is used in place of A for |
| // type deduction. |
| if (isa<RValueReferenceType>(ParamRefType) && |
| ParamRefType->getAsTemplateTypeParmType() && |
| Args[I]->isLvalue(Context) == Expr::LV_Valid) |
| ArgType = Context.getLValueReferenceType(ArgType); |
| } |
| |
| // C++0x [temp.deduct.call]p4: |
| // In general, the deduction process attempts to find template argument |
| // values that will make the deduced A identical to A (after the type A |
| // is transformed as described above). [...] |
| unsigned TDF = 0; |
| |
| // - If the original P is a reference type, the deduced A (i.e., the |
| // type referred to by the reference) can be more cv-qualified than |
| // the transformed A. |
| if (ParamWasReference) |
| TDF |= TDF_ParamWithReferenceType; |
| // - The transformed A can be another pointer or pointer to member |
| // type that can be converted to the deduced A via a qualification |
| // conversion (4.4). |
| if (ArgType->isPointerType() || ArgType->isMemberPointerType()) |
| TDF |= TDF_IgnoreQualifiers; |
| // - If P is a class and P has the form simple-template-id, then the |
| // transformed A can be a derived class of the deduced A. Likewise, |
| // if P is a pointer to a class of the form simple-template-id, the |
| // transformed A can be a pointer to a derived class pointed to by |
| // the deduced A. |
| if (isSimpleTemplateIdType(ParamType) || |
| (isa<PointerType>(ParamType) && |
| isSimpleTemplateIdType( |
| ParamType->getAs<PointerType>()->getPointeeType()))) |
| TDF |= TDF_DerivedClass; |
| |
| if (TemplateDeductionResult Result |
| = ::DeduceTemplateArguments(Context, TemplateParams, |
| ParamType, ArgType, Info, Deduced, |
| TDF)) |
| return Result; |
| |
| // FIXME: C++0x [temp.deduct.call] paragraphs 6-9 deal with function |
| // pointer parameters. |
| } |
| |
| return FinishTemplateArgumentDeduction(FunctionTemplate, Deduced, |
| Specialization, Info); |
| } |
| |
| /// \brief Deduce template arguments when taking the address of a function |
| /// template (C++ [temp.deduct.funcaddr]). |
| /// |
| /// \param FunctionTemplate the function template for which we are performing |
| /// template argument deduction. |
| /// |
| /// \param HasExplicitTemplateArgs whether any template arguments were |
| /// explicitly specified. |
| /// |
| /// \param ExplicitTemplateArguments when @p HasExplicitTemplateArgs is true, |
| /// the explicitly-specified template arguments. |
| /// |
| /// \param NumExplicitTemplateArguments when @p HasExplicitTemplateArgs is true, |
| /// the number of explicitly-specified template arguments in |
| /// @p ExplicitTemplateArguments. This value may be zero. |
| /// |
| /// \param ArgFunctionType the function type that will be used as the |
| /// "argument" type (A) when performing template argument deduction from the |
| /// function template's function type. |
| /// |
| /// \param Specialization if template argument deduction was successful, |
| /// this will be set to the function template specialization produced by |
| /// template argument deduction. |
| /// |
| /// \param Info the argument will be updated to provide additional information |
| /// about template argument deduction. |
| /// |
| /// \returns the result of template argument deduction. |
| Sema::TemplateDeductionResult |
| Sema::DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate, |
| bool HasExplicitTemplateArgs, |
| const TemplateArgument *ExplicitTemplateArgs, |
| unsigned NumExplicitTemplateArgs, |
| QualType ArgFunctionType, |
| FunctionDecl *&Specialization, |
| TemplateDeductionInfo &Info) { |
| FunctionDecl *Function = FunctionTemplate->getTemplatedDecl(); |
| TemplateParameterList *TemplateParams |
| = FunctionTemplate->getTemplateParameters(); |
| QualType FunctionType = Function->getType(); |
| |
| // Substitute any explicit template arguments. |
| llvm::SmallVector<TemplateArgument, 4> Deduced; |
| llvm::SmallVector<QualType, 4> ParamTypes; |
| if (HasExplicitTemplateArgs) { |
| if (TemplateDeductionResult Result |
| = SubstituteExplicitTemplateArguments(FunctionTemplate, |
| ExplicitTemplateArgs, |
| NumExplicitTemplateArgs, |
| Deduced, ParamTypes, |
| &FunctionType, Info)) |
| return Result; |
| } |
| |
| // Template argument deduction for function templates in a SFINAE context. |
| // Trap any errors that might occur. |
| SFINAETrap Trap(*this); |
| |
| // Deduce template arguments from the function type. |
| Deduced.resize(TemplateParams->size()); |
| if (TemplateDeductionResult Result |
| = ::DeduceTemplateArguments(Context, TemplateParams, |
| FunctionType, ArgFunctionType, Info, |
| Deduced, 0)) |
| return Result; |
| |
| return FinishTemplateArgumentDeduction(FunctionTemplate, Deduced, |
| Specialization, Info); |
| } |
| |
| |
| static void |
| MarkDeducedTemplateParameters(Sema &SemaRef, |
| const TemplateArgument &TemplateArg, |
| llvm::SmallVectorImpl<bool> &Deduced); |
| |
| /// \brief Mark the template arguments that are deduced by the given |
| /// expression. |
| static void |
| MarkDeducedTemplateParameters(const Expr *E, |
| llvm::SmallVectorImpl<bool> &Deduced) { |
| const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E); |
| if (!E) |
| return; |
| |
| const NonTypeTemplateParmDecl *NTTP |
| = dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl()); |
| if (!NTTP) |
| return; |
| |
| Deduced[NTTP->getIndex()] = true; |
| } |
| |
| /// \brief Mark the template parameters that are deduced by the given |
| /// type. |
| static void |
| MarkDeducedTemplateParameters(Sema &SemaRef, QualType T, |
| llvm::SmallVectorImpl<bool> &Deduced) { |
| // Non-dependent types have nothing deducible |
| if (!T->isDependentType()) |
| return; |
| |
| T = SemaRef.Context.getCanonicalType(T); |
| switch (T->getTypeClass()) { |
| case Type::ExtQual: |
| MarkDeducedTemplateParameters(SemaRef, |
| QualType(cast<ExtQualType>(T)->getBaseType(), 0), |
| Deduced); |
| break; |
| |
| case Type::Pointer: |
| MarkDeducedTemplateParameters(SemaRef, |
| cast<PointerType>(T)->getPointeeType(), |
| Deduced); |
| break; |
| |
| case Type::BlockPointer: |
| MarkDeducedTemplateParameters(SemaRef, |
| cast<BlockPointerType>(T)->getPointeeType(), |
| Deduced); |
| break; |
| |
| case Type::LValueReference: |
| case Type::RValueReference: |
| MarkDeducedTemplateParameters(SemaRef, |
| cast<ReferenceType>(T)->getPointeeType(), |
| Deduced); |
| break; |
| |
| case Type::MemberPointer: { |
| const MemberPointerType *MemPtr = cast<MemberPointerType>(T.getTypePtr()); |
| MarkDeducedTemplateParameters(SemaRef, MemPtr->getPointeeType(), Deduced); |
| MarkDeducedTemplateParameters(SemaRef, QualType(MemPtr->getClass(), 0), |
| Deduced); |
| break; |
| } |
| |
| case Type::DependentSizedArray: |
| MarkDeducedTemplateParameters(cast<DependentSizedArrayType>(T)->getSizeExpr(), |
| Deduced); |
| // Fall through to check the element type |
| |
| case Type::ConstantArray: |
| case Type::IncompleteArray: |
| MarkDeducedTemplateParameters(SemaRef, |
| cast<ArrayType>(T)->getElementType(), |
| Deduced); |
| break; |
| |
| case Type::Vector: |
| case Type::ExtVector: |
| MarkDeducedTemplateParameters(SemaRef, |
| cast<VectorType>(T)->getElementType(), |
| Deduced); |
| break; |
| |
| case Type::DependentSizedExtVector: { |
| const DependentSizedExtVectorType *VecType |
| = cast<DependentSizedExtVectorType>(T); |
| MarkDeducedTemplateParameters(SemaRef, VecType->getElementType(), Deduced); |
| MarkDeducedTemplateParameters(VecType->getSizeExpr(), Deduced); |
| break; |
| } |
| |
| case Type::FunctionProto: { |
| const FunctionProtoType *Proto = cast<FunctionProtoType>(T); |
| MarkDeducedTemplateParameters(SemaRef, Proto->getResultType(), Deduced); |
| for (unsigned I = 0, N = Proto->getNumArgs(); I != N; ++I) |
| MarkDeducedTemplateParameters(SemaRef, Proto->getArgType(I), Deduced); |
| break; |
| } |
| |
| case Type::TemplateTypeParm: |
| Deduced[cast<TemplateTypeParmType>(T)->getIndex()] = true; |
| break; |
| |
| case Type::TemplateSpecialization: { |
| const TemplateSpecializationType *Spec |
| = cast<TemplateSpecializationType>(T); |
| if (TemplateDecl *Template = Spec->getTemplateName().getAsTemplateDecl()) |
| if (TemplateTemplateParmDecl *TTP |
| = dyn_cast<TemplateTemplateParmDecl>(Template)) |
| Deduced[TTP->getIndex()] = true; |
| |
| for (unsigned I = 0, N = Spec->getNumArgs(); I != N; ++I) |
| MarkDeducedTemplateParameters(SemaRef, Spec->getArg(I), Deduced); |
| |
| break; |
| } |
| |
| // None of these types have any deducible parts. |
| case Type::Builtin: |
| case Type::FixedWidthInt: |
| case Type::Complex: |
| case Type::VariableArray: |
| case Type::FunctionNoProto: |
| case Type::Record: |
| case Type::Enum: |
| case Type::Typename: |
| case Type::ObjCInterface: |
| case Type::ObjCObjectPointer: |
| #define TYPE(Class, Base) |
| #define ABSTRACT_TYPE(Class, Base) |
| #define DEPENDENT_TYPE(Class, Base) |
| #define NON_CANONICAL_TYPE(Class, Base) case Type::Class: |
| #include "clang/AST/TypeNodes.def" |
| break; |
| } |
| } |
| |
| /// \brief Mark the template parameters that are deduced by this |
| /// template argument. |
| static void |
| MarkDeducedTemplateParameters(Sema &SemaRef, |
| const TemplateArgument &TemplateArg, |
| llvm::SmallVectorImpl<bool> &Deduced) { |
| switch (TemplateArg.getKind()) { |
| case TemplateArgument::Null: |
| case TemplateArgument::Integral: |
| break; |
| |
| case TemplateArgument::Type: |
| MarkDeducedTemplateParameters(SemaRef, TemplateArg.getAsType(), Deduced); |
| break; |
| |
| case TemplateArgument::Declaration: |
| if (TemplateTemplateParmDecl *TTP |
| = dyn_cast<TemplateTemplateParmDecl>(TemplateArg.getAsDecl())) |
| Deduced[TTP->getIndex()] = true; |
| break; |
| |
| case TemplateArgument::Expression: |
| MarkDeducedTemplateParameters(TemplateArg.getAsExpr(), Deduced); |
| break; |
| case TemplateArgument::Pack: |
| assert(0 && "FIXME: Implement!"); |
| break; |
| } |
| } |
| |
| /// \brief Mark the template parameters can be deduced by the given |
| /// template argument list. |
| /// |
| /// \param TemplateArgs the template argument list from which template |
| /// parameters will be deduced. |
| /// |
| /// \param Deduced a bit vector whose elements will be set to \c true |
| /// to indicate when the corresponding template parameter will be |
| /// deduced. |
| void |
| Sema::MarkDeducedTemplateParameters(const TemplateArgumentList &TemplateArgs, |
| llvm::SmallVectorImpl<bool> &Deduced) { |
| for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) |
| ::MarkDeducedTemplateParameters(*this, TemplateArgs[I], Deduced); |
| } |