diff options
Diffstat (limited to 'clang/lib/Sema/SemaTemplateDeduction.cpp')
| -rw-r--r-- | clang/lib/Sema/SemaTemplateDeduction.cpp | 61 |
1 files changed, 43 insertions, 18 deletions
diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp index a9fd8fd40ce..93e796ee966 100644 --- a/clang/lib/Sema/SemaTemplateDeduction.cpp +++ b/clang/lib/Sema/SemaTemplateDeduction.cpp @@ -2912,14 +2912,13 @@ static unsigned getPackIndexForParam(Sema &S, /// /// \param OriginalCallArgs If non-NULL, the original call arguments against /// which the deduced argument types should be compared. -Sema::TemplateDeductionResult -Sema::FinishTemplateArgumentDeduction(FunctionTemplateDecl *FunctionTemplate, - SmallVectorImpl<DeducedTemplateArgument> &Deduced, - unsigned NumExplicitlySpecified, - FunctionDecl *&Specialization, - TemplateDeductionInfo &Info, - SmallVectorImpl<OriginalCallArg> const *OriginalCallArgs, - bool PartialOverloading) { +Sema::TemplateDeductionResult Sema::FinishTemplateArgumentDeduction( + FunctionTemplateDecl *FunctionTemplate, + SmallVectorImpl<DeducedTemplateArgument> &Deduced, + unsigned NumExplicitlySpecified, FunctionDecl *&Specialization, + TemplateDeductionInfo &Info, + SmallVectorImpl<OriginalCallArg> const *OriginalCallArgs, + bool PartialOverloading, llvm::function_ref<bool()> CheckNonDependent) { // Unevaluated SFINAE context. EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); SFINAETrap Trap(*this); @@ -2946,6 +2945,18 @@ Sema::FinishTemplateArgumentDeduction(FunctionTemplateDecl *FunctionTemplate, PartialOverloading)) return Result; + // C++ [temp.deduct.call]p10: [DR1391] + // If deduction succeeds for all parameters that contain + // template-parameters that participate in template argument deduction, + // and all template arguments are explicitly specified, deduced, or + // obtained from default template arguments, remaining parameters are then + // compared with the corresponding arguments. For each remaining parameter + // P with a type that was non-dependent before substitution of any + // explicitly-specified template arguments, if the corresponding argument + // A cannot be implicitly converted to P, deduction fails. + if (CheckNonDependent()) + return TDK_NonDependentConversionFailure; + // Form the template argument list from the deduced template arguments. TemplateArgumentList *DeducedArgumentList = TemplateArgumentList::CreateCopy(Context, Builder); @@ -3392,12 +3403,19 @@ static Sema::TemplateDeductionResult DeduceTemplateArgumentsFromCallArgument( /// \param Info the argument will be updated to provide additional information /// about template argument deduction. /// +/// \param CheckNonDependent A callback to invoke to check conversions for +/// non-dependent parameters, between deduction and substitution, per DR1391. +/// If this returns true, substitution will be skipped and we return +/// TDK_NonDependentConversionFailure. The callback is passed the parameter +/// types (after substituting explicit template arguments). +/// /// \returns the result of template argument deduction. Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( FunctionTemplateDecl *FunctionTemplate, TemplateArgumentListInfo *ExplicitTemplateArgs, ArrayRef<Expr *> Args, FunctionDecl *&Specialization, TemplateDeductionInfo &Info, - bool PartialOverloading) { + bool PartialOverloading, + llvm::function_ref<bool(ArrayRef<QualType>)> CheckNonDependent) { if (FunctionTemplate->isInvalidDecl()) return TDK_Invalid; @@ -3425,7 +3443,7 @@ Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( TemplateParameterList *TemplateParams = FunctionTemplate->getTemplateParameters(); SmallVector<DeducedTemplateArgument, 4> Deduced; - SmallVector<QualType, 4> ParamTypes; + SmallVector<QualType, 8> ParamTypes; unsigned NumExplicitlySpecified = 0; if (ExplicitTemplateArgs) { TemplateDeductionResult Result = @@ -3445,7 +3463,7 @@ Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( ParamTypes.push_back(Function->getParamDecl(I)->getType()); } - SmallVector<OriginalCallArg, 4> OriginalCallArgs; + SmallVector<OriginalCallArg, 8> OriginalCallArgs; // Deduce an argument of type ParamType from an expression with index ArgIdx. auto DeduceCallArgument = [&](QualType ParamType, unsigned ArgIdx) { @@ -3464,6 +3482,7 @@ Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( // Deduce template arguments from the function parameters. Deduced.resize(TemplateParams->size()); + SmallVector<QualType, 8> ParamTypesForArgChecking; for (unsigned ParamIdx = 0, NumParamTypes = ParamTypes.size(), ArgIdx = 0; ParamIdx != NumParamTypes; ++ParamIdx) { QualType ParamType = ParamTypes[ParamIdx]; @@ -3475,6 +3494,7 @@ Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( if (ArgIdx >= Args.size()) break; + ParamTypesForArgChecking.push_back(ParamType); if (auto Result = DeduceCallArgument(ParamType, ArgIdx++)) return Result; @@ -3502,20 +3522,25 @@ Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( // parameter pack and 0 otherwise, and we treat each deduction as a // non-deduced context. if (ParamIdx + 1 == NumParamTypes) { - for (; ArgIdx < Args.size(); PackScope.nextPackElement(), ++ArgIdx) + for (; ArgIdx < Args.size(); PackScope.nextPackElement(), ++ArgIdx) { + ParamTypesForArgChecking.push_back(ParamPattern); if (auto Result = DeduceCallArgument(ParamPattern, ArgIdx)) return Result; + } } else { // If the parameter type contains an explicitly-specified pack that we // could not expand, skip the number of parameters notionally created // by the expansion. Optional<unsigned> NumExpansions = ParamExpansion->getNumExpansions(); - if (NumExpansions && !PackScope.isPartiallyExpanded()) + if (NumExpansions && !PackScope.isPartiallyExpanded()) { for (unsigned I = 0; I != *NumExpansions && ArgIdx < Args.size(); - ++I, ++ArgIdx) + ++I, ++ArgIdx) { + ParamTypesForArgChecking.push_back(ParamPattern); // FIXME: Should we add OriginalCallArgs for these? What if the // corresponding argument is a list? PackScope.nextPackElement(); + } + } } // Build argument packs for each of the parameter packs expanded by this @@ -3524,10 +3549,10 @@ Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( return Result; } - return FinishTemplateArgumentDeduction(FunctionTemplate, Deduced, - NumExplicitlySpecified, Specialization, - Info, &OriginalCallArgs, - PartialOverloading); + return FinishTemplateArgumentDeduction( + FunctionTemplate, Deduced, NumExplicitlySpecified, Specialization, Info, + &OriginalCallArgs, PartialOverloading, + [&]() { return CheckNonDependent(ParamTypesForArgChecking); }); } QualType Sema::adjustCCAndNoReturn(QualType ArgFunctionType, |
