diff options
Diffstat (limited to 'clang/lib/Sema/SemaOverload.cpp')
| -rw-r--r-- | clang/lib/Sema/SemaOverload.cpp | 261 |
1 files changed, 184 insertions, 77 deletions
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp index c0321d36a7c..41f4fa746fc 100644 --- a/clang/lib/Sema/SemaOverload.cpp +++ b/clang/lib/Sema/SemaOverload.cpp @@ -590,7 +590,6 @@ clang::MakeDeductionFailureInfo(ASTContext &Context, Result.Result = static_cast<unsigned>(TDK); Result.HasDiagnostic = false; switch (TDK) { - case Sema::TDK_Success: case Sema::TDK_Invalid: case Sema::TDK_InstantiationDepth: case Sema::TDK_TooManyArguments: @@ -646,6 +645,10 @@ clang::MakeDeductionFailureInfo(ASTContext &Context, Result.HasDiagnostic = true; } break; + + case Sema::TDK_Success: + case Sema::TDK_NonDependentConversionFailure: + llvm_unreachable("not a deduction failure"); } return Result; @@ -661,6 +664,7 @@ void DeductionFailureInfo::Destroy() { case Sema::TDK_TooFewArguments: case Sema::TDK_InvalidExplicitArguments: case Sema::TDK_CUDATargetMismatch: + case Sema::TDK_NonDependentConversionFailure: break; case Sema::TDK_Inconsistent: @@ -705,6 +709,7 @@ TemplateParameter DeductionFailureInfo::getTemplateParameter() { case Sema::TDK_DeducedMismatchNested: case Sema::TDK_NonDeducedMismatch: case Sema::TDK_CUDATargetMismatch: + case Sema::TDK_NonDependentConversionFailure: return TemplateParameter(); case Sema::TDK_Incomplete: @@ -736,6 +741,7 @@ TemplateArgumentList *DeductionFailureInfo::getTemplateArgumentList() { case Sema::TDK_Underqualified: case Sema::TDK_NonDeducedMismatch: case Sema::TDK_CUDATargetMismatch: + case Sema::TDK_NonDependentConversionFailure: return nullptr; case Sema::TDK_DeducedMismatch: @@ -764,6 +770,7 @@ const TemplateArgument *DeductionFailureInfo::getFirstArg() { case Sema::TDK_InvalidExplicitArguments: case Sema::TDK_SubstitutionFailure: case Sema::TDK_CUDATargetMismatch: + case Sema::TDK_NonDependentConversionFailure: return nullptr; case Sema::TDK_Inconsistent: @@ -792,6 +799,7 @@ const TemplateArgument *DeductionFailureInfo::getSecondArg() { case Sema::TDK_InvalidExplicitArguments: case Sema::TDK_SubstitutionFailure: case Sema::TDK_CUDATargetMismatch: + case Sema::TDK_NonDependentConversionFailure: return nullptr; case Sema::TDK_Inconsistent: @@ -822,8 +830,8 @@ llvm::Optional<unsigned> DeductionFailureInfo::getCallArgIndex() { void OverloadCandidateSet::destroyCandidates() { for (iterator i = begin(), e = end(); i != e; ++i) { - for (unsigned ii = 0, ie = i->NumConversions; ii != ie; ++ii) - i->Conversions[ii].~ImplicitConversionSequence(); + for (auto &C : i->Conversions) + C.~ImplicitConversionSequence(); if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction) i->DeductionFailure.Destroy(); } @@ -5860,7 +5868,8 @@ Sema::AddOverloadCandidate(FunctionDecl *Function, OverloadCandidateSet &CandidateSet, bool SuppressUserConversions, bool PartialOverloading, - bool AllowExplicit) { + bool AllowExplicit, + ConversionSequenceList EarlyConversions) { const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); assert(Proto && "Functions without a prototype cannot be overloaded"); @@ -5876,10 +5885,11 @@ Sema::AddOverloadCandidate(FunctionDecl *Function, // function, e.g., X::f(). We use an empty type for the implied // object argument (C++ [over.call.func]p3), and the acting context // is irrelevant. - AddMethodCandidate(Method, FoundDecl, Method->getParent(), - QualType(), Expr::Classification::makeSimpleLValue(), + AddMethodCandidate(Method, FoundDecl, Method->getParent(), QualType(), + Expr::Classification::makeSimpleLValue(), /*ThisArg=*/nullptr, Args, CandidateSet, - SuppressUserConversions, PartialOverloading); + SuppressUserConversions, PartialOverloading, + EarlyConversions); return; } // We treat a constructor like a non-member function, since its object @@ -5912,7 +5922,8 @@ Sema::AddOverloadCandidate(FunctionDecl *Function, EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); // Add this candidate - OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size()); + OverloadCandidate &Candidate = + CandidateSet.addCandidate(Args.size(), EarlyConversions); Candidate.FoundDecl = FoundDecl; Candidate.Function = Function; Candidate.Viable = true; @@ -5976,7 +5987,10 @@ Sema::AddOverloadCandidate(FunctionDecl *Function, // Determine the implicit conversion sequences for each of the // arguments. for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { - if (ArgIdx < NumParams) { + if (Candidate.Conversions[ArgIdx].isInitialized()) { + // We already formed a conversion sequence for this parameter during + // template argument deduction. + } else if (ArgIdx < NumParams) { // (C++ 13.3.2p3): for F to be a viable function, there shall // exist for each argument an implicit conversion sequence // (13.3.3.1) that converts that argument to the corresponding @@ -6414,7 +6428,8 @@ Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, Expr *ThisArg, ArrayRef<Expr *> Args, OverloadCandidateSet &CandidateSet, bool SuppressUserConversions, - bool PartialOverloading) { + bool PartialOverloading, + ConversionSequenceList EarlyConversions) { const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); assert(Proto && "Methods without a prototype cannot be overloaded"); @@ -6435,7 +6450,8 @@ Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); // Add this candidate - OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1); + OverloadCandidate &Candidate = + CandidateSet.addCandidate(Args.size() + 1, EarlyConversions); Candidate.FoundDecl = FoundDecl; Candidate.Function = Method; Candidate.IsSurrogate = false; @@ -6497,7 +6513,10 @@ Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, // Determine the implicit conversion sequences for each of the // arguments. for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { - if (ArgIdx < NumParams) { + if (Candidate.Conversions[ArgIdx + 1].isInitialized()) { + // We already formed a conversion sequence for this parameter during + // template argument deduction. + } else if (ArgIdx < NumParams) { // (C++ 13.3.2p3): for F to be a viable function, there shall // exist for each argument an implicit conversion sequence // (13.3.3.1) that converts that argument to the corresponding @@ -6562,19 +6581,30 @@ Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, // functions. TemplateDeductionInfo Info(CandidateSet.getLocation()); FunctionDecl *Specialization = nullptr; - if (TemplateDeductionResult Result - = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, Args, - Specialization, Info, PartialOverloading)) { - OverloadCandidate &Candidate = CandidateSet.addCandidate(); + ConversionSequenceList Conversions; + if (TemplateDeductionResult Result = DeduceTemplateArguments( + MethodTmpl, ExplicitTemplateArgs, Args, Specialization, Info, + PartialOverloading, [&](ArrayRef<QualType> ParamTypes) { + return CheckNonDependentConversions( + MethodTmpl, ParamTypes, Args, CandidateSet, Conversions, + SuppressUserConversions, ActingContext, ObjectType, + ObjectClassification); + })) { + OverloadCandidate &Candidate = + CandidateSet.addCandidate(Conversions.size(), Conversions); Candidate.FoundDecl = FoundDecl; Candidate.Function = MethodTmpl->getTemplatedDecl(); Candidate.Viable = false; - Candidate.FailureKind = ovl_fail_bad_deduction; Candidate.IsSurrogate = false; Candidate.IgnoreObjectArgument = false; Candidate.ExplicitCallArguments = Args.size(); - Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, - Info); + if (Result == TDK_NonDependentConversionFailure) + Candidate.FailureKind = ovl_fail_bad_conversion; + else { + Candidate.FailureKind = ovl_fail_bad_deduction; + Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, + Info); + } return; } @@ -6586,7 +6616,7 @@ Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, ActingContext, ObjectType, ObjectClassification, /*ThisArg=*/ThisArg, Args, CandidateSet, - SuppressUserConversions, PartialOverloading); + SuppressUserConversions, PartialOverloading, Conversions); } /// \brief Add a C++ function template specialization as a candidate @@ -6614,19 +6644,29 @@ Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, // functions. TemplateDeductionInfo Info(CandidateSet.getLocation()); FunctionDecl *Specialization = nullptr; - if (TemplateDeductionResult Result - = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, Args, - Specialization, Info, PartialOverloading)) { - OverloadCandidate &Candidate = CandidateSet.addCandidate(); + ConversionSequenceList Conversions; + if (TemplateDeductionResult Result = DeduceTemplateArguments( + FunctionTemplate, ExplicitTemplateArgs, Args, Specialization, Info, + PartialOverloading, [&](ArrayRef<QualType> ParamTypes) { + return CheckNonDependentConversions(FunctionTemplate, ParamTypes, + Args, CandidateSet, Conversions, + SuppressUserConversions); + })) { + OverloadCandidate &Candidate = + CandidateSet.addCandidate(Conversions.size(), Conversions); Candidate.FoundDecl = FoundDecl; Candidate.Function = FunctionTemplate->getTemplatedDecl(); Candidate.Viable = false; - Candidate.FailureKind = ovl_fail_bad_deduction; Candidate.IsSurrogate = false; Candidate.IgnoreObjectArgument = false; Candidate.ExplicitCallArguments = Args.size(); - Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, - Info); + if (Result == TDK_NonDependentConversionFailure) + Candidate.FailureKind = ovl_fail_bad_conversion; + else { + Candidate.FailureKind = ovl_fail_bad_deduction; + Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, + Info); + } return; } @@ -6634,7 +6674,64 @@ Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, // deduction as a candidate. assert(Specialization && "Missing function template specialization?"); AddOverloadCandidate(Specialization, FoundDecl, Args, CandidateSet, - SuppressUserConversions, PartialOverloading); + SuppressUserConversions, PartialOverloading, + /*AllowExplicit*/false, Conversions); +} + +/// Check that implicit conversion sequences can be formed for each argument +/// whose corresponding parameter has a non-dependent type, per DR1391's +/// [temp.deduct.call]p10. +bool Sema::CheckNonDependentConversions( + FunctionTemplateDecl *FunctionTemplate, ArrayRef<QualType> ParamTypes, + ArrayRef<Expr *> Args, OverloadCandidateSet &CandidateSet, + ConversionSequenceList &Conversions, bool SuppressUserConversions, + CXXRecordDecl *ActingContext, QualType ObjectType, + Expr::Classification ObjectClassification) { + // FIXME: The cases in which we allow explicit conversions for constructor + // arguments never consider calling a constructor template. It's not clear + // that is correct. + const bool AllowExplicit = false; + + auto *FD = FunctionTemplate->getTemplatedDecl(); + auto *Method = dyn_cast<CXXMethodDecl>(FD); + bool HasThisConversion = Method && !isa<CXXConstructorDecl>(Method); + unsigned ThisConversions = HasThisConversion ? 1 : 0; + + Conversions = + CandidateSet.allocateConversionSequences(ThisConversions + Args.size()); + + // Overload resolution is always an unevaluated context. + EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); + + // For a method call, check the 'this' conversion here too. DR1391 doesn't + // require that, but this check should never result in a hard error, and + // overload resolution is permitted to sidestep instantiations. + if (HasThisConversion && !cast<CXXMethodDecl>(FD)->isStatic() && + !ObjectType.isNull()) { + Conversions[0] = TryObjectArgumentInitialization( + *this, CandidateSet.getLocation(), ObjectType, ObjectClassification, + Method, ActingContext); + if (Conversions[0].isBad()) + return true; + } + + for (unsigned I = 0, N = std::min(ParamTypes.size(), Args.size()); I != N; + ++I) { + QualType ParamType = ParamTypes[I]; + if (!ParamType->isDependentType()) { + Conversions[ThisConversions + I] + = TryCopyInitialization(*this, Args[I], ParamType, + SuppressUserConversions, + /*InOverloadResolution=*/true, + /*AllowObjCWritebackConversion=*/ + getLangOpts().ObjCAutoRefCount, + AllowExplicit); + if (Conversions[ThisConversions + I].isBad()) + return true; + } + } + + return false; } /// Determine whether this is an allowable conversion from the result @@ -8875,8 +8972,8 @@ bool clang::isBetterOverloadCandidate(Sema &S, const OverloadCandidate &Cand1, // Define functions that don't require ill-formed conversions for a given // argument to be better candidates than functions that do. - unsigned NumArgs = Cand1.NumConversions; - assert(Cand2.NumConversions == NumArgs && "Overload candidate mismatch"); + unsigned NumArgs = Cand1.Conversions.size(); + assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); bool HasBetterConversion = false; for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { bool Cand1Bad = IsIllFormedConversion(Cand1.Conversions[ArgIdx]); @@ -10099,7 +10196,7 @@ static void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, case ovl_fail_bad_conversion: { unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); - for (unsigned N = Cand->NumConversions; I != N; ++I) + for (unsigned N = Cand->Conversions.size(); I != N; ++I) if (Cand->Conversions[I].isBad()) return DiagnoseBadConversion(S, Cand, I, TakingCandidateAddress); @@ -10168,12 +10265,12 @@ static void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { static void NoteBuiltinOperatorCandidate(Sema &S, StringRef Opc, SourceLocation OpLoc, OverloadCandidate *Cand) { - assert(Cand->NumConversions <= 2 && "builtin operator is not binary"); + assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); std::string TypeStr("operator"); TypeStr += Opc; TypeStr += "("; TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); - if (Cand->NumConversions == 1) { + if (Cand->Conversions.size() == 1) { TypeStr += ")"; S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; } else { @@ -10186,9 +10283,7 @@ static void NoteBuiltinOperatorCandidate(Sema &S, StringRef Opc, static void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, OverloadCandidate *Cand) { - unsigned NoOperands = Cand->NumConversions; - for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { - const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; + for (const ImplicitConversionSequence &ICS : Cand->Conversions) { if (ICS.isBad()) break; // all meaningless after first invalid if (!ICS.isAmbiguous()) continue; @@ -10208,7 +10303,8 @@ static SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { static unsigned RankDeductionFailure(const DeductionFailureInfo &DFI) { switch ((Sema::TemplateDeductionResult)DFI.Result) { case Sema::TDK_Success: - llvm_unreachable("TDK_success while diagnosing bad deduction"); + case Sema::TDK_NonDependentConversionFailure: + llvm_unreachable("non-deduction failure while diagnosing bad deduction"); case Sema::TDK_Invalid: case Sema::TDK_Incomplete: @@ -10311,11 +10407,11 @@ struct CompareOverloadCandidatesForDisplay { // If there's any ordering between the defined conversions... // FIXME: this might not be transitive. - assert(L->NumConversions == R->NumConversions); + assert(L->Conversions.size() == R->Conversions.size()); int leftBetter = 0; unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); - for (unsigned E = L->NumConversions; I != E; ++I) { + for (unsigned E = L->Conversions.size(); I != E; ++I) { switch (CompareImplicitConversionSequences(S, Loc, L->Conversions[I], R->Conversions[I])) { @@ -10364,7 +10460,8 @@ struct CompareOverloadCandidatesForDisplay { } /// CompleteNonViableCandidate - Normally, overload resolution only -/// computes up to the first. Produces the FixIt set if possible. +/// computes up to the first bad conversion. Produces the FixIt set if +/// possible. static void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, ArrayRef<Expr *> Args) { assert(!Cand->Viable); @@ -10377,30 +10474,24 @@ static void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, // Use a implicit copy initialization to check conversion fixes. Cand->Fix.setConversionChecker(TryCopyInitialization); - // Skip forward to the first bad conversion. - unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); - unsigned ConvCount = Cand->NumConversions; - while (true) { + // Attempt to fix the bad conversion. + unsigned ConvCount = Cand->Conversions.size(); + for (unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); /**/; + ++ConvIdx) { assert(ConvIdx != ConvCount && "no bad conversion in candidate"); - ConvIdx++; - if (Cand->Conversions[ConvIdx - 1].isBad()) { - Unfixable = !Cand->TryToFixBadConversion(ConvIdx - 1, S); + if (Cand->Conversions[ConvIdx].isInitialized() && + Cand->Conversions[ConvIdx].isBad()) { + Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S); break; } } - if (ConvIdx == ConvCount) - return; - - assert(!Cand->Conversions[ConvIdx].isInitialized() && - "remaining conversion is initialized?"); - // FIXME: this should probably be preserved from the overload // operation somehow. bool SuppressUserConversions = false; - const FunctionProtoType* Proto; - unsigned ArgIdx = ConvIdx; + const FunctionProtoType *Proto; + unsigned ArgIdx = 0; if (Cand->IsSurrogate) { QualType ConvType @@ -10408,40 +10499,56 @@ static void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) ConvType = ConvPtrType->getPointeeType(); Proto = ConvType->getAs<FunctionProtoType>(); - ArgIdx--; + ArgIdx = 1; } else if (Cand->Function) { Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); if (isa<CXXMethodDecl>(Cand->Function) && !isa<CXXConstructorDecl>(Cand->Function)) - ArgIdx--; + ArgIdx = 1; } else { // Builtin binary operator with a bad first conversion. assert(ConvCount <= 3); - for (; ConvIdx != ConvCount; ++ConvIdx) - Cand->Conversions[ConvIdx] - = TryCopyInitialization(S, Args[ConvIdx], - Cand->BuiltinTypes.ParamTypes[ConvIdx], - SuppressUserConversions, - /*InOverloadResolution*/ true, - /*AllowObjCWritebackConversion=*/ - S.getLangOpts().ObjCAutoRefCount); + for (unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); + ConvIdx != ConvCount; ++ConvIdx) { + if (Cand->Conversions[ConvIdx].isInitialized()) + continue; + if (Cand->BuiltinTypes.ParamTypes[ConvIdx]->isDependentType()) + Cand->Conversions[ConvIdx].setAsIdentityConversion( + Args[ConvIdx]->getType()); + else + Cand->Conversions[ConvIdx] = TryCopyInitialization( + S, Args[ConvIdx], Cand->BuiltinTypes.ParamTypes[ConvIdx], + SuppressUserConversions, + /*InOverloadResolution*/ true, + /*AllowObjCWritebackConversion=*/ + S.getLangOpts().ObjCAutoRefCount); + // FIXME: If the conversion is bad, try to fix it. + } return; } // Fill in the rest of the conversions. unsigned NumParams = Proto->getNumParams(); - for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { - if (ArgIdx < NumParams) { - Cand->Conversions[ConvIdx] = TryCopyInitialization( - S, Args[ArgIdx], Proto->getParamType(ArgIdx), SuppressUserConversions, - /*InOverloadResolution=*/true, - /*AllowObjCWritebackConversion=*/ - S.getLangOpts().ObjCAutoRefCount); - // Store the FixIt in the candidate if it exists. - if (!Unfixable && Cand->Conversions[ConvIdx].isBad()) - Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S); - } - else + for (unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); + ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { + if (Cand->Conversions[ConvIdx].isInitialized()) { + // Found the bad conversion. + } else if (ArgIdx < NumParams) { + if (Proto->getParamType(ArgIdx)->isDependentType()) + Cand->Conversions[ConvIdx].setAsIdentityConversion( + Args[ArgIdx]->getType()); + else { + Cand->Conversions[ConvIdx] = + TryCopyInitialization(S, Args[ArgIdx], Proto->getParamType(ArgIdx), + SuppressUserConversions, + /*InOverloadResolution=*/true, + /*AllowObjCWritebackConversion=*/ + S.getLangOpts().ObjCAutoRefCount); + // Store the FixIt in the candidate if it exists. + if (!Unfixable && Cand->Conversions[ConvIdx].isBad()) + Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S); + } + } else Cand->Conversions[ConvIdx].setEllipsis(); } } |

