diff options
Diffstat (limited to 'clang/lib/Sema/SemaConcept.cpp')
| -rwxr-xr-x | clang/lib/Sema/SemaConcept.cpp | 365 |
1 files changed, 208 insertions, 157 deletions
diff --git a/clang/lib/Sema/SemaConcept.cpp b/clang/lib/Sema/SemaConcept.cpp index 7f0bdc9b478..018ac2d7dc9 100755 --- a/clang/lib/Sema/SemaConcept.cpp +++ b/clang/lib/Sema/SemaConcept.cpp @@ -11,6 +11,7 @@ // //===----------------------------------------------------------------------===// +#include "clang/Sema/SemaConcept.h" #include "clang/Sema/Sema.h" #include "clang/Sema/SemaInternal.h" #include "clang/Sema/SemaDiagnostic.h" @@ -18,12 +19,16 @@ #include "clang/Sema/Template.h" #include "clang/AST/ExprCXX.h" #include "clang/AST/RecursiveASTVisitor.h" +#include "clang/Basic/OperatorPrecedence.h" #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/PointerUnion.h" using namespace clang; using namespace sema; -bool Sema::CheckConstraintExpression(Expr *ConstraintExpression) { +bool +Sema::CheckConstraintExpression(Expr *ConstraintExpression, Token NextToken, + bool *PossibleNonPrimary, + bool IsTrailingRequiresClause) { // C++2a [temp.constr.atomic]p1 // ..E shall be a constant expression of type bool. @@ -31,22 +36,56 @@ bool Sema::CheckConstraintExpression(Expr *ConstraintExpression) { if (auto *BinOp = dyn_cast<BinaryOperator>(ConstraintExpression)) { if (BinOp->getOpcode() == BO_LAnd || BinOp->getOpcode() == BO_LOr) - return CheckConstraintExpression(BinOp->getLHS()) && - CheckConstraintExpression(BinOp->getRHS()); + return CheckConstraintExpression(BinOp->getLHS(), NextToken, + PossibleNonPrimary) && + CheckConstraintExpression(BinOp->getRHS(), NextToken, + PossibleNonPrimary); } else if (auto *C = dyn_cast<ExprWithCleanups>(ConstraintExpression)) - return CheckConstraintExpression(C->getSubExpr()); + return CheckConstraintExpression(C->getSubExpr(), NextToken, + PossibleNonPrimary); + + QualType Type = ConstraintExpression->getType(); + + auto CheckForNonPrimary = [&] { + if (PossibleNonPrimary) + *PossibleNonPrimary = + // We have the following case: + // template<typename> requires func(0) struct S { }; + // The user probably isn't aware of the parentheses required around + // the function call, and we're only going to parse 'func' as the + // primary-expression, and complain that it is of non-bool type. + (NextToken.is(tok::l_paren) && + (IsTrailingRequiresClause || + (Type->isDependentType() && + IsDependentFunctionNameExpr(ConstraintExpression)) || + Type->isFunctionType() || + Type->isSpecificBuiltinType(BuiltinType::Overload))) || + // We have the following case: + // template<typename T> requires size_<T> == 0 struct S { }; + // The user probably isn't aware of the parentheses required around + // the binary operator, and we're only going to parse 'func' as the + // first operand, and complain that it is of non-bool type. + getBinOpPrecedence(NextToken.getKind(), + /*GreaterThanIsOperator=*/true, + getLangOpts().CPlusPlus11) > prec::LogicalAnd; + }; // An atomic constraint! - if (ConstraintExpression->isTypeDependent()) + if (ConstraintExpression->isTypeDependent()) { + CheckForNonPrimary(); return true; + } - QualType Type = ConstraintExpression->getType(); if (!Context.hasSameUnqualifiedType(Type, Context.BoolTy)) { Diag(ConstraintExpression->getExprLoc(), diag::err_non_bool_atomic_constraint) << Type << ConstraintExpression->getSourceRange(); + CheckForNonPrimary(); return false; } + + if (PossibleNonPrimary) + *PossibleNonPrimary = false; return true; } @@ -417,123 +456,25 @@ void Sema::DiagnoseUnsatisfiedConstraint( } } -namespace { -struct AtomicConstraint { - const Expr *ConstraintExpr; - llvm::Optional<llvm::SmallVector<TemplateArgumentLoc, 3>> ParameterMapping; - - AtomicConstraint(Sema &S, const Expr *ConstraintExpr) : - ConstraintExpr(ConstraintExpr) { }; - - bool hasMatchingParameterMapping(ASTContext &C, - const AtomicConstraint &Other) const { - if (!ParameterMapping != !Other.ParameterMapping) - return false; - if (!ParameterMapping) - return true; - if (ParameterMapping->size() != Other.ParameterMapping->size()) - return false; - - for (unsigned I = 0, S = ParameterMapping->size(); I < S; ++I) - if (!C.getCanonicalTemplateArgument((*ParameterMapping)[I].getArgument()) - .structurallyEquals(C.getCanonicalTemplateArgument( - (*Other.ParameterMapping)[I].getArgument()))) - return false; - return true; - } - - bool subsumes(ASTContext &C, const AtomicConstraint &Other) const { - // C++ [temp.constr.order] p2 - // - an atomic constraint A subsumes another atomic constraint B - // if and only if the A and B are identical [...] - // - // C++ [temp.constr.atomic] p2 - // Two atomic constraints are identical if they are formed from the - // same expression and the targets of the parameter mappings are - // equivalent according to the rules for expressions [...] - - // We do not actually substitute the parameter mappings into the - // constraint expressions, therefore the constraint expressions are - // the originals, and comparing them will suffice. - if (ConstraintExpr != Other.ConstraintExpr) - return false; - - // Check that the parameter lists are identical - return hasMatchingParameterMapping(C, Other); - } -}; - -/// \brief A normalized constraint, as defined in C++ [temp.constr.normal], is -/// either an atomic constraint, a conjunction of normalized constraints or a -/// disjunction of normalized constraints. -struct NormalizedConstraint { - enum CompoundConstraintKind { CCK_Conjunction, CCK_Disjunction }; - - using CompoundConstraint = llvm::PointerIntPair< - std::pair<NormalizedConstraint, NormalizedConstraint> *, 1, - CompoundConstraintKind>; - - llvm::PointerUnion<AtomicConstraint *, CompoundConstraint> Constraint; - - NormalizedConstraint(AtomicConstraint *C): Constraint{C} { }; - NormalizedConstraint(ASTContext &C, NormalizedConstraint LHS, - NormalizedConstraint RHS, CompoundConstraintKind Kind) - : Constraint{CompoundConstraint{ - new (C) std::pair<NormalizedConstraint, NormalizedConstraint>{LHS, - RHS}, - Kind}} { }; - - CompoundConstraintKind getCompoundKind() const { - assert(!isAtomic() && "getCompoundKind called on atomic constraint."); - return Constraint.get<CompoundConstraint>().getInt(); - } - - bool isAtomic() const { return Constraint.is<AtomicConstraint *>(); } - - NormalizedConstraint &getLHS() const { - assert(!isAtomic() && "getLHS called on atomic constraint."); - return Constraint.get<CompoundConstraint>().getPointer()->first; - } - - NormalizedConstraint &getRHS() const { - assert(!isAtomic() && "getRHS called on atomic constraint."); - return Constraint.get<CompoundConstraint>().getPointer()->second; +const NormalizedConstraint * +Sema::getNormalizedAssociatedConstraints( + NamedDecl *ConstrainedDecl, ArrayRef<const Expr *> AssociatedConstraints) { + auto CacheEntry = NormalizationCache.find(ConstrainedDecl); + if (CacheEntry == NormalizationCache.end()) { + auto Normalized = + NormalizedConstraint::fromConstraintExprs(*this, ConstrainedDecl, + AssociatedConstraints); + CacheEntry = + NormalizationCache + .try_emplace(ConstrainedDecl, + Normalized + ? new (Context) NormalizedConstraint( + std::move(*Normalized)) + : nullptr) + .first; } - - AtomicConstraint *getAtomicConstraint() const { - assert(isAtomic() && - "getAtomicConstraint called on non-atomic constraint."); - return Constraint.get<AtomicConstraint *>(); - } - - static llvm::Optional<NormalizedConstraint> - fromConstraintExprs(Sema &S, NamedDecl *D, ArrayRef<const Expr *> E) { - assert(E.size() != 0); - auto First = fromConstraintExpr(S, D, E[0]); - if (E.size() == 1) - return First; - auto Second = fromConstraintExpr(S, D, E[1]); - if (!Second) - return llvm::Optional<NormalizedConstraint>{}; - llvm::Optional<NormalizedConstraint> Conjunction; - Conjunction.emplace(S.Context, std::move(*First), std::move(*Second), - CCK_Conjunction); - for (unsigned I = 2; I < E.size(); ++I) { - auto Next = fromConstraintExpr(S, D, E[I]); - if (!Next) - return llvm::Optional<NormalizedConstraint>{}; - NormalizedConstraint NewConjunction(S.Context, std::move(*Conjunction), - std::move(*Next), CCK_Conjunction); - *Conjunction = std::move(NewConjunction); - } - return Conjunction; - } - -private: - static llvm::Optional<NormalizedConstraint> fromConstraintExpr(Sema &S, - NamedDecl *D, - const Expr *E); -}; + return CacheEntry->second; +} static bool substituteParameterMappings(Sema &S, NormalizedConstraint &N, ConceptDecl *Concept, ArrayRef<TemplateArgument> TemplateArgs, @@ -555,11 +496,13 @@ static bool substituteParameterMappings(Sema &S, NormalizedConstraint &N, llvm::SmallBitVector OccurringIndices(TemplateParams->size()); S.MarkUsedTemplateParameters(Atomic.ConstraintExpr, /*OnlyDeduced=*/false, /*Depth=*/0, OccurringIndices); - Atomic.ParameterMapping.emplace(); - Atomic.ParameterMapping->reserve(OccurringIndices.size()); - for (unsigned I = 0, C = TemplateParams->size(); I != C; ++I) + Atomic.ParameterMapping.emplace( + MutableArrayRef<TemplateArgumentLoc>( + new (S.Context) TemplateArgumentLoc[OccurringIndices.count()], + OccurringIndices.count())); + for (unsigned I = 0, J = 0, C = TemplateParams->size(); I != C; ++I) if (OccurringIndices[I]) - Atomic.ParameterMapping->push_back( + new (&(*Atomic.ParameterMapping)[J++]) TemplateArgumentLoc( S.getIdentityTemplateArgumentLoc(TemplateParams->begin()[I], // Here we assume we do not support things like // template<typename A, typename B> @@ -585,6 +528,30 @@ static bool substituteParameterMappings(Sema &S, NormalizedConstraint &N, return false; } +Optional<NormalizedConstraint> +NormalizedConstraint::fromConstraintExprs(Sema &S, NamedDecl *D, + ArrayRef<const Expr *> E) { + assert(E.size() != 0); + auto First = fromConstraintExpr(S, D, E[0]); + if (E.size() == 1) + return First; + auto Second = fromConstraintExpr(S, D, E[1]); + if (!Second) + return None; + llvm::Optional<NormalizedConstraint> Conjunction; + Conjunction.emplace(S.Context, std::move(*First), std::move(*Second), + CCK_Conjunction); + for (unsigned I = 2; I < E.size(); ++I) { + auto Next = fromConstraintExpr(S, D, E[I]); + if (!Next) + return llvm::Optional<NormalizedConstraint>{}; + NormalizedConstraint NewConjunction(S.Context, std::move(*Conjunction), + std::move(*Next), CCK_Conjunction); + *Conjunction = std::move(NewConjunction); + } + return Conjunction; +} + llvm::Optional<NormalizedConstraint> NormalizedConstraint::fromConstraintExpr(Sema &S, NamedDecl *D, const Expr *E) { assert(E != nullptr); @@ -604,11 +571,11 @@ NormalizedConstraint::fromConstraintExpr(Sema &S, NamedDecl *D, const Expr *E) { return None; return NormalizedConstraint( - S.Context, *LHS, *RHS, + S.Context, std::move(*LHS), std::move(*RHS), BO->getOpcode() == BO_LAnd ? CCK_Conjunction : CCK_Disjunction); } } else if (auto *CSE = dyn_cast<const ConceptSpecializationExpr>(E)) { - Optional<NormalizedConstraint> SubNF; + const NormalizedConstraint *SubNF; { Sema::InstantiatingTemplate Inst( S, CSE->getExprLoc(), @@ -623,24 +590,26 @@ NormalizedConstraint::fromConstraintExpr(Sema &S, NamedDecl *D, const Expr *E) { // constraint. If any such substitution results in an invalid type or // expression, the program is ill-formed; no diagnostic is required. // [...] - SubNF = fromConstraintExpr(S, CSE->getNamedConcept(), - CSE->getNamedConcept()->getConstraintExpr()); + ConceptDecl *CD = CSE->getNamedConcept(); + SubNF = S.getNormalizedAssociatedConstraints(CD, + {CD->getConstraintExpr()}); if (!SubNF) return None; } + Optional<NormalizedConstraint> New; + New.emplace(S.Context, *SubNF); + if (substituteParameterMappings( - S, *SubNF, CSE->getNamedConcept(), + S, *New, CSE->getNamedConcept(), CSE->getTemplateArguments(), CSE->getTemplateArgsAsWritten())) return None; - return SubNF; + return New; } return NormalizedConstraint{new (S.Context) AtomicConstraint(S, E)}; } -} // namespace - using NormalForm = llvm::SmallVector<llvm::SmallVector<AtomicConstraint *, 2>, 4>; @@ -703,22 +672,9 @@ static NormalForm makeDNF(const NormalizedConstraint &Normalized) { return Res; } -static bool subsumes(Sema &S, NamedDecl *DP, ArrayRef<const Expr *> P, - NamedDecl *DQ, ArrayRef<const Expr *> Q, bool &Subsumes) { - // C++ [temp.constr.order] p2 - // In order to determine if a constraint P subsumes a constraint Q, P is - // transformed into disjunctive normal form, and Q is transformed into - // conjunctive normal form. [...] - auto PNormalized = NormalizedConstraint::fromConstraintExprs(S, DP, P); - if (!PNormalized) - return true; - const NormalForm PDNF = makeDNF(*PNormalized); - - auto QNormalized = NormalizedConstraint::fromConstraintExprs(S, DQ, Q); - if (!QNormalized) - return true; - const NormalForm QCNF = makeCNF(*QNormalized); - +template<typename AtomicSubsumptionEvaluator> +static bool subsumes(NormalForm PDNF, NormalForm QCNF, + AtomicSubsumptionEvaluator E) { // C++ [temp.constr.order] p2 // Then, P subsumes Q if and only if, for every disjunctive clause Pi in the // disjunctive normal form of P, Pi subsumes every conjunctive clause Qj in @@ -733,7 +689,7 @@ static bool subsumes(Sema &S, NamedDecl *DP, ArrayRef<const Expr *> P, bool Found = false; for (const AtomicConstraint *Pia : Pi) { for (const AtomicConstraint *Qjb : Qj) { - if (Pia->subsumes(S.Context, *Qjb)) { + if (E(*Pia, *Qjb)) { Found = true; break; } @@ -741,13 +697,32 @@ static bool subsumes(Sema &S, NamedDecl *DP, ArrayRef<const Expr *> P, if (Found) break; } - if (!Found) { - Subsumes = false; + if (!Found) return false; - } } } - Subsumes = true; + return true; +} + +template<typename AtomicSubsumptionEvaluator> +static bool subsumes(Sema &S, NamedDecl *DP, ArrayRef<const Expr *> P, + NamedDecl *DQ, ArrayRef<const Expr *> Q, bool &Subsumes, + AtomicSubsumptionEvaluator E) { + // C++ [temp.constr.order] p2 + // In order to determine if a constraint P subsumes a constraint Q, P is + // transformed into disjunctive normal form, and Q is transformed into + // conjunctive normal form. [...] + auto *PNormalized = S.getNormalizedAssociatedConstraints(DP, P); + if (!PNormalized) + return true; + const NormalForm PDNF = makeDNF(*PNormalized); + + auto *QNormalized = S.getNormalizedAssociatedConstraints(DQ, Q); + if (!QNormalized) + return true; + const NormalForm QCNF = makeCNF(*QNormalized); + + Subsumes = subsumes(PDNF, QCNF, E); return false; } @@ -770,8 +745,84 @@ bool Sema::IsAtLeastAsConstrained(NamedDecl *D1, ArrayRef<const Expr *> AC1, Result = CacheEntry->second; return false; } - if (subsumes(*this, D1, AC1, D2, AC2, Result)) + + if (subsumes(*this, D1, AC1, D2, AC2, Result, + [this] (const AtomicConstraint &A, const AtomicConstraint &B) { + return A.subsumes(Context, B); + })) return true; SubsumptionCache.try_emplace(Key, Result); return false; -}
\ No newline at end of file +} + +bool Sema::MaybeEmitAmbiguousAtomicConstraintsDiagnostic(NamedDecl *D1, + ArrayRef<const Expr *> AC1, NamedDecl *D2, ArrayRef<const Expr *> AC2) { + if (isSFINAEContext()) + // No need to work here because our notes would be discarded. + return false; + + if (AC1.empty() || AC2.empty()) + return false; + + auto NormalExprEvaluator = + [this] (const AtomicConstraint &A, const AtomicConstraint &B) { + return A.subsumes(Context, B); + }; + + const Expr *AmbiguousAtomic1 = nullptr, *AmbiguousAtomic2 = nullptr; + auto IdenticalExprEvaluator = + [&] (const AtomicConstraint &A, const AtomicConstraint &B) { + if (!A.hasMatchingParameterMapping(Context, B)) + return false; + const Expr *EA = A.ConstraintExpr, *EB = B.ConstraintExpr; + if (EA == EB) + return true; + + // Not the same source level expression - are the expressions + // identical? + llvm::FoldingSetNodeID IDA, IDB; + EA->Profile(IDA, Context, /*Cannonical=*/true); + EB->Profile(IDB, Context, /*Cannonical=*/true); + if (IDA != IDB) + return false; + + AmbiguousAtomic1 = EA; + AmbiguousAtomic2 = EB; + return true; + }; + + { + // The subsumption checks might cause diagnostics + SFINAETrap Trap(*this); + auto *Normalized1 = getNormalizedAssociatedConstraints(D1, AC1); + if (!Normalized1) + return false; + const NormalForm DNF1 = makeDNF(*Normalized1); + const NormalForm CNF1 = makeCNF(*Normalized1); + + auto *Normalized2 = getNormalizedAssociatedConstraints(D2, AC2); + if (!Normalized2) + return false; + const NormalForm DNF2 = makeDNF(*Normalized2); + const NormalForm CNF2 = makeCNF(*Normalized2); + + bool Is1AtLeastAs2Normally = subsumes(DNF1, CNF2, NormalExprEvaluator); + bool Is2AtLeastAs1Normally = subsumes(DNF2, CNF1, NormalExprEvaluator); + bool Is1AtLeastAs2 = subsumes(DNF1, CNF2, IdenticalExprEvaluator); + bool Is2AtLeastAs1 = subsumes(DNF2, CNF1, IdenticalExprEvaluator); + if (Is1AtLeastAs2 == Is1AtLeastAs2Normally && + Is2AtLeastAs1 == Is2AtLeastAs1Normally) + // Same result - no ambiguity was caused by identical atomic expressions. + return false; + } + + // A different result! Some ambiguous atomic constraint(s) caused a difference + assert(AmbiguousAtomic1 && AmbiguousAtomic2); + + Diag(AmbiguousAtomic1->getBeginLoc(), diag::note_ambiguous_atomic_constraints) + << AmbiguousAtomic1->getSourceRange(); + Diag(AmbiguousAtomic2->getBeginLoc(), + diag::note_ambiguous_atomic_constraints_similar_expression) + << AmbiguousAtomic2->getSourceRange(); + return true; +} |
