diff options
Diffstat (limited to 'source/slang/check.cpp')
| -rw-r--r-- | source/slang/check.cpp | 77 |
1 files changed, 57 insertions, 20 deletions
diff --git a/source/slang/check.cpp b/source/slang/check.cpp index a1b7393fb..6ff8efe9e 100644 --- a/source/slang/check.cpp +++ b/source/slang/check.cpp @@ -546,6 +546,12 @@ namespace Slang // No conversion at all kConversionCost_None = 0, + // Conversions based on explicit sub-typing relationships are the cheapest + // + // TODO(tfoley): We will eventually need a discipline for ranking + // when two up-casts are comparable. + kConversionCost_CastToInterface = 50, + // Conversion that is lossless and keeps the "kind" of the value the same kConversionCost_RankPromotion = 100, @@ -901,6 +907,25 @@ namespace Slang } } + if (auto toDeclRefType = toType->As<DeclRefType>()) + { + auto toTypeDeclRef = toDeclRefType->declRef; + if (auto interfaceDeclRef = toTypeDeclRef.As<InterfaceDeclRef>()) + { + // Trying to convert to an interface type. + // + // We will allow this if the type conforms to the interface. + if (DoesTypeConformToInterface(fromType, interfaceDeclRef)) + { + if (outToExpr) + *outToExpr = CreateImplicitCastExpr(toType, fromExpr); + if (outCost) + *outCost = kConversionCost_CastToInterface; + return true; + } + } + } + // TODO: more cases! return false; @@ -1045,24 +1070,32 @@ namespace Slang return genericDecl; } - virtual void VisitTraitConformanceDecl(TraitConformanceDecl* conformanceDecl) override + virtual void visitInterfaceDecl(InterfaceDecl* decl) override + { + // TODO: do some actual checking of members here + } + + virtual void visitInheritanceDecl(InheritanceDecl* inheritanceDecl) override { - // check the type being conformed to - auto base = conformanceDecl->base; + // check the type being inherited from + auto base = inheritanceDecl->base; base = TranslateTypeNode(base); - conformanceDecl->base = base; + inheritanceDecl->base = base; + + // For now we only allow inheritance from interfaces, so + // we will validate that the type expression names an interface if(auto declRefType = base.type->As<DeclRefType>()) { - if(auto traitDeclRef = declRefType->declRef.As<TraitDeclRef>()) + if(auto interfaceDeclRef = declRefType->declRef.As<InterfaceDeclRef>()) { - conformanceDecl->traitDeclRef = traitDeclRef; return; } } - // We expected a trait here - getSink()->diagnose( conformanceDecl, Diagnostics::expectedATraitGot, base.type); + // If type expression didn't name an interface, we'll emit an error here + // TODO: deal with the case of an error in the type expression (don't cascade) + getSink()->diagnose( base.exp, Diagnostics::expectedAnInterfaceGot, base.type); } RefPtr<ConstantIntVal> checkConstantIntVal( @@ -2479,20 +2512,24 @@ namespace Slang vectorType->elementCount); } - bool DoesTypeConformToTrait( + bool DoesTypeConformToInterface( RefPtr<ExpressionType> type, - TraitDeclRef traitDeclRef) + InterfaceDeclRef interfaceDeclRef) { // for now look up a conformance member... if(auto declRefType = type->As<DeclRefType>()) { if( auto aggTypeDeclRef = declRefType->declRef.As<AggTypeDeclRef>() ) { - for( auto conformanceRef : aggTypeDeclRef.GetMembersOfType<TraitConformanceDeclRef>()) + for( auto inheritanceDeclRef : aggTypeDeclRef.GetMembersOfType<InheritanceDeclRef>()) { - EnsureDecl(conformanceRef.GetDecl()); + EnsureDecl(inheritanceDeclRef.GetDecl()); + + auto inheritedDeclRefType = inheritanceDeclRef.getBaseType()->As<DeclRefType>(); + if (!inheritedDeclRefType) + continue; - if(traitDeclRef.Equals(conformanceRef.GetTraitDeclRef())) + if(interfaceDeclRef.Equals(inheritedDeclRefType->declRef)) return true; } } @@ -2502,12 +2539,12 @@ namespace Slang return false; } - RefPtr<ExpressionType> TryJoinTypeWithTrait( + RefPtr<ExpressionType> TryJoinTypeWithInterface( RefPtr<ExpressionType> type, - TraitDeclRef traitDeclRef) + InterfaceDeclRef interfaceDeclRef) { // The most basic test here should be: does the type declare conformance to the trait. - if(DoesTypeConformToTrait(type, traitDeclRef)) + if(DoesTypeConformToInterface(type, interfaceDeclRef)) return type; // There is a more nuanced case if `type` is a builtin type, and we need to make it @@ -2590,18 +2627,18 @@ namespace Slang // HACK: trying to work trait types in here... if(auto leftDeclRefType = left->As<DeclRefType>()) { - if( auto leftTraitRef = leftDeclRefType->declRef.As<TraitDeclRef>() ) + if( auto leftInterfaceRef = leftDeclRefType->declRef.As<InterfaceDeclRef>() ) { // - return TryJoinTypeWithTrait(right, leftTraitRef); + return TryJoinTypeWithInterface(right, leftInterfaceRef); } } if(auto rightDeclRefType = right->As<DeclRefType>()) { - if( auto rightTraitRef = rightDeclRefType->declRef.As<TraitDeclRef>() ) + if( auto rightInterfaceRef = rightDeclRefType->declRef.As<InterfaceDeclRef>() ) { // - return TryJoinTypeWithTrait(left, rightTraitRef); + return TryJoinTypeWithInterface(left, rightInterfaceRef); } } |