maxmustermann/TypeScript
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

Fix variance computation logic

Browse source
This commit is contained in:
Anders Hejlsberg 2021-08-29 16:00:24 -07:00
parent b45e129f4a
commit 73fc830837
2 changed files with 14 additions and 12 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

25
src/compiler/checker.ts
View file

@ -12896,13 +12896,18 @@ namespace ts {
return result & ObjectFlags.PropagatingFlags;
}
function containsMarkerType(typeArguments: readonly Type[] | undefined) {
return some(typeArguments, t => t === markerSuperType || t === markerSubType || t === markerOtherType);
}
function createTypeReference(target: GenericType, typeArguments: readonly Type[] | undefined): TypeReference {
const id = getTypeListId(typeArguments);
let type = target.instantiations.get(id);
if (!type) {
type = createObjectType(ObjectFlags.Reference, target.symbol) as TypeReference;
target.instantiations.set(id, type);
type.objectFlags |= typeArguments ? getPropagatingFlagsOfTypes(typeArguments, /*excludeKinds*/ 0) : 0;
type.objectFlags |= (typeArguments ? getPropagatingFlagsOfTypes(typeArguments, /*excludeKinds*/ 0) : 0) |
(containsMarkerType(typeArguments) ? ObjectFlags.MarkerType : 0);
type.target = target;
type.resolvedTypeArguments = typeArguments;
}
@ -17385,7 +17390,9 @@ namespace ts {
if (source.flags !== target.flags) return false;
if (source.flags & TypeFlags.Singleton) return true;
}
if (source.flags & TypeFlags.Object && target.flags & TypeFlags.Object) {
// We skip the cache lookup shortcut when we're in a variance computation so the outofbandVarianceMarkerHandler
// will get called for cached results that are unreliable or unmeasurable.
if (source.flags & TypeFlags.Object && target.flags & TypeFlags.Object && !outofbandVarianceMarkerHandler) {
const related = relation.get(getRelationKey(source, target, IntersectionState.None, relation));
if (related !== undefined) {
return !!(related & RelationComparisonResult.Succeeded);
@ -18473,7 +18480,7 @@ namespace ts {
// the order in which things were checked.
if (source.flags & (TypeFlags.Object | TypeFlags.Conditional) && source.aliasSymbol &&
source.aliasTypeArguments && source.aliasSymbol === target.aliasSymbol &&
!(source.aliasTypeArgumentsContainsMarker || target.aliasTypeArgumentsContainsMarker)) {
!(containsMarkerType(source.aliasTypeArguments) || containsMarkerType(target.aliasTypeArguments))) {
const variances = getAliasVariances(source.aliasSymbol);
if (variances === emptyArray) {
return Ternary.Unknown;
@ -19708,18 +19715,14 @@ namespace ts {
// Return a type reference where the source type parameter is replaced with the target marker
// type, and flag the result as a marker type reference.
function getMarkerTypeReference(type: GenericType, source: TypeParameter, target: Type) {
const result = createTypeReference(type, map(type.typeParameters, t => t === source ? target : t));
result.objectFlags |= ObjectFlags.MarkerType;
return result;
return createTypeReference(type, map(type.typeParameters, t => t === source ? target : t));
}
function getAliasVariances(symbol: Symbol) {
const links = getSymbolLinks(symbol);
return getVariancesWorker(links.typeParameters, links, (_links, param, marker) => {
const type = getTypeAliasInstantiation(symbol, instantiateTypes(links.typeParameters!, makeUnaryTypeMapper(param, marker)));
type.aliasTypeArgumentsContainsMarker = true;
return type;
});
return getVariancesWorker(links.typeParameters, links, (_links, param, marker) =>
getTypeAliasInstantiation(symbol, instantiateTypes(links.typeParameters!, makeUnaryTypeMapper(param, marker)))
);
}
// Return an array containing the variance of each type parameter. The variance is effectively

1
src/compiler/types.ts
View file

@ -5150,7 +5150,6 @@ namespace ts {
pattern?: DestructuringPattern; // Destructuring pattern represented by type (if any)
aliasSymbol?: Symbol; // Alias associated with type
aliasTypeArguments?: readonly Type[]; // Alias type arguments (if any)
/* @internal */ aliasTypeArgumentsContainsMarker?: boolean; // Alias type arguments (if any)
/* @internal */
permissiveInstantiation?: Type; // Instantiation with type parameters mapped to wildcard type
/* @internal */