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Merge pull request #3452 from Microsoft/deeplyNestedTypeArgumentInference

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Type argument inference fix for infinitely recursive anonymous types
This commit is contained in:
Jason Freeman
2015-06-12 14:11:14 -07:00
parent b920291643 aeda84704c
commit 72783bcae3
5 changed files with 231 additions and 53 deletions
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96
src/compiler/checker.ts
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@@ -4439,8 +4439,8 @@ namespace ts {
maybeStack[depth][id] = RelationComparisonResult.Succeeded;
depth++;
let saveExpandingFlags = expandingFlags;
if (!(expandingFlags & 1) && isDeeplyNestedGeneric(source, sourceStack)) expandingFlags |= 1;
if (!(expandingFlags & 2) && isDeeplyNestedGeneric(target, targetStack)) expandingFlags |= 2;
if (!(expandingFlags & 1) && isDeeplyNestedGeneric(source, sourceStack, depth)) expandingFlags |= 1;
if (!(expandingFlags & 2) && isDeeplyNestedGeneric(target, targetStack, depth)) expandingFlags |= 2;
let result: Ternary;
if (expandingFlags === 3) {
result = Ternary.Maybe;
@@ -4476,27 +4476,6 @@ namespace ts {
return result;
}
// Return true if the given type is part of a deeply nested chain of generic instantiations. We consider this to be the case
// when structural type comparisons have been started for 10 or more instantiations of the same generic type. It is possible,
// though highly unlikely, for this test to be true in a situation where a chain of instantiations is not infinitely expanding.
// Effectively, we will generate a false positive when two types are structurally equal to at least 10 levels, but unequal at
// some level beyond that.
function isDeeplyNestedGeneric(type: ObjectType, stack: ObjectType[]): boolean {
// We track type references (created by createTypeReference) and instantiated types (created by instantiateType)
if (type.flags & (TypeFlags.Reference | TypeFlags.Instantiated) && depth >= 10) {
let symbol = type.symbol;
let count = 0;
for (let i = 0; i < depth; i++) {
let t = stack[i];
if (t.flags & (TypeFlags.Reference | TypeFlags.Instantiated) && t.symbol === symbol) {
count++;
if (count >= 10) return true;
}
}
}
return false;
}
function propertiesRelatedTo(source: ObjectType, target: ObjectType, reportErrors: boolean): Ternary {
if (relation === identityRelation) {
return propertiesIdenticalTo(source, target);
@@ -4815,6 +4794,27 @@ namespace ts {
}
}
// Return true if the given type is part of a deeply nested chain of generic instantiations. We consider this to be the case
// when structural type comparisons have been started for 10 or more instantiations of the same generic type. It is possible,
// though highly unlikely, for this test to be true in a situation where a chain of instantiations is not infinitely expanding.
// Effectively, we will generate a false positive when two types are structurally equal to at least 10 levels, but unequal at
// some level beyond that.
function isDeeplyNestedGeneric(type: Type, stack: Type[], depth: number): boolean {
// We track type references (created by createTypeReference) and instantiated types (created by instantiateType)
if (type.flags & (TypeFlags.Reference | TypeFlags.Instantiated) && depth >= 5) {
let symbol = type.symbol;
let count = 0;
for (let i = 0; i < depth; i++) {
let t = stack[i];
if (t.flags & (TypeFlags.Reference | TypeFlags.Instantiated) && t.symbol === symbol) {
count++;
if (count >= 5) return true;
}
}
}
return false;
}
function isPropertyIdenticalTo(sourceProp: Symbol, targetProp: Symbol): boolean {
return compareProperties(sourceProp, targetProp, compareTypes) !== Ternary.False;
}
@@ -5129,21 +5129,6 @@ namespace ts {
return false;
}
function isWithinDepthLimit(type: Type, stack: Type[]) {
if (depth >= 5) {
let target = (<TypeReference>type).target;
let count = 0;
for (let i = 0; i < depth; i++) {
let t = stack[i];
if (t.flags & TypeFlags.Reference && (<TypeReference>t).target === target) {
count++;
}
}
return count < 5;
}
return true;
}
function inferFromTypes(source: Type, target: Type) {
if (source === anyFunctionType) {
return;
@@ -5211,22 +5196,27 @@ namespace ts {
else if (source.flags & TypeFlags.ObjectType && (target.flags & (TypeFlags.Reference | TypeFlags.Tuple) ||
(target.flags & TypeFlags.Anonymous) && target.symbol && target.symbol.flags & (SymbolFlags.Method | SymbolFlags.TypeLiteral))) {
// If source is an object type, and target is a type reference, a tuple type, the type of a method, or a type literal, infer from members
if (!isInProcess(source, target) && isWithinDepthLimit(source, sourceStack) && isWithinDepthLimit(target, targetStack)) {
if (depth === 0) {
sourceStack = [];
targetStack = [];
}
sourceStack[depth] = source;
targetStack[depth] = target;
depth++;
inferFromProperties(source, target);
inferFromSignatures(source, target, SignatureKind.Call);
inferFromSignatures(source, target, SignatureKind.Construct);
inferFromIndexTypes(source, target, IndexKind.String, IndexKind.String);
inferFromIndexTypes(source, target, IndexKind.Number, IndexKind.Number);
inferFromIndexTypes(source, target, IndexKind.String, IndexKind.Number);
depth--;
if (isInProcess(source, target)) {
return;
}
if (isDeeplyNestedGeneric(source, sourceStack, depth) && isDeeplyNestedGeneric(target, targetStack, depth)) {
return;
}
if (depth === 0) {
sourceStack = [];
targetStack = [];
}
sourceStack[depth] = source;
targetStack[depth] = target;
depth++;
inferFromProperties(source, target);
inferFromSignatures(source, target, SignatureKind.Call);
inferFromSignatures(source, target, SignatureKind.Construct);
inferFromIndexTypes(source, target, IndexKind.String, IndexKind.String);
inferFromIndexTypes(source, target, IndexKind.Number, IndexKind.Number);
inferFromIndexTypes(source, target, IndexKind.String, IndexKind.Number);
depth--;
}
}