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Type argument inference fix for infinitely recursive anonymous types #3452

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Merged
merged 7 commits into from
Jun 12, 2015
Merged

Type argument inference fix for infinitely recursive anonymous types #3452

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9c4d309
Move inferFromTypes to use isDeeplyNestedGeneric
JsonFreeman Jun 9, 2015
8eb1ecb
Unravel some conditions
JsonFreeman Jun 9, 2015
04b4bc2
Add test
JsonFreeman Jun 9, 2015
f2e04f2
Fix white space
JsonFreeman Jun 9, 2015
9f26803
Merge branch 'master' of https://github.com/Microsoft/TypeScript into…
JsonFreeman Jun 11, 2015
80f523c
Change depth limit from 10 to 5 in isDeeplyNestedGeneric
JsonFreeman Jun 12, 2015
aeda847
Merge branch 'master' of https://github.com/Microsoft/TypeScript into…
JsonFreeman Jun 12, 2015
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96 changes: 43 additions & 53 deletions src/compiler/checker.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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;
}
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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--;
}
}
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What is with this brace?

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That is a white space management error


Expand Down
39 changes: 39 additions & 0 deletions tests/baselines/reference/cyclicGenericTypeInstantiationInference.js
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Original file line number Diff line number Diff line change
@@ -0,0 +1,39 @@
//// [cyclicGenericTypeInstantiationInference.ts]
function foo<T>() {
var z = foo<typeof y>();
var y: {
y2: typeof z
};
return y;
}


function bar<T>() {
var z = bar<typeof y>();
var y: {
y2: typeof z;
}
return y;
}

var a = foo<number>();
var b = bar<number>();

function test<T>(x: typeof a): void { }
test(b);

//// [cyclicGenericTypeInstantiationInference.js]
function foo() {
var z = foo();
var y;
return y;
}
function bar() {
var z = bar();
var y;
return y;
}
var a = foo();
var b = bar();
function test(x) { }
test(b);
61 changes: 61 additions & 0 deletions tests/baselines/reference/cyclicGenericTypeInstantiationInference.symbols
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Original file line number Diff line number Diff line change
@@ -0,0 +1,61 @@
=== tests/cases/compiler/cyclicGenericTypeInstantiationInference.ts ===
function foo<T>() {
>foo : Symbol(foo, Decl(cyclicGenericTypeInstantiationInference.ts, 0, 0))
>T : Symbol(T, Decl(cyclicGenericTypeInstantiationInference.ts, 0, 13))

var z = foo<typeof y>();
>z : Symbol(z, Decl(cyclicGenericTypeInstantiationInference.ts, 1, 7))
>foo : Symbol(foo, Decl(cyclicGenericTypeInstantiationInference.ts, 0, 0))
>y : Symbol(y, Decl(cyclicGenericTypeInstantiationInference.ts, 2, 7))

var y: {
>y : Symbol(y, Decl(cyclicGenericTypeInstantiationInference.ts, 2, 7))

y2: typeof z
>y2 : Symbol(y2, Decl(cyclicGenericTypeInstantiationInference.ts, 2, 12))
>z : Symbol(z, Decl(cyclicGenericTypeInstantiationInference.ts, 1, 7))

};
return y;
>y : Symbol(y, Decl(cyclicGenericTypeInstantiationInference.ts, 2, 7))
}


function bar<T>() {
>bar : Symbol(bar, Decl(cyclicGenericTypeInstantiationInference.ts, 6, 1))
>T : Symbol(T, Decl(cyclicGenericTypeInstantiationInference.ts, 9, 13))

var z = bar<typeof y>();
>z : Symbol(z, Decl(cyclicGenericTypeInstantiationInference.ts, 10, 7))
>bar : Symbol(bar, Decl(cyclicGenericTypeInstantiationInference.ts, 6, 1))
>y : Symbol(y, Decl(cyclicGenericTypeInstantiationInference.ts, 11, 7))

var y: {
>y : Symbol(y, Decl(cyclicGenericTypeInstantiationInference.ts, 11, 7))

y2: typeof z;
>y2 : Symbol(y2, Decl(cyclicGenericTypeInstantiationInference.ts, 11, 12))
>z : Symbol(z, Decl(cyclicGenericTypeInstantiationInference.ts, 10, 7))
}
return y;
>y : Symbol(y, Decl(cyclicGenericTypeInstantiationInference.ts, 11, 7))
}

var a = foo<number>();
>a : Symbol(a, Decl(cyclicGenericTypeInstantiationInference.ts, 17, 3))
>foo : Symbol(foo, Decl(cyclicGenericTypeInstantiationInference.ts, 0, 0))

var b = bar<number>();
>b : Symbol(b, Decl(cyclicGenericTypeInstantiationInference.ts, 18, 3))
>bar : Symbol(bar, Decl(cyclicGenericTypeInstantiationInference.ts, 6, 1))

function test<T>(x: typeof a): void { }
>test : Symbol(test, Decl(cyclicGenericTypeInstantiationInference.ts, 18, 22))
>T : Symbol(T, Decl(cyclicGenericTypeInstantiationInference.ts, 20, 14))
>x : Symbol(x, Decl(cyclicGenericTypeInstantiationInference.ts, 20, 17))
>a : Symbol(a, Decl(cyclicGenericTypeInstantiationInference.ts, 17, 3))

test(b);
>test : Symbol(test, Decl(cyclicGenericTypeInstantiationInference.ts, 18, 22))
>b : Symbol(b, Decl(cyclicGenericTypeInstantiationInference.ts, 18, 3))

66 changes: 66 additions & 0 deletions tests/baselines/reference/cyclicGenericTypeInstantiationInference.types
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@@ -0,0 +1,66 @@
=== tests/cases/compiler/cyclicGenericTypeInstantiationInference.ts ===
function foo<T>() {
>foo : <T>() => { y2: any; }
>T : T

var z = foo<typeof y>();
>z : { y2: any; }
>foo<typeof y>() : { y2: any; }
>foo : <T>() => { y2: any; }
>y : { y2: any; }

var y: {
>y : { y2: any; }

y2: typeof z
>y2 : { y2: any; }
>z : { y2: any; }

};
return y;
>y : { y2: any; }
}


function bar<T>() {
>bar : <T>() => { y2: any; }
>T : T

var z = bar<typeof y>();
>z : { y2: any; }
>bar<typeof y>() : { y2: any; }
>bar : <T>() => { y2: any; }
>y : { y2: any; }

var y: {
>y : { y2: any; }

y2: typeof z;
>y2 : { y2: any; }
>z : { y2: any; }
}
return y;
>y : { y2: any; }
}

var a = foo<number>();
>a : { y2: any; }
>foo<number>() : { y2: any; }
>foo : <T>() => { y2: any; }

var b = bar<number>();
>b : { y2: any; }
>bar<number>() : { y2: any; }
>bar : <T>() => { y2: any; }

function test<T>(x: typeof a): void { }
>test : <T>(x: { y2: any; }) => void
>T : T
>x : { y2: any; }
>a : { y2: any; }

test(b);
>test(b) : void
>test : <T>(x: { y2: any; }) => void
>b : { y2: any; }

22 changes: 22 additions & 0 deletions tests/cases/compiler/cyclicGenericTypeInstantiationInference.ts
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Original file line number Diff line number Diff line change
@@ -0,0 +1,22 @@
function foo<T>() {
var z = foo<typeof y>();
var y: {
y2: typeof z
};
return y;
}


function bar<T>() {
var z = bar<typeof y>();
var y: {
y2: typeof z;
}
return y;
}

var a = foo<number>();
var b = bar<number>();

function test<T>(x: typeof a): void { }
test(b);