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Merged
merged 1 commit into from
Apr 23, 2019
Merged

Track parameter references errors in resolve name rather than secondary pass #30349

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118 changes: 48 additions & 70 deletions src/compiler/checker.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -1232,6 +1232,8 @@ namespace ts {
let lastLocation: Node | undefined;
let lastSelfReferenceLocation: Node | undefined;
let propertyWithInvalidInitializer: Node | undefined;
let associatedDeclarationForContainingInitializer: ParameterDeclaration | BindingElement | undefined;
let withinDeferredContext = false;
const errorLocation = location;
let grandparent: Node;
let isInExternalModule = false;
Expand Down Expand Up @@ -1292,6 +1294,7 @@ namespace ts {
}
}
}
withinDeferredContext = withinDeferredContext || getIsDeferredContext(location, lastLocation);
switch (location.kind) {
case SyntaxKind.SourceFile:
if (!isExternalOrCommonJsModule(<SourceFile>location)) break;
Expand Down Expand Up @@ -1480,6 +1483,19 @@ namespace ts {
// js type aliases do not resolve names from their host, so skip past it
location = getJSDocHost(location);
break;
case SyntaxKind.Parameter:
if (lastLocation && lastLocation === (location as ParameterDeclaration).initializer) {
associatedDeclarationForContainingInitializer = location as ParameterDeclaration;
}
break;
case SyntaxKind.BindingElement:
if (lastLocation && lastLocation === (location as BindingElement).initializer) {
const root = getRootDeclaration(location);
if (root.kind === SyntaxKind.Parameter) {
associatedDeclarationForContainingInitializer = location as BindingElement;
}
}
break;
}
if (isSelfReferenceLocation(location)) {
lastSelfReferenceLocation = location;
Expand Down Expand Up @@ -1584,10 +1600,42 @@ namespace ts {
error(errorLocation!, Diagnostics._0_refers_to_a_UMD_global_but_the_current_file_is_a_module_Consider_adding_an_import_instead, unescapeLeadingUnderscores(name)); // TODO: GH#18217
}
}

// If we're in a parameter initializer, we can't reference the values of the parameter whose initializer we're within or parameters to the right
if (result && associatedDeclarationForContainingInitializer && !withinDeferredContext && (meaning & SymbolFlags.Value) === SymbolFlags.Value) {
const candidate = getMergedSymbol(getLateBoundSymbol(result));
const root = (getRootDeclaration(associatedDeclarationForContainingInitializer) as ParameterDeclaration);
// A parameter initializer or binding pattern initializer within a parameter cannot refer to itself
if (candidate === getSymbolOfNode(associatedDeclarationForContainingInitializer)) {
error(errorLocation, Diagnostics.Parameter_0_cannot_be_referenced_in_its_initializer, declarationNameToString(associatedDeclarationForContainingInitializer.name));
}
// And it cannot refer to any declarations which come after it
else if (candidate.valueDeclaration && candidate.valueDeclaration.pos > associatedDeclarationForContainingInitializer.pos && root.parent.locals && lookup(root.parent.locals, candidate.escapedName, meaning) === candidate) {
error(errorLocation, Diagnostics.Initializer_of_parameter_0_cannot_reference_identifier_1_declared_after_it, declarationNameToString(associatedDeclarationForContainingInitializer.name), declarationNameToString(<Identifier>errorLocation));
}
}
}
return result;
}

function getIsDeferredContext(location: Node, lastLocation: Node | undefined): boolean {
if (location.kind !== SyntaxKind.ArrowFunction && location.kind !== SyntaxKind.FunctionExpression) {
// initializers in instance property declaration of class like entities are executed in constructor and thus deferred
return isTypeQueryNode(location) || ((
isFunctionLikeDeclaration(location) ||
(location.kind === SyntaxKind.PropertyDeclaration && !hasModifier(location, ModifierFlags.Static))
) && (!lastLocation || lastLocation !== (location as FunctionLike | PropertyDeclaration).name)); // A name is evaluated within the enclosing scope - so it shouldn't count as deferred
}
if (lastLocation && lastLocation === (location as FunctionExpression | ArrowFunction).name) {
return false;
}
// generator functions and async functions are not inlined in control flow when immediately invoked
if ((location as FunctionExpression | ArrowFunction).asteriskToken || hasModifier(location, ModifierFlags.Async)) {
return true;
}
return !getImmediatelyInvokedFunctionExpression(location);
}

function isSelfReferenceLocation(node: Node): boolean {
switch (node.kind) {
case SyntaxKind.FunctionDeclaration:
Expand Down Expand Up @@ -26076,74 +26124,6 @@ namespace ts {
}
}

// Check that a parameter initializer contains no references to parameters declared to the right of itself
function checkParameterInitializer(node: HasExpressionInitializer): void {
if (getRootDeclaration(node).kind !== SyntaxKind.Parameter) {
return;
}

const func = getContainingFunction(node);
visit(node.initializer!);

function visit(n: Node): void {
if (isTypeNode(n) || isDeclarationName(n)) {
// do not dive in types
// skip declaration names (i.e. in object literal expressions)
return;
}
if (n.kind === SyntaxKind.PropertyAccessExpression) {
// skip property names in property access expression
return visit((<PropertyAccessExpression>n).expression);
}
else if (n.kind === SyntaxKind.Identifier) {
// check FunctionLikeDeclaration.locals (stores parameters\function local variable)
// if it contains entry with a specified name
const symbol = resolveName(n, (<Identifier>n).escapedText, SymbolFlags.Value | SymbolFlags.Alias, /*nameNotFoundMessage*/undefined, /*nameArg*/undefined, /*isUse*/ false);
if (!symbol || symbol === unknownSymbol || !symbol.valueDeclaration) {
return;
}
if (symbol.valueDeclaration === node) {
error(n, Diagnostics.Parameter_0_cannot_be_referenced_in_its_initializer, declarationNameToString(node.name));
return;
}
// locals map for function contain both parameters and function locals
// so we need to do a bit of extra work to check if reference is legal
const enclosingContainer = getEnclosingBlockScopeContainer(symbol.valueDeclaration);
if (enclosingContainer === func) {
if (symbol.valueDeclaration.kind === SyntaxKind.Parameter ||
symbol.valueDeclaration.kind === SyntaxKind.BindingElement) {
// it is ok to reference parameter in initializer if either
// - parameter is located strictly on the left of current parameter declaration
if (symbol.valueDeclaration.pos < node.pos) {
return;
}
// - parameter is wrapped in function-like entity
if (findAncestor(
n,
current => {
if (current === node.initializer) {
return "quit";
}
return isFunctionLike(current.parent) ||
// computed property names/initializers in instance property declaration of class like entities
// are executed in constructor and thus deferred
(current.parent.kind === SyntaxKind.PropertyDeclaration &&
!(hasModifier(current.parent, ModifierFlags.Static)) &&
isClassLike(current.parent.parent));
})) {
return;
}
// fall through to report error
}
error(n, Diagnostics.Initializer_of_parameter_0_cannot_reference_identifier_1_declared_after_it, declarationNameToString(node.name), declarationNameToString(<Identifier>n));
}
}
else {
return forEachChild(n, visit);
}
}
}

function convertAutoToAny(type: Type) {
return type === autoType ? anyType : type === autoArrayType ? anyArrayType : type;
}
Expand Down Expand Up @@ -26220,7 +26200,6 @@ namespace ts {
else {
checkTypeAssignableToAndOptionallyElaborate(initializerType, getWidenedTypeForVariableLikeDeclaration(node), node, node.initializer);
}
checkParameterInitializer(node);
}
return;
}
Expand All @@ -26237,7 +26216,6 @@ namespace ts {
hasEntries(symbol.exports);
if (!isJSObjectLiteralInitializer && node.parent.parent.kind !== SyntaxKind.ForInStatement) {
checkTypeAssignableToAndOptionallyElaborate(checkExpressionCached(initializer), type, node, initializer, /*headMessage*/ undefined);
checkParameterInitializer(node);
}
}
if (symbol.declarations.length > 1) {
Expand Down
52 changes: 52 additions & 0 deletions tests/baselines/reference/capturedParametersInInitializers1.errors.txt
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Original file line number Diff line number Diff line change
@@ -0,0 +1,52 @@
tests/cases/compiler/capturedParametersInInitializers1.ts(18,20): error TS2373: Initializer of parameter 'y' cannot reference identifier 'z' declared after it.
tests/cases/compiler/capturedParametersInInitializers1.ts(22,26): error TS2373: Initializer of parameter 'y' cannot reference identifier 'z' declared after it.
tests/cases/compiler/capturedParametersInInitializers1.ts(38,21): error TS2373: Initializer of parameter 'y' cannot reference identifier 'z' declared after it.


==== tests/cases/compiler/capturedParametersInInitializers1.ts (3 errors) ====
// ok - usage is deferred
function foo1(y = class {c = x}, x = 1) {
new y().c;
}

// ok - used in file
function foo2(y = function(x: typeof z) {}, z = 1) {

}

// ok -used in type
let a;
function foo3(y = { x: <typeof z>a }, z = 1) {

}

// error - used before declaration
function foo4(y = {z}, z = 1) {
~
!!! error TS2373: Initializer of parameter 'y' cannot reference identifier 'z' declared after it.
}

// error - used before declaration, IIFEs are inlined
function foo5(y = (() => z)(), z = 1) {
~
!!! error TS2373: Initializer of parameter 'y' cannot reference identifier 'z' declared after it.
}

// ok - IIFE inside another function
function foo6(y = () => (() => z)(), z = 1) {
}

// ok - used inside immediately invoked generator function
function foo7(y = (function*() {yield z})(), z = 1) {
}

// ok - used inside immediately invoked async function
function foo8(y = (async () => z)(), z = 1) {
}

// error - used as computed name of method
function foo9(y = {[z]() { return z; }}, z = 1) {
~
!!! error TS2373: Initializer of parameter 'y' cannot reference identifier 'z' declared after it.
}

76 changes: 60 additions & 16 deletions tests/baselines/reference/capturedParametersInInitializers1.js
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Original file line number Diff line number Diff line change
Expand Up @@ -13,28 +13,72 @@ function foo2(y = function(x: typeof z) {}, z = 1) {
let a;
function foo3(y = { x: <typeof z>a }, z = 1) {

}
}

// error - used before declaration
function foo4(y = {z}, z = 1) {
}

// error - used before declaration, IIFEs are inlined
function foo5(y = (() => z)(), z = 1) {
}

// ok - IIFE inside another function
function foo6(y = () => (() => z)(), z = 1) {
}

// ok - used inside immediately invoked generator function
function foo7(y = (function*() {yield z})(), z = 1) {
}

// ok - used inside immediately invoked async function
function foo8(y = (async () => z)(), z = 1) {
}

// error - used as computed name of method
function foo9(y = {[z]() { return z; }}, z = 1) {
}


//// [capturedParametersInInitializers1.js]
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
// ok - usage is deferred
function foo1(y, x) {
if (y === void 0) { y = /** @class */ (function () {
function class_1() {
this.c = x;
}
return class_1;
}()); }
if (x === void 0) { x = 1; }
function foo1(y = class {
constructor() {
this.c = x;
}
}, x = 1) {
new y().c;
}
// ok - used in file
function foo2(y, z) {
if (y === void 0) { y = function (x) { }; }
if (z === void 0) { z = 1; }
function foo2(y = function (x) { }, z = 1) {
}
// ok -used in type
var a;
function foo3(y, z) {
if (y === void 0) { y = { x: a }; }
if (z === void 0) { z = 1; }
let a;
function foo3(y = { x: a }, z = 1) {
}
// error - used before declaration
function foo4(y = { z }, z = 1) {
}
// error - used before declaration, IIFEs are inlined
function foo5(y = (() => z)(), z = 1) {
}
// ok - IIFE inside another function
function foo6(y = () => (() => z)(), z = 1) {
}
// ok - used inside immediately invoked generator function
function foo7(y = (function* () { yield z; })(), z = 1) {
}
// ok - used inside immediately invoked async function
function foo8(y = (() => __awaiter(this, void 0, void 0, function* () { return z; }))(), z = 1) {
}
// error - used as computed name of method
function foo9(y = { [z]() { return z; } }, z = 1) {
}
51 changes: 51 additions & 0 deletions tests/baselines/reference/capturedParametersInInitializers1.symbols
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Original file line number Diff line number Diff line change
Expand Up @@ -36,3 +36,54 @@ function foo3(y = { x: <typeof z>a }, z = 1) {
>z : Symbol(z, Decl(capturedParametersInInitializers1.ts, 12, 37))

}

// error - used before declaration
function foo4(y = {z}, z = 1) {
>foo4 : Symbol(foo4, Decl(capturedParametersInInitializers1.ts, 14, 1))
>y : Symbol(y, Decl(capturedParametersInInitializers1.ts, 17, 14))
>z : Symbol(z, Decl(capturedParametersInInitializers1.ts, 17, 19))
>z : Symbol(z, Decl(capturedParametersInInitializers1.ts, 17, 22))
}

// error - used before declaration, IIFEs are inlined
function foo5(y = (() => z)(), z = 1) {
>foo5 : Symbol(foo5, Decl(capturedParametersInInitializers1.ts, 18, 1))
>y : Symbol(y, Decl(capturedParametersInInitializers1.ts, 21, 14))
>z : Symbol(z, Decl(capturedParametersInInitializers1.ts, 21, 30))
>z : Symbol(z, Decl(capturedParametersInInitializers1.ts, 21, 30))
}

// ok - IIFE inside another function
function foo6(y = () => (() => z)(), z = 1) {
>foo6 : Symbol(foo6, Decl(capturedParametersInInitializers1.ts, 22, 1))
>y : Symbol(y, Decl(capturedParametersInInitializers1.ts, 25, 14))
>z : Symbol(z, Decl(capturedParametersInInitializers1.ts, 25, 36))
>z : Symbol(z, Decl(capturedParametersInInitializers1.ts, 25, 36))
}

// ok - used inside immediately invoked generator function
function foo7(y = (function*() {yield z})(), z = 1) {
>foo7 : Symbol(foo7, Decl(capturedParametersInInitializers1.ts, 26, 1))
>y : Symbol(y, Decl(capturedParametersInInitializers1.ts, 29, 14))
>z : Symbol(z, Decl(capturedParametersInInitializers1.ts, 29, 44))
>z : Symbol(z, Decl(capturedParametersInInitializers1.ts, 29, 44))
}

// ok - used inside immediately invoked async function
function foo8(y = (async () => z)(), z = 1) {
>foo8 : Symbol(foo8, Decl(capturedParametersInInitializers1.ts, 30, 1))
>y : Symbol(y, Decl(capturedParametersInInitializers1.ts, 33, 14))
>z : Symbol(z, Decl(capturedParametersInInitializers1.ts, 33, 36))
>z : Symbol(z, Decl(capturedParametersInInitializers1.ts, 33, 36))
}

// error - used as computed name of method
function foo9(y = {[z]() { return z; }}, z = 1) {
>foo9 : Symbol(foo9, Decl(capturedParametersInInitializers1.ts, 34, 1))
>y : Symbol(y, Decl(capturedParametersInInitializers1.ts, 37, 14))
>[z] : Symbol([z], Decl(capturedParametersInInitializers1.ts, 37, 19))
>z : Symbol(z, Decl(capturedParametersInInitializers1.ts, 37, 40))
>z : Symbol(z, Decl(capturedParametersInInitializers1.ts, 37, 40))
>z : Symbol(z, Decl(capturedParametersInInitializers1.ts, 37, 40))
}

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