Skip to content

Commit

Permalink
Fix array spread with sideeffects (microsoft#41523)
Browse files Browse the repository at this point in the history 
* Fix array spread with sideeffects

* Minor cleanup, ensure multiple emit helpers for outfile tests
  • Loading branch information
@rbuckton @Zzzen
rbuckton authored and Zzzen committed Jan 16, 2021
1 parent 5593c7c commit de0e0fb
Show file tree
Hide file tree
Showing 55 changed files with 5,253 additions and 4,282 deletions.
7 changes: 3 additions & 4 deletions src/compiler/checker.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -24700,7 +24700,7 @@ namespace ts {

function checkSpreadExpression(node: SpreadElement, checkMode?: CheckMode): Type {
if (languageVersion < ScriptTarget.ES2015) {
checkExternalEmitHelpers(node, compilerOptions.downlevelIteration ? ExternalEmitHelpers.SpreadIncludes : ExternalEmitHelpers.SpreadArrays);
checkExternalEmitHelpers(node, compilerOptions.downlevelIteration ? ExternalEmitHelpers.SpreadIncludes : ExternalEmitHelpers.SpreadArray);
}

const arrayOrIterableType = checkExpression(node.expression, checkMode);
Expand Down Expand Up @@ -24728,7 +24728,7 @@ namespace ts {
const e = elements[i];
if (e.kind === SyntaxKind.SpreadElement) {
if (languageVersion < ScriptTarget.ES2015) {
checkExternalEmitHelpers(e, compilerOptions.downlevelIteration ? ExternalEmitHelpers.SpreadIncludes : ExternalEmitHelpers.SpreadArrays);
checkExternalEmitHelpers(e, compilerOptions.downlevelIteration ? ExternalEmitHelpers.SpreadIncludes : ExternalEmitHelpers.SpreadArray);
}
const spreadType = checkExpression((<SpreadElement>e).expression, checkMode, forceTuple);
if (isArrayLikeType(spreadType)) {
Expand Down Expand Up @@ -39053,8 +39053,7 @@ namespace ts {
case ExternalEmitHelpers.Generator: return "__generator";
case ExternalEmitHelpers.Values: return "__values";
case ExternalEmitHelpers.Read: return "__read";
case ExternalEmitHelpers.Spread: return "__spread";
case ExternalEmitHelpers.SpreadArrays: return "__spreadArrays";
case ExternalEmitHelpers.SpreadArray: return "__spreadArray";
case ExternalEmitHelpers.Await: return "__await";
case ExternalEmitHelpers.AsyncGenerator: return "__asyncGenerator";
case ExternalEmitHelpers.AsyncDelegator: return "__asyncDelegator";
Expand Down
62 changes: 21 additions & 41 deletions src/compiler/factory/emitHelpers.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,8 +19,7 @@ namespace ts {
// ES2015 Helpers
createExtendsHelper(name: Identifier): Expression;
createTemplateObjectHelper(cooked: ArrayLiteralExpression, raw: ArrayLiteralExpression): Expression;
createSpreadHelper(argumentList: readonly Expression[]): Expression;
createSpreadArraysHelper(argumentList: readonly Expression[]): Expression;
createSpreadArrayHelper(to: Expression, from: Expression): Expression;
// ES2015 Destructuring Helpers
createValuesHelper(expression: Expression): Expression;
createReadHelper(iteratorRecord: Expression, count: number | undefined): Expression;
Expand Down Expand Up @@ -58,8 +57,7 @@ namespace ts {
// ES2015 Helpers
createExtendsHelper,
createTemplateObjectHelper,
createSpreadHelper,
createSpreadArraysHelper,
createSpreadArrayHelper,
// ES2015 Destructuring Helpers
createValuesHelper,
createReadHelper,
Expand Down Expand Up @@ -284,22 +282,12 @@ namespace ts {
);
}

function createSpreadHelper(argumentList: readonly Expression[]) {
context.requestEmitHelper(readHelper);
context.requestEmitHelper(spreadHelper);
function createSpreadArrayHelper(to: Expression, from: Expression) {
context.requestEmitHelper(spreadArrayHelper);
return factory.createCallExpression(
getUnscopedHelperName("__spread"),
getUnscopedHelperName("__spreadArray"),
/*typeArguments*/ undefined,
argumentList
);
}

function createSpreadArraysHelper(argumentList: readonly Expression[]) {
context.requestEmitHelper(spreadArraysHelper);
return factory.createCallExpression(
getUnscopedHelperName("__spreadArrays"),
/*typeArguments*/ undefined,
argumentList
[to, from]
);
}

Expand Down Expand Up @@ -629,29 +617,15 @@ namespace ts {
};`
};

export const spreadHelper: UnscopedEmitHelper = {
name: "typescript:spread",
importName: "__spread",
scoped: false,
dependencies: [readHelper],
text: `
var __spread = (this && this.__spread) || function () {
for (var ar = [], i = 0; i < arguments.length; i++) ar = ar.concat(__read(arguments[i]));
return ar;
};`
};

export const spreadArraysHelper: UnscopedEmitHelper = {
name: "typescript:spreadArrays",
importName: "__spreadArrays",
export const spreadArrayHelper: UnscopedEmitHelper = {
name: "typescript:spreadArray",
importName: "__spreadArray",
scoped: false,
text: `
var __spreadArrays = (this && this.__spreadArrays) || function () {
for (var s = 0, i = 0, il = arguments.length; i < il; i++) s += arguments[i].length;
for (var r = Array(s), k = 0, i = 0; i < il; i++)
for (var a = arguments[i], j = 0, jl = a.length; j < jl; j++, k++)
r[k] = a[j];
return r;
var __spreadArray = (this && this.__spreadArray) || function (to, from) {
for (var i = 0, il = from.length, j = to.length; i < il; i++, j++)
to[j] = from[i];
return to;
};`
};

Expand Down Expand Up @@ -886,8 +860,7 @@ namespace ts {
awaiterHelper,
extendsHelper,
templateObjectHelper,
spreadHelper,
spreadArraysHelper,
spreadArrayHelper,
valuesHelper,
readHelper,
generatorHelper,
Expand Down Expand Up @@ -917,4 +890,11 @@ namespace ts {
return name => cache[name] || (cache[name] = { get value() { return geti(name); }, set value(v) { seti(name, v); } });
})(name => super[name], (name, value) => super[name] = value);`
};

export function isCallToHelper(firstSegment: Expression, helperName: __String) {
return isCallExpression(firstSegment)
&& isIdentifier(firstSegment.expression)
&& (getEmitFlags(firstSegment.expression) & EmitFlags.HelperName)
&& firstSegment.expression.escapedText === helperName;
}
}
82 changes: 48 additions & 34 deletions src/compiler/transformers/es2015.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3892,17 +3892,41 @@ namespace ts {
*
* @param elements The array of Expression nodes.
* @param needsUniqueCopy A value indicating whether to ensure that the result is a fresh array.
* This should be `true` when spreading into an `ArrayLiteral`, and `false` when spreading into an
* argument list.
* @param multiLine A value indicating whether the result should be emitted on multiple lines.
*/
function transformAndSpreadElements(elements: NodeArray<Expression>, needsUniqueCopy: boolean, multiLine: boolean, hasTrailingComma: boolean): Expression {
// When there is no leading SpreadElement:
//
// [source]
// [a, ...b, c]
//
// [output (downlevelIteration)]
// __spread([a], b, [c])
// __spreadArray(__spreadArray([a], __read(b)), [c])
//
// [output]
// __spreadArrays([a], b, [c])
// __spreadArray(__spreadArray([a], b), [c])
//
// When there *is* a leading SpreadElement:
//
// [source]
// [...a, b]
//
// [output (downlevelIteration)]
// __spreadArray(__spreadArray([], __read(a)), [b])
//
// [output]
// __spreadArray(__spreadArray([], a), [b])
//
// NOTE: We use `isPackedArrayLiteral` below rather than just `isArrayLiteral`
// because ES2015 spread will replace _missing_ array elements with `undefined`,
// so we cannot just use an array as is. For example:
//
// `[1, ...[2, , 3]]` becomes `[1, 2, undefined, 3]`
//
// However, for packed array literals (i.e., an array literal with no OmittedExpression
// elements), we can use the array as-is.

// Map spans of spread expressions into their expressions and spans of other
// expressions into an array literal.
Expand All @@ -3913,43 +3937,33 @@ namespace ts {
)
);

if (compilerOptions.downlevelIteration) {
if (segments.length === 1) {
const firstSegment = segments[0];
if (isCallToHelper(firstSegment, "___spread" as __String)) {
return segments[0];
}
if (segments.length === 1) {
const firstSegment = segments[0];
// If we don't need a unique copy, then we are spreading into an argument list for
// a CallExpression or NewExpression. When using `--downlevelIteration`, we need
// to coerce this into an array for use with `apply`, so we will use the code path
// that follows instead.
if (!needsUniqueCopy && !compilerOptions.downlevelIteration
|| isPackedArrayLiteral(firstSegment) // see NOTE (above)
|| isCallToHelper(firstSegment, "___spreadArray" as __String)) {
return segments[0];
}

return emitHelpers().createSpreadHelper(segments);
}
else {
if (segments.length === 1) {
const firstSegment = segments[0];
if (!needsUniqueCopy
|| isPackedArrayLiteral(firstSegment)
|| isCallToHelper(firstSegment, "___spreadArrays" as __String)) {
return segments[0];
}
}

return emitHelpers().createSpreadArraysHelper(segments);
const helpers = emitHelpers();
const startsWithSpread = isSpreadElement(elements[0]);
let expression: Expression =
startsWithSpread ? factory.createArrayLiteralExpression() :
segments[0];
for (let i = startsWithSpread ? 0 : 1; i < segments.length; i++) {
expression = helpers.createSpreadArrayHelper(
expression,
compilerOptions.downlevelIteration && !isPackedArrayLiteral(segments[i]) ? // see NOTE (above)
helpers.createReadHelper(segments[i], /*count*/ undefined) :
segments[i]);
}
}

function isPackedElement(node: Expression) {
return !isOmittedExpression(node);
}

function isPackedArrayLiteral(node: Expression) {
return isArrayLiteralExpression(node) && every(node.elements, isPackedElement);
}

function isCallToHelper(firstSegment: Expression, helperName: __String) {
return isCallExpression(firstSegment)
&& isIdentifier(firstSegment.expression)
&& (getEmitFlags(firstSegment.expression) & EmitFlags.HelperName)
&& firstSegment.expression.escapedText === helperName;
return expression;
}

function partitionSpread(node: Expression) {
Expand Down
28 changes: 13 additions & 15 deletions src/compiler/types.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -6605,19 +6605,18 @@ namespace ts {
Generator = 1 << 7, // __generator (used by ES2015 generator transformation)
Values = 1 << 8, // __values (used by ES2015 for..of and yield* transformations)
Read = 1 << 9, // __read (used by ES2015 iterator destructuring transformation)
Spread = 1 << 10, // __spread (used by ES2015 array spread and argument list spread transformations)
SpreadArrays = 1 << 11, // __spreadArrays (used by ES2015 array spread and argument list spread transformations)
Await = 1 << 12, // __await (used by ES2017 async generator transformation)
AsyncGenerator = 1 << 13, // __asyncGenerator (used by ES2017 async generator transformation)
AsyncDelegator = 1 << 14, // __asyncDelegator (used by ES2017 async generator yield* transformation)
AsyncValues = 1 << 15, // __asyncValues (used by ES2017 for..await..of transformation)
ExportStar = 1 << 16, // __exportStar (used by CommonJS/AMD/UMD module transformation)
ImportStar = 1 << 17, // __importStar (used by CommonJS/AMD/UMD module transformation)
ImportDefault = 1 << 18, // __importStar (used by CommonJS/AMD/UMD module transformation)
MakeTemplateObject = 1 << 19, // __makeTemplateObject (used for constructing template string array objects)
ClassPrivateFieldGet = 1 << 20, // __classPrivateFieldGet (used by the class private field transformation)
ClassPrivateFieldSet = 1 << 21, // __classPrivateFieldSet (used by the class private field transformation)
CreateBinding = 1 << 22, // __createBinding (use by the module transform for (re)exports and namespace imports)
SpreadArray = 1 << 10, // __spreadArray (used by ES2015 array spread and argument list spread transformations)
Await = 1 << 11, // __await (used by ES2017 async generator transformation)
AsyncGenerator = 1 << 12, // __asyncGenerator (used by ES2017 async generator transformation)
AsyncDelegator = 1 << 13, // __asyncDelegator (used by ES2017 async generator yield* transformation)
AsyncValues = 1 << 14, // __asyncValues (used by ES2017 for..await..of transformation)
ExportStar = 1 << 15, // __exportStar (used by CommonJS/AMD/UMD module transformation)
ImportStar = 1 << 16, // __importStar (used by CommonJS/AMD/UMD module transformation)
ImportDefault = 1 << 17, // __importStar (used by CommonJS/AMD/UMD module transformation)
MakeTemplateObject = 1 << 18, // __makeTemplateObject (used for constructing template string array objects)
ClassPrivateFieldGet = 1 << 19, // __classPrivateFieldGet (used by the class private field transformation)
ClassPrivateFieldSet = 1 << 20, // __classPrivateFieldSet (used by the class private field transformation)
CreateBinding = 1 << 21, // __createBinding (use by the module transform for (re)exports and namespace imports)
FirstEmitHelper = Extends,
LastEmitHelper = CreateBinding,

Expand All @@ -6634,8 +6633,7 @@ namespace ts {
AsyncDelegatorIncludes = Await | AsyncDelegator | AsyncValues,

// Helpers included by ES2015 spread
SpreadIncludes = Read | Spread,

SpreadIncludes = Read | SpreadArray,
}

export const enum EmitHint {
Expand Down
11 changes: 11 additions & 0 deletions src/compiler/utilities.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -7033,6 +7033,17 @@ namespace ts {
}
}

function isPackedElement(node: Expression) {
return !isOmittedExpression(node);
}

/**
* Determines whether the provided node is an ArrayLiteralExpression that contains no missing elements.
*/
export function isPackedArrayLiteral(node: Expression) {
return isArrayLiteralExpression(node) && every(node.elements, isPackedElement);
}

/**
* Indicates whether the result of an `Expression` will be unused.
*
Expand Down
3 changes: 2 additions & 1 deletion src/testRunner/unittests/tsbuild/helpers.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -615,7 +615,8 @@ const { b, ...rest } = { a: 10, b: 30, yy: 30 };
const content = fs.readFileSync(path, "utf8");
fs.writeFileSync(path, `${content}
function ${project}${file}Spread(...b: number[]) { }
${project}${file}Spread(...[10, 20, 30]);`);
const ${project}${file}_ar = [20, 30];
${project}${file}Spread(10, ...${project}${file}_ar);`);

replaceText(fs, `src/${project}/tsconfig.json`, `"strict": false,`, `"strict": false,
"downlevelIteration": true,`);
Expand Down
12 changes: 5 additions & 7 deletions tests/baselines/reference/argumentExpressionContextualTyping.js
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,12 +19,10 @@ baz(["string", 1, true, ...array]); // Error
foo(o); // Error because x has an array type namely (string|number)[]

//// [argumentExpressionContextualTyping.js]
var __spreadArrays = (this && this.__spreadArrays) || function () {
for (var s = 0, i = 0, il = arguments.length; i < il; i++) s += arguments[i].length;
for (var r = Array(s), k = 0, i = 0; i < il; i++)
for (var a = arguments[i], j = 0, jl = a.length; j < jl; j++, k++)
r[k] = a[j];
return r;
var __spreadArray = (this && this.__spreadArray) || function (to, from) {
for (var i = 0, il = from.length, j = to.length; i < il; i++, j++)
to[j] = from[i];
return to;
};
// In a typed function call, argument expressions are contextually typed by their corresponding parameter types.
function foo(_a) {
Expand All @@ -43,5 +41,5 @@ var tuple = ["string", 1, true];
baz(tuple);
baz(["string", 1, true]);
baz(array); // Error
baz(__spreadArrays(["string", 1, true], array)); // Error
baz(__spreadArray(["string", 1, true], array)); // Error
foo(o); // Error because x has an array type namely (string|number)[]
16 changes: 7 additions & 9 deletions tests/baselines/reference/arrayLiteralExpressionContextualTyping.js
View file
Original file line number Diff line number Diff line change
Expand Up @@ -16,12 +16,10 @@ var spr2:[number, number, number] = [1, 2, 3, ...tup]; // Error


//// [arrayLiteralExpressionContextualTyping.js]
var __spreadArrays = (this && this.__spreadArrays) || function () {
for (var s = 0, i = 0, il = arguments.length; i < il; i++) s += arguments[i].length;
for (var r = Array(s), k = 0, i = 0; i < il; i++)
for (var a = arguments[i], j = 0, jl = a.length; j < jl; j++, k++)
r[k] = a[j];
return r;
var __spreadArray = (this && this.__spreadArray) || function (to, from) {
for (var i = 0, il = from.length, j = to.length; i < il; i++, j++)
to[j] = from[i];
return to;
};
// In a contextually typed array literal expression containing no spread elements, an element expression at index N is contextually typed by
// the type of the property with the numeric name N in the contextual type, if any, or otherwise
Expand All @@ -33,6 +31,6 @@ var tup1 = [1, 2, 3, "string"];
var tup2 = [1, 2, 3, "string"]; // Error
// In a contextually typed array literal expression containing one or more spread elements,
// an element expression at index N is contextually typed by the numeric index type of the contextual type, if any.
var spr = __spreadArrays([1, 2, 3], array);
var spr1 = __spreadArrays([1, 2, 3], tup);
var spr2 = __spreadArrays([1, 2, 3], tup); // Error
var spr = __spreadArray([1, 2, 3], array);
var spr1 = __spreadArray([1, 2, 3], tup);
var spr2 = __spreadArray([1, 2, 3], tup); // Error
Loading

0 comments on commit de0e0fb

Please sign in to comment.