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Refactor await/yield production parameter tracking (#10956)

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* test: add test fixtures

* refactor: track AWAIT and YIELD in separate handler

* fix flow errors

* add flow type annotation to production-parameter

* address review comments

* refactor: track [Return] parameter
This commit is contained in:
Huáng Jùnliàng
2020-02-09 23:31:29 +09:00
committed by GitHub
parent 8ab27c8ffe
commit 38529699d6
16 changed files with 650 additions and 73 deletions
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62
packages/babel-parser/src/parser/expression.js
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@@ -33,15 +33,20 @@ import * as charCodes from "charcodes";
import {
BIND_OUTSIDE,
BIND_VAR,
functionFlags,
SCOPE_ARROW,
SCOPE_CLASS,
SCOPE_DIRECT_SUPER,
SCOPE_FUNCTION,
SCOPE_SUPER,
SCOPE_PROGRAM,
SCOPE_ASYNC,
} from "../util/scopeflags";
import { ExpressionErrors } from "./util";
import {
PARAM_AWAIT,
PARAM_RETURN,
PARAM,
functionFlags,
} from "../util/production-parameter";
export default class ExpressionParser extends LValParser {
// Forward-declaration: defined in statement.js
@@ -108,11 +113,12 @@ export default class ExpressionParser extends LValParser {
// Convenience method to parse an Expression only
getExpression(): N.Expression {
let scopeFlags = SCOPE_PROGRAM;
let paramFlags = PARAM;
if (this.hasPlugin("topLevelAwait") && this.inModule) {
scopeFlags |= SCOPE_ASYNC;
paramFlags |= PARAM_AWAIT;
}
this.scope.enter(scopeFlags);
this.scope.enter(SCOPE_PROGRAM);
this.prodParam.enter(paramFlags);
this.nextToken();
const expr = this.parseExpression();
if (!this.match(tt.eof)) {
@@ -131,12 +137,18 @@ export default class ExpressionParser extends LValParser {
// and, *if* the syntactic construct they handle is present, wrap
// the AST node that the inner parser gave them in another node.
// Parse a full expression. The optional arguments are used to
// forbid the `in` operator (in for loops initialization expressions)
// and provide reference for storing '=' operator inside shorthand
// property assignment in contexts where both object expression
// and object pattern might appear (so it's possible to raise
// delayed syntax error at correct position).
// Parse a full expression.
// - `noIn`
// is used to forbid the `in` operator (in for loops initialization expressions)
// When `noIn` is true, the production parameter [In] is not present.
// Whenever [?In] appears in the right-hand sides of a production, we pass
// `noIn` to the subroutine calls.
// - `refExpressionErrors `
// provides reference for storing '=' operator inside shorthand
// property assignment in contexts where both object expression
// and object pattern might appear (so it's possible to raise
// delayed syntax error at correct position).
parseExpression(
noIn?: boolean,
@@ -169,7 +181,7 @@ export default class ExpressionParser extends LValParser {
const startPos = this.state.start;
const startLoc = this.state.startLoc;
if (this.isContextual("yield")) {
if (this.scope.inGenerator) {
if (this.prodParam.hasYield) {
let left = this.parseYield(noIn);
if (afterLeftParse) {
left = afterLeftParse.call(this, left, startPos, startLoc);
@@ -367,7 +379,7 @@ export default class ExpressionParser extends LValParser {
if (
this.match(tt.name) &&
this.state.value === "await" &&
this.scope.inAsync
this.prodParam.hasAwait
) {
throw this.raise(
this.state.start,
@@ -1161,7 +1173,7 @@ export default class ExpressionParser extends LValParser {
this.next();
meta = this.createIdentifier(meta, "function");
if (this.scope.inGenerator && this.eat(tt.dot)) {
if (this.prodParam.hasYield && this.eat(tt.dot)) {
return this.parseMetaProperty(node, meta, "sent");
}
return this.parseFunction(node);
@@ -1833,13 +1845,15 @@ export default class ExpressionParser extends LValParser {
node.generator = !!isGenerator;
const allowModifiers = isConstructor; // For TypeScript parameter properties
this.scope.enter(
functionFlags(isAsync, node.generator) |
SCOPE_FUNCTION |
SCOPE_SUPER |
(inClassScope ? SCOPE_CLASS : 0) |
(allowDirectSuper ? SCOPE_DIRECT_SUPER : 0),
);
this.prodParam.enter(functionFlags(isAsync, node.generator));
this.parseFunctionParams((node: any), allowModifiers);
this.parseFunctionBodyAndFinish(node, type, true);
this.prodParam.exit();
this.scope.exit();
this.state.yieldPos = oldYieldPos;
@@ -1857,7 +1871,8 @@ export default class ExpressionParser extends LValParser {
isAsync: boolean,
trailingCommaPos: ?number,
): N.ArrowFunctionExpression {
this.scope.enter(functionFlags(isAsync, false) | SCOPE_ARROW);
this.scope.enter(SCOPE_FUNCTION | SCOPE_ARROW);
this.prodParam.enter(functionFlags(isAsync, false));
this.initFunction(node, isAsync);
const oldMaybeInArrowParameters = this.state.maybeInArrowParameters;
const oldYieldPos = this.state.yieldPos;
@@ -1872,6 +1887,7 @@ export default class ExpressionParser extends LValParser {
this.state.awaitPos = -1;
this.parseFunctionBody(node, true);
this.prodParam.exit();
this.scope.exit();
this.state.maybeInArrowParameters = oldMaybeInArrowParameters;
this.state.yieldPos = oldYieldPos;
@@ -1949,7 +1965,11 @@ export default class ExpressionParser extends LValParser {
allowExpression,
!oldStrict && useStrict,
);
// FunctionBody[Yield, Await]:
// StatementList[?Yield, ?Await, +Return] opt
this.prodParam.enter(this.prodParam.currentFlags() | PARAM_RETURN);
node.body = this.parseBlock(true, false);
this.prodParam.exit();
this.state.labels = oldLabels;
}
@@ -2140,7 +2160,7 @@ export default class ExpressionParser extends LValParser {
checkKeywords: boolean,
isBinding: boolean,
): void {
if (this.scope.inGenerator && word === "yield") {
if (this.prodParam.hasYield && word === "yield") {
this.raise(
startLoc,
"Can not use 'yield' as identifier inside a generator",
@@ -2149,7 +2169,7 @@ export default class ExpressionParser extends LValParser {
}
if (word === "await") {
if (this.scope.inAsync) {
if (this.prodParam.hasAwait) {
this.raise(
startLoc,
"Can not use 'await' as identifier inside an async function",
@@ -2187,7 +2207,7 @@ export default class ExpressionParser extends LValParser {
: isStrictReservedWord;
if (reservedTest(word, this.inModule)) {
if (!this.scope.inAsync && word === "await") {
if (!this.prodParam.hasAwait && word === "await") {
this.raise(
startLoc,
"Can not use keyword 'await' outside an async function",
@@ -2199,10 +2219,10 @@ export default class ExpressionParser extends LValParser {
}
isAwaitAllowed(): boolean {
if (this.scope.inFunction) return this.scope.inAsync;
if (this.scope.inFunction) return this.prodParam.hasAwait;
if (this.options.allowAwaitOutsideFunction) return true;
if (this.hasPlugin("topLevelAwait")) {
return this.inModule && this.scope.inAsync;
return this.inModule && this.prodParam.hasAwait;
}
return false;
}