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fix(parser): improved performance for edgy cases
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@KFlash
KFlash committed Aug 5, 2019
1 parent 970678a commit c8a3677
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Showing 2 changed files with 55 additions and 129 deletions.
174 changes: 45 additions & 129 deletions src/parser.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1388,15 +1388,7 @@ export function parseSwitchStatement(
let test: ESTree.Expression | null = null;
const consequent: ESTree.Statement[] = [];
if (consumeOpt(parser, context | Context.AllowRegExp, Token.CaseKeyword)) {
test = parseExpressions(
parser,
(context | Context.DisallowIn) ^ Context.DisallowIn,
0,
1,
parser.tokenPos,
parser.linePos,
parser.colPos
);
test = parseExpressions(parser, context, 0, 1, parser.tokenPos, parser.linePos, parser.colPos);
} else {
consume(parser, context | Context.AllowRegExp, Token.DefaultKeyword);
if (seenDefault) report(parser, Errors.MultipleDefaultsInSwitch);
Expand Down Expand Up @@ -4107,7 +4099,7 @@ export function parsePrimaryExpressionExtended(
case Token.LeftParen:
return parseParenthesizedExpression(
parser,
context & ~Context.DisallowIn,
context,
allowAssign,
BindingKind.ArgumentList,
Origin.None,
Expand Down Expand Up @@ -5093,18 +5085,17 @@ export function parseArrayExpressionOrPattern(
: AssignmentKind.Assignable;

if (parser.token === Token.Comma || parser.token === Token.RightBracket) {
if (parser.assignable & AssignmentKind.CannotAssign) destructible |= DestructuringKind.CannotDestruct;
if (parser.assignable & AssignmentKind.CannotAssign) {
destructible |= DestructuringKind.CannotDestruct;
}
} else if (parser.destructible & DestructuringKind.HasToDestruct) {
report(parser, Errors.InvalidDestructuringTarget);
} else {
left = parseMemberOrUpdateExpression(parser, context, left, inGroup, 0, 0, tokenPos, linePos, colPos);

destructible = parser.assignable & AssignmentKind.CannotAssign ? DestructuringKind.CannotDestruct : 0;

if ((parser.token & Token.IsBinaryOp) === Token.IsBinaryOp) {
left = parseBinaryExpression(parser, context, inGroup, start, line, column, 4, token, left);
} else if (consumeOpt(parser, context | Context.AllowRegExp, Token.QuestionMark)) {
left = parseConditionalExpression(parser, context, left as ESTree.Expression, start, line, column);
if (parser.token !== Token.Comma && parser.token !== Token.RightBracket) {
left = parseAssignmentExpression(parser, context, inGroup, tokenPos, linePos, colPos, left);
} else if (parser.token !== Token.Assign) {
destructible |=
parser.assignable & AssignmentKind.CannotAssign
Expand Down Expand Up @@ -5143,8 +5134,6 @@ export function parseArrayExpressionOrPattern(
parser.assignable & AssignmentKind.Assignable && kind & (BindingKind.Empty | BindingKind.ArgumentList)
? DestructuringKind.Assignable
: DestructuringKind.CannotDestruct;
} else if (parser.assignable & AssignmentKind.CannotAssign) {
destructible |= DestructuringKind.CannotDestruct;
}
}

Expand Down Expand Up @@ -5212,16 +5201,7 @@ function parseArrayOrObjectAssignmentPattern(

const { tokenPos, linePos, colPos } = parser;

const right = parseExpression(
parser,
(context | Context.DisallowIn) ^ Context.DisallowIn,
1,
1,
inGroup,
tokenPos,
linePos,
colPos
);
const right = parseExpression(parser, context, 1, 1, inGroup, tokenPos, linePos, colPos);

parser.destructible =
((destructible | DestructuringKind.SeenProto | DestructuringKind.HasToDestruct) ^
Expand Down Expand Up @@ -5312,12 +5292,7 @@ function parseSpreadElement(
if (parser.assignable & AssignmentKind.CannotAssign) {
destructible |= DestructuringKind.CannotDestruct;
} else if (token === closingToken || token === Token.Comma) {
if (scope) {
addVarName(parser, context, scope, tokenValue, kind);
if (origin & Origin.Export) {
updateExportsList(parser, tokenValue);
}
}
if (scope) addVarOrBlock(parser, context, scope, parser.tokenValue, kind, origin);
} else {
destructible |= DestructuringKind.Assignable;
}
Expand All @@ -5340,23 +5315,18 @@ function parseSpreadElement(

destructible |= parser.assignable & AssignmentKind.CannotAssign ? DestructuringKind.CannotDestruct : 0;

token = parser.token;

if ((parser.token & Token.IsBinaryOp) === Token.IsBinaryOp) {
argument = parseBinaryExpression(
if (parser.token !== Token.Comma && parser.token !== closingToken) {
if (parser.token !== Token.Assign) destructible |= DestructuringKind.CannotDestruct;
argument = parseAssignmentExpression(
parser,
context,
1,
start,
line,
column,
4,
token,
argument as ESTree.Expression
inGroup,
tokenPos,
linePos,
colPos,
argument as ESTree.ArgumentExpression
);
} else if (consumeOpt(parser, context | Context.AllowRegExp, Token.QuestionMark)) {
argument = parseConditionalExpression(parser, context, argument as ESTree.Expression, start, line, column);
} else if (token !== Token.Assign) {
} else if (parser.token !== Token.Assign) {
destructible |=
parser.assignable & AssignmentKind.CannotAssign
? DestructuringKind.CannotDestruct
Expand Down Expand Up @@ -5658,6 +5628,8 @@ export function parseObjectLiteralOrPattern(
let destructible: DestructuringKind | AssignmentKind = 0;
let prototypeCount = 0;

context = (context | Context.DisallowIn) ^ Context.DisallowIn;

while (parser.token !== Token.RightBrace) {
const { token, tokenValue, linePos, colPos, tokenPos } = parser;

Expand Down Expand Up @@ -5701,7 +5673,7 @@ export function parseObjectLiteralOrPattern(

const right = parseExpression(
parser,
(context | Context.DisallowIn) ^ Context.DisallowIn,
context,
1,
1,
inGroup,
Expand Down Expand Up @@ -5814,15 +5786,7 @@ export function parseObjectLiteralOrPattern(
const { token } = parser;

if (token !== Token.Comma && token !== Token.RightBrace) {
value = parseAssignmentExpression(
parser,
context & ~Context.DisallowIn,
inGroup,
tokenPos,
linePos,
colPos,
value
);
value = parseAssignmentExpression(parser, context, inGroup, tokenPos, linePos, colPos, value);

if (token !== Token.Assign) destructible |= DestructuringKind.CannotDestruct;
} else if (token !== Token.Assign) {
Expand Down Expand Up @@ -5850,15 +5814,7 @@ export function parseObjectLiteralOrPattern(
const { token } = parser;

if (token !== Token.Comma && token !== Token.RightBrace) {
value = parseAssignmentExpression(
parser,
context & ~Context.DisallowIn,
inGroup,
tokenPos,
tokenPos,
colPos,
value
);
value = parseAssignmentExpression(parser, context, inGroup, tokenPos, tokenPos, colPos, value);
if (token !== Token.Assign) destructible |= DestructuringKind.CannotDestruct;
}
}
Expand Down Expand Up @@ -6009,26 +5965,10 @@ export function parseObjectLiteralOrPattern(
}
} else if (parser.token === Token.Assign) {
if (parser.assignable & AssignmentKind.CannotAssign) destructible |= DestructuringKind.CannotDestruct;
value = parseAssignmentExpression(
parser,
context & ~Context.DisallowIn,
inGroup,
tokenPos,
linePos,
colPos,
value
);
value = parseAssignmentExpression(parser, context, inGroup, tokenPos, linePos, colPos, value);
} else {
destructible |= DestructuringKind.CannotDestruct;
value = parseAssignmentExpression(
parser,
context & ~Context.DisallowIn,
inGroup,
tokenPos,
linePos,
colPos,
value
);
value = parseAssignmentExpression(parser, context, inGroup, tokenPos, linePos, colPos, value);
}
} else if ((parser.token & Token.IsPatternStart) === Token.IsPatternStart) {
value =
Expand Down Expand Up @@ -6166,22 +6106,10 @@ export function parseObjectLiteralOrPattern(
: token === Token.Assign
? 0
: DestructuringKind.Assignable;
value = parseAssignmentExpression(
parser,
(context | Context.DisallowIn) ^ Context.DisallowIn,
inGroup,
tokenPos,
linePos,
colPos,
value
);
value = parseAssignmentExpression(parser, context, inGroup, tokenPos, linePos, colPos, value);
} else {
destructible |= DestructuringKind.CannotDestruct;
if ((parser.token & Token.IsBinaryOp) === Token.IsBinaryOp) {
value = parseBinaryExpression(parser, context, inGroup, start, line, column, 4, token, value);
} else if (consumeOpt(parser, context | Context.AllowRegExp, Token.QuestionMark)) {
value = parseConditionalExpression(parser, context, value, start, line, column);
}
value = parseAssignmentExpression(parser, context, inGroup, tokenPos, linePos, colPos, value);
}
} else if ((parser.token & Token.IsPatternStart) === Token.IsPatternStart) {
value =
Expand Down Expand Up @@ -6386,11 +6314,15 @@ export function parseMethodFormals(
): ESTree.Parameter[] {
// FormalParameter[Yield,GeneratorParameter] :
// BindingElement[?Yield, ?GeneratorParameter]

consume(parser, context, Token.LeftParen);

const params: (ESTree.AssignmentPattern | ESTree.Parameter)[] = [];

parser.flags = (parser.flags | Flags.SimpleParameterList) ^ Flags.SimpleParameterList;

context = (context | Context.DisallowIn) ^ Context.DisallowIn;

let setterArgs = 0;

if (parser.token === Token.RightParen) {
Expand Down Expand Up @@ -6471,26 +6403,16 @@ export function parseMethodFormals(

reinterpretToPattern(parser, left);

if (parser.destructible & DestructuringKind.CannotDestruct) report(parser, Errors.InvalidBindingDestruct);

if (parser.destructible & DestructuringKind.Assignable) report(parser, Errors.InvalidBindingDestruct);
if (parser.destructible & (DestructuringKind.Assignable | DestructuringKind.CannotDestruct))
report(parser, Errors.InvalidBindingDestruct);
}

if (parser.token === Token.Assign) {
nextToken(parser, context | Context.AllowRegExp);

parser.flags |= Flags.SimpleParameterList;

const right = parseExpression(
parser,
(context | Context.DisallowIn) ^ Context.DisallowIn,
1,
1,
0,
parser.tokenPos,
parser.linePos,
parser.colPos
);
const right = parseExpression(parser, context, 1, 1, 0, parser.tokenPos, parser.linePos, parser.colPos);

left = finishNode(parser, context, tokenPos, linePos, colPos, {
type: 'AssignmentPattern',
Expand Down Expand Up @@ -6566,7 +6488,7 @@ export function parseParenthesizedExpression(
nextToken(parser, context | Context.AllowRegExp);

const scope = context & Context.OptionsLexical ? addChildScope(createScope(), ScopeKind.ArrowParams) : void 0;

context = (context | Context.DisallowIn) ^ Context.DisallowIn;
if (consumeOpt(parser, context, Token.RightParen)) {
// Not valid expression syntax, but this is valid in an arrow function
// with no params: `() => body`.
Expand Down Expand Up @@ -6947,6 +6869,8 @@ export function parseFormalParametersOrFormalList(

parser.flags = (parser.flags | Flags.SimpleParameterList) ^ Flags.SimpleParameterList;

context = (context | Context.DisallowIn) ^ Context.DisallowIn;

const params: ESTree.Parameter[] = [];

let isSimpleParameterList: 0 | 1 = 0;
Expand Down Expand Up @@ -7019,26 +6943,17 @@ export function parseFormalParametersOrFormalList(

reinterpretToPattern(parser, left);

if (parser.destructible & DestructuringKind.CannotDestruct) report(parser, Errors.InvalidBindingDestruct);

if (parser.destructible & DestructuringKind.Assignable) report(parser, Errors.InvalidBindingDestruct);
if (parser.destructible & (DestructuringKind.Assignable | DestructuringKind.CannotDestruct)) {
report(parser, Errors.InvalidBindingDestruct);
}
}

if (parser.token === Token.Assign) {
nextToken(parser, context | Context.AllowRegExp);

isSimpleParameterList = 1;

const right = parseExpression(
parser,
(context | Context.DisallowIn) ^ Context.DisallowIn,
1,
1,
inGroup,
parser.tokenPos,
parser.linePos,
parser.colPos
);
const right = parseExpression(parser, context, 1, 1, inGroup, parser.tokenPos, parser.linePos, parser.colPos);

left = finishNode(parser, context, tokenPos, linePos, colPos, {
type: 'AssignmentPattern',
Expand Down Expand Up @@ -7727,16 +7642,17 @@ export function parseClassExpression(
let superClass: ESTree.Expression | null = null;

// All class code is always strict mode implicitly
context = (context & ~Context.InConstructor) | Context.Strict;
context = (context | Context.Strict | Context.InConstructor) ^ Context.InConstructor;

const decorators: ESTree.Decorator[] = context & Context.OptionsNext ? parseDecorators(parser, context) : [];

nextToken(parser, context);

if (((parser.token & 0x10ff) ^ 0x54) > 0x1000) {
if (isStrictReservedWord(parser, context, parser.token)) report(parser, Errors.UnexpectedStrictReserved);
if ((parser.token & Token.IsEvalOrArguments) === Token.IsEvalOrArguments)
if ((parser.token & Token.IsEvalOrArguments) === Token.IsEvalOrArguments) {
report(parser, Errors.StrictEvalArguments);
}

id = parseIdentifier(parser, context, 0);
}
Expand Down Expand Up @@ -7903,7 +7819,7 @@ export function parseClassBody(
const { tokenPos, linePos, colPos } = parser;

consume(parser, context | Context.AllowRegExp, Token.LeftBrace);

context = (context | Context.DisallowIn) ^ Context.DisallowIn;
parser.flags = (parser.flags | Flags.HasConstructor) ^ Flags.HasConstructor;

const body: (ESTree.MethodDefinition | ESTree.FieldDefinition)[] = [];
Expand Down
10 changes: 10 additions & 0 deletions test/parser/miscellaneous/pass.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -6,13 +6,23 @@ import { parseSource } from '../../../src/parser';

describe('Miscellaneous - Pass', () => {
for (const arg of [
'([...[][void (this)] += (3287)])',
'(false in (((5973))) ** (q), false.if --, function () {})',
'(([(2e308.typeof += eval), ...(false), (.88), , ]))',
`[ [].x = y]`,
'for (var [] in {b, y, [.4]: h -= 2e308}) for (; ((this() ? 2e308.m ++ : eval[/B^B=/gim])); (() => class {})(null, ...arguments, ...true, ..."9Â]CÕ")) try {} finally {}',
'a([1 || 1].a = 1)',
'x ([1 || 1].a = 1)',
'x({a: 1 || 1}.a = 1)',
'for(`${x in y}`;;);',
`({} + 1);`,
`async ({} + 1);`,
`async ({} ? [] : 1);`,
'({1: ({}) / (1)});',
'({1: ({}) ? (1) : [1]});',
'({1: (x / y - z)});',
'({1: (x = x) });',
`[({a: 1}.c)] = [];`,
`[({a: 1}.c)] = [];`,
'do ; while(0); i++',
'do if (a) x; else y; while(z)',
Expand Down

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