@ -2,49 +2,39 @@ import { walk } from 'estree-walker';
import modifierNodes , { isModifierNode } from '../ast/modifierNodes.js' ;
import isReference from '../ast/isReference.js' ;
import flatten from '../ast/flatten' ;
import pureFunctions from './pureFunctions.js' ;
let pureFunctions = { } ;
function call ( callee , scope , statement , strongDependencies ) {
while ( callee . type === 'ParenthesizedExpression' ) callee = callee . expression ;
const arrayTypes = 'Array Int8Array Uint8Array Uint8ClampedArray Int16Array Uint16Array Int32Array Uint32Array Float32Array Float64Array' . split ( ' ' ) ;
const simdTypes = 'Int8x16 Int16x8 Int32x4 Float32x4 Float64x2' . split ( ' ' ) ;
const simdMethods = 'abs add and bool check div equal extractLane fromFloat32x4 fromFloat32x4Bits fromFloat64x2 fromFloat64x2Bits fromInt16x8Bits fromInt32x4 fromInt32x4Bits fromInt8x16Bits greaterThan greaterThanOrEqual lessThan lessThanOrEqual load max maxNum min minNum mul neg not notEqual or reciprocalApproximation reciprocalSqrtApproximation replaceLane select selectBits shiftLeftByScalar shiftRightArithmeticByScalar shiftRightLogicalByScalar shuffle splat sqrt store sub swizzle xor' . split ( ' ' ) ;
let allSimdMethods = [ ] ;
simdTypes . forEach ( t => {
simdMethods . forEach ( m => {
allSimdMethods . push ( ` SIMD. ${ t } . ${ m } ` ) ;
} ) ;
} ) ;
if ( callee . type === 'Identifier' ) {
const declaration = scope . findDeclaration ( callee . name ) ||
statement . module . trace ( callee . name ) ;
[
'Array.isArray' ,
'Error' , 'EvalError' , 'InternalError' , 'RangeError' , 'ReferenceError' , 'SyntaxError' , 'TypeError' , 'URIError' ,
'isFinite' , 'isNaN' , 'parseFloat' , 'parseInt' , 'decodeURI' , 'decodeURIComponent' , 'encodeURI' , 'encodeURIComponent' , 'escape' , 'unescape' ,
'Object' , 'Object.create' , 'Object.getNotifier' , 'Object.getOwn' , 'Object.getOwnPropertyDescriptor' , 'Object.getOwnPropertyNames' , 'Object.getOwnPropertySymbols' , 'Object.getPrototypeOf' , 'Object.is' , 'Object.isExtensible' , 'Object.isFrozen' , 'Object.isSealed' , 'Object.keys' ,
'Function' , 'Boolean' ,
'Number' , 'Number.isFinite' , 'Number.isInteger' , 'Number.isNaN' , 'Number.isSafeInteger' , 'Number.parseFloat' , 'Number.parseInt' ,
'Symbol' , 'Symbol.for' , 'Symbol.keyFor' ,
'Math.abs' , 'Math.acos' , 'Math.acosh' , 'Math.asin' , 'Math.asinh' , 'Math.atan' , 'Math.atan2' , 'Math.atanh' , 'Math.cbrt' , 'Math.ceil' , 'Math.clz32' , 'Math.cos' , 'Math.cosh' , 'Math.exp' , 'Math.expm1' , 'Math.floor' , 'Math.fround' , 'Math.hypot' , 'Math.imul' , 'Math.log' , 'Math.log10' , 'Math.log1p' , 'Math.log2' , 'Math.max' , 'Math.min' , 'Math.pow' , 'Math.random' , 'Math.round' , 'Math.sign' , 'Math.sin' , 'Math.sinh' , 'Math.sqrt' , 'Math.tan' , 'Math.tanh' , 'Math.trunc' ,
'Date' , 'Date.UTC' , 'Date.now' , 'Date.parse' ,
'String' , 'String.fromCharCode' , 'String.fromCodePoint' , 'String.raw' ,
'RegExp' ,
'Map' , 'Set' , 'WeakMap' , 'WeakSet' ,
'ArrayBuffer' , 'ArrayBuffer.isView' ,
'DataView' ,
'JSON.parse' , 'JSON.stringify' ,
'Promise' , 'Promise.all' , 'Promise.race' , 'Promise.reject' , 'Promise.resolve' ,
'Intl.Collator' , 'Intl.Collator.supportedLocalesOf' , 'Intl.DateTimeFormat' , 'Intl.DateTimeFormat.supportedLocalesOf' , 'Intl.NumberFormat' , 'Intl.NumberFormat.supportedLocalesOf'
// TODO properties of e.g. window...
] . concat (
arrayTypes ,
arrayTypes . map ( t => ` ${ t } .from ` ) ,
arrayTypes . map ( t => ` ${ t } .of ` ) ,
simdTypes . map ( t => ` SIMD. ${ t } ` ) ,
allSimdMethods
) . forEach ( name => pureFunctions [ name ] = true ) ;
// TODO add others to this list from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects
if ( declaration ) return declaration . run ( strongDependencies ) ;
return ! pureFunctions [ callee . name ] ;
}
if ( /FunctionExpression/ . test ( callee . type ) ) {
return run ( callee . body , scope , statement , strongDependencies ) ;
}
if ( callee . type === 'MemberExpression' ) {
const flattened = flatten ( callee ) ;
if ( flattened ) {
// if we're calling e.g. Object.keys(thing), there are no side-effects
// TODO make pureFunctions configurable
const declaration = scope . findDeclaration ( flattened . name ) || statement . module . trace ( flattened . name ) ;
return ( ! ! declaration || ! pureFunctions [ flattened . keypath ] ) ;
}
}
// complex case like `( a ? b : c )()` or foo[bar].baz()`
// – err on the side of caution
return true ;
}
export default function run ( node , scope , statement , strongDependencies , force ) {
let hasSideEffect = false ;
@ -78,39 +68,7 @@ export default function run ( node, scope, statement, strongDependencies, force
}
else if ( node . type === 'CallExpression' || node . type === 'NewExpression' ) {
if ( node . callee . type === 'Identifier' ) {
const declaration = scope . findDeclaration ( node . callee . name ) ||
statement . module . trace ( node . callee . name ) ;
if ( declaration ) {
if ( declaration . run ( strongDependencies ) ) {
hasSideEffect = true ;
}
} else if ( ! pureFunctions [ node . callee . name ] ) {
hasSideEffect = true ;
}
}
else if ( node . callee . type === 'MemberExpression' ) {
const flattened = flatten ( node . callee ) ;
if ( flattened ) {
// if we're calling e.g. Object.keys(thing), there are no side-effects
// TODO make pureFunctions configurable
const declaration = scope . findDeclaration ( flattened . name ) || statement . module . trace ( flattened . name ) ;
if ( ! ! declaration || ! pureFunctions [ flattened . keypath ] ) {
hasSideEffect = true ;
}
} else {
// is not a keypath like `foo.bar.baz` – could be e.g.
// `foo[bar].baz()`. Err on the side of caution
hasSideEffect = true ;
}
}
// otherwise we're probably dealing with a function expression
else if ( run ( node . callee , scope , statement , strongDependencies , true ) ) {
if ( call ( node . callee , scope , statement , strongDependencies ) ) {
hasSideEffect = true ;
}
}
Rich Harris
9 years ago