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simple eval: fix optional chaining
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@gdh1995
gdh1995 committed Sep 17, 2024
1 parent 3ad1e19 commit 46f430d
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Showing 2 changed files with 40 additions and 28 deletions.
54 changes: 29 additions & 25 deletions lib/simple_eval.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -44,7 +44,7 @@ interface StackFrame { readonly b: VarBindings, readonly c: number, readonly d:
readonly a: AnalysedVars, readonly n: string|null }
interface Isolate extends VarDict {}
interface Ref { readonly y: { [index: number]: number }, readonly i: number /** | ... */ }
interface RefWithOptional { readonly y: { [index: number]: number | EmptyValue }, readonly i: number /** | ... */ }
interface RefWithOptional { readonly y: { [index: number]: number | undefined }, readonly i: number /** | ... */ }
interface Function2 { (this: unknown, ...args: unknown[]): unknown; readonly __fn?: BaseOp<O.fn> }

const enum T { block = 1, blockEnd = 2, semiColon = 4, prefix = 8, action = 16, group = 32, dict = 64, array = 128,
Expand Down Expand Up @@ -223,6 +223,7 @@ const Op = ((o: O, q: unknown, x: unknown, y: unknown): BaseOp<O>=>{
<T extends L>(op: O.literal, q: T, x: BaseLiteral<T>["x"], y: BaseLiteral<T>["y"]): SomeLiteralOps<T>
}
const kEmptyValue: EmptyValue = { c: 9, v: void 0 }
const kOptionalValue = [void 0 as unknown as number] as const
const kBreakBlock: Writable<BreakValue> = { c: 0, v: 0 }
const kUnknown = "(...)"
// `document.all == null` returns `true`
Expand Down Expand Up @@ -916,20 +917,17 @@ const _resolveVarRef = (op: RefOp, getter: R): Ref => {

const Ref = <T extends R>(op: ExprLikeOps, type: T): T extends R.allowOptional ? RefWithOptional : Ref => {
switch (op.o) {
case O.call: case O.access:
const y = op.o === O.call ? evalCall(op) : opEvals[op.x.o](op.x)
case O.call:
const ret = innerEvalCall(op, type)
return { y: ret === kOptionalValue ? ret : [ret], i: 0 } as (ReturnType<typeof Ref<T>>)
case O.access:
const ref = Ref(op.x, R.allowOptional), y = ref.y[ref.i]
if (isLooselyNull(y)) {
for (let par: ExprLikeOps | null = op; par && (par.o === O.call || par.o === O.access); par = par.x) {
if (par.q[0] === "?") {
return type === R.allowOptional ? { y: kEmptyValue as never, i: "v" satisfies keyof EmptyValue as never }
: { y: [void 0 as unknown as number], i: 0 }
}
}
op.o === O.call || throwType(`Cannot read properties of ${y} (reading ${
if (ref.y as unknown === kOptionalValue || op.q[0] === "?") { return { y: kOptionalValue as never, i: 0 } }
throwType(`Cannot read properties of ${y} (reading ${
AccessToString((typeof op.y === "object" ? opEvals[op.y.o](op.y) : op.y) as string, 1)})`)
}
return op.o === O.call ? { y: [y as number], i: 0 }
: { y: y as Ref["y"], i: (typeof op.y === "object" ? opEvals[op.y.o](op.y) : op.y) as number}
return { y: y as unknown as Ref["y"], i: (typeof op.y === "object" ? opEvals[op.y.o](op.y) : op.y) as number}
case O.ref: return (/*#__NOINLINE__*/ _resolveVarRef)(op, type)
default: return { y: [opEvals[op.o](op) as number], i: 0 }
}
Expand All @@ -948,20 +946,20 @@ const evalTry = (stats: readonly StatementOp[], i: number): TryValue => {
exitFrame(locals_.length - oldLocalsPos)
const newVar = next.x, elet = newVar?.y
newVar && StackFrame({ a: [0, elet!, elet!, elet!, 1, 1], v: [newVar.q] }, [newVar.x, ex])
i++; res = evalBlockBody(next.y)
res = evalBlockBody(next.y)
newVar && exitFrame(1); g_exc = null; done = 1
}
} finally { if (indFinal) {
const oldLocals = locals_, oldExc = done ? null : g_exc || newException()
done || (locals_ = locals_.slice(0, oldLocalsPos), oldExc && (oldExc.d = -Math.abs(oldExc.d)))
i = indFinal; res2 = evalBlockBody((stats[i] as BaseStatementOp<"finally">).y)
res2 = evalBlockBody((stats[indFinal] as BaseStatementOp<"finally">).y)
if (res2 !== kEmptyValue) {
res === kBreakBlock && res !== res2 && ((res as Writable<typeof res>).c = (res as Writable<typeof res>).v = 0)
res = res2 // even override break
}
done || (locals_ = oldLocals, oldExc && (oldExc.d = Math.abs(oldExc.d)))
} }
return { c: i, v: res }
return { c: indFinal || i + 1, v: res }
}

const SubBlock = (op: SomeOps<KStatLikeO>): SomeOps<O.block | O.stats> => {
Expand Down Expand Up @@ -1171,15 +1169,17 @@ const evalNever = (op: BaseOp<KStatLikeO | O.pair | O.fnDesc>): void => {
return arr.join("")
}
case "void":
/*#__NOINLINE__*/ evalAccessOrRef(Op(O.access, ".", Op(O.literal, L.plain, y as never, 0)
/*#__NOINLINE__*/ evalAccess(Op(O.access, ".", Op(O.literal, L.plain, y as never, 0)
, Op(O.literal, L.plain, i as never, 0)))
// no break;
default: if (0) { action satisfies "void" } return // lgtm [js/unreachable-statement]
}
}, evalCall = (op: BaseOp<O.call>): unknown => {
}, innerEvalCall = (op: BaseOp<O.call>, getter: R): unknown => {
const left = op.x, { y, i } = Ref(left, R.allowOptional), i2 = evalAccessKey(i)
let func = y[i2 as number] as unknown as { new (...args: unknown[]): object; (...args: unknown[]): unknown }
if (isLooselyNull(func) && (y as unknown === kEmptyValue || op.y === "?.(")) { return }
if (isLooselyNull(func) && (y as unknown === kOptionalValue || op.y === "?.(")) {
return getter & R.allowOptional ? kOptionalValue : void 0
}
const isNew = op.y === "new", noThis = isNew || left.o !== O.access, args = baseEvalCommaList(op.q)
if (typeof func !== "function") {
if (isLooselyNull(func) || func != null) { // here is to detect `document.all`
Expand All @@ -1206,6 +1206,10 @@ const evalNever = (op: BaseOp<KStatLikeO | O.pair | O.fnDesc>): void => {
: args.length === 0 ? new func : args.length === 1 ? new func(args[0])
: (args.unshift(void 0),
new (evalCall.bind.apply<new (args: unknown[]) => object, unknown[], new () => object>(func, args)))
}, evalCall = (op: BaseOp<O.call>): unknown => innerEvalCall(op, R.plain)
, evalAccess = (op: SomeOps<O.access>): unknown => {
const { y, i } = Ref(op, R.plain)
return y[i]
}, evalComposed = (op: BaseOp<O.composed>): unknown => {
if (op.x === "[") { return baseEvalCommaList(op.q as ExprLikeOps[]) }
const Cls = isolate_ !== DefaultIsolate && (isolate_ as unknown as Window).Object || null
Expand All @@ -1220,7 +1224,7 @@ const evalNever = (op: BaseOp<KStatLikeO | O.pair | O.fnDesc>): void => {
for (const item of arr) {
const rawKey = item.q as BaseOp<O.ref>["q"] | Exclude<PairOp["q"], BaseOp<O.comma>>
const key: string = typeof rawKey === "object" ? (rawKey satisfies SomeLiteralOps<L.plain|L.bigint>).x+"" : rawKey
const value = item.o === O.ref ? evalAccessOrRef(item) : item.x.o !== O.fn
const value = item.o === O.ref ? evalRef(item) : item.x.o !== O.fn
? opEvals[item.x.o](item.x) : FunctionFromOp(item.x, isolate_, locals_, key)
obj[key] = value
}
Expand Down Expand Up @@ -1252,7 +1256,7 @@ const evalNever = (op: BaseOp<KStatLikeO | O.pair | O.fnDesc>): void => {
const key: string | number | symbol = typeof item.q === "string" ? item.q
: item.q.o === O.literal ? item.q.x + "" : evalAccessKey(opEvals[item.q.o](item.q))
const prefix: OpValues[O.pair]["y"] = isRef ? null : item.y
const value = isRef ? evalAccessOrRef(item) : item.x.o !== O.fn ? opEvals[item.x.o](item.x)
const value = isRef ? evalRef(item) : item.x.o !== O.fn ? opEvals[item.x.o](item.x)
: FunctionFromOp(item.x, isolate_, locals_, (prefix ? prefix + " " : "") + AccessToString(key))
const desc: PropertyDescriptor = props[key]
if (prefix) {
Expand All @@ -1266,9 +1270,6 @@ const evalNever = (op: BaseOp<KStatLikeO | O.pair | O.fnDesc>): void => {
}
}
return DefaultObject.create(newProto, props)
}, evalAccessOrRef = (op: SomeOps<O.ref | O.access>): unknown => {
const { y, i } = Ref(op, R.plain)
return y[i]
}, evalLiteral = (op: LiteralOp): unknown => {
switch (op.q) {
case L.plain: return op.x
Expand All @@ -1277,6 +1278,9 @@ const evalNever = (op: BaseOp<KStatLikeO | O.pair | O.fnDesc>): void => {
return typeof op.x === "bigint" ? op.x : (op as WritableLiteralOp<L.bigint>).x = (<any> DefaultIsolate).BigInt(op.x)
default: if (0) { op.q satisfies L.array_hole | kTemplateLikeL } return op.x // lgtm [js/unreachable-statement]
}
}, evalRef = (op: BaseOp<O.ref>): unknown => {
const { y, i } = _resolveVarRef(op, R.plain)
return y[i]
}, evalAccessKey = (key: unknown): number | string | symbol => {
if (typeof key === "object" && key !== null) {
const ref = {[key as never]: 1}, names = DefaultObject.getOwnPropertyNames(ref)
Expand All @@ -1290,7 +1294,7 @@ const evalNever = (op: BaseOp<KStatLikeO | O.pair | O.fnDesc>): void => {

const opEvals = [
evalNever, evalNever, evalNever, evalComma, evalNever, evalFn, evalAssign, evalIfElse, evalBinary, evalUnary,
evalCall, /** O.access */ evalAccessOrRef, evalComposed, evalLiteral, /** O.ref */ evalAccessOrRef, evalNever
evalCall, evalAccess, evalComposed, evalLiteral, evalRef, evalNever
] satisfies { [op in keyof OpValues]: (op: SomeOps<op>) => unknown } as {
[op in keyof OpValues]: <T extends keyof OpValues> (op: BaseOp<T>) => unknown
}
Expand Down Expand Up @@ -1433,7 +1437,7 @@ const ToString = (op: StorableEvaluatableOps, allowed: number): string => {
}).join("")
: op.q + (op.q >= "a" && op.q < "zz" ? " " : "") + (ToString(op.x, allowed) || kUnknown)
case O.call: /* O.call: */ {
const args = op.y.length > 0 ? ToString(Op(O.comma, op.q, 0, 0), allowed) || kUnknown : ""
const args = op.q.length > 0 ? ToString(Op(O.comma, op.q, 0, 0), allowed) || "..." : ""
return (op.y === "new" ? "new " : "") + ToWrapped(op, allowed, op.x) + (op.y === "?.(" ? op.y : "(") + args + ")"
}
case O.access: /* O.access: */
Expand Down
14 changes: 11 additions & 3 deletions tests/unit/simple-js-eval.html
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Original file line number Diff line number Diff line change
Expand Up @@ -279,9 +279,17 @@
})
assert(function() { const a = 1; return; a = 2 })
assert(function() {
let a = {b:{0:{d:{1:{f:"g"}}}}};
// return a?.b[0]?.["d"][1].f
return a?.[0]?.().a[1].b[2]()()()
let a = {b:{0:{d:{1:{f:"g"}}, e(){}}}};
(a.b?.[0].d)[1].f;
let b = 1
try { a?.b[1]; } catch (_e) { b += 2; }
try { a?.b[1].d; } catch (_e) { b += 4; }
try { a?.b?.().d.e; } catch (_e) { b += 8; }
try { a?.b[1]?.().d.e; } catch (_e) { b += 8; }
try { a?.b[1].e().f; } catch (_e) { b += 16; }
try { a?.b[0].e().f; } catch (_e) { b += 32; }
try { a?.b[0].e()?.f.g; } catch (_e) { b += 64; }
return [a?.[0]?.().a[1].b[2]()()(), b]
})
assert(function() {
let a = 0, b = 0, c = 0
Expand Down

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