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simple eval: fix assignment-to-constant check
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@gdh1995
gdh1995 committed Sep 18, 2024
1 parent 560dfce commit 84af053
Showing 1 changed file with 45 additions and 50 deletions.
95 changes: 45 additions & 50 deletions lib/simple_eval.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -33,15 +33,14 @@ type VarDict = { [name in VarName]: unknown }
type VarList = readonly VarName[]
type NullableVarList = VarList | null
interface AnalysedVars {
readonly a: [escaped_const: number, escaped_var: number, escaped_let: number,
readonly t: [escaped_const: number, escaped_var: number, escaped_let: number,
local_let: number, local_var: number, local_const: number]
readonly v: VarList
}
type VarBindings = unknown[]
interface Map2<K extends string, V> { readonly m?: SafeDict<V>; // has (k: K): boolean
get (k: K): V | undefined; set (k: K, v: V): unknown }
interface StackFrame { readonly b: VarBindings, readonly c: number, readonly d: number
readonly a: AnalysedVars, readonly n: string|null }
interface StackFrame {readonly o:VarBindings, readonly q:AnalysedVars["t"], readonly x:VarList, readonly y:string|null}
interface Isolate extends VarDict {}
interface Ref { readonly y: { [index: number]: number }, readonly i: number /** | ... */ }
interface RefWithOptional { readonly y: { [index: number]: number | undefined }, readonly i: number /** | ... */ }
Expand Down Expand Up @@ -103,19 +102,18 @@ const enum V { econst = 0, elet = 1, evar = 2, localv = 3, locall = 4, localc =
const enum O { block, stats, stat, comma, pair, fn, assign, ifElse, binary, unary, call, access, composed,
literal, ref, fnDesc }
interface OpValues {
[O.block]: { readonly /** stats */ q: readonly EvaluatableOps[], readonly /** hasFn */ x: null | BOOL,
[O.block]: { readonly /** stats */ q: readonly EvaluatableOps[], readonly /** $hasFn */ x: null | BOOL,
readonly /** $analysed */ y: AnalysedVars | null }
[O.stats]: { readonly /** stats */ q: readonly StatementOp[], readonly x: null, readonly y: null }
[O.stat]: StatementOp
[O.comma]: { readonly /** ops */ q: readonly (EvaluatableOps | PairOp)[], readonly x: 0, readonly y: 0 }
[O.comma]: { readonly /** ops */ q: readonly (EvaluatableOps | PairOp)[], readonly x: 0|null, readonly y: 0|null }
[O.pair]: { readonly /** key */ q: string | SomeLiteralOps<L.plain | L.bigint> | BaseOp<O.comma>,
readonly /** value */ x: ExprLikeOps, readonly /** prefix */ y: null | "get" | "set" }
[O.fn]: { readonly /** args */ q: readonly DeclareOp[] | null,
readonly /** body */ x: ExprLikeOps | StorableBlockOp & {
readonly y: [ $this: number, $arguments:number, $newTarget: number ] | null }
readonly /** $builtins */ y: [ $this: number, $arguments:number, $newTarget: number ] | null }
readonly y: CoreOp<O.fnDesc> & OpValues[O.fnDesc] },
[O.composed]: { readonly q: readonly (ExprLikeOps | PairOp)[], readonly x: "[" | "{"
readonly /** before-inited: 0; bool: 1 | 2 */ y: 0 | 1 | 2 },
[O.composed]: { readonly q: readonly (ExprLikeOps | PairOp)[], readonly x: "[" | "{", readonly/**$simple*/y:null|0|1},
[O.assign]: { readonly /** binary op token */ q: TokenValues[T.assign],
readonly /** source (right value) */ x: ExprLikeOps, readonly /** target (left-v) */ y: ExprLikeOps }
[O.ifElse]: { readonly /** condition */ q: ExprLikeOps,
Expand All @@ -127,7 +125,7 @@ interface OpValues {
[O.access]: { readonly q: "." | "?." | "[" | "?.[", readonly /** target */ x: ExprLikeOps,
readonly /** member */ y: string | number | boolean | ExprLikeOps }
[O.literal]: LiteralOp
[O.ref]: { readonly q: VarName, readonly x: number, readonly y: number }
[O.ref]: { readonly q: VarName, readonly x: number | null, readonly y: number | null }
[O.fnDesc]: ( { readonly q: "fn _", readonly x: RefOp } | { readonly q: "fn", readonly x: RefOp | null }
| { readonly q: "(){", readonly x: VarName | PairOp } | { readonly q: "=>", readonly x: null })
& { readonly /** $analysed */ y: AnalysedVars | null }
Expand Down Expand Up @@ -471,11 +469,11 @@ const parseTree = (tokens_: readonly Token[], inNewFunc: boolean | null | undefi
|| (ctx_[ctx_.length - 1].t === T.callOrAccess && (ctx_.length--, true))
? "new" : newTop.v === "?." ? "?.(" : "()"))
: values_.push(Op(O.access, newTop.v === "?." ? "?.[" : "[", values_.pop()! as ExprLikeOps, val.o === O.literal
&& val.q === 0 ? val.x satisfies string | number | boolean | null ?? val : val as ExprLikeOps))
&& val.q === L.plain ? val.x satisfies string | number | boolean | null ?? val : val as ExprLikeOps))
} else if (top.t !== T.group) {
let arr = val.o === O.comma ? val.q : [val as ExprLikeOps]
if (top.t === T.array) {
values_.push(Op(O.composed, arr as ExprLikeOps[], "[", 0))
values_.push(Op(O.composed, arr as ExprLikeOps[], "[", null))
} else {
(values_[values_.length - 1] as WritableOp<O.composed>).q = arr as (ExprLikeOps | PairOp)[]
}
Expand Down Expand Up @@ -539,7 +537,7 @@ const parseTree = (tokens_: readonly Token[], inNewFunc: boolean | null | undefi
: Op(O.call, [], val as ExprLikeOps, "new"))
break
case T.dot: /* T.dot: */
Build.NDEBUG || val.o === O.literal && val.q === 0 && typeof val.x === "string" || throwSyntax(`Fail: ${val.x}`)
Build.NDEBUG || val.o===O.literal && val.q===L.plain && typeof val.x === "string" || throwSyntax(`Fail: ${val.x}`)
values_.push(Op(O.access, top.v, values_.pop()! as ExprLikeOps, val.x as string))
break
default:
Expand All @@ -558,7 +556,7 @@ const parseTree = (tokens_: readonly Token[], inNewFunc: boolean | null | undefi
switch (cur.t) {
case T.block: case T.dict: /* T.block | T.dict: */
topIsDict = !(before & (T.block | T.blockEnd | T.semiColon | T.prefix | T.groupEnd | T.fn | T.ref | T.literal))
values_.push(topIsDict ? Op(O.composed, null as never, "{", 0) : Op(O.block, null as never, null, null))
values_.push(topIsDict ? Op(O.composed, null as never, "{", null) : Op(O.block, null as never, null, null))
type = topIsDict ? T.dict : T.block,
Build.NDEBUG || ((tokens_[pos_] as OverriddenToken).w = { n: topIsDict ? "dict" : "block", v: "{", t: type })
ctx_.push(Token(type, "{"))
Expand Down Expand Up @@ -613,9 +611,8 @@ const parseTree = (tokens_: readonly Token[], inNewFunc: boolean | null | undefi
break
case T.group: case T.array: /* T.group | T.array: */
if (topIsDict) { type === T.group && ctx_.push(Token(T.colon, ":"), Token(T.fn, "(){")); topIsDict = false }
else {
const top = ctx_[ctx_.length - 1]
top.t & (T.dot | T.fn) && before !== T.fn && consume()
else {
ctx_[ctx_.length - 1].t & (T.dot | T.fn) && before !== T.fn && consume()
if (before & (T.groupEnd | T.ref | T.literal)
|| before === T.blockEnd && (1 << values_[values_.length - 1].o) & (1 << O.composed | 1 << O.fn)) {
ctx_.push(Token(T.callOrAccess, "__call__"))
Expand Down Expand Up @@ -763,7 +760,7 @@ const getEscapeAnalyser = (): (func: BaseOp<O.fn>) => void => {
n2 += n1, n3 += n2, n4 += n3, n5 += n4, n6 += n5
op.o === O.ref ? ((op as WritableOp<O.ref>).x = referred!.length ? 0 : -1, (op as WritableOp<O.ref>).y = n1)
: (declarations.length = n6, (op as WritableOp<O.block> | WritableOp<O.fnDesc>).y = {
a: [n1,n2,n3,n4,n5,n6], v: declarations.map(i => i.y) })
t: [n1,n2,n3,n4,n5,n6], v: declarations.map(i => i.y) })
}
const kFnBuiltinVars: VarList = ["this", "arguments", "new.target"]
const visit = (op: EvaluatableOps | PairOp): void => {
Expand Down Expand Up @@ -865,7 +862,7 @@ const getEscapeAnalyser = (): (func: BaseOp<O.fn>) => void => {

//#region evaluate

const enum R { plain = 0, evenNotFound = 1, eveNotInited = 2, noConst = 4, evenNeitherInitedNOrFound=6, allowOptional=8}
const enum R { plain = 0, evenNotFound = 1, eveNotInited = 2, noConst = 4, evenNeitherInitedNorFound=6, allowOptional=8}

const throwReference = (name: string | number, isLocal: boolean): never => {
throw new ReferenceError(isLocal ? `Cannot access '${name}' before initialization` : `${name} is not defined`)
Expand All @@ -875,36 +872,32 @@ const newException = (noHandler?: 1): NonNullable<typeof g_exc> =>
g_exc = { g: isolate_, l: locals_.slice(0), d: noHandler ? stackDepth_ : -stackDepth_ }

const StackFrame = (analysed: AnalysedVars, defined?: readonly unknown[] | null, scopeName?: string): StackFrame|void=>{
let varDict: VarBindings = []
let i = 0, end = analysed.a[V.all], el = analysed.a[V.elet], lv = analysed.a[V.localv]
const varDict: VarBindings = []
let i = 0, end = analysed.t[V.all], el = analysed.t[V.elet], lv = analysed.t[V.localv]
for (; i < end; i++) {
varDict.push(i < el || i > lv ? kEmptyValue : void 0)
}
for (i = 0, end = defined?.length ?? 0; i < end; i += 2) {
defined![i] as number >= 0 && (varDict[defined![i] as number] = defined![i + 1])
}
const frame: StackFrame = { b: varDict, c: analysed.a[V.econst], d: analysed.a[V.locall],
a: analysed, n: scopeName ?? null }
const frame: StackFrame = { o: varDict, q: analysed.t, x: analysed.v, y: scopeName ?? null }
locals_.push(frame)
if (!Build.NDEBUG) { return frame }
}

const exitFrame = (delta: number): void => {
for (let i = 0; i < delta; i++) {
const frame: StackFrame = locals_.pop()!
frame.b.length = frame.a.a[V.evar]
frame.o.length = frame.q[V.evar]
}
}

const _resolveVarRef = (op: RefOp, getter: R): Ref => {
let level = op.x
let level = op.x!
if (level >= 0) {
const frame = locals_[level], pos = op.y, cur = frame.b[pos]
const frame = locals_[level], pos = op.y!, cur = frame.o[pos]
if (cur === kEmptyValue && !(getter & R.eveNotInited)) { throwReference(op.q, true) }
if (getter & R.noConst && (pos < frame.c || pos >= frame.d)) {
throwType(`invalid assignment to const '${op.q}'`)
}
return { y: frame.b satisfies unknown[] as number[], i: pos }
return { y: frame.o satisfies unknown[] as number[], i: pos }
}
const varName = op.q
if (level === -1) {
Expand Down Expand Up @@ -950,7 +943,7 @@ const evalTry = (stats: readonly EvaluatableOps[], i: number): TryValue => {
g_exc || newException()
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])
newVar && StackFrame({ t: [0, elet!, elet!, elet!, 1, 1], v: [newVar.q] }, [newVar.x, ex])
res = evalBlockBody(next.y)
newVar && exitFrame(1); g_exc = null; done = 1
}
Expand Down Expand Up @@ -979,9 +972,9 @@ const evalFor = (statement: BaseStatementOp<"for">, labels: NullableVarList): St
const body = statement.y, initOp = statement.x.q[0]
const analysedScope = statement.x.y
const forkScope = (): VarBindings => {
const old = locals_[locals_.length - 1], newVars = old.b.slice()
const old = locals_[locals_.length - 1], newVars = old.o.slice()
exitFrame(1)
locals_.push({ b: newVars, c: old.c, d: old.d, a: old.a, n: old.n })
locals_.push({ o: newVars, q: old.q, x: old.x, y: old.y })
return newVars
}
let res: StatValue = kEmptyValue, ref: Writable<Ref>
Expand Down Expand Up @@ -1031,15 +1024,15 @@ const evalFor = (statement: BaseStatementOp<"for">, labels: NullableVarList): St

const evalLet = (action: VarActions | "arg", declarations: readonly DeclareOp[], args: unknown[] | null): void => {
const appendUndefined = action === "arg" || action === "let"
let bindings = action === "var" ? null : locals_[locals_.length - 1].b, op: DeclareOp, varPos: number, ind = -1
let bindings = action === "var" ? null : locals_[locals_.length - 1].o, op: DeclareOp, varPos: number, ind = -1
for (op of declarations) {
ind++
varPos = (op.o === O.assign ? op.y : op.q !== kDots ? op : (declarations[ind + 1] as RefOp)).y
varPos = (op.o === O.assign ? op.y : op.q !== kDots ? op : (declarations[ind + 1] as RefOp)).y!
if (args !== null && op.o === O.ref && op.q === kDots) { bindings![varPos] = args.slice(ind); break }
if (args !== null && ind < args.length && args[ind] !== void 0) { bindings![varPos] = args[ind] }
else if (op.o !== O.assign) { appendUndefined && (bindings![varPos] = void 0) }
else {
(bindings ??= locals_[op.y.x].b)[varPos] = op.x.o === O.fn
(bindings ??= locals_[op.y.x!].o)[varPos] = op.x.o === O.fn
? FunctionFromOp(op.x, isolate_, locals_, op.y.q) : opEvals[op.x.o](op.x)
}
}
Expand All @@ -1050,7 +1043,7 @@ const evalBlockBody = (block: SomeOps<O.block | O.stats>, labels?: VarList): Sta
let res: StatValue|TryValue = kEmptyValue, i = 0, statement:EvaluatableOps, prefix:AllStatPrefix, val:StatementOp["y"]
block.y && StackFrame(block.y as Exclude<typeof block.y, readonly [number, number, number]>)
for (const val2 of block.x ? statements : []) {
val2.o === O.fn && val2.y.q === "fn" && val2.y.x && (locals_[locals_.length - 1].b[val2.y.x.y]
val2.o === O.fn && val2.y.q === "fn" && val2.y.x && (locals_[locals_.length - 1].o[val2.y.x.y!]
= FunctionFromOp(val2, isolate_, locals_, ""))
}
for (i = 0; i < statements.length && res === kEmptyValue; i++) {
Expand Down Expand Up @@ -1129,7 +1122,7 @@ const evalNever = (op: BaseOp<KStatLikeO | O.pair | O.fnDesc>): void => {
return FunctionFromOp(op, isolate_, locals_, "")
}, evalAssign = (op: BaseOp<O.assign>): unknown => {
const action = op.q, target = op.y as RefOp | BaseOp<O.access>, direct = action === "="
const { y, i } = Ref(target, direct ? R.evenNeitherInitedNOrFound : R.plain)
const { y, i } = Ref(target, direct ? R.evenNeitherInitedNorFound : R.plain)
let x: number = direct ? 0 : y[i]
if (action === "??=" ? !isLooselyNull(x) : action === "||=" ? x : action === "&&=" ? !x : false) { return x }
const source = op.x.o !== O.fn ? opEvals[op.x.o](op.x) as number : FunctionFromOp(op.x
Expand All @@ -1142,7 +1135,12 @@ const evalNever = (op: BaseOp<KStatLikeO | O.pair | O.fnDesc>): void => {
default : x = source;
if (0) { action satisfies "=" | "??=" | "&&=" | "||=" | "of" | "in" } break // lgtm [js/unreachable-statement]
}
if (direct && target.o === O.ref) { Ref(target, R.noConst) }
if (target.o === O.ref && target.x! >= 0) {
const analysed = locals_[target.x!].q
if (target.y! < analysed[V.econst] || target.y! >= analysed[V.locall]) {
throwType(`Assignment to constant variable '${target.q}'.`)
}
}
return y[i] = x
}, evalIfElse = (op: BaseOp<O.ifElse>): unknown => {
return opEvals[op.q.o](op.q) ? opEvals[op.x.o](op.x) : opEvals[op.y.o](op.y)
Expand Down Expand Up @@ -1219,12 +1217,10 @@ const evalNever = (op: BaseOp<KStatLikeO | O.pair | O.fnDesc>): void => {
if (op.x === "[") { return baseEvalCommaList(op.q as ExprLikeOps[]) }
const Cls = isolate_ !== DefaultIsolate && (isolate_ as unknown as Window).Object || null
const arr = op.q as SomeOps<O.ref | O.pair>[]
if (!op.y) {
(op as WritableOp<O.composed>).y = <0 | 1 | 2> (1 + <BOOL><BOOL | boolean>(arr as SomeOps<O.ref | O.pair>[]).every(
; (op as WritableOp<O.composed>).y ??= <BOOL> (+(arr as SomeOps<O.ref | O.pair>[]).every(
item => item.o === O.ref ? item.q !== kDots : !item.y && (typeof item.q === "string" || item.q.o === O.literal)
&& (item.x.o !== O.fn || item.x.y.q !== "(){" || (typeof item.q === "string"?item.q:item.q.x) === kProto)))
}
if (op.y === 2) {
if (op.y) {
const obj = (Cls ? new Cls() : {}) as Dict<unknown>
for (const item of arr) {
const rawKey = item.q as BaseOp<O.ref>["q"] | Exclude<PairOp["q"], BaseOp<O.comma>>
Expand Down Expand Up @@ -1317,7 +1313,7 @@ const FunctionFromOp = (fn: BaseOp<O.fn>, globals: Isolate, closures: StackFrame
const oldLocalsPos = locals_.length
const stdArgs = fn.q || builtins && builtins[1] >= 0 ? arguments : void 0
const newVar = type.length > 3 ? (fn as ConcreteFnOp<"fn _">).y.x : null, elet = newVar?.y
newVar && StackFrame({ a: [0, elet!, elet!, elet!, 1, 1], v: [newVar.q] }, [newVar.x, callable])
newVar && StackFrame({ t: [0, elet!, elet!, elet!, 1, 1], v: [newVar.q] }, [newVar.x, callable])
frame = fn.y.y && StackFrame(fn.y.y, builtins && [builtins[0], builtins[0] >= 0 ? this : void 0
, builtins[1], stdArgs, builtins[2], newTarget], stdName)
++stackDepth_
Expand Down Expand Up @@ -1389,7 +1385,7 @@ const ToString = (op: StorableEvaluatableOps, allowed: number): string => {
return arr.length > 0 ? op.o === O.stats ? arr.join("\n")
: "{\n " + replaceAll(arr.join("\n"), "\n", "\n ") + "\n}" : "{ }"
case O.stat: /* O.stat: */ {
const { q: prefix, x: clause, y: child } = op, hasNoCond = !prefix || isVarAction(prefix) || prefix === "labelled"
const { q: prefix, x: clause, y: child } = op, hasNoCond = !prefix || isVarAction(prefix) || prefix === kLabelled
const c = !clause || hasNoCond ? ""
: prefix !== "for"
? ToString(clause as Exclude<typeof clause, BaseStatementOp<"labelled" | VarActions>["x"]>, allowed)
Expand All @@ -1399,15 +1395,15 @@ const ToString = (op: StorableEvaluatableOps, allowed: number): string => {
+ (ToString(clause.q[1]!, allowed) || kUnknown).trim() + "; "
+ (ToString(clause.q[2]!, allowed) || kUnknown).trim()
let x = ToString(child, allowed)
return (hasNoCond ? prefix === "labelled" ? replaceAll(clause, " ", ":\n") + ":" : prefix
return (hasNoCond ? prefix === kLabelled ? replaceAll(clause, " ", ":\n") + ":" : prefix
: prefix + (clause ? c ? ` (${c})` : " " + kUnknown : ""))
+ (!x ? child.o !== O.block ? " " + kUnknown + ";" : " { ... }"
: (x = x.trimLeft(), !prefix ? x : (prefix === "else if" || gTokens[prefix]?.t === T.prefix)
&& child.o !== O.block && (x.length > 40 || x.includes("\n"))
? "\n " + replaceAll(x, "\n", "\n ") : x && " " + x)
+ (child.o !== O.block && (child.o !== O.fn || child.y.q < "f") && !x.endsWith(";")
&& (child.o !== O.comma || child.q.length !== 1 || child.q[0].o !== O.assign
|| !"in of".includes(child.q[0].q)) && prefix !== "labelled" ? ";" : ""))
|| !"in of".includes(child.q[0].q)) && prefix !== kLabelled ? ";" : ""))
}
case O.comma: /* O.comma: */
if (op.q.length === 0) { return " " }
Expand Down Expand Up @@ -1451,7 +1447,7 @@ const ToString = (op: StorableEvaluatableOps, allowed: number): string => {
}
case O.access: /* O.access: */
return (ToWrapped(op, allowed, op.x) || kUnknown) + (op.q.endsWith(".") ? op.q + (op.y as string)
: op.q + ((typeof op.y === "object" ? ToString(op.y, allowed) : op.y + "") || kUnknown) + "]")
: op.q + (typeof op.y === "object" ? ToString(op.y, allowed) || kUnknown : JSON.stringify(op.y)) + "]")
case O.composed: /* O.composed: */
return op.q.length == 0 ? op.x === "{" ? "{}" : "[]"
: op.x + " " + ToString(Op(O.comma, op.q, 0, 0), allowed && (allowed | (1 << O.pair) | (1 << O.comma)))
Expand Down Expand Up @@ -1580,9 +1576,8 @@ const doubleEval_mv2 = function (_functionBody: string | object): unknown {
return func()
}

const exposeStack = (stackArray: StackFrame[]
): { dict: VarBindings | VarDict, name: string }[] =>
stackArray.slice().reverse().map(frame => ({ dict: frame.b, name: frame.n ?? "" }))
const exposeStack = (stackArray: StackFrame[]): { bindings: VarBindings, vars: VarList, name: string }[] =>
stackArray.slice().reverse().map(frame => ({ bindings: frame.o, vars: frame.x, name: frame.y ?? "" }))

if (Build.MV3) {
const browser_ = Build.BTypes&BrowserType.Chrome && (DefaultIsolate as any).chrome || (DefaultIsolate as any).browser
Expand Down

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