Function walkSideEffectsIterative

lib/NormalModule.js:182–343

(rootMod, moduleGraph, ctx)

 * @returns {ConnectionState} the side-effects connection state
 */
const walkSideEffectsIterative = (rootMod, moduleGraph, ctx) => {
	const SideEffectDep = getHarmonyImportSideEffectDependency();

	/** @type {NormalModule[]} */
	const modStack = [rootMod];
	/** @type {Dependency[][]} */
	const depsStack = [rootMod.dependencies];
	const indexStack = [0];
	/** @type {ConnectionState[]} */
	const currentStack = [false];
	rootMod._isEvaluatingSideEffects = true;

	/**
	 * Result from a just-popped child frame, to be applied to the new
	 * top's current dep. `undefined` means "no pending; advance".
	 * @type {ConnectionState | undefined}
	 */
	let pending;

	while (modStack.length > 0) {
		const top = modStack.length - 1;
		const topMod = modStack[top];
		const deps = depsStack[top];
		let index = indexStack[top];
		let current = currentStack[top];

		if (pending !== undefined) {
			const state = pending;
			pending = undefined;
			const dep = deps[index];

			if (state === true) {
				recordSideEffectsBailout(topMod, moduleGraph, dep);
				topMod._isEvaluatingSideEffects = false;
				// `true` is monotonic — safe to memoize regardless of cycle
				// status, matching the direct-bailout branch below.
				topMod._sideEffectsStateGraph = moduleGraph;
				topMod._sideEffectsStateValue = true;
				modStack.pop();
				depsStack.pop();
				indexStack.pop();
				currentStack.pop();
				pending = true;
				continue;
			}
			if (state !== ModuleGraphConnection.CIRCULAR_CONNECTION) {
				current = ModuleGraphConnection.addConnectionStates(current, state);
			}
			index++;
		}

		let descended = false;
		const depCount = deps.length;
		while (index < depCount) {
			const dep = deps[index];
			/** @type {ConnectionState} */
			let state;