Array constructor with length is not eliminated

描述

/** @const {!Array<number>} */
const a = [1];

/** @const {!Array<number>} */
const b = Array(10);
b[0] = 2;

/** @const {!Array<number>} */
const c = [];
c.push(3);

/** @const {!Array<number>} */
const d = Array(10);
d.push(4);

yarn google-closure-compiler -O ADVANCED --js a.js --rewrite_polyfills=false 

Array(10)[0]=2;Array(10).push(4);

贡献者指南

技术栈

javascriptjava

领域

performancebuild system

议题类型

bug

难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。

4

预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。

1-3 hours

活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。

active

清晰度议题是否清楚说明期望改动、验收标准和下一步。

mostly clear

前置要求

Understanding of JavaScriptFamiliarity with closure compiler internals

新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。

30

研究方向

Investigate the closure compiler's dead code elimination pass for arrays created with the Array(length) constructor. Look at the source code in the compiler's optimization module, particularly the parts that deal with array literals and constructor calls. The issue shows that Array(10) is not being removed while array literals like [1] and [] are. The fix likely involves adding a pattern for Array constructor calls in the dead code elimination logic. Check the comments for any maintainer hints and consider testing by building the compiler and running the provided example.