mirror of https://github.com/webpack/webpack.git
124 lines
3.1 KiB
JavaScript
124 lines
3.1 KiB
JavaScript
/*
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MIT License http://www.opensource.org/licenses/mit-license.php
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Author Tobias Koppers @sokra
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*/
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"use strict";
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const { UsageState } = require("../ModuleGraph");
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const { numberToIdentifier } = require("../Template");
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const { assignDeterministicIds } = require("../ids/IdHelpers");
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const {
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concatComparators,
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compareSelect,
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compareStringsNumeric
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} = require("../util/comparators");
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/** @typedef {import("../Compiler")} Compiler */
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/** @typedef {import("../ModuleGraph").ExportsInfo} ExportsInfo */
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const OBJECT = [];
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const ARRAY = [];
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/**
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* @param {ExportsInfo} exportsInfo exports info
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* @param {boolean} canBeArray can be exports info point to an array
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* @returns {boolean} mangle is possible
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*/
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const canMangle = (exportsInfo, canBeArray) => {
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if (exportsInfo.otherExportsInfo.used !== UsageState.Unused) return false;
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let hasSomethingToMangle = false;
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const empty = canBeArray ? ARRAY : OBJECT;
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for (const exportInfo of exportsInfo.exports) {
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if (exportInfo.name in empty) {
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return false;
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}
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if (exportInfo.canMangle === true) {
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hasSomethingToMangle = true;
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}
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}
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return hasSomethingToMangle;
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};
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const comparator = concatComparators(
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// Sort used before unused fields
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compareSelect(
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e => e.used !== false,
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(a, b) => (a === b ? 0 : a ? -1 : 1)
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),
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// Sort by name
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compareSelect(e => e.name, compareStringsNumeric)
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);
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/**
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* @param {ExportsInfo} exportsInfo exports info
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* @param {boolean} canBeArray can be exports info point to an array
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* @returns {void}
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*/
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const mangleExportsInfo = (exportsInfo, canBeArray) => {
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if (!canMangle(exportsInfo, canBeArray)) return;
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const usedNames = new Set();
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const mangleableExports = [];
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// Don't rename 1-2 char exports or exports that can't be mangled
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for (const exportInfo of exportsInfo.ownedExports) {
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const name = exportInfo.name;
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if (typeof exportInfo.usedName !== "string") {
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if (
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exportInfo.canMangle !== true ||
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(name.length === 1 && /^[a-zA-Z0-9_$]/.test(name)) ||
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(name.length === 2 && /^[a-zA-Z_$][a-zA-Z0-9_$]|^[1-9][0-9]/.test(name))
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) {
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exportInfo.usedName = name;
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usedNames.add(name);
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} else {
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mangleableExports.push(exportInfo);
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}
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}
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if (
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exportInfo.exportsInfoOwned &&
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exportInfo.used === UsageState.OnlyPropertiesUsed
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) {
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mangleExportsInfo(exportInfo.exportsInfo, true);
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}
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}
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assignDeterministicIds(
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mangleableExports,
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e => e.name,
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comparator,
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(e, id) => {
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const name = numberToIdentifier(id);
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const size = usedNames.size;
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usedNames.add(name);
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if (size === usedNames.size) return false;
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e.usedName = name;
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return true;
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},
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[26, 52],
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52,
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usedNames.size
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);
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};
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class MangleExportsPlugin {
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/**
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* @param {Compiler} compiler webpack compiler
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* @returns {void}
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*/
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apply(compiler) {
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compiler.hooks.compilation.tap("MangleExportsPlugin", compilation => {
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const moduleGraph = compilation.moduleGraph;
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compilation.hooks.optimizeCodeGeneration.tap(
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"MangleExportsPlugin",
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modules => {
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for (const module of modules) {
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const exportsInfo = moduleGraph.getExportsInfo(module);
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mangleExportsInfo(exportsInfo, false);
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}
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}
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);
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});
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}
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}
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module.exports = MangleExportsPlugin;
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