mirror of https://github.com/webpack/webpack.git
78 lines
2.1 KiB
JavaScript
78 lines
2.1 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 { numberToIdentifer } = require("../Template");
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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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const canMangleSomething = exportsInfo => {
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for (const exportInfo of exportsInfo.exports) {
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if (exportInfo.canMangle === true) {
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return true;
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}
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}
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return false;
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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(e => e.used !== false, (a, b) => (a === b ? 0 : a ? -1 : 1)),
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// Sort by name
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compareSelect(e => e.name, compareStringsNumeric)
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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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if (!canMangleSomething(exportsInfo)) continue;
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const usedNames = new Set();
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const mangleableExports = [];
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// Don't rename single char exports or exports that can't be mangled
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for (const exportInfo of exportsInfo.exports) {
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const name = exportInfo.name;
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if (exportInfo.canMangle === true && /^a-zA-Z_\$$/.test(name)) {
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mangleableExports.push(exportInfo);
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} else {
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exportInfo.usedName = name;
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usedNames.add(name);
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}
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}
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mangleableExports.sort(comparator);
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let i = 0;
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for (const exportInfo of mangleableExports) {
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let newName = numberToIdentifer(i++);
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while (usedNames.has(newName)) {
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newName = numberToIdentifer(i++);
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}
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exportInfo.usedName = newName;
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// we can skip adding newName to usedNames
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// as numberToIdentifier never repeats results
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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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}
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module.exports = MangleExportsPlugin;
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