diff options
Diffstat (limited to 'node_modules/webpack/lib/optimize/MangleExportsPlugin.js')
| -rw-r--r-- | node_modules/webpack/lib/optimize/MangleExportsPlugin.js | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/node_modules/webpack/lib/optimize/MangleExportsPlugin.js b/node_modules/webpack/lib/optimize/MangleExportsPlugin.js new file mode 100644 index 00000000..30884448 --- /dev/null +++ b/node_modules/webpack/lib/optimize/MangleExportsPlugin.js @@ -0,0 +1,177 @@ +/* + MIT License http://www.opensource.org/licenses/mit-license.php + Author Tobias Koppers @sokra +*/ + +"use strict"; + +const { UsageState } = require("../ExportsInfo"); +const { + numberToIdentifier, + NUMBER_OF_IDENTIFIER_START_CHARS, + NUMBER_OF_IDENTIFIER_CONTINUATION_CHARS +} = require("../Template"); +const { assignDeterministicIds } = require("../ids/IdHelpers"); +const { compareSelect, compareStringsNumeric } = require("../util/comparators"); + +/** @typedef {import("../Compiler")} Compiler */ +/** @typedef {import("../ExportsInfo")} ExportsInfo */ +/** @typedef {import("../ExportsInfo").ExportInfo} ExportInfo */ + +/** + * @param {ExportsInfo} exportsInfo exports info + * @returns {boolean} mangle is possible + */ +const canMangle = exportsInfo => { + if (exportsInfo.otherExportsInfo.getUsed(undefined) !== UsageState.Unused) + return false; + let hasSomethingToMangle = false; + for (const exportInfo of exportsInfo.exports) { + if (exportInfo.canMangle === true) { + hasSomethingToMangle = true; + } + } + return hasSomethingToMangle; +}; + +// Sort by name +const comparator = compareSelect(e => e.name, compareStringsNumeric); +/** + * @param {boolean} deterministic use deterministic names + * @param {ExportsInfo} exportsInfo exports info + * @param {boolean | undefined} isNamespace is namespace object + * @returns {void} + */ +const mangleExportsInfo = (deterministic, exportsInfo, isNamespace) => { + if (!canMangle(exportsInfo)) return; + const usedNames = new Set(); + /** @type {ExportInfo[]} */ + const mangleableExports = []; + + // Avoid to renamed exports that are not provided when + // 1. it's not a namespace export: non-provided exports can be found in prototype chain + // 2. there are other provided exports and deterministic mode is chosen: + // non-provided exports would break the determinism + let avoidMangleNonProvided = !isNamespace; + if (!avoidMangleNonProvided && deterministic) { + for (const exportInfo of exportsInfo.ownedExports) { + if (exportInfo.provided !== false) { + avoidMangleNonProvided = true; + break; + } + } + } + for (const exportInfo of exportsInfo.ownedExports) { + const name = exportInfo.name; + if (!exportInfo.hasUsedName()) { + if ( + // Can the export be mangled? + exportInfo.canMangle !== true || + // Never rename 1 char exports + (name.length === 1 && /^[a-zA-Z0-9_$]/.test(name)) || + // Don't rename 2 char exports in deterministic mode + (deterministic && + name.length === 2 && + /^[a-zA-Z_$][a-zA-Z0-9_$]|^[1-9][0-9]/.test(name)) || + // Don't rename exports that are not provided + (avoidMangleNonProvided && exportInfo.provided !== true) + ) { + exportInfo.setUsedName(name); + usedNames.add(name); + } else { + mangleableExports.push(exportInfo); + } + } + if (exportInfo.exportsInfoOwned) { + const used = exportInfo.getUsed(undefined); + if ( + used === UsageState.OnlyPropertiesUsed || + used === UsageState.Unused + ) { + mangleExportsInfo(deterministic, exportInfo.exportsInfo, false); + } + } + } + if (deterministic) { + assignDeterministicIds( + mangleableExports, + e => e.name, + comparator, + (e, id) => { + const name = numberToIdentifier(id); + const size = usedNames.size; + usedNames.add(name); + if (size === usedNames.size) return false; + e.setUsedName(name); + return true; + }, + [ + NUMBER_OF_IDENTIFIER_START_CHARS, + NUMBER_OF_IDENTIFIER_START_CHARS * + NUMBER_OF_IDENTIFIER_CONTINUATION_CHARS + ], + NUMBER_OF_IDENTIFIER_CONTINUATION_CHARS, + usedNames.size + ); + } else { + const usedExports = []; + const unusedExports = []; + for (const exportInfo of mangleableExports) { + if (exportInfo.getUsed(undefined) === UsageState.Unused) { + unusedExports.push(exportInfo); + } else { + usedExports.push(exportInfo); + } + } + usedExports.sort(comparator); + unusedExports.sort(comparator); + let i = 0; + for (const list of [usedExports, unusedExports]) { + for (const exportInfo of list) { + let name; + do { + name = numberToIdentifier(i++); + } while (usedNames.has(name)); + exportInfo.setUsedName(name); + } + } + } +}; + +class MangleExportsPlugin { + /** + * @param {boolean} deterministic use deterministic names + */ + constructor(deterministic) { + this._deterministic = deterministic; + } + /** + * Apply the plugin + * @param {Compiler} compiler the compiler instance + * @returns {void} + */ + apply(compiler) { + const { _deterministic: deterministic } = this; + compiler.hooks.compilation.tap("MangleExportsPlugin", compilation => { + const moduleGraph = compilation.moduleGraph; + compilation.hooks.optimizeCodeGeneration.tap( + "MangleExportsPlugin", + modules => { + if (compilation.moduleMemCaches) { + throw new Error( + "optimization.mangleExports can't be used with cacheUnaffected as export mangling is a global effect" + ); + } + for (const module of modules) { + const isNamespace = + module.buildMeta && module.buildMeta.exportsType === "namespace"; + const exportsInfo = moduleGraph.getExportsInfo(module); + mangleExportsInfo(deterministic, exportsInfo, isNamespace); + } + } + ); + }); + } +} + +module.exports = MangleExportsPlugin; |