diff options
Diffstat (limited to 'node_modules/webpack/lib/optimize/SideEffectsFlagPlugin.js')
| -rw-r--r-- | node_modules/webpack/lib/optimize/SideEffectsFlagPlugin.js | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/node_modules/webpack/lib/optimize/SideEffectsFlagPlugin.js b/node_modules/webpack/lib/optimize/SideEffectsFlagPlugin.js new file mode 100644 index 0000000..5db780c --- /dev/null +++ b/node_modules/webpack/lib/optimize/SideEffectsFlagPlugin.js @@ -0,0 +1,352 @@ +/* + MIT License http://www.opensource.org/licenses/mit-license.php + Author Tobias Koppers @sokra +*/ +"use strict"; + +const mm = require("micromatch"); +const HarmonyExportImportedSpecifierDependency = require("../dependencies/HarmonyExportImportedSpecifierDependency"); +const HarmonyImportSideEffectDependency = require("../dependencies/HarmonyImportSideEffectDependency"); +const HarmonyImportSpecifierDependency = require("../dependencies/HarmonyImportSpecifierDependency"); + +/** @typedef {import("../Module")} Module */ +/** @typedef {import("../Dependency")} Dependency */ + +/** + * @typedef {Object} ExportInModule + * @property {Module} module the module + * @property {string} exportName the name of the export + * @property {boolean} checked if the export is conditional + */ + +/** + * @typedef {Object} ReexportInfo + * @property {Map<string, ExportInModule[]>} static + * @property {Map<Module, Set<string>>} dynamic + */ + +/** + * @param {ReexportInfo} info info object + * @param {string} exportName name of export + * @returns {ExportInModule | undefined} static export + */ +const getMappingFromInfo = (info, exportName) => { + const staticMappings = info.static.get(exportName); + if (staticMappings !== undefined) { + if (staticMappings.length === 1) return staticMappings[0]; + return undefined; + } + const dynamicMappings = Array.from(info.dynamic).filter( + ([_, ignored]) => !ignored.has(exportName) + ); + if (dynamicMappings.length === 1) { + return { + module: dynamicMappings[0][0], + exportName, + checked: true + }; + } + return undefined; +}; + +/** + * @param {ReexportInfo} info info object + * @param {string} exportName name of export of source module + * @param {Module} module the target module + * @param {string} innerExportName name of export of target module + * @param {boolean} checked true, if existence of target module is checked + */ +const addStaticReexport = ( + info, + exportName, + module, + innerExportName, + checked +) => { + let mappings = info.static.get(exportName); + if (mappings !== undefined) { + for (const mapping of mappings) { + if (mapping.module === module && mapping.exportName === innerExportName) { + mapping.checked = mapping.checked && checked; + return; + } + } + } else { + mappings = []; + info.static.set(exportName, mappings); + } + mappings.push({ + module, + exportName: innerExportName, + checked + }); +}; + +/** + * @param {ReexportInfo} info info object + * @param {Module} module the reexport module + * @param {Set<string>} ignored ignore list + * @returns {void} + */ +const addDynamicReexport = (info, module, ignored) => { + const existingList = info.dynamic.get(module); + if (existingList !== undefined) { + for (const key of existingList) { + if (!ignored.has(key)) existingList.delete(key); + } + } else { + info.dynamic.set(module, new Set(ignored)); + } +}; + +class SideEffectsFlagPlugin { + apply(compiler) { + compiler.hooks.normalModuleFactory.tap("SideEffectsFlagPlugin", nmf => { + nmf.hooks.module.tap("SideEffectsFlagPlugin", (module, data) => { + const resolveData = data.resourceResolveData; + if ( + resolveData && + resolveData.descriptionFileData && + resolveData.relativePath + ) { + const sideEffects = resolveData.descriptionFileData.sideEffects; + const hasSideEffects = SideEffectsFlagPlugin.moduleHasSideEffects( + resolveData.relativePath, + sideEffects + ); + if (!hasSideEffects) { + module.factoryMeta.sideEffectFree = true; + } + } + + return module; + }); + nmf.hooks.module.tap("SideEffectsFlagPlugin", (module, data) => { + if (data.settings.sideEffects === false) { + module.factoryMeta.sideEffectFree = true; + } else if (data.settings.sideEffects === true) { + module.factoryMeta.sideEffectFree = false; + } + }); + }); + compiler.hooks.compilation.tap("SideEffectsFlagPlugin", compilation => { + compilation.hooks.optimizeDependencies.tap( + "SideEffectsFlagPlugin", + modules => { + /** @type {Map<Module, ReexportInfo>} */ + const reexportMaps = new Map(); + + // Capture reexports of sideEffectFree modules + for (const module of modules) { + /** @type {Dependency[]} */ + const removeDependencies = []; + for (const dep of module.dependencies) { + if (dep instanceof HarmonyImportSideEffectDependency) { + if (dep.module && dep.module.factoryMeta.sideEffectFree) { + removeDependencies.push(dep); + } + } else if ( + dep instanceof HarmonyExportImportedSpecifierDependency + ) { + if (module.factoryMeta.sideEffectFree) { + const mode = dep.getMode(true); + if ( + mode.type === "safe-reexport" || + mode.type === "checked-reexport" || + mode.type === "dynamic-reexport" || + mode.type === "reexport-non-harmony-default" || + mode.type === "reexport-non-harmony-default-strict" || + mode.type === "reexport-named-default" + ) { + let info = reexportMaps.get(module); + if (!info) { + reexportMaps.set( + module, + (info = { + static: new Map(), + dynamic: new Map() + }) + ); + } + const targetModule = dep._module; + switch (mode.type) { + case "safe-reexport": + for (const [key, id] of mode.map) { + if (id) { + addStaticReexport( + info, + key, + targetModule, + id, + false + ); + } + } + break; + case "checked-reexport": + for (const [key, id] of mode.map) { + if (id) { + addStaticReexport( + info, + key, + targetModule, + id, + true + ); + } + } + break; + case "dynamic-reexport": + addDynamicReexport(info, targetModule, mode.ignored); + break; + case "reexport-non-harmony-default": + case "reexport-non-harmony-default-strict": + case "reexport-named-default": + addStaticReexport( + info, + mode.name, + targetModule, + "default", + false + ); + break; + } + } + } + } + } + } + + // Flatten reexports + for (const info of reexportMaps.values()) { + const dynamicReexports = info.dynamic; + info.dynamic = new Map(); + for (const reexport of dynamicReexports) { + let [targetModule, ignored] = reexport; + for (;;) { + const innerInfo = reexportMaps.get(targetModule); + if (!innerInfo) break; + + for (const [key, reexports] of innerInfo.static) { + if (ignored.has(key)) continue; + for (const { module, exportName, checked } of reexports) { + addStaticReexport(info, key, module, exportName, checked); + } + } + + // Follow dynamic reexport if there is only one + if (innerInfo.dynamic.size !== 1) { + // When there are more then one, we don't know which one + break; + } + + ignored = new Set(ignored); + for (const [innerModule, innerIgnored] of innerInfo.dynamic) { + for (const key of innerIgnored) { + if (ignored.has(key)) continue; + // This reexports ends here + addStaticReexport(info, key, targetModule, key, true); + ignored.add(key); + } + targetModule = innerModule; + } + } + + // Update reexport as all other cases has been handled + addDynamicReexport(info, targetModule, ignored); + } + } + + for (const info of reexportMaps.values()) { + const staticReexports = info.static; + info.static = new Map(); + for (const [key, reexports] of staticReexports) { + for (let mapping of reexports) { + for (;;) { + const innerInfo = reexportMaps.get(mapping.module); + if (!innerInfo) break; + + const newMapping = getMappingFromInfo( + innerInfo, + mapping.exportName + ); + if (!newMapping) break; + mapping = newMapping; + } + addStaticReexport( + info, + key, + mapping.module, + mapping.exportName, + mapping.checked + ); + } + } + } + + // Update imports along the reexports from sideEffectFree modules + for (const pair of reexportMaps) { + const module = pair[0]; + const info = pair[1]; + let newReasons = undefined; + for (let i = 0; i < module.reasons.length; i++) { + const reason = module.reasons[i]; + const dep = reason.dependency; + if ( + (dep instanceof HarmonyExportImportedSpecifierDependency || + (dep instanceof HarmonyImportSpecifierDependency && + !dep.namespaceObjectAsContext)) && + dep._id + ) { + const mapping = getMappingFromInfo(info, dep._id); + if (mapping) { + dep.redirectedModule = mapping.module; + dep.redirectedId = mapping.exportName; + mapping.module.addReason( + reason.module, + dep, + reason.explanation + ? reason.explanation + + " (skipped side-effect-free modules)" + : "(skipped side-effect-free modules)" + ); + // removing the currect reason, by not adding it to the newReasons array + // lazily create the newReasons array + if (newReasons === undefined) { + newReasons = i === 0 ? [] : module.reasons.slice(0, i); + } + continue; + } + } + if (newReasons !== undefined) newReasons.push(reason); + } + if (newReasons !== undefined) { + module.reasons = newReasons; + } + } + } + ); + }); + } + + static moduleHasSideEffects(moduleName, flagValue) { + switch (typeof flagValue) { + case "undefined": + return true; + case "boolean": + return flagValue; + case "string": + if (process.platform === "win32") { + flagValue = flagValue.replace(/\\/g, "/"); + } + return mm.isMatch(moduleName, flagValue, { + matchBase: true + }); + case "object": + return flagValue.some(glob => + SideEffectsFlagPlugin.moduleHasSideEffects(moduleName, glob) + ); + } + } +} +module.exports = SideEffectsFlagPlugin; |