mirror of https://github.com/webpack/webpack.git
397 lines
12 KiB
JavaScript
397 lines
12 KiB
JavaScript
/*
|
|
MIT License http://www.opensource.org/licenses/mit-license.php
|
|
Author Tobias Koppers @sokra
|
|
*/
|
|
|
|
"use strict";
|
|
|
|
const glob2regexp = require("glob-to-regexp");
|
|
const {
|
|
JAVASCRIPT_MODULE_TYPE_AUTO,
|
|
JAVASCRIPT_MODULE_TYPE_ESM,
|
|
JAVASCRIPT_MODULE_TYPE_DYNAMIC
|
|
} = require("../ModuleTypeConstants");
|
|
const { STAGE_DEFAULT } = require("../OptimizationStages");
|
|
const HarmonyExportImportedSpecifierDependency = require("../dependencies/HarmonyExportImportedSpecifierDependency");
|
|
const HarmonyImportSpecifierDependency = require("../dependencies/HarmonyImportSpecifierDependency");
|
|
const formatLocation = require("../formatLocation");
|
|
|
|
/** @typedef {import("estree").ModuleDeclaration} ModuleDeclaration */
|
|
/** @typedef {import("estree").Statement} Statement */
|
|
/** @typedef {import("../Compiler")} Compiler */
|
|
/** @typedef {import("../Dependency")} Dependency */
|
|
/** @typedef {import("../Dependency").DependencyLocation} DependencyLocation */
|
|
/** @typedef {import("../Module")} Module */
|
|
/** @typedef {import("../Module").BuildMeta} BuildMeta */
|
|
/** @typedef {import("../ModuleGraphConnection")} ModuleGraphConnection */
|
|
/** @typedef {import("../NormalModuleFactory").ModuleSettings} ModuleSettings */
|
|
/** @typedef {import("../javascript/JavascriptParser")} JavascriptParser */
|
|
/** @typedef {import("../javascript/JavascriptParser").Range} Range */
|
|
|
|
/**
|
|
* @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
|
|
*/
|
|
|
|
/** @typedef {Map<string, RegExp>} CacheItem */
|
|
|
|
/** @type {WeakMap<any, CacheItem>} */
|
|
const globToRegexpCache = new WeakMap();
|
|
|
|
/**
|
|
* @param {string} glob the pattern
|
|
* @param {Map<string, RegExp>} cache the glob to RegExp cache
|
|
* @returns {RegExp} a regular expression
|
|
*/
|
|
const globToRegexp = (glob, cache) => {
|
|
const cacheEntry = cache.get(glob);
|
|
if (cacheEntry !== undefined) return cacheEntry;
|
|
if (!glob.includes("/")) {
|
|
glob = `**/${glob}`;
|
|
}
|
|
const baseRegexp = glob2regexp(glob, { globstar: true, extended: true });
|
|
const regexpSource = baseRegexp.source;
|
|
const regexp = new RegExp(`^(\\./)?${regexpSource.slice(1)}`);
|
|
cache.set(glob, regexp);
|
|
return regexp;
|
|
};
|
|
|
|
const PLUGIN_NAME = "SideEffectsFlagPlugin";
|
|
|
|
class SideEffectsFlagPlugin {
|
|
/**
|
|
* @param {boolean} analyseSource analyse source code for side effects
|
|
*/
|
|
constructor(analyseSource = true) {
|
|
this._analyseSource = analyseSource;
|
|
}
|
|
|
|
/**
|
|
* Apply the plugin
|
|
* @param {Compiler} compiler the compiler instance
|
|
* @returns {void}
|
|
*/
|
|
apply(compiler) {
|
|
let cache = globToRegexpCache.get(compiler.root);
|
|
if (cache === undefined) {
|
|
cache = new Map();
|
|
globToRegexpCache.set(compiler.root, cache);
|
|
}
|
|
compiler.hooks.compilation.tap(
|
|
PLUGIN_NAME,
|
|
(compilation, { normalModuleFactory }) => {
|
|
const moduleGraph = compilation.moduleGraph;
|
|
normalModuleFactory.hooks.module.tap(PLUGIN_NAME, (module, data) => {
|
|
const resolveData = data.resourceResolveData;
|
|
if (
|
|
resolveData &&
|
|
resolveData.descriptionFileData &&
|
|
resolveData.relativePath
|
|
) {
|
|
const sideEffects = resolveData.descriptionFileData.sideEffects;
|
|
if (sideEffects !== undefined) {
|
|
if (module.factoryMeta === undefined) {
|
|
module.factoryMeta = {};
|
|
}
|
|
const hasSideEffects = SideEffectsFlagPlugin.moduleHasSideEffects(
|
|
resolveData.relativePath,
|
|
sideEffects,
|
|
/** @type {CacheItem} */ (cache)
|
|
);
|
|
module.factoryMeta.sideEffectFree = !hasSideEffects;
|
|
}
|
|
}
|
|
|
|
return module;
|
|
});
|
|
normalModuleFactory.hooks.module.tap(PLUGIN_NAME, (module, data) => {
|
|
const settings = /** @type {ModuleSettings} */ (data.settings);
|
|
if (typeof settings.sideEffects === "boolean") {
|
|
if (module.factoryMeta === undefined) {
|
|
module.factoryMeta = {};
|
|
}
|
|
module.factoryMeta.sideEffectFree = !settings.sideEffects;
|
|
}
|
|
return module;
|
|
});
|
|
if (this._analyseSource) {
|
|
/**
|
|
* @param {JavascriptParser} parser the parser
|
|
* @returns {void}
|
|
*/
|
|
const parserHandler = parser => {
|
|
/** @type {undefined | Statement | ModuleDeclaration} */
|
|
let sideEffectsStatement;
|
|
parser.hooks.program.tap(PLUGIN_NAME, () => {
|
|
sideEffectsStatement = undefined;
|
|
});
|
|
parser.hooks.statement.tap(
|
|
{ name: PLUGIN_NAME, stage: -100 },
|
|
statement => {
|
|
if (sideEffectsStatement) return;
|
|
if (parser.scope.topLevelScope !== true) return;
|
|
switch (statement.type) {
|
|
case "ExpressionStatement":
|
|
if (
|
|
!parser.isPure(
|
|
statement.expression,
|
|
/** @type {Range} */ (statement.range)[0]
|
|
)
|
|
) {
|
|
sideEffectsStatement = statement;
|
|
}
|
|
break;
|
|
case "IfStatement":
|
|
case "WhileStatement":
|
|
case "DoWhileStatement":
|
|
if (
|
|
!parser.isPure(
|
|
statement.test,
|
|
/** @type {Range} */ (statement.range)[0]
|
|
)
|
|
) {
|
|
sideEffectsStatement = statement;
|
|
}
|
|
// statement hook will be called for child statements too
|
|
break;
|
|
case "ForStatement":
|
|
if (
|
|
!parser.isPure(
|
|
statement.init,
|
|
/** @type {Range} */ (statement.range)[0]
|
|
) ||
|
|
!parser.isPure(
|
|
statement.test,
|
|
statement.init
|
|
? /** @type {Range} */ (statement.init.range)[1]
|
|
: /** @type {Range} */ (statement.range)[0]
|
|
) ||
|
|
!parser.isPure(
|
|
statement.update,
|
|
statement.test
|
|
? /** @type {Range} */ (statement.test.range)[1]
|
|
: statement.init
|
|
? /** @type {Range} */ (statement.init.range)[1]
|
|
: /** @type {Range} */ (statement.range)[0]
|
|
)
|
|
) {
|
|
sideEffectsStatement = statement;
|
|
}
|
|
// statement hook will be called for child statements too
|
|
break;
|
|
case "SwitchStatement":
|
|
if (
|
|
!parser.isPure(
|
|
statement.discriminant,
|
|
/** @type {Range} */ (statement.range)[0]
|
|
)
|
|
) {
|
|
sideEffectsStatement = statement;
|
|
}
|
|
// statement hook will be called for child statements too
|
|
break;
|
|
case "VariableDeclaration":
|
|
case "ClassDeclaration":
|
|
case "FunctionDeclaration":
|
|
if (
|
|
!parser.isPure(
|
|
statement,
|
|
/** @type {Range} */ (statement.range)[0]
|
|
)
|
|
) {
|
|
sideEffectsStatement = statement;
|
|
}
|
|
break;
|
|
case "ExportNamedDeclaration":
|
|
case "ExportDefaultDeclaration":
|
|
if (
|
|
!parser.isPure(
|
|
/** @type {TODO} */
|
|
(statement.declaration),
|
|
/** @type {Range} */ (statement.range)[0]
|
|
)
|
|
) {
|
|
sideEffectsStatement = statement;
|
|
}
|
|
break;
|
|
case "LabeledStatement":
|
|
case "BlockStatement":
|
|
// statement hook will be called for child statements too
|
|
break;
|
|
case "EmptyStatement":
|
|
break;
|
|
case "ExportAllDeclaration":
|
|
case "ImportDeclaration":
|
|
// imports will be handled by the dependencies
|
|
break;
|
|
default:
|
|
sideEffectsStatement = statement;
|
|
break;
|
|
}
|
|
}
|
|
);
|
|
parser.hooks.finish.tap(PLUGIN_NAME, () => {
|
|
if (sideEffectsStatement === undefined) {
|
|
/** @type {BuildMeta} */
|
|
(parser.state.module.buildMeta).sideEffectFree = true;
|
|
} else {
|
|
const { loc, type } = sideEffectsStatement;
|
|
moduleGraph
|
|
.getOptimizationBailout(parser.state.module)
|
|
.push(
|
|
() =>
|
|
`Statement (${type}) with side effects in source code at ${formatLocation(
|
|
/** @type {DependencyLocation} */ (loc)
|
|
)}`
|
|
);
|
|
}
|
|
});
|
|
};
|
|
for (const key of [
|
|
JAVASCRIPT_MODULE_TYPE_AUTO,
|
|
JAVASCRIPT_MODULE_TYPE_ESM,
|
|
JAVASCRIPT_MODULE_TYPE_DYNAMIC
|
|
]) {
|
|
normalModuleFactory.hooks.parser
|
|
.for(key)
|
|
.tap(PLUGIN_NAME, parserHandler);
|
|
}
|
|
}
|
|
compilation.hooks.optimizeDependencies.tap(
|
|
{
|
|
name: PLUGIN_NAME,
|
|
stage: STAGE_DEFAULT
|
|
},
|
|
modules => {
|
|
const logger = compilation.getLogger(
|
|
"webpack.SideEffectsFlagPlugin"
|
|
);
|
|
|
|
logger.time("update dependencies");
|
|
|
|
const optimizedModules = new Set();
|
|
|
|
/**
|
|
* @param {Module} module module
|
|
*/
|
|
const optimizeIncomingConnections = module => {
|
|
if (optimizedModules.has(module)) return;
|
|
optimizedModules.add(module);
|
|
if (module.getSideEffectsConnectionState(moduleGraph) === false) {
|
|
const exportsInfo = moduleGraph.getExportsInfo(module);
|
|
for (const connection of moduleGraph.getIncomingConnections(
|
|
module
|
|
)) {
|
|
const dep = connection.dependency;
|
|
let isReexport;
|
|
if (
|
|
(isReexport =
|
|
dep instanceof
|
|
HarmonyExportImportedSpecifierDependency) ||
|
|
(dep instanceof HarmonyImportSpecifierDependency &&
|
|
!dep.namespaceObjectAsContext)
|
|
) {
|
|
if (connection.originModule !== null) {
|
|
optimizeIncomingConnections(connection.originModule);
|
|
}
|
|
// TODO improve for export *
|
|
if (isReexport && dep.name) {
|
|
const exportInfo = moduleGraph.getExportInfo(
|
|
/** @type {Module} */ (connection.originModule),
|
|
dep.name
|
|
);
|
|
exportInfo.moveTarget(
|
|
moduleGraph,
|
|
({ module }) =>
|
|
module.getSideEffectsConnectionState(moduleGraph) ===
|
|
false,
|
|
({ module: newModule, export: exportName }) => {
|
|
moduleGraph.updateModule(dep, newModule);
|
|
moduleGraph.addExplanation(
|
|
dep,
|
|
"(skipped side-effect-free modules)"
|
|
);
|
|
const ids = dep.getIds(moduleGraph);
|
|
dep.setIds(
|
|
moduleGraph,
|
|
exportName
|
|
? [...exportName, ...ids.slice(1)]
|
|
: ids.slice(1)
|
|
);
|
|
return /** @type {ModuleGraphConnection} */ (
|
|
moduleGraph.getConnection(dep)
|
|
);
|
|
}
|
|
);
|
|
continue;
|
|
}
|
|
// TODO improve for nested imports
|
|
const ids = dep.getIds(moduleGraph);
|
|
if (ids.length > 0) {
|
|
const exportInfo = exportsInfo.getExportInfo(ids[0]);
|
|
const target = exportInfo.getTarget(
|
|
moduleGraph,
|
|
({ module }) =>
|
|
module.getSideEffectsConnectionState(moduleGraph) ===
|
|
false
|
|
);
|
|
if (!target) continue;
|
|
|
|
moduleGraph.updateModule(dep, target.module);
|
|
moduleGraph.addExplanation(
|
|
dep,
|
|
"(skipped side-effect-free modules)"
|
|
);
|
|
dep.setIds(
|
|
moduleGraph,
|
|
target.export
|
|
? [...target.export, ...ids.slice(1)]
|
|
: ids.slice(1)
|
|
);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
};
|
|
|
|
for (const module of modules) {
|
|
optimizeIncomingConnections(module);
|
|
}
|
|
logger.timeEnd("update dependencies");
|
|
}
|
|
);
|
|
}
|
|
);
|
|
}
|
|
|
|
/**
|
|
* @param {string} moduleName the module name
|
|
* @param {undefined | boolean | string | string[]} flagValue the flag value
|
|
* @param {Map<string, RegExp>} cache cache for glob to regexp
|
|
* @returns {boolean | undefined} true, when the module has side effects, undefined or false when not
|
|
*/
|
|
static moduleHasSideEffects(moduleName, flagValue, cache) {
|
|
switch (typeof flagValue) {
|
|
case "undefined":
|
|
return true;
|
|
case "boolean":
|
|
return flagValue;
|
|
case "string":
|
|
return globToRegexp(flagValue, cache).test(moduleName);
|
|
case "object":
|
|
return flagValue.some(glob =>
|
|
SideEffectsFlagPlugin.moduleHasSideEffects(moduleName, glob, cache)
|
|
);
|
|
}
|
|
}
|
|
}
|
|
module.exports = SideEffectsFlagPlugin;
|