1 files changed, 81 insertions, 0 deletions
diff --git a/node_modules/webpack/lib/FlagDependencyUsagePlugin.js b/node_modules/webpack/lib/FlagDependencyUsagePlugin.js
new file mode 100644
index 000000000..0be9d54b2
--- /dev/null
+++ b/node_modules/webpack/lib/FlagDependencyUsagePlugin.js
@@ -0,0 +1,81 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+"use strict";
+
+class FlagDependencyUsagePlugin {
+	apply(compiler) {
+		compiler.plugin("compilation", compilation => {
+			compilation.plugin("optimize-modules-advanced", modules => {
+
+				modules.forEach(module => module.used = false);
+
+				const queue = [];
+				compilation.chunks.forEach(chunk => {
+					if(chunk.entryModule) {
+						processModule(chunk.entryModule, true);
+					}
+				});
+
+				while(queue.length) {
+					const queueItem = queue.pop();
+					processDependenciesBlock(queueItem[0], queueItem[1]);
+				}
+
+				function processModule(module, usedExports) {
+					module.used = true;
+					if(module.usedExports === true)
+						return;
+					else if(usedExports === true)
+						module.usedExports = true;
+					else if(Array.isArray(usedExports)) {
+						var old = module.usedExports ? module.usedExports.length : -1;
+						module.usedExports = addToSet(module.usedExports || [], usedExports);
+						if(module.usedExports.length === old)
+							return;
+					} else if(Array.isArray(module.usedExports))
+						return;
+					else
+						module.usedExports = false;
+
+					queue.push([module, module.usedExports]);
+				}
+
+				function processDependenciesBlock(depBlock, usedExports) {
+					depBlock.dependencies.forEach(dep => processDependency(dep));
+					depBlock.variables.forEach(variable => variable.dependencies.forEach(dep => processDependency(dep)));
+					depBlock.blocks.forEach(block => queue.push([block, usedExports]));
+				}
+
+				function processDependency(dep) {
+					const reference = dep.getReference && dep.getReference();
+					if(!reference) return;
+					const module = reference.module;
+					const importedNames = reference.importedNames;
+					const oldUsed = module.used;
+					const oldUsedExports = module.usedExports;
+					if(!oldUsed || (importedNames && (!oldUsedExports || !isSubset(oldUsedExports, importedNames)))) {
+						processModule(module, importedNames);
+					}
+				}
+
+			});
+
+			function addToSet(a, b) {
+				b.forEach(item => {
+					if(a.indexOf(item) < 0)
+						a.push(item);
+				});
+				return a;
+			}
+
+			function isSubset(biggerSet, subset) {
+				if(biggerSet === true) return true;
+				if(subset === true) return false;
+				return subset.every(item => biggerSet.indexOf(item) >= 0);
+			}
+		});
+	}
+}
+module.exports = FlagDependencyUsagePlugin;