mirror of https://github.com/webpack/webpack.git
				
				
				
			
		
			
				
	
	
		
			94 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
			
		
		
	
	
			94 lines
		
	
	
		
			2.5 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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| function FlagDependencyUsagePlugin() {
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| 
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| }
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| module.exports = FlagDependencyUsagePlugin;
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| 
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| FlagDependencyUsagePlugin.prototype.apply = function(compiler) {
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| 	compiler.plugin("compilation", function(compilation) {
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| 		compilation.plugin("optimize-modules-advanced", function(modules) {
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| 
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| 			modules.forEach(function(module) {
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| 				module.used = false;
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| 			})
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| 
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| 			var queue = [];
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| 			compilation.chunks.forEach(function(chunk) {
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| 				if(chunk.entryModule) {
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| 					processModule(chunk.entryModule, true);
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| 				}
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| 			});
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| 
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| 			while(queue.length) {
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| 				var queueItem = queue.pop();
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| 				processDependenciesBlock(queueItem[0], queueItem[1]);
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| 			}
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| 
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| 			function processModule(module, usedExports) {
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| 				module.used = true;
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| 				if(module.usedExports === true)
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| 					return;
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| 				else if(usedExports === true)
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| 					module.usedExports = true;
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| 				else if(Array.isArray(usedExports)) {
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| 					var old = module.usedExports ? module.usedExports.length : -1;
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| 					module.usedExports = addToSet(module.usedExports || [], usedExports);
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| 					if(module.usedExports.length === old)
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| 						return;
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| 				} else if(Array.isArray(module.usedExports))
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| 					return;
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| 				else
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| 					module.usedExports = false;
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| 
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| 				queue.push([module, module.usedExports]);
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| 			}
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| 
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| 			function processDependenciesBlock(depBlock, usedExports) {
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| 				depBlock.dependencies.forEach(function(dep) {
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| 					processDependency(dep, usedExports);
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| 				});
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| 				depBlock.variables.forEach(function(variable) {
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| 					variable.dependencies.forEach(function(dep) {
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| 						processDependency(dep, usedExports);
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| 					});
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| 				});
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| 				depBlock.blocks.forEach(function(block) {
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| 					queue.push([block, usedExports]);
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| 				});
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| 			}
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| 
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| 			function processDependency(dep, usedExports) {
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| 				var reference = dep.getReference && dep.getReference();
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| 				if(!reference) return;
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| 				var module = reference.module;
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| 				var importedNames = reference.importedNames;
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| 				var oldUsed = module.used;
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| 				var oldUsedExports = module.usedExports;
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| 				if(!oldUsed || (importedNames && (!oldUsedExports || !isSubset(oldUsedExports, importedNames)))) {
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| 					processModule(module, importedNames);
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| 				}
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| 			}
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| 
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| 		});
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| 
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| 		function addToSet(a, b) {
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| 			b.forEach(function(item) {
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| 				if(a.indexOf(item) < 0)
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| 					a.push(item);
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| 			});
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| 			return a;
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| 		}
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| 
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| 		function isSubset(biggerSet, subset) {
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| 			if(biggerSet === true) return true;
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| 			if(subset === true) return false;
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| 			return subset.every(function(item) {
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| 				return biggerSet.indexOf(item) >= 0;
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| 			});
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| 		}
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| 	});
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| };
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