713 lines
24 KiB
JavaScript
713 lines
24 KiB
JavaScript
/***********************************************************************
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A JavaScript tokenizer / parser / beautifier / compressor.
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https://github.com/mishoo/UglifyJS2
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-------------------------------- (C) ---------------------------------
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Author: Mihai Bazon
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<mihai.bazon@gmail.com>
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http://mihai.bazon.net/blog
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Distributed under the BSD license:
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Copyright 2012 (c) Mihai Bazon <mihai.bazon@gmail.com>
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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* Redistributions of source code must retain the above
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copyright notice, this list of conditions and the following
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disclaimer.
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* Redistributions in binary form must reproduce the above
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copyright notice, this list of conditions and the following
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disclaimer in the documentation and/or other materials
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provided with the distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER “AS IS” AND ANY
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EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
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OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
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TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
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THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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SUCH DAMAGE.
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***********************************************************************/
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"use strict";
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function SymbolDef(scope, orig, init) {
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this.name = orig.name;
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this.orig = [ orig ];
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this.init = init;
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this.eliminated = 0;
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this.scope = scope;
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this.references = [];
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this.replaced = 0;
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this.global = false;
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this.export = false;
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this.mangled_name = null;
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this.undeclared = false;
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this.id = SymbolDef.next_id++;
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};
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SymbolDef.next_id = 1;
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SymbolDef.prototype = {
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unmangleable: function(options) {
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if (!options) options = {};
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return (this.global && !options.toplevel)
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|| this.export
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|| this.undeclared
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|| (!options.eval && (this.scope.uses_eval || this.scope.uses_with))
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|| (options.keep_fnames
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&& (this.orig[0] instanceof AST_SymbolLambda
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|| this.orig[0] instanceof AST_SymbolDefun))
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|| this.orig[0] instanceof AST_SymbolMethod
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|| (options.keep_classnames
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&& (this.orig[0] instanceof AST_SymbolClass
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|| this.orig[0] instanceof AST_SymbolDefClass));
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},
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mangle: function(options) {
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var cache = options.cache && options.cache.props;
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if (this.global && cache && cache.has(this.name)) {
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this.mangled_name = cache.get(this.name);
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}
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else if (!this.mangled_name && !this.unmangleable(options)) {
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var s = this.scope;
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var sym = this.orig[0];
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if (options.ie8 && sym instanceof AST_SymbolLambda)
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s = s.parent_scope;
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var def;
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if (def = this.redefined()) {
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this.mangled_name = def.mangled_name || def.name;
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} else
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this.mangled_name = s.next_mangled(options, this);
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if (this.global && cache) {
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cache.set(this.name, this.mangled_name);
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}
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}
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},
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redefined: function() {
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return this.defun && this.defun.variables.get(this.name);
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}
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};
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AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
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options = defaults(options, {
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cache: null,
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ie8: false,
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safari10: false,
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});
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// pass 1: setup scope chaining and handle definitions
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var self = this;
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var scope = self.parent_scope = null;
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var labels = new Dictionary();
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var defun = null;
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var in_destructuring = null;
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var for_scopes = [];
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var tw = new TreeWalker(function(node, descend){
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if (node.is_block_scope()) {
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var save_scope = scope;
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node.block_scope = scope = new AST_Scope(node);
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scope.init_scope_vars(save_scope);
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if (!(node instanceof AST_Scope)) {
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scope.uses_with = save_scope.uses_with;
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scope.uses_eval = save_scope.uses_eval;
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scope.directives = save_scope.directives;
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}
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if (options.safari10) {
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if (node instanceof AST_For || node instanceof AST_ForIn) {
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for_scopes.push(scope);
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}
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}
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descend();
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scope = save_scope;
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return true;
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}
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if (node instanceof AST_Destructuring) {
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in_destructuring = node; // These don't nest
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descend();
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in_destructuring = null;
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return true;
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}
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if (node instanceof AST_Scope) {
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node.init_scope_vars(scope);
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var save_scope = scope;
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var save_defun = defun;
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var save_labels = labels;
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defun = scope = node;
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labels = new Dictionary();
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descend();
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scope = save_scope;
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defun = save_defun;
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labels = save_labels;
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return true; // don't descend again in TreeWalker
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}
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if (node instanceof AST_LabeledStatement) {
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var l = node.label;
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if (labels.has(l.name)) {
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throw new Error(string_template("Label {name} defined twice", l));
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}
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labels.set(l.name, l);
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descend();
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labels.del(l.name);
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return true; // no descend again
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}
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if (node instanceof AST_With) {
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for (var s = scope; s; s = s.parent_scope)
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s.uses_with = true;
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return;
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}
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if (node instanceof AST_Symbol) {
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node.scope = scope;
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}
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if (node instanceof AST_Label) {
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node.thedef = node;
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node.references = [];
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}
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if (node instanceof AST_SymbolLambda) {
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defun.def_function(node, node.name == "arguments" ? undefined : defun);
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}
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else if (node instanceof AST_SymbolDefun) {
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// Careful here, the scope where this should be defined is
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// the parent scope. The reason is that we enter a new
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// scope when we encounter the AST_Defun node (which is
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// instanceof AST_Scope) but we get to the symbol a bit
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// later.
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mark_export((node.scope = defun.parent_scope.get_defun_scope()).def_function(node, defun), 1);
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}
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else if (node instanceof AST_SymbolClass) {
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mark_export(defun.def_variable(node, defun), 1);
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}
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else if (node instanceof AST_SymbolImport) {
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scope.def_variable(node);
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}
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else if (node instanceof AST_SymbolDefClass) {
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// This deals with the name of the class being available
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// inside the class.
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mark_export((node.scope = defun.parent_scope).def_function(node, defun), 1);
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}
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else if (node instanceof AST_SymbolVar
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|| node instanceof AST_SymbolLet
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|| node instanceof AST_SymbolConst) {
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var def;
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if (node instanceof AST_SymbolBlockDeclaration) {
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def = scope.def_variable(node, null);
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} else {
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def = defun.def_variable(node, node.TYPE == "SymbolVar" ? null : undefined);
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}
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if (!all(def.orig, function(sym) {
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if (sym === node) return true;
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if (node instanceof AST_SymbolBlockDeclaration) {
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return sym instanceof AST_SymbolLambda;
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}
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return !(sym instanceof AST_SymbolLet || sym instanceof AST_SymbolConst);
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})) {
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js_error(
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node.name + " redeclared",
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node.start.file,
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node.start.line,
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node.start.col,
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node.start.pos
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);
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}
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if (!(node instanceof AST_SymbolFunarg)) mark_export(def, 2);
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def.destructuring = in_destructuring;
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if (defun !== scope) {
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node.mark_enclosed(options);
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var def = scope.find_variable(node);
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if (node.thedef !== def) {
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node.thedef = def;
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node.reference(options);
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}
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}
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}
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else if (node instanceof AST_SymbolCatch) {
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scope.def_variable(node).defun = defun;
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}
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else if (node instanceof AST_LabelRef) {
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var sym = labels.get(node.name);
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if (!sym) throw new Error(string_template("Undefined label {name} [{line},{col}]", {
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name: node.name,
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line: node.start.line,
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col: node.start.col
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}));
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node.thedef = sym;
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}
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if (!(scope instanceof AST_Toplevel) && (node instanceof AST_Export || node instanceof AST_Import)) {
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js_error(
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node.TYPE + " statement may only appear at top level",
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node.start.file,
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node.start.line,
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node.start.col,
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node.start.pos
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);
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}
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function mark_export(def, level) {
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if (in_destructuring) {
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var i = 0;
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do {
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level++;
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} while (tw.parent(i++) !== in_destructuring);
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}
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var node = tw.parent(level);
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def.export = node instanceof AST_Export;
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}
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});
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self.walk(tw);
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// pass 2: find back references and eval
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self.globals = new Dictionary();
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var tw = new TreeWalker(function(node, descend){
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if (node instanceof AST_LoopControl && node.label) {
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node.label.thedef.references.push(node);
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return true;
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}
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if (node instanceof AST_SymbolRef) {
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var name = node.name;
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if (name == "eval" && tw.parent() instanceof AST_Call) {
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for (var s = node.scope; s && !s.uses_eval; s = s.parent_scope) {
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s.uses_eval = true;
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}
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}
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var sym;
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if (tw.parent() instanceof AST_NameMapping && tw.parent(1).module_name
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|| !(sym = node.scope.find_variable(name))) {
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sym = self.def_global(node);
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} else if (sym.scope instanceof AST_Lambda && name == "arguments") {
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sym.scope.uses_arguments = true;
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}
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node.thedef = sym;
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node.reference(options);
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if (node.scope.is_block_scope()
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&& !(sym.orig[0] instanceof AST_SymbolBlockDeclaration)) {
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node.scope = node.scope.get_defun_scope();
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}
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return true;
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}
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// ensure mangling works if catch reuses a scope variable
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var def;
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if (node instanceof AST_SymbolCatch && (def = node.definition().redefined())) {
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var s = node.scope;
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while (s) {
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push_uniq(s.enclosed, def);
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if (s === def.scope) break;
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s = s.parent_scope;
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}
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}
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});
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self.walk(tw);
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// pass 3: fix up any scoping issue with IE8
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if (options.ie8) {
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self.walk(new TreeWalker(function(node, descend) {
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if (node instanceof AST_SymbolCatch) {
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var name = node.name;
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var refs = node.thedef.references;
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var scope = node.thedef.defun;
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var def = scope.find_variable(name) || self.globals.get(name) || scope.def_variable(node);
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refs.forEach(function(ref) {
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ref.thedef = def;
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ref.reference(options);
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});
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node.thedef = def;
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node.reference(options);
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return true;
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}
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}));
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}
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// pass 4: add symbol definitions to loop scopes
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// Safari/Webkit bug workaround - loop init let variable shadowing argument.
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// https://github.com/mishoo/UglifyJS2/issues/1753
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// https://bugs.webkit.org/show_bug.cgi?id=171041
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if (options.safari10) {
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for (var i = 0; i < for_scopes.length; i++) {
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var scope = for_scopes[i];
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scope.parent_scope.variables.each(function(def) {
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push_uniq(scope.enclosed, def);
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});
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}
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}
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});
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AST_Toplevel.DEFMETHOD("def_global", function(node){
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var globals = this.globals, name = node.name;
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if (globals.has(name)) {
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return globals.get(name);
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} else {
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var g = new SymbolDef(this, node);
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g.undeclared = true;
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g.global = true;
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globals.set(name, g);
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return g;
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}
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});
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AST_Scope.DEFMETHOD("init_scope_vars", function(parent_scope){
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this.variables = new Dictionary(); // map name to AST_SymbolVar (variables defined in this scope; includes functions)
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this.functions = new Dictionary(); // map name to AST_SymbolDefun (functions defined in this scope)
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this.uses_with = false; // will be set to true if this or some nested scope uses the `with` statement
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this.uses_eval = false; // will be set to true if this or nested scope uses the global `eval`
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this.parent_scope = parent_scope; // the parent scope
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this.enclosed = []; // a list of variables from this or outer scope(s) that are referenced from this or inner scopes
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this.cname = -1; // the current index for mangling functions/variables
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});
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AST_Node.DEFMETHOD("is_block_scope", return_false);
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AST_Class.DEFMETHOD("is_block_scope", return_false);
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AST_Lambda.DEFMETHOD("is_block_scope", return_false);
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AST_Toplevel.DEFMETHOD("is_block_scope", return_false);
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AST_SwitchBranch.DEFMETHOD("is_block_scope", return_false);
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AST_Block.DEFMETHOD("is_block_scope", return_true);
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AST_IterationStatement.DEFMETHOD("is_block_scope", return_true);
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AST_Lambda.DEFMETHOD("init_scope_vars", function(){
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AST_Scope.prototype.init_scope_vars.apply(this, arguments);
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this.uses_arguments = false;
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this.def_variable(new AST_SymbolFunarg({
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name: "arguments",
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start: this.start,
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end: this.end
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}));
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});
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AST_Symbol.DEFMETHOD("mark_enclosed", function(options) {
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var def = this.definition();
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var s = this.scope;
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while (s) {
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push_uniq(s.enclosed, def);
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if (options.keep_fnames) {
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s.functions.each(function(d) {
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push_uniq(def.scope.enclosed, d);
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});
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}
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if (s === def.scope) break;
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s = s.parent_scope;
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}
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});
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AST_Symbol.DEFMETHOD("reference", function(options) {
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this.definition().references.push(this);
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this.mark_enclosed(options);
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});
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AST_Scope.DEFMETHOD("find_variable", function(name){
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if (name instanceof AST_Symbol) name = name.name;
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return this.variables.get(name)
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|| (this.parent_scope && this.parent_scope.find_variable(name));
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});
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AST_Scope.DEFMETHOD("def_function", function(symbol, init){
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var def = this.def_variable(symbol, init);
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if (!def.init || def.init instanceof AST_Defun) def.init = init;
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this.functions.set(symbol.name, def);
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return def;
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});
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AST_Scope.DEFMETHOD("def_variable", function(symbol, init){
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var def = this.variables.get(symbol.name);
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if (def) {
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def.orig.push(symbol);
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if (def.init && (def.scope !== symbol.scope || def.init instanceof AST_Function)) {
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def.init = init;
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}
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} else {
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def = new SymbolDef(this, symbol, init);
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this.variables.set(symbol.name, def);
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def.global = !this.parent_scope;
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}
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return symbol.thedef = def;
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});
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function next_mangled(scope, options) {
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var ext = scope.enclosed;
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out: while (true) {
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var m = base54(++scope.cname);
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if (!is_identifier(m)) continue; // skip over "do"
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// https://github.com/mishoo/UglifyJS2/issues/242 -- do not
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// shadow a name reserved from mangling.
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if (member(m, options.reserved)) continue;
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// we must ensure that the mangled name does not shadow a name
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// from some parent scope that is referenced in this or in
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// inner scopes.
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for (var i = ext.length; --i >= 0;) {
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var sym = ext[i];
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var name = sym.mangled_name || (sym.unmangleable(options) && sym.name);
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if (m == name) continue out;
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}
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return m;
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}
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}
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AST_Scope.DEFMETHOD("next_mangled", function(options){
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return next_mangled(this, options);
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});
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AST_Toplevel.DEFMETHOD("next_mangled", function(options){
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var name;
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do {
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name = next_mangled(this, options);
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} while (member(name, this.mangled_names));
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return name;
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});
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AST_Function.DEFMETHOD("next_mangled", function(options, def){
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// #179, #326
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// in Safari strict mode, something like (function x(x){...}) is a syntax error;
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// a function expression's argument cannot shadow the function expression's name
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var tricky_def = def.orig[0] instanceof AST_SymbolFunarg && this.name && this.name.definition();
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// the function's mangled_name is null when keep_fnames is true
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var tricky_name = tricky_def ? tricky_def.mangled_name || tricky_def.name : null;
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while (true) {
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var name = next_mangled(this, options);
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if (!tricky_name || tricky_name != name)
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return name;
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}
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});
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AST_Symbol.DEFMETHOD("unmangleable", function(options){
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var def = this.definition();
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return !def || def.unmangleable(options);
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});
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// labels are always mangleable
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AST_Label.DEFMETHOD("unmangleable", return_false);
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AST_Symbol.DEFMETHOD("unreferenced", function(){
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return this.definition().references.length == 0
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&& !(this.scope.uses_eval || this.scope.uses_with);
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});
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AST_Symbol.DEFMETHOD("definition", function(){
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return this.thedef;
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});
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AST_Symbol.DEFMETHOD("global", function(){
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return this.definition().global;
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});
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AST_Toplevel.DEFMETHOD("_default_mangler_options", function(options) {
|
|
options = defaults(options, {
|
|
eval : false,
|
|
ie8 : false,
|
|
keep_classnames: false,
|
|
keep_fnames : false,
|
|
reserved : [],
|
|
toplevel : false,
|
|
});
|
|
if (!Array.isArray(options.reserved)) options.reserved = [];
|
|
// Never mangle arguments
|
|
push_uniq(options.reserved, "arguments");
|
|
return options;
|
|
});
|
|
|
|
AST_Toplevel.DEFMETHOD("mangle_names", function(options){
|
|
options = this._default_mangler_options(options);
|
|
|
|
// We only need to mangle declaration nodes. Special logic wired
|
|
// into the code generator will display the mangled name if it's
|
|
// present (and for AST_SymbolRef-s it'll use the mangled name of
|
|
// the AST_SymbolDeclaration that it points to).
|
|
var lname = -1;
|
|
var to_mangle = [];
|
|
|
|
var mangled_names = this.mangled_names = [];
|
|
if (options.cache) {
|
|
this.globals.each(collect);
|
|
if (options.cache.props) {
|
|
options.cache.props.each(function(mangled_name) {
|
|
push_uniq(mangled_names, mangled_name);
|
|
});
|
|
}
|
|
}
|
|
|
|
var tw = new TreeWalker(function(node, descend){
|
|
if (node instanceof AST_LabeledStatement) {
|
|
// lname is incremented when we get to the AST_Label
|
|
var save_nesting = lname;
|
|
descend();
|
|
lname = save_nesting;
|
|
return true; // don't descend again in TreeWalker
|
|
}
|
|
if (node instanceof AST_Scope) {
|
|
node.variables.each(collect);
|
|
return;
|
|
}
|
|
if (node.is_block_scope()) {
|
|
node.block_scope.variables.each(collect);
|
|
return;
|
|
}
|
|
if (node instanceof AST_Label) {
|
|
var name;
|
|
do name = base54(++lname); while (!is_identifier(name));
|
|
node.mangled_name = name;
|
|
return true;
|
|
}
|
|
if (!options.ie8 && node instanceof AST_SymbolCatch) {
|
|
to_mangle.push(node.definition());
|
|
return;
|
|
}
|
|
});
|
|
this.walk(tw);
|
|
to_mangle.forEach(function(def){ def.mangle(options) });
|
|
|
|
function collect(symbol) {
|
|
if (!member(symbol.name, options.reserved)) {
|
|
to_mangle.push(symbol);
|
|
}
|
|
}
|
|
});
|
|
|
|
AST_Toplevel.DEFMETHOD("find_colliding_names", function(options) {
|
|
var cache = options.cache && options.cache.props;
|
|
var avoid = Object.create(null);
|
|
options.reserved.forEach(to_avoid);
|
|
this.globals.each(add_def);
|
|
this.walk(new TreeWalker(function(node) {
|
|
if (node instanceof AST_Scope) node.variables.each(add_def);
|
|
if (node instanceof AST_SymbolCatch) add_def(node.definition());
|
|
}));
|
|
return avoid;
|
|
|
|
function to_avoid(name) {
|
|
avoid[name] = true;
|
|
}
|
|
|
|
function add_def(def) {
|
|
var name = def.name;
|
|
if (def.global && cache && cache.has(name)) name = cache.get(name);
|
|
else if (!def.unmangleable(options)) return;
|
|
to_avoid(name);
|
|
}
|
|
});
|
|
|
|
AST_Toplevel.DEFMETHOD("expand_names", function(options) {
|
|
base54.reset();
|
|
base54.sort();
|
|
options = this._default_mangler_options(options);
|
|
var avoid = this.find_colliding_names(options);
|
|
var cname = 0;
|
|
this.globals.each(rename);
|
|
this.walk(new TreeWalker(function(node) {
|
|
if (node instanceof AST_Scope) node.variables.each(rename);
|
|
if (node instanceof AST_SymbolCatch) rename(node.definition());
|
|
}));
|
|
|
|
function next_name() {
|
|
var name;
|
|
do {
|
|
name = base54(cname++);
|
|
} while (avoid[name] || !is_identifier(name));
|
|
return name;
|
|
}
|
|
|
|
function rename(def) {
|
|
if (def.global && options.cache) return;
|
|
if (def.unmangleable(options)) return;
|
|
if (member(def.name, options.reserved)) return;
|
|
var d = def.redefined();
|
|
def.name = d ? d.name : next_name();
|
|
def.orig.forEach(function(sym) {
|
|
sym.name = def.name;
|
|
});
|
|
def.references.forEach(function(sym) {
|
|
sym.name = def.name;
|
|
});
|
|
}
|
|
});
|
|
|
|
AST_Node.DEFMETHOD("tail_node", return_this);
|
|
AST_Sequence.DEFMETHOD("tail_node", function() {
|
|
return this.expressions[this.expressions.length - 1];
|
|
});
|
|
|
|
AST_Toplevel.DEFMETHOD("compute_char_frequency", function(options){
|
|
options = this._default_mangler_options(options);
|
|
try {
|
|
AST_Node.prototype.print = function(stream, force_parens) {
|
|
this._print(stream, force_parens);
|
|
if (this instanceof AST_Symbol && !this.unmangleable(options)) {
|
|
base54.consider(this.name, -1);
|
|
} else if (options.properties) {
|
|
if (this instanceof AST_Dot) {
|
|
base54.consider(this.property, -1);
|
|
} else if (this instanceof AST_Sub) {
|
|
skip_string(this.property);
|
|
}
|
|
}
|
|
};
|
|
base54.consider(this.print_to_string(), 1);
|
|
} finally {
|
|
AST_Node.prototype.print = AST_Node.prototype._print;
|
|
}
|
|
base54.sort();
|
|
|
|
function skip_string(node) {
|
|
if (node instanceof AST_String) {
|
|
base54.consider(node.value, -1);
|
|
} else if (node instanceof AST_Conditional) {
|
|
skip_string(node.consequent);
|
|
skip_string(node.alternative);
|
|
} else if (node instanceof AST_Sequence) {
|
|
skip_string(node.tail_node());
|
|
}
|
|
}
|
|
});
|
|
|
|
var base54 = (function() {
|
|
var leading = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$_".split("");
|
|
var digits = "0123456789".split("");
|
|
var chars, frequency;
|
|
function reset() {
|
|
frequency = Object.create(null);
|
|
leading.forEach(function(ch) {
|
|
frequency[ch] = 0;
|
|
});
|
|
digits.forEach(function(ch) {
|
|
frequency[ch] = 0;
|
|
});
|
|
}
|
|
base54.consider = function(str, delta) {
|
|
for (var i = str.length; --i >= 0;) {
|
|
frequency[str[i]] += delta;
|
|
}
|
|
};
|
|
function compare(a, b) {
|
|
return frequency[b] - frequency[a];
|
|
}
|
|
base54.sort = function() {
|
|
chars = mergeSort(leading, compare).concat(mergeSort(digits, compare));
|
|
};
|
|
base54.reset = reset;
|
|
reset();
|
|
function base54(num) {
|
|
var ret = "", base = 54;
|
|
num++;
|
|
do {
|
|
num--;
|
|
ret += chars[num % base];
|
|
num = Math.floor(num / base);
|
|
base = 64;
|
|
} while (num > 0);
|
|
return ret;
|
|
};
|
|
return base54;
|
|
})();
|