4102 lines
175 KiB
JavaScript
4102 lines
175 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 Compressor(options, false_by_default) {
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if (!(this instanceof Compressor))
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return new Compressor(options, false_by_default);
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TreeTransformer.call(this, this.before, this.after);
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this.options = defaults(options, {
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angular : false,
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booleans : !false_by_default,
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cascade : !false_by_default,
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collapse_vars : !false_by_default,
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comparisons : !false_by_default,
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conditionals : !false_by_default,
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dead_code : !false_by_default,
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drop_console : false,
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drop_debugger : !false_by_default,
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evaluate : !false_by_default,
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expression : false,
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global_defs : {},
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hoist_funs : !false_by_default,
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hoist_vars : false,
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if_return : !false_by_default,
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join_vars : !false_by_default,
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keep_fargs : true,
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keep_fnames : false,
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keep_infinity : false,
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loops : !false_by_default,
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negate_iife : !false_by_default,
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passes : 1,
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properties : !false_by_default,
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pure_getters : !false_by_default && "strict",
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pure_funcs : null,
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reduce_vars : !false_by_default,
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screw_ie8 : true,
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sequences : !false_by_default,
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side_effects : !false_by_default,
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switches : !false_by_default,
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top_retain : null,
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toplevel : !!(options && options["top_retain"]),
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unsafe : false,
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unsafe_comps : false,
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unsafe_math : false,
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unsafe_proto : false,
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unsafe_regexp : false,
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unused : !false_by_default,
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warnings : true,
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}, true);
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var pure_funcs = this.options["pure_funcs"];
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if (typeof pure_funcs == "function") {
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this.pure_funcs = pure_funcs;
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} else {
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this.pure_funcs = pure_funcs ? function(node) {
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return pure_funcs.indexOf(node.expression.print_to_string()) < 0;
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} : return_true;
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}
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var top_retain = this.options["top_retain"];
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if (top_retain instanceof RegExp) {
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this.top_retain = function(def) {
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return top_retain.test(def.name);
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};
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} else if (typeof top_retain == "function") {
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this.top_retain = top_retain;
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} else if (top_retain) {
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if (typeof top_retain == "string") {
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top_retain = top_retain.split(/,/);
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}
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this.top_retain = function(def) {
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return top_retain.indexOf(def.name) >= 0;
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};
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}
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var sequences = this.options["sequences"];
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this.sequences_limit = sequences == 1 ? 200 : sequences | 0;
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this.warnings_produced = {};
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};
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Compressor.prototype = new TreeTransformer;
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merge(Compressor.prototype, {
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option: function(key) { return this.options[key] },
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compress: function(node) {
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if (this.option("expression")) {
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node = node.process_expression(true);
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}
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var passes = +this.options.passes || 1;
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for (var pass = 0; pass < passes && pass < 3; ++pass) {
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if (pass > 0 || this.option("reduce_vars"))
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node.reset_opt_flags(this, true);
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node = node.transform(this);
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}
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if (this.option("expression")) {
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node = node.process_expression(false);
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}
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return node;
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},
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info: function() {
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if (this.options.warnings == "verbose") {
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AST_Node.warn.apply(AST_Node, arguments);
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}
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},
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warn: function(text, props) {
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if (this.options.warnings) {
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// only emit unique warnings
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var message = string_template(text, props);
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if (!(message in this.warnings_produced)) {
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this.warnings_produced[message] = true;
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AST_Node.warn.apply(AST_Node, arguments);
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}
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}
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},
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clear_warnings: function() {
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this.warnings_produced = {};
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},
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before: function(node, descend, in_list) {
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if (node._squeezed) return node;
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var was_scope = false;
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if (node instanceof AST_Scope) {
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node = node.hoist_declarations(this);
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was_scope = true;
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}
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// Before https://github.com/mishoo/UglifyJS2/pull/1602 AST_Node.optimize()
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// would call AST_Node.transform() if a different instance of AST_Node is
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// produced after OPT().
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// This corrupts TreeWalker.stack, which cause AST look-ups to malfunction.
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// Migrate and defer all children's AST_Node.transform() to below, which
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// will now happen after this parent AST_Node has been properly substituted
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// thus gives a consistent AST snapshot.
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descend(node, this);
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// Existing code relies on how AST_Node.optimize() worked, and omitting the
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// following replacement call would result in degraded efficiency of both
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// output and performance.
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descend(node, this);
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var opt = node.optimize(this);
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if (was_scope && opt instanceof AST_Scope) {
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opt.drop_unused(this);
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descend(opt, this);
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}
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if (opt === node) opt._squeezed = true;
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return opt;
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}
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});
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(function(){
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function OPT(node, optimizer) {
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node.DEFMETHOD("optimize", function(compressor){
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var self = this;
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if (self._optimized) return self;
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if (compressor.has_directive("use asm")) return self;
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var opt = optimizer(self, compressor);
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opt._optimized = true;
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return opt;
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});
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};
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OPT(AST_Node, function(self, compressor){
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return self;
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});
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AST_Node.DEFMETHOD("equivalent_to", function(node){
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return this.TYPE == node.TYPE && this.print_to_string() == node.print_to_string();
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});
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AST_Node.DEFMETHOD("process_expression", function(insert, compressor) {
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var self = this;
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var tt = new TreeTransformer(function(node) {
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if (insert && node instanceof AST_SimpleStatement) {
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return make_node(AST_Return, node, {
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value: node.body
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});
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}
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if (!insert && node instanceof AST_Return) {
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if (compressor) {
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var value = node.value && node.value.drop_side_effect_free(compressor, true);
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return value ? make_node(AST_SimpleStatement, node, {
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body: value
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}) : make_node(AST_EmptyStatement, node);
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}
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return make_node(AST_SimpleStatement, node, {
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body: node.value || make_node(AST_UnaryPrefix, node, {
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operator: "void",
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expression: make_node(AST_Number, node, {
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value: 0
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})
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})
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});
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}
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if (node instanceof AST_Lambda && node !== self) {
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return node;
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}
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if (node instanceof AST_Block) {
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var index = node.body.length - 1;
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if (index >= 0) {
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node.body[index] = node.body[index].transform(tt);
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}
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}
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if (node instanceof AST_If) {
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node.body = node.body.transform(tt);
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if (node.alternative) {
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node.alternative = node.alternative.transform(tt);
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}
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}
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if (node instanceof AST_With) {
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node.body = node.body.transform(tt);
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}
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return node;
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});
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return self.transform(tt);
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});
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AST_Node.DEFMETHOD("reset_opt_flags", function(compressor, rescan){
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var reduce_vars = rescan && compressor.option("reduce_vars");
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var toplevel = compressor.option("toplevel");
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var safe_ids = Object.create(null);
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var suppressor = new TreeWalker(function(node) {
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if (node instanceof AST_Symbol) {
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var d = node.definition();
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if (node instanceof AST_SymbolRef) d.references.push(node);
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d.fixed = false;
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}
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});
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var tw = new TreeWalker(function(node, descend){
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node._squeezed = false;
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node._optimized = false;
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if (reduce_vars) {
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if (node instanceof AST_Toplevel) node.globals.each(reset_def);
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if (node instanceof AST_Scope) node.variables.each(reset_def);
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if (node instanceof AST_SymbolRef) {
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var d = node.definition();
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d.references.push(node);
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if (d.fixed === undefined || !is_safe(d)
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|| is_modified(node, 0, node.fixed_value() instanceof AST_Lambda)) {
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d.fixed = false;
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} else {
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var parent = tw.parent();
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if (parent instanceof AST_Assign && parent.operator == "=" && node === parent.right
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|| parent instanceof AST_Call && node !== parent.expression
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|| parent instanceof AST_Return && node === parent.value && node.scope !== d.scope
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|| parent instanceof AST_VarDef && node === parent.value) {
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d.escaped = true;
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}
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}
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}
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if (node instanceof AST_SymbolCatch) {
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node.definition().fixed = false;
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}
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if (node instanceof AST_VarDef) {
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var d = node.name.definition();
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if (d.fixed == null) {
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if (node.value) {
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d.fixed = function() {
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return node.value;
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};
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mark(d, false);
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descend();
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} else {
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d.fixed = null;
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}
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mark(d, true);
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return true;
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} else if (node.value) {
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d.fixed = false;
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}
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}
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if (node instanceof AST_Defun) {
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var d = node.name.definition();
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if (!toplevel && d.global || is_safe(d)) {
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d.fixed = false;
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} else {
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d.fixed = node;
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mark(d, true);
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}
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var save_ids = safe_ids;
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safe_ids = Object.create(null);
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descend();
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safe_ids = save_ids;
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return true;
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}
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if (node instanceof AST_Function) {
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push();
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var iife;
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if (!node.name
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&& (iife = tw.parent()) instanceof AST_Call
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&& iife.expression === node) {
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// Virtually turn IIFE parameters into variable definitions:
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// (function(a,b) {...})(c,d) => (function() {var a=c,b=d; ...})()
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// So existing transformation rules can work on them.
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node.argnames.forEach(function(arg, i) {
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var d = arg.definition();
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if (!node.uses_arguments && d.fixed === undefined) {
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d.fixed = function() {
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return iife.args[i] || make_node(AST_Undefined, iife);
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};
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mark(d, true);
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} else {
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d.fixed = false;
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}
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});
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}
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descend();
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pop();
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return true;
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}
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if (node instanceof AST_Accessor) {
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var save_ids = safe_ids;
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safe_ids = Object.create(null);
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descend();
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safe_ids = save_ids;
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return true;
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}
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if (node instanceof AST_Binary
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&& (node.operator == "&&" || node.operator == "||")) {
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node.left.walk(tw);
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push();
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node.right.walk(tw);
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pop();
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return true;
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}
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if (node instanceof AST_Conditional) {
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node.condition.walk(tw);
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push();
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node.consequent.walk(tw);
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pop();
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push();
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node.alternative.walk(tw);
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pop();
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return true;
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}
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if (node instanceof AST_If || node instanceof AST_DWLoop) {
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node.condition.walk(tw);
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push();
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node.body.walk(tw);
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pop();
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if (node.alternative) {
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push();
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node.alternative.walk(tw);
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pop();
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}
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return true;
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}
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if (node instanceof AST_LabeledStatement) {
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push();
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node.body.walk(tw);
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pop();
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return true;
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}
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if (node instanceof AST_For) {
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if (node.init) node.init.walk(tw);
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push();
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if (node.condition) node.condition.walk(tw);
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node.body.walk(tw);
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if (node.step) node.step.walk(tw);
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pop();
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return true;
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}
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if (node instanceof AST_ForIn) {
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node.init.walk(suppressor);
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node.object.walk(tw);
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push();
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node.body.walk(tw);
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pop();
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return true;
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}
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if (node instanceof AST_Try) {
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push();
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walk_body(node, tw);
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pop();
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if (node.bcatch) {
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push();
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node.bcatch.walk(tw);
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pop();
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}
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if (node.bfinally) node.bfinally.walk(tw);
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return true;
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}
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if (node instanceof AST_SwitchBranch) {
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push();
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descend();
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pop();
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return true;
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}
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}
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});
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this.walk(tw);
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function mark(def, safe) {
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safe_ids[def.id] = safe;
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}
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function is_safe(def) {
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if (safe_ids[def.id]) {
|
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if (def.fixed == null) {
|
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var orig = def.orig[0];
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if (orig instanceof AST_SymbolFunarg || orig.name == "arguments") return false;
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def.fixed = make_node(AST_Undefined, orig);
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}
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return true;
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}
|
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}
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function push() {
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safe_ids = Object.create(safe_ids);
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}
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function pop() {
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safe_ids = Object.getPrototypeOf(safe_ids);
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}
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|
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function reset_def(def) {
|
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def.escaped = false;
|
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if (def.scope.uses_eval) {
|
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def.fixed = false;
|
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} else if (toplevel || !def.global || def.orig[0] instanceof AST_SymbolConst) {
|
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def.fixed = undefined;
|
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} else {
|
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def.fixed = false;
|
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}
|
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def.references = [];
|
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def.should_replace = undefined;
|
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}
|
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|
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function is_modified(node, level, func) {
|
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var parent = tw.parent(level);
|
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if (is_lhs(node, parent)
|
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|| !func && parent instanceof AST_Call && parent.expression === node) {
|
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return true;
|
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} else if (parent instanceof AST_PropAccess && parent.expression === node) {
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return !func && is_modified(parent, level + 1);
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}
|
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}
|
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});
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|
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AST_SymbolRef.DEFMETHOD("fixed_value", function() {
|
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var fixed = this.definition().fixed;
|
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if (!fixed || fixed instanceof AST_Node) return fixed;
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return fixed();
|
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});
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|
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function is_reference_const(ref) {
|
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if (!(ref instanceof AST_SymbolRef)) return false;
|
|
var orig = ref.definition().orig;
|
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for (var i = orig.length; --i >= 0;) {
|
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if (orig[i] instanceof AST_SymbolConst) return true;
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}
|
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}
|
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|
|
function find_variable(compressor, name) {
|
|
var scope, i = 0;
|
|
while (scope = compressor.parent(i++)) {
|
|
if (scope instanceof AST_Scope) break;
|
|
if (scope instanceof AST_Catch) {
|
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scope = scope.argname.definition().scope;
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break;
|
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}
|
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}
|
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return scope.find_variable(name);
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}
|
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|
|
function make_node(ctor, orig, props) {
|
|
if (!props) props = {};
|
|
if (orig) {
|
|
if (!props.start) props.start = orig.start;
|
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if (!props.end) props.end = orig.end;
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}
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|
return new ctor(props);
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|
};
|
|
|
|
function make_node_from_constant(val, orig) {
|
|
switch (typeof val) {
|
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case "string":
|
|
return make_node(AST_String, orig, {
|
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value: val
|
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});
|
|
case "number":
|
|
if (isNaN(val)) return make_node(AST_NaN, orig);
|
|
if (isFinite(val)) {
|
|
return 1 / val < 0 ? make_node(AST_UnaryPrefix, orig, {
|
|
operator: "-",
|
|
expression: make_node(AST_Number, orig, { value: -val })
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}) : make_node(AST_Number, orig, { value: val });
|
|
}
|
|
return val < 0 ? make_node(AST_UnaryPrefix, orig, {
|
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operator: "-",
|
|
expression: make_node(AST_Infinity, orig)
|
|
}) : make_node(AST_Infinity, orig);
|
|
case "boolean":
|
|
return make_node(val ? AST_True : AST_False, orig);
|
|
case "undefined":
|
|
return make_node(AST_Undefined, orig);
|
|
default:
|
|
if (val === null) {
|
|
return make_node(AST_Null, orig, { value: null });
|
|
}
|
|
if (val instanceof RegExp) {
|
|
return make_node(AST_RegExp, orig, { value: val });
|
|
}
|
|
throw new Error(string_template("Can't handle constant of type: {type}", {
|
|
type: typeof val
|
|
}));
|
|
}
|
|
};
|
|
|
|
// we shouldn't compress (1,func)(something) to
|
|
// func(something) because that changes the meaning of
|
|
// the func (becomes lexical instead of global).
|
|
function maintain_this_binding(parent, orig, val) {
|
|
if (parent instanceof AST_UnaryPrefix && parent.operator == "delete"
|
|
|| parent instanceof AST_Call && parent.expression === orig
|
|
&& (val instanceof AST_PropAccess || val instanceof AST_SymbolRef && val.name == "eval")) {
|
|
return make_node(AST_Seq, orig, {
|
|
car: make_node(AST_Number, orig, {
|
|
value: 0
|
|
}),
|
|
cdr: val
|
|
});
|
|
}
|
|
return val;
|
|
}
|
|
|
|
function as_statement_array(thing) {
|
|
if (thing === null) return [];
|
|
if (thing instanceof AST_BlockStatement) return thing.body;
|
|
if (thing instanceof AST_EmptyStatement) return [];
|
|
if (thing instanceof AST_Statement) return [ thing ];
|
|
throw new Error("Can't convert thing to statement array");
|
|
};
|
|
|
|
function is_empty(thing) {
|
|
if (thing === null) return true;
|
|
if (thing instanceof AST_EmptyStatement) return true;
|
|
if (thing instanceof AST_BlockStatement) return thing.body.length == 0;
|
|
return false;
|
|
};
|
|
|
|
function loop_body(x) {
|
|
if (x instanceof AST_Switch) return x;
|
|
if (x instanceof AST_For || x instanceof AST_ForIn || x instanceof AST_DWLoop) {
|
|
return (x.body instanceof AST_BlockStatement ? x.body : x);
|
|
}
|
|
return x;
|
|
};
|
|
|
|
function is_iife_call(node) {
|
|
if (node instanceof AST_Call && !(node instanceof AST_New)) {
|
|
return node.expression instanceof AST_Function || is_iife_call(node.expression);
|
|
}
|
|
return false;
|
|
}
|
|
|
|
function tighten_body(statements, compressor) {
|
|
var CHANGED, max_iter = 10;
|
|
do {
|
|
CHANGED = false;
|
|
if (compressor.option("angular")) {
|
|
statements = process_for_angular(statements);
|
|
}
|
|
statements = eliminate_spurious_blocks(statements);
|
|
if (compressor.option("dead_code")) {
|
|
statements = eliminate_dead_code(statements, compressor);
|
|
}
|
|
if (compressor.option("if_return")) {
|
|
statements = handle_if_return(statements, compressor);
|
|
}
|
|
if (compressor.sequences_limit > 0) {
|
|
statements = sequencesize(statements, compressor);
|
|
}
|
|
if (compressor.option("join_vars")) {
|
|
statements = join_consecutive_vars(statements, compressor);
|
|
}
|
|
if (compressor.option("collapse_vars")) {
|
|
statements = collapse_single_use_vars(statements, compressor);
|
|
}
|
|
} while (CHANGED && max_iter-- > 0);
|
|
|
|
return statements;
|
|
|
|
function collapse_single_use_vars(statements, compressor) {
|
|
// Iterate statements backwards looking for a statement with a var/const
|
|
// declaration immediately preceding it. Grab the rightmost var definition
|
|
// and if it has exactly one reference then attempt to replace its reference
|
|
// in the statement with the var value and then erase the var definition.
|
|
|
|
var self = compressor.self();
|
|
var var_defs_removed = false;
|
|
var toplevel = compressor.option("toplevel");
|
|
for (var stat_index = statements.length; --stat_index >= 0;) {
|
|
var stat = statements[stat_index];
|
|
if (stat instanceof AST_Definitions) continue;
|
|
|
|
// Process child blocks of statement if present.
|
|
[stat, stat.body, stat.alternative, stat.bcatch, stat.bfinally].forEach(function(node) {
|
|
node && node.body && collapse_single_use_vars(node.body, compressor);
|
|
});
|
|
|
|
// The variable definition must precede a statement.
|
|
if (stat_index <= 0) break;
|
|
var prev_stat_index = stat_index - 1;
|
|
var prev_stat = statements[prev_stat_index];
|
|
if (!(prev_stat instanceof AST_Definitions)) continue;
|
|
var var_defs = prev_stat.definitions;
|
|
if (var_defs == null) continue;
|
|
|
|
var var_names_seen = {};
|
|
var side_effects_encountered = false;
|
|
var lvalues_encountered = false;
|
|
var lvalues = {};
|
|
|
|
// Scan variable definitions from right to left.
|
|
for (var var_defs_index = var_defs.length; --var_defs_index >= 0;) {
|
|
|
|
// Obtain var declaration and var name with basic sanity check.
|
|
var var_decl = var_defs[var_defs_index];
|
|
if (var_decl.value == null) break;
|
|
var var_name = var_decl.name.name;
|
|
if (!var_name || !var_name.length) break;
|
|
|
|
// Bail if we've seen a var definition of same name before.
|
|
if (var_name in var_names_seen) break;
|
|
var_names_seen[var_name] = true;
|
|
|
|
// Only interested in cases with just one reference to the variable.
|
|
var def = self.find_variable && self.find_variable(var_name);
|
|
if (!def || !def.references || def.references.length !== 1
|
|
|| var_name == "arguments" || (!toplevel && def.global)) {
|
|
side_effects_encountered = true;
|
|
continue;
|
|
}
|
|
var ref = def.references[0];
|
|
|
|
// Don't replace ref if eval() or with statement in scope.
|
|
if (ref.scope.uses_eval || ref.scope.uses_with) break;
|
|
|
|
// Constant single use vars can be replaced in any scope.
|
|
if (var_decl.value.is_constant()) {
|
|
var ctt = new TreeTransformer(function(node) {
|
|
var parent = ctt.parent();
|
|
if (parent instanceof AST_IterationStatement
|
|
&& (parent.condition === node || parent.init === node)) {
|
|
return node;
|
|
}
|
|
if (node === ref)
|
|
return replace_var(node, parent, true);
|
|
});
|
|
stat.transform(ctt);
|
|
continue;
|
|
}
|
|
|
|
// Restrict var replacement to constants if side effects encountered.
|
|
if (side_effects_encountered |= lvalues_encountered) continue;
|
|
|
|
var value_has_side_effects = var_decl.value.has_side_effects(compressor);
|
|
// Non-constant single use vars can only be replaced in same scope.
|
|
if (ref.scope !== self) {
|
|
side_effects_encountered |= value_has_side_effects;
|
|
continue;
|
|
}
|
|
|
|
// Detect lvalues in var value.
|
|
var tw = new TreeWalker(function(node){
|
|
if (node instanceof AST_SymbolRef && is_lvalue(node, tw.parent())) {
|
|
lvalues[node.name] = lvalues_encountered = true;
|
|
}
|
|
});
|
|
var_decl.value.walk(tw);
|
|
|
|
// Replace the non-constant single use var in statement if side effect free.
|
|
var unwind = false;
|
|
var tt = new TreeTransformer(
|
|
function preorder(node) {
|
|
if (unwind) return node;
|
|
var parent = tt.parent();
|
|
if (node instanceof AST_Lambda
|
|
|| node instanceof AST_Try
|
|
|| node instanceof AST_With
|
|
|| node instanceof AST_Case
|
|
|| node instanceof AST_IterationStatement
|
|
|| (parent instanceof AST_If && node !== parent.condition)
|
|
|| (parent instanceof AST_Conditional && node !== parent.condition)
|
|
|| (node instanceof AST_SymbolRef
|
|
&& value_has_side_effects
|
|
&& !are_references_in_scope(node.definition(), self))
|
|
|| (parent instanceof AST_Binary
|
|
&& (parent.operator == "&&" || parent.operator == "||")
|
|
&& node === parent.right)
|
|
|| (parent instanceof AST_Switch && node !== parent.expression)) {
|
|
return side_effects_encountered = unwind = true, node;
|
|
}
|
|
function are_references_in_scope(def, scope) {
|
|
if (def.orig.length === 1
|
|
&& def.orig[0] instanceof AST_SymbolDefun) return true;
|
|
if (def.scope !== scope) return false;
|
|
var refs = def.references;
|
|
for (var i = 0, len = refs.length; i < len; i++) {
|
|
if (refs[i].scope !== scope) return false;
|
|
}
|
|
return true;
|
|
}
|
|
},
|
|
function postorder(node) {
|
|
if (unwind) return node;
|
|
if (node === ref)
|
|
return unwind = true, replace_var(node, tt.parent(), false);
|
|
if (side_effects_encountered |= node.has_side_effects(compressor))
|
|
return unwind = true, node;
|
|
if (lvalues_encountered && node instanceof AST_SymbolRef && node.name in lvalues) {
|
|
side_effects_encountered = true;
|
|
return unwind = true, node;
|
|
}
|
|
}
|
|
);
|
|
stat.transform(tt);
|
|
}
|
|
}
|
|
|
|
// Remove extraneous empty statments in block after removing var definitions.
|
|
// Leave at least one statement in `statements`.
|
|
if (var_defs_removed) for (var i = statements.length; --i >= 0;) {
|
|
if (statements.length > 1 && statements[i] instanceof AST_EmptyStatement)
|
|
statements.splice(i, 1);
|
|
}
|
|
|
|
return statements;
|
|
|
|
function is_lvalue(node, parent) {
|
|
return node instanceof AST_SymbolRef && is_lhs(node, parent);
|
|
}
|
|
function replace_var(node, parent, is_constant) {
|
|
if (is_lvalue(node, parent)) return node;
|
|
|
|
// Remove var definition and return its value to the TreeTransformer to replace.
|
|
var value = maintain_this_binding(parent, node, var_decl.value);
|
|
var_decl.value = null;
|
|
|
|
var_defs.splice(var_defs_index, 1);
|
|
if (var_defs.length === 0) {
|
|
statements[prev_stat_index] = make_node(AST_EmptyStatement, self);
|
|
var_defs_removed = true;
|
|
}
|
|
// Further optimize statement after substitution.
|
|
stat.reset_opt_flags(compressor);
|
|
|
|
compressor.info("Collapsing " + (is_constant ? "constant" : "variable") +
|
|
" " + var_name + " [{file}:{line},{col}]", node.start);
|
|
CHANGED = true;
|
|
return value;
|
|
}
|
|
}
|
|
|
|
function process_for_angular(statements) {
|
|
function has_inject(comment) {
|
|
return /@ngInject/.test(comment.value);
|
|
}
|
|
function make_arguments_names_list(func) {
|
|
return func.argnames.map(function(sym){
|
|
return make_node(AST_String, sym, { value: sym.name });
|
|
});
|
|
}
|
|
function make_array(orig, elements) {
|
|
return make_node(AST_Array, orig, { elements: elements });
|
|
}
|
|
function make_injector(func, name) {
|
|
return make_node(AST_SimpleStatement, func, {
|
|
body: make_node(AST_Assign, func, {
|
|
operator: "=",
|
|
left: make_node(AST_Dot, name, {
|
|
expression: make_node(AST_SymbolRef, name, name),
|
|
property: "$inject"
|
|
}),
|
|
right: make_array(func, make_arguments_names_list(func))
|
|
})
|
|
});
|
|
}
|
|
function check_expression(body) {
|
|
if (body && body.args) {
|
|
// if this is a function call check all of arguments passed
|
|
body.args.forEach(function(argument, index, array) {
|
|
var comments = argument.start.comments_before;
|
|
// if the argument is function preceded by @ngInject
|
|
if (argument instanceof AST_Lambda && comments.length && has_inject(comments[0])) {
|
|
// replace the function with an array of names of its parameters and function at the end
|
|
array[index] = make_array(argument, make_arguments_names_list(argument).concat(argument));
|
|
}
|
|
});
|
|
// if this is chained call check previous one recursively
|
|
if (body.expression && body.expression.expression) {
|
|
check_expression(body.expression.expression);
|
|
}
|
|
}
|
|
}
|
|
return statements.reduce(function(a, stat){
|
|
a.push(stat);
|
|
|
|
if (stat.body && stat.body.args) {
|
|
check_expression(stat.body);
|
|
} else {
|
|
var token = stat.start;
|
|
var comments = token.comments_before;
|
|
if (comments && comments.length > 0) {
|
|
var last = comments.pop();
|
|
if (has_inject(last)) {
|
|
// case 1: defun
|
|
if (stat instanceof AST_Defun) {
|
|
a.push(make_injector(stat, stat.name));
|
|
}
|
|
else if (stat instanceof AST_Definitions) {
|
|
stat.definitions.forEach(function(def) {
|
|
if (def.value && def.value instanceof AST_Lambda) {
|
|
a.push(make_injector(def.value, def.name));
|
|
}
|
|
});
|
|
}
|
|
else {
|
|
compressor.warn("Unknown statement marked with @ngInject [{file}:{line},{col}]", token);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return a;
|
|
}, []);
|
|
}
|
|
|
|
function eliminate_spurious_blocks(statements) {
|
|
var seen_dirs = [];
|
|
return statements.reduce(function(a, stat){
|
|
if (stat instanceof AST_BlockStatement) {
|
|
CHANGED = true;
|
|
a.push.apply(a, eliminate_spurious_blocks(stat.body));
|
|
} else if (stat instanceof AST_EmptyStatement) {
|
|
CHANGED = true;
|
|
} else if (stat instanceof AST_Directive) {
|
|
if (seen_dirs.indexOf(stat.value) < 0) {
|
|
a.push(stat);
|
|
seen_dirs.push(stat.value);
|
|
} else {
|
|
CHANGED = true;
|
|
}
|
|
} else {
|
|
a.push(stat);
|
|
}
|
|
return a;
|
|
}, []);
|
|
};
|
|
|
|
function handle_if_return(statements, compressor) {
|
|
var self = compressor.self();
|
|
var multiple_if_returns = has_multiple_if_returns(statements);
|
|
var in_lambda = self instanceof AST_Lambda;
|
|
var ret = []; // Optimized statements, build from tail to front
|
|
loop: for (var i = statements.length; --i >= 0;) {
|
|
var stat = statements[i];
|
|
switch (true) {
|
|
case (in_lambda && stat instanceof AST_Return && !stat.value && ret.length == 0):
|
|
CHANGED = true;
|
|
// note, ret.length is probably always zero
|
|
// because we drop unreachable code before this
|
|
// step. nevertheless, it's good to check.
|
|
continue loop;
|
|
case stat instanceof AST_If:
|
|
if (stat.body instanceof AST_Return) {
|
|
//---
|
|
// pretty silly case, but:
|
|
// if (foo()) return; return; ==> foo(); return;
|
|
if (((in_lambda && ret.length == 0)
|
|
|| (ret[0] instanceof AST_Return && !ret[0].value))
|
|
&& !stat.body.value && !stat.alternative) {
|
|
CHANGED = true;
|
|
var cond = make_node(AST_SimpleStatement, stat.condition, {
|
|
body: stat.condition
|
|
});
|
|
ret.unshift(cond);
|
|
continue loop;
|
|
}
|
|
//---
|
|
// if (foo()) return x; return y; ==> return foo() ? x : y;
|
|
if (ret[0] instanceof AST_Return && stat.body.value && ret[0].value && !stat.alternative) {
|
|
CHANGED = true;
|
|
stat = stat.clone();
|
|
stat.alternative = ret[0];
|
|
ret[0] = stat.transform(compressor);
|
|
continue loop;
|
|
}
|
|
//---
|
|
// if (foo()) return x; [ return ; ] ==> return foo() ? x : undefined;
|
|
if (multiple_if_returns && (ret.length == 0 || ret[0] instanceof AST_Return)
|
|
&& stat.body.value && !stat.alternative && in_lambda) {
|
|
CHANGED = true;
|
|
stat = stat.clone();
|
|
stat.alternative = ret[0] || make_node(AST_Return, stat, {
|
|
value: null
|
|
});
|
|
ret[0] = stat.transform(compressor);
|
|
continue loop;
|
|
}
|
|
//---
|
|
// if (foo()) return; [ else x... ]; y... ==> if (!foo()) { x...; y... }
|
|
if (!stat.body.value && in_lambda) {
|
|
CHANGED = true;
|
|
stat = stat.clone();
|
|
stat.condition = stat.condition.negate(compressor);
|
|
var body = as_statement_array(stat.alternative).concat(ret);
|
|
var funs = extract_functions_from_statement_array(body);
|
|
stat.body = make_node(AST_BlockStatement, stat, {
|
|
body: body
|
|
});
|
|
stat.alternative = null;
|
|
ret = funs.concat([ stat.transform(compressor) ]);
|
|
continue loop;
|
|
}
|
|
|
|
//---
|
|
// if (a) return b; if (c) return d; e; ==> return a ? b : c ? d : void e;
|
|
//
|
|
// if sequences is not enabled, this can lead to an endless loop (issue #866).
|
|
// however, with sequences on this helps producing slightly better output for
|
|
// the example code.
|
|
if (compressor.option("sequences")
|
|
&& i > 0 && statements[i - 1] instanceof AST_If && statements[i - 1].body instanceof AST_Return
|
|
&& ret.length == 1 && in_lambda && ret[0] instanceof AST_SimpleStatement
|
|
&& !stat.alternative) {
|
|
CHANGED = true;
|
|
ret.push(make_node(AST_Return, ret[0], {
|
|
value: null
|
|
}).transform(compressor));
|
|
ret.unshift(stat);
|
|
continue loop;
|
|
}
|
|
}
|
|
|
|
var ab = aborts(stat.body);
|
|
var lct = ab instanceof AST_LoopControl ? compressor.loopcontrol_target(ab) : null;
|
|
if (ab && ((ab instanceof AST_Return && !ab.value && in_lambda)
|
|
|| (ab instanceof AST_Continue && self === loop_body(lct))
|
|
|| (ab instanceof AST_Break && lct instanceof AST_BlockStatement && self === lct))) {
|
|
if (ab.label) {
|
|
remove(ab.label.thedef.references, ab);
|
|
}
|
|
CHANGED = true;
|
|
var body = as_statement_array(stat.body).slice(0, -1);
|
|
stat = stat.clone();
|
|
stat.condition = stat.condition.negate(compressor);
|
|
stat.body = make_node(AST_BlockStatement, stat, {
|
|
body: as_statement_array(stat.alternative).concat(ret)
|
|
});
|
|
stat.alternative = make_node(AST_BlockStatement, stat, {
|
|
body: body
|
|
});
|
|
ret = [ stat.transform(compressor) ];
|
|
continue loop;
|
|
}
|
|
|
|
var ab = aborts(stat.alternative);
|
|
var lct = ab instanceof AST_LoopControl ? compressor.loopcontrol_target(ab) : null;
|
|
if (ab && ((ab instanceof AST_Return && !ab.value && in_lambda)
|
|
|| (ab instanceof AST_Continue && self === loop_body(lct))
|
|
|| (ab instanceof AST_Break && lct instanceof AST_BlockStatement && self === lct))) {
|
|
if (ab.label) {
|
|
remove(ab.label.thedef.references, ab);
|
|
}
|
|
CHANGED = true;
|
|
stat = stat.clone();
|
|
stat.body = make_node(AST_BlockStatement, stat.body, {
|
|
body: as_statement_array(stat.body).concat(ret)
|
|
});
|
|
stat.alternative = make_node(AST_BlockStatement, stat.alternative, {
|
|
body: as_statement_array(stat.alternative).slice(0, -1)
|
|
});
|
|
ret = [ stat.transform(compressor) ];
|
|
continue loop;
|
|
}
|
|
|
|
ret.unshift(stat);
|
|
break;
|
|
default:
|
|
ret.unshift(stat);
|
|
break;
|
|
}
|
|
}
|
|
return ret;
|
|
|
|
function has_multiple_if_returns(statements) {
|
|
var n = 0;
|
|
for (var i = statements.length; --i >= 0;) {
|
|
var stat = statements[i];
|
|
if (stat instanceof AST_If && stat.body instanceof AST_Return) {
|
|
if (++n > 1) return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
};
|
|
|
|
function eliminate_dead_code(statements, compressor) {
|
|
var has_quit = false;
|
|
var orig = statements.length;
|
|
var self = compressor.self();
|
|
statements = statements.reduce(function(a, stat){
|
|
if (has_quit) {
|
|
extract_declarations_from_unreachable_code(compressor, stat, a);
|
|
} else {
|
|
if (stat instanceof AST_LoopControl) {
|
|
var lct = compressor.loopcontrol_target(stat);
|
|
if ((stat instanceof AST_Break
|
|
&& !(lct instanceof AST_IterationStatement)
|
|
&& loop_body(lct) === self) || (stat instanceof AST_Continue
|
|
&& loop_body(lct) === self)) {
|
|
if (stat.label) {
|
|
remove(stat.label.thedef.references, stat);
|
|
}
|
|
} else {
|
|
a.push(stat);
|
|
}
|
|
} else {
|
|
a.push(stat);
|
|
}
|
|
if (aborts(stat)) has_quit = true;
|
|
}
|
|
return a;
|
|
}, []);
|
|
CHANGED = statements.length != orig;
|
|
return statements;
|
|
};
|
|
|
|
function sequencesize(statements, compressor) {
|
|
if (statements.length < 2) return statements;
|
|
var seq = [], ret = [];
|
|
function push_seq() {
|
|
seq = AST_Seq.from_array(seq);
|
|
if (seq) ret.push(make_node(AST_SimpleStatement, seq, {
|
|
body: seq
|
|
}));
|
|
seq = [];
|
|
};
|
|
statements.forEach(function(stat){
|
|
if (stat instanceof AST_SimpleStatement) {
|
|
if (seqLength(seq) >= compressor.sequences_limit) push_seq();
|
|
var body = stat.body;
|
|
if (seq.length > 0) body = body.drop_side_effect_free(compressor);
|
|
if (body) seq.push(body);
|
|
} else {
|
|
push_seq();
|
|
ret.push(stat);
|
|
}
|
|
});
|
|
push_seq();
|
|
ret = sequencesize_2(ret, compressor);
|
|
CHANGED = ret.length != statements.length;
|
|
return ret;
|
|
};
|
|
|
|
function seqLength(a) {
|
|
for (var len = 0, i = 0; i < a.length; ++i) {
|
|
var stat = a[i];
|
|
if (stat instanceof AST_Seq) {
|
|
len += stat.len();
|
|
} else {
|
|
len++;
|
|
}
|
|
}
|
|
return len;
|
|
};
|
|
|
|
function sequencesize_2(statements, compressor) {
|
|
function cons_seq(right) {
|
|
ret.pop();
|
|
var left = prev.body;
|
|
if (left instanceof AST_Seq) {
|
|
left.add(right);
|
|
} else {
|
|
left = AST_Seq.cons(left, right);
|
|
}
|
|
return left.transform(compressor);
|
|
};
|
|
var ret = [], prev = null;
|
|
statements.forEach(function(stat){
|
|
if (prev) {
|
|
if (stat instanceof AST_For) {
|
|
var opera = {};
|
|
try {
|
|
prev.body.walk(new TreeWalker(function(node){
|
|
if (node instanceof AST_Binary && node.operator == "in")
|
|
throw opera;
|
|
}));
|
|
if (stat.init && !(stat.init instanceof AST_Definitions)) {
|
|
stat.init = cons_seq(stat.init);
|
|
}
|
|
else if (!stat.init) {
|
|
stat.init = prev.body.drop_side_effect_free(compressor);
|
|
ret.pop();
|
|
}
|
|
} catch(ex) {
|
|
if (ex !== opera) throw ex;
|
|
}
|
|
}
|
|
else if (stat instanceof AST_If) {
|
|
stat.condition = cons_seq(stat.condition);
|
|
}
|
|
else if (stat instanceof AST_With) {
|
|
stat.expression = cons_seq(stat.expression);
|
|
}
|
|
else if (stat instanceof AST_Exit && stat.value) {
|
|
stat.value = cons_seq(stat.value);
|
|
}
|
|
else if (stat instanceof AST_Exit) {
|
|
stat.value = cons_seq(make_node(AST_Undefined, stat).transform(compressor));
|
|
}
|
|
else if (stat instanceof AST_Switch) {
|
|
stat.expression = cons_seq(stat.expression);
|
|
}
|
|
}
|
|
ret.push(stat);
|
|
prev = stat instanceof AST_SimpleStatement ? stat : null;
|
|
});
|
|
return ret;
|
|
};
|
|
|
|
function join_consecutive_vars(statements, compressor) {
|
|
var prev = null;
|
|
return statements.reduce(function(a, stat){
|
|
if (stat instanceof AST_Definitions && prev && prev.TYPE == stat.TYPE) {
|
|
prev.definitions = prev.definitions.concat(stat.definitions);
|
|
CHANGED = true;
|
|
}
|
|
else if (stat instanceof AST_For
|
|
&& prev instanceof AST_Var
|
|
&& (!stat.init || stat.init.TYPE == prev.TYPE)) {
|
|
CHANGED = true;
|
|
a.pop();
|
|
if (stat.init) {
|
|
stat.init.definitions = prev.definitions.concat(stat.init.definitions);
|
|
} else {
|
|
stat.init = prev;
|
|
}
|
|
a.push(stat);
|
|
prev = stat;
|
|
}
|
|
else {
|
|
prev = stat;
|
|
a.push(stat);
|
|
}
|
|
return a;
|
|
}, []);
|
|
};
|
|
|
|
};
|
|
|
|
function extract_functions_from_statement_array(statements) {
|
|
var funs = [];
|
|
for (var i = statements.length - 1; i >= 0; --i) {
|
|
var stat = statements[i];
|
|
if (stat instanceof AST_Defun) {
|
|
statements.splice(i, 1);
|
|
funs.unshift(stat);
|
|
}
|
|
}
|
|
return funs;
|
|
}
|
|
|
|
function extract_declarations_from_unreachable_code(compressor, stat, target) {
|
|
if (!(stat instanceof AST_Defun)) {
|
|
compressor.warn("Dropping unreachable code [{file}:{line},{col}]", stat.start);
|
|
}
|
|
stat.walk(new TreeWalker(function(node){
|
|
if (node instanceof AST_Definitions) {
|
|
compressor.warn("Declarations in unreachable code! [{file}:{line},{col}]", node.start);
|
|
node.remove_initializers();
|
|
target.push(node);
|
|
return true;
|
|
}
|
|
if (node instanceof AST_Defun) {
|
|
target.push(node);
|
|
return true;
|
|
}
|
|
if (node instanceof AST_Scope) {
|
|
return true;
|
|
}
|
|
}));
|
|
};
|
|
|
|
function is_undefined(node, compressor) {
|
|
return node.is_undefined
|
|
|| node instanceof AST_Undefined
|
|
|| node instanceof AST_UnaryPrefix
|
|
&& node.operator == "void"
|
|
&& !node.expression.has_side_effects(compressor);
|
|
}
|
|
|
|
// may_throw_on_access()
|
|
// returns true if this node may be null, undefined or contain `AST_Accessor`
|
|
(function(def) {
|
|
AST_Node.DEFMETHOD("may_throw_on_access", function(compressor) {
|
|
var pure_getters = compressor.option("pure_getters");
|
|
return !pure_getters || this._throw_on_access(pure_getters);
|
|
});
|
|
|
|
function is_strict(pure_getters) {
|
|
return /strict/.test(pure_getters);
|
|
}
|
|
|
|
def(AST_Node, is_strict);
|
|
def(AST_Null, return_true);
|
|
def(AST_Undefined, return_true);
|
|
def(AST_Constant, return_false);
|
|
def(AST_Array, return_false);
|
|
def(AST_Object, function(pure_getters) {
|
|
if (!is_strict(pure_getters)) return false;
|
|
for (var i = this.properties.length; --i >=0;)
|
|
if (this.properties[i].value instanceof AST_Accessor) return true;
|
|
return false;
|
|
});
|
|
def(AST_Function, return_false);
|
|
def(AST_UnaryPostfix, return_false);
|
|
def(AST_UnaryPrefix, function() {
|
|
return this.operator == "void";
|
|
});
|
|
def(AST_Binary, function(pure_getters) {
|
|
switch (this.operator) {
|
|
case "&&":
|
|
return this.left._throw_on_access(pure_getters);
|
|
case "||":
|
|
return this.left._throw_on_access(pure_getters)
|
|
&& this.right._throw_on_access(pure_getters);
|
|
default:
|
|
return false;
|
|
}
|
|
})
|
|
def(AST_Assign, function(pure_getters) {
|
|
return this.operator == "="
|
|
&& this.right._throw_on_access(pure_getters);
|
|
})
|
|
def(AST_Conditional, function(pure_getters) {
|
|
return this.consequent._throw_on_access(pure_getters)
|
|
|| this.alternative._throw_on_access(pure_getters);
|
|
})
|
|
def(AST_Seq, function(pure_getters) {
|
|
return this.cdr._throw_on_access(pure_getters);
|
|
});
|
|
def(AST_SymbolRef, function(pure_getters) {
|
|
if (this.is_undefined) return true;
|
|
if (!is_strict(pure_getters)) return false;
|
|
var fixed = this.fixed_value();
|
|
return !fixed || fixed._throw_on_access(pure_getters);
|
|
});
|
|
})(function(node, func) {
|
|
node.DEFMETHOD("_throw_on_access", func);
|
|
});
|
|
|
|
/* -----[ boolean/negation helpers ]----- */
|
|
|
|
// methods to determine whether an expression has a boolean result type
|
|
(function (def){
|
|
var unary_bool = [ "!", "delete" ];
|
|
var binary_bool = [ "in", "instanceof", "==", "!=", "===", "!==", "<", "<=", ">=", ">" ];
|
|
def(AST_Node, return_false);
|
|
def(AST_UnaryPrefix, function(){
|
|
return member(this.operator, unary_bool);
|
|
});
|
|
def(AST_Binary, function(){
|
|
return member(this.operator, binary_bool) ||
|
|
( (this.operator == "&&" || this.operator == "||") &&
|
|
this.left.is_boolean() && this.right.is_boolean() );
|
|
});
|
|
def(AST_Conditional, function(){
|
|
return this.consequent.is_boolean() && this.alternative.is_boolean();
|
|
});
|
|
def(AST_Assign, function(){
|
|
return this.operator == "=" && this.right.is_boolean();
|
|
});
|
|
def(AST_Seq, function(){
|
|
return this.cdr.is_boolean();
|
|
});
|
|
def(AST_True, return_true);
|
|
def(AST_False, return_true);
|
|
})(function(node, func){
|
|
node.DEFMETHOD("is_boolean", func);
|
|
});
|
|
|
|
// methods to determine if an expression has a numeric result type
|
|
(function (def){
|
|
def(AST_Node, return_false);
|
|
def(AST_Number, return_true);
|
|
var unary = makePredicate("+ - ~ ++ --");
|
|
def(AST_Unary, function(){
|
|
return unary(this.operator);
|
|
});
|
|
var binary = makePredicate("- * / % & | ^ << >> >>>");
|
|
def(AST_Binary, function(compressor){
|
|
return binary(this.operator) || this.operator == "+"
|
|
&& this.left.is_number(compressor)
|
|
&& this.right.is_number(compressor);
|
|
});
|
|
def(AST_Assign, function(compressor){
|
|
return binary(this.operator.slice(0, -1))
|
|
|| this.operator == "=" && this.right.is_number(compressor);
|
|
});
|
|
def(AST_Seq, function(compressor){
|
|
return this.cdr.is_number(compressor);
|
|
});
|
|
def(AST_Conditional, function(compressor){
|
|
return this.consequent.is_number(compressor) && this.alternative.is_number(compressor);
|
|
});
|
|
})(function(node, func){
|
|
node.DEFMETHOD("is_number", func);
|
|
});
|
|
|
|
// methods to determine if an expression has a string result type
|
|
(function (def){
|
|
def(AST_Node, return_false);
|
|
def(AST_String, return_true);
|
|
def(AST_UnaryPrefix, function(){
|
|
return this.operator == "typeof";
|
|
});
|
|
def(AST_Binary, function(compressor){
|
|
return this.operator == "+" &&
|
|
(this.left.is_string(compressor) || this.right.is_string(compressor));
|
|
});
|
|
def(AST_Assign, function(compressor){
|
|
return (this.operator == "=" || this.operator == "+=") && this.right.is_string(compressor);
|
|
});
|
|
def(AST_Seq, function(compressor){
|
|
return this.cdr.is_string(compressor);
|
|
});
|
|
def(AST_Conditional, function(compressor){
|
|
return this.consequent.is_string(compressor) && this.alternative.is_string(compressor);
|
|
});
|
|
})(function(node, func){
|
|
node.DEFMETHOD("is_string", func);
|
|
});
|
|
|
|
var unary_side_effects = makePredicate("delete ++ --");
|
|
|
|
function is_lhs(node, parent) {
|
|
if (parent instanceof AST_Unary && unary_side_effects(parent.operator)) return parent.expression;
|
|
if (parent instanceof AST_Assign && parent.left === node) return node;
|
|
}
|
|
|
|
(function (def){
|
|
AST_Node.DEFMETHOD("resolve_defines", function(compressor) {
|
|
if (!compressor.option("global_defs")) return;
|
|
var def = this._find_defs(compressor, "");
|
|
if (def) {
|
|
var node, parent = this, level = 0;
|
|
do {
|
|
node = parent;
|
|
parent = compressor.parent(level++);
|
|
} while (parent instanceof AST_PropAccess && parent.expression === node);
|
|
if (is_lhs(node, parent)) {
|
|
compressor.warn('global_defs ' + this.print_to_string() + ' redefined [{file}:{line},{col}]', this.start);
|
|
} else {
|
|
return def;
|
|
}
|
|
}
|
|
});
|
|
function to_node(value, orig) {
|
|
if (value instanceof AST_Node) return make_node(value.CTOR, orig, value);
|
|
if (Array.isArray(value)) return make_node(AST_Array, orig, {
|
|
elements: value.map(function(value) {
|
|
return to_node(value, orig);
|
|
})
|
|
});
|
|
if (value && typeof value == "object") {
|
|
var props = [];
|
|
for (var key in value) {
|
|
props.push(make_node(AST_ObjectKeyVal, orig, {
|
|
key: key,
|
|
value: to_node(value[key], orig)
|
|
}));
|
|
}
|
|
return make_node(AST_Object, orig, {
|
|
properties: props
|
|
});
|
|
}
|
|
return make_node_from_constant(value, orig);
|
|
}
|
|
def(AST_Node, noop);
|
|
def(AST_Dot, function(compressor, suffix){
|
|
return this.expression._find_defs(compressor, "." + this.property + suffix);
|
|
});
|
|
def(AST_SymbolRef, function(compressor, suffix){
|
|
if (!this.global()) return;
|
|
var name;
|
|
var defines = compressor.option("global_defs");
|
|
if (defines && HOP(defines, (name = this.name + suffix))) {
|
|
var node = to_node(defines[name], this);
|
|
var top = compressor.find_parent(AST_Toplevel);
|
|
node.walk(new TreeWalker(function(node) {
|
|
if (node instanceof AST_SymbolRef) {
|
|
node.scope = top;
|
|
node.thedef = top.def_global(node);
|
|
}
|
|
}));
|
|
return node;
|
|
}
|
|
});
|
|
})(function(node, func){
|
|
node.DEFMETHOD("_find_defs", func);
|
|
});
|
|
|
|
function best_of_expression(ast1, ast2) {
|
|
return ast1.print_to_string().length >
|
|
ast2.print_to_string().length
|
|
? ast2 : ast1;
|
|
}
|
|
|
|
function best_of_statement(ast1, ast2) {
|
|
return best_of_expression(make_node(AST_SimpleStatement, ast1, {
|
|
body: ast1
|
|
}), make_node(AST_SimpleStatement, ast2, {
|
|
body: ast2
|
|
})).body;
|
|
}
|
|
|
|
function best_of(compressor, ast1, ast2) {
|
|
return (first_in_statement(compressor) ? best_of_statement : best_of_expression)(ast1, ast2);
|
|
}
|
|
|
|
// methods to evaluate a constant expression
|
|
(function (def){
|
|
// If the node has been successfully reduced to a constant,
|
|
// then its value is returned; otherwise the element itself
|
|
// is returned.
|
|
// They can be distinguished as constant value is never a
|
|
// descendant of AST_Node.
|
|
AST_Node.DEFMETHOD("evaluate", function(compressor){
|
|
if (!compressor.option("evaluate")) return this;
|
|
try {
|
|
var val = this._eval(compressor);
|
|
return !val || val instanceof RegExp || typeof val != "object" ? val : this;
|
|
} catch(ex) {
|
|
if (ex !== def) throw ex;
|
|
return this;
|
|
}
|
|
});
|
|
var unaryPrefix = makePredicate("! ~ - + void");
|
|
AST_Node.DEFMETHOD("is_constant", function(){
|
|
// Accomodate when compress option evaluate=false
|
|
// as well as the common constant expressions !0 and -1
|
|
if (this instanceof AST_Constant) {
|
|
return !(this instanceof AST_RegExp);
|
|
} else {
|
|
return this instanceof AST_UnaryPrefix
|
|
&& this.expression instanceof AST_Constant
|
|
&& unaryPrefix(this.operator);
|
|
}
|
|
});
|
|
// Obtain the constant value of an expression already known to be constant.
|
|
// Result only valid iff this.is_constant() is true.
|
|
AST_Node.DEFMETHOD("constant_value", function(compressor){
|
|
// Accomodate when option evaluate=false.
|
|
if (this instanceof AST_Constant && !(this instanceof AST_RegExp)) {
|
|
return this.value;
|
|
}
|
|
// Accomodate the common constant expressions !0 and -1 when option evaluate=false.
|
|
if (this instanceof AST_UnaryPrefix
|
|
&& this.expression instanceof AST_Constant) switch (this.operator) {
|
|
case "!":
|
|
return !this.expression.value;
|
|
case "~":
|
|
return ~this.expression.value;
|
|
case "-":
|
|
return -this.expression.value;
|
|
case "+":
|
|
return +this.expression.value;
|
|
default:
|
|
throw new Error(string_template("Cannot evaluate unary expression {value}", {
|
|
value: this.print_to_string()
|
|
}));
|
|
}
|
|
var result = this.evaluate(compressor);
|
|
if (result !== this) {
|
|
return result;
|
|
}
|
|
throw new Error(string_template("Cannot evaluate constant [{file}:{line},{col}]", this.start));
|
|
});
|
|
def(AST_Statement, function(){
|
|
throw new Error(string_template("Cannot evaluate a statement [{file}:{line},{col}]", this.start));
|
|
});
|
|
def(AST_Lambda, function(){
|
|
throw def;
|
|
});
|
|
function ev(node, compressor) {
|
|
if (!compressor) throw new Error("Compressor must be passed");
|
|
|
|
return node._eval(compressor);
|
|
};
|
|
def(AST_Node, function(){
|
|
throw def; // not constant
|
|
});
|
|
def(AST_Constant, function(){
|
|
return this.getValue();
|
|
});
|
|
def(AST_Array, function(compressor){
|
|
if (compressor.option("unsafe")) {
|
|
return this.elements.map(function(element) {
|
|
return ev(element, compressor);
|
|
});
|
|
}
|
|
throw def;
|
|
});
|
|
def(AST_Object, function(compressor){
|
|
if (compressor.option("unsafe")) {
|
|
var val = {};
|
|
for (var i = 0, len = this.properties.length; i < len; i++) {
|
|
var prop = this.properties[i];
|
|
var key = prop.key;
|
|
if (key instanceof AST_Symbol) {
|
|
key = key.name;
|
|
} else if (key instanceof AST_Node) {
|
|
key = ev(key, compressor);
|
|
}
|
|
if (typeof Object.prototype[key] === 'function') {
|
|
throw def;
|
|
}
|
|
val[key] = ev(prop.value, compressor);
|
|
}
|
|
return val;
|
|
}
|
|
throw def;
|
|
});
|
|
def(AST_UnaryPrefix, function(compressor){
|
|
var e = this.expression;
|
|
switch (this.operator) {
|
|
case "!": return !ev(e, compressor);
|
|
case "typeof":
|
|
// Function would be evaluated to an array and so typeof would
|
|
// incorrectly return 'object'. Hence making is a special case.
|
|
if (e instanceof AST_Function) return typeof function(){};
|
|
|
|
e = ev(e, compressor);
|
|
|
|
// typeof <RegExp> returns "object" or "function" on different platforms
|
|
// so cannot evaluate reliably
|
|
if (e instanceof RegExp) throw def;
|
|
|
|
return typeof e;
|
|
case "void": return void ev(e, compressor);
|
|
case "~": return ~ev(e, compressor);
|
|
case "-": return -ev(e, compressor);
|
|
case "+": return +ev(e, compressor);
|
|
}
|
|
throw def;
|
|
});
|
|
def(AST_Binary, function(c){
|
|
var left = this.left, right = this.right, result;
|
|
switch (this.operator) {
|
|
case "&&" : result = ev(left, c) && ev(right, c); break;
|
|
case "||" : result = ev(left, c) || ev(right, c); break;
|
|
case "|" : result = ev(left, c) | ev(right, c); break;
|
|
case "&" : result = ev(left, c) & ev(right, c); break;
|
|
case "^" : result = ev(left, c) ^ ev(right, c); break;
|
|
case "+" : result = ev(left, c) + ev(right, c); break;
|
|
case "*" : result = ev(left, c) * ev(right, c); break;
|
|
case "/" : result = ev(left, c) / ev(right, c); break;
|
|
case "%" : result = ev(left, c) % ev(right, c); break;
|
|
case "-" : result = ev(left, c) - ev(right, c); break;
|
|
case "<<" : result = ev(left, c) << ev(right, c); break;
|
|
case ">>" : result = ev(left, c) >> ev(right, c); break;
|
|
case ">>>" : result = ev(left, c) >>> ev(right, c); break;
|
|
case "==" : result = ev(left, c) == ev(right, c); break;
|
|
case "===" : result = ev(left, c) === ev(right, c); break;
|
|
case "!=" : result = ev(left, c) != ev(right, c); break;
|
|
case "!==" : result = ev(left, c) !== ev(right, c); break;
|
|
case "<" : result = ev(left, c) < ev(right, c); break;
|
|
case "<=" : result = ev(left, c) <= ev(right, c); break;
|
|
case ">" : result = ev(left, c) > ev(right, c); break;
|
|
case ">=" : result = ev(left, c) >= ev(right, c); break;
|
|
default:
|
|
throw def;
|
|
}
|
|
if (isNaN(result) && c.find_parent(AST_With)) {
|
|
// leave original expression as is
|
|
throw def;
|
|
}
|
|
return result;
|
|
});
|
|
def(AST_Conditional, function(compressor){
|
|
return ev(this.condition, compressor)
|
|
? ev(this.consequent, compressor)
|
|
: ev(this.alternative, compressor);
|
|
});
|
|
def(AST_SymbolRef, function(compressor){
|
|
if (!compressor.option("reduce_vars") || this._evaluating) throw def;
|
|
this._evaluating = true;
|
|
try {
|
|
var fixed = this.fixed_value();
|
|
if (!fixed) throw def;
|
|
var value = ev(fixed, compressor);
|
|
if (!HOP(fixed, "_eval")) fixed._eval = function() {
|
|
return value;
|
|
};
|
|
if (value && typeof value == "object" && this.definition().escaped) throw def;
|
|
return value;
|
|
} finally {
|
|
this._evaluating = false;
|
|
}
|
|
});
|
|
def(AST_PropAccess, function(compressor){
|
|
if (compressor.option("unsafe")) {
|
|
var key = this.property;
|
|
if (key instanceof AST_Node) {
|
|
key = ev(key, compressor);
|
|
}
|
|
var val = ev(this.expression, compressor);
|
|
if (val && HOP(val, key)) {
|
|
return val[key];
|
|
}
|
|
}
|
|
throw def;
|
|
});
|
|
})(function(node, func){
|
|
node.DEFMETHOD("_eval", func);
|
|
});
|
|
|
|
// method to negate an expression
|
|
(function(def){
|
|
function basic_negation(exp) {
|
|
return make_node(AST_UnaryPrefix, exp, {
|
|
operator: "!",
|
|
expression: exp
|
|
});
|
|
}
|
|
function best(orig, alt, first_in_statement) {
|
|
var negated = basic_negation(orig);
|
|
if (first_in_statement) {
|
|
var stat = make_node(AST_SimpleStatement, alt, {
|
|
body: alt
|
|
});
|
|
return best_of_expression(negated, stat) === stat ? alt : negated;
|
|
}
|
|
return best_of_expression(negated, alt);
|
|
}
|
|
def(AST_Node, function(){
|
|
return basic_negation(this);
|
|
});
|
|
def(AST_Statement, function(){
|
|
throw new Error("Cannot negate a statement");
|
|
});
|
|
def(AST_Function, function(){
|
|
return basic_negation(this);
|
|
});
|
|
def(AST_UnaryPrefix, function(){
|
|
if (this.operator == "!")
|
|
return this.expression;
|
|
return basic_negation(this);
|
|
});
|
|
def(AST_Seq, function(compressor){
|
|
var self = this.clone();
|
|
self.cdr = self.cdr.negate(compressor);
|
|
return self;
|
|
});
|
|
def(AST_Conditional, function(compressor, first_in_statement){
|
|
var self = this.clone();
|
|
self.consequent = self.consequent.negate(compressor);
|
|
self.alternative = self.alternative.negate(compressor);
|
|
return best(this, self, first_in_statement);
|
|
});
|
|
def(AST_Binary, function(compressor, first_in_statement){
|
|
var self = this.clone(), op = this.operator;
|
|
if (compressor.option("unsafe_comps")) {
|
|
switch (op) {
|
|
case "<=" : self.operator = ">" ; return self;
|
|
case "<" : self.operator = ">=" ; return self;
|
|
case ">=" : self.operator = "<" ; return self;
|
|
case ">" : self.operator = "<=" ; return self;
|
|
}
|
|
}
|
|
switch (op) {
|
|
case "==" : self.operator = "!="; return self;
|
|
case "!=" : self.operator = "=="; return self;
|
|
case "===": self.operator = "!=="; return self;
|
|
case "!==": self.operator = "==="; return self;
|
|
case "&&":
|
|
self.operator = "||";
|
|
self.left = self.left.negate(compressor, first_in_statement);
|
|
self.right = self.right.negate(compressor);
|
|
return best(this, self, first_in_statement);
|
|
case "||":
|
|
self.operator = "&&";
|
|
self.left = self.left.negate(compressor, first_in_statement);
|
|
self.right = self.right.negate(compressor);
|
|
return best(this, self, first_in_statement);
|
|
}
|
|
return basic_negation(this);
|
|
});
|
|
})(function(node, func){
|
|
node.DEFMETHOD("negate", function(compressor, first_in_statement){
|
|
return func.call(this, compressor, first_in_statement);
|
|
});
|
|
});
|
|
|
|
AST_Call.DEFMETHOD("has_pure_annotation", function(compressor) {
|
|
if (!compressor.option("side_effects")) return false;
|
|
if (this.pure !== undefined) return this.pure;
|
|
var pure = false;
|
|
var comments, last_comment;
|
|
if (this.start
|
|
&& (comments = this.start.comments_before)
|
|
&& comments.length
|
|
&& /[@#]__PURE__/.test((last_comment = comments[comments.length - 1]).value)) {
|
|
pure = last_comment;
|
|
}
|
|
return this.pure = pure;
|
|
});
|
|
|
|
// determine if expression has side effects
|
|
(function(def){
|
|
def(AST_Node, return_true);
|
|
|
|
def(AST_EmptyStatement, return_false);
|
|
def(AST_Constant, return_false);
|
|
def(AST_This, return_false);
|
|
|
|
def(AST_Call, function(compressor){
|
|
if (!this.has_pure_annotation(compressor) && compressor.pure_funcs(this)) return true;
|
|
for (var i = this.args.length; --i >= 0;) {
|
|
if (this.args[i].has_side_effects(compressor))
|
|
return true;
|
|
}
|
|
return false;
|
|
});
|
|
|
|
function any(list, compressor) {
|
|
for (var i = list.length; --i >= 0;)
|
|
if (list[i].has_side_effects(compressor))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
def(AST_Block, function(compressor){
|
|
return any(this.body, compressor);
|
|
});
|
|
def(AST_Switch, function(compressor){
|
|
return this.expression.has_side_effects(compressor)
|
|
|| any(this.body, compressor);
|
|
});
|
|
def(AST_Case, function(compressor){
|
|
return this.expression.has_side_effects(compressor)
|
|
|| any(this.body, compressor);
|
|
});
|
|
def(AST_Try, function(compressor){
|
|
return any(this.body, compressor)
|
|
|| this.bcatch && this.bcatch.has_side_effects(compressor)
|
|
|| this.bfinally && this.bfinally.has_side_effects(compressor);
|
|
});
|
|
def(AST_If, function(compressor){
|
|
return this.condition.has_side_effects(compressor)
|
|
|| this.body && this.body.has_side_effects(compressor)
|
|
|| this.alternative && this.alternative.has_side_effects(compressor);
|
|
});
|
|
def(AST_LabeledStatement, function(compressor){
|
|
return this.body.has_side_effects(compressor);
|
|
});
|
|
def(AST_SimpleStatement, function(compressor){
|
|
return this.body.has_side_effects(compressor);
|
|
});
|
|
def(AST_Defun, return_true);
|
|
def(AST_Function, return_false);
|
|
def(AST_Binary, function(compressor){
|
|
return this.left.has_side_effects(compressor)
|
|
|| this.right.has_side_effects(compressor);
|
|
});
|
|
def(AST_Assign, return_true);
|
|
def(AST_Conditional, function(compressor){
|
|
return this.condition.has_side_effects(compressor)
|
|
|| this.consequent.has_side_effects(compressor)
|
|
|| this.alternative.has_side_effects(compressor);
|
|
});
|
|
def(AST_Unary, function(compressor){
|
|
return unary_side_effects(this.operator)
|
|
|| this.expression.has_side_effects(compressor);
|
|
});
|
|
def(AST_SymbolRef, function(compressor){
|
|
return this.undeclared();
|
|
});
|
|
def(AST_Object, function(compressor){
|
|
return any(this.properties, compressor);
|
|
});
|
|
def(AST_ObjectProperty, function(compressor){
|
|
return this.value.has_side_effects(compressor);
|
|
});
|
|
def(AST_Array, function(compressor){
|
|
return any(this.elements, compressor);
|
|
});
|
|
def(AST_Dot, function(compressor){
|
|
return this.expression.may_throw_on_access(compressor)
|
|
|| this.expression.has_side_effects(compressor);
|
|
});
|
|
def(AST_Sub, function(compressor){
|
|
return this.expression.may_throw_on_access(compressor)
|
|
|| this.expression.has_side_effects(compressor)
|
|
|| this.property.has_side_effects(compressor);
|
|
});
|
|
def(AST_Seq, function(compressor){
|
|
return this.car.has_side_effects(compressor)
|
|
|| this.cdr.has_side_effects(compressor);
|
|
});
|
|
})(function(node, func){
|
|
node.DEFMETHOD("has_side_effects", func);
|
|
});
|
|
|
|
// tell me if a statement aborts
|
|
function aborts(thing) {
|
|
return thing && thing.aborts();
|
|
};
|
|
(function(def){
|
|
def(AST_Statement, return_null);
|
|
def(AST_Jump, return_this);
|
|
function block_aborts(){
|
|
var n = this.body.length;
|
|
return n > 0 && aborts(this.body[n - 1]);
|
|
};
|
|
def(AST_BlockStatement, block_aborts);
|
|
def(AST_SwitchBranch, block_aborts);
|
|
def(AST_If, function(){
|
|
return this.alternative && aborts(this.body) && aborts(this.alternative) && this;
|
|
});
|
|
})(function(node, func){
|
|
node.DEFMETHOD("aborts", func);
|
|
});
|
|
|
|
/* -----[ optimizers ]----- */
|
|
|
|
OPT(AST_Directive, function(self, compressor){
|
|
if (compressor.has_directive(self.value) !== self) {
|
|
return make_node(AST_EmptyStatement, self);
|
|
}
|
|
return self;
|
|
});
|
|
|
|
OPT(AST_Debugger, function(self, compressor){
|
|
if (compressor.option("drop_debugger"))
|
|
return make_node(AST_EmptyStatement, self);
|
|
return self;
|
|
});
|
|
|
|
OPT(AST_LabeledStatement, function(self, compressor){
|
|
if (self.body instanceof AST_Break
|
|
&& compressor.loopcontrol_target(self.body) === self.body) {
|
|
return make_node(AST_EmptyStatement, self);
|
|
}
|
|
return self.label.references.length == 0 ? self.body : self;
|
|
});
|
|
|
|
OPT(AST_Block, function(self, compressor){
|
|
self.body = tighten_body(self.body, compressor);
|
|
return self;
|
|
});
|
|
|
|
OPT(AST_BlockStatement, function(self, compressor){
|
|
self.body = tighten_body(self.body, compressor);
|
|
switch (self.body.length) {
|
|
case 1: return self.body[0];
|
|
case 0: return make_node(AST_EmptyStatement, self);
|
|
}
|
|
return self;
|
|
});
|
|
|
|
AST_Scope.DEFMETHOD("drop_unused", function(compressor){
|
|
var self = this;
|
|
if (compressor.has_directive("use asm")) return self;
|
|
var toplevel = compressor.option("toplevel");
|
|
if (compressor.option("unused")
|
|
&& (!(self instanceof AST_Toplevel) || toplevel)
|
|
&& !self.uses_eval
|
|
&& !self.uses_with) {
|
|
var assign_as_unused = !/keep_assign/.test(compressor.option("unused"));
|
|
var drop_funcs = /funcs/.test(toplevel);
|
|
var drop_vars = /vars/.test(toplevel);
|
|
if (!(self instanceof AST_Toplevel) || toplevel == true) {
|
|
drop_funcs = drop_vars = true;
|
|
}
|
|
var in_use = [];
|
|
var in_use_ids = Object.create(null); // avoid expensive linear scans of in_use
|
|
if (self instanceof AST_Toplevel && compressor.top_retain) {
|
|
self.variables.each(function(def) {
|
|
if (compressor.top_retain(def) && !(def.id in in_use_ids)) {
|
|
in_use_ids[def.id] = true;
|
|
in_use.push(def);
|
|
}
|
|
});
|
|
}
|
|
var initializations = new Dictionary();
|
|
// pass 1: find out which symbols are directly used in
|
|
// this scope (not in nested scopes).
|
|
var scope = this;
|
|
var tw = new TreeWalker(function(node, descend){
|
|
if (node !== self) {
|
|
if (node instanceof AST_Defun) {
|
|
if (!drop_funcs && scope === self) {
|
|
var node_def = node.name.definition();
|
|
if (!(node_def.id in in_use_ids)) {
|
|
in_use_ids[node_def.id] = true;
|
|
in_use.push(node_def);
|
|
}
|
|
}
|
|
initializations.add(node.name.name, node);
|
|
return true; // don't go in nested scopes
|
|
}
|
|
if (node instanceof AST_Definitions && scope === self) {
|
|
node.definitions.forEach(function(def){
|
|
if (!drop_vars) {
|
|
var node_def = def.name.definition();
|
|
if (!(node_def.id in in_use_ids)) {
|
|
in_use_ids[node_def.id] = true;
|
|
in_use.push(node_def);
|
|
}
|
|
}
|
|
if (def.value) {
|
|
initializations.add(def.name.name, def.value);
|
|
if (def.value.has_side_effects(compressor)) {
|
|
def.value.walk(tw);
|
|
}
|
|
}
|
|
});
|
|
return true;
|
|
}
|
|
if (assign_as_unused
|
|
&& node instanceof AST_Assign
|
|
&& node.operator == "="
|
|
&& node.left instanceof AST_SymbolRef
|
|
&& !is_reference_const(node.left)
|
|
&& scope === self) {
|
|
node.right.walk(tw);
|
|
return true;
|
|
}
|
|
if (node instanceof AST_SymbolRef) {
|
|
var node_def = node.definition();
|
|
if (!(node_def.id in in_use_ids)) {
|
|
in_use_ids[node_def.id] = true;
|
|
in_use.push(node_def);
|
|
}
|
|
return true;
|
|
}
|
|
if (node instanceof AST_Scope) {
|
|
var save_scope = scope;
|
|
scope = node;
|
|
descend();
|
|
scope = save_scope;
|
|
return true;
|
|
}
|
|
}
|
|
});
|
|
self.walk(tw);
|
|
// pass 2: for every used symbol we need to walk its
|
|
// initialization code to figure out if it uses other
|
|
// symbols (that may not be in_use).
|
|
for (var i = 0; i < in_use.length; ++i) {
|
|
in_use[i].orig.forEach(function(decl){
|
|
// undeclared globals will be instanceof AST_SymbolRef
|
|
var init = initializations.get(decl.name);
|
|
if (init) init.forEach(function(init){
|
|
var tw = new TreeWalker(function(node){
|
|
if (node instanceof AST_SymbolRef) {
|
|
var node_def = node.definition();
|
|
if (!(node_def.id in in_use_ids)) {
|
|
in_use_ids[node_def.id] = true;
|
|
in_use.push(node_def);
|
|
}
|
|
}
|
|
});
|
|
init.walk(tw);
|
|
});
|
|
});
|
|
}
|
|
// pass 3: we should drop declarations not in_use
|
|
var tt = new TreeTransformer(
|
|
function before(node, descend, in_list) {
|
|
if (node instanceof AST_Function
|
|
&& node.name
|
|
&& !compressor.option("keep_fnames")) {
|
|
var def = node.name.definition();
|
|
// any declarations with same name will overshadow
|
|
// name of this anonymous function and can therefore
|
|
// never be used anywhere
|
|
if (!(def.id in in_use_ids) || def.orig.length > 1)
|
|
node.name = null;
|
|
}
|
|
if (node instanceof AST_Lambda && !(node instanceof AST_Accessor)) {
|
|
var trim = !compressor.option("keep_fargs");
|
|
for (var a = node.argnames, i = a.length; --i >= 0;) {
|
|
var sym = a[i];
|
|
if (!(sym.definition().id in in_use_ids)) {
|
|
sym.__unused = true;
|
|
if (trim) {
|
|
a.pop();
|
|
compressor[sym.unreferenced() ? "warn" : "info"]("Dropping unused function argument {name} [{file}:{line},{col}]", {
|
|
name : sym.name,
|
|
file : sym.start.file,
|
|
line : sym.start.line,
|
|
col : sym.start.col
|
|
});
|
|
}
|
|
}
|
|
else {
|
|
trim = false;
|
|
}
|
|
}
|
|
}
|
|
if (drop_funcs && node instanceof AST_Defun && node !== self) {
|
|
if (!(node.name.definition().id in in_use_ids)) {
|
|
compressor[node.name.unreferenced() ? "warn" : "info"]("Dropping unused function {name} [{file}:{line},{col}]", {
|
|
name : node.name.name,
|
|
file : node.name.start.file,
|
|
line : node.name.start.line,
|
|
col : node.name.start.col
|
|
});
|
|
return make_node(AST_EmptyStatement, node);
|
|
}
|
|
return node;
|
|
}
|
|
if (drop_vars && node instanceof AST_Definitions && !(tt.parent() instanceof AST_ForIn && tt.parent().init === node)) {
|
|
var def = node.definitions.filter(function(def){
|
|
if (def.value) def.value = def.value.transform(tt);
|
|
var sym = def.name.definition();
|
|
if (sym.id in in_use_ids) return true;
|
|
if (sym.orig[0] instanceof AST_SymbolCatch) {
|
|
def.value = def.value && def.value.drop_side_effect_free(compressor);
|
|
return true;
|
|
}
|
|
var w = {
|
|
name : def.name.name,
|
|
file : def.name.start.file,
|
|
line : def.name.start.line,
|
|
col : def.name.start.col
|
|
};
|
|
if (def.value && (def._unused_side_effects = def.value.drop_side_effect_free(compressor))) {
|
|
compressor.warn("Side effects in initialization of unused variable {name} [{file}:{line},{col}]", w);
|
|
return true;
|
|
}
|
|
compressor[def.name.unreferenced() ? "warn" : "info"]("Dropping unused variable {name} [{file}:{line},{col}]", w);
|
|
return false;
|
|
});
|
|
// place uninitialized names at the start
|
|
def = mergeSort(def, function(a, b){
|
|
if (!a.value && b.value) return -1;
|
|
if (!b.value && a.value) return 1;
|
|
return 0;
|
|
});
|
|
// for unused names whose initialization has
|
|
// side effects, we can cascade the init. code
|
|
// into the next one, or next statement.
|
|
var side_effects = [];
|
|
for (var i = 0; i < def.length;) {
|
|
var x = def[i];
|
|
if (x._unused_side_effects) {
|
|
side_effects.push(x._unused_side_effects);
|
|
def.splice(i, 1);
|
|
} else {
|
|
if (side_effects.length > 0) {
|
|
side_effects.push(x.value);
|
|
x.value = AST_Seq.from_array(side_effects);
|
|
side_effects = [];
|
|
}
|
|
++i;
|
|
}
|
|
}
|
|
if (side_effects.length > 0) {
|
|
side_effects = make_node(AST_BlockStatement, node, {
|
|
body: [ make_node(AST_SimpleStatement, node, {
|
|
body: AST_Seq.from_array(side_effects)
|
|
}) ]
|
|
});
|
|
} else {
|
|
side_effects = null;
|
|
}
|
|
if (def.length == 0 && !side_effects) {
|
|
return make_node(AST_EmptyStatement, node);
|
|
}
|
|
if (def.length == 0) {
|
|
return in_list ? MAP.splice(side_effects.body) : side_effects;
|
|
}
|
|
node.definitions = def;
|
|
if (side_effects) {
|
|
side_effects.body.unshift(node);
|
|
return in_list ? MAP.splice(side_effects.body) : side_effects;
|
|
}
|
|
return node;
|
|
}
|
|
if (drop_vars && assign_as_unused
|
|
&& node instanceof AST_Assign
|
|
&& node.operator == "="
|
|
&& node.left instanceof AST_SymbolRef) {
|
|
var def = node.left.definition();
|
|
if (!(def.id in in_use_ids)
|
|
&& self.variables.get(def.name) === def) {
|
|
return maintain_this_binding(tt.parent(), node, node.right.transform(tt));
|
|
}
|
|
}
|
|
// certain combination of unused name + side effect leads to:
|
|
// https://github.com/mishoo/UglifyJS2/issues/44
|
|
// https://github.com/mishoo/UglifyJS2/issues/1830
|
|
// that's an invalid AST.
|
|
// We fix it at this stage by moving the `var` outside the `for`.
|
|
if (node instanceof AST_For) {
|
|
descend(node, this);
|
|
if (node.init instanceof AST_BlockStatement) {
|
|
var block = node.init;
|
|
node.init = block.body.pop();
|
|
block.body.push(node);
|
|
return in_list ? MAP.splice(block.body) : block;
|
|
} else if (is_empty(node.init)) {
|
|
node.init = null;
|
|
}
|
|
return node;
|
|
}
|
|
if (node instanceof AST_LabeledStatement && node.body instanceof AST_For) {
|
|
descend(node, this);
|
|
if (node.body instanceof AST_BlockStatement) {
|
|
var block = node.body;
|
|
node.body = block.body.pop();
|
|
block.body.push(node);
|
|
return in_list ? MAP.splice(block.body) : block;
|
|
}
|
|
return node;
|
|
}
|
|
if (node instanceof AST_Scope && node !== self)
|
|
return node;
|
|
}
|
|
);
|
|
self.transform(tt);
|
|
}
|
|
});
|
|
|
|
AST_Scope.DEFMETHOD("hoist_declarations", function(compressor){
|
|
var self = this;
|
|
if (compressor.has_directive("use asm")) return self;
|
|
var hoist_funs = compressor.option("hoist_funs");
|
|
var hoist_vars = compressor.option("hoist_vars");
|
|
if (hoist_funs || hoist_vars) {
|
|
var dirs = [];
|
|
var hoisted = [];
|
|
var vars = new Dictionary(), vars_found = 0, var_decl = 0;
|
|
// let's count var_decl first, we seem to waste a lot of
|
|
// space if we hoist `var` when there's only one.
|
|
self.walk(new TreeWalker(function(node){
|
|
if (node instanceof AST_Scope && node !== self)
|
|
return true;
|
|
if (node instanceof AST_Var) {
|
|
++var_decl;
|
|
return true;
|
|
}
|
|
}));
|
|
hoist_vars = hoist_vars && var_decl > 1;
|
|
var tt = new TreeTransformer(
|
|
function before(node) {
|
|
if (node !== self) {
|
|
if (node instanceof AST_Directive) {
|
|
dirs.push(node);
|
|
return make_node(AST_EmptyStatement, node);
|
|
}
|
|
if (node instanceof AST_Defun && hoist_funs) {
|
|
hoisted.push(node);
|
|
return make_node(AST_EmptyStatement, node);
|
|
}
|
|
if (node instanceof AST_Var && hoist_vars) {
|
|
node.definitions.forEach(function(def){
|
|
vars.set(def.name.name, def);
|
|
++vars_found;
|
|
});
|
|
var seq = node.to_assignments(compressor);
|
|
var p = tt.parent();
|
|
if (p instanceof AST_ForIn && p.init === node) {
|
|
if (seq == null) {
|
|
var def = node.definitions[0].name;
|
|
return make_node(AST_SymbolRef, def, def);
|
|
}
|
|
return seq;
|
|
}
|
|
if (p instanceof AST_For && p.init === node) {
|
|
return seq;
|
|
}
|
|
if (!seq) return make_node(AST_EmptyStatement, node);
|
|
return make_node(AST_SimpleStatement, node, {
|
|
body: seq
|
|
});
|
|
}
|
|
if (node instanceof AST_Scope)
|
|
return node; // to avoid descending in nested scopes
|
|
}
|
|
}
|
|
);
|
|
self = self.transform(tt);
|
|
if (vars_found > 0) {
|
|
// collect only vars which don't show up in self's arguments list
|
|
var defs = [];
|
|
vars.each(function(def, name){
|
|
if (self instanceof AST_Lambda
|
|
&& find_if(function(x){ return x.name == def.name.name },
|
|
self.argnames)) {
|
|
vars.del(name);
|
|
} else {
|
|
def = def.clone();
|
|
def.value = null;
|
|
defs.push(def);
|
|
vars.set(name, def);
|
|
}
|
|
});
|
|
if (defs.length > 0) {
|
|
// try to merge in assignments
|
|
for (var i = 0; i < self.body.length;) {
|
|
if (self.body[i] instanceof AST_SimpleStatement) {
|
|
var expr = self.body[i].body, sym, assign;
|
|
if (expr instanceof AST_Assign
|
|
&& expr.operator == "="
|
|
&& (sym = expr.left) instanceof AST_Symbol
|
|
&& vars.has(sym.name))
|
|
{
|
|
var def = vars.get(sym.name);
|
|
if (def.value) break;
|
|
def.value = expr.right;
|
|
remove(defs, def);
|
|
defs.push(def);
|
|
self.body.splice(i, 1);
|
|
continue;
|
|
}
|
|
if (expr instanceof AST_Seq
|
|
&& (assign = expr.car) instanceof AST_Assign
|
|
&& assign.operator == "="
|
|
&& (sym = assign.left) instanceof AST_Symbol
|
|
&& vars.has(sym.name))
|
|
{
|
|
var def = vars.get(sym.name);
|
|
if (def.value) break;
|
|
def.value = assign.right;
|
|
remove(defs, def);
|
|
defs.push(def);
|
|
self.body[i].body = expr.cdr;
|
|
continue;
|
|
}
|
|
}
|
|
if (self.body[i] instanceof AST_EmptyStatement) {
|
|
self.body.splice(i, 1);
|
|
continue;
|
|
}
|
|
if (self.body[i] instanceof AST_BlockStatement) {
|
|
var tmp = [ i, 1 ].concat(self.body[i].body);
|
|
self.body.splice.apply(self.body, tmp);
|
|
continue;
|
|
}
|
|
break;
|
|
}
|
|
defs = make_node(AST_Var, self, {
|
|
definitions: defs
|
|
});
|
|
hoisted.push(defs);
|
|
};
|
|
}
|
|
self.body = dirs.concat(hoisted, self.body);
|
|
}
|
|
return self;
|
|
});
|
|
|
|
// drop_side_effect_free()
|
|
// remove side-effect-free parts which only affects return value
|
|
(function(def){
|
|
// Drop side-effect-free elements from an array of expressions.
|
|
// Returns an array of expressions with side-effects or null
|
|
// if all elements were dropped. Note: original array may be
|
|
// returned if nothing changed.
|
|
function trim(nodes, compressor, first_in_statement) {
|
|
var ret = [], changed = false;
|
|
for (var i = 0, len = nodes.length; i < len; i++) {
|
|
var node = nodes[i].drop_side_effect_free(compressor, first_in_statement);
|
|
changed |= node !== nodes[i];
|
|
if (node) {
|
|
ret.push(node);
|
|
first_in_statement = false;
|
|
}
|
|
}
|
|
return changed ? ret.length ? ret : null : nodes;
|
|
}
|
|
|
|
def(AST_Node, return_this);
|
|
def(AST_Constant, return_null);
|
|
def(AST_This, return_null);
|
|
def(AST_Call, function(compressor, first_in_statement){
|
|
if (!this.has_pure_annotation(compressor) && compressor.pure_funcs(this)) {
|
|
if (this.expression instanceof AST_Function
|
|
&& (!this.expression.name || !this.expression.name.definition().references.length)) {
|
|
var node = this.clone();
|
|
node.expression = node.expression.process_expression(false, compressor);
|
|
return node;
|
|
}
|
|
return this;
|
|
}
|
|
if (this.pure) {
|
|
compressor.warn("Dropping __PURE__ call [{file}:{line},{col}]", this.start);
|
|
this.pure.value = this.pure.value.replace(/[@#]__PURE__/g, ' ');
|
|
}
|
|
var args = trim(this.args, compressor, first_in_statement);
|
|
return args && AST_Seq.from_array(args);
|
|
});
|
|
def(AST_Accessor, return_null);
|
|
def(AST_Function, return_null);
|
|
def(AST_Binary, function(compressor, first_in_statement){
|
|
var right = this.right.drop_side_effect_free(compressor);
|
|
if (!right) return this.left.drop_side_effect_free(compressor, first_in_statement);
|
|
switch (this.operator) {
|
|
case "&&":
|
|
case "||":
|
|
if (right === this.right) return this;
|
|
var node = this.clone();
|
|
node.right = right;
|
|
return node;
|
|
default:
|
|
var left = this.left.drop_side_effect_free(compressor, first_in_statement);
|
|
if (!left) return this.right.drop_side_effect_free(compressor, first_in_statement);
|
|
return make_node(AST_Seq, this, {
|
|
car: left,
|
|
cdr: right
|
|
});
|
|
}
|
|
});
|
|
def(AST_Assign, return_this);
|
|
def(AST_Conditional, function(compressor){
|
|
var consequent = this.consequent.drop_side_effect_free(compressor);
|
|
var alternative = this.alternative.drop_side_effect_free(compressor);
|
|
if (consequent === this.consequent && alternative === this.alternative) return this;
|
|
if (!consequent) return alternative ? make_node(AST_Binary, this, {
|
|
operator: "||",
|
|
left: this.condition,
|
|
right: alternative
|
|
}) : this.condition.drop_side_effect_free(compressor);
|
|
if (!alternative) return make_node(AST_Binary, this, {
|
|
operator: "&&",
|
|
left: this.condition,
|
|
right: consequent
|
|
});
|
|
var node = this.clone();
|
|
node.consequent = consequent;
|
|
node.alternative = alternative;
|
|
return node;
|
|
});
|
|
def(AST_Unary, function(compressor, first_in_statement){
|
|
if (unary_side_effects(this.operator)) return this;
|
|
if (this.operator == "typeof" && this.expression instanceof AST_SymbolRef) return null;
|
|
var expression = this.expression.drop_side_effect_free(compressor, first_in_statement);
|
|
if (first_in_statement
|
|
&& this instanceof AST_UnaryPrefix
|
|
&& is_iife_call(expression)) {
|
|
if (expression === this.expression && this.operator.length === 1) return this;
|
|
return make_node(AST_UnaryPrefix, this, {
|
|
operator: this.operator.length === 1 ? this.operator : "!",
|
|
expression: expression
|
|
});
|
|
}
|
|
return expression;
|
|
});
|
|
def(AST_SymbolRef, function() {
|
|
return this.undeclared() ? this : null;
|
|
});
|
|
def(AST_Object, function(compressor, first_in_statement){
|
|
var values = trim(this.properties, compressor, first_in_statement);
|
|
return values && AST_Seq.from_array(values);
|
|
});
|
|
def(AST_ObjectProperty, function(compressor, first_in_statement){
|
|
return this.value.drop_side_effect_free(compressor, first_in_statement);
|
|
});
|
|
def(AST_Array, function(compressor, first_in_statement){
|
|
var values = trim(this.elements, compressor, first_in_statement);
|
|
return values && AST_Seq.from_array(values);
|
|
});
|
|
def(AST_Dot, function(compressor, first_in_statement){
|
|
if (this.expression.may_throw_on_access(compressor)) return this;
|
|
return this.expression.drop_side_effect_free(compressor, first_in_statement);
|
|
});
|
|
def(AST_Sub, function(compressor, first_in_statement){
|
|
if (this.expression.may_throw_on_access(compressor)) return this;
|
|
var expression = this.expression.drop_side_effect_free(compressor, first_in_statement);
|
|
if (!expression) return this.property.drop_side_effect_free(compressor, first_in_statement);
|
|
var property = this.property.drop_side_effect_free(compressor);
|
|
if (!property) return expression;
|
|
return make_node(AST_Seq, this, {
|
|
car: expression,
|
|
cdr: property
|
|
});
|
|
});
|
|
def(AST_Seq, function(compressor){
|
|
var cdr = this.cdr.drop_side_effect_free(compressor);
|
|
if (cdr === this.cdr) return this;
|
|
if (!cdr) return this.car;
|
|
return make_node(AST_Seq, this, {
|
|
car: this.car,
|
|
cdr: cdr
|
|
});
|
|
});
|
|
})(function(node, func){
|
|
node.DEFMETHOD("drop_side_effect_free", func);
|
|
});
|
|
|
|
OPT(AST_SimpleStatement, function(self, compressor){
|
|
if (compressor.option("side_effects")) {
|
|
var body = self.body;
|
|
var node = body.drop_side_effect_free(compressor, true);
|
|
if (!node) {
|
|
compressor.warn("Dropping side-effect-free statement [{file}:{line},{col}]", self.start);
|
|
return make_node(AST_EmptyStatement, self);
|
|
}
|
|
if (node !== body) {
|
|
return make_node(AST_SimpleStatement, self, { body: node });
|
|
}
|
|
}
|
|
return self;
|
|
});
|
|
|
|
OPT(AST_DWLoop, function(self, compressor){
|
|
if (!compressor.option("loops")) return self;
|
|
var cond = self.condition.evaluate(compressor);
|
|
if (cond !== self.condition) {
|
|
if (cond) {
|
|
return make_node(AST_For, self, {
|
|
body: self.body
|
|
});
|
|
}
|
|
if (compressor.option("dead_code") && self instanceof AST_While) {
|
|
var a = [];
|
|
extract_declarations_from_unreachable_code(compressor, self.body, a);
|
|
return make_node(AST_BlockStatement, self, { body: a }).optimize(compressor);
|
|
}
|
|
if (self instanceof AST_Do) {
|
|
var has_loop_control = false;
|
|
var tw = new TreeWalker(function(node) {
|
|
if (node instanceof AST_Scope || has_loop_control) return true;
|
|
if (node instanceof AST_LoopControl && tw.loopcontrol_target(node) === self)
|
|
return has_loop_control = true;
|
|
});
|
|
var parent = compressor.parent();
|
|
(parent instanceof AST_LabeledStatement ? parent : self).walk(tw);
|
|
if (!has_loop_control) return self.body;
|
|
}
|
|
}
|
|
if (self instanceof AST_While) {
|
|
return make_node(AST_For, self, self).optimize(compressor);
|
|
}
|
|
return self;
|
|
});
|
|
|
|
function if_break_in_loop(self, compressor) {
|
|
function drop_it(rest) {
|
|
rest = as_statement_array(rest);
|
|
if (self.body instanceof AST_BlockStatement) {
|
|
self.body = self.body.clone();
|
|
self.body.body = rest.concat(self.body.body.slice(1));
|
|
self.body = self.body.transform(compressor);
|
|
} else {
|
|
self.body = make_node(AST_BlockStatement, self.body, {
|
|
body: rest
|
|
}).transform(compressor);
|
|
}
|
|
if_break_in_loop(self, compressor);
|
|
}
|
|
var first = self.body instanceof AST_BlockStatement ? self.body.body[0] : self.body;
|
|
if (first instanceof AST_If) {
|
|
if (first.body instanceof AST_Break
|
|
&& compressor.loopcontrol_target(first.body) === compressor.self()) {
|
|
if (self.condition) {
|
|
self.condition = make_node(AST_Binary, self.condition, {
|
|
left: self.condition,
|
|
operator: "&&",
|
|
right: first.condition.negate(compressor),
|
|
});
|
|
} else {
|
|
self.condition = first.condition.negate(compressor);
|
|
}
|
|
drop_it(first.alternative);
|
|
}
|
|
else if (first.alternative instanceof AST_Break
|
|
&& compressor.loopcontrol_target(first.alternative) === compressor.self()) {
|
|
if (self.condition) {
|
|
self.condition = make_node(AST_Binary, self.condition, {
|
|
left: self.condition,
|
|
operator: "&&",
|
|
right: first.condition,
|
|
});
|
|
} else {
|
|
self.condition = first.condition;
|
|
}
|
|
drop_it(first.body);
|
|
}
|
|
}
|
|
};
|
|
|
|
OPT(AST_For, function(self, compressor){
|
|
if (!compressor.option("loops")) return self;
|
|
if (self.condition) {
|
|
var cond = self.condition.evaluate(compressor);
|
|
if (compressor.option("dead_code") && !cond) {
|
|
var a = [];
|
|
if (self.init instanceof AST_Statement) {
|
|
a.push(self.init);
|
|
}
|
|
else if (self.init) {
|
|
a.push(make_node(AST_SimpleStatement, self.init, {
|
|
body: self.init
|
|
}));
|
|
}
|
|
extract_declarations_from_unreachable_code(compressor, self.body, a);
|
|
return make_node(AST_BlockStatement, self, { body: a }).optimize(compressor);
|
|
}
|
|
if (cond !== self.condition) {
|
|
cond = make_node_from_constant(cond, self.condition).transform(compressor);
|
|
self.condition = best_of_expression(cond, self.condition);
|
|
}
|
|
}
|
|
if_break_in_loop(self, compressor);
|
|
return self;
|
|
});
|
|
|
|
OPT(AST_If, function(self, compressor){
|
|
if (is_empty(self.alternative)) self.alternative = null;
|
|
|
|
if (!compressor.option("conditionals")) return self;
|
|
// if condition can be statically determined, warn and drop
|
|
// one of the blocks. note, statically determined implies
|
|
// “has no side effects”; also it doesn't work for cases like
|
|
// `x && true`, though it probably should.
|
|
var cond = self.condition.evaluate(compressor);
|
|
if (cond !== self.condition) {
|
|
if (cond) {
|
|
compressor.warn("Condition always true [{file}:{line},{col}]", self.condition.start);
|
|
if (compressor.option("dead_code")) {
|
|
var a = [];
|
|
if (self.alternative) {
|
|
extract_declarations_from_unreachable_code(compressor, self.alternative, a);
|
|
}
|
|
a.push(self.body);
|
|
return make_node(AST_BlockStatement, self, { body: a }).optimize(compressor);
|
|
}
|
|
} else {
|
|
compressor.warn("Condition always false [{file}:{line},{col}]", self.condition.start);
|
|
if (compressor.option("dead_code")) {
|
|
var a = [];
|
|
extract_declarations_from_unreachable_code(compressor, self.body, a);
|
|
if (self.alternative) a.push(self.alternative);
|
|
return make_node(AST_BlockStatement, self, { body: a }).optimize(compressor);
|
|
}
|
|
}
|
|
cond = make_node_from_constant(cond, self.condition).transform(compressor);
|
|
self.condition = best_of_expression(cond, self.condition);
|
|
}
|
|
var negated = self.condition.negate(compressor);
|
|
var self_condition_length = self.condition.print_to_string().length;
|
|
var negated_length = negated.print_to_string().length;
|
|
var negated_is_best = negated_length < self_condition_length;
|
|
if (self.alternative && negated_is_best) {
|
|
negated_is_best = false; // because we already do the switch here.
|
|
// no need to swap values of self_condition_length and negated_length
|
|
// here because they are only used in an equality comparison later on.
|
|
self.condition = negated;
|
|
var tmp = self.body;
|
|
self.body = self.alternative || make_node(AST_EmptyStatement, self);
|
|
self.alternative = tmp;
|
|
}
|
|
if (is_empty(self.body) && is_empty(self.alternative)) {
|
|
return make_node(AST_SimpleStatement, self.condition, {
|
|
body: self.condition.clone()
|
|
}).optimize(compressor);
|
|
}
|
|
if (self.body instanceof AST_SimpleStatement
|
|
&& self.alternative instanceof AST_SimpleStatement) {
|
|
return make_node(AST_SimpleStatement, self, {
|
|
body: make_node(AST_Conditional, self, {
|
|
condition : self.condition,
|
|
consequent : self.body.body,
|
|
alternative : self.alternative.body
|
|
})
|
|
}).optimize(compressor);
|
|
}
|
|
if (is_empty(self.alternative) && self.body instanceof AST_SimpleStatement) {
|
|
if (self_condition_length === negated_length && !negated_is_best
|
|
&& self.condition instanceof AST_Binary && self.condition.operator == "||") {
|
|
// although the code length of self.condition and negated are the same,
|
|
// negated does not require additional surrounding parentheses.
|
|
// see https://github.com/mishoo/UglifyJS2/issues/979
|
|
negated_is_best = true;
|
|
}
|
|
if (negated_is_best) return make_node(AST_SimpleStatement, self, {
|
|
body: make_node(AST_Binary, self, {
|
|
operator : "||",
|
|
left : negated,
|
|
right : self.body.body
|
|
})
|
|
}).optimize(compressor);
|
|
return make_node(AST_SimpleStatement, self, {
|
|
body: make_node(AST_Binary, self, {
|
|
operator : "&&",
|
|
left : self.condition,
|
|
right : self.body.body
|
|
})
|
|
}).optimize(compressor);
|
|
}
|
|
if (self.body instanceof AST_EmptyStatement
|
|
&& self.alternative instanceof AST_SimpleStatement) {
|
|
return make_node(AST_SimpleStatement, self, {
|
|
body: make_node(AST_Binary, self, {
|
|
operator : "||",
|
|
left : self.condition,
|
|
right : self.alternative.body
|
|
})
|
|
}).optimize(compressor);
|
|
}
|
|
if (self.body instanceof AST_Exit
|
|
&& self.alternative instanceof AST_Exit
|
|
&& self.body.TYPE == self.alternative.TYPE) {
|
|
return make_node(self.body.CTOR, self, {
|
|
value: make_node(AST_Conditional, self, {
|
|
condition : self.condition,
|
|
consequent : self.body.value || make_node(AST_Undefined, self.body),
|
|
alternative : self.alternative.value || make_node(AST_Undefined, self.alternative)
|
|
}).transform(compressor)
|
|
}).optimize(compressor);
|
|
}
|
|
if (self.body instanceof AST_If
|
|
&& !self.body.alternative
|
|
&& !self.alternative) {
|
|
self = make_node(AST_If, self, {
|
|
condition: make_node(AST_Binary, self.condition, {
|
|
operator: "&&",
|
|
left: self.condition,
|
|
right: self.body.condition
|
|
}),
|
|
body: self.body.body,
|
|
alternative: null
|
|
});
|
|
}
|
|
if (aborts(self.body)) {
|
|
if (self.alternative) {
|
|
var alt = self.alternative;
|
|
self.alternative = null;
|
|
return make_node(AST_BlockStatement, self, {
|
|
body: [ self, alt ]
|
|
}).optimize(compressor);
|
|
}
|
|
}
|
|
if (aborts(self.alternative)) {
|
|
var body = self.body;
|
|
self.body = self.alternative;
|
|
self.condition = negated_is_best ? negated : self.condition.negate(compressor);
|
|
self.alternative = null;
|
|
return make_node(AST_BlockStatement, self, {
|
|
body: [ self, body ]
|
|
}).optimize(compressor);
|
|
}
|
|
return self;
|
|
});
|
|
|
|
OPT(AST_Switch, function(self, compressor){
|
|
if (!compressor.option("switches")) return self;
|
|
var branch;
|
|
var value = self.expression.evaluate(compressor);
|
|
if (value !== self.expression) {
|
|
var expression = make_node_from_constant(value, self.expression).transform(compressor);
|
|
self.expression = best_of_expression(expression, self.expression);
|
|
}
|
|
if (!compressor.option("dead_code")) return self;
|
|
var decl = [];
|
|
var body = [];
|
|
var default_branch;
|
|
var exact_match;
|
|
for (var i = 0, len = self.body.length; i < len && !exact_match; i++) {
|
|
branch = self.body[i];
|
|
if (branch instanceof AST_Default) {
|
|
if (!default_branch) {
|
|
default_branch = branch;
|
|
} else {
|
|
eliminate_branch(branch, body[body.length - 1]);
|
|
}
|
|
} else if (value !== self.expression) {
|
|
var exp = branch.expression.evaluate(compressor);
|
|
if (exp === value) {
|
|
exact_match = branch;
|
|
if (default_branch) {
|
|
var default_index = body.indexOf(default_branch);
|
|
body.splice(default_index, 1);
|
|
eliminate_branch(default_branch, body[default_index - 1]);
|
|
default_branch = null;
|
|
}
|
|
} else if (exp !== branch.expression) {
|
|
eliminate_branch(branch, body[body.length - 1]);
|
|
continue;
|
|
}
|
|
}
|
|
if (aborts(branch)) {
|
|
var prev = body[body.length - 1];
|
|
if (aborts(prev) && prev.body.length == branch.body.length
|
|
&& make_node(AST_BlockStatement, prev, prev).equivalent_to(make_node(AST_BlockStatement, branch, branch))) {
|
|
prev.body = [];
|
|
}
|
|
}
|
|
body.push(branch);
|
|
}
|
|
while (i < len) eliminate_branch(self.body[i++], body[body.length - 1]);
|
|
if (body.length > 0) {
|
|
body[0].body = decl.concat(body[0].body);
|
|
}
|
|
self.body = body;
|
|
while (branch = body[body.length - 1]) {
|
|
var stat = branch.body[branch.body.length - 1];
|
|
if (stat instanceof AST_Break && compressor.loopcontrol_target(stat) === self)
|
|
branch.body.pop();
|
|
if (branch.body.length || branch instanceof AST_Case
|
|
&& (default_branch || branch.expression.has_side_effects(compressor))) break;
|
|
if (body.pop() === default_branch) default_branch = null;
|
|
}
|
|
if (body.length == 0) {
|
|
return make_node(AST_BlockStatement, self, {
|
|
body: decl.concat(make_node(AST_SimpleStatement, self.expression, {
|
|
body: self.expression
|
|
}))
|
|
}).optimize(compressor);
|
|
}
|
|
if (body.length == 1 && (body[0] === exact_match || body[0] === default_branch)) {
|
|
var has_break = false;
|
|
var tw = new TreeWalker(function(node) {
|
|
if (has_break
|
|
|| node instanceof AST_Lambda
|
|
|| node instanceof AST_SimpleStatement) return true;
|
|
if (node instanceof AST_Break && tw.loopcontrol_target(node) === self)
|
|
has_break = true;
|
|
});
|
|
self.walk(tw);
|
|
if (!has_break) {
|
|
body = body[0].body.slice();
|
|
body.unshift(make_node(AST_SimpleStatement, self.expression, {
|
|
body: self.expression
|
|
}));
|
|
return make_node(AST_BlockStatement, self, {
|
|
body: body
|
|
}).optimize(compressor);
|
|
}
|
|
}
|
|
return self;
|
|
|
|
function eliminate_branch(branch, prev) {
|
|
if (prev && !aborts(prev)) {
|
|
prev.body = prev.body.concat(branch.body);
|
|
} else {
|
|
extract_declarations_from_unreachable_code(compressor, branch, decl);
|
|
}
|
|
}
|
|
});
|
|
|
|
OPT(AST_Try, function(self, compressor){
|
|
self.body = tighten_body(self.body, compressor);
|
|
if (self.bcatch && self.bfinally && all(self.bfinally.body, is_empty)) self.bfinally = null;
|
|
if (all(self.body, is_empty)) {
|
|
var body = [];
|
|
if (self.bcatch) extract_declarations_from_unreachable_code(compressor, self.bcatch, body);
|
|
if (self.bfinally) body = body.concat(self.bfinally.body);
|
|
return make_node(AST_BlockStatement, self, {
|
|
body: body
|
|
}).optimize(compressor);
|
|
}
|
|
return self;
|
|
});
|
|
|
|
AST_Definitions.DEFMETHOD("remove_initializers", function(){
|
|
this.definitions.forEach(function(def){ def.value = null });
|
|
});
|
|
|
|
AST_Definitions.DEFMETHOD("to_assignments", function(compressor){
|
|
var reduce_vars = compressor.option("reduce_vars");
|
|
var assignments = this.definitions.reduce(function(a, def){
|
|
if (def.value) {
|
|
var name = make_node(AST_SymbolRef, def.name, def.name);
|
|
a.push(make_node(AST_Assign, def, {
|
|
operator : "=",
|
|
left : name,
|
|
right : def.value
|
|
}));
|
|
if (reduce_vars) name.definition().fixed = false;
|
|
}
|
|
return a;
|
|
}, []);
|
|
if (assignments.length == 0) return null;
|
|
return AST_Seq.from_array(assignments);
|
|
});
|
|
|
|
OPT(AST_Definitions, function(self, compressor){
|
|
if (self.definitions.length == 0)
|
|
return make_node(AST_EmptyStatement, self);
|
|
return self;
|
|
});
|
|
|
|
OPT(AST_Call, function(self, compressor){
|
|
var exp = self.expression;
|
|
if (compressor.option("reduce_vars")
|
|
&& exp instanceof AST_SymbolRef) {
|
|
var def = exp.definition();
|
|
var fixed = exp.fixed_value();
|
|
if (fixed instanceof AST_Defun) {
|
|
def.fixed = fixed = make_node(AST_Function, fixed, fixed).clone(true);
|
|
}
|
|
if (fixed instanceof AST_Function) {
|
|
exp = fixed;
|
|
if (compressor.option("unused")
|
|
&& def.references.length == 1
|
|
&& !(def.scope.uses_arguments
|
|
&& def.orig[0] instanceof AST_SymbolFunarg)
|
|
&& !def.scope.uses_eval
|
|
&& compressor.find_parent(AST_Scope) === def.scope) {
|
|
self.expression = exp;
|
|
}
|
|
}
|
|
}
|
|
if (compressor.option("unused")
|
|
&& exp instanceof AST_Function
|
|
&& !exp.uses_arguments
|
|
&& !exp.uses_eval) {
|
|
var pos = 0, last = 0;
|
|
for (var i = 0, len = self.args.length; i < len; i++) {
|
|
var trim = i >= exp.argnames.length;
|
|
if (trim || exp.argnames[i].__unused) {
|
|
var node = self.args[i].drop_side_effect_free(compressor);
|
|
if (node) {
|
|
self.args[pos++] = node;
|
|
} else if (!trim) {
|
|
self.args[pos++] = make_node(AST_Number, self.args[i], {
|
|
value: 0
|
|
});
|
|
continue;
|
|
}
|
|
} else {
|
|
self.args[pos++] = self.args[i];
|
|
}
|
|
last = pos;
|
|
}
|
|
self.args.length = last;
|
|
}
|
|
if (compressor.option("unsafe")) {
|
|
if (exp instanceof AST_SymbolRef && exp.undeclared()) {
|
|
switch (exp.name) {
|
|
case "Array":
|
|
if (self.args.length != 1) {
|
|
return make_node(AST_Array, self, {
|
|
elements: self.args
|
|
}).optimize(compressor);
|
|
}
|
|
break;
|
|
case "Object":
|
|
if (self.args.length == 0) {
|
|
return make_node(AST_Object, self, {
|
|
properties: []
|
|
});
|
|
}
|
|
break;
|
|
case "String":
|
|
if (self.args.length == 0) return make_node(AST_String, self, {
|
|
value: ""
|
|
});
|
|
if (self.args.length <= 1) return make_node(AST_Binary, self, {
|
|
left: self.args[0],
|
|
operator: "+",
|
|
right: make_node(AST_String, self, { value: "" })
|
|
}).optimize(compressor);
|
|
break;
|
|
case "Number":
|
|
if (self.args.length == 0) return make_node(AST_Number, self, {
|
|
value: 0
|
|
});
|
|
if (self.args.length == 1) return make_node(AST_UnaryPrefix, self, {
|
|
expression: self.args[0],
|
|
operator: "+"
|
|
}).optimize(compressor);
|
|
case "Boolean":
|
|
if (self.args.length == 0) return make_node(AST_False, self);
|
|
if (self.args.length == 1) return make_node(AST_UnaryPrefix, self, {
|
|
expression: make_node(AST_UnaryPrefix, self, {
|
|
expression: self.args[0],
|
|
operator: "!"
|
|
}),
|
|
operator: "!"
|
|
}).optimize(compressor);
|
|
break;
|
|
case "Function":
|
|
// new Function() => function(){}
|
|
if (self.args.length == 0) return make_node(AST_Function, self, {
|
|
argnames: [],
|
|
body: []
|
|
});
|
|
if (all(self.args, function(x){ return x instanceof AST_String })) {
|
|
// quite a corner-case, but we can handle it:
|
|
// https://github.com/mishoo/UglifyJS2/issues/203
|
|
// if the code argument is a constant, then we can minify it.
|
|
try {
|
|
var code = "(function(" + self.args.slice(0, -1).map(function(arg){
|
|
return arg.value;
|
|
}).join(",") + "){" + self.args[self.args.length - 1].value + "})()";
|
|
var ast = parse(code);
|
|
ast.figure_out_scope({ screw_ie8: compressor.option("screw_ie8") });
|
|
var comp = new Compressor(compressor.options);
|
|
ast = ast.transform(comp);
|
|
ast.figure_out_scope({ screw_ie8: compressor.option("screw_ie8") });
|
|
ast.mangle_names();
|
|
var fun;
|
|
try {
|
|
ast.walk(new TreeWalker(function(node){
|
|
if (node instanceof AST_Lambda) {
|
|
fun = node;
|
|
throw ast;
|
|
}
|
|
}));
|
|
} catch(ex) {
|
|
if (ex !== ast) throw ex;
|
|
};
|
|
if (!fun) return self;
|
|
var args = fun.argnames.map(function(arg, i){
|
|
return make_node(AST_String, self.args[i], {
|
|
value: arg.print_to_string()
|
|
});
|
|
});
|
|
var code = OutputStream();
|
|
AST_BlockStatement.prototype._codegen.call(fun, fun, code);
|
|
code = code.toString().replace(/^\{|\}$/g, "");
|
|
args.push(make_node(AST_String, self.args[self.args.length - 1], {
|
|
value: code
|
|
}));
|
|
self.args = args;
|
|
return self;
|
|
} catch(ex) {
|
|
if (ex instanceof JS_Parse_Error) {
|
|
compressor.warn("Error parsing code passed to new Function [{file}:{line},{col}]", self.args[self.args.length - 1].start);
|
|
compressor.warn(ex.toString());
|
|
} else {
|
|
console.log(ex);
|
|
throw ex;
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
else if (exp instanceof AST_Dot && exp.property == "toString" && self.args.length == 0) {
|
|
return make_node(AST_Binary, self, {
|
|
left: make_node(AST_String, self, { value: "" }),
|
|
operator: "+",
|
|
right: exp.expression
|
|
}).optimize(compressor);
|
|
}
|
|
else if (exp instanceof AST_Dot && exp.expression instanceof AST_Array && exp.property == "join") EXIT: {
|
|
var separator;
|
|
if (self.args.length > 0) {
|
|
separator = self.args[0].evaluate(compressor);
|
|
if (separator === self.args[0]) break EXIT; // not a constant
|
|
}
|
|
var elements = [];
|
|
var consts = [];
|
|
exp.expression.elements.forEach(function(el) {
|
|
var value = el.evaluate(compressor);
|
|
if (value !== el) {
|
|
consts.push(value);
|
|
} else {
|
|
if (consts.length > 0) {
|
|
elements.push(make_node(AST_String, self, {
|
|
value: consts.join(separator)
|
|
}));
|
|
consts.length = 0;
|
|
}
|
|
elements.push(el);
|
|
}
|
|
});
|
|
if (consts.length > 0) {
|
|
elements.push(make_node(AST_String, self, {
|
|
value: consts.join(separator)
|
|
}));
|
|
}
|
|
if (elements.length == 0) return make_node(AST_String, self, { value: "" });
|
|
if (elements.length == 1) {
|
|
if (elements[0].is_string(compressor)) {
|
|
return elements[0];
|
|
}
|
|
return make_node(AST_Binary, elements[0], {
|
|
operator : "+",
|
|
left : make_node(AST_String, self, { value: "" }),
|
|
right : elements[0]
|
|
});
|
|
}
|
|
if (separator == "") {
|
|
var first;
|
|
if (elements[0].is_string(compressor)
|
|
|| elements[1].is_string(compressor)) {
|
|
first = elements.shift();
|
|
} else {
|
|
first = make_node(AST_String, self, { value: "" });
|
|
}
|
|
return elements.reduce(function(prev, el){
|
|
return make_node(AST_Binary, el, {
|
|
operator : "+",
|
|
left : prev,
|
|
right : el
|
|
});
|
|
}, first).optimize(compressor);
|
|
}
|
|
// need this awkward cloning to not affect original element
|
|
// best_of will decide which one to get through.
|
|
var node = self.clone();
|
|
node.expression = node.expression.clone();
|
|
node.expression.expression = node.expression.expression.clone();
|
|
node.expression.expression.elements = elements;
|
|
return best_of(compressor, self, node);
|
|
}
|
|
else if (exp instanceof AST_Dot && exp.expression.is_string(compressor) && exp.property == "charAt") {
|
|
var arg = self.args[0];
|
|
var index = arg ? arg.evaluate(compressor) : 0;
|
|
if (index !== arg) {
|
|
return make_node(AST_Sub, exp, {
|
|
expression: exp.expression,
|
|
property: make_node_from_constant(index | 0, arg || exp)
|
|
}).optimize(compressor);
|
|
}
|
|
}
|
|
}
|
|
if (exp instanceof AST_Function) {
|
|
if (exp.body[0] instanceof AST_Return) {
|
|
var value = exp.body[0].value;
|
|
if (!value || value.is_constant()) {
|
|
var args = self.args.concat(value || make_node(AST_Undefined, self));
|
|
return AST_Seq.from_array(args).transform(compressor);
|
|
}
|
|
}
|
|
if (compressor.option("side_effects") && all(exp.body, is_empty)) {
|
|
var args = self.args.concat(make_node(AST_Undefined, self));
|
|
return AST_Seq.from_array(args).transform(compressor);
|
|
}
|
|
}
|
|
if (compressor.option("drop_console")) {
|
|
if (exp instanceof AST_PropAccess) {
|
|
var name = exp.expression;
|
|
while (name.expression) {
|
|
name = name.expression;
|
|
}
|
|
if (name instanceof AST_SymbolRef
|
|
&& name.name == "console"
|
|
&& name.undeclared()) {
|
|
return make_node(AST_Undefined, self).optimize(compressor);
|
|
}
|
|
}
|
|
}
|
|
if (compressor.option("negate_iife")
|
|
&& compressor.parent() instanceof AST_SimpleStatement
|
|
&& is_iife_call(self)) {
|
|
return self.negate(compressor, true);
|
|
}
|
|
return self;
|
|
});
|
|
|
|
OPT(AST_New, function(self, compressor){
|
|
if (compressor.option("unsafe")) {
|
|
var exp = self.expression;
|
|
if (exp instanceof AST_SymbolRef && exp.undeclared()) {
|
|
switch (exp.name) {
|
|
case "Object":
|
|
case "RegExp":
|
|
case "Function":
|
|
case "Error":
|
|
case "Array":
|
|
return make_node(AST_Call, self, self).transform(compressor);
|
|
}
|
|
}
|
|
}
|
|
return self;
|
|
});
|
|
|
|
OPT(AST_Seq, function(self, compressor){
|
|
if (!compressor.option("side_effects"))
|
|
return self;
|
|
self.car = self.car.drop_side_effect_free(compressor, first_in_statement(compressor));
|
|
if (!self.car) return maintain_this_binding(compressor.parent(), self, self.cdr);
|
|
if (compressor.option("cascade")) {
|
|
var left;
|
|
if (self.car instanceof AST_Assign
|
|
&& !self.car.left.has_side_effects(compressor)) {
|
|
left = self.car.left;
|
|
} else if (self.car instanceof AST_Unary
|
|
&& (self.car.operator == "++" || self.car.operator == "--")) {
|
|
left = self.car.expression;
|
|
}
|
|
if (left
|
|
&& !(left instanceof AST_SymbolRef
|
|
&& (left.definition().orig[0] instanceof AST_SymbolLambda
|
|
|| is_reference_const(left)))) {
|
|
var parent, field;
|
|
var cdr = self.cdr;
|
|
while (true) {
|
|
if (cdr.equivalent_to(left)) {
|
|
var car = self.car instanceof AST_UnaryPostfix ? make_node(AST_UnaryPrefix, self.car, {
|
|
operator: self.car.operator,
|
|
expression: left
|
|
}) : self.car;
|
|
if (parent) {
|
|
parent[field] = car;
|
|
return self.cdr;
|
|
}
|
|
return car;
|
|
}
|
|
if (cdr instanceof AST_Binary && !(cdr instanceof AST_Assign)) {
|
|
if (cdr.left.is_constant()) {
|
|
if (cdr.operator == "||" || cdr.operator == "&&") break;
|
|
field = "right";
|
|
} else {
|
|
field = "left";
|
|
}
|
|
} else if (cdr instanceof AST_Call
|
|
|| cdr instanceof AST_Unary && !unary_side_effects(cdr.operator)) {
|
|
field = "expression";
|
|
} else break;
|
|
parent = cdr;
|
|
cdr = cdr[field];
|
|
}
|
|
}
|
|
}
|
|
if (is_undefined(self.cdr, compressor)) {
|
|
return make_node(AST_UnaryPrefix, self, {
|
|
operator : "void",
|
|
expression : self.car
|
|
});
|
|
}
|
|
return self;
|
|
});
|
|
|
|
AST_Unary.DEFMETHOD("lift_sequences", function(compressor){
|
|
if (compressor.option("sequences")) {
|
|
if (this.expression instanceof AST_Seq) {
|
|
var seq = this.expression;
|
|
var x = seq.to_array();
|
|
var e = this.clone();
|
|
e.expression = x.pop();
|
|
x.push(e);
|
|
seq = AST_Seq.from_array(x).transform(compressor);
|
|
return seq;
|
|
}
|
|
}
|
|
return this;
|
|
});
|
|
|
|
OPT(AST_UnaryPostfix, function(self, compressor){
|
|
return self.lift_sequences(compressor);
|
|
});
|
|
|
|
OPT(AST_UnaryPrefix, function(self, compressor){
|
|
var e = self.expression;
|
|
if (self.operator == "delete"
|
|
&& !(e instanceof AST_SymbolRef
|
|
|| e instanceof AST_PropAccess
|
|
|| e instanceof AST_NaN
|
|
|| e instanceof AST_Infinity
|
|
|| e instanceof AST_Undefined)) {
|
|
if (e instanceof AST_Seq) {
|
|
e = e.to_array();
|
|
e.push(make_node(AST_True, self));
|
|
return AST_Seq.from_array(e).optimize(compressor);
|
|
}
|
|
return make_node(AST_Seq, self, {
|
|
car: e,
|
|
cdr: make_node(AST_True, self)
|
|
}).optimize(compressor);
|
|
}
|
|
var seq = self.lift_sequences(compressor);
|
|
if (seq !== self) {
|
|
return seq;
|
|
}
|
|
if (compressor.option("side_effects") && self.operator == "void") {
|
|
e = e.drop_side_effect_free(compressor);
|
|
if (e) {
|
|
self.expression = e;
|
|
return self;
|
|
} else {
|
|
return make_node(AST_Undefined, self).optimize(compressor);
|
|
}
|
|
}
|
|
if (compressor.option("booleans") && compressor.in_boolean_context()) {
|
|
switch (self.operator) {
|
|
case "!":
|
|
if (e instanceof AST_UnaryPrefix && e.operator == "!") {
|
|
// !!foo ==> foo, if we're in boolean context
|
|
return e.expression;
|
|
}
|
|
if (e instanceof AST_Binary) {
|
|
self = best_of(compressor, self, e.negate(compressor, first_in_statement(compressor)));
|
|
}
|
|
break;
|
|
case "typeof":
|
|
// typeof always returns a non-empty string, thus it's
|
|
// always true in booleans
|
|
compressor.warn("Boolean expression always true [{file}:{line},{col}]", self.start);
|
|
return (e instanceof AST_SymbolRef ? make_node(AST_True, self) : make_node(AST_Seq, self, {
|
|
car: e,
|
|
cdr: make_node(AST_True, self)
|
|
})).optimize(compressor);
|
|
}
|
|
}
|
|
if (self.operator == "-" && e instanceof AST_Infinity) {
|
|
e = e.transform(compressor);
|
|
}
|
|
if (e instanceof AST_Binary
|
|
&& (self.operator == "+" || self.operator == "-")
|
|
&& (e.operator == "*" || e.operator == "/" || e.operator == "%")) {
|
|
return make_node(AST_Binary, self, {
|
|
operator: e.operator,
|
|
left: make_node(AST_UnaryPrefix, e.left, {
|
|
operator: self.operator,
|
|
expression: e.left
|
|
}),
|
|
right: e.right
|
|
});
|
|
}
|
|
// avoids infinite recursion of numerals
|
|
if (self.operator != "-"
|
|
|| !(e instanceof AST_Number || e instanceof AST_Infinity)) {
|
|
var ev = self.evaluate(compressor);
|
|
if (ev !== self) {
|
|
ev = make_node_from_constant(ev, self).optimize(compressor);
|
|
return best_of(compressor, ev, self);
|
|
}
|
|
}
|
|
return self;
|
|
});
|
|
|
|
AST_Binary.DEFMETHOD("lift_sequences", function(compressor){
|
|
if (compressor.option("sequences")) {
|
|
if (this.left instanceof AST_Seq) {
|
|
var seq = this.left;
|
|
var x = seq.to_array();
|
|
var e = this.clone();
|
|
e.left = x.pop();
|
|
x.push(e);
|
|
return AST_Seq.from_array(x).optimize(compressor);
|
|
}
|
|
if (this.right instanceof AST_Seq && !this.left.has_side_effects(compressor)) {
|
|
var assign = this.operator == "=" && this.left instanceof AST_SymbolRef;
|
|
var root = this.right.clone();
|
|
var cursor, seq = root;
|
|
while (assign || !seq.car.has_side_effects(compressor)) {
|
|
cursor = seq;
|
|
if (seq.cdr instanceof AST_Seq) {
|
|
seq = seq.cdr = seq.cdr.clone();
|
|
} else break;
|
|
}
|
|
if (cursor) {
|
|
var e = this.clone();
|
|
e.right = cursor.cdr;
|
|
cursor.cdr = e;
|
|
return root.optimize(compressor);
|
|
}
|
|
}
|
|
}
|
|
return this;
|
|
});
|
|
|
|
var commutativeOperators = makePredicate("== === != !== * & | ^");
|
|
|
|
OPT(AST_Binary, function(self, compressor){
|
|
function reversible() {
|
|
return self.left.is_constant()
|
|
|| self.right.is_constant()
|
|
|| !self.left.has_side_effects(compressor)
|
|
&& !self.right.has_side_effects(compressor);
|
|
}
|
|
function reverse(op) {
|
|
if (reversible()) {
|
|
if (op) self.operator = op;
|
|
var tmp = self.left;
|
|
self.left = self.right;
|
|
self.right = tmp;
|
|
}
|
|
}
|
|
if (commutativeOperators(self.operator)) {
|
|
if (self.right.is_constant()
|
|
&& !self.left.is_constant()) {
|
|
// if right is a constant, whatever side effects the
|
|
// left side might have could not influence the
|
|
// result. hence, force switch.
|
|
|
|
if (!(self.left instanceof AST_Binary
|
|
&& PRECEDENCE[self.left.operator] >= PRECEDENCE[self.operator])) {
|
|
reverse();
|
|
}
|
|
}
|
|
}
|
|
self = self.lift_sequences(compressor);
|
|
if (compressor.option("comparisons")) switch (self.operator) {
|
|
case "===":
|
|
case "!==":
|
|
if ((self.left.is_string(compressor) && self.right.is_string(compressor)) ||
|
|
(self.left.is_number(compressor) && self.right.is_number(compressor)) ||
|
|
(self.left.is_boolean() && self.right.is_boolean())) {
|
|
self.operator = self.operator.substr(0, 2);
|
|
}
|
|
// XXX: intentionally falling down to the next case
|
|
case "==":
|
|
case "!=":
|
|
// "undefined" == typeof x => undefined === x
|
|
if (self.left instanceof AST_String
|
|
&& self.left.value == "undefined"
|
|
&& self.right instanceof AST_UnaryPrefix
|
|
&& self.right.operator == "typeof") {
|
|
var expr = self.right.expression;
|
|
if (expr instanceof AST_SymbolRef ? !expr.undeclared()
|
|
: !(expr instanceof AST_PropAccess) || compressor.option("screw_ie8")) {
|
|
self.right = expr;
|
|
self.left = make_node(AST_Undefined, self.left).optimize(compressor);
|
|
if (self.operator.length == 2) self.operator += "=";
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
if (compressor.option("booleans") && self.operator == "+" && compressor.in_boolean_context()) {
|
|
var ll = self.left.evaluate(compressor);
|
|
var rr = self.right.evaluate(compressor);
|
|
if (ll && typeof ll == "string") {
|
|
compressor.warn("+ in boolean context always true [{file}:{line},{col}]", self.start);
|
|
return make_node(AST_Seq, self, {
|
|
car: self.right,
|
|
cdr: make_node(AST_True, self)
|
|
}).optimize(compressor);
|
|
}
|
|
if (rr && typeof rr == "string") {
|
|
compressor.warn("+ in boolean context always true [{file}:{line},{col}]", self.start);
|
|
return make_node(AST_Seq, self, {
|
|
car: self.left,
|
|
cdr: make_node(AST_True, self)
|
|
}).optimize(compressor);
|
|
}
|
|
}
|
|
if (compressor.option("comparisons") && self.is_boolean()) {
|
|
if (!(compressor.parent() instanceof AST_Binary)
|
|
|| compressor.parent() instanceof AST_Assign) {
|
|
var negated = make_node(AST_UnaryPrefix, self, {
|
|
operator: "!",
|
|
expression: self.negate(compressor, first_in_statement(compressor))
|
|
});
|
|
self = best_of(compressor, self, negated);
|
|
}
|
|
if (compressor.option("unsafe_comps")) {
|
|
switch (self.operator) {
|
|
case "<": reverse(">"); break;
|
|
case "<=": reverse(">="); break;
|
|
}
|
|
}
|
|
}
|
|
if (self.operator == "+") {
|
|
if (self.right instanceof AST_String
|
|
&& self.right.getValue() == ""
|
|
&& self.left.is_string(compressor)) {
|
|
return self.left;
|
|
}
|
|
if (self.left instanceof AST_String
|
|
&& self.left.getValue() == ""
|
|
&& self.right.is_string(compressor)) {
|
|
return self.right;
|
|
}
|
|
if (self.left instanceof AST_Binary
|
|
&& self.left.operator == "+"
|
|
&& self.left.left instanceof AST_String
|
|
&& self.left.left.getValue() == ""
|
|
&& self.right.is_string(compressor)) {
|
|
self.left = self.left.right;
|
|
return self.transform(compressor);
|
|
}
|
|
}
|
|
if (compressor.option("evaluate")) {
|
|
switch (self.operator) {
|
|
case "&&":
|
|
var ll = self.left.evaluate(compressor);
|
|
if (!ll) {
|
|
compressor.warn("Condition left of && always false [{file}:{line},{col}]", self.start);
|
|
return maintain_this_binding(compressor.parent(), self, self.left).optimize(compressor);
|
|
} else if (ll !== self.left) {
|
|
compressor.warn("Condition left of && always true [{file}:{line},{col}]", self.start);
|
|
return maintain_this_binding(compressor.parent(), self, self.right).optimize(compressor);
|
|
}
|
|
if (compressor.option("booleans") && compressor.in_boolean_context()) {
|
|
var rr = self.right.evaluate(compressor);
|
|
if (!rr) {
|
|
compressor.warn("Boolean && always false [{file}:{line},{col}]", self.start);
|
|
return make_node(AST_Seq, self, {
|
|
car: self.left,
|
|
cdr: make_node(AST_False, self)
|
|
}).optimize(compressor);
|
|
} else if (rr !== self.right) {
|
|
compressor.warn("Dropping side-effect-free && in boolean context [{file}:{line},{col}]", self.start);
|
|
return self.left.optimize(compressor);
|
|
}
|
|
}
|
|
break;
|
|
case "||":
|
|
var ll = self.left.evaluate(compressor);
|
|
if (!ll) {
|
|
compressor.warn("Condition left of || always false [{file}:{line},{col}]", self.start);
|
|
return maintain_this_binding(compressor.parent(), self, self.right).optimize(compressor);
|
|
} else if (ll !== self.left) {
|
|
compressor.warn("Condition left of || always true [{file}:{line},{col}]", self.start);
|
|
return maintain_this_binding(compressor.parent(), self, self.left).optimize(compressor);
|
|
}
|
|
if (compressor.option("booleans") && compressor.in_boolean_context()) {
|
|
var rr = self.right.evaluate(compressor);
|
|
if (!rr) {
|
|
compressor.warn("Dropping side-effect-free || in boolean context [{file}:{line},{col}]", self.start);
|
|
return self.left.optimize(compressor);
|
|
} else if (rr !== self.right) {
|
|
compressor.warn("Boolean || always true [{file}:{line},{col}]", self.start);
|
|
return make_node(AST_Seq, self, {
|
|
car: self.left,
|
|
cdr: make_node(AST_True, self)
|
|
}).optimize(compressor);
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
var associative = true;
|
|
switch (self.operator) {
|
|
case "+":
|
|
// "foo" + ("bar" + x) => "foobar" + x
|
|
if (self.left instanceof AST_Constant
|
|
&& self.right instanceof AST_Binary
|
|
&& self.right.operator == "+"
|
|
&& self.right.left instanceof AST_Constant
|
|
&& self.right.is_string(compressor)) {
|
|
self = make_node(AST_Binary, self, {
|
|
operator: "+",
|
|
left: make_node(AST_String, self.left, {
|
|
value: "" + self.left.getValue() + self.right.left.getValue(),
|
|
start: self.left.start,
|
|
end: self.right.left.end
|
|
}),
|
|
right: self.right.right
|
|
});
|
|
}
|
|
// (x + "foo") + "bar" => x + "foobar"
|
|
if (self.right instanceof AST_Constant
|
|
&& self.left instanceof AST_Binary
|
|
&& self.left.operator == "+"
|
|
&& self.left.right instanceof AST_Constant
|
|
&& self.left.is_string(compressor)) {
|
|
self = make_node(AST_Binary, self, {
|
|
operator: "+",
|
|
left: self.left.left,
|
|
right: make_node(AST_String, self.right, {
|
|
value: "" + self.left.right.getValue() + self.right.getValue(),
|
|
start: self.left.right.start,
|
|
end: self.right.end
|
|
})
|
|
});
|
|
}
|
|
// (x + "foo") + ("bar" + y) => (x + "foobar") + y
|
|
if (self.left instanceof AST_Binary
|
|
&& self.left.operator == "+"
|
|
&& self.left.is_string(compressor)
|
|
&& self.left.right instanceof AST_Constant
|
|
&& self.right instanceof AST_Binary
|
|
&& self.right.operator == "+"
|
|
&& self.right.left instanceof AST_Constant
|
|
&& self.right.is_string(compressor)) {
|
|
self = make_node(AST_Binary, self, {
|
|
operator: "+",
|
|
left: make_node(AST_Binary, self.left, {
|
|
operator: "+",
|
|
left: self.left.left,
|
|
right: make_node(AST_String, self.left.right, {
|
|
value: "" + self.left.right.getValue() + self.right.left.getValue(),
|
|
start: self.left.right.start,
|
|
end: self.right.left.end
|
|
})
|
|
}),
|
|
right: self.right.right
|
|
});
|
|
}
|
|
// a + -b => a - b
|
|
if (self.right instanceof AST_UnaryPrefix
|
|
&& self.right.operator == "-"
|
|
&& self.left.is_number(compressor)) {
|
|
self = make_node(AST_Binary, self, {
|
|
operator: "-",
|
|
left: self.left,
|
|
right: self.right.expression
|
|
});
|
|
break;
|
|
}
|
|
// -a + b => b - a
|
|
if (self.left instanceof AST_UnaryPrefix
|
|
&& self.left.operator == "-"
|
|
&& reversible()
|
|
&& self.right.is_number(compressor)) {
|
|
self = make_node(AST_Binary, self, {
|
|
operator: "-",
|
|
left: self.right,
|
|
right: self.left.expression
|
|
});
|
|
break;
|
|
}
|
|
case "*":
|
|
associative = compressor.option("unsafe_math");
|
|
case "&":
|
|
case "|":
|
|
case "^":
|
|
// a + +b => +b + a
|
|
if (self.left.is_number(compressor)
|
|
&& self.right.is_number(compressor)
|
|
&& reversible()
|
|
&& !(self.left instanceof AST_Binary
|
|
&& self.left.operator != self.operator
|
|
&& PRECEDENCE[self.left.operator] >= PRECEDENCE[self.operator])) {
|
|
var reversed = make_node(AST_Binary, self, {
|
|
operator: self.operator,
|
|
left: self.right,
|
|
right: self.left
|
|
});
|
|
if (self.right instanceof AST_Constant
|
|
&& !(self.left instanceof AST_Constant)) {
|
|
self = best_of(compressor, reversed, self);
|
|
} else {
|
|
self = best_of(compressor, self, reversed);
|
|
}
|
|
}
|
|
if (associative && self.is_number(compressor)) {
|
|
// a + (b + c) => (a + b) + c
|
|
if (self.right instanceof AST_Binary
|
|
&& self.right.operator == self.operator) {
|
|
self = make_node(AST_Binary, self, {
|
|
operator: self.operator,
|
|
left: make_node(AST_Binary, self.left, {
|
|
operator: self.operator,
|
|
left: self.left,
|
|
right: self.right.left,
|
|
start: self.left.start,
|
|
end: self.right.left.end
|
|
}),
|
|
right: self.right.right
|
|
});
|
|
}
|
|
// (n + 2) + 3 => 5 + n
|
|
// (2 * n) * 3 => 6 + n
|
|
if (self.right instanceof AST_Constant
|
|
&& self.left instanceof AST_Binary
|
|
&& self.left.operator == self.operator) {
|
|
if (self.left.left instanceof AST_Constant) {
|
|
self = make_node(AST_Binary, self, {
|
|
operator: self.operator,
|
|
left: make_node(AST_Binary, self.left, {
|
|
operator: self.operator,
|
|
left: self.left.left,
|
|
right: self.right,
|
|
start: self.left.left.start,
|
|
end: self.right.end
|
|
}),
|
|
right: self.left.right
|
|
});
|
|
} else if (self.left.right instanceof AST_Constant) {
|
|
self = make_node(AST_Binary, self, {
|
|
operator: self.operator,
|
|
left: make_node(AST_Binary, self.left, {
|
|
operator: self.operator,
|
|
left: self.left.right,
|
|
right: self.right,
|
|
start: self.left.right.start,
|
|
end: self.right.end
|
|
}),
|
|
right: self.left.left
|
|
});
|
|
}
|
|
}
|
|
// (a | 1) | (2 | d) => (3 | a) | b
|
|
if (self.left instanceof AST_Binary
|
|
&& self.left.operator == self.operator
|
|
&& self.left.right instanceof AST_Constant
|
|
&& self.right instanceof AST_Binary
|
|
&& self.right.operator == self.operator
|
|
&& self.right.left instanceof AST_Constant) {
|
|
self = make_node(AST_Binary, self, {
|
|
operator: self.operator,
|
|
left: make_node(AST_Binary, self.left, {
|
|
operator: self.operator,
|
|
left: make_node(AST_Binary, self.left.left, {
|
|
operator: self.operator,
|
|
left: self.left.right,
|
|
right: self.right.left,
|
|
start: self.left.right.start,
|
|
end: self.right.left.end
|
|
}),
|
|
right: self.left.left
|
|
}),
|
|
right: self.right.right
|
|
});
|
|
}
|
|
}
|
|
}
|
|
}
|
|
// x && (y && z) ==> x && y && z
|
|
// x || (y || z) ==> x || y || z
|
|
// x + ("y" + z) ==> x + "y" + z
|
|
// "x" + (y + "z")==> "x" + y + "z"
|
|
if (self.right instanceof AST_Binary
|
|
&& self.right.operator == self.operator
|
|
&& (self.operator == "&&"
|
|
|| self.operator == "||"
|
|
|| (self.operator == "+"
|
|
&& (self.right.left.is_string(compressor)
|
|
|| (self.left.is_string(compressor)
|
|
&& self.right.right.is_string(compressor))))))
|
|
{
|
|
self.left = make_node(AST_Binary, self.left, {
|
|
operator : self.operator,
|
|
left : self.left,
|
|
right : self.right.left
|
|
});
|
|
self.right = self.right.right;
|
|
return self.transform(compressor);
|
|
}
|
|
var ev = self.evaluate(compressor);
|
|
if (ev !== self) {
|
|
ev = make_node_from_constant(ev, self).optimize(compressor);
|
|
return best_of(compressor, ev, self);
|
|
}
|
|
return self;
|
|
});
|
|
|
|
OPT(AST_SymbolRef, function(self, compressor){
|
|
var def = self.resolve_defines(compressor);
|
|
if (def) {
|
|
return def.optimize(compressor);
|
|
}
|
|
// testing against !self.scope.uses_with first is an optimization
|
|
if (compressor.option("screw_ie8")
|
|
&& self.undeclared()
|
|
&& (!self.scope.uses_with || !compressor.find_parent(AST_With))) {
|
|
switch (self.name) {
|
|
case "undefined":
|
|
return make_node(AST_Undefined, self).optimize(compressor);
|
|
case "NaN":
|
|
return make_node(AST_NaN, self).optimize(compressor);
|
|
case "Infinity":
|
|
return make_node(AST_Infinity, self).optimize(compressor);
|
|
}
|
|
}
|
|
if (compressor.option("evaluate")
|
|
&& compressor.option("reduce_vars")
|
|
&& is_lhs(self, compressor.parent()) !== self) {
|
|
var d = self.definition();
|
|
var fixed = self.fixed_value();
|
|
if (fixed) {
|
|
if (d.should_replace === undefined) {
|
|
var init = fixed.evaluate(compressor);
|
|
if (init !== fixed && (compressor.option("unsafe_regexp") || !(init instanceof RegExp))) {
|
|
init = make_node_from_constant(init, fixed);
|
|
var value = init.optimize(compressor).print_to_string().length;
|
|
var fn;
|
|
if (has_symbol_ref(fixed)) {
|
|
fn = function() {
|
|
var result = init.optimize(compressor);
|
|
return result === init ? result.clone(true) : result;
|
|
};
|
|
} else {
|
|
value = Math.min(value, fixed.print_to_string().length);
|
|
fn = function() {
|
|
var result = best_of_expression(init.optimize(compressor), fixed);
|
|
return result === init || result === fixed ? result.clone(true) : result;
|
|
};
|
|
}
|
|
var name = d.name.length;
|
|
var overhead = 0;
|
|
if (compressor.option("unused") && (!d.global || compressor.option("toplevel"))) {
|
|
overhead = (name + 2 + value) / d.references.length;
|
|
}
|
|
d.should_replace = value <= name + overhead ? fn : false;
|
|
} else {
|
|
d.should_replace = false;
|
|
}
|
|
}
|
|
if (d.should_replace) {
|
|
return d.should_replace();
|
|
}
|
|
}
|
|
}
|
|
return self;
|
|
|
|
function has_symbol_ref(value) {
|
|
var found;
|
|
value.walk(new TreeWalker(function(node) {
|
|
if (node instanceof AST_SymbolRef) found = true;
|
|
if (found) return true;
|
|
}));
|
|
return found;
|
|
}
|
|
});
|
|
|
|
function is_atomic(lhs, self) {
|
|
return lhs instanceof AST_SymbolRef || lhs.TYPE === self.TYPE;
|
|
}
|
|
|
|
OPT(AST_Undefined, function(self, compressor){
|
|
if (compressor.option("unsafe")) {
|
|
var undef = find_variable(compressor, "undefined");
|
|
if (undef) {
|
|
var ref = make_node(AST_SymbolRef, self, {
|
|
name : "undefined",
|
|
scope : undef.scope,
|
|
thedef : undef
|
|
});
|
|
ref.is_undefined = true;
|
|
return ref;
|
|
}
|
|
}
|
|
var lhs = is_lhs(compressor.self(), compressor.parent());
|
|
if (lhs && is_atomic(lhs, self)) return self;
|
|
return make_node(AST_UnaryPrefix, self, {
|
|
operator: "void",
|
|
expression: make_node(AST_Number, self, {
|
|
value: 0
|
|
})
|
|
});
|
|
});
|
|
|
|
OPT(AST_Infinity, function(self, compressor){
|
|
var lhs = is_lhs(compressor.self(), compressor.parent());
|
|
if (lhs && is_atomic(lhs, self)) return self;
|
|
if (compressor.option("keep_infinity")
|
|
&& !(lhs && !is_atomic(lhs, self))
|
|
&& !find_variable(compressor, "Infinity"))
|
|
return self;
|
|
return make_node(AST_Binary, self, {
|
|
operator: "/",
|
|
left: make_node(AST_Number, self, {
|
|
value: 1
|
|
}),
|
|
right: make_node(AST_Number, self, {
|
|
value: 0
|
|
})
|
|
});
|
|
});
|
|
|
|
OPT(AST_NaN, function(self, compressor){
|
|
var lhs = is_lhs(compressor.self(), compressor.parent());
|
|
if (lhs && !is_atomic(lhs, self)
|
|
|| find_variable(compressor, "NaN")) {
|
|
return make_node(AST_Binary, self, {
|
|
operator: "/",
|
|
left: make_node(AST_Number, self, {
|
|
value: 0
|
|
}),
|
|
right: make_node(AST_Number, self, {
|
|
value: 0
|
|
})
|
|
});
|
|
}
|
|
return self;
|
|
});
|
|
|
|
var ASSIGN_OPS = [ '+', '-', '/', '*', '%', '>>', '<<', '>>>', '|', '^', '&' ];
|
|
var ASSIGN_OPS_COMMUTATIVE = [ '*', '|', '^', '&' ];
|
|
OPT(AST_Assign, function(self, compressor){
|
|
self = self.lift_sequences(compressor);
|
|
if (self.operator == "=" && self.left instanceof AST_SymbolRef && self.right instanceof AST_Binary) {
|
|
// x = expr1 OP expr2
|
|
if (self.right.left instanceof AST_SymbolRef
|
|
&& self.right.left.name == self.left.name
|
|
&& member(self.right.operator, ASSIGN_OPS)) {
|
|
// x = x - 2 ---> x -= 2
|
|
self.operator = self.right.operator + "=";
|
|
self.right = self.right.right;
|
|
}
|
|
else if (self.right.right instanceof AST_SymbolRef
|
|
&& self.right.right.name == self.left.name
|
|
&& member(self.right.operator, ASSIGN_OPS_COMMUTATIVE)
|
|
&& !self.right.left.has_side_effects(compressor)) {
|
|
// x = 2 & x ---> x &= 2
|
|
self.operator = self.right.operator + "=";
|
|
self.right = self.right.left;
|
|
}
|
|
}
|
|
return self;
|
|
});
|
|
|
|
OPT(AST_Conditional, function(self, compressor){
|
|
if (!compressor.option("conditionals")) return self;
|
|
if (self.condition instanceof AST_Seq) {
|
|
var car = self.condition.car;
|
|
self.condition = self.condition.cdr;
|
|
return AST_Seq.cons(car, self);
|
|
}
|
|
var cond = self.condition.evaluate(compressor);
|
|
if (cond !== self.condition) {
|
|
if (cond) {
|
|
compressor.warn("Condition always true [{file}:{line},{col}]", self.start);
|
|
return maintain_this_binding(compressor.parent(), self, self.consequent);
|
|
} else {
|
|
compressor.warn("Condition always false [{file}:{line},{col}]", self.start);
|
|
return maintain_this_binding(compressor.parent(), self, self.alternative);
|
|
}
|
|
}
|
|
var negated = cond.negate(compressor, first_in_statement(compressor));
|
|
if (best_of(compressor, cond, negated) === negated) {
|
|
self = make_node(AST_Conditional, self, {
|
|
condition: negated,
|
|
consequent: self.alternative,
|
|
alternative: self.consequent
|
|
});
|
|
}
|
|
var condition = self.condition;
|
|
var consequent = self.consequent;
|
|
var alternative = self.alternative;
|
|
// x?x:y --> x||y
|
|
if (condition instanceof AST_SymbolRef
|
|
&& consequent instanceof AST_SymbolRef
|
|
&& condition.definition() === consequent.definition()) {
|
|
return make_node(AST_Binary, self, {
|
|
operator: "||",
|
|
left: condition,
|
|
right: alternative
|
|
});
|
|
}
|
|
// if (foo) exp = something; else exp = something_else;
|
|
// |
|
|
// v
|
|
// exp = foo ? something : something_else;
|
|
if (consequent instanceof AST_Assign
|
|
&& alternative instanceof AST_Assign
|
|
&& consequent.operator == alternative.operator
|
|
&& consequent.left.equivalent_to(alternative.left)
|
|
&& (!self.condition.has_side_effects(compressor)
|
|
|| consequent.operator == "="
|
|
&& !consequent.left.has_side_effects(compressor))) {
|
|
return make_node(AST_Assign, self, {
|
|
operator: consequent.operator,
|
|
left: consequent.left,
|
|
right: make_node(AST_Conditional, self, {
|
|
condition: self.condition,
|
|
consequent: consequent.right,
|
|
alternative: alternative.right
|
|
})
|
|
});
|
|
}
|
|
// x ? y(a) : y(b) --> y(x ? a : b)
|
|
if (consequent instanceof AST_Call
|
|
&& alternative.TYPE === consequent.TYPE
|
|
&& consequent.args.length == 1
|
|
&& alternative.args.length == 1
|
|
&& consequent.expression.equivalent_to(alternative.expression)
|
|
&& !consequent.expression.has_side_effects(compressor)) {
|
|
consequent.args[0] = make_node(AST_Conditional, self, {
|
|
condition: self.condition,
|
|
consequent: consequent.args[0],
|
|
alternative: alternative.args[0]
|
|
});
|
|
return consequent;
|
|
}
|
|
// x?y?z:a:a --> x&&y?z:a
|
|
if (consequent instanceof AST_Conditional
|
|
&& consequent.alternative.equivalent_to(alternative)) {
|
|
return make_node(AST_Conditional, self, {
|
|
condition: make_node(AST_Binary, self, {
|
|
left: self.condition,
|
|
operator: "&&",
|
|
right: consequent.condition
|
|
}),
|
|
consequent: consequent.consequent,
|
|
alternative: alternative
|
|
});
|
|
}
|
|
// x ? y : y --> x, y
|
|
if (consequent.equivalent_to(alternative)) {
|
|
return make_node(AST_Seq, self, {
|
|
car: self.condition,
|
|
cdr: consequent
|
|
}).optimize(compressor);
|
|
}
|
|
|
|
if (is_true(self.consequent)) {
|
|
if (is_false(self.alternative)) {
|
|
// c ? true : false ---> !!c
|
|
return booleanize(self.condition);
|
|
}
|
|
// c ? true : x ---> !!c || x
|
|
return make_node(AST_Binary, self, {
|
|
operator: "||",
|
|
left: booleanize(self.condition),
|
|
right: self.alternative
|
|
});
|
|
}
|
|
if (is_false(self.consequent)) {
|
|
if (is_true(self.alternative)) {
|
|
// c ? false : true ---> !c
|
|
return booleanize(self.condition.negate(compressor));
|
|
}
|
|
// c ? false : x ---> !c && x
|
|
return make_node(AST_Binary, self, {
|
|
operator: "&&",
|
|
left: booleanize(self.condition.negate(compressor)),
|
|
right: self.alternative
|
|
});
|
|
}
|
|
if (is_true(self.alternative)) {
|
|
// c ? x : true ---> !c || x
|
|
return make_node(AST_Binary, self, {
|
|
operator: "||",
|
|
left: booleanize(self.condition.negate(compressor)),
|
|
right: self.consequent
|
|
});
|
|
}
|
|
if (is_false(self.alternative)) {
|
|
// c ? x : false ---> !!c && x
|
|
return make_node(AST_Binary, self, {
|
|
operator: "&&",
|
|
left: booleanize(self.condition),
|
|
right: self.consequent
|
|
});
|
|
}
|
|
|
|
return self;
|
|
|
|
function booleanize(node) {
|
|
if (node.is_boolean()) return node;
|
|
// !!expression
|
|
return make_node(AST_UnaryPrefix, node, {
|
|
operator: "!",
|
|
expression: node.negate(compressor)
|
|
});
|
|
}
|
|
|
|
// AST_True or !0
|
|
function is_true(node) {
|
|
return node instanceof AST_True
|
|
|| (node instanceof AST_UnaryPrefix
|
|
&& node.operator == "!"
|
|
&& node.expression instanceof AST_Constant
|
|
&& !node.expression.value);
|
|
}
|
|
// AST_False or !1
|
|
function is_false(node) {
|
|
return node instanceof AST_False
|
|
|| (node instanceof AST_UnaryPrefix
|
|
&& node.operator == "!"
|
|
&& node.expression instanceof AST_Constant
|
|
&& !!node.expression.value);
|
|
}
|
|
});
|
|
|
|
OPT(AST_Boolean, function(self, compressor){
|
|
if (compressor.option("booleans")) {
|
|
var p = compressor.parent();
|
|
if (p instanceof AST_Binary && (p.operator == "=="
|
|
|| p.operator == "!=")) {
|
|
compressor.warn("Non-strict equality against boolean: {operator} {value} [{file}:{line},{col}]", {
|
|
operator : p.operator,
|
|
value : self.value,
|
|
file : p.start.file,
|
|
line : p.start.line,
|
|
col : p.start.col,
|
|
});
|
|
return make_node(AST_Number, self, {
|
|
value: +self.value
|
|
});
|
|
}
|
|
return make_node(AST_UnaryPrefix, self, {
|
|
operator: "!",
|
|
expression: make_node(AST_Number, self, {
|
|
value: 1 - self.value
|
|
})
|
|
});
|
|
}
|
|
return self;
|
|
});
|
|
|
|
OPT(AST_Sub, function(self, compressor){
|
|
var prop = self.property;
|
|
if (prop instanceof AST_String && compressor.option("properties")) {
|
|
prop = prop.getValue();
|
|
if (RESERVED_WORDS(prop) ? compressor.option("screw_ie8") : is_identifier_string(prop)) {
|
|
return make_node(AST_Dot, self, {
|
|
expression : self.expression,
|
|
property : prop
|
|
}).optimize(compressor);
|
|
}
|
|
var v = parseFloat(prop);
|
|
if (!isNaN(v) && v.toString() == prop) {
|
|
self.property = make_node(AST_Number, self.property, {
|
|
value: v
|
|
});
|
|
}
|
|
}
|
|
var ev = self.evaluate(compressor);
|
|
if (ev !== self) {
|
|
ev = make_node_from_constant(ev, self).optimize(compressor);
|
|
return best_of(compressor, ev, self);
|
|
}
|
|
return self;
|
|
});
|
|
|
|
OPT(AST_Dot, function(self, compressor){
|
|
var def = self.resolve_defines(compressor);
|
|
if (def) {
|
|
return def.optimize(compressor);
|
|
}
|
|
var prop = self.property;
|
|
if (RESERVED_WORDS(prop) && !compressor.option("screw_ie8")) {
|
|
return make_node(AST_Sub, self, {
|
|
expression : self.expression,
|
|
property : make_node(AST_String, self, {
|
|
value: prop
|
|
})
|
|
}).optimize(compressor);
|
|
}
|
|
if (compressor.option("unsafe_proto")
|
|
&& self.expression instanceof AST_Dot
|
|
&& self.expression.property == "prototype") {
|
|
var exp = self.expression.expression;
|
|
if (exp instanceof AST_SymbolRef && exp.undeclared()) switch (exp.name) {
|
|
case "Array":
|
|
self.expression = make_node(AST_Array, self.expression, {
|
|
elements: []
|
|
});
|
|
break;
|
|
case "Object":
|
|
self.expression = make_node(AST_Object, self.expression, {
|
|
properties: []
|
|
});
|
|
break;
|
|
case "String":
|
|
self.expression = make_node(AST_String, self.expression, {
|
|
value: ""
|
|
});
|
|
break;
|
|
}
|
|
}
|
|
var ev = self.evaluate(compressor);
|
|
if (ev !== self) {
|
|
ev = make_node_from_constant(ev, self).optimize(compressor);
|
|
return best_of(compressor, ev, self);
|
|
}
|
|
return self;
|
|
});
|
|
|
|
function literals_in_boolean_context(self, compressor) {
|
|
if (compressor.option("booleans") && compressor.in_boolean_context()) {
|
|
return best_of(compressor, self, make_node(AST_Seq, self, {
|
|
car: self,
|
|
cdr: make_node(AST_True, self)
|
|
}).optimize(compressor));
|
|
}
|
|
return self;
|
|
};
|
|
OPT(AST_Array, literals_in_boolean_context);
|
|
OPT(AST_Object, literals_in_boolean_context);
|
|
OPT(AST_RegExp, literals_in_boolean_context);
|
|
|
|
OPT(AST_Return, function(self, compressor){
|
|
if (self.value && is_undefined(self.value, compressor)) {
|
|
self.value = null;
|
|
}
|
|
return self;
|
|
});
|
|
|
|
OPT(AST_VarDef, function(self, compressor){
|
|
var defines = compressor.option("global_defs");
|
|
if (defines && HOP(defines, self.name.name)) {
|
|
compressor.warn('global_defs ' + self.name.name + ' redefined [{file}:{line},{col}]', self.start);
|
|
}
|
|
return self;
|
|
});
|
|
|
|
})();
|