diff options
Diffstat (limited to 'node_modules/handlebars/node_modules/uglify-js/lib/compress.js')
| -rw-r--r-- | node_modules/handlebars/node_modules/uglify-js/lib/compress.js | 4101 |
1 files changed, 0 insertions, 4101 deletions
diff --git a/node_modules/handlebars/node_modules/uglify-js/lib/compress.js b/node_modules/handlebars/node_modules/uglify-js/lib/compress.js deleted file mode 100644 index d8a491ebc..000000000 --- a/node_modules/handlebars/node_modules/uglify-js/lib/compress.js +++ /dev/null @@ -1,4101 +0,0 @@ -/*********************************************************************** - - A JavaScript tokenizer / parser / beautifier / compressor. - https://github.com/mishoo/UglifyJS2 - - -------------------------------- (C) --------------------------------- - - Author: Mihai Bazon - <mihai.bazon@gmail.com> - http://mihai.bazon.net/blog - - Distributed under the BSD license: - - Copyright 2012 (c) Mihai Bazon <mihai.bazon@gmail.com> - - Redistribution and use in source and binary forms, with or without - modification, are permitted provided that the following conditions - are met: - - * Redistributions of source code must retain the above - copyright notice, this list of conditions and the following - disclaimer. - - * Redistributions in binary form must reproduce the above - copyright notice, this list of conditions and the following - disclaimer in the documentation and/or other materials - provided with the distribution. - - THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER “AS IS” AND ANY - EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR - PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE - LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, - OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, - PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR - PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY - THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR - TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF - THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - SUCH DAMAGE. - - ***********************************************************************/ - -"use strict"; - -function Compressor(options, false_by_default) { - if (!(this instanceof Compressor)) - return new Compressor(options, false_by_default); - TreeTransformer.call(this, this.before, this.after); - this.options = defaults(options, { - angular : false, - booleans : !false_by_default, - cascade : !false_by_default, - collapse_vars : !false_by_default, - comparisons : !false_by_default, - conditionals : !false_by_default, - dead_code : !false_by_default, - drop_console : false, - drop_debugger : !false_by_default, - evaluate : !false_by_default, - expression : false, - global_defs : {}, - hoist_funs : !false_by_default, - hoist_vars : false, - if_return : !false_by_default, - join_vars : !false_by_default, - keep_fargs : true, - keep_fnames : false, - keep_infinity : false, - loops : !false_by_default, - negate_iife : !false_by_default, - passes : 1, - properties : !false_by_default, - pure_getters : !false_by_default && "strict", - pure_funcs : null, - reduce_vars : !false_by_default, - screw_ie8 : true, - sequences : !false_by_default, - side_effects : !false_by_default, - switches : !false_by_default, - top_retain : null, - toplevel : !!(options && options["top_retain"]), - unsafe : false, - unsafe_comps : false, - unsafe_math : false, - unsafe_proto : false, - unsafe_regexp : false, - unused : !false_by_default, - warnings : true, - }, true); - var pure_funcs = this.options["pure_funcs"]; - if (typeof pure_funcs == "function") { - this.pure_funcs = pure_funcs; - } else { - this.pure_funcs = pure_funcs ? function(node) { - return pure_funcs.indexOf(node.expression.print_to_string()) < 0; - } : return_true; - } - var top_retain = this.options["top_retain"]; - if (top_retain instanceof RegExp) { - this.top_retain = function(def) { - return top_retain.test(def.name); - }; - } else if (typeof top_retain == "function") { - this.top_retain = top_retain; - } else if (top_retain) { - if (typeof top_retain == "string") { - top_retain = top_retain.split(/,/); - } - this.top_retain = function(def) { - return top_retain.indexOf(def.name) >= 0; - }; - } - var sequences = this.options["sequences"]; - this.sequences_limit = sequences == 1 ? 200 : sequences | 0; - this.warnings_produced = {}; -}; - -Compressor.prototype = new TreeTransformer; -merge(Compressor.prototype, { - option: function(key) { return this.options[key] }, - compress: function(node) { - if (this.option("expression")) { - node = node.process_expression(true); - } - var passes = +this.options.passes || 1; - for (var pass = 0; pass < passes && pass < 3; ++pass) { - if (pass > 0 || this.option("reduce_vars")) - node.reset_opt_flags(this, true); - node = node.transform(this); - } - if (this.option("expression")) { - node = node.process_expression(false); - } - return node; - }, - info: function() { - if (this.options.warnings == "verbose") { - AST_Node.warn.apply(AST_Node, arguments); - } - }, - warn: function(text, props) { - if (this.options.warnings) { - // only emit unique warnings - var message = string_template(text, props); - if (!(message in this.warnings_produced)) { - this.warnings_produced[message] = true; - AST_Node.warn.apply(AST_Node, arguments); - } - } - }, - clear_warnings: function() { - this.warnings_produced = {}; - }, - before: function(node, descend, in_list) { - if (node._squeezed) return node; - var was_scope = false; - if (node instanceof AST_Scope) { - node = node.hoist_declarations(this); - was_scope = true; - } - // Before https://github.com/mishoo/UglifyJS2/pull/1602 AST_Node.optimize() - // would call AST_Node.transform() if a different instance of AST_Node is - // produced after OPT(). - // This corrupts TreeWalker.stack, which cause AST look-ups to malfunction. - // Migrate and defer all children's AST_Node.transform() to below, which - // will now happen after this parent AST_Node has been properly substituted - // thus gives a consistent AST snapshot. - descend(node, this); - // Existing code relies on how AST_Node.optimize() worked, and omitting the - // following replacement call would result in degraded efficiency of both - // output and performance. - descend(node, this); - var opt = node.optimize(this); - if (was_scope && opt instanceof AST_Scope) { - opt.drop_unused(this); - descend(opt, this); - } - if (opt === node) opt._squeezed = true; - return opt; - } -}); - -(function(){ - - function OPT(node, optimizer) { - node.DEFMETHOD("optimize", function(compressor){ - var self = this; - if (self._optimized) return self; - if (compressor.has_directive("use asm")) return self; - var opt = optimizer(self, compressor); - opt._optimized = true; - return opt; - }); - }; - - OPT(AST_Node, function(self, compressor){ - return self; - }); - - AST_Node.DEFMETHOD("equivalent_to", function(node){ - return this.TYPE == node.TYPE && this.print_to_string() == node.print_to_string(); - }); - - AST_Node.DEFMETHOD("process_expression", function(insert, compressor) { - var self = this; - var tt = new TreeTransformer(function(node) { - if (insert && node instanceof AST_SimpleStatement) { - return make_node(AST_Return, node, { - value: node.body - }); - } - if (!insert && node instanceof AST_Return) { - if (compressor) { - var value = node.value && node.value.drop_side_effect_free(compressor, true); - return value ? make_node(AST_SimpleStatement, node, { - body: value - }) : make_node(AST_EmptyStatement, node); - } - return make_node(AST_SimpleStatement, node, { - body: node.value || make_node(AST_UnaryPrefix, node, { - operator: "void", - expression: make_node(AST_Number, node, { - value: 0 - }) - }) - }); - } - if (node instanceof AST_Lambda && node !== self) { - return node; - } - if (node instanceof AST_Block) { - var index = node.body.length - 1; - if (index >= 0) { - node.body[index] = node.body[index].transform(tt); - } - } - if (node instanceof AST_If) { - node.body = node.body.transform(tt); - if (node.alternative) { - node.alternative = node.alternative.transform(tt); - } - } - if (node instanceof AST_With) { - node.body = node.body.transform(tt); - } - return node; - }); - return self.transform(tt); - }); - - AST_Node.DEFMETHOD("reset_opt_flags", function(compressor, rescan){ - var reduce_vars = rescan && compressor.option("reduce_vars"); - var toplevel = compressor.option("toplevel"); - var safe_ids = Object.create(null); - var suppressor = new TreeWalker(function(node) { - if (node instanceof AST_Symbol) { - var d = node.definition(); - if (node instanceof AST_SymbolRef) d.references.push(node); - d.fixed = false; - } - }); - var tw = new TreeWalker(function(node, descend){ - node._squeezed = false; - node._optimized = false; - if (reduce_vars) { - if (node instanceof AST_Toplevel) node.globals.each(reset_def); - if (node instanceof AST_Scope) node.variables.each(reset_def); - if (node instanceof AST_SymbolRef) { - var d = node.definition(); - d.references.push(node); - if (d.fixed === undefined || !is_safe(d) - || is_modified(node, 0, node.fixed_value() instanceof AST_Lambda)) { - d.fixed = false; - } else { - var parent = tw.parent(); - if (parent instanceof AST_Assign && parent.operator == "=" && node === parent.right - || parent instanceof AST_Call && node !== parent.expression - || parent instanceof AST_Return && node === parent.value && node.scope !== d.scope - || parent instanceof AST_VarDef && node === parent.value) { - d.escaped = true; - } - } - } - if (node instanceof AST_SymbolCatch) { - node.definition().fixed = false; - } - if (node instanceof AST_VarDef) { - var d = node.name.definition(); - if (d.fixed == null) { - if (node.value) { - d.fixed = function() { - return node.value; - }; - mark(d, false); - descend(); - } else { - d.fixed = null; - } - mark(d, true); - return true; - } else if (node.value) { - d.fixed = false; - } - } - if (node instanceof AST_Defun) { - var d = node.name.definition(); - if (!toplevel && d.global || is_safe(d)) { - d.fixed = false; - } else { - d.fixed = node; - mark(d, true); - } - var save_ids = safe_ids; - safe_ids = Object.create(null); - descend(); - safe_ids = save_ids; - return true; - } - if (node instanceof AST_Function) { - push(); - var iife; - if (!node.name - && (iife = tw.parent()) instanceof AST_Call - && iife.expression === node) { - // Virtually turn IIFE parameters into variable definitions: - // (function(a,b) {...})(c,d) => (function() {var a=c,b=d; ...})() - // So existing transformation rules can work on them. - node.argnames.forEach(function(arg, i) { - var d = arg.definition(); - if (!node.uses_arguments && d.fixed === undefined) { - d.fixed = function() { - return iife.args[i] || make_node(AST_Undefined, iife); - }; - mark(d, true); - } else { - d.fixed = false; - } - }); - } - descend(); - pop(); - return true; - } - if (node instanceof AST_Accessor) { - var save_ids = safe_ids; - safe_ids = Object.create(null); - descend(); - safe_ids = save_ids; - return true; - } - if (node instanceof AST_Binary - && (node.operator == "&&" || node.operator == "||")) { - node.left.walk(tw); - push(); - node.right.walk(tw); - pop(); - return true; - } - if (node instanceof AST_Conditional) { - node.condition.walk(tw); - push(); - node.consequent.walk(tw); - pop(); - push(); - node.alternative.walk(tw); - pop(); - return true; - } - if (node instanceof AST_If || node instanceof AST_DWLoop) { - node.condition.walk(tw); - push(); - node.body.walk(tw); - pop(); - if (node.alternative) { - push(); - node.alternative.walk(tw); - pop(); - } - return true; - } - if (node instanceof AST_LabeledStatement) { - push(); - node.body.walk(tw); - pop(); - return true; - } - if (node instanceof AST_For) { - if (node.init) node.init.walk(tw); - push(); - if (node.condition) node.condition.walk(tw); - node.body.walk(tw); - if (node.step) node.step.walk(tw); - pop(); - return true; - } - if (node instanceof AST_ForIn) { - node.init.walk(suppressor); - node.object.walk(tw); - push(); - node.body.walk(tw); - pop(); - return true; - } - if (node instanceof AST_Try) { - push(); - walk_body(node, tw); - pop(); - if (node.bcatch) { - push(); - node.bcatch.walk(tw); - pop(); - } - if (node.bfinally) node.bfinally.walk(tw); - return true; - } - if (node instanceof AST_SwitchBranch) { - push(); - descend(); - pop(); - return true; - } - } - }); - this.walk(tw); - - function mark(def, safe) { - safe_ids[def.id] = safe; - } - - function is_safe(def) { - if (safe_ids[def.id]) { - if (def.fixed == null) { - var orig = def.orig[0]; - if (orig instanceof AST_SymbolFunarg || orig.name == "arguments") return false; - def.fixed = make_node(AST_Undefined, orig); - } - return true; - } - } - - function push() { - safe_ids = Object.create(safe_ids); - } - - function pop() { - safe_ids = Object.getPrototypeOf(safe_ids); - } - - function reset_def(def) { - def.escaped = false; - if (def.scope.uses_eval) { - def.fixed = false; - } else if (toplevel || !def.global || def.orig[0] instanceof AST_SymbolConst) { - def.fixed = undefined; - } else { - def.fixed = false; - } - def.references = []; - def.should_replace = undefined; - } - - function is_modified(node, level, func) { - var parent = tw.parent(level); - if (is_lhs(node, parent) - || !func && parent instanceof AST_Call && parent.expression === node) { - return true; - } else if (parent instanceof AST_PropAccess && parent.expression === node) { - return !func && is_modified(parent, level + 1); - } - } - }); - - AST_SymbolRef.DEFMETHOD("fixed_value", function() { - var fixed = this.definition().fixed; - if (!fixed || fixed instanceof AST_Node) return fixed; - return fixed(); - }); - - function is_reference_const(ref) { - if (!(ref instanceof AST_SymbolRef)) return false; - var orig = ref.definition().orig; - for (var i = orig.length; --i >= 0;) { - if (orig[i] instanceof AST_SymbolConst) return true; - } - } - - 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) { - scope = scope.argname.definition().scope; - break; - } - } - return scope.find_variable(name); - } - - function make_node(ctor, orig, props) { - if (!props) props = {}; - if (orig) { - if (!props.start) props.start = orig.start; - if (!props.end) props.end = orig.end; - } - return new ctor(props); - }; - - function make_node_from_constant(val, orig) { - switch (typeof val) { - case "string": - return make_node(AST_String, orig, { - value: val - }); - 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 }) - }) : make_node(AST_Number, orig, { value: val }); - } - return val < 0 ? make_node(AST_UnaryPrefix, orig, { - 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; - }); - -})(); |