diff options
Diffstat (limited to 'node_modules/uglify-es/lib/scope.js')
| -rw-r--r-- | node_modules/uglify-es/lib/scope.js | 712 |
1 files changed, 712 insertions, 0 deletions
diff --git a/node_modules/uglify-es/lib/scope.js b/node_modules/uglify-es/lib/scope.js new file mode 100644 index 00000000..7b2e4c02 --- /dev/null +++ b/node_modules/uglify-es/lib/scope.js @@ -0,0 +1,712 @@ +/*********************************************************************** + + 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 SymbolDef(scope, orig, init) { + this.name = orig.name; + this.orig = [ orig ]; + this.init = init; + this.eliminated = 0; + this.scope = scope; + this.references = []; + this.replaced = 0; + this.global = false; + this.export = false; + this.mangled_name = null; + this.undeclared = false; + this.id = SymbolDef.next_id++; +}; + +SymbolDef.next_id = 1; + +SymbolDef.prototype = { + unmangleable: function(options) { + if (!options) options = {}; + + return (this.global && !options.toplevel) + || this.export + || this.undeclared + || (!options.eval && (this.scope.uses_eval || this.scope.uses_with)) + || (options.keep_fnames + && (this.orig[0] instanceof AST_SymbolLambda + || this.orig[0] instanceof AST_SymbolDefun)) + || this.orig[0] instanceof AST_SymbolMethod + || (options.keep_classnames + && (this.orig[0] instanceof AST_SymbolClass + || this.orig[0] instanceof AST_SymbolDefClass)); + }, + mangle: function(options) { + var cache = options.cache && options.cache.props; + if (this.global && cache && cache.has(this.name)) { + this.mangled_name = cache.get(this.name); + } + else if (!this.mangled_name && !this.unmangleable(options)) { + var s = this.scope; + var sym = this.orig[0]; + if (options.ie8 && sym instanceof AST_SymbolLambda) + s = s.parent_scope; + var def; + if (def = this.redefined()) { + this.mangled_name = def.mangled_name || def.name; + } else + this.mangled_name = s.next_mangled(options, this); + if (this.global && cache) { + cache.set(this.name, this.mangled_name); + } + } + }, + redefined: function() { + return this.defun && this.defun.variables.get(this.name); + } +}; + +AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){ + options = defaults(options, { + cache: null, + ie8: false, + safari10: false, + }); + + // pass 1: setup scope chaining and handle definitions + var self = this; + var scope = self.parent_scope = null; + var labels = new Dictionary(); + var defun = null; + var in_destructuring = null; + var for_scopes = []; + var tw = new TreeWalker(function(node, descend){ + if (node.is_block_scope()) { + var save_scope = scope; + node.block_scope = scope = new AST_Scope(node); + scope.init_scope_vars(save_scope); + if (!(node instanceof AST_Scope)) { + scope.uses_with = save_scope.uses_with; + scope.uses_eval = save_scope.uses_eval; + scope.directives = save_scope.directives; + } + if (options.safari10) { + if (node instanceof AST_For || node instanceof AST_ForIn) { + for_scopes.push(scope); + } + } + descend(); + scope = save_scope; + return true; + } + if (node instanceof AST_Destructuring) { + in_destructuring = node; // These don't nest + descend(); + in_destructuring = null; + return true; + } + if (node instanceof AST_Scope) { + node.init_scope_vars(scope); + var save_scope = scope; + var save_defun = defun; + var save_labels = labels; + defun = scope = node; + labels = new Dictionary(); + descend(); + scope = save_scope; + defun = save_defun; + labels = save_labels; + return true; // don't descend again in TreeWalker + } + if (node instanceof AST_LabeledStatement) { + var l = node.label; + if (labels.has(l.name)) { + throw new Error(string_template("Label {name} defined twice", l)); + } + labels.set(l.name, l); + descend(); + labels.del(l.name); + return true; // no descend again + } + if (node instanceof AST_With) { + for (var s = scope; s; s = s.parent_scope) + s.uses_with = true; + return; + } + if (node instanceof AST_Symbol) { + node.scope = scope; + } + if (node instanceof AST_Label) { + node.thedef = node; + node.references = []; + } + if (node instanceof AST_SymbolLambda) { + defun.def_function(node, node.name == "arguments" ? undefined : defun); + } + else if (node instanceof AST_SymbolDefun) { + // Careful here, the scope where this should be defined is + // the parent scope. The reason is that we enter a new + // scope when we encounter the AST_Defun node (which is + // instanceof AST_Scope) but we get to the symbol a bit + // later. + mark_export((node.scope = defun.parent_scope.get_defun_scope()).def_function(node, defun), 1); + } + else if (node instanceof AST_SymbolClass) { + mark_export(defun.def_variable(node, defun), 1); + } + else if (node instanceof AST_SymbolImport) { + scope.def_variable(node); + } + else if (node instanceof AST_SymbolDefClass) { + // This deals with the name of the class being available + // inside the class. + mark_export((node.scope = defun.parent_scope).def_function(node, defun), 1); + } + else if (node instanceof AST_SymbolVar + || node instanceof AST_SymbolLet + || node instanceof AST_SymbolConst) { + var def; + if (node instanceof AST_SymbolBlockDeclaration) { + def = scope.def_variable(node, null); + } else { + def = defun.def_variable(node, node.TYPE == "SymbolVar" ? null : undefined); + } + if (!all(def.orig, function(sym) { + if (sym === node) return true; + if (node instanceof AST_SymbolBlockDeclaration) { + return sym instanceof AST_SymbolLambda; + } + return !(sym instanceof AST_SymbolLet || sym instanceof AST_SymbolConst); + })) { + js_error( + node.name + " redeclared", + node.start.file, + node.start.line, + node.start.col, + node.start.pos + ); + } + if (!(node instanceof AST_SymbolFunarg)) mark_export(def, 2); + def.destructuring = in_destructuring; + if (defun !== scope) { + node.mark_enclosed(options); + var def = scope.find_variable(node); + if (node.thedef !== def) { + node.thedef = def; + node.reference(options); + } + } + } + else if (node instanceof AST_SymbolCatch) { + scope.def_variable(node).defun = defun; + } + else if (node instanceof AST_LabelRef) { + var sym = labels.get(node.name); + if (!sym) throw new Error(string_template("Undefined label {name} [{line},{col}]", { + name: node.name, + line: node.start.line, + col: node.start.col + })); + node.thedef = sym; + } + if (!(scope instanceof AST_Toplevel) && (node instanceof AST_Export || node instanceof AST_Import)) { + js_error( + node.TYPE + " statement may only appear at top level", + node.start.file, + node.start.line, + node.start.col, + node.start.pos + ); + } + + function mark_export(def, level) { + if (in_destructuring) { + var i = 0; + do { + level++; + } while (tw.parent(i++) !== in_destructuring); + } + var node = tw.parent(level); + def.export = node instanceof AST_Export; + } + }); + self.walk(tw); + + // pass 2: find back references and eval + self.globals = new Dictionary(); + var tw = new TreeWalker(function(node, descend){ + if (node instanceof AST_LoopControl && node.label) { + node.label.thedef.references.push(node); + return true; + } + if (node instanceof AST_SymbolRef) { + var name = node.name; + if (name == "eval" && tw.parent() instanceof AST_Call) { + for (var s = node.scope; s && !s.uses_eval; s = s.parent_scope) { + s.uses_eval = true; + } + } + var sym; + if (tw.parent() instanceof AST_NameMapping && tw.parent(1).module_name + || !(sym = node.scope.find_variable(name))) { + sym = self.def_global(node); + } else if (sym.scope instanceof AST_Lambda && name == "arguments") { + sym.scope.uses_arguments = true; + } + node.thedef = sym; + node.reference(options); + if (node.scope.is_block_scope() + && !(sym.orig[0] instanceof AST_SymbolBlockDeclaration)) { + node.scope = node.scope.get_defun_scope(); + } + return true; + } + // ensure mangling works if catch reuses a scope variable + var def; + if (node instanceof AST_SymbolCatch && (def = node.definition().redefined())) { + var s = node.scope; + while (s) { + push_uniq(s.enclosed, def); + if (s === def.scope) break; + s = s.parent_scope; + } + } + }); + self.walk(tw); + + // pass 3: fix up any scoping issue with IE8 + if (options.ie8) { + self.walk(new TreeWalker(function(node, descend) { + if (node instanceof AST_SymbolCatch) { + var name = node.name; + var refs = node.thedef.references; + var scope = node.thedef.defun; + var def = scope.find_variable(name) || self.globals.get(name) || scope.def_variable(node); + refs.forEach(function(ref) { + ref.thedef = def; + ref.reference(options); + }); + node.thedef = def; + node.reference(options); + return true; + } + })); + } + + // pass 4: add symbol definitions to loop scopes + // Safari/Webkit bug workaround - loop init let variable shadowing argument. + // https://github.com/mishoo/UglifyJS2/issues/1753 + // https://bugs.webkit.org/show_bug.cgi?id=171041 + if (options.safari10) { + for (var i = 0; i < for_scopes.length; i++) { + var scope = for_scopes[i]; + scope.parent_scope.variables.each(function(def) { + push_uniq(scope.enclosed, def); + }); + } + } +}); + +AST_Toplevel.DEFMETHOD("def_global", function(node){ + var globals = this.globals, name = node.name; + if (globals.has(name)) { + return globals.get(name); + } else { + var g = new SymbolDef(this, node); + g.undeclared = true; + g.global = true; + globals.set(name, g); + return g; + } +}); + +AST_Scope.DEFMETHOD("init_scope_vars", function(parent_scope){ + this.variables = new Dictionary(); // map name to AST_SymbolVar (variables defined in this scope; includes functions) + this.functions = new Dictionary(); // map name to AST_SymbolDefun (functions defined in this scope) + this.uses_with = false; // will be set to true if this or some nested scope uses the `with` statement + this.uses_eval = false; // will be set to true if this or nested scope uses the global `eval` + this.parent_scope = parent_scope; // the parent scope + this.enclosed = []; // a list of variables from this or outer scope(s) that are referenced from this or inner scopes + this.cname = -1; // the current index for mangling functions/variables +}); + +AST_Node.DEFMETHOD("is_block_scope", return_false); +AST_Class.DEFMETHOD("is_block_scope", return_false); +AST_Lambda.DEFMETHOD("is_block_scope", return_false); +AST_Toplevel.DEFMETHOD("is_block_scope", return_false); +AST_SwitchBranch.DEFMETHOD("is_block_scope", return_false); +AST_Block.DEFMETHOD("is_block_scope", return_true); +AST_IterationStatement.DEFMETHOD("is_block_scope", return_true); + +AST_Lambda.DEFMETHOD("init_scope_vars", function(){ + AST_Scope.prototype.init_scope_vars.apply(this, arguments); + this.uses_arguments = false; + this.def_variable(new AST_SymbolFunarg({ + name: "arguments", + start: this.start, + end: this.end + })); +}); + +AST_Symbol.DEFMETHOD("mark_enclosed", function(options) { + var def = this.definition(); + var s = this.scope; + while (s) { + push_uniq(s.enclosed, def); + if (options.keep_fnames) { + s.functions.each(function(d) { + push_uniq(def.scope.enclosed, d); + }); + } + if (s === def.scope) break; + s = s.parent_scope; + } +}); + +AST_Symbol.DEFMETHOD("reference", function(options) { + this.definition().references.push(this); + this.mark_enclosed(options); +}); + +AST_Scope.DEFMETHOD("find_variable", function(name){ + if (name instanceof AST_Symbol) name = name.name; + return this.variables.get(name) + || (this.parent_scope && this.parent_scope.find_variable(name)); +}); + +AST_Scope.DEFMETHOD("def_function", function(symbol, init){ + var def = this.def_variable(symbol, init); + if (!def.init || def.init instanceof AST_Defun) def.init = init; + this.functions.set(symbol.name, def); + return def; +}); + +AST_Scope.DEFMETHOD("def_variable", function(symbol, init){ + var def = this.variables.get(symbol.name); + if (def) { + def.orig.push(symbol); + if (def.init && (def.scope !== symbol.scope || def.init instanceof AST_Function)) { + def.init = init; + } + } else { + def = new SymbolDef(this, symbol, init); + this.variables.set(symbol.name, def); + def.global = !this.parent_scope; + } + return symbol.thedef = def; +}); + +function next_mangled(scope, options) { + var ext = scope.enclosed; + out: while (true) { + var m = base54(++scope.cname); + if (!is_identifier(m)) continue; // skip over "do" + + // https://github.com/mishoo/UglifyJS2/issues/242 -- do not + // shadow a name reserved from mangling. + if (member(m, options.reserved)) continue; + + // we must ensure that the mangled name does not shadow a name + // from some parent scope that is referenced in this or in + // inner scopes. + for (var i = ext.length; --i >= 0;) { + var sym = ext[i]; + var name = sym.mangled_name || (sym.unmangleable(options) && sym.name); + if (m == name) continue out; + } + return m; + } +} + +AST_Scope.DEFMETHOD("next_mangled", function(options){ + return next_mangled(this, options); +}); + +AST_Toplevel.DEFMETHOD("next_mangled", function(options){ + var name; + do { + name = next_mangled(this, options); + } while (member(name, this.mangled_names)); + return name; +}); + +AST_Function.DEFMETHOD("next_mangled", function(options, def){ + // #179, #326 + // in Safari strict mode, something like (function x(x){...}) is a syntax error; + // a function expression's argument cannot shadow the function expression's name + + var tricky_def = def.orig[0] instanceof AST_SymbolFunarg && this.name && this.name.definition(); + + // the function's mangled_name is null when keep_fnames is true + var tricky_name = tricky_def ? tricky_def.mangled_name || tricky_def.name : null; + + while (true) { + var name = next_mangled(this, options); + if (!tricky_name || tricky_name != name) + return name; + } +}); + +AST_Symbol.DEFMETHOD("unmangleable", function(options){ + var def = this.definition(); + return !def || def.unmangleable(options); +}); + +// labels are always mangleable +AST_Label.DEFMETHOD("unmangleable", return_false); + +AST_Symbol.DEFMETHOD("unreferenced", function(){ + return this.definition().references.length == 0 + && !(this.scope.uses_eval || this.scope.uses_with); +}); + +AST_Symbol.DEFMETHOD("definition", function(){ + return this.thedef; +}); + +AST_Symbol.DEFMETHOD("global", function(){ + return this.definition().global; +}); + +AST_Toplevel.DEFMETHOD("_default_mangler_options", function(options) { + options = defaults(options, { + eval : false, + ie8 : false, + keep_classnames: false, + keep_fnames : false, + reserved : [], + toplevel : false, + }); + if (!Array.isArray(options.reserved)) options.reserved = []; + // Never mangle arguments + push_uniq(options.reserved, "arguments"); + return options; +}); + +AST_Toplevel.DEFMETHOD("mangle_names", function(options){ + options = this._default_mangler_options(options); + + // We only need to mangle declaration nodes. Special logic wired + // into the code generator will display the mangled name if it's + // present (and for AST_SymbolRef-s it'll use the mangled name of + // the AST_SymbolDeclaration that it points to). + var lname = -1; + var to_mangle = []; + + var mangled_names = this.mangled_names = []; + if (options.cache) { + this.globals.each(collect); + if (options.cache.props) { + options.cache.props.each(function(mangled_name) { + push_uniq(mangled_names, mangled_name); + }); + } + } + + var tw = new TreeWalker(function(node, descend){ + if (node instanceof AST_LabeledStatement) { + // lname is incremented when we get to the AST_Label + var save_nesting = lname; + descend(); + lname = save_nesting; + return true; // don't descend again in TreeWalker + } + if (node instanceof AST_Scope) { + node.variables.each(collect); + return; + } + if (node.is_block_scope()) { + node.block_scope.variables.each(collect); + return; + } + if (node instanceof AST_Label) { + var name; + do name = base54(++lname); while (!is_identifier(name)); + node.mangled_name = name; + return true; + } + if (!options.ie8 && node instanceof AST_SymbolCatch) { + to_mangle.push(node.definition()); + return; + } + }); + this.walk(tw); + to_mangle.forEach(function(def){ def.mangle(options) }); + + function collect(symbol) { + if (!member(symbol.name, options.reserved)) { + to_mangle.push(symbol); + } + } +}); + +AST_Toplevel.DEFMETHOD("find_colliding_names", function(options) { + var cache = options.cache && options.cache.props; + var avoid = Object.create(null); + options.reserved.forEach(to_avoid); + this.globals.each(add_def); + this.walk(new TreeWalker(function(node) { + if (node instanceof AST_Scope) node.variables.each(add_def); + if (node instanceof AST_SymbolCatch) add_def(node.definition()); + })); + return avoid; + + function to_avoid(name) { + avoid[name] = true; + } + + function add_def(def) { + var name = def.name; + if (def.global && cache && cache.has(name)) name = cache.get(name); + else if (!def.unmangleable(options)) return; + to_avoid(name); + } +}); + +AST_Toplevel.DEFMETHOD("expand_names", function(options) { + base54.reset(); + base54.sort(); + options = this._default_mangler_options(options); + var avoid = this.find_colliding_names(options); + var cname = 0; + this.globals.each(rename); + this.walk(new TreeWalker(function(node) { + if (node instanceof AST_Scope) node.variables.each(rename); + if (node instanceof AST_SymbolCatch) rename(node.definition()); + })); + + function next_name() { + var name; + do { + name = base54(cname++); + } while (avoid[name] || !is_identifier(name)); + return name; + } + + function rename(def) { + if (def.global && options.cache) return; + if (def.unmangleable(options)) return; + if (member(def.name, options.reserved)) return; + var d = def.redefined(); + def.name = d ? d.name : next_name(); + def.orig.forEach(function(sym) { + sym.name = def.name; + }); + def.references.forEach(function(sym) { + sym.name = def.name; + }); + } +}); + +AST_Node.DEFMETHOD("tail_node", return_this); +AST_Sequence.DEFMETHOD("tail_node", function() { + return this.expressions[this.expressions.length - 1]; +}); + +AST_Toplevel.DEFMETHOD("compute_char_frequency", function(options){ + options = this._default_mangler_options(options); + try { + AST_Node.prototype.print = function(stream, force_parens) { + this._print(stream, force_parens); + if (this instanceof AST_Symbol && !this.unmangleable(options)) { + base54.consider(this.name, -1); + } else if (options.properties) { + if (this instanceof AST_Dot) { + base54.consider(this.property, -1); + } else if (this instanceof AST_Sub) { + skip_string(this.property); + } + } + }; + base54.consider(this.print_to_string(), 1); + } finally { + AST_Node.prototype.print = AST_Node.prototype._print; + } + base54.sort(); + + function skip_string(node) { + if (node instanceof AST_String) { + base54.consider(node.value, -1); + } else if (node instanceof AST_Conditional) { + skip_string(node.consequent); + skip_string(node.alternative); + } else if (node instanceof AST_Sequence) { + skip_string(node.tail_node()); + } + } +}); + +var base54 = (function() { + var leading = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$_".split(""); + var digits = "0123456789".split(""); + var chars, frequency; + function reset() { + frequency = Object.create(null); + leading.forEach(function(ch) { + frequency[ch] = 0; + }); + digits.forEach(function(ch) { + frequency[ch] = 0; + }); + } + base54.consider = function(str, delta) { + for (var i = str.length; --i >= 0;) { + frequency[str[i]] += delta; + } + }; + function compare(a, b) { + return frequency[b] - frequency[a]; + } + base54.sort = function() { + chars = mergeSort(leading, compare).concat(mergeSort(digits, compare)); + }; + base54.reset = reset; + reset(); + function base54(num) { + var ret = "", base = 54; + num++; + do { + num--; + ret += chars[num % base]; + num = Math.floor(num / base); + base = 64; + } while (num > 0); + return ret; + }; + return base54; +})(); |