X-Git-Url: http://git.asbjorn.biz/?p=jquery.git;a=blobdiff_plain;f=build%2Flib%2Fprocess.js;fp=build%2Flib%2Fprocess.js;h=edcf599dc88f7190310a087a44fe36d85a7c0d16;hp=0000000000000000000000000000000000000000;hb=d503845d0cf45632c0d7c3542ffd1b19257a8e5e;hpb=9c76ac4f6d295a5b593048e54b4c4231c092e58a diff --git a/build/lib/process.js b/build/lib/process.js new file mode 100644 index 0000000..edcf599 --- /dev/null +++ b/build/lib/process.js @@ -0,0 +1,1562 @@ +/*********************************************************************** + + A JavaScript tokenizer / parser / beautifier / compressor. + + This version is suitable for Node.js. With minimal changes (the + exports stuff) it should work on any JS platform. + + This file implements some AST processors. They work on data built + by parse-js. + + Exported functions: + + - ast_mangle(ast, include_toplevel) -- mangles the + variable/function names in the AST. Returns an AST. Pass true + as second argument to mangle toplevel names too. + + - ast_squeeze(ast) -- employs various optimizations to make the + final generated code even smaller. Returns an AST. + + - gen_code(ast, beautify) -- generates JS code from the AST. Pass + true (or an object, see the code for some options) as second + argument to get "pretty" (indented) code. + + -------------------------------- (C) --------------------------------- + + Author: Mihai Bazon + + http://mihai.bazon.net/blog + + Distributed under the BSD license: + + Copyright 2010 (c) Mihai Bazon + + 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. + + ***********************************************************************/ + +var jsp = require("./parse-js"), + slice = jsp.slice, + member = jsp.member, + PRECEDENCE = jsp.PRECEDENCE, + OPERATORS = jsp.OPERATORS; + +/* -----[ helper for AST traversal ]----- */ + +function ast_walker(ast) { + function _vardefs(defs) { + return MAP(defs, function(def){ + var a = [ def[0] ]; + if (def.length > 1) + a[1] = walk(def[1]); + return a; + }); + }; + var walkers = { + "string": function(str) { + return [ "string", str ]; + }, + "num": function(num) { + return [ "num", num ]; + }, + "name": function(name) { + return [ "name", name ]; + }, + "toplevel": function(statements) { + return [ "toplevel", MAP(statements, walk) ]; + }, + "block": function(statements) { + var out = [ "block" ]; + if (statements != null) + out.push(MAP(statements, walk)); + return out; + }, + "var": function(defs) { + return [ "var", _vardefs(defs) ]; + }, + "const": function(defs) { + return [ "const", _vardefs(defs) ]; + }, + "try": function(t, c, f) { + return [ + "try", + MAP(t, walk), + c != null ? [ c[0], MAP(c[1], walk) ] : null, + f != null ? MAP(f, walk) : null + ]; + }, + "throw": function(expr) { + return [ "throw", walk(expr) ]; + }, + "new": function(ctor, args) { + return [ "new", walk(ctor), MAP(args, walk) ]; + }, + "switch": function(expr, body) { + return [ "switch", walk(expr), MAP(body, function(branch){ + return [ branch[0] ? walk(branch[0]) : null, + MAP(branch[1], walk) ]; + }) ]; + }, + "break": function(label) { + return [ "break", label ]; + }, + "continue": function(label) { + return [ "continue", label ]; + }, + "conditional": function(cond, t, e) { + return [ "conditional", walk(cond), walk(t), walk(e) ]; + }, + "assign": function(op, lvalue, rvalue) { + return [ "assign", op, walk(lvalue), walk(rvalue) ]; + }, + "dot": function(expr) { + return [ "dot", walk(expr) ].concat(slice(arguments, 1)); + }, + "call": function(expr, args) { + return [ "call", walk(expr), MAP(args, walk) ]; + }, + "function": function(name, args, body) { + return [ "function", name, args.slice(), MAP(body, walk) ]; + }, + "defun": function(name, args, body) { + return [ "defun", name, args.slice(), MAP(body, walk) ]; + }, + "if": function(conditional, t, e) { + return [ "if", walk(conditional), walk(t), walk(e) ]; + }, + "for": function(init, cond, step, block) { + return [ "for", walk(init), walk(cond), walk(step), walk(block) ]; + }, + "for-in": function(has_var, key, hash, block) { + return [ "for-in", has_var, key, walk(hash), walk(block) ]; + }, + "while": function(cond, block) { + return [ "while", walk(cond), walk(block) ]; + }, + "do": function(cond, block) { + return [ "do", walk(cond), walk(block) ]; + }, + "return": function(expr) { + return [ "return", walk(expr) ]; + }, + "binary": function(op, left, right) { + return [ "binary", op, walk(left), walk(right) ]; + }, + "unary-prefix": function(op, expr) { + return [ "unary-prefix", op, walk(expr) ]; + }, + "unary-postfix": function(op, expr) { + return [ "unary-postfix", op, walk(expr) ]; + }, + "sub": function(expr, subscript) { + return [ "sub", walk(expr), walk(subscript) ]; + }, + "object": function(props) { + return [ "object", MAP(props, function(p){ + return p.length == 2 + ? [ p[0], walk(p[1]) ] + : [ p[0], walk(p[1]), p[2] ]; // get/set-ter + }) ]; + }, + "regexp": function(rx, mods) { + return [ "regexp", rx, mods ]; + }, + "array": function(elements) { + return [ "array", MAP(elements, walk) ]; + }, + "stat": function(stat) { + return [ "stat", walk(stat) ]; + }, + "seq": function() { + return [ "seq" ].concat(MAP(slice(arguments), walk)); + }, + "label": function(name, block) { + return [ "label", name, walk(block) ]; + }, + "with": function(expr, block) { + return [ "with", walk(expr), walk(block) ]; + }, + "atom": function(name) { + return [ "atom", name ]; + } + }; + + var user = {}; + var stack = []; + function walk(ast) { + if (ast == null) + return null; + try { + stack.push(ast); + var type = ast[0]; + var gen = user[type]; + if (gen) { + var ret = gen.apply(ast, ast.slice(1)); + if (ret != null) + return ret; + } + gen = walkers[type]; + return gen.apply(ast, ast.slice(1)); + } finally { + stack.pop(); + } + }; + + function with_walkers(walkers, cont){ + var save = {}, i; + for (i in walkers) if (HOP(walkers, i)) { + save[i] = user[i]; + user[i] = walkers[i]; + } + var ret = cont(); + for (i in save) if (HOP(save, i)) { + if (!save[i]) delete user[i]; + else user[i] = save[i]; + } + return ret; + }; + + return { + walk: walk, + with_walkers: with_walkers, + parent: function() { + return stack[stack.length - 2]; // last one is current node + }, + stack: function() { + return stack; + } + }; +}; + +/* -----[ Scope and mangling ]----- */ + +function Scope(parent) { + this.names = {}; // names defined in this scope + this.mangled = {}; // mangled names (orig.name => mangled) + this.rev_mangled = {}; // reverse lookup (mangled => orig.name) + this.cname = -1; // current mangled name + this.refs = {}; // names referenced from this scope + this.uses_with = false; // will become TRUE if eval() is detected in this or any subscopes + this.uses_eval = false; // will become TRUE if with() is detected in this or any subscopes + this.parent = parent; // parent scope + this.children = []; // sub-scopes + if (parent) { + this.level = parent.level + 1; + parent.children.push(this); + } else { + this.level = 0; + } +}; + +var base54 = (function(){ + var DIGITS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$_"; + return function(num) { + var ret = ""; + do { + ret = DIGITS.charAt(num % 54) + ret; + num = Math.floor(num / 54); + } while (num > 0); + return ret; + }; +})(); + +Scope.prototype = { + has: function(name) { + for (var s = this; s; s = s.parent) + if (HOP(s.names, name)) + return s; + }, + has_mangled: function(mname) { + for (var s = this; s; s = s.parent) + if (HOP(s.rev_mangled, mname)) + return s; + }, + toJSON: function() { + return { + names: this.names, + uses_eval: this.uses_eval, + uses_with: this.uses_with + }; + }, + + next_mangled: function() { + // we must be careful that the new mangled name: + // + // 1. doesn't shadow a mangled name from a parent + // scope, unless we don't reference the original + // name from this scope OR from any sub-scopes! + // This will get slow. + // + // 2. doesn't shadow an original name from a parent + // scope, in the event that the name is not mangled + // in the parent scope and we reference that name + // here OR IN ANY SUBSCOPES! + // + // 3. doesn't shadow a name that is referenced but not + // defined (possibly global defined elsewhere). + for (;;) { + var m = base54(++this.cname), prior; + + // case 1. + prior = this.has_mangled(m); + if (prior && this.refs[prior.rev_mangled[m]] === prior) + continue; + + // case 2. + prior = this.has(m); + if (prior && prior !== this && this.refs[m] === prior && !prior.has_mangled(m)) + continue; + + // case 3. + if (HOP(this.refs, m) && this.refs[m] == null) + continue; + + // I got "do" once. :-/ + if (!is_identifier(m)) + continue; + + return m; + } + }, + get_mangled: function(name, newMangle) { + if (this.uses_eval || this.uses_with) return name; // no mangle if eval or with is in use + var s = this.has(name); + if (!s) return name; // not in visible scope, no mangle + if (HOP(s.mangled, name)) return s.mangled[name]; // already mangled in this scope + if (!newMangle) return name; // not found and no mangling requested + + var m = s.next_mangled(); + s.rev_mangled[m] = name; + return s.mangled[name] = m; + }, + define: function(name) { + if (name != null) + return this.names[name] = name; + } +}; + +function ast_add_scope(ast) { + + var current_scope = null; + var w = ast_walker(), walk = w.walk; + var having_eval = []; + + function with_new_scope(cont) { + current_scope = new Scope(current_scope); + var ret = current_scope.body = cont(); + ret.scope = current_scope; + current_scope = current_scope.parent; + return ret; + }; + + function define(name) { + return current_scope.define(name); + }; + + function reference(name) { + current_scope.refs[name] = true; + }; + + function _lambda(name, args, body) { + return [ this[0], define(name), args, with_new_scope(function(){ + MAP(args, define); + return MAP(body, walk); + })]; + }; + + return with_new_scope(function(){ + // process AST + var ret = w.with_walkers({ + "function": _lambda, + "defun": _lambda, + "with": function(expr, block) { + for (var s = current_scope; s; s = s.parent) + s.uses_with = true; + }, + "var": function(defs) { + MAP(defs, function(d){ define(d[0]) }); + }, + "const": function(defs) { + MAP(defs, function(d){ define(d[0]) }); + }, + "try": function(t, c, f) { + if (c != null) return [ + "try", + MAP(t, walk), + [ define(c[0]), MAP(c[1], walk) ], + f != null ? MAP(f, walk) : null + ]; + }, + "name": function(name) { + if (name == "eval") + having_eval.push(current_scope); + reference(name); + }, + "for-in": function(has_var, name) { + if (has_var) define(name); + else reference(name); + } + }, function(){ + return walk(ast); + }); + + // the reason why we need an additional pass here is + // that names can be used prior to their definition. + + // scopes where eval was detected and their parents + // are marked with uses_eval, unless they define the + // "eval" name. + MAP(having_eval, function(scope){ + if (!scope.has("eval")) while (scope) { + scope.uses_eval = true; + scope = scope.parent; + } + }); + + // for referenced names it might be useful to know + // their origin scope. current_scope here is the + // toplevel one. + function fixrefs(scope, i) { + // do children first; order shouldn't matter + for (i = scope.children.length; --i >= 0;) + fixrefs(scope.children[i]); + for (i in scope.refs) if (HOP(scope.refs, i)) { + // find origin scope and propagate the reference to origin + for (var origin = scope.has(i), s = scope; s; s = s.parent) { + s.refs[i] = origin; + if (s === origin) break; + } + } + }; + fixrefs(current_scope); + + return ret; + }); + +}; + +/* -----[ mangle names ]----- */ + +function ast_mangle(ast, do_toplevel) { + var w = ast_walker(), walk = w.walk, scope; + + function get_mangled(name, newMangle) { + if (!do_toplevel && !scope.parent) return name; // don't mangle toplevel + return scope.get_mangled(name, newMangle); + }; + + function _lambda(name, args, body) { + if (name) name = get_mangled(name); + body = with_scope(body.scope, function(){ + args = MAP(args, function(name){ return get_mangled(name) }); + return MAP(body, walk); + }); + return [ this[0], name, args, body ]; + }; + + function with_scope(s, cont) { + var _scope = scope; + scope = s; + for (var i in s.names) if (HOP(s.names, i)) { + get_mangled(i, true); + } + var ret = cont(); + ret.scope = s; + scope = _scope; + return ret; + }; + + function _vardefs(defs) { + return MAP(defs, function(d){ + return [ get_mangled(d[0]), walk(d[1]) ]; + }); + }; + + return w.with_walkers({ + "function": _lambda, + "defun": function() { + // move function declarations to the top when + // they are not in some block. + var ast = _lambda.apply(this, arguments); + switch (w.parent()[0]) { + case "toplevel": + case "function": + case "defun": + return MAP.at_top(ast); + } + return ast; + }, + "var": function(defs) { + return [ "var", _vardefs(defs) ]; + }, + "const": function(defs) { + return [ "const", _vardefs(defs) ]; + }, + "name": function(name) { + return [ "name", get_mangled(name) ]; + }, + "try": function(t, c, f) { + return [ "try", + MAP(t, walk), + c != null ? [ get_mangled(c[0]), MAP(c[1], walk) ] : null, + f != null ? MAP(f, walk) : null ]; + }, + "toplevel": function(body) { + return with_scope(this.scope, function(){ + return [ "toplevel", MAP(body, walk) ]; + }); + }, + "for-in": function(has_var, name, obj, stat) { + return [ "for-in", has_var, get_mangled(name), walk(obj), walk(stat) ]; + } + }, function() { + return walk(ast_add_scope(ast)); + }); +}; + +/* -----[ + - compress foo["bar"] into foo.bar, + - remove block brackets {} where possible + - join consecutive var declarations + - various optimizations for IFs: + - if (cond) foo(); else bar(); ==> cond?foo():bar(); + - if (cond) foo(); ==> cond&&foo(); + - if (foo) return bar(); else return baz(); ==> return foo?bar():baz(); // also for throw + - if (foo) return bar(); else something(); ==> {if(foo)return bar();something()} + ]----- */ + +var warn = function(){}; + +function best_of(ast1, ast2) { + return gen_code(ast1).length > gen_code(ast2[0] == "stat" ? ast2[1] : ast2).length ? ast2 : ast1; +}; + +function last_stat(b) { + if (b[0] == "block" && b[1] && b[1].length > 0) + return b[1][b[1].length - 1]; + return b; +} + +function aborts(t) { + if (t) { + t = last_stat(t); + if (t[0] == "return" || t[0] == "break" || t[0] == "continue" || t[0] == "throw") + return true; + } +}; + +function negate(c) { + var not_c = [ "unary-prefix", "!", c ]; + switch (c[0]) { + case "unary-prefix": + return c[1] == "!" ? c[2] : not_c; + case "binary": + var op = c[1], left = c[2], right = c[3]; + switch (op) { + case "<=": return [ "binary", ">", left, right ]; + case "<": return [ "binary", ">=", left, right ]; + case ">=": return [ "binary", "<", left, right ]; + case ">": return [ "binary", "<=", left, right ]; + case "==": return [ "binary", "!=", left, right ]; + case "!=": return [ "binary", "==", left, right ]; + case "===": return [ "binary", "!==", left, right ]; + case "!==": return [ "binary", "===", left, right ]; + case "&&": return best_of(not_c, [ "binary", "||", negate(left), negate(right) ]); + case "||": return best_of(not_c, [ "binary", "&&", negate(left), negate(right) ]); + } + break; + } + return not_c; +}; + +function make_conditional(c, t, e) { + if (c[0] == "unary-prefix" && c[1] == "!") { + return e ? [ "conditional", c[2], e, t ] : [ "binary", "||", c[2], t ]; + } else { + return e ? [ "conditional", c, t, e ] : [ "binary", "&&", c, t ]; + } +}; + +function empty(b) { + return !b || (b[0] == "block" && (!b[1] || b[1].length == 0)); +}; + +function ast_squeeze(ast, options) { + options = defaults(options, { + make_seqs : true, + dead_code : true, + no_warnings : false, + extra : false + }); + + var w = ast_walker(), walk = w.walk, scope; + + function with_scope(s, cont) { + var _scope = scope; + scope = s; + var ret = cont(); + ret.scope = s; + scope = _scope; + return ret; + }; + + function is_constant(node) { + return node[0] == "string" || node[0] == "num"; + }; + + function find_first_execute(node) { + if (!node) + return false; + + switch (node[0]) { + case "num": + case "string": + case "name": + return node; + case "call": + case "conditional": + case "for": + case "if": + case "new": + case "return": + case "stat": + case "switch": + case "throw": + return find_first_execute(node[1]); + case "binary": + return find_first_execute(node[2]); + case "assign": + if (node[1] === true) + return find_first_execute(node[3]); + break; + case "var": + if (node[1][0].length > 1) + return find_first_execute(node[1][0][1]); + break; + } + return null; + } + + function find_assign_recursive(p, v) { + if (p[0] == "assign" && p[1] != true || p[0] == "unary-prefix") { + if (p[2][0] == "name" && v[0] == "name" && p[2][1] == v[1]) + return true; + return false; + } + + if (p[0] != "assign" || p[1] !== true) + return false; + + if ((is_constant(p[3]) && p[3][0] == v[0] && p[3][1] == v[1]) || + (p[3][0] == "name" && v[0] == "name" && p[3][1] == v[1]) || + (p[2][0] == "name" && v[0] == "name" && p[2][1] == v[1])) + return true; + + return find_assign_recursive(p[3], v); + }; + + function rmblock(block) { + if (block != null && block[0] == "block" && block[1] && block[1].length == 1) + block = block[1][0]; + return block; + }; + + function clone(obj) { + if (obj && obj.constructor == Array) + return MAP(obj, clone); + return obj; + }; + + function make_seq_to_statements(node) { + if (node[0] != "seq") { + switch (node[0]) { + case "var": + case "const": + return [ node ]; + default: + return [ [ "stat", node ] ]; + } + } + + var ret = []; + for (var i = 1; i < node.length; i++) + ret.push.apply(ret, make_seq_to_statements(node[i])); + + return ret; + }; + + function _lambda(name, args, body) { + return [ this[0], name, args, with_scope(body.scope, function(){ + return tighten(MAP(body, walk), "lambda"); + }) ]; + }; + + // we get here for blocks that have been already transformed. + // this function does a few things: + // 1. discard useless blocks + // 2. join consecutive var declarations + // 3. remove obviously dead code + // 4. transform consecutive statements using the comma operator + // 5. if block_type == "lambda" and it detects constructs like if(foo) return ... - rewrite like if (!foo) { ... } + function tighten(statements, block_type) { + statements = statements.reduce(function(a, stat){ + if (stat[0] == "block") { + if (stat[1]) { + a.push.apply(a, stat[1]); + } + } else { + a.push(stat); + } + return a; + }, []); + + if (options.extra) { + // Detightening things. We do this because then we can assume that the + // statements are structured in a specific way. + statements = (function(a, prev) { + statements.forEach(function(cur) { + switch (cur[0]) { + case "for": + if (cur[1] != null) { + a.push.apply(a, make_seq_to_statements(cur[1])); + cur[1] = null; + } + a.push(cur); + break; + case "stat": + var stats = make_seq_to_statements(cur[1]); + stats.forEach(function(s) { + if (s[1][0] == "unary-postfix") + s[1][0] = "unary-prefix"; + }); + a.push.apply(a, stats); + break; + default: + a.push(cur); + } + }); + return a; + })([]); + + statements = (function(a, prev) { + statements.forEach(function(cur) { + if (!(prev && prev[0] == "stat")) { + a.push(cur); + prev = cur; + return; + } + + var p = prev[1]; + var c = find_first_execute(cur); + if (c && find_assign_recursive(p, c)) { + var old_cur = clone(cur); + c.splice(0, c.length); + c.push.apply(c, p); + var tmp_cur = best_of(cur, [ "toplevel", [ prev, old_cur ] ]); + if (tmp_cur == cur) { + a[a.length -1] = cur; + } else { + cur = old_cur; + a.push(cur); + } + } else { + a.push(cur); + } + prev = cur; + }); + return a; + })([]); + } + + statements = (function(a, prev){ + statements.forEach(function(cur){ + if (prev && ((cur[0] == "var" && prev[0] == "var") || + (cur[0] == "const" && prev[0] == "const"))) { + prev[1] = prev[1].concat(cur[1]); + } else { + a.push(cur); + prev = cur; + } + }); + return a; + })([]); + + if (options.dead_code) statements = (function(a, has_quit){ + statements.forEach(function(st){ + if (has_quit) { + if (member(st[0], [ "function", "defun" , "var", "const" ])) { + a.push(st); + } + else if (!options.no_warnings) + warn("Removing unreachable code: " + gen_code(st, true)); + } + else { + a.push(st); + if (member(st[0], [ "return", "throw", "break", "continue" ])) + has_quit = true; + } + }); + return a; + })([]); + + if (options.make_seqs) statements = (function(a, prev) { + statements.forEach(function(cur){ + if (prev && prev[0] == "stat" && cur[0] == "stat") { + prev[1] = [ "seq", prev[1], cur[1] ]; + } else { + a.push(cur); + prev = cur; + } + }); + return a; + })([]); + + if (options.extra) { + statements = (function(a, prev){ + statements.forEach(function(cur){ + var replaced = false; + if (prev && cur[0] == "for" && cur[1] == null && (prev[0] == "var" || prev[0] == "const" || prev[0] == "stat")) { + cur[1] = prev; + a[a.length - 1] = cur; + } else { + a.push(cur); + } + prev = cur; + }); + return a; + })([]); + } + + if (block_type == "lambda") statements = (function(i, a, stat){ + while (i < statements.length) { + stat = statements[i++]; + if (stat[0] == "if" && !stat[3]) { + if (stat[2][0] == "return" && stat[2][1] == null) { + a.push(make_if(negate(stat[1]), [ "block", statements.slice(i) ])); + break; + } + var last = last_stat(stat[2]); + if (last[0] == "return" && last[1] == null) { + a.push(make_if(stat[1], [ "block", stat[2][1].slice(0, -1) ], [ "block", statements.slice(i) ])); + break; + } + } + a.push(stat); + } + return a; + })(0, []); + + return statements; + }; + + function make_if(c, t, e) { + c = walk(c); + t = walk(t); + e = walk(e); + + if (empty(t)) { + c = negate(c); + t = e; + e = null; + } else if (empty(e)) { + e = null; + } else { + // if we have both else and then, maybe it makes sense to switch them? + (function(){ + var a = gen_code(c); + var n = negate(c); + var b = gen_code(n); + if (b.length < a.length) { + var tmp = t; + t = e; + e = tmp; + c = n; + } + })(); + } + if (empty(e) && empty(t)) + return [ "stat", c ]; + var ret = [ "if", c, t, e ]; + if (t[0] == "stat") { + if (e) { + if (e[0] == "stat") { + ret = best_of(ret, [ "stat", make_conditional(c, t[1], e[1]) ]); + } + } + else { + ret = best_of(ret, [ "stat", make_conditional(c, t[1]) ]); + } + } + else if (e && t[0] == e[0] && (t[0] == "return" || t[0] == "throw")) { + ret = best_of(ret, [ t[0], make_conditional(c, t[1], e[1] ) ]); + } + else if (e && aborts(t)) { + ret = [ [ "if", c, t ] ]; + if (e[0] == "block") { + if (e[1]) ret = ret.concat(e[1]); + } + else { + ret.push(e); + } + ret = walk([ "block", ret ]); + } + else if (t && aborts(e)) { + ret = [ [ "if", negate(c), e ] ]; + if (t[0] == "block") { + if (t[1]) ret = ret.concat(t[1]); + } else { + ret.push(t); + } + ret = walk([ "block", ret ]); + } + return ret; + }; + + return w.with_walkers({ + "sub": function(expr, subscript) { + if (subscript[0] == "string") { + var name = subscript[1]; + if (is_identifier(name)) { + return [ "dot", walk(expr), name ]; + } + } + }, + "if": make_if, + "toplevel": function(body) { + return [ "toplevel", with_scope(this.scope, function(){ + return tighten(MAP(body, walk)); + }) ]; + }, + "switch": function(expr, body) { + var last = body.length - 1; + return [ "switch", walk(expr), MAP(body, function(branch, i){ + var block = tighten(MAP(branch[1], walk)); + if (i == last && block.length > 0) { + var node = block[block.length - 1]; + if (node[0] == "break" && !node[1]) + block.pop(); + } + return [ branch[0] ? walk(branch[0]) : null, block ]; + }) ]; + }, + "function": _lambda, + "defun": _lambda, + "block": function(body) { + if (body) return rmblock([ "block", tighten(MAP(body, walk)) ]); + }, + "binary": function(op, left, right) { + left = walk(left); + right = walk(right); + var best = [ "binary", op, left, right ]; + if (is_constant(right)) { + if (is_constant(left)) { + var val = null; + switch (op) { + case "+": val = left[1] + right[1]; break; + case "*": val = left[1] * right[1]; break; + case "/": val = left[1] / right[1]; break; + case "-": val = left[1] - right[1]; break; + case "<<": val = left[1] << right[1]; break; + case ">>": val = left[1] >> right[1]; break; + case ">>>": val = left[1] >>> right[1]; break; + } + if (val != null) { + best = best_of(best, [ typeof val == "string" ? "string" : "num", val ]); + } + } else if (left[0] == "binary" && left[1] == "+" && left[3][0] == "string") { + best = best_of(best, [ "binary", "+", left[2], [ "string", left[3][1] + right[1] ] ]); + } + } + return best; + }, + "conditional": function(c, t, e) { + return make_conditional(walk(c), walk(t), walk(e)); + }, + "try": function(t, c, f) { + return [ + "try", + tighten(MAP(t, walk)), + c != null ? [ c[0], tighten(MAP(c[1], walk)) ] : null, + f != null ? tighten(MAP(f, walk)) : null + ]; + }, + "unary-prefix": function(op, cond) { + if (op == "!") { + cond = walk(cond); + if (cond[0] == "unary-prefix" && cond[1] == "!") { + var p = w.parent(); + if (p[0] == "unary-prefix" && p[1] == "!") + return cond[2]; + return [ "unary-prefix", "!", cond ]; + } + return best_of(this, negate(cond)); + } + }, + "name": function(name) { + switch (name) { + case "true": return [ "unary-prefix", "!", [ "num", 0 ]]; + case "false": return [ "unary-prefix", "!", [ "num", 1 ]]; + } + }, + "new": function(ctor, args) { + if (ctor[0] == "name" && ctor[1] == "Array" && !scope.has("Array")) { + if (args.length != 1) { + return [ "array", args ]; + } else { + return [ "call", [ "name", "Array" ], args ]; + } + } + }, + "call": function(expr, args) { + if (expr[0] == "name" && expr[1] == "Array" && args.length != 1 && !scope.has("Array")) { + return [ "array", args ]; + } + } + }, function() { + return walk(ast_add_scope(ast)); + }); +}; + +/* -----[ re-generate code from the AST ]----- */ + +var DOT_CALL_NO_PARENS = jsp.array_to_hash([ + "name", + "array", + "string", + "dot", + "sub", + "call", + "regexp" +]); + +function make_string(str) { + var dq = 0, sq = 0; + str = str.replace(/[\\\b\f\n\r\t\x22\x27]/g, function(s){ + switch (s) { + case "\\": return "\\\\"; + case "\b": return "\\b"; + case "\f": return "\\f"; + case "\n": return "\\n"; + case "\r": return "\\r"; + case "\t": return "\\t"; + case '"': ++dq; return '"'; + case "'": ++sq; return "'"; + } + return s; + }); + if (dq > sq) { + return "'" + str.replace(/\x27/g, "\\'") + "'"; + } else { + return '"' + str.replace(/\x22/g, '\\"') + '"'; + } +}; + +function gen_code(ast, beautify) { + if (beautify) beautify = defaults(beautify, { + indent_start : 0, + indent_level : 4, + quote_keys : false, + space_colon : false + }); + var indentation = 0, + newline = beautify ? "\n" : "", + space = beautify ? " " : ""; + + function indent(line) { + if (line == null) + line = ""; + if (beautify) + line = repeat_string(" ", beautify.indent_start + indentation * beautify.indent_level) + line; + return line; + }; + + function with_indent(cont, incr) { + if (incr == null) incr = 1; + indentation += incr; + try { return cont.apply(null, slice(arguments, 1)); } + finally { indentation -= incr; } + }; + + function add_spaces(a) { + if (beautify) + return a.join(" "); + var b = []; + for (var i = 0; i < a.length; ++i) { + var next = a[i + 1]; + b.push(a[i]); + if (next && + ((/[a-z0-9_\x24]$/i.test(a[i].toString()) && /^[a-z0-9_\x24]/i.test(next.toString())) || + (/[\+\-]$/.test(a[i].toString()) && /^[\+\-]/.test(next.toString())))) { + b.push(" "); + } + } + return b.join(""); + }; + + function add_commas(a) { + return a.join("," + space); + }; + + function parenthesize(expr) { + var gen = make(expr); + for (var i = 1; i < arguments.length; ++i) { + var el = arguments[i]; + if ((el instanceof Function && el(expr)) || expr[0] == el) + return "(" + gen + ")"; + } + return gen; + }; + + function best_of(a) { + if (a.length == 1) { + return a[0]; + } + if (a.length == 2) { + var b = a[1]; + a = a[0]; + return a.length <= b.length ? a : b; + } + return best_of([ a[0], best_of(a.slice(1)) ]); + }; + + function needs_parens(expr) { + if (expr[0] == "function") { + // dot/call on a literal function requires the + // function literal itself to be parenthesized + // only if it's the first "thing" in a + // statement. This means that the parent is + // "stat", but it could also be a "seq" and + // we're the first in this "seq" and the + // parent is "stat", and so on. Messy stuff, + // but it worths the trouble. + var a = slice($stack), self = a.pop(), p = a.pop(); + while (p) { + if (p[0] == "stat") return true; + if ((p[0] == "seq" && p[1] === self) || + (p[0] == "call" && p[1] === self) || + (p[0] == "binary" && p[2] === self)) { + self = p; + p = a.pop(); + } else { + return false; + } + } + } + return !HOP(DOT_CALL_NO_PARENS, expr[0]); + }; + + function make_num(num) { + var str = num.toString(10), a = [ str.replace(/^0\./, ".") ], m; + if (Math.floor(num) === num) { + a.push("0x" + num.toString(16).toLowerCase(), // probably pointless + "0" + num.toString(8)); // same. + if ((m = /^(.*?)(0+)$/.exec(num))) { + a.push(m[1] + "e" + m[2].length); + } + } else if ((m = /^0?\.(0+)(.*)$/.exec(num))) { + a.push(m[2] + "e-" + (m[1].length + m[2].length), + str.substr(str.indexOf("."))); + } + return best_of(a); + }; + + var generators = { + "string": make_string, + "num": make_num, + "name": make_name, + "toplevel": function(statements) { + return make_block_statements(statements) + .join(newline + newline); + }, + "block": make_block, + "var": function(defs) { + return "var " + add_commas(MAP(defs, make_1vardef)) + ";"; + }, + "const": function(defs) { + return "const " + add_commas(MAP(defs, make_1vardef)) + ";"; + }, + "try": function(tr, ca, fi) { + var out = [ "try", make_block(tr) ]; + if (ca) out.push("catch", "(" + ca[0] + ")", make_block(ca[1])); + if (fi) out.push("finally", make_block(fi)); + return add_spaces(out); + }, + "throw": function(expr) { + return add_spaces([ "throw", make(expr) ]) + ";"; + }, + "new": function(ctor, args) { + args = args.length > 0 ? "(" + add_commas(MAP(args, make)) + ")" : ""; + return add_spaces([ "new", parenthesize(ctor, "seq", "binary", "conditional", "assign", function(expr){ + var w = ast_walker(), has_call = {}; + try { + w.with_walkers({ + "call": function() { throw has_call }, + "function": function() { return this } + }, function(){ + w.walk(expr); + }); + } catch(ex) { + if (ex === has_call) + return true; + throw ex; + } + }) + args ]); + }, + "switch": function(expr, body) { + return add_spaces([ "switch", "(" + make(expr) + ")", make_switch_block(body) ]); + }, + "break": function(label) { + var out = "break"; + if (label != null) + out += " " + make_name(label); + return out + ";"; + }, + "continue": function(label) { + var out = "continue"; + if (label != null) + out += " " + make_name(label); + return out + ";"; + }, + "conditional": function(co, th, el) { + return add_spaces([ parenthesize(co, "assign", "seq", "conditional"), "?", + parenthesize(th, "seq"), ":", + parenthesize(el, "seq") ]); + }, + "assign": function(op, lvalue, rvalue) { + if (op && op !== true) op += "="; + else op = "="; + return add_spaces([ make(lvalue), op, parenthesize(rvalue, "seq") ]); + }, + "dot": function(expr) { + var out = make(expr), i = 1; + if (expr[0] == "num") + out += "."; + else if (needs_parens(expr)) + out = "(" + out + ")"; + while (i < arguments.length) + out += "." + make_name(arguments[i++]); + return out; + }, + "call": function(func, args) { + var f = make(func); + if (needs_parens(func)) + f = "(" + f + ")"; + return f + "(" + add_commas(MAP(args, function(expr){ + return parenthesize(expr, "seq"); + })) + ")"; + }, + "function": make_function, + "defun": make_function, + "if": function(co, th, el) { + var out = [ "if", "(" + make(co) + ")", el ? make_then(th) : make(th) ]; + if (el) { + out.push("else", make(el)); + } + return add_spaces(out); + }, + "for": function(init, cond, step, block) { + var out = [ "for" ]; + init = (init != null ? make(init) : "").replace(/;*\s*$/, ";" + space); + cond = (cond != null ? make(cond) : "").replace(/;*\s*$/, ";" + space); + step = (step != null ? make(step) : "").replace(/;*\s*$/, ""); + var args = init + cond + step; + if (args == "; ; ") args = ";;"; + out.push("(" + args + ")", make(block)); + return add_spaces(out); + }, + "for-in": function(has_var, key, hash, block) { + var out = add_spaces([ "for", "(" ]); + if (has_var) + out += "var "; + out += add_spaces([ make_name(key) + " in " + make(hash) + ")", make(block) ]); + return out; + }, + "while": function(condition, block) { + return add_spaces([ "while", "(" + make(condition) + ")", make(block) ]); + }, + "do": function(condition, block) { + return add_spaces([ "do", make(block), "while", "(" + make(condition) + ")" ]) + ";"; + }, + "return": function(expr) { + var out = [ "return" ]; + if (expr != null) out.push(make(expr)); + return add_spaces(out) + ";"; + }, + "binary": function(operator, lvalue, rvalue) { + var left = make(lvalue), right = make(rvalue); + // XXX: I'm pretty sure other cases will bite here. + // we need to be smarter. + // adding parens all the time is the safest bet. + if (member(lvalue[0], [ "assign", "conditional", "seq" ]) || + lvalue[0] == "binary" && PRECEDENCE[operator] > PRECEDENCE[lvalue[1]]) { + left = "(" + left + ")"; + } + if (member(rvalue[0], [ "assign", "conditional", "seq" ]) || + rvalue[0] == "binary" && PRECEDENCE[operator] >= PRECEDENCE[rvalue[1]]) { + right = "(" + right + ")"; + } + return add_spaces([ left, operator, right ]); + }, + "unary-prefix": function(operator, expr) { + var val = make(expr); + if (!(expr[0] == "num" || (expr[0] == "unary-prefix" && !HOP(OPERATORS, operator + expr[1])) || !needs_parens(expr))) + val = "(" + val + ")"; + return operator + (jsp.is_alphanumeric_char(operator.charAt(0)) ? " " : "") + val; + }, + "unary-postfix": function(operator, expr) { + var val = make(expr); + if (!(expr[0] == "num" || (expr[0] == "unary-postfix" && !HOP(OPERATORS, operator + expr[1])) || !needs_parens(expr))) + val = "(" + val + ")"; + return val + operator; + }, + "sub": function(expr, subscript) { + var hash = make(expr); + if (needs_parens(expr)) + hash = "(" + hash + ")"; + return hash + "[" + make(subscript) + "]"; + }, + "object": function(props) { + if (props.length == 0) + return "{}"; + return "{" + newline + with_indent(function(){ + return MAP(props, function(p){ + if (p.length == 3) { + // getter/setter. The name is in p[0], the arg.list in p[1][2], the + // body in p[1][3] and type ("get" / "set") in p[2]. + return indent(make_function(p[0], p[1][2], p[1][3], p[2])); + } + var key = p[0], val = make(p[1]); + if (beautify && beautify.quote_keys) { + key = make_string(key); + } else if (typeof key == "number" || !beautify && +key + "" == key) { + key = make_num(+key); + } else if (!is_identifier(key)) { + key = make_string(key); + } + return indent(add_spaces(beautify && beautify.space_colon + ? [ key, ":", val ] + : [ key + ":", val ])); + }).join("," + newline); + }) + newline + indent("}"); + }, + "regexp": function(rx, mods) { + return "/" + rx + "/" + mods; + }, + "array": function(elements) { + if (elements.length == 0) return "[]"; + return add_spaces([ "[", add_commas(MAP(elements, function(el){ + return parenthesize(el, "seq"); + })), "]" ]); + }, + "stat": function(stmt) { + return make(stmt).replace(/;*\s*$/, ";"); + }, + "seq": function() { + return add_commas(MAP(slice(arguments), make)); + }, + "label": function(name, block) { + return add_spaces([ make_name(name), ":", make(block) ]); + }, + "with": function(expr, block) { + return add_spaces([ "with", "(" + make(expr) + ")", make(block) ]); + }, + "atom": function(name) { + return make_name(name); + }, + "comment1": function(text) { + return "//" + text + "\n"; + }, + "comment2": function(text) { + return "/*" + text + "*/"; + } + }; + + // The squeezer replaces "block"-s that contain only a single + // statement with the statement itself; technically, the AST + // is correct, but this can create problems when we output an + // IF having an ELSE clause where the THEN clause ends in an + // IF *without* an ELSE block (then the outer ELSE would refer + // to the inner IF). This function checks for this case and + // adds the block brackets if needed. + function make_then(th) { + if (th[0] == "do") { + // https://github.com/mishoo/UglifyJS/issues/#issue/57 + // IE croaks with "syntax error" on code like this: + // if (foo) do ... while(cond); else ... + // we need block brackets around do/while + return make([ "block", [ th ]]); + } + var b = th; + while (true) { + var type = b[0]; + if (type == "if") { + if (!b[3]) + // no else, we must add the block + return make([ "block", [ th ]]); + b = b[3]; + } + else if (type == "while" || type == "do") b = b[2]; + else if (type == "for" || type == "for-in") b = b[4]; + else break; + } + return make(th); + }; + + function make_function(name, args, body, keyword) { + var out = keyword || "function"; + if (name) { + out += " " + make_name(name); + } + out += "(" + add_commas(MAP(args, make_name)) + ")"; + return add_spaces([ out, make_block(body) ]); + }; + + function make_name(name) { + return name.toString(); + }; + + function make_block_statements(statements) { + for (var a = [], last = statements.length - 1, i = 0; i <= last; ++i) { + var stat = statements[i]; + var code = make(stat); + if (code != ";") { + if (!beautify && i == last) + code = code.replace(/;+\s*$/, ""); + a.push(code); + } + } + return MAP(a, indent); + }; + + function make_switch_block(body) { + var n = body.length; + if (n == 0) return "{}"; + return "{" + newline + MAP(body, function(branch, i){ + var has_body = branch[1].length > 0, code = with_indent(function(){ + return indent(branch[0] + ? add_spaces([ "case", make(branch[0]) + ":" ]) + : "default:"); + }, 0.5) + (has_body ? newline + with_indent(function(){ + return make_block_statements(branch[1]).join(newline); + }) : ""); + if (!beautify && has_body && i < n - 1) + code += ";"; + return code; + }).join(newline) + newline + indent("}"); + }; + + function make_block(statements) { + if (!statements) return ";"; + if (statements.length == 0) return "{}"; + return "{" + newline + with_indent(function(){ + return make_block_statements(statements).join(newline); + }) + newline + indent("}"); + }; + + function make_1vardef(def) { + var name = def[0], val = def[1]; + if (val != null) + name = add_spaces([ name, "=", make(val) ]); + return name; + }; + + var $stack = []; + + function make(node) { + var type = node[0]; + var gen = generators[type]; + if (!gen) + throw new Error("Can't find generator for \"" + type + "\""); + $stack.push(node); + var ret = gen.apply(type, node.slice(1)); + $stack.pop(); + return ret; + }; + + return make(ast); +}; + +/* -----[ Utilities ]----- */ + +function repeat_string(str, i) { + if (i <= 0) return ""; + if (i == 1) return str; + var d = repeat_string(str, i >> 1); + d += d; + if (i & 1) d += str; + return d; +}; + +function defaults(args, defs) { + var ret = {}; + if (args === true) + args = {}; + for (var i in defs) if (HOP(defs, i)) { + ret[i] = (args && HOP(args, i)) ? args[i] : defs[i]; + } + return ret; +}; + +function is_identifier(name) { + return /^[a-z_$][a-z0-9_$]*$/i.test(name) + && name != "this" + && !HOP(jsp.KEYWORDS_ATOM, name) + && !HOP(jsp.RESERVED_WORDS, name) + && !HOP(jsp.KEYWORDS, name); +}; + +function HOP(obj, prop) { + return Object.prototype.hasOwnProperty.call(obj, prop); +}; + +// some utilities + +var MAP; + +(function(){ + MAP = function(a, f, o) { + var ret = []; + for (var i = 0; i < a.length; ++i) { + var val = f.call(o, a[i], i); + if (val instanceof AtTop) ret.unshift(val.v); + else ret.push(val); + } + return ret; + }; + MAP.at_top = function(val) { return new AtTop(val) }; + function AtTop(val) { this.v = val }; +})(); + +/* -----[ Exports ]----- */ + +exports.ast_walker = ast_walker; +exports.ast_mangle = ast_mangle; +exports.ast_squeeze = ast_squeeze; +exports.gen_code = gen_code; +exports.ast_add_scope = ast_add_scope; +exports.ast_squeeze_more = require("./squeeze-more").ast_squeeze_more; +exports.set_logger = function(logger) { warn = logger };