1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
|
/***********************************************************************
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.
***********************************************************************/
function SymbolDef(scope, orig) {
this.name = orig.name;
this.orig = [ orig ];
this.scope = scope;
this.references = [];
this.global = false;
this.mangled_name = null;
this.undeclared = false;
};
SymbolDef.prototype = {
unmangleable: function() {
return this.global || this.undeclared || this.scope.uses_eval || this.scope.uses_with;
},
mangle: function() {
if (!this.mangled_name && !this.unmangleable())
this.mangled_name = this.scope.next_mangled();
}
};
AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
// This does what ast_add_scope did in UglifyJS v1.
//
// Part of it could be done at parse time, but it would complicate
// the parser (and it's already kinda complex). It's also worth
// having it separated because we might need to call it multiple
// times on the same tree.
// pass 1: setup scope chaining and handle definitions
var self = this;
var scope = self.parent_scope = null;
var labels = {};
var tw = new TreeWalker(function(node, descend){
if (node instanceof AST_Scope) {
node.init_scope_vars();
var save_scope = node.parent_scope = scope;
scope = node;
descend();
scope = save_scope;
return true; // don't descend again in TreeWalker
}
if (node instanceof AST_Directive) {
node.scope = scope;
push_uniq(scope.directives, node.value);
return true;
}
if (node instanceof AST_With) {
for (var s = scope; s; s = s.parent_scope)
s.uses_with = true;
return;
}
if (node instanceof AST_LabeledStatement) {
var l = node.label;
if (labels[l.name])
throw new Error(string_template("Label {name} defined twice", l));
labels[l.name] = l;
descend();
delete labels[l.name];
return true; // no descend again
}
if (node instanceof AST_SymbolDeclaration) {
node.init_scope_vars();
}
if (node instanceof AST_Symbol) {
node.scope = scope;
}
if (node instanceof AST_Label) {
node.thedef = node;
node.init_scope_vars();
var p = tw.parent(); // AST_LabeledStatement
var block = p.body;
if (block instanceof AST_StatementWithBody)
block = block.body;
node.label_target = block;
}
if (node instanceof AST_LoopControl) {
if (!node.label) {
var a = tw.stack, i = a.length - 1;
while (--i >= 0) {
var p = a[i];
if (p instanceof AST_For
|| p instanceof AST_ForIn
|| p instanceof AST_DWLoop
|| p instanceof AST_Switch) {
node.loopcontrol_target = p.body;
break;
}
}
}
}
else if (node instanceof AST_SymbolLambda) {
scope.def_function(node);
node.init.push(tw.parent());
}
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.
(node.scope = scope.parent_scope).def_function(node);
node.init.push(tw.parent());
}
else if (node instanceof AST_SymbolVar) {
scope.def_variable(node);
var def = tw.parent();
if (def.value) node.init.push(def);
}
else if (node instanceof AST_SymbolCatch) {
// XXX: this is wrong according to ECMA-262 (12.4). the
// `catch` argument name should be visible only inside the
// catch block. For a quick fix AST_Catch should inherit
// from AST_Scope. Keeping it this way because of IE,
// which doesn't obey the standard. (it introduces the
// identifier in the enclosing scope)
scope.def_variable(node);
}
if (node instanceof AST_LabelRef) {
var sym = labels[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;
}
});
self.walk(tw);
// pass 2: find back references and eval
var func = null;
var globals = self.globals = {};
var tw = new TreeWalker(function(node, descend){
if (node instanceof AST_Lambda) {
var prev_func = func;
func = node;
descend();
func = prev_func;
return true;
}
if (node instanceof AST_LabelRef) {
node.reference();
return true;
}
if (node instanceof AST_SymbolRef) {
var name = node.name;
var sym = node.scope.find_variable(name);
if (!sym) {
var g;
if (HOP(globals, name)) {
g = globals[name];
} else {
g = new SymbolDef(self, node);
g.undeclared = true;
globals[name] = g;
}
node.thedef = g;
if (name == "eval") {
for (var s = node.scope; s && !s.uses_eval; s = s.parent_scope)
s.uses_eval = true;
}
if (name == "arguments") {
func.uses_arguments = true;
}
} else {
node.thedef = sym;
}
node.reference();
return true;
}
});
self.walk(tw);
});
AST_Scope.DEFMETHOD("init_scope_vars", function(){
this.directives = []; // contains the directives defined in this scope, i.e. "use strict"
this.variables = {}; // map name to AST_SymbolVar (variables defined in this scope; includes functions)
this.functions = {}; // 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 = null; // 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_Scope.DEFMETHOD("strict", function(){
return this.has_directive("use strict");
});
AST_Lambda.DEFMETHOD("init_scope_vars", function(){
AST_Scope.prototype.init_scope_vars.call(this);
this.uses_arguments = false;
});
AST_SymbolRef.DEFMETHOD("reference", function() {
var def = this.definition();
def.references.push(this);
var orig_scope = def.scope, s = this.scope;
while (s) {
push_uniq(s.enclosed, def);
s = s.parent_scope;
}
});
AST_SymbolDeclaration.DEFMETHOD("init_scope_vars", function(){
this.init = [];
});
AST_Label.DEFMETHOD("init_scope_vars", function(){
this.references = [];
});
AST_LabelRef.DEFMETHOD("reference", function(){
this.thedef.references.push(this);
});
AST_Scope.DEFMETHOD("find_variable", function(name){
if (name instanceof AST_Symbol) name = name.name;
return HOP(this.variables, name)
? this.variables[name]
: (this.parent_scope && this.parent_scope.find_variable(name));
});
AST_Scope.DEFMETHOD("has_directive", function(value){
return this.parent_scope && this.parent_scope.has_directive(value)
|| (this.directives.indexOf(value) >= 0 ? this : null);
});
AST_Scope.DEFMETHOD("def_function", function(symbol){
this.functions[symbol.name] = this.def_variable(symbol);
});
AST_Scope.DEFMETHOD("def_variable", function(symbol){
var def;
if (!HOP(this.variables, symbol.name)) {
def = new SymbolDef(this, symbol);
this.variables[symbol.name] = def;
def.global = !this.parent_scope;
} else {
def = this.variables[symbol.name];
def.orig.push(symbol);
}
return symbol.thedef = def;
});
AST_Scope.DEFMETHOD("next_mangled", function(){
var ext = this.enclosed, n = ext.length;
out: while (true) {
var m = base54(++this.cname);
if (!is_identifier(m)) continue; // skip over "do"
// 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 = n; --i >= 0;) {
var sym = ext[i];
var name = sym.mangled_name || (sym.unmangleable() && sym.name);
if (m == name) continue out;
}
return m;
}
});
AST_Scope.DEFMETHOD("references", function(sym){
if (sym instanceof AST_Symbol) sym = sym.definition();
return this.enclosed.indexOf(sym) < 0 ? null : sym;
});
AST_Symbol.DEFMETHOD("unmangleable", function(){
return this.definition().unmangleable();
});
// labels are always mangleable
AST_Label.DEFMETHOD("unmangleable", function(){
return false;
});
AST_Symbol.DEFMETHOD("unreferenced", function(){
return this.definition().references.length == 0
&& !(this.scope.uses_eval || this.scope.uses_with);
});
AST_Symbol.DEFMETHOD("undeclared", function(){
return this.definition().undeclared;
});
AST_Symbol.DEFMETHOD("definition", function(){
return this.thedef;
});
AST_Symbol.DEFMETHOD("global", function(){
return this.definition().global;
});
AST_LoopControl.DEFMETHOD("target", function(){
if (this.label) return this.label.definition().label_target;
return this.loopcontrol_target;
});
AST_Toplevel.DEFMETHOD("mangle_names", function(options){
options = defaults(options, {
sort: false
});
// 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 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) {
var p = tw.parent();
var is_setget = p instanceof AST_ObjectSetter || p instanceof AST_ObjectGetter;
var a = node.variables;
for (var i in a) if (HOP(a, i)) {
var symbol = a[i];
if (!(is_setget && symbol instanceof AST_SymbolLambda))
to_mangle.push(symbol);
}
return;
}
if (node instanceof AST_Label) {
var name;
do name = base54(++lname); while (!is_identifier(name));
node.mangled_name = name;
return;
}
});
this.walk(tw);
if (options.sort) to_mangle = mergeSort(to_mangle, function(a, b){
return b.references.length - a.references.length;
});
to_mangle.forEach(function(def){ def.mangle(options) });
});
AST_Toplevel.DEFMETHOD("compute_char_frequency", function(){
var tw = new TreeWalker(function(node){
if (node instanceof AST_Constant)
base54.consider(node.print_to_string());
else if (node instanceof AST_Return)
base54.consider("return");
else if (node instanceof AST_Throw)
base54.consider("throw");
else if (node instanceof AST_Continue)
base54.consider("continue");
else if (node instanceof AST_Break)
base54.consider("break");
else if (node instanceof AST_Debugger)
base54.consider("debugger");
else if (node instanceof AST_Directive)
base54.consider(node.value);
else if (node instanceof AST_While)
base54.consider("while");
else if (node instanceof AST_Do)
base54.consider("do while");
else if (node instanceof AST_If) {
base54.consider("if");
if (node.alternative) base54.consider("else");
}
else if (node instanceof AST_Var)
base54.consider("var");
else if (node instanceof AST_Const)
base54.consider("const");
else if (node instanceof AST_Lambda)
base54.consider("function");
else if (node instanceof AST_For)
base54.consider("for");
else if (node instanceof AST_ForIn)
base54.consider("for in");
else if (node instanceof AST_Switch)
base54.consider("switch");
else if (node instanceof AST_Case)
base54.consider("case");
else if (node instanceof AST_Default)
base54.consider("default");
else if (node instanceof AST_With)
base54.consider("with");
else if (node instanceof AST_ObjectSetter)
base54.consider("set" + node.key);
else if (node instanceof AST_ObjectGetter)
base54.consider("get" + node.key);
else if (node instanceof AST_ObjectKeyVal)
base54.consider(node.key);
else if (node instanceof AST_New)
base54.consider("new");
else if (node instanceof AST_This)
base54.consider("this");
else if (node instanceof AST_Try)
base54.consider("try");
else if (node instanceof AST_Catch)
base54.consider("catch");
else if (node instanceof AST_Finally)
base54.consider("finally");
else if (node instanceof AST_Symbol && node.unmangleable())
base54.consider(node.name);
else if (node instanceof AST_Unary || node instanceof AST_Binary)
base54.consider(node.operator);
else if (node instanceof AST_Dot)
base54.consider(node.property);
});
this.walk(tw);
});
var base54 = (function() {
var string = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$_0123456789";
var chars, frequency;
function reset() {
frequency = {};
chars = string.split("");
chars.map(function(ch){ frequency[ch] = 0 });
}
base54.consider = function(str){
for (var i = str.length; --i >= 0;) {
var ch = str.charAt(i);
if (string.indexOf(ch) >= 0)
++frequency[ch];
}
};
base54.sort = function() {
chars = mergeSort(chars, function(a, b){
if (is_digit(a) && !is_digit(b)) return 1;
if (is_digit(b) && !is_digit(a)) return -1;
return frequency[b] - frequency[a];
});
};
base54.reset = reset;
reset();
base54.get = function(){ return chars };
base54.freq = function(){ return frequency };
function base54(num) {
var ret = "", base = 54;
do {
ret += chars[num % base];
num = Math.floor(num / base);
base = 64;
} while (num > 0);
return ret;
};
return base54;
})();
AST_Toplevel.DEFMETHOD("scope_warnings", function(options){
options = defaults(options, {
undeclared : false, // this makes a lot of noise
unreferenced : true,
assign_to_global : true,
func_arguments : true,
nested_defuns : true,
eval : true
});
var tw = new TreeWalker(function(node){
if (options.undeclared
&& node instanceof AST_SymbolRef
&& node.undeclared())
{
// XXX: this also warns about JS standard names,
// i.e. Object, Array, parseInt etc. Should add a list of
// exceptions.
AST_Node.warn("Undeclared symbol: {name} [{line},{col}]", {
name: node.name,
line: node.start.line,
col: node.start.col
});
}
if (options.assign_to_global)
{
var sym = null;
if (node instanceof AST_Assign && node.left instanceof AST_SymbolRef)
sym = node.left;
else if (node instanceof AST_ForIn && node.init instanceof AST_SymbolRef)
sym = node.init;
if (sym
&& (sym.undeclared()
|| (sym.global() && sym.scope !== sym.definition().scope))) {
AST_Node.warn("{msg}: {name} [{line},{col}]", {
msg: sym.undeclared() ? "Accidental global?" : "Assignment to global",
name: sym.name,
line: sym.start.line,
col: sym.start.col
});
}
}
if (options.eval
&& node instanceof AST_SymbolRef
&& node.undeclared()
&& node.name == "eval") {
AST_Node.warn("Eval is used [{line},{col}]", node.start);
}
if (options.unreferenced
&& node instanceof AST_SymbolDeclaration
&& node.unreferenced()) {
AST_Node.warn("{type} {name} is declared but not referenced [{line},{col}]", {
type: node instanceof AST_Label ? "Label" : "Symbol",
name: node.name,
line: node.start.line,
col: node.start.col
});
}
if (options.func_arguments
&& node instanceof AST_Lambda
&& node.uses_arguments) {
AST_Node.warn("arguments used in function {name} [{line},{col}]", {
name: node.name ? node.name.name : "anonymous",
line: node.start.line,
col: node.start.col
});
}
if (options.nested_defuns
&& node instanceof AST_Defun
&& !(tw.parent() instanceof AST_Scope)) {
AST_Node.warn("Function {name} declared in nested statement [{line},{col}]", {
name: node.name.name,
line: node.start.line,
col: node.start.col
});
}
});
this.walk(tw);
});
|