@@ -297,6 +297,8 @@ merge(Compressor.prototype, {
297 297
if (node instanceof AST_SymbolRef) d.references.push(node);
298 298
d.fixed = false;
299 299
});
300 +
var in_loop = null;
301 +
var loop_ids = Object.create(null);
300 302
var tw = new TreeWalker(function(node, descend) {
301 303
node._squeezed = false;
302 304
node._optimized = false;
@@ -307,7 +309,7 @@ merge(Compressor.prototype, {
307 309
var d = node.definition();
308 310
d.references.push(node);
309 311
if (d.fixed === undefined || !safe_to_read(d)
310 -
|| is_modified(node, 0, is_immutable(node.fixed_value()))) {
312 +
|| is_modified(node, 0, is_immutable(node))) {
311 313
d.fixed = false;
312 314
} else {
313 315
var parent = tw.parent();
@@ -329,6 +331,7 @@ merge(Compressor.prototype, {
329 331
d.fixed = function() {
330 332
return node.value;
331 333
};
334 +
loop_ids[d.id] = in_loop;
332 335
mark(d, false);
333 336
descend();
334 337
} else {
@@ -384,6 +387,7 @@ merge(Compressor.prototype, {
384 387
d.fixed = function() {
385 388
return iife.args[i] || make_node(AST_Undefined, iife);
386 389
};
390 +
loop_ids[d.id] = in_loop;
387 391
mark(d, true);
388 392
} else {
389 393
d.fixed = false;
@@ -431,10 +435,13 @@ merge(Compressor.prototype, {
431 435
return true;
432 436
}
433 437
if (node instanceof AST_DWLoop) {
438 +
var saved_loop = in_loop;
439 +
in_loop = node;
434 440
push();
435 441
node.condition.walk(tw);
436 442
node.body.walk(tw);
437 443
pop();
444 +
in_loop = saved_loop;
438 445
return true;
439 446
}
440 447
if (node instanceof AST_LabeledStatement) {
@@ -445,6 +452,8 @@ merge(Compressor.prototype, {
445 452
}
446 453
if (node instanceof AST_For) {
447 454
if (node.init) node.init.walk(tw);
455 +
var saved_loop = in_loop;
456 +
in_loop = node;
448 457
if (node.condition) {
449 458
push();
450 459
node.condition.walk(tw);
@@ -458,14 +467,18 @@ merge(Compressor.prototype, {
458 467
node.step.walk(tw);
459 468
pop();
460 469
}
470 +
in_loop = saved_loop;
461 471
return true;
462 472
}
463 473
if (node instanceof AST_ForIn) {
464 474
node.init.walk(suppressor);
465 475
node.object.walk(tw);
476 +
var saved_loop = in_loop;
477 +
in_loop = node;
466 478
push();
467 479
node.body.walk(tw);
468 480
pop();
481 +
in_loop = saved_loop;
469 482
return true;
470 483
}
471 484
if (node instanceof AST_Try) {
@@ -535,10 +548,23 @@ merge(Compressor.prototype, {
535 548
}
536 549
def.references = [];
537 550
def.should_replace = undefined;
538 -
}
539 - 540 -
function is_immutable(value) {
541 -
return value && value.is_constant() || value instanceof AST_Lambda;
551 +
def.single_use = undefined;
552 +
}
553 + 554 +
function is_immutable(node) {
555 +
var value = node.fixed_value();
556 +
if (!value) return false;
557 +
if (value.is_constant()) return true;
558 +
if (compressor.option("unused")) {
559 +
var d = node.definition();
560 +
if (d.single_use === undefined) {
561 +
d.single_use = loop_ids[d.id] === in_loop
562 +
&& d.scope === node.scope
563 +
&& value.is_constant_expression();
564 +
}
565 +
if (d.references.length == 1 && d.single_use) return true;
566 +
}
567 +
return value instanceof AST_Lambda;
542 568
}
543 569 544 570
function is_modified(node, level, immutable) {
@@ -2115,6 +2141,22 @@ merge(Compressor.prototype, {
2115 2141
}
2116 2142
def(AST_Node, return_false);
2117 2143
def(AST_Constant, return_true);
2144 +
def(AST_Function, function(){
2145 +
var self = this;
2146 +
var result = true;
2147 +
self.walk(new TreeWalker(function(node) {
2148 +
if (!result) return true;
2149 +
if (node instanceof AST_SymbolRef) {
2150 +
var def = node.definition();
2151 +
if (self.enclosed.indexOf(def) >= 0
2152 +
&& self.variables.get(def.name) !== def) {
2153 +
result = false;
2154 +
return true;
2155 +
}
2156 +
}
2157 +
}));
2158 +
return result;
2159 +
});
2118 2160
def(AST_Unary, function(){
2119 2161
return this.expression.is_constant_expression();
2120 2162
});
@@ -4078,12 +4120,13 @@ merge(Compressor.prototype, {
4078 4120
d.fixed = fixed = make_node(AST_Function, fixed, fixed);
4079 4121
}
4080 4122
if (compressor.option("unused")
4081 -
&& fixed instanceof AST_Function
4082 4123
&& d.references.length == 1
4083 -
&& !(d.scope.uses_arguments && d.orig[0] instanceof AST_SymbolFunarg)
4084 -
&& !d.scope.uses_eval
4085 -
&& compressor.find_parent(AST_Scope) === fixed.parent_scope) {
4086 -
return fixed.clone(true);
4124 +
&& (d.single_use || fixed instanceof AST_Function
4125 +
&& !(d.scope.uses_arguments && d.orig[0] instanceof AST_SymbolFunarg)
4126 +
&& !d.scope.uses_eval
4127 +
&& compressor.find_parent(AST_Scope) === fixed.parent_scope)) {
4128 +
var value = fixed.optimize(compressor);
4129 +
return value === fixed ? fixed.clone(true) : value;
4087 4130
}
4088 4131
if (compressor.option("evaluate") && fixed) {
4089 4132
if (d.should_replace === undefined) {
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4