JoBoEVD/UglifyJS
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it's not safe to assume that property access is side-effect-free

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(getters/setters + various browser bugs will trigger side effects; also, an
exception is thrown when the expression is undefined)
This commit is contained in:
Mihai Bazon
2012-09-25 10:32:14 +03:00
parent 368ac8f93c
commit ea6d1ea701
1 changed files with 11 additions and 8 deletions
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19
lib/compress.js
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@@ -732,12 +732,15 @@ function Compressor(options, false_by_default) {
return true; return true;
return false; return false;
}); });
def(AST_Dot, function(){ // def(AST_Dot, function(){
return this.expression.has_side_effects(); // return this.expression.has_side_effects();
}); // });
def(AST_Sub, function(){ // def(AST_Sub, function(){
return this.expression.has_side_effects() // return this.expression.has_side_effects()
|| this.property.has_side_effects(); // || this.property.has_side_effects();
// });
def(AST_PropAccess, function(){
return true;
}); });
def(AST_Seq, function(){ def(AST_Seq, function(){
return this.car.has_side_effects() return this.car.has_side_effects()
@@ -1405,9 +1408,9 @@ function Compressor(options, false_by_default) {
AST_Seq.DEFMETHOD("optimize", function(compressor){ AST_Seq.DEFMETHOD("optimize", function(compressor){
var self = this; var self = this;
if (self.cdr instanceof AST_Seq)
self.cdr = self.cdr.optimize(compressor);
if (compressor.option("cascade")) { if (compressor.option("cascade")) {
if (self.cdr instanceof AST_Seq)
self.cdr = self.cdr.optimize(compressor);
if (self.car instanceof AST_Assign if (self.car instanceof AST_Assign
&& !self.car.left.has_side_effects() && !self.car.left.has_side_effects()
&& self.car.left.equivalent_to(self.cdr)) { && self.car.left.equivalent_to(self.cdr)) {