&& !node.expression.has_side_effects(compressor);
}
+ (function(def) {
+ def(AST_Node, return_false);
+ def(AST_Null, return_true);
+ def(AST_Undefined, return_true);
+ def(AST_UnaryPrefix, function() {
+ return this.operator == "void";
+ });
+ def(AST_PropAccess, function(compressor) {
+ return !compressor.option("unsafe");
+ });
+ def(AST_SymbolRef, function(compressor) {
+ if (this.is_undefined) return true;
+ if (compressor.option("unsafe")) return false;
+ var fixed = this.fixed_value();
+ return !fixed || fixed.may_eq_null(compressor);
+ });
+ })(function(node, func) {
+ node.DEFMETHOD("may_eq_null", func);
+ });
+
/* -----[ boolean/negation helpers ]----- */
// methods to determine whether an expression has a boolean result type
|| this.expression.has_side_effects(compressor);
});
def(AST_SymbolRef, function(compressor){
- return this.global() && this.undeclared();
+ return this.undeclared();
});
def(AST_Object, function(compressor){
return any(this.properties, compressor);
});
def(AST_Dot, function(compressor){
if (!compressor.option("pure_getters")) return true;
- return this.expression.has_side_effects(compressor);
+ return this.expression.may_eq_null(compressor)
+ || this.expression.has_side_effects(compressor);
});
def(AST_Sub, function(compressor){
if (!compressor.option("pure_getters")) return true;
- return this.expression.has_side_effects(compressor)
+ return this.expression.may_eq_null(compressor)
+ || this.expression.has_side_effects(compressor)
|| this.property.has_side_effects(compressor);
});
- def(AST_PropAccess, function(compressor){
- return !compressor.option("pure_getters");
- });
def(AST_Seq, function(compressor){
return this.car.has_side_effects(compressor)
|| this.cdr.has_side_effects(compressor);
});
def(AST_Dot, function(compressor, first_in_statement){
if (!compressor.option("pure_getters")) return this;
+ if (this.expression.may_eq_null(compressor)) return this;
return this.expression.drop_side_effect_free(compressor, first_in_statement);
});
def(AST_Sub, function(compressor, first_in_statement){
if (!compressor.option("pure_getters")) return this;
+ if (this.expression.may_eq_null(compressor)) return this;
var expression = this.expression.drop_side_effect_free(compressor, first_in_statement);
if (!expression) return this.property.drop_side_effect_free(compressor, first_in_statement);
var property = this.property.drop_side_effect_free(compressor);
// testing against !self.scope.uses_with first is an optimization
if (compressor.option("screw_ie8")
&& self.undeclared()
- && !isLHS(self, compressor.parent())
&& (!self.scope.uses_with || !compressor.find_parent(AST_With))) {
switch (self.name) {
case "undefined":
--- /dev/null
+side_effects: {
+ options = {
+ pure_getters: true,
+ reduce_vars: false,
+ side_effects: true,
+ toplevel: true,
+ unsafe: false,
+ }
+ input: {
+ var a, b = null, c = {};
+ a.prop;
+ b.prop;
+ c.prop;
+ d.prop;
+ null.prop;
+ (void 0).prop;
+ undefined.prop;
+ }
+ expect: {
+ var a, b = null, c = {};
+ a.prop;
+ b.prop;
+ c.prop;
+ d.prop;
+ null.prop;
+ (void 0).prop;
+ (void 0).prop;
+ }
+}
+
+side_effects_reduce_vars: {
+ options = {
+ pure_getters: true,
+ reduce_vars: true,
+ side_effects: true,
+ toplevel: true,
+ unsafe: false,
+ }
+ input: {
+ var a, b = null, c = {};
+ a.prop;
+ b.prop;
+ c.prop;
+ d.prop;
+ null.prop;
+ (void 0).prop;
+ undefined.prop;
+ }
+ expect: {
+ var a, b = null, c = {};
+ a.prop;
+ b.prop;
+ d.prop;
+ null.prop;
+ (void 0).prop;
+ (void 0).prop;
+ }
+}
+
+side_effects_unsafe: {
+ options = {
+ pure_getters: true,
+ reduce_vars: false,
+ side_effects: true,
+ toplevel: true,
+ unsafe: true,
+ }
+ input: {
+ var a, b = null, c = {};
+ a.prop;
+ b.prop;
+ c.prop;
+ d.prop;
+ null.prop;
+ (void 0).prop;
+ undefined.prop;
+ }
+ expect: {
+ var a, b = null, c = {};
+ d;
+ null.prop;
+ (void 0).prop;
+ (void 0).prop;
+ }
+}