aboutsummaryrefslogtreecommitdiff
path: root/lib/compress.js
diff options
context:
space:
mode:
Diffstat (limited to 'lib/compress.js')
-rw-r--r--lib/compress.js116
1 files changed, 84 insertions, 32 deletions
diff --git a/lib/compress.js b/lib/compress.js
index 71081350..0a195940 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -2532,6 +2532,20 @@ merge(Compressor.prototype, {
return this.operator == "+" &&
(this.left.is_string(compressor) || this.right.is_string(compressor));
});
+ var fn = makePredicate([
+ "charAt",
+ "substr",
+ "substring",
+ "toLowerCase",
+ "toString",
+ "toUpperCase",
+ "trim",
+ ]);
+ def(AST_Call, function(compressor) {
+ if (!compressor.option("unsafe")) return false;
+ var exp = this.expression;
+ return exp instanceof AST_Dot && fn[exp.property];
+ });
def(AST_Conditional, function(compressor) {
return this.consequent.is_string(compressor) && this.alternative.is_string(compressor);
});
@@ -2539,6 +2553,9 @@ merge(Compressor.prototype, {
return this.tail_node().is_string(compressor);
});
def(AST_String, return_true);
+ def(AST_Sub, function(compressor) {
+ return this.expression.is_string(compressor) && this.property instanceof AST_Number;
+ });
def(AST_SymbolRef, function(compressor) {
var fixed = this.fixed_value();
if (!fixed) return false;
@@ -3127,25 +3144,31 @@ merge(Compressor.prototype, {
return this.pure || !compressor.pure_funcs(this);
});
AST_Node.DEFMETHOD("is_call_pure", return_false);
- AST_Dot.DEFMETHOD("is_call_pure", function(compressor) {
- if (!compressor.option("unsafe")) return;
- var expr = this.expression;
+ AST_Call.DEFMETHOD("is_call_pure", function(compressor) {
+ if (!compressor.option("unsafe")) return false;
+ var dot = this.expression;
+ if (!(dot instanceof AST_Dot)) return false;
+ var exp = dot.expression;
var map;
- if (expr instanceof AST_Array) {
+ var prop = dot.property;
+ if (exp instanceof AST_Array) {
map = native_fns.Array;
- } else if (expr.is_boolean(compressor)) {
+ } else if (exp.is_boolean(compressor)) {
map = native_fns.Boolean;
- } else if (expr.is_number(compressor)) {
+ } else if (exp.is_number(compressor)) {
map = native_fns.Number;
- } else if (expr instanceof AST_RegExp) {
+ } else if (exp instanceof AST_RegExp) {
map = native_fns.RegExp;
- } else if (expr.is_string(compressor)) {
- if (this.property == "replace") return false;
+ } else if (exp.is_string(compressor)) {
map = native_fns.String;
- } else if (!this.may_throw_on_access(compressor)) {
+ if (prop == "replace") {
+ var arg = this.args[1];
+ if (arg && !arg.is_string(compressor)) return false;
+ }
+ } else if (!dot.may_throw_on_access(compressor)) {
map = native_fns.Object;
}
- return map && map[this.property];
+ return map && map[prop];
});
// determine if expression has side effects
@@ -3170,8 +3193,7 @@ merge(Compressor.prototype, {
});
def(AST_Call, function(compressor) {
if (!this.is_expr_pure(compressor)
- && (!this.expression.is_call_pure(compressor)
- || this.expression.has_side_effects(compressor))) {
+ && (!this.is_call_pure(compressor) || this.expression.has_side_effects(compressor))) {
return true;
}
return any(this.args, compressor);
@@ -4162,16 +4184,15 @@ merge(Compressor.prototype, {
});
def(AST_Call, function(compressor, first_in_statement) {
if (!this.is_expr_pure(compressor)) {
- if (this.expression.is_call_pure(compressor)) {
+ var exp = this.expression;
+ if (this.is_call_pure(compressor)) {
var exprs = this.args.slice();
- exprs.unshift(this.expression.expression);
+ exprs.unshift(exp.expression);
exprs = trim(exprs, compressor, first_in_statement);
return exprs && make_sequence(this, exprs);
}
- if (this.expression instanceof AST_Function
- && (!this.expression.name || !this.expression.name.definition().references.length)) {
+ if (exp instanceof AST_Function && (!exp.name || !exp.name.definition().references.length)) {
var node = this.clone();
- var exp = node.expression;
exp.process_expression(false, compressor);
exp.walk(new TreeWalker(function(node) {
if (node instanceof AST_Return && node.value) {
@@ -4963,15 +4984,21 @@ merge(Compressor.prototype, {
}
break;
case "charAt":
- if (exp.expression.is_string(compressor)) {
- var arg = self.args[0];
- var index = arg ? arg.evaluate(compressor) : 0;
- if (index !== arg) {
- return make_node(AST_Sub, exp, {
- expression: exp.expression,
- property: make_node_from_constant(index | 0, arg || exp)
- }).optimize(compressor);
- }
+ if (self.args.length < 2) {
+ var node = make_node(AST_Sub, self, {
+ expression: exp.expression,
+ property: self.args.length ? make_node(AST_Binary, self.args[0], {
+ operator: "|",
+ left: make_node(AST_Number, self, {
+ value: 0
+ }),
+ right: self.args[0]
+ }) : make_node(AST_Number, self, {
+ value: 0
+ })
+ });
+ node.is_string = return_true;
+ return node.optimize(compressor);
}
break;
case "apply":
@@ -5610,7 +5637,8 @@ merge(Compressor.prototype, {
}
break;
}
- if (compressor.option("booleans") && self.operator == "+" && compressor.in_boolean_context()) {
+ if (compressor.option("booleans") && compressor.in_boolean_context()) switch (self.operator) {
+ case "+":
var ll = self.left.evaluate(compressor);
var rr = self.right.evaluate(compressor);
if (ll && typeof ll == "string") {
@@ -5627,6 +5655,20 @@ merge(Compressor.prototype, {
make_node(AST_True, self)
]).optimize(compressor);
}
+ break;
+ case "==":
+ if (self.left instanceof AST_String && self.left.getValue() == "" && self.right.is_string(compressor)) {
+ return make_node(AST_UnaryPrefix, self, {
+ operator: "!",
+ expression: self.right
+ }).optimize(compressor);
+ }
+ break;
+ case "!=":
+ if (self.left instanceof AST_String && self.left.getValue() == "" && self.right.is_string(compressor)) {
+ return self.right.optimize(compressor);
+ }
+ break;
}
if (compressor.option("comparisons") && self.is_boolean(compressor)) {
if (!(compressor.parent() instanceof AST_Binary)
@@ -5646,12 +5688,12 @@ merge(Compressor.prototype, {
if (self.right instanceof AST_String
&& self.right.getValue() == ""
&& self.left.is_string(compressor)) {
- return self.left;
+ return self.left.optimize(compressor);
}
if (self.left instanceof AST_String
&& self.left.getValue() == ""
&& self.right.is_string(compressor)) {
- return self.right;
+ return self.right.optimize(compressor);
}
if (self.left instanceof AST_Binary
&& self.left.operator == "+"
@@ -5659,7 +5701,7 @@ merge(Compressor.prototype, {
&& self.left.left.getValue() == ""
&& self.right.is_string(compressor)) {
self.left = self.left.right;
- return self.transform(compressor);
+ return self.optimize(compressor);
}
}
if (compressor.option("evaluate")) {
@@ -5918,6 +5960,16 @@ merge(Compressor.prototype, {
&& self.right instanceof AST_Call
&& self.right.expression instanceof AST_Dot
&& indexFns[self.right.expression.property]) {
+ if (compressor.option("booleans")
+ && (self.operator == "==" || self.operator == "!=")
+ && self.left instanceof AST_Number
+ && self.left.getValue() == 0
+ && compressor.in_boolean_context()) {
+ return (self.operator == "==" ? make_node(AST_UnaryPrefix, self, {
+ operator: "!",
+ expression: self.right
+ }) : self.right).optimize(compressor);
+ }
if (compressor.option("comparisons") && is_indexOf_match_pattern()) {
var node = make_node(AST_UnaryPrefix, self, {
operator: "!",
@@ -6229,7 +6281,7 @@ merge(Compressor.prototype, {
if (parent instanceof AST_Exit) {
if (in_try(level, parent)) break;
if (is_reachable(def.scope, [ def ])) break;
- if (self.operator == "=") return self.right;
+ if (self.operator == "=") return self.right.optimize(compressor);
def.fixed = false;
return make_node(AST_Binary, self, {
operator: self.operator.slice(0, -1),