Rename clean_getters to pure_getters; add pure_funcs.

1 files changed, 11 insertions, 4 deletions

diff --git a/lib/compress.js b/lib/compress.js
index 76cbc748..4dd273b5 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -66,7 +66,8 @@ function Compressor(options, false_by_default) {
         join_vars     : !false_by_default,
         cascade       : !false_by_default,
         side_effects  : !false_by_default,
-        clean_getters : false,
+        pure_getters  : false,
+        pure_funcs    : null,
         negate_iife   : !false_by_default,
         screw_ie8     : false,
 
@@ -809,6 +810,12 @@ merge(Compressor.prototype, {
         def(AST_Constant, function(compressor){ return false });
         def(AST_This, function(compressor){ return false });
 
+        def(AST_Call, function(compressor){
+            var pure = compressor.option("pure_funcs");
+            if (!pure) return true;
+            return pure.indexOf(this.expression.print_to_string()) < 0;
+        });
+
         def(AST_Block, function(compressor){
             for (var i = this.body.length; --i >= 0;) {
                 if (this.body[i].has_side_effects(compressor))
@@ -855,16 +862,16 @@ merge(Compressor.prototype, {
             return false;
         });
         def(AST_Dot, function(compressor){
-            if (!compressor.option("clean_getters")) return true;
+            if (!compressor.option("pure_getters")) return true;
             return this.expression.has_side_effects(compressor);
         });
         def(AST_Sub, function(compressor){
-            if (!compressor.option("clean_getters")) return true;
+            if (!compressor.option("pure_getters")) return true;
             return this.expression.has_side_effects(compressor)
                 || this.property.has_side_effects(compressor);
         });
         def(AST_PropAccess, function(compressor){
-            return !compressor.option("clean_getters");
+            return !compressor.option("pure_getters");
         });
         def(AST_Seq, function(compressor){
             return this.car.has_side_effects(compressor)