Fixes brython-dev#673 : Brython does not mangle private attribute names

www/src/Lib/browser/local_storage.py

@@ -4,7 +4,7 @@
 
 has_local_storage = hasattr(window, 'localStorage')
 
-class __UnProvided():
+class _UnProvided():
     pass
 
 class LocalStorage():
@@ -55,10 +55,10 @@ def get(self, key, default=None):
             raise TypeError("key must be string")
         return self.store.getItem(key) or default
 
-    def pop(self, key, default=__UnProvided()):
+    def pop(self, key, default=_UnProvided()):
         if (not isinstance(key, str)):
             raise TypeError("key must be string")
-        if type(default) is __UnProvided:
+        if type(default) is _UnProvided:
             ret = self.get(key)
             del self[key]  # will throw key error if doesn't exist
             return ret

www/src/Lib/browser/object_storage.py

@@ -1,6 +1,6 @@
 import json
 
-class __UnProvided():
+class _UnProvided():
     pass
 
 
@@ -26,8 +26,8 @@ def get(self, key, default=None):
             return self.storage[json.dumps(key)]
         return default
 
-    def pop(self, key, default=__UnProvided()):
-        if type(default) is __UnProvided or json.dumps(key) in self.storage:
+    def pop(self, key, default=_UnProvided()):
+        if type(default) is _UnProvided or json.dumps(key) in self.storage:
             return json.loads(self.storage.pop(json.dumps(key)))
         return default
 

www/src/Lib/sys.py

@@ -79,7 +79,7 @@ def getrecursionlimit():
 version += " (default, %s) \n[Javascript 1.5] on Brython" % __BRYTHON__.compiled_date
 hexversion = 0x03000000   # python 3.0
 
-class __version_info(object):
+class _version_info(object):
     def __init__(self, version_info):
         self.version_info = version_info
         self.major = version_info[0]
@@ -143,12 +143,12 @@ def __ne__(self,other):
 
 
 #eventually this needs to be the real python version such as 3.0, 3.1, etc
-version_info=__version_info(__BRYTHON__.version_info)
+version_info = _version_info(__BRYTHON__.version_info)
 
 class _implementation:
   def __init__(self):
       self.name='brython'
-      self.version = __version_info(__BRYTHON__.implementation)
+      self.version = _version_info(__BRYTHON__.implementation) 
       self.hexversion = self.version.hexversion()
       self.cache_tag=None
 

www/src/brython.js

@@ -70,7 +70,7 @@ $B.regexIdentifier=/^(?:[\$A-Z_a-z\xAA\xB5\xBA\xC0-\xD6\xD8-\xF6\xF8-\u02C1\u02C
 __BRYTHON__.implementation=[3,3,4,'dev',0]
 __BRYTHON__.__MAGIC__="3.3.4"
 __BRYTHON__.version_info=[3,3,0,'alpha',0]
-__BRYTHON__.compiled_date="2017-09-19 15:43:35.611851"
+__BRYTHON__.compiled_date="2017-09-19 18:19:02.668328"
 __BRYTHON__.builtin_module_names=["posix","sys","errno","time","_ajax","_base64","_jsre","_multiprocessing","_posixsubprocess","_profile","_svg","_sys","builtins","dis","hashlib","json","long_int","math","modulefinder","random","_abcoll","_codecs","_collections","_csv","_functools","_imp","_io","_random","_socket","_sre","_string","_struct","_sysconfigdata","_testcapi","_thread","_warnings","_weakref"]
 
 ;(function($B){var js,$pos,res,$op
@@ -995,7 +995,10 @@ this.default_list=[]
 this.other_args=null
 this.other_kw=null
 this.after_star=[]
-this.set_name=function(name){var id_ctx=new $IdCtx(this,name)
+this.set_name=function(name){try{name=$mangle(name,this.parent.tree[0])}catch(err){console.log(err)
+console.log('parent',this.parent)
+throw err}
+var id_ctx=new $IdCtx(this,name)
 this.name=name
 this.id=this.scope.id+'_'+name
 this.id=this.id.replace(/\./g,'_')
@@ -1602,7 +1605,7 @@ return ''}}
 function $IdCtx(C,value){
 this.type='id'
 this.toString=function(){return '(id) '+this.value+':'+(this.tree||'')}
-this.value=value
+this.value=$mangle(value,C)
 this.parent=C
 this.tree=[]
 C.tree[C.tree.length]=this
@@ -2644,6 +2647,12 @@ function $to_js(tree,sep){if(sep===undefined){sep=','}
 return tree.map($to_js_map).join(sep)}
 function $arbo(ctx){while(ctx.parent!=undefined){ctx=ctx.parent}
 return ctx}
+function $mangle(name,C){
+if(name.substr(0,2)=="__" && name.substr(name.length-2)!=="__"){var klass=null,scope=$get_scope(C)
+while(true){if(scope.ntype=="module"){return name}
+else if(scope.ntype=="class"){var class_name=scope.C.tree[0].name
+while(class_name.charAt(0)=='_'){class_name=class_name.substr(1)}
+return '_' + class_name + name}else{if(scope.parent && scope.parent.C){scope=$get_scope(scope.C.tree[0])}else{return name}}}}else{return name}}
 function $transition(C,token){
 switch(C.type){case 'abstract_expr':
 switch(token){case 'id':
@@ -2740,6 +2749,7 @@ $_SyntaxError(C,'token '+token+' after '+C)
 case 'attribute':
 if(token==='id'){var name=arguments[2]
 if(noassign[name]===true){$_SyntaxError(C,["cannot assign to "+name])}
+name=$mangle(name,C)
 C.name=name
 return C.parent}
 $_SyntaxError(C,token)

www/src/py2js.js

@@ -1941,6 +1941,13 @@ function $DefCtx(context){
     this.after_star = []
 
     this.set_name = function(name){
+        try{
+        name = $mangle(name, this.parent.tree[0])
+        }catch(err){
+    console.log(err)
+    console.log('parent', this.parent)
+    throw err
+        }
         var id_ctx = new $IdCtx(this,name)
         this.name = name
         this.id = this.scope.id+'_'+name
@@ -3163,7 +3170,7 @@ function $IdCtx(context,value){
 
     this.type = 'id'
     this.toString = function(){return '(id) '+this.value+':'+(this.tree||'')}
-    this.value = value
+    this.value = $mangle(value, context)
     this.parent = context
     this.tree = []
     context.tree[context.tree.length]=this
@@ -5383,6 +5390,27 @@ function $arbo(ctx){
     return ctx
 }
 
+function $mangle(name, context){
+    // If name starts with __ and doesn't end with __, and if it is defined
+    // in a class, "mangle" it, ie preprend _<classname>
+    if(name.substr(0, 2)=="__" && name.substr(name.length-2)!=="__"){
+        var klass = null,
+            scope = $get_scope(context)
+        while(true){
+            if(scope.ntype=="module"){return name}
+            else if(scope.ntype=="class"){
+                var class_name = scope.context.tree[0].name
+                while(class_name.charAt(0)=='_'){class_name=class_name.substr(1)}
+                return '_' + class_name + name
+            }else{
+                if(scope.parent && scope.parent.context){
+                    scope = $get_scope(scope.context.tree[0])
+                }else{return name}
+            }
+        }
+    }else{return name}
+}
+
 // Function called in function $tokenise for each token found in the
 // Python source code
 
@@ -5507,6 +5535,7 @@ function $transition(context,token){
             var name = arguments[2]
             if(noassign[name]===true){$_SyntaxError(context,
                 ["cannot assign to "+name])}
+            name = $mangle(name, context)
             context.name=name
             return context.parent
         }

www/src/version_info.js

@@ -1,7 +1,7 @@
 __BRYTHON__.implementation = [3, 3, 4, 'dev', 0]
 __BRYTHON__.__MAGIC__ = "3.3.4"
 __BRYTHON__.version_info = [3, 3, 0, 'alpha', 0]
-__BRYTHON__.compiled_date = "2017-09-19 15:43:35.611851"
+__BRYTHON__.compiled_date = "2017-09-19 18:19:02.668328"
 __BRYTHON__.builtin_module_names = ["posix","sys", "errno", "time","_ajax",
     "_base64",
     "_jsre",

www/tests/issues.py

@@ -1435,6 +1435,50 @@ def x(self):
 assert 0.1 is 0.1
 assert not(1 is 1.0)
 
+# issue 673
+class A:
+    __z = 7
+    def __init__(self):
+        self.__x = 20
+
+a = A()
+assert a._A__x == 20
+assert a._A__z == 7
+
+
+class Mapping:
+    def __init__(self, iterable):
+        self.items_list = []
+        self.__update(iterable)
+
+    def update(self, iterable):
+        for item in iterable:
+            self.items_list.append(item)
+
+    __update = update   # private copy of original update() method
+
+class MappingSubclass(Mapping):
+
+    def update(self, keys, values):
+        # provides new signature for update()
+        # but does not break __init__()
+        for item in zip(keys, values):
+            self.items_list.append(item)
+
+mapping = Mapping(range(3))
+mapping.update(range(7, 10))
+assert mapping.items_list == [0, 1, 2, 7, 8, 9]
+
+map2 = MappingSubclass(range(3))
+map2.update(['a', 'b'], [8, 9])
+assert map2.items_list == [0, 1, 2, ('a', 8), ('b', 9)]
+
+class B:
+    def __print(self, name):
+        return name
+
+assert B()._B__print('ok') == 'ok'
+
 # issue 680
 class A:
     def __getattribute__(self, name):