Library privacy.

dart/frog/leg/namer.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * Assigns JavaScript identifiers to Dart variables, class-names and members.
  */
 class Namer {
   final Compiler compiler;
 
@@ skipping 16 matching lines @@
   Namer(this.compiler)
       : globals = new Map<Element, String>(),
         usedGlobals = new Map<String, int>();
 
   final String CURRENT_ISOLATE = "\$";
   final String ISOLATE = "Isolate";
 
 
   String closureInvocationName(Selector selector) {
     // TODO(floitsch): mangle, while not conflicting with instance names.
-    return instanceMethodInvocationName(CLOSURE_INVOCATION_NAME, selector);
+    return instanceMethodInvocationName(null, CLOSURE_INVOCATION_NAME,
+                                        selector);
   }
 
-  String instanceMethodName(SourceString name, int arity) {
+  String instanceMethodName(LibraryElement lib, SourceString name, int arity) {
     // TODO(floitsch): mangle, while preserving uniqueness.
-    return '${name.slowToString()}\$$arity';
+    if (name.isPrivate()) {

[kasperl, 2012/03/13 13:43:51]

How about refactoring this pattern?

[ahe, 2012/03/17 22:19:44]

Done.

+      return '_${getName(lib)}${name.slowToString()}\$$arity';
+    } else {
+      return '${name.slowToString()}\$$arity';
+    }
   }
 
-  String instanceMethodInvocationName(SourceString name, Selector selector) {
+  String instanceMethodInvocationName(LibraryElement lib, SourceString name,
+                                      Selector selector) {
     // TODO(floitsch): mangle, while preserving uniqueness.
     StringBuffer buffer = new StringBuffer();
     List<SourceString> names = selector.getOrderedNamedArguments();
     for (SourceString name in names) {
       buffer.add(@'$');
       name.printOn(buffer);
     }
-    return '${name.slowToString()}\$${selector.argumentCount}$buffer';
+    if (name.isPrivate()) {
+      return '_${getName(lib)}${name.slowToString()}\$${selector.argumentCount}$buffer';

[ngeoffray, 2012/03/13 12:47:11]

line too long

[ahe, 2012/03/17 22:19:44]

Done.

+    } else {
+      return '${name.slowToString()}\$${selector.argumentCount}$buffer';
+    }
   }
 
-  String instanceFieldName(SourceString name) {
-    return name.slowToString();
+  String instanceFieldName(LibraryElement lib, SourceString name) {
+    if (name.isPrivate()) {
+      return '_${getName(lib)}${name.slowToString()}';
+    } else {
+      return name.slowToString();
+    }
   }
 
-  String setterName(SourceString name) {
-    return 'set\$${name.slowToString()}';
+  String setterName(LibraryElement lib, SourceString name) {
+    if (name.isPrivate()) {
+      return 'set\$_${getName(lib)}${name.slowToString()}';
+    } else {
+      return 'set\$${name.slowToString()}';
+    }
   }
 
-  String getterName(SourceString name) {
-    return 'get\$${name.slowToString()}';
+  String getterName(LibraryElement lib, SourceString name) {
+    if (name.isPrivate()) {
+      return 'get\$_${getName(lib)}${name.slowToString()}';
+    } else {
+      return 'get\$${name.slowToString()}';
+    }
   }
 
   String getFreshGlobalName(String proposedName) {
     int usedCount = usedGlobals[proposedName];
     if (usedCount === null) {
       // No element with this name has been used before.
       usedGlobals[proposedName] = 1;
       return proposedName;
     } else {
       // Not the first time we see this name. Append a number to make it unique.
       String name;
       do {
         usedCount++;
         name = '$proposedName$usedCount';
       } while (usedGlobals[name] !== null);
       usedGlobals[proposedName] = usedCount;
       return name;
     }
   }
 
   /**
    * Returns a preferred JS-id for the given top-level or static element.
    * The returned id is guaranteed to be a valid JS-id.
    */
   String _computeGuess(Element element) {
     assert(!element.isInstanceMember());
+    LibraryElement lib = element.getLibrary();
     if (element.kind == ElementKind.GENERATIVE_CONSTRUCTOR) {
       FunctionElement functionElement = element;
-      return instanceMethodName(
-          element.name, functionElement.parameterCount(compiler));
+      return instanceMethodName(lib, element.name,
+                                functionElement.parameterCount(compiler));
     } else {
       // TODO(floitsch): deal with named constructors.
       String name;
       if (element.kind == ElementKind.GETTER) {
-        name = getterName(element.name);
+        name = getterName(lib, element.name);

[floitsch, 2012/03/13 13:28:56]

I agree that this makes the code maybe even simpler, but we don't need to care
for the library for static elements.

[ahe, 2012/03/13 15:48:58]

Good point, I didn't think about that.

Actually, the code may be simpler if static methods and constructors aren't
prefixed. I didn't like what I had to do for constructors.

       } else if (element.kind == ElementKind.SETTER) {
-        name = setterName(element.name);
+        name = setterName(lib, element.name);
       } else if (element.kind == ElementKind.FUNCTION) {
         FunctionElement functionElement = element;
         name = element.name.slowToString();
         name = '$name\$${functionElement.parameterCount(compiler)}';

[floitsch, 2012/03/13 13:28:56]

Actually we don't need to care for the parameterCount either.

[ahe, 2012/03/13 15:48:58]

Another good point I didn't think about.

+      } else if (element.kind === ElementKind.LIBRARY) {
+        name = 'lib';

[ngeoffray, 2012/03/13 12:47:11]

Very surprised by this, it should not happen.

[ahe, 2012/03/13 15:48:58]

It is because I started using getName on libraries to get a unique prefix. See
line 44.

       } else {
         name = '${element.name.slowToString()}';
       }
       // Prefix the name with '$' if it is reserved.
       if (jsReserved.contains(name)) {
         name = "\$$name";
         assert(!jsReserved.contains(name));
       }
       return name;
     }
   }
 
   String getBailoutName(Element element) {
     return '${getName(element)}\$bailout';
   }
 
   /**
    * Returns a preferred JS-id for the given element. The returned id is
    * guaranteed to be a valid JS-id. Globals and static fields are furthermore
    * guaranteed to be unique.
    *
    * For accessing statics consider calling
    * [isolateAccess]/[isolateBailoutAccess] or [isolatePropertyAccess] instead.
    */
   String getName(Element element) {
     if (element.isInstanceMember()) {
       if (element.kind == ElementKind.GENERATIVE_CONSTRUCTOR_BODY) {
         ConstructorBodyElement bodyElement = element;
         SourceString name = bodyElement.constructor.name;
-        return instanceMethodName(name, bodyElement.parameterCount(compiler));
+        return instanceMethodName(element.getLibrary(),
+                                  name, bodyElement.parameterCount(compiler));
       } else if (element.kind == ElementKind.FUNCTION) {
         FunctionElement functionElement = element;
-        return instanceMethodName(
-            element.name, functionElement.parameterCount(compiler));
+        return instanceMethodName(element.getLibrary(),
+                                  element.name,
+                                  functionElement.parameterCount(compiler));
       } else if (element.kind == ElementKind.GETTER) {
-        return getterName(element.name);
+        return getterName(element.getLibrary(), element.name);
       } else if (element.kind == ElementKind.SETTER) {
-        return setterName(element.name);
+        return setterName(element.getLibrary(), element.name);
       } else {
-        return instanceFieldName(element.name);
+        return instanceFieldName(element.getLibrary(), element.name);
       }
     } else {
       // Dealing with a top-level or static element.
       String cached = globals[element];
       if (cached !== null) return cached;
 
       String guess = _computeGuess(element);
       switch (element.kind) {
         case ElementKind.VARIABLE:
         case ElementKind.PARAMETER:
           // The name is not guaranteed to be unique.
           return guess;
 
         case ElementKind.GENERATIVE_CONSTRUCTOR:
         case ElementKind.FUNCTION:
         case ElementKind.CLASS:
         case ElementKind.FIELD:
         case ElementKind.GETTER:
         case ElementKind.SETTER:
         case ElementKind.TYPEDEF:
+        case ElementKind.LIBRARY:

[ngeoffray, 2012/03/13 12:47:11]

ditto.

           String result = getFreshGlobalName(guess);
           globals[element] = result;
           return result;
 
         default:
           compiler.internalError('getName for unknown kind: ${element.kind}',
                                  node: element.parseNode(compiler));
       }
     }
   }
@@ skipping 11 matching lines @@
   }
 
   String isolateBailoutAccess(Element element) {
     return '${isolateAccess(element)}\$bailout';
   }
 
   String operatorIs(Element element) {
     return 'is\$${getName(element)}';
   }
 }