[gwt-contrib] Issue3796 Patch

[cromwellian]

Reviewers: ,

Description:
Syntax error due to inlining of numeric literal into jsni function

Java code:
public class Main implements EntryPoint {
   private native static String toFixed(double value, int n) /*-{
     return value.toFixed(n);
   }-*/;

   public void onModuleLoad() {
     Window.alert(toFixed(42.0, 2));
   }
}

Output:
$wnd.alert(42.toFixed(2))
// syntax error 42.toFixed(2) should be (42).toFixed(2)


This patch handles both invocations (42.method()) and name refs
(42.field).


Please review this at http://gwt-code-reviews.appspot.com/47809

Affected files:
   dev/core/src/com/google/gwt/dev/js/JsToStringGenerationVisitor.java


Index: dev/core/src/com/google/gwt/dev/js/JsToStringGenerationVisitor.java
===================================================================
--- dev/core/src/com/google/gwt/dev/js/JsToStringGenerationVisitor.java  
(revision 5638)
+++ dev/core/src/com/google/gwt/dev/js/JsToStringGenerationVisitor.java  
(working copy)
@@ -982,6 +982,14 @@
      p.print(CHARS_IF);
    }

+  // Issue #3796, inlining of numeric literals can produce illegal JS
+  // expressions. x = 42, x.method() is legal. 42.method() is illegal.
+  // The fix is to add parentheses, e.g. (42).method()
+  private boolean _isWeirdLiteralDot(JsExpression parent, JsExpression  
child) {
+    return child instanceof JsNumberLiteral && (parent instanceof  
JsInvocation
+        || parent instanceof JsNameRef);
+  }
+
    private void _in() {
      p.print(CHARS_IN);
    }
@@ -1044,9 +1052,10 @@
        boolean wrongAssoc) {
      int parentPrec = JsPrecedenceVisitor.exec(parent);
      int childPrec = JsPrecedenceVisitor.exec(child);
-    return (parentPrec > childPrec || (parentPrec == childPrec &&  
wrongAssoc));
+    return (parentPrec > childPrec || (parentPrec == childPrec &&  
wrongAssoc) ||
+            _isWeirdLiteralDot(parent, child));
    }
-
+
    private boolean _parenPop(JsExpression parent, JsExpression child,
        boolean wrongAssoc) {
      boolean doPop = _parenCalc(parent, child, wrongAssoc);



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