Attachment 218320 Details for Bug 383780 – patch for migration FAQ

[patch] patch for migration FAQ

Fixed-bug-383780-compiler-Eclipse-42-creates-ambiguo-doc.patch (text/plain), 2.43 KB, created by Ayushman Jain

on 2012-07-05 04:17:16 EDT

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Creator: Ayushman Jain

Created: 2012-07-05 04:17:16 EDT

Size: 2.43 KB

patch

obsolete

>diff --git a/bundles/org.eclipse.jdt.doc.isv/porting/3.8/faq.html b/bundles/org.eclipse.jdt.doc.isv/porting/3.8/faq.html
>index 5355d88..8881492 100644
>--- a/bundles/org.eclipse.jdt.doc.isv/porting/3.8/faq.html
>+++ b/bundles/org.eclipse.jdt.doc.isv/porting/3.8/faq.html
>@@ -13,10 +13,52 @@
> <h1>Eclipse 3.8 Plug-in Migration FAQ</h1>
> 
> <ol>
>-	<li>None</li>
>-
>+	<li><a href="#illegalAmbiguousVarargs">Why does my varargs code which was legal in 3.7 and earlier no longer compile with 3.8 (Juno)?</a></li>
>+</ol>
>+<h2><a name="illegalAmbiguousVarargs">Why does my varargs code which was legal in 3.7 and earlier no longer compile with 3.8 (Juno)?</a></h2>
>+<p>
>+JDK 6 and below had a bug because of which the following code was considered legal:</p>
>+<pre>
>+public class VarargPrimitiveTest {
>+    public static void test(int... a) {
>+        System.out.println(Arrays.toString(a));
>+    }
>+
>+    public static <T> void test(Object... a) {
>+        System.out.println(Arrays.toString(a));
>+    }
>+
>+    public static void main(String[] args) {
>+        test(1);
>+    }
>+}
>+</pre>
>+<p>However, this bug was fixed in JDK 7 and the above code now reports an ambiguous invocation error at the call site for test(..).
>+This was thereby fixed for Eclipse Juno via bug <a href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=346038">346038</a> across all
>+compliance levels. This is why the above code will no longer compile with Juno.</p>
>+
>+<p>If you still want the above code to compile in compliance < 1.7, to mimic JDK 6 or below, you can use the
>+system property <b>tolerateIllegalAmbiguousVarargsInvocation</b> to force Eclipse to tolerate the ambiguous varargs cases
>+such as above. This property can be set in the eclipse.ini file after the -vmargs setting as shown below:</p>
>+<pre>
>+...
>+-vmargs
>+-DtolerateIllegalAmbiguousVarargsInvocation=true
>+...
>+</pre>
>+<p>Note that with this setting, Eclipse Juno does not only mimic JDK 6 and below in letting the above code compile, but also
>+mimics JDK 6 and below in raising an error in cases such as below, even though they're legal in both JDK 7 and in Eclipse Juno when
>+the tolerateIllegalAmbiguousVarargsInvocation is disabled:</p>
>+<pre>
>+class Test {
>+        public static void foo(int ...i) {}
>+        public static void foo(double...d) {}
>+
>+        public static void main(String[] args) {
>+            foo(1, 2, 3);     // foo flagged ambiguous
>+        }
>+}
>+</pre>
> </ol>
> 
> <!--

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