Bug 88395 - [1.5][compiler] Binary compat problem with enum/switch codegen
Summary: [1.5][compiler] Binary compat problem with enum/switch codegen
Status: VERIFIED FIXED
Alias: None
Product: JDT
Classification: Eclipse Project
Component: Core (show other bugs)
Version: 3.1   Edit
Hardware: PC Windows XP
: P3 normal (vote)
Target Milestone: 3.1 RC1   Edit
Assignee: Olivier Thomann CLA
QA Contact:
URL:
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Depends on:
Blocks:
 
Reported: 2005-03-17 17:30 EST by Tim Hanson CLA
Modified: 2005-05-27 04:47 EDT (History)
1 user (show)

See Also:

Attachments
Apply on HEAD (23.27 KB, patch)
2005-05-20 15:03 EDT, Olivier Thomann CLA 		no flags Details | Diff
Apply on HEAD of org.eclipse.jdt.core.tests.compiler (5.04 KB, patch)
2005-05-20 15:06 EDT, Olivier Thomann CLA 		no flags Details | Diff
Apply on HEAD (23.41 KB, patch)
2005-05-20 15:30 EDT, Olivier Thomann CLA 		no flags Details | Diff
Apply on HEAD (22.91 KB, patch)
2005-05-20 15:33 EDT, Olivier Thomann CLA 		no flags Details | Diff
Apply on HEAD of org.eclipse.jdt.core.tests.compiler (8.80 KB, patch)
2005-05-20 15:34 EDT, Olivier Thomann CLA 		no flags Details | Diff
Show Obsolete (3) View All Add an attachment (proposed patch, testcase, etc.)

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Description Tim Hanson CLA 2005-03-17 17:30:58 EST 
Compile the following two files:

Color.java:
----------------------
package pack;
enum Color {WHITE, BLACK}
----------------------

Test.java:
package pack;
import static pack.Color.*;

public class Test {
    public static void main(String[] args) {
        Color c = BLACK;
        switch(c) {
        case BLACK:
            System.out.println("Black");
            break;
        case WHITE:
            System.out.println("White");
            break;
        }
    }

}
-----------------------------------------

Execute pack.Test and it will print out:
Black
as expected.

Now reorder the two constants inside Color.java and recompile ONLY Color.java.
Now execute pack.Test and it will print out:
White

This violates 13.4.26 of JLS V3

The problem is that the generated switch depends on the ordinal value from the
enum. javac creates a translation table from compile time ordinal-> run time
ordinal and switches based on the translated value.
Comment 1 Olivier Thomann CLA 2005-05-20 15:03:58 EDT 
Created attachment 21522 [details]
Apply on HEAD
Comment 2 Olivier Thomann CLA 2005-05-20 15:06:43 EDT 
Created attachment 21523 [details]
Apply on HEAD of  org.eclipse.jdt.core.tests.compiler

Corresponding regression tests. I will add more.
Comment 3 Olivier Thomann CLA 2005-05-20 15:12:51 EDT 
I just found a bug in my patch when I have two switchs for the same enum type. I
create the synthetic field twice. I am investigating.
Comment 4 Olivier Thomann CLA 2005-05-20 15:30:07 EDT 
Created attachment 21527 [details]
Apply on HEAD
Comment 5 Olivier Thomann CLA 2005-05-20 15:33:08 EDT 
Created attachment 21528 [details]
Apply on HEAD

Remove HashMap from SwitchStatement to replace it with a SyntheticMethodBinding
field. A switch statement can only have one synthetic method. So there is no
need for a hash map.
Comment 6 Olivier Thomann CLA 2005-05-20 15:34:01 EDT 
Created attachment 21529 [details]
Apply on HEAD of  org.eclipse.jdt.core.tests.compiler

More tests.
Comment 7 Olivier Thomann CLA 2005-05-20 16:02:57 EDT 
Fixed and released in HEAD.
Regression tests in
org.eclipse.jdt.core.tests.compiler.regression.EnumTest.test105-111.

Changes in:
org.eclipse.jdt.internal.compiler.ClassFile
org.eclipse.jdt.internal.compiler.ast.SwitchStatement
org.eclipse.jdt.internal.compiler.codegen.CodeStream
org.eclipse.jdt.internal.compiler.codegen.ConstantPool
org.eclipse.jdt.internal.compiler.lookup.SourceTypeBinding
org.eclipse.jdt.internal.compiler.lookup.SyntheticMethodBinding
org.eclipse.jdt.internal.compiler.lookup.TypeConstants
Comment 8 Frederic Fusier CLA 2005-05-27 04:47:10 EDT 
Verified for 3.1 RC1 with build I20050527-0010.