[bug #35327] "Changed type signature" debug output

[Fred Kiefer]

URL:
  <http://savannah.gnu.org/bugs/?35327>

                 Summary: "Changed type signature" debug output
                 Project: GNUstep
            Submitted by: FredKiefer
            Submitted on: Do 19 Jan 2012 09:16:18 GMT
                Category: Base/Foundation
                Severity: 2 - Minor
              Item Group: Bug
                  Status: None
                 Privacy: Public
             Assigned to: None
             Open/Closed: Open
         Discussion Lock: Any

    _______________________________________________________

Details:

When starting up Ink with debug output enabled (openapp Ink/Ink
--GNU-Debug=dflt) I get the following message a lot:

File GSFFIInvocation.m: 604. In GSFFIInvocationCallback Changed type signature
'Vv52@0:8@16@24@32C40@44' to 'Vv56@0:8@16@24@32C40@48' for
'postNotificationName:object:userInfo:deliverImmediately:for:'


Wolfgang Lux analysed the issue and came up with this explanation:
>I think the problem is in NSMethodSignature, which seems to reconstruct the
Objective-C types.
>Try this on your machine:

>  printf("%s\n", [[NSMethodSignature signatureWithObjCTypes:
"Vv52@0:8@16@24@32C40@44"] methodType]);

>It should print Vv56@0:8@16@24@32C40@48. So it looks like
NSMethodTypeSignature is enforcing stricter alignment constraints than the
compiler.


And that was the output I got whit gcc 4.6 on OpenSuse 12.1.
Now I don't know whether gcc is wrong here or base, but it would be great to
get them to agree on the signature of the method. As I understand it a
disagreement here may easily lead to stack corruption.





    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/bugs/?35327>

_______________________________________________
  Nachricht geschickt von/durch Savannah
  http://savannah.gnu.org/