Change to signature of JAWT_GetAWT in Windows libraries

Question

We have noticed a change of the signature for the function JAWT_GetAWT in the Windows libraries at about JDK 1.6 u14.
The function is no longer exported as JAWT_GetAWT@8
instead it is exported as JAWT_GetAWT
Is this a deliberate/permanent change to the exporting of this function?

Answer 1

jschell wrote:
Kattamine wrote:
Not true, the ordinal for the function is 1, the @8 is name mangling indicating the size of the variables
Interesting statement. Some research provided the following....
[http://msdn.microsoft.com/en-us/library/bb687850.aspx]
'For 32-bit Windows API function calls, the convention for the decoration of C-compiled functions is as follows: function_name becomes functionname@n where n is the number of bytes expressed as a decimal taken up by all the arguments, with the bytes for each rounded up to the nearest multiple of four. "
The link is under MS Office 2007 so hopefully it is up to date.
It does however say it is just a convention. That word could suggest that it doesn't need to follow your statement.
Thankyou for the confirmation that what I said was correct.
For info, you may also like to check, the convention is typically broken when you specify a specific name for export, say through a .DEF file.
{quote:title=jschell wrote:}{quote}
{quote:title=Kattamine wrote:}{quote}
If we where using a .lib to access it, we might not have a trouble, however we are using loadlibrary and GetProcAddress.
We now have to do the following to support multiple versions of the 1.6 JRE
          PJAWT_GETAWT JAWT_GetAWT = (PJAWT_GETAWT)GetProcAddress(_hAWT, "JAWT_GetAWT");     // newer version 1.6
          if(!JAWT_GetAWT)
               JAWT_GetAWT = (PJAWT_GETAWT)GetProcAddress(_hAWT, "_JAWT_GetAWT@8");
          if(JAWT_GetAWT)Undocumented features do not require that the provider supports them in any way, including changing them or removing them at any time.
So you must test for every single build version.As you say, undocumented features do not require support, it has been an unofficially documented feature used since JRE 1.3 when it was introduced to have people use the even less documented feature in prior versions that was sun specific. In all the versions between 1.3 and 1.6u14 we have not seen this change, but as you say, it could have changed with each build.
Thats all ok, now at least there will be one document thread somewhere describing that the method has changed and why people will have to make updates, that it is still unsupported and it is still unclear if the change was deliberate or not.