Re: RFA: libjava seems to miss some files for win32

[Andrew Haley <aph@redhat.com>]

On 07/19/2009 02:29 PM, Dave Korn wrote:
> Kai Tietz wrote:
> 
>> There are a lot of issues about casting HANDLE values into jint types,
>> which is for x86 valid, but for x64 can lead potential to pointer
>> truncations. Those part need some review by libjava maintainers. My
>> patch simply casts those kind of pointers via __UINTPTR_TYPE__ into
>> integer scalar before casting it into jint. I put comments at those
>> places, where some rework is necessary.
> 
>   Argh.  You're replacing a bunch of warnings that draw attention to a real
> problem by a bunch of silent fixmes in the code.  That's a bit scary to me.

Me too.  That patch will not be accepted.

>> Index: gcc/libjava/gnu/java/net/natPlainSocketImplWin32.cc
>> ===================================================================
>> --- gcc.orig/libjava/gnu/java/net/natPlainSocketImplWin32.cc	2009-07-19 12:06:54.200476000 +0200
>> +++ gcc/libjava/gnu/java/net/natPlainSocketImplWin32.cc	2009-07-19 12:13:45.727476500 +0200
>> @@ -58,7 +58,8 @@
>>  
>>    // We use native_fd in place of fd here.  From leaving fd null we avoid
>>    // the double close problem in FileDescriptor.finalize.
>> -  native_fd = (jint) hSocket;
>> +  // Fixme, it isn't correct to cast a HANDLE to integer scalar here for x64
>> +  native_fd = (jint) (__UINTPTR_TYPE__) hSocket;
>>  }
> 
> 
>   Question is, can we change the sizes of the members of class objects, such
> as gnu::java::net::PlainSocketImpl::native_fd, or do these objects and their
> layout form part of an ABI, and/or do they ever get serialised?  The Java guys
> will be able to tell us.

Yes, you can change them.  Yes, they are part of an ABI.  native_fd should be
a jlong.

Andrew.