Define JNIEXPORT as visibility default with GCC?
jeremymanson at google.com
Fri Feb 15 08:41:14 PST 2013
Can we just blacklist 4.1.2 explicitly?
On Fri, Feb 15, 2013 at 2:20 AM, David Holmes <david.holmes at oracle.com>wrote:
> On 15/02/2013 5:26 PM, Jeremy Manson wrote:
>> a) I don't know what's going on behind the scenes, but if this sounds
>> like a good idea to folks, can we open a bug and get the process
>> otherwise rolling?
>> b) Martin, where did the 4.2 restriction come from? Both Apple's site
>> and the gcc wiki say that visibility support arrived in 4.0:
> From the original push for 6588413 in linux gcc.make:
> +# version 4 and above support fvisibility=hidden (matches jni_x86.h file)
> +# except 4.1.2 gives pointless warnings that can't be disabled (afaik)
> So it was limited on x86 to >2 (which I think was a typo: intended to be
> >=2 or >1 ?)
> Of course the bsd port copied the linux file.
> http://gcc.gnu.org/wiki/**Visibility <http://gcc.gnu.org/wiki/Visibility>
>> On Thu, Feb 14, 2013 at 3:01 PM, David DeHaven <david.dehaven at oracle.com
>> <mailto:david.dehaven at oracle.**com <david.dehaven at oracle.com>>> wrote:
>> >>>> +#if defined(__GNUC__) && (__GNUC__ > 4) || (__GNUC__ == 4) &&
>> >>>> (__GNUC_MINOR__ > 2)
>> >>>> + #define JNIEXPORT __attribute__((visibility("**
>> >>>> + #define JNIIMPORT __attribute__((visibility("**
>> >>> The default compiler in Xcode 4.1 is llvm-gcc 4.2, it seems.
>> The conditional above excludes that. Is this intentional?
>> >> It's *is* gcc, with a LLVM backend.
>> > Yes, but it identifies itself as GCC 4.2, so the conditional
>> doesn't fire.
>> I assume this was not the intent and the version check is just wrong.
>> It may be that they deliberately stayed with gcc 4.2 to keep parity with
>> clang, which only supports 4.2 (or it may not, because clang supports
>> lots of 4.3+ features).
>> > If Xcode is fine with the #define, I suggest to drop the version
>> check completely. We already do not support compiling with GCC
>> versions which are so old that they lack visibility support.
>> If it were Mac only, I'd agree.
>> The same header is currently used for all "unix-like" OS's (which
>> may change, if I have my way), so Solaris and Linux would also be
>> affected. Most Linux distros have used gcc 4 for quite a while now,
>> I've no idea what Solaris uses and embedded targets are a wild
>> mishmash of whatever someone manages to cobble together, so the
>> simpler __GNUC__ check may still be appropriate.
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the hotspot-runtime-dev