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.
David
http://gcc.gnu.org/wiki/Visibility
https://developer.apple.com/library/mac/#documentation/DeveloperTools/Conceptual/CppRuntimeEnv/Articles/SymbolVisibility.html
On Thu, Feb 14, 2013 at 3:01 PM, David DeHaven <david.deha...@oracle.com
<mailto:david.deha...@oracle.com>> wrote:
>>>> +#if defined(__GNUC__) && (__GNUC__ > 4) || (__GNUC__ == 4) &&
>>>> (__GNUC_MINOR__ > 2)
>>>> + #define JNIEXPORT __attribute__((visibility("default")))
>>>> + #define JNIIMPORT __attribute__((visibility("default")))
>>>
>>> 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.
-DrD-
