OpenJDK fails to build with GCC when the #include<time.h> inside zip.cpp comes from a non-sysroot path
david.holmes at oracle.com
Mon Dec 3 00:11:06 UTC 2018
On 30/11/2018 11:41 pm, Patrick Zhang wrote:
> Thanks Florian, the "-isystem /usr/include" is helpful to my case, I see gcc.gnu.org says that "it gets the same special treatment that is applied to the standard system directories". As such the issue gets hidden (error suppressed).
> Hi David,
> Thanks for your suggestion. My intention was to limit the influence range as far as I could since I don't have other systems except CentOS/Fedora to verify (even just smoke test) all paths.
You'd need some assistance testing a wider range of platforms but that
can be arranged.
> In addition, if we make below update, does it mean the macro " _REENTRANT " can be removed too? This is probably the only place where _REENTRANT gets used AFAIK.
_REENTRANT is also examined by system headers. It's probably legacy but
would require more investigation.
> #ifdef _MSC_VER // Windows
> #define gmtime_r(t, s) gmtime(t)
> -----Original Message-----
> From: Florian Weimer <fweimer at redhat.com>
> Sent: Thursday, November 29, 2018 8:02 PM
> To: David Holmes <david.holmes at oracle.com>
> Cc: Patrick Zhang <patrick at os.amperecomputing.com>; jdk-dev at openjdk.java.net; core-libs-dev at openjdk.java.net
> Subject: Re: OpenJDK fails to build with GCC when the #include<time.h> inside zip.cpp comes from a non-sysroot path
> * David Holmes:
>> This should really be being discussed on core-libs-dev.
> Okay, moving the conversation.
>>> diff -r 70a423caee44 src/share/native/com/sun/java/util/jar/pack/zip.cpp
>>> --- a/src/share/native/com/sun/java/util/jar/pack/zip.cpp Tue Oct 09 08:33:33 2018 +0100
>>> +++ b/src/share/native/com/sun/java/util/jar/pack/zip.cpp Wed Nov 28 22:13:12 2018 -0500
>>> @@ -415,9 +415,7 @@
>>> ((uLong)h << 11) | ((uLong)m << 5) | ((uLong)s >> 1);
>>> -#ifdef _REENTRANT // solaris
>>> -extern "C" struct tm *gmtime_r(const time_t *, struct tm *); -#else
>>> +#if !defined(_REENTRANT) // linux
>>> #define gmtime_r(t, s) gmtime(t)
>> Under the theme "two wrongs don't make a right" the use of _REENTRANT
>> here is totally inappropriate AFAICS. It seems to be a misguided
>> attempt at determining whether we need the thread-safe gmtime_r or not
>> - and the answer to that should always be yes IMHO.
>> We define _REENTRANT for:
>> - linux
>> - gcc
>> - xlc
>> So the original code will define:
>> extern "C" struct tm *gmtime_r(const time_t *, struct tm *);
>> for linux (and AIX with xlc?) but not Solaris, OS X or Windows.
>> But Solaris has gmtime_r anyway. So the existing code seems a really
>> convoluted hack. AFAICS we have gmtime_r everywhere but Windows (where
>> gmtime is already thread-safe). So it seems to me that all we should
>> need here is:
>> -#ifdef _REENTRANT // solaris
>> -extern "C" struct tm *gmtime_r(const time_t *, struct tm *); -#else
>> +#ifdef _MSC_VER // Windows
>> #define gmtime_r(t, s) gmtime(t)
> That looks much cleaner.
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