RFR 9: 8074818: Resolve disabled warnings for libjava (original) (raw)

Martin Buchholz martinrb at google.com
Wed May 27 16:54:30 UTC 2015

Evil header file io_util.h effectively requires its callers to include fcntl.h first (on platforms where fcntl.h defines O_SYNC and D_SYNC) and that is a BIG NONO. I would try hard to fix io_util.h now (instead of adding workarounds to callers) and further, if any of its callers were including fcntl.h merely for io_util.h's benefit, remove those include statements. IWYU!

Admittedly, google has far more IWYU religion than most. https://code.google.com/p/include-what-you-use/

On Wed, May 27, 2015 at 7:24 AM, Roger Riggs <Roger.Riggs at oracle.com> wrote:

Hi Martin,

Untangling the past a bit. Perhaps this code could be cleaner but priority-wise, I've got some other things to do first. The Windows fcntl.h does not define OSYNC/ODSYNC so its relative include order is not significant. The explicit define of OSYNC and ODSYNC make the API to the Unix and Windows file support APIs consistent. On Windows file access is done using CreateFileW to get the native Windows semantics. The OSYNC/DSYNC flags are mapped to the corresponding flags/attributes to CreateFileW. Roger

On 5/27/2015 2:59 AM, Martin Buchholz wrote: On Tue, May 26, 2015 at 7:52 PM, Roger Riggs <Roger.Riggs at oracle.com> wrote: Hi, Sadly, but not entirely unexpectedly there is an anomaly in the include files: It seems that Windows does not define OSYNC and ODSYNC. To make up for the absence jdk/src/java.base/share/native/libjava/ioutil.h conditionally defines them. There is no problem if the system include files appear first, but in the other order, fcntl.h tries to re-define it. In the recommended order, there is no issue. We should work hard to remove order dependencies in include files. I see that ioutil.h includes <fcntl.h>, but only on BSD. Why not include it wherever it is available, (which may be all supported platforms!) before trying to define OSYNC and DSYNC?

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