RFR: build pragma error with gcc 4.4.7 (original) (raw)

David Holmes david.holmes at oracle.com
Tue Apr 24 04:11:57 UTC 2018

On 24/04/2018 1:27 PM, Andrew Hughes wrote:

On 23 April 2018 at 20:19, Kim Barrett <kim.barrett at oracle.com> wrote:

On Apr 21, 2018, at 11:18 AM, Andrew Hughes <gnu.andrew at redhat.com> wrote:

On 19 March 2018 at 23:23, Kim Barrett <kim.barrett at oracle.com> wrote: There are also problems with the patch as provided.

(1) Since PRAGMADIAGPUSH/POP do nothing in the version of gcc this change is being made in support of, the warning would be disabled for all following code in any translation unit that includes this file. That doesn't seem good. No, but it's really the only solution on those compilers. We have such usage already elsewhere e.g. // Silence -Wformat-security warning for fatal() PRAGMADIAGPUSH PRAGMAFORMATNONLITERALIGNORED fatal(buf); PRAGMADIAGPOP return true; // silence compiler warnings } in src/hotspot/oscpu/linuxzero/oslinuxzero.cpp If there are other warnings, then they will picked up on newer compilers, especially when building with -Werror. I don't think it's likely people are doing development on older compilers, but rather that we have to use them to build for older platforms. I would be a lot more comfortable if the possibly do-nothing push/pop and the associated code were in a .cpp file, rather than in a .hpp file where it could affect some open-ended and unexpected set of code. Ah yes, sorry, I missed that this was a .hpp, while the others were .cpp. But I think this is moot if os::readdir can be changed to call ::readdir rather than ::readdirr, as appears to be the case, possibly with some documentation about not sharing the DIR* among multiple threads, at least not without locking. I think so too for OpenJDK 11, but I'm reluctant to backport such a change to older JDKs. I guess if we want to continue to workaround the warning there, we'll need to move the function into the .cpp file. That seemed to be what Michal was planning to do, but hasn’t gotten back to it yet. Indeed. He has a patch that does that, that I've already reviewed. Just waiting for him to post it publicly :)

He already has:

RFR: 8179887 - Build failure with glibc >= 2.24: error: 'int readdir_r(DIR*, dirent*, dirent**)' is deprecated

on both the mailing lists this email has gone to.

David

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