Re: C nitpick about pgwin32_dispatch_queued_signals()
Bryan Green <dbryan.green@gmail.com>
From: Bryan Green <dbryan.green@gmail.com>
To: Laurenz Albe <laurenz.albe@cybertec.at>, Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-hackers@lists.postgresql.org
Date: 2025-11-02T16:52:52Z
Lists: pgsql-hackers
On 11/2/2025 10:50 AM, Laurenz Albe wrote: > On Sun, 2025-11-02 at 11:47 -0500, Tom Lane wrote: >> Bryan Green <dbryan.green@gmail.com> writes: >>> On 11/2/2025 7:05 AM, Christian Ullrich wrote: >>>> the current MSVC compiler deems it necessary to issue >>>> warning C4053: one void operand for '?:' >>>> for a line with CHECK_FOR_INTERRUPTS(). This boils down to this bit of >>>> miscadmin.h (line 116 in master): >>>> >>>> #define INTERRUPTS_PENDING_CONDITION() \ >>>> (unlikely(UNBLOCKED_SIGNAL_QUEUE()) ? >>>> pgwin32_dispatch_queued_signals() : 0, \ >>>> unlikely(InterruptPending)) >>>> #endif >>>> >>>> The C spec says that of the possible results of the :? operator, either >>>> none or both can be void, and pgwin32_dispatch_queued_signals() is void >>>> (and has been as far back as I can find it). >> >>> Yeah, this is a bug, or at least a spec violation. We should fix it in >>> my opinion-- it's non-conforming C. Others may disagree, though. >> >> Agreed. >> >> >> Let's go with your #1 (casting the 0 to void). >> But can't we simplify that to just >> >> #define INTERRUPTS_PENDING_CONDITION() \ >> (unlikely(UNBLOCKED_SIGNAL_QUEUE()) ? >> pgwin32_dispatch_queued_signals() : (void) 0, \ >> unlikely(InterruptPending)) >> #endif >> >> that is, the only change needed is s/0/(void) 0/. > > +1 > > Laurenz Albe Option 1 works for me as well. Hopefully, it works for Christian as well.
Commits
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Avoid mixing void and integer in a conditional expression.
- 78d542b2bc0a 13.23 landed
- d26997c71281 14.20 landed
- cd55abab4fa4 15.15 landed
- d5e9c7115027 16.11 landed
- 436d9ed690eb 17.7 landed
- fdbc67572762 18.1 landed
- 645c1e2752d9 19 (unreleased) landed