Обсуждение: Fix for compiler warning triggered in WinGetFuncArgInPartition()
Hello, This is a minor change that avoids a "maybe uninitialized" warning that I've been seeing since: 25a30bbd423 Add IGNORE NULLS/RESPECT NULLS option to Window functions. src/backend/postgres_lib.a.p/executor_nodeWindowAgg.c.o../src/backend/executor/nodeWindowAgg.c: In function ‘WinGetFuncArgInPartition’:../src/backend/executor/nodeWindowAgg.c:3809:33: warning:‘notnull_relpos’ may be used uninitialized [-Wmaybe-uninitialized] 3809 | } while (notnull_offset < notnull_relpos); | ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~../src/backend/executor/nodeWindowAgg.c:3723:33: note: ‘notnull_relpos’was declared here 3723 | int notnull_relpos; | ^~~~~~~~~~~~~~ To calm the compiler's nerves this patch moves the initialization of notnull_relpos to later in the function. best. -greg
Вложения
On Thu, Oct 09, 2025 at 10:21:23AM -0400, Greg Burd wrote: > ‘WinGetFuncArgInPartition’:../src/backend/executor/nodeWindowAgg.c:3809:33: > warning:‘notnull_relpos’ may be used uninitialized > [-Wmaybe-uninitialized] 3809 | } while (notnull_offset < > notnull_relpos); | > ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~../src/backend/executor/nodeWindowAgg.c:3723:33: > note: ‘notnull_relpos’was declared here 3723 | int > notnull_relpos; | ^~~~~~~~~~~~~~ Just curious, what compiler/version is this? I skimmed the buildfarm a bit but didn't find any such warnings. -- nathan
On Thu, Oct 09, 2025 at 09:41:15AM -0500, Nathan Bossart wrote: > On Thu, Oct 09, 2025 at 10:21:23AM -0400, Greg Burd wrote: >> ‘WinGetFuncArgInPartition’:../src/backend/executor/nodeWindowAgg.c:3809:33: >> warning:‘notnull_relpos’ may be used uninitialized >> [-Wmaybe-uninitialized] 3809 | } while (notnull_offset < >> notnull_relpos); | >> ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~../src/backend/executor/nodeWindowAgg.c:3723:33: >> note: ‘notnull_relpos’was declared here 3723 | int >> notnull_relpos; | ^~~~~~~~~~~~~~ > > Just curious, what compiler/version is this? I skimmed the buildfarm a bit > but didn't find any such warnings. Looks like Tom just fixed this: https://postgr.es/c/71540dc -- nathan
On Oct 9 2025, at 10:45 am, Nathan Bossart <nathandbossart@gmail.com> wrote: > On Thu, Oct 09, 2025 at 09:41:15AM -0500, Nathan Bossart wrote: >> On Thu, Oct 09, 2025 at 10:21:23AM -0400, Greg Burd wrote: >>> ‘WinGetFuncArgInPartition’:../src/backend/executor/nodeWindowAgg.c:3809:33: >>> warning:‘notnull_relpos’ may be used uninitialized >>> [-Wmaybe-uninitialized] 3809 | } while (notnull_offset < >>> notnull_relpos); | >>> ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~../src/backend/executor/nodeWindowAgg.c:3723:33: >>> note: ‘notnull_relpos’was declared here 3723 | int >>> >>> notnull_relpos; | ^~~~~~~~~~~~~~ >> >> Just curious, what compiler/version is this? I skimmed the buildfarm >> a bit >> but didn't find any such warnings. > > Looks like Tom just fixed this: https://postgr.es/c/71540dc Scooped! Thanks Tom. :) regards. -greg > -- > nathan
Greg Burd <greg@burd.me> writes:
> To calm the compiler's nerves this patch moves the initialization of
> notnull_relpos to later in the function.
I was seeing the same warning for "forward" in the buildfarm,
so I moved all of these initializations down. Otherwise,
looks like we independently invented the same fix ...
regards, tom lane
Nathan Bossart <nathandbossart@gmail.com> writes:
> Just curious, what compiler/version is this? I skimmed the buildfarm a bit
> but didn't find any such warnings.
My warning-scraping script found
arowana | 2025-10-07 04:51:16 | nodeWindowAgg.c:3723:8: warning: 'forward' may be used uninitialized in this
function[-Wmaybe-uninitialized]
arowana | 2025-10-07 04:51:16 | nodeWindowAgg.c:3790:8: warning: 'notnull_relpos' may be used uninitialized in
thisfunction [-Wmaybe-uninitialized]
buri | 2025-10-05 21:30:13 | nodeWindowAgg.c:3723:8: warning: 'forward' may be used uninitialized in this
function[-Wmaybe-uninitialized]
buri | 2025-10-05 21:30:13 | nodeWindowAgg.c:3790:8: warning: 'notnull_relpos' may be used uninitialized in
thisfunction [-Wmaybe-uninitialized]
dhole | 2025-10-05 07:34:51 | nodeWindowAgg.c:3723:8: warning: 'forward' may be used uninitialized in this
function[-Wmaybe-uninitialized]
dhole | 2025-10-05 07:34:51 | nodeWindowAgg.c:3790:8: warning: 'notnull_relpos' may be used uninitialized in
thisfunction [-Wmaybe-uninitialized]
rhinoceros | 2025-10-09 11:10:27 | nodeWindowAgg.c:3724:8: warning: 'forward' may be used uninitialized in this
function[-Wmaybe-uninitialized]
rhinoceros | 2025-10-09 11:10:27 | nodeWindowAgg.c:3809:2: warning: 'notnull_relpos' may be used uninitialized in
thisfunction [-Wmaybe-uninitialized]
shelduck | 2025-10-09 12:14:10 | nodeWindowAgg.c:3724:6: warning: 'forward' may be used uninitialized in this
function[-Wmaybe-uninitialized]
shelduck | 2025-10-09 12:14:10 | nodeWindowAgg.c:3809:2: warning: 'notnull_relpos' may be used uninitialized in
thisfunction [-Wmaybe-uninitialized]
These all seem to be RHEL7 derivatives running gcc 4.8.something.
Since Greg saw it only for notnull_relpos, I'm guessing he's
running something else.
regards, tom lane
On Oct 9 2025, at 11:28 am, Tom Lane <tgl@sss.pgh.pa.us> wrote: > Nathan Bossart <nathandbossart@gmail.com> writes: >> Just curious, what compiler/version is this? I skimmed the buildfarm >> a bit >> but didn't find any such warnings. > > My warning-scraping script found > > arowana | 2025-10-07 04:51:16 | nodeWindowAgg.c:3723:8: warning: > 'forward' may be used uninitialized in this function [-Wmaybe-uninitialized] > arowana | 2025-10-07 04:51:16 | nodeWindowAgg.c:3790:8: warning: > 'notnull_relpos' may be used uninitialized in this function [-Wmaybe-uninitialized] > buri | 2025-10-05 21:30:13 | nodeWindowAgg.c:3723:8: warning: > 'forward' may be used uninitialized in this function [-Wmaybe-uninitialized] > buri | 2025-10-05 21:30:13 | nodeWindowAgg.c:3790:8: warning: > 'notnull_relpos' may be used uninitialized in this function [-Wmaybe-uninitialized] > dhole | 2025-10-05 07:34:51 | nodeWindowAgg.c:3723:8: warning: > 'forward' may be used uninitialized in this function [-Wmaybe-uninitialized] > dhole | 2025-10-05 07:34:51 | nodeWindowAgg.c:3790:8: warning: > 'notnull_relpos' may be used uninitialized in this function [-Wmaybe-uninitialized] > rhinoceros | 2025-10-09 11:10:27 | nodeWindowAgg.c:3724:8: warning: > 'forward' may be used uninitialized in this function [-Wmaybe-uninitialized] > rhinoceros | 2025-10-09 11:10:27 | nodeWindowAgg.c:3809:2: warning: > 'notnull_relpos' may be used uninitialized in this function [-Wmaybe-uninitialized] > shelduck | 2025-10-09 12:14:10 | nodeWindowAgg.c:3724:6: warning: > 'forward' may be used uninitialized in this function [-Wmaybe-uninitialized] > shelduck | 2025-10-09 12:14:10 | nodeWindowAgg.c:3809:2: warning: > 'notnull_relpos' may be used uninitialized in this function [-Wmaybe-uninitialized] > > These all seem to be RHEL7 derivatives running gcc 4.8.something. > Since Greg saw it only for notnull_relpos, I'm guessing he's > running something else. GCC 14.2.1 on Fedora 42. I wonder why I didn't see the warning for 'forward' too. > regards, tom lane best. -greg