* warning: unsequenced modification and access to 'sa_avail'
@ 2021-03-27 16:05 Jeffrey Walton
2021-03-27 17:01 ` Philipp
0 siblings, 1 reply; 5+ messages in thread
From: Jeffrey Walton @ 2021-03-27 16:05 UTC (permalink / raw)
To: Emacs developers
Hi Everyone,
I'm building Emacs 27.2 on the Apple M1 machine. I think the compiler
is complaining about undefined behavior:
sa_avail -= (size), alloca (size)
I think it is equivalent to something like this:
data[i] = data[i++];
/usr/bin/clang -c -I/usr/local/include -DNDEBUG -Demacs -I. -I.
-I../lib -I../lib -I/usr/local/include/libxml2
-I/usr/local/include -MMD -MF deps/doc.d -MP
-I/usr/local/include -I/usr/local/include/p11-kit-1 -Wno-switch
-Wno-pointer-sign -Wno-string-plus-int -Wno-unknown-attributes
-Wno-initializer-overrides -Wno-tautological-compare
-Wno-tautological-constant-out-of-range-compare -g2 -O2 -fno-common
-arch arm64 -fPIC -pthread doc.c
/usr/bin/clang -c -I/usr/local/include -DNDEBUG -Demacs -I. -I.
-I../lib -I../lib -I/usr/local/include/libxml2
-I/usr/local/include -MMD -MF deps/editfns.d -MP
-I/usr/local/include -I/usr/local/include/p11-kit-1 -Wno-switch
-Wno-pointer-sign -Wno-string-plus-int -Wno-unknown-attributes
-Wno-initializer-overrides -Wno-tautological-compare
-Wno-tautological-constant-out-of-range-compare -g2 -O2 -fno-common
-arch arm64 -fPIC -pthread editfns.c
editfns.c:2063:18: warning: unsequenced modification and access to 'sa_avail'
[-Wunsequenced]
.deletions = SAFE_ALLOCA (del_bytes),
^
./lisp.h:4817:9: note: expanded from macro 'SAFE_ALLOCA'
? AVAIL_ALLOCA (size) \
^
./lisp.h:4812:38: note: expanded from macro 'AVAIL_ALLOCA'
#define AVAIL_ALLOCA(size) (sa_avail -= (size), alloca (size))
^
Jeff
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: warning: unsequenced modification and access to 'sa_avail'
2021-03-27 16:05 warning: unsequenced modification and access to 'sa_avail' Jeffrey Walton
@ 2021-03-27 17:01 ` Philipp
2021-03-27 17:10 ` Jeffrey Walton
0 siblings, 1 reply; 5+ messages in thread
From: Philipp @ 2021-03-27 17:01 UTC (permalink / raw)
To: noloader; +Cc: Emacs developers
> Am 27.03.2021 um 17:05 schrieb Jeffrey Walton <noloader@gmail.com>:
>
> Hi Everyone,
>
> I'm building Emacs 27.2 on the Apple M1 machine. I think the compiler
> is complaining about undefined behavior:
>
> sa_avail -= (size), alloca (size)
>
> I think it is equivalent to something like this:
>
> data[i] = data[i++];
>
> /usr/bin/clang -c -I/usr/local/include -DNDEBUG -Demacs -I. -I.
> -I../lib -I../lib -I/usr/local/include/libxml2
> -I/usr/local/include -MMD -MF deps/doc.d -MP
> -I/usr/local/include -I/usr/local/include/p11-kit-1 -Wno-switch
> -Wno-pointer-sign -Wno-string-plus-int -Wno-unknown-attributes
> -Wno-initializer-overrides -Wno-tautological-compare
> -Wno-tautological-constant-out-of-range-compare -g2 -O2 -fno-common
> -arch arm64 -fPIC -pthread doc.c
> /usr/bin/clang -c -I/usr/local/include -DNDEBUG -Demacs -I. -I.
> -I../lib -I../lib -I/usr/local/include/libxml2
> -I/usr/local/include -MMD -MF deps/editfns.d -MP
> -I/usr/local/include -I/usr/local/include/p11-kit-1 -Wno-switch
> -Wno-pointer-sign -Wno-string-plus-int -Wno-unknown-attributes
> -Wno-initializer-overrides -Wno-tautological-compare
> -Wno-tautological-constant-out-of-range-compare -g2 -O2 -fno-common
> -arch arm64 -fPIC -pthread editfns.c
> editfns.c:2063:18: warning: unsequenced modification and access to 'sa_avail'
> [-Wunsequenced]
> .deletions = SAFE_ALLOCA (del_bytes),
> ^
> ./lisp.h:4817:9: note: expanded from macro 'SAFE_ALLOCA'
> ? AVAIL_ALLOCA (size) \
> ^
> ./lisp.h:4812:38: note: expanded from macro 'AVAIL_ALLOCA'
> #define AVAIL_ALLOCA(size) (sa_avail -= (size), alloca (size))
> ^
>
This has already been fixed by commit 6a4ed891d84b1ca1e4d68a6de9dd374f1fadd971, which hasn't made it into the release though.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: warning: unsequenced modification and access to 'sa_avail'
2021-03-27 17:01 ` Philipp
@ 2021-03-27 17:10 ` Jeffrey Walton
2021-03-27 17:17 ` Philipp
2021-03-27 19:05 ` Andreas Schwab
0 siblings, 2 replies; 5+ messages in thread
From: Jeffrey Walton @ 2021-03-27 17:10 UTC (permalink / raw)
To: Philipp; +Cc: Emacs developers
On Sat, Mar 27, 2021 at 1:01 PM Philipp <p.stephani2@gmail.com> wrote:
>
> > Am 27.03.2021 um 17:05 schrieb Jeffrey Walton <noloader@gmail.com>:
> >
> > I'm building Emacs 27.2 on the Apple M1 machine. I think the compiler
> > is complaining about undefined behavior:
> >
> > sa_avail -= (size), alloca (size)
> >
> > I think it is equivalent to something like this:
> >
> > data[i] = data[i++];
> >
> > /usr/bin/clang -c -I/usr/local/include -DNDEBUG -Demacs -I. -I.
> > -I../lib -I../lib -I/usr/local/include/libxml2
> > -I/usr/local/include -MMD -MF deps/doc.d -MP
> > -I/usr/local/include -I/usr/local/include/p11-kit-1 -Wno-switch
> > -Wno-pointer-sign -Wno-string-plus-int -Wno-unknown-attributes
> > -Wno-initializer-overrides -Wno-tautological-compare
> > -Wno-tautological-constant-out-of-range-compare -g2 -O2 -fno-common
> > -arch arm64 -fPIC -pthread doc.c
> > /usr/bin/clang -c -I/usr/local/include -DNDEBUG -Demacs -I. -I.
> > -I../lib -I../lib -I/usr/local/include/libxml2
> > -I/usr/local/include -MMD -MF deps/editfns.d -MP
> > -I/usr/local/include -I/usr/local/include/p11-kit-1 -Wno-switch
> > -Wno-pointer-sign -Wno-string-plus-int -Wno-unknown-attributes
> > -Wno-initializer-overrides -Wno-tautological-compare
> > -Wno-tautological-constant-out-of-range-compare -g2 -O2 -fno-common
> > -arch arm64 -fPIC -pthread editfns.c
> > editfns.c:2063:18: warning: unsequenced modification and access to 'sa_avail'
> > [-Wunsequenced]
> > .deletions = SAFE_ALLOCA (del_bytes),
> > ^
> > ./lisp.h:4817:9: note: expanded from macro 'SAFE_ALLOCA'
> > ? AVAIL_ALLOCA (size) \
> > ^
> > ./lisp.h:4812:38: note: expanded from macro 'AVAIL_ALLOCA'
> > #define AVAIL_ALLOCA(size) (sa_avail -= (size), alloca (size))
> > ^
> >
>
> This has already been fixed by commit 6a4ed891d84b1ca1e4d68a6de9dd374f1fadd971, which hasn't made it into the release though.
Thanks Philipp.
Forgive my ignorance... Where is that commit? I can't seem to find it
at https://git.savannah.gnu.org/cgit/emacs.git/log/?h=emacs-27.
Searching the logs for your name, and searching for
6a4ed891d84b1ca1e4d68a6de9dd374f1fadd971 (and 6a4ed891d84b) returns 0
hits.
Jeff
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: warning: unsequenced modification and access to 'sa_avail'
2021-03-27 17:10 ` Jeffrey Walton
@ 2021-03-27 17:17 ` Philipp
2021-03-27 19:05 ` Andreas Schwab
1 sibling, 0 replies; 5+ messages in thread
From: Philipp @ 2021-03-27 17:17 UTC (permalink / raw)
To: noloader; +Cc: Emacs developers
> Am 27.03.2021 um 18:10 schrieb Jeffrey Walton <noloader@gmail.com>:
>
> On Sat, Mar 27, 2021 at 1:01 PM Philipp <p.stephani2@gmail.com> wrote:
>>
>>> Am 27.03.2021 um 17:05 schrieb Jeffrey Walton <noloader@gmail.com>:
>>>
>>> I'm building Emacs 27.2 on the Apple M1 machine. I think the compiler
>>> is complaining about undefined behavior:
>>>
>>> sa_avail -= (size), alloca (size)
>>>
>>> I think it is equivalent to something like this:
>>>
>>> data[i] = data[i++];
>>>
>>> /usr/bin/clang -c -I/usr/local/include -DNDEBUG -Demacs -I. -I.
>>> -I../lib -I../lib -I/usr/local/include/libxml2
>>> -I/usr/local/include -MMD -MF deps/doc.d -MP
>>> -I/usr/local/include -I/usr/local/include/p11-kit-1 -Wno-switch
>>> -Wno-pointer-sign -Wno-string-plus-int -Wno-unknown-attributes
>>> -Wno-initializer-overrides -Wno-tautological-compare
>>> -Wno-tautological-constant-out-of-range-compare -g2 -O2 -fno-common
>>> -arch arm64 -fPIC -pthread doc.c
>>> /usr/bin/clang -c -I/usr/local/include -DNDEBUG -Demacs -I. -I.
>>> -I../lib -I../lib -I/usr/local/include/libxml2
>>> -I/usr/local/include -MMD -MF deps/editfns.d -MP
>>> -I/usr/local/include -I/usr/local/include/p11-kit-1 -Wno-switch
>>> -Wno-pointer-sign -Wno-string-plus-int -Wno-unknown-attributes
>>> -Wno-initializer-overrides -Wno-tautological-compare
>>> -Wno-tautological-constant-out-of-range-compare -g2 -O2 -fno-common
>>> -arch arm64 -fPIC -pthread editfns.c
>>> editfns.c:2063:18: warning: unsequenced modification and access to 'sa_avail'
>>> [-Wunsequenced]
>>> .deletions = SAFE_ALLOCA (del_bytes),
>>> ^
>>> ./lisp.h:4817:9: note: expanded from macro 'SAFE_ALLOCA'
>>> ? AVAIL_ALLOCA (size) \
>>> ^
>>> ./lisp.h:4812:38: note: expanded from macro 'AVAIL_ALLOCA'
>>> #define AVAIL_ALLOCA(size) (sa_avail -= (size), alloca (size))
>>> ^
>>>
>>
>> This has already been fixed by commit 6a4ed891d84b1ca1e4d68a6de9dd374f1fadd971, which hasn't made it into the release though.
>
> Thanks Philipp.
>
> Forgive my ignorance... Where is that commit? I can't seem to find it
> at https://git.savannah.gnu.org/cgit/emacs.git/log/?h=emacs-27.
> Searching the logs for your name, and searching for
> 6a4ed891d84b1ca1e4d68a6de9dd374f1fadd971 (and 6a4ed891d84b) returns 0
> hits.
>
Try 'git show 6a4ed891d84b1ca1e4d68a6de9dd374f1fadd971'. Right now it's the ninth-most recent commit on the emacs-27 branch.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: warning: unsequenced modification and access to 'sa_avail'
2021-03-27 17:10 ` Jeffrey Walton
2021-03-27 17:17 ` Philipp
@ 2021-03-27 19:05 ` Andreas Schwab
1 sibling, 0 replies; 5+ messages in thread
From: Andreas Schwab @ 2021-03-27 19:05 UTC (permalink / raw)
To: Jeffrey Walton; +Cc: Philipp, Emacs developers
On Mär 27 2021, Jeffrey Walton wrote:
> Forgive my ignorance... Where is that commit? I can't seem to find it
> at https://git.savannah.gnu.org/cgit/emacs.git/log/?h=emacs-27.
https://git.savannah.gnu.org/cgit/emacs.git/commit/?h=6a4ed891d84b1ca1e4d68a6de9dd374f1fadd971
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
"And now for something completely different."
^ permalink raw reply [flat|nested] 5+ messages in thread
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2021-03-27 16:05 warning: unsequenced modification and access to 'sa_avail' Jeffrey Walton
2021-03-27 17:01 ` Philipp
2021-03-27 17:10 ` Jeffrey Walton
2021-03-27 17:17 ` Philipp
2021-03-27 19:05 ` Andreas Schwab
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