* [Bug middle-end/93644] [10/11 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
@ 2020-05-11 14:28 ` msebor at gcc dot gnu.org
2020-08-17 21:27 ` bruno at clisp dot org
` (17 subsequent siblings)
18 siblings, 0 replies; 19+ messages in thread
From: msebor at gcc dot gnu.org @ 2020-05-11 14:28 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |eggert at cs dot ucla.edu
--- Comment #8 from Martin Sebor <msebor at gcc dot gnu.org> ---
*** Bug 95044 has been marked as a duplicate of this bug. ***
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
2020-05-11 14:28 ` [Bug middle-end/93644] [10/11 Regression] spurious -Wreturn-local-addr with PHI of PHI msebor at gcc dot gnu.org
@ 2020-08-17 21:27 ` bruno at clisp dot org
2020-11-26 22:01 ` eggert at cs dot ucla.edu
` (16 subsequent siblings)
18 siblings, 0 replies; 19+ messages in thread
From: bruno at clisp dot org @ 2020-08-17 21:27 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
Bruno Haible <bruno at clisp dot org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |bruno at clisp dot org
--- Comment #9 from Bruno Haible <bruno at clisp dot org> ---
We now have a generic workaround to this bug:
If the bug occurs in a function foo:
1. Rename foo to foo_internal, mark it as '__attribute__ ((__noinline__))
static' and add a 'char stack_buf[1024]' parameter.
2. In the function foo_internal, drop the stack-allocated buffer and use the
new parameter instead.
3. Create a new function foo, with the same signature as before, that merely
allocates a 'char stack_buf[1024]' on the stack and passes it to foo_internal.
For an example, see
https://git.savannah.gnu.org/gitweb/?p=gnulib.git;a=commitdiff;h=2a3468c9f263596815a3383c0157ba9a81cf2d24
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
2020-05-11 14:28 ` [Bug middle-end/93644] [10/11 Regression] spurious -Wreturn-local-addr with PHI of PHI msebor at gcc dot gnu.org
2020-08-17 21:27 ` bruno at clisp dot org
@ 2020-11-26 22:01 ` eggert at cs dot ucla.edu
2020-12-17 1:59 ` eggert at cs dot ucla.edu
` (15 subsequent siblings)
18 siblings, 0 replies; 19+ messages in thread
From: eggert at cs dot ucla.edu @ 2020-11-26 22:01 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
--- Comment #10 from eggert at cs dot ucla.edu ---
The generic workaround that Bruno describes ran into problems in Gnulib, as
it's enabled only when compiled with -DGCC_LINT, and some users don't compile
it that way. So we now have a more elaborate workaround:
https://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=5a8a1598e1243599feb302f0f75d947553f2918f
that causes GCC to issue warnings like the following when the file is not
compiled with -DGCC_LINT:
careadlinkat.c:58:4: warning: #warning "GCC might issue a bogus
-Wreturn-local-addr warning here." [-Wcpp]
58 | # warning "GCC might issue a bogus -Wreturn-local-addr warning here."
| ^~~~~~~
careadlinkat.c:59:4: warning: #warning "See
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644>." [-Wcpp]
59 | # warning "See <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644>."
| ^~~~~~~
careadlinkat.c: In function ‘careadlinkat’:
careadlinkat.c:193:10: warning: function may return address of local variable
[-Wreturn-local-addr]
193 | return readlink_stk (fd, filename, buffer, buffer_size, alloc,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
194 | preadlinkat, stack_buf);
| ~~~~~~~~~~~~~~~~~~~~~~~
careadlinkat.c:192:8: note: declared here
192 | char stack_buf[STACK_BUF_SIZE];
| ^~~~~~~~~
but obviously this is awkward and it would be better if the bug were fixed.
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
` (2 preceding siblings ...)
2020-11-26 22:01 ` eggert at cs dot ucla.edu
@ 2020-12-17 1:59 ` eggert at cs dot ucla.edu
2020-12-17 2:05 ` eggert at cs dot ucla.edu
` (14 subsequent siblings)
18 siblings, 0 replies; 19+ messages in thread
From: eggert at cs dot ucla.edu @ 2020-12-17 1:59 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
--- Comment #11 from eggert at cs dot ucla.edu ---
Created attachment 49783
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=49783&action=edit
another instance of a -Wreturn-local-addr false alarm
I ran into a different instance of the bug today, while working on another
Gnulib source file lib/canonicalize.c. A stripped-down test case attached. To
reproduce the problem:
$ gcc -O2 -S return-local-addr.i
return-local-addr.i: In function ‘canonicalize_filename_mode’:
cc1: warning: function may return address of local variable
[-Wreturn-local-addr]
return-local-addr.i:28:25: note: declared here
28 | struct scratch_buffer rname_buffer;
| ^~~~~~~~~~~~
This is with GCC 10.2.1 20201125 (Red Hat 10.2.1-9) on x86-64.
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
` (3 preceding siblings ...)
2020-12-17 1:59 ` eggert at cs dot ucla.edu
@ 2020-12-17 2:05 ` eggert at cs dot ucla.edu
2020-12-17 5:52 ` noloader at gmail dot com
` (13 subsequent siblings)
18 siblings, 0 replies; 19+ messages in thread
From: eggert at cs dot ucla.edu @ 2020-12-17 2:05 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
--- Comment #12 from eggert at cs dot ucla.edu ---
There are really two bugs here:
(A) GCC emits the false alarm.
(B) there's no way to shut off the false alarm, not even with '# pragma GCC
diagnostic ignored "-Wreturn-local-addr"'.
Although this bug report's replies have been about (A), even fixing (B) would
be a real help with Gnulib.
Should I file a separate bug report for (B)? I assume (B)'s easier to fix.
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
` (4 preceding siblings ...)
2020-12-17 2:05 ` eggert at cs dot ucla.edu
@ 2020-12-17 5:52 ` noloader at gmail dot com
2021-02-12 0:55 ` msebor at gcc dot gnu.org
` (12 subsequent siblings)
18 siblings, 0 replies; 19+ messages in thread
From: noloader at gmail dot com @ 2020-12-17 5:52 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
--- Comment #13 from Jeffrey Walton <noloader at gmail dot com> ---
On Wed, Dec 16, 2020 at 9:05 PM eggert at cs dot ucla.edu
<gcc-bugzilla@gcc.gnu.org> wrote:
> ...
> (B) there's no way to shut off the false alarm, not even with '# pragma GCC
> diagnostic ignored "-Wreturn-local-addr"'.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53431
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
` (5 preceding siblings ...)
2020-12-17 5:52 ` noloader at gmail dot com
@ 2021-02-12 0:55 ` msebor at gcc dot gnu.org
2021-04-27 11:38 ` [Bug middle-end/93644] [10/11/12 " jakub at gcc dot gnu.org
` (11 subsequent siblings)
18 siblings, 0 replies; 19+ messages in thread
From: msebor at gcc dot gnu.org @ 2021-02-12 0:55 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
--- Comment #14 from Martin Sebor <msebor at gcc dot gnu.org> ---
I looks like this might be another opportunity to use the predicate analysis
from tree-ssa-uninit.c (once it's generalized).
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11/12 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
` (6 preceding siblings ...)
2021-02-12 0:55 ` msebor at gcc dot gnu.org
@ 2021-04-27 11:38 ` jakub at gcc dot gnu.org
2021-05-03 14:27 ` jochen447 at concept dot de
` (10 subsequent siblings)
18 siblings, 0 replies; 19+ messages in thread
From: jakub at gcc dot gnu.org @ 2021-04-27 11:38 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|11.0 |11.2
--- Comment #15 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 11.1 has been released, retargeting bugs to GCC 11.2.
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11/12 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
` (7 preceding siblings ...)
2021-04-27 11:38 ` [Bug middle-end/93644] [10/11/12 " jakub at gcc dot gnu.org
@ 2021-05-03 14:27 ` jochen447 at concept dot de
2021-05-04 12:31 ` rguenth at gcc dot gnu.org
` (9 subsequent siblings)
18 siblings, 0 replies; 19+ messages in thread
From: jochen447 at concept dot de @ 2021-05-03 14:27 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
Jochen Roemmler <jochen447 at concept dot de> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jochen447 at concept dot de
--- Comment #16 from Jochen Roemmler <jochen447 at concept dot de> ---
Created attachment 50739
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50739&action=edit
another minimal example to demonstrate the false alarm
This is another instance of the test case. A senseless, yet perfectly valid
piece of C code. It creates the false positive warning if compiled like this:
gcc -Wreturn-local-addr -O1 -fisolate-erroneous-paths-dereference -c
pr93644_2.c
pr93644_2.c: In function ‘buildVname’:
pr93644_2.c:28:12: warning: function may return address of local variable
[-Wreturn-local-addr]
28 | return vname;
| ^~~~~
pr93644_2.c:18:17: note: declared here
18 | char buf[256];
| ^~~
I'm using gcc version 11.1.1 20210428 (Red Hat 11.1.1-1) (GCC)
However, I can silence the warning using
# pragma GCC diagnostic ignored "-Wreturn-local-addr"
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11/12 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
` (8 preceding siblings ...)
2021-05-03 14:27 ` jochen447 at concept dot de
@ 2021-05-04 12:31 ` rguenth at gcc dot gnu.org
2021-07-28 7:04 ` rguenth at gcc dot gnu.org
` (8 subsequent siblings)
18 siblings, 0 replies; 19+ messages in thread
From: rguenth at gcc dot gnu.org @ 2021-05-04 12:31 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11/12 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
` (9 preceding siblings ...)
2021-05-04 12:31 ` rguenth at gcc dot gnu.org
@ 2021-07-28 7:04 ` rguenth at gcc dot gnu.org
2021-10-06 2:01 ` egallager at gcc dot gnu.org
` (7 subsequent siblings)
18 siblings, 0 replies; 19+ messages in thread
From: rguenth at gcc dot gnu.org @ 2021-07-28 7:04 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|11.2 |11.3
--- Comment #17 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 11.2 is being released, retargeting bugs to GCC 11.3
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11/12 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
` (10 preceding siblings ...)
2021-07-28 7:04 ` rguenth at gcc dot gnu.org
@ 2021-10-06 2:01 ` egallager at gcc dot gnu.org
2021-10-06 15:16 ` msebor at gcc dot gnu.org
` (6 subsequent siblings)
18 siblings, 0 replies; 19+ messages in thread
From: egallager at gcc dot gnu.org @ 2021-10-06 2:01 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
--- Comment #18 from Eric Gallager <egallager at gcc dot gnu.org> ---
This affects musl's getcwd implementation, btw:
https://git.musl-libc.org/cgit/musl/tree/src/unistd/getcwd.c?id=v1.2.2
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11/12 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
` (11 preceding siblings ...)
2021-10-06 2:01 ` egallager at gcc dot gnu.org
@ 2021-10-06 15:16 ` msebor at gcc dot gnu.org
2022-03-10 4:20 ` grgoffe at yahoo dot com
` (5 subsequent siblings)
18 siblings, 0 replies; 19+ messages in thread
From: msebor at gcc dot gnu.org @ 2021-10-06 15:16 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
--- Comment #19 from Martin Sebor <msebor at gcc dot gnu.org> ---
GCC 12 has changed to point the warning at the closing curly as suggested in
pr90735 so its output now looks like this:
pr93644.c: In function ‘careadlinkat’:
pr93644.c:30:1: warning: function may return address of local variable
[-Wreturn-local-addr]
30 | }
| ^
pr93644.c:6:8: note: declared here
6 | char stack_buf[1024];
| ^~~~~~~~~
With that change the warning can also be suppressed by #pragma GCC diagnostic
placed before the closing curly.
GCC 12 also has separated the uninitialized predicate analyzer into a
standalone module but no warning except -Wmaybe-uninitialized makes use of it
yet. This bug might be an opportunity to try it out.
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11/12 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
` (12 preceding siblings ...)
2021-10-06 15:16 ` msebor at gcc dot gnu.org
@ 2022-03-10 4:20 ` grgoffe at yahoo dot com
2022-04-21 7:47 ` rguenth at gcc dot gnu.org
` (4 subsequent siblings)
18 siblings, 0 replies; 19+ messages in thread
From: grgoffe at yahoo dot com @ 2022-03-10 4:20 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
George R. Goffe <grgoffe at yahoo dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |grgoffe at yahoo dot com
--- Comment #20 from George R. Goffe <grgoffe at yahoo dot com> ---
Hi,
I'm seeing this message from the "current" findutils.
What is the solution?
Best regards,
George...
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11/12 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
` (13 preceding siblings ...)
2022-03-10 4:20 ` grgoffe at yahoo dot com
@ 2022-04-21 7:47 ` rguenth at gcc dot gnu.org
2022-12-13 0:14 ` [Bug middle-end/93644] [10/11/12/13 " egallager at gcc dot gnu.org
` (3 subsequent siblings)
18 siblings, 0 replies; 19+ messages in thread
From: rguenth at gcc dot gnu.org @ 2022-04-21 7:47 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|11.3 |11.4
--- Comment #21 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 11.3 is being released, retargeting bugs to GCC 11.4.
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11/12/13 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
` (14 preceding siblings ...)
2022-04-21 7:47 ` rguenth at gcc dot gnu.org
@ 2022-12-13 0:14 ` egallager at gcc dot gnu.org
2023-05-29 10:02 ` [Bug middle-end/93644] [10/11/12/13/14 " jakub at gcc dot gnu.org
` (2 subsequent siblings)
18 siblings, 0 replies; 19+ messages in thread
From: egallager at gcc dot gnu.org @ 2022-12-13 0:14 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
--- Comment #22 from Eric Gallager <egallager at gcc dot gnu.org> ---
(In reply to George R. Goffe from comment #20)
> Hi,
>
> I'm seeing this message from the "current" findutils.
>
Likewise with libiconv.
> What is the solution?
One hasn't been figured out yet; just use -Wno-cpp and -Wno-return-local-addr
for now, I guess...
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11/12/13/14 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
` (15 preceding siblings ...)
2022-12-13 0:14 ` [Bug middle-end/93644] [10/11/12/13 " egallager at gcc dot gnu.org
@ 2023-05-29 10:02 ` jakub at gcc dot gnu.org
2023-06-15 15:49 ` pinskia at gcc dot gnu.org
2023-06-15 15:49 ` pinskia at gcc dot gnu.org
18 siblings, 0 replies; 19+ messages in thread
From: jakub at gcc dot gnu.org @ 2023-05-29 10:02 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|11.4 |11.5
--- Comment #23 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 11.4 is being released, retargeting bugs to GCC 11.5.
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11/12/13/14 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
` (16 preceding siblings ...)
2023-05-29 10:02 ` [Bug middle-end/93644] [10/11/12/13/14 " jakub at gcc dot gnu.org
@ 2023-06-15 15:49 ` pinskia at gcc dot gnu.org
2023-06-15 15:49 ` pinskia at gcc dot gnu.org
18 siblings, 0 replies; 19+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-06-15 15:49 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |nullplanwichmann at web dot de
--- Comment #24 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
*** Bug 110267 has been marked as a duplicate of this bug. ***
^ permalink raw reply [flat|nested] 19+ messages in thread* [Bug middle-end/93644] [10/11/12/13/14 Regression] spurious -Wreturn-local-addr with PHI of PHI
[not found] <bug-93644-4@http.gcc.gnu.org/bugzilla/>
` (17 preceding siblings ...)
2023-06-15 15:49 ` pinskia at gcc dot gnu.org
@ 2023-06-15 15:49 ` pinskia at gcc dot gnu.org
18 siblings, 0 replies; 19+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-06-15 15:49 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |dixyes at gmail dot com
--- Comment #25 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
*** Bug 105868 has been marked as a duplicate of this bug. ***
^ permalink raw reply [flat|nested] 19+ messages in thread