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* [Bug c/108115] New: spurious pointer used after realloc warning
@ 2022-12-15 0:13 tony@develop-help.com
2022-12-15 0:37 ` [Bug middle-end/108115] " pinskia at gcc dot gnu.org
2022-12-15 0:40 ` pinskia at gcc dot gnu.org
0 siblings, 2 replies; 3+ messages in thread
From: tony@develop-help.com @ 2022-12-15 0:13 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108115
Bug ID: 108115
Summary: spurious pointer used after realloc warning
Product: gcc
Version: 12.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: tony@develop-help.com
Target Milestone: ---
Created attachment 54097
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54097&action=edit
Code that demonstrates the warning
gcc 12.0.1 produces a spurious warning when an access to an integer copy of a
pointer is accessed within an unrelated runtime conditional.
With the attachment:
$ /opt/gcc-12.1.0/bin/gcc -c -std=c99 -O2 -Wall -Wextra gcc-20507-simple.c
gcc-20507-simple.c: In function ‘my_realloc’:
gcc-20507-simple.c:13:15: warning: pointer ‘p’ may be used after ‘realloc’
[-Wuse-after-free]
13 | uintptr_t u = (uintptr_t)p;
| ^
gcc-20507-simple.c:15:18: note: call to ‘realloc’ here
15 | void *newp = realloc(p, newsz);
| ^~~~~~~~~~~~~~~~~
$ /opt/gcc-12.1.0/bin/gcc -c -std=c99 -O2 -Wall -Wextra -DDEBUG=1
gcc-20507-simple.c
(no diagnostics)
Note that p is not used after the realloc() in either case.
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug middle-end/108115] spurious pointer used after realloc warning
2022-12-15 0:13 [Bug c/108115] New: spurious pointer used after realloc warning tony@develop-help.com
@ 2022-12-15 0:37 ` pinskia at gcc dot gnu.org
2022-12-15 0:40 ` pinskia at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu.org @ 2022-12-15 0:37 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108115
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
See Also| |https://gcc.gnu.org/bugzill
| |a/show_bug.cgi?id=104215
Resolution|--- |DUPLICATE
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
A dup of bug 106119.
*** This bug has been marked as a duplicate of bug 106119 ***
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug middle-end/108115] spurious pointer used after realloc warning
2022-12-15 0:13 [Bug c/108115] New: spurious pointer used after realloc warning tony@develop-help.com
2022-12-15 0:37 ` [Bug middle-end/108115] " pinskia at gcc dot gnu.org
@ 2022-12-15 0:40 ` pinskia at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu.org @ 2022-12-15 0:40 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108115
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2022-12-15
Status|RESOLVED |NEW
Resolution|DUPLICATE |---
Ever confirmed|0 |1
See Also| |https://gcc.gnu.org/bugzill
| |a/show_bug.cgi?id=106119
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Maybe not exactly a dup. But what is happening is we are sinking the cast to
the conditional which moves it across the free.
But definitely related to PR 106119 and PR 104215 .
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-12-15 0:40 UTC | newest]
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2022-12-15 0:13 [Bug c/108115] New: spurious pointer used after realloc warning tony@develop-help.com
2022-12-15 0:37 ` [Bug middle-end/108115] " pinskia at gcc dot gnu.org
2022-12-15 0:40 ` pinskia at gcc dot gnu.org
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