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* [Bug analyzer/109131] New: -Wanalyzer-deref-before-check false positive seen in git's builtin/show-ref.c @ 2023-03-14 19:30 dmalcolm at gcc dot gnu.org 2023-10-27 17:50 ` [Bug analyzer/109131] " alexey.lapshin at espressif dot com ` (4 more replies) 0 siblings, 5 replies; 6+ messages in thread From: dmalcolm at gcc dot gnu.org @ 2023-03-14 19:30 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109131 Bug ID: 109131 Summary: -Wanalyzer-deref-before-check false positive seen in git's builtin/show-ref.c Product: gcc Version: 13.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: analyzer Assignee: dmalcolm at gcc dot gnu.org Reporter: dmalcolm at gcc dot gnu.org Target Milestone: --- Created attachment 54664 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54664&action=edit Reduced reproducer Trunk erroneously emits: deref-before-check-git-show-ref.c: In function 'cmd_show_ref': deref-before-check-git-show-ref.c:39:8: warning: check of 'argv' for NULL after already dereferencing it [-Wanalyzer-deref-before-check] 39 | if (!pattern) | ^ 'cmd_show_ref': events 1-8 | | 31 | if (exclude_arg) | | ^ | | | | | (1) following 'false' branch... |...... | 34 | pattern = argv; | | ~~~~~~~~~~~~~~ | | | | | (2) ...to here | 35 | if (!*pattern) | | ~ ~~~~~~~~ | | | | | | | (3) pointer 'argv' is dereferenced here | | (4) following 'false' branch... |...... | 38 | if (verify) { | | ~~~~~~~ | | || | | |(5) ...to here | | (6) following 'true' branch... | 39 | if (!pattern) | | ~~~~~~~~~ | | || | | |(7) ...to here | | (8) pointer 'argv' is checked for NULL here but it was already dereferenced at (3) | on the attached. https://godbolt.org/z/oW4hvqx7K ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug analyzer/109131] -Wanalyzer-deref-before-check false positive seen in git's builtin/show-ref.c 2023-03-14 19:30 [Bug analyzer/109131] New: -Wanalyzer-deref-before-check false positive seen in git's builtin/show-ref.c dmalcolm at gcc dot gnu.org @ 2023-10-27 17:50 ` alexey.lapshin at espressif dot com 2024-02-15 19:56 ` [Bug analyzer/109131] [13/14 Regression] " dmalcolm at gcc dot gnu.org ` (3 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: alexey.lapshin at espressif dot com @ 2023-10-27 17:50 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109131 Alexey <alexey.lapshin at espressif dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |alexey.lapshin at espressif dot co | |m --- Comment #1 from Alexey <alexey.lapshin at espressif dot com> --- There is a smaller reproducer: ``` struct a { int b; }; void foo(struct a *p) { if (p->b) p = 0; if (p && p->b) // "p" can be 0 but warning ; } ``` ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug analyzer/109131] [13/14 Regression] -Wanalyzer-deref-before-check false positive seen in git's builtin/show-ref.c 2023-03-14 19:30 [Bug analyzer/109131] New: -Wanalyzer-deref-before-check false positive seen in git's builtin/show-ref.c dmalcolm at gcc dot gnu.org 2023-10-27 17:50 ` [Bug analyzer/109131] " alexey.lapshin at espressif dot com @ 2024-02-15 19:56 ` dmalcolm at gcc dot gnu.org 2024-03-04 13:00 ` rguenth at gcc dot gnu.org ` (2 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: dmalcolm at gcc dot gnu.org @ 2024-02-15 19:56 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109131 David Malcolm <dmalcolm at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Ever confirmed|0 |1 Status|UNCONFIRMED |NEW Last reconfirmed| |2024-02-15 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug analyzer/109131] [13/14 Regression] -Wanalyzer-deref-before-check false positive seen in git's builtin/show-ref.c 2023-03-14 19:30 [Bug analyzer/109131] New: -Wanalyzer-deref-before-check false positive seen in git's builtin/show-ref.c dmalcolm at gcc dot gnu.org 2023-10-27 17:50 ` [Bug analyzer/109131] " alexey.lapshin at espressif dot com 2024-02-15 19:56 ` [Bug analyzer/109131] [13/14 Regression] " dmalcolm at gcc dot gnu.org @ 2024-03-04 13:00 ` rguenth at gcc dot gnu.org 2024-03-08 15:38 ` law at gcc dot gnu.org 2024-05-21 9:14 ` [Bug analyzer/109131] [13/14/15 " jakub at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: rguenth at gcc dot gnu.org @ 2024-03-04 13:00 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109131 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|--- |13.3 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug analyzer/109131] [13/14 Regression] -Wanalyzer-deref-before-check false positive seen in git's builtin/show-ref.c 2023-03-14 19:30 [Bug analyzer/109131] New: -Wanalyzer-deref-before-check false positive seen in git's builtin/show-ref.c dmalcolm at gcc dot gnu.org ` (2 preceding siblings ...) 2024-03-04 13:00 ` rguenth at gcc dot gnu.org @ 2024-03-08 15:38 ` law at gcc dot gnu.org 2024-05-21 9:14 ` [Bug analyzer/109131] [13/14/15 " jakub at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: law at gcc dot gnu.org @ 2024-03-08 15:38 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109131 Jeffrey A. Law <law at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |law at gcc dot gnu.org Priority|P3 |P2 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug analyzer/109131] [13/14/15 Regression] -Wanalyzer-deref-before-check false positive seen in git's builtin/show-ref.c 2023-03-14 19:30 [Bug analyzer/109131] New: -Wanalyzer-deref-before-check false positive seen in git's builtin/show-ref.c dmalcolm at gcc dot gnu.org ` (3 preceding siblings ...) 2024-03-08 15:38 ` law at gcc dot gnu.org @ 2024-05-21 9:14 ` jakub at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: jakub at gcc dot gnu.org @ 2024-05-21 9:14 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109131 Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|13.3 |13.4 --- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> --- GCC 13.3 is being released, retargeting bugs to GCC 13.4. ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2024-05-21 9:14 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2023-03-14 19:30 [Bug analyzer/109131] New: -Wanalyzer-deref-before-check false positive seen in git's builtin/show-ref.c dmalcolm at gcc dot gnu.org 2023-10-27 17:50 ` [Bug analyzer/109131] " alexey.lapshin at espressif dot com 2024-02-15 19:56 ` [Bug analyzer/109131] [13/14 Regression] " dmalcolm at gcc dot gnu.org 2024-03-04 13:00 ` rguenth at gcc dot gnu.org 2024-03-08 15:38 ` law at gcc dot gnu.org 2024-05-21 9:14 ` [Bug analyzer/109131] [13/14/15 " jakub at gcc dot gnu.org
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