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From: "dmalcolm at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug analyzer/105273] -Wanalyzer-use-of-uninitialized-value warns on "missing" default for switch when callers can be statically determined Date: Thu, 12 Jan 2023 20:06:27 +0000 [thread overview] Message-ID: <bug-105273-4-KmtjxD4Uim@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-105273-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105273 --- Comment #5 from David Malcolm <dmalcolm at gcc dot gnu.org> --- Similar thing seen in linuxdoom-1.10: p_floor.c: In function ‘EV_BuildStairs’: p_floor.c:503:22: warning: use of uninitialized value ‘speed’ [CWE-457] [-Wanalyzer-use-of-uninitialized-value] 503 | floor->speed = speed; | ~~~~~~~~~~~~~^~~~~~~ ‘EV_BuildStairs’: events 1-9 | | 472 | fixed_t speed; | | ^~~~~ | | | | | (1) region created on stack here | | (2) capacity: 4 bytes |...... | 476 | while ((secnum = P_FindSectorFromLineTag(line,secnum)) >= 0) | | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | | | | | (3) following ‘true’ branch (when ‘secnum >= 0’)... | 477 | { | 478 | sec = §ors[secnum]; | | ~~~~~~~~~~~~~~~~ | | | | | (4) ...to here |...... | 481 | if (sec->specialdata) | | ~ | | | | | (5) following ‘false’ branch... |...... | 485 | rtn = 1; | | ~~~~~~~ | | | | | (6) ...to here |...... | 492 | switch(type) | | ~~~~~~ | | | | | (7) following ‘default:’ branch... |...... | 503 | floor->speed = speed; | | ~~~~~~~~~~~~~~~~~~~~ | | | | | (8) ...to here | | (9) use of uninitialized value ‘speed’ here | and also with "stairsize". In both cases the analyzer considers the case of taking the "default" branch at: | 492 | switch(type) | | ~~~~~~ | | | | | (7) following ‘default:’ branch... which would leave this uninitialized, where: int EV_BuildStairs ( line_t* line, stair_e type ) and p_spec.h has: typedef enum { build8, // slowly build by 8 turbo16 // quickly build by 16 } stair_e; and the only calls to EV_BuildStairs are in other TUs: p_spec.c: 576: EV_BuildStairs(line,build8); p_spec.c: 739: EV_BuildStairs(line,turbo16); p_switch.c: 350: if (EV_BuildStairs(line,build8)) p_switch.c: 488: if (EV_BuildStairs(line,turbo16)) Probably should assume that a switch on an enum takes one of the enum's values.
next prev parent reply other threads:[~2023-01-12 20:06 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-04-14 11:23 [Bug analyzer/105273] New: " avarab at gmail dot com 2022-04-14 11:25 ` [Bug analyzer/105273] " avarab at gmail dot com 2022-04-14 11:37 ` avarab at gmail dot com 2022-04-14 17:28 ` egallager at gcc dot gnu.org 2022-04-14 21:04 ` dmalcolm at gcc dot gnu.org 2023-01-12 20:06 ` dmalcolm at gcc dot gnu.org [this message] 2023-01-12 21:05 ` dmalcolm at gcc dot gnu.org 2023-01-13 22:52 ` cvs-commit at gcc dot gnu.org 2023-01-13 22:56 ` dmalcolm at gcc dot gnu.org 2023-03-29 23:36 ` dmalcolm at gcc dot gnu.org
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