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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug analyzer/94839] New: False positive with -fanalyzer and direct field assignment from calloc Date: Wed, 29 Apr 2020 02:15:49 +0000 [thread overview] Message-ID: <bug-94839-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94839 Bug ID: 94839 Summary: False positive with -fanalyzer and direct field assignment from calloc Product: gcc Version: 10.0 Status: UNCONFIRMED Keywords: diagnostic Severity: normal Priority: P3 Component: analyzer Assignee: dmalcolm at gcc dot gnu.org Reporter: pinskia at gcc dot gnu.org Target Milestone: --- Take: struct bitmap { int min; int max; int *vec; }; int bitmap_create(struct bitmap *bm, int min, int max) { int sz; sz = (max / sizeof(int)) + 1; bm->min = min; bm->max = max; bm->vec = __builtin_calloc(sz, sizeof(int)); if (!bm->vec) return (-12); return 0; } ----- CUT ---- This gives (at -O2 -fanalyzer -W -Wall ): In function ‘bitmap_create’: t6666_1.c:18:12: warning: leak of ‘<unknown>’ [CWE-401] [-Wanalyzer-malloc-leak] 18 | if (!bm->vec) | ^ ‘bitmap_create’: events 1-3 | | 13 | sz = (max / sizeof(int)) + 1; | | ~~~~~^~~~~~~~~~~~~~ | | | | | (1) allocated here |...... | 18 | if (!bm->vec) | | ~ | | | | | (2) assuming ‘<unknown>’ is non-NULL | | (3) following ‘false’ branch... | ‘bitmap_create’: event 4 | |cc1: | (4): ...to here | ‘bitmap_create’: event 5 | | 18 | if (!bm->vec) | | ^ | | | | | (5) ‘<unknown>’ leaks here; was allocated at (1) | Except there is no leaking as assign the calloc to bm->vec . If we change the type of vec to void*, there is no warning.
next reply other threads:[~2020-04-29 2:15 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-04-29 2:15 pinskia at gcc dot gnu.org [this message] 2020-04-29 2:17 ` [Bug analyzer/94839] " pinskia at gcc dot gnu.org 2020-08-13 20:31 ` dmalcolm at gcc dot gnu.org 2020-08-13 20:34 ` dmalcolm at gcc dot gnu.org
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