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From: "msebor at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c/60488] New: missing -Wmaybe-uninitialized on a conditional with goto Date: Mon, 10 Mar 2014 16:17:00 -0000 [thread overview] Message-ID: <bug-60488-4@http.gcc.gnu.org/bugzilla/> (raw) http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60488 Bug ID: 60488 Summary: missing -Wmaybe-uninitialized on a conditional with goto Product: gcc Version: 4.8.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: msebor at gmail dot com The -Wmaybe-uninitialized option is documented like so: "For an automatic variable, if there exists a path from the function entry to a use of the variable that is initialized, but there exist some other paths for which the variable is not initialized, the compiler emits a warning if it cannot prove the uninitialized paths are not executed at run time." In the program below, when f(&a) returns zero, the variable b is considered to have been initialized by the call to f(&b) when it's used as the argument in the first call to g(b). However, when f(&a) returns non-zero, the variable b is used uninitialized in the second call to g(b). Therefore, there exists a path through the function where b is used initialized as well as one where it's used uninitialized. Thus, GCC should issue a warning. It, however, does not. $ cat t.c && gcc -O2 -Wuninitialized -Wmaybe-uninitialized -c -o/dev/null t.c int f (int**); void g (int*); int foo (void) { int *a, *b; if (f (&a) || f (&b)) goto end; g (a); g (b); return 0; end: g (b); return 1; }
next reply other threads:[~2014-03-10 16:17 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-03-10 16:17 msebor at gmail dot com [this message] 2014-06-25 19:43 ` [Bug middle-end/60488] " manu at gcc dot gnu.org 2014-06-25 19:44 ` manu at gcc dot gnu.org 2021-03-26 23:53 ` [Bug middle-end/60488] missing uninitialized warning (address taken, VOP) msebor at gcc dot gnu.org 2021-03-27 8:57 ` manu at gcc dot gnu.org 2021-03-29 17:43 ` msebor at gcc dot gnu.org 2021-03-30 16:25 ` manu at gcc dot gnu.org 2021-04-06 19:59 ` msebor at gcc dot gnu.org
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