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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/109364] Missing return statement in a non void function gives only a warning but produces a forced crash. Date: Fri, 31 Mar 2023 23:24:50 +0000 [thread overview] Message-ID: <bug-109364-4-mM1JRB1sOR@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-109364-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109364 --- Comment #11 from Jonathan Wakely <redi at gcc dot gnu.org> --- I already explained this on reddit, and it's already explained in PR 43943. There are programs that are valid and must not give an error. int f() { } int main() { } This never calls f() so there is no problem. -Werror=return-type would fail to compile this valid program. int g(bool b) { if (b) return 1; } int main() { g(true); } This program calls g(true) which is OK, it never calls g(false). -Werror=return-type would fail to compile this valid program. The C++ standard says these programs must be accepted without errors. What GCC does is allow you to compile broken code, but it warns, and since GCC 13 it tries to prevent completely unpredictable undefined behaviour if you accidentally do fall off the end of a function without returning.
prev parent reply other threads:[~2023-03-31 23:24 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-03-31 18:34 [Bug c++/109364] New: " contact at thunderperfectwitchcraft dot org 2023-03-31 18:38 ` [Bug c++/109364] " pinskia at gcc dot gnu.org 2023-03-31 18:40 ` pinskia at gcc dot gnu.org 2023-03-31 22:17 ` contact at thunderperfectwitchcraft dot org 2023-03-31 22:19 ` pinskia at gcc dot gnu.org 2023-03-31 22:21 ` contact at thunderperfectwitchcraft dot org 2023-03-31 22:37 ` pinskia at gcc dot gnu.org 2023-03-31 22:46 ` contact at thunderperfectwitchcraft dot org 2023-03-31 22:54 ` pinskia at gcc dot gnu.org 2023-03-31 22:57 ` redi at gcc dot gnu.org 2023-03-31 23:00 ` contact at thunderperfectwitchcraft dot org 2023-03-31 23:24 ` redi at gcc dot gnu.org [this message]
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