https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120597
Bug ID: 120597
Summary: False positive -Wreturn-type after std::unreachable()
or __builtin_unreachable()
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: janschultke at googlemail dot com
Target Milestone: ---
Consider this example (https://godbolt.org/z/oK7nKPjbP):
> struct S { ~S(); };
>
> int f();
>
> int g() {
> S s;
> if (f()) return 0;
> __builtin_unreachable();
> f(); // warning: control reaches end of non-void function [-Wreturn-type]
> }
Normally, placing a function call after __builtin_unreachable() has no effect
on whether -Wreturn-type is emitted, but a combination of non-trivial
destruction and the conditional return beforehand result in a warning anyway.
This is obviously a false positive because control cannot reach the end of a
function if we unconditionally call __builtin_unreachable() somewhere in the
middle.
