https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91950
Bug ID: 91950
Summary: -Wreturn-type false positive due to CWG 1766
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: john.boyer at tutanota dot com
Target Milestone: ---
Given the following code:
enum class foo
{
bar,
baz,
};
int func(foo f)
{
switch (f)
{
case foo::bar:
return 5;
case foo::baz:
return 10;
}
}
GCC will produce the following bug:
source>:16:1: warning: control reaches end of non-void function [-Wreturn-type]
16 | }
| ^
This diagnostic is incorrect since CWG 1766:
http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1766. Static
casting a number that is not in the range of an enum class is undefined
behavior. It is therefore impossible for standard-compliant code to have an
invalid enum class value, and this diagnostic should not be displayed as
control flow can never reach the end of the function.
