https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96507
Bug ID: 96507
Summary: Feature request: improve "-Waddress" (or equivalent)
for function references inside structs
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: federico.kircheis at gmail dot com
Target Milestone: ---
This is a feature request.
I'm compiling the code with "-Wall -Wextra -pedantic"
----
#include <utility>
void foo(){}
int main(){
void(&f)() = foo;
static_assert(!std::is_pointer<decltype(f)>::value, "should not be a
pointer");
return f != 0;
}
----
gcc correctly triggers the warning "warning: the address of 'void foo()' will
never be NULL [-Waddress]" (nitpick nullptr in the error message would be
better than NULL).
Also for following example gcc emits the desired diagnostic
----
#include <utility>
void foo(){}
using fun = void();
fun& get_fun();
int main(){
fun& f = get_fun();
static_assert(!std::is_pointer<decltype(f)>::value, "should not be a
pointer");
return f != 0;
}
----
But if the function reference is inside a struct:
----
#include <utility>
void foo(){}
using fun = void();
struct s{
fun& f;
};
s get_fun();
int main(){
s ss = get_fun();
static_assert(!std::is_pointer<decltype(ss.f)>::value, "should not be a
pointer");
return ss.f != 0;
}
----
then gcc does not emit any diagnostic (notice: it does if it can inline
get_fun()), even if "knows" that it cannot be null, as the static_assert does
not fire.
As reference: https://godbolt.org/z/vqohqM
