[Bug tree-optimization/109801] -Wmaybe-uninitialized warning with -O1 on move constructor

[szhong at perforce dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109801

--- Comment #7 from Scott Zhong <szhong at perforce dot com> ---
(In reply to rguent...@suse.de from comment #6)
> > Am 25.05.2023 um 20:24 schrieb pinskia at gcc dot gnu.org 
> > <gcc-bugzi...@gcc.gnu.org>:
> > 
> > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109801
> > 
> > --- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
> > (In reply to Scott Zhong from comment #4)
> >> The move constructor "steals" resources rather than make copies of them, 
> >> and
> >> leave the argument in some valid but otherwise indeterminate state. It is
> >> reasonable that size_ is not initialized in the context of a move
> >> constructor.
> 
> Maybe, but you still copy an uninitialized variable so the diagnostic is
> correct.

If I understand you correctly, the following example should produce an
uninitialized variable diagnostics and the fact that it doesn't means it is a
bug in the compiler?

#include <algorithm>

class table
{
public:
    table()
       : size_(0) {}
    table(table&& other) {
        std::swap(size_, other.size_);
    }
    ~table() {}
private:
    int size_;
};

int main()
{
    table container(std::move(table()));
    return (0);
}