[Bug c++/16190] New: spurious warning about non-virtual destructor

[ncm-nospam at cantrip dot org]

The C++ compiler warns about correct code, under -Wall.

cat >bug.cc <<EOF
  struct foo { 
    virtual void f() {} 
    ~foo() {} 
  };
EOF
gcc -c -Wall bug.cc

  bug.cc:1: warning: struct foo' has virtual functions but 
  non-virtual destructor

It is possible to write bad code that instantiates a "foo"
and deletes it polymorphically, but in common coding patterns
the instances may never be destroyed polymorphically -- always
created on the stack, or as a member of another object -- so 
the warning is spurious.  This warning should at least be moved
to "-Weffc++", if not removed entirely.

If it is considered too useful to remove entirely, it should be 
applied only when a "foo" is actually created in a new-expression, 
and thus actually could be deleted polymorphically.

-- 
           Summary: spurious warning about non-virtual destructor
           Product: gcc
           Version: 3.4.1
            Status: UNCONFIRMED
          Severity: minor
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ncm-nospam at cantrip dot org
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: any
  GCC host triplet: any
GCC target triplet: any


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16190