[Bug c++/18855] New: illegal code compiles and segfaults in runtime

["istvan dot zolyomi at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

The following mistyped illegal code compiles. The resulted executable crashes
because of the accepted illegal pointers.

// ---------------------------------------------------------------------------
struct Base {};

struct Derived : protected Base {
    operator const Base* () const {
        return *this; // --- Illegal type, should be written without *
    }
};

int main()
{
    Derived der;
    const Base *bp = static_cast<const Base*>(der);

    (void) bp; // --- Avoid warning

    return 0;
}
// ------------------------------------------------------------------------

Compiled with the command:

g++ -Wall -ansi -pedantic source.cpp


Detailed configuration info is:

Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --enable-shared --enable-threads=posix
--disable-checking --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --host=i386-redhat-linux
Thread model: posix
gcc version 3.4.1 20040714 (Red Hat 3.4.1-7)
GNU C++ version 3.4.1 20040714 (Red Hat 3.4.1-7) (i386-redhat-linux)
        compiled by GNU C version 3.4.1 20040714 (Red Hat 3.4.1-7).
GGC heuristics: --param ggc-min-expand=64 --param ggc-min-heapsize=64160
 as -V -Qy -o /tmp/cco9w5Jv.o /tmp/ccCvMY8N.s

-- 
           Summary: illegal code compiles and segfaults in runtime
           Product: gcc
           Version: 3.4.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: istvan dot zolyomi at gmail dot com
                CC: gcc-bugs at gcc dot gnu dot org,scamel at elte dot hu
 GCC build triplet: gcc version 3.4.1 20040714 (Red Hat 3.4.1-7)
  GCC host triplet: Linux
GCC target triplet: i386


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18855