🚀 go-pugleaf

The following program compiles without error under gcc-2.3.3.  It
should instead give an error message, since f is not accessible
through D.  Substituting the commented-out declaration of x causes gcc
to correctly identify an error.  For some reason, the extra level of
derivation makes a difference.

P. Hilfinger

Session:

% gcc-2.3.3 -v -Wall -o misc misc.C
Reading specs from /usr/sww/lib/gcc-lib/sparc-sun-sunos4.1/2.3.3/specs
gcc version 2.3.3
 /usr/sww/lib/gcc-lib/sparc-sun-sunos4.1/2.3.3/cpp -lang-c++ -v -undef -D__GNUC__=2 -D__GNUG__=2 -D__cplusplus -Dsparc -Dsun -Dunix -D__sparc__ -D__sun__ -D__unix__ -D__sparc -D__sun -D__unix -Wall misc.C /usr/tmp/cca04944.i
GNU CPP version 2.3.3 (sparc)
 /usr/sww/lib/gcc-lib/sparc-sun-sunos4.1/2.3.3/cc1plus /usr/tmp/cca04944.i -quiet -dumpbase misc.cc -Wall -version -o /usr/tmp/cca04944.s
GNU C++ version 2.3.3 (sparc) compiled by GNU C version 2.3.3.
 as -o /usr/tmp/cca049441.o /usr/tmp/cca04944.s
 /usr/sww/lib/gcc-lib/sparc-sun-sunos4.1/2.3.3/ld -e start -dc -dp -o misc /lib/crt0.o -L/usr/sww/lib/gcc-lib/sparc-sun-sunos4.1/2.3.3 -L/usr/sww/lib /usr/tmp/cca049441.o -lgcc -lc -lgcc
% 

Source: 

------------------------------cut here----------------------------------------
class A {
public:
    virtual void f() {}
};

class C: public A {
private:
    void f() {  }
};

class D : public C {
};

int main()
{
    D* x = new D;
//  C* x = new C;

    x -> f();
    return 0;
}