C++ demangler horrors

[Alexandre Oliva]

On Jul  1, 2003, "H. J. Lu" <hjl@lucon.org> wrote:

> I don't get it. Are you saying you can link with libiberty before
> libiberty is done?

No.  I'm just concerned about dependencies that might go missing.
Modifying a file in a different directory is very bad practice in my
book.

> Can you tell me how a parallel build will fail with my proposal?

At first, it seemed to me that it obviously didn't, but that still
didn't make it right.

Now consider a Cygwin build.  The Cygwin library must not depend on
the demangle target, otherwise we're back to the original problem.
But both the Cygwin library and the demangler depend on libiberty.
Now consider that the Cygwin library may be linked with libiberty
while the demangler modifies libiberty.  Oops.

Also, consider the case that the cygwin library might, for whatever
reason, want to use the demangler from libiberty.  What now?  Should
it really get the wrong demangler, or fail to link?

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer                 aoliva@{redhat.com, gcc.gnu.org}
CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist                Professional serial bug killer