easy to miss bug (even in structured debug)

[Mark S. Miller <mark>]

Date: Mon, 20 Nov 89 14:11:09 PST
   From: tribble (Eric Dean Tribble)

   I occasionally worry about bugs resulting from passing NULL pointers
   rather than pointers to objects.  The 'fetch' operations make this
   especially easy.  I check these by considering the types {Foo *|NULL}
   different from {Foo*} when I walk through the code in my mind.

   Is there an anolgous scheme for structured debug?  Can we add this
   stronger type-checking in xlint?

I'll let Michael address the structured debug issues.  

Roland: let's talk about this tomorrow as well.  I think this is
probably easy (or at least possible) to XLint for.