From: John P. Hartmann. JOHN at EMEAVM1
RE: Null input fields with structured output.
When the output placement is a member, the data will be put in the
same position irrespective of what went before, so the structure is
not lost, but you raise an interesting question:
If any field is put into a strucutre, should the output record be
expanded to contain the entire structure?
If you say yes, that is fine; I think I can manage to pad to the size
of the structure without too much trouble, but if you also insist that
each member initialised according to its type, then explain what
you'll do when the structure is dropped from under you (once data
start to move, the structure situation is no longer stable--it is
while SPEC scans the operands, for it does not give up control in that
process and it carefully samples the structure definitions to avoid
dangling pointers).
SPEC could put a lock on the structures it uses, but then it must also
remember to take them out, which is something I'd rather not promise.
And several stages could put a lock on structures, which would lead to
lots of book-keeping. Sure operating systems do it all the time, so
it is doable.
j. [EMAIL PROTECTED]
