AT&T 7300 C compiler/ variable name lengths (general)

[Fred Fish]

> "d0", and so forth.  The SV/68 compiler has a nice way of dealing with
> this; '_' is not prepended to externals, but internal identifiers
> that should be hidden have a '%' in their names, making clashes with
> C identifiers impossible.  The register names recognized by the assembler
> have '%'s in them.

Yes, the assembler uses "%a0", sdb prints it as "a0", and sdb expects
input from the user to be "a0%"  (as in a0%!45 to set a0 to 45).
Of course "splimit%!45", to set global variable "splimit%" to 45 gives
"Unknown register variable".  Nice and consistent!  :-)

-Fred