stack memory allocation - (nf)

[guy at rlgvax.UUCP]

Other way around; "alloca" was done as part of PWB/UNIX and was picked up
by Berkeley (like so many other things that have leaked out the back door...),
so it *is* available on PWB/UNIX 1.0 and System III (and possibly V).  Just
look in /lib/libPW.a, unless the implementors of UNIX on that machine decided
they didn't want to bother with "alloca" and rewrote the SCCS and other code
not to use it....  The "-lPW" and "-lpw" libraries were probably written by
the PWB/UNIX folks, and used heavily by PWB-specific software like SCCS.  I
don't know of any new software written with it (especially post-V7 software).
Since the libraries were changed for V7 (f'rinstance, Standard I/O was moved
to "-lc"), I suspect they decided to leave "-lPW" around (but canned "-lpw")
so nobody had to rewrite SCCS (it's OLD code and gives "lint" a coronary) but
decided it wasn't a real supported library and didn't document it; I think
"alloca" is in the PWB/UNIX 1.0 manual but it's not in the System III manual.

	Guy Harris
	{seismo,mcnc,we13,brl-bmd,allegra}!rlgvax!guy