V7 C vs. PCC

[SATZ at SU-SIERRA.ARPA]

From:  Greg Satz <SATZ at SU-SIERRA.ARPA>


I scaned the last two years of unix-wizards archives looking for some
information about the portable C compiler. Since I couldn't find what
I was looking there, I thought I would ask here:

I have a C compiler for the DEC-20. It faithfully parses what is
specified in Kernighan and Ritchie's book. The problem with this is that
it can't parse much code that comes from Berkeley. I don't want to start
any religious battles over what is better. I only want to modifiy this
compiler to make it the best it can be.

>From K+R, page 197:
	"The names of members and tags may be the same as ordinary
	variables. However, names of tags and members must be mutually
	distinct.

	Two members may share a common initial sequence of members; that
	is, the same member may appear in two different structures if it
	has the same type in both and if all previous members are the
	same in both."

My question becomes:
	Why did PCC diverge from this condiition? What other features
are in PCC that aren't in K+R's V7 compiler? I guess I am asking for a
comprehensive list of differences.
-------