V7M/src/cmd/c/README

The C compiler was changed in two places to build a version
suitable for use with the overlayed kernel.  The header file
c0.h defines the size of the stack frame (STAUTO, actually
the offset to the first auto variable).  The value is controlled
by the symbol OVERLAY; define it to get the overlay version.
(The way I do this is to change the makefile by adding -DOVERLAY
to the definition of CFLAGS.)  Files c02.c and c11.c were also
changed so that the value STAUTO is properly propagated
through the compiler.  Look for the symbol SETSTK to find the
changes.  Note the both passes of the compiler must be replaced,
as well as adding the new first pass ovc0.

The make procedure has been modified to make both the overlay
and non-overlay C compilers.
The make procedure is as follows:

	make -f mfnov c0	(makes c0 pass)
	make -f mfov ovc0 c1 c2	(makes other passes)

Fred Canter 8/30/81

Cc was changed to call the overlay first pass if the -V option
is specified.  The -V option also causes the overlay assembler
to be called.