Path: utzoo!attcan!uunet!samsung!zaphod.mps.ohio-state.edu!uwm.edu!bbn.com!saustin
From: saustin@bbn.com (Steve Austin)
Newsgroups: comp.lang.c++
Subject: Re: porting C++ to tranputers
Keywords: ports, transputers
Message-ID: <59874@bbn.BBN.COM>
Date: 8 Oct 90 15:02:12 GMT
References: <1011@oscsunb.osc.edu>
Sender: news@bbn.com
Lines: 59

raghu@osc.edu (Raghu Machiraju) writes:

>Has there been any attempt to port the AT&T translator to the transputer.
>If anybody has done so or is aware of such an effort would he/she be kind
>enough  to share his/her experiences . More specifically I am interested in 
>using the Logical Sytems C compiler for the port .

I haven't ported AT&T's translator to RUN on a transputer, but it is
trivially easy to get C++ code compiled FOR a transputer - or anything
else really - if you have a C compiler for the target machine.

The program 'CC' is just a shell script which takes the C++ program,
runs it through the pre-processor, runs the output of this through
cfront and then compiles the resulting C code with the standard compiler.

It is easy to divert the last step (compiling with the default cc) and
then compile with the cross-compiler. If you don't want to mess around with
the shell script environment variables, you can yse the -Fc switch to get
C code produced from the standard output of CC, redirect this to a temporary
file and compile this.

I have also got this to work when the C++ and C compilers run on different
machines by using some "rsh" hacks.

There are some minor difficulies to be overcome.

1.	"munch" may not work, since the nm command for the non-native code
	may not be compatible. I have avoided this by not using globals
	variables which have constructors. The action of munch is to construct
	a special function called _main(), which calls these constructors
	at the star of main().

2.	You have to write a dummy *C* _main() i.e.
		void	_main() {}
	so that you don't get a complaint that the symbol _main is
	undefined when you link.

3.	You have to write code for "operator new" and "operator delete"
	(in C++). I just wrote new as a wrapper for "malloc" and delete as
	a wrapper for "free".

4.	Watch out for problems with include files. The only problem I had
	was that SUN's ctype.h seems to be different from anybody else's.
	This is a difference between the character table being defined
	as _ctype_ in on and __ctype in another (or something like that).
	However, your mileage may vary.

Running CC on a SUN, I have done this successfully for the following
processors.

	Transputer
	IBM RS6000
	I860

	Steve Austin

P.S. No guarantees of accuracy here. I speak for myself, not my employer.

P.P.S Yes, I know this is a hack - no flames please.