Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!rutgers!cbmvax!daveh
From: daveh@cbmvax.cbm.UUCP (Dave Haynie)
Newsgroups: comp.sys.cbm
Subject: Re: C-power bugs
Message-ID: <988@cbmvax.cbmvax.cbm.UUCP>
Date: Thu, 13-Nov-86 12:51:32 EST
Article-I.D.: cbmvax.988
Posted: Thu Nov 13 12:51:32 1986
Date-Received: Thu, 13-Nov-86 21:48:51 EST
References: <156@uwslh.UUCP>
Organization: Commodore Technology, West Chester, PA
Lines: 59

> 
> 	The problem: passing 'char' variables by value to procedures.  It took
> me a year to discover this, and after I changed how I was passing chars, I
> haven't had problems since.  I have talked with several people VERY familiar
> with C, and this is what we have come up with.  Apparently, when C (in 
> general)> passes a char variable, it is expanded to the size of an int, 
> pushed on the stack, the procedure is called, the variable (now size int) 
> is popped off, and it is 'decomposed' down to a char size again.  

Just a point here - while I wouldn't be surprised if the method you
describe is actually what C-Power does, being thet you're running on a 
6510, that has nothing to do which C language in general.  This is a
compiler implementation detail, and will change from machine to machine.
On the Amiga, for instance, the first several parameters in a function
call are passed in machine registers, not on the stack.  

> However, C-power seems to leave out the 'decomposition' step...
> Chris Lishka                   /lishka@uwslh.uucp
> Wisconsin State Lab of Hygiene -lishka%uwslh.uucp@rsch.wisc.edu
>                                \{seismo, harvard,topaz,...}!uwvax!uwslh!lishka

I don't actually own C64 C-Power, though I played with a friend's copy
about a year ago for a weekend.  I didn't run across this bug, but I
encountered another compiler error.  It seems if I were to use either:

#define BYTE char;

or 

typedef char BYTE;

and then create a function like:

BYTE Wombat(x,y,x)
BYTE x,y,z;
{...}

The compiler would choke, claiming some sort of syntax error.  I think this
was fixed in later versions, and the best way to find out about any of
the compiler upgrades or any other information is to call the C-Power BBS,
the number should be in the front of your manual.  The BBS is in Canada, 
and they (as of last I heard) only support Punter (often pronounced
Punt-Her) protocol.  I've been considering the C-128 version of the
C-Power compiler; its a really good compiler, very fast, and the editor
with error checking is really nice.  Then again, I have all these Amiga
around to write C code on...

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dave Haynie	{caip,ihnp4,allegra,seismo}!cbmvax!daveh

	"Laws to supress tend to strengthen what they would prohibit.
	 This is the fine point on which all the legal professions of
	 history have based their job security."
						-Bene Gesserit Coda

These opinions are my own, though for a small fee they may be yours too.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~