Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!rutgers!mephisto!ncar!boulder!uswat!uswmrg2!steve
From: steve@uswmrg2.UUCP (Steve Martin)
Newsgroups: comp.sys.mac.programmer
Subject: Re: string initialization in assembly from Think C
Message-ID: <1990Jul18.161030.15283@uswmrg2.UUCP>
Date: 18 Jul 90 16:10:30 GMT
References: <569@ohs.UUCP>
Reply-To: steve@uswmrg2.UUCP (Steve Martin)
Organization: US West Marketing Resources Group, Aurora CO.
Lines: 39

In article <569@ohs.UUCP> stay@ohs.UUCP (Steve Taylor) writes:
>I'm using Think C 4.01 on an SE 30.  I was getting an address error
>(On a Mac Plus) so I checked out the assembled code in macsbug and
>here's what I found:
>
>C Code:
>
>CompareP(p1, p2)
>char *p1, *p2;
>{
>	int 		i, ok = true;
>	long		secs;
>	DateTimeRec	theDate;
>	char		backp[4][16] = {
>	"\x39\x0c\x1d\x1a\x05\x00\x00\x37\x00\x0c\x43\x3b\x0a\x01\x09\x0e",
>	"\x39\x0c\x1d\x1a\x05\x00\x00\x37\x00\x0c\x43\x3b\x0a\x01\x09\x0e",
>	"\x39\x0c\x1d\x1a\x05\x00\x00\x37\x00\x0c\x43\x3b\x0a\x01\x09\x0e",
>	"\x39\x0c\x1d\x1a\x05\x00\x00\x37\x00\x0c\x43\x3b\x0a\x01\x09\x0e",
>	};
>}
>
>Now, since at the time of execution A5 is 0021638E, it's obvious that
>the odd address put into A1 on line 000E and accessed (by a long
>operation) on line 0014 is the problem.  What I want to know is (1) how
>did my my string constants get put at an odd offset from A5),
>and (2) if Think C put them there, shouldn't it have known
>it couldn't MOVE.L them?  And, (3) how am I supposed to initialize
>my array of strings so that this doesn't happen?  (I changed it to
>a BlockMove, Thus performing my own initialization, and it worked fine.)
>Am I making ridiculous assumptions about what all of this means?

Yup, I ran into that same problem.  I think it is a bug in Think C.  To
fix it declare your char array to be static.  Think C then word aligns
the data!  Don't ask me why.

-- 
Steve Martin                         | Nothing I say can be held against
U S West Marketing Resources Group   | Me or my employer!
(...uswat.uswest.com!uswmrg2!steve)