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From: cpca@marlin.jcu.edu.au (Colin Adams)
Newsgroups: comp.sys.amiga.programmer
Subject: Re: ANOTHER SAS C BUG
Message-ID: <1991Apr4.035633.16520@marlin.jcu.edu.au>
Date: 4 Apr 91 03:56:33 GMT
References: <1991Apr1.050544.13878@cs.cornell.edu> <98@hdwr1.medar.com> <1991Apr2.194634.27075@cs.cornell.edu>
Organization: James Cook University of North Queensland
Lines: 51

In article <1991Apr2.194634.27075@cs.cornell.edu> johnhlee@cs.cornell.edu (John H. Lee) writes:
>In article <98@hdwr1.medar.com> jseymour@medar.com (James Seymour) writes:
>>John, you are correct in that what the original poster was complaining about
>>is, indeed, a portability "bug".  You are incorrect regarding your comment
>>on how the string should be declared however (does this belong in the C
>>newsgroup?).
>>
>>char *str = "hello";		/* declare a pointer to a char array,
>>				   initialize pointer to a string */
>>
>>char str[] = "hello";		/* declare a character array, initialized
>>				   in length and contents */
>>
>>BIG difference.  Especially if a function in another function is told
>>that str *contains* a pointer to char, when in reality it *is* the start
>>of the character array itself. [I've bitten myself with that one more times
>>than I'd care to count :-)].  Lastly, the amount of memory consumed is
>>not the same for each.  The first declaration takes up <pointer_sized> more
>>memory than the second (although generally this is an insignificant
>>point).  Which way it should be declared depends on what the program[mer]
>>needs.
>

Here's a real SAS C bug

void main()
{
	char *p;

	p = "Well lets's create a really big string here, even though"
	"SAS C only supports strings which are 256 bytes long, but"
	" with this neat new string concatenation feature you can put"
	" strings on several lines.  Unfortunately SAS C doesn't check"
	" if you go over the end of the buffer like this string will,"
	" which will cause the compiler to trash memory and "
	"crash somewhere.  Sometimes this stuffs up the lexical "
	"analysis causing 'Guru trapped' requesters! "
	"Well it was just great fun finding this. ";
}

This mightn't crash SAS as I can't try it from this DECStation, but
you'll get the general idea.  Yes, I do intend to mail them about
it...



-- 
Colin Adams                                  
Computer Science Department                     James Cook University 
Internet : cpca@marlin.jcu.edu.au               North Queensland
'And on the eight day, God created Manchester'