Xref: news2.mv.net comp.os.msdos.djgpp:8075
From: "Mike Marcelais" <michmarc AT microsoft DOT com>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: struct ffblk bug in C++ ?
Date: 30 Aug 1996 16:23:13 GMT
Organization: Microsoft Corporation
Lines: 34
Message-ID: <01bb9690$3b7faa20$ba27379d@michmarc2>
References: <01bb95f3$71842da0$529033c2 AT megar DOT fc-net DOT fr>
NNTP-Posting-Host: 157.55.39.186
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

| #include <dir.h>
| #include <stdio.h>
| main()
| {
| 	int	s;
| 	struct	ffblk dta;
| 	s=findfirst("*.*",&dta,0x10);
| 	while(s!=0)
| 	{	printf("%s\n",dta.ff_name);
| 		s=findnext(&dta);
| 	}
| }
| 
| It works perfectly when compiled in C (TEST.C)
| But when I rename it to TEST.CPP, the program doesn't work: the first two
| letters of ALL entries are missing !!
| I think that it is a bug in the declaration of the ffblk struct. Did you
| ever found this problem ?

Actually, I read here that it is a known problem with the C++ compiler.  The
fix is to provide `wrapper' functions for all of the fields in the findfirst
structure in a C compiled file and use those functions to access the fields. 
[My guess: DJGPP C++ does not pack structures by default like C does, and the
ffblk structure is probably laid out non-ideally, so C++ pads it for speed.]


-- 
+------------------------+----------------------+
| Mike Marcelais         | Excel Developer and  |
| michmarc AT microsoft DOT com | Magic Rules Guru     |
+------------------------+----------------------+
| Opinions expressed in this post are mine, and |
| do not necessarily reflect those of Microsoft |
+--= Moonstone Dragon =---------------= UDIC =--+