Subj : Re: Bad object file in record (Newbie to Borland)
To   : borland.public.cpp.borlandcpp
From : Bob Gonder
Date : Fri Jul 09 2004 07:24 pm

Richard wrote:

>I am a new user to borland and am currently using Borland C++ version 5.

Welcome.
BTW, If you turn on line wrapping, it makes reading and replying to
your posts easier.

>  I have a requirement to import a dynamic link library built using VC6++.

>  As I understand it, I use the implib for the .dll to convert the file. Eg.
>c:\bc5\bin\implib 'target.lib' 'source.dll'
>This works fine and I am able to run my program in WIN32, Console mode.

Yep, so far very good.

>  However, I have a requirement to use this under DOS mode.

Not so very good.

>When I try to compile and link the file again using DOS mode, I get the error message.
>
>'Bad object file record in library file.  module DllMain near module file offset 0x0000002B'
>
>Questions...
>1.  Can anyone explain the difference between DOS and Win32 support?

DOS is 16 bit, Win32 is 32 bit. The memory addressing is totally
different, and the size of parameters passed on the stack are
different.   There are supposed to be methods floating around called
"thunk"ing, but I never could find enough info, or figure out how to
use it (I also wanted to use it with a normal lib, not a dll).

Is the DLL written for 32bit or 16 bit code?
Probably 32 bits these days, which doesn't play nice with 16bit DOS
apps.  I suspect that VC6 only supports 32bits, but don't know for
sure.  You're probably out of luck getting a VC DLL to work with a DOS
app.  

Q1: Does it *really* need to be DOS?  Perhaps a Windows Console
application (32 bit) would do the job? (Guess not, as you already have
that)
Q2: Does it *really* need to be a VC6 DLL? Couldn't you work it out so
it's compiled as a normal DOS Lib file? Perhaps you could even use
BC++5 itself to compile it !

>2.  Presumably it's OK to call DLL's from DOS applications.  Am I right in assuming this.

Never done it myself. BC++3 claimed to support it, but my recolection
was that they were Borland DOS DLLs that were supported, and not the
16 bit Windows 3.x that was out at the time, but could be mistaken. I
seem to recall one of the TeamB'ers saying it worked with Windows
DLLs, but again, the crystal ball is fuzzy on that.

>3.  Can anyone help me to try and resolve this issue.

I see only 4 solutions.
1) Write everything for DOS.
2) Write everything for Win32 (console or GUI)
3) Investigate thunking which may or may not work for you.
4) Investigate DOS Extenders that put the cpu in (I always forget
what's real and what's protected) essentially the same mode as Win32
(32 bit addressing, flat memory space), where you stand a better
chance of the 32bit VC code working.
Mind you, no guarantees from me on 3 or 4.

.