April 29, 2005
Hello!
 I want to link D object files with C objects files, but I'm running with
some compatibility problems because I want to use a different compiler for C
code (Mingw or VC++).
For what I've learned (correct me if I'm wrong) DMD produces OMF object
files and Mingw and VC++ produce COFF object files (I don't even know if
these last two COFF files are compatible).
I would appreciate some help on this issue. Can DMD only produce files in
the OMF format? (an outdated and bad format for what I've read) Or is there
a tool to convert betwen these two formats? (I did a quick search on google
but didn't find anything) Are there any issues in the convertion?

Bruno Medeiros


April 29, 2005
Sounds like fairytail to me... It would be too nice if all things were comatible ;]

In article <d4u9hk$1npu$1@digitaldaemon.com>, Bruno Medeiros says...
>
>Hello!
> I want to link D object files with C objects files, but I'm running with
>some compatibility problems because I want to use a different compiler for C
>code (Mingw or VC++).
>For what I've learned (correct me if I'm wrong) DMD produces OMF object
>files and Mingw and VC++ produce COFF object files (I don't even know if
>these last two COFF files are compatible).
>I would appreciate some help on this issue. Can DMD only produce files in
>the OMF format? (an outdated and bad format for what I've read) Or is there
>a tool to convert betwen these two formats? (I did a quick search on google
>but didn't find anything) Are there any issues in the convertion?
>
>Bruno Medeiros
>
>


April 29, 2005
Bruno Medeiros wrote:
> Hello!
>  I want to link D object files with C objects files, but I'm running with some compatibility problems because I want to use a different compiler for C code (Mingw or VC++).
> For what I've learned (correct me if I'm wrong) DMD produces OMF object files and Mingw and VC++ produce COFF object files (I don't even know if these last two COFF files are compatible).
> I would appreciate some help on this issue. Can DMD only produce files in the OMF format? (an outdated and bad format for what I've read) Or is there a tool to convert betwen these two formats? (I did a quick search on google but didn't find anything) Are there any issues in the convertion?
> 
> Bruno Medeiros 
> 
> 

You may want to try this: use ndisasm to disassemble the OMF and then nasm to assemble it to COFF. You can find both at nasm.sourceforge.net .
I don't know if this will work, and I believe that even if it does you'll run across several other problems like name mangling etc.
Regarding Mingw/VC++ COFF - they are somewhat compatible, I was able to link object files from both compilers; of course I was sticking to C to avoid problems with new/delete and name mangling.

Regards,
JJ
April 30, 2005
"Bruno Medeiros" <daiphoenixNOSPAM@lycos.com> wrote in message news:d4u9hk$1npu$1@digitaldaemon.com...
> Hello!
>  I want to link D object files with C objects files, but I'm running with
> some compatibility problems because I want to use a different compiler for
C
> code (Mingw or VC++).
> For what I've learned (correct me if I'm wrong) DMD produces OMF object
> files and Mingw and VC++ produce COFF object files (I don't even know if
> these last two COFF files are compatible).
> I would appreciate some help on this issue. Can DMD only produce files in
> the OMF format? (an outdated and bad format for what I've read) Or is
there
> a tool to convert betwen these two formats? (I did a quick search on
google
> but didn't find anything) Are there any issues in the convertion?

This issue comes up often. I updated the FAQ for it. www.digitalmars.com/d/faq.html#omf


May 17, 2005
Walter wrote:
> "Bruno Medeiros" <daiphoenixNOSPAM@lycos.com> wrote in message
> news:d4u9hk$1npu$1@digitaldaemon.com...
> 
>>Hello!
>> I want to link D object files with C objects files, but I'm running with
>>some compatibility problems because I want to use a different compiler for
> 
> C
> 
>>code (Mingw or VC++).
>>For what I've learned (correct me if I'm wrong) DMD produces OMF object
>>files and Mingw and VC++ produce COFF object files (I don't even know if
>>these last two COFF files are compatible).
>>I would appreciate some help on this issue. Can DMD only produce files in
>>the OMF format? (an outdated and bad format for what I've read) Or is
> 
> there
> 
>>a tool to convert betwen these two formats? (I did a quick search on
> 
> google
> 
>>but didn't find anything) Are there any issues in the convertion?
> 
> 
> This issue comes up often. I updated the FAQ for it.
> www.digitalmars.com/d/faq.html#omf
> 
> 

Yup, I've read it, and made some simple tests and it worked. A few more questions though:

> "conforming to the usual C ABI interface"
Well, a restriction like that was to be expected. But that also means I can use C++ code that I can put inside a extern "C" {}  , right?


It says on the FAQ you can convert libraries "that come in the form of a DLL", but on the coff2omf page it says you can also convert .obj files. I tried a simple test with MingW and a VStudio 2005 generated .obj's. The MingW .obj worked, the VStudio .obj didn't (link errors with the Debug .obj, and runtime access violations with the Release .obj). What more should I know about converting .obj files (besides that they should have the C ABI) ? Or should I just stick with import libraries?


Also, is the DM coff2omf tool freely available? On the DM website it says it's part of the (paid) Extended Utility package, and I had to use google to find a download link, which did happen to be on the DM site though (ftp://ftp.digitalmars.com/Digital_Mars_C++/Patch/COFF2OMF.zip), but for which I don't even know if its the latest version.


Bruno Medeiros
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