[Mingw-notify] [ mingw-Bugs-729213 ] Windows DLL linking problem

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Bugs item #729213, was opened at 2003-04-29 06:14
Message generated for change (Comment added) made by infidel
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=102435&aid=729213&group_id=2435

Category: gcc
Group: None
Status: Deleted
Resolution: Invalid
Priority: 5
Submitted By: Federico Andres Lois (flois)
>Assigned to: Luke Dunstan (infidel)
Summary: Windows DLL linking problem

Initial Comment:
Hi, i had been trying to link a VC6.0 ready made library for RPC 
with DLL. So i had made the import libraries using the dllwrap tool 
provided with Dev-Cpp. I am using the last Beta version of Dev-
Cpp which package the Mingw 3.2 compiler, i had tracked down 
the problem to the linker. I put this as a bug report because the 
linker generate a windows error message when trying to link this 
project. I had tried linking with the --allow-multiple-definition 
directive but cannot link the project either.

Take a look at the attach, it is the complete project so you can 
trigger the error.

My specs are:

Windows XP Professional
256 MB Memory
Dev-Cpp Beta 4.9.8.0


--------------------- Cut here -------------------------

Configured with C:\ARCHIV~2\MISDOC~1\RPCGcc\Configured 
with ../gcc/configure --with-gcc --with-gnu-ld --with-gnu-as --
host=mingw32 --target=mingw32 --prefix=/mingw --enable-
threads --disable-nls --enable-languages=f77,c++,objc,ada --
disable-win32-registry --disable-shared
Thread model C:\ARCHIV~2\MISDOC~1\RPCGcc\Thread 
model win32
crtstuff.c C:\Archivos de Datos\Mis Documentos\RPCGcc\d32-
rpc.lib(.text+0x110) multiple definition of `atexit'
crt1.c C:\Program Files\Dev-Cpp\lib\crt2.o(.text+0x40) first defined 
here
crtstuff.c C:\Archivos de Datos\Mis Documentos\RPCGcc\d32-
rpc.lib(.text+0x140) multiple definition of `_onexit'
crt1.c C:\Program Files\Dev-Cpp\lib\crt2.o(.text+0x60) first defined 
here
.
.
.
crtstuff.c C:\Archivos de Datos\Mis Documentos\RPCGcc\d32-
rpc.lib(.rdata+0x0) multiple definition of `__EH_FRAME_BEGIN__'
crtstuff.c C:\Program Files\Dev-Cpp\lib\gcc-lib\mingw32\3.2
\crtbegin.o(.eh_frame+0x0) first defined here
 C:\ARCHIV~2\MISDOC~1\RPCGcc\Makefile.win [Build Error] 
[RPCCLI~1.exe] Error 1

--------------------------------------------------------

Greetings
Federico Andres Lois
Xenocide Programming Team

----------------------------------------------------------------------

>Comment By: Luke Dunstan (infidel)
Date: 2003-04-30 10:43

Message:
Logged In: YES 
user_id=30442

When you say this is a "VC 6.0 ready-made library", was it 
supplied with an import library d32-rpc.lib? If so, the first thing 
you should try is using that import library with MinGW, 
because there is no easy automatic way to generate one for 
this DLL. The problem is that the functions use the stdcall 
convention so the MinGW linker is looking for symbols 
like "clnt_create@16", but the DLL itself only 
exports "clnt_create".

One way to get around this manually is to modify the line in 
your .def file to "clnt_create@16", then generate the import 
library with:

dlltool --input-def d32-rpc.def --output-lib d32-rpc.lib --dllname 
d32-rpc.dll --kill-at

Then remove the unnecessary linker flags and the linker will 
stop complaining about this symbol. As I said though, it 
would be preferable to use the original MSVC import library 
because otherwise you will have to modify each line in 
the .def file that the linker complains about.


----------------------------------------------------------------------

Comment By: Federico Andres Lois (flois)
Date: 2003-04-29 23:25

Message:
Logged In: YES 
user_id=127707

Hi,
In fact that makefile is from like 6 hours of tweaking and trying different 
flags for the linker, compiler and everything... the only one i was thinking 
could work was --allow-multiple-definition cause in the error message 
sais it has multiple definitions... I used to work with both VC and Borland 
compilers and use a pretty similar process to create an import library 
from the DLL, i had switched to GCC like a week ago for a new project i 
am working on, so i am a complete newbie... I had reported as a bug 
report because of the Windows Error, not because i couldnt make it 
work (even though i need help on that too if you can provide it).

I had tried with both dllwrap and dlltool, with no success.

The procedure i have to do is (at least in the other compilers), is it the 
same for GCC?

Given the DLL, i create the import library for the DLL.
Use that import library in the linker...
and run the program... Can you explain me how or should i post this in 
the forums?

Thanks in advance

Greetings
Federico Andres Lois
Xenocide Programming Team

----------------------------------------------------------------------

Comment By: Luke Dunstan (infidel)
Date: 2003-04-29 10:44

Message:
Logged In: YES 
user_id=30442

Your d32-rpc.lib is a DLL, not an import library, because you 
used dllwrap to generate it instead of dlltool. The flags "--allow-
multiple-definition" and especially "--allow-shlib-undefined" in 
your makefile are almost certainly incorrect too. And why are 
you using -nostdlib? Sorry, but it just looks like random flags 
have been added without knowing what they do :-)


----------------------------------------------------------------------

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