How to port c++ program to linux using winelib

Boaz Harrosh boaz at
Mon Oct 18 10:41:46 CDT 2004

Eric Frias wrote:

>Does anyone have a solution they're happy with?
<>Not happy and is a bit out of dated but it Looks it could still work 

Do a .spec file for each C++ dll with one c function like:
void mydll_export( )
// you need real code + .spec declaration

In your app or in the dlls that use the above dll do a function like:
void using_ddls()
   mydll_export( ) ;
   mydll2_export() ;
// this code forces the winebuild to pull-in listed dlls as well

link every thing the regular wine way this way DLLS load in the right 
order, get initialized, and their Windows "import tables", like calls to 
kernel32 etc, gets initialized by the loader.
But (and here is where I'm out of dated) also specify the .so as a link 
option to the gcc linker. (ld)

In the old system, before winegcc. One would do -lmydll on the winebuild 
command line. And than in turn -lmydll on the ld command line - for 
resolve of C++ symbols. Now that we use winegcc I'm not sure what is the 
switch for additional libs like .so and static libs. Look maybe it is 
documented. (Dimi how do you add external libs to a winelib link stage 
under winegcc?)

But be careful with this approach. It is an order of a magnitude slower 
on load time than DLL linkage on windows. I came to a dead end with one 
of my projects, where I managed to compile and run every thing but I had 
to revert to PE compiled code because it took my app 4-6 minutes to 
load. (PE takes 40 seconds). It was a 1.2 M lines of C++ code divided in 
to 37 DLLs + MFC in a dll.

We have talked about the right solution with Alexander on Wineconf. What 
he suggested was:
1 - make the __declspec( export ) macro expand to a gcc "section" 
declaration. So the compilers put all of them in a special section. No 
one knew how C++ classes behave with "sections" and we suspected each 
member function has to be put into the section by hand. On windows a 
__declspec( export ) on the class declaration automatically exports all 
members. Maybe MinGW could help out here.

2 - Use a tool like nm or readelf to extract all symbols (including 
C++), in above section, and with a script convert them to a .spec file.

3- I think that current winebuild have problems with some variants of 
the C++ mangled symbols like the use of the "@" character. So maybe a 
new "C++" style function should be added to the .spec syntax, that will 
not try to interpret the symbols.

Free life

More information about the wine-devel mailing list