Re: [Mingw-users] DLL link problems

[Steven E. <ste...@ya...>]

I had problems like this recently on a project I am working on where we are moving from MS_VC to
mingw. From what understand the compiler will mangle the C++ and the resulting exported name will
be hosed. What you need to do is run dllwrap to generate a new def with the mangled name and then
alias the export name like so:

(old def from MS_VC)
Exports foobar.dll
foo
foobar
bar

(new def - mingw)
Exports foobar.dll
foo
foobar=Z_foobar@4
bar=_bar@8

Once I did this the program that imported are c++ ran with no problems. There could be more going
on here but I think this sums it up. Also I dont know if the new *.def can be used with MS_VC
because I dont think it mangles the names internaly the same way g++ does.

Anyway it worked for me but I'm still learning to program so what do I know
Steven

--- Rosen Georgiev <ros...@ya...> wrote:
> I have two problem while linking a DLL file.
> 
> 1. C object files can't access functions in C++ object
> files
> 	I get error like :
> 
> gpu.o(.text+0x239):gpu.c: undefined reference to
> `InitDraw'
> 'InitDraw' is declered in a cpp file
> 
> But when i rename all the *.c files to *.cpp so they
> compile 
> with the C++ syntax this is no longer a problem.
> But then i have the next problem :
> 
> 2. All the export functions declared in the DEF file
> give errors
> like this one:
> 
> gpup.exp(.edata+0x34):fake: undefined reference to
> `GPUconfigure'
> 
> And in the file i have a function 
> long CALLBACK GPUconfigure() { return 0; }
> 
> # ========== The makefile looks like (if he could be
> the reason)
> PROJECT = gpup.dll
> DEF_FILE = gpup.def
> 
> GCC = gcc
> DLLWRAP = dllwrap
> CFLAGS = -Ic:\dx7sdk\include -fvtable-thunks -c
> -mwindows -O3
> LDFLAGS = -Lc:\dx7sdk\lib
> LIBS = -ld3dim -ld3drm -ld3dx -ld3dxd -ld3dxof -lddraw
> -ldinput \
> 	-ldplayx -ldsetup -ldsound -ldxguid -lwinmm
> 
> CC = $(GCC) $(CFLAGS)
> 
> OBJS_CPP = gpu.o gpucmnds.o draw.o
> 
> OBJS_C = 
> OBJS = $(OBJS_CPP) $(OBJS_C)
> 
> $(PROJECT) : $(OBJS)
> 	$(DLLWRAP) $(LDFLAGS) $(OBJS) --dllname $(PROJECT)
> -def $(DEF_FILE)  $(LIBS)
> 
> $(OBJS_CPP) : %.o : %.cpp
> 	$(CC) -o $@ $^
> $(OBJS_C) : %.o : %.c
> 	$(CC) -o $@ $^
> #============
> 
> Can someone tell me how to get around this?
> 
> TNX in advance
> 
> 
> __________________________________________________
> Do You Yahoo!?
> Yahoo! Health - Feel better, live better
> http://health.yahoo.com
> 
> 
> -------------------------------------------------------
> This sf.net email is sponsored by:ThinkGeek
> Welcome to geek heaven.
> http://thinkgeek.com/sf
> _______________________________________________
> MinGW-users mailing list
> Min...@li...
> 
> You may change your MinGW Account Options or unsubscribe at:
> https://lists.sourceforge.net/lists/listinfo/mingw-users


__________________________________________________
Do You Yahoo!?
Yahoo! Health - Feel better, live better
http://health.yahoo.com