Using a windows dll from a winelib or possibly native linux app.
Hi, I have been trying to develop an application using a vendor provided dll from an external vendor to work under linux. If we develop the app on a windows box and move it over to the wine environment it works, but it would be preferable to have a more native approach. So I tried using winelib and have progressed to a point where I have an application that compiles using the vendor supplied header files under gcc, and a vendor.dll.spec file that describes the DLL. However when I compile everything, the generated vendor.dll.so file does contain the correct symbols but they are undefined. Having played around using winemaker and winedump while trying to read up everything on winelib I am now stuck and not sure how to proceed forward. Thanks Arthur
On Tue, 2003-12-09 at 23:58, Arthur Bergman wrote:
If we develop the app on a windows box and move it over to the wine environment it works, but it would be preferable to have a more native approach. So I tried using winelib and have progressed to a point where I have an application that compiles using the vendor supplied header files under gcc, and a vendor.dll.spec file that describes the DLL.
Well done. It took me a significant amount of effort just to get that far in a similar project!
However when I compile everything, the generated vendor.dll.so file does contain the correct symbols but they are undefined. Having played around using winemaker and winedump while trying to read up everything on winelib I am now stuck and not sure how to proceed forward.
I found a piece of WineLib documentation (sorry: I don't have an appropriate cross-reference handy) that advocates that you write a shim layer between your Linux code and your vendor's DLL. Basically, regardless of how clever WineLib really is, you still can't statically link an ELF object file against a PE COFF DLL. That's the reason you see undefined symbols---they really are undefined! You can, however, achieve what you want through another layer of indirection! :) Basically, you have to define simple statically-linked definitions for those symbols which merely call through to the dynamically linked versions contained in your vendor's DLL. It works like this: * the vendor's DLL exports some function ReturnType FunctionName(ParameterType) * you've got to write your own module that wraps this: #include <windows.h> #include <vendor_dll.h> static ReturnType (*FunctionName_pointer) (ParameterType); void InitialiseVendorDLL() { /* BE SURE TO CALL THIS SOMEWHERE EARLY */ HINSTANCE dll; dll = LoadLibrary("vendor.dll"); /* N.B. ADD YOUR OWN ERROR CHECKING */ FunctionName_pointer = GetProcAddress(dll, "FunctionName"); } ReturnType FunctionName(ParameterType p) { return FunctionName_pointer(p); } Compile and link against /that/ (or similar specialised for your particular situation), and you're undefined symbols will now have a definition, and your code should work as advertised. At the very least, all this worked for me!
Thanks
You're welcome. Please let me know how you get along with this.
Arthur
-- Kevin.
On December 9, 2003 08:14 pm, Kevin Cousins wrote:
Compile and link against /that/ (or similar specialised for your particular situation), and you're undefined symbols will now have a definition, and your code should work as advertised. At the very least, all this worked for me!
Yes, it will work, but it's a lot more work than it needs to be. Follow Alexandre's advice earlier in this thread, it will work just fine. -- Dimi.
Arthur Bergman <abergman(a)fotango.com> writes:
I have been trying to develop an application using a vendor provided dll from an external vendor to work under linux. If we develop the app on a windows box and move it over to the wine environment it works, but it would be preferable to have a more native approach. So I tried using winelib and have progressed to a point where I have an application that compiles using the vendor supplied header files under gcc, and a vendor.dll.spec file that describes the DLL. However when I compile everything, the generated vendor.dll.so file does contain the correct symbols but they are undefined. Having played around using winemaker and winedump while trying to read up everything on winelib I am now stuck and not sure how to proceed forward.
You shouldn't compile to a .dll.so since you don't have the dll code. What you should do is generate a libvendor.def from the spec file (with winebuild --def) and then link your app as a winelib app, adding -lvendor to the import list. winebuild will then resolve the symbols properly to point to the native dll. -- Alexandre Julliard julliard(a)winehq.com
See if I understand what you need: - vendor.dll (windows binary only) - myapp.exe.so (winelib application that uses vendor.dll API and compiles against "vendor" header files ) Check that you have done the following 1) wrote a vendor.dll.spec (spec syntax for all functions used from "vendor" headers) 2) compiled a libvendor.def file from above .spec file using winebuild (put libvendor.def in a directory specified by -L) <Makefile> # libvendor.def generation libvendor.def: vendor.dll.spec $(LDPATH) $(WINEBUILD) -fPIC -o $@ --def vendor.dll.spec \ $(vendor_dll_DLL_PATH) $(WINE_DLL_PATH) $(GLOBAL_DLL_PATH) \ $(vendor_dll_DLLS:%=-l%) $(GLOBAL_DLLS:%=-l%) </Makefile> 3) make a myapp.exe.spec.c using winebuild including "vendor" to the list of needed dlls like kernel32 and advapi32 ... (this was done for you by winemaker Just add vendor at the end of the dlls list) 4) link myapp.exe.so with myapp.exe.spec.o (also done by winemaker) 5) Have vendor.dll available in runtime Hope that helps Free Life Boaz Arthur Bergman wrote:
Hi,
I have been trying to develop an application using a vendor provided dll from an external vendor to work under linux. If we develop the app on a windows box and move it over to the wine environment it works, but it would be preferable to have a more native approach. So I tried using winelib and have progressed to a point where I have an application that compiles using the vendor supplied header files under gcc, and a vendor.dll.spec file that describes the DLL. However when I compile everything, the generated vendor.dll.so file does contain the correct symbols but they are undefined. Having played around using winemaker and winedump while trying to read up everything on winelib I am now stuck and not sure how to proceed forward.
Thanks Arthur
participants (5)
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Alexandre Julliard -
Arthur Bergman -
Boaz Harrosh -
Dimitrie O. Paun -
Kevin Cousins