On 10-Dec-14 15:56, Yitzchak Gale wrote:
No, no. If you have existing .def file the single thing to do is 'dlltool -l <import library name> -D <dll file name> -d <.def filename>'. I tried that - there was no output. Note that in dlltool --help it says that -D is for *input* DLL file. I did this multiple times with success :) I think there is something wrong with your .def file, perhaps.
In this use case dlltool needs *no* DLL itself -- only its name. For some reasons dlltool ignores a clause of 'LIBRARY' statement in .def file and uses whatever name you supply to -D option. For example, to generate import library for icuin52.dll you can use the following command-line: dlltool -l libicudt.a -D icuin52.dll -d icuin52.def where icuin52.def is the single input *file*, others arguments are parameters only, you need no have physically present icuin52.dll at all.
The problem is how to obtain .def file from existing dll… 1. Use Microsoft 'dumpbin' utility, which gives a list of exported symbols when run with '/EXPORTS' flag. The utility should be available from VS community edition at least. I have full VS 10, so I have dumpbin. But the exports list it creates has many C++ mangled symbols, like:
??0?$EnumSet@W4UDateFormatBooleanAttribute@@$0A@$03@icu_54@@QEAA@AEBV01@@Z
When I try to create a .exp using dlltool with a .def containing junk like that, it fails:
dqsfc.s: Assembler messages: dqsfc.s:4102: Error: bad expression dqsfc.s:4102: Fatal error: rva without symbol dlltool: as exited with status 1 These are mangled Visual C++ names, you can't use them at all and you don't need them at all, you should simply remove all of them from your .def file.
2. Try to link to DLLs *directly* -- using binutils' facility to link against DLL directly instead of it's import lib. That would be much better. If we can get that to work, we can teach cabal how to do it too. Then FFI will work again on Windows 64 bits. The problem is that binutils does not understand DLLs from VS on 64 bits, it seems. I successfully used several Windows 64 Visual C++- generated DLLs through FFI. Usually there are no problems with them if your generate import libraries as described above.
Cheers, Kyra