On Thursday, 21 January 2016 at 23:07:06 UTC, jmh530 wrote:
On Thursday, 21 January 2016 at 22:54:26 UTC, Dibyendu Majumdar
wrote:
On Thursday, 21 January 2016 at 22:49:06 UTC, jmh530 wrote:
I'm not trying to created a shared library in D. My goal is
to use a shared library from C in D. Right now, I'm working
with a simple test case to make sure I could understand it
before working with the actual shared library I want to use.
I recall some discussion in LearningD (don't have it in front
of me now) that different types of shared libraries are
needed on 32bit vs. 64bit because there is a different
linker. This is what I did to created the shared library:
gcc -Wall -fPIC -c <file>.c -I.
gcc -shared -o <libfile>.dll <file>.o -I.
implib <libfile>.lib <libfile>.dll
Okay then you don't need the /IMPLIB option. But you do need
to specify the library via -L as I mentioned before.
i.e. use:
dmd -m64 -L/LIBPATH:<path to lib> -L<library name> prog.d
Where <library name> is yourlib.lib and this is present along
with the DLL in the path you gave.
Plus your prog.d needs to have appropriate code. Example:
module app;
extern (C) void testing();
void main()
{
testing();
}
Here testing() is provided in the DLL.
I ran
dmd -m64 <file>.d -L/LIBPATH:<path to lib> -L<library name>
and got
<library name> : fatal error LNK1136: invalid or corrupt file
--- errorlevel 1136
At least that's progress.
The linker will most certainly get confused by this "-L<library
name>" - as it will take it for an object file. The difference is
that a library is a collection of object files.
The GNU linker ld, for instance, uses the -l<libname> switch for
adding libraries to link against and -L<path> to add a search
path to look for the libraries passed in with -l<libname>.
If you leave it to the compiler to invoke the linker you need to
remember the -L compiler switch is passing what follows to the
linker (minus the -L compiler switch).
I.e. -L-LC:\lib\path will be passed on as "-LC:\lib\path",
-L-lsomelib => "-lsomelib", etc.
You won't find help about linker options on any compiler manual.
You have to refer to your linker manual.
Also make sure to adhere to naming conventions. It could very
well be your linker quits with an error message if you pass it
-lsomelib for a file somelib.lib when it expects to find the file
libsomelib.lib instead.
LNK1136 is for a corrupt or abnormally small file. I did notice
that the original dll was 82kb and the lib file was 2kb.
The lib for a 'DLL' is small because it just tells the linker
where to find the code in the 'DLL' - the actual code is in the
'DLL'.
Hope the helps
