I have built a toy dynamic shared library on Mac OS X (in C), and I have verified that it works from C. Now I would like to call it from D. So I have created the following interface file:

$ cat hello.di
extern (C):
    void printHelloWorld();

which I try to compile and run. But I get the following error:

$ dmd main.d -L-lhello
ld: library not found for -lhello
clang: error: linker command failed with exit code 1 (use -v to see invocation)
--- errorlevel 1

I gather that mac os x doesn't know where to find libhello.dylib (it is in the current directory). So how do I pass that information?

Thanks!
TJB

On Friday, 15 May 2015 at 03:33:47 UTC, TJB wrote:
> I have built a toy dynamic shared library on Mac OS X (in C), and I have verified that it works from C. Now I would like to call it from D. So I have created the following interface file:
>
> $ cat hello.di
> extern (C):
>     void printHelloWorld();
>
> which I try to compile and run. But I get the following error:
>
> $ dmd main.d -L-lhello
> ld: library not found for -lhello
> clang: error: linker command failed with exit code 1 (use -v to see invocation)
> --- errorlevel 1
>
> I gather that mac os x doesn't know where to find libhello.dylib (it is in the current directory). So how do I pass that information?
>
> Thanks!
> TJB

Off the top of my head: does adding -L-L$(pwd) help?

> Off the top of my head: does adding -L-L$(pwd) help?

This is what I get:

$ dmd main.d -L-L$(pwd) -lhello
Error: unrecognized switch '-lhello'

Sorry if this is completely elementary and I am being quite dumb.

Thanks,
TJB

On Friday, 15 May 2015 at 19:39:53 UTC, TJB wrote:
>> Off the top of my head: does adding -L-L$(pwd) help?
>
> This is what I get:
>
> $ dmd main.d -L-L$(pwd) -lhello
> Error: unrecognized switch '-lhello'
>
> Sorry if this is completely elementary and I am being quite dumb.
>
> Thanks,
> TJB

should be

$ dmd main.d -L-L$(pwd) -L-lhello

The -L means "send the following argument to the linker". Note that you may also find you need to help OS X find the dylib when running the program, either by moving it to one of the system locations or using DYLD_LIBRARY_PATH or DYLD_FALLBACK_LIBRARY_PATH (see http://stackoverflow.com/questions/3146274/is-it-ok-to-use-dyld-library-path-on-mac-os-x-and-whats-the-dynamic-library-s). However, I think the runtime linker looks in the present directory by default, so you might get away with it.

On 2015-05-15 21:49, John Colvin wrote:

> Note that you may also find you need to help OS X find the dylib when running the
> program, either by moving it to one of the system locations or using
> DYLD_LIBRARY_PATH or DYLD_FALLBACK_LIBRARY_PATH

That should not be necessary.

-- 
/Jacob Carlborg

On Friday, 15 May 2015 at 19:49:30 UTC, John Colvin wrote:
> On Friday, 15 May 2015 at 19:39:53 UTC, TJB wrote:
>>> Off the top of my head: does adding -L-L$(pwd) help?
>>
>> This is what I get:
>>
>> $ dmd main.d -L-L$(pwd) -lhello
>> Error: unrecognized switch '-lhello'
>>
>> Sorry if this is completely elementary and I am being quite dumb.
>>
>> Thanks,
>> TJB
>
> should be
>
> $ dmd main.d -L-L$(pwd) -L-lhello
>

This works perfectly. A big thanks!