Re: What is swipl's default DLL search path on Windows?

Jan,

Thanks! win_add_dll_directory worked great out of the box!
I will take a look of the swipl-ld source and see what I can do.

Haitao



On Sat, Feb 1, 2014 at 12:52 AM, Jan Wielemaker <[email protected]> wrote:

> On 02/01/2014 07:06 AM, Haitao Zhang wrote:
> > I am compiling an extension that depends on libgcc and libstdc++. I get
> > module not found errors for libgcc and libstdc++ when use_foreign_library
> > even though the DLLs are in the first directory of the PATH. If I compile
> > with -static-libgcc and -static-libstdc++ the errors go away.
> >
> > I wonder if swipl controls where the DLLs are searched for or if this is
> > controlled by Windows?
>
> That is a very difficult story.  The best pointer into it is
>
>   http://www.swi-prolog.org/pldoc/doc_for?object=win_add_dll_directory/2
>
> The intend is that use_foreign_library/1 uses absolute_file_name/3 to
> locate the target and calls  LoadLibraryEx() such that this also searches
> in the directory of the DLL for dependencies.  If Prolog cannot find the
> file using absolute_file_name/3, it just calls LoadLibraryEx() using the
> base name of the file and leaves the search entirely to the OS.
>
> What really happens depends on the Windows version.  Study LoadLibraryEx()
> and the source code if you want to understand all the details.  The docs
> contain so many `if's that it is hard to tell a clear story.
>
> > Another observation: when using swipl-ld I must specify at least one .c
> or
> > .cc file. I can't seem to just use it to invoke the linker on .o files
> > only. I can work around by observing the -v output and invoke the gcc/g++
> > myself but it seems that one should be able to use swipl-ld for linking
> > only? Also if one specifies g++ to be the compiler the default linker is
> > still gcc. But if one specifies g++ to be the linker the compiler gets
> set
> > to be g++ as well.
>
> Seems like a dubious feature.  Please consider submitting a patch.  Sources
> are in src/swipl-ld.c.
>
> Sorry for the somewhat unclear answer
>
>         Cheers --- Jan
>
-------------- next part --------------
HTML attachment scrubbed and removed