I was wondering if I could get some feeback on an ECL feature request that I posted here: https://gitlab.com/embeddable-common-lisp/ecl/issues/336 https://gitlab.com/embeddable-common-lisp/ecl/issues/336
Here is the text:
I would like to be able to call functions using dynamic FFI in the program into which ECL has been embedded.
In Linux, you can do this by calling `dlopen` with `NULL` for the filename.
If filename is NULL, then the returned handle is for the main
program.
http://man7.org/linux/man-pages/man3/dlopen.3.html
Looking at ECL source code, it does not seem to be supported. `dlopen` is called in `c/ffi/libraries.d` like this:
char *filename_string = (char*)filename->base_string.self; #ifdef HAVE_DLFCN_H block->cblock.handle = dlopen(filename_string, RTLD_NOW|RTLD_GLOBAL);
So, I guess there's no way to set `filename_string = NULL`.
One way to do it would be to say if you call
(ffi:load-foreign-library "")
Then it will skip the checks to see if the file exists and just call `dlopen(NULL, ...`
Another way would be to make a new function `ffi:load-main-program`. I don't have any suggestions as to which would be better as I am very new to Lisp.
Thank you for your attention.
Hey,
see may comment under the issue. This addition looks like a plausible feature to implement and it seems that it can work also on Windows.
I like the second proposal, to make it a separate function ffi:load-main-program, because this is different from loading libraries.
If someone steps in and implements it, it is important to add regression test to src/tests/normal-tests/embedding.lsp (so we can check if it works on other platforms / architectures by simply issueing make check) and adding information about this interface to the new documentation to src/doc/new-doc/extensions/ffi_dffi.txi . Also implementation should cover also Windows. Otherwise I'm putting it in my backlog, but I probably won't tackle it very soon.
Best regards, Daniel