Hi, I'm trying to load guile-grcypt with guile 3.0.7 and after my previous fix (https://git.savannah.gnu.org/cgit/guile.git/commit/?id=1f100a4f20c3a6e57922fb26fce212997e2a03cb) guile-gcrypt still does not load properly.
TLDR; Using RTLD_LOCAL instead of RTLD_GLOBAL (default) causes issues on macOS. https://git.savannah.gnu.org/cgit/guile.git/tree/module/system/foreign-library.scm#n181 In the case of guile-gcrypt this is what I'm getting: ------------------------- scheme@(guile-user)> (use-modules (gcrypt hmac)) dyld: lazy symbol binding failed: Symbol not found: __gcry_check_version Referenced from: /usr/local/lib/libgcrypt.dylib Expected in: flat namespace dyld: Symbol not found: __gcry_check_version Referenced from: /usr/local/lib/libgcrypt.dylib Expected in: flat namespace ------------------------- Looking at gcrypt symbols I can see: ❯ nm -gU /usr/local/lib/libgcrypt.dylib | grep gcry_check_version 0000000000005954 T __gcry_check_version 0000000000002aa7 T _gcry_check_version Actually in libgcrypt the public functions are: gcry_check_version and _gcry_check_version (no extra underscore). I think extra underscores are automatically added when building the library but I'm not sure why and when and what systems. And when you call dlsym() you don't need to add those extra underscores. The following code (which uses RTLD_GLOBAL) works fine: ./a.out gcry_check_version ------------------------- #include <dlfcn.h> #include <stdio.h> int main(int argc, char *argv[]) { char* (*fptr)(char *); void *handle = dlopen("/usr/local/lib/libgcrypt.dylib", RTLD_LAZY | RTLD_GLOBAL); if (handle == NULL) { printf("OOOPS: %s\n", dlerror()); } else { *(void **)(&fptr) = dlsym(handle, argv[1]); if (fptr == NULL) { printf("NOT FOUND: %s : %s\n", argv[1], dlerror()); } else { printf("FOUND: %s %s\n", argv[1], (*fptr)(NULL)); } } return 0; } ------------------------- But if we change to RTLD_LOCAL we get a crash like in guile's case. Sorry for being too vague but I'm not familiar with how all this works. All I know is that using RTLD_GLOBAL fixes the issue. Also, from dlopen man page I read: ------------------------- RTLD_GLOBAL Symbols exported from this image (dynamic library or bundle) will be available to any images build with -flat_namespace option to ld(1) or to calls to dlsym() when using a special handle. RTLD_LOCAL Symbols exported from this image (dynamic library or bundle) are generally hidden and only availble to dlsym() when directly using the handle returned by this call to dlopen(). ------------------------- But I don't fully get what this means. Any help would be really appreciated. Thank you, Aleix
