While attempting to package libegit2
(https://github.com/magit/libegit2), I found that any attempt at loading
a dynamic module from emacs would seemingly work (it returns t), but not
actually work: no module api functions invoked from C seem to have any
effect, including defining functions and printing messages. Here's an
example
-------------------------------
#include <stdio.h>
#include <stdlib.h>
#include <emacs-module.h>
int plugin_is_GPL_compatible;
static emacs_value
hello(emacs_env *env, ptrdiff_t nargs, emacs_value args[], void *data)
{
const char str[] = "Hello Emacs";
return env->make_string(env, str, sizeof(str) - 1);
}
/* Module init function. */
int
emacs_module_init(struct emacs_runtime *ert)
{
emacs_env *env = ert->get_environment(ert);
emacs_value hellofn = env->make_function(env, 0, 0, hello, "return
hello string", NULL);
// Bind NAME to FUN.
// (defalias 'hello-c '(lambda () "Hello Emacs"))
emacs_value defalias_sym = env->intern(env, "defalias");
emacs_value hello_sym = env->intern(env, "hello-c");
emacs_value defalias_args[] = { hello_sym, hellofn };
env->funcall(env, defalias_sym, 2, defalias_args);
// Provide FEATURE to Emacs.
// (provide 'hello-core)
emacs_value feature_sym = env->intern(env, "hello-module");
emacs_value provide_sym = env->intern(env, "provide");
emacs_value provide_args[] = { feature_sym };
env->funcall(env, provide_sym, 1, provide_args);
char message[] = "TEST MESSAGE!";
emacs_value message_str = env->make_string(env, message,
sizeof(message) - 1);
emacs_value message_sym = env->intern(env, "message");
emacs_value message_args[] = {message_str};
// spam a bit just to be sure
env->funcall(env, message_sym, 1, message_args);
env->funcall(env, message_sym, 1, message_args);
env->funcall(env, message_sym, 1, message_args);
return 0;
}
-------------------------------
Assuming the above file is named emacs-module-test.c:
-------------------------------
$ gcc -fPIC -shared emacs-module-test.c -o hello-module.so
$ emacs -Q -L . --batch -l hello-module --eval "(message (hello-c))"
=> Symbol's function definition is void: hello-c
-------------------------------
As far as I can tell, this should work. Our emacs is built with
'--with-modules', and 'MODULES' is in system-configuration-features. Any
idea what's going wrong?
- reepca
