Also print function data when printing module functions.

This is especially useful in cases where modules only use a single
entry point and use the data to dispatch to the actual function.  Such
a design is common for languages such as Go and C++.

* src/emacs-module.c (module_function_data): New function.

* src/print.c (print_vectorlike): Use it to print module function data
if not NULL.
(print_object): Adapt size of buffer.

* test/data/emacs-module/mod-test.c (emacs_module_init): Pass some
non-NULL data to ‘mod-test-sum’.
(Fmod_test_sum): Check that correct data is passed through.

* test/src/emacs-module-tests.el (mod-test-sum-test)
(module-function-object): Adapt unit tests.

2 files changed, 8 insertions, 3 deletions

diff --git a/test/data/emacs-module/mod-test.c b/test/data/emacs-module/mod-test.c
index 1a0a879a1bc..ec6948921f2 100644
--- a/test/data/emacs-module/mod-test.c
+++ b/test/data/emacs-module/mod-test.c
@@ -24,6 +24,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #include <errno.h>
 #include <limits.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -86,6 +87,7 @@ static emacs_value
 Fmod_test_sum (emacs_env *env, ptrdiff_t nargs, emacs_value args[], void *data)
 {
   assert (nargs == 2);
+  assert ((uintptr_t) data == 0x1234);
 
   intmax_t a = env->extract_integer (env, args[0]);
   intmax_t b = env->extract_integer (env, args[1]);
@@ -587,7 +589,8 @@ emacs_module_init (struct emacs_runtime *ert)
                  env->make_function (env, amin, amax, csym, doc, data))
 
   DEFUN ("mod-test-return-t", Fmod_test_return_t, 1, 1, NULL, NULL);
-  DEFUN ("mod-test-sum", Fmod_test_sum, 2, 2, "Return A + B\n\n(fn a b)", NULL);
+  DEFUN ("mod-test-sum", Fmod_test_sum, 2, 2, "Return A + B\n\n(fn a b)",
+         (void *) (uintptr_t) 0x1234);
   DEFUN ("mod-test-signal", Fmod_test_signal, 0, 0, NULL, NULL);
   DEFUN ("mod-test-throw", Fmod_test_throw, 0, 0, NULL, NULL);
   DEFUN ("mod-test-non-local-exit-funcall", Fmod_test_non_local_exit_funcall,
diff --git a/test/src/emacs-module-tests.el b/test/src/emacs-module-tests.el
index c61abfdf683..48d2e86a605 100644
--- a/test/src/emacs-module-tests.el
+++ b/test/src/emacs-module-tests.el
@@ -60,8 +60,9 @@
     (should (eq 0
                 (string-match
                  (concat "#<module function "
-                         "\\(at \\(0x\\)?[[:xdigit:]]+\\( from .*\\)?"
-                         "\\|Fmod_test_sum from .*\\)>")
+                         "\\(at \\(0x\\)?[[:xdigit:]]+ "
+                         "with data 0x1234\\( from .*\\)?"
+                         "\\|Fmod_test_sum with data 0x1234 from .*\\)>")
                  (prin1-to-string (nth 1 descr)))))
     (should (= (nth 2 descr) 3)))
   (should-error (mod-test-sum "1" 2) :type 'wrong-type-argument)
@@ -97,6 +98,7 @@ changes."
              (rx bos "#<module function "
                  (or "Fmod_test_sum"
                      (and "at 0x" (+ hex-digit)))
+                 " with data 0x1234"
                  (? " from " (* nonl) "mod-test" (* nonl) )
                  ">" eos)
              (prin1-to-string func)))))