Add dynamic module test and helper script

Add 'modhelp.py' script (python2) to automate module testing and
module generation.

To build and test all modules in the modules/ dir
  $ ./modhelp.py test

To generate a module from template code (good starting point)
  $ ./modhelp init mynewtestmodule

See the script -h option for more documentation.

* modules/modhelp.py: New module helper script.
* modules/mod-test/Makefile: New file. Makefile for the test module.
* modules/mod-test/mod-test.c: New file. Test module source file.
* modules/mod-test/test.el: New file. ert test suite for the test module.
* modules/.gitignore: New file. Local .gitignore file.

Co-authored-by: Philipp Stephani <phst@google.com>

1 files changed, 254 insertions, 0 deletions

diff --git a/modules/mod-test/mod-test.c b/modules/mod-test/mod-test.c
new file mode 100644
index 00000000000..2de53152b1b
--- /dev/null
+++ b/modules/mod-test/mod-test.c
@@ -0,0 +1,254 @@
+#include <assert.h>
+#include <stdio.h>
+#include <emacs_module.h>
+
+int plugin_is_GPL_compatible;
+
+/*
+ * Always return symbol 't'
+ */
+static emacs_value Fmod_test_return_t (emacs_env *env, int nargs, emacs_value args[], void *data)
+{
+  return env->intern (env, "t");
+}
+
+
+/*
+ * Expose simple sum function
+ */
+static int64_t sum (int64_t a, int64_t b)
+{
+  return a + b;
+}
+
+static emacs_value Fmod_test_sum (emacs_env *env, int nargs, emacs_value args[], void* data)
+{
+  int64_t a = env->extract_integer (env, args[0]);
+  int64_t b = env->extract_integer (env, args[1]);
+
+  int64_t r = sum(a, b);
+
+  return env->make_integer (env, r);
+}
+
+
+/*
+ * Signal '(error 56)
+ */
+static emacs_value Fmod_test_signal (emacs_env *env, int nargs, emacs_value args[], void* data)
+{
+  assert (env->non_local_exit_check (env) == emacs_funcall_exit_return);
+  env->non_local_exit_signal (env, env->intern (env, "error"), env->make_integer (env, 56));
+  return NULL;
+}
+
+
+/*
+ * Throw '(tag 65)
+ */
+static emacs_value Fmod_test_throw (emacs_env *env, int nargs, emacs_value args[], void* data)
+{
+  assert (env->non_local_exit_check (env) == emacs_funcall_exit_return);
+  env->non_local_exit_throw (env, env->intern (env, "tag"), env->make_integer (env, 65));
+  return NULL;
+}
+
+
+/*
+ * Call argument function, catch all non-local exists and return
+ * either normal result or a list describing the non-local exit.
+ */
+static emacs_value Fmod_test_non_local_exit_funcall (emacs_env *env, int nargs, emacs_value args[], void* data)
+{
+  assert (nargs == 1);
+  const emacs_value result = env->funcall (env, args[0], 0, NULL);
+  emacs_value non_local_exit_symbol, non_local_exit_data;
+  enum emacs_funcall_exit code = env->non_local_exit_get (env, &non_local_exit_symbol, &non_local_exit_data);
+  switch (code)
+    {
+    case emacs_funcall_exit_return:
+      return result;
+    case emacs_funcall_exit_signal:
+      {
+        env->non_local_exit_clear (env);
+        const emacs_value Flist = env->intern (env, "list");
+        emacs_value list_args[] = {env->intern (env, "signal"), non_local_exit_symbol, non_local_exit_data};
+        return env->funcall (env, Flist, 3, list_args);
+      }
+    case emacs_funcall_exit_throw:
+      {
+        env->non_local_exit_clear (env);
+        const emacs_value Flist = env->intern (env, "list");
+        emacs_value list_args[] = {env->intern (env, "throw"), non_local_exit_symbol, non_local_exit_data};
+        return env->funcall (env, Flist, 3, list_args);
+      }
+    }
+  /* never reached */
+  return env->intern (env, "nil");;
+}
+
+
+/*
+ * Return a global referrence
+ */
+static emacs_value Fmod_test_globref_make (emacs_env *env, int nargs, emacs_value args[], void* data)
+{
+  /* make a big string and make it global */
+  size_t i;
+  char str[26*100];
+
+  for (i = 0; i < sizeof (str); i++)
+    {
+      str[i] = 'a' + (i % 26);
+    }
+
+  /* we don't need to null-terminate str */
+  emacs_value lisp_str = env->make_string (env, str, sizeof (str));
+  return env->make_global_ref (env, lisp_str);
+}
+
+
+/*
+ * Return a copy of the argument string where every 'a' is replaced with 'b'.
+ */
+static emacs_value Fmod_test_string_a_to_b (emacs_env *env, int nargs, emacs_value args[], void* data)
+{
+  emacs_value lisp_str = args[0];
+  size_t size = 0;
+  char * buf = NULL;
+  size_t i;
+
+  env->copy_string_contents (env, lisp_str, buf, &size);
+  buf = malloc (size);
+  env->copy_string_contents (env, lisp_str, buf, &size);
+
+  for (i = 0; i+1 < size; i++) {
+    if (buf[i] == 'a')
+      buf[i] = 'b';
+  }
+
+  return env->make_string (env, buf, size-1);
+}
+
+
+/*
+ * Embedded pointers in lisp objects.
+ */
+
+/* C struct (pointer to) that will be embedded */
+struct super_struct
+{
+  int amazing_int;
+  char large_unused_buffer[512];
+};
+
+/* Associated finalizer */
+static void finalizer (void *p)
+{
+  if (p)
+    free (p);
+}
+
+/*
+ * Return a new user-pointer to a super_struct, with amazing_int set
+ * to the passed parameter.
+ */
+static emacs_value Fmod_test_userptr_make (emacs_env *env, int nargs, emacs_value args[], void *data)
+{
+  struct super_struct *p = calloc (1, sizeof(*p));
+  p->amazing_int = env->extract_integer (env, args[0]);
+  return env->make_user_ptr (env, finalizer, p);
+}
+
+/*
+ * Return the amazing_int of a passed 'user-pointer to a super_struct'.
+ */
+static emacs_value Fmod_test_userptr_get (emacs_env *env, int nargs, emacs_value args[], void *data)
+{
+  struct super_struct *p = env->get_user_ptr (env, args[0]);
+  return env->make_integer (env, p->amazing_int);
+}
+
+
+/*
+ * Fill vector in args[0] with value in args[1]
+ */
+static emacs_value Fmod_test_vector_fill (emacs_env *env, int nargs, emacs_value args[], void *data)
+{
+  size_t i;
+  emacs_value vec = args[0];
+  emacs_value val = args[1];
+  const size_t size = env->vec_size (env, vec);
+  for (i = 0; i < size; i++)
+    env->vec_set (env, vec, i, val);
+  return env->intern (env, "t");
+}
+
+
+/*
+ * Return whether all elements of vector in args[0] are 'eq' to value in args[1]
+ */
+static emacs_value Fmod_test_vector_eq (emacs_env *env, int nargs, emacs_value args[], void *data)
+{
+  size_t i;
+  emacs_value vec = args[0];
+  emacs_value val = args[1];
+  const size_t size = env->vec_size (env, vec);
+  for (i = 0; i < size; i++)
+    if (!env->eq (env, env->vec_get (env, vec, i), val))
+        return env->intern (env, "nil");
+  return env->intern (env, "t");
+}
+
+
+/*
+ * Lisp utilities for easier readability (simple wrappers)
+ */
+
+/* Provide FEATURE to Emacs */
+static void provide (emacs_env *env, const char *feature)
+{
+  emacs_value Qfeat = env->intern (env, feature);
+  emacs_value Qprovide = env->intern (env, "provide");
+  emacs_value args[] = { Qfeat };
+
+  env->funcall (env, Qprovide, 1, args);
+}
+
+/* Binds NAME to FUN */
+static void bind_function (emacs_env *env, const char *name, emacs_value Sfun)
+{
+  emacs_value Qfset = env->intern (env, "fset");
+  emacs_value Qsym = env->intern (env, name);
+  emacs_value args[] = { Qsym, Sfun };
+
+  env->funcall (env, Qfset, 2, args);
+}
+
+/*
+ * Module init function.
+ */
+int emacs_module_init (struct emacs_runtime *ert)
+{
+  emacs_env *env = ert->get_environment (ert);
+
+#define DEFUN(lsym, csym, amin, amax, doc, data) \
+  bind_function (env, lsym, 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", NULL);
+  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, 1, 1, NULL, NULL);
+  DEFUN ("mod-test-globref-make", Fmod_test_globref_make, 0, 0, NULL, NULL);
+  DEFUN ("mod-test-string-a-to-b", Fmod_test_string_a_to_b, 1, 1, NULL, NULL);
+  DEFUN ("mod-test-userptr-make", Fmod_test_userptr_make, 1, 1, NULL, NULL);
+  DEFUN ("mod-test-userptr-get", Fmod_test_userptr_get, 1, 1, NULL, NULL);
+  DEFUN ("mod-test-vector-fill", Fmod_test_vector_fill, 2, 2, NULL, NULL);
+  DEFUN ("mod-test-vector-eq", Fmod_test_vector_eq, 2, 2, NULL, NULL);
+
+#undef DEFUN
+
+  provide (env, "mod-test");
+  return 0;
+}