Add error message to Augeas.Error

[ocaml-augeas.git] / augeas-c.c

diff --git a/augeas-c.c b/augeas-c.c
index 5dbaa83..7f0531f 100644 (file)
--- a/augeas-c.c
+++ b/augeas-c.c
@@ -44,6 +44,7 @@ extern CAMLprim value ocaml_augeas_defvar (value tv, value namev, value exprv);
 extern CAMLprim value ocaml_augeas_get (value tv, value pathv);
 extern CAMLprim value ocaml_augeas_exists (value tv, value pathv);
 extern CAMLprim value ocaml_augeas_insert (value tv, value beforev, value pathv, value labelv);
+extern CAMLprim value ocaml_augeas_label (value tv, value pathv);
 extern CAMLprim value ocaml_augeas_mv (value tv, value srcv, value destv);
 extern CAMLprim value ocaml_augeas_rm (value tv, value pathv);
 extern CAMLprim value ocaml_augeas_match (value tv, value pathv);
@@ -86,8 +87,9 @@ static void
 raise_error_and_maybe_close (augeas_t t, const char *msg, bool close_handle)
 {
   value *exn = caml_named_value ("Augeas.Error");
-  value args[4];
+  value args[5];
   const int code = aug_error (t);
+  const char *aug_err_msg;
   const char *aug_err_minor;
   const char *aug_err_details;
   int ocaml_code = -1;
@@ -99,6 +101,7 @@ raise_error_and_maybe_close (augeas_t t, const char *msg, bool close_handle)
     caml_raise_out_of_memory ();
   }
 
+  aug_err_msg = aug_error_message (t);
   aug_err_minor = aug_error_minor_message (t);
   aug_err_details = aug_error_details (t);
 
@@ -115,13 +118,14 @@ raise_error_and_maybe_close (augeas_t t, const char *msg, bool close_handle)
     Store_field (args[0], 0, Val_int (code));
   }
   args[1] = caml_copy_string (msg);
-  args[2] = caml_copy_string (aug_err_minor ? : "");
-  args[3] = caml_copy_string (aug_err_details ? : "");
+  args[2] = caml_copy_string (aug_err_msg);
+  args[3] = caml_copy_string (aug_err_minor ? : "");
+  args[4] = caml_copy_string (aug_err_details ? : "");
 
   if (close_handle)
     aug_close (t);
 
-  caml_raise_with_args (*exn, 4, args);
+  caml_raise_with_args (*exn, 5, args);
 }
 #define raise_error(t, msg) raise_error_and_maybe_close(t, msg, false)
 
@@ -129,15 +133,16 @@ static void
 raise_init_error (const char *msg)
 {
   value *exn = caml_named_value ("Augeas.Error");
-  value args[4];
+  value args[5];
 
   args[0] = caml_alloc (1, 0);
   Store_field (args[0], 0, Val_int (-1));
   args[1] = caml_copy_string (msg);
-  args[2] = caml_copy_string ("augeas initialization failed");
-  args[3] = caml_copy_string ("");
+  args[2] = caml_copy_string ("aug_init failed");
+  args[3] = caml_copy_string ("augeas initialization failed");
+  args[4] = caml_copy_string ("");
 
-  caml_raise_with_args (*exn, 4, args);
+  caml_raise_with_args (*exn, 5, args);
 }
 
 static const char *
@@ -363,6 +368,32 @@ ocaml_augeas_insert (value tv, value beforev, value pathv, value labelv)
   CAMLreturn (Val_unit);
 }
 
+/* val label : t -> path -> string option */
+CAMLprim value
+ocaml_augeas_label (value tv, value pathv)
+{
+  CAMLparam2 (tv, pathv);
+  CAMLlocal2 (optv, v);
+  augeas_t t = Augeas_t_val (tv);
+  const char *path = String_val (pathv);
+  const char *val;
+  int r;
+
+  r = aug_label (t, path, &val);
+  if (r == 1 && val) {         /* Return Some val */
+    v = caml_copy_string (val);
+    optv = caml_alloc (1, 0);
+    Field (optv, 0) = v;
+  } else if (r == 0 || !val)   /* Return None */
+    optv = Val_int (0);
+  else if (r == -1)            /* Error or multiple matches */
+    raise_error (t, "Augeas.label");
+  else
+    caml_failwith ("Augeas.label: bad return value");
+
+  CAMLreturn (optv);
+}
+
 /* val mv : t -> path -> path -> unit */
 CAMLprim value
 ocaml_augeas_mv (value tv, value srcv, value destv)