ocaml/guestfs_c.c avoid signed/unsigned-comparison warning

[libguestfs.git] / ocaml / guestfs_c.c

diff --git a/ocaml/guestfs_c.c b/ocaml/guestfs_c.c
index 87139b4..9a7454d 100644 (file)
--- a/ocaml/guestfs_c.c
+++ b/ocaml/guestfs_c.c
@@ -16,6 +16,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include <config.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -32,6 +33,15 @@
 
 #include "guestfs_c.h"
 
+/* This macro was added in OCaml 3.10.  Backport for earlier versions. */
+#ifndef CAMLreturnT
+#define CAMLreturnT(type, result) do{ \
+  type caml__temp_result = (result); \
+  caml_local_roots = caml__frame; \
+  return (caml__temp_result); \
+}while(0)
+#endif
+
 /* Allocate handles and deal with finalization. */
 static void
 guestfs_finalize (value gv)
@@ -111,15 +121,19 @@ ocaml_guestfs_close (value gv)
   CAMLreturn (Val_unit);
 }
 
-/* Copy string array value. */
+/* Copy string array value.
+ * The return value is only 'safe' provided we don't allocate anything
+ * further on the OCaml heap (ie. cannot trigger the OCaml GC) because
+ * that could move the strings around.
+ */
 char **
-ocaml_guestfs_strings_val (value sv)
+ocaml_guestfs_strings_val (guestfs_h *g, value sv)
 {
   CAMLparam1 (sv);
   char **r;
-  int i;
+  unsigned int i;
 
-  r = malloc (sizeof (char *) * (Wosize_val (sv) + 1));
+  r = guestfs_safe_malloc (g, sizeof (char *) * (Wosize_val (sv) + 1));
   for (i = 0; i < Wosize_val (sv); ++i)
     r[i] = String_val (Field (sv, i));
   r[i] = NULL;