ocaml: Fix thread safety of strings in bindings (RHBZ#604691).

[libguestfs.git] / ocaml / guestfs_c.c

diff --git a/ocaml/guestfs_c.c b/ocaml/guestfs_c.c
index 86fa293..71f416a 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 +33,19 @@
 
 #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
+
+/* These prototypes are solely to quiet gcc warning.  */
+CAMLprim value ocaml_guestfs_create (void);
+CAMLprim value ocaml_guestfs_close (value gv);
+
 /* Allocate handles and deal with finalization. */
 static void
 guestfs_finalize (value gv)
@@ -41,7 +55,7 @@ guestfs_finalize (value gv)
 }
 
 static struct custom_operations guestfs_custom_operations = {
-  "guestfs_custom_operations",
+  (char *) "guestfs_custom_operations",
   guestfs_finalize,
   custom_compare_default,
   custom_hash_default,
@@ -79,6 +93,17 @@ ocaml_guestfs_raise_error (guestfs_h *g, const char *func)
   CAMLnoreturn;
 }
 
+void
+ocaml_guestfs_raise_closed (const char *func)
+{
+  CAMLparam0 ();
+  CAMLlocal1 (v);
+
+  v = caml_copy_string (func);
+  caml_raise_with_arg (*caml_named_value ("ocaml_guestfs_closed"), v);
+  CAMLnoreturn;
+}
+
 /* Guestfs.create */
 CAMLprim value
 ocaml_guestfs_create (void)
@@ -111,21 +136,17 @@ ocaml_guestfs_close (value gv)
   CAMLreturn (Val_unit);
 }
 
-/* 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.
- */
+/* Copy string array value. */
 char **
 ocaml_guestfs_strings_val (guestfs_h *g, value sv)
 {
   CAMLparam1 (sv);
   char **r;
-  int i;
+  unsigned int i;
 
   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] = guestfs_safe_strdup (g, String_val (Field (sv, i)));
   r[i] = NULL;
 
   CAMLreturnT (char **, r);
@@ -135,8 +156,9 @@ ocaml_guestfs_strings_val (guestfs_h *g, value sv)
 void
 ocaml_guestfs_free_strings (char **argv)
 {
-  /* Don't free the actual strings - they are String_vals on
-   * the OCaml heap.
-   */
+  unsigned int i;
+
+  for (i = 0; argv[i] != NULL; ++i)
+    free (argv[i]);
   free (argv);
 }