Add a way to free any C strings we pass; always do it initially.

Author: jnthn

src/ops/nqp_dyncall.ops

@@ -230,8 +230,10 @@ inline op nqp_native_call_build(out PMC, in PMC, in STR, in STR, in STR, in PMC,
  * presumably a type object).
  */
 inline op nqp_native_call(out PMC, in PMC, in PMC, in PMC) :base_core {
-    PMC *args   = $4;
-    PMC *result = PMCNULL;
+    PMC *args        = $4;
+    PMC *result      = PMCNULL;
+    char **free_strs = NULL;
+    INTVAL num_strs  = 0;
     INTVAL i;
 
     /* Get native call body, so we can locate the call info. */
@@ -282,6 +284,9 @@ inline op nqp_native_call(out PMC, in PMC, in PMC, in PMC) :base_core {
                         body->arg_types[i] == DYNCALL_ARG_UTF16STR ? Parrot_utf16_encoding_ptr :
                                                                      Parrot_utf8_encoding_ptr);
                     dcArgPointer(vm, str);
+                    if (!free_strs)
+                        free_strs = mem_sys_allocate(body->num_args * sizeof(char *));
+                    free_strs[num_strs] = str;
                 }
                 break;
             case DYNCALL_ARG_CSTRUCT:
@@ -291,7 +296,7 @@ inline op nqp_native_call(out PMC, in PMC, in PMC, in PMC) :base_core {
                 dcArgPointer(vm, NULL);
         }
     }
-    
+
     /* Call and process return values. */
     switch (body->ret_type) {
         case DYNCALL_ARG_VOID:
@@ -329,6 +334,13 @@ inline op nqp_native_call(out PMC, in PMC, in PMC, in PMC) :base_core {
             result = $2;
     }
 
+    /* Free any memory that we need to. */
+    if (free_strs) {
+        for (i = 0; i < num_strs; i++)
+            Parrot_str_free_cstring(free_strs[i]);
+        mem_sys_free(free_strs);
+    }
+    
     /* Finally, free call VM. */
     dcFree(vm);