marshal: avoid NULL pointer arithmetic

This is UB and clang warns about this. Ensure we use an int of the
same size as a pointer and convert it directly.

diff --git a/src/marshal.c b/src/marshal.c
index 16dabe574e1efa463bb278cb42bb16e2f0f45708..0cde547c401266289fdee6f0a56bf645fe6ca8c8 100644 (file)
--- a/src/marshal.c
+++ b/src/marshal.c
@@ -63,7 +63,7 @@ struct marshal_info marshal_info_ignore = {
 struct ref {
        TAILQ_ENTRY(ref) next;
        void *pointer;
-       int dummy;              /* To renumerate pointers */
+       uintptr_t dummy;        /* To renumerate pointers */
 };
 TAILQ_HEAD(ref_l, ref);
 
@@ -78,7 +78,7 @@ marshal_serialize_(struct marshal_info *mi, void *unserialized, void **input,
        size_t len;
        struct marshal_subinfo *current;
        struct marshal_serialized *new = NULL, *serialized = NULL;
-       int dummy = 1;
+       uintptr_t dummy = 1;
 
        log_debug("marshal", "start serialization of %s", mi->name);
 
@@ -116,7 +116,7 @@ marshal_serialize_(struct marshal_info *mi, void *unserialized, void **input,
                goto marshal_error;
        }
        /* We don't use the original pointer but a dummy one. */
-       serialized->orig = (unsigned char*)NULL + dummy;
+       serialized->orig = (unsigned char*)dummy;
 
        /* Append the new reference */
        if (!(cref = calloc(1, sizeof(struct ref)))) {
@@ -163,7 +163,7 @@ marshal_serialize_(struct marshal_info *mi, void *unserialized, void **input,
                if (current->kind == pointer && !skip) {
                        TAILQ_FOREACH(cref, refs, next) {
                                if (source == cref->pointer) {
-                                       void *fakepointer = (unsigned char*)NULL + cref->dummy;
+                                       void *fakepointer = (unsigned char*)cref->dummy;
                                        memcpy((unsigned char *)serialized->object + current->offset,
                                            &fakepointer, sizeof(void *));
                                        break;