Add some more nonnull attributes.
diff --git a/libdw/libdw.h b/libdw/libdw.h
index f3ab3ae..351aef2 100644
--- a/libdw/libdw.h
+++ b/libdw/libdw.h
@@ -237,22 +237,23 @@
/* Return child of current DIE. */
extern int dwarf_child (Dwarf_Die *die, Dwarf_Die *result)
- __nonnull_attribute__ (2);
+ __nonnull_attribute__ (1, 2);
/* Return sibling of given DIE. */
extern int dwarf_siblingof (Dwarf_Die *die, Dwarf_Die *result)
__nonnull_attribute__ (2);
/* Check whether the DIE has children. */
-extern int dwarf_haschildren (Dwarf_Die *die);
+extern int dwarf_haschildren (Dwarf_Die *die) __nonnull_attribute__ (1);
/* Get attributes of the DIE. */
extern ptrdiff_t dwarf_getattrs (Dwarf_Die *die,
int (*callback) (Dwarf_Attribute *, void *),
- void *arg, ptrdiff_t offset);
+ void *arg, ptrdiff_t offset)
+ __nonnull_attribute__ (2);
/* Return tag of given DIE. */
-extern int dwarf_tag (Dwarf_Die *die);
+extern int dwarf_tag (Dwarf_Die *die) __nonnull_attribute__ (1);
/* Return specific attribute of DIE. */