X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Flibpspp%2Fhmap.h;h=c9e764dec563a92df08491839259e5f061884963;hb=ece48101c54930c528980a980ee070d9c77971c2;hp=e73d84fd153764ec96935c6242dc2388820c5757;hpb=015e221b0f8578afee769528572c76387f26c629;p=pspp

diff --git a/src/libpspp/hmap.h b/src/libpspp/hmap.h
index e73d84fd15..c9e764dec5 100644
--- a/src/libpspp/hmap.h
+++ b/src/libpspp/hmap.h
@@ -1,5 +1,5 @@
 /* PSPP - a program for statistical analysis.
-   Copyright (C) 2008 Free Software Foundation, Inc.
+   Copyright (C) 2008, 2009 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -116,12 +116,14 @@
    */
 
 #include <stddef.h>
+#include <libpspp/cast.h>
 
 /* Returns the data structure corresponding to the given NODE,
    assuming that NODE is embedded as the given MEMBER name in
    data type STRUCT.  NODE must not be a null pointer. */
 #define HMAP_DATA(NODE, STRUCT, MEMBER)                         \
-  ((STRUCT *) ((char *) (NODE) - offsetof (STRUCT, MEMBER)))
+        (CHECK_POINTER_HAS_TYPE (NODE, struct hmap_node *),     \
+         UP_CAST (NODE, STRUCT, MEMBER))
 
 /* Like HMAP_DATA, except that a null NODE yields a null pointer
    result. */