Added offset.h

[r5928]

diff --git a/ir/adt/Makefile.in b/ir/adt/Makefile.in
index 912e45d..35f03e9 100644 (file)
--- a/ir/adt/Makefile.in
+++ b/ir/adt/Makefile.in
@@ -16,7 +16,7 @@ topdir = ../..
 subdir := ir/adt
 disable_libiberty := @disable_libiberty@
 
-INSTALL_HEADERS_ADT = pset.h set.h pmap.h eset.h hashptr.h array.h pdeq.h iterator.h align.h fourcc.h
+INSTALL_HEADERS_ADT = pset.h set.h pmap.h eset.h hashptr.h array.h pdeq.h iterator.h align.h fourcc.h offset.h
 
 SOURCES = Makefile.in                          \
        array.c obst.h pdeq.c   \

diff --git a/ir/adt/offset.h b/ir/adt/offset.h
new file mode 100644 (file)
index 0000000..6f797a6
--- /dev/null
+++ b/ir/adt/offset.h
@@ -0,0 +1,34 @@
+/**
+ * @file   offset.h
+ * @date   31.05.2005
+ * @author Sebastian Hack
+ *
+ * Firm's own offset_of and container_of
+ *
+ * Copyright (C) 2005 Universitaet Karlsruhe
+ * Released under the GPL
+ */
+
+#ifndef _OFFSET_H
+#define _OFFSET_H
+
+/**
+ * Get the offset of a member of a struct.
+ * @param type   The type of the struct member is in.
+ * @param member The name of the member.
+ * @return       The offset of member in type in bytes.
+ */
+#define offset_of(type, member) \
+  ((char *) &(((type *) 0)->member) - (char *) 0)
+
+/**
+ * Make pointer to the struct from a pointer to a member of that struct.
+ * @param ptr     The pointer to the member.
+ * @param type    The type of the struct.
+ * @param member  The name of the member.
+ * @return        A pointer to the struct member is in.
+ */
+#define container_of(ptr, type, member) \
+       ((type *) ((char *) (ptr) - offset_of(type, member)))
+
+#endif /* _OFFSET_H */