1 files changed, 64 insertions, 0 deletions
diff --git a/src/include/access/attnum.h b/src/include/access/attnum.h
new file mode 100644
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--- /dev/null
+++ b/src/include/access/attnum.h
@@ -0,0 +1,64 @@
+/*-------------------------------------------------------------------------
+ *
+ * attnum.h
+ *	  POSTGRES attribute number definitions.
+ *
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/access/attnum.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef ATTNUM_H
+#define ATTNUM_H
+
+
+/*
+ * user defined attribute numbers start at 1.   -ay 2/95
+ */
+typedef int16 AttrNumber;
+
+#define InvalidAttrNumber		0
+#define MaxAttrNumber			32767
+
+/* ----------------
+ *		support macros
+ * ----------------
+ */
+/*
+ * AttributeNumberIsValid
+ *		True iff the attribute number is valid.
+ */
+#define AttributeNumberIsValid(attributeNumber) \
+	((bool) ((attributeNumber) != InvalidAttrNumber))
+
+/*
+ * AttrNumberIsForUserDefinedAttr
+ *		True iff the attribute number corresponds to an user defined attribute.
+ */
+#define AttrNumberIsForUserDefinedAttr(attributeNumber) \
+	((bool) ((attributeNumber) > 0))
+
+/*
+ * AttrNumberGetAttrOffset
+ *		Returns the attribute offset for an attribute number.
+ *
+ * Note:
+ *		Assumes the attribute number is for a user defined attribute.
+ */
+#define AttrNumberGetAttrOffset(attNum) \
+( \
+	AssertMacro(AttrNumberIsForUserDefinedAttr(attNum)), \
+	((attNum) - 1) \
+)
+
+/*
+ * AttrOffsetGetAttrNumber
+ *		Returns the attribute number for an attribute offset.
+ */
+#define AttrOffsetGetAttrNumber(attributeOffset) \
+	 ((AttrNumber) (1 + (attributeOffset)))
+
+#endif							/* ATTNUM_H */