Initial revision

lang/pc/libpc/unp.c

@@ -0,0 +1,49 @@
+/*
+ * (c) copyright 1983 by the Vrije Universiteit, Amsterdam, The Netherlands.
+ *
+ *          This product is part of the Amsterdam Compiler Kit.
+ *
+ * Permission to use, sell, duplicate or disclose this software must be
+ * obtained in writing. Requests for such permissions may be sent to
+ *
+ *      Dr. Andrew S. Tanenbaum
+ *      Wiskundig Seminarium
+ *      Vrije Universiteit
+ *      Postbox 7161
+ *      1007 MC Amsterdam
+ *      The Netherlands
+ *
+ */
+
+/* Author: J.W. Stevenson */
+
+#include	<pc_err.h>
+
+extern		_trp();
+
+#define	assert()	/* nothing */
+
+struct descr {
+	int	low;
+	int	diff;
+	int	size;
+};
+
+_unp(ad,zd,i,ap,zp) int i; struct descr *ad,*zd; char *ap,*zp; {
+
+	if (zd->diff > ad->diff ||
+			(i -= ad->low) < 0 ||
+			(i+zd->diff) > ad->diff)
+		_trp(EUNPACK);
+	ap += (i * ad->size);
+	i = (zd->diff + 1) * zd->size;
+	if (zd->size == 1) {
+		assert(ad->size == 2);
+		while (--i >= 0)
+			*((int *)ap)++ = *zp++;
+	} else {
+		assert(ad->size == zd->size);
+		while (--i >= 0)
+			*ap++ = *zp++;
+	}
+}