1 files changed, 44 insertions, 0 deletions
diff --git a/sys/symtab/stfree.x b/sys/symtab/stfree.x
new file mode 100644
index 00000000..1a960fe5
--- /dev/null
+++ b/sys/symtab/stfree.x
@@ -0,0 +1,44 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	"symtab.h"
+
+# STFREE -- Free storage back to the last marker.  No storage is actually
+# returned to the system, rather the storage is made available for reuse
+# by SYMTAB (the stacks are pruned).
+
+procedure stfree (stp, marker)
+
+pointer	stp			# symtab descriptor
+int	marker			# magic marker
+
+int	el
+pointer	index, stab, ep, mp
+
+begin
+	index = ST_INDEX(stp)
+	stab  = ST_STABP(stp)
+	mp    = stab + marker
+	ep    = NULL
+
+	# Ignore requests with out of range markers.
+	if (marker <= 0 || marker >= ST_STABOP(stp))
+	    return
+
+	# Descend the global (time ordered) list, unlinking each symbol until
+	# the marker position is reached.
+
+	for (el = ST_LASTSYMBOL(stp);  el > marker;  el = E_NEXTGLOB(ep)) {
+	    ep = stab + el
+	    Memi[index+E_THREAD(ep)] = E_NEXTHASH(ep)
+	}
+
+	# Reset the stack pointers and set the head of the global list to
+	# point to the symbol immediately preceding the marker.
+
+	ST_NSYMBOLS(stp) = M_NSYMBOLS(mp)
+	ST_SBUFOP(stp)   = M_SBUFOP(mp)
+	ST_STABOP(stp)   = marker
+
+	if (ep != NULL)
+	    ST_LASTSYMBOL(stp) = E_NEXTGLOB(ep)
+end