From cfa3372e78791c57bc490988c31e101f6078be37 Mon Sep 17 00:00:00 2001
From: "Charles B. Haley" <cbh@research.uucp>
Date: Wed, 14 Nov 1979 02:41:20 -0800
Subject: [PATCH] BSD 3 development Work on file usr/src/cmd/pi/lab.c

Co-Authored-By: Bill Joy <wnj@ucbvax.Berkeley.EDU>
Co-Authored-By: Ken Thompson <ken@research.uucp>
Synthesized-from: 3bsd
---
 usr/src/cmd/pi/lab.c | 133 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 133 insertions(+)
 create mode 100644 usr/src/cmd/pi/lab.c

diff --git a/usr/src/cmd/pi/lab.c b/usr/src/cmd/pi/lab.c
new file mode 100644
index 0000000000..6427abcfef
--- /dev/null
+++ b/usr/src/cmd/pi/lab.c
@@ -0,0 +1,133 @@
+/* Copyright (c) 1979 Regents of the University of California */
+#
+/*
+ * pi - Pascal interpreter code translator
+ *
+ * Charles Haley, Bill Joy UCB
+ * Version 1.2 November 1978
+ */
+
+#include "whoami"
+#include "0.h"
+#include "tree.h"
+#include "opcode.h"
+
+/*
+ * Label enters the definitions
+ * of the label declaration part
+ * into the namelist.
+ */
+label(r, l)
+	int *r, l;
+{
+#ifndef PI0
+	register *ll;
+	register struct nl *p, *lp;
+
+	lp = NIL;
+#else
+	send(REVLAB, r);
+#endif
+	line = l;
+#ifndef PI1
+	if (parts & (CPRT|TPRT|VPRT))
+		error("Label declarations must precede const, type and var declarations");
+	if (parts & LPRT)
+		error("All labels must be declared in one label part");
+	parts |= LPRT;
+#endif
+#ifndef PI0
+	for (ll = r; ll != NIL; ll = ll[2]) {
+		l = getlab();
+		p = enter(defnl(ll[1], LABEL, 0, l));
+		/*
+		 * Get the label for the eventual target
+		 */
+		p->value[1] = getlab();
+		p->chain = lp;
+		p->nl_flags |= (NFORWD|NMOD);
+		p->value[NL_GOLEV] = NOTYET;
+		p->entloc = l;
+		lp = p;
+		/*
+		 * This operator is between
+		 * the bodies of two procedures
+		 * and provides a target for
+		 * gotos for this label via TRA.
+		 */
+		putlab(l);
+		put2(O_GOTO | cbn<<9, p->value[1]);
+	}
+	gotos[cbn] = lp;
+#	ifdef PTREE
+	    {
+		pPointer	Labels = LabelDCopy( r );
+
+		pDEF( PorFHeader[ nesting ] ).PorFLabels = Labels;
+	    }
+#	endif
+#endif
+}
+
+#ifndef PI0
+/*
+ * Gotoop is called when
+ * we get a statement "goto label"
+ * and generates the needed tra.
+ */
+gotoop(s)
+	char *s;
+{
+	register struct nl *p;
+
+	gocnt++;
+	p = lookup(s);
+	if (p == NIL)
+		return (NIL);
+	put2(O_TRA4, p->entloc);
+	if (bn == cbn)
+		if (p->nl_flags & NFORWD) {
+			if (p->value[NL_GOLEV] == NOTYET) {
+				p->value[NL_GOLEV] = level;
+				p->value[NL_GOLINE] = line;
+			}
+		} else
+			if (p->value[NL_GOLEV] == DEAD) {
+				recovered();
+				error("Goto %s is into a structured statement", p->symbol);
+			}
+}
+
+/*
+ * Labeled is called when a label
+ * definition is encountered, and
+ * marks that it has been found and
+ * patches the associated GOTO generated
+ * by gotoop.
+ */
+labeled(s)
+	char *s;
+{
+	register struct nl *p;
+
+	p = lookup(s);
+	if (p == NIL)
+		return (NIL);
+	if (bn != cbn) {
+		error("Label %s not defined in correct block", s);
+		return;
+	}
+	if ((p->nl_flags & NFORWD) == 0) {
+		error("Label %s redefined", s);
+		return;
+	}
+	p->nl_flags &= ~NFORWD;
+	patch4(p->entloc);
+	if (p->value[NL_GOLEV] != NOTYET)
+		if (p->value[NL_GOLEV] < level) {
+			recovered();
+			error("Goto %s from line %d is into a structured statement", s, p->value[NL_GOLINE]);
+		}
+	p->value[NL_GOLEV] = level;
+}
+#endif
-- 
2.20.1