From 7bd60afb8f35fcbfc74b138b25bd5905d2e6f26e Mon Sep 17 00:00:00 2001
From: Stefan Kempf <stefan@cvs.openbsd.org>
Date: Fri, 12 Oct 2007 18:14:15 +0000
Subject: From master repo: > Add zero checks when dividing or taking modulo.
 ok otto@

---
 usr.bin/pcc/cpp/cpp.c | 19 ++++++++++++++++++-
 usr.bin/pcc/cpp/cpp.h |  3 ++-
 usr.bin/pcc/cpp/cpy.y | 15 +++++++++++++--
 3 files changed, 33 insertions(+), 4 deletions(-)

(limited to 'usr.bin')

diff --git a/usr.bin/pcc/cpp/cpp.c b/usr.bin/pcc/cpp/cpp.c
index 74005f0b045..4506592c717 100644
--- a/usr.bin/pcc/cpp/cpp.c
+++ b/usr.bin/pcc/cpp/cpp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpp.c,v 1.2 2007/10/07 19:26:27 otto Exp $	*/
+/*	$OpenBSD: cpp.c,v 1.3 2007/10/12 18:14:14 stefan Exp $	*/
 
 /*
  * Copyright (c) 2004 Anders Magnusson (ragge@ludd.luth.se).
@@ -727,6 +727,23 @@ id:			savstr((usch *)yytext);
 bad:	error("bad define");
 }
 
+void
+warning(usch *s)
+{
+	usch *t;
+	usch *sb = stringbuf;
+
+	flbuf();
+	savch(0);
+	if (ifiles != NULL) {
+		t = sheap("%s:%d: warning: ", ifiles->fname, ifiles->lineno);
+		write (2, t, strlen((char *)t));
+	}
+	write (2, s, strlen((char *)s));
+	write (2, "\n", 1);
+	stringbuf = sb;
+}
+
 void
 xerror(usch *s)
 {
diff --git a/usr.bin/pcc/cpp/cpp.h b/usr.bin/pcc/cpp/cpp.h
index d12968dcf08..d3e7773a522 100644
--- a/usr.bin/pcc/cpp/cpp.h
+++ b/usr.bin/pcc/cpp/cpp.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpp.h,v 1.2 2007/10/12 07:22:44 otto Exp $	*/
+/*	$OpenBSD: cpp.h,v 1.3 2007/10/12 18:14:14 stefan Exp $	*/
 
 /*
  * Copyright (c) 2004 Anders Magnusson (ragge@ludd.luth.se).
@@ -143,6 +143,7 @@ void putch(int);
 void putstr(usch *s);
 void line(void);
 usch *sheap(char *fmt, ...);
+void warning(usch *);
 void xerror(usch *);
 #define error(...) xerror(sheap(__VA_ARGS__))
 void expmac(struct recur *);
diff --git a/usr.bin/pcc/cpp/cpy.y b/usr.bin/pcc/cpp/cpy.y
index ed73fceebcc..37ba7371fbc 100644
--- a/usr.bin/pcc/cpp/cpy.y
+++ b/usr.bin/pcc/cpp/cpy.y
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpy.y,v 1.2 2007/10/12 07:22:44 otto Exp $	*/
+/*	$OpenBSD: cpy.y,v 1.3 2007/10/12 18:14:14 stefan Exp $	*/
 
 /*
  * Copyright (c) 2004 Anders Magnusson (ragge@ludd.luth.se).
@@ -275,6 +275,18 @@ eval(struct nd *tree)
 	l = eval(tree->nd_left);
 	r = eval(tree->nd_right);
 	t = l.type || r.type;
+	if (tree->op == '/' || tree->op == '%') {
+		if ((t && r.v.uval == 0) || (!t && r.v.val == 0)) {
+			warning(tree->op == '/' ? "division by zero" :
+		                "modulus by zero");
+			if (t)
+				ret.v.uval = 0;
+			else
+				ret.v.val = 0;
+			ret.type = t;
+			goto out;
+		}
+	}
 	switch (tree->op) {
 		EVALBIN(EQ, ==, t, l, r, 0);
 		EVALBIN(NE, !=, t, l, r, 0);
@@ -285,7 +297,6 @@ eval(struct nd *tree)
 		EVALBIN('+', +, t, l, r, t);
 		EVALBIN('-', -, t, l, r, t);
 		EVALBIN('*', *, t, l, r, t);
-		// XXX check /,% by zero
 		EVALBIN('/', /, t, l, r, t);
 		EVALBIN('%', %, t, l, r, t);
 		EVALBIN('&', &, t, l, r, t);
-- 
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