Module Name: src
Committed By: rillig
Date: Fri Apr 8 21:48:19 UTC 2022
Modified Files:
src/tests/usr.bin/xlint/lint1: msg_048.c msg_048.exp
src/usr.bin/xlint: Makefile.inc
src/usr.bin/xlint/lint1: decl.c
Log Message:
lint: fix undefined behavior on enum overflow (since 1995)
GCC had optimized the check away, due to the obvious integer overflow 'x
- 1 == INT_MAX'. To prevent further bugs like this, compile with
-ftrapv.
To generate a diff of this commit:
cvs rdiff -u -r1.3 -r1.4 src/tests/usr.bin/xlint/lint1/msg_048.c \
src/tests/usr.bin/xlint/lint1/msg_048.exp
cvs rdiff -u -r1.20 -r1.21 src/usr.bin/xlint/Makefile.inc
cvs rdiff -u -r1.268 -r1.269 src/usr.bin/xlint/lint1/decl.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/tests/usr.bin/xlint/lint1/msg_048.c
diff -u src/tests/usr.bin/xlint/lint1/msg_048.c:1.3 src/tests/usr.bin/xlint/lint1/msg_048.c:1.4
--- src/tests/usr.bin/xlint/lint1/msg_048.c:1.3 Fri Apr 8 21:29:29 2022
+++ src/tests/usr.bin/xlint/lint1/msg_048.c Fri Apr 8 21:48:19 2022
@@ -1,10 +1,10 @@
-/* $NetBSD: msg_048.c,v 1.3 2022/04/08 21:29:29 rillig Exp $ */
+/* $NetBSD: msg_048.c,v 1.4 2022/04/08 21:48:19 rillig Exp $ */
# 3 "msg_048.c"
// Test for message: overflow in enumeration values: %s [48]
/*
- * Before decl.c 1.TODO from 2022-04-TODO, the comparison for enum constant
+ * Before decl.c 1.269 from 2022-04-08, the comparison for enum constant
* overflow was done in signed arithmetic, and since 'enumval' wrapped
* around, its value became INT_MIN, at least on platforms where integer
* overflow was defined as 2-complements wrap-around. When comparing
@@ -16,9 +16,7 @@ enum int_limits {
MAX_MINUS_2 = 0x7ffffffd,
MAX_MINUS_1,
MAX,
- /* TODO: expect: overflow in enumeration values: MIN */
- MIN
+ /* expect+1: overflow in enumeration values: MIN [48] */
+ MIN,
+ MIN_PLUS_1
};
-
-TODO: "Add example code that triggers the above message." /* expect: 249 */
-TODO: "Add example code that almost triggers the above message."
Index: src/tests/usr.bin/xlint/lint1/msg_048.exp
diff -u src/tests/usr.bin/xlint/lint1/msg_048.exp:1.3 src/tests/usr.bin/xlint/lint1/msg_048.exp:1.4
--- src/tests/usr.bin/xlint/lint1/msg_048.exp:1.3 Fri Apr 8 21:29:29 2022
+++ src/tests/usr.bin/xlint/lint1/msg_048.exp Fri Apr 8 21:48:19 2022
@@ -1 +1 @@
-msg_048.c(23): error: syntax error ':' [249]
+msg_048.c(20): warning: overflow in enumeration values: MIN [48]
Index: src/usr.bin/xlint/Makefile.inc
diff -u src/usr.bin/xlint/Makefile.inc:1.20 src/usr.bin/xlint/Makefile.inc:1.21
--- src/usr.bin/xlint/Makefile.inc:1.20 Sun Feb 27 07:50:09 2022
+++ src/usr.bin/xlint/Makefile.inc Fri Apr 8 21:48:19 2022
@@ -1,4 +1,4 @@
-# $NetBSD: Makefile.inc,v 1.20 2022/02/27 07:50:09 rillig Exp $
+# $NetBSD: Makefile.inc,v 1.21 2022/04/08 21:48:19 rillig Exp $
.include <bsd.own.mk>
@@ -19,6 +19,8 @@ CPPFLAGS+= -I${.CURDIR}/../common
CLEANFILES+= *.gcno *.gcda *.gcov
+CFLAGS+= ${ACTIVE_CC:Mgcc:%=-ftrapv}
+
.if exists(${.CURDIR}/../../Makefile.inc)
.include "${.CURDIR}/../../Makefile.inc"
.endif
Index: src/usr.bin/xlint/lint1/decl.c
diff -u src/usr.bin/xlint/lint1/decl.c:1.268 src/usr.bin/xlint/lint1/decl.c:1.269
--- src/usr.bin/xlint/lint1/decl.c:1.268 Sun Apr 3 10:05:22 2022
+++ src/usr.bin/xlint/lint1/decl.c Fri Apr 8 21:48:19 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: decl.c,v 1.268 2022/04/03 10:05:22 rillig Exp $ */
+/* $NetBSD: decl.c,v 1.269 2022/04/08 21:48:19 rillig Exp $ */
/*
* Copyright (c) 1996 Christopher G. Demetriou. All Rights Reserved.
@@ -38,7 +38,7 @@
#include <sys/cdefs.h>
#if defined(__RCSID) && !defined(lint)
-__RCSID("$NetBSD: decl.c,v 1.268 2022/04/03 10:05:22 rillig Exp $");
+__RCSID("$NetBSD: decl.c,v 1.269 2022/04/08 21:48:19 rillig Exp $");
#endif
#include <sys/param.h>
@@ -1926,11 +1926,11 @@ enumeration_constant(sym_t *sym, int val
sym->s_type = dcs->d_tagtyp;
sym->s_value.v_tspec = INT;
sym->s_value.v_quad = val;
- if (impl && val - 1 == TARG_INT_MAX) {
+ if (impl && val == TARG_INT_MIN) {
/* overflow in enumeration values: %s */
warning(48, sym->s_name);
}
- enumval = val + 1;
+ enumval = val == TARG_INT_MAX ? TARG_INT_MIN : val + 1;
return sym;
}
