Module Name: src
Committed By: rillig
Date: Sun Sep 5 17:49:55 UTC 2021
Modified Files:
src/tests/usr.bin/xlint/lint1: msg_162.c msg_162.exp
src/usr.bin/xlint/lint1: Makefile tree.c
Log Message:
lint: do not warn about comparison 'unsigned <= 0'
Seen in scanners generated by Flex, and about 50 occurrences in the
NetBSD src and xsrc tree, all of which are not suspicious of being bugs.
To generate a diff of this commit:
cvs rdiff -u -r1.5 -r1.6 src/tests/usr.bin/xlint/lint1/msg_162.c \
src/tests/usr.bin/xlint/lint1/msg_162.exp
cvs rdiff -u -r1.86 -r1.87 src/usr.bin/xlint/lint1/Makefile
cvs rdiff -u -r1.378 -r1.379 src/usr.bin/xlint/lint1/tree.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_162.c
diff -u src/tests/usr.bin/xlint/lint1/msg_162.c:1.5 src/tests/usr.bin/xlint/lint1/msg_162.c:1.6
--- src/tests/usr.bin/xlint/lint1/msg_162.c:1.5 Sun Sep 5 16:47:24 2021
+++ src/tests/usr.bin/xlint/lint1/msg_162.c Sun Sep 5 17:49:55 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: msg_162.c,v 1.5 2021/09/05 16:47:24 rillig Exp $ */
+/* $NetBSD: msg_162.c,v 1.6 2021/09/05 17:49:55 rillig Exp $ */
# 3 "msg_162.c"
// Test for message: comparison of %s with %s, op %s [162]
@@ -23,7 +23,7 @@ left_unsigned(unsigned int ui)
if (ui >= 0) {
}
- /* expect+1: warning: comparison of unsigned int with 0, op <= [162] */
+ /* before 2021-09-05: comparison of unsigned int with 0, op <= [162] */
if (ui <= 0) {
}
}
@@ -47,7 +47,7 @@ right_unsigned(unsigned int ui)
if (0 <= ui) {
}
- /* expect+1: warning: comparison of 0 with unsigned int, op >= [162] */
+ /* before 2021-09-05: comparison of 0 with unsigned int, op >= [162] */
if (0 >= ui) {
}
}
@@ -97,11 +97,18 @@ compare_operators(unsigned int x)
/* expect+1: warning: comparison of unsigned int with negative constant, op <= [162] */
take_bool(x <= -1);
/*
- * XXX: The expression 'x <= 0' is equivalent to 'x < 1', so lint
- * should not warn about it, just as it doesn't warn about the
- * inverted condition, which is 'x > 0'.
+ * Before tree.c 1.379 from 2021-09-05, lint warned about
+ * 'unsigned <= 0' as well as '0 >= unsigned'. In all cases where
+ * the programmer knows whether the underlying data type is signed or
+ * unsigned, it is clearer to express the same thought as
+ * 'unsigned == 0', but that's a stylistic issue only.
+ *
+ * Removing this particular case of the warning is not expected to
+ * miss any bugs. The expression 'x <= 0' is equivalent to 'x < 1',
+ * so lint should not warn about it, just as it doesn't warn about
+ * the inverted condition, which is 'x > 0'.
*/
- /* expect+1: warning: comparison of unsigned int with 0, op <= [162] */
+ /* before 2021-09-05: comparison of unsigned int with 0, op <= [162] */
take_bool(x <= 0);
take_bool(x <= 1);
Index: src/tests/usr.bin/xlint/lint1/msg_162.exp
diff -u src/tests/usr.bin/xlint/lint1/msg_162.exp:1.5 src/tests/usr.bin/xlint/lint1/msg_162.exp:1.6
--- src/tests/usr.bin/xlint/lint1/msg_162.exp:1.5 Sun Sep 5 16:47:24 2021
+++ src/tests/usr.bin/xlint/lint1/msg_162.exp Sun Sep 5 17:49:55 2021
@@ -1,18 +1,15 @@
msg_162.c(15): warning: comparison of unsigned int with negative constant, op < [162]
msg_162.c(19): warning: comparison of unsigned int with 0, op < [162]
msg_162.c(23): warning: comparison of unsigned int with 0, op >= [162]
-msg_162.c(27): warning: comparison of unsigned int with 0, op <= [162]
msg_162.c(39): warning: comparison of negative constant with unsigned int, op > [162]
msg_162.c(43): warning: comparison of 0 with unsigned int, op > [162]
msg_162.c(47): warning: comparison of 0 with unsigned int, op <= [162]
-msg_162.c(51): warning: comparison of 0 with unsigned int, op >= [162]
msg_162.c(76): warning: comparison of unsigned char with negative constant, op == [162]
msg_162.c(92): warning: comparison of unsigned int with negative constant, op < [162]
msg_162.c(94): warning: comparison of unsigned int with 0, op < [162]
msg_162.c(98): warning: comparison of unsigned int with negative constant, op <= [162]
-msg_162.c(105): warning: comparison of unsigned int with 0, op <= [162]
-msg_162.c(109): warning: comparison of unsigned int with negative constant, op > [162]
-msg_162.c(114): warning: comparison of unsigned int with negative constant, op >= [162]
-msg_162.c(116): warning: comparison of unsigned int with 0, op >= [162]
-msg_162.c(120): warning: comparison of unsigned int with negative constant, op == [162]
-msg_162.c(125): warning: comparison of unsigned int with negative constant, op != [162]
+msg_162.c(116): warning: comparison of unsigned int with negative constant, op > [162]
+msg_162.c(121): warning: comparison of unsigned int with negative constant, op >= [162]
+msg_162.c(123): warning: comparison of unsigned int with 0, op >= [162]
+msg_162.c(127): warning: comparison of unsigned int with negative constant, op == [162]
+msg_162.c(132): warning: comparison of unsigned int with negative constant, op != [162]
Index: src/usr.bin/xlint/lint1/Makefile
diff -u src/usr.bin/xlint/lint1/Makefile:1.86 src/usr.bin/xlint/lint1/Makefile:1.87
--- src/usr.bin/xlint/lint1/Makefile:1.86 Sun Sep 5 16:36:56 2021
+++ src/usr.bin/xlint/lint1/Makefile Sun Sep 5 17:49:55 2021
@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.86 2021/09/05 16:36:56 rillig Exp $
+# $NetBSD: Makefile,v 1.87 2021/09/05 17:49:55 rillig Exp $
.include <bsd.own.mk>
@@ -20,7 +20,6 @@ LINTFLAGS+= -T
LOBJS.${PROG}+= ${SRCS:M*.y:.y=.ln}
LOBJS.${PROG}+= ${SRCS:M*.l:.l=.ln}
LINTFLAGS.scan.c+= -X 107,126,330,331,332,333 # strict bool mode
-LINTFLAGS.scan.c+= -X 162 # comparison of 'unsigned <= 0'
LINTFLAGS.scan.c+= -X 192,214 # due to suppressed bool errors
LINTFLAGS.scan.c+= -X 307 # static variable unused
Index: src/usr.bin/xlint/lint1/tree.c
diff -u src/usr.bin/xlint/lint1/tree.c:1.378 src/usr.bin/xlint/lint1/tree.c:1.379
--- src/usr.bin/xlint/lint1/tree.c:1.378 Sun Sep 5 16:03:55 2021
+++ src/usr.bin/xlint/lint1/tree.c Sun Sep 5 17:49:55 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: tree.c,v 1.378 2021/09/05 16:03:55 rillig Exp $ */
+/* $NetBSD: tree.c,v 1.379 2021/09/05 17:49:55 rillig Exp $ */
/*
* Copyright (c) 1994, 1995 Jochen Pohl
@@ -37,7 +37,7 @@
#include <sys/cdefs.h>
#if defined(__RCSID) && !defined(lint)
-__RCSID("$NetBSD: tree.c,v 1.378 2021/09/05 16:03:55 rillig Exp $");
+__RCSID("$NetBSD: tree.c,v 1.379 2021/09/05 17:49:55 rillig Exp $");
#endif
#include <float.h>
@@ -4232,7 +4232,7 @@ check_integer_comparison(op_t op, tnode_
/* comparison of %s with %s, op %s */
warning(162, type_name(ln->tn_type),
"negative constant", op_name(op));
- } else if (op == LT || op == GE || (hflag && op == LE)) {
+ } else if (op == LT || op == GE) {
/* comparison of %s with %s, op %s */
warning(162, type_name(ln->tn_type), "0", op_name(op));
}
@@ -4244,7 +4244,7 @@ check_integer_comparison(op_t op, tnode_
/* comparison of %s with %s, op %s */
warning(162, "negative constant",
type_name(rn->tn_type), op_name(op));
- } else if (op == GT || op == LE || (hflag && op == GE)) {
+ } else if (op == GT || op == LE) {
/* comparison of %s with %s, op %s */
warning(162, "0", type_name(rn->tn_type), op_name(op));
}
