Module Name: src
Committed By: rillig
Date: Fri Aug 27 17:59:46 UTC 2021
Modified Files:
src/tests/usr.bin/xlint/lint1: msg_117.c msg_117.exp
Log Message:
tests/lint: document correct lint warnings for '>>'
The previous commit contained wrong assumptions. Upon closer
inspection, the lint warning is correct.
To generate a diff of this commit:
cvs rdiff -u -r1.8 -r1.9 src/tests/usr.bin/xlint/lint1/msg_117.c
cvs rdiff -u -r1.7 -r1.8 src/tests/usr.bin/xlint/lint1/msg_117.exp
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_117.c
diff -u src/tests/usr.bin/xlint/lint1/msg_117.c:1.8 src/tests/usr.bin/xlint/lint1/msg_117.c:1.9
--- src/tests/usr.bin/xlint/lint1/msg_117.c:1.8 Fri Aug 27 17:49:31 2021
+++ src/tests/usr.bin/xlint/lint1/msg_117.c Fri Aug 27 17:59:46 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: msg_117.c,v 1.8 2021/08/27 17:49:31 rillig Exp $ */
+/* $NetBSD: msg_117.c,v 1.9 2021/08/27 17:59:46 rillig Exp $ */
# 3 "msg_117.c"
// Test for message: bitwise '%s' on signed value possibly nonportable [117]
@@ -47,15 +47,22 @@ shr_unsigned_char(unsigned char uc)
}
unsigned char
-shr_unsigned_char_promoted(unsigned char bit)
+shr_unsigned_char_promoted_signed(unsigned char bit)
{
/*
- * Before TODO from TODO, lint wrongly warned that the bitwise shift
- * might be on a signed value, which was wrong. Even though the
- * expression has type 'int', the value of the expression cannot be
- * negative, as long as int is larger than char, which holds for all
- * platforms supported by lint.
+ * The possible values for 'bit' range from 0 to 255. Subtracting 1
+ * from 0 results in a negative expression value.
*/
/* expect+1: warning: bitwise '>>' on signed value possibly nonportable [117] */
return (unsigned char)((bit - 1) >> 5);
}
+
+unsigned char
+shr_unsigned_char_promoted_unsigned(unsigned char bit)
+{
+ /*
+ * To prevent the above warning, the intermediate expression must be
+ * cast to 'unsigned char'.
+ */
+ return (unsigned char)((unsigned char)(bit - 1) >> 5);
+}
Index: src/tests/usr.bin/xlint/lint1/msg_117.exp
diff -u src/tests/usr.bin/xlint/lint1/msg_117.exp:1.7 src/tests/usr.bin/xlint/lint1/msg_117.exp:1.8
--- src/tests/usr.bin/xlint/lint1/msg_117.exp:1.7 Fri Aug 27 17:49:31 2021
+++ src/tests/usr.bin/xlint/lint1/msg_117.exp Fri Aug 27 17:59:46 2021
@@ -4,4 +4,4 @@ msg_117.c(29): warning: bitwise '>>' on
msg_117.c(29): warning: shift amount 4660 is greater than bit-size 32 of 'int' [122]
msg_117.c(35): warning: bitwise '>>' on signed value possibly nonportable [117]
msg_117.c(35): warning: negative shift [121]
-msg_117.c(60): warning: bitwise '>>' on signed value possibly nonportable [117]
+msg_117.c(57): warning: bitwise '>>' on signed value possibly nonportable [117]
