Module Name: src
Committed By: rillig
Date: Tue Oct 29 20:39:53 UTC 2024
Modified Files:
src/tests/usr.bin/xlint/lint1: msg_129.c
Log Message:
tests/lint: demonstrate wrong warning about 'null effect'
Seen in sys/timevar.h:250 and other places.
To generate a diff of this commit:
cvs rdiff -u -r1.8 -r1.9 src/tests/usr.bin/xlint/lint1/msg_129.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_129.c
diff -u src/tests/usr.bin/xlint/lint1/msg_129.c:1.8 src/tests/usr.bin/xlint/lint1/msg_129.c:1.9
--- src/tests/usr.bin/xlint/lint1/msg_129.c:1.8 Wed Aug 2 18:51:25 2023
+++ src/tests/usr.bin/xlint/lint1/msg_129.c Tue Oct 29 20:39:52 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: msg_129.c,v 1.8 2023/08/02 18:51:25 rillig Exp $ */
+/* $NetBSD: msg_129.c,v 1.9 2024/10/29 20:39:52 rillig Exp $ */
# 3 "msg_129.c"
// Test for message: expression has null effect [129]
@@ -64,7 +64,7 @@ legitimate_use_cases(int arg)
*/
(void)local;
- /* This is a short-hand notation for a do-nothing command. */
+ /* This is a shorthand notation for a do-nothing command. */
(void)0;
/*
@@ -78,7 +78,8 @@ legitimate_use_cases(int arg)
/*
* This variant of the do-nothing command is commonly used in
* preprocessor macros since it works nicely with if-else and if-then
- * statements. It is longer than the above variant though.
+ * statements. It is longer than the above variant, and it is not
+ * embeddable into an expression.
*/
do {
} while (0);
@@ -94,3 +95,31 @@ legitimate_use_cases(int arg)
/* expect+1: warning: expression has null effect [129] */
(void)(void)0;
}
+
+int
+return_statement_expression(int arg)
+{
+ ({
+ int local = arg;
+ /* XXX: redundant warning, also occurs outside the braces. */
+ /* expect+1: warning: expression has null effect [129] */
+ local + 4;
+ /* expect+1: warning: expression has null effect [129] */
+ });
+
+ if (arg == 1)
+ return ({
+ int local = arg;
+ /* FIXME: The expression _does_ have an effect. */
+ /* expect+1: warning: expression has null effect [129] */
+ local;
+ });
+ if (arg == 2)
+ return ({
+ int local = arg;
+ /* FIXME: The expression _does_ have an effect. */
+ /* expect+1: warning: expression has null effect [129] */
+ local + 4;
+ });
+ return 0;
+}
