Module Name: src
Committed By: rillig
Date: Wed May 18 19:25:12 UTC 2022
Modified Files:
src/tests/usr.bin/xlint/lint1: msg_160.c msg_160.exp
Log Message:
tests/lint: add more examples for warning in comma expression
To generate a diff of this commit:
cvs rdiff -u -r1.6 -r1.7 src/tests/usr.bin/xlint/lint1/msg_160.c
cvs rdiff -u -r1.5 -r1.6 src/tests/usr.bin/xlint/lint1/msg_160.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_160.c
diff -u src/tests/usr.bin/xlint/lint1/msg_160.c:1.6 src/tests/usr.bin/xlint/lint1/msg_160.c:1.7
--- src/tests/usr.bin/xlint/lint1/msg_160.c:1.6 Sat Oct 9 21:25:39 2021
+++ src/tests/usr.bin/xlint/lint1/msg_160.c Wed May 18 19:25:12 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: msg_160.c,v 1.6 2021/10/09 21:25:39 rillig Exp $ */
+/* $NetBSD: msg_160.c,v 1.7 2022/05/18 19:25:12 rillig Exp $ */
# 3 "msg_160.c"
// Test for message: operator '==' found where '=' was expected [160]
@@ -57,14 +57,48 @@ unparenthesized(int a, int b, int c, _Bo
eval(a == (b == c));
}
-/* Seen in bin/csh/dir.c 1.35 from 2020-08-09, line 223. */
void
-assignment_in_comma_expression(void)
+assignment_in_comma_expression(int len)
{
- int len;
+ /*
+ * No extra parentheses, just a comma operator.
+ *
+ * The usual interpretation is that the left-hand operand of the
+ * comma is a preparation, most often an assignment, and the
+ * right-hand operand of the comma is the actual condition.
+ */
+ /* FIXME: The following code is totally fine. */
+ /* expect+1: warning: operator '==' found where '=' was expected [160] */
+ if (len = 3 * len + 1, len == 0)
+ return;
+
+ /* Seen in bin/csh/dir.c 1.35 from 2020-08-09, line 223. */
+ /*
+ * The extra parentheses are typically used to inform the compiler
+ * that an assignment using '=' is intentional, in particular it is
+ * not a typo of the comparison operator '=='.
+ *
+ * The comma operator in a condition is seldom used, which makes it
+ * reasonable to assume that the code author selected the operators
+ * on purpose.
+ *
+ * In this case the parentheses are redundant, it's quite possible
+ * that they come from a macro expansion though.
+ */
+ /* FIXME: The following code is totally fine. */
+ /* expect+1: warning: operator '==' found where '=' was expected [160] */
+ if ((len = 3 * len + 1, len == 0))
+ return;
+
+ /*
+ * If the comma expression is part of a larger expression, the
+ * parentheses are required to mark the operator precedence. The
+ * parentheses must therefore not be interpreted as changing the
+ * intention from a condition to an assignment.
+ */
/* FIXME: The following code is totally fine. */
/* expect+1: warning: operator '==' found where '=' was expected [160] */
- if ((len = 3, len == 0))
+ if ((len = 3 * len + 1, len == 0) && len < 2)
return;
}
Index: src/tests/usr.bin/xlint/lint1/msg_160.exp
diff -u src/tests/usr.bin/xlint/lint1/msg_160.exp:1.5 src/tests/usr.bin/xlint/lint1/msg_160.exp:1.6
--- src/tests/usr.bin/xlint/lint1/msg_160.exp:1.5 Sat Oct 9 21:25:39 2021
+++ src/tests/usr.bin/xlint/lint1/msg_160.exp Wed May 18 19:25:12 2022
@@ -1,3 +1,5 @@
msg_160.c(30): warning: operator '==' found where '=' was expected [160]
msg_160.c(43): warning: operator '==' found where '=' was expected [160]
-msg_160.c(68): warning: operator '==' found where '=' was expected [160]
+msg_160.c(73): warning: operator '==' found where '=' was expected [160]
+msg_160.c(91): warning: operator '==' found where '=' was expected [160]
+msg_160.c(102): warning: operator '==' found where '=' was expected [160]
