Wed May 18 19:25:12 2022 UTC ()
tests/lint: add more examples for warning in comma expression


(rillig)
diff -r1.6 -r1.7 src/tests/usr.bin/xlint/lint1/msg_160.c
diff -r1.5 -r1.6 src/tests/usr.bin/xlint/lint1/msg_160.exp
cvs diff -r1.6 -r1.7 src/tests/usr.bin/xlint/lint1/msg_160.c (expand / switch to unified diff)

--- src/tests/usr.bin/xlint/lint1/msg_160.c 2021/10/09 21:25:39 1.6
+++ src/tests/usr.bin/xlint/lint1/msg_160.c 2022/05/18 19:25:12 1.7
@@ -1,14 +1,14 @@ @@ -1,14 +1,14 @@
1/* $NetBSD: msg_160.c,v 1.6 2021/10/09 21:25:39 rillig Exp $ */ 1/* $NetBSD: msg_160.c,v 1.7 2022/05/18 19:25:12 rillig Exp $ */
2# 3 "msg_160.c" 2# 3 "msg_160.c"
3 3
4// Test for message: operator '==' found where '=' was expected [160] 4// Test for message: operator '==' found where '=' was expected [160]
5 5
6/* lint1-extra-flags: -h */ 6/* lint1-extra-flags: -h */
7 7
8_Bool 8_Bool
9both_equal_or_unequal(int a, int b, int c, int d) 9both_equal_or_unequal(int a, int b, int c, int d)
10{ 10{
11 /* 11 /*
12 * Before tree.c 1.201 from 2021-01-31, lint warned about each of 12 * Before tree.c 1.201 from 2021-01-31, lint warned about each of
13 * the '==' subexpressions even though there is nothing surprising 13 * the '==' subexpressions even though there is nothing surprising
14 * about them. 14 * about them.
@@ -47,24 +47,58 @@ unparenthesized(int a, int b, int c, _Bo @@ -47,24 +47,58 @@ unparenthesized(int a, int b, int c, _Bo
47 * Before tree.c 1.201 from 2021-01-31, lint warned about the 47 * Before tree.c 1.201 from 2021-01-31, lint warned about the
48 * parenthesized '==' subexpression even though there is nothing 48 * parenthesized '==' subexpression even though there is nothing
49 * surprising about it. 49 * surprising about it.
50 */ 50 */
51 eval((a == b) == c); 51 eval((a == b) == c);
52 /* 52 /*
53 * Before tree.c 1.201 from 2021-01-31, lint warned about the 53 * Before tree.c 1.201 from 2021-01-31, lint warned about the
54 * parenthesized '==' subexpression even though there is nothing 54 * parenthesized '==' subexpression even though there is nothing
55 * surprising about it. 55 * surprising about it.
56 */ 56 */
57 eval(a == (b == c)); 57 eval(a == (b == c));
58} 58}
59 59
60/* Seen in bin/csh/dir.c 1.35 from 2020-08-09, line 223. */ 
61void 60void
62assignment_in_comma_expression(void) 61assignment_in_comma_expression(int len)
63{ 62{
64 int len; 
65 63
 64 /*
 65 * No extra parentheses, just a comma operator.
 66 *
 67 * The usual interpretation is that the left-hand operand of the
 68 * comma is a preparation, most often an assignment, and the
 69 * right-hand operand of the comma is the actual condition.
 70 */
 71 /* FIXME: The following code is totally fine. */
 72 /* expect+1: warning: operator '==' found where '=' was expected [160] */
 73 if (len = 3 * len + 1, len == 0)
 74 return;
 75
 76 /* Seen in bin/csh/dir.c 1.35 from 2020-08-09, line 223. */
 77 /*
 78 * The extra parentheses are typically used to inform the compiler
 79 * that an assignment using '=' is intentional, in particular it is
 80 * not a typo of the comparison operator '=='.
 81 *
 82 * The comma operator in a condition is seldom used, which makes it
 83 * reasonable to assume that the code author selected the operators
 84 * on purpose.
 85 *
 86 * In this case the parentheses are redundant, it's quite possible
 87 * that they come from a macro expansion though.
 88 */
 89 /* FIXME: The following code is totally fine. */
 90 /* expect+1: warning: operator '==' found where '=' was expected [160] */
 91 if ((len = 3 * len + 1, len == 0))
 92 return;
 93
 94 /*
 95 * If the comma expression is part of a larger expression, the
 96 * parentheses are required to mark the operator precedence. The
 97 * parentheses must therefore not be interpreted as changing the
 98 * intention from a condition to an assignment.
 99 */
66 /* FIXME: The following code is totally fine. */ 100 /* FIXME: The following code is totally fine. */
67 /* expect+1: warning: operator '==' found where '=' was expected [160] */ 101 /* expect+1: warning: operator '==' found where '=' was expected [160] */
68 if ((len = 3, len == 0)) 102 if ((len = 3 * len + 1, len == 0) && len < 2)
69 return; 103 return;
70} 104}
cvs diff -r1.5 -r1.6 src/tests/usr.bin/xlint/lint1/Attic/msg_160.exp (expand / switch to unified diff)

--- src/tests/usr.bin/xlint/lint1/Attic/msg_160.exp 2021/10/09 21:25:39 1.5
+++ src/tests/usr.bin/xlint/lint1/Attic/msg_160.exp 2022/05/18 19:25:12 1.6
@@ -1,3 +1,5 @@ @@ -1,3 +1,5 @@
1msg_160.c(30): warning: operator '==' found where '=' was expected [160] 1msg_160.c(30): warning: operator '==' found where '=' was expected [160]
2msg_160.c(43): warning: operator '==' found where '=' was expected [160] 2msg_160.c(43): warning: operator '==' found where '=' was expected [160]
3msg_160.c(68): warning: operator '==' found where '=' was expected [160] 3msg_160.c(73): warning: operator '==' found where '=' was expected [160]
 4msg_160.c(91): warning: operator '==' found where '=' was expected [160]
 5msg_160.c(102): warning: operator '==' found where '=' was expected [160]