[src/trunk]: src/tests/usr.bin/xlint/lint1 lint: demonstrate bug in assignmen...

[rillig <rillig%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/e81eb2b638a6
branches:  trunk
changeset: 1019866:e81eb2b638a6
user:      rillig <rillig%NetBSD.org@localhost>
date:      Mon Mar 22 15:05:00 2021 +0000

description:
lint: demonstrate bug in assignment of compound literal

Seen in external/mpl/bind/dist/lib/dns/rbtdb.c, update_rrsetstats.

diffstat:

 tests/usr.bin/xlint/lint1/msg_171.c   |  20 +++++++++++++++++++-
 tests/usr.bin/xlint/lint1/msg_171.exp |   1 +
 2 files changed, 20 insertions(+), 1 deletions(-)

diffs (39 lines):

diff -r b41899b654a4 -r e81eb2b638a6 tests/usr.bin/xlint/lint1/msg_171.c
--- a/tests/usr.bin/xlint/lint1/msg_171.c       Mon Mar 22 14:11:02 2021 +0000
+++ b/tests/usr.bin/xlint/lint1/msg_171.c       Mon Mar 22 15:05:00 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: msg_171.c,v 1.2 2021/01/24 16:12:45 rillig Exp $       */
+/*     $NetBSD: msg_171.c,v 1.3 2021/03/22 15:05:00 rillig Exp $       */
 # 3 "msg_171.c"
 
 // Test for message: assignment type mismatch (%s != %s) [171]
@@ -17,3 +17,21 @@
        vp = *s;                /* expect: 171 */
        *s = vp;                /* expect: 171 */
 }
+
+/*
+ * C99 6.5.2.5 says that a compound literal evaluates to an unnamed object
+ * with automatic storage duration, like any normal named object.  It is an
+ * lvalue, which means that it is possible to take the address of the object.
+ * Seen in external/mpl/bind/dist/lib/dns/rbtdb.c, update_rrsetstats.
+ */
+void
+pointer_to_compound_literal(void)
+{
+       struct point {
+               int x;
+               int y;
+       };
+       struct point *p = &(struct point){
+           12, 5,
+       };                      /* expect: 171 *//*FIXME*/
+}
diff -r b41899b654a4 -r e81eb2b638a6 tests/usr.bin/xlint/lint1/msg_171.exp
--- a/tests/usr.bin/xlint/lint1/msg_171.exp     Mon Mar 22 14:11:02 2021 +0000
+++ b/tests/usr.bin/xlint/lint1/msg_171.exp     Mon Mar 22 15:05:00 2021 +0000
@@ -2,3 +2,4 @@
 msg_171.c(15): error: assignment type mismatch (struct != int) [171]
 msg_171.c(17): error: assignment type mismatch (pointer != struct) [171]
 msg_171.c(18): error: assignment type mismatch (struct != pointer) [171]
+msg_171.c(36): error: assignment type mismatch (struct != pointer) [171]