[src/trunk]: src/tests/usr.bin/xlint/lint1 tests/lint: add test for conversio...

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

details:   https://anonhg.NetBSD.org/src/rev/95c135b979cb
branches:  trunk
changeset: 374430:95c135b979cb
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sat Apr 22 17:30:35 2023 +0000

description:
tests/lint: add test for conversions to and from a union type

Additionally, fix the line numbers in another test.

diffstat:

 tests/usr.bin/xlint/lint1/msg_159.c |   6 +-
 tests/usr.bin/xlint/lint1/msg_247.c |  61 ++++++++++++++++++++++++++++++++++++-
 2 files changed, 63 insertions(+), 4 deletions(-)

diffs (93 lines):

diff -r e34edcc00a1b -r 95c135b979cb tests/usr.bin/xlint/lint1/msg_159.c
--- a/tests/usr.bin/xlint/lint1/msg_159.c       Sat Apr 22 15:32:49 2023 +0000
+++ b/tests/usr.bin/xlint/lint1/msg_159.c       Sat Apr 22 17:30:35 2023 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: msg_159.c,v 1.5 2023/04/22 15:14:37 rillig Exp $       */
+/*     $NetBSD: msg_159.c,v 1.6 2023/04/22 17:30:35 rillig Exp $       */
 # 3 "msg_159.c"
 
 // Test for message: assignment in conditional context [159]
@@ -21,9 +21,9 @@ example(int a, int b)
                return "comparison, parenthesized";
 
        if (
-# 20 "msg_159.c" 3 4
+# 25 "msg_159.c" 3 4
            (a == b)
-# 22 "msg_159.c"
+# 27 "msg_159.c"
            )
                return "comparison, parenthesized, from system header";
 
diff -r e34edcc00a1b -r 95c135b979cb tests/usr.bin/xlint/lint1/msg_247.c
--- a/tests/usr.bin/xlint/lint1/msg_247.c       Sat Apr 22 15:32:49 2023 +0000
+++ b/tests/usr.bin/xlint/lint1/msg_247.c       Sat Apr 22 17:30:35 2023 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: msg_247.c,v 1.27 2023/03/28 14:44:35 rillig Exp $      */
+/*     $NetBSD: msg_247.c,v 1.28 2023/04/22 17:30:35 rillig Exp $      */
 # 3 "msg_247.c"
 
 // Test for message: pointer cast from '%s' to '%s' may be troublesome [247]
@@ -332,3 +332,62 @@ unnecessary_cast_from_array_to_pointer(i
 
        return (double *)storage_2d;
 }
+
+
+typedef void (*function)(void);
+
+typedef struct {
+       function m_function_array[5];
+} struct_function_array;
+
+typedef union {
+       int um_int;
+       double um_double;
+       struct_function_array um_function_array;
+} anything;
+
+static int *p_int;
+static double *p_double;
+static function p_function;
+static struct_function_array *p_function_array;
+static anything *p_anything;
+
+void
+conversions_from_and_to_union(void)
+{
+       /* Self-assignment, disguided by a cast to its own type. */
+       p_int = (int *)p_int;
+       /* Self-assignment, disguided by a cast to a pointer. */
+       p_int = (void *)p_int;
+
+       /* expect+1: warning: illegal combination of 'pointer to int' and 'pointer to double', op '=' [124] */
+       p_int = p_double;
+       /* expect+1: warning: pointer cast from 'pointer to double' to 'pointer to int' may be troublesome [247] */
+       p_int = (int *)p_double;
+
+       /* expect+1: warning: illegal combination of 'pointer to union typedef anything' and 'pointer to double', op '=' [124] */
+       p_anything = p_double;
+       /*  FIXME: OK, since the union 'anything' has a 'double' member. */
+       /* expect+1: warning: pointer cast from 'pointer to double' to 'pointer to union typedef anything' may be troublesome [247] */
+       p_anything = (anything *)p_double;
+       /* expect+1: warning: illegal combination of 'pointer to double' and 'pointer to union typedef anything', op '=' [124] */
+       p_double = p_anything;
+       /* FIXME: OK, since the union 'anything' has a 'double' member. */
+       /* expect+1: warning: pointer cast from 'pointer to union typedef anything' to 'pointer to double' may be troublesome [247] */
+       p_double = (double *)p_anything;
+
+       /*
+        * Casting to an intermediate union does not make casting between two
+        * incompatible types better.
+        */
+       /* expect+2: warning: pointer cast from 'pointer to int' to 'pointer to union typedef anything' may be troublesome [247] */
+       /* expect+1: warning: illegal combination of 'pointer to function(void) returning void' and 'pointer to union typedef anything', op '=' [124] */
+       p_function = (anything *)p_int;
+
+       /* expect+2: warning: converting 'pointer to function(void) returning void' to 'pointer to union typedef anything' is questionable [229] */
+       /* expect+1: warning: illegal combination of 'pointer to function(void) returning void' and 'pointer to union typedef anything', op '=' [124] */
+       p_function = (anything *)p_function_array->m_function_array[0];
+
+       /* expect+1: warning: illegal combination of 'pointer to int' and 'pointer to function(void) returning void', op '=' [124] */
+       p_int = p_function;
+}