[src/trunk]: src/common/lib/libc/misc workaround a GCC 8 warning:

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

details:   https://anonhg.NetBSD.org/src/rev/7b337239398e
branches:  trunk
changeset: 464383:7b337239398e
user:      mrg <mrg%NetBSD.org@localhost>
date:      Fri Oct 04 12:12:47 2019 +0000

description:
workaround a GCC 8 warning:

- code that will be unreachable on platforms with
  sizeof(double) != sizeof(unsigned long) triggered an valid out
  of bounds warning.  avoid the error by using sizeof ul.
- also assert that the sizes are the same if entering here.

both from kamil@.

diffstat:

 common/lib/libc/misc/ubsan.c |  9 +++++----
 1 files changed, 5 insertions(+), 4 deletions(-)

diffs (31 lines):

diff -r 2944b85a2afa -r 7b337239398e common/lib/libc/misc/ubsan.c
--- a/common/lib/libc/misc/ubsan.c      Fri Oct 04 12:11:38 2019 +0000
+++ b/common/lib/libc/misc/ubsan.c      Fri Oct 04 12:12:47 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ubsan.c,v 1.6 2019/06/17 18:55:37 kamil Exp $  */
+/*     $NetBSD: ubsan.c,v 1.7 2019/10/04 12:12:47 mrg Exp $    */
 
 /*-
  * Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -38,9 +38,9 @@
 
 #include <sys/cdefs.h>
 #if defined(_KERNEL)
-__KERNEL_RCSID(0, "$NetBSD: ubsan.c,v 1.6 2019/06/17 18:55:37 kamil Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ubsan.c,v 1.7 2019/10/04 12:12:47 mrg Exp $");
 #else
-__RCSID("$NetBSD: ubsan.c,v 1.6 2019/06/17 18:55:37 kamil Exp $");
+__RCSID("$NetBSD: ubsan.c,v 1.7 2019/10/04 12:12:47 mrg Exp $");
 #endif
 
 #if defined(_KERNEL)
@@ -1403,7 +1403,8 @@
 
        switch (zDeserializeTypeWidth(pType)) {
        case WIDTH_64:
-               memcpy(&D, &ulNumber, sizeof(double));
+               ASSERT(sizeof(D) == sizeof(ulNumber));
+               memcpy(&D, &ulNumber, sizeof(ulNumber));
                snprintf(pBuffer, zBUfferLength, "%g", D);
                break;
        case WIDTH_32: