qemu/0038-hw-usb-dev-mtp-Fix-GCC-9-build-warn.patch

From: Alistair Francis <Alistair.Francis@wdc.com>
Date: Sat, 4 May 2019 07:58:55 -0600
Subject: hw/usb/dev-mtp: Fix GCC 9 build warning

Fix this warning with GCC 9 on Fedora 30:
hw/usb/dev-mtp.c:1715:36: error: taking address of packed member of 'struct <anonymous>' may result in an unaligned pointer value [-Werror=address-of-packed-member]
 1715 |                             dataset->filename);
      |                             ~~~~~~~^~~~~~~~~~

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 hw/usb/dev-mtp.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c
index 99548b012d..8233beacab 100644
--- a/hw/usb/dev-mtp.c
+++ b/hw/usb/dev-mtp.c
@@ -1711,9 +1711,22 @@ static void usb_mtp_write_metadata(MTPState *s, uint64_t dlen)
     assert(!s->write_pending);
     assert(p != NULL);
 
+/*
+ * We are about to access a packed struct. We are confident that the pointer
+ * address won't be unaligned, so we ignore GCC warnings.
+ */
+#if defined(CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE) && QEMU_GNUC_PREREQ(9, 0)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Waddress-of-packed-member"
+#endif
+
     filename = utf16_to_str(MIN(dataset->length, filename_chars),
                             dataset->filename);
 
+#if defined(CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE) && QEMU_GNUC_PREREQ(9, 0)
+#pragma GCC diagnostic pop
+#endif
+
     if (strchr(filename, '/')) {
         usb_mtp_queue_result(s, RES_PARAMETER_NOT_SUPPORTED, d->trans,
                              0, 0, 0, 0);