Murilo Opsfelder Araujo <muriloo@linux.ibm.com> writes:
Building QEMU on Fedora 37 (Rawhide Prerelease) ppc64le failed with the
following error:
$ ../configure --prefix=/usr/local/qemu-disabletcg
--target-list=ppc-softmmu,ppc64-softmmu --disable-tcg --disable-linux-user
...
$ make -j$(nproc)
...
FAILED: libqemuutil.a.p/qobject_block-qdict.c.o
cc -m64 -mlittle-endian -Ilibqemuutil.a.p -I. -I..
-Isubprojects/libvhost-user -I../subprojects/libvhost-user -Iqapi -Itrace -Iui
-Iui/shader -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include
-I/usr/include/sysprof-4 -I/usr/include/lib
mount -I/usr/include/blkid -I/usr/include/gio-unix-2.0
-I/usr/include/p11-kit-1 -I/usr/include/pixman-1 -fdiagnostics-color=auto -Wall
-Winvalid-pch -Werror -std=gnu11 -O2 -g -isystem /root/qemu/linux-headers
-isystem linux-headers -iquote
. -iquote /root/qemu -iquote /root/qemu/include -iquote
/root/qemu/disas/libvixl -pthread -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2
-D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes
-Wredundant-decls -Wundef -Wwrite
-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -fwrapv
-Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security
-Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs
-Wendif-label
s -Wexpansion-to-defined -Wimplicit-fallthrough=2
-Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi
-fstack-protector-strong -fPIE -MD -MQ libqemuutil.a.p/qobject_block-qdict.c.o
-MF libqemuutil.a.p/qobject_block-qdict.c.o.d -
o libqemuutil.a.p/qobject_block-qdict.c.o -c ../qobject/block-qdict.c
In file included from /root/qemu/include/qapi/qmp/qdict.h:16,
from /root/qemu/include/block/qdict.h:13,
from ../qobject/block-qdict.c:11:
/root/qemu/include/qapi/qmp/qobject.h: In function ‘qdict_array_split’:
/root/qemu/include/qapi/qmp/qobject.h:49:17: error: ‘subqdict’ may be used
uninitialized [-Werror=maybe-uninitialized]
49 | typeof(obj) _obj = (obj); \
| ^~~~
../qobject/block-qdict.c:227:16: note: ‘subqdict’ declared here
227 | QDict *subqdict;
| ^~~~~~~~
cc1: all warnings being treated as errors
Fix build failure by initializing the QDict variable with NULL.
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Hanna Reitz <hreitz@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
---
qobject/block-qdict.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/qobject/block-qdict.c b/qobject/block-qdict.c
index 1487cc5dd8..b26524429c 100644
--- a/qobject/block-qdict.c
+++ b/qobject/block-qdict.c
@@ -224,7 +224,7 @@ void qdict_array_split(QDict *src, QList **dst)
for (i = 0; i < UINT_MAX; i++) {
QObject *subqobj;
bool is_subqdict;
- QDict *subqdict;
+ QDict *subqdict = NULL;
char indexstr[32], prefix[32];
size_t snprintf_ret;
The compiler's warning is actually spurious. Your patch is the
minimally invasive way to shut it up. But I wonder whether we can
make the code clearer instead. Let's have a look:
/*
* There may be either a single subordinate object (named
* "%u") or multiple objects (each with a key prefixed "%u."),
* but not both.
*/
if (!subqobj == !is_subqdict) {
break;
Because of this, ...
}
if (is_subqdict) {
... subqobj is non-null here, and ...
qdict_extract_subqdict(src, &subqdict, prefix);
assert(qdict_size(subqdict) > 0);
} else {
... null here.
qobject_ref(subqobj);
qdict_del(src, indexstr);
}
qlist_append_obj(*dst, subqobj ?: QOBJECT(subqdict));
What about this:
if (is_subqdict) {
qdict_extract_subqdict(src, &subqdict, prefix);
assert(qdict_size(subqdict) > 0);
qlist_append_obj(*dst, subqobj);
} else {
qobject_ref(subqobj);
qdict_del(src, indexstr);
qlist_append_obj(*dst, QOBJECT(subqdict));
}