Markus Armbruster 84e5261cdf qapi: Improve qobject input visitor error reporting ... Error messages refer to nodes of the QObject being visited by name. Trouble is the names are sometimes less than helpful: * The name of the root QObject is whatever @name argument got passed to the visitor, except NULL gets mapped to "null". We commonly pass NULL. Not good. Avoiding errors "at the root" mitigates. For instance, visit_start_struct() can only fail when the visited object is not a dictionary, and we commonly ensure it is beforehand. * The name of a QDict's member is the member key. Good enough only when this happens to be unique. * The name of a QList's member is "null". Not good. Improve error messages by referring to nodes by path instead, as follows: * The path of the root QObject is whatever @name argument got passed to the visitor, except NULL gets mapped to "<anonymous>". * The path of a root QDict's member is the member key. * The path of a root QList's member is "[%u]", where %u is the list index, starting at zero. * The path of a non-root QDict's member is the path of the QDict concatenated with "." and the member key. * The path of a non-root QList's member is the path of the QList concatenated with "[%u]", where %u is the list index. For example, the incorrect QMP command { "execute": "blockdev-add", "arguments": { "node-name": "foo", "driver": "raw", "file": {"driver": "file" } } } now fails with {"error": {"class": "GenericError", "desc": "Parameter 'file.filename' is missing"}} instead of {"error": {"class": "GenericError", "desc": "Parameter 'filename' is missing"}} and { "execute": "input-send-event", "arguments": { "device": "bar", "events": [ [] ] } } now fails with {"error": {"class": "GenericError", "desc": "Invalid parameter type for 'events[0]', expected: object"}} instead of {"error": {"class": "GenericError", "desc": "Invalid parameter type for 'null', expected: QDict"}} Aside: calling the thing "parameter" is suboptimal for QMP, because the root object is "arguments" there. The qobject output visitor doesn't have this problem because it should not fail. Same for dealloc and clone visitors. The string visitors don't have this problem because they visit just one value, whose name needs to be passed to the visitor as @name. The string output visitor shouldn't fail anyway. The options visitor uses QemuOpts names. Their name space is flat, so the use of QDict member keys as names is fine. NULL names used with roots and lists could conceivably result in bad error messages. Left for another day. Backports commit a9fc37f6bc3f2ab90585cb16493da9f6dcfbfbcf from qemu		2018-03-02 12:05:53 -05:00
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common.json
Makefile.objs
qapi-clone-visitor.c
qapi-dealloc-visitor.c
qapi-visit-core.c
qobject-input-visitor.c	qapi: Improve qobject input visitor error reporting	2018-03-02 12:05:53 -05:00
qobject-output-visitor.c	qapi: rename QmpOutputVisitor to QObjectOutputVisitor	2018-02-27 08:05:33 -05:00
string-input-visitor.c