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2016-02-19qapi: Simplify excess input reporting in input visitorsEric Blake
When reporting that an unvisited member remains at the end of an input visit for a struct, we were using g_hash_table_find() coupled with a callback function that always returns true, to locate an arbitrary member of the hash table. But if all we need is an arbitrary entry, we can get that from a single-use iterator, without needing a tautological callback function. Technically, our cast of &(GQueue *) to (void **) is not strict C (while void * must be able to hold all other pointers, nothing says a void ** has to be the same width or representation as a GQueue **). The kosher way to write it would be the verbose: void *tmp; GQueue *any; if (g_hash_table_iter_next(&iter, NULL, &tmp)) { any = tmp; But our code base (not to mention glib itself) already has other cases of assuming that ALL pointers have the same width and representation, where a compiler would have to go out of its way to mis-compile our borderline behavior. Suggested-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <1455778109-6278-2-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08qapi: Drop unused error argument for list and implicit structEric Blake
No backend was setting an error when ending the visit of a list or implicit struct, or when moving to the next list node. Make the callers a bit easier to follow by making this a part of the contract, and removing the errp argument - callers can then unconditionally end an object as part of cleanup without having to think about whether a second error is dominated by a first, because there is no second error. A later patch will then tackle the larger task of splitting visit_end_struct(), which can indeed set an error. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1454075341-13658-24-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08qapi: Tighten qmp_input_end_list()Eric Blake
The only way that qmp_input_pop() will set errp is if a dictionary was the most recent thing pushed. Since we don't have any push(struct)/pop(list) or push(list)/pop(struct) mismatches (such a mismatch is a programming bug), we therefore cannot set errp inside qmp_input_end_list(). Make this obvious by using &error_abort. A later patch will then remove the errp parameter of qmp_input_pop(), but that will first require the larger task of splitting visit_end_struct(). Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1454075341-13658-23-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08qapi: Drop unused 'kind' for struct/enum visitEric Blake
visit_start_struct() and visit_type_enum() had a 'kind' argument that was usually set to either the stringized version of the corresponding qapi type name, or to NULL (although some clients didn't even get that right). But nothing ever used the argument. It's even hard to argue that it would be useful in a debugger, as a stack backtrace also tells which type is being visited. Therefore, drop the 'kind' argument as dead. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <1454075341-13658-22-git-send-email-eblake@redhat.com> [Harmless rebase mistake cleaned up] Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08qapi: Swap 'name' in visit_* callbacks to match public APIEric Blake
As explained in the previous patches, matching argument order of 'name, &value' to JSON's "name":value makes sense. However, while the last two patches were easy with Coccinelle, I ended up doing this one all by hand. Now all the visitor callbacks match the main interface. The compiler is able to enforce that all clients match the changed interface in visitor-impl.h, even where two pointers are being swapped, because only one of the two pointers is const (if that were not the case, then C's looseness on treating 'char *' like 'void *' would have made review a bit harder). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <1454075341-13658-21-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08qapi: Make all visitors supply uint64 callbacksEric Blake
Our qapi visitor contract supports multiple integer visitors, but left the type_uint64 visitor as optional (falling back on type_int64); which in turn can lead to awkward behavior with numbers larger than INT64_MAX (the user has to be aware of twos complement, and deal with negatives). This patch does not address the disparity in handling large values as negatives. It merely moves the fallback from uint64 to int64 from the visitor core to the visitors, where the issue can actually be fixed, by implementing the missing type_uint64() callbacks on top of the respective type_int64() callbacks, and with a FIXME comment explaining why that's wrong. With that done, we now have a type_uint64() callback in every driver, so we can make it mandatory from the core. And although the type_int64() callback can cover the entire valid range of type_uint{8,16,32} on valid user input, using type_uint64() to avoid mixed signedness makes more sense. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1454075341-13658-15-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08qapi: Prefer type_int64 over type_int in visitorsEric Blake
The qapi builtin type 'int' is basically shorthand for the type 'int64'. In fact, since no visitor was providing the optional type_int64() callback, visit_type_int64() was just always falling back to type_int(), cementing the equivalence between the types. However, some visitors are providing a type_uint64() callback. For purposes of code consistency, it is nicer if all visitors use the paired type_int64/type_uint64 names rather than the mismatched type_int/type_uint64. So this patch just renames the signed int callbacks in place, dropping the type_int() callback as redundant, and a later patch will focus on the unsigned int callbacks. Add some FIXMEs to questionable reuse of errp in code touched by the rename, while at it (the reuse works as long as the callbacks don't modify value when setting an error, but it's not a good example to set) - a later patch will then fix those. No change in functionality here, although further cleanups are in the pipeline. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1454075341-13658-14-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-04qapi: Clean up includesPeter Maydell
Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 1454089805-5470-8-git-send-email-peter.maydell@linaro.org
2015-12-17qapi: Simplify visits of optional fieldsEric Blake
None of the visitor callbacks would set an error when testing if an optional field was present; make this part of the interface contract by eliminating the errp argument. The resulting generated code has a nice diff: |- visit_optional(v, &has_fdset_id, "fdset-id", &err); |- if (err) { |- goto out; |- } |+ visit_optional(v, &has_fdset_id, "fdset-id"); | if (has_fdset_id) { | visit_type_int(v, &fdset_id, "fdset-id", &err); | if (err) { | goto out; | } | } Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1449033659-25497-9-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17qapi: Fix alternates that accept 'number' but not 'int'Eric Blake
The QMP input visitor allows integral values to be assigned by promotion to a QTYPE_QFLOAT. However, when parsing an alternate, we did not take this into account, such that an alternate that accepts 'number' and some other type, but not 'int', would reject integral values. With this patch, we now have the following desirable table: alternate has case selected for 'int' 'number' QTYPE_QINT QTYPE_QFLOAT no no error error no yes 'number' 'number' yes no 'int' error yes yes 'int' 'number' While it is unlikely that we will ever use 'number' in an alternate other than in the testsuite, it never hurts to be more precise in what we allow. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1449033659-25497-8-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17qapi: Simplify visiting of alternate typesEric Blake
Previously, working with alternates required two lookup arrays and some indirection: for type Foo, we created Foo_qtypes[] which maps each qtype to a value of the generated FooKind enum, then look up that value in FooKind_lookup[] like we do for other union types. This has a couple of subtle bugs. First, the generator was creating a call with a parameter '(int *) &(*obj)->type' where type is an enum type; this is unsafe if the compiler chooses to store the enum type in a different size than int, where assigning through the wrong size pointer can corrupt data or cause a SIGBUS. Related bug, not not fixed in this patch: qapi-visit.py's gen_visit_enum() generates a cast of its enum * argument to int *. Marked FIXME. Second, since the values of the FooKind enum start at zero, all entries of the Foo_qtypes[] array that were not explicitly initialized will map to the same branch of the union as the first member of the alternate, rather than triggering a desired failure in visit_get_next_type(). Fortunately, the bug seldom bites; the very next thing the input visitor does is try to parse the incoming JSON with the wrong parser, which normally fails; the output visitor is not used with a C struct in that state, and the dealloc visitor has nothing to clean up (so there is no leak). However, the second bug IS observable in one case: parsing an integer causes unusual behavior in an alternate that contains at least a 'number' member but no 'int' member, because the 'number' parser accepts QTYPE_QINT in addition to the expected QTYPE_QFLOAT (that is, since 'int' is not a member, the type QTYPE_QINT accidentally maps to FooKind 0; if this enum value is the 'number' branch the integer parses successfully, but if the 'number' branch is not first, some other branch tries to parse the integer and rejects it). A later patch will worry about fixing alternates to always parse all inputs that a non-alternate 'number' would accept, for now this is still marked FIXME in the updated test-qmp-input-visitor.c, to merely point out that new undesired behavior of 'ans' matches the existing undesired behavior of 'asn'. This patch fixes the default-initialization bug by deleting the indirection, and modifying get_next_type() to directly assign a QTypeCode parameter. This in turn fixes the type-casting bug, as we are no longer casting a pointer to enum to a questionable size. There is no longer a need to generate an implicit FooKind enum associated with the alternate type (since the QMP wire format never uses the stringized counterparts of the C union member names). Since the updated visit_get_next_type() does not know which qtypes are expected, the generated visitor is modified to generate an error statement if an unexpected type is encountered. Callers now have to know the QTYPE_* mapping when looking at the discriminator; but so far, only the testsuite was even using the C struct of an alternate types. I considered the possibility of keeping the internal enum FooKind, but initialized differently than most generated arrays, as in: typedef enum FooKind { FOO_KIND_A = QTYPE_QDICT, FOO_KIND_B = QTYPE_QINT, } FooKind; to create nicer aliases for knowing when to use foo->a or foo->b when inspecting foo->type; but it turned out to add too much complexity, especially without a client. There is a user-visible side effect to this change, but I consider it to be an improvement. Previously, the invalid QMP command: {"execute":"blockdev-add", "arguments":{"options": {"driver":"raw", "id":"a", "file":true}}} failed with: {"error": {"class": "GenericError", "desc": "Invalid parameter type for 'file', expected: QDict"}} (visit_get_next_type() succeeded, and the error comes from the visit_type_BlockdevOptions() expecting {}; there is no mention of the fact that a string would also work). Now it fails with: {"error": {"class": "GenericError", "desc": "Invalid parameter type for 'file', expected: BlockdevRef"}} (the error when the next type doesn't match any expected types for the overall alternate). Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1449033659-25497-5-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-29qstring: Make conversion from QObject * accept nullMarkus Armbruster
qobject_to_qstring() crashes on null, which is a trap for the unwary. Return null instead, and simplify a few callers. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1444918537-18107-7-git-send-email-armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-10-29qfloat qint: Make conversion from QObject * accept nullMarkus Armbruster
qobject_to_qfloat() and qobject_to_qint() crash on null, which is a trap for the unwary. Return null instead, and simplify a few callers. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1444918537-18107-5-git-send-email-armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-10-29qbool: Make conversion from QObject * accept nullMarkus Armbruster
qobject_to_qbool() crashes on null, which is a trap for the unwary. Return null instead, and simplify a few callers. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1444918537-18107-3-git-send-email-armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-09-21qapi: Introduce a first class 'any' typeMarkus Armbruster
It's first class, because unlike '**', it actually works, i.e. doesn't require 'gen': false. '**' will go away next. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
2015-06-22qerror: Clean up QERR_ macros to expand into a single stringMarkus Armbruster
These macros expand into error class enumeration constant, comma, string. Unclean. Has been that way since commit 13f59ae. The error class is always ERROR_CLASS_GENERIC_ERROR since the previous commit. Clean up as follows: * Prepend every use of a QERR_ macro by ERROR_CLASS_GENERIC_ERROR, and delete it from the QERR_ macro. No change after preprocessing. * Rewrite error_set(ERROR_CLASS_GENERIC_ERROR, ...) into error_setg(...). Again, no change after preprocessing. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-06-22qobject: Use 'bool' for qboolEric Blake
We require a C99 compiler, so let's use 'bool' instead of 'int' when dealing with boolean values. There are few enough clients to fix them all in one pass. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Andreas Färber <afaerber@suse.de> Reviewed-by: Alberto Garcia <berto@igalia.com> Acked-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2014-05-15qapi: Replace start_optional()/end_optional() by optional()Markus Armbruster
Semantics of end_optional() differ subtly from the other end_FOO() callbacks: when start_FOO() succeeds, the matching end_FOO() gets called regardless of what happens in between. end_optional() gets called only when everything in between succeeds as well. Entirely undocumented, like all of the visitor API. The only user of Visitor Callback end_optional() never did anything, and was removed in commit 9f9ab46. I'm about to clean up error handling in the generated visitor code, and end_optional() is in my way. No users mean no test cases, and making non-trivial cleanup transformations without test cases doesn't strike me as a good idea. Drop end_optional(), and rename start_optional() to optional(). We can always go back to a pair of callbacks when we have an actual need. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-04-25qerror.h: Remove QERR defines that are only used onceCole Robinson
Just hardcode them in the callers Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Markus Armbruster <armbru@redhat.com> Signed-off-by: Cole Robinson <crobinso@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2013-07-26qapi: Anonymous unionsKevin Wolf
The discriminator for anonymous unions is the data type. This allows to have a union type that allows both of these: { 'file': 'my_existing_block_device_id' } { 'file': { 'filename': '/tmp/mydisk.qcow2', 'read-only': true } } Unions like this are specified in the schema with an empty dict as discriminator. For this example you could take: { 'union': 'BlockRef', 'discriminator': {}, 'data': { 'definition': 'BlockOptions', 'reference': 'str' } } { 'type': 'ExampleObject', 'data: { 'file': 'BlockRef' } } Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-07-26qapi: Add consume argument to qmp_input_get_object()Kevin Wolf
This allows to just look at the next element without actually consuming it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-07-26qapi: Add visitor for implicit structsKevin Wolf
These can be used when an embedded struct is parsed and members not belonging to the struct may be present in the input (e.g. parsing a flat namespace QMP union, where fields from both the base and one of the alternative types are mixed in the JSON object) Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2012-12-19misc: move include files to include/qemu/Paolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19qapi: move include files to include/qobject/Paolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-05-14qapi: QMP input visitor, handle floats parsed as intsMichael Roth
JSON numbers can be interpreted as either integers or floating point values depending on their representation. As a result, QMP input visitor might visit a QInt when it was expecting a QFloat, so add handling to account for this. Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Acked-by: Andreas Färber <afaerber@suse.de>
2012-04-23qapi: g_hash_table_find() instead of GHashTableIter.NODA, Kai
GHashTableIter was first introduced in glib 2.16. This patch removes it in favor of older g_hash_table_find() for better compatibility with RHEL5. Signed-off-by: NODA, Kai <nodakai@gmail.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-03-27qapi: add strict mode to input visitorPaolo Bonzini
While QMP in general is designed so that it is possible to ignore unknown arguments, in the case of the QMP server it is better to reject them to detect bad clients. In fact, we're already doing this at the top level in the argument checker. To extend this to complex structures, add a mode to the input visitor where it checks for unvisited keys and raises an error if it finds one. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-03-27qapi: place outermost object on qiv stackPaolo Bonzini
This is a slight change in the implementation of QMPInputVisitor that helps when adding strict mode. Const QObjects cannot be inc/decref-ed, and that's why QMPInputVisitor relies heavily on weak references to inner objects. I'm not removing the weak references now, but since refcount+const is a lost battle in C (C++ has "mutable") I think removing const is fine in this case. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-03-27qapi: untangle next_listPaolo Bonzini
Right now, the semantics of next_list are complicated. The caller must: * call start_list * call next_list for each element *including the first* * on the first call to next_list, the second argument should point to NULL and the result is the head of the list. On subsequent calls, the second argument should point to the last node (last result of next_list) and next_list itself tacks the element at the tail of the list. This works for both input and output visitor, but having the visitor write memory when it is only reading the list is ugly. Plus, relying on *list to detect the first call is tricky and undocumented. We can initialize so->entry in next_list instead of start_list, leaving it NULL in start_list. This way next_list sees clearly whether it is on the first call---as a bonus, it discriminates the cases based on internal state of the visitor rather than external state. We can also pull the assignment of the list head from generated code up to next_list. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-03-27qapi: fix memory leak on errorPaolo Bonzini
QmpInputVisitor would leak the malloced struct if the stack was overflowed. This can be easily fixed using error_propagate. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-03-27qapi: fail hard on stack imbalancePaolo Bonzini
QmpOutputVisitor will segfault if an imbalanced end function is called. So we can abort in QmpInputVisitor too. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-02-21qapi: drop qmp_input_end_optionalPaolo Bonzini
This method is optional, do not implement it if it is empty. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-02-21qapi: allow sharing enum implementation across visitorsPaolo Bonzini
Most visitors will use the same code for enum parsing. Move it to the core. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-19qapi: protect against NULL QObject in qmp_input_get_objectPaolo Bonzini
A NULL qobj can occur when a parameter is fetched via qdict_get, but the parameter is not in the command. By returning NULL, the caller can choose whether to raise a missing parameter error, an invalid parameter type error, or use a default value. For example, qom-set could can use this to reset a property to its default value, though at this time it will fail with "Invalid parameter type". In any case, anything is better than crashing! Reviewed-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-10-04qapi: modify visitor code generation for list iterationMichael Roth
Modify logic such that we never assign values to the list head argument to progress through the list on subsequent iterations, instead rely only on having our return value passed back in as an argument on the next call. Also update QMP I/O visitors and test cases accordingly, and add a missing test case for QmpOutputVisitor. Reviewed-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2011-08-20Use glib memory allocation and free functionsAnthony Liguori
qemu_malloc/qemu_free no longer exist after this commit. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-07-21qapi: add QMP input visitorMichael Roth
A type of Visiter class that is used to walk a qobject's structure and assign each entry to the corresponding native C type. Command marshaling function will use this to pull out QMP command parameters recieved over the wire and pass them as native arguments to the corresponding C functions. Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>