summaryrefslogtreecommitdiffstats
path: root/qapi/qapi-visit-core.c
Commit message (Collapse)AuthorAgeFilesLines
* Include qemu-common.h exactly where neededMarkus Armbruster2019-06-121-1/+0Star
| | | | | | | | | | | | | | | | No header includes qemu-common.h after this commit, as prescribed by qemu-common.h's file comment. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20190523143508.25387-5-armbru@redhat.com> [Rebased with conflicts resolved automatically, except for include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and net/tap-bsd.c fixed up]
* Include qapi/qmp/qobject.h exactly where neededMarkus Armbruster2018-02-091-1/+0Star
| | | | | | | Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-11-armbru@redhat.com>
* qapi: Change data type of the FOO_lookup generated for enum FOOMarc-André Lureau2017-09-041-11/+13
| | | | | | | | | | | | | | | | | | | | Currently, a FOO_lookup is an array of strings terminated by a NULL sentinel. A future patch will generate enums with "holes". NULL-termination will cease to work then. To prepare for that, store the length in the FOO_lookup by wrapping it in a struct and adding a member for the length. The sentinel will be dropped next. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20170822132255.23945-13-marcandre.lureau@redhat.com> [Basically redone] Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1503564371-26090-16-git-send-email-armbru@redhat.com> [Rebased]
* qapi: Convert indirect uses of FOO_lookup[...] to qapi_enum_lookup()Markus Armbruster2017-09-041-1/+1
| | | | | | Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1503564371-26090-15-git-send-email-armbru@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
* qapi: Generate FOO_str() macro for QAPI enum FOOMarkus Armbruster2017-09-041-1/+0Star
| | | | | | | | | The next commit will put it to use. May look pointless now, but we're going to change the FOO_lookup's type, and then it'll help. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1503564371-26090-13-git-send-email-armbru@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
* qapi: Use qapi_enum_parse() in input_type_enum()Markus Armbruster2017-09-041-9/+4Star
| | | | | | Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1503564371-26090-11-git-send-email-armbru@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
* qapi: Use QNull for a more regular visit_type_null()Markus Armbruster2017-07-241-3/+4
| | | | | | | | | Make visit_type_null() take an @obj argument like its buddies. This helps keep the next commit simple. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
* qapi: Remove visit_start_alternate() parameter promote_intMarc-André Lureau2017-06-201-3/+3
| | | | | | | | | | | | | | | Before the previous commit, parameter promote_int = true made visit_start_alternate() with an input visitor avoid QTYPE_QINT variants and create QTYPE_QFLOAT variants instead. This was used where QTYPE_QINT variants were invalid. The previous commit fused QTYPE_QINT with QTYPE_QFLOAT, rendering promote_int useless and unused. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20170607163635.17635-8-marcandre.lureau@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Make input visitors detect unvisited list tailsMarkus Armbruster2017-03-051-0/+8
| | | | | | | | | | | | | | | | | Fix the design flaw demonstrated in the previous commit: new method check_list() lets input visitors report that unvisited input remains for a list, exactly like check_struct() lets them report that unvisited input remains for a struct or union. Implement the method for the qobject input visitor (straightforward), and the string input visitor (less so, due to the magic list syntax there). The opts visitor's list magic is even more impenetrable, and all I can do there today is a stub with a FIXME comment. No worse than before. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1488544368-30622-26-git-send-email-armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
* qapi: add missing trace_visit_type_enum() callStefan Hajnoczi2017-01-311-0/+1
| | | | | | | | | | | A trace event exists for enums but it's never called. This patch fixes this oversight so that enums are traced just like the other QAPI types. Suggested-by: Daniel P. Berrange <berrange@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20170126171613.1399-2-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* qapi: add trace events for visitorDaniel P. Berrange2016-10-251-6/+45
| | | | | | | | | | | | Allow tracing of the operation of visitors Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1475246744-29302-4-git-send-email-berrange@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> [visit_type_uint8() & friends rearranged slightly for clarity] Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Add new clone visitorEric Blake2016-07-061-9/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have a couple places in the code base that want to deep-clone one QAPI object into another, and they were resorting to serializing the struct out to QObject then reparsing it. A much more efficient version can be done by adding a new clone visitor. Since cloning is still relatively uncommon, expose the use of the new visitor via a QAPI_CLONE() macro that takes care of type-punning the underlying function pointer, rather than generating lots of unused functions for types that won't be cloned. And yes, we're relying on the compiler treating all pointers equally, even though a strict C program cannot portably do so - but we're not the first one in the qemu code base to expect it to work (hello, glib!). The choice of adding a fourth visitor type deserves some explanation. On the surface, the clone visitor is mostly an input visitor (it takes arbitrary input - in this case, another QAPI object - and creates a new QAPI object during the course of the visit). But ever since commit da72ab0 consolidated enum visits based on the visitor type, using VISITOR_INPUT would cause us to run visit_type_str(), even though for cloning there is nothing to do (we just copy the enum value across, without regards to its mapping to strings). Also, since our input happens to be a QAPI object, we can also satisfy the internal checks for VISITOR_OUTPUT. So in the end, I settled with a new VISITOR_CLONE, and chose its value such that many internal checks can use 'v->type & mask', sticking to 'v->type == value' where the difference matters. Note that we can only clone objects (including alternates) and lists, not built-ins or enums. The visitor core hides integer width from the actual visitor (since commit 04e070d), and as long as that's the case, we can't clone top-level integers. Then again, those can always be cloned by direct copy, since they are not objects with deep pointers, so it's no real loss. And restricting cloning to just objects and lists is cleaner than restricting it to non-integers. As such, I documented that the clone visitor is for direct use only by code internal to QAPI, and should not be used on incomplete objects (other than a hack to work around the fact that we allow NULL in place of "" in visit_type_str() in other output visitors). Note that as written, the clone visitor will never fail on a complete object. Scalars (including enums) not at the root of the clone copy just fine with no additional effort while visiting the scalar, by virtue of a g_memdup() each time we push another struct onto the stack. Cloning a string requires deduplication of a pointer, which means it can also provide the guarantee of an input visitor of never producing NULL even when still accepting NULL in place of "" the way the QMP output visitor does. Cloning an 'any' type could be possible by incrementing the QObject refcnt, but it's not obvious whether that is better than implementing a QObject deep clone. So for now, we document it as unsupported, and intentionally omit the .type_any() callback to let a developer know their usage needs implementation. Add testsuite coverage for several different clone situations, to ensure that the code is working. I also tested that valgrind was happy with the test. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1465490926-28625-14-git-send-email-eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Add new visit_complete() functionEric Blake2016-07-061-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Making each output visitor provide its own output collection function was the only remaining reason for exposing visitor sub-types to the rest of the code base. Add a polymorphic visit_complete() function which is a no-op for input visitors, and which populates an opaque pointer for output visitors. For maximum type-safety, also add a parameter to the output visitor constructors with a type-correct version of the output pointer, and assert that the two uses match. This approach was considered superior to either passing the output parameter only during construction (action at a distance during visit_free() feels awkward) or only during visit_complete() (defeating type safety makes it easier to use incorrectly). Most callers were function-local, and therefore a mechanical conversion; the testsuite was a bit trickier, but the previous cleanup patch minimized the churn here. The visit_complete() function may be called at most once; doing so lets us use transfer semantics rather than duplication or ref-count semantics to get the just-built output back to the caller, even though it means our behavior is not idempotent. Generated code is simplified as follows for events: |@@ -26,7 +26,7 @@ void qapi_event_send_acpi_device_ost(ACP | QDict *qmp; | Error *err = NULL; | QMPEventFuncEmit emit; |- QmpOutputVisitor *qov; |+ QObject *obj; | Visitor *v; | q_obj_ACPI_DEVICE_OST_arg param = { | info |@@ -39,8 +39,7 @@ void qapi_event_send_acpi_device_ost(ACP | | qmp = qmp_event_build_dict("ACPI_DEVICE_OST"); | |- qov = qmp_output_visitor_new(); |- v = qmp_output_get_visitor(qov); |+ v = qmp_output_visitor_new(&obj); | | visit_start_struct(v, "ACPI_DEVICE_OST", NULL, 0, &err); | if (err) { |@@ -55,7 +54,8 @@ void qapi_event_send_acpi_device_ost(ACP | goto out; | } | |- qdict_put_obj(qmp, "data", qmp_output_get_qobject(qov)); |+ visit_complete(v, &obj); |+ qdict_put_obj(qmp, "data", obj); | emit(QAPI_EVENT_ACPI_DEVICE_OST, qmp, &err); and for commands: | { | Error *err = NULL; |- QmpOutputVisitor *qov = qmp_output_visitor_new(); | Visitor *v; | |- v = qmp_output_get_visitor(qov); |+ v = qmp_output_visitor_new(ret_out); | visit_type_AddfdInfo(v, "unused", &ret_in, &err); |- if (err) { |- goto out; |+ if (!err) { |+ visit_complete(v, ret_out); | } |- *ret_out = qmp_output_get_qobject(qov); |- |-out: | error_propagate(errp, err); Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1465490926-28625-13-git-send-email-eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Add new visit_free() functionEric Blake2016-07-061-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Making each visitor provide its own (awkwardly-named) FOO_cleanup() is unusual, when we can instead have a polymorphic visit_free() interface. Over the next few patches, we can use the polymorphic functions to eliminate the need for a FOO_get_visitor() function for accessing specific visitor functionality, once everything can be accessed directly through the Visitor* interfaces. The dealloc visitor is the first one converted to completely use the new entry point, since qapi_dealloc_visitor_cleanup() was the only reason that qapi_dealloc_get_visitor() existed, and only generated and testsuite code was even using it. With the new visit_free() entry point in place, we no longer need to expose the QapiDeallocVisitor subtype through qapi_dealloc_visitor_new(), and can get by with less generated code, with diffs that look like: | void qapi_free_ACPIOSTInfo(ACPIOSTInfo *obj) | { |- QapiDeallocVisitor *qdv; | Visitor *v; | | if (!obj) { | return; | } | |- qdv = qapi_dealloc_visitor_new(); |- v = qapi_dealloc_get_visitor(qdv); |+ v = qapi_dealloc_visitor_new(); | visit_type_ACPIOSTInfo(v, NULL, &obj, NULL); |- qapi_dealloc_visitor_cleanup(qdv); |+ visit_free(v); |} Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1465490926-28625-5-git-send-email-eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Add parameter to visit_end_*Eric Blake2016-07-061-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rather than making the dealloc visitor track of stack of pointers remembered during visit_start_* in order to free them during visit_end_*, it's a lot easier to just make all callers pass the same pointer to visit_end_*. The generated code has access to the same pointer, while all other users are doing virtual walks and can pass NULL. The dealloc visitor is then greatly simplified. All three visit_end_*() functions intentionally take a void**, even though the visit_start_*() functions differ between void**, GenericList**, and GenericAlternate**. This is done for several reasons: when doing a virtual walk, passing NULL doesn't care what the type is, but when doing a generated walk, we already have to cast the caller's specific FOO* to call visit_start, while using void** lets us use visit_end without a cast. Also, an upcoming patch will add a clone visitor that wants to use the same implementation for all three visit_end callbacks, which is made easier if all three share the same signature. For visitors with already track per-object state (the QMP visitors via a stack, and the string visitors which do not allow nesting), add an assertion that the caller is indeed passing the same pointer to paired calls. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1465490926-28625-4-git-send-email-eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Change visit_type_FOO() to no longer return partial objectsEric Blake2016-05-121-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Returning a partial object on error is an invitation for a careless caller to leak memory. We already fixed things in an earlier patch to guarantee NULL if visit_start fails ("qapi: Guarantee NULL obj on input visitor callback error"), but that does not help the case where visit_start succeeds but some other failure happens before visit_end, such that we leak a partially constructed object outside visit_type_FOO(). As no one outside the testsuite was actually relying on these semantics, it is cleaner to just document and guarantee that ALL pointer-based visit_type_FOO() functions always leave a safe value in *obj during an input visitor (either the new object on success, or NULL if an error is encountered), so callers can now unconditionally use qapi_free_FOO() to clean up regardless of whether an error occurred. The decision is done by adding visit_is_input(), then updating the generated code to check if additional cleanup is needed based on the type of visitor in use. Note that we still leave *obj unchanged after a scalar-based visit_type_FOO(); I did not feel like auditing all uses of visit_type_Enum() to see if the callers would tolerate a specific sentinel value (not to mention having to decide whether it would be better to use 0 or ENUM__MAX as that sentinel). Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1461879932-9020-25-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Simplify semantics of visit_next_list()Eric Blake2016-05-121-5/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The semantics of the list visit are somewhat baroque, with the following pseudocode when FooList is used: start() for (prev = head; cur = next(prev); prev = &cur) { visit(&cur->value) } Note that these semantics (advance before visit) requires that the first call to next() return the list head, while all other calls return the next element of the list; that is, every visitor implementation is required to track extra state to decide whether to return the input as-is, or to advance. It also requires an argument of 'GenericList **' to next(), solely because the first iteration might need to modify the caller's GenericList head, so that all other calls have to do a layer of dereferencing. Thankfully, we only have two uses of list visits in the entire code base: one in spapr_drc (which completely avoids visit_next_list(), feeding in integers from a different source than uint8List), and one in qapi-visit.py. That is, all other list visitors are generated in qapi-visit.c, and share the same paradigm based on a qapi FooList type, so we can refactor how lists are laid out with minimal churn among clients. We can greatly simplify things by hoisting the special case into the start() routine, and flipping the order in the loop to visit before advance: start(head) for (tail = *head; tail; tail = next(tail)) { visit(&tail->value) } With the simpler semantics, visitors have less state to track, the argument to next() is reduced to 'GenericList *', and it also becomes obvious whether an input visitor is allocating a FooList during visit_start_list() (rather than the old way of not knowing if an allocation happened until the first visit_next_list()). As a minor drawback, we now allocate in two functions instead of one, and have to pass the size to both functions (unless we were to tweak the input visitors to cache the size to start_list for reuse during next_list, but that defeats the goal of less visitor state). The signature of visit_start_list() is chosen to match visit_start_struct(), with the new parameters after 'name'. The spapr_drc case is a virtual visit, done by passing NULL for list, similarly to how NULL is passed to visit_start_struct() when a qapi type is not used in those visits. It was easy to provide these semantics for qmp-output and dealloc visitors, and a bit harder for qmp-input (several prerequisite patches refactored things to make this patch straightforward). But it turned out that the string and opts visitors munge enough other state during visit_next_list() to make it easier to just document and require a GenericList visit for now; an assertion will remind us to adjust things if we need the semantics in the future. Several pre-requisite cleanup patches made the reshuffling of the various visitors easier; particularly the qmp input visitor. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1461879932-9020-24-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Split visit_end_struct() into piecesEric Blake2016-05-121-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As mentioned in previous patches, we want to call visit_end_struct() functions unconditionally, so that visitors can release resources tied up since the matching visit_start_struct() without also having to worry about error priority if more than one error occurs. Even though error_propagate() can be safely used to ignore a second error during cleanup caused by a first error, it is simpler if the cleanup cannot set an error. So, split out the error checking portion (basically, input visitors checking for unvisited keys) into a new function visit_check_struct(), which can be safely skipped if any earlier errors are encountered, and leave the cleanup portion (which never fails, but must be called unconditionally if visit_start_struct() succeeded) in visit_end_struct(). Generated code in qapi-visit.c has diffs resembling: |@@ -59,10 +59,12 @@ void visit_type_ACPIOSTInfo(Visitor *v, | goto out_obj; | } | visit_type_ACPIOSTInfo_members(v, obj, &err); |- error_propagate(errp, err); |- err = NULL; |+ if (err) { |+ goto out_obj; |+ } |+ visit_check_struct(v, &err); | out_obj: |- visit_end_struct(v, &err); |+ visit_end_struct(v); | out: and in qapi-event.c: @@ -47,7 +47,10 @@ void qapi_event_send_acpi_device_ost(ACP | goto out; | } | visit_type_q_obj_ACPI_DEVICE_OST_arg_members(v, &param, &err); |- visit_end_struct(v, err ? NULL : &err); |+ if (!err) { |+ visit_check_struct(v, &err); |+ } |+ visit_end_struct(v); | if (err) { | goto out; Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1461879932-9020-20-git-send-email-eblake@redhat.com> [Conflict with a doc fixup resolved] Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Add visit_type_null() visitorEric Blake2016-05-121-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Right now, qmp-output-visitor happens to produce a QNull result if nothing is actually visited between the creation of the visitor and the request for the resulting QObject. A stronger protocol would require that a QMP output visit MUST visit something. But to still be able to produce a JSON 'null' output, we need a new visitor function that states our intentions. Yes, we could say that such a visit must go through visit_type_any(), but that feels clunky. So this patch introduces the new visit_type_null() interface and its no-op interface in the dealloc visitor, and stubs in the qmp visitors (the next patch will finish the implementation). For the visitors that will not implement the callback, document the situation. The code in qapi-visit-core unconditionally dereferences the callback pointer, so that a segfault will inform a developer if they need to implement the callback for their choice of visitor. Note that JSON has a primitive null type, with the single value null; likewise with the QNull type for QObject; but for QAPI, we just have the 'null' value without a null type. We may eventually want to add more support in QAPI for null (most likely, we'd use it via an alternate type that permits 'null' or an object); but we'll create that usage when we need it. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1461879932-9020-15-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Document visitor interfaces, add assertionsEric Blake2016-05-121-1/+17
| | | | | | | | | | | | | | | | | | | | | | | The visitor interface for mapping between QObject/QemuOpts/string and QAPI is scandalously under-documented, making changes to visitor core, individual visitors, and users of visitors difficult to coordinate. Among other questions: when is it safe to pass NULL, vs. when a string must be provided; which visitors implement which callbacks; the difference between concrete and virtual visits. Correct this by retrofitting proper contracts, and document where some of the interface warts remain (for example, we may want to modify visit_end_* to require the same 'obj' as the visit_start counterpart, so the dealloc visitor can be simplified). Later patches in this series will tackle some, but not all, of these warts. Add assertions to (partially) enforce the contract. Some of these were only made possible by recent cleanup commits. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1461879932-9020-13-git-send-email-eblake@redhat.com> [Doc fix from Eric squashed in] Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Guarantee NULL obj on input visitor callback errorEric Blake2016-05-121-4/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Our existing input visitors were not very consistent on errors in a function taking 'TYPE **obj'. These are start_struct(), start_alternate(), type_str(), and type_any(). next_list() is similar, but can't fail (see commit 08f9541). While all of them set '*obj' to allocated storage on success, it was not obvious whether '*obj' was guaranteed safe on failure, or whether it was left uninitialized. But a future patch wants to guarantee that visit_type_FOO() does not leak a partially-constructed obj back to the caller; it is easier to implement this if we can reliably state that input visitors assign '*obj' regardless of success or failure, and that on failure *obj is NULL. Add assertions to enforce consistency in the final setting of err vs. *obj. The opts-visitor start_struct() doesn't set an error, but it also was doing a weird check for 0 size; all callers pass in non-zero size if obj is non-NULL. The testsuite has at least one spot where we no longer need to pre-initialize a variable prior to a visit; valgrind confirms that the test is still fine with the cleanup. A later patch will document the design constraint implemented here. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1461879932-9020-3-git-send-email-eblake@redhat.com> [visit_start_alternate()'s assertion tightened, commit message tweaked] Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi-visit: Add visitor.type classificationEric Blake2016-05-121-13/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | We have three classes of QAPI visitors: input, output, and dealloc. Currently, all implementations of these visitors have one thing in common based on their visitor type: the implementation used for the visit_type_enum() callback. But since we plan to add more such common behavior, in relation to documenting and further refining the semantics, it makes more sense to have the visitor implementations advertise which class they belong to, so the common qapi-visit-core code can use that information in multiple places. A later patch will better document the types of visitors directly in visitor.h. For this patch, knowing the class of a visitor implementation lets us make input_type_enum() and output_type_enum() become static functions, by replacing the callback function Visitor.type_enum() with the simpler enum member Visitor.type. Share a common assertion in qapi-visit-core as part of the refactoring. Move comments in opts-visitor.c to match the refactored layout. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1461879932-9020-2-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
* include/qemu/osdep.h: Don't include qapi/error.hMarkus Armbruster2016-03-221-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the Error typedef. Since then, we've moved to include qemu/osdep.h everywhere. Its file comment explains: "To avoid getting into possible circular include dependencies, this file should not include any other QEMU headers, with the exceptions of config-host.h, compiler.h, os-posix.h and os-win32.h, all of which are doing a similar job to this file and are under similar constraints." qapi/error.h doesn't do a similar job, and it doesn't adhere to similar constraints: it includes qapi-types.h. That's in excess of 100KiB of crap most .c files don't actually need. Add the typedef to qemu/typedefs.h, and include that instead of qapi/error.h. Include qapi/error.h in .c files that need it and don't get it now. Include qapi-types.h in qom/object.h for uint16List. Update scripts/clean-includes accordingly. Update it further to match reality: replace config.h by config-target.h, add sysemu/os-posix.h, sysemu/os-win32.h. Update the list of includes in the qemu/osdep.h comment quoted above similarly. This reduces the number of objects depending on qapi/error.h from "all of them" to less than a third. Unfortunately, the number depending on qapi-types.h shrinks only a little. More work is needed for that one. Signed-off-by: Markus Armbruster <armbru@redhat.com> [Fix compilation without the spice devel packages. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* qapi: Change visit_start_implicit_struct to visit_start_alternateEric Blake2016-02-191-23/+17Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After recent changes, the only remaining use of visit_start_implicit_struct() is for allocating the space needed when visiting an alternate. Since the term 'implicit struct' is hard to explain, rename the function to its current usage. While at it, we can merge the functionality of visit_get_next_type() into the same function, making it more like visit_start_struct(). Generated code is now slightly smaller: | { | Error *err = NULL; | |- visit_start_implicit_struct(v, (void**) obj, sizeof(BlockdevRef), &err); |+ visit_start_alternate(v, name, (GenericAlternate **)obj, sizeof(**obj), |+ true, &err); | if (err) { | goto out; | } |- visit_get_next_type(v, name, &(*obj)->type, true, &err); |- if (err) { |- goto out_obj; |- } | switch ((*obj)->type) { | case QTYPE_QDICT: | visit_start_struct(v, name, NULL, 0, &err); ... | } |-out_obj: |- visit_end_implicit_struct(v); |+ visit_end_alternate(v); | out: | error_propagate(errp, err); | } Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1455778109-6278-16-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Don't box branches of flat unionsEric Blake2016-02-191-8/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's no reason to do two malloc's for a flat union; let's just inline the branch struct directly into the C union branch of the flat union. Surprisingly, fewer clients were actually using explicit references to the branch types in comparison to the number of flat unions thus modified. This lets us reduce the hack in qapi-types:gen_variants() added in the previous patch; we no longer need to distinguish between alternates and flat unions. The change to unboxed structs means that u.data (added in commit cee2dedb) is now coincident with random fields of each branch of the flat union, whereas beforehand it was only coincident with pointers (since all branches of a flat union have to be objects). Note that this was already the case for simple unions - but there we got lucky. Remember, visit_start_union() blindly returns true for all visitors except for the dealloc visitor, where it returns the value !!obj->u.data, and that this result then controls whether to proceed with the visit to the variant. Pre-patch, this meant that flat unions were testing whether the boxed pointer was still NULL, and thereby skipping visit_end_implicit_struct() and avoiding a NULL dereference if the pointer had not been allocated. The same was true for simple unions where the current branch had pointer type, except there we bypassed visit_type_FOO(). But for simple unions where the current branch had scalar type, the contents of that scalar meant that the decision to call visit_type_FOO() was data-dependent - the reason we got lucky there is that visit_type_FOO() for all scalar types in the dealloc visitor is a no-op (only the pointer variants had anything to free), so it did not matter whether the dealloc visit was skipped. But with this patch, we would risk leaking memory if we could skip a call to visit_type_FOO_fields() based solely on a data-dependent decision. But notice: in the dealloc visitor, visit_type_FOO() already handles a NULL obj - it was only the visit_type_implicit_FOO() that was failing to check for NULL. And now that we have refactored things to have the branch be part of the parent struct, we no longer have a separate pointer that can be NULL in the first place. So we can just delete the call to visit_start_union() altogether, and blindly visit the branch type; there is no change in behavior except to the dealloc visitor, where we now unconditionally visit the branch, but where that visit is now always safe (for a flat union, we can no longer dereference NULL, and for a simple union, visit_type_FOO() was already safely handling NULL on pointer types). Unfortunately, simple unions are not as easy to switch to unboxed layout; because we are special-casing the hidden implicit type with a single 'data' member, we really DO need to keep calling another layer of visit_start_struct(), with a second malloc; although there are some cleanups planned for simple unions in later patches. visit_start_union() and gen_visit_implicit_struct() are now unused. Drop them. Note that after this patch, the only remaining use of visit_start_implicit_struct() is for alternate types; the next patch will do further cleanup based on that fact. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1455778109-6278-14-git-send-email-eblake@redhat.com> [Dead code deletion squashed in, commit message updated accordingly] Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Adjust layout of FooList typesEric Blake2016-02-191-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | By sticking the next pointer first, we don't need a union with 64-bit padding for smaller types. On 32-bit platforms, this can reduce the size of uint8List from 16 bytes (or 12, depending on whether 64-bit ints can tolerate 4-byte alignment) down to 8. It has no effect on 64-bit platforms (where alignment still dictates a 16-byte struct); but fewer anonymous unions is still a win in my book. It requires visit_next_list() to gain a size parameter, to know what size element to allocate; comparable to the size parameter of visit_start_struct(). I debated about going one step further, to allow for fewer casts, by doing: typedef GenericList GenericList; struct GenericList { GenericList *next; }; struct FooList { GenericList base; Foo *value; }; so that you convert to 'GenericList *' by '&foolist->base', and back by 'container_of(generic, GenericList, base)' (as opposed to the existing '(GenericList *)foolist' and '(FooList *)generic'). But doing that would require hoisting the declaration of GenericList prior to inclusion of qapi-types.h, rather than its current spot in visitor.h; it also makes iteration a bit more verbose through 'foolist->base.next' instead of 'foolist->next'. Note that for lists of objects, the 'value' payload is still hidden behind a boxed pointer. Someday, it would be nice to do: struct FooList { FooList *next; Foo value; }; for one less level of malloc for each list element. This patch is a step in that direction (now that 'next' is no longer at a fixed non-zero offset within the struct, we can store more than just a pointer's-worth of data as the value payload), but the actual conversion would be a task for another series, as it will touch a lot of code. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1455778109-6278-10-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Drop unused error argument for list and implicit structEric Blake2016-02-081-6/+6
| | | | | | | | | | | | | | | | | 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>
* qapi: Drop unused 'kind' for struct/enum visitEric Blake2016-02-081-9/+6Star
| | | | | | | | | | | | | | | | | 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>
* qapi: Swap 'name' in visit_* callbacks to match public APIEric Blake2016-02-081-19/+19
| | | | | | | | | | | | | | | | | | | 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>
* qapi: Swap visit_* arguments for consistent 'name' placementEric Blake2016-02-081-24/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | JSON uses "name":value, but many of our visitor interfaces were called with visit_type_FOO(v, &value, name, errp). This can be a bit confusing to have to mentally swap the parameter order to match JSON order. It's particularly bad for visit_start_struct(), where the 'name' parameter is smack in the middle of the otherwise-related group of 'obj, kind, size' parameters! It's time to do a global swap of the parameter ordering, so that the 'name' parameter is always immediately after the Visitor argument. Additional reason in favor of the swap: the existing include/qjson.h prefers listing 'name' first in json_prop_*(), and I have plans to unify that file with the qapi visitors; listing 'name' first in qapi will minimize churn to the (admittedly few) qjson.h clients. Later patches will then fix docs, object.h, visitor-impl.h, and those clients to match. Done by first patching scripts/qapi*.py by hand to make generated files do what I want, then by running the following Coccinelle script to affect the rest of the code base: $ spatch --sp-file script `git grep -l '\bvisit_' -- '**/*.[ch]'` I then had to apply some touchups (Coccinelle insisted on TAB indentation in visitor.h, and botched the signature of visit_type_enum() by rewriting 'const char *const strings[]' to the syntactically invalid 'const char*const[] strings'). The movement of parameters is sufficient to provoke compiler errors if any callers were missed. // Part 1: Swap declaration order @@ type TV, TErr, TObj, T1, T2; identifier OBJ, ARG1, ARG2; @@ void visit_start_struct -(TV v, TObj OBJ, T1 ARG1, const char *name, T2 ARG2, TErr errp) +(TV v, const char *name, TObj OBJ, T1 ARG1, T2 ARG2, TErr errp) { ... } @@ type bool, TV, T1; identifier ARG1; @@ bool visit_optional -(TV v, T1 ARG1, const char *name) +(TV v, const char *name, T1 ARG1) { ... } @@ type TV, TErr, TObj, T1; identifier OBJ, ARG1; @@ void visit_get_next_type -(TV v, TObj OBJ, T1 ARG1, const char *name, TErr errp) +(TV v, const char *name, TObj OBJ, T1 ARG1, TErr errp) { ... } @@ type TV, TErr, TObj, T1, T2; identifier OBJ, ARG1, ARG2; @@ void visit_type_enum -(TV v, TObj OBJ, T1 ARG1, T2 ARG2, const char *name, TErr errp) +(TV v, const char *name, TObj OBJ, T1 ARG1, T2 ARG2, TErr errp) { ... } @@ type TV, TErr, TObj; identifier OBJ; identifier VISIT_TYPE =~ "^visit_type_"; @@ void VISIT_TYPE -(TV v, TObj OBJ, const char *name, TErr errp) +(TV v, const char *name, TObj OBJ, TErr errp) { ... } // Part 2: swap caller order @@ expression V, NAME, OBJ, ARG1, ARG2, ERR; identifier VISIT_TYPE =~ "^visit_type_"; @@ ( -visit_start_struct(V, OBJ, ARG1, NAME, ARG2, ERR) +visit_start_struct(V, NAME, OBJ, ARG1, ARG2, ERR) | -visit_optional(V, ARG1, NAME) +visit_optional(V, NAME, ARG1) | -visit_get_next_type(V, OBJ, ARG1, NAME, ERR) +visit_get_next_type(V, NAME, OBJ, ARG1, ERR) | -visit_type_enum(V, OBJ, ARG1, ARG2, NAME, ERR) +visit_type_enum(V, NAME, OBJ, ARG1, ARG2, ERR) | -VISIT_TYPE(V, OBJ, NAME, ERR) +VISIT_TYPE(V, NAME, OBJ, ERR) ) Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <1454075341-13658-19-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Consolidate visitor small integer callbacksEric Blake2016-02-081-94/+54Star
| | | | | | | | | | | | | | | | | | | | Commit 4e27e819 introduced optional visitor callbacks for all sorts of int types, but no visitor has supplied any of the callbacks for sizes less than 64 bits. In other words, the generic implementation based on using type_[u]int64() followed by bounds-checking works just fine. In the interest of simplicity, it's easier to make the visitor callback interface not have to worry about the other sizes. Adding some helper functions minimizes the boilerplate required to correct FIXMEs added earlier with regards to questionable reuse of errp, particularly now that we can guarantee from a single file audit that value is unchanged if an error is set. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <1454075341-13658-16-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Make all visitors supply uint64 callbacksEric Blake2016-02-081-25/+11Star
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* qapi: Prefer type_int64 over type_int in visitorsEric Blake2016-02-081-14/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* qapi-visit: Kill unused visit_end_union()Eric Blake2016-02-081-7/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The generated code can call visit_end_union() without having called visit_start_union(). Example: if (!*obj) { goto out_obj; } visit_type_CpuInfoBase_fields(v, (CpuInfoBase **)obj, &err); if (err) { goto out_obj; // if we go from here... } if (!visit_start_union(v, !!(*obj)->u.data, &err) || err) { goto out_obj; } switch ((*obj)->arch) { [...] } out_obj: // ... then *obj is true, and ... error_propagate(errp, err); err = NULL; if (*obj) { // we end up here visit_end_union(v, !!(*obj)->u.data, &err); } error_propagate(errp, err); Harmless only because no visitor implements end_union(). Clean it up anyway, by deleting the function as useless. Messed up since we have visit_end_union (commit cee2ded). Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1453902888-20457-3-git-send-email-armbru@redhat.com> [expand scope of patch to delete rather than repair] Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1454075341-13658-13-git-send-email-eblake@redhat.com>
* qapi: Clean up includesPeter Maydell2016-02-041-0/+1
| | | | | | | | | | | 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
* qapi: Shorter visits of optional fieldsEric Blake2015-12-171-1/+2
| | | | | | | | | | | | | | | | | | | | | For less code, reflect the determined boolean value of an optional visit back to the caller instead of making the caller read the boolean after the fact. The resulting generated code has the following diff: |- visit_optional(v, &has_fdset_id, "fdset-id"); |- if (has_fdset_id) { |+ if (visit_optional(v, &has_fdset_id, "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: <1449033659-25497-10-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
* qapi: Simplify visits of optional fieldsEric Blake2015-12-171-3/+2Star
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* qapi: Fix alternates that accept 'number' but not 'int'Eric Blake2015-12-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* qapi: Simplify visiting of alternate typesEric Blake2015-12-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* qapi: Introduce a first class 'any' typeMarkus Armbruster2015-09-211-0/+6
| | | | | | | | | | | 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>
* qerror: Clean up QERR_ macros to expand into a single stringMarkus Armbruster2015-06-221-14/+14
| | | | | | | | | | | | | | | | | | | | | 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>
* qom: Make enum string tables const-correctDaniel P. Berrange2015-06-191-3/+3
| | | | | | | | | | | | | | | | The enum string table parameters in various QOM/QAPI methods are declared 'const char *strings[]'. This results in const warnings if passed a variable that was declared as static const char * const strings[] = { .... }; Add the extra const annotation to the parameters, since neither the string elements, nor the array itself should ever be modified. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Andreas Färber <afaerber@suse.de>
* qapi: add visit_start_union and visit_end_unionMichael Roth2014-09-261-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In some cases an input visitor might bail out on filling out a struct for various reasons, such as missing fields when running in strict mode. In the case of a QAPI Union type, this may lead to cases where the .kind field which encodes the union type is uninitialized. Subsequently, other visitors, such as the dealloc visitor, may use this .kind value as if it were initialized, leading to assumptions about the union type which in this case may lead to segfaults. For example, freeing an integer value. However, we can generally rely on the fact that the always-present .data void * field that we generate for these union types will always be NULL in cases where .kind is uninitialized (at least, there shouldn't be a reason where we'd do this purposefully). So pass this information on to Visitor implementation via these optional start_union/end_union interfaces so this information can be used to guard against the situation above. We will make use of this information in a subsequent patch for the dealloc visitor. Cc: qemu-stable@nongnu.org Reported-by: Fam Zheng <famz@redhat.com> Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
* qapi: Replace uncommon use of the error API by the common oneMarkus Armbruster2014-05-151-130/+101Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We commonly use the error API like this: err = NULL; foo(..., &err); if (err) { goto out; } bar(..., &err); Every error source is checked separately. The second function is only called when the first one succeeds. Both functions are free to pass their argument to error_set(). Because error_set() asserts no error has been set, this effectively means they must not be called with an error set. The qapi-generated code uses the error API differently: // *errp was initialized to NULL somewhere up the call chain frob(..., errp); gnat(..., errp); Errors accumulate in *errp: first error wins, subsequent errors get dropped. To make this work, the second function does nothing when called with an error set. Requires non-null errp, or else the second function can't see the first one fail. This usage has also bled into visitor tests, and two device model object property getters rtc_get_date() and balloon_stats_get_all(). With the "accumulate" technique, you need fewer error checks in callers, and buy that with an error check in every callee. Can be nice. However, mixing the two techniques is confusing. You can't use the "accumulate" technique with functions designed for the "check separately" technique. You can use the "check separately" technique with functions designed for the "accumulate" technique, but then error_set() can't catch you setting an error more than once. Standardize on the "check separately" technique for now, because it's overwhelmingly prevalent. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
* qapi: Replace start_optional()/end_optional() by optional()Markus Armbruster2014-05-151-11/+4Star
| | | | | | | | | | | | | | | | | | | | | | | 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>
* qapi: Remove unused Visitor callbacks start_handle(), end_handle()Markus Armbruster2014-05-151-15/+0Star
| | | | | | | | | These have never been called or implemented by anything, and their intended use is undocumented, like all of the visitor API. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
* qapi: make visit_type_size fallback to type_intVasilis Liaskovitis2013-07-301-1/+10
| | | | | | | | | | | | | | | Currently visit_type_size checks if the visitor's type_size function pointer is NULL. If not, it calls it, otherwise it calls v->type_uint64(). But neither of these pointers are ever set. Fallback to calling v->type_int() in this third (default) case. Signed-off-by: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com> Signed-off-by: Igor Mammedov <imammedo@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Andreas Färber <afaerber@suse.de> Message-id: 1375109277-25561-6-git-send-email-imammedo@redhat.com Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
* qapi: Anonymous unionsKevin Wolf2013-07-261-0/+9
| | | | | | | | | | | | | | | | | | | | | 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>
* qapi: Add visitor for implicit structsKevin Wolf2013-07-261-0/+16
| | | | | | | | | | 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>
* qapi: move include files to include/qobject/Paolo Bonzini2012-12-191-3/+3
| | | | Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-11-06 13:31:56 +0100