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2020-07-10qapi: Make visitor functions taking Error ** return bool, not voidMarkus Armbruster
See recent commit "error: Document Error API usage rules" for rationale. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200707160613.848843-18-armbru@redhat.com>
2019-09-19cutils: Move size_to_str() from "qemu-common.h" to "qemu/cutils.h"Philippe Mathieu-Daudé
"qemu/cutils.h" contains various qemu_strtosz_*() functions useful to convert strings to size. It seems natural to have the opposite usage (from size to string) there too. The function definition is already in util/cutils.c. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Message-Id: <20190903120555.7551-1-philmd@redhat.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2017-07-24qapi: Use QNull for a more regular visit_type_null()Markus Armbruster
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>
2017-06-30qapi: add explicit null to string input and output visitorsGreg Kurz
This may be used for deprecated object properties that are kept for backwards compatibility. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Markus Armbruster <armbru@redhat.com> Tested-by: Andrea Bolognani <abologna@redhat.com> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-05-17utils: provide size_to_str()Peter Xu
Moving the algorithm from print_type_size() into size_to_str() so that other component can also leverage it. With that, refactor print_type_size(). The assert() in that logic is removed though, since even UINT64_MAX would not overflow. Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <1494562661-9063-3-git-send-email-peterx@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2016-07-06qapi: Add new visit_complete() functionEric Blake
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>
2016-07-06string-output-visitor: Favor new visit_free() functionEric Blake
Now that we have a polymorphic visit_free(), we no longer need string_output_visitor_cleanup(); however, we still need to expose the subtype for string_output_get_string(). Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1465490926-28625-9-git-send-email-eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-07-06qapi: Add new visit_free() functionEric Blake
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>
2016-07-06qapi: Add parameter to visit_end_*Eric Blake
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>
2016-07-04range: Eliminate direct Range member accessMarkus Armbruster
Users of struct Range mess liberally with its members, which makes refactoring hard. Create a set of methods, and convert all users to call them instead of accessing members. The methods have carefully worded contracts, and use assertions to check them. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-06-30qapi: Simplify use of range.hEric Blake
Calling our function g_list_insert_sorted_merged is a misnomer, since we are NOT writing a glib function. Furthermore, we are making every caller pass the same comparator function of range_merge(): any caller that would try otherwise would break in weird ways since our internal call to ranges_can_merge() is hard-coded to operate only on ranges, rather than paying attention to the caller's comparator. Better is to fix things so that callers don't have to care about our internal comparator, by picking a function name and updating the parameter type away from a gratuitous use of void*, to make it obvious that we are operating specifically on a list of ranges and not a generic list. Plus, refactoring the code here will make it easier to plug a memory leak in the next patch. range_compare() is now internal only, and moves to the .c file. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1464712890-14262-3-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12qapi: Simplify semantics of visit_next_list()Eric Blake
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>
2016-05-12qapi-visit: Add visitor.type classificationEric Blake
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>
2016-02-19qapi: Adjust layout of FooList typesEric Blake
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>
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: 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>
2016-02-08qapi: Avoid use of misnamed DO_UPCAST()Eric Blake
The macro DO_UPCAST() is incorrectly named: it converts from a parent class to a derived class (which is a downcast). Better, and more consistent with some of the other qapi visitors, is to use the container_of() macro through a to_FOO() helper. Names like 'to_ov()' may be a bit short, but for a static helper it doesn't hurt too much, and matches existing practice in files like qmp-input-visitor.c. Our current definition of container_of() is weaker than DO_UPCAST(), in that it does not require the derived class to have Visitor as its first member, but this does not hurt our usage patterns in qapi visitors. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <1454075341-13658-3-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
2015-06-22Include qapi/qmp/qerror.h exactly where neededMarkus Armbruster
In particular, don't include it into headers. 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>
2014-06-23qapi/string-output-visitor: fix human outputHu Tao
"0x1-0x10" looks better than "0x1-10" Signed-off-by: Hu Tao <hutao@cn.fujitsu.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2014-06-19qapi/string-output-visitor: fix bugsMichael S. Tsirkin
in human mode, we are creating the string: 16-31 (16-31) instead of 16-17 (10-1f) because we forgot to pass 'true' as the human parameter on one of the two calls to format_string. Also, this is a worsening of quality; previously we would produce 16 (0x10) to make it obvious which number was hex. Fix these issues. Reported-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2014-06-19qapi: fix build on glib < 2.28Michael S. Tsirkin
The following commits: qapi: make string output visitor parse int list qapi: make string input visitor parse int list break with glib < 2.28 since they use the new g_list_free_full function. Open-code that to fix build on old systems. Cc: Hu Tao <hutao@cn.fujitsu.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-06-19qapi: make string output visitor parse int listHu Tao
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> MST: split up patch
2014-02-14qapi: Refine human printing of sizesPaolo Bonzini
This fixes several bugs or shortcomings of the previous pretty-printer. In particular: * use PRIu64 instead of casting to long long * the exact value is included too * the correct unit of measure (MiB, GiB, etc.) is used. PiB and EiB are added too. * due to an off-by-one error, 512*2^30 was printed as 0.500MiB rather than 512MiB. floor(log2(val)) is equal to 63 - clz(val), while the code used 64. * The desired specification is %g rather than %f, which always uses three decimals in the current code. However %g would switch to scientific notation when the integer part is >= 1000 (e.g. 1000*2^30). To keep the code simple, switch to the higher power when the integer part is >= 1000; overflow is avoided by using frexp instead of clz. Suggested-by: Eric Blake <eblake@redhat.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-02-14qapi: Add human mode to StringOutputVisitorPaolo Bonzini
This will be used by "info qtree". For numbers it prints both the decimal and hex values. For sizes it rounds to the nearest power of 2^10. For strings, it puts quotes around the string and separates NULL and empty string. Reviewed-by: Igor Mammedov <imammedo@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andreas Färber <afaerber@suse.de>
2012-12-19qapi: move include files to include/qobject/Paolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-06-08qapi: String visitor, use %f representation for floatsMichael Roth
Currently string-output-visitor formats floats as %g, which is nice in that trailing 0's are automatically truncated, but otherwise this causes some issues: - it uses 6 significant figures instead of 6 decimal places, which means something like 155777.5 (which even has an exact floating point representation) will be rounded to 155778 when converted to a string. - output will be presented in scientific notation when the normalized form requires a 10^x multiplier. Not a huge deal, but arguably less readable for command-line arguments. - due to using scientific notation for numbers requiring more than 6 significant figures, instead of hard-defined decimal places, it fails a lot of the test-visitor-serialization unit tests for floats. Instead, let's just use %f, which is what the QJSON and the QMP visitors use. Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Andreas Färber <afaerber@suse.de>
2012-02-21qapi: add string-based visitorsPaolo Bonzini
String based visitors provide a consistent interface for parsing strings to C values, as well as consuming C values as strings. They will be used to parse command-line options. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>