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path: root/docs/qapi-code-gen.txt
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2014-09-26qapi: Update docs given recent event, spacing fixesEric Blake
Commit 21cd70d added event support but didn't document what the generated code looks like. Commit 05dfb26 removed some unwanted spaces in the generated code, but didn't reflect those changes into the documentation. Finally, the docs start with a big disclaimer about QMP not using QAPI yet, which feels rather stale. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2014-06-27qapi script: clean up in scriptsWenchao Xia
This patch improve docs and uses c_type(argentry, is_param=True) in script. Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-06-23qapi script: add event supportWenchao Xia
qapi-event.py will parse the schema and generate qapi-event.c, then the API in qapi-event.c can be used to handle events in qemu code. All API have prefix "qapi_event". The script mainly includes two parts: generate API for each event define, generate an enum type for all defined events. Since in some cases the real emit behavior may change, for example, qemu-img would not send a event, a callback layer is used to control the behavior. As a result, the stubs at compile time can be saved, the binding of block layer code and monitor code will become looser. Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-16qapi: skip redundant includesBenoît Canet
The purpose of this change is to help create a json file containing common definitions; each bit of generated C code must be emitted only one time. A second history global to all QAPISchema instances has been added to detect when a file is included more than one time and skip these includes. It does not act as a stack and the changes made to it by the __init__ function are propagated back to the caller so it's really a global state. Signed-off-by: Benoit Canet <benoit@irqsave.net> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-15qapi: Show qapi-commands.py invocation in qapi-code-gen.txtMarkus Armbruster
While there, pare down the shell prompts. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-15qapi: Replace uncommon use of the error API by the common oneMarkus Armbruster
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>
2014-05-15qapi: Normalize marshalling's visitor initialization and cleanupMarkus Armbruster
Input and output marshalling functions do it differently. Change them to work the same: initialize the I/O visitor, use it, clean it up, initialize the dealloc visitor, use it, clean it up. This delays dealloc visitor initialization in output marshalling functions, and input visitor cleanup in input marshalling functions. No functional change, but the latter will be convenient when I change the error handling. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-15qapi: Update qapi-code-gen.txt example to match current codeMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-09qapi: Document optional arguments' backwards compatibilityEric Blake
Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-08qapi: Add a primitive to include other files from a QAPI schema fileLluís Vilanova
The primitive uses JSON syntax, and include paths are relative to the file using the directive: { 'include': 'path/to/file.json' } Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-08qapi: Use an explicit input fileLluís Vilanova
Use an explicit input file on the command-line instead of reading from standard input. It also outputs the proper file name when there's an error. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-03-11qapi script: do not allow string discriminatorWenchao Xia
Since enum based discriminators provide better type-safety and ensure that future qapi additions do not forget to adjust dependent unions, forbid using string as discriminator from now on. Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-03-11qapi script: support enum type as discriminator in unionWenchao Xia
By default, any union will automatically generate a enum type as "[UnionName]Kind" in C code, and it is duplicated when the discriminator is specified as a pre-defined enum type in schema. After this patch, the pre-defined enum type will be really used as the switch case condition in generated C code, if discriminator is an enum field. Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2013-10-26qapi: fix documentation exampleEric Blake
The QMP wire format uses "", not '', around strings. * docs/qapi-code-gen.txt: Fix typo. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-10-11qapi-types/visit.py: Inheritance for structsKevin Wolf
This introduces a new 'base' key for struct definitions that refers to another struct type. On the JSON level, the fields of the base type are included directly into the same namespace as the fields of the defined type, like with unions. On the C level, a pointer to a struct of the base type is included. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@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: Flat unions with arbitrary discriminatorKevin Wolf
Instead of the rather verbose syntax that distinguishes base and subclass fields... { "type": "file", "read-only": true, "data": { "filename": "test" } } ...we can now have both in the same namespace, allowing a more direct mapping of the command line, and moving fields between the common base and subclasses without breaking the API: { "driver": "file", "read-only": true, "filename": "test" } Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-07-26docs: Document QAPI union typesKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2012-07-23qapi: fix error propagationPaolo Bonzini
Don't overwrite / leak previously set errors. Make traversal cope with missing mandatory sub-structs. Don't try to end a container that could not be started. v1->v2: - unchanged v2->v3: - instead of examining, assert that we never overwrite errors with error_set() - allow visitors to set a NULL struct pointer successfully, so traversal of incomplete objects can continue - check for a NULL "obj" before accessing "(*obj)->has_XXX" (this is not a typo, "obj != NULL" implies "*obj != NULL" here) - fix start_struct / end_struct balance for unions as well Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.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>
2011-11-17Fix some spelling bugs in documentation and commentsStefan Weil
These errors were detected by codespell: remaing -> remaining soley -> solely virutal -> virtual seperate -> separate libcacard.txt still needs some more patches. Signed-off-by: Stefan Weil <sw@weilnetz.de> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-11-01qapi: fix typos in documentation JSON examplesStefan Hajnoczi
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-08-29Fix spelling in comments and debug messages (recieve -> receive)Stefan Weil
Signed-off-by: Stefan Weil <weil@mail.berlios.de> Reviewed-by: Andreas Färber <andreas.faerber@web.de> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-07-21qapi: add QAPI code generation documentationMichael Roth
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>