aboutsummaryrefslogtreecommitdiff
path: root/scripts/qapi-commands.py
AgeCommit message (Collapse)Author
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>
2016-07-06qmp-input-visitor: Favor new visit_free() functionEric Blake
Now that we have a polymorphic visit_free(), we no longer need qmp_input_visitor_cleanup(); which in turn means we no longer need to return a subtype from qmp_input_visitor_new() nor a public upcast function. Generated code changes to qmp-marshal.c look like: |@@ -52,11 +52,10 @@ void qmp_marshal_add_fd(QDict *args, QOb | { | Error *err = NULL; | AddfdInfo *retval; |- QmpInputVisitor *qiv = qmp_input_visitor_new(QOBJECT(args), true); | Visitor *v; | q_obj_add_fd_arg arg = {0}; | |- v = qmp_input_get_visitor(qiv); |+ v = qmp_input_visitor_new(QOBJECT(args), true); | visit_start_struct(v, NULL, NULL, 0, &err); | if (err) { | goto out; Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1465490926-28625-8-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>
2016-05-12qapi: Split visit_end_struct() into piecesEric Blake
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>
2016-05-12qapi-commands: Wrap argument visit in visit_start_structEric Blake
The qmp-input visitor was allowing callers to play rather fast and loose: when visiting a QDict, you could grab members of the root dictionary without first pushing into the dict; among the culprit callers was the generated marshal code on the 'arguments' dictionary of a QMP command. But we are about to tighten the input visitor, at which point the generated marshal code MUST follow the same paradigms as everyone else, of pushing into the struct before grabbing its keys. Generated code grows as follows: |@@ -515,7 +641,12 @@ void qmp_marshal_blockdev_backup(QDict * | BlockdevBackup arg = {0}; | | v = qmp_input_get_visitor(qiv); |+ visit_start_struct(v, NULL, NULL, 0, &err); |+ if (err) { |+ goto out; |+ } | visit_type_BlockdevBackup_members(v, &arg, &err); |+ visit_end_struct(v, err ? NULL : &err); | if (err) { | goto out; | } |@@ -527,7 +715,9 @@ out: | qmp_input_visitor_cleanup(qiv); | qdv = qapi_dealloc_visitor_new(); | v = qapi_dealloc_get_visitor(qdv); |+ visit_start_struct(v, NULL, NULL, 0, NULL); | visit_type_BlockdevBackup_members(v, &arg, NULL); |+ visit_end_struct(v, NULL); | qapi_dealloc_visitor_cleanup(qdv); | } The use of 'err ? NULL : &err' is temporary; a later patch will clean that up when it splits visit_end_struct(). Prior to this patch, the fact that there was no final visit_end_struct() meant that even though we are using a strict input visit, the marshalling code was not detecting excess input at the top level (only in nested levels). Fortunately, we have code in monitor.c:qmp_check_client_args() that also checks for no excess arguments at the top level. But as the generated code is more compact than the manual check, a later patch will clean up monitor.c to drop the redundancy added here. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1461879932-9020-9-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12qapi: Consolidate QMP input visitor creationEric Blake
Rather than having two separate ways to create a QMP input visitor, where the safer approach has the more verbose name, it is better to consolidate things into a single function where the caller must explicitly choose whether to be strict or to ignore excess input. This patch is the strictly mechanical conversion; the next patch will then audit which uses can be made stricter. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1461879932-9020-6-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-03-18qapi-commands: Inline single-use helpers of gen_marshal()Eric Blake
Originally, gen_marshal_input_visit() (or gen_visitor_input_block() before commit f1538019) was factored out to make it easy to do two passes of a visit to each member of a (possibly-implicit) object, without duplicating lots of code. But after recent changes, those visits now occupy a single line of emitted code, and the helper method has become a series of conditionals both before and after the one important line, making it rather awkward to see at a glance what gets emitted on the first (parsing) or second (deallocation) pass. It's a lot easier to read the generator code if we just inline both uses directly into gen_marshal(), without all the conditionals. Once we've done that, it's easy to notice that gen_marshal_vars() is used only once, and inlining it too lets us consolidate some mcgen() calls that used to be split across helpers. gen_call() remains a single-use helper function, but it has enough indentation and complexity that inlining it would hamper legibility. No change to generated output. The fact that the diffstat shows a net reduction in lines is an argument in favor of this cleanup. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1458254921-17042-10-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-03-18qapi-commands: Utilize implicit struct visitsEric Blake
Rather than generate inline per-member visits, take advantage of the 'visit_type_FOO_members()' function for command marshalling. This is possible now that implicit structs can be visited like any other. Generate call arguments from a stack- allocated struct, rather than a list of local variables: |@@ -57,26 +57,15 @@ void qmp_marshal_add_fd(QDict *args, QOb | QmpInputVisitor *qiv = qmp_input_visitor_new_strict(QOBJECT(args)); | QapiDeallocVisitor *qdv; | Visitor *v; |- bool has_fdset_id = false; |- int64_t fdset_id = 0; |- bool has_opaque = false; |- char *opaque = NULL; |+ q_obj_add_fd_arg arg = {0}; | | v = qmp_input_get_visitor(qiv); |- if (visit_optional(v, "fdset-id", &has_fdset_id)) { |- visit_type_int(v, "fdset-id", &fdset_id, &err); |- if (err) { |- goto out; |- } |- } |- if (visit_optional(v, "opaque", &has_opaque)) { |- visit_type_str(v, "opaque", &opaque, &err); |- if (err) { |- goto out; |- } |+ visit_type_q_obj_add_fd_arg_members(v, &arg, &err); |+ if (err) { |+ goto out; | } | |- retval = qmp_add_fd(has_fdset_id, fdset_id, has_opaque, opaque, &err); |+ retval = qmp_add_fd(arg.has_fdset_id, arg.fdset_id, arg.has_opaque, arg.opaque, &err); | if (err) { | goto out; | } |@@ -88,12 +77,7 @@ out: | qmp_input_visitor_cleanup(qiv); | qdv = qapi_dealloc_visitor_new(); | v = qapi_dealloc_get_visitor(qdv); |- if (visit_optional(v, "fdset-id", &has_fdset_id)) { |- visit_type_int(v, "fdset-id", &fdset_id, NULL); |- } |- if (visit_optional(v, "opaque", &has_opaque)) { |- visit_type_str(v, "opaque", &opaque, NULL); |- } |+ visit_type_q_obj_add_fd_arg_members(v, &arg, NULL); | qapi_dealloc_visitor_cleanup(qdv); | } This also has the nice side effect of eliminating a chance of collision between argument QMP names and local variables. This patch also paves the way for some followup simplifications in the generator, in subsequent patches. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1458254921-17042-9-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-03-18qapi: Fix command with named empty argument typeEric Blake
The generator special-cased { 'command':'foo', 'data': {} } to avoid emitting a visitor variable, but failed to see that { 'struct':'NamedEmptyType, 'data': {} } { 'command':'foo', 'data':'NamedEmptyType' } needs the same treatment. There, the generator happily generates a visitor to get no arguments, and a visitor to destroy no arguments; and the compiler isn't happy with that, as demonstrated by the updated qapi-schema-test.json: tests/test-qmp-marshal.c: In function ‘qmp_marshal_user_def_cmd0’: tests/test-qmp-marshal.c:264:14: error: variable ‘v’ set but not used [-Werror=unused-but-set-variable] Visitor *v; ^ No change to generated code except for the testsuite addition. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1458254921-17042-3-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-03-18qapi: Assert in places where variants are not handledEric Blake
We are getting closer to the point where we could use one union as the base or variant type within another union type (as long as there are no collisions between any possible combination of member names allowed across all discriminator choices). But until we get to that point, it is worth asserting that variants are not present in places where we are not prepared to handle them: when exploding a type into a parameter list, we do not expect variants. The qapi.py code is already checking this, via the older check_type() method; but someday we hope to get rid of that and move checking into QAPISchema*.check(). The two asserts added here make sure any refactoring still catches problems, and makes it locally obvious why we can iterate over only type.members without worrying about type.variants. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1458254921-17042-2-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-03-05qapi: Rename 'fields' to 'members' in generatorEric Blake
C types and JSON objects don't have fields, but members. We shouldn't gratuitously invent terminology. This patch is a strict renaming of generator code internals (including testsuite comments), before later patches rename C interfaces. No change to generated code with this patch. Suggested-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1457021813-10704-2-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-16qapi: Clean up includes in generated filesEric Blake
As a followup to commit cbf2115, clean up the includes in files generated by QAPI so that osdep.h is included first in .c files, and headers which it implies are not included manually. This patch is done manually, since Coccinelle (and therefore scripts/clean-includes) doesn't see into the generator scripts. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-02-08qapi: Swap visit_* arguments for consistent 'name' placementEric Blake
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>
2015-11-02qapi: More robust conditions for when labels are neededEric Blake
We were using regular expressions to see if ret included any earlier text that emitted a 'goto out;' line, to decide whether we needed to output an 'out:' label. But this is fragile, if the ret text can possibly combine more than one generated function body, where the first function used a goto but the second does not. Change the code to just check for the known conditions which cause an error check to be needed. Besides, it's slightly more efficient to use plain checks than regular expression searching. No change to generated code. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1445898903-12082-4-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12qapi: Simplify gen_visit_fields() error handlingEric Blake
Since we have consolidated all generated code to use 'err' as the name of the local variable for error detection, we can simplify the decision on whether to skip error detection (useful for deallocation paths) to be a boolean. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1443565276-4535-18-git-send-email-eblake@redhat.com> [Change to gen_visit_fields() simplified] Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12qapi: Share gen_visit_fields()Eric Blake
Consolidate the code between visit, command marshalling, and event generation that iterates over the members of a struct. It reduces code duplication in the generator, so that a future patch can reduce the size of generated code while touching only one instead of three locations. There are no changes to the generated marshal code. The visitor code becomes slightly more verbose, but remains semantically equivalent, and is actually easier to read as it follows a more common idiom: | visit_optional(v, &(*obj)->has_device, "device", &err); |- if (!err && (*obj)->has_device) { |- visit_type_str(v, &(*obj)->device, "device", &err); |- } | if (err) { | goto out; | } |+ if ((*obj)->has_device) { |+ visit_type_str(v, &(*obj)->device, "device", &err); |+ if (err) { |+ goto out; |+ } |+ } The event code becomes slightly more verbose, but this is arguably a bug fix: although the visitors are not well documented, use of an optional member should not be attempted unless guarded by a prior call to visit_optional(). Works only because the output qmp visitor has a no-op visit_optional(): |+ visit_optional(v, &has_offset, "offset", &err); |+ if (err) { |+ goto out; |+ } | if (has_offset) { | visit_type_int(v, &offset, "offset", &err); Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1443565276-4535-17-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12qapi: Share gen_err_check()Eric Blake
qapi-commands has a nice helper gen_err_check(), but did not use it everywhere. In fact, using it in more places makes it easier to reduce the lines of code used for generating error checks. This in turn will make it easier for later patches to consolidate another common pattern among the generators. The generated code has fewer blank lines in qapi-event.c functions, but has no semantic difference. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1443565276-4535-16-git-send-email-eblake@redhat.com> [Drop another blank line for symmetry] Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12qapi: Consistent generated code: minimize push_indent() usageEric Blake
We had some pointless differences in the generated code for visit, command marshalling, and events; unifying them makes it easier for future patches to consolidate to common helper functions. This is one patch of a series to clean up these differences. This patch reduces the number of push_indent()/pop_indent() pairs so that generated code is typically already at its natural output indentation in the python files. It is easier to reason about generated code if the reader does not have to track how much spacing will be inserted alongside the code, and moreso when all of the generators use the same patterns (qapi-type and qapi-event were already using in-place indentation). Arguably, the resulting python may be a bit harder to read with C code at the same indentation as python; on the other hand, not having to think about push_indent() is a win, and most decent editors provide syntax highlighting that makes it easier to visually distinguish python code from string literals that will become C code. There is no change to the generated output. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1443565276-4535-15-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12qapi: Consistent generated code: prefer visitor 'v'Eric Blake
We had some pointless differences in the generated code for visit, command marshalling, and events; unifying them makes it easier for future patches to consolidate to common helper functions. This is one patch of a series to clean up these differences. This patch names the local visitor variable 'v' rather than 'm'. Related objects, such as 'QapiDeallocVisitor', are also named by their initials instead of an unrelated leading m. No change in semantics to the generated code. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1443565276-4535-12-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12qapi: Consistent generated code: prefer error 'err'Eric Blake
We had some pointless differences in the generated code for visit, command marshalling, and events; unifying them makes it easier for future patches to consolidate to common helper functions. This is one patch of a series to clean up these differences. This patch consistently names the local error variable 'err' rather than 'local_err'. No change in semantics to the generated code. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1443565276-4535-11-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-09-21qapi-commands: De-duplicate output marshaling functionsMarkus Armbruster
gen_marshal_output() uses its parameter name only for name of the generated function. Name it after the type being marshaled instead of its caller, and drop duplicates. Saves 7 copies of qmp_marshal_output_int() in qemu-ga, and one copy of qmp_marshal_output_str() in qemu-system-*. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1442401589-24189-19-git-send-email-armbru@redhat.com>
2015-09-21qapi: De-duplicate parameter list generationMarkus Armbruster
Generated qapi-event.[ch] lose line breaks. No change otherwise. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1442401589-24189-18-git-send-email-armbru@redhat.com>
2015-09-21qapi: Rename qmp_marshal_input_FOO() to qmp_marshal_FOO()Markus Armbruster
These functions marshal both input and output. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1442401589-24189-17-git-send-email-armbru@redhat.com>
2015-09-21qapi-commands: Rearrange codeMarkus Armbruster
Rename gen_marshal_input() to gen_marshal(), because the generated function marshals both arguments and results. Rename gen_visitor_input_containers_decl() to gen_marshal_vars(), and move the other variable declarations there, too. Rename gen_visitor_input_block() to gen_marshal_input_visit(), and rearrange its code slightly. Rename gen_marshal_input_decl() to gen_marshal_proto(), because the result isn't a full declaration, unlike gen_command_decl()'s. New gen_marshal_decl() actually returns a full declaration. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1442401589-24189-16-git-send-email-armbru@redhat.com>
2015-09-21qapi: Clean up after recent conversions to QAPISchemaVisitorMarkus Armbruster
Generate just 'FOO' instead of 'struct FOO' when possible. Drop helper functions that are now unused. Make pep8 and pylint reasonably happy. Rename generate_FOO() functions to gen_FOO() for consistency. Use more consistent and sensible variable names. Consistently use c_ for mapping keys when their value is a C identifier or type. Simplify gen_enum() and gen_visit_union() Consistently use single quotes for C text string literals. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1442401589-24189-14-git-send-email-armbru@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-21qapi: Replace dirty is_c_ptr() by method c_null()Markus Armbruster
is_c_ptr() looks whether the end of the C text for the type looks like a pointer. Works, but is fragile. We now have a better tool: use QAPISchemaType method c_null(). The initializers for non-pointers become prettier: 0, false or the enumeration constant with the value 0 instead of {0}. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1442401589-24189-13-git-send-email-armbru@redhat.com>
2015-09-21qapi-commands: Convert to QAPISchemaVisitorMarkus Armbruster
Output unchanged apart from reordering and white-space. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <1442401589-24189-9-git-send-email-armbru@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
2015-09-21qapi: New QAPISchema intermediate reperesentationMarkus Armbruster
The QAPI code generators work with a syntax tree (nested dictionaries) plus a few symbol tables (also dictionaries) on the side. They have clearly outgrown these simple data structures. There's lots of rummaging around in dictionaries, and information is recomputed on the fly. For the work I'm going to do, I want more clearly defined and more convenient interfaces. Going forward, I also want less coupling between the back-ends and the syntax tree, to make messing with the syntax easier. Create a bunch of classes to represent QAPI schemata. Have the QAPISchema initializer call the parser, then walk the syntax tree to create the new internal representation, and finally perform semantic analysis. Shortcut: the semantic analysis still relies on existing check_exprs() to do the actual semantic checking. All this code needs to move into the classes. Mark as TODO. Simple unions are lowered to flat unions. Flat unions and structs are represented as a more general object type. Catching name collisions in generated code would be nice. Mark as TODO. We generate array types eagerly, even though most of them aren't used. Mark as TODO. Nothing uses the new intermediate representation just yet, thus no change to generated files. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04qapi: Generated code cleanupMarkus Armbruster
Clean up white-space, brace placement, and superfluous #ifdef QAPI_TYPES_BUILTIN_CLEANUP_DEF. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04qapi-commands: Drop useless initializationMarkus Armbruster
In generated command handlers, the assignment to retval dominates its only use. Therefore, its initialization is useless. Drop it. Suggested-by: Eric Blake <eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04qapi-commands: Don't feed output of mcgen() to mcgen() againMarkus Armbruster
Multiple passes through mcgen() is prone to produce unwanted blank lines, which we then combat by sprinkling .rstrip() on top. Just don't do it. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04qapi-commands: Inline gen_marshal_output_call()Markus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04qapi-commands: Fix gen_err_check(e) for e and e != 'local_err'Markus Armbruster
gen_err_check() hard-codes 'local_err' instead of substituting the argument. Currently harmless, since all callers pass either None or 'local_err'. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04qapi: Drop unused and useless parameters and variablesMarkus Armbruster
gen_sync_call()'s parameter indent is useless: gen_sync_call() uses it only as optional argument for push_indent() and pop_indent(), their default is four, and gen_sync_call()'s only caller passes four. Drop the parameter. gen_visitor_input_containers_decl()'s parameter obj is always "QOBJECT(args)". Use that, and drop the parameter. Drop unused parameters of gen_marshal_output(), gen_marshal_input_decl(), generate_visit_struct_body(), generate_visit_list(), generate_visit_enum(), generate_declaration(), generate_enum_declaration(), generate_decl_enum(). Drop unused variables in generate_event_enum_lookup(), generate_enum_lookup(), generate_visit_struct_fields(), check_event(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04qapi: Clean up cgen() and mcgen()Markus Armbruster
Commit 05dfb26 added eatspace stripping to mcgen(). Move it to cgen(), just in case somebody gets tempted to use cgen() directly instead of via mcgen(). cgen() indents blank lines. No such lines get generated right now, but fix it anyway. We use triple-quoted strings for program text, like this: ''' Program text any number of lines ''' Keeps the program text relatively readable, but puts an extra newline at either end. mcgen() "fixes" that by dropping the first and last line outright. Drop only the newlines. This unmasks a bug in qapi-commands.py: four quotes instead of three. Fix it up. Output doesn't change Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
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>
2015-06-22qmp: Wean off qerror_report()Markus Armbruster
The traditional QMP command handler interface int qmp_FOO(Monitor *mon, const QDict *params, QObject **ret_data); doesn't provide for returning an Error object. Instead, the handler is expected to stash it in the monitor with qerror_report(). When we rebased QMP on top of QAPI, we didn't change this interface. Instead, commit 776574d introduced "middle mode" as a temporary aid for converting existing QMP commands to QAPI one by one. More than three years later, we're still using it. Middle mode has two effects: * Instead of the native input marshallers static void qmp_marshal_input_FOO(QDict *, QObject **, Error **) it generates input marshallers conforming to the traditional QMP command handler interface. * It suppresses generation of code to register them with qmp_register_command() This permits giving them internal linkage. As long as we need qmp-commands.hx, we can't use the registry behind qmp_register_command(), so the latter has to stay for now. The former has to go to get rid of qerror_report(). Changing all QMP commands to fit the QAPI mold in one go was impractical back when we started, but by now there are just a few stragglers left: do_qmp_capabilities(), qmp_qom_set(), qmp_qom_get(), qmp_object_add(), qmp_netdev_add(), do_device_add(). Switch middle mode to generate native input marshallers, and adapt the stragglers. Simplifies both the monitor code and the stragglers. Rename do_qmp_capabilities() to qmp_capabilities(), and do_device_add() to qmp_device_add, because that's how QMP command handlers are named today. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-05-14qapi: Inline gen_command_decl_prologue(), gen_command_def_prologue()Markus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2015-05-14qapi: Factor open_output(), close_output() out of generatorsMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2015-05-14qapi: Factor parse_command_line() out of the generatorsMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2015-05-14qapi: qapi-commands.py option --type is unused, drop itMarkus Armbruster
Anything but --type sync (which is the default) suppresses output entirely, which makes no sense. Dates back to the initial commit c17d990. Commit message says "Currently only generators for synchronous qapi/qmp functions are supported", so maybe output other than "synchronous qapi/qmp" was planned at the time, to be selected with --type. Should other kinds of output ever materialize, we can put the option back. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2015-05-14qapi: Support downstream events and commandsEric Blake
Enhance the testsuite to cover downstream events and commands. Events worked without more tweaks, but commands needed a few final updates in the generator to mangle names in the appropriate places. In making those tweaks, it was easier to drop type_visitor() and inline its actions instead. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-05-14qapi: Rename identical c_fun()/c_var() into c_name()Eric Blake
Now that the two functions are identical, we only need one of them, and we might as well give it a more descriptive name. Basically, the function serves as the translation from a QAPI name into a (portion of a) C identifier, without regards to whether it is a variable or function name. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-05-05qapi: Drop support for inline nested typesEric Blake
A future patch will be using a 'name':{dictionary} entry in the QAPI schema to specify a default value for an optional argument (see previous commit messages for more details why); but existing use of inline nested structs conflicts with that goal. Now that all commands have been changed to avoid inline nested structs, nuke support for them, and turn it into a hard error. Update the testsuite to reflect tighter parsing rules. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-05-05qapi: Unify type bypass and add testsEric Blake
For a few QMP commands, we are forced to pass an arbitrary type without tracking it properly in QAPI. Among the existing clients, this unnamed type was spelled 'dict', 'visitor', and '**'; this patch standardizes on '**', matching the documentation changes earlier in the series. Meanwhile, for the 'gen' key, we have been ignoring the value, although the schema consistently used "'no'" ('success-response' was hard-coded to checking for 'no'). But now that we can support a literal "false" in the schema, we might as well use that rather than ignoring the value or special-casing a random string. Note that these are one-way switches (use of 'gen':true is not the same as omitting 'gen'). Also, the use of '**' requires 'gen':false, but the use of 'gen':false does not mandate the use of '**'. There is no difference to the generated code. Add some tests on what we'd like to guarantee, although it will take later patches to clean up test results and actually enforce the use of a bool parameter. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2014-06-23qapi: Suppress unwanted space between type and identifierAmos Kong
We always generate a space between type and identifier in parameter and variable declarations, even when idiomatic C style doesn't have a space there. Suppress it. Signed-off-by: Amos Kong <akong@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-06-23qapi: add const prefix to 'char *' insider c_type()Amos Kong
It's ugly to add const prefix for parameter type by an if statement outside c_type(). This patch adds a parameter to do it. Signed-off-by: Amos Kong <akong@redhat.com> Suggested-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-21qapi: zero-initialize all QMP command parametersMichael Roth
In general QMP command parameter values are specified by consumers of the QMP/HMP interface, but in the case of optional parameters these values may be left uninitialized. It is considered a bug for code to make use of optional parameters that have not been flagged as being present by the marshalling code (via corresponding has_<parameter> parameter), however our marshalling code will still pass these uninitialized values on to the corresponding QMP function (to then be ignored). Some compilers (clang in particular) consider this unsafe however, and generate warnings as a result. As reported by Peter Maydell: This is something clang's -fsanitize=undefined spotted. The code generated by qapi-commands.py in qmp-marshal.c for qmp_marshal_* functions where there are some optional arguments looks like this: bool has_force = false; bool force; mi = qmp_input_visitor_new_strict(QOBJECT(args)); v = qmp_input_get_visitor(mi); visit_type_str(v, &device, "device", errp); visit_start_optional(v, &has_force, "force", errp); if (has_force) { visit_type_bool(v, &force, "force", errp); } visit_end_optional(v, errp); qmp_input_visitor_cleanup(mi); if (error_is_set(errp)) { goto out; } qmp_eject(device, has_force, force, errp); In the case where has_force is false, we never initialize force, but then we use it by passing it to qmp_eject. I imagine we don't then actually use the value, but clang complains in particular for 'bool' variables because the value that ends up being loaded from memory for 'force' is not either 0 or 1 (being uninitialized stack contents). Fix this by initializing all QMP command parameters to {0} in the marshalling code prior to passing them on to the QMP functions. Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Reported-by: Peter Maydell <peter.maydell@linaro.org> Tested-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@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>