From a680ea072fd96ed28ccc479f018abb4bae649104 Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Fri, 4 Nov 2022 17:06:43 +0100 Subject: docs/devel/qapi-code-gen: Update example to match current code MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Markus Armbruster Reviewed-by: Daniel P. Berrangé Message-Id: <20221104160712.3005652-2-armbru@redhat.com> --- docs/devel/qapi-code-gen.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'docs/devel/qapi-code-gen.rst') diff --git a/docs/devel/qapi-code-gen.rst b/docs/devel/qapi-code-gen.rst index cd9b544376..997313fce7 100644 --- a/docs/devel/qapi-code-gen.rst +++ b/docs/devel/qapi-code-gen.rst @@ -1748,7 +1748,7 @@ Example:: QTAILQ_INIT(cmds); qmp_register_command(cmds, "my-command", - qmp_marshal_my_command, QCO_NO_OPTIONS); + qmp_marshal_my_command, 0, 0); } [Uninteresting stuff omitted...] -- cgit 1.4.1 From 7df184613c911c93490ee36eb73f97159ebe728a Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Fri, 4 Nov 2022 17:06:44 +0100 Subject: qapi: Tidy up whitespace in generated code MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Markus Armbruster Reviewed-by: Daniel P. Berrangé Message-Id: <20221104160712.3005652-3-armbru@redhat.com> --- docs/devel/qapi-code-gen.rst | 1 - scripts/qapi/commands.py | 7 +++---- scripts/qapi/events.py | 1 - 3 files changed, 3 insertions(+), 6 deletions(-) (limited to 'docs/devel/qapi-code-gen.rst') diff --git a/docs/devel/qapi-code-gen.rst b/docs/devel/qapi-code-gen.rst index 997313fce7..b56ea4546d 100644 --- a/docs/devel/qapi-code-gen.rst +++ b/docs/devel/qapi-code-gen.rst @@ -1664,7 +1664,6 @@ Example:: $ cat qapi-generated/example-qapi-commands.c [Uninteresting stuff omitted...] - static void qmp_marshal_output_UserDefOne(UserDefOne *ret_in, QObject **ret_out, Error **errp) { diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py index 38ca38a7b9..cf68aaf0bf 100644 --- a/scripts/qapi/commands.py +++ b/scripts/qapi/commands.py @@ -83,7 +83,7 @@ def gen_call(name: str, trace_qmp_enter_%(name)s(req_json->str); } - ''', +''', upper=upper, name=name) ret += mcgen(''' @@ -124,13 +124,13 @@ def gen_call(name: str, trace_qmp_exit_%(name)s(ret_json->str, true); } - ''', +''', upper=upper, name=name) else: ret += mcgen(''' trace_qmp_exit_%(name)s("{}", true); - ''', +''', name=name) return ret @@ -316,7 +316,6 @@ class QAPISchemaGenCommandVisitor(QAPISchemaModularCVisitor): #include "qapi/error.h" #include "%(visit)s.h" #include "%(commands)s.h" - ''', commands=commands, visit=visit)) diff --git a/scripts/qapi/events.py b/scripts/qapi/events.py index 27b44c49f5..e762d53d19 100644 --- a/scripts/qapi/events.py +++ b/scripts/qapi/events.py @@ -196,7 +196,6 @@ class QAPISchemaGenEventVisitor(QAPISchemaModularCVisitor): #include "qapi/error.h" #include "qapi/qmp/qdict.h" #include "qapi/qmp-event.h" - ''', events=events, visit=visit, prefix=self._prefix)) -- cgit 1.4.1 From 94f9bd33eece74810aee86de866b3cc86c3b0aec Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Fri, 4 Nov 2022 17:06:45 +0100 Subject: docs/devel/qapi-code-gen: Extend example for next commit's change MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The next commit will change the code generated for some optional members. The example schema contains an optional member affected by the change. Add one that is not affected. Signed-off-by: Markus Armbruster Reviewed-by: Daniel P. Berrangé Message-Id: <20221104160712.3005652-4-armbru@redhat.com> --- docs/devel/qapi-code-gen.rst | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) (limited to 'docs/devel/qapi-code-gen.rst') diff --git a/docs/devel/qapi-code-gen.rst b/docs/devel/qapi-code-gen.rst index b56ea4546d..3a817ba498 100644 --- a/docs/devel/qapi-code-gen.rst +++ b/docs/devel/qapi-code-gen.rst @@ -1357,7 +1357,7 @@ qmp_my_command(); everything else is produced by the generator. :: $ cat example-schema.json { 'struct': 'UserDefOne', - 'data': { 'integer': 'int', '*string': 'str' } } + 'data': { 'integer': 'int', '*string': 'str', '*flag': 'bool' } } { 'command': 'my-command', 'data': { 'arg1': ['UserDefOne'] }, @@ -1412,6 +1412,8 @@ Example:: int64_t integer; bool has_string; char *string; + bool has_flag; + bool flag; }; void qapi_free_UserDefOne(UserDefOne *obj); @@ -1531,6 +1533,11 @@ Example:: return false; } } + if (visit_optional(v, "flag", &obj->has_flag)) { + if (!visit_type_bool(v, "flag", &obj->flag, errp)) { + return false; + } + } return true; } @@ -1916,6 +1923,12 @@ Example:: { "type", QLIT_QSTR("str"), }, {} })), + QLIT_QDICT(((QLitDictEntry[]) { + { "default", QLIT_QNULL, }, + { "name", QLIT_QSTR("flag"), }, + { "type", QLIT_QSTR("bool"), }, + {} + })), {} })), }, { "meta-type", QLIT_QSTR("object"), }, @@ -1949,6 +1962,12 @@ Example:: { "name", QLIT_QSTR("str"), }, {} })), + QLIT_QDICT(((QLitDictEntry[]) { + { "json-type", QLIT_QSTR("boolean"), }, + { "meta-type", QLIT_QSTR("builtin"), }, + { "name", QLIT_QSTR("bool"), }, + {} + })), {} })); -- cgit 1.4.1 From 44ea9d9be33c8a4cf89132e0dc2b3029733bcaf4 Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Fri, 4 Nov 2022 17:06:46 +0100 Subject: qapi: Start to elide redundant has_FOO in generated C MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In QAPI, absent optional members are distinct from any present value. We thus represent an optional schema member FOO as two C members: a FOO with the member's type, and a bool has_FOO. Likewise for function arguments. However, has_FOO is actually redundant for a pointer-valued FOO, which can be null only when has_FOO is false, i.e. has_FOO == !!FOO. Except for arrays, where we a null FOO can also be a present empty array. The redundant has_FOO are a nuisance to work with. Improve the generator to elide them. Uses of has_FOO need to be replaced as follows. Tests of has_FOO become the equivalent comparison of FOO with null. For brevity, this is commonly done by implicit conversion to bool. Assignments to has_FOO get dropped. Likewise for arguments to has_FOO parameters. Beware: code may violate the invariant has_FOO == !!FOO before the transformation, and get away with it. The above transformation can then break things. Two cases: * Absent: if code ignores FOO entirely when !has_FOO (except for freeing it if necessary), even non-null / uninitialized FOO works. Such code is known to exist. * Present: if code ignores FOO entirely when has_FOO, even null FOO works. Such code should not exist. In both cases, replacing tests of has_FOO by FOO reverts their sense. We have to fix the value of FOO then. To facilitate review of the necessary updates to handwritten code, add means to opt out of this change, and opt out for all QAPI schema modules where the change requires updates to handwritten code. The next few commits will remove these opt-outs in reviewable chunks, then drop the means to opt out. Signed-off-by: Markus Armbruster Reviewed-by: Daniel P. Berrangé Message-Id: <20221104160712.3005652-5-armbru@redhat.com> --- docs/devel/qapi-code-gen.rst | 5 ++-- docs/devel/writing-monitor-commands.rst | 14 +++++----- scripts/qapi/commands.py | 2 +- scripts/qapi/events.py | 2 +- scripts/qapi/gen.py | 2 +- scripts/qapi/schema.py | 48 +++++++++++++++++++++++++++++++++ scripts/qapi/types.py | 2 +- scripts/qapi/visit.py | 17 ++++++++++-- 8 files changed, 77 insertions(+), 15 deletions(-) (limited to 'docs/devel/qapi-code-gen.rst') diff --git a/docs/devel/qapi-code-gen.rst b/docs/devel/qapi-code-gen.rst index 3a817ba498..5edc49aa74 100644 --- a/docs/devel/qapi-code-gen.rst +++ b/docs/devel/qapi-code-gen.rst @@ -1410,7 +1410,6 @@ Example:: struct UserDefOne { int64_t integer; - bool has_string; char *string; bool has_flag; bool flag; @@ -1525,10 +1524,12 @@ Example:: bool visit_type_UserDefOne_members(Visitor *v, UserDefOne *obj, Error **errp) { + bool has_string = !!obj->string; + if (!visit_type_int(v, "integer", &obj->integer, errp)) { return false; } - if (visit_optional(v, "string", &obj->has_string)) { + if (visit_optional(v, "string", &has_string)) { if (!visit_type_str(v, "string", &obj->string, errp)) { return false; } diff --git a/docs/devel/writing-monitor-commands.rst b/docs/devel/writing-monitor-commands.rst index 2fefedcd98..2c11e71665 100644 --- a/docs/devel/writing-monitor-commands.rst +++ b/docs/devel/writing-monitor-commands.rst @@ -166,9 +166,9 @@ and user defined types. Now, let's update our C implementation in monitor/qmp-cmds.c:: - void qmp_hello_world(bool has_message, const char *message, Error **errp) + void qmp_hello_world(const char *message, Error **errp) { - if (has_message) { + if (message) { printf("%s\n", message); } else { printf("Hello, world\n"); @@ -210,9 +210,9 @@ file. Basically, most errors are set by calling the error_setg() function. Let's say we don't accept the string "message" to contain the word "love". If it does contain it, we want the "hello-world" command to return an error:: - void qmp_hello_world(bool has_message, const char *message, Error **errp) + void qmp_hello_world(const char *message, Error **errp) { - if (has_message) { + if (message) { if (strstr(message, "love")) { error_setg(errp, "the word 'love' is not allowed"); return; @@ -467,9 +467,9 @@ There are a number of things to be noticed: allocated by the regular g_malloc0() function. Note that we chose to initialize the memory to zero. This is recommended for all QAPI types, as it helps avoiding bad surprises (specially with booleans) -4. Remember that "next_deadline" is optional? All optional members have a - 'has_TYPE_NAME' member that should be properly set by the implementation, - as shown above +4. Remember that "next_deadline" is optional? Non-pointer optional + members have a 'has_TYPE_NAME' member that should be properly set + by the implementation, as shown above 5. Even static strings, such as "alarm_timer->name", should be dynamically allocated by the implementation. This is so because the QAPI also generates a function to free its types and it cannot distinguish between dynamically diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py index cf68aaf0bf..79c5e5c3a9 100644 --- a/scripts/qapi/commands.py +++ b/scripts/qapi/commands.py @@ -64,7 +64,7 @@ def gen_call(name: str, elif arg_type: assert not arg_type.variants for memb in arg_type.members: - if memb.optional: + if memb.need_has(): argstr += 'arg.has_%s, ' % c_name(memb.name) argstr += 'arg.%s, ' % c_name(memb.name) diff --git a/scripts/qapi/events.py b/scripts/qapi/events.py index e762d53d19..3cf01e96b6 100644 --- a/scripts/qapi/events.py +++ b/scripts/qapi/events.py @@ -60,7 +60,7 @@ def gen_param_var(typ: QAPISchemaObjectType) -> str: for memb in typ.members: ret += sep sep = ', ' - if memb.optional: + if memb.need_has(): ret += 'has_' + c_name(memb.name) + sep if memb.type.name == 'str': # Cast away const added in build_params() diff --git a/scripts/qapi/gen.py b/scripts/qapi/gen.py index 113b49134d..b5a8d03e8e 100644 --- a/scripts/qapi/gen.py +++ b/scripts/qapi/gen.py @@ -121,7 +121,7 @@ def build_params(arg_type: Optional[QAPISchemaObjectType], for memb in arg_type.members: ret += sep sep = ', ' - if memb.optional: + if memb.need_has(): ret += 'bool has_%s, ' % c_name(memb.name) ret += '%s %s' % (memb.type.c_param_type(), c_name(memb.name)) diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py index 3728340c37..58b00982ea 100644 --- a/scripts/qapi/schema.py +++ b/scripts/qapi/schema.py @@ -253,6 +253,11 @@ class QAPISchemaType(QAPISchemaEntity): return None return self.name + def need_has_if_optional(self): + # When FOO is a pointer, has_FOO == !!FOO, i.e. has_FOO is redundant. + # Except for arrays; see QAPISchemaArrayType.need_has_if_optional(). + return not self.c_type().endswith(POINTER_SUFFIX) + def check(self, schema): QAPISchemaEntity.check(self, schema) for feat in self.features: @@ -352,6 +357,11 @@ class QAPISchemaArrayType(QAPISchemaType): self._element_type_name = element_type self.element_type = None + def need_has_if_optional(self): + # When FOO is an array, we still need has_FOO to distinguish + # absent (!has_FOO) from present and empty (has_FOO && !FOO). + return True + def check(self, schema): super().check(schema) self.element_type = schema.resolve_type( @@ -745,6 +755,44 @@ class QAPISchemaObjectTypeMember(QAPISchemaMember): self.optional = optional self.features = features or [] + def need_has(self): + assert self.type + # Temporary hack to support dropping the has_FOO in reviewable chunks + opt_out = [ + 'qapi/acpi.json', + 'qapi/audio.json', + 'qapi/block-core.json', + 'qapi/block-export.json', + 'qapi/block.json', + 'qapi/char.json', + 'qapi/crypto.json', + 'qapi/dump.json', + 'qapi/introspect.json', + 'qapi/job.json', + 'qapi/machine.json', + 'qapi/machine-target.json', + 'qapi/migration.json', + 'qapi/misc.json', + 'qapi/net.json', + 'qapi/pci.json', + 'qapi/qdev.json', + 'qapi/qom.json', + 'qapi/replay.json', + 'qapi/rocker.json', + 'qapi/run-state.json', + 'qapi/stats.json', + 'qapi/tpm.json', + 'qapi/transaction.json', + 'qapi/ui.json', + 'qapi/virtio.json', + 'qga/qapi-schema.json', + 'tests/qapi-schema/qapi-schema-test.json'] + if self.info and any(self.info.fname.endswith(mod) + for mod in opt_out): + return self.optional + # End of temporary hack + return self.optional and self.type.need_has_if_optional() + def check(self, schema): assert self.defined_in self.type = schema.resolve_type(self._type_name, self.info, diff --git a/scripts/qapi/types.py b/scripts/qapi/types.py index 477d027001..c39d054d2c 100644 --- a/scripts/qapi/types.py +++ b/scripts/qapi/types.py @@ -142,7 +142,7 @@ def gen_struct_members(members: List[QAPISchemaObjectTypeMember]) -> str: ret = '' for memb in members: ret += memb.ifcond.gen_if() - if memb.optional: + if memb.need_has(): ret += mcgen(''' bool has_%(c_name)s; ''', diff --git a/scripts/qapi/visit.py b/scripts/qapi/visit.py index 380fa197f5..26a584ee4c 100644 --- a/scripts/qapi/visit.py +++ b/scripts/qapi/visit.py @@ -71,6 +71,16 @@ bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp) ''', c_name=c_name(name)) + sep = '' + for memb in members: + if memb.optional and not memb.need_has(): + ret += mcgen(''' + bool has_%(c_name)s = !!obj->%(c_name)s; +''', + c_name=c_name(memb.name)) + sep = '\n' + ret += sep + if base: ret += mcgen(''' if (!visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, errp)) { @@ -82,10 +92,13 @@ bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp) for memb in members: ret += memb.ifcond.gen_if() if memb.optional: + has = 'has_' + c_name(memb.name) + if memb.need_has(): + has = 'obj->' + has ret += mcgen(''' - if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) { + if (visit_optional(v, "%(name)s", &%(has)s)) { ''', - name=memb.name, c_name=c_name(memb.name)) + name=memb.name, has=has) indent.increase() special_features = gen_special_features(memb.features) if special_features != '0': -- cgit 1.4.1