Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> writes:
> Add and option to generate trace events. We should generate both trace
> events and trace-events files for further trace events code generation.
Can you explain why we want trace generation to be optional?
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
> ---
> scripts/qapi/commands.py | 91 ++++++++++++++++++++++++++++++++++------
> scripts/qapi/main.py | 10 +++--
> 2 files changed, 85 insertions(+), 16 deletions(-)
>
> diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
> index 21001bbd6b..8cd1aa41ce 100644
> --- a/scripts/qapi/commands.py
> +++ b/scripts/qapi/commands.py
> @@ -53,7 +53,8 @@ def gen_command_decl(name: str,
> def gen_call(name: str,
> arg_type: Optional[QAPISchemaObjectType],
> boxed: bool,
> - ret_type: Optional[QAPISchemaType]) -> str:
> + ret_type: Optional[QAPISchemaType],
> + add_trace_events: bool) -> str:
> ret = ''
>
> argstr = ''
> @@ -71,21 +72,65 @@ def gen_call(name: str,
> if ret_type:
> lhs = 'retval = '
>
> - ret = mcgen('''
> + name = c_name(name)
> + upper = name.upper()
>
> - %(lhs)sqmp_%(c_name)s(%(args)s&err);
> - error_propagate(errp, err);
> -''',
> - c_name=c_name(name), args=argstr, lhs=lhs)
> - if ret_type:
> + if add_trace_events:
> ret += mcgen('''
> +
> + if (trace_event_get_state_backends(TRACE_QMP_ENTER_%(upper)s)) {
> + g_autoptr(GString) req_json = qobject_to_json(QOBJECT(args));
Humor me: blank line between declarations and statements, please.
> + trace_qmp_enter_%(name)s(req_json->str);
> + }
> + ''',
> + upper=upper, name=name)
> +
> + ret += mcgen('''
> +
> + %(lhs)sqmp_%(name)s(%(args)s&err);
> +''',
> + name=name, args=argstr, lhs=lhs)
pycodestyle-3 gripes:
scripts/qapi/commands.py:92:17: E128 continuation line under-indented for
visual indent
> +
> + ret += mcgen('''
> if (err) {
> +''')
> +
> + if add_trace_events:
> + ret += mcgen('''
> + trace_qmp_exit_%(name)s(error_get_pretty(err), false);
> +''',
> + name=name)
> +
> + ret += mcgen('''
> + error_propagate(errp, err);
> goto out;
> }
> +''')
> +
> + if ret_type:
> + ret += mcgen('''
>
> qmp_marshal_output_%(c_name)s(retval, ret, errp);
> ''',
> c_name=ret_type.c_name())
> +
> + if add_trace_events:
> + if ret_type:
> + ret += mcgen('''
> +
> + if (trace_event_get_state_backends(TRACE_QMP_EXIT_%(upper)s)) {
> + g_autoptr(GString) ret_json = qobject_to_json(*ret);
Humor me: blank line between declarations and statements, please.
> + trace_qmp_exit_%(name)s(ret_json->str, true);
> + }
> + ''',
> + upper=upper, name=name)
scripts/qapi/commands.py:126:22: E128 continuation line under-indented for
visual indent
> + else:
> + ret += mcgen('''
> +
> + trace_qmp_exit_%(name)s("{}", true);
> + ''',
> + name=name)
> +
> return ret
The generated code changes like this when trace generation is enabled
(next patch):
@@ -52,14 +55,25 @@ void qmp_marshal_query_acpi_ospm_status(
goto out;
}
+ if
(trace_event_get_state_backends(TRACE_QMP_ENTER_QUERY_ACPI_OSPM_STATUS)) {
+ g_autoptr(GString) req_json = qobject_to_json(QOBJECT(args));
+ trace_qmp_enter_query_acpi_ospm_status(req_json->str);
+ }
+
retval = qmp_query_acpi_ospm_status(&err);
if (err) {
+ trace_qmp_exit_query_acpi_ospm_status(error_get_pretty(err),
false);
error_propagate(errp, err);
goto out;
}
qmp_marshal_output_ACPIOSTInfoList(retval, ret, errp);
+ if
(trace_event_get_state_backends(TRACE_QMP_EXIT_QUERY_ACPI_OSPM_STATUS)) {
+ g_autoptr(GString) ret_json = qobject_to_json(*ret);
+ trace_qmp_exit_query_acpi_ospm_status(ret_json->str, true);
+ }
+
out:
visit_free(v);
v = qapi_dealloc_visitor_new();
The trace_qmp_enter_query_acpi_ospm_status() and the second
trace_qmp_exit_query_acpi_ospm_status() is guarded by
trace_event_get_state_backends(), the first is not. Intentional?
Have you considered something like
@@ -52,14 +55,25 @@ void qmp_marshal_query_acpi_ospm_status(
goto out;
}
+ if
(trace_event_get_state_backends(TRACE_QMP_ENTER_QUERY_ACPI_OSPM_STATUS)) {
+ g_autoptr(GString) req_json = qobject_to_json(QOBJECT(args));
+ trace_qmp_enter_query_acpi_ospm_status(req_json->str);
+ }
+
retval = qmp_query_acpi_ospm_status(&err);
if (err) {
error_propagate(errp, err);
goto out;
}
qmp_marshal_output_ACPIOSTInfoList(retval, ret, errp);
out:
+ if
(trace_event_get_state_backends(TRACE_QMP_EXIT_QUERY_ACPI_OSPM_STATUS)) {
+ g_autoptr(GString) result_json
+ = qobject_to_json(err ? error_get_pretty(err) : *ret);
+
+ trace_qmp_exit_query_acpi_ospm_status(ret_json->str, !err);
+ }
+
visit_free(v);
v = qapi_dealloc_visitor_new();
>
>
> @@ -122,10 +167,17 @@ def gen_marshal_decl(name: str) -> str:
> proto=build_marshal_proto(name))
>
>
> +def gen_trace(name: str) -> str:
> + name = c_name(name)
> + return f"""\
> +qmp_enter_{name}(const char *json) "%s"\n
> +qmp_exit_{name}(const char *result, bool succeeded) "%s %d"\n"""
Why not mcgen()?
The generated FOO.trace-events look like this:
$ cat bld-clang/qapi/qapi-commands-control.trace-events
qmp_enter_qmp_capabilities(const char *json) "%s"
qmp_exit_qmp_capabilities(const char *result, bool succeeded) "%s %d"
qmp_enter_query_version(const char *json) "%s"
qmp_exit_query_version(const char *result, bool succeeded) "%s %d"
qmp_enter_query_commands(const char *json) "%s"
qmp_exit_query_commands(const char *result, bool succeeded) "%s %d"
qmp_enter_quit(const char *json) "%s"
qmp_exit_quit(const char *result, bool succeeded) "%s %d"
Either drop the blank lines, or put them between the pairs instead of
within. I'd do the former.
We generate lots of empty FOO.trace-events. I guess that's okay.
> +
scripts/qapi/commands.py:176:1: E302 expected 2 blank lines, found 1
> def gen_marshal(name: str,
> arg_type: Optional[QAPISchemaObjectType],
> boxed: bool,
> - ret_type: Optional[QAPISchemaType]) -> str:
> + ret_type: Optional[QAPISchemaType],
> + add_trace_events: bool) -> str:
> have_args = boxed or (arg_type and not arg_type.is_empty())
> if have_args:
> assert arg_type is not None
> @@ -180,7 +232,7 @@ def gen_marshal(name: str,
> }
> ''')
>
> - ret += gen_call(name, arg_type, boxed, ret_type)
> + ret += gen_call(name, arg_type, boxed, ret_type, add_trace_events)
>
> ret += mcgen('''
>
> @@ -238,11 +290,12 @@ def gen_register_command(name: str,
>
>
> class QAPISchemaGenCommandVisitor(QAPISchemaModularCVisitor):
> - def __init__(self, prefix: str):
> + def __init__(self, prefix: str, add_trace_events: bool):
> super().__init__(
> prefix, 'qapi-commands',
> ' * Schema-defined QAPI/QMP commands', None, __doc__)
> self._visited_ret_types: Dict[QAPIGenC, Set[QAPISchemaType]] = {}
> + self.add_trace_events = add_trace_events
>
> def _begin_user_module(self, name: str) -> None:
> self._visited_ret_types[self._genc] = set()
> @@ -261,6 +314,15 @@ def _begin_user_module(self, name: str) -> None:
>
> ''',
> commands=commands, visit=visit))
> +
> + if self.add_trace_events and c_name(commands) != 'qapi_commands':
> + self._genc.add(mcgen('''
> +#include "trace/trace-qapi.h"
> +#include "qapi/qmp/qjson.h"
> +#include "trace/trace-%(nm)s_trace_events.h"
> +''',
> + nm=c_name(commands)))
Why c_name(commands), and not just commands?
> +
> self._genh.add(mcgen('''
> #include "%(types)s.h"
>
> @@ -322,7 +384,9 @@ def visit_command(self,
> with ifcontext(ifcond, self._genh, self._genc):
> self._genh.add(gen_command_decl(name, arg_type, boxed, ret_type))
> self._genh.add(gen_marshal_decl(name))
> - self._genc.add(gen_marshal(name, arg_type, boxed, ret_type))
> + self._genc.add(gen_marshal(name, arg_type, boxed, ret_type,
> + self.add_trace_events))
> + self._gent.add(gen_trace(name))
> with self._temp_module('./init'):
> with ifcontext(ifcond, self._genh, self._genc):
> self._genc.add(gen_register_command(
> @@ -332,7 +396,8 @@ def visit_command(self,
>
> def gen_commands(schema: QAPISchema,
> output_dir: str,
> - prefix: str) -> None:
> - vis = QAPISchemaGenCommandVisitor(prefix)
> + prefix: str,
> + add_trace_events: bool) -> None:
> + vis = QAPISchemaGenCommandVisitor(prefix, add_trace_events)
> schema.visit(vis)
> vis.write(output_dir)
> diff --git a/scripts/qapi/main.py b/scripts/qapi/main.py
> index f2ea6e0ce4..7fab71401c 100644
> --- a/scripts/qapi/main.py
> +++ b/scripts/qapi/main.py
> @@ -32,7 +32,8 @@ def generate(schema_file: str,
> output_dir: str,
> prefix: str,
> unmask: bool = False,
> - builtins: bool = False) -> None:
> + builtins: bool = False,
> + add_trace_events: bool = False) -> None:
> """
> Generate C code for the given schema into the target directory.
>
> @@ -49,7 +50,7 @@ def generate(schema_file: str,
> schema = QAPISchema(schema_file)
> gen_types(schema, output_dir, prefix, builtins)
> gen_visit(schema, output_dir, prefix, builtins)
> - gen_commands(schema, output_dir, prefix)
> + gen_commands(schema, output_dir, prefix, add_trace_events)
> gen_events(schema, output_dir, prefix)
> gen_introspect(schema, output_dir, prefix, unmask)
>
> @@ -74,6 +75,8 @@ def main() -> int:
> parser.add_argument('-u', '--unmask-non-abi-names', action='store_true',
> dest='unmask',
> help="expose non-ABI names in introspection")
> + parser.add_argument('--add-trace-events', action='store_true',
> + help="add trace events to qmp marshals")
> parser.add_argument('schema', action='store')
> args = parser.parse_args()
>
> @@ -88,7 +91,8 @@ def main() -> int:
> output_dir=args.output_dir,
> prefix=args.prefix,
> unmask=args.unmask,
> - builtins=args.builtins)
> + builtins=args.builtins,
> + add_trace_events=args.add_trace_events)
> except QAPIError as err:
> print(f"{sys.argv[0]}: {str(err)}", file=sys.stderr)
> return 1
Missing: documentation for the tracing feature in
docs/devel/qapi-code-gen.rst. We can talk about the level of detail
last.
Also missing is the example update:
diff --git a/docs/devel/qapi-code-gen.rst b/docs/devel/qapi-code-gen.rst
index a3b5473089..feafed79b5 100644
--- a/docs/devel/qapi-code-gen.rst
+++ b/docs/devel/qapi-code-gen.rst
@@ -1690,8 +1690,8 @@ Example::
}
retval = qmp_my_command(arg.arg1, &err);
- error_propagate(errp, err);
if (err) {
+ error_propagate(errp, err);
goto out;
}
