Markus Armbruster
2021-Sep-15 19:24 UTC
[Libguestfs] [PATCH RFC 0/5] Subject: [PATCH RFC 0/5] qapi: Add feature flags to enum members
PATCH 1+2 add feature flags to enum members. Awkward due to an
introspection design mistake; see PATCH 1 for details. Feedback
welcome, in particular from management application guys.
PATCH 3+4 implement policy deprecated-input={reject,crash} for enum
values.
Policy deprecated-output=hide is not implemented, because we can't
hide a value without hiding the entire member, which is almost
certainly more than the requester of this policy bargained for.
Perhaps we want a new policy deprecated-output=crash to help us catch
unwanted use of deprecated enum values. Thoughts?
PATCH 5 puts the new feature flags to use. It makes sense only on top
of Vladimir's deprecation of drive-backup. See its commit message for
a reference.
Based on my "[PATCH 00/22] qapi: Remove simple unions from the schema
language".
Based-on: Message-Id: <20210913123932.3306639-1-armbru at redhat.com>
Markus Armbruster (5):
qapi: Enable enum member introspection to show more than name
qapi: Add feature flags to enum members
qapi: Move compat policy from QObject to generic visitor
qapi: Implement deprecated-input={reject,crash} for enum values
block: Deprecate transaction type drive-backup
docs/devel/qapi-code-gen.rst | 4 ++-
qapi/compat.json | 3 +++
qapi/introspect.json | 23 ++++++++++++++--
qapi/transaction.json | 5 +++-
include/qapi/qobject-input-visitor.h | 4 ---
include/qapi/qobject-output-visitor.h | 4 ---
include/qapi/util.h | 6 ++++-
include/qapi/visitor-impl.h | 3 +++
include/qapi/visitor.h | 9 +++++++
qapi/qapi-visit-core.c | 27 ++++++++++++++++---
qapi/qmp-dispatch.c | 4 +--
qapi/qobject-input-visitor.c | 14 +---------
qapi/qobject-output-visitor.c | 14 +---------
scripts/qapi/expr.py | 3 ++-
scripts/qapi/introspect.py | 19 ++++++++++---
scripts/qapi/schema.py | 22 +++++++++++++--
scripts/qapi/types.py | 17 +++++++++++-
tests/qapi-schema/doc-good.json | 5 +++-
tests/qapi-schema/doc-good.out | 3 +++
tests/qapi-schema/doc-good.txt | 3 +++
.../qapi-schema/enum-dict-member-unknown.err | 2 +-
tests/qapi-schema/qapi-schema-test.json | 3 ++-
tests/qapi-schema/qapi-schema-test.out | 1 +
tests/qapi-schema/test-qapi.py | 1 +
24 files changed, 144 insertions(+), 55 deletions(-)
--
2.31.1
Markus Armbruster
2021-Sep-15 19:24 UTC
[Libguestfs] [PATCH RFC 1/5] qapi: Enable enum member introspection to show more than name
The next commit will add feature flags to enum members. There's a
problem, though: query-qmp-schema shows an enum type's members as an
array of member names (SchemaInfoEnum member @values). If it showed
an array of objects with a name member, we could simply add more
members to these objects. Since it's just strings, we can't.
I can see three ways to correct this design mistake:
1. Do it the way we should have done it, plus compatibility goo.
We want a ['SchemaInfoEnumMember'] member in SchemaInfoEnum. Since
changing @values would be a compatibility break, add a new member
@members instead.
@values is now redundant. We should be able to get rid of it
eventually.
In my testing, output of qemu-system-x86_64's query-qmp-schema
grows by 11% (18.5KiB).
2. Like 1, but omit "boring" elements of @member, and empty @member.
@values does not become redundant. Output of query-qmp-schema
grows only as we make enum members non-boring.
3. Versioned query-qmp-schema.
query-qmp-schema provides either @values or @members. The QMP
client can select which version it wants.
This commit implements 1. simply because it's the solution I thought
of first. I'm prepared to implement one of the others if we decide
that's what we want.
Signed-off-by: Markus Armbruster <armbru at redhat.com>
---
qapi/introspect.json | 20 ++++++++++++++++++--
scripts/qapi/introspect.py | 18 ++++++++++++++----
2 files changed, 32 insertions(+), 6 deletions(-)
diff --git a/qapi/introspect.json b/qapi/introspect.json
index 39bd303778..250748cd95 100644
--- a/qapi/introspect.json
+++ b/qapi/introspect.json
@@ -142,14 +142,30 @@
#
# Additional SchemaInfo members for meta-type 'enum'.
#
-# @values: the enumeration type's values, in no particular order.
+# @members: the enum type's members, in no particular order.
+#
+# @values: the enumeration type's member names, in no particular order.
+# Redundant with @members. Just for backward compatibility.
#
# Values of this type are JSON string on the wire.
#
# Since: 2.5
##
{ 'struct': 'SchemaInfoEnum',
- 'data': { 'values': ['str'] } }
+ 'data': { 'members': [ 'SchemaInfoEnumMember' ],
+ 'values': ['str'] } }
+
+##
+# @SchemaInfoEnumMember:
+#
+# An object member.
+#
+# @name: the member's name, as defined in the QAPI schema.
+#
+# Since: 6.1
+##
+{ 'struct': 'SchemaInfoEnumMember',
+ 'data': { 'name': 'str' } }
##
# @SchemaInfoArray:
diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py
index 4c079ee627..6334546363 100644
--- a/scripts/qapi/introspect.py
+++ b/scripts/qapi/introspect.py
@@ -68,6 +68,7 @@
# TypedDict constructs, so they are broadly typed here as simple
# Python Dicts.
SchemaInfo = Dict[str, object]
+SchemaInfoEnumMember = Dict[str, object]
SchemaInfoObject = Dict[str, object]
SchemaInfoObjectVariant = Dict[str, object]
SchemaInfoObjectMember = Dict[str, object]
@@ -274,8 +275,16 @@ def _gen_tree(self, name: str, mtype: str, obj: Dict[str,
object],
obj['features'] = self._gen_features(features)
self._trees.append(Annotated(obj, ifcond, comment))
- def _gen_member(self, member: QAPISchemaObjectTypeMember
- ) -> Annotated[SchemaInfoObjectMember]:
+ @staticmethod
+ def _gen_enum_member(member: QAPISchemaEnumMember
+ ) -> Annotated[SchemaInfoEnumMember]:
+ obj: SchemaInfoEnumMember = {
+ 'name': member.name,
+ }
+ return Annotated(obj, member.ifcond)
+
+ def _gen_object_member(self, member: QAPISchemaObjectTypeMember
+ ) -> Annotated[SchemaInfoObjectMember]:
obj: SchemaInfoObjectMember = {
'name': member.name,
'type': self._use_type(member.type)
@@ -305,7 +314,8 @@ def visit_enum_type(self, name: str, info:
Optional[QAPISourceInfo],
prefix: Optional[str]) -> None:
self._gen_tree(
name, 'enum',
- {'values': [Annotated(m.name, m.ifcond) for m in members]},
+ {'members': [self._gen_enum_member(m) for m in members],
+ 'values': [Annotated(m.name, m.ifcond) for m in members]},
ifcond, features
)
@@ -322,7 +332,7 @@ def visit_object_type_flat(self, name: str, info:
Optional[QAPISourceInfo],
members: List[QAPISchemaObjectTypeMember],
variants: Optional[QAPISchemaVariants]) ->
None:
obj: SchemaInfoObject = {
- 'members': [self._gen_member(m) for m in members]
+ 'members': [self._gen_object_member(m) for m in members]
}
if variants:
obj['tag'] = variants.tag_member.name
--
2.31.1
Markus Armbruster
2021-Sep-15 19:24 UTC
[Libguestfs] [PATCH RFC 2/5] qapi: Add feature flags to enum members
This is quite similar to commit 84ab008687 "qapi: Add feature flags to
struct members", only for enums instead of structs.
Signed-off-by: Markus Armbruster <armbru at redhat.com>
---
docs/devel/qapi-code-gen.rst | 4 +++-
qapi/compat.json | 2 ++
qapi/introspect.json | 5 ++++-
scripts/qapi/expr.py | 3 ++-
scripts/qapi/introspect.py | 5 +++--
scripts/qapi/schema.py | 22 +++++++++++++++++--
tests/qapi-schema/doc-good.json | 5 ++++-
tests/qapi-schema/doc-good.out | 3 +++
tests/qapi-schema/doc-good.txt | 3 +++
.../qapi-schema/enum-dict-member-unknown.err | 2 +-
tests/qapi-schema/qapi-schema-test.json | 3 ++-
tests/qapi-schema/qapi-schema-test.out | 1 +
tests/qapi-schema/test-qapi.py | 1 +
13 files changed, 49 insertions(+), 10 deletions(-)
diff --git a/docs/devel/qapi-code-gen.rst b/docs/devel/qapi-code-gen.rst
index b2569de486..00334e9fb8 100644
--- a/docs/devel/qapi-code-gen.rst
+++ b/docs/devel/qapi-code-gen.rst
@@ -200,7 +200,9 @@ Syntax::
'*if': COND,
'*features': FEATURES }
ENUM-VALUE = STRING
- | { 'name': STRING, '*if': COND }
+ | { 'name': STRING,
+ '*if': COND,
+ '*features': FEATURES }
Member 'enum' names the enum type.
diff --git a/qapi/compat.json b/qapi/compat.json
index ae3afc22df..1d2b76f00c 100644
--- a/qapi/compat.json
+++ b/qapi/compat.json
@@ -42,6 +42,8 @@
# with feature 'deprecated'. We may want to extend it to cover
# semantic aspects, CLI, and experimental features.
#
+# Limitation: not implemented for deprecated enumeration values.
+#
# @deprecated-input: how to handle deprecated input (default 'accept')
# @deprecated-output: how to handle deprecated output (default
'accept')
#
diff --git a/qapi/introspect.json b/qapi/introspect.json
index 250748cd95..e1219914c9 100644
--- a/qapi/introspect.json
+++ b/qapi/introspect.json
@@ -162,10 +162,13 @@
#
# @name: the member's name, as defined in the QAPI schema.
#
+# @features: names of features associated with the member, in no
+# particular order.
+#
# Since: 6.1
##
{ 'struct': 'SchemaInfoEnumMember',
- 'data': { 'name': 'str' } }
+ 'data': { 'name': 'str', '*features': [
'str' ] } }
##
# @SchemaInfoArray:
diff --git a/scripts/qapi/expr.py b/scripts/qapi/expr.py
index 819ea6ad97..3cb389e875 100644
--- a/scripts/qapi/expr.py
+++ b/scripts/qapi/expr.py
@@ -472,7 +472,7 @@ def check_enum(expr: _JSONObject, info: QAPISourceInfo)
-> None:
for m in members]
for member in members:
source = "'data' member"
- check_keys(member, info, source, ['name'], ['if'])
+ check_keys(member, info, source, ['name'], ['if',
'features'])
member_name = member['name']
check_name_is_str(member_name, info, source)
source = "%s '%s'" % (source, member_name)
@@ -483,6 +483,7 @@ def check_enum(expr: _JSONObject, info: QAPISourceInfo)
-> None:
permit_upper=permissive,
permit_underscore=permissive)
check_if(member, info, source)
+ check_features(member.get('features'), info)
def check_struct(expr: _JSONObject, info: QAPISourceInfo) -> None:
diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py
index 6334546363..67c7d89aae 100644
--- a/scripts/qapi/introspect.py
+++ b/scripts/qapi/introspect.py
@@ -275,12 +275,13 @@ def _gen_tree(self, name: str, mtype: str, obj: Dict[str,
object],
obj['features'] = self._gen_features(features)
self._trees.append(Annotated(obj, ifcond, comment))
- @staticmethod
- def _gen_enum_member(member: QAPISchemaEnumMember
+ def _gen_enum_member(self, member: QAPISchemaEnumMember
) -> Annotated[SchemaInfoEnumMember]:
obj: SchemaInfoEnumMember = {
'name': member.name,
}
+ if member.features:
+ obj['features'] = self._gen_features(member.features)
return Annotated(obj, member.ifcond)
def _gen_object_member(self, member: QAPISchemaObjectTypeMember
diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
index 004d7095ff..6d5f46509a 100644
--- a/scripts/qapi/schema.py
+++ b/scripts/qapi/schema.py
@@ -708,6 +708,19 @@ def describe(self, info):
class QAPISchemaEnumMember(QAPISchemaMember):
role = 'value'
+ def __init__(self, name, info, ifcond=None, features=None):
+ super().__init__(name, info, ifcond)
+ for f in features or []:
+ assert isinstance(f, QAPISchemaFeature)
+ f.set_defined_in(name)
+ self.features = features or []
+
+ def connect_doc(self, doc):
+ super().connect_doc(doc)
+ if doc:
+ for f in self.features:
+ doc.connect_feature(f)
+
class QAPISchemaFeature(QAPISchemaMember):
role = 'feature'
@@ -980,9 +993,14 @@ def _make_features(self, features, info):
QAPISchemaIfCond(f.get('if')))
for f in features]
+ def _make_enum_member(self, name, ifcond, features, info):
+ return QAPISchemaEnumMember(name, info,
+ QAPISchemaIfCond(ifcond),
+ self._make_features(features, info))
+
def _make_enum_members(self, values, info):
- return [QAPISchemaEnumMember(v['name'], info,
- QAPISchemaIfCond(v.get('if')))
+ return [self._make_enum_member(v['name'], v.get('if'),
+ v.get('features'), info)
for v in values]
def _make_array_type(self, element_type, info):
diff --git a/tests/qapi-schema/doc-good.json b/tests/qapi-schema/doc-good.json
index a20acffd8b..ce05bc3eac 100644
--- a/tests/qapi-schema/doc-good.json
+++ b/tests/qapi-schema/doc-good.json
@@ -57,11 +57,14 @@
#
# Features:
# @enum-feat: Also _one_ {and only}
+# @enum-member-feat: a member feature
#
# @two is undocumented
##
{ 'enum': 'Enum',
- 'data': [ { 'name': 'one', 'if':
'IFONE' }, 'two' ],
+ 'data': [ { 'name': 'one', 'if':
'IFONE',
+ 'features': [ 'enum-member-feat' ] },
+ 'two' ],
'features': [ 'enum-feat' ],
'if': 'IFCOND' }
diff --git a/tests/qapi-schema/doc-good.out b/tests/qapi-schema/doc-good.out
index 5a324e2627..9dd65b9d92 100644
--- a/tests/qapi-schema/doc-good.out
+++ b/tests/qapi-schema/doc-good.out
@@ -13,6 +13,7 @@ module doc-good.json
enum Enum
member one
if IFONE
+ feature enum-member-feat
member two
if IFCOND
feature enum-feat
@@ -108,6 +109,8 @@ The _one_ {and only}
feature=enum-feat
Also _one_ {and only}
+ feature=enum-member-feat
+a member feature
section=None
@two is undocumented
doc symbol=Base
diff --git a/tests/qapi-schema/doc-good.txt b/tests/qapi-schema/doc-good.txt
index 701402ee5e..b3b76bd43f 100644
--- a/tests/qapi-schema/doc-good.txt
+++ b/tests/qapi-schema/doc-good.txt
@@ -56,6 +56,9 @@ Features
"enum-feat"
Also _one_ {and only}
+"enum-member-feat"
+ a member feature
+
"two" is undocumented
diff --git a/tests/qapi-schema/enum-dict-member-unknown.err
b/tests/qapi-schema/enum-dict-member-unknown.err
index f8617ea179..235cde0c49 100644
--- a/tests/qapi-schema/enum-dict-member-unknown.err
+++ b/tests/qapi-schema/enum-dict-member-unknown.err
@@ -1,3 +1,3 @@
enum-dict-member-unknown.json: In enum 'MyEnum':
enum-dict-member-unknown.json:2: 'data' member has unknown key
'bad-key'
-Valid keys are 'if', 'name'.
+Valid keys are 'features', 'if', 'name'.
diff --git a/tests/qapi-schema/qapi-schema-test.json
b/tests/qapi-schema/qapi-schema-test.json
index b10490ccc6..c30b9ab94c 100644
--- a/tests/qapi-schema/qapi-schema-test.json
+++ b/tests/qapi-schema/qapi-schema-test.json
@@ -301,7 +301,8 @@
'TEST_IF_COND_2'] } } ] }
{ 'enum': 'FeatureEnum1',
- 'data': [ 'eins', 'zwei', 'drei' ],
+ 'data': [ 'eins', 'zwei',
+ { 'name': 'drei', 'features': [
'deprecated' ] } ],
'features': [ 'feature1' ] }
{ 'union': 'FeatureUnion1',
diff --git a/tests/qapi-schema/qapi-schema-test.out
b/tests/qapi-schema/qapi-schema-test.out
index 0b49dc3044..6de54507e8 100644
--- a/tests/qapi-schema/qapi-schema-test.out
+++ b/tests/qapi-schema/qapi-schema-test.out
@@ -341,6 +341,7 @@ enum FeatureEnum1
member eins
member zwei
member drei
+ feature deprecated
feature feature1
object q_obj_FeatureUnion1-base
member tag: FeatureEnum1 optional=False
diff --git a/tests/qapi-schema/test-qapi.py b/tests/qapi-schema/test-qapi.py
index 73cffae2b6..46b41baa3c 100755
--- a/tests/qapi-schema/test-qapi.py
+++ b/tests/qapi-schema/test-qapi.py
@@ -37,6 +37,7 @@ def visit_enum_type(self, name, info, ifcond, features,
members, prefix):
for m in members:
print(' member %s' % m.name)
self._print_if(m.ifcond, indent=8)
+ self._print_features(m.features, indent=8)
self._print_if(ifcond)
self._print_features(features)
--
2.31.1
Markus Armbruster
2021-Sep-15 19:24 UTC
[Libguestfs] [PATCH RFC 3/5] qapi: Move compat policy from QObject to generic visitor
The next commit needs to access compat policy from the generic visitor
core. Move it there from qobject input and output visitor.
Signed-off-by: Markus Armbruster <armbru at redhat.com>
---
include/qapi/qobject-input-visitor.h | 4 ----
include/qapi/qobject-output-visitor.h | 4 ----
include/qapi/visitor-impl.h | 3 +++
include/qapi/visitor.h | 9 +++++++++
qapi/qapi-visit-core.c | 9 +++++++++
qapi/qmp-dispatch.c | 4 ++--
qapi/qobject-input-visitor.c | 14 +-------------
qapi/qobject-output-visitor.c | 14 +-------------
8 files changed, 25 insertions(+), 36 deletions(-)
diff --git a/include/qapi/qobject-input-visitor.h
b/include/qapi/qobject-input-visitor.h
index 8d69388810..95985e25e5 100644
--- a/include/qapi/qobject-input-visitor.h
+++ b/include/qapi/qobject-input-visitor.h
@@ -15,7 +15,6 @@
#ifndef QOBJECT_INPUT_VISITOR_H
#define QOBJECT_INPUT_VISITOR_H
-#include "qapi/qapi-types-compat.h"
#include "qapi/visitor.h"
typedef struct QObjectInputVisitor QObjectInputVisitor;
@@ -59,9 +58,6 @@ typedef struct QObjectInputVisitor QObjectInputVisitor;
*/
Visitor *qobject_input_visitor_new(QObject *obj);
-void qobject_input_visitor_set_policy(Visitor *v,
- CompatPolicyInput deprecated);
-
/*
* Create a QObject input visitor for @obj for use with keyval_parse()
*
diff --git a/include/qapi/qobject-output-visitor.h
b/include/qapi/qobject-output-visitor.h
index f2a2f92a00..2b1726baf5 100644
--- a/include/qapi/qobject-output-visitor.h
+++ b/include/qapi/qobject-output-visitor.h
@@ -15,7 +15,6 @@
#define QOBJECT_OUTPUT_VISITOR_H
#include "qapi/visitor.h"
-#include "qapi/qapi-types-compat.h"
typedef struct QObjectOutputVisitor QObjectOutputVisitor;
@@ -54,7 +53,4 @@ typedef struct QObjectOutputVisitor QObjectOutputVisitor;
*/
Visitor *qobject_output_visitor_new(QObject **result);
-void qobject_output_visitor_set_policy(Visitor *v,
- CompatPolicyOutput deprecated);
-
#endif
diff --git a/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h
index 3b950f6e3d..72b6537bef 100644
--- a/include/qapi/visitor-impl.h
+++ b/include/qapi/visitor-impl.h
@@ -122,6 +122,9 @@ struct Visitor
/* Must be set */
VisitorType type;
+ /* Optional */
+ struct CompatPolicy compat_policy;
+
/* Must be set for output visitors, optional otherwise. */
void (*complete)(Visitor *v, void *opaque);
diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h
index b3c9ef7a81..dcb96018a9 100644
--- a/include/qapi/visitor.h
+++ b/include/qapi/visitor.h
@@ -16,6 +16,7 @@
#define QAPI_VISITOR_H
#include "qapi/qapi-builtin-types.h"
+#include "qapi/qapi-types-compat.h"
/*
* The QAPI schema defines both a set of C data types, and a QMP wire
@@ -477,6 +478,14 @@ bool visit_deprecated_accept(Visitor *v, const char *name,
Error **errp);
*/
bool visit_deprecated(Visitor *v, const char *name);
+/*
+ * Set policy for handling deprecated management interfaces.
+ *
+ * Intended use: call visit_set_policy(v, &compat_policy) when
+ * visiting management interface input or output.
+ */
+void visit_set_policy(Visitor *v, CompatPolicy *policy);
+
/*
* Visit an enum value.
*
diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index a641adec51..066f77a26d 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -19,6 +19,10 @@
#include "qapi/visitor-impl.h"
#include "trace.h"
+/* Zero-initialization must result in default policy */
+QEMU_BUILD_BUG_ON(COMPAT_POLICY_INPUT_ACCEPT || COMPAT_POLICY_OUTPUT_ACCEPT);
+
+
void visit_complete(Visitor *v, void *opaque)
{
assert(v->type != VISITOR_OUTPUT || v->complete);
@@ -153,6 +157,11 @@ bool visit_deprecated(Visitor *v, const char *name)
return true;
}
+void visit_set_policy(Visitor *v, CompatPolicy *policy)
+{
+ v->compat_policy = *policy;
+}
+
bool visit_is_input(Visitor *v)
{
return v->type == VISITOR_INPUT;
diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c
index 59600210ce..7e943a0af5 100644
--- a/qapi/qmp-dispatch.c
+++ b/qapi/qmp-dispatch.c
@@ -32,7 +32,7 @@ Visitor *qobject_input_visitor_new_qmp(QObject *obj)
{
Visitor *v = qobject_input_visitor_new(obj);
- qobject_input_visitor_set_policy(v, compat_policy.deprecated_input);
+ visit_set_policy(v, &compat_policy);
return v;
}
@@ -40,7 +40,7 @@ Visitor *qobject_output_visitor_new_qmp(QObject **result)
{
Visitor *v = qobject_output_visitor_new(result);
- qobject_output_visitor_set_policy(v, compat_policy.deprecated_output);
+ visit_set_policy(v, &compat_policy);
return v;
}
diff --git a/qapi/qobject-input-visitor.c b/qapi/qobject-input-visitor.c
index 04b790412e..71b24a4429 100644
--- a/qapi/qobject-input-visitor.c
+++ b/qapi/qobject-input-visitor.c
@@ -14,7 +14,6 @@
#include "qemu/osdep.h"
#include <math.h>
-#include "qapi/compat-policy.h"
#include "qapi/error.h"
#include "qapi/qobject-input-visitor.h"
#include "qapi/visitor-impl.h"
@@ -44,7 +43,6 @@ typedef struct StackObject {
struct QObjectInputVisitor {
Visitor visitor;
- CompatPolicyInput deprecated_policy;
/* Root of visit at visitor creation. */
QObject *root;
@@ -667,9 +665,7 @@ static void qobject_input_optional(Visitor *v, const char
*name, bool *present)
static bool qobject_input_deprecated_accept(Visitor *v, const char *name,
Error **errp)
{
- QObjectInputVisitor *qiv = to_qiv(v);
-
- switch (qiv->deprecated_policy) {
+ switch (v->compat_policy.deprecated_input) {
case COMPAT_POLICY_INPUT_ACCEPT:
return true;
case COMPAT_POLICY_INPUT_REJECT:
@@ -739,14 +735,6 @@ Visitor *qobject_input_visitor_new(QObject *obj)
return &v->visitor;
}
-void qobject_input_visitor_set_policy(Visitor *v,
- CompatPolicyInput deprecated)
-{
- QObjectInputVisitor *qiv = to_qiv(v);
-
- qiv->deprecated_policy = deprecated;
-}
-
Visitor *qobject_input_visitor_new_keyval(QObject *obj)
{
QObjectInputVisitor *v = qobject_input_visitor_base_new(obj);
diff --git a/qapi/qobject-output-visitor.c b/qapi/qobject-output-visitor.c
index e4873308d4..9b7f510036 100644
--- a/qapi/qobject-output-visitor.c
+++ b/qapi/qobject-output-visitor.c
@@ -13,7 +13,6 @@
*/
#include "qemu/osdep.h"
-#include "qapi/compat-policy.h"
#include "qapi/qobject-output-visitor.h"
#include "qapi/visitor-impl.h"
#include "qemu/queue.h"
@@ -32,7 +31,6 @@ typedef struct QStackEntry {
struct QObjectOutputVisitor {
Visitor visitor;
- CompatPolicyOutput deprecated_policy;
QSLIST_HEAD(, QStackEntry) stack; /* Stack of unfinished containers */
QObject *root; /* Root of the output visit */
@@ -212,9 +210,7 @@ static bool qobject_output_type_null(Visitor *v, const char
*name,
static bool qobject_output_deprecated(Visitor *v, const char *name)
{
- QObjectOutputVisitor *qov = to_qov(v);
-
- return qov->deprecated_policy != COMPAT_POLICY_OUTPUT_HIDE;
+ return v->compat_policy.deprecated_output != COMPAT_POLICY_OUTPUT_HIDE;
}
/* Finish building, and return the root object.
@@ -275,11 +271,3 @@ Visitor *qobject_output_visitor_new(QObject **result)
return &v->visitor;
}
-
-void qobject_output_visitor_set_policy(Visitor *v,
- CompatPolicyOutput deprecated)
-{
- QObjectOutputVisitor *qov = to_qov(v);
-
- qov->deprecated_policy = deprecated;
-}
--
2.31.1
Markus Armbruster
2021-Sep-15 19:24 UTC
[Libguestfs] [PATCH RFC 4/5] qapi: Implement deprecated-input={reject, crash} for enum values
This copies the code implementing the policy from qapi/qmp-dispatch.c
to qapi/qobject-input-visitor.c. I hope to avoid that in a future
revision.
Signed-off-by: Markus Armbruster <armbru at redhat.com>
---
qapi/compat.json | 3 ++-
include/qapi/util.h | 6 +++++-
qapi/qapi-visit-core.c | 18 +++++++++++++++---
scripts/qapi/types.py | 17 ++++++++++++++++-
4 files changed, 38 insertions(+), 6 deletions(-)
diff --git a/qapi/compat.json b/qapi/compat.json
index 1d2b76f00c..74a8493d3d 100644
--- a/qapi/compat.json
+++ b/qapi/compat.json
@@ -42,7 +42,8 @@
# with feature 'deprecated'. We may want to extend it to cover
# semantic aspects, CLI, and experimental features.
#
-# Limitation: not implemented for deprecated enumeration values.
+# Limitation: deprecated-output policy @hide is not implemented for
+# enumeration values. They behave the same as with policy @accept.
#
# @deprecated-input: how to handle deprecated input (default 'accept')
# @deprecated-output: how to handle deprecated output (default
'accept')
diff --git a/include/qapi/util.h b/include/qapi/util.h
index d7bfb30e25..257c600f99 100644
--- a/include/qapi/util.h
+++ b/include/qapi/util.h
@@ -11,9 +11,13 @@
#ifndef QAPI_UTIL_H
#define QAPI_UTIL_H
+/* QEnumLookup flags */
+#define QAPI_ENUM_DEPRECATED 1
+
typedef struct QEnumLookup {
const char *const *array;
- int size;
+ const unsigned char *const flags;
+ const int size;
} QEnumLookup;
const char *qapi_enum_lookup(const QEnumLookup *lookup, int val);
diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index 066f77a26d..49136ae88e 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -393,7 +393,7 @@ static bool input_type_enum(Visitor *v, const char *name,
int *obj,
const QEnumLookup *lookup, Error **errp)
{
int64_t value;
- char *enum_str;
+ g_autofree char *enum_str = NULL;
if (!visit_type_str(v, name, &enum_str, errp)) {
return false;
@@ -402,11 +402,23 @@ static bool input_type_enum(Visitor *v, const char *name,
int *obj,
value = qapi_enum_parse(lookup, enum_str, -1, NULL);
if (value < 0) {
error_setg(errp, QERR_INVALID_PARAMETER, enum_str);
- g_free(enum_str);
return false;
}
- g_free(enum_str);
+ if (lookup->flags && (lookup->flags[value] &
QAPI_ENUM_DEPRECATED)) {
+ switch (v->compat_policy.deprecated_input) {
+ case COMPAT_POLICY_INPUT_ACCEPT:
+ break;
+ case COMPAT_POLICY_INPUT_REJECT:
+ error_setg(errp, "Deprecated value '%s' disabled by
policy",
+ enum_str);
+ return false;
+ case COMPAT_POLICY_INPUT_CRASH:
+ default:
+ abort();
+ }
+ }
+
*obj = value;
return true;
}
diff --git a/scripts/qapi/types.py b/scripts/qapi/types.py
index 831294fe42..ab2441adc9 100644
--- a/scripts/qapi/types.py
+++ b/scripts/qapi/types.py
@@ -38,6 +38,8 @@
def gen_enum_lookup(name: str,
members: List[QAPISchemaEnumMember],
prefix: Optional[str] = None) -> str:
+ max_index = c_enum_const(name, '_MAX', prefix)
+ flags = ''
ret = mcgen('''
const QEnumLookup %(c_name)s_lookup = {
@@ -52,13 +54,26 @@ def gen_enum_lookup(name: str,
''',
index=index, name=memb.name)
ret += memb.ifcond.gen_endif()
+ if 'deprecated' in (f.name for f in memb.features):
+ flags += mcgen('''
+ [%(index)s] = QAPI_ENUM_DEPRECATED,
+''',
+ index=index)
+
+ if flags:
+ ret += mcgen('''
+ },
+ .flags = (const unsigned char[%(max_index)s]) {
+''',
+ max_index=max_index)
+ ret += flags
ret += mcgen('''
},
.size = %(max_index)s
};
''',
- max_index=c_enum_const(name, '_MAX', prefix))
+ max_index=max_index)
return ret
--
2.31.1
Markus Armbruster
2021-Sep-15 19:24 UTC
[Libguestfs] [PATCH RFC 5/5] block: Deprecate transaction type drive-backup
Several moons ago, Vladimir posted
Subject: [PATCH v2 3/3] qapi: deprecate drive-backup
Date: Wed, 5 May 2021 16:58:03 +0300
Message-Id: <20210505135803.67896-4-vsementsov at virtuozzo.com>
https://lists.gnu.org/archive/html/qemu-devel/2021-05/msg01394.html
with this
TODO: We also need to deprecate drive-backup transaction action..
But union members in QAPI doesn't support 'deprecated' feature.
I tried
to dig a bit, but failed :/ Markus, could you please help with it? At
least by advice?
This is one way to resolve it. Sorry it took so long.
John explored another way, namely adding feature flags to union
branches. Could also be useful, say to add different features to
branches in multiple unions sharing the same tag enum.
Signed-off-by: Markus Armbruster <armbru at redhat.com>
---
qapi/transaction.json | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/qapi/transaction.json b/qapi/transaction.json
index d7fc73d7df..0be6f83f6d 100644
--- a/qapi/transaction.json
+++ b/qapi/transaction.json
@@ -41,6 +41,9 @@
##
# @TransactionActionKind:
#
+# Features:
+# @deprecated: Member @drive-backup is deprecated. Use FIXME instead.
+#
# Since: 6.1
##
{ 'enum': 'TransactionActionKind',
@@ -49,7 +52,7 @@
'block-dirty-bitmap-disable',
'block-dirty-bitmap-merge',
'blockdev-backup', 'blockdev-snapshot',
'blockdev-snapshot-internal-sync',
'blockdev-snapshot-sync',
- 'drive-backup' ] }
+ { 'name': 'drive-backup', 'features': [
'deprecated' ] } ] }
##
# @AbortWrapper:
--
2.31.1
Vladimir Sementsov-Ogievskiy
2021-Sep-16 07:18 UTC
[Libguestfs] [PATCH RFC 0/5] Subject: [PATCH RFC 0/5] qapi: Add feature flags to enum members
Great! Thanks for working on this! 15.09.2021 22:24, Markus Armbruster wrote:> PATCH 1+2 add feature flags to enum members. Awkward due to an > introspection design mistake; see PATCH 1 for details. Feedback > welcome, in particular from management application guys. > > PATCH 3+4 implement policy deprecated-input={reject,crash} for enum > values. > > Policy deprecated-output=hide is not implemented, because we can't > hide a value without hiding the entire member, which is almost > certainly more than the requester of this policy bargained for. > Perhaps we want a new policy deprecated-output=crash to help us catch > unwanted use of deprecated enum values. Thoughts?I think crash policy for output is doubtful. If we have query-* command that returns a lot of things and some of them are deprecated the whole command will always crash.. Deprecated is "use" of the deprecated field, but we can't control does user use a specific field or not. If some deprecated output is a consequence of deprecated input, we'd better always show it.. Or in other words, we shouldn't deprecate such output, deprecating of the corresponding input is enough. So, we are saying about showing some internal state to the user. And part of this state becomes deprecated because internal implementation changed. I think the only correct thing to do is handle deprecated=hide by hand, in the place where we set this deprecated field. Only at this place we can decide, should we simulate old deprecated output value or not. For this we'll need a possibility to get current policy at any place, but that doesn't seem to be a problem, I see, it's just a global variable compat_policy.> > PATCH 5 puts the new feature flags to use. It makes sense only on top > of Vladimir's deprecation of drive-backup. See its commit message for > a reference. > > Based on my "[PATCH 00/22] qapi: Remove simple unions from the schema > language". > > Based-on: Message-Id: <20210913123932.3306639-1-armbru at redhat.com> > > Markus Armbruster (5): > qapi: Enable enum member introspection to show more than name > qapi: Add feature flags to enum members > qapi: Move compat policy from QObject to generic visitor > qapi: Implement deprecated-input={reject,crash} for enum values > block: Deprecate transaction type drive-backup > > docs/devel/qapi-code-gen.rst | 4 ++- > qapi/compat.json | 3 +++ > qapi/introspect.json | 23 ++++++++++++++-- > qapi/transaction.json | 5 +++- > include/qapi/qobject-input-visitor.h | 4 --- > include/qapi/qobject-output-visitor.h | 4 --- > include/qapi/util.h | 6 ++++- > include/qapi/visitor-impl.h | 3 +++ > include/qapi/visitor.h | 9 +++++++ > qapi/qapi-visit-core.c | 27 ++++++++++++++++--- > qapi/qmp-dispatch.c | 4 +-- > qapi/qobject-input-visitor.c | 14 +--------- > qapi/qobject-output-visitor.c | 14 +--------- > scripts/qapi/expr.py | 3 ++- > scripts/qapi/introspect.py | 19 ++++++++++--- > scripts/qapi/schema.py | 22 +++++++++++++-- > scripts/qapi/types.py | 17 +++++++++++- > tests/qapi-schema/doc-good.json | 5 +++- > tests/qapi-schema/doc-good.out | 3 +++ > tests/qapi-schema/doc-good.txt | 3 +++ > .../qapi-schema/enum-dict-member-unknown.err | 2 +- > tests/qapi-schema/qapi-schema-test.json | 3 ++- > tests/qapi-schema/qapi-schema-test.out | 1 + > tests/qapi-schema/test-qapi.py | 1 + > 24 files changed, 144 insertions(+), 55 deletions(-) >-- Best regards, Vladimir