[PATCH 7/9] qapi: Generalize enum member policy checking

Markus Armbruster posted 9 patches 4 years, 3 months ago
There is a newer version of this series
[PATCH 7/9] qapi: Generalize enum member policy checking
Posted by Markus Armbruster 4 years, 3 months ago
The code to check enumeration value policy can see special feature
flag 'deprecated' in QEnumLookup member flags[value].  I want to make
feature flag 'unstable' visible there as well, so I can add policy for
it.

Instead of extending flags[], replace it by @special_features (a
bitset of QapiSpecialFeature), because that's how special features get
passed around elsewhere.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 include/qapi/util.h    |  5 +----
 qapi/qapi-visit-core.c |  3 ++-
 scripts/qapi/types.py  | 22 ++++++++++++----------
 3 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/include/qapi/util.h b/include/qapi/util.h
index 7a8d5c7d72..0cc98db9f9 100644
--- a/include/qapi/util.h
+++ b/include/qapi/util.h
@@ -15,12 +15,9 @@ typedef enum {
     QAPI_DEPRECATED,
 } QapiSpecialFeature;
 
-/* QEnumLookup flags */
-#define QAPI_ENUM_DEPRECATED 1
-
 typedef struct QEnumLookup {
     const char *const *array;
-    const unsigned char *const flags;
+    const unsigned char *const special_features;
     const int size;
 } QEnumLookup;
 
diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index b4a81f1757..5572d90efb 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -407,7 +407,8 @@ static bool input_type_enum(Visitor *v, const char *name, int *obj,
         return false;
     }
 
-    if (lookup->flags && (lookup->flags[value] & QAPI_ENUM_DEPRECATED)) {
+    if (lookup->special_features
+        && (lookup->special_features[value] & QAPI_DEPRECATED)) {
         switch (v->compat_policy.deprecated_input) {
         case COMPAT_POLICY_INPUT_ACCEPT:
             break;
diff --git a/scripts/qapi/types.py b/scripts/qapi/types.py
index ab2441adc9..3013329c24 100644
--- a/scripts/qapi/types.py
+++ b/scripts/qapi/types.py
@@ -16,7 +16,7 @@
 from typing import List, Optional
 
 from .common import c_enum_const, c_name, mcgen
-from .gen import QAPISchemaModularCVisitor, ifcontext
+from .gen import QAPISchemaModularCVisitor, gen_special_features, ifcontext
 from .schema import (
     QAPISchema,
     QAPISchemaEnumMember,
@@ -39,7 +39,7 @@ def gen_enum_lookup(name: str,
                     members: List[QAPISchemaEnumMember],
                     prefix: Optional[str] = None) -> str:
     max_index = c_enum_const(name, '_MAX', prefix)
-    flags = ''
+    feats = ''
     ret = mcgen('''
 
 const QEnumLookup %(c_name)s_lookup = {
@@ -54,19 +54,21 @@ 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:
+        special_features = gen_special_features(memb.features)
+        if special_features != '0':
+            feats += mcgen('''
+        [%(index)s] = %(special_features)s,
+''',
+                           index=index, special_features=special_features)
+
+    if feats:
         ret += mcgen('''
     },
-    .flags = (const unsigned char[%(max_index)s]) {
+    .special_features = (const unsigned char[%(max_index)s]) {
 ''',
                      max_index=max_index)
-        ret += flags
+        ret += feats
 
     ret += mcgen('''
     },
-- 
2.31.1

Re: [PATCH 7/9] qapi: Generalize enum member policy checking
Posted by John Snow 4 years, 3 months ago
On Mon, Oct 25, 2021 at 1:26 AM Markus Armbruster <armbru@redhat.com> wrote:

> The code to check enumeration value policy can see special feature
> flag 'deprecated' in QEnumLookup member flags[value].  I want to make
> feature flag 'unstable' visible there as well, so I can add policy for
> it.
>
> Instead of extending flags[], replace it by @special_features (a
> bitset of QapiSpecialFeature), because that's how special features get
> passed around elsewhere.
>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>  include/qapi/util.h    |  5 +----
>  qapi/qapi-visit-core.c |  3 ++-
>  scripts/qapi/types.py  | 22 ++++++++++++----------
>  3 files changed, 15 insertions(+), 15 deletions(-)
>
> diff --git a/include/qapi/util.h b/include/qapi/util.h
> index 7a8d5c7d72..0cc98db9f9 100644
> --- a/include/qapi/util.h
> +++ b/include/qapi/util.h
> @@ -15,12 +15,9 @@ typedef enum {
>      QAPI_DEPRECATED,
>  } QapiSpecialFeature;
>
> -/* QEnumLookup flags */
> -#define QAPI_ENUM_DEPRECATED 1
> -
>  typedef struct QEnumLookup {
>      const char *const *array;
> -    const unsigned char *const flags;
> +    const unsigned char *const special_features;
>      const int size;
>  } QEnumLookup;
>
> diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
> index b4a81f1757..5572d90efb 100644
> --- a/qapi/qapi-visit-core.c
> +++ b/qapi/qapi-visit-core.c
> @@ -407,7 +407,8 @@ static bool input_type_enum(Visitor *v, const char
> *name, int *obj,
>          return false;
>      }
>
> -    if (lookup->flags && (lookup->flags[value] & QAPI_ENUM_DEPRECATED)) {
> +    if (lookup->special_features
> +        && (lookup->special_features[value] & QAPI_DEPRECATED)) {
>          switch (v->compat_policy.deprecated_input) {
>          case COMPAT_POLICY_INPUT_ACCEPT:
>              break;
> diff --git a/scripts/qapi/types.py b/scripts/qapi/types.py
> index ab2441adc9..3013329c24 100644
> --- a/scripts/qapi/types.py
> +++ b/scripts/qapi/types.py
> @@ -16,7 +16,7 @@
>  from typing import List, Optional
>
>  from .common import c_enum_const, c_name, mcgen
> -from .gen import QAPISchemaModularCVisitor, ifcontext
> +from .gen import QAPISchemaModularCVisitor, gen_special_features,
> ifcontext
>  from .schema import (
>      QAPISchema,
>      QAPISchemaEnumMember,
> @@ -39,7 +39,7 @@ def gen_enum_lookup(name: str,
>                      members: List[QAPISchemaEnumMember],
>                      prefix: Optional[str] = None) -> str:
>      max_index = c_enum_const(name, '_MAX', prefix)
> -    flags = ''
> +    feats = ''
>      ret = mcgen('''
>
>  const QEnumLookup %(c_name)s_lookup = {
> @@ -54,19 +54,21 @@ 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:
> +        special_features = gen_special_features(memb.features)
> +        if special_features != '0':
>

Though, I have to admit the common reoccurrence of this pattern suggests to
me that gen_special_features really ought to be returning something false-y
in these cases. Something about testing for the empty case with something
that represents, but isn't empty, gives me a brief pause.

Not willing to wage war over it.


> +            feats += mcgen('''
> +        [%(index)s] = %(special_features)s,
> +''',
> +                           index=index, special_features=special_features)
> +
> +    if feats:
>          ret += mcgen('''
>      },
> -    .flags = (const unsigned char[%(max_index)s]) {
> +    .special_features = (const unsigned char[%(max_index)s]) {
>  ''',
>                       max_index=max_index)
> -        ret += flags
> +        ret += feats
>
>      ret += mcgen('''
>      },
> --
> 2.31.1
>
>
Python bits: Acked-by: John Snow <jsnow@redhat.com>
Re: [PATCH 7/9] qapi: Generalize enum member policy checking
Posted by Markus Armbruster 4 years, 3 months ago
John Snow <jsnow@redhat.com> writes:

> On Mon, Oct 25, 2021 at 1:26 AM Markus Armbruster <armbru@redhat.com> wrote:
>
>> The code to check enumeration value policy can see special feature
>> flag 'deprecated' in QEnumLookup member flags[value].  I want to make
>> feature flag 'unstable' visible there as well, so I can add policy for
>> it.
>>
>> Instead of extending flags[], replace it by @special_features (a
>> bitset of QapiSpecialFeature), because that's how special features get
>> passed around elsewhere.
>>
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> ---
>>  include/qapi/util.h    |  5 +----
>>  qapi/qapi-visit-core.c |  3 ++-
>>  scripts/qapi/types.py  | 22 ++++++++++++----------
>>  3 files changed, 15 insertions(+), 15 deletions(-)
>>
>> diff --git a/include/qapi/util.h b/include/qapi/util.h
>> index 7a8d5c7d72..0cc98db9f9 100644
>> --- a/include/qapi/util.h
>> +++ b/include/qapi/util.h
>> @@ -15,12 +15,9 @@ typedef enum {
>>      QAPI_DEPRECATED,
>>  } QapiSpecialFeature;
>>
>> -/* QEnumLookup flags */
>> -#define QAPI_ENUM_DEPRECATED 1
>> -
>>  typedef struct QEnumLookup {
>>      const char *const *array;
>> -    const unsigned char *const flags;
>> +    const unsigned char *const special_features;
>>      const int size;
>>  } QEnumLookup;
>>
>> diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
>> index b4a81f1757..5572d90efb 100644
>> --- a/qapi/qapi-visit-core.c
>> +++ b/qapi/qapi-visit-core.c
>> @@ -407,7 +407,8 @@ static bool input_type_enum(Visitor *v, const char
>> *name, int *obj,
>>          return false;
>>      }
>>
>> -    if (lookup->flags && (lookup->flags[value] & QAPI_ENUM_DEPRECATED)) {
>> +    if (lookup->special_features
>> +        && (lookup->special_features[value] & QAPI_DEPRECATED)) {
>>          switch (v->compat_policy.deprecated_input) {
>>          case COMPAT_POLICY_INPUT_ACCEPT:
>>              break;
>> diff --git a/scripts/qapi/types.py b/scripts/qapi/types.py
>> index ab2441adc9..3013329c24 100644
>> --- a/scripts/qapi/types.py
>> +++ b/scripts/qapi/types.py
>> @@ -16,7 +16,7 @@
>>  from typing import List, Optional
>>
>>  from .common import c_enum_const, c_name, mcgen
>> -from .gen import QAPISchemaModularCVisitor, ifcontext
>> +from .gen import QAPISchemaModularCVisitor, gen_special_features,
>> ifcontext
>>  from .schema import (
>>      QAPISchema,
>>      QAPISchemaEnumMember,
>> @@ -39,7 +39,7 @@ def gen_enum_lookup(name: str,
>>                      members: List[QAPISchemaEnumMember],
>>                      prefix: Optional[str] = None) -> str:
>>      max_index = c_enum_const(name, '_MAX', prefix)
>> -    flags = ''
>> +    feats = ''
>>      ret = mcgen('''
>>
>>  const QEnumLookup %(c_name)s_lookup = {
>> @@ -54,19 +54,21 @@ 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:
>> +        special_features = gen_special_features(memb.features)
>> +        if special_features != '0':
>>
>
> Though, I have to admit the common reoccurrence of this pattern suggests to
> me that gen_special_features really ought to be returning something false-y
> in these cases. Something about testing for the empty case with something
> that represents, but isn't empty, gives me a brief pause.
>
> Not willing to wage war over it.

I habitually start stupid, and when stupid confuses or annoys me later,
I smarten it up some.

Let's see how this instance of "stupid" ages, okay?

>> +            feats += mcgen('''
>> +        [%(index)s] = %(special_features)s,
>> +''',
>> +                           index=index, special_features=special_features)
>> +
>> +    if feats:
>>          ret += mcgen('''
>>      },
>> -    .flags = (const unsigned char[%(max_index)s]) {
>> +    .special_features = (const unsigned char[%(max_index)s]) {
>>  ''',
>>                       max_index=max_index)
>> -        ret += flags
>> +        ret += feats
>>
>>      ret += mcgen('''
>>      },
>> --
>> 2.31.1
>>
>>
> Python bits: Acked-by: John Snow <jsnow@redhat.com>

Thanks!

Re: [PATCH 7/9] qapi: Generalize enum member policy checking
Posted by John Snow 4 years, 3 months ago
On Tue, Oct 26, 2021 at 5:43 AM Markus Armbruster <armbru@redhat.com> wrote:

> John Snow <jsnow@redhat.com> writes:
>
> > On Mon, Oct 25, 2021 at 1:26 AM Markus Armbruster <armbru@redhat.com>
> wrote:
> >
> >> The code to check enumeration value policy can see special feature
> >> flag 'deprecated' in QEnumLookup member flags[value].  I want to make
> >> feature flag 'unstable' visible there as well, so I can add policy for
> >> it.
> >>
> >> Instead of extending flags[], replace it by @special_features (a
> >> bitset of QapiSpecialFeature), because that's how special features get
> >> passed around elsewhere.
> >>
> >> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> >> ---
> >>  include/qapi/util.h    |  5 +----
> >>  qapi/qapi-visit-core.c |  3 ++-
> >>  scripts/qapi/types.py  | 22 ++++++++++++----------
> >>  3 files changed, 15 insertions(+), 15 deletions(-)
> >>
> >> diff --git a/include/qapi/util.h b/include/qapi/util.h
> >> index 7a8d5c7d72..0cc98db9f9 100644
> >> --- a/include/qapi/util.h
> >> +++ b/include/qapi/util.h
> >> @@ -15,12 +15,9 @@ typedef enum {
> >>      QAPI_DEPRECATED,
> >>  } QapiSpecialFeature;
> >>
> >> -/* QEnumLookup flags */
> >> -#define QAPI_ENUM_DEPRECATED 1
> >> -
> >>  typedef struct QEnumLookup {
> >>      const char *const *array;
> >> -    const unsigned char *const flags;
> >> +    const unsigned char *const special_features;
> >>      const int size;
> >>  } QEnumLookup;
> >>
> >> diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
> >> index b4a81f1757..5572d90efb 100644
> >> --- a/qapi/qapi-visit-core.c
> >> +++ b/qapi/qapi-visit-core.c
> >> @@ -407,7 +407,8 @@ static bool input_type_enum(Visitor *v, const char
> >> *name, int *obj,
> >>          return false;
> >>      }
> >>
> >> -    if (lookup->flags && (lookup->flags[value] &
> QAPI_ENUM_DEPRECATED)) {
> >> +    if (lookup->special_features
> >> +        && (lookup->special_features[value] & QAPI_DEPRECATED)) {
> >>          switch (v->compat_policy.deprecated_input) {
> >>          case COMPAT_POLICY_INPUT_ACCEPT:
> >>              break;
> >> diff --git a/scripts/qapi/types.py b/scripts/qapi/types.py
> >> index ab2441adc9..3013329c24 100644
> >> --- a/scripts/qapi/types.py
> >> +++ b/scripts/qapi/types.py
> >> @@ -16,7 +16,7 @@
> >>  from typing import List, Optional
> >>
> >>  from .common import c_enum_const, c_name, mcgen
> >> -from .gen import QAPISchemaModularCVisitor, ifcontext
> >> +from .gen import QAPISchemaModularCVisitor, gen_special_features,
> >> ifcontext
> >>  from .schema import (
> >>      QAPISchema,
> >>      QAPISchemaEnumMember,
> >> @@ -39,7 +39,7 @@ def gen_enum_lookup(name: str,
> >>                      members: List[QAPISchemaEnumMember],
> >>                      prefix: Optional[str] = None) -> str:
> >>      max_index = c_enum_const(name, '_MAX', prefix)
> >> -    flags = ''
> >> +    feats = ''
> >>      ret = mcgen('''
> >>
> >>  const QEnumLookup %(c_name)s_lookup = {
> >> @@ -54,19 +54,21 @@ 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:
> >> +        special_features = gen_special_features(memb.features)
> >> +        if special_features != '0':
> >>
> >
> > Though, I have to admit the common reoccurrence of this pattern suggests
> to
> > me that gen_special_features really ought to be returning something
> false-y
> > in these cases. Something about testing for the empty case with something
> > that represents, but isn't empty, gives me a brief pause.
> >
> > Not willing to wage war over it.
>
> I habitually start stupid, and when stupid confuses or annoys me later,
> I smarten it up some.
>
> Let's see how this instance of "stupid" ages, okay?
>
>
"I see what you're saying, but mehhhhh" is a relatable feeling ;)

>
> >> +            feats += mcgen('''
> >> +        [%(index)s] = %(special_features)s,
> >> +''',
> >> +                           index=index,
> special_features=special_features)
> >> +
> >> +    if feats:
> >>          ret += mcgen('''
> >>      },
> >> -    .flags = (const unsigned char[%(max_index)s]) {
> >> +    .special_features = (const unsigned char[%(max_index)s]) {
> >>  ''',
> >>                       max_index=max_index)
> >> -        ret += flags
> >> +        ret += feats
> >>
> >>      ret += mcgen('''
> >>      },
> >> --
> >> 2.31.1
> >>
> >>
> > Python bits: Acked-by: John Snow <jsnow@redhat.com>
>
> Thanks!
>
>