[PATCH net-next v3 11/12] tools: ynl-gen: don't init enum checks for classic netlink

[Jakub Kicinski <kuba@kernel.org>]

rt-link has a vlan-protocols enum with:

   name: 8021q     value: 33024
   name: 8021ad    value: 34984

It's nice to have, since it converts the values to strings in Python.
For C, however, the codegen is trying to use enums to generate strict
policy checks. Parsing such sparse enums is not possible via policies.

Since for classic netlink we don't support kernel codegen and policy
generation - skip the auto-generation of checks from enums.

Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
v3:
 - improve grammar
v2: https://lore.kernel.org/20250425024311.1589323-12-kuba@kernel.org
 - move the comment about the skip before the if
v1: https://lore.kernel.org/4b8339b7-9dc6-4231-a60f-0c9f6296358a@intel.com
---
 tools/net/ynl/pyynl/ynl_gen_c.py | 46 ++++++++++++++++++--------------
 1 file changed, 26 insertions(+), 20 deletions(-)

diff --git a/tools/net/ynl/pyynl/ynl_gen_c.py b/tools/net/ynl/pyynl/ynl_gen_c.py
index 2d185c7ea16c..1dd9580086cd 100755
--- a/tools/net/ynl/pyynl/ynl_gen_c.py
+++ b/tools/net/ynl/pyynl/ynl_gen_c.py
@@ -357,26 +357,10 @@ from lib import SpecFamily, SpecAttrSet, SpecAttr, SpecOperation, SpecEnumSet, S
         if 'byte-order' in attr:
             self.byte_order_comment = f" /* {attr['byte-order']} */"
 
-        if 'enum' in self.attr:
-            enum = self.family.consts[self.attr['enum']]
-            low, high = enum.value_range()
-            if 'min' not in self.checks:
-                if low != 0 or self.type[0] == 's':
-                    self.checks['min'] = low
-            if 'max' not in self.checks:
-                self.checks['max'] = high
-
-        if 'min' in self.checks and 'max' in self.checks:
-            if self.get_limit('min') > self.get_limit('max'):
-                raise Exception(f'Invalid limit for "{self.name}" min: {self.get_limit("min")} max: {self.get_limit("max")}')
-            self.checks['range'] = True
-
-        low = min(self.get_limit('min', 0), self.get_limit('max', 0))
-        high = max(self.get_limit('min', 0), self.get_limit('max', 0))
-        if low < 0 and self.type[0] == 'u':
-            raise Exception(f'Invalid limit for "{self.name}" negative limit for unsigned type')
-        if low < -32768 or high > 32767:
-            self.checks['full-range'] = True
+        # Classic families have some funny enums, don't bother
+        # computing checks, since we only need them for kernel policies
+        if not family.is_classic():
+            self._init_checks()
 
         # Added by resolve():
         self.is_bitfield = None
@@ -401,6 +385,28 @@ from lib import SpecFamily, SpecAttrSet, SpecAttr, SpecOperation, SpecEnumSet, S
         else:
             self.type_name = '__' + self.type
 
+    def _init_checks(self):
+        if 'enum' in self.attr:
+            enum = self.family.consts[self.attr['enum']]
+            low, high = enum.value_range()
+            if 'min' not in self.checks:
+                if low != 0 or self.type[0] == 's':
+                    self.checks['min'] = low
+            if 'max' not in self.checks:
+                self.checks['max'] = high
+
+        if 'min' in self.checks and 'max' in self.checks:
+            if self.get_limit('min') > self.get_limit('max'):
+                raise Exception(f'Invalid limit for "{self.name}" min: {self.get_limit("min")} max: {self.get_limit("max")}')
+            self.checks['range'] = True
+
+        low = min(self.get_limit('min', 0), self.get_limit('max', 0))
+        high = max(self.get_limit('min', 0), self.get_limit('max', 0))
+        if low < 0 and self.type[0] == 'u':
+            raise Exception(f'Invalid limit for "{self.name}" negative limit for unsigned type')
+        if low < -32768 or high > 32767:
+            self.checks['full-range'] = True
+
     def _attr_policy(self, policy):
         if 'flags-mask' in self.checks or self.is_bitfield:
             if self.is_bitfield:
-- 
2.49.0