tools: ynl: use 1 as the default for first entry in attrs/ops

Pretty much all families use value: 1 or reserve as unspec
the first entry in attribute set and the first operation.
Make this the default. Update documentation (the doc for
values of operations just refers back to doc for attrs
so updating only attrs).

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/Documentation/userspace-api/netlink/specs.rst b/Documentation/userspace-api/netlink/specs.rst
index 1424ab1b9b337771f2cb2afdd45f998f110d691c..32e53328d113db6bbd32da53309b604062bb01af 100644 (file)
--- a/Documentation/userspace-api/netlink/specs.rst
+++ b/Documentation/userspace-api/netlink/specs.rst
@@ -197,7 +197,12 @@ value
 Numerical attribute ID, used in serialized Netlink messages.
 The ``value`` property can be skipped, in which case the attribute ID
 will be the value of the previous attribute plus one (recursively)
-and ``0`` for the first attribute in the attribute set.
+and ``1`` for the first attribute in the attribute set.
+
+Attributes (and operations) use ``1`` as the default value for the first
+entry (unlike enums in definitions which start from ``0``) because
+entry ``0`` is almost always reserved as undefined. Spec can explicitly
+set value to ``0`` if needed.
 
 Note that the ``value`` of an attribute is defined only in its main set
 (not in subsets).

diff --git a/tools/net/ynl/lib/nlspec.py b/tools/net/ynl/lib/nlspec.py
index dff31dad36c50bcb1c6adbfa9de33a28b9e9abf1..9d394e50de23d3e864c274ee41cb7c7735d8f074 100644 (file)
--- a/tools/net/ynl/lib/nlspec.py
+++ b/tools/net/ynl/lib/nlspec.py
@@ -96,7 +96,7 @@ class SpecAttrSet(SpecElement):
         self.attrs_by_val = collections.OrderedDict()
 
         if self.subset_of is None:
-            val = 0
+            val = 1
             for elem in self.yaml['attributes']:
                 if 'value' in elem:
                     val = elem['value']
@@ -252,7 +252,7 @@ class SpecFamily(SpecElement):
         self._resolution_list.append(elem)
 
     def _dictify_ops_unified(self):
-        val = 0
+        val = 1
         for elem in self.yaml['operations']['list']:
             if 'value' in elem:
                 val = elem['value']
@@ -263,7 +263,7 @@ class SpecFamily(SpecElement):
             self.msgs[op.name] = op
 
     def _dictify_ops_directional(self):
-        req_val = rsp_val = 0
+        req_val = rsp_val = 1
         for elem in self.yaml['operations']['list']:
             if 'notify' in elem:
                 if 'value' in elem:

diff --git a/tools/net/ynl/ynl-gen-c.py b/tools/net/ynl/ynl-gen-c.py
index 274e9c566f61b09d093958d1d4fd89b8c9b17905..62f8f2c3c56c83a363dc7d6ab071e62f8e01f545 100755 (executable)
--- a/tools/net/ynl/ynl-gen-c.py
+++ b/tools/net/ynl/ynl-gen-c.py
@@ -2044,14 +2044,17 @@ def render_uapi(family, cw):
     max_value = f"({cnt_name} - 1)"
 
     uapi_enum_start(family, cw, family['operations'], 'enum-name')
+    val = 0
     for op in family.msgs.values():
         if separate_ntf and ('notify' in op or 'event' in op):
             continue
 
         suffix = ','
-        if 'value' in op:
-            suffix = f" = {op['value']},"
+        if op.value != val:
+            suffix = f" = {op.value},"
+            val = op.value
         cw.p(op.enum_name + suffix)
+        val += 1
     cw.nl()
     cw.p(cnt_name + ('' if max_by_define else ','))
     if not max_by_define: