tools: ynl-gen: move the count into a presence struct too

While we reshuffle the presence members, move the counts as well.
Previously array count members would have been place directly in
the struct, so:

struct family_op_req {
struct {
u32 a:1;
u32 b:1;
} _present;
struct {
u32 bin;
} _len;

u32 a;
u64 b;
const unsigned char *bin;
u32 n_multi; << count
u32 *multi; << objects
};

Since len has been moved to its own presence struct move the count
as well:

struct family_op_req {
struct {
u32 a:1;
u32 b:1;
} _present;
struct {
u32 bin;
} _len;
struct {
u32 multi; << count
} _count;

u32 a;
u64 b;
const unsigned char *bin;
u32 *multi; << objects
};

This improves the consistency and allows us to remove some hacks
in the codegen. Unlike for len there is no known name collision
with the existing scheme.

Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

tools/net/ynl/pyynl/ynl_gen_c.py

···
             pfx = '__' if space == 'user' else ''
             return f"{pfx}u32 {self.c_name}:1;"
 
-        if self.presence_type() == 'len':
+        if self.presence_type() in {'len', 'count'}:
             pfx = '__' if space == 'user' else ''
             return f"{pfx}u32 {self.c_name};"
 
···
     def struct_member(self, ri):
         member = self._complex_member_type(ri)
         if member:
-            if self.is_multi_val():
-                ri.cw.p(f"unsigned int n_{self.c_name};")
             ptr = '*' if self.is_multi_val() else ''
             if self.is_recursive_for_op(ri):
                 ptr = '*'
···
             lines += [f"free({var}->{ref}{self.c_name});"]
         elif self.attr['type'] == 'string':
             lines += [
-                f"for (i = 0; i < {var}->{ref}n_{self.c_name}; i++)",
+                f"for (i = 0; i < {var}->{ref}_count.{self.c_name}; i++)",
                 f"free({var}->{ref}{self.c_name}[i]);",
                 f"free({var}->{ref}{self.c_name});",
             ]
         elif 'type' not in self.attr or self.attr['type'] == 'nest':
             lines += [
-                f"for (i = 0; i < {var}->{ref}n_{self.c_name}; i++)",
+                f"for (i = 0; i < {var}->{ref}_count.{self.c_name}; i++)",
                 f'{self.nested_render_name}_free(&{var}->{ref}{self.c_name}[i]);',
                 f"free({var}->{ref}{self.c_name});",
             ]
···
     def attr_put(self, ri, var):
         if self.attr['type'] in scalars:
             put_type = self.type
-            ri.cw.p(f"for (i = 0; i < {var}->n_{self.c_name}; i++)")
+            ri.cw.p(f"for (i = 0; i < {var}->_count.{self.c_name}; i++)")
             ri.cw.p(f"ynl_attr_put_{put_type}(nlh, {self.enum_name}, {var}->{self.c_name}[i]);")
         elif self.attr['type'] == 'binary' and 'struct' in self.attr:
-            ri.cw.p(f"for (i = 0; i < {var}->n_{self.c_name}; i++)")
+            ri.cw.p(f"for (i = 0; i < {var}->_count.{self.c_name}; i++)")
             ri.cw.p(f"ynl_attr_put(nlh, {self.enum_name}, &{var}->{self.c_name}[i], sizeof(struct {c_lower(self.attr['struct'])}));")
         elif self.attr['type'] == 'string':
-            ri.cw.p(f"for (i = 0; i < {var}->n_{self.c_name}; i++)")
+            ri.cw.p(f"for (i = 0; i < {var}->_count.{self.c_name}; i++)")
             ri.cw.p(f"ynl_attr_put_str(nlh, {self.enum_name}, {var}->{self.c_name}[i]->str);")
         elif 'type' not in self.attr or self.attr['type'] == 'nest':
-            ri.cw.p(f"for (i = 0; i < {var}->n_{self.c_name}; i++)")
+            ri.cw.p(f"for (i = 0; i < {var}->_count.{self.c_name}; i++)")
             self._attr_put_line(ri, var, f"{self.nested_render_name}_put(nlh, " +
                                 f"{self.enum_name}, &{var}->{self.c_name}[i])")
         else:
             raise Exception(f"Put of MultiAttr sub-type {self.attr['type']} not supported yet")
 
     def _setter_lines(self, ri, member, presence):
-        # For multi-attr we have a count, not presence, hack up the presence
-        presence = presence[:-(len('_count.') + len(self.c_name))] + "n_" + self.c_name
         return [f"{member} = {self.c_name};",
                 f"{presence} = n_{self.c_name};"]
 
···
                      'ynl_attr_for_each_nested(attr2, attr) {',
                      '\tif (ynl_attr_validate(yarg, attr2))',
                      '\t\treturn YNL_PARSE_CB_ERROR;',
-                     f'\t{var}->n_{self.c_name}++;',
+                     f'\t{var}->_count.{self.c_name}++;',
                      '}']
         return get_lines, None, local_vars
 
···
         ri.cw.p(f'array = ynl_attr_nest_start(nlh, {self.enum_name});')
         if self.sub_type in scalars:
             put_type = self.sub_type
-            ri.cw.block_start(line=f'for (i = 0; i < {var}->n_{self.c_name}; i++)')
+            ri.cw.block_start(line=f'for (i = 0; i < {var}->_count.{self.c_name}; i++)')
             ri.cw.p(f"ynl_attr_put_{put_type}(nlh, i, {var}->{self.c_name}[i]);")
             ri.cw.block_end()
         elif self.sub_type == 'binary' and 'exact-len' in self.checks:
-            ri.cw.p(f'for (i = 0; i < {var}->n_{self.c_name}; i++)')
+            ri.cw.p(f'for (i = 0; i < {var}->_count.{self.c_name}; i++)')
             ri.cw.p(f"ynl_attr_put(nlh, i, {var}->{self.c_name}[i], {self.checks['exact-len']});")
         else:
             raise Exception(f"Put for ArrayNest sub-type {self.attr['sub-type']} not supported, yet")
         ri.cw.p('ynl_attr_nest_end(nlh, array);')
 
     def _setter_lines(self, ri, member, presence):
-        # For multi-attr we have a count, not presence, hack up the presence
-        presence = presence[:-(len('_count.') + len(self.c_name))] + "n_" + self.c_name
         return [f"{member} = {self.c_name};",
                 f"{presence} = n_{self.c_name};"]
 
···
 
         ri.cw.block_start(line=f"if (n_{aspec.c_name})")
         ri.cw.p(f"dst->{aspec.c_name} = calloc(n_{aspec.c_name}, sizeof(*dst->{aspec.c_name}));")
-        ri.cw.p(f"dst->n_{aspec.c_name} = n_{aspec.c_name};")
+        ri.cw.p(f"dst->_count.{aspec.c_name} = n_{aspec.c_name};")
         ri.cw.p('i = 0;')
         if 'nested-attributes' in aspec:
             ri.cw.p(f"parg.rsp_policy = &{aspec.nested_render_name}_nest;")
···
         aspec = struct[anest]
         ri.cw.block_start(line=f"if (n_{aspec.c_name})")
         ri.cw.p(f"dst->{aspec.c_name} = calloc(n_{aspec.c_name}, sizeof(*dst->{aspec.c_name}));")
-        ri.cw.p(f"dst->n_{aspec.c_name} = n_{aspec.c_name};")
+        ri.cw.p(f"dst->_count.{aspec.c_name} = n_{aspec.c_name};")
         ri.cw.p('i = 0;')
         if 'nested-attributes' in aspec:
             ri.cw.p(f"parg.rsp_policy = &{aspec.nested_render_name}_nest;")
···
         ri.cw.p(ri.fixed_hdr + ' _hdr;')
         ri.cw.nl()
 
-    for type_filter in ['present', 'len']:
+    for type_filter in ['present', 'len', 'count']:
         meta_started = False
         for _, attr in struct.member_list():
             line = attr.presence_member(ri.ku_space, type_filter)

tools/net/ynl/samples/devlink.c

···
 	ynl_dump_foreach(devs, d) {
 		struct devlink_info_get_req *info_req;
 		struct devlink_info_get_rsp *info_rsp;
+		unsigned i;
 
 		printf("%s/%s:\n", d->bus_name, d->dev_name);
 
···
 
 		if (info_rsp->_len.info_driver_name)
 			printf("    driver: %s\n", info_rsp->info_driver_name);
-		if (info_rsp->n_info_version_running)
+		if (info_rsp->_count.info_version_running)
 			printf("    running fw:\n");
-		for (unsigned i = 0; i < info_rsp->n_info_version_running; i++)
+		for (i = 0; i < info_rsp->_count.info_version_running; i++)
 			printf("        %s: %s\n",
 			       info_rsp->info_version_running[i].info_version_name,
 			       info_rsp->info_version_running[i].info_version_value);