schema: add missing extensions() for access to module level

cffi/cdefs.h

@@ -361,6 +361,14 @@ LY_ERR lys_print_module(struct ly_out *, const struct lys_module *, LYS_OUTFORMA
 #define LYS_PRINT_NO_SUBSTMT ...
 #define LYS_PRINT_SHRINK ...
 
+struct lysc_module {
+	struct lys_module *mod;
+	struct lysc_node *data;
+	struct lysc_node_action *rpcs;
+	struct lysc_node_notif *notifs;
+	struct lysc_ext_instance *exts;
+};
+
 struct lys_module {
     struct ly_ctx *ctx;
     const char *name;

libyang/schema.py

@@ -180,6 +180,29 @@ def parsed_identities(self) -> Iterator["PIdentity"]:
         for i in ly_array_iter(self.cdata.parsed.identities):
             yield PIdentity(self.context, i, self)
 
+    def extensions(self) -> Iterator["ExtensionCompiled"]:
+        compiled = ffi.cast("struct lysc_module *", self.cdata.compiled)
+        if compiled == ffi.NULL:
+            return
+        exts = ffi.cast("struct lysc_ext_instance *", self.cdata.compiled.exts)
+        if exts == ffi.NULL:
+            return
+        for extension in ly_array_iter(exts):
+            yield ExtensionCompiled(self.context, extension)
+
+    def get_extension(
+        self, name: str, prefix: Optional[str] = None, arg_value: Optional[str] = None
+    ) -> Optional["ExtensionCompiled"]:
+        for ext in self.extensions():
+            if ext.name() != name:
+                continue
+            if prefix is not None and ext.module().name() != prefix:
+                continue
+            if arg_value is not None and ext.argument() != arg_value:
+                continue
+            return ext
+        return None
+
     def __str__(self) -> str:
         return self.name()
 

tests/test_schema.py

@@ -129,6 +129,19 @@ def test_mod_revisions(self):
         self.assertEqual(revisions[0].date(), "1999-04-01")
         self.assertEqual(revisions[1].date(), "1990-04-01")
 
+    def test_mod_extensions(self):
+        assert self.module is not None  # pyright doesn't understand assertIsNotNone()
+        exts = list(self.module.extensions())
+        self.assertEqual(len(exts), 1)
+        ext = self.module.get_extension("compile-validation", prefix="omg-extensions")
+        self.assertEqual(ext.argument(), "module-level")
+        sub_exts = list(ext.extensions())
+        self.assertEqual(len(sub_exts), 1)
+        ext = sub_exts[0]
+        self.assertEqual(ext.name(), "compile-validation")
+        self.assertEqual(ext.module().name(), "omg-extensions")
+        self.assertEqual(ext.argument(), "module-sub-level")
+
 
 # -------------------------------------------------------------------------------------
 class RevisionTest(unittest.TestCase):

tests/yang/yolo/yolo-system.yang

@@ -155,6 +155,10 @@ module yolo-system {
     }
   }
 
+  ext:compile-validation "module-level" {
+    ext:compile-validation "module-sub-level";
+  }
+
   container conf {
     description
       "Configuration.";