context: add LY_CTX_LEAFREF_EXTENDED option

This patch adds the ability to create context with an additional option
for extended leafrefs, which can use deref() functions.

Fixes: #85
Signed-off-by: Stefan Gula <steweg@gmail.com>
Signed-off-by: Samuel Gauthier <samuel.gauthier@6wind.com>

Author: steweg

cffi/cdefs.h

@@ -14,6 +14,7 @@ struct ly_ctx;
 #define LY_CTX_EXPLICIT_COMPILE ...
 #define LY_CTX_REF_IMPLEMENTED ...
 #define LY_CTX_SET_PRIV_PARSED ...
+#define LY_CTX_LEAFREF_EXTENDED ...
 
 
 typedef enum {

cffi/source.c

@@ -9,6 +9,6 @@
 #if (LY_VERSION_MAJOR != 2)
 #error "This version of libyang bindings only works with libyang 2.x"
 #endif
-#if (LY_VERSION_MINOR < 25)
-#error "Need at least libyang 2.25"
+#if (LY_VERSION_MINOR < 37)
+#error "Need at least libyang 2.37"
 #endif

libyang/context.py

@@ -28,6 +28,7 @@ def __init__(
         search_path: Optional[str] = None,
         disable_searchdir_cwd: bool = True,
         explicit_compile: Optional[bool] = False,
+        leafref_extended: bool = False,
         yanglib_path: Optional[str] = None,
         yanglib_fmt: str = "json",
         cdata=None,  # C type: "struct ly_ctx *"
@@ -41,6 +42,8 @@ def __init__(
             options |= lib.LY_CTX_DISABLE_SEARCHDIR_CWD
         if explicit_compile:
             options |= lib.LY_CTX_EXPLICIT_COMPILE
+        if leafref_extended:
+            options |= lib.LY_CTX_LEAFREF_EXTENDED
         # force priv parsed
         options |= lib.LY_CTX_SET_PRIV_PARSED
 

tests/test_context.py

@@ -106,3 +106,8 @@ def test_ctx_parse_module(self):
             with Context(YANG_DIR) as ctx:
                 mod = ctx.parse_module_file(f, features=["turbo-boost", "networking"])
                 self.assertIsInstance(mod, Module)
+
+    def test_ctx_leafref_extended(self):
+        with Context(YANG_DIR, leafref_extended=True) as ctx:
+            mod = ctx.load_module("yolo-leafref-extended")
+            self.assertIsInstance(mod, Module)

tests/yang/yolo/yolo-leafref-extended.yang

@@ -0,0 +1,31 @@
+module yolo-leafref-extended {
+  yang-version 1.1;
+  namespace "urn:yang:yolo:leafref-extended";
+  prefix leafref-ext;
+
+  revision 2025-01-25 {
+    description
+      "Initial version.";
+  }
+
+  list list1 {
+    key leaf1;
+    leaf leaf1 {
+      type string;
+    }
+    leaf-list leaflist2 {
+      type string;
+    }
+  }
+
+  leaf ref1 {
+    type leafref {
+      path "../list1/leaf1";
+    }
+  }
+  leaf ref2 {
+    type leafref {
+      path "deref(../ref1)/../leaflist2";
+    }
+  }
+}