handle const struct member

tests/parser/functions/test_default_parameters.py

@@ -304,6 +304,17 @@ def foo(a: address = empty(address)):
 def foo(a: int112 = min_value(int112)):
     self.A = a
     """,
+    """
+struct X:
+    x: int128
+    y: address
+
+BAR: constant(X) = X({x: 1, y: 0x0000000000000000000000000000000000012345})
+
+@external
+def out_literals(a: int128 = BAR.x + 1) -> X:
+    return BAR
+    """,
 ]
 
 

vyper/semantics/types/utils.py

@@ -135,7 +135,13 @@ def _failwith(type_name):
 
 
 def derive_folded_value(node: vy_ast.VyperNode):
-    if isinstance(node, vy_ast.BinOp):
+    if isinstance(node, vy_ast.Attribute):
+        val = derive_folded_value(node.value)
+        # constant struct members
+        if isinstance(val, dict):
+            return val[node.attr]
+        return None
+    elif isinstance(node, vy_ast.BinOp):
         left = derive_folded_value(node.left)
         right = derive_folded_value(node.right)
         if left is None or right is None:
@@ -181,7 +187,7 @@ def derive_folded_value(node: vy_ast.VyperNode):
         values = [derive_folded_value(v) for v in node.values]
         if any(v is None for v in values):
             return None
-        return {k: v for (k, v) in zip(node.keys, values)}
+        return {k.id: v for (k, v) in zip(node.keys, values)}
     elif isinstance(node, (vy_ast.List, vy_ast.Tuple)):
         val = [derive_folded_value(e) for e in node.elements]
         if None in val: