fix[lang]: fix importing of flag types (#3871)

fix imports for flag types. this is a missed case from 8ccacb3.

this commit adds flags into the module data and threads them through
codegen.

---------

Co-authored-by: Charles Cooper <cooper.charles.m@gmail.com>

tests/functional/codegen/modules/test_flag_imports.py

@@ -0,0 +1,41 @@
+def test_import_flag_types(make_input_bundle, get_contract):
+    lib1 = """
+import lib2
+
+flag Roles:
+    ADMIN
+    USER
+
+enum Roles2:
+    ADMIN
+    USER
+
+role: Roles
+role2: Roles2
+role3: lib2.Roles3
+    """
+    lib2 = """
+flag Roles3:
+    ADMIN
+    USER
+    NOBODY
+    """
+    contract = """
+import lib1
+
+initializes: lib1
+
+@external
+def bar(r: lib1.Roles, r2: lib1.Roles2, r3: lib1.lib2.Roles3) -> bool:
+    lib1.role = r
+    lib1.role2 = r2
+    lib1.role3 = r3
+    assert lib1.role == lib1.Roles.ADMIN
+    assert lib1.role2 == lib1.Roles2.USER
+    assert lib1.role3 == lib1.lib2.Roles3.NOBODY
+    return True
+    """
+
+    input_bundle = make_input_bundle({"lib1.vy": lib1, "lib2.vy": lib2})
+    c = get_contract(contract, input_bundle=input_bundle)
+    assert c.bar(1, 2, 4) is True

vyper/ast/grammar.lark

@@ -98,7 +98,7 @@ tuple_def: "(" ( NAME | array_def | dyn_array_def | tuple_def ) ( "," ( NAME | a
 // NOTE: Map takes a basic type and maps to another type (can be non-basic, including maps)
 _MAP: "HashMap"
 map_def: _MAP "[" ( NAME | array_def ) "," type "]"
-imported_type: NAME "." NAME
+imported_type: NAME ("." NAME)+
 type: ( NAME | imported_type | array_def | tuple_def | map_def | dyn_array_def )
 
 // Structs can be composed of 1+ basic types or other custom_types

vyper/codegen/expr.py

@@ -206,12 +206,9 @@ def parse_Name(self):
     def parse_Attribute(self):
         typ = self.expr._metadata["type"]
 
-        # MyFlag.foo
-        if (
-            isinstance(typ, FlagT)
-            and isinstance(self.expr.value, vy_ast.Name)
-            and typ.name == self.expr.value.id
-        ):
+        # check if we have a flag constant, e.g.
+        # [lib1].MyFlag.FOO
+        if isinstance(typ, FlagT) and is_type_t(self.expr.value._metadata["type"], FlagT):
             # 0, 1, 2, .. 255
             flag_id = typ._flag_members[self.expr.attr]
             value = 2**flag_id  # 0 => 0001, 1 => 0010, 2 => 0100, etc.

vyper/semantics/analysis/module.py

@@ -657,6 +657,7 @@ def _validate_self_namespace():
 
     def visit_FlagDef(self, node):
         obj = FlagT.from_FlagDef(node)
+        node._metadata["flag_type"] = obj
         self.namespace[node.name] = obj
 
     def visit_EventDef(self, node):

vyper/semantics/types/module.py

@@ -300,6 +300,10 @@ def __init__(self, module: vy_ast.Module, name: Optional[str] = None):
             # add the type of the event so it can be used in call position
             self.add_member(e.name, TYPE_T(e._metadata["event_type"]))  # type: ignore
 
+        for f in self.flag_defs:
+            self.add_member(f.name, TYPE_T(f._metadata["flag_type"]))
+            self._helper.add_member(f.name, TYPE_T(f._metadata["flag_type"]))
+
         for s in self.struct_defs:
             # add the type of the struct so it can be used in call position
             self.add_member(s.name, TYPE_T(s._metadata["struct_type"]))  # type: ignore
@@ -347,6 +351,10 @@ def function_defs(self):
     def event_defs(self):
         return self._module.get_children(vy_ast.EventDef)
 
+    @cached_property
+    def flag_defs(self):
+        return self._module.get_children(vy_ast.FlagDef)
+
     @property
     def struct_defs(self):
         return self._module.get_children(vy_ast.StructDef)