wip: implement methods for structs

test contract:
```
struct Foo:
    user: address
    balance: uint256

    def decrement_balance(self, amount: uint256):
        self.balance -= amount

@external
def foo(f: Foo):
    s: Foo = f
    s.decrement_balance(1)
```

vyper/codegen/expr.py

@@ -677,21 +677,22 @@ def parse_Call(self):
             return arg_ir
 
         if isinstance(func_t, MemberFunctionT):
-            darray = Expr(self.expr.func.value, self.context).ir_node
-            assert isinstance(darray.typ, DArrayT)
+            ptr = Expr(self.expr.func.value, self.context).ir_node
+
+            if isinstance(ptr.typ, StructT):
+                return self_call.ir_for_self_call(self.expr, self.context, ptr=ptr)
+
+            assert isinstance(ptr.typ, DArrayT)
             args = [Expr(x, self.context).ir_node for x in self.expr.args]
             if self.expr.func.attr == "pop":
                 # TODO consider moving this to builtins
-                darray = Expr(self.expr.func.value, self.context).ir_node
                 assert len(self.expr.args) == 0
                 return_item = not self.is_stmt
-                return pop_dyn_array(darray, return_popped_item=return_item)
+                return pop_dyn_array(ptr, return_popped_item=return_item)
             elif self.expr.func.attr == "append":
                 (arg,) = args
-                check_assign(
-                    dummy_node_for_type(darray.typ.value_type), dummy_node_for_type(arg.typ)
-                )
-                return append_dyn_array(darray, arg)
+                check_assign(dummy_node_for_type(ptr.typ.value_type), dummy_node_for_type(arg.typ))
+                return append_dyn_array(ptr, arg)
 
         assert isinstance(func_t, ContractFunctionT)
         assert func_t.is_internal or func_t.is_constructor

vyper/codegen/module.py

@@ -31,6 +31,8 @@ def _runtime_reachable_functions(module_t, id_generator):
     for fn_t in ret:
         id_generator.ensure_id(fn_t)
 
+    print("ENTER", ret)
+
     return ret
 
 

vyper/codegen/self_call.py

@@ -1,7 +1,10 @@
+from typing import Optional
+
 from vyper.codegen.core import _freshname, eval_once_check, make_setter
 from vyper.codegen.ir_node import IRnode
 from vyper.evm.address_space import MEMORY
 from vyper.exceptions import StateAccessViolation
+from vyper.semantics.types.function import MemberFunctionT
 from vyper.semantics.types.subscriptable import TupleT
 
 
@@ -20,7 +23,7 @@ def _align_kwargs(func_t, args_ir):
     return [i.default_value for i in unprovided_kwargs]
 
 
-def ir_for_self_call(stmt_expr, context):
+def ir_for_self_call(stmt_expr, context, ptr: Optional[IRnode] = None):
     from vyper.codegen.expr import Expr  # TODO rethink this circular import
 
     # ** Internal Call **
@@ -39,7 +42,10 @@ def ir_for_self_call(stmt_expr, context):
     default_vals_ir = [Expr(x, context).ir_node for x in default_vals]
 
     args_ir = pos_args_ir + default_vals_ir
-    assert len(args_ir) == len(func_t.arguments)
+    if isinstance(func_t, MemberFunctionT):
+        assert len(args_ir) == len(func_t.arg_types)
+    else:
+        assert len(args_ir) == len(func_t.arguments)
 
     args_tuple_t = TupleT([x.typ for x in args_ir])
     args_as_tuple = IRnode.from_list(["multi"] + [x for x in args_ir], typ=args_tuple_t)
@@ -89,6 +95,9 @@ def ir_for_self_call(stmt_expr, context):
         copy_args = make_setter(args_dst, args_as_tuple)
 
     goto_op = ["goto", func_t._ir_info.internal_function_label(context.is_ctor_context)]
+    if ptr is not None:
+        goto_op += [ptr]
+
     # pass return buffer to subroutine
     if return_buffer is not None:
         goto_op += [return_buffer]

vyper/semantics/analysis/module.py

@@ -127,15 +127,16 @@ def _analyze_call_graph(module_ast: vy_ast.Module):
         for call in function_calls:
             try:
                 call_t = get_exact_type_from_node(call.func)
-            except VyperException:
+            except VyperException as e:
                 # there is a problem getting the call type. this might be
                 # an issue, but it will be handled properly later. right now
                 # we just want to be able to construct the call graph.
+                print("ENTER", e, call)
                 continue
 
-            if isinstance(call_t, ContractFunctionT) and (
+            if isinstance(call_t, MemberFunctionT) or (isinstance(call_t, ContractFunctionT) and (
                 call_t.is_internal or call_t.is_constructor
-            ):
+            )):
                 fn_t.called_functions.add(call_t)
 
     for func in function_defs:

vyper/semantics/types/function.py

@@ -848,6 +848,15 @@ def __init__(
         self.return_type = return_type
         self.is_modifying = is_modifying
 
+        self._ir_info = None
+
+    @classmethod
+    def from_FunctionDef(cls, structname: str, funcdef: vy_ast.FunctionDef):
+        args = funcdef.args.args[1:]
+        argtypes = [type_from_annotation(arg.annotation) for arg in args]
+        return_type = _parse_return_type(funcdef)
+        return cls(structname, funcdef.name, argtypes, return_type, True)
+
     @property
     def modifiability(self):
         return Modifiability.MODIFIABLE if self.is_modifying else Modifiability.RUNTIME_CONSTANT
@@ -856,6 +865,18 @@ def modifiability(self):
     def _id(self):
         return self.name
 
+    @property
+    def n_positional_args(self):
+        return len(self.arg_types)
+
+    @property
+    def n_total_args(self):
+        return self.n_positional_args
+
+    @property
+    def keyword_args(self):
+        return []
+
     def __repr__(self):
         return f"{self.underlying_type._id} member function '{self.name}'"
 

vyper/semantics/types/subscriptable.py

@@ -236,8 +236,10 @@ def __init__(self, value_type: VyperType, length: int) -> None:
 
         from vyper.semantics.types.function import MemberFunctionT
 
-        self.add_member("append", MemberFunctionT(self, "append", [self.value_type], None, True))
-        self.add_member("pop", MemberFunctionT(self, "pop", [], self.value_type, True))
+        self.add_member(
+            "append", MemberFunctionT(self._id, "append", [self.value_type], None, True)
+        )
+        self.add_member("pop", MemberFunctionT(self._id, "pop", [], self.value_type, True))
 
     def __repr__(self):
         return f"DynArray[{self.value_type}, {self.length}]"

vyper/semantics/types/user.py

@@ -19,6 +19,7 @@
 from vyper.semantics.analysis.utils import check_modifiability, validate_expected_type
 from vyper.semantics.data_locations import DataLocation
 from vyper.semantics.types.base import VyperType
+from vyper.semantics.types.function import MemberFunctionT
 from vyper.semantics.types.subscriptable import HashMapT
 from vyper.semantics.types.utils import type_from_abi, type_from_annotation
 from vyper.utils import keccak256
@@ -324,14 +325,11 @@ def tuple_keys(self):
         return [k for (k, _v) in self.tuple_items()]
 
     def tuple_items(self):
-        return list(self.members.items())
+        return list(self.member_types.items())
 
     @cached_property
     def member_types(self):
-        """
-        Alias to match TupleT API without shadowing `members` on TupleT
-        """
-        return self.members
+        return {k: v for k, v in self.members.items() if not isinstance(v, MemberFunctionT)}
 
     @classmethod
     def from_StructDef(cls, base_node: vy_ast.StructDef) -> "StructT":
@@ -351,23 +349,30 @@ def from_StructDef(cls, base_node: vy_ast.StructDef) -> "StructT":
         struct_name = base_node.name
         members: dict[str, VyperType] = {}
         for node in base_node.body:
-            if not isinstance(node, vy_ast.AnnAssign):
+            if not isinstance(node, (vy_ast.AnnAssign, vy_ast.FunctionDef)):
                 raise StructureException(
-                    "Struct declarations can only contain variable definitions", node
+                    "Struct declarations can only contain variable or function definitions", node
                 )
-            if node.value is not None:
-                raise StructureException("Cannot assign a value during struct declaration", node)
-            if not isinstance(node.target, vy_ast.Name):
-                raise StructureException("Invalid syntax for struct member name", node.target)
-            member_name = node.target.id
+            if isinstance(node, vy_ast.AnnAssign):
+                if node.value is not None:
+                    raise StructureException(
+                        "Cannot assign a value during struct declaration", node
+                    )
+                if not isinstance(node.target, vy_ast.Name):
+                    raise StructureException("Invalid syntax for struct member name", node.target)
+                member_name = node.target.id
+                typ = type_from_annotation(node.annotation)
+            else:
+                member_name = node.name
+                typ = MemberFunctionT.from_FunctionDef(struct_name, node)
 
             if member_name in members:
                 # TODO: add prev_decl
                 raise NamespaceCollision(
-                    f"struct member '{member_name}' has already been declared", node.value
+                    f"struct member '{member_name}' has already been declared", node
                 )
 
-            members[member_name] = type_from_annotation(node.annotation)
+            members[member_name] = typ
 
         return cls(struct_name, members, ast_def=base_node)