refactor: merge annotation.py and local.py (vyperlang#3456)

This commit merges two phases of analysis: typechecking
(`vyper/semantics/analysis/local.py`) and annotation of ast nodes with
types (`vyper/semantics/analysis/annotation.py`). This is both for
consistency with how it is done for `analysis/module.py`, and also
because it increases internal consistency, as some typechecking was
being done in `annotation.py`. It is also easier to maintain this way,
since bugfixes or modifications to typechecking need to only be done in
one place, rather than two passes. Lastly, it also probably improves
performance, because it collapses two passes into one (and calls
`get_*_type_from_node` less often).

This commit also fixes a bug with accessing the iterator when the
iterator is an empty list literal.

tests/parser/syntax/test_list.py

@@ -305,8 +305,9 @@ def foo():
     """
 @external
 def foo():
+    x: DynArray[uint256, 3] = [1, 2, 3]
     for i in [[], []]:
-        pass
+        x = i
     """,
 ]
 

vyper/ast/nodes.pyi

@@ -142,6 +142,7 @@ class Expr(VyperNode):
 
 class UnaryOp(ExprNode):
     op: VyperNode = ...
+    operand: VyperNode = ...
 
 class USub(VyperNode): ...
 class Not(VyperNode): ...
@@ -165,12 +166,15 @@ class BitXor(VyperNode): ...
 
 class BoolOp(ExprNode):
     op: VyperNode = ...
+    values: list[VyperNode] = ...
 
 class And(VyperNode): ...
 class Or(VyperNode): ...
 
 class Compare(ExprNode):
     op: VyperNode = ...
+    left: VyperNode = ...
+    right: VyperNode = ...
 
 class Eq(VyperNode): ...
 class NotEq(VyperNode): ...
@@ -179,6 +183,7 @@ class LtE(VyperNode): ...
 class Gt(VyperNode): ...
 class GtE(VyperNode): ...
 class In(VyperNode): ...
+class NotIn(VyperNode): ...
 
 class Call(ExprNode):
     args: list = ...

vyper/builtins/_signatures.py

@@ -74,7 +74,7 @@ def decorator_fn(self, node, context):
     return decorator_fn
 
 
-class BuiltinFunction:
+class BuiltinFunction(VyperType):
     _has_varargs = False
     _kwargs: Dict[str, KwargSettings] = {}
 

vyper/builtins/functions.py

@@ -475,6 +475,12 @@ def evaluate(self, node):
 
         return vy_ast.Int.from_node(node, value=length)
 
+    def infer_arg_types(self, node):
+        self._validate_arg_types(node)
+        # return a concrete type
+        typ = get_possible_types_from_node(node.args[0]).pop()
+        return [typ]
+
     def build_IR(self, node, context):
         arg = Expr(node.args[0], context).ir_node
         if arg.value == "~calldata":

vyper/semantics/analysis/common.py

@@ -10,10 +10,17 @@ class VyperNodeVisitorBase:
     def visit(self, node, *args):
         if isinstance(node, self.ignored_types):
             return
+
+        # iterate over the MRO until we find a matching visitor function
+        # this lets us use a single function to broadly target several
+        # node types with a shared parent
+        for class_ in node.__class__.mro():
+            ast_type = class_.__name__
+            visitor_fn = getattr(self, f"visit_{ast_type}", None)
+            if visitor_fn:
+                return visitor_fn(node, *args)
+
         node_type = type(node).__name__
-        visitor_fn = getattr(self, f"visit_{node_type}", None)
-        if visitor_fn is None:
-            raise StructureException(
-                f"Unsupported syntax for {self.scope_name} namespace: {node_type}", node
-            )
-        visitor_fn(node, *args)
+        raise StructureException(
+            f"Unsupported syntax for {self.scope_name} namespace: {node_type}", node
+        )