fix some small bugs

vyper/semantics/analysis/constant_folding.py

@@ -1,6 +1,7 @@
 from vyper import ast as vy_ast
 from vyper.exceptions import InvalidLiteral, UndeclaredDefinition, UnfoldableNode
 from vyper.semantics.analysis.common import VyperNodeVisitorBase
+from vyper.semantics.analysis.base import VarInfo
 from vyper.semantics.namespace import get_namespace
 
 
@@ -13,6 +14,9 @@ def visit(self, node):
                 # ignore bubbled up exceptions
                 pass
 
+        if node.has_folded_value:
+            return node.get_folded_value()
+
         try:
             for class_ in node.__class__.mro():
                 ast_type = class_.__name__
@@ -22,26 +26,24 @@ def visit(self, node):
                     folded_value = visitor_fn(node)
                     node._set_folded_value(folded_value)
                     return folded_value
-            else:
-                raise UnfoldableNode
         except UnfoldableNode:
             # ignore bubbled up exceptions
-            pass
+            return node
 
     def visit_Constant(self, node) -> vy_ast.ExprNode:
         return node
 
     def visit_Name(self, node) -> vy_ast.ExprNode:
         namespace = get_namespace()
         try:
-            ret = namespace[node]
+            varinfo = namespace[node.id]
         except UndeclaredDefinition:
             raise UnfoldableNode("unknown name", node)
 
-        if not isinstance(ret, vy_ast.VariableDecl) and not ret.is_constant:
+        if not isinstance(varinfo, VarInfo) or not varinfo.is_constant:
             raise UnfoldableNode("not a constant", node)
 
-        return ret.value.get_folded_value()
+        return varinfo.decl_node.value.get_folded_value()
 
     def visit_UnaryOp(self, node):
         operand = node.operand.get_folded_value()

vyper/semantics/analysis/module.py

@@ -4,6 +4,7 @@
 
 import vyper.builtins.interfaces
 from vyper import ast as vy_ast
+from vyper.semantics.analysis.constant_folding import ConstantFolder
 from vyper.ast.validation import validate_literal_nodes
 from vyper.compiler.input_bundle import ABIInput, FileInput, FilesystemInputBundle, InputBundle
 from vyper.evm.opcodes import version_check
@@ -159,6 +160,9 @@ def analyze(self) -> ModuleT:
             if count == len(to_visit):
                 err_list.raise_if_not_empty()
 
+        # run constant folding recursively on all nodes
+        ConstantFolder().visit(self.ast)
+
         self.module_t = ModuleT(self.ast)
         self.ast._metadata["type"] = self.module_t
 
@@ -308,6 +312,8 @@ def _validate_self_namespace():
         if node.is_constant:
             assert node.value is not None  # checked in VariableDecl.validate()
 
+            ConstantFolder().visit(node.value)
+
             ExprVisitor().visit(node.value, type_)  # performs validate_expected_type
 
             if not check_modifiability(node.value, Modifiability.CONSTANT):