From 6a87f5466b360a1046500866a49408207b9bf884 Mon Sep 17 00:00:00 2001
From: tserg <8017125+tserg@users.noreply.github.com>
Date: Sun, 22 Sep 2024 17:13:35 +0800
Subject: [PATCH 01/15] support .vyi const

---
 vyper/semantics/analysis/constant_folding.py |  8 +++---
 vyper/semantics/types/module.py              | 29 ++++++++++++++------
 2 files changed, 24 insertions(+), 13 deletions(-)

diff --git a/vyper/semantics/analysis/constant_folding.py b/vyper/semantics/analysis/constant_folding.py
index 6e4166dc52..88645d7b75 100644
--- a/vyper/semantics/analysis/constant_folding.py
+++ b/vyper/semantics/analysis/constant_folding.py
@@ -2,6 +2,7 @@
 from vyper.exceptions import InvalidLiteral, UnfoldableNode, VyperException
 from vyper.semantics.analysis.base import VarInfo
 from vyper.semantics.analysis.common import VyperNodeVisitorBase
+from vyper.semantics.types.module import InterfaceT
 from vyper.semantics.namespace import get_namespace
 
 
@@ -105,12 +106,11 @@ def visit_Attribute(self, node) -> vy_ast.ExprNode:
         # not super type-safe but we don't care. just catch AttributeErrors
         # and move on
         try:
-            module_t = namespace[value.id].module_t
-
+            ns_member = namespace[value.id]
+            module_t = ns_member if isinstance(ns_member, InterfaceT) else ns_member.module_t
             for module_name in path:
                 module_t = module_t.members[module_name].module_t
-
-            varinfo = module_t.get_member(node.attr, node)
+            varinfo = module_t.get_type_member(node.attr, node) if isinstance(module_t, InterfaceT) else module_t.get_member(node.attr, node)
 
             return varinfo.decl_node.value.get_folded_value()
         except (VyperException, AttributeError, KeyError):
diff --git a/vyper/semantics/types/module.py b/vyper/semantics/types/module.py
index ba72842c65..d1568a5c96 100644
--- a/vyper/semantics/types/module.py
+++ b/vyper/semantics/types/module.py
@@ -10,7 +10,7 @@
     StructureException,
     UnfoldableNode,
 )
-from vyper.semantics.analysis.base import Modifiability
+from vyper.semantics.analysis.base import Modifiability, VarInfo
 from vyper.semantics.analysis.utils import (
     check_modifiability,
     get_exact_type_from_node,
@@ -45,28 +45,33 @@ def __init__(
         functions: dict,
         events: dict,
         structs: dict,
+        constants: dict,
     ) -> None:
         validate_unique_method_ids(list(functions.values()))
 
-        members = functions | events | structs
+        members = functions | events | structs | constants
 
         # sanity check: by construction, there should be no duplicates.
-        assert len(members) == len(functions) + len(events) + len(structs)
+        assert len(members) == len(functions) + len(events) + len(structs) + len(constants)
 
         super().__init__(functions)
 
-        self._helper = VyperType(events | structs)
+        self._helper = VyperType(events | structs | constants)
         self._id = _id
         self._helper._id = _id
         self.functions = functions
         self.events = events
         self.structs = structs
+        self.constants = constants
 
         self.decl_node = decl_node
 
     def get_type_member(self, attr, node):
-        # get an event or struct from this interface
-        return TYPE_T(self._helper.get_member(attr, node))
+        # get an event, struct or constant from this interface
+        type_member = self._helper.get_member(attr, node)
+        if isinstance(type_member, (EventT, StructT)):
+            return TYPE_T(type_member)
+        return type_member
 
     @property
     def getter_signature(self):
@@ -161,10 +166,12 @@ def _from_lists(
         function_list: list[tuple[str, ContractFunctionT]],
         event_list: list[tuple[str, EventT]],
         struct_list: list[tuple[str, StructT]],
+        constant_list: list[tuple[str, VarInfo]],
     ) -> "InterfaceT":
         functions = {}
         events = {}
         structs = {}
+        constants = {}
 
         seen_items: dict = {}
 
@@ -187,7 +194,11 @@ def _mark_seen(name, item):
             _mark_seen(name, struct)
             structs[name] = struct
 
-        return cls(interface_name, decl_node, functions, events, structs)
+        for name, constant in constant_list:
+            _mark_seen(name, constant)
+            constants[name] = constant
+
+        return cls(interface_name, decl_node, functions, events, structs, constants)
 
     @classmethod
     def from_json_abi(cls, name: str, abi: dict) -> "InterfaceT":
@@ -247,8 +258,8 @@ def from_ModuleT(cls, module_t: "ModuleT") -> "InterfaceT":
         # these are accessible via import, but they do not show up
         # in the ABI json
         structs = [(node.name, node._metadata["struct_type"]) for node in module_t.struct_defs]
-
-        return cls._from_lists(module_t._id, module_t.decl_node, funcs, events, structs)
+        constants = [(node.target.id, node.target._metadata["varinfo"]) for node in module_t.variable_decls if node.target._metadata["varinfo"].modifiability is Modifiability.CONSTANT]
+        return cls._from_lists(module_t._id, module_t.decl_node, funcs, events, structs, constants)
 
     @classmethod
     def from_InterfaceDef(cls, node: vy_ast.InterfaceDef) -> "InterfaceT":

From 9edcd528cd274a668ac24749a739f83fc670beac Mon Sep 17 00:00:00 2001
From: tserg <8017125+tserg@users.noreply.github.com>
Date: Sun, 22 Sep 2024 17:26:05 +0800
Subject: [PATCH 02/15] fix lint

---
 vyper/semantics/analysis/constant_folding.py |  6 +++++-
 vyper/semantics/types/module.py              | 19 +++++++++++++------
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/vyper/semantics/analysis/constant_folding.py b/vyper/semantics/analysis/constant_folding.py
index 88645d7b75..b42bd9d005 100644
--- a/vyper/semantics/analysis/constant_folding.py
+++ b/vyper/semantics/analysis/constant_folding.py
@@ -110,7 +110,11 @@ def visit_Attribute(self, node) -> vy_ast.ExprNode:
             module_t = ns_member if isinstance(ns_member, InterfaceT) else ns_member.module_t
             for module_name in path:
                 module_t = module_t.members[module_name].module_t
-            varinfo = module_t.get_type_member(node.attr, node) if isinstance(module_t, InterfaceT) else module_t.get_member(node.attr, node)
+            varinfo = (
+                module_t.get_type_member(node.attr, node)
+                if isinstance(module_t, InterfaceT)
+                else module_t.get_member(node.attr, node)
+            )
 
             return varinfo.decl_node.value.get_folded_value()
         except (VyperException, AttributeError, KeyError):
diff --git a/vyper/semantics/types/module.py b/vyper/semantics/types/module.py
index d1568a5c96..b97870c376 100644
--- a/vyper/semantics/types/module.py
+++ b/vyper/semantics/types/module.py
@@ -45,10 +45,12 @@ def __init__(
         functions: dict,
         events: dict,
         structs: dict,
-        constants: dict,
+        constants: Optional[dict] = None,
     ) -> None:
         validate_unique_method_ids(list(functions.values()))
 
+        constants = constants if constants else {}
+
         members = functions | events | structs | constants
 
         # sanity check: by construction, there should be no duplicates.
@@ -166,7 +168,7 @@ def _from_lists(
         function_list: list[tuple[str, ContractFunctionT]],
         event_list: list[tuple[str, EventT]],
         struct_list: list[tuple[str, StructT]],
-        constant_list: list[tuple[str, VarInfo]],
+        constant_list: Optional[list[tuple[str, VarInfo]]] = None,
     ) -> "InterfaceT":
         functions = {}
         events = {}
@@ -194,9 +196,10 @@ def _mark_seen(name, item):
             _mark_seen(name, struct)
             structs[name] = struct
 
-        for name, constant in constant_list:
-            _mark_seen(name, constant)
-            constants[name] = constant
+        if constant_list:
+            for name, constant in constant_list:
+                _mark_seen(name, constant)
+                constants[name] = constant
 
         return cls(interface_name, decl_node, functions, events, structs, constants)
 
@@ -258,7 +261,11 @@ def from_ModuleT(cls, module_t: "ModuleT") -> "InterfaceT":
         # these are accessible via import, but they do not show up
         # in the ABI json
         structs = [(node.name, node._metadata["struct_type"]) for node in module_t.struct_defs]
-        constants = [(node.target.id, node.target._metadata["varinfo"]) for node in module_t.variable_decls if node.target._metadata["varinfo"].modifiability is Modifiability.CONSTANT]
+        constants = [
+            (node.target.id, node.target._metadata["varinfo"])
+            for node in module_t.variable_decls
+            if node.target._metadata["varinfo"].modifiability is Modifiability.CONSTANT
+        ]
         return cls._from_lists(module_t._id, module_t.decl_node, funcs, events, structs, constants)
 
     @classmethod

From 2065c238993991e5db8e63e6f734db05b43b80ea Mon Sep 17 00:00:00 2001
From: tserg <8017125+tserg@users.noreply.github.com>
Date: Sun, 22 Sep 2024 17:28:36 +0800
Subject: [PATCH 03/15] fix more lint

---
 vyper/semantics/analysis/constant_folding.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/vyper/semantics/analysis/constant_folding.py b/vyper/semantics/analysis/constant_folding.py
index b42bd9d005..ee4a061a08 100644
--- a/vyper/semantics/analysis/constant_folding.py
+++ b/vyper/semantics/analysis/constant_folding.py
@@ -2,8 +2,8 @@
 from vyper.exceptions import InvalidLiteral, UnfoldableNode, VyperException
 from vyper.semantics.analysis.base import VarInfo
 from vyper.semantics.analysis.common import VyperNodeVisitorBase
-from vyper.semantics.types.module import InterfaceT
 from vyper.semantics.namespace import get_namespace
+from vyper.semantics.types.module import InterfaceT
 
 
 def constant_fold(module_ast: vy_ast.Module):

From c718e2864761322d1b6ef5adc911fae2996427d0 Mon Sep 17 00:00:00 2001
From: tserg <8017125+tserg@users.noreply.github.com>
Date: Mon, 23 Sep 2024 21:56:24 +0800
Subject: [PATCH 04/15] apply bts suggestions

---
 vyper/semantics/types/module.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/vyper/semantics/types/module.py b/vyper/semantics/types/module.py
index b97870c376..8cb3dc6ee0 100644
--- a/vyper/semantics/types/module.py
+++ b/vyper/semantics/types/module.py
@@ -49,7 +49,7 @@ def __init__(
     ) -> None:
         validate_unique_method_ids(list(functions.values()))
 
-        constants = constants if constants else {}
+        constants = constants or {}
 
         members = functions | events | structs | constants
 
@@ -264,7 +264,7 @@ def from_ModuleT(cls, module_t: "ModuleT") -> "InterfaceT":
         constants = [
             (node.target.id, node.target._metadata["varinfo"])
             for node in module_t.variable_decls
-            if node.target._metadata["varinfo"].modifiability is Modifiability.CONSTANT
+            if node.is_constant
         ]
         return cls._from_lists(module_t._id, module_t.decl_node, funcs, events, structs, constants)
 

From 8a932a3702a9bd131aee9e79afa49ee94bcb359f Mon Sep 17 00:00:00 2001
From: tserg <8017125+tserg@users.noreply.github.com>
Date: Mon, 23 Sep 2024 21:57:14 +0800
Subject: [PATCH 05/15] fix public constants case

---
 vyper/semantics/types/module.py | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/vyper/semantics/types/module.py b/vyper/semantics/types/module.py
index 8cb3dc6ee0..fa95cb83fa 100644
--- a/vyper/semantics/types/module.py
+++ b/vyper/semantics/types/module.py
@@ -50,11 +50,16 @@ def __init__(
         validate_unique_method_ids(list(functions.values()))
 
         constants = constants or {}
+        public_constants = {
+            k: varinfo for k, varinfo in constants.items() if varinfo.decl_node.is_public
+        }
 
         members = functions | events | structs | constants
 
         # sanity check: by construction, there should be no duplicates.
-        assert len(members) == len(functions) + len(events) + len(structs) + len(constants)
+        assert len(members) == len(functions) + len(events) + len(structs) + len(constants) - len(
+            public_constants
+        )
 
         super().__init__(functions)
 
@@ -179,9 +184,15 @@ def _from_lists(
 
         def _mark_seen(name, item):
             if name in seen_items:
+                prev = seen_items[name]
+                if (
+                    isinstance(prev, ContractFunctionT)
+                    and isinstance(item, VarInfo)
+                    and item.decl_node.is_public
+                ):
+                    return
                 msg = f"multiple functions or events named '{name}'!"
-                prev_decl = seen_items[name].decl_node
-                raise NamespaceCollision(msg, item.decl_node, prev_decl=prev_decl)
+                raise NamespaceCollision(msg, item.decl_node, prev_decl=prev.decl_node)
             seen_items[name] = item
 
         for name, function in function_list:

From 69e5b3e9bc38426e68aafc8c9463083ce1de77c3 Mon Sep 17 00:00:00 2001
From: tserg <8017125+tserg@users.noreply.github.com>
Date: Thu, 26 Sep 2024 22:27:24 +0800
Subject: [PATCH 06/15] change signatures

---
 vyper/semantics/types/module.py | 30 +++++++++++++-----------------
 1 file changed, 13 insertions(+), 17 deletions(-)

diff --git a/vyper/semantics/types/module.py b/vyper/semantics/types/module.py
index fa95cb83fa..480aecde96 100644
--- a/vyper/semantics/types/module.py
+++ b/vyper/semantics/types/module.py
@@ -45,11 +45,10 @@ def __init__(
         functions: dict,
         events: dict,
         structs: dict,
-        constants: Optional[dict] = None,
+        constants: dict,
     ) -> None:
         validate_unique_method_ids(list(functions.values()))
 
-        constants = constants or {}
         public_constants = {
             k: varinfo for k, varinfo in constants.items() if varinfo.decl_node.is_public
         }
@@ -171,8 +170,8 @@ def _from_lists(
         interface_name: str,
         decl_node: Optional[vy_ast.VyperNode],
         function_list: list[tuple[str, ContractFunctionT]],
-        event_list: list[tuple[str, EventT]],
-        struct_list: list[tuple[str, StructT]],
+        event_list: Optional[list[tuple[str, EventT]]] = None,
+        struct_list: Optional[list[tuple[str, StructT]]] = None,
         constant_list: Optional[list[tuple[str, VarInfo]]] = None,
     ) -> "InterfaceT":
         functions = {}
@@ -199,13 +198,15 @@ def _mark_seen(name, item):
             _mark_seen(name, function)
             functions[name] = function
 
-        for name, event in event_list:
-            _mark_seen(name, event)
-            events[name] = event
+        if event_list:
+            for name, event in event_list:
+                _mark_seen(name, event)
+                events[name] = event
 
-        for name, struct in struct_list:
-            _mark_seen(name, struct)
-            structs[name] = struct
+        if struct_list:
+            for name, struct in struct_list:
+                _mark_seen(name, struct)
+                structs[name] = struct
 
         if constant_list:
             for name, constant in constant_list:
@@ -239,8 +240,7 @@ def from_json_abi(cls, name: str, abi: dict) -> "InterfaceT":
         for item in [i for i in abi if i.get("type") == "event"]:
             events.append((item["name"], EventT.from_abi(item)))
 
-        structs: list = []  # no structs in json ABI (as of yet)
-        return cls._from_lists(name, None, functions, events, structs)
+        return cls._from_lists(name, None, functions, events)
 
     @classmethod
     def from_ModuleT(cls, module_t: "ModuleT") -> "InterfaceT":
@@ -294,11 +294,7 @@ def from_InterfaceDef(cls, node: vy_ast.InterfaceDef) -> "InterfaceT":
                 )
             functions.append((func_ast.name, ContractFunctionT.from_InterfaceDef(func_ast)))
 
-        # no structs or events in InterfaceDefs
-        events: list = []
-        structs: list = []
-
-        return cls._from_lists(node.name, node, functions, events, structs)
+        return cls._from_lists(node.name, node, functions)
 
 
 # Datatype to store all module information.

From 8439d5bf15369d6b171bb74d2c474c6a0fec9509 Mon Sep 17 00:00:00 2001
From: tserg <8017125+tserg@users.noreply.github.com>
Date: Sat, 28 Sep 2024 22:38:50 +0800
Subject: [PATCH 07/15] add flags

---
 vyper/semantics/types/module.py | 30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/vyper/semantics/types/module.py b/vyper/semantics/types/module.py
index 480aecde96..c1f75db83e 100644
--- a/vyper/semantics/types/module.py
+++ b/vyper/semantics/types/module.py
@@ -21,7 +21,7 @@
 from vyper.semantics.types.base import TYPE_T, VyperType, is_type_t
 from vyper.semantics.types.function import ContractFunctionT
 from vyper.semantics.types.primitives import AddressT
-from vyper.semantics.types.user import EventT, StructT, _UserType
+from vyper.semantics.types.user import EventT, FlagT, StructT, _UserType
 from vyper.utils import OrderedSet, sha256sum
 
 if TYPE_CHECKING:
@@ -45,6 +45,7 @@ def __init__(
         functions: dict,
         events: dict,
         structs: dict,
+        flags: dict,
         constants: dict,
     ) -> None:
         validate_unique_method_ids(list(functions.values()))
@@ -53,21 +54,22 @@ def __init__(
             k: varinfo for k, varinfo in constants.items() if varinfo.decl_node.is_public
         }
 
-        members = functions | events | structs | constants
+        members = functions | events | structs | flags | constants
 
         # sanity check: by construction, there should be no duplicates.
-        assert len(members) == len(functions) + len(events) + len(structs) + len(constants) - len(
-            public_constants
-        )
+        assert len(members) == len(functions) + len(events) + len(structs) + len(flags) + len(
+            constants
+        ) - len(public_constants)
 
         super().__init__(functions)
 
-        self._helper = VyperType(events | structs | constants)
+        self._helper = VyperType(events | structs | flags | constants)
         self._id = _id
         self._helper._id = _id
         self.functions = functions
         self.events = events
         self.structs = structs
+        self.flags = flags
         self.constants = constants
 
         self.decl_node = decl_node
@@ -75,7 +77,7 @@ def __init__(
     def get_type_member(self, attr, node):
         # get an event, struct or constant from this interface
         type_member = self._helper.get_member(attr, node)
-        if isinstance(type_member, (EventT, StructT)):
+        if isinstance(type_member, (EventT, FlagT, StructT)):
             return TYPE_T(type_member)
         return type_member
 
@@ -172,11 +174,13 @@ def _from_lists(
         function_list: list[tuple[str, ContractFunctionT]],
         event_list: Optional[list[tuple[str, EventT]]] = None,
         struct_list: Optional[list[tuple[str, StructT]]] = None,
+        flag_list: Optional[list[tuple[str, FlagT]]] = None,
         constant_list: Optional[list[tuple[str, VarInfo]]] = None,
     ) -> "InterfaceT":
         functions = {}
         events = {}
         structs = {}
+        flags = {}
         constants = {}
 
         seen_items: dict = {}
@@ -208,12 +212,17 @@ def _mark_seen(name, item):
                 _mark_seen(name, struct)
                 structs[name] = struct
 
+        if flag_list:
+            for name, flag in flag_list:
+                _mark_seen(name, flag)
+                flags[name] = flag
+
         if constant_list:
             for name, constant in constant_list:
                 _mark_seen(name, constant)
                 constants[name] = constant
 
-        return cls(interface_name, decl_node, functions, events, structs, constants)
+        return cls(interface_name, decl_node, functions, events, structs, flags, constants)
 
     @classmethod
     def from_json_abi(cls, name: str, abi: dict) -> "InterfaceT":
@@ -272,12 +281,15 @@ def from_ModuleT(cls, module_t: "ModuleT") -> "InterfaceT":
         # these are accessible via import, but they do not show up
         # in the ABI json
         structs = [(node.name, node._metadata["struct_type"]) for node in module_t.struct_defs]
+        flags = [(node.name, node._metadata["flag_type"]) for node in module_t.flag_defs]
         constants = [
             (node.target.id, node.target._metadata["varinfo"])
             for node in module_t.variable_decls
             if node.is_constant
         ]
-        return cls._from_lists(module_t._id, module_t.decl_node, funcs, events, structs, constants)
+        return cls._from_lists(
+            module_t._id, module_t.decl_node, funcs, events, structs, flags, constants
+        )
 
     @classmethod
     def from_InterfaceDef(cls, node: vy_ast.InterfaceDef) -> "InterfaceT":

From 2539997354502e84a95549e6fe9162359d66ca7b Mon Sep 17 00:00:00 2001
From: tserg <8017125+tserg@users.noreply.github.com>
Date: Wed, 2 Oct 2024 16:27:46 +0800
Subject: [PATCH 08/15] add tests

---
 .../codegen/modules/test_interface_imports.py | 53 +++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/tests/functional/codegen/modules/test_interface_imports.py b/tests/functional/codegen/modules/test_interface_imports.py
index c0fae6496c..485430516e 100644
--- a/tests/functional/codegen/modules/test_interface_imports.py
+++ b/tests/functional/codegen/modules/test_interface_imports.py
@@ -58,3 +58,56 @@ def foo() -> bool:
     c = get_contract(main, input_bundle=input_bundle)
 
     assert c.foo() is True
+
+
+def test_import_interface_constants(make_input_bundle, get_contract):
+    ifaces = """
+FOO: constant(uint256) = 3
+
+interface IFoo:
+    def foo() -> DynArray[uint256, FOO]: nonpayable
+    """
+
+    contract = """
+import ifaces
+
+implements: ifaces
+
+@external
+def foo() -> DynArray[uint256, ifaces.FOO]:
+    return [1, 2, ifaces.FOO]
+    """
+
+    input_bundle = make_input_bundle({"ifaces.vyi": ifaces})
+
+    c = get_contract(contract, input_bundle=input_bundle)
+
+    assert c.foo() == [1, 2, 3]
+
+
+def test_import_interface_flags(make_input_bundle, get_contract):
+    ifaces = """
+flag Foo:
+    BOO
+    MOO
+    POO
+
+interface IFoo:
+    def foo() -> Foo: nonpayable
+    """
+
+    contract = """
+import ifaces
+
+implements: ifaces
+
+@external
+def foo() -> ifaces.Foo:
+    return ifaces.Foo.POO
+    """
+
+    input_bundle = make_input_bundle({"ifaces.vyi": ifaces})
+
+    c = get_contract(contract, input_bundle=input_bundle)
+
+    assert c.foo() == 4

From d2e8aea3486a9733608009bf7613794cdc71ec4c Mon Sep 17 00:00:00 2001
From: tserg <8017125+tserg@users.noreply.github.com>
Date: Fri, 4 Oct 2024 16:05:47 +0800
Subject: [PATCH 09/15] apply cc suggestions

---
 vyper/semantics/types/module.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/vyper/semantics/types/module.py b/vyper/semantics/types/module.py
index c1f75db83e..4ddab64188 100644
--- a/vyper/semantics/types/module.py
+++ b/vyper/semantics/types/module.py
@@ -77,7 +77,7 @@ def __init__(
     def get_type_member(self, attr, node):
         # get an event, struct or constant from this interface
         type_member = self._helper.get_member(attr, node)
-        if isinstance(type_member, (EventT, FlagT, StructT)):
+        if isinstance(type_member, _UserType):
             return TYPE_T(type_member)
         return type_member
 

From 76824a100be428e88124ab229070f18054b208fc Mon Sep 17 00:00:00 2001
From: tserg <8017125+tserg@users.noreply.github.com>
Date: Sat, 12 Oct 2024 09:34:36 +0800
Subject: [PATCH 10/15] rollback constants

---
 .../codegen/modules/test_interface_imports.py | 25 ---------------
 vyper/semantics/analysis/constant_folding.py  | 12 +++----
 vyper/semantics/analysis/local.py             |  2 ++
 vyper/semantics/types/module.py               | 32 +++----------------
 4 files changed, 11 insertions(+), 60 deletions(-)

diff --git a/tests/functional/codegen/modules/test_interface_imports.py b/tests/functional/codegen/modules/test_interface_imports.py
index 485430516e..3f0f8cb010 100644
--- a/tests/functional/codegen/modules/test_interface_imports.py
+++ b/tests/functional/codegen/modules/test_interface_imports.py
@@ -60,31 +60,6 @@ def foo() -> bool:
     assert c.foo() is True
 
 
-def test_import_interface_constants(make_input_bundle, get_contract):
-    ifaces = """
-FOO: constant(uint256) = 3
-
-interface IFoo:
-    def foo() -> DynArray[uint256, FOO]: nonpayable
-    """
-
-    contract = """
-import ifaces
-
-implements: ifaces
-
-@external
-def foo() -> DynArray[uint256, ifaces.FOO]:
-    return [1, 2, ifaces.FOO]
-    """
-
-    input_bundle = make_input_bundle({"ifaces.vyi": ifaces})
-
-    c = get_contract(contract, input_bundle=input_bundle)
-
-    assert c.foo() == [1, 2, 3]
-
-
 def test_import_interface_flags(make_input_bundle, get_contract):
     ifaces = """
 flag Foo:
diff --git a/vyper/semantics/analysis/constant_folding.py b/vyper/semantics/analysis/constant_folding.py
index 9ef3f2ec93..5556905687 100644
--- a/vyper/semantics/analysis/constant_folding.py
+++ b/vyper/semantics/analysis/constant_folding.py
@@ -3,7 +3,6 @@
 from vyper.semantics.analysis.base import VarInfo
 from vyper.semantics.analysis.common import VyperNodeVisitorBase
 from vyper.semantics.namespace import get_namespace
-from vyper.semantics.types.module import InterfaceT
 
 
 def constant_fold(module_ast: vy_ast.Module):
@@ -91,6 +90,7 @@ def visit_Name(self, node) -> vy_ast.ExprNode:
             raise UnfoldableNode("unknown name", node)
 
     def visit_Attribute(self, node) -> vy_ast.ExprNode:
+        print("visit Attribute")
         namespace = get_namespace()
         path = []
         value = node.value
@@ -101,20 +101,16 @@ def visit_Attribute(self, node) -> vy_ast.ExprNode:
         path.reverse()
 
         if not isinstance(value, vy_ast.Name):
+            print("not foldable")
             raise UnfoldableNode("not a module", value)
 
         # not super type-safe but we don't care. just catch AttributeErrors
         # and move on
         try:
-            ns_member = namespace[value.id]
-            module_t = ns_member if isinstance(ns_member, InterfaceT) else ns_member.module_t
+            module_t = namespace[value.id].module_t
             for module_name in path:
                 module_t = module_t.members[module_name].module_t
-            varinfo = (
-                module_t.get_type_member(node.attr, node)
-                if isinstance(module_t, InterfaceT)
-                else module_t.get_member(node.attr, node)
-            )
+            varinfo = module_t.get_member(node.attr, node)
 
             return varinfo.decl_node.value.get_folded_value()
         except (VyperException, AttributeError, KeyError):
diff --git a/vyper/semantics/analysis/local.py b/vyper/semantics/analysis/local.py
index b5292b1dad..46a05f5328 100644
--- a/vyper/semantics/analysis/local.py
+++ b/vyper/semantics/analysis/local.py
@@ -700,6 +700,7 @@ def visit(self, node, typ):
             self.visit(folded_node, typ)
 
     def visit_Attribute(self, node: vy_ast.Attribute, typ: VyperType) -> None:
+        print("local - visit_Attribute")
         _validate_msg_data_attribute(node)
 
         # CMC 2023-10-19 TODO generalize this to mutability check on every node.
@@ -714,6 +715,7 @@ def visit_Attribute(self, node: vy_ast.Attribute, typ: VyperType) -> None:
             _validate_pure_access(node, typ)
 
         value_type = get_exact_type_from_node(node.value)
+        print("value type: ", value_type)
 
         _validate_address_code(node, value_type)
 
diff --git a/vyper/semantics/types/module.py b/vyper/semantics/types/module.py
index 4ddab64188..33e7ff1ab3 100644
--- a/vyper/semantics/types/module.py
+++ b/vyper/semantics/types/module.py
@@ -46,31 +46,23 @@ def __init__(
         events: dict,
         structs: dict,
         flags: dict,
-        constants: dict,
     ) -> None:
         validate_unique_method_ids(list(functions.values()))
 
-        public_constants = {
-            k: varinfo for k, varinfo in constants.items() if varinfo.decl_node.is_public
-        }
-
-        members = functions | events | structs | flags | constants
+        members = functions | events | structs | flags
 
         # sanity check: by construction, there should be no duplicates.
-        assert len(members) == len(functions) + len(events) + len(structs) + len(flags) + len(
-            constants
-        ) - len(public_constants)
+        assert len(members) == len(functions) + len(events) + len(structs) + len(flags)
 
         super().__init__(functions)
 
-        self._helper = VyperType(events | structs | flags | constants)
+        self._helper = VyperType(events | structs | flags)
         self._id = _id
         self._helper._id = _id
         self.functions = functions
         self.events = events
         self.structs = structs
         self.flags = flags
-        self.constants = constants
 
         self.decl_node = decl_node
 
@@ -175,13 +167,11 @@ def _from_lists(
         event_list: Optional[list[tuple[str, EventT]]] = None,
         struct_list: Optional[list[tuple[str, StructT]]] = None,
         flag_list: Optional[list[tuple[str, FlagT]]] = None,
-        constant_list: Optional[list[tuple[str, VarInfo]]] = None,
     ) -> "InterfaceT":
         functions = {}
         events = {}
         structs = {}
         flags = {}
-        constants = {}
 
         seen_items: dict = {}
 
@@ -217,12 +207,7 @@ def _mark_seen(name, item):
                 _mark_seen(name, flag)
                 flags[name] = flag
 
-        if constant_list:
-            for name, constant in constant_list:
-                _mark_seen(name, constant)
-                constants[name] = constant
-
-        return cls(interface_name, decl_node, functions, events, structs, flags, constants)
+        return cls(interface_name, decl_node, functions, events, structs, flags)
 
     @classmethod
     def from_json_abi(cls, name: str, abi: dict) -> "InterfaceT":
@@ -282,14 +267,7 @@ def from_ModuleT(cls, module_t: "ModuleT") -> "InterfaceT":
         # in the ABI json
         structs = [(node.name, node._metadata["struct_type"]) for node in module_t.struct_defs]
         flags = [(node.name, node._metadata["flag_type"]) for node in module_t.flag_defs]
-        constants = [
-            (node.target.id, node.target._metadata["varinfo"])
-            for node in module_t.variable_decls
-            if node.is_constant
-        ]
-        return cls._from_lists(
-            module_t._id, module_t.decl_node, funcs, events, structs, flags, constants
-        )
+        return cls._from_lists(module_t._id, module_t.decl_node, funcs, events, structs, flags)
 
     @classmethod
     def from_InterfaceDef(cls, node: vy_ast.InterfaceDef) -> "InterfaceT":

From be6001565cfa3e0a1741673eb9fab7acb4ccbd08 Mon Sep 17 00:00:00 2001
From: tserg <8017125+tserg@users.noreply.github.com>
Date: Sat, 12 Oct 2024 09:36:02 +0800
Subject: [PATCH 11/15] remove debug prints

---
 vyper/semantics/analysis/local.py | 2 --
 1 file changed, 2 deletions(-)

diff --git a/vyper/semantics/analysis/local.py b/vyper/semantics/analysis/local.py
index 1e3d05678e..809c6532c6 100644
--- a/vyper/semantics/analysis/local.py
+++ b/vyper/semantics/analysis/local.py
@@ -700,7 +700,6 @@ def visit(self, node, typ):
             self.visit(folded_node, typ)
 
     def visit_Attribute(self, node: vy_ast.Attribute, typ: VyperType) -> None:
-        print("local - visit_Attribute")
         _validate_msg_data_attribute(node)
 
         # CMC 2023-10-19 TODO generalize this to mutability check on every node.
@@ -715,7 +714,6 @@ def visit_Attribute(self, node: vy_ast.Attribute, typ: VyperType) -> None:
             _validate_pure_access(node, typ)
 
         value_type = get_exact_type_from_node(node.value)
-        print("value type: ", value_type)
 
         _validate_address_code(node, value_type)
 

From 223d6b3f73cb7f35f79129eab3ab4f683e9deeae Mon Sep 17 00:00:00 2001
From: tserg <8017125+tserg@users.noreply.github.com>
Date: Sat, 12 Oct 2024 09:38:41 +0800
Subject: [PATCH 12/15] more rollbacks

---
 vyper/semantics/types/module.py | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/vyper/semantics/types/module.py b/vyper/semantics/types/module.py
index 33e7ff1ab3..46ec6d4a75 100644
--- a/vyper/semantics/types/module.py
+++ b/vyper/semantics/types/module.py
@@ -10,7 +10,7 @@
     StructureException,
     UnfoldableNode,
 )
-from vyper.semantics.analysis.base import Modifiability, VarInfo
+from vyper.semantics.analysis.base import Modifiability
 from vyper.semantics.analysis.utils import (
     check_modifiability,
     get_exact_type_from_node,
@@ -68,10 +68,7 @@ def __init__(
 
     def get_type_member(self, attr, node):
         # get an event, struct or constant from this interface
-        type_member = self._helper.get_member(attr, node)
-        if isinstance(type_member, _UserType):
-            return TYPE_T(type_member)
-        return type_member
+        return TYPE_T(self._helper.get_member(attr, node))
 
     @property
     def getter_signature(self):
@@ -177,15 +174,9 @@ def _from_lists(
 
         def _mark_seen(name, item):
             if name in seen_items:
-                prev = seen_items[name]
-                if (
-                    isinstance(prev, ContractFunctionT)
-                    and isinstance(item, VarInfo)
-                    and item.decl_node.is_public
-                ):
-                    return
                 msg = f"multiple functions or events named '{name}'!"
-                raise NamespaceCollision(msg, item.decl_node, prev_decl=prev.decl_node)
+                prev_decl = seen_items[name].decl_node
+                raise NamespaceCollision(msg, item.decl_node, prev_decl=prev_decl)
             seen_items[name] = item
 
         for name, function in function_list:
@@ -267,6 +258,7 @@ def from_ModuleT(cls, module_t: "ModuleT") -> "InterfaceT":
         # in the ABI json
         structs = [(node.name, node._metadata["struct_type"]) for node in module_t.struct_defs]
         flags = [(node.name, node._metadata["flag_type"]) for node in module_t.flag_defs]
+
         return cls._from_lists(module_t._id, module_t.decl_node, funcs, events, structs, flags)
 
     @classmethod

From 39e955dbcde0dddc983351f54644c833736dd790 Mon Sep 17 00:00:00 2001
From: tserg <8017125+tserg@users.noreply.github.com>
Date: Sat, 12 Oct 2024 09:39:08 +0800
Subject: [PATCH 13/15] remove more debug prints

---
 vyper/semantics/analysis/constant_folding.py | 2 --
 1 file changed, 2 deletions(-)

diff --git a/vyper/semantics/analysis/constant_folding.py b/vyper/semantics/analysis/constant_folding.py
index 5556905687..80c5b5ab04 100644
--- a/vyper/semantics/analysis/constant_folding.py
+++ b/vyper/semantics/analysis/constant_folding.py
@@ -90,7 +90,6 @@ def visit_Name(self, node) -> vy_ast.ExprNode:
             raise UnfoldableNode("unknown name", node)
 
     def visit_Attribute(self, node) -> vy_ast.ExprNode:
-        print("visit Attribute")
         namespace = get_namespace()
         path = []
         value = node.value
@@ -101,7 +100,6 @@ def visit_Attribute(self, node) -> vy_ast.ExprNode:
         path.reverse()
 
         if not isinstance(value, vy_ast.Name):
-            print("not foldable")
             raise UnfoldableNode("not a module", value)
 
         # not super type-safe but we don't care. just catch AttributeErrors

From 785b606572711203bd1ddca2d3518ada4521b194 Mon Sep 17 00:00:00 2001
From: tserg <8017125+tserg@users.noreply.github.com>
Date: Sat, 12 Oct 2024 09:40:09 +0800
Subject: [PATCH 14/15] clean up

---
 vyper/semantics/analysis/constant_folding.py | 2 ++
 vyper/semantics/types/module.py              | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/vyper/semantics/analysis/constant_folding.py b/vyper/semantics/analysis/constant_folding.py
index 80c5b5ab04..98cab0f8cb 100644
--- a/vyper/semantics/analysis/constant_folding.py
+++ b/vyper/semantics/analysis/constant_folding.py
@@ -106,8 +106,10 @@ def visit_Attribute(self, node) -> vy_ast.ExprNode:
         # and move on
         try:
             module_t = namespace[value.id].module_t
+
             for module_name in path:
                 module_t = module_t.members[module_name].module_t
+
             varinfo = module_t.get_member(node.attr, node)
 
             return varinfo.decl_node.value.get_folded_value()
diff --git a/vyper/semantics/types/module.py b/vyper/semantics/types/module.py
index 46ec6d4a75..11f083fb54 100644
--- a/vyper/semantics/types/module.py
+++ b/vyper/semantics/types/module.py
@@ -67,7 +67,7 @@ def __init__(
         self.decl_node = decl_node
 
     def get_type_member(self, attr, node):
-        # get an event, struct or constant from this interface
+        # get an event, struct or flag from this interface
         return TYPE_T(self._helper.get_member(attr, node))
 
     @property

From d936b866506d4a3b7368a318ded5da217dbb6833 Mon Sep 17 00:00:00 2001
From: Charles Cooper <cooper.charles.m@gmail.com>
Date: Mon, 14 Oct 2024 21:28:44 -0400
Subject: [PATCH 15/15] small cleanup

---
 vyper/semantics/types/module.py | 34 ++++++++++++++-------------------
 1 file changed, 14 insertions(+), 20 deletions(-)

diff --git a/vyper/semantics/types/module.py b/vyper/semantics/types/module.py
index 866d302a78..dabeaf21b6 100644
--- a/vyper/semantics/types/module.py
+++ b/vyper/semantics/types/module.py
@@ -165,10 +165,10 @@ def _from_lists(
         struct_list: Optional[list[tuple[str, StructT]]] = None,
         flag_list: Optional[list[tuple[str, FlagT]]] = None,
     ) -> "InterfaceT":
-        functions = {}
-        events = {}
-        structs = {}
-        flags = {}
+        functions: dict[str, ContractFunctionT] = {}
+        events: dict[str, EventT] = {}
+        structs: dict[str, StructT] = {}
+        flags: dict[str, FlagT] = {}
 
         seen_items: dict = {}
 
@@ -179,24 +179,18 @@ def _mark_seen(name, item):
                 raise NamespaceCollision(msg, item.decl_node, prev_decl=prev_decl)
             seen_items[name] = item
 
-        for name, function in function_list:
-            _mark_seen(name, function)
-            functions[name] = function
+        def _process(dst_dict, items):
+            if items is None:
+                return
 
-        if event_list:
-            for name, event in event_list:
-                _mark_seen(name, event)
-                events[name] = event
+            for name, item in items:
+                _mark_seen(name, item)
+                dst_dict[name] = item
 
-        if struct_list:
-            for name, struct in struct_list:
-                _mark_seen(name, struct)
-                structs[name] = struct
-
-        if flag_list:
-            for name, flag in flag_list:
-                _mark_seen(name, flag)
-                flags[name] = flag
+        _process(functions, function_list)
+        _process(events, event_list)
+        _process(structs, struct_list)
+        _process(flags, flag_list)
 
         return cls(interface_name, decl_node, functions, events, structs, flags)