From 4c66c8c10a9164e464a3cf786bc199f854a9beac Mon Sep 17 00:00:00 2001
From: Charles Cooper <cooper.charles.m@gmail.com>
Date: Thu, 9 May 2024 18:26:28 -0400
Subject: [PATCH] fix[lang]: recursion in `uses` analysis for nonreentrant
 functions (#3971)

this commit fixes `uses` analysis for nonreentrant functions, which are
called recursively.

a partial fix for this was applied in cb940684a9137, but it missed the
case where a nonreentrant function is deep in the call tree.
---
 .../syntax/modules/test_initializers.py       | 80 +++++++++++++------
 vyper/semantics/types/function.py             |  6 +-
 2 files changed, 62 insertions(+), 24 deletions(-)

diff --git a/tests/functional/syntax/modules/test_initializers.py b/tests/functional/syntax/modules/test_initializers.py
index 2193050a5f..29d611d54a 100644
--- a/tests/functional/syntax/modules/test_initializers.py
+++ b/tests/functional/syntax/modules/test_initializers.py
@@ -1300,52 +1300,86 @@ def foo():
     assert e.value._hint == "try importing lib1 first"
 
 
-def test_nonreentrant_exports(make_input_bundle):
+@pytest.fixture
+def nonreentrant_library_bundle(make_input_bundle):
+    # test simple case
     lib1 = """
 # lib1.vy
-@external
+@internal
 @nonreentrant
 def bar():
     pass
+
+# lib1.vy
+@external
+@nonreentrant
+def ext_bar():
+    pass
     """
-    main = """
+    # test case with recursion
+    lib2 = """
+@internal
+def bar():
+    self.baz()
+
+@external
+def ext_bar():
+    self.baz()
+
+@nonreentrant
+@internal
+def baz():
+    return
+    """
+    # test case with nested recursion
+    lib3 = """
 import lib1
+uses: lib1
 
-exports: lib1.bar  # line 4
+@internal
+def bar():
+    lib1.bar()
+
+@external
+def ext_bar():
+    lib1.bar()
+    """
+
+    return make_input_bundle({"lib1.vy": lib1, "lib2.vy": lib2, "lib3.vy": lib3})
+
+
+@pytest.mark.parametrize("lib", ("lib1", "lib2", "lib3"))
+def test_nonreentrant_exports(nonreentrant_library_bundle, lib):
+    main = f"""
+import {lib}
+
+exports: {lib}.ext_bar  # line 4
 
 @external
 def foo():
     pass
     """
-    input_bundle = make_input_bundle({"lib1.vy": lib1})
     with pytest.raises(ImmutableViolation) as e:
-        compile_code(main, input_bundle=input_bundle)
-    assert e.value._message == "Cannot access `lib1` state!" + NONREENTRANT_NOTE
-    hint = "add `uses: lib1` or `initializes: lib1` as a top-level statement to your contract"
+        compile_code(main, input_bundle=nonreentrant_library_bundle)
+    assert e.value._message == f"Cannot access `{lib}` state!" + NONREENTRANT_NOTE
+    hint = f"add `uses: {lib}` or `initializes: {lib}` as a top-level statement to your contract"
     assert e.value._hint == hint
     assert e.value.annotations[0].lineno == 4
 
 
-def test_internal_nonreentrant_import(make_input_bundle):
-    lib1 = """
-# lib1.vy
-@internal
-@nonreentrant
-def bar():
-    pass
-    """
-    main = """
-import lib1
+@pytest.mark.parametrize("lib", ("lib1", "lib2", "lib3"))
+def test_internal_nonreentrant_import(nonreentrant_library_bundle, lib):
+    main = f"""
+import {lib}
 
 @external
 def foo():
-    lib1.bar()  # line 6
+    {lib}.bar()  # line 6
     """
-    input_bundle = make_input_bundle({"lib1.vy": lib1})
     with pytest.raises(ImmutableViolation) as e:
-        compile_code(main, input_bundle=input_bundle)
-    assert e.value._message == "Cannot access `lib1` state!" + NONREENTRANT_NOTE
+        compile_code(main, input_bundle=nonreentrant_library_bundle)
+    assert e.value._message == f"Cannot access `{lib}` state!" + NONREENTRANT_NOTE
 
-    hint = "add `uses: lib1` or `initializes: lib1` as a top-level statement to your contract"
+    hint = f"add `uses: {lib}` or `initializes: {lib}` as a top-level statement to your contract"
     assert e.value._hint == hint
     assert e.value.annotations[0].lineno == 6
diff --git a/vyper/semantics/types/function.py b/vyper/semantics/types/function.py
index 86fd90f0f9..7eab0958a6 100644
--- a/vyper/semantics/types/function.py
+++ b/vyper/semantics/types/function.py
@@ -165,7 +165,11 @@ def get_variable_accesses(self):
         return self._variable_reads | self._variable_writes
 
     def uses_state(self):
-        return self.nonreentrant or uses_state(self.get_variable_accesses())
+        return (
+            self.nonreentrant
+            or uses_state(self.get_variable_accesses())
+            or any(f.nonreentrant for f in self.reachable_internal_functions)
+        )
 
     def get_used_modules(self):
         # _used_modules is populated during analysis