From 162c74d2af77070c6983e0f97fcb593eda4d29d1 Mon Sep 17 00:00:00 2001
From: Richard Si <sichard26@gmail.com>
Date: Wed, 28 Feb 2024 11:52:42 -0500
Subject: [PATCH] [mypyc] Remangle redefined names produced by async with
 (#16408)

Fixes mypyc/mypyc#1001.

---------

Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
---
 mypyc/irbuild/builder.py       |  7 ++++---
 mypyc/test-data/run-async.test | 28 ++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/mypyc/irbuild/builder.py b/mypyc/irbuild/builder.py
index 9d160b08505d..69f3ad9c495f 100644
--- a/mypyc/irbuild/builder.py
+++ b/mypyc/irbuild/builder.py
@@ -1246,14 +1246,15 @@ def add_var_to_env_class(
     ) -> AssignmentTarget:
         # First, define the variable name as an attribute of the environment class, and then
         # construct a target for that attribute.
-        self.fn_info.env_class.attributes[var.name] = rtype
-        attr_target = AssignmentTargetAttr(base.curr_env_reg, var.name)
+        name = remangle_redefinition_name(var.name)
+        self.fn_info.env_class.attributes[name] = rtype
+        attr_target = AssignmentTargetAttr(base.curr_env_reg, name)
 
         if reassign:
             # Read the local definition of the variable, and set the corresponding attribute of
             # the environment class' variable to be that value.
             reg = self.read(self.lookup(var), self.fn_info.fitem.line)
-            self.add(SetAttr(base.curr_env_reg, var.name, reg, self.fn_info.fitem.line))
+            self.add(SetAttr(base.curr_env_reg, name, reg, self.fn_info.fitem.line))
 
         # Override the local definition of the variable to instead point at the variable in
         # the environment class.
diff --git a/mypyc/test-data/run-async.test b/mypyc/test-data/run-async.test
index 85ad172d61df..8488632e6574 100644
--- a/mypyc/test-data/run-async.test
+++ b/mypyc/test-data/run-async.test
@@ -143,3 +143,31 @@ async def foo() -> AsyncIterable[int]:
 yields, val = run_generator(async_iter(foo()))
 assert yields == (0,1,2), yields
 assert val == 'lol no', val
+
+[case testAsyncWithVarReuse]
+class ConMan:
+    async def __aenter__(self) -> int:
+        return 1
+    async def __aexit__(self, *exc: object):
+        pass
+
+class ConManB:
+    async def __aenter__(self) -> int:
+        return 2
+    async def __aexit__(self, *exc: object):
+        pass
+
+async def x() -> None:
+    value = 2
+    async with ConMan() as f:
+        value += f
+    assert value == 3, value
+    async with ConManB() as f:
+        value += f
+    assert value == 5, value
+
+[typing fixtures/typing-full.pyi]
+[file driver.py]
+import asyncio
+import native
+asyncio.run(native.x())