From 11da7d4e210c6e358c65c7b2bf02360e7b6351ad Mon Sep 17 00:00:00 2001
From: Ken Jin <kenjin@python.org>
Date: Tue, 14 Apr 2026 23:46:54 +0800
Subject: [PATCH] gh-148047: Revert "GH-148047: Check early whether
 tail-calling is possible for MSVC builds on Windows (#148036)" (#148558)

This reverts commit cbd81d59cfea4f7b881642e804646da3a328a712.
---
 .../Build/2026-04-03-20-09-46.gh-issue-148047.HE6iGK.rst | 2 --
 PCbuild/pythoncore.vcxproj                               | 9 ---------
 2 files changed, 11 deletions(-)
 delete mode 100644 Misc/NEWS.d/next/Build/2026-04-03-20-09-46.gh-issue-148047.HE6iGK.rst

diff --git a/Misc/NEWS.d/next/Build/2026-04-03-20-09-46.gh-issue-148047.HE6iGK.rst b/Misc/NEWS.d/next/Build/2026-04-03-20-09-46.gh-issue-148047.HE6iGK.rst
deleted file mode 100644
index e43a2695a131..000000000000
--- a/Misc/NEWS.d/next/Build/2026-04-03-20-09-46.gh-issue-148047.HE6iGK.rst
+++ /dev/null
@@ -1,2 +0,0 @@
-Fail fast with an explicit and clear error message if tail-calling is not
-possible for MSVC builds on Windows. Patch by Chris Eibl.
diff --git a/PCbuild/pythoncore.vcxproj b/PCbuild/pythoncore.vcxproj
index 9356a66dfb46..61bee29c0af3 100644
--- a/PCbuild/pythoncore.vcxproj
+++ b/PCbuild/pythoncore.vcxproj
@@ -749,13 +749,4 @@
   <Target Name="_DeletePyBuildDirTxt" BeforeTargets="PrepareForBuild">
     <Delete Files="$(OutDir)pybuilddir.txt" />
   </Target>
-
-  <Target Name="_CheckTailCalling" BeforeTargets="PrepareForBuild" Condition="'$(UseTailCallInterp)' == 'true' and $(PlatformToolset) != 'ClangCL'">
-    <Error Text="MSVC supports tail-calling only for x64."
-           Condition="$(Platform) != 'x64'" />
-    <Error Text="Platform toolset >= v145 is required for tail-calling."
-           Condition="$(PlatformToolset.Replace('v', '0')) &lt; '145'" />
-    <Error Text="MSVC requires optimization to be enabled for tail-calling."
-           Condition="$(Configuration) == 'Debug'" />
-  </Target>
 </Project>
-- 
2.47.3