From 8f44e7863654700d5f99d70a79146ae640e9e57f Mon Sep 17 00:00:00 2001
From: Brett Cannon <brett@python.org>
Date: Wed, 23 Jul 2025 10:42:08 -0700
Subject: [PATCH] Touch up `Setup.local` handling in `Tools/wasm/wasi` The
 comment in the generated file is more self-explanatory. The checks for
 unexpected file contents are also strengthened.

---
 Tools/wasm/wasi/__main__.py | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/Tools/wasm/wasi/__main__.py b/Tools/wasm/wasi/__main__.py
index 54ccc95157d57d..f3c97ff3fd11a0 100644
--- a/Tools/wasm/wasi/__main__.py
+++ b/Tools/wasm/wasi/__main__.py
@@ -23,7 +23,8 @@
 BUILD_DIR = CROSS_BUILD_DIR / "build"
 
 LOCAL_SETUP = CHECKOUT / "Modules" / "Setup.local"
-LOCAL_SETUP_MARKER = "# Generated by Tools/wasm/wasi.py\n".encode("utf-8")
+LOCAL_SETUP_MARKER = ("# Generated by Tools/wasm/wasi .\n"
+                      "# Required to statically build extension modules.").encode("utf-8")
 
 WASMTIME_VAR_NAME = "WASMTIME"
 WASMTIME_HOST_RUNNER_VAR = f"{{{WASMTIME_VAR_NAME}}}"
@@ -141,9 +142,12 @@ def build_python_is_pydebug():
 def configure_build_python(context, working_dir):
     """Configure the build/host Python."""
     if LOCAL_SETUP.exists():
-        print(f"👍 {LOCAL_SETUP} exists ...")
+        if LOCAL_SETUP.read_bytes() == LOCAL_SETUP_MARKER:
+            print(f"👍 {LOCAL_SETUP} exists ...")
+        else:
+            print(f"⚠️ {LOCAL_SETUP} exists, but has unexpected contents")
     else:
-        print(f"📝 Touching {LOCAL_SETUP} ...")
+        print(f"📝 Creating {LOCAL_SETUP} ...")
         LOCAL_SETUP.write_bytes(LOCAL_SETUP_MARKER)
 
     configure = [os.path.relpath(CHECKOUT / 'configure', working_dir)]
@@ -297,9 +301,8 @@ def clean_contents(context):
         shutil.rmtree(CROSS_BUILD_DIR)
 
     if LOCAL_SETUP.exists():
-        with LOCAL_SETUP.open("rb") as file:
-            if file.read(len(LOCAL_SETUP_MARKER)) == LOCAL_SETUP_MARKER:
-                print(f"🧹 Deleting generated {LOCAL_SETUP} ...")
+        if LOCAL_SETUP.read_bytes() == LOCAL_SETUP_MARKER:
+            print(f"🧹 Deleting generated {LOCAL_SETUP} ...")
 
 
 def main():