gh-98925: Lower marshal recursion depth for WASI (GH-98938)

brettcannon · web-flow · commit 9711265182f1 · 2022-11-01T15:51:05.000-07:00
For wasmtime 2.0, the stack depth cost is 6% higher. This causes the default max `marshal` recursion depth to blow the stack.

As the default marshal depth is 2000 and Windows is set to 1000, split the difference and choose 1500 for WASI to be safe.
diff --git a/.gitignore b/.gitignore
@@ -116,6 +116,7 @@ PCbuild/win32/
 Tools/unicode/data/
 /autom4te.cache
 /build/
+/builddir/
 /config.cache
 /config.log
 /config.status
diff --git a/Lib/test/test_marshal.py b/Lib/test/test_marshal.py
@@ -260,6 +260,8 @@ def test_recursion_limit(self):
         #if os.name == 'nt' and support.Py_DEBUG:
         if os.name == 'nt':
             MAX_MARSHAL_STACK_DEPTH = 1000
+        elif sys.platform == 'wasi':
+            MAX_MARSHAL_STACK_DEPTH = 1500
         else:
             MAX_MARSHAL_STACK_DEPTH = 2000
         for i in range(MAX_MARSHAL_STACK_DEPTH - 2):
diff --git a/Misc/NEWS.d/next/Core and Builtins/2022-10-31-18-03-10.gh-issue-98925.zpdjVd.rst b/Misc/NEWS.d/next/Core and Builtins/2022-10-31-18-03-10.gh-issue-98925.zpdjVd.rst
@@ -0,0 +1,2 @@
+Lower the recursion depth for marshal on WASI to support (in-development)
+wasmtime 2.0.
diff --git a/Python/marshal.c b/Python/marshal.c
@@ -34,6 +34,8 @@ module marshal
  */
 #if defined(MS_WINDOWS)
 #define MAX_MARSHAL_STACK_DEPTH 1000
+#elif defined(__wasi__)
+#define MAX_MARSHAL_STACK_DEPTH 1500
 #else
 #define MAX_MARSHAL_STACK_DEPTH 2000
 #endif

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+Lower the recursion depth for marshal on WASI to support (in-development)`
	`2`	`+wasmtime 2.0.`