Closes #22869: Move PyOS_CheckStack back to pythonrun.c

1 files changed, 37 insertions, 0 deletions

diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index d435ef4..992a5a3 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -1376,6 +1376,43 @@ cleanup:
 }
 
 
+#if defined(USE_STACKCHECK)
+#if defined(WIN32) && defined(_MSC_VER)
+
+/* Stack checking for Microsoft C */
+
+#include <malloc.h>
+#include <excpt.h>
+
+/*
+ * Return non-zero when we run out of memory on the stack; zero otherwise.
+ */
+int
+PyOS_CheckStack(void)
+{
+    __try {
+        /* alloca throws a stack overflow exception if there's
+           not enough space left on the stack */
+        alloca(PYOS_STACK_MARGIN * sizeof(void*));
+        return 0;
+    } __except (GetExceptionCode() == STATUS_STACK_OVERFLOW ?
+                    EXCEPTION_EXECUTE_HANDLER :
+            EXCEPTION_CONTINUE_SEARCH) {
+        int errcode = _resetstkoflw();
+        if (errcode == 0)
+        {
+            Py_FatalError("Could not reset the stack!");
+        }
+    }
+    return 1;
+}
+
+#endif /* WIN32 && _MSC_VER */
+
+/* Alternate implementations can be added here... */
+
+#endif /* USE_STACKCHECK */
+
 /* Deprecated C API functions still provided for binary compatiblity */
 
 #undef PyParser_SimpleParseFile