Better _ZSt15get_new_handlerv fix

Author: DinoV

Include/internal/pycore_mimalloc.h

@@ -14,6 +14,9 @@
 
 #ifdef WITH_MIMALLOC
 #  define MI_NO_PTHREAD_ATFORK 1
+// CPython never uses mimalloc's C++ operator new APIs, so don't define a weak
+// std::get_new_handler() (_ZSt15get_new_handlerv) in libpython.
+#  define MI_NO_CXX_NEW_HANDLER 1
 #  ifdef MS_WINDOWS
 // Initialize from a CRT initializer and use FLS for thread cleanup instead
 // of TLS callbacks, which run during DLL attach before the CRT is set up.

Objects/mimalloc/alloc/alloc.c

@@ -822,7 +822,9 @@ static bool mi_try_new_handler(void) {
 #else
 typedef void (*std_new_handler_t)(void);
 
-#if (defined(__GNUC__) || (defined(__clang__) && !defined(_MSC_VER)))  // exclude clang-cl, see issue #631
+// Define MI_NO_CXX_NEW_HANDLER to not define a weak `std::get_new_handler` (`_ZSt15get_new_handlerv`)
+// when the C++ new-handler is never used (e.g. when only the C API is used).
+#if (defined(__GNUC__) || (defined(__clang__) && !defined(_MSC_VER))) && !defined(MI_NO_CXX_NEW_HANDLER)  // exclude clang-cl, see issue #631
 std_new_handler_t __attribute__((weak)) _ZSt15get_new_handlerv(void) {
   return NULL;
 }

Tools/build/smelly.py

@@ -20,7 +20,7 @@
 # mimalloc doesn't use static, but it's symbols are not exported
 # from the shared library.  They do show up in the static library
 # before its linked into an executable.
-ALLOWED_STATIC_PREFIXES = ('mi_', '_mi_', '__mi', '_ZSt')
+ALLOWED_STATIC_PREFIXES = ('mi_', '_mi_', '__mi')
 
 # "Legacy": some old symbols are prefixed by "PY_".
 EXCEPTIONS = frozenset({