Fix Python 3.13+ by calling CPython API

Author: VaggelisD

mypyc/lib-rt/static_data.c

@@ -55,6 +55,7 @@ intern_strings(void) {
     INTERN_STRING(endswith, "endswith");
     INTERN_STRING(get_type_hints, "get_type_hints");
     INTERN_STRING(keys, "keys");
+    INTERN_STRING(lower, "lower");
     INTERN_STRING(items, "items");
     INTERN_STRING(join, "join");
     INTERN_STRING(register_, "register");
@@ -66,6 +67,7 @@ intern_strings(void) {
     INTERN_STRING(throw_, "throw");
     INTERN_STRING(translate, "translate");
     INTERN_STRING(update, "update");
+    INTERN_STRING(upper, "upper");
     INTERN_STRING(values, "values");
     return 0;
 }

mypyc/lib-rt/static_data.h

@@ -47,6 +47,7 @@ typedef struct mypyc_interned_str_struct {
     PyObject *endswith;
     PyObject *get_type_hints;
     PyObject *keys;
+    PyObject *lower;
     PyObject *items;
     PyObject *join;
     PyObject *register_;
@@ -58,6 +59,7 @@ typedef struct mypyc_interned_str_struct {
     PyObject *throw_;
     PyObject *translate;
     PyObject *update;
+    PyObject *upper;
     PyObject *values;
 } mypyc_interned_str_struct;
 

mypyc/lib-rt/str_ops.c

@@ -7,10 +7,9 @@
 #include <Python.h>
 #include "CPy.h"
 
-// On 3.13+, _PyUnicode_CheckConsistency and _PyUnicode_ToLowerFull/ToUpperFull
-// were moved from the public API to internal/pycore_unicodeobject.h.
+// The _PyUnicode_CheckConsistency definition has been moved to the internal API
 // https://github.com/python/cpython/pull/106398
-#if CPY_3_13_FEATURES
+#if defined(Py_DEBUG) && CPY_3_13_FEATURES
 #include "internal/pycore_unicodeobject.h"
 #endif
 
@@ -684,7 +683,12 @@ static int CPy_ASCII_Upper(unsigned char c) { return Py_TOUPPER(c); }
 
 static PyObject *CPyStr_ChangeCase(PyObject *self,
                                     int (*ascii_func)(unsigned char),
-                                    int (*unicode_func)(Py_UCS4, Py_UCS4 *)) {
+#if CPY_3_13_FEATURES
+                                    PyObject *method_name
+#else
+                                    int (*unicode_func)(Py_UCS4, Py_UCS4 *)
+#endif
+                                    ) {
     Py_ssize_t len = PyUnicode_GET_LENGTH(self);
     if (len == 0) {
         Py_INCREF(self);
@@ -703,6 +707,11 @@ static PyObject *CPyStr_ChangeCase(PyObject *self,
         return res;
     }
 
+#if CPY_3_13_FEATURES
+    // On 3.13+, _PyUnicode_ToLowerFull/ToUpperFull are no longer exported,
+    // so fall back to CPython's method implementation for non-ASCII strings.
+    return PyObject_CallMethodNoArgs(self, method_name);
+#else
     // General Unicode: unicode_func handles 1-to-N expansion.
     // Worst case: each codepoint expands to 3 (per Unicode standard).
     // The tmp buffer is short-lived, and PyUnicode_FromKindAndData
@@ -724,14 +733,23 @@ static PyObject *CPyStr_ChangeCase(PyObject *self,
     PyObject *res = PyUnicode_FromKindAndData(PyUnicode_4BYTE_KIND, tmp, out_len);
     PyMem_Free(tmp);
     return res;
+#endif
 }
 
 PyObject *CPyStr_Lower(PyObject *self) {
+#if CPY_3_13_FEATURES
+    return CPyStr_ChangeCase(self, CPy_ASCII_Lower, mypyc_interned_str.lower);
+#else
     return CPyStr_ChangeCase(self, CPy_ASCII_Lower, _PyUnicode_ToLowerFull);
+#endif
 }
 
 PyObject *CPyStr_Upper(PyObject *self) {
+#if CPY_3_13_FEATURES
+    return CPyStr_ChangeCase(self, CPy_ASCII_Upper, mypyc_interned_str.upper);
+#else
     return CPyStr_ChangeCase(self, CPy_ASCII_Upper, _PyUnicode_ToUpperFull);
+#endif
 }
 
 bool CPyStr_IsDigit(PyObject *str) {