Added the const qualifier for char* argument of Py_EnterRecursiveCall().

Doc/c-api/exceptions.rst

@@ -674,7 +674,7 @@ level, both in the core and in extension modules.  They are needed if the
 recursive code does not necessarily invoke Python code (which tracks its
 recursion depth automatically).
 
-.. c:function:: int Py_EnterRecursiveCall(char *where)
+.. c:function:: int Py_EnterRecursiveCall(const char *where)
 
    Marks a point where a recursive C-level call is about to be performed.
 

Include/ceval.h

@@ -79,7 +79,7 @@ PyAPI_FUNC(int) Py_GetRecursionLimit(void);
     do{ if(_Py_MakeEndRecCheck(PyThreadState_GET()->recursion_depth))  \
       PyThreadState_GET()->overflowed = 0;  \
     } while(0)
-PyAPI_FUNC(int) _Py_CheckRecursiveCall(char *where);
+PyAPI_FUNC(int) _Py_CheckRecursiveCall(const char *where);
 PyAPI_DATA(int) _Py_CheckRecursionLimit;
 
 #ifdef USE_STACKCHECK

Python/ceval.c

@@ -712,7 +712,7 @@ Py_SetRecursionLimit(int new_limit)
    to guarantee that _Py_CheckRecursiveCall() is regularly called.
    Without USE_STACKCHECK, there is no need for this. */
 int
-_Py_CheckRecursiveCall(char *where)
+_Py_CheckRecursiveCall(const char *where)
 {
     PyThreadState *tstate = PyThreadState_GET();