Added the const qualifier to char* variables that refer to readonly internal

UTF-8 represenatation of Unicode objects.

Python/bltinmodule.c

@@ -1893,7 +1893,7 @@ builtin_input_impl(PyObject *module, PyObject *prompt)
         char *s = NULL;
         PyObject *stdin_encoding = NULL, *stdin_errors = NULL;
         PyObject *stdout_encoding = NULL, *stdout_errors = NULL;
-        char *stdin_encoding_str, *stdin_errors_str;
+        const char *stdin_encoding_str, *stdin_errors_str;
         PyObject *result;
         size_t len;
 
@@ -1914,7 +1914,7 @@ builtin_input_impl(PyObject *module, PyObject *prompt)
             Py_DECREF(tmp);
         if (prompt != NULL) {
             /* We have a prompt, encode it as stdout would */
-            char *stdout_encoding_str, *stdout_errors_str;
+            const char *stdout_encoding_str, *stdout_errors_str;
             PyObject *stringpo;
             stdout_encoding = _PyObject_GetAttrId(fout, &PyId_encoding);
             stdout_errors = _PyObject_GetAttrId(fout, &PyId_errors);

Python/ceval.c

@@ -5440,8 +5440,8 @@ _PyEval_RequestCodeExtraIndex(freefunc free)
 static void
 dtrace_function_entry(PyFrameObject *f)
 {
-    char* filename;
-    char* funcname;
+    const char *filename;
+    const char *funcname;
     int lineno;
 
     filename = PyUnicode_AsUTF8(f->f_code->co_filename);
@@ -5454,8 +5454,8 @@ dtrace_function_entry(PyFrameObject *f)
 static void
 dtrace_function_return(PyFrameObject *f)
 {
-    char* filename;
-    char* funcname;
+    const char *filename;
+    const char *funcname;
     int lineno;
 
     filename = PyUnicode_AsUTF8(f->f_code->co_filename);
@@ -5471,7 +5471,7 @@ maybe_dtrace_line(PyFrameObject *frame,
                   int *instr_lb, int *instr_ub, int *instr_prev)
 {
     int line = frame->f_lineno;
-    char *co_filename, *co_name;
+    const char *co_filename, *co_name;
 
     /* If the last instruction executed isn't in the current
        instruction window, reset the window.

Python/codecs.c

@@ -1131,7 +1131,7 @@ PyCodec_SurrogatePassErrors(PyObject *exc)
     PyObject *restuple;
     PyObject *object;
     PyObject *encode;
-    char *encoding;
+    const char *encoding;
     int code;
     int bytelength;
     Py_ssize_t i;

Python/compile.c

@@ -4039,7 +4039,7 @@ compiler_visit_keyword(struct compiler *c, keyword_ty k)
 static int
 expr_constant(struct compiler *c, expr_ty e)
 {
-    char *id;
+    const char *id;
     switch (e->kind) {
     case Ellipsis_kind:
         return 1;

Python/getargs.c

@@ -74,7 +74,7 @@ static const char *converttuple(PyObject *, const char **, va_list *, int,
                                 int *, char *, size_t, int, freelist_t *);
 static const char *convertsimple(PyObject *, const char **, va_list *, int,
                                  char *, size_t, freelist_t *);
-static Py_ssize_t convertbuffer(PyObject *, void **p, const char **);
+static Py_ssize_t convertbuffer(PyObject *, const void **p, const char **);
 static int getbuffer(PyObject *, Py_buffer *, const char**);
 
 static int vgetargskeywords(PyObject *, PyObject *,
@@ -625,7 +625,7 @@ convertsimple(PyObject *arg, const char **p_format, va_list *p_va, int flags,
 
     const char *format = *p_format;
     char c = *format++;
-    char *sarg;
+    const char *sarg;
 
     switch (c) {
 
@@ -897,7 +897,7 @@ convertsimple(PyObject *arg, const char **p_format, va_list *p_va, int flags,
             }
             break;
         }
-        count = convertbuffer(arg, p, &buf);
+        count = convertbuffer(arg, (const void **)p, &buf);
         if (count < 0)
             return converterr(buf, arg, msgbuf, bufsize);
         if (*format == '#') {
@@ -928,7 +928,7 @@ convertsimple(PyObject *arg, const char **p_format, va_list *p_va, int flags,
                 if (sarg == NULL)
                     return converterr(CONV_UNICODE,
                                       arg, msgbuf, bufsize);
-                PyBuffer_FillInfo(p, arg, sarg, len, 1, 0);
+                PyBuffer_FillInfo(p, arg, (void *)sarg, len, 1, 0);
             }
             else { /* any bytes-like object */
                 const char *buf;
@@ -943,7 +943,7 @@ convertsimple(PyObject *arg, const char **p_format, va_list *p_va, int flags,
             format++;
         } else if (*format == '#') { /* a string or read-only bytes-like object */
             /* "s#" or "z#" */
-            void **p = (void **)va_arg(*p_va, char **);
+            const void **p = (const void **)va_arg(*p_va, const char **);
             FETCH_SIZE;
 
             if (c == 'z' && arg == Py_None) {
@@ -970,7 +970,7 @@ convertsimple(PyObject *arg, const char **p_format, va_list *p_va, int flags,
             format++;
         } else {
             /* "s" or "z" */
-            char **p = va_arg(*p_va, char **);
+            const char **p = va_arg(*p_va, const char **);
             Py_ssize_t len;
             sarg = NULL;
 
@@ -1300,7 +1300,7 @@ convertsimple(PyObject *arg, const char **p_format, va_list *p_va, int flags,
 }
 
 static Py_ssize_t
-convertbuffer(PyObject *arg, void **p, const char **errmsg)
+convertbuffer(PyObject *arg, const void **p, const char **errmsg)
 {
     PyBufferProcs *pb = Py_TYPE(arg)->tp_as_buffer;
     Py_ssize_t count;

Python/import.c

@@ -1035,7 +1035,7 @@ _imp_create_builtin(PyObject *module, PyObject *spec)
 {
     struct _inittab *p;
     PyObject *name;
-    char *namestr;
+    const char *namestr;
     PyObject *mod;
 
     name = PyObject_GetAttrString(spec, "name");

Python/pylifecycle.c

@@ -193,7 +193,8 @@ add_flag(int flag, const char *envs)
 static char*
 get_codec_name(const char *encoding)
 {
-    char *name_utf8, *name_str;
+    const char *name_utf8;
+    char *name_str;
     PyObject *codec, *name = NULL;
 
     codec = _PyCodec_Lookup(encoding);
@@ -1284,8 +1285,7 @@ initstdio(void)
        when import.c tries to write to stderr in verbose mode. */
     encoding_attr = PyObject_GetAttrString(std, "encoding");
     if (encoding_attr != NULL) {
-        const char * std_encoding;
-        std_encoding = PyUnicode_AsUTF8(encoding_attr);
+        const char *std_encoding = PyUnicode_AsUTF8(encoding_attr);
         if (std_encoding != NULL) {
             PyObject *codec_info = _PyCodec_Lookup(std_encoding);
             Py_XDECREF(codec_info);

Python/pythonrun.c

@@ -154,7 +154,7 @@ PyRun_InteractiveOneObject(FILE *fp, PyObject *filename, PyCompilerFlags *flags)
     PyObject *m, *d, *v, *w, *oenc = NULL, *mod_name;
     mod_ty mod;
     PyArena *arena;
-    char *ps1 = "", *ps2 = "", *enc = NULL;
+    const char *ps1 = "", *ps2 = "", *enc = NULL;
     int errcode = 0;
     _Py_IDENTIFIER(encoding);
     _Py_IDENTIFIER(__main__);
@@ -511,8 +511,8 @@ PyErr_Print(void)
 static void
 print_error_text(PyObject *f, int offset, PyObject *text_obj)
 {
-    char *text;
-    char *nl;
+    const char *text;
+    const char *nl;
 
     text = PyUnicode_AsUTF8(text_obj);
     if (text == NULL)

Python/structmember.c

@@ -249,7 +249,7 @@ PyMember_SetOne(char *addr, PyMemberDef *l, PyObject *v)
         Py_XDECREF(oldv);
         break;
     case T_CHAR: {
-        char *string;
+        const char *string;
         Py_ssize_t len;
 
         string = PyUnicode_AsUTF8AndSize(v, &len);

Python/sysmodule.c

@@ -108,7 +108,7 @@ sys_displayhook_unencodable(PyObject *outf, PyObject *o)
 {
     PyObject *stdout_encoding = NULL;
     PyObject *encoded, *escaped_str, *repr_str, *buffer, *result;
-    char *stdout_encoding_str;
+    const char *stdout_encoding_str;
     int ret;
 
     stdout_encoding = _PyObject_GetAttrId(outf, &PyId_encoding);
@@ -2404,7 +2404,7 @@ sys_format(_Py_Identifier *key, FILE *fp, const char *format, va_list va)
 {
     PyObject *file, *message;
     PyObject *error_type, *error_value, *error_traceback;
-    char *utf8;
+    const char *utf8;
 
     PyErr_Fetch(&error_type, &error_value, &error_traceback);
     file = _PySys_GetObjectId(key);