Issue #25923: Added more const qualifiers to signatures of static and private functions.

35 files changed, 112 insertions, 95 deletions

diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index fccc8ba..ac5e5fa 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -3195,7 +3195,7 @@ _validate_paramflags(PyTypeObject *type, PyObject *paramflags)
 }
 
 static int
-_get_name(PyObject *obj, char **pname)
+_get_name(PyObject *obj, const char **pname)
 {
 #ifdef MS_WIN32
     if (PyLong_Check(obj)) {
@@ -3223,7 +3223,7 @@ _get_name(PyObject *obj, char **pname)
 static PyObject *
 PyCFuncPtr_FromDll(PyTypeObject *type, PyObject *args, PyObject *kwds)
 {
-    char *name;
+    const char *name;
     int (* address)(void);
     PyObject *ftuple;
     PyObject *dll;
diff --git a/Modules/_ctypes/callbacks.c b/Modules/_ctypes/callbacks.c
index 7cd6164..00e8e66 100644
--- a/Modules/_ctypes/callbacks.c
+++ b/Modules/_ctypes/callbacks.c
@@ -77,7 +77,7 @@ PyTypeObject PyCThunk_Type = {
 /**************************************************************/
 
 static void
-PrintError(char *msg, ...)
+PrintError(const char *msg, ...)
 {
     char buf[512];
     PyObject *f = PySys_GetObject("stderr");
diff --git a/Modules/_ctypes/callproc.c b/Modules/_ctypes/callproc.c
index 68981fe..870a0d4 100644
--- a/Modules/_ctypes/callproc.c
+++ b/Modules/_ctypes/callproc.c
@@ -928,7 +928,7 @@ static PyObject *GetResult(PyObject *restype, void *result, PyObject *checker)
  * Raise a new exception 'exc_class', adding additional text to the original
  * exception string.
  */
-void _ctypes_extend_error(PyObject *exc_class, char *fmt, ...)
+void _ctypes_extend_error(PyObject *exc_class, const char *fmt, ...)
 {
     va_list vargs;
     PyObject *tp, *v, *tb, *s, *cls_str, *msg_str;
diff --git a/Modules/_ctypes/ctypes.h b/Modules/_ctypes/ctypes.h
index 0d3f724..b06ba8a 100644
--- a/Modules/_ctypes/ctypes.h
+++ b/Modules/_ctypes/ctypes.h
@@ -327,7 +327,7 @@ extern int
 PyCData_set(PyObject *dst, PyObject *type, SETFUNC setfunc, PyObject *value,
           Py_ssize_t index, Py_ssize_t size, char *ptr);
 
-extern void _ctypes_extend_error(PyObject *exc_class, char *fmt, ...);
+extern void _ctypes_extend_error(PyObject *exc_class, const char *fmt, ...);
 
 struct basespec {
     CDataObject *base;
diff --git a/Modules/_curses_panel.c b/Modules/_curses_panel.c
index a9c406f..26bf094 100644
--- a/Modules/_curses_panel.c
+++ b/Modules/_curses_panel.c
@@ -56,7 +56,7 @@ static struct PyModuleDef _curses_panelmodule;
  */
 
 static PyObject *
-PyCursesCheckERR(int code, char *fname)
+PyCursesCheckERR(int code, const char *fname)
 {
     if (code != ERR) {
         Py_INCREF(Py_None);
diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c
index e8b7ae8..3e5e195 100644
--- a/Modules/_datetimemodule.c
+++ b/Modules/_datetimemodule.c
@@ -873,7 +873,7 @@ get_tzinfo_member(PyObject *self)
  * this returns NULL.  Else result is returned.
  */
 static PyObject *
-call_tzinfo_method(PyObject *tzinfo, char *name, PyObject *tzinfoarg)
+call_tzinfo_method(PyObject *tzinfo, const char *name, PyObject *tzinfoarg)
 {
     PyObject *offset;
 
diff --git a/Modules/_io/_iomodule.h b/Modules/_io/_iomodule.h
index 0c6eae2..3c48ff3 100644
--- a/Modules/_io/_iomodule.h
+++ b/Modules/_io/_iomodule.h
@@ -60,7 +60,7 @@ extern PyObject *_PyIncrementalNewlineDecoder_decode(
    * Otherwise, the line ending is specified by readnl, a str object */
 extern Py_ssize_t _PyIO_find_line_ending(
     int translated, int universal, PyObject *readnl,
-    int kind, char *start, char *end, Py_ssize_t *consumed);
+    int kind, const char *start, const char *end, Py_ssize_t *consumed);
 
 /* Return 1 if an EnvironmentError with errno == EINTR is set (and then
    clears the error indicator), 0 otherwise.
diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index 6bb2200..16f8cdf 100644
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -659,7 +659,7 @@ _bufferedreader_raw_read(buffered *self, char *start, Py_ssize_t len);
 
 /* Sets the current error to BlockingIOError */
 static void
-_set_BlockingIOError(char *msg, Py_ssize_t written)
+_set_BlockingIOError(const char *msg, Py_ssize_t written)
 {
     PyObject *err;
     PyErr_Clear();
diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c
index dbd604a..8bf3922 100644
--- a/Modules/_io/fileio.c
+++ b/Modules/_io/fileio.c
@@ -540,7 +540,7 @@ err_closed(void)
 }
 
 static PyObject *
-err_mode(char *action)
+err_mode(const char *action)
 {
     _PyIO_State *state = IO_STATE();
     if (state != NULL)
@@ -1043,7 +1043,7 @@ _io_FileIO_truncate_impl(fileio *self, PyObject *posobj)
 }
 #endif /* HAVE_FTRUNCATE */
 
-static char *
+static const char *
 mode_string(fileio *self)
 {
     if (self->created) {
diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index d018623..140da10 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -1648,8 +1648,8 @@ _io_TextIOWrapper_read_impl(textio *self, Py_ssize_t n)
 /* NOTE: `end` must point to the real end of the Py_UCS4 storage,
    that is to the NUL character. Otherwise the function will produce
    incorrect results. */
-static char *
-find_control_char(int kind, char *s, char *end, Py_UCS4 ch)
+static const char *
+find_control_char(int kind, const char *s, const char *end, Py_UCS4 ch)
 {
     if (kind == PyUnicode_1BYTE_KIND) {
         assert(ch < 256);
@@ -1669,13 +1669,13 @@ find_control_char(int kind, char *s, char *end, Py_UCS4 ch)
 Py_ssize_t
 _PyIO_find_line_ending(
     int translated, int universal, PyObject *readnl,
-    int kind, char *start, char *end, Py_ssize_t *consumed)
+    int kind, const char *start, const char *end, Py_ssize_t *consumed)
 {
     Py_ssize_t len = ((char*)end - (char*)start)/kind;
 
     if (translated) {
         /* Newlines are already translated, only search for \n */
-        char *pos = find_control_char(kind, start, end, '\n');
+        const char *pos = find_control_char(kind, start, end, '\n');
         if (pos != NULL)
             return (pos - start)/kind + 1;
         else {
@@ -1687,7 +1687,7 @@ _PyIO_find_line_ending(
         /* Universal newline search. Find any of \r, \r\n, \n
          * The decoder ensures that \r\n are not split in two pieces
          */
-        char *s = start;
+        const char *s = start;
         for (;;) {
             Py_UCS4 ch;
             /* Fast path for non-control chars. The loop always ends
@@ -1717,21 +1717,21 @@ _PyIO_find_line_ending(
         /* Assume that readnl is an ASCII character. */
         assert(PyUnicode_KIND(readnl) == PyUnicode_1BYTE_KIND);
         if (readnl_len == 1) {
-            char *pos = find_control_char(kind, start, end, nl[0]);
+            const char *pos = find_control_char(kind, start, end, nl[0]);
             if (pos != NULL)
                 return (pos - start)/kind + 1;
             *consumed = len;
             return -1;
         }
         else {
-            char *s = start;
-            char *e = end - (readnl_len - 1)*kind;
-            char *pos;
+            const char *s = start;
+            const char *e = end - (readnl_len - 1)*kind;
+            const char *pos;
             if (e < s)
                 e = s;
             while (s < e) {
                 Py_ssize_t i;
-                char *pos = find_control_char(kind, s, end, nl[0]);
+                const char *pos = find_control_char(kind, s, end, nl[0]);
                 if (pos == NULL || pos >= e)
                     break;
                 for (i = 1; i < readnl_len; i++) {
diff --git a/Modules/_json.c b/Modules/_json.c
index f63d758..3c857ae 100644
--- a/Modules/_json.c
+++ b/Modules/_json.c
@@ -112,7 +112,7 @@ encoder_listencode_dict(PyEncoderObject *s, _PyAccu *acc, PyObject *dct, Py_ssiz
 static PyObject *
 _encoded_const(PyObject *obj);
 static void
-raise_errmsg(char *msg, PyObject *s, Py_ssize_t end);
+raise_errmsg(const char *msg, PyObject *s, Py_ssize_t end);
 static PyObject *
 encoder_encode_string(PyEncoderObject *s, PyObject *obj);
 static PyObject *
@@ -323,7 +323,7 @@ escape_unicode(PyObject *pystr)
 }
 
 static void
-raise_errmsg(char *msg, PyObject *s, Py_ssize_t end)
+raise_errmsg(const char *msg, PyObject *s, Py_ssize_t end)
 {
     /* Use JSONDecodeError exception to raise a nice looking ValueError subclass */
     static PyObject *JSONDecodeError = NULL;
diff --git a/Modules/_localemodule.c b/Modules/_localemodule.c
index b1d6add..a92fb10 100644
--- a/Modules/_localemodule.c
+++ b/Modules/_localemodule.c
@@ -49,7 +49,7 @@ PyDoc_STRVAR(setlocale__doc__,
 
 /* the grouping is terminated by either 0 or CHAR_MAX */
 static PyObject*
-copy_grouping(char* s)
+copy_grouping(const char* s)
 {
     int i;
     PyObject *result, *val = NULL;
diff --git a/Modules/_pickle.c b/Modules/_pickle.c
index 487b533..9d36346 100644
--- a/Modules/_pickle.c
+++ b/Modules/_pickle.c
@@ -2187,7 +2187,7 @@ error:
 }
 
 static int
-write_utf8(PicklerObject *self, char *data, Py_ssize_t size)
+write_utf8(PicklerObject *self, const char *data, Py_ssize_t size)
 {
     char header[9];
     Py_ssize_t len;
diff --git a/Modules/_posixsubprocess.c b/Modules/_posixsubprocess.c
index 8bedab5..a0109fb 100644
--- a/Modules/_posixsubprocess.c
+++ b/Modules/_posixsubprocess.c
@@ -72,7 +72,7 @@ _enable_gc(int need_to_reenable_gc, PyObject *gc_module)
 
 /* Convert ASCII to a positive int, no libc call. no overflow. -1 on error. */
 static int
-_pos_int_from_ascii(char *name)
+_pos_int_from_ascii(const char *name)
 {
     int num = 0;
     while (*name >= '0' && *name <= '9') {
diff --git a/Modules/_scproxy.c b/Modules/_scproxy.c
index 66b6e34..68be458 100644
--- a/Modules/_scproxy.c
+++ b/Modules/_scproxy.c
@@ -130,7 +130,7 @@ error:
 }
 
 static int
-set_proxy(PyObject* proxies, char* proto, CFDictionaryRef proxyDict,
+set_proxy(PyObject* proxies, const char* proto, CFDictionaryRef proxyDict,
                 CFStringRef enabledKey,
                 CFStringRef hostKey, CFStringRef portKey)
 {
diff --git a/Modules/_sre.c b/Modules/_sre.c
index f597a70..fb0ab03 100644
--- a/Modules/_sre.c
+++ b/Modules/_sre.c
@@ -714,7 +714,7 @@ _sre_SRE_Pattern_search_impl(PatternObject *self, PyObject *string,
 }
 
 static PyObject*
-call(char* module, char* function, PyObject* args)
+call(const char* module, const char* function, PyObject* args)
 {
     PyObject* name;
     PyObject* mod;
diff --git a/Modules/_ssl.c b/Modules/_ssl.c
index 8818d26..5968ed5 100644
--- a/Modules/_ssl.c
+++ b/Modules/_ssl.c
@@ -378,7 +378,7 @@ fail:
 }
 
 static PyObject *
-PySSL_SetError(PySSLSocket *obj, int ret, char *filename, int lineno)
+PySSL_SetError(PySSLSocket *obj, int ret, const char *filename, int lineno)
 {
     PyObject *type = PySSLErrorObject;
     char *errstr = NULL;
@@ -460,7 +460,7 @@ PySSL_SetError(PySSLSocket *obj, int ret, char *filename, int lineno)
 }
 
 static PyObject *
-_setSSLError (char *errstr, int errcode, char *filename, int lineno) {
+_setSSLError (const char *errstr, int errcode, const char *filename, int lineno) {
 
     if (errstr == NULL)
         errcode = ERR_peek_last_error();
diff --git a/Modules/_struct.c b/Modules/_struct.c
index b18c71d..820e004 100644
--- a/Modules/_struct.c
+++ b/Modules/_struct.c
@@ -1189,7 +1189,7 @@ static formatdef lilendian_table[] = {
 
 
 static const formatdef *
-whichtable(char **pfmt)
+whichtable(const char **pfmt)
 {
     const char *fmt = (*pfmt)++; /* May be backed out of later */
     switch (*fmt) {
@@ -1268,7 +1268,7 @@ prepare_s(PyStructObject *self)
 
     fmt = PyBytes_AS_STRING(self->s_format);
 
-    f = whichtable((char **)&fmt);
+    f = whichtable(&fmt);
 
     s = fmt;
     size = 0;
@@ -1457,7 +1457,7 @@ s_dealloc(PyStructObject *s)
 }
 
 static PyObject *
-s_unpack_internal(PyStructObject *soself, char *startfrom) {
+s_unpack_internal(PyStructObject *soself, const char *startfrom) {
     formatcode *code;
     Py_ssize_t i = 0;
     PyObject *result = PyTuple_New(soself->s_len);
diff --git a/Modules/_testmultiphase.c b/Modules/_testmultiphase.c
index 2005205..03eda27 100644
--- a/Modules/_testmultiphase.c
+++ b/Modules/_testmultiphase.c
@@ -61,7 +61,7 @@ Example_getattro(ExampleObject *self, PyObject *name)
 }
 
 static int
-Example_setattr(ExampleObject *self, char *name, PyObject *v)
+Example_setattr(ExampleObject *self, const char *name, PyObject *v)
 {
     if (self->x_attr == NULL) {
         self->x_attr = PyDict_New();
diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
index 41ad5f9..768df81 100644
--- a/Modules/_tkinter.c
+++ b/Modules/_tkinter.c
@@ -841,7 +841,7 @@ PyTclObject_dealloc(PyTclObject *self)
     Py_DECREF(tp);
 }
 
-static char*
+static const char *
 PyTclObject_TclString(PyObject *self)
 {
     return Tcl_GetString(((PyTclObject*)self)->value);
@@ -1726,7 +1726,7 @@ static int
 varname_converter(PyObject *in, void *_out)
 {
     char *s;
-    char **out = (char**)_out;
+    const char **out = (const char**)_out;
     if (PyBytes_Check(in)) {
         if (PyBytes_Size(in) > INT_MAX) {
             PyErr_SetString(PyExc_OverflowError, "bytes object is too long");
@@ -1846,7 +1846,7 @@ var_invoke(EventFunc func, PyObject *selfptr, PyObject *args, int flags)
 static PyObject *
 SetVar(PyObject *self, PyObject *args, int flags)
 {
-    char *name1, *name2;
+    const char *name1, *name2;
     PyObject *newValue;
     PyObject *res = NULL;
     Tcl_Obj *newval, *ok;
@@ -1915,7 +1915,7 @@ Tkapp_GlobalSetVar(PyObject *self, PyObject *args)
 static PyObject *
 GetVar(PyObject *self, PyObject *args, int flags)
 {
-    char *name1, *name2=NULL;
+    const char *name1, *name2=NULL;
     PyObject *res = NULL;
     Tcl_Obj *tres;
 
diff --git a/Modules/_winapi.c b/Modules/_winapi.c
index 3e7f187..c4d4264 100644
--- a/Modules/_winapi.c
+++ b/Modules/_winapi.c
@@ -675,7 +675,7 @@ _winapi_CreatePipe_impl(PyModuleDef *module, PyObject *pipe_attrs,
 /* helpers for createprocess */
 
 static unsigned long
-getulong(PyObject* obj, char* name)
+getulong(PyObject* obj, const char* name)
 {
     PyObject* value;
     unsigned long ret;
@@ -691,7 +691,7 @@ getulong(PyObject* obj, char* name)
 }
 
 static HANDLE
-gethandle(PyObject* obj, char* name)
+gethandle(PyObject* obj, const char* name)
 {
     PyObject* value;
     HANDLE ret;
diff --git a/Modules/binascii.c b/Modules/binascii.c
index 9df48da..a306acd 100644
--- a/Modules/binascii.c
+++ b/Modules/binascii.c
@@ -256,7 +256,8 @@ static PyObject *
 binascii_a2b_uu_impl(PyModuleDef *module, Py_buffer *data)
 /*[clinic end generated code: output=5779f39b0b48459f input=7cafeaf73df63d1c]*/
 {
-    unsigned char *ascii_data, *bin_data;
+    const unsigned char *ascii_data;
+    unsigned char *bin_data;
     int leftbits = 0;
     unsigned char this_ch;
     unsigned int leftchar = 0;
@@ -342,7 +343,8 @@ static PyObject *
 binascii_b2a_uu_impl(PyModuleDef *module, Py_buffer *data)
 /*[clinic end generated code: output=181021b69bb9a414 input=00fdf458ce8b465b]*/
 {
-    unsigned char *ascii_data, *bin_data;
+    unsigned char *ascii_data;
+    const unsigned char *bin_data;
     int leftbits = 0;
     unsigned char this_ch;
     unsigned int leftchar = 0;
@@ -389,7 +391,7 @@ binascii_b2a_uu_impl(PyModuleDef *module, Py_buffer *data)
 
 
 static int
-binascii_find_valid(unsigned char *s, Py_ssize_t slen, int num)
+binascii_find_valid(const unsigned char *s, Py_ssize_t slen, int num)
 {
     /* Finds & returns the (num+1)th
     ** valid character for base64, or -1 if none.
@@ -426,7 +428,8 @@ static PyObject *
 binascii_a2b_base64_impl(PyModuleDef *module, Py_buffer *data)
 /*[clinic end generated code: output=3e351b702bed56d2 input=5872acf6e1cac243]*/
 {
-    unsigned char *ascii_data, *bin_data;
+    const unsigned char *ascii_data;
+    unsigned char *bin_data;
     int leftbits = 0;
     unsigned char this_ch;
     unsigned int leftchar = 0;
@@ -522,7 +525,8 @@ static PyObject *
 binascii_b2a_base64_impl(PyModuleDef *module, Py_buffer *data, int newline)
 /*[clinic end generated code: output=19e1dd719a890b50 input=7b2ea6fa38d8924c]*/
 {
-    unsigned char *ascii_data, *bin_data;
+    unsigned char *ascii_data;
+    const unsigned char *bin_data;
     int leftbits = 0;
     unsigned char this_ch;
     unsigned int leftchar = 0;
@@ -589,7 +593,8 @@ static PyObject *
 binascii_a2b_hqx_impl(PyModuleDef *module, Py_buffer *data)
 /*[clinic end generated code: output=60bcdbbd28b105cd input=0d914c680e0eed55]*/
 {
-    unsigned char *ascii_data, *bin_data;
+    const unsigned char *ascii_data;
+    unsigned char *bin_data;
     int leftbits = 0;
     unsigned char this_ch;
     unsigned int leftchar = 0;
@@ -667,7 +672,8 @@ static PyObject *
 binascii_rlecode_hqx_impl(PyModuleDef *module, Py_buffer *data)
 /*[clinic end generated code: output=0905da344dbf0648 input=e1f1712447a82b09]*/
 {
-    unsigned char *in_data, *out_data;
+    const unsigned char *in_data;
+    unsigned char *out_data;
     unsigned char ch;
     Py_ssize_t in, inend, len;
     _PyBytesWriter writer;
@@ -728,7 +734,8 @@ static PyObject *
 binascii_b2a_hqx_impl(PyModuleDef *module, Py_buffer *data)
 /*[clinic end generated code: output=5a987810d5e3cdbb input=9596ebe019fe12ba]*/
 {
-    unsigned char *ascii_data, *bin_data;
+    unsigned char *ascii_data;
+    const unsigned char *bin_data;
     int leftbits = 0;
     unsigned char this_ch;
     unsigned int leftchar = 0;
@@ -782,7 +789,8 @@ static PyObject *
 binascii_rledecode_hqx_impl(PyModuleDef *module, Py_buffer *data)
 /*[clinic end generated code: output=f7afd89b789946ab input=54cdd49fc014402c]*/
 {
-    unsigned char *in_data, *out_data;
+    const unsigned char *in_data;
+    unsigned char *out_data;
     unsigned char in_byte, in_repeat;
     Py_ssize_t in_len;
     _PyBytesWriter writer;
@@ -899,7 +907,7 @@ static unsigned int
 binascii_crc_hqx_impl(PyModuleDef *module, Py_buffer *data, unsigned int crc)
 /*[clinic end generated code: output=167c2dac62625717 input=add8c53712ccceda]*/
 {
-    unsigned char *bin_data;
+    const unsigned char *bin_data;
     Py_ssize_t len;
 
     crc &= 0xffff;
@@ -1050,7 +1058,7 @@ binascii_crc32_impl(PyModuleDef *module, Py_buffer *data, unsigned int crc)
 #ifdef USE_ZLIB_CRC32
 /* This was taken from zlibmodule.c PyZlib_crc32 (but is PY_SSIZE_T_CLEAN) */
 {
-    Byte *buf;
+    const Byte *buf;
     Py_ssize_t len;
     int signed_val;
 
@@ -1061,7 +1069,7 @@ binascii_crc32_impl(PyModuleDef *module, Py_buffer *data, unsigned int crc)
 }
 #else  /* USE_ZLIB_CRC32 */
 { /* By Jim Ahlstrom; All rights transferred to CNRI */
-    unsigned char *bin_data;
+    const unsigned char *bin_data;
     Py_ssize_t len;
     unsigned int result;
 
@@ -1144,7 +1152,7 @@ static PyObject *
 binascii_a2b_hex_impl(PyModuleDef *module, Py_buffer *hexstr)
 /*[clinic end generated code: output=d61da452b5c6d290 input=9e1e7f2f94db24fd]*/
 {
-    char* argbuf;
+    const char* argbuf;
     Py_ssize_t arglen;
     PyObject *retval;
     char* retbuf;
@@ -1232,7 +1240,8 @@ binascii_a2b_qp_impl(PyModuleDef *module, Py_buffer *data, int header)
 {
     Py_ssize_t in, out;
     char ch;
-    unsigned char *ascii_data, *odata;
+    const unsigned char *ascii_data;
+    unsigned char *odata;
     Py_ssize_t datalen = 0;
     PyObject *rv;
 
@@ -1338,13 +1347,14 @@ binascii_b2a_qp_impl(PyModuleDef *module, Py_buffer *data, int quotetabs,
 /*[clinic end generated code: output=a87ca9ccb94e2a9f input=7f2a9aaa008e92b2]*/
 {
     Py_ssize_t in, out;
-    unsigned char *databuf, *odata;
+    const unsigned char *databuf;
+    unsigned char *odata;
     Py_ssize_t datalen = 0, odatalen = 0;
     PyObject *rv;
     unsigned int linelen = 0;
     unsigned char ch;
     int crlf = 0;
-    unsigned char *p;
+    const unsigned char *p;
 
     databuf = data->buf;
     datalen = data->len;
@@ -1353,7 +1363,7 @@ binascii_b2a_qp_impl(PyModuleDef *module, Py_buffer *data, int quotetabs,
     /* XXX: this function has the side effect of converting all of
      * the end of lines to be the same depending on this detection
      * here */
-    p = (unsigned char *) memchr(databuf, '\n', datalen);
+    p = (const unsigned char *) memchr(databuf, '\n', datalen);
     if ((p != NULL) && (p > databuf) && (*(p-1) == '\r'))
         crlf = 1;
 
diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
index cb7222d..0c6f444 100644
--- a/Modules/gcmodule.c
+++ b/Modules/gcmodule.c
@@ -738,7 +738,7 @@ handle_weakrefs(PyGC_Head *unreachable, PyGC_Head *old)
 }
 
 static void
-debug_cycle(char *msg, PyObject *op)
+debug_cycle(const char *msg, PyObject *op)
 {
     PySys_FormatStderr("gc: %s <%s %p>\n",
                        msg, Py_TYPE(op)->tp_name, op);
diff --git a/Modules/getaddrinfo.c b/Modules/getaddrinfo.c
index 33d7078..13a9e40 100644
--- a/Modules/getaddrinfo.c
+++ b/Modules/getaddrinfo.c
@@ -198,7 +198,7 @@ if (pai->ai_flags & AI_CANONNAME) {\
 
 #define ERR(err) { error = (err); goto bad; }
 
-char *
+const char *
 gai_strerror(int ecode)
 {
     if (ecode < 0 || ecode > EAI_MAX)
diff --git a/Modules/main.c b/Modules/main.c
index 4358cc8..35d07fd 100644
--- a/Modules/main.c
+++ b/Modules/main.c
@@ -103,7 +103,7 @@ PYTHONHASHSEED: if this variable is set to 'random', a random value is used\n\
 ";
 
 static int
-usage(int exitcode, wchar_t* program)
+usage(int exitcode, const wchar_t* program)
 {
     FILE *f = exitcode ? stderr : stdout;
 
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index 9359eb2..6b3e139 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -876,7 +876,7 @@ math_1_to_int(PyObject *arg, double (*func) (double), int can_overflow)
 }
 
 static PyObject *
-math_2(PyObject *args, double (*func) (double, double), char *funcname)
+math_2(PyObject *args, double (*func) (double, double), const char *funcname)
 {
     PyObject *ox, *oy;
     double x, y, r;
@@ -1673,7 +1673,7 @@ PyDoc_STRVAR(math_modf_doc,
    in that int is larger than PY_SSIZE_T_MAX. */
 
 static PyObject*
-loghelper(PyObject* arg, double (*func)(double), char *funcname)
+loghelper(PyObject* arg, double (*func)(double), const char *funcname)
 {
     /* If it is int, do it ourselves. */
     if (PyLong_Check(arg)) {
diff --git a/Modules/parsermodule.c b/Modules/parsermodule.c
index 4c5f2ef..deae049 100644
--- a/Modules/parsermodule.c
+++ b/Modules/parsermodule.c
@@ -578,13 +578,13 @@ parser_issuite(PyST_Object *self, PyObject *args, PyObject *kw)
 }
 
 
-/*  err_string(char* message)
+/*  err_string(const char* message)
  *
  *  Sets the error string for an exception of type ParserError.
  *
  */
 static void
-err_string(char *message)
+err_string(const char *message)
 {
     PyErr_SetString(parser_error, message);
 }
@@ -597,7 +597,7 @@ err_string(char *message)
  *
  */
 static PyObject*
-parser_do_parse(PyObject *args, PyObject *kw, char *argspec, int type)
+parser_do_parse(PyObject *args, PyObject *kw, const char *argspec, int type)
 {
     char*     string = 0;
     PyObject* res    = 0;
@@ -984,7 +984,7 @@ build_node_tree(PyObject *tuple)
 /*
  *  Validation routines used within the validation section:
  */
-static int validate_terminal(node *terminal, int type, char *string);
+static int validate_terminal(node *terminal, int type, const char *string);
 
 #define validate_ampersand(ch)  validate_terminal(ch,      AMPER, "&")
 #define validate_circumflex(ch) validate_terminal(ch, CIRCUMFLEX, "^")
@@ -1082,7 +1082,7 @@ validate_numnodes(node *n, int num, const char *const name)
 
 
 static int
-validate_terminal(node *terminal, int type, char *string)
+validate_terminal(node *terminal, int type, const char *string)
 {
     int res = (validate_ntype(terminal, type)
                && ((string == 0) || (strcmp(string, STR(terminal)) == 0)));
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 7a2b661..367e4f2 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -949,7 +949,8 @@ path_converter(PyObject *o, void *p) {
 }
 
 static void
-argument_unavailable_error(char *function_name, char *argument_name) {
+argument_unavailable_error(const char *function_name, const char *argument_name)
+{
     PyErr_Format(PyExc_NotImplementedError,
         "%s%s%s unavailable on this platform",
         (function_name != NULL) ? function_name : "",
@@ -972,7 +973,8 @@ dir_fd_unavailable(PyObject *o, void *p)
 }
 
 static int
-fd_specified(char *function_name, int fd) {
+fd_specified(const char *function_name, int fd)
+{
     if (fd == -1)
         return 0;
 
@@ -981,7 +983,8 @@ fd_specified(char *function_name, int fd) {
 }
 
 static int
-follow_symlinks_specified(char *function_name, int follow_symlinks) {
+follow_symlinks_specified(const char *function_name, int follow_symlinks)
+{
     if (follow_symlinks)
         return 0;
 
@@ -990,7 +993,8 @@ follow_symlinks_specified(char *function_name, int follow_symlinks) {
 }
 
 static int
-path_and_dir_fd_invalid(char *function_name, path_t *path, int dir_fd) {
+path_and_dir_fd_invalid(const char *function_name, path_t *path, int dir_fd)
+{
     if (!path->narrow && !path->wide && (dir_fd != DEFAULT_DIR_FD)) {
         PyErr_Format(PyExc_ValueError,
                      "%s: can't specify dir_fd without matching path",
@@ -1001,7 +1005,8 @@ path_and_dir_fd_invalid(char *function_name, path_t *path, int dir_fd) {
 }
 
 static int
-dir_fd_and_fd_invalid(char *function_name, int dir_fd, int fd) {
+dir_fd_and_fd_invalid(const char *function_name, int dir_fd, int fd)
+{
     if ((dir_fd != DEFAULT_DIR_FD) && (fd != -1)) {
         PyErr_Format(PyExc_ValueError,
                      "%s: can't specify both dir_fd and fd",
@@ -1012,8 +1017,9 @@ dir_fd_and_fd_invalid(char *function_name, int dir_fd, int fd) {
 }
 
 static int
-fd_and_follow_symlinks_invalid(char *function_name, int fd,
-                               int follow_symlinks) {
+fd_and_follow_symlinks_invalid(const char *function_name, int fd,
+                               int follow_symlinks)
+{
     if ((fd > 0) && (!follow_symlinks)) {
         PyErr_Format(PyExc_ValueError,
                      "%s: cannot use fd and follow_symlinks together",
@@ -1024,8 +1030,9 @@ fd_and_follow_symlinks_invalid(char *function_name, int fd,
 }
 
 static int
-dir_fd_and_follow_symlinks_invalid(char *function_name, int dir_fd,
-                                   int follow_symlinks) {
+dir_fd_and_follow_symlinks_invalid(const char *function_name, int dir_fd,
+                                   int follow_symlinks)
+{
     if ((dir_fd != DEFAULT_DIR_FD) && (!follow_symlinks)) {
         PyErr_Format(PyExc_ValueError,
                      "%s: cannot use dir_fd and follow_symlinks together",
@@ -1220,7 +1227,7 @@ posix_error(void)
 
 #ifdef MS_WINDOWS
 static PyObject *
-win32_error(char* function, const char* filename)
+win32_error(const char* function, const char* filename)
 {
     /* XXX We should pass the function name along in the future.
        (winreg.c also wants to pass the function name.)
@@ -1235,7 +1242,7 @@ win32_error(char* function, const char* filename)
 }
 
 static PyObject *
-win32_error_object(char* function, PyObject* filename)
+win32_error_object(const char* function, PyObject* filename)
 {
     /* XXX - see win32_error for comments on 'function' */
     errno = GetLastError();
@@ -2100,7 +2107,7 @@ _pystat_fromstructstat(STRUCT_STAT *st)
 
 
 static PyObject *
-posix_do_stat(char *function_name, path_t *path,
+posix_do_stat(const char *function_name, path_t *path,
               int dir_fd, int follow_symlinks)
 {
     STRUCT_STAT st;
@@ -4561,7 +4568,7 @@ typedef struct {
 #if defined(HAVE_FUTIMESAT) || defined(HAVE_UTIMENSAT)
 
 static int
-utime_dir_fd(utime_t *ut, int dir_fd, char *path, int follow_symlinks)
+utime_dir_fd(utime_t *ut, int dir_fd, const char *path, int follow_symlinks)
 {
 #ifdef HAVE_UTIMENSAT
     int flags = follow_symlinks ? 0 : AT_SYMLINK_NOFOLLOW;
@@ -4610,7 +4617,7 @@ utime_fd(utime_t *ut, int fd)
 #ifdef UTIME_HAVE_NOFOLLOW_SYMLINKS
 
 static int
-utime_nofollow_symlinks(utime_t *ut, char *path)
+utime_nofollow_symlinks(utime_t *ut, const char *path)
 {
 #ifdef HAVE_UTIMENSAT
     UTIME_TO_TIMESPEC;
@@ -4626,7 +4633,7 @@ utime_nofollow_symlinks(utime_t *ut, char *path)
 #ifndef MS_WINDOWS
 
 static int
-utime_default(utime_t *ut, char *path)
+utime_default(utime_t *ut, const char *path)
 {
 #ifdef HAVE_UTIMENSAT
     UTIME_TO_TIMESPEC;
@@ -7323,7 +7330,7 @@ _check_dirW(WCHAR *src, WCHAR *dest)
 
 /* Return True if the path at src relative to dest is a directory */
 static int
-_check_dirA(char *src, char *dest)
+_check_dirA(const char *src, char *dest)
 {
     WIN32_FILE_ATTRIBUTE_DATA src_info;
     char dest_parent[MAX_PATH];
@@ -11835,7 +11842,7 @@ error:
 #else /* POSIX */
 
 static char *
-join_path_filename(char *path_narrow, char* filename, Py_ssize_t filename_len)
+join_path_filename(const char *path_narrow, const char* filename, Py_ssize_t filename_len)
 {
     Py_ssize_t path_len;
     Py_ssize_t size;
@@ -11867,7 +11874,7 @@ join_path_filename(char *path_narrow, char* filename, Py_ssize_t filename_len)
 }
 
 static PyObject *
-DirEntry_from_posix_info(path_t *path, char *name, Py_ssize_t name_len,
+DirEntry_from_posix_info(path_t *path, const char *name, Py_ssize_t name_len,
                          ino_t d_ino
 #ifdef HAVE_DIRENT_D_TYPE
                          , unsigned char d_type
diff --git a/Modules/pyexpat.c b/Modules/pyexpat.c
index b45e3da..9267c69 100644
--- a/Modules/pyexpat.c
+++ b/Modules/pyexpat.c
@@ -91,7 +91,7 @@ static struct HandlerInfo handler_info[64];
  * false on an exception.
  */
 static int
-set_error_attr(PyObject *err, char *name, int value)
+set_error_attr(PyObject *err, const char *name, int value)
 {
     PyObject *v = PyLong_FromLong(value);
 
@@ -218,7 +218,7 @@ flag_error(xmlparseobject *self)
 }
 
 static PyObject*
-call_with_frame(char *funcname, int lineno, PyObject* func, PyObject* args,
+call_with_frame(const char *funcname, int lineno, PyObject* func, PyObject* args,
                 xmlparseobject *self)
 {
     PyObject *res;
@@ -766,7 +766,7 @@ readinst(char *buf, int buf_size, PyObject *meth)
 {
     PyObject *str;
     Py_ssize_t len;
-    char *ptr;
+    const char *ptr;
 
     str = PyObject_CallFunction(meth, "n", buf_size);
     if (str == NULL)
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index bae9634..7ab534e 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -904,7 +904,7 @@ static PyThread_type_lock netdb_lock;
    an error occurred; then an exception is raised. */
 
 static int
-setipaddr(char *name, struct sockaddr *addr_ret, size_t addr_ret_size, int af)
+setipaddr(const char *name, struct sockaddr *addr_ret, size_t addr_ret_size, int af)
 {
     struct addrinfo hints, *res;
     int error;
@@ -1085,7 +1085,7 @@ makeipaddr(struct sockaddr *addr, int addrlen)
    an error occurred. */
 
 static int
-setbdaddr(char *name, bdaddr_t *bdaddr)
+setbdaddr(const char *name, bdaddr_t *bdaddr)
 {
     unsigned int b0, b1, b2, b3, b4, b5;
     char ch;
diff --git a/Modules/timemodule.c b/Modules/timemodule.c
index 31f0ce5..0b6d461 100644
--- a/Modules/timemodule.c
+++ b/Modules/timemodule.c
@@ -311,7 +311,7 @@ tmtotuple(struct tm *p)
    Returns non-zero on success (parallels PyArg_ParseTuple).
 */
 static int
-parse_time_t_args(PyObject *args, char *format, time_t *pwhen)
+parse_time_t_args(PyObject *args, const char *format, time_t *pwhen)
 {
     PyObject *ot = NULL;
     time_t whent;
diff --git a/Modules/xxlimited.c b/Modules/xxlimited.c
index 40c1760..c1a9be9 100644
--- a/Modules/xxlimited.c
+++ b/Modules/xxlimited.c
@@ -89,7 +89,7 @@ Xxo_getattro(XxoObject *self, PyObject *name)
 }
 
 static int
-Xxo_setattr(XxoObject *self, char *name, PyObject *v)
+Xxo_setattr(XxoObject *self, const char *name, PyObject *v)
 {
     if (self->x_attr == NULL) {
         self->x_attr = PyDict_New();
diff --git a/Modules/xxmodule.c b/Modules/xxmodule.c
index 85230d9..0764407 100644
--- a/Modules/xxmodule.c
+++ b/Modules/xxmodule.c
@@ -76,7 +76,7 @@ Xxo_getattro(XxoObject *self, PyObject *name)
 }
 
 static int
-Xxo_setattr(XxoObject *self, char *name, PyObject *v)
+Xxo_setattr(XxoObject *self, const char *name, PyObject *v)
 {
     if (self->x_attr == NULL) {
         self->x_attr = PyDict_New();
diff --git a/Modules/zipimport.c b/Modules/zipimport.c
index 7220faf..87c8cfc 100644
--- a/Modules/zipimport.c
+++ b/Modules/zipimport.c
@@ -815,7 +815,7 @@ static PyTypeObject ZipImporter_Type = {
    4 bytes, encoded as little endian. This partially reimplements
    marshal.c:r_long() */
 static long
-get_long(unsigned char *buf) {
+get_long(const unsigned char *buf) {
     long x;
     x =  buf[0];
     x |= (long)buf[1] <<  8;
diff --git a/Modules/zlibmodule.c b/Modules/zlibmodule.c
index a15fdb2..7d2f55a 100644
--- a/Modules/zlibmodule.c
+++ b/Modules/zlibmodule.c
@@ -53,7 +53,7 @@ typedef struct
 } compobject;
 
 static void
-zlib_error(z_stream zst, int err, char *msg)
+zlib_error(z_stream zst, int err, const char *msg)
 {
     const char *zmsg = Z_NULL;
     /* In case of a version mismatch, zst.msg won't be initialized.