RFC: constify Cython output all over the place (newbie approach)

You know, when developing code, it is very tedious to look for meaningful
errors and warnings in presence of tons of noise like

    warning: deprecated conversion from string constant to ‘char*’

And you know what? It seems in the next version of gcc, this deprecation
warnings will be turned into errors.

----

Python sources already use 'const' keyword freely, so I think it's time to add
constify bits all over the place.

Cython/Compiler/ModuleNode.py

@@ -487,9 +487,9 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
             code.putln('static PyObject *%s;' % Naming.preimport_cname)
         code.putln('static int %s;' % Naming.lineno_cname)
         code.putln('static int %s = 0;' % Naming.clineno_cname)
-        code.putln('static char * %s= %s;' % (Naming.cfilenm_cname, Naming.file_c_macro))
-        code.putln('static char *%s;' % Naming.filename_cname)
-        code.putln('static char **%s;' % Naming.filetable_cname)
+        code.putln('static const char * %s= %s;' % (Naming.cfilenm_cname, Naming.file_c_macro))
+        code.putln('static const char *%s;' % Naming.filename_cname)
+        code.putln('static const char **%s;' % Naming.filetable_cname)
         if env.doc:
             code.putln('')
             code.putln('static char %s[] = "%s";' % (env.doc_cname, env.doc))
@@ -513,7 +513,7 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
     
     def generate_filename_table(self, code):
         code.putln("")
-        code.putln("static char *%s[] = {" % Naming.filenames_cname)
+        code.putln("static const char *%s[] = {" % Naming.filenames_cname)
         if code.filename_list:
             for source_desc in code.filename_list:
                 filename = os.path.basename(source_desc.get_filenametable_entry())

Cython/Compiler/Nodes.py

@@ -1466,7 +1466,7 @@ class DefNode(FuncDefNode):
             reqd_kw_flags = []
             has_reqd_kwds = False
             code.put(
-                "static char *%s[] = {" %
+                "static const char *%s[] = {" %
                     Naming.kwdlist_cname)
             for arg in self.args:
                 if arg.is_generic:
@@ -1619,7 +1619,7 @@ class DefNode(FuncDefNode):
 
         argformat = '"%s"' % string.join(arg_formats, "")
         pt_arglist = [Naming.args_cname, Naming.kwds_cname, argformat,
-                      Naming.kwdlist_cname] + arg_addrs
+                      '(char **)/*temp.hack*/'+Naming.kwdlist_cname] + arg_addrs
         pt_argstring = string.join(pt_arglist, ", ")
         code.putln(
             'if (unlikely(!PyArg_ParseTupleAndKeywords(%s))) %s' % (
@@ -4219,9 +4219,9 @@ missing_kwarg:
 
 unraisable_exception_utility_code = [
 """
-static void __Pyx_WriteUnraisable(char *name); /*proto*/
+static void __Pyx_WriteUnraisable(const char *name); /*proto*/
 ""","""
-static void __Pyx_WriteUnraisable(char *name) {
+static void __Pyx_WriteUnraisable(const char *name) {
     PyObject *old_exc, *old_val, *old_tb;
     PyObject *ctx;
     PyErr_Fetch(&old_exc, &old_val, &old_tb);
@@ -4241,13 +4241,13 @@ static void __Pyx_WriteUnraisable(char *name) {
 
 traceback_utility_code = [
 """
-static void __Pyx_AddTraceback(char *funcname); /*proto*/
+static void __Pyx_AddTraceback(const char *funcname); /*proto*/
 ""","""
 #include "compile.h"
 #include "frameobject.h"
 #include "traceback.h"
 
-static void __Pyx_AddTraceback(char *funcname) {
+static void __Pyx_AddTraceback(const char *funcname) {
     PyObject *py_srcfile = 0;
     PyObject *py_funcname = 0;
     PyObject *py_globals = 0;