fix some C++ compiler warnings about char* constants

Cython/Compiler/Buffer.py

@@ -601,10 +601,14 @@ class GetAndReleaseBufferUtilityCode(object):
 
         find_buffer_types(env)
 
-        proto, impl = TempitaUtilityCode.load_as_string(
+        util_code = TempitaUtilityCode.load(
             "GetAndReleaseBuffer", from_file="Buffer.c",
             context=dict(types=types))
 
+        proto = util_code.format_code(util_code.proto)
+        impl = util_code.format_code(
+            util_code.inject_string_constants(util_code.impl, output))
+
         proto_code.putln(proto)
         code.putln(impl)
 

Cython/Utility/Buffer.c

@@ -121,8 +121,8 @@ static int __Pyx_GetBuffer(PyObject *obj, Py_buffer *view, int flags) {
 
   #if PY_VERSION_HEX < 0x02060000
     if (obj->ob_type->tp_dict &&
-        (getbuffer_cobj = PyMapping_GetItemString(obj->ob_type->tp_dict,
-                                             "__pyx_getbuffer"))) {
+        (getbuffer_cobj = PyObject_GetItem(obj->ob_type->tp_dict,
+                                           PYIDENT("__pyx_getbuffer")))) {
         getbufferproc func;
 
       #if PY_VERSION_HEX >= 0x02070000 && !(PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION == 0)
@@ -170,8 +170,8 @@ static void __Pyx_ReleaseBuffer(Py_buffer *view) {
 
   #if PY_VERSION_HEX < 0x02060000
     if (obj->ob_type->tp_dict &&
-        (releasebuffer_cobj = PyMapping_GetItemString(obj->ob_type->tp_dict,
-                                                      "__pyx_releasebuffer"))) {
+        (releasebuffer_cobj = PyObject_GetItem(obj->ob_type->tp_dict,
+                                               PYIDENT("__pyx_releasebuffer")))) {
         releasebufferproc func;
 
       #if PY_VERSION_HEX >= 0x02070000 && !(PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION == 0)