new_mmap_object(), Windows flavor.

On a box where sizeof(size_t) == 4, C doesn't define
what happens when a size_t value is shifted right by
32 bits, and this caused test_mmap to fail on Windows
in a debug build.  So use different code to break
the size apart depending on how large size_t actually
is.

This looks like an illusion, since lots of code in this
module still appears to assume sizes can't be more
than 32 bits (e.g., the internal _GetMapSize() still
returns an int), but at least test_mmap passes again.

diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index bdbda22f937de2570e1a5889500bd10b03e32e14..dbb958d5401ef42f1e583e0860b0f5410fe5482f 100644 (file)
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -980,6 +980,8 @@ new_mmap_object(PyObject *self, PyObject *args, PyObject *kwdict)
        mmap_object *m_obj;
        PyObject *map_size_obj = NULL;
        int map_size;
+       DWORD size_hi;  /* upper 32 bits of m_obj->size */
+       DWORD size_lo;  /* lower 32 bits of m_obj->size */
        char *tagname = "";
        DWORD dwErr = 0;
        int fileno;
@@ -1089,11 +1091,23 @@ new_mmap_object(PyObject *self, PyObject *args, PyObject *kwdict)
                m_obj->tagname = NULL;
 
        m_obj->access = (access_mode)access;
+       /* DWORD is a 4-byte int.  If we're on a box where size_t consumes
+        * more then 4 bytes, we need to break it apart.  Else (size_t
+        * consumes 4 bytes), C doesn't define what happens if we shift
+        * right by 32, so we need different code.
+        */
+#if SIZEOF_SIZE_T > 4
+       size_hi = (DWORD)(m_obj->size >> 32);
+       size_lo = (DWORD)(m_obj->size & 0xFFFFFFFF);
+#else
+       size_hi = 0;
+       size_lo = (DWORD)m_obj->size;
+#endif
        m_obj->map_handle = CreateFileMapping (m_obj->file_handle,
                                               NULL,
                                               flProtect,
-                                              (DWORD)(m_obj->size >> 32),
-                                              (DWORD)(m_obj->size & 0xFFFFFFFF),
+                                              size_hi,
+                                              size_lo,
                                               m_obj->tagname);
        if (m_obj->map_handle != NULL) {
                m_obj->data = (char *) MapViewOfFile (m_obj->map_handle,