define HAVE_LARGEFILE_SUPPORT in setup.h when large files support is available and test for it in wx/filefn.h (closes #10844); document that wx/filefn.h must be included before testing for wxHAS_LARGE_(F)FILES

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@60823 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/doxygen/mainpages/const_cpp.h

@@ -197,8 +197,12 @@ Currently the following symbols exist:
     implemented in a generic way, using a critical section.}
 @itemdef{wxHAS_CONFIG_TEMPLATE_RW, Defined if the currently used compiler
     supports template Read() and Write() methods in wxConfig.}
-@itemdef{wxHAS_LARGE_FILES, Defined if wxFile supports files more than 4GB in size.}
-@itemdef{wxHAS_LARGE_FFILES, Defined if wxFFile supports files more than 4GB in size.}
+@itemdef{wxHAS_LARGE_FILES, Defined if wxFile supports files more than 4GB in
+    size (notice that you must include @c wx/filefn.h before testing for this
+    symbol).}
+@itemdef{wxHAS_LARGE_FFILES, Defined if wxFFile supports files more than 4GB in
+    size (notice that you must include @c wx/filefn.h before testing for this
+    symbol).}
 @itemdef{wxHAS_MULTIPLE_FILEDLG_FILTERS, Defined if wxFileDialog supports multiple ('|'-separated) filters.}
 @itemdef{wxHAS_POWER_EVENTS, Defined if wxPowerEvent are ever generated on the current platform.}
 @itemdef{wxHAS_RADIO_MENU_ITEMS,

include/wx/filefn.h

@@ -446,16 +446,16 @@ enum wxFileKind
     #define wxHAS_NATIVE_LSTAT
 #else // Unix or Windows using unknown compiler, assume POSIX supported
     typedef off_t wxFileOffset;
-    #ifdef _LARGE_FILES
+    #ifdef HAVE_LARGEFILE_SUPPORT
         #define wxFileOffsetFmtSpec wxLongLongFmtSpec
         wxCOMPILE_TIME_ASSERT( sizeof(off_t) == sizeof(wxLongLong_t),
                                 BadFileSizeType );
         // wxFile is present and supports large files
-        #ifdef wxUSE_FILE
+        #if wxUSE_FILE
             #define wxHAS_LARGE_FILES
         #endif
         // wxFFile is present and supports large files
-        #if SIZEOF_LONG == 8 || defined HAVE_FSEEKO
+        #if wxUSE_FFILE && (SIZEOF_LONG == 8 || defined HAVE_FSEEKO)
             #define wxHAS_LARGE_FFILES
         #endif
     #else

setup.h.in

@@ -753,8 +753,11 @@
  * Define if compiler has __thread keyword.
  */
 #undef HAVE___THREAD_KEYWORD
+/*
+ * Define if large (64 bit file offsets) files are supported.
+ */
+#undef HAVE_LARGEFILE_SUPPORT
 
-/* compatibility */
 /*
  * Use OpenGL
  */