Globally replace _T() with wxT().

Standardize on using a single macro across all wxWidgets sources and solve the name clash with Sun CC standard headers (see #10660).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@61508 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/chartype.h

@@ -222,7 +222,7 @@
 
 
 /* ------------------------------------------------------------------------- */
-/* define _T() and related macros                                            */
+/* define wxT() and related macros                                           */
 /* ------------------------------------------------------------------------- */
 
 /* BSD systems define _T() to be something different in ctype.h, override it */
@@ -231,15 +231,19 @@
     #undef _T
 #endif
 
-/* could already be defined by tchar.h (it's quasi standard) */
-#ifndef _T
+/*
+   wxT ("wx text") macro turns a literal string constant into a wide char
+   constant. It is mostly unnecessary with wx 2.9 but defined for
+   compatibility.
+ */
+#ifndef wxT
     #if !wxUSE_UNICODE
-        #define _T(x) x
+        #define wxT(x) x
     #else /* Unicode */
         /* use wxCONCAT_HELPER so that x could be expanded if it's a macro */
-        #define _T(x) wxCONCAT_HELPER(L, x)
+        #define wxT(x) wxCONCAT_HELPER(L, x)
     #endif /* ASCII/Unicode */
-#endif /* !defined(_T) */
+#endif /* !defined(wxT) */
 
 /*
    wxS ("wx string") macro can be used to create literals using the same
@@ -253,13 +257,25 @@
     #define wxS(x) x
 #endif
 
-/* although global macros with such names are normally bad, we want to have  */
-/* another name for _T() which should be used to avoid confusion between     */
-/* _T() and _() in wxWidgets sources */
-#define wxT(x)       _T(x)
+/*
+    _T() is a synonym for wxT() familiar to Windows programmers. As this macro
+    has even higher risk of conflicting with system headers, its use is
+    discouraged and you may predefine wxNO__T to disable it. Additionally, we
+    do it ourselves for Sun CC which is known to use it in its standard headers
+    (see #10660).
+ */
+#if defined(__SUNPRO_C) || defined(__SUNPRO_CC)
+    #ifndef wxNO__T
+        #define wxNO__T
+    #endif
+#endif
+
+#if !defined(_T) && !defined(wxNO__T)
+    #define _T(x) wxT(x)
+#endif
 
 /* a helper macro allowing to make another macro Unicode-friendly, see below */
-#define wxAPPLY_T(x) _T(x)
+#define wxAPPLY_T(x) wxT(x)
 
 /* Unicode-friendly __FILE__, __DATE__ and __TIME__ analogs */
 #ifndef __TFILE__