Remove configure test for override keyword.

Detect its support in the code by testing __cplusplus value and using specific
checks for MSVC and Clang as configure detects it as being available when
using recent g++ versions in non-C++11 mode, which do support this keyword but
warn when it is used without -std={gnu,c}++11 option, which makes actually
using it a bad idea in this case.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76174 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

acinclude.m4

@@ -255,39 +255,6 @@ AC_DEFUN([WX_CPP_EXPLICIT],
   fi
 ])
 
-dnl ---------------------------------------------------------------------------
-dnl WX_CPP_OVERRIDE checks whether the C++ compiler support the override
-dnl keyword and defines HAVE_OVERRIDE if this is the case
-dnl ---------------------------------------------------------------------------
-
-AC_DEFUN([WX_CPP_OVERRIDE],
-[
-  AC_CACHE_CHECK([if C++ compiler supports the override keyword],
-                 wx_cv_override,
-  [
-    AC_LANG_SAVE
-    AC_LANG_CPLUSPLUS
-
-    AC_TRY_COMPILE(
-      [
-        struct Base { virtual void Foo() = 0; };
-        struct Derived : Base { virtual void Foo() override { } };
-      ],
-      [
-        return 0;
-      ],
-      wx_cv_override=yes,
-      wx_cv_override=no
-    )
-
-    AC_LANG_RESTORE
-  ])
-
-  if test "$wx_cv_override" = "yes"; then
-    AC_DEFINE(HAVE_OVERRIDE)
-  fi
-])
-
 dnl ---------------------------------------------------------------------------
 dnl WX_CHECK_FUNCS(FUNCTIONS...,
 dnl                [ACTION-IF-FOUND],

configure

@@ -21173,62 +21173,6 @@ $as_echo "$wx_cv_explicit" >&6; }
   fi
 
 
-
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking if C++ compiler supports the override keyword" >&5
-$as_echo_n "checking if C++ compiler supports the override keyword... " >&6; }
-if ${wx_cv_override+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-
-
-    ac_ext=cpp
-ac_cpp='$CXXCPP $CPPFLAGS'
-ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
-
-
-    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-        struct Base { virtual void Foo() = 0; };
-        struct Derived : Base { virtual void Foo() override { } };
-
-int
-main ()
-{
-
-        return 0;
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
-  wx_cv_override=yes
-else
-  wx_cv_override=no
-
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-
-    ac_ext=c
-ac_cpp='$CPP $CPPFLAGS'
-ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_c_compiler_gnu
-
-
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $wx_cv_override" >&5
-$as_echo "$wx_cv_override" >&6; }
-
-  if test "$wx_cv_override" = "yes"; then
-    $as_echo "#define HAVE_OVERRIDE 1" >>confdefs.h
-
-  fi
-
-
 if test "x$SUNCXX" = xyes; then
     CXXFLAGS="-features=tmplife $GNU_SOURCE_FLAG $CXXFLAGS"
 fi

configure.in

@@ -1793,9 +1793,6 @@ WX_CPP_NEW_HEADERS(, AC_DEFINE(wxUSE_IOSTREAMH))
 dnl check whether C++ compiler supports explicit keyword
 WX_CPP_EXPLICIT
 
-dnl check whether C++ compiler supports override keyword
-WX_CPP_OVERRIDE
-
 dnl With Sun CC, temporaries have block scope by default. This flag is needed
 dnl to get the expression scope behaviour that conforms to the standard.
 if test "x$SUNCXX" = xyes; then

include/wx/defs.h

@@ -269,21 +269,21 @@ typedef short int WXTYPE;
     #define wxEXPLICIT
 #endif /*  HAVE_EXPLICIT/!HAVE_EXPLICIT */
 
-/*  check for override keyword support */
+/* check for override keyword support */
 #ifndef HAVE_OVERRIDE
-    #if defined(__VISUALC__) && (__VISUALC__ >= 1400)
+    #if __cplusplus >= 201103L
-        /*
+        /* All C++11 compilers should have it. */
-           VC++ 8.0+ support C++/CLI's override, sealed, and abstract in native
-           code as a nonstandard extension, and C++/CLI's override fortunately
-           matches C++11's
-         */
         #define HAVE_OVERRIDE
-    #elif wxCHECK_GCC_VERSION(4, 7) && __cplusplus >= 201103L
+    #elif wxCHECK_VISUALC_VERSION(8)
+        /*
+           VC++ 8.0+ do support override keyword but don't define __cplusplus
+           as indicating C++11 support, so handle this case specially.
+         */
         #define HAVE_OVERRIDE
     #elif WX_HAS_CLANG_FEATURE(cxx_override_control)
         #define HAVE_OVERRIDE
     #endif
-#endif /*  !HAVE_OVERRIDE */
+#endif /* !HAVE_OVERRIDE */
 
 #ifdef HAVE_OVERRIDE
     #define wxOVERRIDE override

setup.h.in

@@ -698,11 +698,6 @@
  */
 #undef HAVE_EXPLICIT
 
-/*
- * Define if your compiler supports the override keyword
- */
-#undef HAVE_OVERRIDE
-
 /*
  * Define if your compiler has C99 va_copy
  */