Handle WITH_* options for utilities better.

I.e., don't offer them on platforms which don't support them.

CMakeLists.txt

@@ -48,8 +48,6 @@ cmake_dependent_option(WITH_SHADERS "Build Shaders library" ON "NOT WITH_DEBUGTO
 cmake_dependent_option(WITH_SHAPES "Build Shapes library" ON "NOT WITH_DEBUGTOOLS" ON)
 option(WITH_TEXT "Build Text library" ON)
 cmake_dependent_option(WITH_TEXTURETOOLS "Build TextureTools library" ON "NOT WITH_TEXT;NOT WITH_DISTANCEFIELDCONVERTER" ON)
-option(WITH_MAGNUMINFO "Build magnum-info utility" OFF)
-cmake_dependent_option(WITH_DISTANCEFIELDCONVERTER "Build magnum-distancefield utility" OFF "NOT TARGET_GLES" OFF)
 
 # Application libraries
 if(CORRADE_TARGET_NACL)
@@ -63,6 +61,14 @@ else()
     option(WITH_SDL2APPLICATION "Build Sdl2Application library" OFF)
 endif()
 
+# Utilities (currently depending on WindowlessGlxApplication)
+if(UNIX OR CORRADE_TARGET_NACL)
+    option(WITH_MAGNUMINFO "Build magnum-info utility" OFF)
+endif()
+if(UNIX)
+    cmake_dependent_option(WITH_DISTANCEFIELDCONVERTER "Build magnum-distancefieldconverter utility" OFF "NOT TARGET_GLES" OFF)
+endif()
+
 # Plugins
 cmake_dependent_option(WITH_MAGNUMFONT "Build MagnumFont plugin" OFF "WITH_TEXT" OFF)
 cmake_dependent_option(WITH_MAGNUMFONTCONVERTER "Build MagnumFontConverter plugin" OFF "NOT MAGNUM_TARGET_GLES;WITH_TEXT" OFF)

src/Platform/CMakeLists.txt

@@ -178,7 +178,7 @@ endif()
 # Magnum Info
 if(WITH_MAGNUMINFO)
     if(NOT UNIX AND NOT CORRADE_TARGET_NACL)
-        message(FATAL_ERROR "magnum-info is not available on this platform. Set WITH_MAGNUMINFO to OFF to suppress this warning.")
+        message(FATAL_ERROR "magnum-info is not available on this platform. Set WITH_MAGNUMINFO to OFF to skip building it.")
     endif()
 
     add_executable(magnum-info magnum-info.cpp)