1 Note for Windows users: 2 3 It is highly recommended to declare the Windows OS version you are 4 targetting when building the library as well as when using it. You can do so 5 thanks to the well known Microsoft macros WINVER, _WIN32_WINDOWS or 6 _WIN32_WINNT, see your platform SDK documentation for a description 7 of those macros and how to use them. To define it when building the 8 library, use the configure script --extra-cxxflag option. Here is the 9 configuration to build STLport using Visual Studio 2005 and targetting 10 Windows XP: 11 12 configure -c msvc8 --extra-cxxflag "/D_WIN32_WINNT=0x0501" 13 14 If you do not declare it at build time STLport will adapt to the PSDK in 15 use, windows.h gives a default value to WINVER. However, when using the 16 library, windows.h is not necessarily included, at least not by STLport 17 internally, so none of the macros are defined which will result in an 18 inconsistency in the build process which most of time will generate undefined 19 behavior at runtime. 20 21 Here is the main reason for following this advise, the Windows 95 22 compatibility issue: 23 24 Because of a modification in the behavior of the Win32 API functions 25 InterlockedIncrement and InterlockedDecrement after Windows 95, STLport 26 libraries built for Windows 95 cannot be used to generate an application 27 built for Windows XP for instance. So, if you build STLport with a Windows 28 95 PSDK, STLport will be ready for Windows 95. If you then use it without 29 defining _WIN32_WINDOWS to signal Windows 95 compatibility, STLport will 30 consider that it can use latest Windows OS features like the new 31 InterlockedIncrement and InterlockedDecrement functions which change the 32 memory footprint of some internal STLport objects making it incompatible 33 with the libraries built for Windows 95. 34 35 Normally, doing so wouldn't generate any compilation or link error, you 36 would only experiment undefined behavior at runtime. In order to make this 37 problem more obvious STLport forces a link time error in debug mode (_DEBUG 38 macro defined). 39 40 Unresolved symbol will be: 41 - 'building_for_at_least_windows98_but_library_built_for_windows95' 42 if you are trying to use STLport libraries built for Windows 98 or later 43 to generate an application targetting the Windows 95 platform. 44 - 'building_for_windows95_but_library_built_for_at_least_windows98' 45 if you are trying to use STLport libraries built for Windows 95 to generate 46 an appliation targetting the 47 48 Windows XP platform for instance. 49 50 Of course, targetting the latest Windows OS versions will give you the best 51 performance from STLport. This is why when none of the platform macros are 52 defined STLport consider that there is no minimum OS requirement and will 53 use the latest API functions. There is only one exception to this behavior, 54 the SwitchToThread function that is used only if you define _WIN32_WINNT to a 55 value higher or equal to 0X0400. 56
