Prerequisites for using dynamic libraries
To use dynamic libraries in a KasperskyOS-based solution, the following conditions must be met:
- Processes that use dynamic libraries must have access to the file systems in which the files of the dynamic libraries are stored. Access to file systems is provided by VFS, which may be implemented in the context of the processes using the dynamic libraries, or may be a separate process. The dynamic libraries must not be used by VFS or other software that is used by VFS to work with storage (such as a storage driver).
- The toolchain must support dynamic linking.
The KasperskyOS SDK comes with a separate toolchain for each supported processor architecture. A required toolchain may not support dynamic linking. To check whether dynamic linking is supported, you need to use the
CMakeget_property()command in theCMakeLists.txtroot file as follows:get_property(CAN_SHARED GLOBAL PROPERTY TARGET_SUPPORTS_SHARED_LIBS) if(CAN_SHARED) message(STATUS "Dynamic linking is supported.") endif() - The executable code of programs that use dynamic libraries must be built with the
-rdynamicflag (with dynamic linking).If the toolchain supports dynamic linking, the
CMakeinitialize_platform()command causes this flag to be used automatically for building all executable files defined viaCMakeadd_executable()commands.
If the CMake initialize_platform(FORCE_STATIC) command is called in the CMakeLists.txt root file, the toolchain supporting dynamic linking performs static linking of executable files.
The CMake project_static_executable_header_default() command affects the build of executable files defined via subsequent CMake add_executable() commands in one CMakeLists.txt file. The toolchain that supports dynamic linking performs static linking of these executable files.
The CMake platform_target_force_static() command affects the build of one executable file defined via the CMake add_executable() command. The toolchain that supports dynamic linking performs static linking of this executable file.
The executable code of programs that is built with the -rdynamic flag is linked to a static library if a dynamic library is not found. For example, if the CMake target_link_libraries(client -lm) command is being used, the client program is linked to the static library libm.a if the dynamic library libm.so is not found.