Force submodules to be present (usability) [#CLICKHOUSE-3]

CMakeLists.txt

@@ -6,15 +6,20 @@ set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${ClickHouse_SOURCE_DIR}/cmake/Modul
 if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
     # Require at least gcc 7
     if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7 AND NOT CMAKE_VERSION VERSION_LESS 2.8.9)
-        message (FATAL_ERROR "GCC version must be at least 7! For example, if GCC 7 is available under gcc-7, g++-7 names, do the following: export CC=gcc-7 CXX=g++-7; rm -rf CMakeCache.txt CMakeFiles; and re run cmake or ./release.")
+        message (FATAL_ERROR "GCC version must be at least 7. For example, if GCC 7 is available under gcc-7, g++-7 names, do the following: export CC=gcc-7 CXX=g++-7; rm -rf CMakeCache.txt CMakeFiles; and re run cmake or ./release.")
     endif ()
 elseif (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
     # Require at least clang 5
     if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5)
-        message (FATAL_ERROR "Clang version must be at least 5!")
+        message (FATAL_ERROR "Clang version must be at least 5.")
     endif ()
 else ()
-    message (WARNING "You are using an unsupported compiler! Compilation has only been tested with Clang 5+ and GCC 7+.")
+    message (WARNING "You are using an unsupported compiler. Compilation has only been tested with Clang 5+ and GCC 7+.")
+endif ()
+
+# Check that submodules are present
+if (NOT EXISTS "${ClickHouse_SOURCE_DIR}/contrib/boost/boost")
+    message (FATAL_ERROR "Submodules are not initialized. Run\n\tgit submodule update --init --recursive")
 endif ()
 
 # Write compile_commands.json

cmake/find_boost.cmake

 option (USE_INTERNAL_BOOST_LIBRARY "Set to FALSE to use system boost library instead of bundled" ${NOT_UNBUNDLED})
 
-# Test random file existing in all package variants
-if (USE_INTERNAL_BOOST_LIBRARY AND NOT EXISTS "${ClickHouse_SOURCE_DIR}/contrib/boost/libs/system/src/error_code.cpp")
-   message (WARNING "submodules in contrib/boost is missing. to fix try run: \n git submodule update --init --recursive")
-   set (USE_INTERNAL_BOOST_LIBRARY 0)
-endif ()
-
 if (NOT USE_INTERNAL_BOOST_LIBRARY)
     set (Boost_USE_STATIC_LIBS ${USE_STATIC_LIBRARIES})
     set (BOOST_ROOT "/usr/local")