ClickHouse/utils/db-generator/CMakeLists.txt

clickhouse_add_executable (query_db_generator query_db_generator.cpp)
target_link_libraries(query_db_generator PRIVATE clickhouse_parsers boost::program_options)
Prefix overridden add_executable() command with "clickhouse_" A simple HelloWorld program with zero includes except iostream triggers a build of ca. 2000 source files. The reason is that ClickHouse's top-level CMakeLists.txt overrides "add_executable()" to link all binaries against "clickhouse_new_delete". This links against "clickhouse_common_io", which in turn has lots of 3rd party library dependencies ... Without linking "clickhouse_new_delete", the number of compiled files for "HelloWorld" goes down to ca. 70. As an example, the self-extracting-executable needs none of its current dependencies but other programs may also benefit. In order to restore access to the original "add_executable()", the overriding version is now prefixed. There is precedence for a "clickhouse_" prefix (as opposed to "ch_"), for example "clickhouse_split_debug_symbols". In general prefixing makes sense also because overriding CMake commands relies on undocumented behavior and is considered not-so-great practice (). () https://crascit.com/2018/09/14/do-not-redefine-cmake-commands/ 2022-07-11 17:19:15 +00:00			`clickhouse_add_executable (query_db_generator query_db_generator.cpp)`
			`target_link_libraries(query_db_generator PRIVATE clickhouse_parsers boost::program_options)`