build: cmake: build release.cc as a library

so we can attach compiling definitions in a simpler way.

this change is based on Botond Dénes's change which gives an overhaul
to the existing CMake building system.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

CMakeLists.txt

@@ -229,7 +229,6 @@ set(scylla_sources
     redis/command_factory.cc
     redis/commands.cc
     redis/lolwut.cc
-    release.cc
     repair/repair.cc
     repair/row_level.cc
     replica/database.cc
@@ -322,7 +321,9 @@ add_subdirectory(sstables)
 add_subdirectory(test)
 add_subdirectory(types)
 add_subdirectory(utils)
-
+include(add_version_library)
+add_version_library(scylla_version
+    release.cc)
 add_executable(scylla
     ${scylla_sources}
     ${scylla_gen_sources})
@@ -334,6 +335,7 @@ target_link_libraries(scylla PRIVATE
     cql3
     idl
     schema
+    scylla_version
     sstables
     test-perf
     types
@@ -397,23 +399,6 @@ target_include_directories(scylla PRIVATE
     "${CMAKE_CURRENT_SOURCE_DIR}"
     "${scylla_gen_build_dir}")
 
-###
-### Generate version file and supply appropriate compile definitions for release.cc
-###
-execute_process(COMMAND ${CMAKE_SOURCE_DIR}/SCYLLA-VERSION-GEN --output-dir "${CMAKE_BINARY_DIR}/gen" RESULT_VARIABLE scylla_version_gen_res)
-if(scylla_version_gen_res)
-    message(SEND_ERROR "Version file generation failed. Return code: ${scylla_version_gen_res}")
-endif()
-
-file(READ "${CMAKE_BINARY_DIR}/gen/SCYLLA-VERSION-FILE" scylla_version)
-string(STRIP "${scylla_version}" scylla_version)
-
-file(READ "${CMAKE_BINARY_DIR}/gen/SCYLLA-RELEASE-FILE" scylla_release)
-string(STRIP "${scylla_release}" scylla_release)
-
-get_property(release_cdefs SOURCE "${CMAKE_SOURCE_DIR}/release.cc" PROPERTY COMPILE_DEFINITIONS)
-list(APPEND release_cdefs "SCYLLA_VERSION=\"${scylla_version}\"" "SCYLLA_RELEASE=\"${scylla_release}\"")
-set_source_files_properties("${CMAKE_SOURCE_DIR}/release.cc" PROPERTIES COMPILE_DEFINITIONS "${release_cdefs}")
 
 # TODO: create cmake/ directory and move utilities (generate functions etc) there
 # TODO: Build tests if BUILD_TESTING=on (using CTest module)

cmake/add_version_library.cmake

@@ -0,0 +1,21 @@
+###
+### Generate version file and supply appropriate compile definitions for release.cc
+###
+function(add_version_library name source)
+  set(version_file ${CMAKE_CURRENT_BINARY_DIR}/SCYLLA-VERSION-FILE)
+  set(release_file ${CMAKE_CURRENT_BINARY_DIR}/SCYLLA-RELEASE-FILE)
+  execute_process(
+    COMMAND ${CMAKE_SOURCE_DIR}/SCYLLA-VERSION-GEN --output-dir "${CMAKE_CURRENT_BINARY_DIR}"
+    WORKING_DIRECTORY ${CMAKE_SOURCE_DIR})
+  file(STRINGS ${version_file} scylla_version)
+  file(STRINGS ${release_file} scylla_release)
+
+  add_library(${name} OBJECT ${source})
+  target_compile_definitions(${name}
+    PRIVATE
+      SCYLLA_VERSION=\"${scylla_version}\"
+      SCYLLA_RELEASE=\"${scylla_release}\")
+  target_link_libraries(${name}
+    PRIVATE
+      Seastar::seastar)
+endfunction(add_version_library)