Fixes per code review

Author: Alexander Damian

CMakeLists.txt

@@ -123,15 +123,14 @@ endif()
 find_package(RdKafka ${FIND_PACKAGE_QUIET} CONFIG)
 set(RDKAFKA_TARGET_IMPORTS ${RdKafka_FOUND})
 if (NOT RdKafka_FOUND)
-    message(STATUS "RdKafkaConfig.cmake not found. Please set RDKAFKA_ROOT or RDKAFKA_DIR if a config file is installed. Attempting to find module instead...")
+    message(STATUS "RdKafkaConfig.cmake not found. Attempting to find module instead...")
     find_package(RdKafka REQUIRED ${FIND_PACKAGE_QUIET} MODULE)
     if (NOT RdKafka_FOUND)
-        message(FATAL_ERROR "RdKafka module not found. Please set RDKAFKA_ROOT to the install path.")
+        message(FATAL_ERROR "RdKafka module not found. Please set RDKAFKA_ROOT to the install path or RDKAFKA_DIR pointing to the RdKafka configuration file location.")
     else()
         message(STATUS "RdKafka module found.")
     endif()
 else()
-    set(RdKafka_DEPENDENCIES RdKafka::rdkafka)
     message(STATUS "RdKafka configuration file found: ${RdKafka_CONFIG}")
 endif()
 

README.md

@@ -54,7 +54,7 @@ int main() {
 In order to compile _cppkafka_ you need:
 
 * _librdkafka >= 0.9.4_
-* _CMake >= 3.10_
+* _CMake >= 3.9.2_
 * A compiler with good C++11 support (e.g. gcc >= 4.8). This was tested successfully on _g++ 4.8.3_. 
 * The boost library (for boost::optional)
 

cmake/FindRdKafka.cmake

@@ -3,14 +3,16 @@
 # - RdKafka_LIBNAME : The name of the library, i.e. librdkafka.a, librdkafka.so, etc.
 # - RdKafka_LIBRARY_DIR : The directory where the library is located.
 # - RdKafka_LIBRARY_PATH : The full library path i.e. ${RdKafka_LIBRARY_DIR}/${RdKafka_LIBNAME}
-# - RdKafka_DEPENDENCIES : Libs needed to link with RdKafka
+# - RdKafka::rdkafka : Imported library containing all above properties set.
 
 if (CPPKAFKA_RDKAFKA_STATIC_LIB)
     set(RDKAFKA_PREFIX ${CMAKE_STATIC_LIBRARY_PREFIX})
     set(RDKAFKA_SUFFIX ${CMAKE_STATIC_LIBRARY_SUFFIX})
+    set(RDKAFKA_LIBRARY_TYPE STATIC)
 else()
     set(RDKAFKA_PREFIX ${CMAKE_SHARED_LIBRARY_PREFIX})
     set(RDKAFKA_SUFFIX ${CMAKE_SHARED_LIBRARY_SUFFIX})
+    set(RDKAFKA_LIBRARY_TYPE SHARED)
 endif()
 
 set(RdKafka_LIBNAME ${RDKAFKA_PREFIX}rdkafka${RDKAFKA_SUFFIX})
@@ -60,13 +62,13 @@ try_compile(RdKafka_FOUND ${CMAKE_CURRENT_BINARY_DIR}
             CMAKE_FLAGS "-DINCLUDE_DIRECTORIES=${RdKafka_INCLUDE_DIR}")
 
 if (RdKafka_FOUND)
-    if (CPPKAFKA_RDKAFKA_STATIC_LIB)
-        set(RdKafka_DEPENDENCIES ${RdKafka_LIBNAME} pthread rt ssl crypto dl z)
-    else()
-        set(RdKafka_DEPENDENCIES ${RdKafka_LIBNAME} pthread)
-    endif()
-    include_directories(SYSTEM ${RdKafka_INCLUDE_DIR})
-    link_directories(${RdKafka_LIBRARY_DIR})
+    add_library(RdKafka::rdkafka ${RDKAFKA_LIBRARY_TYPE} IMPORTED GLOBAL)
+    set(RDKAFKA_DEPENDENCIES pthread rt ssl crypto dl z)
+    set_target_properties(RdKafka::rdkafka PROPERTIES
+            IMPORTED_NAME RdKafka
+            IMPORTED_LOCATION "${RdKafka_LIBRARY_PATH}"
+            INTERFACE_INCLUDE_DIRECTORIES "${RdKafka_INCLUDE_DIR}"
+            INTERFACE_LINK_LIBRARIES "${RDKAFKA_DEPENDENCIES}")
     message(STATUS "Found valid rdkafka version")
     mark_as_advanced(
         RDKAFKA_LIBRARY

cmake/config.cmake.in

@@ -13,15 +13,14 @@ find_dependency(Boost REQUIRED)
 find_dependency(RdKafka QUIET CONFIG)
 set(RDKAFKA_TARGET_IMPORTS ${RdKafka_FOUND})
 if (NOT RdKafka_FOUND)
-    message(STATUS "RdKafkaConfig.cmake not found. Please set RDKAFKA_ROOT or RDKAFKA_DIR if a config file is installed. Attempting to find module instead...")
+    message(STATUS "RdKafkaConfig.cmake not found. Attempting to find module instead...")
     find_dependency(RdKafka REQUIRED QUIET MODULE)
     if (NOT RdKafka_FOUND)
-        message(FATAL_ERROR "RdKafka module not found. Please set RDKAFKA_ROOT to the install path.")
+        message(FATAL_ERROR "RdKafka module not found. Please set RDKAFKA_ROOT to the install path or RDKAFKA_DIR pointing to the RdKafka configuration file location.")
     else()
         message(STATUS "RdKafka module found.")
     endif()
 else()
-    set(RdKafka_DEPENDENCIES RdKafka::rdkafka)
     message(STATUS "RdKafka configuration file found: ${RdKafka_CONFIG}")
 endif()
 

examples/CMakeLists.txt

@@ -4,7 +4,7 @@ add_custom_target(examples)
 macro(create_example example_name)
     string(REPLACE "_" "-" sanitized_name ${example_name})
     add_executable(${sanitized_name} EXCLUDE_FROM_ALL "${example_name}_example.cpp")
-    target_link_libraries(${sanitized_name} cppkafka ${RdKafka_DEPENDENCIES} Boost::boost Boost::program_options)
+    target_link_libraries(${sanitized_name} cppkafka RdKafka::rdkafka Boost::boost Boost::program_options)
     add_dependencies(examples ${sanitized_name})
 endmacro()
 

src/CMakeLists.txt

@@ -27,7 +27,7 @@ set(SOURCES
 )
 
 set(TARGET_NAME         cppkafka)
-set(PKG_DIR             "${PROJECT_SOURCE_DIR}/package")
+set(PKG_DIR             "${CMAKE_BINARY_DIR}/package")
 set(PKG_CONFIG_FILE     "${PKG_DIR}/${TARGET_NAME}.pc")
 set(CONFIG_FILE         "${PKG_DIR}/${PROJECT_NAME}Config.cmake")
 set(VERSION_FILE        "${PKG_DIR}/${PROJECT_NAME}ConfigVersion.cmake")
@@ -42,12 +42,11 @@ add_library(${TARGET_NAME} ${CPPKAFKA_LIBRARY_TYPE} ${SOURCES})
 set_target_properties(${TARGET_NAME} PROPERTIES VERSION ${CPPKAFKA_VERSION}
                                                  SOVERSION ${CPPKAFKA_VERSION})
 # In CMake >= 3.15 Boost::boost == Boost::headers
-set(DEPENDENCIES ${RdKafka_DEPENDENCIES})
+target_link_libraries(${TARGET_NAME} PRIVATE RdKafka::rdkafka Boost::boost)
 if (WIN32)
     # On windows ntohs and related are in ws2_32
-    set(DEPENDENCIES ${DEPENDENCIES} ws2_32.lib)
+    target_link_libraries(${TARGET_NAME} PRIVATE ws2_32.lib)
 endif()
-target_link_libraries(${TARGET_NAME} PRIVATE ${DEPENDENCIES})
 
 # Install cppkafka target and specify all properties needed for the exported file
 install(

tests/CMakeLists.txt

@@ -25,6 +25,6 @@ add_executable(cppkafka_tests
 )
 
 # In CMake >= 3.15 Boost::boost == Boost::headers
-target_link_libraries(cppkafka_tests cppkafka ${RdKafka_DEPENDENCIES} Boost::boost Boost::program_options )
+target_link_libraries(cppkafka_tests cppkafka RdKafka::rdkafka Boost::boost Boost::program_options )
 add_dependencies(tests cppkafka_tests)
 add_test(cppkafka cppkafka_tests)