Improve build system a bit

CMakeLists.txt

@@ -6,23 +6,6 @@ set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_CURRENT_SOURCE_DIR}/cmake/")
 
 include_directories(${CMAKE_SOURCE_DIR}/include/cppkafka)
 
-set(GOOGLETEST_ROOT ${CMAKE_SOURCE_DIR}/third_party/googletest)
-set(GOOGLETEST_INCLUDE ${GOOGLETEST_ROOT}/googletest/include)
-set(GOOGLETEST_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/googletest)
-set(GOOGLETEST_LIBRARY ${GOOGLETEST_BINARY_DIR}/googletest)
-
-include(ExternalProject)
-
-ExternalProject_Add(
-    googletest
-    DOWNLOAD_COMMAND ""
-    SOURCE_DIR ${GOOGLETEST_ROOT}
-    BINARY_DIR ${GOOGLETEST_BINARY_DIR}
-    CMAKE_CACHE_ARGS "-DBUILD_GTEST:bool=ON" "-DBUILD_GMOCK:bool=OFF"
-                     "-Dgtest_force_shared_crt:bool=ON"
-    INSTALL_COMMAND ""
-)
-
 # Look for Boost (just need boost.optional headers here)
 find_package(Boost REQUIRED)
 include_directories(${Boost_INCLUDE_DIRS})
@@ -47,8 +30,31 @@ configure_file(
 
 add_subdirectory(src)
 add_subdirectory(include)
-# Make sure we build googletest before anything else
+
-add_dependencies(cppkafka googletest)
-enable_testing()
-add_subdirectory(tests)
 add_subdirectory(examples)
+
+set(GOOGLETEST_ROOT ${CMAKE_SOURCE_DIR}/third_party/googletest)
+if(EXISTS "${GOOGLETEST_ROOT}/CMakeLists.txt")
+    set(GOOGLETEST_INCLUDE ${GOOGLETEST_ROOT}/googletest/include)
+    set(GOOGLETEST_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/googletest)
+    set(GOOGLETEST_LIBRARY ${GOOGLETEST_BINARY_DIR}/googletest)
+
+    include(ExternalProject)
+
+    ExternalProject_Add(
+      googletest
+      DOWNLOAD_COMMAND ""
+      SOURCE_DIR ${GOOGLETEST_ROOT}
+      BINARY_DIR ${GOOGLETEST_BINARY_DIR}
+      CMAKE_CACHE_ARGS "-DBUILD_GTEST:bool=ON" "-DBUILD_GMOCK:bool=OFF"
+                       "-Dgtest_force_shared_crt:bool=ON"
+      INSTALL_COMMAND ""
+    )
+
+    enable_testing()
+    add_subdirectory(tests)
+    # Make sure we build googletest before anything else
+    add_dependencies(cppkafka googletest)
+else()
+    message(STATUS "Disabling tests")
+endif()

examples/CMakeLists.txt

@@ -1,8 +1,13 @@
-find_package(Boost REQUIRED COMPONENTS program_options)
+find_package(Boost COMPONENTS program_options)
 
-link_libraries(${Boost_LIBRARIES} cppkafka ${RDKAFKA_LIBRARY} ${ZOOKEEPER_LIBRARY})
+if (Boost_PROGRAM_OPTIONS_FOUND)
+    link_libraries(${Boost_LIBRARIES} cppkafka ${RDKAFKA_LIBRARY} ${ZOOKEEPER_LIBRARY})
 
-include_directories(${CMAKE_CURRENT_SOURCE_DIR}/../include)
+    include_directories(${CMAKE_CURRENT_SOURCE_DIR}/../include)
 
-add_executable(kafka_producer kafka_producer.cpp)
+    add_executable(kafka_producer kafka_producer.cpp)
-add_executable(kafka_consumer kafka_consumer.cpp)
+    add_executable(kafka_consumer kafka_consumer.cpp)
+    add_custom_target(examples DEPENDS kafka_producer kafka_consumer)
+else()
+    message(STATUS "Disabling examples since boost.program_options was not found")
+endif()

tests/CMakeLists.txt

@@ -10,9 +10,12 @@ set(KAFKA_TEST_INSTANCE "kafka-vm:9092"
 set(ZOOKEEPER_TEST_INSTANCE "kafka-vm:2181" 
     CACHE STRING "The zookeeper instance to which to connect to run tests")
 
+add_custom_target(tests)
+
 macro(create_test test_name)
-    add_executable(${test_name}_test "${test_name}_test.cpp")
+    add_executable(${test_name}_test EXCLUDE_FROM_ALL "${test_name}_test.cpp")
     add_test(${test_name} ${test_name}_test)
+    add_dependencies(tests ${test_name}_test)
 endmacro()
 
 add_definitions("-DKAFKA_TEST_INSTANCE=\"${KAFKA_TEST_INSTANCE}\"")