Why isn't cmake locating gtest and gmock libs? - c++

Question

Here's a link to my project, just in case.
So, here's my CMakeLists.txt file:
cmake_minimum_required (VERSION 2.6)
enable_testing()
project (IeiuniumTela)
set (IeiuniumTela_VERSION_MAJOR 1)
set (IeiuniumTela_VERSION_MINOR 0)
set (IeiuniumTela_VERSION_PATCH 0)
set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/build/lib)
set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/build/lib)
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/build/bin)
# TODO: Make conditional for OS X compilation
set(CMAKE_CXX_COMPILER g++-4.7)
set(CMAKE_CC_COMPILER gcc-4.7)
# TODO: Require gcc >= 4.7
set(SOURCES "${SOURCES}" "${CMAKE_BINARY_DIR}/src/http/request.cpp")
set(SOURCES "${SOURCES}" "${CMAKE_BINARY_DIR}/src/http/response.cpp")
set(SOURCES "${SOURCES}" "${CMAKE_BINARY_DIR}/src/http/server.cpp")
set(SOURCES "${SOURCES}" "${CMAKE_BINARY_DIR}/src/log.cpp")
set(SOURCES "${SOURCES}" "${CMAKE_BINARY_DIR}/src/main.cpp")
set(CMAKE_CXX_FLAGS "-std=c++11 ${CMAKE_CXX_FLAGS}")
set(CMAKE_CXX_FLAGS "-Wall ${CMAKE_CXX_FLAGS}")
add_executable(ieiunium_tela.srv ${SOURCES})
target_link_libraries(ieiunium_tela.srv yaml-cpp)
target_link_libraries(ieiunium_tela.srv boost_system-mt)
set(GTEST_DIR "${CMAKE_BINARY_DIR}/../gtest-1.6.0")
include_directories(SYSTEM "${GTEST_DIR}/include")
find_library(GTEST_LIBRARY
NAMES gtest
libgtest
libgtest.a
PATHS "${GTEST_DIR}")
find_library(GTEST_LIBRARY_MAIN
NAMES gtest_main
libgtest_main
libgtest.a
PATHS "${GTEST_DIR}")
set(GMOCK_DIR "${CMAKE_BINARY_DIR}/../gmock-1.6.0")
include_directories(SYSTEM "${GMOCK_DIR}/include")
include_directories(SYSTEM "${GMOCK_DIR}/gtest/include")
find_library(GMOCK_LIBRARY
NAMES gmock
libgmock
libgmock.a
PATHS "${GMOCK_DIR}")
find_library(GMOCK_LIBRARY_MAIN
NAMES gmock_main
libgmock_main
libgmock_main.a
PATHS "${GMOCK_DIR}")
set(TEST_SOURCES "${TEST_SOURCES}" "${CMAKE_BINARY_DIR}/test/unit/http/test_request.cpp")
set(TEST_SOURCES "${TEST_SOURCES}" "${CMAKE_BINARY_DIR}/test/unit/http/test_response.cpp")
set(TEST_SOURCES "${TEST_SOURCES}" "${CMAKE_BINARY_DIR}/test/unit/http/test_server.cpp")
set(TEST_SOURCES "${TEST_SOURCES}" "${CMAKE_BINARY_DIR}/test/unit/test_log.cpp")
set(TEST_SOURCES "${TEST_SOURCES}" "${CMAKE_BINARY_DIR}/test/unit/test_main.cpp")
add_executable(ieiunium_tela.srv_TEST ${TEST_SOURCES})
target_link_libraries(ieiunium_tela.srv_TEST ${GTEST_LIBRARY} ${GTEST_LIBRARY_MAIN})
target_link_libraries(ieiunium_tela.srv_TEST ${GMOCK_LIBRARY} ${GMOCK_LIBRARY_MAIN})
And, here's my question: Why isn't cmake finding my gtest/gmock libs?
I've gone into their respective directories and built them using ./configure && make -j4 and a brief find for the shared libraries shows them there.

Answer 1

Another option would be to build gtest and gmock as part of your main CMake build rather than building them separately and using find_package() or find_library(). This comes with some advantages, including:
They are built with the same compiler and settings as your main build, so there won't be issues with mismatched symbols, etc.
No manual steps required before the build and no need to tell CMake where to find things in your main CMakeLists.txt.
I recently wrote an article about how to download and build gtest as part of your build. Unlike the more commonly suggested approaches, my article shows how to download gtest during configure time (i.e. when CMake is run), which then allows you to bring it into your project using add_subdirectory(). This makes the gtest and gtest_main CMake targets directly available to your project, so you can just link against them like any other library. The approach is general and may work for mock too. You can find that article here:
https://crascit.com/2015/07/25/cmake-gtest/
Update: This approach is now also part of the googletest documentation.

Answer 2

The gtest/gmock libraries aren't built to the actual root of these projects. I believe on Linux they're built to "lib" inside the root.
To tell CMake to search in "lib" but without modifying your GTEST_DIR or GMOCK_DIR variables, you can use the PATH_SUFFIXES argument to the find_library command:
find_library(GTEST_LIBRARY
NAMES gtest
libgtest
libgtest.a
PATHS "${GTEST_DIR}"
PATH_SUFFIXES lib)
You can add a list of suffixes to give values appropriate for Windows builds too if required.
There is a standard CMake module provided to find gtest (FindGTest). You could look at the code in there for ideas, or actually use it instead of your own code. Unfortunately, there isn't a FindGMock module.
I have a couple of other minor points.
It might be worth considering allowing the GTEST_DIR and GMOCK_DIR variables to be set by the user via the -D flag to allow these to exist anywhere relative to your project's root. In that case, you'd only set them inside the CMakeLists.txt if they weren't already set.
Another minor point is that GMock comes with GTest included. You could just allow users to build GMock, and then find and use the version inside the GMock tree.