cmake improvements (#24)

- adds an `INTERFACE` cmake library for easier consumption as a subproject
- Removes GNU dependencies
- Updates google test to 1.8.0 and substantially simplifies the google test build
- adds caching to our CI system to improve build speed
- Add options to avoid building the unit tests/documentation (this will be helpful for subdirectories)

.travis.yml

@@ -2,6 +2,13 @@ sudo: required
 dist: trusty
 language: cpp
 
+cache: 
+  ccache: true
+  directories:
+    - cmake-3.4.3-Linux-x86_64/bin
+    - cmake-3.4.3-Linux-x86_64/plugins
+    - cmake-3.4.3-Linux-x86_64/share
+
 os:
   - linux
 compiler:
@@ -29,9 +36,10 @@ env:
 install:
   - sudo apt-get update -qq
   - sudo apt-get install -y -qq lcov curl
-  - if [ "$CXX" = "g++" ]; then export CXX="g++-4.9" CC="gcc-4.9"; fi
-  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then wget --no-check-certificate http://cmake.org/files/v3.4/cmake-3.4.3-Linux-x86_64.tar.gz ;fi
-  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then tar -xzf cmake-3.4.3-Linux-x86_64.tar.gz ;fi
+  - if [[ "$CXX" = "g++" ]]; then export CXX="g++-4.9" CC="gcc-4.9"; fi
+  - pwd
+  - ls
+  - if [[ ! -f "cmake-3.4.3-Linux-x86_64/bin/cmake" ]]; then wget --no-check-certificate http://cmake.org/files/v3.4/cmake-3.4.3-Linux-x86_64.tar.gz && tar -xvf cmake-3.4.3-Linux-x86_64.tar.gz; fi
 
 script:
   - mkdir build && cd build

3rdParty/gtest/CMakeLists.txt

@@ -2,19 +2,18 @@
 
 cmake_minimum_required(VERSION 3.0.0 FATAL_ERROR)
 PROJECT(gtest)
-SET(TARGET_NAME gtest)
-STRING(TOUPPER ${TARGET_NAME} TARGET_NAME_UPPER)
+STRING(TOUPPER ${PROJECT_NAME} PROJECT_NAME_UPPER)
 
-SET(VERSION_${TARGET_NAME_UPPER} "?.?.?" CACHE STRING "${TARGET_NAME} version string")
-SET(${TARGET_NAME_UPPER}_DIR ${CMAKE_CURRENT_BINARY_DIR}/src CACHE STRING "${TARGET_NAME} source directory")
+SET(VERSION_${PROJECT_NAME_UPPER} "?.?.?" CACHE STRING "${PROJECT_NAME} version string")
+SET(${PROJECT_NAME_UPPER}_DIR ${CMAKE_CURRENT_BINARY_DIR}/src CACHE STRING "${PROJECT_NAME} source directory")
 
 include(ExternalProject)
 ExternalProject_Add(
-	${TARGET_NAME}-ext
-	URL ${CMAKE_CURRENT_SOURCE_DIR}/gtest-${VERSION_GTEST}.zip
-	DOWNLOAD_DIR ${GTEST_DIR}
-	SOURCE_DIR ${GTEST_DIR}
-	PATCH_COMMAND ${PATCH} -p 0 -d ${GTEST_DIR} -i ${CMAKE_CURRENT_SOURCE_DIR}/patch.diff 
+	${PROJECT_NAME}-ext
+	URL ${CMAKE_CURRENT_SOURCE_DIR}/${PROJECT_NAME}-${VERSION_${PROJECT_NAME_UPPER}}.zip
+	DOWNLOAD_DIR ${${PROJECT_NAME_UPPER}_DIR}
+	SOURCE_DIR ${${PROJECT_NAME_UPPER}_DIR}
+	CMAKE_ARGS -DBUILD_GMOCK=OFF -DBUILD_GTEST=ON -Dgtest_force_shared_crt=ON
 	INSTALL_COMMAND ""
 	BUILD_IN_SOURCE 1
 )
@@ -24,23 +23,24 @@ ExternalProject_Add(
 # ------------------------------------------------------------------------------------------------------------------------------
 
 # Library
-add_library(${TARGET_NAME} STATIC IMPORTED GLOBAL)
+add_library(${PROJECT_NAME} STATIC IMPORTED GLOBAL)
 IF(WIN32)
-	SET_TARGET_PROPERTIES(${TARGET_NAME} PROPERTIES 
-		IMPORTED_LOCATION_DEBUG ${GTEST_DIR}/Debug/${CMAKE_FIND_LIBRARY_PREFIXES}gtest${CMAKE_FIND_LIBRARY_SUFFIXES}
-		IMPORTED_LOCATION_RELEASE ${GTEST_DIR}/Release/${CMAKE_FIND_LIBRARY_PREFIXES}gtest${CMAKE_FIND_LIBRARY_SUFFIXES}
-		IMPORTED_LOCATION_MINSIZEREL ${GTEST_DIR}/MinSizeRel/${CMAKE_FIND_LIBRARY_PREFIXES}gtest${CMAKE_FIND_LIBRARY_SUFFIXES}
-		IMPORTED_LOCATION_RELWITHDEBINFO ${GTEST_DIR}/RelWithDebInfo/${CMAKE_FIND_LIBRARY_PREFIXES}gtest${CMAKE_FIND_LIBRARY_SUFFIXES}
+	SET_TARGET_PROPERTIES(${PROJECT_NAME} PROPERTIES 
+		IMPORTED_LOCATION_DEBUG ${${PROJECT_NAME_UPPER}_DIR}/googletest/Debug/${CMAKE_FIND_LIBRARY_PREFIXES}${PROJECT_NAME}${CMAKE_FIND_LIBRARY_SUFFIXES}
+		IMPORTED_LOCATION_RELEASE ${${PROJECT_NAME_UPPER}_DIR}/googletest/Release/${CMAKE_FIND_LIBRARY_PREFIXES}${PROJECT_NAME}${CMAKE_FIND_LIBRARY_SUFFIXES}
+		IMPORTED_LOCATION_MINSIZEREL ${${PROJECT_NAME_UPPER}_DIR}/googletest/MinSizeRel/${CMAKE_FIND_LIBRARY_PREFIXES}${PROJECT_NAME}${CMAKE_FIND_LIBRARY_SUFFIXES}
+		IMPORTED_LOCATION_RELWITHDEBINFO ${${PROJECT_NAME_UPPER}_DIR}/googletest/RelWithDebInfo/${CMAKE_FIND_LIBRARY_PREFIXES}${PROJECT_NAME}${CMAKE_FIND_LIBRARY_SUFFIXES}
 	)
 ELSE(WIN32)
-	SET_TARGET_PROPERTIES(${TARGET_NAME} PROPERTIES 
-		IMPORTED_LOCATION ${GTEST_DIR}/${CMAKE_FIND_LIBRARY_PREFIXES}gtest${CMAKE_STATIC_LIBRARY_SUFFIX}
+	SET_TARGET_PROPERTIES(${PROJECT_NAME} PROPERTIES 
+		IMPORTED_LOCATION ${${PROJECT_NAME_UPPER}_DIR}/googletest/${CMAKE_FIND_LIBRARY_PREFIXES}${PROJECT_NAME}${CMAKE_STATIC_LIBRARY_SUFFIX}
 		INTERFACE_LINK_LIBRARIES -pthread
 	)
 ENDIF(WIN32)
-add_dependencies(${TARGET_NAME} ${TARGET_NAME}-ext)
+add_dependencies(${PROJECT_NAME} ${PROJECT_NAME}-ext)
 
-SET(${TARGET_NAME_UPPER}_INCLUDE_DIRS ${${TARGET_NAME_UPPER}_DIR}/include CACHE STRING "${TARGET_NAME} include directory")
-SET(${TARGET_NAME_UPPER}_LIBRARIES ${TARGET_NAME} CACHE STRING "${TARGET_NAME} library location")
+SET(INCLUDE_DIR ${${PROJECT_NAME_UPPER}_DIR}/googletest/include)
+FILE(MAKE_DIRECTORY ${INCLUDE_DIR})
+SET_TARGET_PROPERTIES(${PROJECT_NAME} PROPERTIES INTERFACE_INCLUDE_DIRECTORIES ${INCLUDE_DIR})
 
-MARK_AS_ADVANCED(${TARGET_NAME_UPPER}_DIR ${TARGET_NAME_UPPER}_INCLUDE_DIRS ${TARGET_NAME_UPPER}_LIBRARIES)
+MARK_AS_ADVANCED(${PROJECT_NAME_UPPER}_DIR)

CMakeLists.txt

@@ -1,8 +1,9 @@
 cmake_minimum_required(VERSION 3.2 FATAL_ERROR)
 
-GET_FILENAME_COMPONENT(BRANCH ${CMAKE_CURRENT_SOURCE_DIR} NAME)
-PROJECT(${BRANCH})
-SET(TARGET_NAME ${BRANCH})
+PROJECT(units)
+
+OPTION(BUILD_TESTS "Build unit tests" ON)
+OPTION(BUILD_DOCS "Build the documentation" OFF)
 
 SET(CMAKE_CXX_STANDARD 14)
 SET(CMAKE_CXX_STANDARD_REQUIRED TRUE)
@@ -11,22 +12,31 @@ if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
 	set( ENV{CL} /MP )
 endif()
 
-SET(VERSION_GTEST "1.7.0" CACHE STRING "Google Test framework version")
-
-enable_testing ()
-
-add_subdirectory(3rdParty/gnuWin)
-add_subdirectory(3rdParty/gtest)
-
-add_subdirectory(unitTests)
+# header-only library target. To use this project as a subdirectory,
+# add the following to your code:
+#
+# add_subdirectory(units) # or whatever you named the directory
+# target_link_libraries(${PROJECT_NAME} units)
+add_library(${PROJECT_NAME} INTERFACE)
+target_include_directories(${PROJECT_NAME} INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/include)
+
+# unit tests
+if(BUILD_TESTS)
+	set(VERSION_GTEST "1.8.0" CACHE STRING "Google Test framework version")
+	enable_testing ()
+	add_subdirectory(3rdParty/gtest)
+	add_subdirectory(unitTests)
+endif(BUILD_TESTS)
 
 # add a target to generate API documentation with Doxygen
-find_package(Doxygen)
-if(DOXYGEN_FOUND)
-	configure_file(${CMAKE_CURRENT_SOURCE_DIR}/docs/Doxyfile.in ${CMAKE_CURRENT_BINARY_DIR}/Doxyfile @ONLY)
-	add_custom_target(doc ALL
-		${DOXYGEN_EXECUTABLE} ${CMAKE_CURRENT_BINARY_DIR}/Doxyfile
-		WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/docs
-		COMMENT "Generating API documentation with Doxygen" VERBATIM
-	)
-endif(DOXYGEN_FOUND)
+if(BUILD_DOCS)
+	find_package(Doxygen)
+	if(DOXYGEN_FOUND)
+		configure_file(${CMAKE_CURRENT_SOURCE_DIR}/docs/Doxyfile.in ${CMAKE_CURRENT_BINARY_DIR}/Doxyfile @ONLY)
+		add_custom_target(doc ALL
+			${DOXYGEN_EXECUTABLE} ${CMAKE_CURRENT_BINARY_DIR}/Doxyfile
+			WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/docs
+			COMMENT "Generating API documentation with Doxygen" VERBATIM
+		)
+	endif(DOXYGEN_FOUND)
+endif(BUILD_DOCS)

unitTests/CMakeLists.txt

@@ -1,5 +1,4 @@
-SET(TARGET_NAME unitLibTest)
-PROJECT(${TARGET_NAME})	# it's a pun, GET IT!?!?
+PROJECT(unitLibTest)
 
 # use absolute paths to help coveralls
 get_filename_component(MAIN main.cpp ABSOLUTE)
@@ -12,11 +11,10 @@ ${INC}
 
 LIST(APPEND INCLUDE_DIRS
 ../include
-${GTEST_INCLUDE_DIRS}
 )
 
 LIST(APPEND LIBRARIES
-${GTEST_LIBRARIES}
+gtest
 )
 
 # coveralls support
@@ -31,10 +29,10 @@ if (COVERALLS)
 endif()
 
 include_directories(${INCLUDE_DIRS})
-ADD_EXECUTABLE(${TARGET_NAME} ${SOURCE_CODE})
-ADD_TEST(NAME ${TARGET_NAME} COMMAND ${TARGET_NAME})
-TARGET_LINK_LIBRARIES(${TARGET_NAME} ${LIBRARIES})
+ADD_EXECUTABLE(${PROJECT_NAME} ${SOURCE_CODE})
+ADD_TEST(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME})
+TARGET_LINK_LIBRARIES(${PROJECT_NAME} ${LIBRARIES})
 
 IF(WIN32)
-	set_target_properties(${TARGET_NAME} PROPERTIES LINK_FLAGS "/machine:x64")
+	set_target_properties(${PROJECT_NAME} PROPERTIES LINK_FLAGS "/machine:x64")
 ENDIF(WIN32)