Add GTest with FetchContent (#120)

* Add missing GTest linking
* Add unit testing switch
* Rename UNIT_TESTING to be fff-specific
* Add fff.h generation toggle
* Use options instead of variables for disabling build elements
* Add interface library for when the header is not regenerated
* Update build script and README

CMakeLists.txt

@@ -6,29 +6,41 @@ project(fff)
 
 set(CMAKE_CXX_STANDARD 11)
 
-# Add the gtest library which will be used below
-add_subdirectory(gtest)
-
 # Enable ctest
 enable_testing()
 
+add_library(fff INTERFACE)
+
+option(FFF_GENERATE "If enabled, fff.h will be regenerated using ruby" OFF)
+
 # Generate fff.h if fakegen.rb changed
-add_custom_command(
-  OUTPUT
-    ${CMAKE_CURRENT_LIST_DIR}/fff.h
-  COMMAND
-    ruby ${CMAKE_CURRENT_LIST_DIR}/fakegen.rb >> ${CMAKE_CURRENT_LIST_DIR}/fff.h
-  DEPENDS
-    ${CMAKE_CURRENT_LIST_DIR}/fakegen.rb
-    ${CMAKE_CURRENT_LIST_DIR}/LICENSE
-)
-add_custom_target(fff_h DEPENDS ${CMAKE_CURRENT_LIST_DIR}/fff.h)
+if(FFF_GENERATE)
+  add_custom_command(
+    OUTPUT
+      ${CMAKE_CURRENT_LIST_DIR}/fff.h
+    COMMAND
+      ruby ${CMAKE_CURRENT_LIST_DIR}/fakegen.rb >> ${CMAKE_CURRENT_LIST_DIR}/fff.h
+    DEPENDS
+      ${CMAKE_CURRENT_LIST_DIR}/fakegen.rb
+      ${CMAKE_CURRENT_LIST_DIR}/LICENSE
+  )
+  add_custom_target(fff_h DEPENDS ${CMAKE_CURRENT_LIST_DIR}/fff.h)
+else()
+  add_library(fff_h INTERFACE)
+  set_target_properties(fff_h
+    PROPERTIES PUBLIC_HEADER "fff.h"
+  )
+endif()
+
+add_dependencies(fff fff_h)
 
 # Add an interface library for fff.h
-add_library(fff INTERFACE)
-add_dependencies(fff fff_h)
 target_include_directories(fff INTERFACE ${CMAKE_CURRENT_LIST_DIR})
 
-# Add tests and samples
-add_subdirectory(test)
-add_subdirectory(examples)
+option(FFF_UNIT_TESTING "If enabled, fff tests will be compiled and run" OFF)
+
+if(FFF_UNIT_TESTING)
+  # Add tests and samples
+  add_subdirectory(test)
+  add_subdirectory(examples)
+endif()

README.md

@@ -35,7 +35,7 @@ To run all the tests and sample apps, simply call `$ buildandtest`. This script
 will call down into CMake with the following:
 
 ```shell
-cmake -GNinja -B build
+cmake -B build -DFFF_GENERATE=ON -DFFF_UNIT_TESTING=ON
 cmake --build build
 ctest --test-dir build --output-on-failure
 ```

buildandtest

@@ -6,7 +6,7 @@ rm -fr build fff.h
 mkdir build
 
 # Configure the build
-cmake -GNinja -B build || exit -1
+cmake -B build -DFFF_GENERATE=ON -DFFF_UNIT_TESTING=ON || exit -1
 
 # Build all targets
 cmake --build build || exit -1

examples/driver_testing/CMakeLists.txt

@@ -7,7 +7,7 @@ add_executable(driver_test
     src/driver.test.cpp
 )
 target_include_directories(driver_test PRIVATE include)
-target_link_libraries(driver_test PRIVATE gtest fff)
+target_link_libraries(driver_test PRIVATE GTest::gtest_main fff)
 target_compile_definitions(driver_test PUBLIC TEST_USER_OWN_TR1_TUPLE=1 TESTING)
 
 # Create the driver fff test binary
@@ -16,7 +16,7 @@ add_executable(driver_fff_test
     src/driver.test.fff.cpp
 )
 target_include_directories(driver_fff_test PRIVATE include)
-target_link_libraries(driver_fff_test PRIVATE gtest fff)
+target_link_libraries(driver_fff_test PRIVATE GTest::gtest_main fff)
 target_compile_definitions(driver_fff_test PUBLIC TEST_USER_OWN_TR1_TUPLE=1 TESTING)
 
 # Add tests to ctest

examples/embedded_ui/CMakeLists.txt

@@ -9,7 +9,7 @@ target_link_libraries(ui_test_ansic PRIVATE fff)
 # Create the ui_test_cpp test binary
 add_executable(ui_test_cpp src/UI_test_cpp.cpp src/UI.c)
 target_include_directories(ui_test_cpp PRIVATE include)
-target_link_libraries(ui_test_cpp PRIVATE gtest fff)
+target_link_libraries(ui_test_cpp PRIVATE GTest::gtest_main fff)
 
 # Add tests to ctest
 add_test(

gtest/CMakeLists.txt

@@ -1,12 +0,0 @@
-# Copyright 2022 Google LLC
-# SPDX-License-Identifier: Apache-2.0
-
-cmake_minimum_required(VERSION 3.20.0)
-
-find_package(Threads REQUIRED)
-set(CMAKE_EXE_LINKER_FLAGS " -static")
-
-# Create the gtest library
-add_library(gtest src/gtest-all.cc src/gtest-main.cc)
-target_include_directories(gtest PUBLIC include include/gtest)
-target_link_libraries(gtest PRIVATE Threads::Threads -static-libstdc++)

gtest/src/gtest-main.cc

@@ -1,6 +0,0 @@
-#include "gtest.h"
-
-int main(int argc, char **argv) {
-  ::testing::InitGoogleTest(&argc, argv);
-  return RUN_ALL_TESTS();
-}

test/CMakeLists.txt

@@ -8,6 +8,17 @@ set(
     src/test_cases.include
 )
 
+include(FetchContent)
+
+FetchContent_Declare(
+  googletest
+  GIT_REPOSITORY https://github.com/google/googletest.git
+  GIT_TAG v1.12.0
+)
+
+set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
+FetchContent_MakeAvailable(googletest)
+
 # Create the C test executable
 add_executable(c_test src/fff_test_c.c ${COMMON_FILE_LIST})
 target_include_directories(c_test PRIVATE include)
@@ -16,7 +27,7 @@ target_link_libraries(c_test PRIVATE fff)
 # Create the C++ test executable
 add_executable(cpp_test src/fff_test_cpp.cpp ${COMMON_FILE_LIST})
 target_include_directories(cpp_test PRIVATE include)
-target_link_libraries(cpp_test PRIVATE gtest fff)
+target_link_libraries(cpp_test PRIVATE GTest::gtest_main fff)
 
 # Create the C global test executable
 add_executable(c_global_test
@@ -36,7 +47,7 @@ add_executable(cpp_global_test
     ${COMMON_FILE_LIST}
 )
 target_include_directories(cpp_global_test PRIVATE include)
-target_link_libraries(cpp_global_test PRIVATE gtest fff)
+target_link_libraries(cpp_global_test PRIVATE GTest::gtest_main fff)
 
 # Create the C++ custom function signature executable
 add_executable(cpp_custom_fn_signature_test
@@ -44,7 +55,7 @@ add_executable(cpp_custom_fn_signature_test
     ${COMMON_FILE_LIST}
 )
 target_include_directories(cpp_custom_fn_signature_test PRIVATE include)
-target_link_libraries(cpp_custom_fn_signature_test PRIVATE gtest fff)
+target_link_libraries(cpp_custom_fn_signature_test PRIVATE GTest::gtest_main fff)
 # Due to a bug in WinLibs for Windows it's not currently possible to use:
 #   target_precompile_headers(cpp_custom_fn_signature_test PUBLIC include/custom_function.hpp)
 # See more info at target_precompile_headers(cpp_custom_fn_signature_test PUBLIC include/custom_function.hpp)