GoogleTest CMake 链接未定义函数答案

【问题标题】：GoogleTest CMake linking undefined functionGoogleTest CMake 链接未定义函数
【发布时间】：2017-05-09 03:37:14
【问题描述】：

我正在使用 Clion，并在此帖子的帮助下设置了 GoogleTest：
Setup Google test in CLion

终于让一切正常工作，除了我似乎无法从另一个文件调用任何函数，我不断收到“未定义的引用”错误。我不明白我错过了什么，所有文件似乎都正确链接。

CMakeLists.txt：

cmake_minimum_required(VERSION 3.6)
project(ComplexNumber)
add_subdirectory(src)
add_subdirectory(test)

src/CMakeLists.txt：

set(core_SRCS main.c ComplexNumber.c)
add_library(core ${core_SRCS})
add_executable(exe main.c)
target_link_libraries(exe core)

测试/CMakeLists.txt：

cmake_minimum_required(VERSION 3.3)

project(Test)

project(Example)

include(CTest)
enable_testing()

#set(gtest_disable_pthreads on) #needed in MinGW
include(F:/Programming/C/AYED/ComplexNumber/.repo/DownloadProject/DownloadProject.cmake)
download_project(
        PROJ                googletest
        GIT_REPOSITORY      https://github.com/google/googletest.git
        GIT_TAG             master
        UPDATE_DISCONNECTED 1
)

add_subdirectory(${googletest_SOURCE_DIR} ${googletest_BINARY_DIR} EXCLUDE_FROM_ALL)

set(test_SRCS Test.cpp)
add_executable(runUnitTests ${test_SRCS})
target_link_libraries(runUnitTests gtest gmock core)
add_test(runUnitTests runUnitTests)

测试/Test.cpp：

#include <gtest/gtest.h>
#include "../src/ComplexNumber.h"

int main(int argc, char **argv) {
    ::testing::InitGoogleTest(&argc, argv);
    return RUN_ALL_TESTS();
}

TEST(ComplexNumberTest, positives){
    ComplexNumber complexNumber1 = {5, -2};
    ComplexNumber complexNumber2 = {7, 6};
    ComplexNumber result = {12, 4};
    ComplexNumber complexNumber3 = *sum(&complexNumber1, &complexNumber2);
    EXPECT_EQ(complexNumber3.realNumber, result.realNumber);
}

错误信息：

CMakeFiles\runUnitTests.dir/objects.a(Test.cpp.obj): In function `ZN32ComplexNumberTest_positives_Test8TestBodyEv':
F:/Programming/C/AYED/ComplexNumber/test/Test.cpp:14: undefined reference to `sum(ComplexNumber*, ComplexNumber*)'
collect2.exe: error: ld returned 1 exit status
Test\CMakeFiles\runUnitTests.dir\build.make:99: recipe for target 'Test/runUnitTests.exe' failed
mingw32-make.exe[3]: *** [Test/runUnitTests.exe] Error 1
CMakeFiles\Makefile2:1106: recipe for target 'Test/CMakeFiles/runUnitTests.dir/all' failed
mingw32-make.exe[2]: *** [Test/CMakeFiles/runUnitTests.dir/all] Error 2
CMakeFiles\Makefile2:1118: recipe for target 'Test/CMakeFiles/runUnitTests.dir/rule' failed
mingw32-make.exe[1]: *** [Test/CMakeFiles/runUnitTests.dir/rule] Error 2
mingw32-make.exe: *** [runUnitTests] Error 2
Makefile:551: recipe for target 'runUnitTests' failed

【问题讨论】：

标签： c++ c cmake googletest

【解决方案1】：

一些cmets，我认为最终会帮助您解决问题

1)

使用add_library 创建库时，最好准确说明这将是什么类型的库：

add_library(core STATIC ${core_SRCS})

2)

将main 源文件放在库中不是一个好主意。库不应包含 main 函数，否则会发生什么，就像你的情况一样，当你的可执行文件中有两个 main 函数时？因此，src/CMakeLists.txt 应该是：

set(core_SRCS ComplexNumber.c)
add_library(core ${core_SRCS})
add_executable(exe main.c)
target_link_libraries(exe core)

3)

确保sum(ComplexNumber*, ComplexNumber*) 在ComplexNumber.c 中定义。

【讨论】：