Linux上CLion中的数学库链接错误[重复]答案

【问题标题】：Math library linking error in CLion on Linux [duplicate]Linux上CLion中的数学库链接错误[重复]
【发布时间】：2019-11-12 12:14:09
【问题描述】：

要完成我的作业，我需要#include "math.h"，但在更新 GCC 和 CMake 后，CLion 无法链接我的项目文件。我应该怎么做才能解决这个问题？

在Settings -> Build, Execution and Deployment -> Toolchains CLion 说CMake 版本是3.15.3 而GDB 版本是8.3 并且没关系。我已经厌倦了重新安装 GCC、CMake 和 CLion，但它没有用。我也厌倦了在 StackOverflow 上搜索一些信息，但仍然没有任何效果。

Main.c:

#include <stdio.h>
#include <math.h>
int main() {
    FILE *output;
    output = fopen("/home/vadimsam/CLionProjects/untitled/data.txt", "w");

    double x=0.,v=0.,t=0.,m=0.,k=0.,dt = 1e-5,xn,vn;

    while (t < 1e1) {
        vn = -x*sqrt((k/m))*cos(sqrt((k/m))*t)+v*cos(sqrt((k/m))*t);
        xn = -x*cos(sqrt((k/m))*t)+(v/sqrt((k/m)))*sin(sqrt((k/m))*t);
        t += dt; x = xn; v = vn;
        fprintf(output, "%lf %lf %lf\n", t, x, v);
    }
    fclose(output);
    return 0;
}

CMakeLists.txt：

cmake_minimum_required(VERSION 3.15)
project(untitled2 C)
set(CMAKE_C_STANDARD 11)
add_executable(untitled2 main.c)

编译器输出：

====================[ Build | untitled2 | Debug ]===============================
/home/vadimsam/.local/share/JetBrains/Toolbox/apps/CLion/ch-0/193.5096.27/bin/cmake/linux/bin/cmake --build /home/vadimsam/CLionProjects/untitled2/cmake-build-debug --target untitled2 -- -j 8
Scanning dependencies of target untitled2
[ 50%] Building C object CMakeFiles/untitled2.dir/main.c.o
[100%] Linking C executable untitled2
CMakeFiles/untitled2.dir/main.c.o: In function `main':
/home/vadimsam/CLionProjects/untitled2/main.c:10: undefined reference to `sqrt'
/home/vadimsam/CLionProjects/untitled2/main.c:10: undefined reference to `sqrt'
/home/vadimsam/CLionProjects/untitled2/main.c:10: undefined reference to `cos'
/home/vadimsam/CLionProjects/untitled2/main.c:10: undefined reference to `sqrt'
/home/vadimsam/CLionProjects/untitled2/main.c:10: undefined reference to `cos'
/home/vadimsam/CLionProjects/untitled2/main.c:11: undefined reference to `sqrt'
/home/vadimsam/CLionProjects/untitled2/main.c:11: undefined reference to `cos'
/home/vadimsam/CLionProjects/untitled2/main.c:11: undefined reference to `sqrt'
/home/vadimsam/CLionProjects/untitled2/main.c:11: undefined reference to `sqrt'
/home/vadimsam/CLionProjects/untitled2/main.c:11: undefined reference to `sin'
collect2: error: ld returned 1 exit status
CMakeFiles/untitled2.dir/build.make:83: recipe for target 'untitled2' failed
make[3]: *** [untitled2] Error 1
CMakeFiles/Makefile2:75: recipe for target 'CMakeFiles/untitled2.dir/all' failed
make[2]: *** [CMakeFiles/untitled2.dir/all] Error 2
CMakeFiles/Makefile2:82: recipe for target 'CMakeFiles/untitled2.dir/rule' failed
make[1]: *** [CMakeFiles/untitled2.dir/rule] Error 2
Makefile:118: recipe for target 'untitled2' failed
make: *** [untitled2] Error 2

我需要编译我的项目。

【问题讨论】：

标签： c gcc cmake linker-errors clion

【解决方案1】：

数学库通常链接为一个单独的库（方便地命名为m），您明确需要与之链接。

您告诉 CLion（通过其 CMakeLists.txt 文件）使用 target_link_libraries 命令链接库：

target_link_libraries(untitled2 m)

【讨论】：

@ВадимСамохвалов 您使用add_executable 命令创建目标untitled2。您可以将其放在目标创建下方的任何位置。