链接 GMP 库时出错

Posted 2023-02-22

【中文标题】链接 GMP 库时出错

【英文标题】：error linking GMP library

【发布时间】：2015-03-27 18:35:32

【问题描述】：

我有以下 CMakeList.txt

cmake_minimum_required(VERSION 2.8)
set(CMAKE_MODULE_PATH "$CMAKE_SOURCE_DIR")
find_package(GMP REQUIRED)
add_executable(Turrial main.cpp)

用下面的简单源文件main.cpp

#include <iostream>
#include <gmp.h>
#include <cstdio>

using namespace std;
int main() 
    mpz_t a,b;
    mpz_init_set_str(a,"45",10);
    mpz_init_set_str(b,"12",10);
    mpz_add(a,a,b);
    cout <<mpz_get_str(NULL,10,a)<<endl;    
    

我在网上找到了一个 FindGMP.cmake 文件：

set(GMP_PREFIX "" CACHE PATH "path ")


find_path(GMP_INCLUDE_DIR gmp.h gmpxx.h 
    PATHS $GMP_PREFIX/include /usr/include /usr/local/include )

find_library(GMP_LIBRARY NAMES gmp libgmp 
    PATHS $GMP_PREFIX/lib /usr/lib /usr/local/lib)


if(GMP_INCLUDE_DIR AND GMP_LIBRARY)
    get_filename_component(GMP_LIBRARY_DIR $GMP_LIBRARY PATH)
    set(GMP_FOUND TRUE)
endif()

if(GMP_FOUND)
   if(NOT GMP_FIND_QUIETLY)
      MESSAGE(STATUS "Found GMP: $GMP_LIBRARY")
   endif()
elseif(GMP_FOUND)
   if(GMP_FIND_REQUIRED)
      message(FATAL_ERROR "Could not find GMP")
   endif()
endif(

当我运行 cmake 时，我有以下输出：

moyle@localhost:~/Desktop/gmptri$ cmake .
-- Found GMP: /usr/local/lib/libgmp.so
-- Configuring done
-- Generating done
-- Build files have been written to: /home/moyle/Desktop/gmptri

然后我运行 make 并收到以下错误：

  (precise)moyle@localhost:~/Desktop/gmptri$ make VERBOSE=1
/usr/bin/cmake -H/home/moyle/Desktop/gmptri -B/home/moyle/Desktop/gmptri --check-build-system CMakeFiles/Makefile.cmake 0
/usr/bin/cmake -E cmake_progress_start /home/moyle/Desktop/gmptri/CMakeFiles /home/moyle/Desktop/gmptri/CMakeFiles/progress.marks
make -f CMakeFiles/Makefile2 all
make[1]: Entering directory `/home/moyle/Desktop/gmptri'
make -f CMakeFiles/Turrial.dir/build.make CMakeFiles/Turrial.dir/depend
make[2]: Entering directory `/home/moyle/Desktop/gmptri'
cd /home/moyle/Desktop/gmptri && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /home/moyle/Desktop/gmptri /home/moyle/Desktop/gmptri /home/moyle/Desktop/gmptri /home/moyle/Desktop/gmptri /home/moyle/Desktop/gmptri/CMakeFiles/Turrial.dir/DependInfo.cmake --color=
make[2]: Leaving directory `/home/moyle/Desktop/gmptri'
make -f CMakeFiles/Turrial.dir/build.make CMakeFiles/Turrial.dir/build
make[2]: Entering directory `/home/moyle/Desktop/gmptri'
Linking CXX executable Turrial
/usr/bin/cmake -E cmake_link_script CMakeFiles/Turrial.dir/link.txt --verbose=1
/usr/bin/c++       CMakeFiles/Turrial.dir/main.cpp.o  -o Turrial -rdynamic 
CMakeFiles/Turrial.dir/main.cpp.o: In function `main':
main.cpp:(.text+0x1a): undefined reference to `__gmpz_init_set_str'
main.cpp:(.text+0x30): undefined reference to `__gmpz_init_set_str'
main.cpp:(.text+0x47): undefined reference to `__gmpz_add'
collect2: ld returned 1 exit status
make[2]: *** [Turrial] Error 1
make[2]: Leaving directory `/home/moyle/Desktop/gmptri'
make[1]: *** [CMakeFiles/Turrial.dir/all] Error 2
make[1]: Leaving directory `/home/moyle/Desktop/gmptri'
make: *** [all] Error 2

谁能帮帮我？

【问题讨论】：

您可以在详细模式下运行构建以查看该阶段正在执行的命令吗？

@EtanReisner 我编辑了这个问题。

【参考方案1】：

您忘记将库与可执行文件链接。

find_package(GMP REQUIRED)
add_executable(Turrial main.cpp)
target_link_libraries(Turrial gmp libgmp)

【讨论】：

如果使用 GMP 的 C++ 接口 (#include <gmpxx.h>)，我不得不去target_link_libraries(Turrial gmp gmpxx)

@HolKann 我也有类似的问题。 cmake 正确找到了 gmp 库，但是当我运行 make 时，它返回错误：ld: library not found for -lgmp。我使用相同的FindGMP.cmake 文件和下面的指令。