将外部库从 git 添加到我的 C 项目

Question

我是创建 CMake 文件的新手 我已经搜索了很多，但我仍然不明白为什么我不能使用外部库中的任何函数，但可以使用头文件中的#define变量

我正在尝试添加此库：https://github.com/pq-crystals/dilithium

我的CMakeLists.txt：

cmake_minimum_required(VERSION 3.10)
project(react-native-dilithium VERSION 1.0.0)

include(FetchContent)

FetchContent_Declare(dilithium                              
  GIT_REPOSITORY https://github.com/pq-crystals/dilithium.git
  GIT_TAG        master        
)

FetchContent_MakeAvailable(dilithium)

add_library(dilithium SHARED)
target_sources(dilithium PUBLIC ${dilithium_SOURCE_DIR})
set_target_properties(dilithium PROPERTIES LINKER_LANGUAGE CXX PROPERTIES DILITHIUM_MODE 5 PROPERTIES DILITHIUM_USE_AES TRUE)

add_executable(cpp_test main.cpp)

target_include_directories(cpp_test PUBLIC 
  ${dilithium_BINARY_DIR}
  ${dilithium_SOURCE_DIR}/ref
)


target_link_libraries(cpp_test PUBLIC dilithium)

我希望这能起作用：

#include <iostream>
#include <api.h>

using namespace std;

int main(int argc, char* argv[]) {
    // Message to sign
    const char* message = "This is a message to be signed.";
    size_t message_len = strlen(message);

    // Private key (replace with your actual key)
    unsigned char private_key[pqcrystals_dilithium5aes_ref_SECRETKEYBYTES];

    // Signature buffer (allocate enough space based on parameter set)
    unsigned char signature[pqcrystals_dilithium5aes_ref_BYTES];
    size_t signature_len = sizeof(signature);

    // Call the signing function
    int result = pqcrystals_dilithium5aes_ref_signature(
        signature, &signature_len,
        (const unsigned char*)message, message_len,
        private_key
    );

    return 0;
}

但是当我尝试使用 pqcrystals_dilithium5aes_ref_signature 时发生错误

错误：

ld: Undefined symbols:
  pqcrystals_dilithium5aes_ref_signature(unsigned char*, unsigned long*, unsigned char const*, unsigned long, unsigned char const*), referenced from:
      _main in main.cpp.o
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [cpp_test] Error 1
make[1]: *** [CMakeFiles/cpp_test.dir/all] Error 2
make: *** [all] Error 2

Answer 1

既然库作者不关心 C++，你就必须关心他们。改变

#include <api.h>

到

extern "C" {
#include <api.h>
}