Question

我正在尝试使用cpprest-sdk库：https://github.com/Microsoft/cpprestsdk

为rest API创建一个HTTP客户端。

我正在将MacBook Pro与最新版本的MacO（10.14.2）配合使用。

我使用brew作为包管理器，并安装了boost命令：
酿造助推器

依赖性版本：
clang：Apple LLVM版本10.0.0（clang-1000.11.45.5）
cmake：3.13.2
提升：稳定的1.68.0（瓶装），HEAD

首先，我尝试遵循此规则：
https://github.com/Microsoft/cpprestsdk/wiki/How-to-build-for-Mac-OS-X

所以我也用boost安装了cpprestsdk：
加强安装cpprestsdk

然后，我在一个main.cpp中使用了本教程中的代码：

#include <cpprest/http_client.h>
#include <cpprest/filestream.h>

using namespace utility;                    // Common utilities like string conversions
using namespace web;                        // Common features like URIs.
using namespace web::http;                  // Common HTTP functionality
using namespace web::http::client;          // HTTP client features
using namespace concurrency::streams;       // Asynchronous streams

int main(int argc, char* argv[])
{
    auto fileStream = std::make_shared<ostream>();

    // Open stream to output file.
    pplx::task<void> requestTask = fstream::open_ostream(U("results.html")).then([=](ostream outFile)
     {
         *fileStream = outFile;

         // Create http_client to send the request.
         http_client client(U("http://www.bing.com/"));

         // Build request URI and start the request.
         uri_builder builder(U("/search"));
         builder.append_query(U("q"), U("cpprestsdk github"));
         return client.request(methods::GET, builder.to_string());
     })

    // Handle response headers arriving.
    .then([=](http_response response)
    {
        printf("Received response status code:%u\n", response.status_code());

        // Write response body into the file.
        return response.body().read_to_end(fileStream->streambuf());
    })

    // Close the file stream.
    .then([=](size_t)
    {
        return fileStream->close();
    });

    // Wait for all the outstanding I/O to complete and handle any exceptions
    try
    {
        requestTask.wait();
    }
    catch (const std::exception &e)
    {
        printf("Error exception:%s\n", e.what());
    }

    return 0;
}

然后我创建了一个CMake构建文件CMakeLists.txt，如它们在cpprestsdk的自述文件中所述：

cmake_minimum_required(VERSION 3.13)
project(cpprest-example)

set(CMAKE_CXX_STANDARD 14)

find_package(cpprestsdk REQUIRED)

add_executable(cpprest-example main.cpp)
target_link_libraries(cpprest-example PRIVATE cpprestsdk::cpprest)

首先，我遇到了CMake无法优化openssl的问题，因此我不得不添加两个env参数，如下所述：
CMake not able to find OpenSSL library

然后它可以编译，但是在链接期间失败，并显示错误：

Scanning dependencies of target cpprest-example
[ 50%] Building CXX object CMakeFiles/cpprest-example.dir/main.cpp.o
[100%] Linking CXX executable cpprest-example
Undefined symbols for architecture x86_64:
  "boost::this_thread::interruption_point()", referenced from:
      boost::condition_variable::wait(boost::unique_lock<boost::mutex>&) in main.cpp.o
      boost::condition_variable::do_wait_until(boost::unique_lock<boost::mutex>&, boost::detail::real_platform_timepoint const&) in main.cpp.o
  "boost::chrono::steady_clock::now()", referenced from:
      bool boost::condition_variable::wait_for<long long, boost::ratio<1l, 1000l>, pplx::details::event_impl::wait(unsigned int)::'lambda0'()>(boost::unique_lock<boost::mutex>&, boost::chrono::duration<long long, boost::ratio<1l, 1000l> > const&, pplx::details::event_impl::wait(unsigned int)::'lambda0'()) in main.cpp.o
      bool boost::condition_variable::wait_until<boost::chrono::steady_clock, boost::chrono::duration<long long, boost::ratio<1l, 1000000000l> >, pplx::details::event_impl::wait(unsigned int)::'lambda0'()>(boost::unique_lock<boost::mutex>&, boost::chrono::time_point<boost::chrono::steady_clock, boost::chrono::duration<long long, boost::ratio<1l, 1000000000l> > > const&, pplx::details::event_impl::wait(unsigned int)::'lambda0'()) in main.cpp.o
  "boost::detail::get_current_thread_data()", referenced from:
      boost::detail::interruption_checker::interruption_checker(_opaque_pthread_mutex_t*, _opaque_pthread_cond_t*) in main.cpp.o
  "boost::system::detail::system_category_instance", referenced from:
      boost::system::system_category() in main.cpp.o
  "boost::system::detail::generic_category_instance", referenced from:
      boost::system::generic_category() in main.cpp.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [cpprest-example] Error 1
make[1]: *** [CMakeFiles/cpprest-example.dir/all] Error 2
make: *** [all] Error 2

奇怪的是，如果我使用CMake构建cpprestsdk代码库，它可以正常工作，并且其中一个示例是相同的代码： https://github.com/Microsoft/cpprestsdk/tree/master/Release/samples/BingRequest

该示例项目已成功构建并运行正常。

我还尝试从brew上卸载cpprestsdk，并对克隆的存储库进行CMake构建，然后“ make -j4 && make install”。这样会在本地安装cpprestsdk标头和库，但最终会导致相同的错误。

似乎没有找到Boost库，我尝试使用find_package（BOOST 1.68.0）和类似的东西，但是由于相同的错误而失败。

任何人都可以看到我在做什么吗？

在MacO上构建cpprest-sdk时将问题与Boost关联起来

0 个答案: