Xcode有关lstdc++报错

报错信息如下:

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Undefined symbol: std::ios_base::Init::Init()

Undefined symbol: std::ios_base::Init::~Init()

Undefined symbol: std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&)

Undefined symbol: std::string::assign(std::string const&)

Undefined symbol: std::basic_fstream<char, std::char_traits<char> >::basic_fstream()

Undefined symbol: std::basic_fstream<char, std::char_traits<char> >::open(char const*, std::_Ios_Openmode)

Undefined symbol: std::basic_fstream<char, std::char_traits<char> >::close()

Undefined symbol: std::basic_fstream<char, std::char_traits<char> >::~basic_fstream()

Undefined symbol: std::string::_Rep::_S_empty_rep_storage

Undefined symbol: std::string::_Rep::_M_destroy(std::allocator<char> const&)

Undefined symbol: std::ostream::tellp()

Undefined symbol: operator delete[](void*)

Undefined symbol: std::istream::tellg()

Undefined symbol: ___cxa_rethrow

Undefined symbol: std::ostream::write(char const*, long)

Undefined symbol: std::__throw_length_error(char const*)

Undefined symbol: ___cxa_end_catch

Undefined symbol: operator delete(void*)

Undefined symbol: ___cxa_guard_release

Undefined symbol: ___cxa_guard_abort

Undefined symbol: ___cxa_pure_virtual

Undefined symbol: std::istream::read(char*, long)

Undefined symbol: ___gxx_personality_v0

Undefined symbol: operator new[](unsigned long)

Undefined symbol: std::string::compare(std::string const&) const

Undefined symbol: vtable for __cxxabiv1::__si_class_type_info

Undefined symbol: std::istream::seekg(long long, std::_Ios_Seekdir)

Undefined symbol: vtable for __cxxabiv1::__vmi_class_type_info

Undefined symbol: std::__throw_bad_alloc()

Undefined symbol: vtable for __cxxabiv1::__class_type_info

Undefined symbol: operator new(unsigned long)

Undefined symbol: std::basic_filebuf<char, std::char_traits<char> >::is_open() const

Undefined symbol: ___cxa_begin_catch

Undefined symbol: ___cxa_guard_acquire

Undefined symbol: std::terminate()

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这是因为Xcode10彻底废弃了libstdc++，相关的库文件libstdc++.6.0.9.dylib、libstdc++.6.dylib、libstdc++.dylib、libstdc++.6.0.9.tbd、libstdc++.6.tbd、libstdc++.tbd也从Xcode10中删除了。

最好的解决办法还是尽快转到libc++开发

如果还想要继续在Xcode10上编译依赖libstdc++的项目或库，可以通过把Xcode9中的libstdc++相关库文件复制到Xcode10中即可。
在Xcode9中搜索libstdc++相关的库，可以找到四个相关的文件：

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/usr/lib/libstdc++.6.0.9.dylib

/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/lib/libstdc++.6.0.9.tbd

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/lib/libstdc++.6.0.9.tbd

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/usr/lib/libstdc++.6.0.9.tbd

解决办法

1.下载 libstdc文件
2.运行对应的 xcode版本的脚本

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注意点: 如果xcode路径不是脚本中的路径,需要自行修改

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3.打开终端cd到libstdc--master文件夹,执行sudo sh install.sh，没有任何提示即脚本运行成功
4.重启Xcode，在TARGETS->Build Phases->Link Binary With Libraries中添加libstdc++相关的库，运行程序，真机和模拟器都能启动。

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