Question

我正在尝试使用clang ++来使用以下Crypto ++（加密方案的C ++类库）示例来处理iMac。

实施例

SHA256 hash;

byte digest[ SHA256::DIGESTSIZE ];

hash.CalculateDigest( digest, (byte*) &value[ 0 ], value.size( ) );

HexEncoder encoder;

string result = String::empty;

encoder.Attach( new StringSink( result ) );

encoder.Put( digest, sizeof( digest ) );

encoder.MessageEnd( );

构建命令

Apple clang version 2.1 (tags/Apple/clang-163.7.1) (based on LLVM 3.0svn)
Target: x86_64-apple-darwin11.4.0
Thread model: posix
 "/usr/bin/clang" -cc1 -triple x86_64-apple-macosx10.7.4 -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -main-file-name checksum_impl.cpp -pic-level 2 -mdisable-fp-elim -relaxed-aliasing -masm-verbose -munwind-tables -target-cpu core2 -target-linker-version 123.2.1 -v -resource-dir /usr/bin/../lib/clang/2.1 -D framework_EXPORTS -I /Users/Ben/Dropbox/appon/build/../source -nostdinc++ -cxx-isystem /usr/include/c++/v1 -Wall -Wextra -Weffc++ -pedantic -std=c++0x -fdeprecated-macro -ferror-limit 19 -fmessage-length 175 -stack-protector 1 -fblocks -fcxx-exceptions -fexceptions -fdiagnostics-show-option -fcolor-diagnostics -o CMakeFiles/framework.dir/Users/Ben/Dropbox/source/example.cpp.o -x c++ /Users/Ben/Dropbox/source/example.cpp
clang -cc1 version 2.1 based upon llvm 3.0svn hosted on x86_64-apple-darwin11.4.0
#include "..." search starts here:
#include <...> search starts here:
 /Users/Ben/Dropbox/build/../source
 /usr/include/c++/v1
 /usr/local/include
 /usr/bin/../lib/clang/2.1/include
 /usr/include
 /System/Library/Frameworks (framework directory)
 /Library/Frameworks (framework directory)
End of search list.

链接器输出

clang: warning: argument unused during compilation: '-std=c++0x'
Undefined symbols for architecture x86_64:
  "CryptoPP::Filter::TransferTo2(CryptoPP::BufferedTransformation&, unsigned long long&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool)", referenced from:
      vtable for CryptoPP::SimpleProxyFilter in checksum_impl.cpp.o
      vtable for CryptoPP::Bufferless<CryptoPP::Filter> in checksum_impl.cpp.o
      vtable for CryptoPP::Unflushable<CryptoPP::Filter> in checksum_impl.cpp.o
  "CryptoPP::Filter::CopyRangeTo2(CryptoPP::BufferedTransformation&, unsigned long long&, unsigned long long, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool) const", referenced from:
      vtable for CryptoPP::SimpleProxyFilter in checksum_impl.cpp.o
      vtable for CryptoPP::Bufferless<CryptoPP::Filter> in checksum_impl.cpp.o
      vtable for CryptoPP::Unflushable<CryptoPP::Filter> in checksum_impl.cpp.o
  "CryptoPP::BufferedTransformation::ChannelCreatePutSpace(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, unsigned long&)", referenced from:
      vtable for CryptoPP::SimpleProxyFilter in checksum_impl.cpp.o
      vtable for CryptoPP::Bufferless<CryptoPP::Filter> in checksum_impl.cpp.o
      vtable for CryptoPP::Unflushable<CryptoPP::Filter> in checksum_impl.cpp.o
  "CryptoPP::BufferedTransformation::ChannelPut2(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, unsigned char const*, unsigned long, int, bool)", referenced from:
      vtable for CryptoPP::SimpleProxyFilter in checksum_impl.cpp.o
      vtable for CryptoPP::Bufferless<CryptoPP::Filter> in checksum_impl.cpp.o
      vtable for CryptoPP::Unflushable<CryptoPP::Filter> in checksum_impl.cpp.o
  "CryptoPP::BufferedTransformation::ChannelPutModifiable2(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, unsigned char*, unsigned long, int, bool)", referenced from:
      vtable for CryptoPP::SimpleProxyFilter in checksum_impl.cpp.o
      vtable for CryptoPP::Bufferless<CryptoPP::Filter> in checksum_impl.cpp.o
      vtable for CryptoPP::Unflushable<CryptoPP::Filter> in checksum_impl.cpp.o
  "CryptoPP::BufferedTransformation::ChannelFlush(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool, int, bool)", referenced from:
      vtable for CryptoPP::SimpleProxyFilter in checksum_impl.cpp.o
      vtable for CryptoPP::Bufferless<CryptoPP::Filter> in checksum_impl.cpp.o
  "CryptoPP::BufferedTransformation::ChannelMessageSeriesEnd(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, int, bool)", referenced from:
      vtable for CryptoPP::SimpleProxyFilter in checksum_impl.cpp.o
      vtable for CryptoPP::Bufferless<CryptoPP::Filter> in checksum_impl.cpp.o
      vtable for CryptoPP::Unflushable<CryptoPP::Filter> in checksum_impl.cpp.o
  "CryptoPP::BufferedTransformation::SetRetrievalChannel(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)", referenced from:
      vtable for CryptoPP::SimpleProxyFilter in checksum_impl.cpp.o
      vtable for CryptoPP::Bufferless<CryptoPP::Filter> in checksum_impl.cpp.o
      vtable for CryptoPP::Unflushable<CryptoPP::Filter> in checksum_impl.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: *** [all] Error 2

我正在使用Crypto ++ 5.6.2的最新开发版本，因为以前的版本5.6.1无法使用clang ++构建。但是我遇到了构建问题，说明我缺少x86_64架构的符号。

任何提示都将不胜感激。

Answer 1

Crypto ++ 5.6.2使用make选项在LLVM版本6.1.0（clang-602.0.53）上成功构建：

CXXFLAGS="-std=c++11 -stdlib=libstdc++ -DCRYPTOPP_DISABLE_ASM -Wno-c++11-narrowing"

相应地这个脚本：https://github.com/mapnik/mapnik-packaging/blob/master/osx/scripts/build_cryptopp.sh

自小牛队以来

-stdlib = libstdc ++需要MacOSX，请参阅：When is it necessary to use use the flag -stdlib=libstdc++?

Answer 2

你需要在编译器命令中使用-lcryptopp链接到提供这些符号的库，这些符号应该是libcryptopp.so

查看您的“构建命令”（这不是您正在运行的命令，它是您正在运行的命令的输出，如果您显示它将会更容易阅读实际的命令）似乎你正在将.cpp文件编译成.o文件，但是获取链接器错误，这很奇怪，因为生成.o文件通常是步骤在链接之前。你想做什么步骤？也许您还需要添加-c，因此它只会编译而不会尝试链接。链接时您仍需要-lcryptopp。

Answer 3

除了Jonathon的答案，因为当指定 -lcryptopp时，这是一个相当普遍的问题 ...

架构x86_64的未定义符号。 CryptoPP::Filter::TransferTo2(CryptoPP::BufferedTransformation&, unsigned long long&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool)" ...

__1表示您正在使用LLVM C ++运行时（libc++）。在某些地方，您可能正在与GNU C ++运行时混合和匹配（libstdc++）。 GNU C ++运行时（libstdc++）在其符号上缺少__1装饰。

您应该浏览项目和所有预先构建的库，并确保它们正在使用其中一个库。对于每个，您应该使用（1）CXXFLAGS（LLVM）或（2）-stdlib=libc++（GNU）的-stdlib=libstdc++。

请注意，像Xcode这样的IDE可能会使用与Crypto ++不同的-stdlib=...设置。在这种情况下，让Xcode与Crypto ++匹配，或者重建Crypto ++库以匹配Xcode。

如果Xcode正在使用LLVM的libc++并且你必须重建Crypto ++，那么打开GNUmakefile并重新编写本节（第90行）：

ifeq ($(UNAME),Darwin) AR = libtool ARFLAGS = -static -o CXX = c++ IS_GCC2 = $(shell $(CXX) -v 2>&1 | $(EGREP) -c gcc-932) ifeq ($(IS_GCC2),1) CXXFLAGS += -fno-coalesce-templates -fno-coalesce-static-vtables LDLIBS += -lstdc++ LDFLAGS += -flat_namespace -undefined suppress -m endif endif

如果您想使用LLVM的libc++，请删除：

# GNU C++ Runtime LDLIBS += -lstdc++

并添加：

# LLVM C++ Runtime CXXFLAGS += -stdlib=libc++

为完整起见，如果您想使用GNU的运行时，请删除LDLIBS += -lstdc++并添加CXXFLAGS += -stdlib=libstdc++。

您还可以将CXX = c++更改为CXX ?= c++，以便makefile将使用c++ ，如果未在环境或命令行中指定。

如果感兴趣，__1是用于版本控制的内联命名空间。请参阅What are inline namespaces for?和Where does the __1 symbol come from when using LLVM's libc++?。

Answer 4

这个问题与Crypto ++没有被移植到llvm-clang ++有关。有关支持的编译器，请参阅here。

我的解决方案是使用GCrypt。

抱歉，我无法提供有关失败原因的详细信息。

使用Crypto ++和clang

4 个答案: