我正在尝试制作一个简单的程序，其中嵌入了Google的V8 Javascript引擎。说明似乎很简单，但我得到一个奇怪的链接错误。
我使用的是Mac OS X 10.9，而我正在使用Xamarin Studio作为我的IDE，它似乎使用g ++作为编译器。
我使用instructions on their site编译了v8。具体来说，在所有make dependencies之后，我跑了：
make x64.release
这似乎成功完成。
这是我在尝试构建项目时得到的输出：
g++ -o "/Users/mike/Projects/vate/vate/bin/Debug/vate" "/Users/mike/Projects/vate/vate/bin/Debug/hello_world.o" -v -L"/Users/mike/Projects/v8/xcodebuild/Debug" -l"icudata" -l"icui18n" -l"v8_snapshot" -l"icuuc" -l"v8_libbase" -l"v8_base" -l"v8_libplatform"
Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn)
Target: x86_64-apple-darwin13.3.0
Thread model: posix
"/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld" -demangle -dynamic -arch x86_64 -macosx_version_min 10.9.0 -o /Users/mike/Projects/vate/vate/bin/Debug/vate -L/Users/mike/Projects/v8/xcodebuild/Debug /Users/mike/Projects/vate/vate/bin/Debug/hello_world.o -licudata -licui18n -lv8_snapshot -licuuc -lv8_libbase -lv8_base -lv8_libplatform -lc++ -lSystem /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/clang/5.1/lib/darwin/libclang_rt.osx.a
Undefined symbols for architecture x86_64:
"std::string::c_str() const", referenced from:
v8::internal::Logger::SharedLibraryEvent(std::string const&, unsigned long, unsigned long) in libv8_base.a(log.o)
"std::allocator::allocator()", referenced from:
v8::base::OS::GetSharedLibraryAddresses() in libv8_libbase.a(platform-macos.o)
"std::allocator::~allocator()", referenced from:
v8::base::OS::GetSharedLibraryAddresses() in libv8_libbase.a(platform-macos.o)
"std::basic_string, std::allocator >::basic_string(char const*, std::allocator const&)", referenced from:
v8::base::OS::GetSharedLibraryAddresses() in libv8_libbase.a(platform-macos.o)
"std::basic_string, std::allocator >::basic_string(std::string const&)", referenced from:
v8::base::OS::SharedLibraryAddress::SharedLibraryAddress(v8::base::OS::SharedLibraryAddress const&) in libv8_libbase.a(platform-macos.o)
v8::base::OS::SharedLibraryAddress::SharedLibraryAddress(std::string const&, unsigned long, unsigned long) in libv8_libbase.a(platform-macos.o)
"std::basic_string, std::allocator >::~basic_string()", referenced from:
v8::base::OS::SharedLibraryAddress::~SharedLibraryAddress() in libv8_base.a(log.o)
v8::base::OS::GetSharedLibraryAddresses() in libv8_libbase.a(platform-macos.o)
v8::base::OS::SharedLibraryAddress::~SharedLibraryAddress() in libv8_libbase.a(platform-macos.o)
"std::string::operator=(std::string const&)", referenced from:
v8::base::OS::SharedLibraryAddress::operator=(v8::base::OS::SharedLibraryAddress const&) in libv8_libbase.a(platform-macos.o)
"std::_Rb_tree_decrement(std::_Rb_tree_node_base*)", referenced from:
std::_Rb_tree_iterator >::operator--() in libv8_base.a(allocation-tracker.o)
std::_Rb_tree_iterator >::operator--() in libv8_base.a(lithium-codegen.o)
std::_Rb_tree_iterator::operator--() in libv8_base.a(verifier.o)
std::_Rb_tree_iterator::operator--() in libv8_base.a(instruction.o)
std::_Rb_tree_iterator >::operator--() in libv8_base.a(instruction-selector.o)
std::_Rb_tree_iterator::operator--() in libv8_base.a(typer.o)
std::_Rb_tree_iterator::operator--() in libv8_base.a(graph-visualizer.o)
...
"std::_Rb_tree_increment(std::_Rb_tree_node_base const*)", referenced from:
std::_Rb_tree_const_iterator >::operator++() in libv8_base.a(lithium.o)
std::_Rb_tree_const_iterator::operator++() in libv8_base.a(verifier.o)
std::_Rb_tree_const_iterator >::operator++() in libv8_base.a(instruction.o)
std::_Rb_tree_const_iterator::operator++() in libv8_base.a(typer.o)
std::_Rb_tree_const_iterator::operator++() in libv8_base.a(graph-visualizer.o)
"std::_Rb_tree_increment(std::_Rb_tree_node_base*)", referenced from:
std::_Rb_tree_iterator >::operator++() in libv8_base.a(allocation-tracker.o)
std::_Rb_tree_iterator >::operator++(int) in libv8_base.a(allocation-tracker.o)
"std::__throw_length_error(char const*)", referenced from:
std::vector >::_M_insert_aux(__gnu_cxx::__normal_iterator > >, v8::base::OS::SharedLibraryAddress const&) in libv8_libbase.a(platform-macos.o)
std::vector >::_M_insert_aux(__gnu_cxx::__normal_iterator > >, v8::internal::compiler::Reducer* const&) in libv8_base.a(pipeline.o)
std::vector >::_M_fill_insert(__gnu_cxx::__normal_iterator > >, unsigned long, v8::internal::compiler::Node* const&) in libv8_base.a(ast-graph-builder.o)
std::vector >::_M_insert_aux(__gnu_cxx::__normal_iterator > >, v8::internal::compiler::Node* const&) in libv8_base.a(ast-graph-builder.o)
std::vector >::_M_insert_aux(__gnu_cxx::__normal_iterator > >, v8::internal::compiler::FrameStateDescriptor* const&) in libv8_base.a(instruction.o)
std::vector >::_M_insert_aux(__gnu_cxx::__normal_iterator > >, v8::internal::compiler::Node* const&) in libv8_base.a(simplified-lowering.o)
std::vector >::reserve(unsigned long) in libv8_base.a(instruction-selector.o)
...
"std::__throw_out_of_range(char const*)", referenced from:
std::vector >::_M_range_check(unsigned long) const in libv8_base.a(graph-reducer.o)
std::vector >::_M_range_check(unsigned long) const in libv8_base.a(ast-graph-builder.o)
std::vector >::_M_range_check(unsigned long) const in libv8_base.a(verifier.o)
std::vector >::_M_range_check(unsigned long) const in libv8_base.a(verifier.o)
std::vector >::_M_range_check(unsigned long) const in libv8_base.a(graph-replay.o)
std::vector >::_M_range_check(unsigned long) const in libv8_base.a(js-context-specialization.o)
std::vector >::_M_range_check(unsigned long) const in libv8_base.a(graph-builder.o)
...
"std::_Rb_tree_rebalance_for_erase(std::_Rb_tree_node_base*, std::_Rb_tree_node_base&)", referenced from:
std::_Rb_tree, std::_Select1st >, std::less, std::allocator > >::erase(std::_Rb_tree_iterator >) in libv8_base.a(allocation-tracker.o)
"std::_Rb_tree_insert_and_rebalance(bool, std::_Rb_tree_node_base*, std::_Rb_tree_node_base*, std::_Rb_tree_node_base&)", referenced from:
std::_Rb_tree, std::_Select1st >, std::less, std::allocator > >::_M_insert(std::_Rb_tree_node_base*, std::_Rb_tree_node_base*, std::pair const&) in libv8_base.a(allocation-tracker.o)
std::_Rb_tree, v8::internal::Handle, std::_Identity >, std::less >, v8::internal::zone_allocator > >::_M_insert(std::_Rb_tree_node_base*, std::_Rb_tree_node_base*, v8::internal::Handle const&) in libv8_base.a(lithium-codegen.o)
std::_Rb_tree, std::less, v8::internal::zone_allocator >::_M_insert(std::_Rb_tree_node_base*, std::_Rb_tree_node_base*, v8::internal::compiler::Node* const&) in libv8_base.a(verifier.o)
std::_Rb_tree, std::less, v8::internal::zone_allocator >::_M_insert(std::_Rb_tree_node_base*, std::_Rb_tree_node_base*, int const&) in libv8_base.a(instruction.o)
std::_Rb_tree, std::_Select1st >, std::less, v8::internal::zone_allocator > >::_M_insert(std::_Rb_tree_node_base*, std::_Rb_tree_node_base*, std::pair const&) in libv8_base.a(instruction-selector.o)
std::_Rb_tree, std::less, v8::internal::zone_allocator >::_M_insert(std::_Rb_tree_node_base*, std::_Rb_tree_node_base*, v8::internal::compiler::Node* const&) in libv8_base.a(typer.o)
std::_Rb_tree, std::less, v8::internal::zone_allocator >::_M_insert(std::_Rb_tree_node_base*, std::_Rb_tree_node_base*, v8::internal::compiler::Node* const&) in libv8_base.a(graph-visualizer.o)
...
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
我有一种感觉，我编译v8错误，或者可能是为了不同的编译器，但我找不到任何方法来定制它。有没有人见过这个？
答案 0 :(得分：3)
我已经弄清楚了。我有两个问题：
我对我实际使用的编译器感到困惑。在OSX上，g ++实际上符号链接到clang ++，所以我需要使用Clang约定编译V8，而不是g ++
根据此错误，有关在Google页面上使用clang进行编译的说明不正确：https://code.google.com/p/v8/issues/detail?id=3072
作为参考，要使用clang进行编译，您需要像下面这样配置您的环境：
export CXX=`which clang++` export CC=`which clang` export CPP="`which clang` -E -std=c++11 -stdlib=libc++" export LINK="`which clang++` -std=c++11 -stdlib=libc++" export CXX_host=`which clang++` export CC_host=`which clang` export CPP_host="`which clang` -E" export LINK_host=`which clang++` export GYP_DEFINES="clang=1 mac_deployment_target=10.9"
然后，您可以正常运行make whatever命令。
显然，要求安装xcode以便存在clang和clang ++。