为什么这适用于 G++ 而不是 CLANG?

尝试学习C/C++。

为什么在使用g++而不是clang时这样做？但是当我将相同的程序转换为普通 C 并使用gcc和clang时，它可以工作......

代码：

#include <iostream>
#ifndef ARCH
#define ARCH "Undefined"
#endif
using namespace std;
int main() {
char str[] = "Hello C++";
cout << "Value of str is : " << str << endl;
cout << "Value of str is : " << ARCH << endl;
exit(0);
}

使用g++我运行g++ "-DARCH="`uname -m`"" hello.cpp，它工作得很好。

使用clang我运行clang "-DARCH="`uname -m`"" hello.cpp，但它失败了。

Undefined symbols for architecture x86_64:
"std::__1::locale::use_facet(std::__1::locale::id&) const", referenced from:
std::__1::ctype<char> const& std::__1::use_facet<std::__1::ctype<char> >(std::__1::locale const&) in hello-7c7087.o
"std::__1::ios_base::getloc() const", referenced from:
std::__1::basic_ios<char, std::__1::char_traits<char> >::widen(char) const in hello-7c7087.o
"std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::__init(unsigned long, char)", referenced from:
std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::basic_string(unsigned long, char) in hello-7c7087.o
"std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::~basic_string()", referenced from:
std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> > std::__1::__pad_and_output<char, std::__1::char_traits<char> >(std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> >, char const*, char const*, char const*, std::__1::ios_base&, char) in hello-7c7087.o
"std::__1::basic_ostream<char, std::__1::char_traits<char> >::put(char)", referenced from:
std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::endl<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) in hello-7c7087.o
"std::__1::basic_ostream<char, std::__1::char_traits<char> >::flush()", referenced from:
std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::endl<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) in hello-7c7087.o
"std::__1::basic_ostream<char, std::__1::char_traits<char> >::sentry::sentry(std::__1::basic_ostream<char, std::__1::char_traits<char> >&)", referenced from:
std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in hello-7c7087.o
"std::__1::basic_ostream<char, std::__1::char_traits<char> >::sentry::~sentry()", referenced from:
std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in hello-7c7087.o
"std::__1::cout", referenced from:
_main in hello-7c7087.o
"std::__1::ctype<char>::id", referenced from:
std::__1::ctype<char> const& std::__1::use_facet<std::__1::ctype<char> >(std::__1::locale const&) in hello-7c7087.o
"std::__1::locale::~locale()", referenced from:
std::__1::basic_ios<char, std::__1::char_traits<char> >::widen(char) const in hello-7c7087.o
"std::__1::ios_base::__set_badbit_and_consider_rethrow()", referenced from:
std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in hello-7c7087.o
"std::__1::ios_base::clear(unsigned int)", referenced from:
std::__1::ios_base::setstate(unsigned int) in hello-7c7087.o
"std::terminate()", referenced from:
___clang_call_terminate in hello-7c7087.o
"___cxa_begin_catch", referenced from:
std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in hello-7c7087.o
___clang_call_terminate in hello-7c7087.o
"___cxa_call_unexpected", referenced from:
std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> >::ostreambuf_iterator(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) in hello-7c7087.o
"___cxa_end_catch", referenced from:
std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in hello-7c7087.o
"___gxx_personality_v0", referenced from:
std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in hello-7c7087.o
std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> > std::__1::__pad_and_output<char, std::__1::char_traits<char> >(std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> >, char const*, char const*, char const*, std::__1::ios_base&, char) in hello-7c7087.o
std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> >::ostreambuf_iterator(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) in hello-7c7087.o
std::__1::basic_ios<char, std::__1::char_traits<char> >::widen(char) const in hello-7c7087.o
Dwarf Exception Unwind Info (__eh_frame) in hello-7c7087.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

对我来说真正没有意义的是，如果我将代码转换为 C，它会双向工作。

提前感谢！