clang++ 2.9, 3.0 and 3.1 do not link with the C++ standard library

[roland@…]

The clang++-mp-2.9 compiler from the MacPorts (from port clang-2.9) does not seem to link C++ code correctly. In particular, the linker does not link with the C++ standard library.

For instance, compiling a very simple program does not work, since the linker is unable to find iostream classes and other required routines from the C++ standard library:

% cat a.cc
#include <iostream>

int
main ()
{
  std::cout << "Hello World!" << std::endl;
}
% clang++-mp-2.9 a.cc
Undefined symbols for architecture x86_64:
  "std::ios_base::Init::~Init()", referenced from:
      ___cxx_global_var_init in cc-FzHhK1.o
  "std::ios_base::Init::Init()", referenced from:
      ___cxx_global_var_init in cc-FzHhK1.o
  "std::basic_ostream<char, std::char_traits<char> >& std::endl<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&)", referenced from:
      _main in cc-FzHhK1.o
  "std::cout", referenced from:
      _main in cc-FzHhK1.o
  "std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)", referenced from:
      _main in cc-FzHhK1.o
  "std::ostream::operator<<(std::ostream& (*)(std::ostream&))", referenced from:
      _main in cc-FzHhK1.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Here is the output of the compiler with the -v option:

% clang++-mp-2.9 -v a.cc
clang version 2.9 (tags/RELEASE_29/final)
Target: x86_64-apple-darwin10
Thread model: posix
 "/opt/local/libexec/llvm-2.9/bin/clang" -cc1 -triple x86_64-apple-darwin10.0.0 -emit-obj -mrelax-all -disable-free -main-file-name a.cc -pic-level 1 -mdisable-fp-elim -masm-verbose -munwind-tables -target-cpu core2 -target-linker-version 127.2 -v -resource-dir /opt/local/libexec/llvm-2.9/bin/../lib/clang/2.9 -ferror-limit 19 -fmessage-length 80 -stack-protector 1 -fblocks -fcxx-exceptions -fexceptions -fdiagnostics-show-option -fcolor-diagnostics -o /var/folders/TT/TTWwnJg92RaMtk+BYog6aU+++TI/-Tmp-/cc-z6esE6.o -x c++ a.cc
clang -cc1 version 2.9 based upon llvm 2.9 hosted on x86_64-apple-darwin10
#include "..." search starts here:
#include <...> search starts here:
 /usr/include/c++/4.2.1
 /usr/include/c++/4.2.1/i686-apple-darwin10/x86_64
 /usr/include/c++/4.2.1/backward
 /usr/include/c++/4.0.0
 /usr/include/c++/4.0.0/i686-apple-darwin8
 /usr/include/c++/4.0.0/backward
 /usr/local/include
 /opt/local/libexec/llvm-2.9/bin/../lib/clang/2.9/include
 /usr/include
 /System/Library/Frameworks (framework directory)
 /Library/Frameworks (framework directory)
End of search list.
 "/opt/local/bin/ld" -demangle -dynamic -arch x86_64 -macosx_version_min 10.6.0 -o a.out -lcrt1.10.6.o /var/folders/TT/TTWwnJg92RaMtk+BYog6aU+++TI/-Tmp-/cc-z6esE6.o -lSystem
Undefined symbols for architecture x86_64:
  "std::ios_base::Init::~Init()", referenced from:
      ___cxx_global_var_init in cc-z6esE6.o
  "std::ios_base::Init::Init()", referenced from:
      ___cxx_global_var_init in cc-z6esE6.o
  "std::basic_ostream<char, std::char_traits<char> >& std::endl<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&)", referenced from:
      _main in cc-z6esE6.o
  "std::cout", referenced from:
      _main in cc-z6esE6.o
  "std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)", referenced from:
      _main in cc-z6esE6.o
  "std::ostream::operator<<(std::ostream& (*)(std::ostream&))", referenced from:
      _main in cc-z6esE6.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

My environment is Mac OS X 10.6 with the latest MacPorts.

I have the same problem with clang++-mp-3.0 (port clang-3.0) and clang++-mp-3.0 (port clang-3.0).

Note that the old clang++ compiler from port clang (version 2.8) that is still installed on my system does not have this problem:

% clang++ -v a.cc
clang version 2.8 (branches/release_28)
Target: x86_64-apple-darwin10
Thread model: posix
 "/opt/local/bin/clang" -cc1 -triple x86_64-apple-darwin10.0.0 -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -main-file-name a.cc -pic-level 1 -mdisable-fp-elim -masm-verbose -munwind-tables -target-cpu core2 -target-linker-version 97.14 -v -resource-dir /opt/local/lib/clang/2.8 -ferror-limit 19 -fmessage-length 80 -stack-protector 1 -fblocks -fexceptions -fdiagnostics-show-option -fcolor-diagnostics -o /var/folders/TT/TTWwnJg92RaMtk+BYog6aU+++TI/-Tmp-/cc-1NH4kO.o -x c++ a.cc
clang -cc1 version 2.8 based upon llvm 2.8 hosted on x86_64-apple-darwin10
#include "..." search starts here:
#include <...> search starts here:
 /usr/include/c++/4.2.1
 /usr/include/c++/4.2.1/i686-apple-darwin10/x86_64
 /usr/include/c++/4.2.1/backward
 /usr/include/c++/4.0.0
 /usr/include/c++/4.0.0/i686-apple-darwin8
 /usr/include/c++/4.0.0/backward
 /usr/local/include
 /opt/local/lib/clang/2.8/include
 /usr/include
 /System/Library/Frameworks (framework directory)
 /Library/Frameworks (framework directory)
End of search list.
 "/opt/local/bin/../libexec/gcc/i686-apple-darwin10/4.2.1/ld" -dynamic -arch x86_64 -macosx_version_min 10.6.0 -o a.out -lcrt1.10.6.o -L/usr/lib/gcc/i686-apple-darwin10/4.2.1/x86_64 -L/usr/lib/gcc/i686-apple-darwin10/4.2.1/x86_64 -L/usr/lib/i686-apple-darwin10/4.2.1 -L/usr/lib/gcc/i686-apple-darwin10/4.2.1 -L/usr/lib/gcc/i686-apple-darwin10/4.2.1 -L/opt/local/bin/../lib -L/usr/lib/gcc/i686-apple-darwin10/4.2.1/../../../i686-apple-darwin10/4.2.1 -L/usr/lib/gcc/i686-apple-darwin10/4.2.1/../../.. /var/folders/TT/TTWwnJg92RaMtk+BYog6aU+++TI/-Tmp-/cc-1NH4kO.o -lstdc++ -lSystem -lgcc

Here, the compiler actually links with libstdc++.

[jeremyhu (Jeremy Huddleston Sequoia)]

Interestingly, using the file directly instead of the symlink works. eg:

$ /opt/local/libexec/llvm-2.9/bin/clang++ test.cc 

[jeremyhu (Jeremy Huddleston Sequoia)]

r89146

[roland@…]

I have just upgraded clang-2.9, clang-3.0 and clang-3.1 to their latest versions. There is another problem regarding the linker in all three ports:

% clang++-mp-2.9 a.cc
ld: unknown option: -demangle
clang: error: linker command failed with exit code 1 (use -v to see invocation)
% clang++-mp-3.0 a.cc
ld: unknown option: -demangle
clang: error: linker command failed with exit code 1 (use -v to see invocation)
% clang++-mp-3.1 a.cc
ld: unknown option: -demangle
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Using the clang++ binary from the /opt/local/libexec/llvm-x.y/bin/ directory produces the same error:

% /opt/local/libexec/llvm-2.9/bin/clang++ a.cc
ld: unknown option: -demangle
clang: error: linker command failed with exit code 1 (use -v to see invocation)
% /opt/local/libexec/llvm-3.0/bin/clang++ a.cc
ld: unknown option: -demangle
clang: error: linker command failed with exit code 1 (use -v to see invocation)
% /opt/local/libexec/llvm-3.1/bin/clang++ a.cc
ld: unknown option: -demangle
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Here is the output of clang++-mp-2.9 with the -v option:

% clang++-mp-2.9 -v a.cc
clang version 2.9 (tags/RELEASE_29/final)
Target: x86_64-apple-darwin10
Thread model: posix
 "/opt/local/libexec/llvm-2.9/bin/clang" -cc1 -triple x86_64-apple-darwin10.0.0 -emit-obj -mrelax-all -disable-free -main-file-name a.cc -pic-level 1 -mdisable-fp-elim -masm-verbose -munwind-tables -target-cpu core2 -target-linker-version 127.2 -v -resource-dir /opt/local/libexec/llvm-2.9/bin/../lib/clang/2.9 -ferror-limit 19 -fmessage-length 80 -stack-protector 1 -fblocks -fcxx-exceptions -fexceptions -fdiagnostics-show-option -fcolor-diagnostics -o /var/folders/TT/TTWwnJg92RaMtk+BYog6aU+++TI/-Tmp-/cc-CZUJ1t.o -x c++ a.cc
clang -cc1 version 2.9 based upon llvm 2.9 hosted on x86_64-apple-darwin10
#include "..." search starts here:
#include <...> search starts here:
 /usr/include/c++/4.2.1
 /usr/include/c++/4.2.1/i686-apple-darwin10/x86_64
 /usr/include/c++/4.2.1/backward
 /usr/include/c++/4.0.0
 /usr/include/c++/4.0.0/i686-apple-darwin8
 /usr/include/c++/4.0.0/backward
 /usr/local/include
 /opt/local/libexec/llvm-2.9/bin/../lib/clang/2.9/include
 /usr/include
 /System/Library/Frameworks (framework directory)
 /Library/Frameworks (framework directory)
End of search list.
 "/usr/libexec/gcc/i686-apple-darwin10/4.2.1/ld" -demangle -dynamic -arch x86_64 -macosx_version_min 10.6.0 -o a.out -lcrt1.10.6.o /var/folders/TT/TTWwnJg92RaMtk+BYog6aU+++TI/-Tmp-/cc-CZUJ1t.o /usr/lib/libstdc++.6.dylib -lSystem
ld: unknown option: -demangle
clang: error: linker command failed with exit code 1 (use -v to see invocation)

(clang++-mp-3.0 and clang++-mp-3.1 show similar error messages.)

[jeremyhu (Jeremy Huddleston Sequoia)]

That is a different issue, so file a new bug report. This one is fixed.