How should I best to install and use libc++ from svn on OS X

Question

Due to a bug in the release version of clang, I need to compile and install it from SVN trunk. I figured I might as well also compile SVN trunk libc++ at the same time. I am running an up to date OS X 10.10.1, with macports installed libs and binaries where needed.

I've managed to compile clang and libc++ using the commands at the end of this post, installing them into $HOME/usr/local/. Compiling my program with $HOME/usr/local/bin/clang++ works fine. However, when running the executables, the version of libc++ used is the system version. (As seen by setting export DYLD_PRINT_LIBRARIES=1 before running it.)

I then tried export DYLD_LIBRARY_PATH=$HOME/usr/local/lib which makes all executables use the new version of libc++. However, it seems that some other executables do not like this change in which libc++ is being used. For example, ls fails with the following errors:

dyld: Symbol not found: __ZTISt9bad_alloc
  Referenced from: /usr/lib/libutil.dylib
  Expected in: /Users/d97sjan/usr/local/lib/libc++.1.dylib
in /usr/lib/libutil.dylib
Trace/BPT trap: 5

Is this a bug in libc++ or dyld, or am I just crazy to believe that swapping out libc++ globally by setting DYLD_LIBRARY_PATH is feasible?

I can make it work by running my executable with DYLD_LIBRARY_PATH=$HOME/usr/local/lib a.out, but I'd rather have a cleaner solution if possible.

Any ideas or comments of how to make it work, or rather how it should be done?

Edit: After comment by "The Paramagnetic Croissant" on that it's not feasible to swap out libc++ for other binaries [although it works for some]. Can I at compile time add some hints in my binary to dyld so that it loads the correct libc++? Or should I just stick with the standard libc++ and just compile my own clang? What's anyone's advice?

Code for compiling and installing clang and libc++

# From http://clang.llvm.org/get_started.html
svn co -q http://llvm.org/svn/llvm-project/llvm/trunk llvm
svn co -q http://llvm.org/svn/llvm-project/cfe/trunk llvm/tools/clang
svn co -q http://llvm.org/svn/llvm-project/clang-tools-extra/trunk llvm/tools/clang/tools/extra
svn co -q http://llvm.org/svn/llvm-project/compiler-rt/trunk llvm/projects/compiler-rt
#From http://libcxx.llvm.org/
svn co -q http://llvm.org/svn/llvm-project/libcxx/trunk llvm/projects/libcxx

mkdir llvm_build_release
cd llvm_build_release
cmake -GNinja -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=$HOME/usr/local -DLLVM_TARGETS_TO_BUILD=host ../llvm
ninja
ninja install

Answer 1

If your issue is with the runtime and you want to do this, I suggest you use MacPorts as I added support for this into the libcxx and libcxxabi ports last month.

Specifically, install the libcxx and libcxxabi ports with the +replacemnt_libcxx variant set at build time, and we'll build you a root that you can install in /opt/local/var/system_roots. To install the root, use darwinup:

  sudo darwinup install /opt/local/var/system_roots/libcxxabi-*
  sudo darwinup install /opt/local/var/system_roots/libcxx-*

As this will replace a system library, be prepared to boot into target disk mode and uninstall the roots if something goes wrong:

  sudo darwinup -p /Volumes/TargetDisk list
  sudo darwinup -p /Volumes/TargetDisk uninstall <id for libcxx root>
  sudo darwinup -p /Volumes/TargetDisk uninstall <id for libcxxabi root>

Also note that the versions of libcxx and libcxxabi are the ones from llvm-3.5.0. I am not sure the exact differences between that version and what is in OS X 10.10.1, and I am not sure if it contains the fix you need or not. If it doesn't, please file an issue in MacPorts trac, and I'll cherry pick it in for you.

---

If your issue is with with the STL, then again, I suggest you use MacPorts and just install the clang ports you want:

sudo port -v -s install clang-3.4
sudo port -v -s install clang-3.5
sudo port -v -s install clang-3.6

You can then use the clang++-mp-3.4 (or 3.5/3.6) compiler from the command line or use 'sudo port select clang' to set what you want to be default for 'clang++'