How to properly set run paths, search paths, and install names? How to properly set run paths, search paths, and install names? xcode xcode

How to properly set run paths, search paths, and install names?


Typically, in my dylib's target, I set INSTALL_PATH aka "Installation Directory" to the prefix I want (e.g. @executable_path/../Frameworks).

I leave LD_DYLIB_INSTALL_NAME aka "Dynamic Library Install Name" set to its default value, which is $(DYLIB_INSTALL_NAME_BASE:standardizepath)/$(EXECUTABLE_PATH).

Xcode expands that based on your target's name, so it might end up being @executable_path/../Frameworks/MyFramework.framework/Versions/A/MyFramework, for instance.

The important thing to realize is that the install path is built into the dylib, as part of its build process. Later on, when you link B.dylib that refers to A.dylib, A.dylib's install path is copied into B.dylib. (That's what otool is showing you -- those copied install paths.) So it's best to get the correct install path built into the dylib in the first place.

Before trying to get all the dylibs working together, check each one individually. Build it, then otool -L on the built dylib. The first line for each architecture should be what LD_DYLIB_INSTALL_NAME was showing you.

Once you have that organized, try to get the dylibs linking against each other. It should be much more straightforward.


install_name_tool is very useful for setting the names and paths. Its especially useful if the program runs its self-tests in the build directory, and then things change during a make install. In this case, you can use install_name_tool without the need for a separate build.

install_name_tool is also useful because Apple's LD does not honor rpath linker options like Linux/GCC does. That is, you need to use a different set of commands to set them.

Here's the man page for it. Its included in its entirety because it discusses other options, like -headerpad_max_install_names.

INSTALL_NAME_TOOL(1)                                      INSTALL_NAME_TOOL(1)NAME       install_name_tool - change dynamic shared library install namesSYNOPSIS       install_name_tool  [-change  old  new  ]  ...  [-rpath  old  new  ] ...       [-add_rpath new ] ... [-delete_rpath new ] ... [-id name] fileDESCRIPTION       Install_name_tool changes the dynamic shared library install names  and       or  adds,  changes  or  deletes the rpaths recorded in a Mach-O binary.       For this tool to work when the install names or rpaths are  larger  the       binary  should  be  built  with  the ld(1) -headerpad_max_install_names       option.       -change old new              Changes the dependent shared library install name old to new  in              the specified Mach-O binary.  More than one of these options can              be specified.  If the Mach-O binary does  not  contain  the  old              install  name  in  a  specified  -change  option  the  option is              ignored.       -id name              Changes the shared library  identification  name  of  a  dynamic              shared  library  to name.  If the Mach-O binary is not a dynamic              shared library and the -id option is specified it is ignored.       -rpath old new              Changes the rpath path name old to new in the  specified  Mach-O              binary.   More  than  one of these options can be specified.  If              the Mach-O binary does not contain the old rpath path name in  a              specified -rpath it is an error.       -add_rpath new              Adds  the  rpath  path  name new in the specified Mach-O binary.              More than one of these options can be specified.  If the  Mach-O              binary  already  contains  the  new rpath path name specified in              -add_rpath it is an error.       -delete_rpath old              deletes the rpath path name old in the specified Mach-O  binary.              More  than one of these options can be specified.  If the Mach-O              binary does not contains the old rpath path  name  specified  in              -delete_rpath it is an error.SEE ALSO       ld(1)