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)