[CMake] Add RPATHS parameter to llvm_add_executable/library

[sgraenitz]

Summary

This allows to set target-specific LC_RPATH load commands on macOS. It would be useful to locate LLDB.framework in LLDB tools.

[sgraenitz]

More requirements for RPATH handling in LLDB came up. We will do it manually over there instead of adding support in LLVM. Added D55316 to avoid the need for reverting default settings.

cmake/modules/AddLLVM.cmake

 #     Should set SONAME link flags and create symlinks
 #   PLUGIN_TOOL
 #     The tool (i.e. cmake target) that this plugin will link against
 #   )
 function(llvm_add_library name)
   cmake_parse_arguments(ARG
     "MODULE;SHARED;STATIC;OBJECT;DISABLE_LLVM_LINK_LLVM_DYLIB;SONAME"
     "OUTPUT_NAME;PLUGIN_TOOL"
-    "ADDITIONAL_HEADERS;DEPENDS;LINK_COMPONENTS;LINK_LIBS;OBJLIBS"
+    "ADDITIONAL_HEADERS;DEPENDS;LINK_COMPONENTS;LINK_LIBS;OBJLIBS;RPATHS"
     ${ARGN})
   list(APPEND LLVM_COMMON_DEPENDS ${ARG_DEPENDS})
   if(ARG_ADDITIONAL_HEADERS)
     # Pass through ADDITIONAL_HEADERS.
     set(ARG_ADDITIONAL_HEADERS ADDITIONAL_HEADERS ${ARG_ADDITIONAL_HEADERS})
   endif()
   if(ARG_OBJLIBS)
     set(ALL_FILES ${ARG_OBJLIBS})
llvm_add_library(${name_static} STATIC
       LINK_COMPONENTS ${ARG_LINK_COMPONENTS}
       )
     # FIXME: Add name_static to anywhere in TARGET ${name}'s PROPERTY.
     set(ARG_STATIC)
   endif()
 
   if(ARG_MODULE)
     add_library(${name} MODULE ${ALL_FILES})
-    llvm_setup_rpath(${name})
+    llvm_setup_rpath(${name} RPATHS ${ARG_RPATHS})
   elseif(ARG_SHARED)
     add_windows_version_resource_file(ALL_FILES ${ALL_FILES})
     add_library(${name} SHARED ${ALL_FILES})
 
-    llvm_setup_rpath(${name})
+    llvm_setup_rpath(${name} RPATHS ${ARG_RPATHS})
 
   else()
     add_library(${name} STATIC ${ALL_FILES})
   endif()
 
   setup_dependency_debugging(${name} ${LLVM_COMMON_DEPENDS})
 
   if(DEFINED windows_resource_file)
macro(add_llvm_loadable_module name)
   set_target_properties(${name} PROPERTIES FOLDER "Loadable modules")
 endmacro(add_llvm_loadable_module name)
 
 
 macro(add_llvm_executable name)
   cmake_parse_arguments(ARG
     "DISABLE_LLVM_LINK_LLVM_DYLIB;IGNORE_EXTERNALIZE_DEBUGINFO;NO_INSTALL_RPATH"
     "ENTITLEMENTS"
-    "DEPENDS"
+    "DEPENDS;RPATHS"
     ${ARGN})
 
   llvm_process_sources( ALL_FILES ${ARG_UNPARSED_ARGUMENTS} )
 
   list(APPEND LLVM_COMMON_DEPENDS ${ARG_DEPENDS})
 
   # Generate objlib
   if(LLVM_ENABLE_OBJLIB)
if( EXCLUDE_FROM_ALL )
     add_executable(${name} EXCLUDE_FROM_ALL ${ALL_FILES})
   else()
     add_executable(${name} ${ALL_FILES})
   endif()
 
   setup_dependency_debugging(${name} ${LLVM_COMMON_DEPENDS})
 
   if(NOT ARG_NO_INSTALL_RPATH)
-    llvm_setup_rpath(${name})
+    llvm_setup_rpath(${name} RPATHS ${ARG_RPATHS})
   endif()
 
   if(DEFINED windows_resource_file)
     set_windows_version_resource_properties(${name} ${windows_resource_file})
   endif()
 
   # $<TARGET_OBJECTS> doesn't require compile flags.
   if(NOT LLVM_ENABLE_OBJLIB)
function(llvm_codesign name)
   endif()
 endfunction()
 
 function(llvm_setup_rpath name)
   if(CMAKE_INSTALL_RPATH)
     return()
   endif()
 
-  if(LLVM_INSTALL_PREFIX AND NOT (LLVM_INSTALL_PREFIX STREQUAL CMAKE_INSTALL_PREFIX))
-    set(extra_libdir ${LLVM_LIBRARY_DIR})
-  elseif(LLVM_BUILD_LIBRARY_DIR)
-    set(extra_libdir ${LLVM_LIBRARY_DIR})
-  endif()
-
   if (APPLE)
     set(_install_name_dir INSTALL_NAME_DIR "@rpath")
-    set(_install_rpath "@loader_path/../lib" ${extra_libdir})
+    set(_install_rpath_default "@loader_path/../lib")
   elseif(UNIX)
-    set(_install_rpath "\$ORIGIN/../lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+    set(_install_rpath_default "\$ORIGIN/../lib${LLVM_LIBDIR_SUFFIX}")
     if(${CMAKE_SYSTEM_NAME} MATCHES "(FreeBSD|DragonFly)")
       set_property(TARGET ${name} APPEND_STRING PROPERTY
                    LINK_FLAGS " -Wl,-z,origin ")
     endif()
     if(LLVM_LINKER_IS_GNULD)
       # $ORIGIN is not interpreted at link time by ld.bfd
       set_property(TARGET ${name} APPEND_STRING PROPERTY
                    LINK_FLAGS " -Wl,-rpath-link,${LLVM_LIBRARY_OUTPUT_INTDIR} ")
     endif()
   else()
     return()
   endif()
 
+  if(DEFINED ARG_RPATHS)
+    set(_install_rpath ${ARG_RPATHS})
+  else()
+    set(_install_rpath ${_install_rpath_default})
+  endif()
+
+  if(LLVM_INSTALL_PREFIX AND NOT (LLVM_INSTALL_PREFIX STREQUAL CMAKE_INSTALL_PREFIX))
+    list(APPEND _install_rpath ${LLVM_LIBRARY_DIR})
+  elseif(LLVM_BUILD_LIBRARY_DIR)
+    list(APPEND _install_rpath ${LLVM_LIBRARY_DIR})
+  endif()
+
   set_target_properties(${name} PROPERTIES
                         BUILD_WITH_INSTALL_RPATH On
                         INSTALL_RPATH "${_install_rpath}"
                         ${_install_name_dir})
 endfunction()
 
 function(setup_dependency_debugging name)
   if(NOT LLVM_DEPENDENCY_DEBUGGING)