[CMake] Re: RPATH and $ORIGIN

[Iker Arizmendi]

I did try $$ and it helps, but not always (see the end of
the original post). The problem is that $ symbols that are
part of the _value_ of the CMake *_LINKER_FLAGS variables
are treated using rules that aren't clear at all (at least
to me). On my system, a single $ is all that's needed for
shared library linker flags but $$ is required for exe
linker flags. But on another system the situation is the
opposite (shared libs get $$, exes get $).

For the time being, I'm using the macro below to paper over
the differences (on Linux, at least).

Iker

# =========================================================
MACRO (APPEND_CMAKE_INSTALL_RPATH RPATH_DIRS)
   IF (NOT ${ARGC} EQUAL 1)
     MESSAGE(SEND_ERROR "APPEND_CMAKE_INSTALL_RPATH takes 1 argument")
   ENDIF (NOT ${ARGC} EQUAL 1)
   FOREACH ( RPATH_DIR ${RPATH_DIRS} )
     IF ( NOT ${RPATH_DIR} STREQUAL "" )
        FILE( TO_CMAKE_PATH ${RPATH_DIR} RPATH_DIR )
        STRING( SUBSTRING ${RPATH_DIR} 0 1 RPATH_FIRST_CHAR )
        IF ( NOT ${RPATH_FIRST_CHAR} STREQUAL "/" )
          # relative path; CMake handling for these is unclear,
          # add them directly to the linker line. Add both $ORIGIN
          # and $$ORIGIN to ensure correct behavior for exes and
          # shared libraries.
          SET ( RPATH_DIR "$ORIGIN/${RPATH_DIR}:$$ORIGIN/${RPATH_DIR}" )
          SET ( CMAKE_EXE_LINKER_FLAGS
                "${CMAKE_EXE_LINKER_FLAGS} -Wl,-rpath,'${RPATH_DIR}'" )
          SET ( CMAKE_SHARED_LINKER_FLAGS
                "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-rpath,'${RPATH_DIR}'" )
        ELSE ( NOT ${RPATH_FIRST_CHAR} STREQUAL "/" )
          # absolute path
          SET ( CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_RPATH}:${RPATH_DIR}" )
        ENDIF ( NOT ${RPATH_FIRST_CHAR} STREQUAL "/" )
     ENDIF ( NOT ${RPATH_DIR} STREQUAL "" )
   ENDFOREACH ( RPATH_DIR )
ENDMACRO ( APPEND_CMAKE_INSTALL_RPATH )

The macro takes a list of paths and can be used like this:

    APPEND_CMAKE_INSTALL_RPATH(".;../../;/usr/local/lib")

 > Oh, sorry.  Rereading your mail message more closely, you want a "$"
 > character to pass through properly.
 >
 > Did you try "$$" in the original code (not the one with the single quotes)?
 >
 >     SET(CMAKE_INSTALL_RPATH
 >        "${CMAKE_INSTALL_RPATH}:$$ORIGIN/../xxx")
 >
 > Or perhaps other stuff like on this recent wiki addition?
 >
 > http://www.cmake.org/Wiki/CMake:VariablesListsStrings#Escaping
 >
 > There was a recent thread called "how to escape the $ dollar sign?"
 >
 > James


-- 
Iker Arizmendi
AT&T Labs - Research
Speech and Image Processing Lab
e: iker at research.att.com
w: http://research.att.com
p: 973-360-8516