[mlir] Don't set RPATH for libMLIR

[makslevental]

By default llvm_add_library calls llvm_setup_rpath, which has the strange effect that even libs inside of install/lib have non-empty self-referential RPATHs; e.g., on Mac

$ llvm-install/lib/libMLIR.dylib | grep RPATH -A4
          cmd LC_RPATH
      cmdsize 32
         path @loader_path/../lib (offset 12)

which is bad/awkward if you want to move libMLIR (like into a wheel...).

Now possibly we want to do this for all shlibs but I think we definitely want to do this for libMLIR because it should have no runtime lib deps.

[llvmbot]

@llvm/pr-subscribers-mlir-core

Author: Maksim Levental (makslevental)

Changes

By default llvm_add_library calls llvm_setup_rpath, which has the strange effect that even libs inside of install/lib have non-empty self-referential RPATHs; e.g., on Mac

$ llvm-install/lib/libMLIR.dylib | grep RPATH -A4
          cmd LC_RPATH
      cmdsize 32
         path @<!-- -->loader_path/../lib (offset 12)

which is bad/awkward if you want to move libMLIR (like into a wheel...).

Now possibly we want to do this for all shlibs but I think we definitely want to do this for libMLIR because it should have no runtime lib deps (at least until this lands).

---

Full diff: https://github.com/llvm/llvm-project/pull/121180.diff

1 Files Affected:

• (modified) mlir/tools/mlir-shlib/CMakeLists.txt (+1)

diff --git a/mlir/tools/mlir-shlib/CMakeLists.txt b/mlir/tools/mlir-shlib/CMakeLists.txt
index a33c70c5807bea..293409a51f27ef 100644
--- a/mlir/tools/mlir-shlib/CMakeLists.txt
+++ b/mlir/tools/mlir-shlib/CMakeLists.txt
@@ -35,6 +35,7 @@ if(LLVM_BUILD_LLVM_DYLIB)
     MLIR
     SHARED
     EXCLUDE_FROM_LIBMLIR
+    NO_INSTALL_RPATH
     ${INSTALL_WITH_TOOLCHAIN}
     mlir-shlib.cpp
     ${_OBJECTS}

[llvmbot]

@llvm/pr-subscribers-mlir

Author: Maksim Levental (makslevental)

Changes

By default llvm_add_library calls llvm_setup_rpath, which has the strange effect that even libs inside of install/lib have non-empty self-referential RPATHs; e.g., on Mac

$ llvm-install/lib/libMLIR.dylib | grep RPATH -A4
          cmd LC_RPATH
      cmdsize 32
         path @<!-- -->loader_path/../lib (offset 12)

which is bad/awkward if you want to move libMLIR (like into a wheel...).

Now possibly we want to do this for all shlibs but I think we definitely want to do this for libMLIR because it should have no runtime lib deps (at least until this lands).

---

Full diff: https://github.com/llvm/llvm-project/pull/121180.diff

1 Files Affected:

• (modified) mlir/tools/mlir-shlib/CMakeLists.txt (+1)

diff --git a/mlir/tools/mlir-shlib/CMakeLists.txt b/mlir/tools/mlir-shlib/CMakeLists.txt
index a33c70c5807bea..293409a51f27ef 100644
--- a/mlir/tools/mlir-shlib/CMakeLists.txt
+++ b/mlir/tools/mlir-shlib/CMakeLists.txt
@@ -35,6 +35,7 @@ if(LLVM_BUILD_LLVM_DYLIB)
     MLIR
     SHARED
     EXCLUDE_FROM_LIBMLIR
+    NO_INSTALL_RPATH
     ${INSTALL_WITH_TOOLCHAIN}
     mlir-shlib.cpp
     ${_OBJECTS}

[makslevental]

ah shoot it libMLIR actually does have a runtime dep on libLLVM

/Users/mlevental/dev_projects/eudsl/llvm-install/lib/libMLIR.dylib:
        @rpath/libMLIR.dylib (compatibility version 0.0.0, current version 0.0.0)
        @rpath/libLLVM.dylib (compatibility version 1.0.0, current version 20.0.0)
        /usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 1800.105.0)
        /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1351.0.0)

[makslevental]

FYI I cooked this up as a workaround:

if(APPLE OR UNIX)
  set(_origin_prefix "\$ORIGIN")
  if(APPLE)
    set(_origin_prefix "@loader_path")
  endif()
  if (STANDALONE_BUILD)
    get_target_property(_mlir_loc MLIR LOCATION)
    get_target_property(_llvm_loc LLVM LOCATION)
  else()
    set(_mlir_loc "$<TARGET_FILE:MLIR>")
    set(_llvm_loc "$<TARGET_FILE:LLVM>")
  endif()
  set(_old_rpath "${_origin_prefix}/../lib${LLVM_LIBDIR_SUFFIX}")
  if(APPLE)
    execute_process(COMMAND install_name_tool -rpath "${_old_rpath}" ${_origin_prefix} "${_mlir_loc}" ERROR_VARIABLE rpath_err)
    execute_process(COMMAND install_name_tool -rpath "${_old_rpath}" ${_origin_prefix} "${_llvm_loc}" ERROR_VARIABLE rpath_err)
    # maybe already updated...
    if (rpath_err AND NOT rpath_err MATCHES "no LC_RPATH load command with path: ${_old_rpath}")
      message(FATAL_ERROR "couldn't update rpath because: ${rpath_err}")
    endif()
  else()
    # sneaky sneaky - undocumented
    file(RPATH_CHANGE FILE "${_mlir_loc}" OLD_RPATH "${_old_rpath}" NEW_RPATH "${_origin_prefix}")
    file(RPATH_CHANGE FILE "${_llvm_loc}" OLD_RPATH "${_old_rpath}" NEW_RPATH "${_origin_prefix}")
  endif()
endif()