[CMake] Add $ORIGIN/../../../../lib to rpath if BUILD_SHARED_LIBS or LLVM_LINK_LLVM_D...

Summary:
lib/python2.7/dist-packages/lldb/_lldb.so is a symlink to lib/liblldb.so,
which depends on lib/libLLVM*.so (-DBUILD_SHARED_LIBS=ON) or lib/libLLVM-10git.so
(-DLLVM_LINK_LLVM_DYLIB=ON). Add an additional rpath `$ORIGIN/../../../../lib` so
that _lldb.so can be loaded from Python.

This fixes an import error from lib/python2.7/dist-packages/lldb/__init__.py

  from . import _lldb
  ImportError: libLLVMAArch64CodeGen.so.10git: cannot open shared object file: No such file or directory

 The following configurations will work:

* -DBUILD_SHARED_LIBS=ON
* -DBUILD_SHARED_LIBS=OFF -DLLVM_LINK_LLVM_DYLIB=ON
* -DBUILD_SHARED_LIBS=OFF -DLLVM_LINK_LLVM_DYLIB=ON -DCLANG_LINK_CLANG_DYLIB=ON
  (-DCLANG_LINK_CLANG_DYLIB=ON depends on -DLLVM_LINK_LLVM_DYLIB=ON)

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D71800

diff --git a/lldb/source/API/CMakeLists.txt b/lldb/source/API/CMakeLists.txt
index d036caf..eea409b 100644 (file)
--- a/lldb/source/API/CMakeLists.txt
+++ b/lldb/source/API/CMakeLists.txt
@@ -111,6 +111,14 @@ add_lldb_library(liblldb SHARED ${option_framework}
   ${option_install_prefix}
 )
 
+# lib/pythonX.Y/dist-packages/lldb/_lldb.so is a symlink to lib/liblldb.so,
+# which depends on lib/libLLVM*.so (BUILD_SHARED_LIBS) or lib/libLLVM-10git.so
+# (LLVM_LINK_LLVM_DYLIB). Add an additional rpath $ORIGIN/../../../../lib so
+# that _lldb.so can be loaded from Python.
+if(LLDB_ENABLE_PYTHON AND (BUILD_SHARED_LIBS OR LLVM_LINK_LLVM_DYLIB) AND UNIX AND NOT APPLE)
+  set_property(TARGET liblldb APPEND PROPERTY INSTALL_RPATH "\$ORIGIN/../../../../lib${LLVM_LIBDIR_SUFFIX}")
+endif()
+
 if (MSVC)
   set_source_files_properties(SBReproducer.cpp PROPERTIES COMPILE_FLAGS /bigobj)
 endif()