Link with libclang-cpp for out-of-tree build

Signed-off-by: Alexey Sotkin <alexey.sotkin@intel.com>

.travis.yml

@@ -30,11 +30,17 @@ addons:
       - llvm-10-tools
       - llvm-10-dev
       - libclang-10-dev
-      - lldb-10
 
 install:
   - wget https://github.com/KhronosGroup/SPIRV-LLVM-Translator/releases/download/dev-build/SPIRV-LLVM-Translator-dev-build-linux-Release.zip -O /tmp/SPIRV-LLVM-Translator-dev-build-linux-${BUILD_TYPE}.zip
   - unzip /tmp/SPIRV-LLVM-Translator-dev-build-linux-${BUILD_TYPE}.zip -d spirv-llvm-translator
+# This is a work-around for a "wrong" dependency between libclang-10-dev and
+# libclang-cpp10-dev packages from apt.llv.org. Normally, we should just
+# install them both, as it is done on the master(ocl-open-110) branch. But for
+# some reason (a bug?) they remove each other when being installed via apt get.
+# Basically, all we need from libclang-cpp10-dev is the symlink below. Without
+# this symlink linker can't find libclang-cpp.so.10.
+  - sudo ln -s ${TRAVIS_ROOT}/usr/lib/llvm-10/lib/libclang-cpp.so.10 ${TRAVIS_ROOT}/usr/lib/llvm-10/lib/libclang-cpp.so
 
 compiler:
   - gcc

CMakeLists.txt

@@ -119,7 +119,7 @@ if(NOT USE_PREBUILT_LLVM)
 
     set(CLANG_BASE_REVISION master)
     set(SPIRV_BASE_REVISION master)
-    set(TARGET_BRANCH "ocl-open-90")
+    set(TARGET_BRANCH "ocl-open-100")
 
     apply_patches(${CLANG_SOURCE_DIR}
                   ${CMAKE_CURRENT_SOURCE_DIR}/patches/clang
@@ -206,27 +206,22 @@ link_directories(
     ${LLVM_LIBRARY_DIRS}
 )
 
-set(ADDITIONAL_LIBS ${CMAKE_DL_LIBS})
+set(OPENCL_CLANG_LINK_LIBS ${CMAKE_DL_LIBS})
 
 if(NOT LLVMSPIRVLib IN_LIST LLVM_AVAILABLE_LIBS)
   # SPIRV-LLVM-Translator is not included into LLVM as a component.
   # So, we need to list it here explicitly as an external library
-  list(APPEND ADDITIONAL_LIBS LLVMSPIRVLib)
+  list(APPEND OPENCL_CLANG_LINK_LIBS LLVMSPIRVLib)
 endif()
 
 add_subdirectory(cl_headers)
 
 set(LLVM_REQUIRES_EH ON)
 
-add_llvm_library(${TARGET_NAME} SHARED
-  ${TARGET_INCLUDE_FILES}
-  ${TARGET_SOURCE_FILES}
-  $<TARGET_OBJECTS:cl_headers>
-
-  DEPENDS CClangCompileOptions
-  LINK_COMPONENTS
-    all
-  LINK_LIBS
+if(USE_PREBUILT_LLVM OR CLANG_LINK_CLANG_DYLIB)
+  list(APPEND OPENCL_CLANG_LINK_LIBS clang-cpp)
+else()
+  list(APPEND OPENCL_CLANG_LINK_LIBS
 # The list of clang libraries is taken from clang makefile
 # (build/tools/clang/tools/driver/CMakeFiles/clang.dir/link.txt)
 # All duplicate libraries are there on purpose
@@ -258,7 +253,19 @@ add_llvm_library(${TARGET_NAME} SHARED
     clangAST
     clangLex
     clangBasic
-    ${ADDITIONAL_LIBS}
+  )
+endif()
+
+add_llvm_library(${TARGET_NAME} SHARED
+  ${TARGET_INCLUDE_FILES}
+  ${TARGET_SOURCE_FILES}
+  $<TARGET_OBJECTS:cl_headers>
+
+  DEPENDS CClangCompileOptions
+  LINK_COMPONENTS
+    all
+  LINK_LIBS
+    ${OPENCL_CLANG_LINK_LIBS}
   )
 
 # Configure resource file on Windows