Build LLVM at CMake configure time and use CMake config file. (#4144)

* Build LLVM at CMake config time and use CMake config file for dependencies.

* Temp save.

* Codegen functioning.

* Support prebuilt LLVM.

* Remove zlib.

* Relax CMake minimum version.

* Fix bug.

* Lower CMake version requirement.

* Pass more args.

* Add proper quote.

* Remove quotes.

* Try to separate flags for external projects.

* Don't pass flags to LLVM.

* Pass CXX abi.

* Remove stale print.

* Update gtest flags.

* Try to fix build issue.

* Patch LLVM to prevent building clang-tools-extra.
Co-authored-by: aslepko <44713115+aslepko@users.noreply.github.com>

CMakeLists.txt

@@ -110,54 +110,6 @@ if (APPLE)
     endif()
 endif()
 
-if (NGRAPH_MLIR_ENABLE)
-    #MLIR uses the latest version of LLVM which requires C++14.
-    set(NGRAPH_CXX_STANDARD 14)
-else()
-    set(NGRAPH_CXX_STANDARD 11)
-endif()
-set(CMAKE_CXX_STANDARD ${NGRAPH_CXX_STANDARD})
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
-set(CMAKE_CXX_EXTENSIONS OFF)
-
-# Create compilation database compile_commands.json
-set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
-
-set(CMAKE_POSITION_INDEPENDENT_CODE ON)
-
-# Setup CMAKE_ARGS to be forwarded to External Projects
-set(NGRAPH_FORWARD_CMAKE_ARGS
-    -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
-    -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
-    -DCMAKE_CXX_STANDARD:STRING=${CMAKE_CXX_STANDARD}
-    -DCMAKE_CXX_STANDARD_REQUIRED:BOOL=${CMAKE_CXX_STANDARD_REQUIRED}
-    -DCMAKE_CXX_EXTENSIONS:BOOL=${CMAKE_CXX_EXTENSIONS}
-    -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=${CMAKE_EXPORT_COMPILE_COMMANDS}
-    -DCMAKE_POSITION_INDEPENDENT_CODE:BOOL=${CMAKE_POSITION_INDEPENDENT_CODE}
-    )
-
-if (CMAKE_OSX_SYSROOT)
-    set(NGRAPH_FORWARD_CMAKE_ARGS
-            ${NGRAPH_FORWARD_CMAKE_ARGS}
-            -DCMAKE_OSX_SYSROOT=${CMAKE_OSX_SYSROOT}
-            )
-endif()
-
-if (NOT MSVC)
-    if(NOT CMAKE_BUILD_TYPE)
-        set(CMAKE_BUILD_TYPE "Release" CACHE STRING "Build type" FORCE)
-    endif()
-
-    set(NGRAPH_FORWARD_CMAKE_ARGS
-            ${NGRAPH_FORWARD_CMAKE_ARGS}
-            -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
-            )
-endif()
-message(STATUS "NGRAPH_FORWARD_CMAKE_ARGS ${NGRAPH_FORWARD_CMAKE_ARGS}")
-
-# Prevent Eigen from using any LGPL3 code
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DEIGEN_MPL2_ONLY -DTBB_USE_THREADING_TOOLS")
-
 ngraph_var(NGRAPH_USE_PREBUILT_MLIR DEFAULT "FALSE")
 ngraph_var(NGRAPH_USE_PREBUILT_LLVM DEFAULT "FALSE")
 
@@ -276,7 +228,6 @@ if (NGRAPH_CPU_ENABLE)
     NORMALIZE_BOOL(NGRAPH_TBB_ENABLE)
 endif()
 
-message(STATUS "NGRAPH_CXX_STANDARD:                  ${NGRAPH_CXX_STANDARD}")
 message(STATUS "NGRAPH_UNIT_TEST_ENABLE:              ${NGRAPH_UNIT_TEST_ENABLE}")
 message(STATUS "NGRAPH_DOC_BUILD_ENABLE:              ${NGRAPH_DOC_BUILD_ENABLE}")
 message(STATUS "NGRAPH_TOOLS_ENABLE:                  ${NGRAPH_TOOLS_ENABLE}")
@@ -317,6 +268,51 @@ if("${CMAKE_GENERATOR}" STREQUAL "Ninja" AND (NGRAPH_TOOLS_ENABLE OR NGRAPH_CPU_
     message(FATAL_ERROR "Ninja generator not supported.")
 endif()
 
+if (NGRAPH_CPU_ENABLE AND NGRAPH_MLIR_ENABLE)
+    #MLIR uses the latest version of LLVM which requires C++14.
+    set(NGRAPH_CXX_STANDARD 14)
+else()
+    set(NGRAPH_CXX_STANDARD 11)
+endif()
+set(CMAKE_CXX_STANDARD ${NGRAPH_CXX_STANDARD})
+message(STATUS "NGRAPH_CXX_STANDARD:                  ${NGRAPH_CXX_STANDARD}")
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+
+# Create compilation database compile_commands.json
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+
+# Setup CMAKE_ARGS to be forwarded to External Projects
+set(NGRAPH_FORWARD_CMAKE_ARGS
+    -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
+    -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
+    -DCMAKE_CXX_STANDARD:STRING=${CMAKE_CXX_STANDARD}
+    -DCMAKE_CXX_STANDARD_REQUIRED:BOOL=${CMAKE_CXX_STANDARD_REQUIRED}
+    -DCMAKE_CXX_EXTENSIONS:BOOL=${CMAKE_CXX_EXTENSIONS}
+    -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=${CMAKE_EXPORT_COMPILE_COMMANDS}
+    -DCMAKE_POSITION_INDEPENDENT_CODE:BOOL=${CMAKE_POSITION_INDEPENDENT_CODE}
+    )
+
+if (CMAKE_OSX_SYSROOT)
+    set(NGRAPH_FORWARD_CMAKE_ARGS
+            ${NGRAPH_FORWARD_CMAKE_ARGS}
+            -DCMAKE_OSX_SYSROOT=${CMAKE_OSX_SYSROOT}
+            )
+endif()
+
+if (NOT MSVC)
+    if(NOT CMAKE_BUILD_TYPE)
+        set(CMAKE_BUILD_TYPE "Release" CACHE STRING "Build type" FORCE)
+    endif()
+
+    set(NGRAPH_FORWARD_CMAKE_ARGS
+            ${NGRAPH_FORWARD_CMAKE_ARGS}
+            -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
+            )
+endif()
+message(STATUS "NGRAPH_FORWARD_CMAKE_ARGS ${NGRAPH_FORWARD_CMAKE_ARGS}")
 
 #-----------------------------------------------------------------------------------------------
 # Installation logic...
@@ -352,17 +348,41 @@ if (LINUX)
 endif()
 
 #-----------------------------------------------------------------------------------------------
-# Compiler-specific logic...
+# Compile Flags to pass to external projects...
 #-----------------------------------------------------------------------------------------------
 
-# Compiler-specific logic...
-if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "^(Apple)?Clang$" AND NOT NGRAPH_BUILD_DIR)
-    message( STATUS "Setting clang flags...")
-    include( cmake/clang_4_0_flags.cmake )
+include(cmake/sdl.cmake)
+
+if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+    if (DEFINED NGRAPH_USE_CXX_ABI)
+        message( STATUS "nGraph using CXX11 ABI: " ${NGRAPH_USE_CXX_ABI} )
+        list(APPEND NGRAPH_COMMON_FLAGS -D_GLIBCXX_USE_CXX11_ABI=${NGRAPH_USE_CXX_ABI})
+    endif()
 endif()
 
+string(REPLACE " " ";" NGRAPH_CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
+string(REPLACE " " ";" NGRAPH_CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
+list(APPEND NGRAPH_COMMON_CXX_FLAGS ${NGRAPH_CMAKE_CXX_FLAGS} ${NGRAPH_COMMON_FLAGS})
+list(APPEND NGRAPH_COMMON_C_FLAGS ${NGRAPH_CMAKE_C_FLAGS} ${NGRAPH_COMMON_FLAGS})
+message(STATUS "NGRAPH_COMMON_CXX_FLAGS ${NGRAPH_COMMON_CXX_FLAGS}")
+message(STATUS "NGRAPH_COMMON_C_FLAGS ${NGRAPH_COMMON_C_FLAGS}")
+
+# Set baseline flags for nGraph source files
+string(REPLACE ";" " " CMAKE_ORIGINAL_CXX_FLAGS "${NGRAPH_COMMON_CXX_FLAGS}")
+
+#-----------------------------------------------------------------------------------------------
+# Compile Flags for nGraph...
+#-----------------------------------------------------------------------------------------------
+
+# Prevent Eigen from using any LGPL3 code
+set(CMAKE_CXX_FLAGS "${CMAKE_ORIGINAL_CXX_FLAGS} -DEIGEN_MPL2_ONLY -DTBB_USE_THREADING_TOOLS")
+
 if (WIN32)
     string(REPLACE "/W3" "/W0" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
+endif()
+
+# Compiler-specific logic...
+if (WIN32)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /EHsc /MP")
 
     if (CMAKE_CXX_COMPILER_ID MATCHES MSVC)
@@ -380,17 +400,11 @@ else()
     # set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility-inlines-hidden")
 endif()
 
-include(cmake/sdl.cmake)
-
-if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-    if (DEFINED NGRAPH_USE_CXX_ABI)
-        message( STATUS "nGraph using CXX11 ABI: " ${NGRAPH_USE_CXX_ABI} )
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D_GLIBCXX_USE_CXX11_ABI=${NGRAPH_USE_CXX_ABI}")
-    endif()
+if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "^(Apple)?Clang$" AND NOT NGRAPH_BUILD_DIR)
+    message( STATUS "Setting clang flags...")
+    include( cmake/clang_4_0_flags.cmake )
 endif()
 
-set(CMAKE_ORIGINAL_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-
 ngraph_var(NGRAPH_WARNINGS_AS_ERRORS DEFAULT "OFF")
 if (${NGRAPH_WARNINGS_AS_ERRORS})
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror")
@@ -607,9 +621,7 @@ else()
 endif()
 
 if(NGRAPH_CODEGEN_ENABLE)
-    if (NGRAPH_USE_PREBUILT_LLVM OR DEFINED LLVM_TARBALL_URL)
-        include(cmake/external_llvm_prebuilt.cmake)
-    elseif (NOT MSVC)
+    if (NOT MSVC)
         include(cmake/external_llvm.cmake)
     else()
         message(FATAL_ERROR "CODEGEN is not supported on Windows!")

cmake/clang_4_0_flags.cmake

@@ -14,31 +14,31 @@
 # limitations under the License.
 # ******************************************************************************
 
-add_compile_options(-Werror=return-type)
-add_compile_options(-Werror=inconsistent-missing-override)
-add_compile_options(-Werror=comment)
-add_compile_options(-pedantic-errors)
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror=return-type")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror=inconsistent-missing-override")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror=comment")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -pedantic-errors")
+#set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Weverything")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall")
 
 # whitelist errors here
-#add_compile_options(-Weverything)
-add_compile_options(-Wall)
-# add_compile_options(-Wno-gnu-zero-variadic-macro-arguments)
-#add_compile_options(-Wno-c++98-compat-pedantic)
-#add_compile_options(-Wno-weak-vtables)
-#add_compile_options(-Wno-global-constructors)
-#add_compile_options(-Wno-exit-time-destructors)
-#add_compile_options(-Wno-missing-prototypes)
-#add_compile_options(-Wno-missing-noreturn)
-#add_compile_options(-Wno-covered-switch-default)
-#add_compile_options(-Wno-undef)
+#set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-gnu-zero-variadic-macro-arguments")
+#set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-c++98-compat-pedantic")
+#set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-weak-vtables")
+#set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-global-constructors")
+#set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-exit-time-destructors")
+#set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-missing-prototypes")
+#set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-missing-noreturn")
+#set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-covered-switch-default")
+#set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-undef")
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "AppleClang")
     if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 9.1.0)
-        #add_compile_options(-Wno-zero-as-null-pointer-constant)
+        #set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-zero-as-null-pointer-constant")
     endif()
 endif()
 
 # should remove these
-add_compile_options(-Wno-float-conversion)
-add_compile_options(-Wno-padded)
-add_compile_options(-Wno-conversion)
-add_compile_options(-Wno-undefined-func-template)
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-float-conversion")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-padded")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-conversion")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-undefined-func-template")

cmake/external_gtest.cmake

@@ -44,9 +44,9 @@ endif()
 if(UNIX)
     # workaround for compile error
     # related: https://github.com/intel/mkl-dnn/issues/55
-    set(GTEST_CXX_FLAGS "-Wno-unused-result ${CMAKE_CXX_FLAGS} -Wno-undef")
+    set(GTEST_CXX_FLAGS "-Wno-unused-result ${CMAKE_ORIGINAL_CXX_FLAGS} -Wno-undef")
 else()
-    set(GTEST_CXX_FLAGS ${CMAKE_CXX_FLAGS})
+    set(GTEST_CXX_FLAGS ${CMAKE_ORIGINAL_CXX_FLAGS})
 endif()
 
 #Build for ninja

cmake/external_llvm.cmake

@@ -14,173 +14,32 @@
 # limitations under the License.
 # ******************************************************************************
 
-include(ExternalProject)
+set(LLVM_PROJECT_ROOT ${EXTERNAL_PROJECTS_ROOT}/llvm-project)
+set(LLVM_INSTALL_ROOT ${EXTERNAL_PROJECTS_ROOT}/llvm)
 
-set(NGRAPH_LLVM_VERSION 8.0.0)
+configure_file(${CMAKE_SOURCE_DIR}/cmake/llvm_fetch.cmake.in ${LLVM_PROJECT_ROOT}/CMakeLists.txt @ONLY)
 
-ExternalProject_Add(
-    ext_clang
-    PREFIX clang
-    URL http://releases.llvm.org/${NGRAPH_LLVM_VERSION}/cfe-${NGRAPH_LLVM_VERSION}.src.tar.xz
-    URL_HASH SHA1=3cb1e10af3955174a3ca5e560f674f24fac2a02f
-    CONFIGURE_COMMAND ""
-    BUILD_COMMAND ""
-    INSTALL_COMMAND ""
-    UPDATE_COMMAND ""
-    EXCLUDE_FROM_ALL TRUE
-)
+execute_process(COMMAND "${CMAKE_COMMAND}" -G "${CMAKE_GENERATOR}" -DCMAKE_CXX_FLAGS:STRING=${CMAKE_ORIGINAL_CXX_FLAGS} .
+    WORKING_DIRECTORY "${LLVM_PROJECT_ROOT}")
 
-ExternalProject_Get_Property(ext_clang SOURCE_DIR)
-set(CLANG_SOURCE_DIR ${SOURCE_DIR})
-
-ExternalProject_Add(
-    ext_openmp
-    PREFIX openmp
-    URL http://releases.llvm.org/${NGRAPH_LLVM_VERSION}/openmp-${NGRAPH_LLVM_VERSION}.src.tar.xz
-    URL_HASH SHA1=90462a0f720a9a40ecbda9636c24d627b5dc05db
-    CONFIGURE_COMMAND ""
-    BUILD_COMMAND ""
-    INSTALL_COMMAND ""
-    UPDATE_COMMAND ""
-    EXCLUDE_FROM_ALL TRUE
-)
-
-ExternalProject_Get_Property(ext_openmp SOURCE_DIR)
-set(OPENMP_SOURCE_DIR ${SOURCE_DIR})
-
-if(DEFINED CMAKE_ASM_COMPILER)
-    set(LLVM_CMAKE_ASM_COMPILER ${CMAKE_ASM_COMPILER})
-else()
-    set(LLVM_CMAKE_ASM_COMPILER ${CMAKE_C_COMPILER})
-endif()
-
-if(WIN32)
-    set(LLVM_DEPENDS ext_clang)
+# clone and build llvm
+include(ProcessorCount)
+ProcessorCount(N)
+if(("${CMAKE_GENERATOR}" STREQUAL "Unix Makefiles") AND (NOT N EQUAL 0))
+    execute_process(COMMAND "${CMAKE_COMMAND}" --build . --target ext_llvm -- -j${N}
+        WORKING_DIRECTORY "${LLVM_PROJECT_ROOT}")
 else()
-    set(LLVM_DEPENDS ext_clang ext_openmp)
-    set(PASS_LLVM_OPENMP_DIR -DLLVM_EXTERNAL_OPENMP_SOURCE_DIR=${OPENMP_SOURCE_DIR})
+    execute_process(COMMAND "${CMAKE_COMMAND}" --build . --target ext_llvm
+        WORKING_DIRECTORY "${LLVM_PROJECT_ROOT}")
 endif()
 
-ExternalProject_Add(
-    ext_llvm
-    PREFIX llvm
-    DEPENDS ${LLVM_DEPENDS}
-    URL http://releases.llvm.org/${NGRAPH_LLVM_VERSION}/llvm-${NGRAPH_LLVM_VERSION}.src.tar.xz
-    URL_HASH SHA1=0689345d73911e24a07b24cc82dab4fb46b8c323
-    CMAKE_GENERATOR ${CMAKE_GENERATOR}
-    CMAKE_GENERATOR_PLATFORM ${CMAKE_GENERATOR_PLATFORM}
-    CMAKE_GENERATOR_TOOLSET ${CMAKE_GENERATOR_TOOLSET}
-    CMAKE_ARGS ${NGRAPH_FORWARD_CMAKE_ARGS}
-                -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
-                -DCMAKE_ASM_COMPILER=${LLVM_CMAKE_ASM_COMPILER}
-                -DCMAKE_INSTALL_PREFIX=${EXTERNAL_PROJECTS_ROOT}/llvm
-                -DLLVM_INCLUDE_DOCS=OFF
-                -DLLVM_INCLUDE_TESTS=OFF
-                -DLLVM_INCLUDE_GO_TESTS=OFF
-                -DLLVM_INCLUDE_EXAMPLES=OFF
-                -DLLVM_INCLUDE_BENCHMARKS=OFF
-                -DLLVM_BUILD_TOOLS=OFF
-                -DLLVM_BUILD_UTILS=OFF
-                -DLLVM_BUILD_RUNTIMES=OFF
-                -DLLVM_BUILD_RUNTIME=OFF
-                -DLLVM_TARGETS_TO_BUILD=X86
-                -DLLVM_ENABLE_BINDINGS=OFF
-                -DLLVM_ENABLE_TERMINFO=OFF
-                -DLLVM_ENABLE_ZLIB=OFF
-                -DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN=ON
-                -DLIBOMP_OMPT_SUPPORT=OFF
-                -DCLANG_BUILD_TOOLS=OFF
-                -DCLANG_ENABLE_ARCMT=OFF
-                -DCLANG_ANALYZER_ENABLE_Z3_SOLVER=OFF
-                -DCLANG_ENABLE_STATIC_ANALYZER=OFF
-                -DLLVM_EXTERNAL_CLANG_SOURCE_DIR=${CLANG_SOURCE_DIR}
-                ${PASS_LLVM_OPENMP_DIR}
-    UPDATE_COMMAND ""
-    EXCLUDE_FROM_ALL TRUE
-)
-
-ExternalProject_Get_Property(ext_llvm INSTALL_DIR)
-
-set(LLVM_LINK_LIBS
-    # Do not change order of libraries !!!
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangTooling${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangCodeGen${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangFrontendTool${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangFrontend${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangDriver${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangSerialization${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangParse${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangSema${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangCrossTU${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangAnalysis${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangRewriteFrontend${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangEdit${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangAST${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangLex${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangBasic${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMLTO${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMPasses${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMObjCARCOpts${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMSymbolize${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMDebugInfoPDB${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMDebugInfoDWARF${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMMIRParser${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMCoverage${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMTableGen${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMDlltoolDriver${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMOrcJIT${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMObjectYAML${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMLibDriver${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMOption${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMX86Disassembler${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMX86AsmParser${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMX86CodeGen${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMGlobalISel${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMSelectionDAG${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMAsmPrinter${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMDebugInfoCodeView${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMDebugInfoMSF${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMX86Desc${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMMCDisassembler${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMX86Info${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMX86AsmPrinter${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMX86Utils${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMMCJIT${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMLineEditor${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMInterpreter${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMExecutionEngine${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMRuntimeDyld${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMCodeGen${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMTarget${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMCoroutines${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMipo${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMAggressiveInstCombine${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMInstrumentation${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMVectorize${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMScalarOpts${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMLinker${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMIRReader${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMAsmParser${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMInstCombine${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMTransformUtils${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMBitWriter${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMAnalysis${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMProfileData${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMObject${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMMCParser${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMMC${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMBitReader${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMCore${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMBinaryFormat${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMSupport${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMDemangle${CMAKE_STATIC_LIBRARY_SUFFIX}
-)
-
-if(LINUX OR APPLE)
-    set(LLVM_LINK_LIBS ${LLVM_LINK_LIBS} m)
-endif()
+message(STATUS "LLVM_INSTALL_ROOT: ${LLVM_INSTALL_ROOT}")
+find_package(Clang REQUIRED CONFIG
+    HINTS ${LLVM_INSTALL_ROOT}/lib/cmake/clang NO_DEFAULT_PATH)
+message(STATUS "CLANG_CMAKE_DIR: ${CLANG_CMAKE_DIR}")
+message(STATUS "CLANG_INCLUDE_DIRS: ${CLANG_INCLUDE_DIRS}")
+message(STATUS "LLVM_INCLUDE_DIRS: ${LLVM_INCLUDE_DIRS}")
 
 add_library(libllvm INTERFACE)
-add_dependencies(libllvm ext_llvm)
-target_include_directories(libllvm SYSTEM INTERFACE ${INSTALL_DIR}/include)
-target_link_libraries(libllvm INTERFACE ${LLVM_LINK_LIBS})
+target_include_directories(libllvm INTERFACE ${CLANG_INCLUDE_DIRS} ${LLVM_INCLUDE_DIR})
+target_link_libraries(libllvm INTERFACE clangHandleCXX clangHandleLLVM)

cmake/external_llvm_prebuilt.cmake

-# ******************************************************************************
-# Copyright 2017-2020 Intel Corporation
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-# ******************************************************************************
-
-include(ExternalProject)
-
-find_package(ZLIB REQUIRED)
-
-# Override default LLVM binaries
-if(NOT DEFINED LLVM_TARBALL_URL)
-    if(APPLE)
-        set(NGRAPH_LLVM_VERSION 8.0.0)
-        set(LLVM_TARBALL_URL http://releases.llvm.org/${NGRAPH_LLVM_VERSION}/clang+llvm-${NGRAPH_LLVM_VERSION}-x86_64-apple-darwin.tar.xz)
-        set(LLVM_SHA1_HASH a5674f2ce5b9ed1b67d92689d319ed3b46d66e29)
-    elseif(LINUX)
-        set(NGRAPH_LLVM_VERSION 8.0.0)
-        if(EXISTS /etc/lsb-release)
-            execute_process(COMMAND grep DISTRIB_RELEASE /etc/lsb-release OUTPUT_VARIABLE UBUNTU_VER_LINE)
-            string(REGEX MATCH "[0-9.]+" UBUNTU_VER ${UBUNTU_VER_LINE})
-            message(STATUS "Ubuntu version: ${UBUNTU_VER} detected.")
-            set(LLVM_TARBALL_URL http://releases.llvm.org/${NGRAPH_LLVM_VERSION}/clang+llvm-${NGRAPH_LLVM_VERSION}-x86_64-linux-gnu-ubuntu-${UBUNTU_VER}.tar.xz)
-            if(UBUNTU_VER MATCHES "14.04")
-                set(LLVM_SHA1_HASH 552ea458b70961b7922a4bbe9de1434688342dbf)
-            elseif(UBUNTU_VER MATCHES "16.04")
-                set(LLVM_SHA1_HASH 2be69be355b012ae206dbc0ea7d84b831d77dc27)
-            elseif(UBUNTU_VER MATCHES "18.04")
-                set(LLVM_SHA1_HASH 6aeb8aa0998d37be67d886b878f27de5e5ccc5e4)
-            else()
-                message(FATAL_ERROR "No prebuilt LLVM available for Ubuntu ${UBUNTU_VER} on llvm.org, please set LLVM_TARBALL_URL manually.")
-            endif()
-        else()
-            message(FATAL_ERROR "Prebuilt LLVM: Only Ubuntu Linux is supported.")
-        endif()
-    else()
-        message(FATAL_ERROR "Prebuilt LLVM: unsupported OS.")
-    endif()
-else()
-    if(NOT DEFINED LLVM_SHA1_HASH)
-        message(FATAL_ERROR "Prebuilt LLVM: please provide LLVM_SHA_HASH.")
-    endif()
-endif()
-
-ExternalProject_Add(
-    ext_llvm
-    PREFIX llvm
-    URL ${LLVM_TARBALL_URL}
-    URL_HASH SHA1=${LLVM_SHA1_HASH}
-    CONFIGURE_COMMAND ""
-    BUILD_COMMAND ""
-    INSTALL_COMMAND ""
-    UPDATE_COMMAND ""
-    DOWNLOAD_NO_PROGRESS TRUE
-    EXCLUDE_FROM_ALL TRUE
-    )
-
-ExternalProject_Get_Property(ext_llvm SOURCE_DIR)
-set(INSTALL_DIR ${SOURCE_DIR})
-
-set(LLVM_LINK_LIBS
-    # Do not change order of libraries !!!
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangTooling${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangCodeGen${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangFrontendTool${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangFrontend${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangDriver${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangSerialization${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangParse${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangSema${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangCrossTU${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangAnalysis${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangRewriteFrontend${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangEdit${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangAST${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangLex${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}clangBasic${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMLTO${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMPasses${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMObjCARCOpts${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMSymbolize${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMDebugInfoPDB${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMDebugInfoDWARF${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMMIRParser${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMCoverage${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMTableGen${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMDlltoolDriver${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMOrcJIT${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMObjectYAML${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMLibDriver${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMOption${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMX86Disassembler${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMX86AsmParser${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMX86CodeGen${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMGlobalISel${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMSelectionDAG${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMAsmPrinter${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMDebugInfoCodeView${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMDebugInfoMSF${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMX86Desc${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMMCDisassembler${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMX86Info${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMX86AsmPrinter${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMX86Utils${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMMCJIT${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMLineEditor${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMInterpreter${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMExecutionEngine${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMRuntimeDyld${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMCodeGen${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMTarget${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMCoroutines${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMipo${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMAggressiveInstCombine${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMInstrumentation${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMVectorize${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMScalarOpts${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMLinker${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMIRReader${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMAsmParser${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMInstCombine${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMTransformUtils${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMBitWriter${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMAnalysis${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMProfileData${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMObject${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMMCParser${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMMC${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMBitReader${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMCore${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMBinaryFormat${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMSupport${CMAKE_STATIC_LIBRARY_SUFFIX}
-    ${INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}LLVMDemangle${CMAKE_STATIC_LIBRARY_SUFFIX}
-)
-
-if(APPLE)
-    set(LLVM_LINK_LIBS ${LLVM_LINK_LIBS} curses z m)
-else()
-    set(LLVM_LINK_LIBS ${LLVM_LINK_LIBS} tinfo z m)
-endif()
-
-add_library(libllvm INTERFACE)
-add_dependencies(libllvm ext_llvm)
-target_include_directories(libllvm SYSTEM INTERFACE ${INSTALL_DIR}/include)
-target_link_libraries(libllvm INTERFACE ${LLVM_LINK_LIBS})

cmake/llvm.patch

+diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
+index 27754f3394..6ca3882728 100644
+--- a/llvm/CMakeLists.txt
++++ b/llvm/CMakeLists.txt
+@@ -118,12 +118,6 @@ foreach(proj ${LLVM_ENABLE_PROJECTS})
+   string(TOUPPER "${proj}" upper_proj)
+   STRING(REGEX REPLACE "-" "_" upper_proj ${upper_proj})
+   set(LLVM_EXTERNAL_${upper_proj}_SOURCE_DIR   "${CMAKE_CURRENT_SOURCE_DIR}/../${proj}")
+-  # There is a widely spread opinion that clang-tools-extra should be merged
+-  # into clang. The following simulates it by always enabling clang-tools-extra
+-  # when enabling clang.
+-  if (proj STREQUAL "clang")
+-    set(LLVM_EXTERNAL_CLANG_TOOLS_EXTRA_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../clang-tools-extra")
+-  endif()
+ endforeach()
+ 
+ # Build llvm with ccache if the package is present

cmake/llvm_fetch.cmake.in

+# ******************************************************************************
+# Copyright 2017-2020 Intel Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ******************************************************************************
+
+cmake_minimum_required(VERSION 3.4.3)
+
+include(ExternalProject)
+
+project(llvm NONE)
+
+set(NGRAPH_USE_PREBUILT_LLVM @NGRAPH_USE_PREBUILT_LLVM@)
+set(LLVM_TARBALL_URL @LLVM_TARBALL_URL@)
+set(LLVM_SHA1_HASH @LLVM_SHA1_HASH@)
+
+if(NGRAPH_USE_PREBUILT_LLVM)
+    message(STATUS "LLVM: Using prebuilt LLVM")
+    # Override default LLVM binaries
+    if(NOT DEFINED LLVM_TARBALL_URL)
+        if(APPLE)
+            set(NGRAPH_LLVM_VERSION 8.0.0)
+            set(LLVM_TARBALL_URL http://releases.llvm.org/${NGRAPH_LLVM_VERSION}/clang+llvm-${NGRAPH_LLVM_VERSION}-x86_64-apple-darwin.tar.xz)
+            set(LLVM_SHA1_HASH a5674f2ce5b9ed1b67d92689d319ed3b46d66e29)
+        elseif(UNIX AND NOT APPLE)
+            set(NGRAPH_LLVM_VERSION 8.0.0)
+            if(EXISTS /etc/lsb-release)
+                execute_process(COMMAND grep DISTRIB_RELEASE /etc/lsb-release OUTPUT_VARIABLE UBUNTU_VER_LINE)
+                string(REGEX MATCH "[0-9.]+" UBUNTU_VER ${UBUNTU_VER_LINE})
+                message(STATUS "Ubuntu version: ${UBUNTU_VER} detected.")
+                set(LLVM_TARBALL_URL http://releases.llvm.org/${NGRAPH_LLVM_VERSION}/clang+llvm-${NGRAPH_LLVM_VERSION}-x86_64-linux-gnu-ubuntu-${UBUNTU_VER}.tar.xz)
+                if(UBUNTU_VER MATCHES "14.04")
+                    set(LLVM_SHA1_HASH 552ea458b70961b7922a4bbe9de1434688342dbf)
+                elseif(UBUNTU_VER MATCHES "16.04")
+                    set(LLVM_SHA1_HASH 2be69be355b012ae206dbc0ea7d84b831d77dc27)
+                elseif(UBUNTU_VER MATCHES "18.04")
+                    set(LLVM_SHA1_HASH 6aeb8aa0998d37be67d886b878f27de5e5ccc5e4)
+                else()
+                    message(FATAL_ERROR "No prebuilt LLVM available for Ubuntu ${UBUNTU_VER} on llvm.org, please set LLVM_TARBALL_URL manually.")
+                endif()
+            else()
+                message(FATAL_ERROR "Prebuilt LLVM: Only Ubuntu Linux is supported.")
+            endif()
+        else()
+            message(FATAL_ERROR "Prebuilt LLVM: unsupported OS.")
+        endif()
+    else()
+        if(NOT DEFINED LLVM_SHA1_HASH)
+            message(FATAL_ERROR "Prebuilt LLVM: please provide LLVM_SHA_HASH.")
+        endif()
+    endif()
+
+    ExternalProject_Add(
+        ext_llvm
+        PREFIX llvm
+        URL ${LLVM_TARBALL_URL}
+        URL_HASH SHA1=${LLVM_SHA1_HASH}
+        CONFIGURE_COMMAND ""
+        BUILD_COMMAND ""
+        INSTALL_COMMAND ""
+        UPDATE_COMMAND ""
+        SOURCE_DIR @LLVM_INSTALL_ROOT@
+        DOWNLOAD_NO_PROGRESS TRUE
+        EXCLUDE_FROM_ALL TRUE
+        )
+
+else()
+    message(STATUS "LLVM: Building LLVM from source")
+
+    # Revert prior changes to make incremental build work.
+    set(LLVM_PATCH_REVERT_COMMAND cd @LLVM_PROJECT_ROOT@/llvm/src/ext_llvm && git reset HEAD --hard)
+
+    set(LLVM_CMAKE_ARGS @NGRAPH_FORWARD_CMAKE_ARGS@
+                   -DCMAKE_INSTALL_PREFIX=@LLVM_INSTALL_ROOT@
+                   -DLLVM_ENABLE_PROJECTS:STRING=clang$<SEMICOLON>openmp
+                   -DLLVM_INCLUDE_DOCS=OFF
+                   -DLLVM_INCLUDE_TESTS=OFF
+                   -DLLVM_INCLUDE_GO_TESTS=OFF
+                   -DLLVM_INCLUDE_EXAMPLES=OFF
+                   -DLLVM_INCLUDE_BENCHMARKS=OFF
+                   -DLLVM_BUILD_TOOLS=OFF
+                   -DLLVM_BUILD_UTILS=OFF
+                   -DLLVM_BUILD_RUNTIMES=OFF
+                   -DLLVM_BUILD_RUNTIME=OFF
+                   -DLLVM_TARGETS_TO_BUILD=X86
+                   -DLLVM_ENABLE_BINDINGS=OFF
+                   -DLLVM_ENABLE_TERMINFO=OFF
+                   -DLLVM_ENABLE_ZLIB=OFF
+                   -DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN=ON
+                   -DLIBOMP_OMPT_SUPPORT=OFF
+                   -DCLANG_ENABLE_ARCMT=OFF
+                   -DCLANG_ANALYZER_ENABLE_Z3_SOLVER=OFF
+                   -DCLANG_ENABLE_STATIC_ANALYZER=OFF)
+
+    if(${CMAKE_VERSION} VERSION_LESS 3.7)
+        ExternalProject_Add(
+            ext_llvm
+            PREFIX llvm
+            GIT_REPOSITORY https://github.com/llvm/llvm-project.git
+            GIT_TAG llvmorg-8.0.0
+            CMAKE_GENERATOR "@CMAKE_GENERATOR@"
+            CMAKE_GENERATOR_PLATFORM @CMAKE_GENERATOR_PLATFORM@
+            CMAKE_GENERATOR_TOOLSET @CMAKE_GENERATOR_TOOLSET@
+            UPDATE_COMMAND ""
+            CONFIGURE_COMMAND ${CMAKE_COMMAND} ../ext_llvm/llvm -G "@CMAKE_GENERATOR@" ${LLVM_CMAKE_ARGS} -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
+            PATCH_COMMAND ${LLVM_PATCH_REVERT_COMMAND}
+            COMMAND git apply --ignore-space-change --ignore-whitespace @CMAKE_CURRENT_SOURCE_DIR@/cmake/llvm.patch
+            DOWNLOAD_NO_PROGRESS TRUE
+            EXCLUDE_FROM_ALL TRUE
+            )
+    else()
+        ExternalProject_Add(
+            ext_llvm
+            PREFIX llvm
+            GIT_REPOSITORY https://github.com/llvm/llvm-project.git
+            GIT_TAG llvmorg-8.0.0
+            GIT_SHALLOW 1
+            CMAKE_GENERATOR "@CMAKE_GENERATOR@"
+            CMAKE_GENERATOR_PLATFORM @CMAKE_GENERATOR_PLATFORM@
+            CMAKE_GENERATOR_TOOLSET @CMAKE_GENERATOR_TOOLSET@
+            CMAKE_ARGS ${LLVM_CMAKE_ARGS} -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
+            UPDATE_COMMAND ""
+            PATCH_COMMAND ${LLVM_PATCH_REVERT_COMMAND}
+            COMMAND git apply --ignore-space-change --ignore-whitespace @CMAKE_CURRENT_SOURCE_DIR@/cmake/llvm.patch
+            SOURCE_SUBDIR llvm
+            DOWNLOAD_NO_PROGRESS TRUE
+            EXCLUDE_FROM_ALL TRUE
+            )
+    endif()
+endif()

cmake/sdl.cmake

@@ -23,14 +23,13 @@ endif()
 set(SDL_cmake_included true)
 
 if(UNIX)
-    set(SDL_CXX_FLAGS "-O2 -Wformat -Wformat-security")
-    set(SDL_CXX_FLAGS "${SDL_CXX_FLAGS} -D_FORTIFY_SOURCE=2")
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D_FORTIFY_SOURCE=2")
+    list(APPEND NGRAPH_COMMON_FLAGS -Wformat -Wformat-security)
+    list(APPEND NGRAPH_COMMON_FLAGS -O2 -D_FORTIFY_SOURCE=2)
     if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
         if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.9)
-            set(SDL_CXX_FLAGS "${SDL_CXX_FLAGS} -fstack-protector-all")
+            list(APPEND NGRAPH_COMMON_FLAGS -fstack-protector-all)
         else()
-            set(SDL_CXX_FLAGS "${SDL_CXX_FLAGS} -fstack-protector-strong")
+            list(APPEND NGRAPH_COMMON_FLAGS -fstack-protector-strong)
         endif()
 
         # GCC might be very paranoid for partial structure initialization, e.g.
@@ -42,12 +41,10 @@ if(UNIX)
         # set(CMAKE_SRC_CCXX_FLAGS "${CMAKE_SRC_CCXX_FLAGS} -Wmissing-field-initializers")
         # set(CMAKE_EXAMPLE_CCXX_FLAGS "${CMAKE_EXAMPLE_CCXX_FLAGS} -Wmissing-field-initializers")
     elseif("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
-        set(SDL_CXX_FLAGS "${SDL_CXX_FLAGS} -fstack-protector-all")
+        list(APPEND NGRAPH_COMMON_FLAGS -fstack-protector-all)
     elseif("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Intel")
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstack-protector")
+        list(APPEND NGRAPH_COMMON_FLAGS -fstack-protector)
     endif()
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${SDL_CXX_FLAGS}")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${SDL_CXX_FLAGS}")
     if(APPLE)
         set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-bind_at_load")
         set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,-bind_at_load")

src/ngraph/codegen/CMakeLists.txt

@@ -35,10 +35,8 @@ if(NOT WIN32)
    set_source_files_properties(compiler.cpp PROPERTIES COMPILE_FLAGS "-fno-rtti")
 endif()
 
-get_target_property(LLVM_INCLUDE_DIR libllvm INTERFACE_INCLUDE_DIRECTORIES)
-
 # find_file(HEADER_1 cmath HINTS /usr/include/c++/7)
-get_filename_component(CLANG_INCLUDE_DIR ${LLVM_INCLUDE_DIR}/../lib/clang/${NGRAPH_LLVM_VERSION}/include ABSOLUTE)
+get_filename_component(CLANG_INTRIN_INCLUDE_DIR ${LLVM_INCLUDE_DIRS}/../lib/clang/${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH}/include ABSOLUTE)
 
 if(NGRAPH_CPU_ENABLE)
     get_target_property(MKLDNN_INCLUDE_DIR libmkldnn INTERFACE_INCLUDE_DIRECTORIES)
@@ -47,7 +45,7 @@ if(NGRAPH_CPU_ENABLE)
     list(APPEND HEADER_SEARCH_DEFINES MKLDNN_HEADERS_PATH="${MKLDNN_INCLUDE_DIR}")
 endif()
 
-list(APPEND HEADER_SEARCH_DEFINES CLANG_BUILTIN_HEADERS_PATH="${CLANG_INCLUDE_DIR}")
+list(APPEND HEADER_SEARCH_DEFINES CLANG_BUILTIN_HEADERS_PATH="${CLANG_INTRIN_INCLUDE_DIR}")
 list(APPEND HEADER_SEARCH_DEFINES NGRAPH_HEADERS_PATH="${NGRAPH_INCLUDE_PATH}")
 
 if(NGRAPH_TBB_ENABLE)

src/resource/CMakeLists.txt

@@ -31,9 +31,8 @@ set (SRC
 
 add_executable(resource_generator EXCLUDE_FROM_ALL ${SRC})
 add_dependencies(resource_generator libllvm)
-get_target_property(LLVM_INCLUDE_DIR libllvm INTERFACE_INCLUDE_DIRECTORIES)
-get_filename_component(CLANG_INCLUDE_DIR ${LLVM_INCLUDE_DIR}/../lib/clang/${NGRAPH_LLVM_VERSION}/include ABSOLUTE)
-list(APPEND HEADER_SEARCH_DEFINES CLANG_BUILTIN_HEADERS_PATH="${CLANG_INCLUDE_DIR}")
+get_filename_component(CLANG_INTRIN_INCLUDE_DIR ${LLVM_INCLUDE_DIRS}/../lib/clang/${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH}/include ABSOLUTE)
+list(APPEND HEADER_SEARCH_DEFINES CLANG_BUILTIN_HEADERS_PATH="${CLANG_INTRIN_INCLUDE_DIR}")
 list(APPEND HEADER_SEARCH_DEFINES NGRAPH_HEADERS_PATH="${NGRAPH_INCLUDE_PATH}")
 
 if(NGRAPH_CPU_ENABLE)