Improve codegen's header search path finding logic for various Linux distributions. (#2468)

src/ngraph/codegen/CMakeLists.txt

@@ -33,10 +33,10 @@ add_library(codegen SHARED ${SRC})
 # This must be kept in sync with the LLVM + Clang version in use
 set_source_files_properties(compiler.cpp PROPERTIES COMPILE_FLAGS "-fno-rtti")
 
-get_target_property(LLVM_LIB_DIR libllvm INTERFACE_INCLUDE_DIRECTORIES)
+get_target_property(LLVM_INCLUDE_DIR libllvm INTERFACE_INCLUDE_DIRECTORIES)
 
 # find_file(HEADER_1 cmath HINTS /usr/include/c++/7)
-get_filename_component(LLVM_LIB_DIR ${LLVM_LIB_DIR}/../lib/clang/5.0.2/include ABSOLUTE)
+get_filename_component(CLANG_INCLUDE_DIR ${LLVM_INCLUDE_DIR}/../lib/clang/5.0.2/include ABSOLUTE)
 
 if(NGRAPH_CPU_ENABLE)
     get_target_property(MKLDNN_INCLUDE_DIR libmkldnn INTERFACE_INCLUDE_DIRECTORIES)
@@ -45,7 +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="${LLVM_LIB_DIR}")
+list(APPEND HEADER_SEARCH_DEFINES CLANG_BUILTIN_HEADERS_PATH="${CLANG_INCLUDE_DIR}")
 list(APPEND HEADER_SEARCH_DEFINES NGRAPH_HEADERS_PATH="${NGRAPH_INCLUDE_PATH}")
 
 if(NGRAPH_DISTRIBUTED_ENABLE)
@@ -76,7 +76,7 @@ set_source_files_properties(compiler.cpp PROPERTIES COMPILE_DEFINITIONS "${HEADE
 # Generate the resource file containing all headers used by the codegen compiler
 add_custom_target(header_resource
     resource_generator --output ${CMAKE_BINARY_DIR}/header_resource.hpp --base codegen
-    DEPENDS resource_generator ext_llvm
+    DEPENDS resource_generator
     BYPRODUCTS
 )
 if (NGRAPH_CPU_ENABLE)
@@ -99,5 +99,5 @@ if (NGRAPH_CPU_ENABLE)
 endif()
 target_include_directories(codegen SYSTEM PRIVATE ${CMAKE_BINARY_DIR})
 target_link_libraries(codegen PRIVATE libllvm ngraph)
+set_target_properties(codegen PROPERTIES LIBRARY_OUTPUT_DIRECTORY ${NGRAPH_BUILD_DIR})
 install(TARGETS codegen DESTINATION ${NGRAPH_INSTALL_LIB})
-

src/ngraph/codegen/compiler.hpp

@@ -78,7 +78,7 @@ public:
     bool is_debuginfo_enabled() { return m_debuginfo_enabled; }
     void set_precompiled_header_source(const std::string& source);
     const std::string& get_precompiled_header_source() const;
-    void add_header_search_path(const std::string& path);
+    void add_header_search_path(const std::string& path, bool check_path = false);
 
     std::unique_ptr<ngraph::codegen::Module>
         compile(std::unique_ptr<clang::CodeGenAction>& compiler_action, const std::string& source);
@@ -95,8 +95,10 @@ private:
     std::string m_precompiled_header_source;
 
     bool is_version_number(const std::string& path);
+    int full_version_number(const std::string& path, const std::string& gpp_ver);
     std::string find_header_version(const std::string& path);
     std::string find_os_specific_path(const std::string& path);
+    std::string find_rh_devtoolset_path();
     void configure_search_path();
     void load_headers_from_resource();
 };