change debug enable from cmake flag to environment var so it can be c… (#462)

* change debug enable from cmake flag to environment var so it can be changed without rebuild

src/ngraph/CMakeLists.txt

@@ -186,8 +186,6 @@ if (NGRAPH_CPU_ENABLE AND LLVM_INCLUDE_DIR AND
           "EIGEN_HEADERS_PATH=\"${EIGEN_INCLUDE_DIR}\";MKLDNN_HEADERS_PATH=\"${MKLDNN_INCLUDE_DIR}\";CLANG_BUILTIN_HEADERS_PATH=\"${LLVM_LIB_DIR}/clang/5.0.1/include\";NGRAPH_HEADERS_PATH=\"${NGRAPH_INCLUDE_PATH}\";INSTALLED_HEADERS_PATH=\"${CMAKE_INSTALL_PREFIX}/include\";")
     endif()
     set(NGRAPH_CPU_DEBUGINFO_ENABLE 0 CACHE STRING "Enable debuginfo in the CPU backend")
-    set_property(SOURCE codegen/compiler.cpp APPEND_STRING PROPERTY COMPILE_DEFINITIONS
-      "NGCPU_DEBUGINFO=${NGRAPH_CPU_DEBUGINFO_ENABLE};")
 
     # GPU backend current requires CPU because they share compiler.cpp,
     # and compiler.cpp requires MKLDNN

src/ngraph/codegen/compiler.cpp

@@ -123,7 +123,7 @@ static std::string GetExecutablePath(const char* Argv0)
 
 codegen::StaticCompiler::StaticCompiler()
     : m_precompiled_header_valid(false)
-    , m_debuginfo_enabled(false)
+    , m_debuginfo_enabled((std::getenv("NGRAPH_COMPILER_DEBUGINFO_ENABLE") != nullptr))
     , m_enable_diag_output((std::getenv("NGRAPH_COMPILER_DIAG_ENABLE") != nullptr))
     , m_source_name("code.cpp")
 {
@@ -133,9 +133,6 @@ codegen::StaticCompiler::StaticCompiler()
 void codegen::StaticCompiler::initialize()
 {
     m_extra_search_path_list.clear();
-#if NGCPU_DEBUGINFO
-    m_debuginfo_enabled = true;
-#endif
 
     InitializeNativeTarget();
     LLVMInitializeNativeAsmPrinter();