Fixes various compiler diagnostics

Found with LLVM 3.9.1 and then fixed the most severe categories.

include/util/exception_utils.hpp

@@ -5,11 +5,11 @@
 // Helper macros, don't use these ones
 // STRIP the OSRM_PROJECT_DIR from the front of a filename.  Expected to come
 // from CMake's CURRENT_SOURCE_DIR, which doesn't have a trailing /, hence the +1
-#define _PROJECT_RELATIVE_PATH(x) std::string(x).substr(strlen(OSRM_PROJECT_DIR) + 1)
+#define PROJECT_RELATIVE_PATH_(x) std::string(x).substr(strlen(OSRM_PROJECT_DIR) + 1)
 // Return the path of a file, relative to the OSRM_PROJECT_DIR
-#define _OSRM_SOURCE_FILE _PROJECT_RELATIVE_PATH(__FILE__)
+#define OSRM_SOURCE_FILE_ PROJECT_RELATIVE_PATH_(__FILE__)
 
 // This is the macro to use
-#define SOURCE_REF std::string(" (at ") + _OSRM_SOURCE_FILE + ":" + std::to_string(__LINE__) + ")"
+#define SOURCE_REF std::string(" (at ") + OSRM_SOURCE_FILE_ + ":" + std::to_string(__LINE__) + ")"
 
-#endif // SOURCE_MACROS_HPP
+#endif // SOURCE_MACROS_HPP

include/util/geojson_debug_logger.hpp

@@ -47,7 +47,7 @@ class GeojsonLogger
     // cannot lock, is tooling for locked function
     static void output(bool first, const util::json::Array &array)
     {
-        for (const auto object : array.values)
+        for (const auto &object : array.values)
         {
             if (!first)
                 ofs << ",\n\t\t";