diff --git a/include/rosa/support/log.h b/include/rosa/support/log.h
index 0a4e905..60345a6 100644
--- a/include/rosa/support/log.h
+++ b/include/rosa/support/log.h
@@ -1,150 +1,159 @@
 /*******************************************************************************
  *
  * File:     log.h
  *
  * Contents: Facility for logging
  *
  * Copyright 2017
  *
  * Author: David Juhasz (david.juhasz@tuwien.ac.at)
  *
  ******************************************************************************/
 
 #ifndef ROSA_SUPPORT_LOG_H
 #define ROSA_SUPPORT_LOG_H
 
 #include "rosa/config/config.h"
 #include "rosa/support/terminal_colors.h"
 #include <iostream>
 #include <string>
 
+// NOTE: One call for the various logging macros below is supposed to be used
+// for registering one log entry. That goes natural with the non-stream
+// implementations, which accept one string as argument. A more flexible way
+// for printing log entries, for example colorizing text, is to use macros
+// providing a log stream. It is important to note, however, that the stream
+// obtained from one macro evaluation fits for printing one log entry, without
+// nested/overlapping log entry emissions and the entry being closed with a
+// newline. Should this simple recommendation not being followed, the result
+// becomes hard to read due to missing line breaks and overlapping entries.
+// FIXME: Thread-safety is another issue, which need to be addressed for proper
+// logging.
+
 /* ****************************************************************************
  *                                Log Levels                                  *
  * ****************************************************************************/
 
 namespace rosa {
 
 // Type-safe definition of log levels, use this in code.
 // NOTE: Keep values in sync with the corresponding preprocessor definitions
 // below.
 enum class LogLevel {
   Error,
   Warning,
   Info,
   Debug,
   Trace,
   // Number of log levels:
   NumLogLevels
 };
 
 // Converts a LogLevel to its string representation.
 // PRE: logLevel != LogLevel::NumLogLevels
 std::string logLevelToString(const LogLevel logLevel);
 
 // Prints colorized tag for the given LogLevel.
 // PRE: logLevel != LogLevel::NumLogLevels
 std::ostream &operator<<(std::ostream &os, const LogLevel logLevel);
 
 } // End namespace rosa
 
 // Valid log levels, only for preprocessor definitions below.
 // NOTE: Keep in sync with the values of enum class rosa::LogLevel.
 #define ROSA_LOG_LEVEL_ERROR 0
 #define ROSA_LOG_LEVEL_WARNING 1
 #define ROSA_LOG_LEVEL_INFO 2
 #define ROSA_LOG_LEVEL_DEBUG 3
 #define ROSA_LOG_LEVEL_TRACE 4
 
 /* ****************************************************************************
  *                           Logger Implementation                            *
  * ****************************************************************************/
 
 // Stream to print logs to.
 // FIXME: Make it configurable, e.g. printing into a file.
 #define ROSA_LOG_OSTREAM std::clog
 
 // Simple logging implementation printing a string message.
-// FIXME: Make logging thread-safe.
 #define ROSA_LOG_IMPL(level, output)                                           \
   do {                                                                         \
-    ROSA_LOG_OSTREAM << level << " " << __func__ << "@" << __FILENAME__ << ":" \
-                     << __LINE__ << ": " << (output) << std::endl;             \
+    ROSA_LOG_OSTREAM << (level) << " " << __func__ << "@" << __FILENAME__      \
+                     << ":" << __LINE__ << ": " << (output) << std::endl;      \
   } while (false)
 
 // Simple logging implementation providing a stream to print to.
-// FIXME: Make logging thread-safe.
 #define ROSA_LOG_STREAM_IMPL(level)                                            \
-  do {                                                                         \
-    ROSA_LOG_OSTREAM << level << " " << __func__ << "@" << __FILENAME__ << ":" \
-                     << __LINE__ << ": ";                                      \
-  } while (false);                                                             \
-  ROSA_LOG_OSTREAM
+  ([](void) -> std::ostream & {                                                \
+    return ROSA_LOG_OSTREAM << (level) << " " << __func__ << "@"               \
+                            << __FILENAME__ << ":" << __LINE__ << ": ";        \
+  }())
 
 namespace rosa {
 // Dummy ostream printing to nowhere.
 extern std::ostream LogSink;
 } // End namespace rosa
 
 // A stream ignoring all its input.
 #define ROSA_LOG_STREAM_IGNORE rosa::LogSink
 
 /* ****************************************************************************
  *                            Logging Interface                               *
  * ****************************************************************************/
 
 // Define logging macros if logging is enabled.
 #ifdef ROSA_LOG_LEVEL
 
 #define LOG_ERROR_STREAM ROSA_LOG_STREAM_IMPL(rosa::LogLevel::Error)
 #define LOG_ERROR(output) ROSA_LOG_IMPL(rosa::LogLevel::Error, output)
 
 #if ROSA_LOG_LEVEL >= ROSA_LOG_LEVEL_WARNING
 #define LOG_WARNING_STREAM ROSA_LOG_STREAM_IMPL(rosa::LogLevel::Warning)
 #define LOG_WARNING(output) ROSA_LOG_IMPL(rosa::LogLevel::Warning, output)
 #endif
 
 #if ROSA_LOG_LEVEL >= ROSA_LOG_LEVEL_INFO
 #define LOG_INFO_STREAM ROSA_LOG_STREAM_IMPL(rosa::LogLevel::Info)
 #define LOG_INFO(output) ROSA_LOG_IMPL(rosa::LogLevel::Info, output)
 #endif
 
 #if ROSA_LOG_LEVEL >= ROSA_LOG_LEVEL_DEBUG
 #define LOG_DEBUG_STREAM ROSA_LOG_STREAM_IMPL(rosa::LogLevel::Debug)
 #define LOG_DEBUG(output) ROSA_LOG_IMPL(rosa::LogLevel::Debug, output)
 #endif
 
 #if ROSA_LOG_LEVEL >= ROSA_LOG_LEVEL_TRACE
 #define LOG_TRACE_STREAM ROSA_LOG_STREAM_IMPL(rosa::LogLevel::Trace)
 #define LOG_TRACE(output) ROSA_LOG_IMPL(rosa::LogLevel::Trace, output)
 #endif
 
 #endif // defined ROSA_LOG_LEVEL
 
 // Define all disabled logging features as void.
 #ifndef LOG_ERROR
 #define LOG_ERROR_STREAM ROSA_LOG_STREAM_IGNORE
 #define LOG_ERROR(output) ROSA_IGNORE_UNUSED(output)
 #endif
 
 #ifndef LOG_WARNING
 #define LOG_WARNING_STREAM ROSA_LOG_STREAM_IGNORE
 #define LOG_WARNING(output) ROSA_IGNORE_UNUSED(output)
 #endif
 
 #ifndef LOG_INFO
 #define LOG_INFO_STREAM ROSA_LOG_STREAM_IGNORE
 #define LOG_INFO(output) ROSA_IGNORE_UNUSED(output)
 #endif
 
 #ifndef LOG_DEBUG
 #define LOG_DEBUG_STREAM ROSA_LOG_STREAM_IGNORE
 #define LOG_DEBUG(output) ROSA_IGNORE_UNUSED(output)
 #endif
 
 #ifndef LOG_TRACE
 #define LOG_TRACE_STREAM ROSA_LOG_STREAM_IGNORE
 #define LOG_TRACE(output) ROSA_IGNORE_UNUSED(output)
 #endif
 
 #endif // ROSA_SUPPORT_LOG_H