Add CMake argument ENABLE_VERBOSE_LOGGING, disable trace/debug logging in Release builds

Author: kblaschke

BUILDING-cmake.md

@@ -115,13 +115,14 @@ Note that `ENABLE_GLES` will be forcibly set to `ON` for Emscripten and Android
 The following table contains a list of build options which are only useful in special circumstances, e.g. when
 developing libprojectM, trying experimental features or building the library for a special use-case/environment.
 
-| CMake option           | Default | Required dependencies          | Description                                                                                                                                                   |
-|------------------------|---------|--------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------|
-| `ENABLE_SDL_UI`        | `ON`    | `SDL2`                         | Builds the SDL-based test application. Only used for development testing, will not be installed.                                                              |
-| `ENABLE_INSTALL`       | `OFF`   | Building as a CMake subproject | Enable projectM install targets when built as a subproject via `add_subdirectory()`.                                                                          |
-| `ENABLE_DEBUG_POSTFIX` | `ON`    |                                | Adds `d` (by default) to the name of any binary file in debug builds.                                                                                         |
-| `ENABLE_SYSTEM_GLM`    | `OFF`   |                                | Builds against a system-installed GLM library.                                                                                                                |
-| `ENABLE_CXX_INTERFACE` | `OFF`   |                                | Exports symbols for the `ProjectM` and `PCM` C++ classes and installs the additional the headers. Using the C++ interface is not recommended and unsupported. |
+| CMake option             | Default | Required dependencies          | Description                                                                                                                                                                                                                                      |
+|--------------------------|---------|--------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `ENABLE_SDL_UI`          | `ON`    | `SDL2`                         | Builds the SDL-based test application. Only used for development testing, will not be installed.                                                                                                                                                 |
+| `ENABLE_INSTALL`         | `OFF`   | Building as a CMake subproject | Enable projectM install targets when built as a subproject via `add_subdirectory()`.                                                                                                                                                             |
+| `ENABLE_DEBUG_POSTFIX`   | `ON`    |                                | Adds `d` (by default) to the name of any binary file in debug builds.                                                                                                                                                                            |
+| `ENABLE_SYSTEM_GLM`      | `OFF`   |                                | Builds against a system-installed GLM library.                                                                                                                                                                                                   |
+| `ENABLE_CXX_INTERFACE`   | `OFF`   |                                | Exports symbols for the `ProjectM` and `PCM` C++ classes and installs the additional the headers. Using the C++ interface is not recommended and unsupported.                                                                                    |
+| `ENABLE_VERBOSE_LOGGING` | `OFF`   |                                | Enables code for `TRACE` and `DEBUG` log levels in release builds. By default, these will only be compiled for `Debug` builds. Enabling this will negatively affect performance, even if the actual log level is set to `INFORMATION` or higher. |
 
 ### Path options
 

CMakeLists.txt

@@ -25,6 +25,7 @@ option(ENABLE_DEBUG_POSTFIX "Add \"d\" (by default) after library names for debu
 option(ENABLE_PLAYLIST "Enable building the playlist management library" ON)
 option(ENABLE_BOOST_FILESYSTEM "Force the use of boost::filesystem, even if the compiler supports C++17." OFF)
 option(ENABLE_SDL_UI "Build the SDL2-based developer test UI. Ignored when building with Emscripten or for Android." OFF)
+option(ENABLE_VERBOSE_LOGGING "Enables TRACE and DEBUG logging even in release builds, negatively affecting the performance." OFF)
 
 option(BUILD_TESTING "Build the libprojectM test suite" OFF)
 option(BUILD_DOCS "Build documentation" OFF)
@@ -208,6 +209,11 @@ else()
     set(CMAKE_VISIBILITY_INLINES_HIDDEN ON)
 endif()
 
+# Disable trace/debug logging in release builds unless explicitly requested
+add_compile_definitions(
+        $<$<OR:$<CONFIG:Debug>,$<BOOL:${ENABLE_VERBOSE_LOGGING}>>:ENABLE_DEBUG_LOGGING>
+        )
+
 if(BUILD_DOCS)
     find_package(Doxygen REQUIRED)
     find_package(Sphinx REQUIRED breathe exhale)
@@ -220,15 +226,15 @@ if(BUILD_DOCS)
     set(DOXYGEN_EXCLUDE_PATTERNS "*.cpp")
 
     doxygen_add_docs(
-        projectm_doxygen
-        src
-        COMMENT "Generate HTML documentation")
+            projectm_doxygen
+            src
+            COMMENT "Generate HTML documentation")
 
     sphinx_add_docs(
-        projectm_sphinx
-        BREATHE_PROJECTS projectm_doxygen
-        BUILDER html
-        SOURCE_DIRECTORY docs)
+            projectm_sphinx
+            BREATHE_PROJECTS projectm_doxygen
+            BUILDER html
+            SOURCE_DIRECTORY docs)
 endif()
 
 add_subdirectory(vendor)

src/libprojectM/Logging.hpp

@@ -109,6 +109,7 @@ class Logging
     thread_local static LogLevel m_threadLogLevel; //!< The thread-specific log level.
 };
 
+#ifdef ENABLE_DEBUG_LOGGING
 #define LOG_TRACE(message)                                                            \
     if (Logging::HasCallback() && Logging::GetLogLevel() == Logging::LogLevel::Trace) \
     {                                                                                 \
@@ -120,6 +121,10 @@ class Logging
     {                                                                                 \
         Logging::Log(message, Logging::LogLevel::Debug);                              \
     }
+#else
+#define LOG_TRACE(message)
+#define LOG_DEBUG(message)
+#endif
 
 #define LOG_INFO(message)                                                                   \
     if (Logging::HasCallback() && Logging::GetLogLevel() <= Logging::LogLevel::Information) \