GLib's configure options and corresponding macros ================================================= --buildtype={plain,release,minsize,custom} none --buildtype={debug,debugoptimized} [debugoptimized is the default] -DG_ENABLE_DEBUG -g -Dglib_asserts=false -DG_DISABLE_ASSERT -Dglib_checks=false -DG_DISABLE_CHECKS Besides these, there are some local feature specific options, but my main focus here is to concentrate on macros that affect overall GLib behaviour and/or third party code. Notes on GLib's internal and global macros ========================================== G_DISABLE_ASSERT The g_assert() and g_assert_not_reached() become non-functional with this define. The motivation is to speed up end-user apps by avoiding expensive checks. This macro can affect third-party code. Defining it when building GLib will only disable the assertion macros for GLib itself, but third-party code that passes -DG_DISABLE_ASSERT to the compiler upon its own build will end up with the non-functional variants after including glib.h as well. NOTE: Code inside the assertion macros should not have side effects that affect the operation of the program. G_DISABLE_CHECKS This macro is similar to G_DISABLE_ASSERT, it affects third-party code as mentioned above and the NOTE about G_DISABLE_ASSERT applies too. The macros that become non-functional here are g_return_if_fail(), g_return_val_if_fail(), g_return_if_reached() and g_return_val_if_reached(). Additionally the glib_mem_profiler_table and g_mem_profile() from gmem.h become non-functional if this macro is supplied. This macro also switches off certain checks in the GSignal code. G_ENABLE_DEBUG Quite a bit of additional debugging code is compiled into GLib for this macro, and since it is a globally visible define, third-party code may be affected by it similar to G_DISABLE_ASSERT. The additional code executed/compiled for this macro currently involve: - extra validity checks for GDate - memory profiling traps in gmem.c (consult debugging.txt for details) - BREAKPOINT abortion for fatal log levels in gmessage.c instead of plain abort() to allow debuggers trapping and overriding them - added verbosity of gscanner.c to catch deprecated code paths - added verbosity of gutils.c to catch deprecated code paths - object ref/unref traps (consult debugging.txt) and object bookkeeping in gobject.c - extra validity checks in gsignal.c