_DEBUG - Turns on all debug Messages (set by compiler).
RELEASE_SHOW_DEBUG, RELEASE_SHOW_WARN, RELEASE_SHOW_INFO, RELEASE_SHOW_ASSERT - turns on the appropriate category of debug messages even if it's a Release build.
Operating system and platform settings
LL_WINDOWS - Enables Windows specific code.
LL_LINUX - Enables Linux specific code.
LL_DARWIN - Enables mac os x specific code.
LL_LITTLE_ENDIAN, LL_BIG_ENDIAN - Notifies the build that the underlying machine stores multi-byte values in particular orders.
LL_RELEASE_FOR_DOWNLOAD - This is set for the compilation of the general released viewers from Linden Lab. It appears to remove features which were being tested in the Firstlook viewers. In particular, setting this appears removes to remove the support for dynamic mirrors.
_CORY_TESTING - Enables a few menu items in the server debug menu that allow you to force import/export objects, code is buggy and deprecated. (Could be fixed to work again, pretty easy to enable export(fix file i/o functions)(oft crashes viewer). Import is fairly dead, I got it to import prims, but not textures.)
HACKED_GODLIKE_VIEWER - Makes client always treat user as a Linden, even if they are not.
TOGGLE_HACKED_GODLIKE_VIEWER - Enables the hacked Godmode option on the Client debug menu, which allows the user to be treated by the client as if they were a Linden even if they are not.
DEBUG_VOLUME DEBUG_MISS CRC_CHECK LL_DEBUG_PUMPS _PATCH_SIZE_16_AND_32_ONLY SABINRIG DEBUG_UPDATE_TYPE IGNORE_DEAD ORPHAN_SPAM IDC_STATIC APSTUDIO_INVOKED DEBUG_AGP CTYPE_WORKAROUND LSL_INCLUDE_DEBUG_INFO - Include debug information in scripts? EMERGENCY_DEBUG_PRINTOUTS EMIT_CIL_ASSEMBLER GL_GLEXT_FUNCTION_POINTERS TIME_THROTTLE_MESSAGES kAUDIO_ENABLE_WIND SIGBUS SIGSYS DIFF_INVENTORY_FILES MORPH_PANEL_SHOW_SPINNERS LL_RELEASE_FOR_DOWNLOAD LL_CHECK_FOR_FINITE WCOREDUMP - On Non-Windows, function to work out if a child thread dumped core or not TEST_HARNESS LL_DARWIN PROCESSOR_FREQUENCY_MEASURE_AVAILABLE HAVE_NETINET_IN_H HAVE_SA_LEN FT_FREETYPE_H SIOCGIFHWADDR SIOCGENADDR