6.2. Older Functions for Deciding When an Input File Has Changed

SCons still supports two functions that used to be the primary methods for configuring the decision about whether or not an input file has changed. These functions have been officially deprecated as SCons version 2.0, and their use is discouraged, mainly because they rely on a somewhat confusing distinction between how source files and target files are handled. These functions are documented here mainly in case you encounter them in older SConscript files.