The example given above uses the
LATE_DIRS macro. Here are the macros that you can
place within a makefile:
EARLY_DIRS
LATE_DIRS
LIST
MAKEFILE
CHECKFORCE
The EARLY_DIRS and LATE_DIRS macros
To give you some control over the ordering of the directories, the macros EARLY_DIRS and LATE_DIRS specify directories to recurse into before or after all others. You'd use this facility with directory trees that contain one directory that depends on another directory at
the same level; you want the independent directory to be done first, followed by the dependent directory.
The LIST macro
The LIST macro serves as a tag for the particular directory level that the makefile is found in.
The MAKEFILE macro
The MAKEFILE macro specifies the name of the makefile that recurse.mk should search for in the child directories.
The CHECKFORCE macro
The CHECKFORCE macro is a trigger. Its actual value is unimportant, but if you set it, the recurse.mk file looks for Makefile.force files in the subdirectories. If it finds one, make recurses into that directory, even if the LIST macro settings would normally prevent this from happening.