MAKE Variable Works
Recursive make commands should always use the variable MAKE,
not the explicit command name ‘make’, as shown here:
subsystem:
cd subdir && $(MAKE)
The value of this variable is the file name with which make was
invoked. If this file name was /bin/make, then the command executed
is ‘cd subdir && /bin/make’. If you use a special version of
make to run the top-level makefile, the same special version will be
executed for recursive invocations.
As a special feature, using the variable MAKE in the commands of
a rule alters the effects of the ‘-t’ (‘--touch’), ‘-n’
(‘--just-print’), or ‘-q’ (‘--question’) option.
Using the MAKE variable has the same effect as using a ‘+’
character at the beginning of the command line. See Instead of Executing the Commands. This special feature
is only enabled if the MAKE variable appears directly in the
command script: it does not apply if the MAKE variable is
referenced through expansion of another variable. In the latter case
you must use the ‘+’ token to get these special effects.
Consider the command ‘make -t’ in the above example. (The
‘-t’ option marks targets as up to date without actually running
any commands; see Instead of Execution.) Following the usual
definition of ‘-t’, a ‘make -t’ command in the example would
create a file named subsystem and do nothing else. What you
really want it to do is run ‘cd subdir && make -t’; but that would
require executing the command, and ‘-t’ says not to execute
commands.
The special feature makes this do what you want: whenever a command
line of a rule contains the variable MAKE, the flags ‘-t’,
‘-n’ and ‘-q’ do not apply to that line. Command lines
containing MAKE are executed normally despite the presence of a
flag that causes most commands not to be run. The usual
MAKEFLAGS mechanism passes the flags to the sub-make
(see Communicating Options to a Sub-make), so your request to touch the files, or print the
commands, is propagated to the subsystem.