MAKE Variable (GNU make)
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5.7.1 How the 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 recipe 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 recipe of a rule alters the effects of the ‘-t
’ (‘--touch
’), ‘-n
’ (‘--just-print
’), or ‘-q
’ (‘--question
’ /@w ) option. Using the MAKE
variable has the same effect as using a ‘+
’ character at the beginning of the recipe line. See Instead of Executing the Recipes. This special feature is only enabled if the MAKE
variable appears directly in the recipe: 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 recipes; 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 recipe, and ‘-t
’ says not to execute recipes.
The special feature makes this do what you want: whenever a recipe line of a rule contains the variable MAKE
, the flags ‘-t
’, ‘-n
’ and ‘-q
’ do not apply to that line. Recipe lines containing MAKE
are executed normally despite the presence of a flag that causes most recipes 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 recipes, is propagated to the subsystem.
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