GNU make manual 翻译( 一百四十三)

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') option.  Using the `MAKE' variable has the same
effect as using a `+' character at the beginning of the recipe line.
*Note Instead of Executing the Recipes: Instead of Execution.  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 *note 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' (*note Communicating Options to a Sub-`make':
Options/Recursion.), so your request to touch the files, or print the
recipes, is propagated to the subsystem.