CODEWITHSUNDEEP
makefilegnu-make
Chris Tonkinson
Chris Tonkinson

Reputation: 14459

How to call Makefile from another Makefile?

I'm getting some unexpected results calling one makefile from another. I have two makefiles, one called /path/to/project/makefile and one called /path/to/project/gtest-1.4.0/make/Makefile. I'm attempting to have the former call the latter. In /path/to/project/makefile, I have

dev: $(OBJ_FILES)
  $(CPPC) $(LIBS) $(FLAGS_DEV) $(OBJ_FILES) -o $(BIN_DIR)/$(PROJECT)
  $(MAKE) -f ./gtest-1.4.0/make/Makefile

clean:
  rm -f ./*~ ./gmon.out ./core $(SRC_DIR)/*~ $(OBJ_DIR)/*.o
  rm -f ../svn-commit.tmp~
  rm -f $(BIN_DIR)/$(PROJECT)
  make -f gtest-1.4.0/make/Makefile clean

And in /path/to/project/gtest-1.4.0/make/Makefile I have

all: $(TESTS)

clean:
  rm -f $(TESTS) gtest.a gtest_main.a *.o

Issuing the following:

cd /path/to/project
make

Outputs:

make -f ./gtest-1.4.0/make/Makefile
make[1]: Entering directory `/path/to/project'
make[1]: Nothing to be done for `all'.
make[1]: Leaving directory `/path/to/project'

However, when I issue these commands:

cd /path/to/project
make clean

I see:

make -f gtest-1.4.0/make/Makefile clean
make[1]: Entering directory `/path/to/project'
rm -f  gtest.a gtest_main.a *.o
make[1]: Leaving directory `/path/to/project'

I don't understand: In both cases, /path/to/project/makefile is telling me it's entering the current working directory. In the first case, it doesn't think it has work to do (when it does) and in the second case, it's able to find the appropriate directive (when the output is telling me it's looking in the wrong directory) yet it tries to run the rm command in /path/to/project, instead of /path/to/makefile/gtest-1.4.0/make/.

Am I missing something fundamental to calling makefiles from one another? Have I made an egregious conceptual mistake, or hit a common pitfall? How do I effectively change directories and call a second makefile from within the first? My understanding was that simply calling make -f <name> would be enough.

This is make/gmake 3.81 in bash.

Upvotes: 169

Views: 230410

Answers (5)

David
David

Reputation: 352

in parent makefile put

clean:
    cd $(PWD)/path/to/project/gtest-1.4.0 && $(MAKE) clean

in order this to work, under /path/to/project/gtest-1.4.0 must exist a makefile with clean option like follow

child makefile

clean:
    rm -f where_you_want

Upvotes: 0

anon
anon

Reputation:

I'm not really too clear what you are asking, but using the -f command line option just specifies a file - it doesn't tell make to change directories. If you want to do the work in another directory, you need to cd to the directory:

clean:
    cd gtest-1.4.0 && $(MAKE) clean

Note that each line in Makefile runs in a separate shell, so there is no need to change the directory back.

Upvotes: 164

Aadishri
Aadishri

Reputation: 1471

http://www.gnu.org/software/make/manual/make.html#Recursion

 subsystem:
         cd subdir && $(MAKE)

or, equivalently, this :

 subsystem:
         $(MAKE) -C subdir

Upvotes: 61

Tader
Tader

Reputation: 26832

Instead of the -f of make you might want to use the -C <path> option. This first changes the to the path '<path>', and then calles make there.

Example:

clean:
  rm -f ./*~ ./gmon.out ./core $(SRC_DIR)/*~ $(OBJ_DIR)/*.o
  rm -f ../svn-commit.tmp~
  rm -f $(BIN_DIR)/$(PROJECT)
  $(MAKE) -C gtest-1.4.0/make clean

Upvotes: 144

John Knoeller
John Knoeller

Reputation: 34128

It seems clear that $(TESTS) is empty so your 1.4.0 makefile is effectively

all: 

clean:
  rm -f  gtest.a gtest_main.a *.o

Indeed, all has nothing to do. and clean does exactly what it says rm -f gtest.a ...

Upvotes: 1

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