Homework 5

If you need more information about the GNU make system, you can find its manual at http://www.gnu.org/software/make/manual/make.html. For instance, you may find the section entitled An Introduction to Makefiles helpful.

1. What are the three parts of a make rule? (1 pt.)
2. Describe one way in which a makefile is different from a shell script. (1~pt.)
3. Write a rule to compile file.cc into file.o with the command g++ -c file.cc such that the compilation happens only if file.cc is newer than file.o. (1~pt.)
4. What does it mean for a target to be phony? (1~pt.)

5. Listed below is a makefile for an imaginary programming language. Draw the dependency graph of that makefile. Hint, clean is a target, and should have a node in the graph. Does clean have any dependencies? Is anything dependent on it? (2~pt.)

   executable: file1.x file2.x common.s
       compile file1.x file2.x -s common.s
   file1.x: file1.p file1.s
       compile file1.p -s file1.s
   file2.x: file2.p common.s
       compile file2.p -s common.s
   clean:
       rm executable file1.x file2.x

6. Listed below are the files being built by this makefile with their time stamps. The larger a number, the newer a file. I am about to run make on the above makefile. For each rule, tell me whether its action will be run. (1~pt.ea.)

   Time Stamp	File Name
   3	executable
   7	file1.x
   6	file2.x
   5	file1.p
   2	file2.p
   4	file1.s
   8	common.s

Submission

Please create a text file (not MS Word, not PDF, just plain text) for your answers and a PDF file for your drawing for question 5. Place both files in an archive and upload the archive to the moodle.