Compiling and Makefiles

Compiling small programs on Unix/Linux

Using Makefiles to Manage Larger Programs

• Create a file called Makefile (or makefile) that identifies compilation steps, outputs, and dependencies.
  Format:

  target: dependency1 dependency2 dependency3            all on one line
          command-to-produce-target-using-dependencies   on next line
  

  
  Example:

  pp0b:   myProj.h file1.c file2.c
          gcc -o pp0b file1.c file2.c
  

• Most dependency lists are longer; best practice is one per line. (Use backslash to treat multiple lines as one line.)
  Example:

  pp0b:   myProj.h \                    continue on next line
          file1.c \                     continue on next line
          file2.c                       last dependency
          gcc -o pp0b file1.c file2.c   command is on separate line
  

• Run make:

          make
  

  If a target does not exist or any dependencies have been updated (newer than target), make will run the command. It will not run commands for any targets that are already up-to-date.
• If the makefile is not called Makefile (or makefile):

          make -f myMakefile
  

• You can specify the target (output) to make:

          make -f myMakefile pp0b
  

Longer Makefile Example

This example has four targets: two executables (testpp1a and disassembler), a target that represents both (all), and a target that removes intermediate and final output files (clean).

all:        testpp1a \
            disassembler

testpp1a:   pp1.h \
            printFuncs.h \
            verifyMIPSInstruction.c \
            binToDec.c \
            printDebug.c \
            printError.c \
            testpp1a.c
            gcc verifyMIPSInstruction.c binToDec.c printDebug.c \
                printError.c testpp1a.c -o testpp1a

# The assembler will probably have other source files in addition to these.
disassembler:   disassembler.h \
                printFuncs.h \
                verifyMIPSInstruction.c \
                binToDec.c \
                getRegName.c \
                printDebug.c \
                printError.c \
                disassembler.c
                gcc verifyMIPSInstruction.c binToDec.c getRegName.c \
                    printDebug.c printError.c disassembler.c -o disassembler

clean: 
        rm -rf *.o testpp1a disassembler