My Notes for Makefile

Although make is part of the gnu toolset, its use is not restricted to compile a c++ program. make can be used to do various kinds of work.

Here is my notes on makefile for my future self. I find it of great help to keep these notes handy. For example, I often come back for this one

Macro

• Define macro(variable, but it’s called macro in makefile) with equal sign, multiple values can be assigned to one macro. use macro in the form of $(A)

A = a b c
$(A)

Rules

• The structure of a rule

%.o: $(DEPS)
	$(CC) -c -o $@ $< $(CFLAGS)

• %.o: target file
• $(DEPS): file dependency (to generate target)
• \tab+command: usual linux commands

My notes:

• Type make will run the first rule in a Makefile.

• Special rule: .PHONY: clean tells make that clean is not a file. Always execute commands under the clean rule, even if there’s a clean file in the working directory.

• Automatic variables

  • $@ target of the rule
  • $< first prerequisite
  • $^ all prerequisite

• Sublime will transform tab to 4 spaces, turn that off for makefile

• @ before a command will prevent printing the command before executing.

• % for quoting.

Resources

gnu make manual

A Simple Makefile Tutorial

An interesting SO question of makefile use case