gnu make - Makefile: all vs default targets -

talking respect gnu make, difference between phony targets all: , default:.

cc=g++ default: hello  hello: hello.cpp      $(cc) -o hello hello.cpp 

and

cc=g++ all: hello  hello: hello.cpp      $(cc) -o hello hello.cpp 

both of them same job.

you can call them shirley if like; neither of labels mention has special semantics. default behavior of make run first target in makefile if don't specify target command-line argument. if override behavior, there .default: special target.

there convention have target named all builds everything, human convention, not special case or requirement far make concerned.

similarly, there (weak) convention call default target default, similarly, human label (and overlaps , possibly conflicts all convention).

so following makefile same thing:

.phony: shirley default default: hello all: hello shirley: hello  hello: hello.cpp # (make knows how build executable out of .cpp file) 

you can omit or of phony targets above, , difference humans won't able make shirley when (effectively) mean make hello.

bottom line: construct makefile make reasonable end-user expects without reading readme files or inspecting makefile. make all (and should have target name, satisfy human conventions, if it's not default) depends on project , users' expectations.

don't call me shirley.