Makefile中对目标的可选依赖性

Question

是否可以在Makefile(GNUMake(中创建对目标的可选依赖？

help:
@echo Usage:
clean:
@echo Cleaning...
build: clean?
@echo Building...

预期输出：

$ make
Usage:
$ make clean
Cleaning...
$ make build
Building...
$ make build clean
Cleaning...
Building...
$ make clean build
Cleaning...
Building...

目标集是固定的并且不能扩展，即

rebuild: clean build
.PHONY: rebuild

不可接受。

Answer 1

是的，您可以这样做：

build: $(filter clean,$(MAKECMDGOALS))
@echo Building...

请参阅：https://www.gnu.org/software/make/manual/html_node/Goals.html和https://www.gnu.org/software/make/manual/html_node/Text-Functions.html#index-过滤