makefile - 如何在不同目标之间显式运行 'make clean'？

Question

我正在寻找以下行为:

# make debug (project is rebuilt. this works fine.)
# make debug (project is not rebuilt because no changes have been made.)
# make release (this is a different target than the currently-built one. I want 'make clean' to run before the release target is built)
# make release (project is not rebuilt because no changes have been made.)

谢谢。

Answer 1

有趣的问题。我能想到的唯一方法是在外部记录最近的目标(例如将其回显到文件)，然后检查它是否与当前目标相同或不同。如果它们相同，只需运行常规构建过程；如果它们不同，首先运行 make clean。

我对此进行了第一次尝试，以说明该过程(未经测试)。

debug release:ifneq ($(MAKECMDGOALS),$(shell cat last_target.txt))    $(MAKE) cleanendif    @echo $@ > last_target.txt    [regular build commands]

这假设两个目标具有相同的配方(某些变量具有不同的设置)。如果它们有不同的配方，则显然必须在两个配方中插入条件部分和回显命令。