为什么未触发.PHONY隐式模式规则? [英] Why are .PHONY implicit pattern rules not triggered?

问题描述

我有以下递归Makefile:

I have the following recursive makefile:

.PHONY: all clean

%.subdir:
    $(MAKE) -C src $*
    $(MAKE) -C dict $*

all: all.subdir

clean: clean.subdir

它工作正常:

$ make all
make -C src all
make[1]: Entering directory `/or-1.3.6-fix/src'
make[1]: Nothing to be done for `all'.
make[1]: Leaving directory `/or-1.3.6-fix/src'
make -C dict all
make[1]: Entering directory `/or-1.3.6-fix/dict'
make[1]: Nothing to be done for `all'.
make[1]: Leaving directory `/or-1.3.6-fix/dict'

但是将%.subdir规则定义为虚假会更合乎逻辑:

But it would be more logical to define %.subdir rules as phony:

.PHONY: all clean all.subdir clean.subdir

现在停止我想要的工作:

and now make stops working as I want:

$ make all
make: Nothing to be done for `all'.
$ make -d all
...
Updating goal targets....
Considering target file `all'.
 File `all' does not exist.
  Considering target file `all.subdir'.
   File `all.subdir' does not exist.
   Finished prerequisites of target file `all.subdir'.
  Must remake target `all.subdir'.
  Successfully remade target file `all.subdir'.
 Finished prerequisites of target file `all'.
Must remake target `all'.
Successfully remade target file `all'.
make: Nothing to be done for `all'.

有人可以向我解释原因(或者甚至更好地指点我做文档)吗?

Can somebody explain me why (or even better point me to make documentation)?

推荐答案

是的，将subdir规则定义为PHONY更有意义.但是Make不考虑PHONY目标的隐式规则，因此您必须重写该规则.我建议以下内容:

You're right, it would make more sense to define the subdir rules as PHONY. But Make does not consider implicit rules for PHONY targets, so you'll have to rewrite that rule. I suggest the following:

SUBDIR_TARGETS = all.subdir clean.subdir
.PHONY: all clean $(SUBDIR_TARGETS) 

$(SUBDIR_TARGETS): %.subdir:
    $(MAKE) -C src $*
    $(MAKE) -C dict $*

all: all.subdir
clean: clean.subdir

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