Escaping colons in filenames in a Makefile

问题:

Is there a way to get GNU make to work correctly with filenames that contain colons?

The specific problem I'm running into happens to involve a pattern rule. Here's a simplified version that does not depend on cutting and pasting tab characters:

% make --version
GNU Make 3.81
Copyright (C) 2006  Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.

This program built for x86_64-redhat-linux-gnu
% cat Makefile
COLON := \:
all: ; true
%.bar: ; cp $< $@
x.bar: x.foo
%.foo: ; touch $@
a$(COLON)b.bar: a$(COLON)b.foo
all: x.bar a$(COLON)b.bar
clean: ; rm -f *.foo *.bar
% make clean
rm -f *.foo *.bar
% make
touch x.foo
cp x.foo x.bar
cp  a\:b.bar
cp: missing destination file operand after `a:b.bar'
Try `cp --help' for more information.
make: *** [a\:b.bar] Error 1

Replacing $(COLON) with a literal : produces exactly the same result. Without the backslash, it does this:

Makefile:6: *** target pattern contains no `%'.  Stop.

回答1:

The following hack worked for me, though it unfortunately relies on $(shell).

# modify file names immediately
PRE := $(shell rename : @COLON@ *)
# example variables that I need
XDLS = $(wildcard *.xdl)
YYYS = $(patsubst %.xdl,%.yyy,$(XDLS))
# restore file names later
POST = $(shell rename @COLON@ : *)

wrapper: $(YYYS)
    @# restore file names
    $(POST)

$(YYYS):
    @# show file names after $(PRE) renaming but before $(POST) renaming
    @ls

Because PRE is assigned with :=, its associated shell command is run before the XDLS variable is evaluated. The key is to then put the colons back in place after the fact by explicitly invoking $(POST).

回答2:

I doubt it's possible: see this discussion about colons in Makefiles. In summary, GNU make has never worked well with filenames that contain whitespace or colons. The maintainer, Paul D. Smith, says that adding support for escaping would tend to break existing makefiles. Furthermore, adding such support would require significant changes to the code.

You might be able to work around with some sort of nasty temporary file arrangement.

Good luck!

回答3:

There is another way i've found today when dealing with Makefile variables defining filenames (containing colons).

# definition
SOME_FNAME = $(NAME)__colon__$(VERSION)

# usage in target
foo:
    $(do_something) $(subst __colon__,:,$(SOME_FNAME))

回答4:

I am not positivie this should work, but the reason it says "missing destination file" is simple:

%.bar: ; cp $< $@

That line says to copy the target from the first dependency. your a:b.bar does not have any dependency, so the cp fails. what did you want it to copy ? a:b.foo ? in that case, you would need:

%.bar: %.foo ; cp $< $@