Makefile and sub makefile, phony task nothing to be done - makefile

Directory tree
.
| Makefile
| src
| Makefile
| spec
| test
in ./Makefile
default: all
.DEFAULT:
$(MAKE) -C $#
in src/Makefile
.PHONY: all spec test ...
spec:
bundle exec cucumber ../spec
When I am in the src directory the "make spec" works well.
..././src/# make spec
blablabla
But when I am in the root directory i get that there is "nothing to be done" but it is a phony target
..././# make spec
make: Nothing to be done for `spec'.
I suppose it is a problem with the name of task that is the same as the name of the directory, with a sub makefile.

I suppose it is a problem with the name of task that is the same as the name of the directory, with a sub makefile.
Yep.
Try something like:
all :
forward_ : ;
% : forward_
$(MAKE) -C $#
.PHONY : all forward_
Phony forward_ target is supposed to trigger re-evaluation of % target even when there is an existing file or directory with $# name.

Related

Build make target if contents of directory have changed

I need a Makefile that allows me to enter make foo-program and, if any foo-program/**/*.hs file has changed since last build, build the target (output in foo-program/.stack-work).
Here is my directory tree:
project/
|-bar-other-program/
|-.stack-work/ # Generated output goes here
|-src/
|-BarOtherProgram.hs
|-test/
|-Tests.hs
|-foo-program/
|-.stack-work/ # Generated output goes here
|-src/
|-FooProgram.hs
|-test/
|-Tests.hs
|-notes/ # non-source, so no Make target for this
Here is what I have so far:
# evaluates to 'bar-other-program foo-program'
PROGS := $(shell find * -type f -name '*.hs' | cut -d'/' -f1 | uniq)
.SECONDEXPANSION:
$(PROGS): $$(wildcard $$#/src/*.hs) $$(wildcard $$#/test/*.hs)
# do-build $#
When I run make foo-program, whether the source has changed or not, I get:
make: Nothing to be done for 'foo-program'
UPDATE: My final (non-abstracted) Makefile can be found on GitHub. Note that my solution took a different turn than I intended when I wrote up this question. Looking at that Makefile also might also make it more clear as to my original goal.
I am not quite sure of the the purpose of cut -d'/' there.
But if you just want a list of *.hs files in the current directory (recursively found) and then build a target/executable based on whether they have changed, you can do something like this:
PROGS = $(subst ./,,$(shell find . -type f -name '*.hs'))
DEPS = $(addprefix stackwork/,$(addsuffix .dep,$(basename $(PROGS))))
DIRS = $(dir $(DEPS))
.PHONY: foo-program
foo-program: $(DEPS) $(DIRS)
stackwork/%.dep: %.hs | $(DIRS)
#echo making $#
#touch $#
$(DIRS):
#echo creating dir $#
#mkdir -p $#
clean:
#rm -rf $(DEPS) $(DIRS)
Where:
PROGS is your list of .hs files
DEPS is a list of generated dependency files (empty but date stamps will be used)
DIRS is a list of output directories that need to be created (I guess they don't exist by default since they are output folders?)
foo-program is a rule that you can call (PHONY because at the moment it does not create a real file)
%.dep: %.hs is a rule how to generate a .dep file (this could be a .o .obj or any other file type) which depends on its .hs file equivalent.
$(DIRS): is a rule to create your output directories if needed.
So if the .dep files don't exist, all of the .hs files will be "compiled". If all the .dep files exist and are up to date, then nothing will be compiled. If one or more file is out of date then just those files will be built. Here is the output of running this on my PC with a few test files:
admin#osboxes:~/sandbox$ make
creating dir stackwork/
creating dir stackwork/test/
creating dir stackwork/test/test2/
making stackwork/file.dep
making stackwork/test/file.dep
making stackwork/test/test2/file2.dep
admin#osboxes:~/sandbox$ make
make: Nothing to be done for 'foo-program'.
admin#osboxes:~/sandbox$ touch test/file.hs
admin#osboxes:~/sandbox$ make
making stackwork/test/file.dep
admin#osboxes:~/sandbox$ make
make: Nothing to be done for 'foo-program'.

How to tell make to watch dependencies of a sub-make target?

I was investigating on the same question here, but I was not very clear of what I was asking, even for myself. Sorry for those who spent time answering my unclear question.
So let's try again with a more realistic example. We consider this structure:
.
├── Makefile
└── src/
├── bar
├── foo
└── Makefile
Where the main Makefile is:
all: src/foobar
src/foobar:
make -C $(dir $#)
And the sub-makefile is:
foobar: foo bar
join $^ > $#
If I run make for the first time (from ./) everything works as expected, foobar is produced.
$ make
make -C src/
make[1]: Entering directory '/project/src'
join foo bar > foobar
make[1]: Leaving directory '/project/src'
$ make
make: Nothing to be done for 'all'.
However if I touch any of the foobar dependencies. The parent Makefile will not regenerate the target. Here, I perfectly understand the behavior of Make, but I want to tell it to be aware of foobar' dependencies.
$ touch src/foo
$ make
make: Nothing to be done for 'all'.
My current solution which is not very neat is to ask for the dependencies. So the src/Makefile become:
src=foo bar
foobar: $(src)
#echo "Joining"
join $^ > $#
files: $(src)
#echo $^
And the ./Makefile:
all: src/foobar
src=$(addprefix src/,$(shell make --no-print-directory -C src files | tr '\n' ' '))
src/foobar: $(src)
make -C $(dir $#)
I must also say that this particular example could be simplified using a single Makefile only. My real example is quite more complex. The src/Makefile generate an executable while the parent Makefile do lots of other things (packing in a specific format, generate the documentation, build other sub-makefiles and so on). Thus, I want to keep these tasks well separated and I need to different Makefiles.
In the main Makefile create a dependency for the child target or directory that is always in need of building, and let the child Make then do the real work.
There is a good example here: http://owen.sj.ca.us/~rk/howto/slides/make/slides/makerecurs.html.
To translate for your case, change your main Makefile to be:
all: src/foobar
src/foobar: force
$(MAKE) $(MFLAGS) -C src
force:
true
I also added $(MFLAGS) which will pass same flags from parent to child make.

Makefile pattern rule either ignores phony rule or spontaneously deletes output file

I'm trying to write a makefile to produce several output files for each of several sources, using pattern rules.
I have the following Makefile (GNU Make 3.8.1):
all : foo.all bar.all
%.all : %.pdf %.svg
#echo Made $*
%.pdf :
touch $#
%.svg :
touch $#
.PHONY: foo.all bar.all
Since *.all do not represent real output files, I tried marking them as .PHONY. However, running make then doesn't work:
$ ls
Makefile
$ make
make: Nothing to be done for `all'.
According to make -d:
No implicit rule found for `all'.
Considering target file `foo.all'.
File `foo.all' does not exist.
Finished prerequisites of target file `foo.all'.
Must remake target `foo.all'.
Successfully remade target file `foo.all'.
Considering target file `bar.all'.
File `bar.all' does not exist.
Finished prerequisites of target file `bar.all'.
Must remake target `bar.all'.
Successfully remade target file `bar.all'.
Finished prerequisites of target file `all'.
Must remake target `all'.
Successfully remade target file `all'.
make: Nothing to be done for `all'.
which seems to be pretending to run the %.all rules, but skipping the bodies.
But with the .PHONY line commented out, Make runs the targets, but then spontaneously decides to delete the output files:
$ make
touch foo.pdf
touch foo.svg
Made foo
touch bar.pdf
touch bar.svg
Made bar
rm foo.pdf foo.svg bar.pdf bar.svg
According to make -d, it says:
Removing intermediate files...
Minimal example
A minimal example giving anomalous behavior:
%.all: %.out
#echo Made $*
%.out:
touch $#
I expect running make somefile.all to cause it to create the file somefile.out, but it gets deleted:
$ make somefile.all
touch somefile.out
Made somefile
rm somefile.out
Keeping make from deleting intermediary files
I recommend against using .PRECIOUS (see below as to why). Using .SECONDARY would preserve the .out files:
TARGETS=foo bar
all: $(TARGETS:=.all)
%.all: %.out
#echo Made $*
%.out:
touch $#
.SECONDARY: $(TARGETS:=.out)
$(TARGETS:=.all) just appends .all to all names in TARGETS. $(TARGETS:=.out) appends .out. We apparently cannot use %.out as a target of .SECONDARY. These just save having to relist all targets individually.
I prefer to not use .PRECIOUS for this because the documentation says
if make is killed or interrupted during the execution of their recipes, the target is not deleted.
This can leave corrupted files in the file system. Here's an example.
all: foo.all bar.all
%.all: %.out
#echo Made $*
%.out:
sh -e -c 'echo "{1, 2, 3" > $#; FAIL!; echo "}" >> $#'
.PRECIOUS: %.out
The FAIL! command simulates a tool that crashes in the middle of its work. Here's a shell session working with the Makefile above:
$ ls
Makefile
$ make
sh -e -c 'echo "{1, 2, 3" > foo.out; FAIL!; echo "}" >> foo.out'
sh: 1: FAIL!: not found
make: *** [foo.out] Error 127
$ cat foo.out
{1, 2, 3
Yikes... my foo.out file is incomplete. Let's try making again:
$ make
Made foo
sh -e -c 'echo "{1, 2, 3" > bar.out; FAIL!; echo "}" >> bar.out'
sh: 1: FAIL!: not found
make: *** [bar.out] Error 127
$ cat *.out
{1, 2, 3
{1, 2, 3
Make is none the wiser about files left around by earlier runs so when you run make again, it will take the corrupted files at face value. foo.out was not remade (despite the "Made foo" message) because it already exists and the Makefile went straight to trying to make bar.
.SECONDARY makes it so that:
The targets which .SECONDARY depends on are treated as intermediate files, except that they are never automatically deleted.
This means they are never automatically deleted just because they are intermediate files. The default make behavior of deleting targets that were being rebuilt if the tool rebuilding them crashed is not affected.
Using .PHONY with pattern rules
It seems though that .PHONY works only for targets that are explicit, not inferred. I've not found documentation confirming this. However, this works:
TARGETS:=foo bar
TARGETS_all:=$(TARGETS:=.all)
.PHONY: all
all: $(TARGETS_all)
.PHONY: $(TARGETS_all)
$(TARGETS_all): %.all: %.out
#echo Made $*
%.out:
touch $#
.SECONDARY: $(TARGETS:=.out)
In this rule $(TARGETS_all): %.all: %.out $(TARGETS_all): gives the list of targets to which the pattern can be applied. It makes foo.all and bar.all explicit targets. Without this, they would be inferred targets.
You can test that it works by creating file called foo.all in your directory and run make over and over. The foo.all file has no effect on make.
Your somefile.out files are considered intermediate by GNU make, which is why they are automatically deleted in your example. You can instruct GNU make to preserve these files by use the of .PRECIOUS special target, like this:
%.all: %.out
#echo Made $*
%.out:
touch $#
.PRECIOUS: %.out

In Makefiles, how to re-enable --print-directory in a sub-directory when --no-print-directory has been set?

First, let me say that I am aware of the cons of using recursive Makefiles. So if you are here just to tell me don't use it, please don't.
Imagine this directory structure:
rootdir
`-- subdir
|-- a
|-- b
`-- c
Let's say the Makefile on rootdir reads like this:
.PHONY: all
all:
# build some stuff
$(MAKE) -C subdir
and the one in subdir reads like this:
.PHONY: all
all:
# nothing here except redirecting make to each of the subdirectories
$(MAKE) -C a
$(MAKE) -C b
$(MAKE) -C c
and another Makefile in each of a, b and c folders building something.
Since the Makefile in subdir serves no purpose except redirecting make, I want make not to print: Entering directory rootdir/subdir and Leaving directory rootdir/subdir to clean up the output a bit.
On the other hand, since there are commands being executed in the subfolders a, b and c, I do want make to print these outputs. Here's what I thought would work:
rootdir's Makefile:
.PHONY: all
all:
# build some stuff
$(MAKE) --no-print-directory -C subdir
subdir's Makefile:
.PHONY: all
all:
# nothing here except redirecting make to each of the subdirectories
$(MAKE) --print-directory -C a
$(MAKE) --print-directory -C b
$(MAKE) --print-directory -C c
The problem is, once the --no-print-directory is given to make when calling make for subdir, --print-directory doesn't enable it again when calling make for a, b or c.
So my question is, how can I re-enable printing directories when a parent make has disabled it?
Make command line flags get communicated to sub-makes via MAKEFLAGS variable. You may like to replace --no-print-directory (if any) from MAKEFLAGS with w manually before invoking the sub-makes:
${MAKE} MAKEFLAGS="$(subst --no-print-directory,w,${MAKEFLAGS})" -C ...

makefile can not detect missing prerequisites file

I have a makefile that takes care of copying file from folder A to folder B.
here I have simple makefile to describe the problem I encounter.
ex:
all: a.txt b.txt
%.txt: test/%.txt
cp -a $< $#
when I invoke make command:
make
It copy 2 txt files.
after that, I remove a.txt in test folder and run make again
rm test/a.txt
make
I suppose make will detect unavailable prerequisites but it output:
make: Nothing to be done for `all'.
How can I have error output for this situation?
thanks!!
You are using a pattern rule, which Make ignores if the prerequisites are not available. Try this:
TEXTS := a.txt b.txt
all: $(TEXTS)
$(TEXTS): % : test/%
cp -a $< $#

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