How to have dependencies that result from another target in Makefile? - makefile

I've tweak "a bit" Make so I can use it as a "kind of" cli for some tasks.
MAKEFLAGS += --no-builtin-rules
MAKEFLAGS += --no-builtin-variables
MAKEFLAGS += --no-print-directory
SHELL := /bin/bash
.ONESHELL:
.PHONY: project_list
project_list: all_projects_info.json
echo "Filtering project list with:" >&2
echo " PROJECT_FILTER: $(PROJECT_FILTER)" >&2
jq -r -S '.[] | select(
(.projectId | test("$(PROJECT_FILTER)"))
) | .projectId' $^ > $#
.PHONY: get_storage_info
get_storage_info: project_list
PROJECT_LIST=$$(cat $<)
$(MAKE) -f $(MKFILE) -j storage_info.json PROJECT_LIST="$$PROJECT_LIST"
all_projects_info.json:
curl -X GET https://toto/get_all_my_projects_info >$#
# here it's PHONY because we want to always rebuild it
.PHONY: storage_info.json
storage_info.json: $(STORAGE_INFO_JSON_FILES)
jq -s -S '[.[]?.items?[]?]' $(STORAGE_INFO_JSON_FILES) > $#
storage_info/:
mkdir -p $#
STORAGE_INFO_JSON_FILES=$(foreach project_name,$(PROJECT_LIST),storage_info/$(project_name).json)
$(STORAGE_INFO_JSON_FILES): storage_info/%.json: | storage_info/
curl \
-X GET \
"https://storage_api/list_s3?project=$*" \
2> /dev/null > $#
As you can see here, I've got 2 "command":
project_list witch list all project I can access too,
get_storage_info witch list all bucket in projects.
The trick here is because I've got a lot of projects and buckets, I may want to filter like this:
make get_storage_info PROJECT="foo"
And it will print ONLY bucket in project with foo in their name.
It's quit handy and fast (only the first time it may be slow, the time to get all informations).
What is bothering me, I've not found a better way than to call a sub make command (with the exact list of project to take into account).
Is it possible to express dynamic dependencies of a target ?
But something that can result from another target ?
Thanks.

I don't see anything wrong with invoking a submake. That's IMO the best way to do it, especially if you want to add -j to it.
It's not really possible to get rid of this easily. It's not the fact that you want to express a dynamic dependency: that can be done. The problem is you want the list of dependencies to be extracted from the results of running another rule. But that's not how make works: make always starts with the final target and works its way backwards. So, by the time you get around to building the prerequisite file, the target that depended on it has already been processed (not its recipe of course, but all the prerequisites).

Related

How to make GNU make run in batches?

I'd like to use make to process a large number of inputs to outputs using a script (python, say.) The problem is that the script takes an incredibly short amount of time to run per input, but the initialization takes a while (python engine + library initialization.) So, a naive makefile that just has an input->output rule ends up being dominated by this initialization time. Parallelism doesn't help with that.
The python script can accept multiple inputs and outputs, as so:
python my_process -i in1 -o out1 -i in2 -o out2 ...
and this is the recommended way to use the script.
How can I make a Makefile rule that best uses my_process, by sending in out of date input-output pairs in batches? Something like parallel but aware of which outputs are out of date.
I would prefer to avoid recursive make, if at all possible.
I don't completely grasp your problem: do you really want make to operate in batches or do you want a kind of perpetual make process checking the file system on the fly and feeding to the Python process whenever it finds necessary? If the latter, this is quite the opposite of a batch mode and rather a pipeline.
For the batch mode there is a work-around which needs a dummy file recording the last runnning time. In this case we are abusing make for because the makefile is in this part a one-trick pony which is unintuitive and against the good rules:
SOURCES := $(wildcard in*)
lastrun : $(SOURCES)
python my_process $(foreach src,$?,-i $(src) -o $(patsubst in%,out%,$(src)))
touch lastrun
PS: please note that this solution has a substantial flaw in that it doesn't detect the update of in-files when they happen during the run of the makefile. All in all it is more advisable to simply collect the filenames of the in-files which were updated by the update process itself and avoid make althogether.
This is what I ended up going with, a makefile with one layer of recursion.
I tried using $? both with grouped and ungrouped targets, but couldn't get the exact behavior needed. If one of the output targets was deleted, the rule would be re-run but $? wouldn't necessarily have some input files but not the correct corresponding input file, very strange.
Makefile:
all:
INDIR=in
OUTDIR=out
INFILES=$(wildcard in/*)
OUTFILES=$(patsubst in/%, out/%, $(INFILES))
ifdef FIRST_PASS
#Discover which input-output pairs are out of date
$(shell mkdir -p $(OUTDIR); echo -n > $(OUTDIR)/.needs_rebuild)
$(OUTFILES) : out/% : in/%
#echo $# $^ >> $(OUTDIR)/.needs_rebuild
all: $(OUTFILES)
#echo -n
else
#Recurse to run FIRST_PASS, builds .needs_rebuild:
$(shell $(MAKE) -f $(CURDIR)/$(firstword $(MAKEFILE_LIST)) FIRST_PASS=1)
#Convert .needs_rebuild into batches, creates all_batches phony target for convenience
$(shell cat $(OUTDIR)/.needs_rebuild | ./make_batches.sh 32 > $(OUTDIR)/.batches)
-include $(OUTDIR)/.batches
batch%:
#In this rule, $^ is all inputs needing rebuild.
#The corresponding utputs can be computed using a patsubst:
targets="$(patsubst in/%, out/%, $^)"; touch $$targets
clean:
rm -rf $(OUTDIR)
all: all_batches
endif
make_batches.sh:
#!/bin/bash
set -beEu -o pipefail
batch_size=$1
function _make_batches {
batch_num=$1
shift 1
#echo ".PHONY: batch$batch_num"
echo "all_batches: batch$batch_num"
while (( $# >= 1 )); do
read out in <<< $1
shift 1
echo "batch$batch_num: $in"
echo "$out: batch$batch_num"
done
}
export -f _make_batches
echo ".PHONY: all_batches"
parallel -N$batch_size -- _make_batches {#} {} \;
Unfortunately, the makefile is a one trick pony and there's quite a bit of boilerplate to pull this recipe off.

Makefile - Execute a rule for every field in a variable

I have my project binary located at my repository's root, along with a Makefile used to build it.
This binary uses many of my self-made libraries, located in my lib/ folder
For the purpose of building (and cleaning) my repository's binary, I want to implement the following execution :
Instead of hardcoding the following lines,
clean_binaries:
make -C clean lib/folder1 -s
make -C clean lib/folder2 -s
make -C clean lib/another_folder -s
I created the BIN_PATH variable, containing the previous paths.
BIN_PATHS = lib/folder1 \
lib/folder2 \
lib/another_folder
And made a simple rule like this one :
clean_binaries: $(BIN_PATHS)
make -C clean $< -s
BUT it only executes the line for the first field of the variable (lib/folder1), which is not what I want to do.
I thought about using implicit rules(?), just like I compile the .c files, but I couldn't get it right.
In the end, I simply wonder how to execute a rule for every field of a given variable, and this inside a Makefile, if there is any way to do so.
Thank you for your answers :]
The way you get GNU make to generate a sequence of commands that vary by the
fields in a variable is to use the foreach function, e.g.
Makefile
BIN_PATHS := lib/folder1 lib/folder2 lib/another_folder
.PHONY: clean_binaries
clean_binaries:
$(foreach path,$(BIN_PATHS),make -C $(path) clean ;)
which runs like:
$ make
make -C lib/folder1 clean -s; make -C lib/folder2 clean -s; make -C lib/another_folder clean -s;
not requiring a shell-loop.
Note also that you need to correct:
make -C clean <directory>
to:
make -C <directory> clean

Make - Dependency building different than explicit build

I have a rule in my makefile:
$(OW_GROUP_ONE_C): $(OW_GROUP_ONE_PNG)
for file in $^; \
do \`enter code here`
grit $$file -ftc -fh\! -fa -gt -gz\! -gB4 -m\! -p -pzl -pu16 -o $#; \
done
It builds a single c file out of different images, those are iterated in a for loop (They are, I checked using an echo)
The rule which depends on that is
$(OW_GROUP_ONE_O): $(OW_GROUP_ONE_C)
$(CC) $(CFLAGS) -c -o $# $<
which is executed via
$(SPRITES_BINARY): $(NORMAL_PAL_OBJ) $(SHINY_PAL_OBJ) $(SPRITE_FRONT_OBJ) $(SPRITE_BACK_OBJ) $(NORMAL_CASTFORM_PAL_OBJ) $(SHINY_CASTFORM_PAL_OBJ) $(CASTFORM_FRONT_OBJ) $(CASTFORM_BACK_OBJ) $(OW_GROUP_ONE_O)
If I execute the rule by calling "make $(OW_GROUP_ONE_C)" everything works fine, but as soon as the rule is executed via dependency from another rule, the loop seems to just read the first file. I again used echo to check, but the loop accumulates all files in the list. I don't know what the deal i, the tool (GRIT - GBA raster image transmogrifier) should be able to handle that, but there must be a difference between calling the rule explicit if it works that way...
Thanks in advance for any hints!

What's the standard makefile idiom for trying different ways to make a target

I have a makefile that uses a source file from the internet. There are two locations where the file resides, neither of which I consider very dependable, so I also keep a local copy. So the relevant lines of my makefile look like:
src.c:
wget -nv http://location.com/$# || wget -nv http://otherplace.com/$# || cp local/$# .
src.o: src.c
$(CC) -o $# $<
Is this the "right way" to do this? What if there are multiple steps in each different way of creating the target - how do I tell make "Try A. If A fails, try B. If B fails, ..."?
The right thing to do is this:
.PHONY: phony
src.c: phony
if (wget -nv http://location.com/$# -O $#.temp) && ! diff $#.temp $# >/dev/null; then \
mv $#.temp $#; \
fi
I shortened your command to a single wget but you can put whatever you want there, including a sequence of ||s to achieve "try this, if not, try that etc". Just make sure it outputs to a temporary file (and does not hang indefinitely !) .
It is in fact important to use phony here, and not only .PHONY. Can you see why?
Also, with this method, there is no longer a need to keep another "local" copy and/or use cp. Your target src.c is your "local copy" - the latest one you were able to successfully get from the Internet.

Getting the name of the makefile from the makefile

How to get the name of the makefile in the makefile?
Thanks.
Note:
I would need that because I would like my makefile to call itself, but the makefile is not called Makefile, so I'd like to write something like this:
target:
($MAKE) -f ($MAKEFILENAME) other_target
location = $(CURDIR)/$(word $(words $(MAKEFILE_LIST)),$(MAKEFILE_LIST))
WHERE_ART_THOU := $(location)
$(warning $(WHERE_ART_THOU))
I also believe this is GNU make-specific, but I'm not too sure.
(Should you have any questions, refer to amazingly written GNU make manual. But remember, that, just like Makefile, this manual should be read completely before putting the concepts into practice).
I couldn't figure out how it is done easily. As far as I understand, you'll have to do some manual job.
Later I will describe how it could be done and show scripts that introduce current_makefile variable. But I would like to stress an important concept at the first place.
You should understand that if we had some kind of variable current_makefile, that expands to the current makefile name, then it will have to change during the process of reading makefiles. That means that it should be used withinin "immediate" expansion context -- i.e. within commands that are executed during reading the makefile. Most commands, however, are executed after makefiles are read. Therefore, some commands will print the correct value smoothly, while in certain places, where "deferred" expansion is used, it will always expand to the root makefile name.
If you would want to use this variable within rule text, for example, you'll have to do tricks, because rule text always has deferred expansion. So, if your have the rule
rule:
echo In makefile $(current_makefile):
echo Making target $#
it will always print the name of the root makefile. Instead, to force immediate expansion, you will have to create another variable with makefile-specific name (i.e. names of such variables should be different in each makefile):
this_makefile_unique_name := $(current_makefile)
rule:
echo In makefile $(current_makefile):
echo Making target $#
or use eval:.
define make_rule
rule:
echo In makefile $(1):
echo Making target $$#
$(eval $(call make_rule,$(current_makefile)))
If you want to use the name of current makefile for debug purpose only, consider special debugging functions, like warning or info:.
$(warning We're in makefile $(current_makefile))
These functions use "immediate" expansion and will print the correct value.
How to define such a $(current_makefile)?
You have to manually maintain stack of makefile inclusions. When you include a makefile, its name is placed to the top of the stack; when you return from included makefile to the outer one, the topmost name is popped out of stack. This is achieved by inserting special calls to the beginning and the end of makefile:
# Beginning of makefile
$(eval $(makefile_names_push))
#... makefile text
$(warning $(current_makefile))
#...
$(eval $(makefile_names_pop))
#End of file
Now define the functions at the beginning of your root makefile.
lastword=$(word $(words $(1)),$(1))
define makefile_names_push
current_makefile := $$(CURDIR)/$$(call lastword,$$(MAKEFILE_LIST))
makefile_stack :=$$(makefile_stack) $$(current_makefile)
endef
define makefile_names_pop
makefile_stack := $$(filter-out $$(current_makefile),$$(makefile_stack))
current_makefile := $$(call lastword,$$(makefile_stack))
endef
If you're sure your make is new enough (version 3.81+), replace lastword call with builtin function:.
#inctead of $$(call lastword,$$(MAKEFILE_LIST))
$$(lastword $$(MAKEFILE_LIST))
Is it useful?
Totally useless. An only use that might be useful here is to make 100 makefiles that are symlinks to one makefile, the rules in these makefiles depending on their names. But it can be achieved within one makefile and foreach-eval technique described in the manual. So my post was a complete waste of time, though I had some fun :-)
This returns the name of the first Makefile called, i.e. the one at the bottom of the call stack:
MAKEFILE_JUSTNAME := $(firstword $(MAKEFILE_LIST))
MAKEFILE_COMPLETE := $(CURDIR)/$(MAKEFILE_JUSTNAME)
When used in non-cross-recursive situations (e.g. for makedepend), it is just the name of the current makefile.
I wanted to do something similar (for echoing the contents of the Makefile) for when I use Make for managing simple repetitive tasks. I came across this page and found it was exactly what I was after and really useful for my limited understanding of make.
My result after reading this page:
# Makefile - 'make' and 'make help' now echo the makefile.
help:
cat $(lastword $(MAKEFILE_LIST))
start:
sudo -u www /path/to/webapp/myhttpd restart
stop:
sudo kill `cat /path/to/webapp/data/httpd.pid`
A quick excursion to Google suggests this site has the answer.
G'day,
If you make a copy of your original makefile, say makefile_test, and then enter the command:
make -np -f makefile_test 2>&1 | tee output
That will evaluate the makefile and your make environment but not execute any of the commands. Looking through the output file for references to makefile_test will show you what is set in make's environment and where that value is being set.
N.B. This can generate a lot of info! And don't add the -d (debug) switch which will generate tons of additional output about make's decision process but minimal additional info about make's env.
HTH
The solutions here addresses 1) POSIX make with 2) Invoked, non included, makefile in 3) A Unix alike platform.
What the OP asked for:
target:
#pid=$$$$; \
while test `ps -ocomm= $$pid` != make; do \
pid=`ps -oppid= $$pid`; \
done; \
MAKEFILENAME=`ps -oargs= $$pid|sed 's/^.* -f *\([^ ]*\).*$$/\1/'`; \
test -z "$$MAKEFILENAME" -a -f Makefile && MAKEFILENAME=Makefile; \
test -z "$$MAKEFILENAME" -a -f makefile && MAKEFILENAME=makefile; \
export MAKEFILENAME; \
$(MAKE) -e -f $$MAKEFILENAME other_target
The targets depends on the makefile, kind of bloated:
TARGET1_MAKEFILENAME = target1_preamble
all: target1 target2...
target1: $(TARGET1_MAKEFILENAME) other_dependencies...
#test $(TARGET1_MAKEFILENAME) == target1_preamble && exit 0; \
built_instructions_for_target1;
target1_preamble:
#pid=$$$$; \
while test `ps -ocomm= $$pid` != make; do \
pid=`ps -oppid= $$pid`; \
done; \
MAKEFILENAME=`ps -oargs= $$pid|sed 's/^.* -f *\([^ ]*\).*$$/\1/'`; \
test -z "$$MAKEFILENAME" -a -f Makefile && MAKEFILENAME=Makefile; \
test -z "$$MAKEFILENAME" -a -f makefile && MAKEFILENAME=makefile; \
export MAKEFILENAME; \
$(MAKE) -e -f $$MAKEFILENAME target1;
Can be a bit simplified if make is invoked only for all targets.
MAKEFILENAME = invoked_makefile_placeholder
all: target1 target2...
target1: $(MAKEFILENAME) other_dependencies...
#test $(MAKEFILENAME) == invoked_makefile_placeholder && exit 0; \
built_instructions_for_target1;
invoked_makefile_placeholder:
#pid=$$$$; \
while test `ps -ocomm= $$pid` != make; do \
pid=`ps -oppid= $$pid`; \
done; \
MAKEFILENAME=`ps -oargs= $$pid|sed 's/^.* -f *\([^ ]*\).*$$/\1/'`; \
test -z "$$MAKEFILENAME" -a -f Makefile && MAKEFILENAME=Makefile; \
test -z "$$MAKEFILENAME" -a -f makefile && MAKEFILENAME=makefile; \
export MAKEFILENAME; \
$(MAKE) -e -f $$MAKEFILENAME
With the previous approach is trivial to implement a solution for included makefiles based in grep and a unique pattern contained in the makefile.
I never answer when I feel the question got a proper solution.

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