wildcards in cygwin make in cmd.exe - cmd

im trying to make a simple makefile that will build multiple artifacts named after subdirs of the src directory. here is my dir structure:
>find .
.
./makefile
./src
./src/binA
./src/binA/main.java
./src/binB
./src/binB/main.cpp
./src/binC
./src/binC/main.scala
and here is the makefile i am trying to use. for some reason the binary target refuses to expand its dependencies with when i use both a pattern and a wildcard in the same rule
>cat makefile
dirs := $(shell find src -mindepth 1 -type d)
all: $(dirs:src/%=bin/%.exe)
#echo $(dirs)
bin/%.exe: src/%/*
#echo "$# <-- $^"
i know dirs is getting set properly
src/binA src/binB src/binC
this is the error i get
>make
make: *** No rule to make target `bin/binA.exe', needed by `all'. Stop.
how can i make a generic rule that will properly expand its dependencies to be the contents of a subdir that is based on its name

i was able to get this to work by changing the rule matcher to bin/%.exe: $(wildcard src/%/*) and add a .SECONDARYEXPANSION: before that.

Related

GNU Make: Canned recipe which is meant to generate prerequisites for rule causes error "No rule to make target"

I have this simple Makefile:
define some_canned_recipe
find 'foobar' -print
endef
run-something: $(call some_canned_recipe)
#$(info ** [Make] run-something)
#touch $#
I want the 'run-something' rule to be run if and only if one or more files or directories has changed under subdirectory 'foobar'. When I invoke 'make run-something' inside WSL2 however I get this error:
make: *** No rule to make target 'find', needed by 'run-something'. Stop.
Is there a way to achieve what I want (in terms of dynamically generating the prerequisites for the 'run-something' rule)?
PS: I'm aware that a silly solution would be:
define some_canned_recipe
$(shell find 'foobar' -print)
endef
even though this works its not really a good idea because $(shell ...) will run even when the rule 'run-something' is not being targeted.
You can do this using secondary expansion combined with implicit rules:
.SECONDEXPANSION:
run-something:
run-%: $$(shell find 'foobar' -print)
#$(info ** [Make] $#)
#touch $#
(note the $$ before the shell function)
I make no comments on whether I think this is the best way to do it :).

Make doesn't realize that it's done

This is my first ever post to stackoverflow. It ought to be straightforward, but I have this problem whenever I try to write a makefile and I've never been able to figure out a satisfactory solution. Apologies if there is already a solution somewhere on the site. I couldn't find one.
What I'm trying to do is as follows:
Search my src directory for matching source files.
Compile the src code into a sandbox.
Here's my directory structure:
makefile
src1
file1.src
file2.src
src2
file3.src
subfolder
src3
file4.src
file5.src
And here's my makefile:
BUILDDIR := ./sandbox
SRC_DIRS := ./
SRCS := $(shell find $(SRC_DIRS) -name *.src)
OBJS := $(addprefix $(BUILDDIR)/o., $(notdir $(SRCS) ) )
# make print-X prints value of variable X
print-%: ; #echo $* = $($*)
.PHONY: help
help:
#echo "make <all|clean>"
.PHONY: all
all: $(OBJS)
#echo "compilation done"
$(OBJS) : $(SRCS) $(BUILDDIR)/.create
#echo "\"compiling\" $< to produce $#"
cp $< $#
$(BUILDDIR)/.create:
#echo "creating sandbox"
mkdir -p $(BUILDDIR) && cd $(BUILDDIR)
#touch $#
.PHONY: clean
clean:
#echo "deleting sandbox"
#rm -rf $(BUILDDIR)
If I type make all, the file works as expected. However, if I type make all again, instead of saying everything is up to data, I end up with the following contents in the sandbox:
o.file1.src o.file2.src o.file3.src o.file4.src o.file5.src o.o.file1.src o.o.file2.src o.o.file3.src o.o.file4.src o.o.file5.src
And the process of creating objects of objects continues recursively as many times as I type make.
Any help would be appreciated.
Incidentally, please don't post solutions that rely on the build in compile functions of make. I'm looking for a general solution that can be used for any task. For example, in this instance, I'm trying to read the source files into a tool using its command line interface.
Well, first, by having your sandbox as a subdirectory of your source directory, then using find on the source directory, every time you run it you're going to find all the files in both the source directory and all its subdirectories, including the sandbox. If the built files in the sandbox have the same names as the files in the source directories, the find will find them all.
Maybe instead of:
SRCS := $(shell find $(SRC_DIRS) -name *.src)
you want something like:
SRCS := $(shell find $(SRC_DIRS) -name $(notdir $(BUILDDIR)) -prune -o -name *.src -print)
Or, alternatively, don't make your sandbox a subdirectory of your source directory. Or, make sure that whatever name you give to the files in the sandbox directory won't match the *.src pattern you give to find.
But beyond that this is wrong:
$(OBJS) : $(SRCS) $(BUILDDIR)/.create
Suppose SRCS is foo.src bar.src, which means OBJS is sandbox/o.foo.src sandbox/o.bar.src. Then the above expands to this:
sandbox/o.foo.src sandbox/o.bar.src : foo.src bar.src sandbox/.create
This is a common mistake; people seem to think that make will go through the targets and prerequisites and match them up, so the first target depends on the first prerequisite and the second target depends on the second one etc. but of course this cannot work correctly and that's not how make works. Make treats the above as if you'd written one rule for each target, with the same prerequisites; like this:
sandbox/o.foo.src : foo.src bar.src sandbox/.create
sandbox/o.bar.src : foo.src bar.src sandbox/.create
You can see this won't do what you want at all, since the $< will always be foo.src which is clearly wrong.
You need to write a single pattern rule that will build ONE target. Then make sure the pattern applies to all the targets.
You have made things hard for yourself by trying to "flatten" a directory structure of multiple source subdirectories, into a single level of target directory (by using the $(notdir $(SRCS))). Because of this, there's no pattern that will match the same target and directory, unless you write a separate rule for every subdirectory.
Luckily there is a solution for this: VPATH. This should work for you:
VPATH := $(sort $(dir $(SRCS))
$(BUILDDIR)/o.%.src : %.src $(BUILDDIR)/.create
#echo "\"compiling\" $< to produce $#"
cp $< $#
The VPATH tells make to go look in all the directories that it found any sources in, whenever it can't find one to build.
The basic problem is that your SRCS is all files in all subdirectories that match the pattern *.src (when you run make). That means that all your object files ($(OBJS)) also match, so they copied as well.
The solution is to change your SRCS pattern so it does not match the "object" files in the build directory. Possibilities:
SRCS := $(wildcard *.src)
or
SRCS := $(shell find $(SRC_DIRS) -name $(notdir $(BUILDDIR)) -prune -false -o -name *.src)
or change the names of your "object" files so they don't end in .src
If I type make all, the file works as expected.
By which I take you to mean that directory ./sandbox exists and contains these files:
o.file1.src
o.file2.src
o.file3.src
o.file4.src
o.file5.src
However, if I type make all again, instead of saying everything is up to data, I end up with the following contents in the sandbox:
o.file1.src o.file2.src o.file3.src o.file4.src o.file5.src o.o.file1.src o.o.file2.src o.o.file3.src o.o.file4.src o.o.file5.src
Of course you do, because everything is not up to date at that point, according to the target list you create. This line ...
SRCS := $(shell find $(SRC_DIRS) -name *.src)
... defines SRCS as a list of all the files under path ./ (which is the value of SRC_DIRS) that ends in .src. That includes any such files in ./sandbox, which include all the files placed there by the first make run. You generate a corresponding target file to build for each source, and those targets corresponding to sources built by the previous make run will not, in general, exist yet. So make builds them, just as you instructed it.
The best solution, short of abandoning that automatic source identification altogether, would probably be to change your naming scheme so that outputs cannot be mistaken so easily for sources. For example, if you want the output names to have the form foo.src, then have the corresponding input named something like foo.src.in. In that particular case, you could convert from source names to target names with
OBJS := $(addprefix $(BUILDDIR)/o., $(basename $(notdir $(SRCS) ) ) )
Alternatively, you could modify the find command to skip the sandbox directory, maybe by modifying SRC_DIRS:
SRC_DIRS = src1 src2 subfolder/src3
(These specific alternatives are not mutually exclusive.)

Makefile pattern for 1:1 recipe with a prerequisite that differs from target in both directory and file extension

For each .md file underneath a directory called src, I want to generate an HTML file underneath a new directory pub with the same internal directory structure, e.g.
src/foo/hello.md -> pub/foo/hello.html
src/bar/world.md -> pub/bar/world.html
I'm stuck on writing the prerequisites for each html file. Here's what I have so far:
SRCS = $(shell find src -name "*.md")
HTML = $(subst src/,pub/,$(SRCS:.md=.html))
%.html: %.md
#echo "placeholder to generate $# from $<"
publish: $(HTML)
As written, I get
$ make publish
make: *** No rule to make target `pub/foo/hello.html', needed by `publish'. Stop.
If I remove the prerequisites like this:
%.html: %.md
#echo "placeholder to generate $# from $<"
then I get:
$ make publish
placeholder to generate pub/foo/hello.html from
placeholder to generate pub/bar/world.html from
which is closer, but does not handle the prerequisite Markdown file.
How do I write a pattern for the prerequisite with both differing root directory and extension?
Just write the prefix and the suffix in the pattern:
pub/%.html : src/%.md
...

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'.

make wildcard subdirectory targets

I have a "lib" directory in my applications main directory, which contains an arbitrary number of subdirectories, each having its own Makefile.
I would like to have a single Makefile in the main directory, that calls each subdirectory's Makefile. I know this is possible if I manually list the subdirs, but I would like to have it done automatically.
I was thinking of something like the following, but it obviously does not work. Note that I also have clean, test, etc. targets, so % is probably not a good idea at all.
LIBS=lib/*
all: $(LIBS)
%:
(cd $#; $(MAKE))
Any help is appreciated!
The following will work with GNU make:
LIBS=$(wildcard lib/*)
all: $(LIBS)
.PHONY: force
$(LIBS): force
cd $# && pwd
If there might be something other than directories in lib, you could alternatively use:
LIBS=$(shell find lib -type d)
To address the multiple targets issue, you can build special targets for each directory, then strip off the prefix for the sub-build:
LIBS=$(wildcard lib/*)
clean_LIBS=$(addprefix clean_,$(LIBS))
all: $(LIBS)
clean: $(clean_LIBS)
.PHONY: force
$(LIBS): force
echo make -C $#
$(clean_LIBS): force
echo make -C $(patsubst clean_%,%,$#) clean
There is also a way of listing sub-directories with gmake commands only, without using any shell commands:
test:
#echo $(filter %/, $(wildcard lib/*/))
This will list all sub-directories with trailing '/'. To remove it you can use the substitute pattern:
subdirs = $(filter %/, $(wildcard lib/*/))
test:
#echo $(subdirs:%/=%)
Then to actually create rules executing makefiles in each sub-directory you can use a small trick - a phony target in a non-existent directory. I think in this case an example will tell more than any explanation:
FULL_DIRS =$(filter %/, $(wildcard lib/*/))
LIB_DIRS =$(FULL_DIRS:%/=%)
DIRS_CMD =$(foreach subdir, $(LIB_DIRS), make-rule/$(subdir))
make-rule/%:
cd $* && $(MAKE)
all: DIRS_CMD
Basically, target 'all' lists all sub-directories as prerequisites. For example, if LIB_DIRS contained lib/folder1 lib/folder2 then the expansion would look like this:
all: make-rule/lib/folder1 make-rule/lib/folder2
Then 'make', in order to execute rule 'all', tries to match each prerequisite with an existing target. In this case the target is 'make-rule/%:', which uses '$*' to extract the string after 'make-rule/' and uses it as argument in the recipe. For example, the first prerequisite would be matched and expanded like this:
make-rule/lib/folder1:
cd lib/folder1 && $(MAKE)
What if you want to call different targets than all in an unknown number of subdirectories?
The following Makefile uses macros so create a forwarding dummy-target for a number of subdirectories to apply the given target from the command line to each of them:
# all direct directories of this dir. uses "-printf" to get rid of the "./"
DIRS=$(shell find . -maxdepth 1 -mindepth 1 -type d -not -name ".*" -printf '%P\n')
# "all" target is there by default, same logic as via the macro
all: $(DIRS)
$(DIRS):
$(MAKE) -C $#
.PHONY: $(DIRS)
# if explcit targets where given: use them in the macro down below. each target will be delivered to each subdirectory contained in $(DIRS).
EXTRA_TARGETS=$(MAKECMDGOALS)
define RECURSIVE_MAKE_WITH_TARGET
# create new variable, with the name of the target as prefix. it holds all
# subdirectories with the target as suffix
$(1)_DIRS=$$(addprefix $(1)_,$$(DIRS))
# create new target with the variable holding all the subdirectories+suffix as
# prerequisite
$(1): $$($1_DIRS)
# use list to create target to fullfill prerequisite. the rule is to call
# recursive make into the subdir with the target
$$($(1)_DIRS):
$$(MAKE) -C $$(patsubst $(1)_%,%,$$#) $(1)
# and make all targets .PHONY
.PHONY: $$($(1)_DIRS)
endef
# evaluate the macro for all given list of targets
$(foreach t,$(EXTRA_TARGETS),$(eval $(call RECURSIVE_MAKE_WITH_TARGET,$(t))))
Hope this helps. Really helpfull when dealing with paralelism: make -j12 clean all in a tree with makefiles having these targets... As always: playing with make is dangerous, different meta-levels of programming are too close together ,-)

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