I dont know much makefile stuff I've been tending to learn bits as required.
The biggest failing of my makefiles is that I have been listing all the files manually, while this hasn't been a problem my current project is getting unwieldy. I have 4 directories each with sources files.
How can I get all the object file listing without having to list them manually.
This doesn't work, but it shows what I've been trying to do.
VPATH = Lib GameCode Moot/Moot Moot/Impl
OBJS = $(subst .cpp, .o, $(VPATH))
foobar: $(OBJS)
g++ -o $# $^
%.o: %.cpp
g++ -c $< -o $# -I Moot
clean:
rm main.o lib.o foo.o foobar
Personally, I never had any problem in listing all files manually. Listing a file to the makefile takes negligible time compared to adding filling it with useful content.
To get all files from different directories, one might suggest using wildcard function. So my_sources:=$(wildcard *.cpp dir1/*.cpp) will make the variable contain source files that match wildcard expression.
However, I find it less convenient than using usual Linux find command via shell:
# Find all sources
my_sources:=$(shell find -iname '*.cpp')
# Make targets out of them
OBJS=$(my_sources:%.cpp=%.o)
Find is more powerful than Make's builtin wildcard. You might also want to use other shell capabilities, such as pipelines, for example, to filter output of find (if Make's filter-out function is not enough). Or something like this, to avoid excessive variables:
OBJS:=$(shell find -iname '*.cpp' | sed 's/\.cpp$/.o/')
You name it!
Using VPATH or vpath will not work for your problem.. it provides a search path to find files but you still need to list the files. If you just need to compile all and any .c/.cpp files found in those directories then this should work:
foobar: $(shell ls Lib/*.cpp) $(shell ls GameCode/*.cpp) $(shell ls Moot/Moot/*.cpp) $(shell ls Moot/Impl/*cpp)
g++ -o $# $^
clean:
rm foobar $(shell ls Lib/*.o) $(shell ls GameCode/*.o) $(shell ls Moot/Moot/*.o) $(shell ls Moot/Impl/*o)
The VPATH info is not needed, the substitution of .o for .cpp can go as can the override of the implicit rule. Additionally, not the use of ls instead of find to look in, and only in, the specfified directory.
Related
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.)
I have a series of directories organized like this:
foo/
foo.file1 foo.file2
bar/
bar.file1 bar.file2
baz/
baz.file1 baz.file2
Right now I'm processing these files using a script that does all the checking for file existence etc but I thought that perhaps I could use a Makefile for it (since said script is very fragile), to avoid reprocessing files that did not change.
The problem is that each directory is independent, and I'd need to do, for example:
foo.file1.processed: foo.file1
run_random_program foo.file1 -o foo.file1.processed
for each of the 71 directories that are in total in that path. This looks like being extremely tedious and I wonder if there's something that would prevent me from writing all of this by hand.
Is such a thing possible?
EDIT: Some examples that show what I have in mind, had I a single Makefile for each directory:
file1.cds.callable: file1.callable
long_script_name -i $< -o $#
file1.rds: file1.cds.callable
another_long_script_name $< additional_file_in_folder $#
file1.csv: file1.rds
yet_another_script $< $#
Seems like pattern rules are exactly what you need:
# These are the original source files (based on the example)
CALLABLE := $(wildcard */*.callable)
# These are the final targets
TARGETS := $(CALLABLE:%.callable=%.csv)
all: $(TARGETS)
%.csv : %.rds
yet_another_script $< $#
%.rds: %.cds.callable
another_long_script_name $< additional_file_in_folder $#
%.cds.callable: %.callable
long_script_name -i $< -o $#
I have several directories which may have subdirectories, and I'm going to compress each one to a file if any file in that directory is changed.
For example, I have 2 directories dir1 dir2, and I want to compress them to comp_dir1.tar.gz and comp_dir2.tar.gz.
I wrote the following code:
comp_%.tar.gz : %/$(shell find % -name "*")
tar -czvf $# $<
But I got the error:
find: ‘%’: No such file or directory
It is obvious that I can't use "%" in the shell command.
Is there any way to solve this?
What you need in any case is a list of the directories you want to compress. Using that, you can use a GNU Make feature Remaking Makefiles to generate "dependency files" which include all files found in these directories. Here is a working example:
DIRECTORIES:=dir1 dir2
ARCHIVES:=$(addsuffix .tar.gz,$(addprefix comp_,$(DIRECTORIES)))
all: $(ARCHIVES)
comp_%.tar.gz.d: %
echo $(#:.d=) $(#): $(shell find $< -name "*") > $(#)
# include the dependency files, this will cause GNU make to attempt creating
# them using the above pattern rule.
-include $(addsuffix .d,$(ARCHIVES))
comp_%.tar.gz: %
tar czvf $# $<
.PHONY: all
the makefile below processes files matching the patterncontent/%.md and outputs the targets in the html directory. Source files are named with the convention of putting a leading number in front of them, like content/01.index.md or content/O2.second-page.md and so on. I would like to remove the leading 0x. number sequence in the target file. For instance, content/01.index.html would generate html/index.html.
How can I do this?
Thanks
MD_FILES = $(shell find content/ -type f -name '*.md')
HTML_FILES = $(patsubst content/%.md, html/%.html, $(MD_FILES))
all: $(HTML_FILES) html/static
html/%.html : content/%.md
mkdir -p $(#D)
python generator/generate.py $< $#
.PHONY: html/static
html/static :
rsync -rupE generator/static html/
.PHONY: clean
clean:
rm -fr html
Replace:
html/%.html : content/%.md
mkdir -p $(#D)
python generator/generate.py $< $#
with:
html/%.html : content/%.md
mkdir -p $(#D)
file='$(#F)'; python generator/generate.py $< "$(#D)/${file#*.}"
Unfortunately, I can't think of a good way of doing that in make itself. I can think of one way but it isn't as simple as that escaping and it isn't safe for files with spaces (not that that matters much here since make already can't handle those).
IMHO, it is a bad idea to use find or wildcards to list files in makefiles. This is because developers have temporary or debugging files sometimes. It is best to list files explicitly. This way, it forces the developer to think about their intent.
If you agree to list files explicitly, then in this case it is best to list the target files, rather than source files, and here is your answer:
HTML_FILES := html/index.html html/second-page.html
.SECONDEXPANSION:
$(HTML_FILES): html/%.html : $$(wildcard content/*.$$*.md)
(put recipe here, using $# and $<)
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 ,-)