I'm using GNU Make 3.80. In my Makefile, I use automatic variable $# to refer to the current target.
#echo current target is ... [$#]
ifeq ($#,sms)
#echo yep, they are equal
else
#echo no, they are not equal
endif
It seems that $# expands to sms, as shown in the output below.
Output is:
current target is ... [sms]
no, they are not equal
My question: since $# (apparently) expands to sms, shouldn't the "true" branch of the ifeq conditional be executed (with the consequence that the output should read yep, they are equal)? [I am at a loss as to why the output is no, they are not equal.]
From the GNU Make manual:
10.5.3 Automatic Variables
...
It's very important that you recognize the
limited scope in which automatic
variable values are available: they
only have values within the recipe.
... there is a special feature of GNU
make, secondary expansion (see
Secondary Expansion), which will allow
automatic variable values to be used
in prerequisite lists.
That is, $# can only be used inside the section containing commands to build the target and, with some restrictions, inside the prerequisites list.
However you can use shell commands to implement conditions inside the list of commands used to build the target:
#echo current target is ... [$#]
if [[ "$#" == "sms" ]]; then \
echo yep, they are equal; \
else \
echo no, they are not equal; \
fi
Also if you want to check what targets were specified on the command line use MAKECMDGOALS variable.
Related
As part of my makefile I need to download and build ZLib. However I want to ensure that when I download ZLib, it is correct by comparing the sha256 of the downloaded .tar.gz against the known correct sha256 value. This need to work on multiple platforms.
I have so far something like the following, however the value of ZLIB_SHA256_ACTUAL always seems to be blank when I compare it with ZLIB_SHA256, so my makefile always exits with an error because the checksums are not the same. I am newish to Makefiles, can someone tell me what I am doing wrong please?
ZLIB_VER = 1.2.11
ZLIB_SHA256 = c3e5e9fdd5004dcb542feda5ee4f0ff0744628baf8ed2dd5d66f8ca1197cb1a1
SHA256_CMD = sha256sum
ifeq ($(PLATFORM), OS_MACOSX)
SHA256_CMD = openssl sha256 -r
endif
ifeq ($(PLATFORM), OS_SOLARIS)
SHA256_CMD = digest -a sha256
endif
libz.a:
-rm -rf zlib-$(ZLIB_VER)
curl -O -L http://zlib.net/zlib-$(ZLIB_VER).tar.gz
ZLIB_SHA256_ACTUAL = $(SHA256_CMD) zlib-$(ZLIB_VER).tar.gz
ifneq ($(ZLIB_SHA256), $(ZLIB_SHA256_ACTUAL))
$(error zlib-$(ZLIB_VER).tar.gz checksum mismatch, expected="$(ZLIB_SHA256)" actual="$(ZLIB_SHA256_ACTUAL)")
endif
tar xvzf zlib-$(ZLIB_VER).tar.gz
cd zlib-$(ZLIB_VER) && CFLAGS='-fPIC' ./configure --static && make
cp zlib-$(ZLIB_VER)/libz.a .
A makefile consists of two different programming languages in one file. Most of the file uses makefile syntax, that make understands and parses. But the recipes of the rules use shell syntax, which make doesn't try to interpret: it just passes the contents of the recipe to the shell to interpret.
The recipe is the part of the makefile indented with a TAB character, after a target definition. So in your example above, the target definition is libz.a: and all the lines after that which are indented with a TAB, are recipe lines. They are passed to the shell, not run by make.
The recipe is a single block of lines; you cannot intersperse recipe lines with makefile lines. Once make sees the first non-recipe line, that's the end of the recipe and make starts treating the remaining lines as if they were makefile lines.
Let's look at your rule:
libz.a:
-rm -rf zlib-$(ZLIB_VER)
curl -O -L http://zlib.net/zlib-$(ZLIB_VER).tar.gz
OK, this is fine: you've created a target libz.a and provided two command lines, which are valid shell commands, in your recipe.
ZLIB_SHA256_ACTUAL = $(SHA256_CMD) zlib-$(ZLIB_VER).tar.gz
OK, now you have problems; this is a make variable assignment, not a shell command, but since you've indented it with a TAB make will not interpret it: make will just pass it to the shell. That's not a valid shell command (in the shell, variable assignments cannot have spaces around the equal sign); this is trying to run a program named literally ZLIB_SHA256_ACTUAL and pass it the arguments = and the expansion of the SHA256_CMD variable. Even if this was recognized as a make assignment it wouldn't do what you want since it would just set the value of the variable to the string openssl sha256 -r zlib-1.2.11.tar.gz: you want to run that command and set the variable to the output.
Then the next lines:
ifneq ($(ZLIB_SHA256), $(ZLIB_SHA256_ACTUAL))
$(error zlib-$(ZLIB_VER).tar.gz checksum mismatch, expected="$(ZLIB_SHA256)" actual="$(ZLIB_SHA256_ACTUAL)")
endif
Again, this is wrong because these are make commands but you've put them into a recipe which means they'll be passed to the shell, but the shell doesn't know anything about them.
However, they never get the chance to be passed to the shell because the one thing make does with a recipe before it sends it off to the shell is expand all make variables and functions. So, when make expands this it runs the error function and that immediately fails and make never has a chance to try to run the recipe.
This is the tricky part of make. Maybe I've just confused you with all of the above stuff.
The short, simple answer is: you have to use shell commands to perform operations in a recipe. You cannot use make commands (like ifeq etc.), and if you want to set variables in a recipe they have to be shell variables, not make variables.
So, you want something like this, which uses shell syntax not make syntax for the variable assignment and test.
EDIT Note your SHA generation command doesn't print just the SHA it also prints the name of the file, so you can't compare them as strings: they'll never be the same. You need to do something fancier; there are many ways to go about it. Here I decided to use case to do the comparison:
libz.a:
-rm -rf zlib-$(ZLIB_VER)
curl -O -L http://zlib.net/zlib-$(ZLIB_VER).tar.gz
ZLIB_SHA256_ACTUAL=`$(SHA256_CMD) zlib-$(ZLIB_VER).tar.gz`; \
case "$$ZLIB_SHA256_ACTUAL " in \
($(ZLIB_SHA256)\ *) : ok ;; \
(*) echo zlib-$(ZLIB_VER).tar.gz checksum mismatch, expected=\"$(ZLIB_SHA256)\" actual=\"$$ZLIB_SHA256_ACTUAL\"; \
exit 1 ;; \
esac
tar xvzf zlib-$(ZLIB_VER).tar.gz
cd zlib-$(ZLIB_VER) && CFLAGS='-fPIC' ./configure --static && $(MAKE)
cp zlib-$(ZLIB_VER)/libz.a .
Note that each logical line in the recipe is passed to a new instance of the shell, so if you want to set a shell variable and test its value you have to combine physical lines into one logical line with the backslash/newline syntax.
Also, when running a sub-make in a recipe you should always use the variable $(MAKE) and never use just make.
I am processing some files and want to at one point create two categories depending on the filename so I can compare the two. Is this possible in a makefile?
%.output1: %.input
ifneq (,$(findstring filename1,$(echo $<)))
mv $<.output1 $#
endif
%.output2: %.input
ifneq (,$(findstring filename2,$(echo $<)))
mv $<.output2 $#
endif
%.output_final: %.output1 %.output2
do_something
I think there is two things wrong with this code:
There is a mistake in the ifneq line.
%.output1 %.output2 will always use the same filename - it may not be possible to do this in 'make' and this may require ruffus.
You have tab-indented the ifneq line so make doesn't consider it a make directive and is considering it a shell command and attempting to pass it to the shell to execute (hence the shell error you removed in your recent edit).
Use spaces (or no indentation) on that line to have make process it correctly. That being said having done that you cannot use $< in the comparison as it will not be set at that point.
$(echo) is also not a make function. You have mixed/confused processing times. You cannot combine make and shell operations that way. (Not that you need echo there to begin with.)
If you want the comparison to happen at shell time then do not use make constructs and instead use shell constructs:
%.output1: %.input
if [ filename1 = '$<' ]; then
mv $<.output1 $#
fi
Though that is also incorrect as $< is %.input and $# is %.output1 for whatever stem matched the %. That rule should probably look more like this (though I'm having trouble understanding what you are even trying to have this rule do so I may have gotten this wrong).
%.output1: %.input
# If the stem that matched the '%' is equal to 'filename1'
if [ filename1 = '$*' ]; then
# Then copy the prerequisite/input file to the output file name.
cp $< $#
fi
I'm not sure I understand your second question point. The % in a single rule will always match the same thing but between rules it can differ.
This %.output_final: %.output1 %.output2 target will map the target file foo.output_final to the prerequisite files foo.output1 and foo.output2. But will also map any other *.output_final file to appropriately matching prerequisite files.
How can I use $(MAKEFLAGS) (or another way of passing variables defined on the command line to sub-make) in a way that supports invocation from shell with both make VAR=val and make -args?
I need my subprojects configurable, but I hate autotools, so I'm using make variables for this, e.g. invoking from shell:
$ make USE_SSE3=1
and USE_SSE3 needs to apply to all builds in all sub-makefiles.
The manual states that:
if you do ‘make -ks’ then MAKEFLAGS gets the value ‘ks’.
Therefore I'm using -$(MAKEFLAGS) (with a dash prefix) in my Makefile.
However, that expands into invalid arguments when variables with no flags are used. If I run:
$ make FOO=bar
then sub-make gets invalid -FOO=bar. OTOH without the dash prefix variable definitions work, then but make -s, etc. don't.
Is there a syntax/variable/hack that makes passing of arguments and lone variable definitions work with sub-makefiles?
The legacy $(MKFLAGS) doesn't have the weird dash prefix problem, but it doesn't include variable definitions either. I've tried fixing the variable with $(patsubst), but that only made things worse by trimming whitespace.
I need the solution to be compatible with the outdated GNU Make 3.81 shipped with Mac OS X Mavericks.
foo:
$(MAKE) -C subproject -$(MAKEFLAGS)
$ make foo -s # MAKEFLAGS = 's'
$ make foo BAR=baz # MAKEFLAGS = 'BAR=baz'
$ make foo -j8 # MAKEFLAGS = ' --job-server=…'
You shouldn't set MAKEFLAGS at all. Why do you want to? You didn't give any reason to do so.
MAKEFLAGS is intended, really, to be an internal implementation passing arguments from a parent make to a child make. It's not intended, generally, to be modified by a makefile. About the only thing you can usefully do to it is add new flags.
If you just run the recursive make using the $(MAKE) variable rather than hardcoding make, it will Just Work:
recurse:
#$(MAKE) all FOO=bar
or whatever.
Years too late I got your answer if I got it right.
You can construct $(MAKEARGS) manually yourself like:
MAKEARGS := $(strip \
$(foreach v,$(.VARIABLES),\
$(if $(filter command\ line,$(origin $(v))),\
$(v)=$(value $(v)) ,)))
MAKEARGS := assign static
strip cleans leading and trailing whitespaces.
foreach v iterate over all variable names.
origin $(v) check if variable origin is "command line".
$(v)=$(value $(v)) output env assignment string.
Alternatively you can unpick the $(MAKEFLAGS) like:
MAKEARGS := $(wordlist 2,$(words $(MAKEFLAGS)),$(MAKEFLAGS))
MAKEFLAGS := $(firstword $(MAKEFLAGS))
Which can leave you with cleaner code for further recursions IMHO. I say this because I sometimes need to keep apart arguments and flags in certain cases. Especially as you get caught in debugging a recursion djungle.
But for any specific case one should consult the manual about recursive options processing.
Changing the $(MAKEFLAGS) can lead to unwanted malfunction.
Another useful information for the willing user could be that the $(MAKEFLAGS) variable is basically the whole argument list passed to make, not only the flag characters. So $(info MAKEFLAGS = $(MAKEFLAGS)) can give you something like:
MAKEFLAGS = rRw -- VAR=val
Cheers
To check if -B is present in make flags i do :
BB_CLOBBER := $(shell echo $(MAKEFLAGS) | grep wB)
ifeq (,$(BB_CLOBBER))
# also force clobber make if these files are missing
BB_CLOBBER := $(shell (test -e $(bb_gen)/minimal/.config && test -e $(bb_gen)/full/.config) || echo "B")
endif
bb_prepare:
ifneq (,$(BB_CLOBBER))
#rm -rf $(bb_gen)/full
...
i'm new to gnu make.
i searched around but i cannot find anything working...
I have a list of tool prefix suxh as:
DEFTOOL= /usr/bin/i686-mingw32- /usr/bin/x86_64-w64-mingw32- /usr/bin/
I want to change the extension of the binary file if string "mingw" is in the current tool, so
$(foreach c, $(DEFTOOL),$(call dist_make, $(c)))
...
define dist_make
result= ${shell echo $(1) | grep mingw }
echo x$(result)x
# $(if $(result),\
# $(1)gcc $(DIST_CFLAGS) -o cap2hccap$(WINEXT) ./cap2hccap.c; echo "windows";,
# $(1)gcc $(DIST_CFLAGS) -o cap2hccap$(LNXEXT) ./cap2hccap.c; echo "linux"; \
# )
endef
where LNXEXT is empty and WINEXT is ".exe".
i cannot get this working....
how can i known if the argument of the function contains "mingw" ?
PS:
i known that the 64bit and the 32bit mingw output is the same but i will fix it when i have understood how check if a string is inside another.
If you known a better way to automate cross dev building spit it out :)
Your question is a little unclear. If you want to change a variable, outside of any rule:
ifneq ($(findstring mingw,$(DEFTOOL)),)
FILENAME = foo.xxx
endif
If you want to rename a file conditionally within a rule:
someTarget:
ifneq ($(findstring mingw,$(DEFTOOL)),)
mv foo.aaa foo.xxx
endif
You could also put the conditional within the command, but I can't see why you'd want to.
I have a makefile that defines several rules where the target is a foreach function.
$(foreach var,$(list), $($(var)_stuff) $($(var)_more_stuff)):
#echo Building $# from $^...
$(CC) $(FLAGS) ...
Is there any way to get make to quit when encountering an error without going through the entire list.
One workaround is to "manually" invoke exit on failure.
For example, assume we have a directory called scripts with a number of shell scripts (with filenames that end with .sh) that we want to execute.
Then a variable declaration like this:
LIST_OF_SCRIPTS ?= $(wildcard scripts/*.sh)
will give us a list of those scripts, and a target like this:
run-all-scripts
#$(foreach scriptfile,$(LIST_OF_SCRIPTS),$(scriptfile);)
will run all of those scripts, but as you note, the foreach loop will keep going whether or not one of the scripts returns an error code. Adding a || exit to the command will force the subcommand to exit on error, which Make will then treat as a failure.
E.g.,
run-all-scripts
#$(foreach scriptfile,$(LIST_OF_SCRIPTS),$(scriptfile) || exit;)
will do what you want (I believe).
Specifically, using your pseudo-code example, I think you want something like this:
$(foreach var,$(list), $($(var)_stuff) $($(var)_more_stuff)):
#echo Building $# from $^...
($(CC) $(FLAGS) ...) || exit
(where all I've changed is wrapping the (CC) $(FLAGS) ... bit in parens and appending || exit to make it fail on error).
The foreach is completely evaluated and substituted before any of the rules are executed. So the behaviour of this should be identical to as if you had hardcoded the rule without using the foreach. In other words, it's not directly relevant to the problem.
There are only a few possible explanations for what you're seeing, mostly described in the manual here:
You are running Make with -k or --keep-going
You are running Make with -i or --ignore-errors
Your targets is defined as prerequisites of the special .IGNORE target
Your recipe starts with a -
Your recipe isn't actually returning a non-zero exit status
Not sure about your example, but maybe problem is in ; - look at Makefile : show and execute:
dirs = $(shell ls)
clean:
$(foreach dir,$(dirs),echo $(dir);)
produce:
$ make clean
echo bin; echo install.sh; echo Makefile; echo README.md; echo utils;
So make check exit code only for last command: echo utils.