Platform-dependent Makefile - makefile

I read OS detecting makefile, but I'd rather have two different Makefile, one for Windows and one for Linux, and source them from inside the main Makefile. Something like:
ifeq ($(OS),Windows_NT)
# run the commands in the MakefileWin file
else
# run the commands in the MakefileLinux file
endif
Is it possible without a shell script, just using make commands? Thanks

Why not just use include?
ifeq ($(OS),Windows_NT)
include Makefilewin
else
include MakefileLinux
endif
?

Related

How to unhide commands in Makefile?

I want to troubleshoot Makefile. A lot of commands are hidden using the # prefix. e.g.
all:
#echo "building..."
how can I tell make to show all the commands? I tried the -d option and it does not show hidden commands.
Maybe try running make with V=1 or VERBOSE=1
I'm not exactly sure this is what you are looking for, but here is a related technique:
Prefixing commands with # in a makefile recipe can be convenient, so output does not get too much cluttered, but, as you may have discovered, in some situations it can be useful to actually see what command is executed.
One solution is to avoid using the # character in a makefile but use instead a variable. Say, a one-letter one. Say L, for "log output" (but its your choice).
Then, prefix all your commands in your makefile with that variable:
target: prerequ
$(L)do_this $< $#
$(L)do_that $< $#
An simply define the variable, using some command-line switch:
ifeq "$(LOG)" ""
LOG=no
endif
ifeq "$(LOG)" "Y"
L=#
endif
Then, you can launch make from the shell like this $make target (no logging) or like this:
$ make target LOG=Y
And all the executed commands will show up!

Stop make if argument not passed

I have a makefile
PATH = "MyFolder_"{ver}
compile:
[list_of_commands] $PATH
And run it like this
make ver="1.1" compile
How do I stop compiling in case if no ver specified?
I want something like this
#input
make compile
And then output
No version specified. Compilation terminated.
There are many ways to do it. Partly it depends on which version of make you're using, and which operating system you're running it on (which shell make invokes).
Note you should NOT use a variable PATH in your makefile; that's the system's PATH variable and resetting it will break all your recipes.
Also it's usually a bad idea to include quotes in the variable like that. If you want it quoted then add the quotes in the recipe.
If you have GNU make you can do this:
ifeq ($(ver),)
$(error No version specified.)
endif
If you don't have GNU make but you're using a UNIX system or Windows with a UNIX shell, you can do this:
MYPATH = MyFolder_$(ver)
compile:
[ -n "$(ver)" ] || { echo "No version specified."; exit 1; }
[list_of_commands] "$(MYPATH)"
If you're using Windows with Windows command.com then you can do something similar but I'm not sure of the details.

shellscripts in Makefiles do not work as expected

I found many answers here and elsewhere on the topic, but none that worked. Please help me out here.
I need to set some environment variables, which is partly done in some scripts, called from a master script, partly directly. Here is a minimal Makefile that shows the unwanted behaviour:
FC := ifort
SHELL := /bin/bash
some_target: load_ifort
$(FC) file.f
load_ifort:
source /usr/local2/bin/ifort-compilervars.sh ia32
export LM_LICENSE_FILE=/usr/local2/misc/intel2013/flexlm/server.lic
if I call make, I get an "ifort: command not found" error. If I execute the two comamnds by hand on the command line before calling make, ifort is found and everything is good.
What am I missing???
Each line in a recipe gets executed in a separate subshell. So you create one shell which sources the .sh file, then exits and forgets everything, then another shell which starts with a clean slate.
The straightforward solution in your case would be to collect all these commands in a single variable. I have factored out the LM_LICENSE_FILE assignment because that can be done in Make directly, but you could include that in the FC variable as well.
LM_LICENSE_FILE := /usr/local2/misc/intel2013/flexlm/server.lic
export LM_LICENSE_FILE
FC := source /usr/local2/bin/ifort-compilervars.sh ia32; \
ifort
some_target:
$(FC) file.f
If the shell commands can be straightforwardly run by Make as well, you could include them, or perhaps translate the sh file into Make commands by a simple script.
Another option would be to create a simple wrapper in your PATH; maybe call it fc:
#!/bin/sh
. /usr/local2/bin/ifort-compilervars.sh ia32
ifort "$#"
then just use fc where you currently have $(FC). (If the ifort-compilervars.sh file contains Bash constructs, in spite of the name, you should change the shebang to #!/bin/bash.)
As a rule, only one-liner shell commands "work". From the comment about "bash", it seems likely you are using GNU make. In your example, the word "source" is not found in the GNU make manual's index. (If you found this in a working example, it would be helpful to start from that). There are two types of variables of interest:
makefile variables, which live in the make program
environment variables, which are "exported"
The latter would include $PATH, which is used to find programs. For updating that, you do need shell commands. But (lacking some special provision in the make program), exported variables from a shell script are not passed up into the make program and made available for the next line of the makefile.
You could reorganize the makefile to provide a rule which combines the source command and other initialization into a shell command which then recurs (carrying those variables along) into a subprocess which would then do the compiles. Something like
build:
sh -c "source /usr/local2/bin/ifort-compilervars.sh ia32; \
export LM_LICENSE_FILE=/usr/local2/misc/intel2013/flexlm/server.lic; \
$(MAKE) some_target"
some_target: load_ifort
$(FC) file.f

MAKEFILES variable environment

How to use MAKEFILES variable environment? I writing in a bash MAKEFILES=/home/toker/mymake, but if I'm running a /home/toker/bundocode/gettingstart/testMF/Makefile then /home/toker/mymake doesn't executed. When I'm type $MAKEFILES in the bash then bash: /home/toker/mymake: Permission denied is displayed.
The MAKEFILES variable contains one or more makefiles, not the make program. From the above messages it looks like mymake is a make program you're trying to run. The shell decides what programs to run (by looking in directories listed in the $PATH environment variable) and the shell doesn't pay any special attention to the MAKEFILES variable. Only once make is running does it look at the MAKEFILES variable to see what other makefiles it might want to parse.
What is in the /usr/toker/mymake file? What do you mean by running a .../Makefile? One typically runs make, not a makefile. Then make reads in the makefile. There are ways to change a makefile to be executable but I don't think that's what you're looking for here.
ETA:
If the file /usr/toker/mymake is actually a makefile (BTW, convention typically uses .mk extensions to denote makefiles although there's no really official extension), then you can do this:
$ cat /usr/toker/mymake
$(info loaded /usr/toker/mymake)
foo: ; #echo building $#
$ export MAKEFILES=/usr/toker/mymake
$ cat Makefile
bar: foo ; #echo building $#
$ make
loaded /usr/toker/mymake
building foo
building bar
If you can show an example of exactly what you did (show the makefile and the commands you typed and the results you got) and explain what you don't understand about it, then we can see much more accurately what's going on than by you trying to describe it in words).

How to handle setting up environment in makefile?

So, to compile my executable, I need to have the library locations set up correctly. The problem is, the setup comes from a bunch of scripts that do the env variable exporting, and what needs to be set up may change (beyond my control) so I need to use those scripts instead of copying their functionality. To compile in regular command line, I need to do something like:
setup library1
setup library2
source some_other_setup_script.bash
g++ blah.c
# setup is a executable on my system that run some scripts
How would I write a makefile that accomplishes that? As far as I tried, the env variable exporting does not carry over (i.e. "export VAR=remember; echo $VAR" won't work)
You can also add environment variables properly with the machinery of GNU make, like so:
export TEST:="Something Good!"
test:
echo $$TEST
This (I think) has different semantics from:
TEST2:="Something not quite so useful?"
test2:
echo ${TEST2}
Which (again, I think) does the substitution within make before passing along to the shell. Note that the export command doesn't work within a target block, just unindented as an immediately executed command.
If variable exporting is not working the way it does on your command line, that suggests that Make is choosing a shell different from the one you're using, with different syntax for handling variables (export VAR=remember; echo $VAR works fine for me). Make uses /bin/sh by default, but you can override this with the SHELL variable, which Make does not import from the environment. I suggest setting SHELL (in the Makefile) to whatever you're using in your environment and trying the export VAR=remember experiment again.
Ultimately you will need to define the variable and execute the compiler in a shell list or even a script, rather than in separate make commands. There are a couple of refinements you could add, however. You could tell make about the script:
maintarget: script.sh blah.c
source script.sh; g++ blah.c
script.sh:
setup include script here
Another thing would be to just execute all that stuff in the same shell
maintarget: blah.c
run this; run that; run the other thing; g++ blah.c
I believe all make versions will run a ; list in the same shell, but you can always force a subshell with (list) or by calling specifically a shell script as a compiler command wrapper.
Don't forget to have the appropriate targets depend on your scripts themselves. BTW, some make versions (pmake aka bsd make) can execute a command when defining a make variable, and all versions of make then exports those. But I don't think gmake can do that.
You could write another shell script that executes all those commands, then prints out variable assignments that make can use. Run the script, pipe its output to a file, then include that file from your Makefile. For example:
Makefile:
all:
echo $(FOO)
test.mk: test.sh
./$< > $#
include test.mk
test.sh
echo "FOO=1"
Running "make" in the directory containing this Makefile produces:
make: Entering directory `/home/luser/build/mktest'
Makefile:7: test.mk: No such file or directory
./test.sh > test.mk
make: Leaving directory `/home/luser/build/mktest'
make: Entering directory `/home/luser/build/mktest'
echo 1
1
make: Leaving directory `/home/luser/build/mktest'
make creates test.mk by running the shell script, then includes it. test.mk contains the output of test.sh, and is parsed as a Makefile. See http://www.gnu.org/software/make/manual/make.html#Include for more details.
We use a variant of this in Mozilla's client.mk to let you define options in a "mozconfig" file:
http://mxr.mozilla.org/mozilla-central/source/client.mk#138
Restatement: How do I get a shell variable into a make file?
Something like:
MYVAR := $(shell echo $(MYVAR)) <any_makefile_additions_here>
So, this defines MYVAR inside a MAKEFILE when an environment variable named MYVAR is also set.
It might be of interest, that, in order to override an option that is already defined in a makefile, make supports (I am referring to GNU Make 3.82, but other version probably too) the option -e.
Example:
Makefile:
CC=gcc
...
Run make:
CC=gcc-4.7
make -e
will use gcc-4.7 instead of gcc.

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