I have a Makefile that call a bunch of makers such as compilers and small scripts. Sometime (often a ClearCase issue), the executable flag is missing or worse the script is missing.
What is the best way to check the executable flag and the existence of a list of programs in a Makefile.
My first implementation was to foreach on each executable and call them, then catch the exit flag. Because that check takes some time, I had to ifdef it in order to bypass the check for all makes rules that does not need to use these scripts. For example the case of make clean only call rm which has to be installed on all platforms. I don't need to check the other programs.
The second implementation was just to check the execution flag with a $(shell) and a [ -x foo ] combined in a ifdef directive. I feed this solution is a bit ugly.
The third solution is to call a shell script that do the job. However, this shell script must remain executable in any case. I can do FOO != chmod u+x checker but this is also quite ugly.
What would be the best solution?
Will an approach like the following help?
target: source ./script_1
test -x ./script_1 || chmod +x ./script_1
./script_1 < source > target
Related
I'm using automake.
I'd like to have a script run each time I run 'make'.
This script does a git diff and generates an MD5 sum of the diff.
The hash is written as a #define in repos_version.h
e.g.:
#define REPOS_DIFF "-190886e9f895e80c42cf6b426dc85afd"
The script only rewrites this file if it doesn't exist or if the diff has is different to what is in repos_version.h already. But the script needs to be run for each make.
main.c includes repos_version.h and prints out the hash when the executable is run.
Here's Attempt 1 for Makefile.am
all: config.h
#chmod +x gen_diff_hash.sh
#./gen_diff_hash.sh
$(MAKE) $(AM_MAKEFLAGS) all-recursive
This work, but I get the following error
Makefile:1234: warning: overriding recipe for target all'
Makefile:734: warning: ignoring old recipe for targetall'
Here's Attempt 2 for Makefile.am
all-local:
#chmod +x gen_diff_hash.sh
#./gen_diff_hash.sh
main.c: repos_version.h
However, this doesn't work, as all-local seems to be run too late. A second run of 'make' does get the desired result, but that's not a runner.
So neither are great.
Any ideas?
I've been reading through the automake hooks documentation, but I can't see anything that suits my needs.
You could ensure the script is always run every time Make loads the Makefile, by executing it via $(shell ./gen_diff_hash.sh) and assigning it to a throwaway variable (or using it in some other construct like an ifeq or something).
Note, that this is not POSIX, and on Make implementations other than GNU this isn't valid syntax. GNU Make 4.x supports using VAR != ./gen_diff_hash.sh as well, which is compatible with BSD Make at least.
But maybe it would be a better idea to create a .PHONY: gendiff target that runs the script, and make the header depend on this gendiff. The target would then be re-evaluated every time Make checks if repos_version.h is up-to-date, rather than every time Make is run at all.
I'm trying to put together a Makefile that will create a folder and clone repositories from GIT
I'm having trouble putting it all together so I'm starting with a generic Makefile
My makefile:
$(shell mkdir -p myDir)
$(shell git.sh)
The shell script that I am trying to get to invoke
#!/bin/sh
REPOSRC="my bitbucket repo URL"
LOCALREPO="myDir"
# We do it this way so that we can abstract if from just git later on
LOCALREPO_VC_DIR=$LOCALREPO/.git
if [ ! -d $LOCALREPO_VC_DIR ]
then
git clone $REPOSRC $LOCALREPO
else
cd $LOCALREPO
git pull $REPOSRC
fi
# End
When I run make I'm getting the following error:
Makefile:2: *** missing separator. Stop.
Also, is this the correct way to go about this task?
What you have is not a makefile. It's really a shell script written in makefile syntax (and, as you've discovered from the errors, not correct makefile syntax).
Make is a tool that allows commands to be run to update a set of target files, or not run if any of the target files don't need to be updated, based on comparing timestamps of the target files and their prerequisite files. These dependency relationships can be chained.
That's all that make is for.
To prototypical example is compiling a program: if any of the source files have been modified then you need to recompile the object files for those sources; if object files are updated then libraries might need to be re-created; if object or library files are updated then programs might need to be re-linked.
If your problem space doesn't map, or can't be made to map, to that mechanism, then make and makefiles are not the correct tool for the job you have in mind. Based on your description of your problem, make is not the right tool for this job.
You should just write a shell script, as you've basically done here already, and move forward.
If you do want to write a makefile you should spend some time understanding the syntax of makefiles and how they work, rather than just searching on Stack Overflow and trying to put together a makefile based on the answers. For example, try reading at least the introduction of the GNU make manual.
With $(shell ...) construct you substitute shell command output into the makefile. Of course after calling mkdir or invoking git the output is not a valid makefile.
Your makefile should be like this
all:
mkdir -p myDir
./git.sh
note that indentation after all: has to be done with tabs.
And it looks like you don't need make for your task. Just shell script would be enough.
I know nothing about shell scripting but something has come up and I need to be able to understand what two lines of code do so that I can modify a project I am working on
SDKROOT= make -C $TEMP_DIR -f $PROJECT_DIR/greg/Makefile VPATH=$PROJECT_DIR/greg || exit $?
$TEMP_DIR/greg -o $DERIVED_FILES_DIR/${INPUT_FILE_BASE}.m $INPUT_FILE_PATH
will you please explain what these two lines of code do... I know what the variables are and the path names but the rest of the syntax is confusing and foreign. Please help.
The first line:
SDKROOT= make -C $TEMP_DIR -f $PROJECT_DIR/greg/Makefile VPATH=$PROJECT_DIR/greg || exit $?
SDKROOT= sets the environment variable SDKROOT to nothing for the execution of the make command.
make is the build tool, and it's being run with the following options:
-C $TEMP_DIR: means run make in the directory $TEMP_DIR
-f $PROJECT_DIR/greg/Makefile specifies to make to use the Makefile in $PROJECT_DIR/greg
VPATH=$PROJECT_DIR/greg sets another variable, VPATH to $PROJECT_DIR/greg. VPATH specifies to make a search path for prerequisits.
|| exit $? means that if the make command fails the script should exit with the same error code as make, as $? means the return code of the last run program/command.
The second line:
$TEMP_DIR/greg -o $DERIVED_FILES_DIR/${INPUT_FILE_BASE}.m $INPUT_FILE_PATH
appears to be running the command $TEMP_DIR/greg with the option -o $DERIVED_FILES_DIR/${INPUT_FILE_BASE}.m and with some input from $INPUT_FILE_PATH. This looks like the program which may have been built from the previous line's make command, so it's hard to know exactly what it does.
EDIT
The SDKROOT is an environment variable used by XCode to say where the SDK it's using is installed. It will be a path like /Developer/SDKs/MacOSX"${HOST_VERSION}".sdk/ for instance. The value should be setup somewhere in XCode I imagine (I don't used xcode so can't be more helpful than that.). By doing SDKROOT= at the beginning of the command the value of SDKROOT will be nothing/blank. The reason for this is that the code being compiled will use resources which exist in the SDKROOT, rather than local ones; such resources may be classes, config or libraries for example.
I'd like to simplify the workflow so that rather than issuing these commands
$ make program_unittest
... output of $MAKE ...
$ ./program_unittest args
I could have my program automatically attempt to compile itself (if the source has been updated) when it is run, so that I do not have to go back and run make myself.
Here's what I'm thinking: My unit test build should first check if there is a makefile in the directory it's in, and if so, fork and exec make with the target corresponding to itself. If make determines "nothing to be done", it will continue on its way (running the unit-tests). However, if make actually performs a compilation, one of two things may happen. gcc (invoked by make) might be able to overwrite the build (an older version of which is already running) during compilation, in which case I can then perhaps exec it. If my system does not permit gcc to overwrite the program which is in use, then I have to quit the program before running make.
So this has become quite involved already. Are there perhaps more elegant solutions? Maybe I could use a bash script? How do I ascertain if make issued compilation commands or not?
Why not have make run the unit tests?
I have a Makefile that starts by running a tool before applying the build rules (which this tool writes for me). If this tool, which is a python script, exits with a non-null status code, I want GNU Make to stop right there and not go on with building the program.
Currently, I do something like this (top level, i.e. column 1):
$(info Generating build rules...)
$(shell python collect_sources.py)
include BuildRules.mk
But this does not stop make if collect_sources.py exits with a status code of 1. This also captures the standard output of collect_sources.py but does not print it out, so I have the feeling I'm looking in the wrong direction.
If at all possible, the solution should even work when a simple MS-DOS shell is the standard system shell.
Any suggestion?
There might be a better way, but I tried the following and it works:
$(if $(shell if your_command; then echo ok; fi), , $(error your_command failed))
Here I did assume that your_command does not give any output, but it shouldn't be hard to work around such a situation.
Edit: To make it work with the default Windows shell (and probably any decent shell) you could write your_command && echo ok instead of the if within the shell function. I do not think this is possible for (older) DOS shells. For these you probably want to adapt your_command or write a wrapper script to print something on error (or success).
Ok, here's my own solution, which is unfortunately not based on the status code of the collect_sources.py script, but which Works For Me (TM) and lets me see any output that the script produces:
SHELL_OUTPUT := $(shell python collect_sources.py 2>&1)
ifeq ($(filter error: [Errno %],$(SHELL_OUTPUT)),)
$(info $(SHELL_OUTPUT))
else
$(error $(SHELL_OUTPUT))
endif
The script is written so that any error produces an output beginning with "collect_sources: error:". Additionally, if python cannot find or execute the given script, it outputs an error message containing the message "[Errno 2]" or similar. So this little piece of code just captures the output (redirecting stderr to stdout) and searches for error messages. If none is found, it simply uses $(info) to print the output, otherwise it uses $(error), which effectively makes Make stop.
Note that the indentation in the ifeq ... endif is done with spaces. If tabs are used, Make thinks you're trying to invoke a command and complains about it.
You should use a regular target to create BuildRules.mk:
BuildRules.mk: collect_sources.py
python $< >$#
include BuildRules.mk
This is the standard trick to use when automatically generating dependencies.
Fixing https://stackoverflow.com/a/226974/192373
.PHONY: BuildRules.mk
BuildRules.mk: collect_sources.py
echo Generating build rules...)
python $< >$#
$(MAKE) -f BuildRules.mk
Make sure you're not invoking make/gmake with the -k option.