Having this simple makefile rule:
exe:
for i in *; do [ -x "$$i" ] && echo "$$i"; done
Will output:
for i in *; do [ -x "$i" ] && echo "$i"; done
executablefile
make: *** [makefile:6: exe] Error 1
So it does, what I want, but even then, error with no other message. But not only for this particular example (which I still do not get), I would like to know, how to get some more info from bugs in makefile (is there a makefile debugger?). From makefile manual the *** is for fatal error, which ends compilation, but yet it outputs the executablefile (so it did compiled to that point). Apart from fatal error, - warnings give more info, so why do not do fatal errors as well?
explanation of this example
some advices how to debug makefile scripts
This is not an error from make, that's why there's no other information.
Make runs a shell and gives the shell your recipe to invoke. If the shell exits with success (exit code 0) then make assumes that the command it ran worked. If the shell exits with failure (any exit code other than 0), then make assumes the command it ran failed. Make doesn't know why it failed, make assumes that whatever command failed will have printed some information about why. All make knows is the exit code, so that's all make can tell you:
make: *** [makefile:6: exe] Error 1
This means that make ran the recipe for target exe at makefile line number 6, and that command exited with an error code 1 (which is not 0, hence a failure).
Why did this happen? Let's look at your shell script:
for i in *; do [ -x "$$i" ] && echo "$$i"; done
Let's suppose the last file matching * (so the last time we go through the loop) the file is not executable. That means the test of the last file [ -x "$$i" ] will fail. Since that's the last command that the shell runs before it exits, that will be the exit code of the shell, and you have a failure.
You need to be sure that the shell exits with success. One way to do that is ensure the last command the shell runs is always success; maybe something like this:
for i in *; do [ -x "$$i" ] && echo "$$i"; done; true
Related
As part of a bash script, which has set -e, I do make distclean which, obviously, fails with the following error, if I have run distclean before calling the script:
make: *** No rule to make target 'distclean'. Stop
Is there way to do distclean and not fail if there's nothing to clean?
If you're okay with the error message being printed, and just want to ignore the failure and keep going, a common idiom is to append || :.
The general syntax here is cmd1 || cmd2. If cmd1 fails then it runs cmd2. : is the (unusual) name of a command that always succeeds, so || : has the effect of ignoring the first command's exit code.
make distclean || :
If you would rather not see an error message at all, you could check if the Makefile exists first:
if [[ -e Makefile ]]; then make distclean; fi
You could do a
make distclean || echo "(Error from make ignored)"
to make it explicit what's happening.
I have the following target in my makefile
omp: main_omp.c omp_impl.o
if [[ ! -e ../bin/ ]]; then mkdir ../bin/ fi
gcc $(CFLAGS) ... # compilation et cetera
On executing make omp in the same directory causes make to terminate with the following error
if [[ ! -e ../bin ]]; then mkdir ../bin fi
/bin/sh: 1: Syntax error: end of file unexpected (expecting "fi")
make: *** [makefile:10: omp] Error 2
Executing the if ... fi statement in the terminal works as intended. I tried different combinations of double quotes, splitting into different lines etc and nothing works.
How do I fix this problem? Why is make running into an EOF over here?
You state:
Executing the if ... fi statement in the terminal works as intended.
I doubt that. If I cut-and-paste your example, I get a continuation prompt from the shell:
if [[ ! -e ../bin/ ]]; then mkdir ../bin/ fi
>
And that is logical. Your shell (either via the prompt or via make) sees that you want to execute mkdir with two arguments ../bin and fi. The solution is of course to make sure that the shell sees the fi as the next "command". To do that, you need to add a ; before the fi.
Given a Makefile that's often times run with the -j flag for parallel builds. I want it to terminate with a result message. I would like this message to say if the build failed, and if it failed, what the error was. It doesn't have to say anything if the build succeeded (although it could) but it must warn the user when a target failed to build and why.
This behavior is already there during sequential builds, but not during parallel builds. Parallel builds interweaves the output and an error message is often overlooked because output from other targets might push the failed target's error off screen. A careless developer might see no errors on his/her screen and assume the build succeeded.
It's quite an intuitive feature and I've searched for an answer, but it doesn't seem like there's any straight forward solutions. Any ideas?
You basically run
make -j 8 2> >(tee /tmp/error.log)
test $? -ne 0 && echo "build errors:"
cat /tmp/error.log
and you get all of stderr after the build finishes.
-- EDIT --
Updating to use tee, to output on stdout and into file:
Make returns non-zero if one of its recipe's fails so you could do something like this from the command line (assuming bash shell):
make 2>&1 | tee build.log
[ ${PIPESTATUS}[0] -eq 0 ] || ( echo "MAKE FAILED!"; grep --color build.log "Error:" )
The ${PIPESTATUS}[0] gives you the exit code of the first command (make 2>&1) as opposed to the exit status of the entire command (which would the exit status of tee if the make failed). It is bash specific, so it won't work in zsh for example.
Alternatively you could add the same logic as the top level target of a recursive make.
ifndef IN_RECURSION
export IN_RECURSION:=1
$(info At top level -- defining default target)
_default:
#echo "doing recursive call of make"
#$(MAKE) $(MAKECMDGOALS) IN_RECURSION=1 2>&1 | tee build.log; \
[ ${PIPESTATUS}[0] -eq 0 ] || ( echo "MAKE FAILED!"; grep --color "Error:" build.log )
.PHONY: _default
endif
all:
....
Note that in this case the \ used to catinate the two recipe lines is crucial, as the second command must run in the same shell instance as the first.
I have a target such as this:
.PHONY: do-symlink
do-symlink:
ln -s $(HERE_ONE_FILE) $(THERE_ONE_DIR)/
ln -s $(HERE_TWO_FILE) $(THERE_ONE_DIR)/
# check if those succeed or failed. I want to make sure both have passed
if succeeded:
do_something
else:
do_something_else
How can i check that they are both succeed? and if so, do something based on it?
So first of all, if a make recipe line fails, make fails, and stops executing the recipe. So if you put a recipe line at the end #echo "succeeded", then this will on run if all previous lines worked. As far as printing if something specific if one fails, you can use bash || for that
all:
#command1 || { echo "command1 failed"; exit 1 }
#command2 || { echo "command2 failed"; exit 1 }
#echo "command1 and command2 passed"
Notice the exit 1's in there. Normally, false || echo "false" would have a return status of 0 (pass), because the exit status is taken from the last command run (echo "false"), which will always succeed. This would cause make to always continue running the next recipe line. You may want this, however, you can preserve the failure by compounding the statement and doing an exit 1 at the end.
For running both commands regardless of exit status, and then handling the exits after, prefix the recipe lines with -. This will cause make to not stop running if the command fails. Notice however that each recipe line is run in its own shell, so one recipe line cannot directly access the return code from another line. You could output to a file and then access that file in a later recipe line:
all:
-#command1; echo $? > .commands.result
-#command2; echo $? >> .commands.result
#if grep -q "^00$" .commands.result; then \
echo both commands passed; \
else \
echo "at least one command failed"
(or you could always concatenate all the recipes lines into a single bash command and pass the variables around as well).
I have the following lines in my makefile:
.PHONY : clean
clean:
#echo "Running Clean"
$(shell if [ -e exe ]; then rm exe; else echo "no files"; fi)
When I run:
make clean
I get the following output on the shell
Running Clean
no files
make: no: Command not found
Makefile:22: recipe for target 'clean' failed
make: *** [clean] Error 127
Any suggestions?
The problem is the use of $(shell ...). What you want is:
.PHONY : clean
clean:
#echo "Running Clean"
#if [ -e exe ]; then rm exe; else echo "no files"; fi
As far as an explanation of what's going wrong -- when you first run the clean target, make will expand all make variables and functions in the recipes before it starts running them -- because $(shell ...) only has one $, this is considered a make function. Make runs the command, which outputs no files to stdout, and replaces the call with that string, and then starts executing the recipes... So now make sees the following:
clean:
#echo "Running Clean"
no files
When it tries to run no files, due to the lack of a #, it echos the line to the screen, and then passes the command to the shell. Because the shell doesn't recognize the keyword no it outputs the error you're seeing. Make itself then fails because the shell returned an error.
Hey all I'm the same guy who asked this question but I found an answer right after I posted this, I think I'll leave this up (unless this is against stackoverflow etiquette) in case someone else has the same problems. My solution was echoing the string to stdout.
$(shell if [ -e exe ]; then rm exe; else echo "no files" >&2; fi)