It is actually executing the command, changing the directory to some_directory
, however, this is performed in a sub-process shell, and affects neither make nor the shell you're working from.
If you're looking to perform more tasks within some_directory
, you need to add a semi-colon and append the other commands as well. Note that you cannot use newlines as they are interpreted by make as the end of the rule, so any newlines you use for clarity needs to be escaped by a backslash.
For example:
all:
cd some_dir; echo "I'm in some_dir"; \
gcc -Wall -o myTest myTest.c
Note also that the semicolon is necessary between every command even though you add a backslash and a newline. This is due to the fact that the entire string is parsed as a single line by the shell. As noted in the comments, you should use '&&' to join commands, which mean they only get executed if the preceding command was successful.
all:
cd some_dir && echo "I'm in some_dir" && \
gcc -Wall -o myTest myTest.c
This is especially crucial when doing destructive work, such as clean-up, as you'll otherwise destroy the wrong stuff, should the cd
fail for whatever reason.
A common usage though is to call make in the sub directory, which you might want to look into. There's a command line option for this so you don't have to call cd
yourself, so your rule would look like this
all:
$(MAKE) -C some_dir all
which will change into some_dir
and execute the Makefile
in there with the target "all". As a best practice, use $(MAKE)
instead of calling make
directly, as it'll take care to call the right make instance (if you, for example, use a special make version for your build environment), as well as provide slightly different behavior when running using certain switches, such as -t
.
For the record, make always echos the command it executes (unless explicitly suppressed), even if it has no output, which is what you're seeing.
Best Answer
I am working this same issue and so far I have had limited success using the QMAKE_EXTRA_TARGETS variable to build the docs target like so:
where Doxyfile has the basic doxygen config settings minus the INPUT symbol which I am appending via 'echo' to include only the unsatisfied Makefile dependencies in $(SOURCES).
This approach seems to work in that it only recreates documentation for source files that have changed which is good but I have encountered another problem in that my qmake project file is built with the debug_and_release CONFIG option so that it generates Makefile, Makefile.Debug, and Makefile.Release but SOURCES are only defined in the debug and release Makefiles forcing me to explicitly do a
make -f Makefile.Debug docs
instead of the more simple and intuitivemake docs
to build the docs.Anybody ever tackled the problem from this QMAKE_EXTRA_TARGETS perspective before?