CODEWITHSUNDEEP
makefileconfigureautotools
qdii
qdii

Reputation: 12963

Hide targets when configure is run with certain options

My configure.ac lets the user specify --enable-monitor. In a subdirectory, I have a Makefile.in which contains a certain number of targets to build. I would like some of them to be only available when the user has specified --enable-monitor

Put differently, I want the user to be only able to run make monitor when ./configure has been run with --enable-monitor.

How can I do that?

Upvotes: 1

Views: 242

Answers (1)

William Pursell
William Pursell

Reputation: 212404

It should be sufficient to put this in configure.ac:

AC_ARG_ENABLE([monitor],[help string],[use_monitor=yes])
AM_CONDITIONAL([USE_MONITOR],[test "$use_monitor" = yes])

and this in Makefile.am:

if USE_MONITOR
bin_PROGRAMS = monitor
else
monitor:
    @echo Target not supported >&2 && exit 1
endif

The else clause with an explicit monitor target is used to override and default rules that Make might otherwise use. Note that "help string" ought to be more useful and constructed using AS_HELP_STRING, but those details have been omitted for brevity.

--EDIT--

Since automake is not being used, you can replace the AM_CONDITIONAL line in configure.ac with something like:

AC_SUBST([USE_MONITOR],[$use_monitor])

and then do checks in Makefile.in like:

monitor:
        @if test "@USE_MONITOR@" = yes; then \
            ... ; \
        else \
            echo Target not supported >&2 && exit 1; \
        fi

Upvotes: 1

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