Peter,
On Sep 24, 2008, at 10:24 AM, Peter Johansson wrote:
John Richetta wrote:
(I'm an autotools newbie.)
What is the automake sanctioned way of providing different top-
level make targets, that build my application with different options?
For example, say I want to build foo_nondebug, and foo_debug, and
(luckily) all of my application code resides in the subdirectories
of the top level directory containing the top-level Makefile.
Obviously, if I invoke make from one of these targets, I can use
the traditional trick of passing a sub-make arguments (like
FOO_DEBUG=-g or FOO_DEBUG=<empty>).
I use the following snippet in one my projects:
AC_ARG_ENABLE(debug,
[AS_HELP_STRING([--enable-debug],[turn on debug options and
code])],
[SD_CXXFLAGS="$SD_CXXFLAGS -g -O"],
[SD_CPPFLAGS="-DNDEBUG" SD_CXXFLAGS="$SD_CXXFLAGS -O3"])
# Export flags
AC_SUBST([SVNDIGEST_CPPFLAGS], $SD_CPPFLAGS)
AC_SUBST([SVNDIGEST_CXXFLAGS], $SD_CXXFLAGS)
and then in each Makefile.am:
AM_CPPFLAGS = $(SVNDIGEST_CPPFLAGS)
AM_CXXFLAGS = $(SVNDIGEST_CXXFLAGS)
This is definitely better than no solution. I was aware that
something like this was possible, but I appreciate seeing the details.
This will add a switch to configure so we can call ./configure --
enable-debug when we wanna build in debug mode, and else ignore the
option. Their is no dependency, so if I switch between the modes in
the same builddir I need to issue make clean.
This is certainly workable, but I would prefer to avoid using the
(lengthy) configure process to change simple things like compile
options for this application. If it's not possible, I guess we'll
have to live with that. Obviously, side-stepping any issues arising
from stale .o files is a good thing, to put it mildly.
It would be best if somehow I could ensure that make clean was always
run after a reconfigure. I'm guessing I can probably figure out how
to do that - build in some dependency on config.status's timestamp,
perhaps?
Hope this helps.
Cheers,
Thanks for your helpful reply.
-jar
