Hi Michael,
* Michael Schulz wrote on Sat, Nov 05, 2005 at 05:23:30PM CET:
>
> I'm newbe to autoconf, automake.
> I try to make a target in Makefile.am that compiles the base source code
> with some extra code and extra libs.
> But a 'make fb' only compiles the base source code. Makefile.am:
*snip*
> fb:
> @if test "$(LINUX_FRAMEBUFFER)" = "yes"; then \
> echo -e "\n*** Compile moll with image support via Linux
> framebuffer! ***\n"; \
> echo -e "\n/* Define to 1 if you have Linux framebuffer.
> */\n#define HAVE_LINUX_FB 1" >> $(srcdir)/config.h; \
> SOURCES="$(SOURCES) $(moll_fb_sources)"; \
> LIBS="$(LIBS) $(LIBS_IMAGE)"; \
> $(MAKE) all; \
> else \
> echo -e "\nNo support for Linux framebuffer!\n"; \
> fi
Well, I don't quite understand what you are trying to achieve.
First, I guess there is a typo in your Makefile.am: Did you mean
moll_SOURCES="$(moll_SOURCES) $(moll_fb_SOURCES)"
above? My following explanations assume you did.
Next thing: setting of environment variables does not override the value
of make macros (variables) by default. One uses either
make target FOO=bar
to set $(FOO), or
FOO=bar make -e target
or, equivalently,
FOO=bar; export FOO; make -e target
but the latter two cause all other environment variables to influence
the make settings as well! (Imagine you had SHELL=/bin/csh, which is
not so uncommon, unfortunately; that would be pretty bad.)
Let's go on: Your snippet uses
echo -e
which is not quite portable; under ksh or ash, it will print "-e", for
example. For non-ancient hosts, printf is quite portable and easier to
use.
Third, automake needs to know all sources at the time it is run.
Fortunately, you can achieve this by either: defining two different
targets you would like to build, or by using an automake conditional.
Example with automake conditional: Put
AM_CONDITIONAL([FRAMEBUF], [test "$LINUX_FRAMEBUFFER" = yes])
in configure.ac (in case $LINUX_FRAMEBUFFER is set in there), and
in Makefile.am, put
if FRAMEBUF
moll_SOURCES += $(moll_fb_sources)
endif
Be sure to also look at the Automake documentation of conditionals,
though.
The other way (two targets) would be similar to this:
bin_PROGRAMS = moll moll_fb
moll_SOURCES = ...
moll_fb_SOURCES = $(moll_SOURCES) $(moll_fb_sources)
but I don't know whether that's applicable in your case.
Lastly, it's not too good an idea to invoke 'make' from within a
Makefile, unless you have to. It basically destroys its ability
to know what has already been updated and what hasn't.
I hope this helps you a bit further.
Cheers,
Ralf
