Re: [Mingw-users] Compiler switch for Uinx boxes and Windows

[Keith M. <kei...@to...>]

Rux Li wrote:
> Makefile may have to switch between different platform. For
> example, my MinGW have no readline library. But I want include
> it on my Linux porting.

You normally would use a configure script to achieve this; have
it check for available libraries, and write an appropriate LIBS
macro definition into the Makefile, then add $(LIBS) into the
$(CC) command lines.

I'd use Autoconf for this...

<file name="configure.ac">
AC_INIT
AC_PROG_CC
AC_CKECK_LIBS([readline])
AC_CONFIG_FILES([Makefile])
AC_OUTPUT
</file>

As developer, you run:

$ autoconf

which translates the above file into a configure script.  You
add *both* the above configure.ac, *and* the generated configure
script to your packaged distribution.  Additionally, you add a
*template* for the Makefile, called Makefile.in; you *don't*
supply any Makefile itself.

<file name="Makefile.in">
 :
CC = @CC@
CFLAGS = @CFLAGS@
CPPFLAGS = @CPPFLAGS@
LDFLAGS = @LDFLAGS@
LIBS = @LIBS@
EXEEXT = @EXEEXT@
 :
%$(EXEEXT): %.c
<TAB>$(CC) -o $@ $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) $(LIBS)
 :
</file>

Now, your user first runs the configure script, which generates
a Makefile, based on your Makefile.in, with appropriate @NAME@
substitution fields filled in, and $(LIBS) will represent those
that you named in AC_CHECK_LIBS, and which are actually present
on the user's system.  He can then proceed with a normal `make'
and `make install', as appropriate.

Once learned, it really is very easy to achieve this sort of thing,
but I appreciate that it may be intimidating for a newbie.

HTH,
Keith.