11.1.2 Extra Macros for Libtool
There are several macros which can be added to `configure.in' which
will change the default behaviour of
libtool. If they are
used they must appear before the call to the `AC_PROG_LIBTOOL'
macro. Note that these macros only change the default behaviour, and
options passed in to
configure on the command line will always
override the defaults. The most up to date information about these
macros is available from the Libtool Manual.
- This macro tells
libtool that on platforms which require
relinking at install time, it should build executables so that they can
be run from the build tree at the expense of relinking during
installation, as if `--disable-fast-install' had been passed on
the command line.
- These macros tell
libtool to not try and build either
shared or static libraries respectively.
libtool will always
try to build something however, so even if you turn off static
library building in `configure.in', building your package for a
target host without shared library support will fallback to building
The time spent waiting for builds during development can be reduced a
little by including these macros temporarily. Don't forget to remove
them before you release the project though!
In addition to the macros provided with `AC_PROG_LIBTOOL', there
are a few shell variables that you may need to set yourself, depending
on the structure of your project:
- If your project uses the `AC_REPLACE_FUNCS' macro, or any of the
other macros which add object names to the `LIBOBJS' variable, you
will also need to provide an equivalent `LTLIBOBJS' definition. At
the moment, you must do it manually, but needing to do that is
considered to be a bug and will fixed in a future release of Autoconf.
The manual generation of `LTLIBOBJS' is a simple matter of
replacing the names of the objects mentioned in `LIBOBJS' with
.lo suffixed Libtool object names. The easiest way to
do this is to add the following snippet to your `configure.in' near
the end, just before the call to `AC_OUTPUT'.
Xsed="sed -e s/^X//"
[$Xsed -e "s,\.[^.]* ,.lo ,g;s,\.[^.]*$,.lo,"]`
Xsed is not usually necessary, though it can prevent problems
echo command in the event that one of the `LIBOBJS'
files begins with a `-' character. It is also a good habit to
write shell code like this, as it will avoid problems in your programs.
- If your project uses the `AC_FUNC_ALLOCA' macro, you will need to
provide a definition of `LTALLOCA' equivalent to the `ALLOCA'
value provided by the macro.
Xsed="sed -e s/^X//"
LTALLOCA=`echo X"$ALLOCA"|[$Xsed -e "s,\.$[^.]*,.lo,g"]`
Obviously you don't need to redefine
Xsed if you already use it
for `LTLIBOBJS' above.
- To help you write
make rules for automatic updating of the
Libtool configuration files, you can use the value of
`LIBTOOL_DEPS' after the call to `AC_PROG_LIBTOOL':
Then add the following to the top level `Makefile.in':
If you are using
automake in your project, it will generate
equivalent rules automatically. You don't need to use this except in
circumstances where you want to use
autoconf, but not