Using Libtool
* Creating Object Files:: Compiling object files for libraries.
-* Linking Libraries::
+* Linking Libraries:: Creating libraries from object files.
* Linking Executables:: Linking object files against libtool libraries.
* Installing Libraries:: Making libraries available to users.
* Installing Executables:: Making programs available to users.
Configuring Libtool
-* Invoking ltconfig::
-* ltconfig Example::
-* AM_PROG_LIBTOOL::
+* Invoking ltconfig:: @file{ltconfig} command line options.
+* ltconfig Example:: Manually configuring a @file{libtool}.
+* AM_PROG_LIBTOOL:: Configuring @file{libtool} in @file{configure.in}.
Including Libtool with Your Package
argument:
@example
-a23$ libtool gcc -g -O -c foo.c
-gcc -g -O -c foo.c -o foo.lo
-a23$ libtool gcc -g -O -c hello.c
-gcc -g -O -c hello.c -o hello.lo
+a23$ @kbd{libtool gcc -g -O -c foo.c}
+gcc -g -O -c foo.c
+ln -s foo.o foo.lo
+a23$ @kbd{libtool gcc -g -O -c hello.c}
+gcc -g -O -c hello.c
+ln -s hello.o hello.lo
a23$
@end example
+Note that libtool creates two object files for each invocation. The
+`.lo' file is a library object, and the `.o' file is a standard object
+file. On `a23', these files are identical, because only static
+libraries are supported.
+
On shared library systems, libtool automatically inserts the PIC
-generation flags into the compilation command:
+generation flags into the compilation command, so that the library
+object and the standard object differ:
@example
burger$ @kbd{libtool gcc -g -O -c foo.c}
-gcc -g -O -c -fPIC -DPIC foo.c -o foo.lo
+gcc -g -O -c -fPIC -DPIC foo.c
+mv -f foo.o foo.lo
+gcc -g -O -c foo.c
burger$ @kbd{libtool gcc -g -O -c hello.c}
-gcc -g -O -c -fPIC -DPIC hello.c -o hello.lo
-burger$
+gcc -g -O -c -fPIC -DPIC hello.c
+mv -f hello.o hello.lo
+gcc -g -O -c hello.c
+burger$
@end example
@node Linking Libraries, Linking Executables, Creating Object Files, Using Libtool
@example
burger$ @kbd{libtool gcc -g -O -o libhello.la foo.o hello.o}
-libtool: cannot build libtool library `libhello.la' from non-libtool objects
+libtool: cannot build libtool library `libhello.la' from non-libtool \
+ objects
burger$
@end example
Aha! Libtool caught a common error@dots{} trying to build a library
-from standard objects instead of library objects.@footnote{The converse,
-however, is perfectly legal. Library objects can do anything that
-standard objects can do@dots{} it makes sense to link them directly into
-programs.} This doesn't matter much for static libraries, but on shared
-library systems, it is of great importance.
+from standard objects instead of library objects. This doesn't matter
+for static libraries, but on shared library systems, it is of great
+importance.
So, let's try again, this time with the library object files:
@file{/usr/local/lib}:
@example
-a23$ @kbd{libtool gcc -g -O -o libhello.la foo.lo hello.lo -rpath /usr/local/lib}
-mkdir LIBS
-ar cru LIBS/libhello.a foo.lo hello.lo
-ranlib LIBS/libhello.a
+a23$ @kbd{libtool gcc -g -O -o libhello.la foo.lo hello.lo \
+ -rpath /usr/local/lib}
+mkdir .libs
+ar cru .libs/libhello.a foo.o hello.o
+ranlib .libs/libhello.a
creating libhello.la
a23$
@end example
Now, let's try the same trick on the shared library platform:
@example
-burger$ @kbd{libtool gcc -g -O -o libhello.la foo.lo hello.lo -rpath /usr/local/lib}
-mkdir LIBS
-ld -Bshareable -o LIBS/libhello.so.0.0 foo.lo hello.lo
-ar cru LIBS/libhello.a foo.lo hello.lo
-ranlib LIBS/libhello.a
+burger$ @kbd{libtool gcc -g -O -o libhello.la foo.lo hello.lo \
+ -rpath /usr/local/lib}
+mkdir .libs
+rm -f .libs/libhello.*
+ld -Bshareable -o .libs/libhello.so.0.0 foo.lo hello.lo
+ar cru .libs/libhello.a foo.o hello.o
+ranlib .libs/libhello.a
creating libhello.la
burger$
@end example
@file{ld} command to create a shared library, as well as the static
library.
-Note how libtool creates extra files in the @file{LIBS} subdirectory,
+Note how libtool creates extra files in the @file{.libs} subdirectory,
rather than the current directory. This feature is to make it easier to
clean up the build directory, and to help ensure that other programs
fail horribly if you accidentally forget to use libtool when you should.
burger$
@end example
-This is libtool's way:
+Libtool's way is almost the same@footnote{However, you should never use
+@samp{-L} or @samp{-l} flags to link against an uninstalled libtool
+library. Just specify the relative path to the `.la' file, such as
+@file{../intl/libintl.la}.}:
@example
a23$ @kbd{libtool gcc -g -O -o hell main.o libhello.la}
-gcc -g -O -o hell main.o ./LIBS/libhello.a
+gcc -g -O -o hell main.o ./.libs/libhello.a
a23$
@end example
That looks too simple to be true. All libtool did was transform
-@file{libhello.la} to @file{./LIBS/libhello.a}, but remember that
+@file{libhello.la} to @file{./.libs/libhello.a}, but remember that
`a23' has no shared libraries.
On `burger' the situation is different:
@example
burger$ @kbd{libtool gcc -g -O -o hell main.o libhello.la}
-gcc -g -O -o LIBS/hell main.o -L./LIBS -R/usr/local/lib -lhello
+gcc -g -O -o .libs/hell main.o -L./.libs -R/usr/local/lib -lhello
creating hell
burger$
@end example
Notice that the executable, @file{hell} was actually created in the
-@file{LIBS} subdirectory. Then, a wrapper script was created in the
+@file{.libs} subdirectory. Then, a wrapper script was created in the
current directory.
On NetBSD 1.2, libtool encodes the installation directory of
@file{libhello}, @file{/usr/local/lib}, by using the @code{-R} compiler
flag. Then, the wrapper script guarantees that the executable finds the
-correct shared library (the one in @file{./LIBS}) until it is properly
+correct shared library (the one in @file{./.libs}) until it is properly
installed.
Let's compare the two different programs:
burger$ @kbd{ls -l hell.old libhello.a}
-rwxr-xr-x 1 gord gord 15481 Nov 14 12:11 hell.old
-rw-r--r-- 1 gord gord 4274 Nov 13 18:02 libhello.a
-burger$ @kbd{ls -l LIBS/hell LIBS/libhello.*}
--rwxr-xr-x 1 gord gord 11602 Nov 14 12:10 LIBS/hell
--rw-r--r-- 1 gord gord 4352 Nov 13 18:44 LIBS/libhello.a
--rwxr-xr-x 1 gord gord 12205 Nov 13 18:44 LIBS/libhello.so.0.0
+burger$ @kbd{ls -l .libs/hell .libs/libhello.*}
+-rwxr-xr-x 1 gord gord 11647 Nov 14 12:10 .libs/hell
+-rw-r--r-- 1 gord gord 4274 Nov 13 18:44 .libs/libhello.a
+-rwxr-xr-x 1 gord gord 12205 Nov 13 18:44 .libs/libhello.so.0.0
burger$
@end example
@example
a23# @kbd{libtool cp libhello.la /usr/local/lib/libhello.la}
-cp libhello.la /local/lib/libhello.la
-cp LIBS/libhello.a /local/lib/libhello.a
-ranlib /local/lib/libhello.a
+cp libhello.la /usr/local/lib/libhello.la
+cp .libs/libhello.a /usr/local/lib/libhello.a
+ranlib /usr/local/lib/libhello.a
a23#
@end example
Here is the shared library example:
@example
-burger# libtool install -c libhello.la /usr/local/lib/libhello.la
-install -c LIBS/libhello.so.0.0 /usr/local/lib/libhello.so.0.0
+burger# @kbd{libtool install -c libhello.la /usr/local/lib/libhello.la}
+install -c .libs/libhello.so.0.0 /usr/local/lib/libhello.so.0.0
install -c libhello.la /usr/local/lib/libhello.la
-install -c LIBS/libhello.a /usr/local/lib/libhello.a
+install -c .libs/libhello.a /usr/local/lib/libhello.a
ranlib /usr/local/lib/libhello.a
burger#
@end example
@example
burger# libtool install -c hell /usr/local/bin/hell
-install -c LIBS/hell /usr/local/bin/hell
+install -c .libs/hell /usr/local/bin/hell
burger#
@end example
@example
burger$ @kbd{libtool gcc -o libfoo.a main.o foo.lo hello.lo}
rm -f libfoo.a
-ar cru libfoo.a main.o foo.lo hello.lo
+ar cru libfoo.a main.o foo.o hello.o
ranlib libfoo.a
burger$
@end example
@end table
If the @var{output-file} ends in `.la', then a libtool library is
-created, which must be build only from library objects (`.lo' files).
-The @samp{-rpath} option is required. In the current implementation,
-libtool libraries may not depend on other uninstalled libtool
-libraries.
+created, which must be built only from library objects (`.lo'
+files)@footnote{Object files with a `.l_o' suffix are also accepted, to
+help with Automake's @code{ansi2knr} support (@pxref{ANSI, , Automatic
+de-ANSI-fication, automake.info, The Automake Manual}).} The
+@samp{-rpath} option is required. In the current implementation,
+libtool libraries may not depend on other uninstalled libtool libraries.
If the @var{output-file} ends in `.a', then a standard library is
created using @file{ar} and possibly @file{ranlib}.
+If @var{output-file} ends in `.o' or `.lo', then a reloadable object
+file is created from the input files (generally using @samp{ld -r}).
+This method is called @dfn{incremental linking}.
+
Otherwise, an executable program is created.
@node Install Mode, Finish Mode, Link Mode, Invoking libtool
When you invoke the @file{libtoolize} program (@pxref{Invoking
libtoolize}), it will tell you where to find a definition of
-@file{AM_PROG_LIBTOOL}. If you use Automake, the @file{aclocal} program
-will automatically add @file{AM_PROG_LIBTOOL} support to your
-@file{configure} script.
+@code{AM_PROG_LIBTOOL}. If you use Automake, the @file{aclocal} program
+will automatically add @code{AM_PROG_LIBTOOL} support to your
+@file{configure} script.@footnote{@code{AM_PROG_LIBTOOL} requires that
+you define the Makefile variable @code{top_builddir} in your
+@file{Makefile.in}. Automake does this automatically, but Autoconf
+users should set it to the relative path to the top of your build
+directory (@file{../..}, for example).}
@node Distributing, , Configuring, Integrating Libtool
@comment node-name, next, previous, up
# ltconfig - Create a system-specific libtool.
# When updating this script, search for LINENUM and fix line number refs.
# @configure_input@
-# Copyright (C) 1996, Free Software Foundation, Inc.
+# Copyright (C) 1996, 1997, Free Software Foundation, Inc.
# Gordon Matzigkeit <gord@gnu.ai.mit.edu>, 1996
#
# This file is free software; you can redistribute it and/or modify it
help="Try \`$progname --help' for more information."
# Global variables:
+can_build_shared=yes
enable_shared=yes
# All known linkers require a `.a' archive for static linking.
enable_static=yes
echo $ac_n "checking for $compiler option to produce PIC... $ac_c" 1>&6
pic_flag=
profile_flag_pattern=
+special_shlib_compile_flags=
wl=
link_static_flag=
link_static_flag='-non_shared'
;;
+ *-*-sco3.2v5*)
+ pic_flag='-Kpic'
+ link_static_flag='-dn'
+ special_shlib_compile_flags='-belf'
+ ;;
+
*-*-solaris2*)
pic_flag='-KPIC'
link_static_flag='-Bstatic'
;;
esac
-# FIXME actually try compiling an object file with the pic flag?
-
if test -n "$pic_flag"; then
echo $ac_t "$pic_flag" 1>&6
pic_flag=" $pic_flag"
echo $ac_t none 1>&6
fi
+# Check for any special shared library compilation flags.
+if test -n "$special_shlib_compile_flags"; then
+ echo "$progname: warning: \`$CC' requires \`$special_shlib_compile_flags' to build shared libraries" 1>&2
+ if echo "$old_CC $old_CFLAGS " | egrep -e "[ ]$special_shlib_compile_flags[ ]" >/dev/null; then :
+ else
+ echo "$progname: add \`$special_shlib_compile_flags' to the CC or CFLAGS env variable and reconfigure" 1>&2
+ can_build_shared=no
+ fi
+fi
+
echo $ac_n "checking for $compiler option to statically link programs... $ac_c" 1>&6
if test -n "$link_static_flag"; then
echo $ac_t "$link_static_flag" 1>&6
;;
*-*-irix5* | *-*-irix6*)
- archive_cmds='$LD -shared -o $lib -soname $install_libdir/$soname -set_version $verstring$libobjs -lc$deplibs'
+ archive_cmds='$LD -shared -o $lib -soname $soname -set_version $verstring$libobjs -lc$deplibs'
link_rpath_flag='${wl}-rpath ${wl}$libdir'
;;
;;
*-*-osf3*)
- archive_cmds='$LD -shared -o $lib -soname $install_libdir/$soname -set_version $verstring$libobjs -lc$deplibs'
+ archive_cmds='$LD -shared -o $lib -soname $soname -set_version $verstring$libobjs -lc$deplibs'
link_rpath_flag='${wl}-rpath ${wl}$libdir'
;;
+ *-*-sco3.2v5*)
+ archive_cmds='$LD -G -o $lib$libobjs$deplibs'
+ ;;
+
*-*-solaris2*)
archive_cmds='$LD -G -z text -h $soname -o $lib$libobjs$deplibs'
link_rpath_flag='-R$libdir'
test -n "$reload_flag" && reload_flag=" $reload_flag"
# PORTME Fill in your ld.so characteristics
-can_build_shared=yes
lib_names=
soname_spec=
postinstall_cmds=
postinstall_cmds='chmod 555 $lib'
;;
-*-*-irix5*)
+*-*-irix5* | *-*-irix6*)
version_type=osf
- soname_spec='$libname.so.$major'
- lib_names='$libname.so.$versuffix $libname.so.$major $libname.so'
+ soname_spec='$libname.so'
+ lib_names='$libname.so.$versuffix $libname.so'
shlibpath_var=LD_LIBRARY_PATH
;;
;;
*-*-osf3*)
+ version_type=osf
+ soname_spec='$libname.so'
+ lib_names='$libname.so.$versuffix $libname.so'
+ shlibpath_var=LD_LIBRARY_PATH
+ ;;
+
+*-*-sco3.2v5*)
version_type=osf
soname_spec='$libname.so.$major'
lib_names='$libname.so.$versuffix $libname.so.$major $libname.so'
projects / thirdparty / libtool.git / commitdiff
