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Here is such a module, <TT>`ltdl-module.c'</TT>:</P><P><TABLE width=100%><tr><td> </td><td class=example bgcolor=#6688aa><br><pre></pre></td></tr></table></P><P>To take full advantage of the new module loader, the module itself<STRONG>must</STRONG> be compiled with Libtool. Otherwise dependent librarieswill not have been stored when libltdl tries to load the moduleon an architecture that doesn't load them natively, or which doesn'thave shared libraries at all (see section <A HREF="autobook_173.html#SEC173">18.4 dlpreopen Loading</A>).</P><P><TABLE width=100%><tr><td> </td><td class=example bgcolor=#6688aa><br><pre>$ libtool --mode=compile gcc -c ltdl-module.crm -f .libs/ltdl-module.logcc -c ltdl-module.c -fPIC -DPIC -o .libs/ltdl-module.logcc -c ltdl-module.c -o ltdl-module.o >/dev/null 2>&1mv -f .libs/ltdl-module.lo ltdl-module.lo$ libtool --mode=link gcc -g -o ltdl-module.la -rpath `pwd` \-no-undefined -module -avoid-version ltdl-module.lo -lmrm -fr .libs/ltdl-module.la .libs/ltdl-module.* .libs/ltdl-module.*gcc -shared ltdl-module.lo -lm -lc -Wl,-soname \-Wl,ltdl-module.so -o .libs/ltdl-module.soar cru .libs/ltdl-module.a ltdl-module.ocreating ltdl-module.la(cd .libs && rm -f ltdl-module.la && ln -s ../ltdl-module.la \ltdl-module.la)</pre></td></tr></table></P><P>You can see from the interaction below that <TT>`ltdl-loader'</TT> does notload the math library, <TT>`libm'</TT>, and that the shared part of theLibtool module, <TT>`ltdl-module'</TT>, does have a reference to it. Thepseudo-library also has a note of the <TT>`libm'</TT> dependency so thatlibltdl will be able to load it even on architectures that can'tdo it natively:</P><P><TABLE width=100%><tr><td> </td><td class=example bgcolor=#6688aa><br><pre>$ libtool --mode=execute ldd ltdl-loader libltdl.so.0 => /usr/lib/libltdl.so.0 (0x4001a000) libdl.so.2 => /lib/libdl.so.2 (0x4001f000) libc.so.6 => /lib/libc.so.6 (0x40023000) /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x40000000)$ ldd .libs/ltdl-module.so libm.so.6 => /lib/libm.so.6 (0x40008000) libc.so.6 => /lib/libc.so.6 (0x40025000) /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x80000000)$ fgrep depend ltdl-module.la# Libraries that this one depends upon.dependency_libs=' -lm'</pre></td></tr></table></P><P>This module is now ready to load from <TT>`ltdl-loader'</TT>:</P><P><TABLE width=100%><tr><td> </td><td class=example bgcolor=#6688aa><br><pre>$ ltdl-loader ltdl-module 9Square root of 9 is 3.000000 => 0</pre></td></tr></table></P><P><A NAME="Portable Library Design"></A></TR></TABLE><BR> <FONT SIZE="-1">This document was generatedby <I>Gary V. Vaughan</I> on <I>September, 12 2004</I>using <A HREF="http://www.mathematik.uni-kl.de/~obachman/Texi2html"><I>texi2html</I></A></BODY></HTML>⌨️ 快捷键说明
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