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| <h3 class="appendixsec">D.1 Adding New Functions</h3> |
| |
| <p>The process of building the library is driven by the makefiles, which |
| make heavy use of special features of GNU <code>make</code>. The makefiles |
| are very complex, and you probably don't want to try to understand them. |
| But what they do is fairly straightforward, and only requires that you |
| define a few variables in the right places. |
| |
| <p>The library sources are divided into subdirectories, grouped by topic. |
| |
| <p>The <samp><span class="file">string</span></samp> subdirectory has all the string-manipulation |
| functions, <samp><span class="file">math</span></samp> has all the mathematical functions, etc. |
| |
| <p>Each subdirectory contains a simple makefile, called <samp><span class="file">Makefile</span></samp>, |
| which defines a few <code>make</code> variables and then includes the global |
| makefile <samp><span class="file">Rules</span></samp> with a line like: |
| |
| <pre class="smallexample"> include ../Rules |
| </pre> |
| <p class="noindent">The basic variables that a subdirectory makefile defines are: |
| |
| <dl> |
| <dt><code>subdir</code><dd>The name of the subdirectory, for example <samp><span class="file">stdio</span></samp>. |
| This variable <strong>must</strong> be defined. |
| |
| <br><dt><code>headers</code><dd>The names of the header files in this section of the library, |
| such as <samp><span class="file">stdio.h</span></samp>. |
| |
| <br><dt><code>routines</code><dt><code>aux</code><dd>The names of the modules (source files) in this section of the library. |
| These should be simple names, such as ‘<samp><span class="samp">strlen</span></samp>’ (rather than |
| complete file names, such as <samp><span class="file">strlen.c</span></samp>). Use <code>routines</code> for |
| modules that define functions in the library, and <code>aux</code> for |
| auxiliary modules containing things like data definitions. But the |
| values of <code>routines</code> and <code>aux</code> are just concatenated, so there |
| really is no practical difference. |
| |
| <br><dt><code>tests</code><dd>The names of test programs for this section of the library. These |
| should be simple names, such as ‘<samp><span class="samp">tester</span></samp>’ (rather than complete file |
| names, such as <samp><span class="file">tester.c</span></samp>). ‘<samp><span class="samp">make tests</span></samp>’<!-- /@w --> will build and |
| run all the test programs. If a test program needs input, put the test |
| data in a file called <samp><var>test-program</var><span class="file">.input</span></samp>; it will be given to |
| the test program on its standard input. If a test program wants to be |
| run with arguments, put the arguments (all on a single line) in a file |
| called <samp><var>test-program</var><span class="file">.args</span></samp>. Test programs should exit with |
| zero status when the test passes, and nonzero status when the test |
| indicates a bug in the library or error in building. |
| |
| <br><dt><code>others</code><dd>The names of “other” programs associated with this section of the |
| library. These are programs which are not tests per se, but are other |
| small programs included with the library. They are built by |
| ‘<samp><span class="samp">make others</span></samp>’<!-- /@w -->. |
| |
| <br><dt><code>install-lib</code><dt><code>install-data</code><dt><code>install</code><dd>Files to be installed by ‘<samp><span class="samp">make install</span></samp>’<!-- /@w -->. Files listed in |
| ‘<samp><span class="samp">install-lib</span></samp>’ are installed in the directory specified by |
| ‘<samp><span class="samp">libdir</span></samp>’ in <samp><span class="file">configparms</span></samp> or <samp><span class="file">Makeconfig</span></samp> |
| (see <a href="Installation.html#Installation">Installation</a>). Files listed in <code>install-data</code> are |
| installed in the directory specified by ‘<samp><span class="samp">datadir</span></samp>’ in |
| <samp><span class="file">configparms</span></samp> or <samp><span class="file">Makeconfig</span></samp>. Files listed in <code>install</code> |
| are installed in the directory specified by ‘<samp><span class="samp">bindir</span></samp>’ in |
| <samp><span class="file">configparms</span></samp> or <samp><span class="file">Makeconfig</span></samp>. |
| |
| <br><dt><code>distribute</code><dd>Other files from this subdirectory which should be put into a |
| distribution tar file. You need not list here the makefile itself or |
| the source and header files listed in the other standard variables. |
| Only define <code>distribute</code> if there are files used in an unusual way |
| that should go into the distribution. |
| |
| <br><dt><code>generated</code><dd>Files which are generated by <samp><span class="file">Makefile</span></samp> in this subdirectory. |
| These files will be removed by ‘<samp><span class="samp">make clean</span></samp>’<!-- /@w -->, and they will |
| never go into a distribution. |
| |
| <br><dt><code>extra-objs</code><dd>Extra object files which are built by <samp><span class="file">Makefile</span></samp> in this |
| subdirectory. This should be a list of file names like <samp><span class="file">foo.o</span></samp>; |
| the files will actually be found in whatever directory object files are |
| being built in. These files will be removed by ‘<samp><span class="samp">make clean</span></samp>’<!-- /@w -->. |
| This variable is used for secondary object files needed to build |
| <code>others</code> or <code>tests</code>. |
| </dl> |
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