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| author | Indrajith K L | 2022-12-03 17:00:20 +0530 |
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| committer | Indrajith K L | 2022-12-03 17:00:20 +0530 |
| commit | f5c4671bfbad96bf346bd7e9a21fc4317b4959df (patch) | |
| tree | 2764fc62da58f2ba8da7ed341643fc359873142f /ctags/docs/parser-in-c.html | |
| download | cli-tools-windows-master.tar.gz cli-tools-windows-master.tar.bz2 cli-tools-windows-master.zip | |
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diff --git a/ctags/docs/parser-in-c.html b/ctags/docs/parser-in-c.html new file mode 100644 index 0000000..a9dcbde --- /dev/null +++ b/ctags/docs/parser-in-c.html @@ -0,0 +1,199 @@ + +<!DOCTYPE html> + +<html> + <head> + <meta charset="utf-8" /> + <meta name="viewport" content="width=device-width, initial-scale=1.0" /><meta name="generator" content="Docutils 0.17.1: http://docutils.sourceforge.net/" /> + + <title>Writing a parser in C — Universal Ctags 0.3.0 documentation</title> + <link rel="stylesheet" type="text/css" href="_static/pygments.css" /> + <link rel="stylesheet" type="text/css" href="_static/classic.css" /> + + <script data-url_root="./" id="documentation_options" src="_static/documentation_options.js"></script> + <script src="_static/jquery.js"></script> + <script src="_static/underscore.js"></script> + <script src="_static/doctools.js"></script> + + <link rel="index" title="Index" href="genindex.html" /> + <link rel="search" title="Search" href="search.html" /> + <link rel="next" title="Input text stream" href="internal.html" /> + <link rel="prev" title="Extending ctags with a parser written in C" href="extending.html" /> + </head><body> + <div class="related" role="navigation" aria-label="related navigation"> + <h3>Navigation</h3> + <ul> + <li class="right" style="margin-right: 10px"> + <a href="genindex.html" title="General Index" + accesskey="I">index</a></li> + <li class="right" > + <a href="internal.html" title="Input text stream" + accesskey="N">next</a> |</li> + <li class="right" > + <a href="extending.html" title="Extending ctags with a parser written in C" + accesskey="P">previous</a> |</li> + <li class="nav-item nav-item-0"><a href="index.html">Universal Ctags 0.3.0 documentation</a> »</li> + <li class="nav-item nav-item-1"><a href="extending.html" accesskey="U">Extending ctags with a parser written in C</a> »</li> + <li class="nav-item nav-item-this"><a href="">Writing a parser in C</a></li> + </ul> + </div> + + <div class="document"> + <div class="documentwrapper"> + <div class="bodywrapper"> + <div class="body" role="main"> + + <section id="writing-a-parser-in-c"> +<span id="writing-parser-in-c"></span><h1>Writing a parser in C<a class="headerlink" href="#writing-a-parser-in-c" title="Permalink to this headline">¶</a></h1> +<p>The section is based on the section “Integrating a new language parser” in “<a class="reference external" href="http://ctags.sourceforge.net/EXTENDING.html">How +to Add Support for a New Language to Exuberant Ctags (EXTENDING)</a>” of Exuberant Ctags documents.</p> +<p>Now suppose that I want to truly integrate compiled-in support for Swine into +ctags.</p> +<section id="registering-a-parser"> +<h2>Registering a parser<a class="headerlink" href="#registering-a-parser" title="Permalink to this headline">¶</a></h2> +<p>First, I create a new module, <code class="docutils literal notranslate"><span class="pre">swine.c</span></code>, and add one externally visible function +to it, <code class="docutils literal notranslate"><span class="pre">extern</span> <span class="pre">parserDefinition</span> <span class="pre">*SwineParser(void)</span></code>, and add its name to the +table in <code class="docutils literal notranslate"><span class="pre">parsers.h</span></code>. The job of this parser definition function is to create +an instance of the <code class="docutils literal notranslate"><span class="pre">parserDefinition</span></code> structure (using <code class="docutils literal notranslate"><span class="pre">parserNew()</span></code>) and +populate it with information defining how files of this language are recognized, +what kinds of tags it can locate, and the function used to invoke the parser on +the currently open file.</p> +<p>The structure <code class="docutils literal notranslate"><span class="pre">parserDefinition</span></code> allows assignment of the following fields:</p> +<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="k">struct</span> <span class="nc">sParserDefinition</span> <span class="p">{</span> + <span class="cm">/* defined by parser */</span> + <span class="kt">char</span><span class="o">*</span> <span class="n">name</span><span class="p">;</span> <span class="cm">/* name of language */</span> + <span class="n">kindDefinition</span><span class="o">*</span> <span class="n">kindTable</span><span class="p">;</span> <span class="cm">/* tag kinds handled by parser */</span> + <span class="kt">unsigned</span> <span class="kt">int</span> <span class="n">kindCount</span><span class="p">;</span> <span class="cm">/* size of 'kinds' list */</span> + <span class="k">const</span> <span class="kt">char</span> <span class="o">*</span><span class="k">const</span> <span class="o">*</span><span class="n">extensions</span><span class="p">;</span> <span class="cm">/* list of default extensions */</span> + <span class="k">const</span> <span class="kt">char</span> <span class="o">*</span><span class="k">const</span> <span class="o">*</span><span class="n">patterns</span><span class="p">;</span> <span class="cm">/* list of default file name patterns */</span> + <span class="k">const</span> <span class="kt">char</span> <span class="o">*</span><span class="k">const</span> <span class="o">*</span><span class="n">aliases</span><span class="p">;</span> <span class="cm">/* list of default aliases (alternative names) */</span> + <span class="n">parserInitialize</span> <span class="n">initialize</span><span class="p">;</span> <span class="cm">/* initialization routine, if needed */</span> + <span class="n">parserFinalize</span> <span class="n">finalize</span><span class="p">;</span> <span class="cm">/* finalize routine, if needed */</span> + <span class="n">simpleParser</span> <span class="n">parser</span><span class="p">;</span> <span class="cm">/* simple parser (common case) */</span> + <span class="n">rescanParser</span> <span class="n">parser2</span><span class="p">;</span> <span class="cm">/* rescanning parser (unusual case) */</span> + <span class="n">selectLanguage</span><span class="o">*</span> <span class="n">selectLanguage</span><span class="p">;</span> <span class="cm">/* may be used to resolve conflicts */</span> + <span class="kt">unsigned</span> <span class="kt">int</span> <span class="n">method</span><span class="p">;</span> <span class="cm">/* See METHOD_ definitions above */</span> + <span class="kt">unsigned</span> <span class="kt">int</span> <span class="n">useCork</span><span class="p">;</span> <span class="cm">/* bit fields of corkUsage */</span> + <span class="p">...</span> +<span class="p">};</span> +</pre></div> +</div> +<p>The <code class="docutils literal notranslate"><span class="pre">name</span></code> field must be set to a non-empty string. Also either <code class="docutils literal notranslate"><span class="pre">parser</span></code> or +<code class="docutils literal notranslate"><span class="pre">parser2</span></code> must set to point to a parsing routine which will generate the tag +entries. All other fields are optional.</p> +</section> +<section id="reading-input-file-stream"> +<h2>Reading input file stream<a class="headerlink" href="#reading-input-file-stream" title="Permalink to this headline">¶</a></h2> +<p>Now all that is left is to implement the parser. In order to do its job, the +parser should read the file stream using using one of the two I/O interfaces: +either the character-oriented <code class="docutils literal notranslate"><span class="pre">getcFromInputFile()</span></code>, or the line-oriented +<code class="docutils literal notranslate"><span class="pre">readLineFromInputFile()</span></code>.</p> +<p>See “<a class="reference internal" href="internal.html#input-text-stream"><span class="std std-ref">Input text stream</span></a>” for more details.</p> +</section> +<section id="parsing"> +<h2>Parsing<a class="headerlink" href="#parsing" title="Permalink to this headline">¶</a></h2> +<p>How our Swine parser actually parses the contents of the file is entirely up to +the writer of the parser--it can be as crude or elegant as desired. You will +note a variety of examples from the most complex (<code class="docutils literal notranslate"><span class="pre">parsers/cxx/*.[hc]</span></code>) to the +simplest (<code class="docutils literal notranslate"><span class="pre">parsers/make.[ch]</span></code>).</p> +</section> +<section id="adding-a-tag-to-the-tag-file"> +<h2>Adding a tag to the tag file<a class="headerlink" href="#adding-a-tag-to-the-tag-file" title="Permalink to this headline">¶</a></h2> +<p>When the Swine parser identifies an interesting token for which it wants to add +a tag to the tag file, it should create a <code class="docutils literal notranslate"><span class="pre">tagEntryInfo</span></code> structure and +initialize it by calling <code class="docutils literal notranslate"><span class="pre">initTagEntry()</span></code>, which initializes defaults and +fills information about the current line number and the file position of the +beginning of the line. After filling in information defining the current entry +(and possibly overriding the file position or other defaults), the parser passes +this structure to <code class="docutils literal notranslate"><span class="pre">makeTagEntry()</span></code>.</p> +<p>See “<a class="reference internal" href="internal.html#output-tag-stream"><span class="std std-ref">Output tag stream</span></a>” for more details.</p> +</section> +<section id="adding-the-parser-to-ctags"> +<h2>Adding the parser to <code class="docutils literal notranslate"><span class="pre">ctags</span></code><a class="headerlink" href="#adding-the-parser-to-ctags" title="Permalink to this headline">¶</a></h2> +<p>Lastly, be sure to add your the name of the file containing your parser (e.g. +<code class="docutils literal notranslate"><span class="pre">parsers/swine.c</span></code>) to the macro <code class="docutils literal notranslate"><span class="pre">PARSER_SRCS</span></code> in the file <code class="docutils literal notranslate"><span class="pre">source.mak</span></code>, so +that your new module will be compiled into the program.</p> +</section> +<section id="misc"> +<h2>Misc.<a class="headerlink" href="#misc" title="Permalink to this headline">¶</a></h2> +<p>This is all there is to it. All other details are specific to the parser and how +it wants to do its job.</p> +<p>There are some support functions which can take care of some commonly needed +parsing tasks, such as <em>keyword table lookups</em> (see <code class="docutils literal notranslate"><span class="pre">main/keyword.c</span></code>), which you +can make use of if desired (examples of its use can be found in <code class="docutils literal notranslate"><span class="pre">parsers/c.c</span></code>, +<code class="docutils literal notranslate"><span class="pre">parsers/eiffel.c</span></code>, and <code class="docutils literal notranslate"><span class="pre">parsers/fortran.c</span></code>).</p> +<p>Support functions can be found in <code class="docutils literal notranslate"><span class="pre">main/*.h</span></code> excluding <code class="docutils literal notranslate"><span class="pre">main/*_p.h</span></code>.</p> +<p>Almost everything is already taken care of automatically for you by the +infrastructure. Writing the actual parsing algorithm is the hardest part, but is +not constrained by any need to conform to anything in ctags other than that +mentioned above.</p> +<p>There are several different approaches used in the parsers inside Universal +Ctags and you can browse through these as examples of how to go about creating +your own.</p> +</section> +</section> + + + <div class="clearer"></div> + </div> + </div> + </div> + <div class="sphinxsidebar" role="navigation" aria-label="main navigation"> + <div class="sphinxsidebarwrapper"> + <h3><a href="index.html">Table of Contents</a></h3> + <ul> +<li><a class="reference internal" href="#">Writing a parser in C</a><ul> +<li><a class="reference internal" href="#registering-a-parser">Registering a parser</a></li> +<li><a class="reference internal" href="#reading-input-file-stream">Reading input file stream</a></li> +<li><a class="reference internal" href="#parsing">Parsing</a></li> +<li><a class="reference internal" href="#adding-a-tag-to-the-tag-file">Adding a tag to the tag file</a></li> +<li><a class="reference internal" href="#adding-the-parser-to-ctags">Adding the parser to <code class="docutils literal notranslate"><span class="pre">ctags</span></code></a></li> +<li><a class="reference internal" href="#misc">Misc.</a></li> +</ul> +</li> +</ul> + + <h4>Previous topic</h4> + <p class="topless"><a href="extending.html" + title="previous chapter">Extending ctags with a parser written in C</a></p> + <h4>Next topic</h4> + <p class="topless"><a href="internal.html" + title="next chapter">Input text stream</a></p> +<div id="searchbox" style="display: none" role="search"> + <h3 id="searchlabel">Quick search</h3> + <div class="searchformwrapper"> + <form class="search" action="search.html" method="get"> + <input type="text" name="q" aria-labelledby="searchlabel" /> + <input type="submit" value="Go" /> + </form> + </div> +</div> +<script>$('#searchbox').show(0);</script> + </div> + </div> + <div class="clearer"></div> + </div> + <div class="related" role="navigation" aria-label="related navigation"> + <h3>Navigation</h3> + <ul> + <li class="right" style="margin-right: 10px"> + <a href="genindex.html" title="General Index" + >index</a></li> + <li class="right" > + <a href="internal.html" title="Input text stream" + >next</a> |</li> + <li class="right" > + <a href="extending.html" title="Extending ctags with a parser written in C" + >previous</a> |</li> + <li class="nav-item nav-item-0"><a href="index.html">Universal Ctags 0.3.0 documentation</a> »</li> + <li class="nav-item nav-item-1"><a href="extending.html" >Extending ctags with a parser written in C</a> »</li> + <li class="nav-item nav-item-this"><a href="">Writing a parser in C</a></li> + </ul> + </div> + <div class="footer" role="contentinfo"> + © Copyright 2015, Universal Ctags Team. + Last updated on 11 Jun 2021. + Created using <a href="https://www.sphinx-doc.org/">Sphinx</a> 4.0.2. + </div> + </body> +</html>
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