Quelle usage.html Sprache: HTML

products/Sources/formale Sprachen/C/Accent/doc/usage.html

<HTML>

<HEAD>
<TITLE>Using the ACCENT Compiler Compiler</TITLE>

</HEAD>

<BODY bgcolor="white">

<TABLE cellspacing=20>

   <TR>

      <TD valign="top">
  <img src="logo.gif">
      </TD>

      <TD valign="bottom" align="left">
  <a href="index.html">The Accent Compiler Compiler</a>
  <h1>Using the ACCENT Compiler Compiler</h1>
      </TD>

   </TR>

   <TR>

      <TD align="right" valign="top">
  
  <font face="helvetica">
  <a href="index.html">Accent</a><br>
  <a href="overview.html">Overview</a><br>
  <a href="tutorial.html">Tutorial</a><br>
  <a href="language.html">Language</a><br>
  <a href="installation.html">Installation</a><br>
  Usage<br>
  <a href="lex.html">Lex</a><br>
  <a href="algorithms.html">Algorithms</a><br>
  <a href="distribution.html">Distribution</a><br>
  </font>
      </TD>

      <TD valign="top">
      

<h3>How To Generate a Language Processor</h3>

<table>
<tr>
<td bgcolor="#e9e9d2">
<pre>

  spec.acc     spec.lex  auxil.c  art.o
   |            |         |        |
   |            |         |        |
   V            V         |        |
  +------+     +---+      |        |
  |ACCENT|     |LEX|      |        |
  +------+     +---+      |        |
   |            |         |        |
   |            |         |        |
   V            V         |        |
  yygrammar.h  lex.yy.c   |        |
  yygrammar.c   |         |        |
   |            |         |        |
   +------------+--+------+--------+
                   |
                   V
                  +--+
                  |CC|
                  +--+
                   |
                   |
                   V
                  calculator

</pre>
</td>
</tr>
</table>

<h3>Accent</h3>

<i>Accent</i> is invoked with the command
<pre>
   accent file
</pre>
This reads the grammar in <tt>file</tt>
and generates the output files
<tt>yygrammar.h</tt> and
<tt>yygrammar.c</tt>.
<p>
<tt>yygrammar.h</tt> contains definitions of token codes
and a definition of the type <tt>YYSTYPE</tt> (which is only
effective if there is no previous definition specified by the user).
<p>
<tt>yygrammar.c</tt> contains the grammar encoding and a generated
tree walker that performs the semantic actions specified by the user.
<p>
Example:
<pre>
   accent spec.acc
</pre>
The file
<a href="spec.acc">spec.acc</a>
contains the <i>Accent</i> specification of a simple desk calculator.

<h3>Lex</h3>

The scanner should be generated with <i>Lex</i>.
<i>Lex</i> is invoked by the command
<pre>
   lex file
</pre>
which reads the specification in <tt>file</tt>,
a table of regular expressions and corresponding actions,
and generates a file <tt>yy.lex.c</tt>.
This file contains the function <tt>yylex()</tt>,
the lexical analyzer which is invoked by the parser.
<p>
Example:
<pre>
   lex spec.lex
</pre>
The file
<a href="spec.lex">spec.lex</a>
contains the <i>Lex</i> specification
for the desk calculator.

<h3>Auxiliary Functions</h3>
The user has to prepare some auxiliary functions:
<p>
There should be a <tt>main()</tt> function that invokes
the parser function <tt>yyparse()</tt>.
<p>
<tt>yyerror(char *msg)</tt>
is invoked by the parser when an error is detected. It should print
the text <tt>msg</tt> and perhaps the current line number.
<p>
The scanner needs a function <tt>yywrap()</tt>
(it can be used to switch to a further input file).
In its simplest form it just returns <tt>1</tt>
(indicating no further input file).
<p>
In our example, the file
<a href="auxil.c"><tt>auxil.c</tt></a>
defines these functions.

<h3>Accent Runtime</h3>
To create a functioning parser one also has to supply
the <i>Accent Runtime</i>.
This is contained in the file <tt>art.o</tt> in the
directory <tt>art</tt> of the distribution.

<h3>Compiling and Linking</h3>

The <i>C</i> compiler is used
to compile the sources and create the object program.
<p>
Example:
<pre>
cc -o calculator yygrammar.c lex.yy.c auxil.c $ART
</pre>
(where <tt>$ART</tt> refers to the Accent runtime).
<p>
The file
<a href="build"><tt>build</tt></a>
contains a shell script to produce and run the desk calculator.
<p>
Invoking the optimizer during compilation increases parser speed
by a factor of two.
For the GNU C compiler you should specify <tt>-O3</tt> as an option
when compiling the Accent runtime and the generated program.
      
      <br>
      <br>
      <font face="helvetica" size="1">
      <a href="http://accent.compilertools.net">accent.compilertools.net</a>
      </font>
      </TD>
   </TR>
</TABLE>

</BODY>
</HTML>

quality100%

¤ Dauer der Verarbeitung: 0.24 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.