mingw/info/gdb/How-modes-are-displayed.html

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  18 <h5 class="subsubsection">How modes are displayed</h5>
  19
  20    <p>The Chill Datatype- (Mode) support of GDB is directly related
  21 with the functionality of the <small>GNU</small> Chill compiler, and therefore deviates
  22 slightly from the standard specification of the Chill language. The
  23 provided modes are:
  24
  25      <dl>
  26 <dt><code></code><em>Discrete modes:</em><code></code>
  27      <dd>
  28           <ul>
  29 <li><em>Integer Modes</em> which are predefined by <code>BYTE, UBYTE, INT,
  30 UINT, LONG, ULONG</code>,
  31 <li><em>Boolean Mode</em> which is predefined by <code>BOOL</code>,
  32 <li><em>Character Mode</em> which is predefined by <code>CHAR</code>,
  33 <li><em>Set Mode</em> which is displayed by the keyword <code>SET</code>.
  34           <pre class="smallexample">               (gdb) ptype x
  35                type = SET (karli = 10, susi = 20, fritzi = 100)
  36                </pre>
  37           If the type is an unnumbered set the set element values are omitted.
  38 <li><em>Range Mode</em> which is displayed by
  39           <pre class="smallexample">               <code>type = &lt;basemode&gt;(&lt;lower bound&gt; : &lt;upper bound&gt;)</code>
  40                </pre>
  41           where <code>&lt;lower bound&gt;, &lt;upper bound&gt;</code> can be of any discrete literal
  42 expression (e.g. set element names).
  43 </ul>
  44
  45      <br><dt><code></code><em>Powerset Mode:</em><code></code>
  46      <dd>A Powerset Mode is displayed by the keyword <code>POWERSET</code> followed by
  47 the member mode of the powerset.  The member mode can be any discrete mode.
  48      <pre class="smallexample">          (gdb) ptype x
  49           type = POWERSET SET (egon, hugo, otto)
  50           </pre>
  51
  52      <br><dt><code></code><em>Reference Modes:</em><code></code>
  53      <dd>
  54           <ul>
  55 <li><em>Bound Reference Mode</em> which is displayed by the keyword <code>REF</code>
  56 followed by the mode name to which the reference is bound.
  57 <li><em>Free Reference Mode</em> which is displayed by the keyword <code>PTR</code>.
  58 </ul>
  59
  60      <br><dt><code></code><em>Procedure mode</em><code></code>
  61      <dd>The procedure mode is displayed by <code>type = PROC(&lt;parameter list&gt;)
  62 &lt;return mode&gt; EXCEPTIONS (&lt;exception list&gt;)</code>. The <code>&lt;parameter
  63 list&gt;</code> is a list of the parameter modes.  <code>&lt;return mode&gt;</code> indicates
  64 the mode of the result of the procedure if any.  The exceptionlist lists
  65 all possible exceptions which can be raised by the procedure.
  66
  67      <br><dt><code></code><em>Synchronization Modes:</em><code></code>
  68      <dd>
  69           <ul>
  70 <li><em>Event Mode</em> which is displayed by
  71           <pre class="smallexample">               <code>EVENT (&lt;event length&gt;)</code>
  72                </pre>
  73           where <code>(&lt;event length&gt;)</code> is optional.
  74 <li><em>Buffer Mode</em> which is displayed by
  75           <pre class="smallexample">               <code>BUFFER (&lt;buffer length&gt;)&lt;buffer element mode&gt;</code>
  76                </pre>
  77           where <code>(&lt;buffer length&gt;)</code> is optional.
  78 </ul>
  79
  80      <br><dt><code></code><em>Timing Modes:</em><code></code>
  81      <dd>
  82           <ul>
  83 <li><em>Duration Mode</em> which is predefined by <code>DURATION</code>
  84 <li><em>Absolute Time Mode</em> which is predefined by <code>TIME</code>
  85 </ul>
  86
  87      <br><dt><code></code><em>Real Modes:</em><code></code>
  88      <dd>Real Modes are predefined with <code>REAL</code> and <code>LONG_REAL</code>.
  89
  90      <br><dt><code></code><em>String Modes:</em><code></code>
  91      <dd>
  92           <ul>
  93 <li><em>Character String Mode</em> which is displayed by
  94           <pre class="smallexample">               <code>CHARS(&lt;string length&gt;)</code>
  95                </pre>
  96           followed by the keyword <code>VARYING</code> if the String Mode is a varying
  97 mode
  98 <li><em>Bit String Mode</em> which is displayed by
  99           <pre class="smallexample">               <code>BOOLS(&lt;string
 100                length&gt;)</code>
 101                </pre>
 102           </ul>
 103
 104      <br><dt><code></code><em>Array Mode:</em><code></code>
 105      <dd>The Array Mode is displayed by the keyword <code>ARRAY(&lt;range&gt;)</code>
 106 followed by the element mode (which may in turn be an array mode).
 107      <pre class="smallexample">          (gdb) ptype x
 108           type = ARRAY (1:42)
 109                     ARRAY (1:20)
 110                        SET (karli = 10, susi = 20, fritzi = 100)
 111           </pre>
 112
 113      <br><dt><code></code><em>Structure Mode</em><code></code>
 114      <dd>The Structure mode is displayed by the keyword <code>STRUCT(&lt;field
 115 list&gt;)</code>.  The <code>&lt;field list&gt;</code> consists of names and modes of fields
 116 of the structure.  Variant structures have the keyword <code>CASE &lt;field&gt;
 117 OF &lt;variant fields&gt; ESAC</code> in their field list.  Since the current version
 118 of the GNU Chill compiler doesn't implement tag processing (no runtime
 119 checks of variant fields, and therefore no debugging info), the output
 120 always displays all variant fields.
 121      <pre class="smallexample">          (gdb) ptype str
 122           type = STRUCT (
 123               as x,
 124               bs x,
 125               CASE bs OF
 126               (karli):
 127                   cs a
 128               (ott):
 129                   ds x
 130               ESAC
 131           )
 132           </pre>
 133      </dl>
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