contents/reference/lttng-modules/lttng-modules-tp-struct-entry.md

   1 ---
   2 id: lttng-modules-tp-struct-entry
   3 ---
   4
   5 This table describes possible entries for the `TP_STRUCT__entry()` part
   6 of `LTTNG_TRACEPOINT_EVENT()`:
   7
   8 <div class="table">
   9 <table class="func-desc">
  10     <thead>
  11         <tr>
  12             <th>Macro</th>
  13             <th>Description/arguments</th>
  14         </tr>
  15     </thead>
  16     <tbody>
  17         <tr>
  18             <td>
  19                 <ul>
  20                     <li><code class="no-bg">__field(<span class="arg">t</span>, <span class="arg">n</span>)</code></li>
  21                 </ul>
  22             </td>
  23             <td>
  24                 <p>Standard integer, displayed in base&nbsp;10</p>
  25                 <ul>
  26                     <li>
  27                         <code class="arg">t</code> integer C type
  28                         (<code>int</code>, <code>unsigned char</code>,
  29                         <code>size_t</code>, etc.)
  30                     </li>
  31                     <li><code class="arg">n</code> field name</li>
  32                 </ul>
  33             </td>
  34         </tr>
  35         <tr>
  36             <td>
  37                 <ul>
  38                     <li><code class="no-bg">__field_hex(<span class="arg">t</span>, <span class="arg">n</span>)</code></li>
  39                 </ul>
  40             </td>
  41             <td>
  42                 <p>Standard integer, displayed in base&nbsp;16</p>
  43                 <ul>
  44                     <li><code class="arg">t</code> integer C type</li>
  45                     <li><code class="arg">n</code> field name</li>
  46                 </ul>
  47             </td>
  48         </tr>
  49         <tr>
  50             <td>
  51                 <ul>
  52                     <li><code class="no-bg">__field_oct(<span class="arg">t</span>, <span class="arg">n</span>)</code></li>
  53                 </ul>
  54             </td>
  55             <td>
  56                 <p>Standard integer, displayed in base&nbsp;8</p>
  57                 <ul>
  58                     <li>
  59                         <code class="arg">t</code> integer C type
  60                     </li>
  61                     <li><code class="arg">n</code> field name</li>
  62                 </ul>
  63             </td>
  64         </tr>
  65         <tr>
  66             <td>
  67                 <ul>
  68                     <li><code class="no-bg">__field_network(<span class="arg">t</span>, <span class="arg">n</span>)</code></li>
  69                 </ul>
  70             </td>
  71             <td>
  72                 <p>
  73                     Integer in network byte order (big endian),
  74                     displayed in base&nbsp;10
  75                 </p>
  76                 <ul>
  77                     <li>
  78                         <code class="arg">t</code> integer C type
  79                     </li>
  80                     <li><code class="arg">n</code> field name</li>
  81                 </ul>
  82             </td>
  83         </tr>
  84         <tr>
  85             <td>
  86                 <ul>
  87                     <li><code class="no-bg">__field_network_hex(<span class="arg">t</span>, <span class="arg">n</span>)</code></li>
  88                 </ul>
  89             </td>
  90             <td>
  91                 <p>
  92                     Integer in network byte order (big endian),
  93                     displayed in base&nbsp;16
  94                 </p>
  95                 <ul>
  96                     <li>
  97                         <code class="arg">t</code> integer C type
  98                     </li>
  99                     <li><code class="arg">n</code> field name</li>
 100                 </ul>
 101             </td>
 102         </tr>
 103         <tr>
 104             <td>
 105                 <ul>
 106                     <li><code class="no-bg">__array(<span class="arg">t</span>, <span class="arg">n</span>, <span class="arg">s</span>)</code></li>
 107                 </ul>
 108             </td>
 109             <td>
 110                 <p>Statically-sized array, elements displayed in base&nbsp;10</p>
 111                 <ul>
 112                     <li>
 113                         <code class="arg">t</code> array element C type
 114                     </li>
 115                     <li><code class="arg">n</code> field name</li>
 116                     <li><code class="arg">s</code> number of elements</li>
 117                 </ul>
 118             </td>
 119         </tr>
 120         <tr>
 121             <td>
 122                 <ul>
 123                     <li><code class="no-bg">__array_hex(<span class="arg">t</span>, <span class="arg">n</span>, <span class="arg">s</span>)</code></li>
 124                 </ul>
 125             </td>
 126             <td>
 127                 <p>Statically-sized array, elements displayed in base&nbsp;16</p>
 128                 <ul>
 129                     <li>
 130                         <code class="arg">t</code> array element C type
 131                     </li>
 132                     <li><code class="arg">n</code> field name</li>
 133                     <li><code class="arg">s</code> number of elements</li>
 134                 </ul>
 135             </td>
 136         </tr>
 137         <tr>
 138             <td>
 139                 <ul>
 140                     <li><code class="no-bg">__array_text(<span class="arg">t</span>, <span class="arg">n</span>, <span class="arg">s</span>)</code></li>
 141                 </ul>
 142             </td>
 143             <td>
 144                 <p>Statically-sized array, displayed as text</p>
 145                 <ul>
 146                     <li>
 147                         <code class="arg">t</code> array element C type
 148                         (always <code>char</code>)
 149                     </li>
 150                     <li><code class="arg">n</code> field name</li>
 151                     <li><code class="arg">s</code> number of elements</li>
 152                 </ul>
 153             </td>
 154         </tr>
 155         <tr>
 156             <td>
 157                 <ul>
 158                     <li><code class="no-bg">__dynamic_array(<span class="arg">t</span>, <span class="arg">n</span>, <span class="arg">s</span>)</code></li>
 159                 </ul>
 160             </td>
 161             <td>
 162                 <p>Dynamically-sized array, displayed in base&nbsp;10</p>
 163                 <ul>
 164                     <li>
 165                         <code class="arg">t</code> array element C type
 166                     </li>
 167                     <li><code class="arg">n</code> field name</li>
 168                     <li><code class="arg">s</code> length C expression</li>
 169                 </ul>
 170             </td>
 171         </tr>
 172         <tr>
 173             <td>
 174                 <ul>
 175                     <li><code class="no-bg">__dynamic_array_hex(<span class="arg">t</span>, <span class="arg">n</span>, <span class="arg">s</span>)</code></li>
 176                 </ul>
 177             </td>
 178             <td>
 179                 <p>Dynamically-sized array, displayed in base&nbsp;16</p>
 180                 <ul>
 181                     <li>
 182                         <code class="arg">t</code> array element C type
 183                     </li>
 184                     <li><code class="arg">n</code> field name</li>
 185                     <li><code class="arg">s</code> length C expression</li>
 186                 </ul>
 187             </td>
 188         </tr>
 189         <tr>
 190             <td>
 191                 <ul>
 192                     <li><code class="no-bg">__dynamic_array_text(<span class="arg">t</span>, <span class="arg">n</span>, <span class="arg">s</span>)</code></li>
 193                 </ul>
 194             </td>
 195             <td>
 196                 <p>Dynamically-sized array, displayed as text</p>
 197                 <ul>
 198                     <li>
 199                         <code class="arg">t</code> array element C type
 200                         (always <code>char</code>)
 201                     </li>
 202                     <li><code class="arg">n</code> field name</li>
 203                     <li><code class="arg">s</code> length C expression</li>
 204                 </ul>
 205             </td>
 206         </tr>
 207         <tr>
 208             <td>
 209                 <ul>
 210                     <li><code class="no-bg">__string(<span class="arg">n</span>, <span class="arg">s</span>)</code></li>
 211                 </ul>
 212             </td>
 213             <td>
 214                 <p>
 215                     Null-terminated string; undefined behavior
 216                     if <code class="arg">s</code> is <code>NULL</code>
 217                 </p>
 218                 <ul>
 219                     <li><code class="arg">n</code> field name</li>
 220                     <li><code class="arg">s</code> string source (pointer)</li>
 221                 </ul>
 222             </td>
 223         </tr>
 224     </tbody>
 225 </table>
 226 </div>
 227
 228 The above macros should cover the majority of cases. For advanced items,
 229 see `probes/lttng-events.h`.