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| <h3 class="section">7.90 <code>.stabd, .stabn, .stabs</code></h3> |
| |
| <p><a name="index-symbolic-debuggers_002c-information-for-477"></a><a name="index-g_t_0040code_007bstab_0040var_007bx_007d_007d-directives-478"></a>There are three directives that begin ‘<samp><span class="samp">.stab</span></samp>’. |
| All emit symbols (see <a href="Symbols.html#Symbols">Symbols</a>), for use by symbolic debuggers. |
| The symbols are not entered in the <samp><span class="command">as</span></samp> hash table: they |
| cannot be referenced elsewhere in the source file. |
| Up to five fields are required: |
| |
| <dl> |
| <dt><var>string</var><dd>This is the symbol's name. It may contain any character except |
| ‘<samp><span class="samp">\000</span></samp>’, so is more general than ordinary symbol names. Some |
| debuggers used to code arbitrarily complex structures into symbol names |
| using this field. |
| |
| <br><dt><var>type</var><dd>An absolute expression. The symbol's type is set to the low 8 bits of |
| this expression. Any bit pattern is permitted, but <code>ld</code> |
| and debuggers choke on silly bit patterns. |
| |
| <br><dt><var>other</var><dd>An absolute expression. The symbol's “other” attribute is set to the |
| low 8 bits of this expression. |
| |
| <br><dt><var>desc</var><dd>An absolute expression. The symbol's descriptor is set to the low 16 |
| bits of this expression. |
| |
| <br><dt><var>value</var><dd>An absolute expression which becomes the symbol's value. |
| </dl> |
| |
| <p>If a warning is detected while reading a <code>.stabd</code>, <code>.stabn</code>, |
| or <code>.stabs</code> statement, the symbol has probably already been created; |
| you get a half-formed symbol in your object file. This is |
| compatible with earlier assemblers! |
| |
| |
| <a name="index-g_t_0040code_007bstabd_007d-directive-479"></a> |
| <dl><dt><code>.stabd </code><var>type</var><code> , </code><var>other</var><code> , </code><var>desc</var><dd> |
| The “name” of the symbol generated is not even an empty string. |
| It is a null pointer, for compatibility. Older assemblers used a |
| null pointer so they didn't waste space in object files with empty |
| strings. |
| |
| <p>The symbol's value is set to the location counter, |
| relocatably. When your program is linked, the value of this symbol |
| is the address of the location counter when the <code>.stabd</code> was |
| assembled. |
| |
| <p><a name="index-g_t_0040code_007bstabn_007d-directive-480"></a><br><dt><code>.stabn </code><var>type</var><code> , </code><var>other</var><code> , </code><var>desc</var><code> , </code><var>value</var><dd>The name of the symbol is set to the empty string <code>""</code>. |
| |
| <p><a name="index-g_t_0040code_007bstabs_007d-directive-481"></a><br><dt><code>.stabs </code><var>string</var><code> , </code><var>type</var><code> , </code><var>other</var><code> , </code><var>desc</var><code> , </code><var>value</var><dd>All five fields are specified. |
| </dl> |
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