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<title>STABS: Symbol Table Format</title>

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<a name="Symbol-Table-Format"></a>
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<p>
Next: <a href="Transformations-On-Symbol-Tables.html#Transformations-On-Symbol-Tables" accesskey="n" rel="next">Transformations On Symbol Tables</a>, Up: <a href="Symbol-Tables.html#Symbol-Tables" accesskey="u" rel="up">Symbol Tables</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Symbol-Types-Index.html#Symbol-Types-Index" title="Index" rel="index">Index</a>]</p>
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<a name="Symbol-Table-Format-1"></a>
<h3 class="section">7.1 Symbol Table Format</h3>

<p>Each time the assembler encounters a stab directive, it puts
each field of the stab into a corresponding field in a symbol table
entry of its output file.  If the stab contains a string field, the
symbol table entry for that stab points to a string table entry
containing the string data from the stab.  Assembler labels become
relocatable addresses.  Symbol table entries in a.out have the format:
</p>
<div class="example">
<pre class="example">struct internal_nlist {
  unsigned long n_strx;         /* index into string table of name */
  unsigned char n_type;         /* type of symbol */
  unsigned char n_other;        /* misc info (usually empty) */
  unsigned short n_desc;        /* description field */
  bfd_vma n_value;              /* value of symbol */
};
</pre></div>

<p>If the stab has a string, the <code>n_strx</code> field holds the offset in
bytes of the string within the string table.  The string is terminated
by a NUL character.  If the stab lacks a string (for example, it was
produced by a <code>.stabn</code> or <code>.stabd</code> directive), the
<code>n_strx</code> field is zero.
</p>
<p>Symbol table entries with <code>n_type</code> field values greater than 0x1f
originated as stabs generated by the compiler (with one random
exception).  The other entries were placed in the symbol table of the
executable by the assembler or the linker.
</p>


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