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<a name="Transformations-On-Symbol-Tables"></a>
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Previous: <a href="Symbol-Table-Format.html#Symbol-Table-Format" accesskey="p" rel="prev">Symbol Table Format</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="Transformations-on-Symbol-Tables"></a>
<h3 class="section">7.2 Transformations on Symbol Tables</h3>

<p>The linker concatenates object files and does fixups of externally
defined symbols.
</p>
<p>You can see the transformations made on stab data by the assembler and
linker by examining the symbol table after each pass of the build.  To
do this, use &lsquo;<samp>nm -ap</samp>&rsquo;, which dumps the symbol table, including
debugging information, unsorted.  For stab entries the columns are:
<var>value</var>, <var>other</var>, <var>desc</var>, <var>type</var>, <var>string</var>.  For
assembler and linker symbols, the columns are: <var>value</var>, <var>type</var>,
<var>string</var>.
</p>
<p>The low 5 bits of the stab type tell the linker how to relocate the
value of the stab.  Thus for stab types like <code>N_RSYM</code> and
<code>N_LSYM</code>, where the value is an offset or a register number, the
low 5 bits are <code>N_ABS</code>, which tells the linker not to relocate the
value.
</p>
<p>Where the value of a stab contains an assembly language label,
it is transformed by each build step.  The assembler turns it into a
relocatable address and the linker turns it into an absolute address.
</p>
<table class="menu" border="0" cellspacing="0">
<tr><td align="left" valign="top">&bull; <a href="Transformations-On-Static-Variables.html#Transformations-On-Static-Variables" accesskey="1">Transformations On Static Variables</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">
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<tr><td align="left" valign="top">&bull; <a href="Transformations-On-Global-Variables.html#Transformations-On-Global-Variables" accesskey="2">Transformations On Global Variables</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Stab-Section-Transformations.html#Stab-Section-Transformations" accesskey="3">Stab Section Transformations</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">For some object file formats,
                                           things are a bit different.
</td></tr>
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