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Up:&nbsp;<a rel="up" accesskey="u" href="Symbol-Tables.html#Symbol-Tables">Symbol Tables</a>
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<h3 class="section">7.2 Transformations on Symbol Tables</h3>
<p>The linker concatenates object files and does fixups of externally
defined symbols.
<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><span class="samp">nm -ap</span></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>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>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.
<ul class="menu">
<li><a accesskey="1" href="Transformations-On-Static-Variables.html#Transformations-On-Static-Variables">Transformations On Static Variables</a>
<li><a accesskey="2" href="Transformations-On-Global-Variables.html#Transformations-On-Global-Variables">Transformations On Global Variables</a>
<li><a accesskey="3" href="Stab-Section-Transformations.html#Stab-Section-Transformations">Stab Section Transformations</a>: For some object file formats,
things are a bit different.
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