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| <a name="Linker-Functions"></a> |
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| Next: <a href="Hash-Tables.html#Hash-Tables" accesskey="n" rel="next">Hash Tables</a>, Previous: <a href="File-Caching.html#File-Caching" accesskey="p" rel="prev">File Caching</a>, Up: <a href="BFD-front-end.html#BFD-front-end" accesskey="u" rel="up">BFD front end</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="BFD-Index.html#BFD-Index" title="Index" rel="index">Index</a>]</p> |
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| <a name="Linker-Functions-1"></a> |
| <h3 class="section">2.17 Linker Functions</h3> |
| <a name="index-Linker"></a> |
| <p>The linker uses three special entry points in the BFD target |
| vector. It is not necessary to write special routines for |
| these entry points when creating a new BFD back end, since |
| generic versions are provided. However, writing them can |
| speed up linking and make it use significantly less runtime |
| memory. |
| </p> |
| <p>The first routine creates a hash table used by the other |
| routines. The second routine adds the symbols from an object |
| file to the hash table. The third routine takes all the |
| object files and links them together to create the output |
| file. These routines are designed so that the linker proper |
| does not need to know anything about the symbols in the object |
| files that it is linking. The linker merely arranges the |
| sections as directed by the linker script and lets BFD handle |
| the details of symbols and relocs. |
| </p> |
| <p>The second routine and third routines are passed a pointer to |
| a <code>struct bfd_link_info</code> structure (defined in |
| <code>bfdlink.h</code>) which holds information relevant to the link, |
| including the linker hash table (which was created by the |
| first routine) and a set of callback functions to the linker |
| proper. |
| </p> |
| <p>The generic linker routines are in <code>linker.c</code>, and use the |
| header file <code>genlink.h</code>. As of this writing, the only back |
| ends which have implemented versions of these routines are |
| a.out (in <code>aoutx.h</code>) and ECOFF (in <code>ecoff.c</code>). The a.out |
| routines are used as examples throughout this section. |
| </p> |
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| <tr><td align="left" valign="top">• <a href="Creating-a-Linker-Hash-Table.html#Creating-a-Linker-Hash-Table" accesskey="1">Creating a Linker Hash Table</a>:</td><td> </td><td align="left" valign="top"> |
| </td></tr> |
| <tr><td align="left" valign="top">• <a href="Adding-Symbols-to-the-Hash-Table.html#Adding-Symbols-to-the-Hash-Table" accesskey="2">Adding Symbols to the Hash Table</a>:</td><td> </td><td align="left" valign="top"> |
| </td></tr> |
| <tr><td align="left" valign="top">• <a href="Performing-the-Final-Link.html#Performing-the-Final-Link" accesskey="3">Performing the Final Link</a>:</td><td> </td><td align="left" valign="top"> |
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| Next: <a href="Hash-Tables.html#Hash-Tables" accesskey="n" rel="next">Hash Tables</a>, Previous: <a href="File-Caching.html#File-Caching" accesskey="p" rel="prev">File Caching</a>, Up: <a href="BFD-front-end.html#BFD-front-end" accesskey="u" rel="up">BFD front end</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="BFD-Index.html#BFD-Index" title="Index" rel="index">Index</a>]</p> |
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