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			90 lines
		
	
	
	
		
			4.3 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
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								<title>Creating a Linker Hash Table - Untitled</title>
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								<link rel="up" href="Linker-Functions.html#Linker-Functions" title="Linker Functions">
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								<link rel="next" href="Adding-Symbols-to-the-Hash-Table.html#Adding-Symbols-to-the-Hash-Table" title="Adding Symbols to the Hash Table">
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								This file documents the BFD library.
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								Copyright (C) 1991, 2000, 2001, 2003, 2006, 2007 Free Software Foundation, Inc.
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								Permission is granted to copy, distribute and/or modify this document
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								Free Software'', the Front-Cover texts being (a) (see below), and with
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								     A GNU Manual
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								<p>
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								<a name="Creating-a-Linker-Hash-Table"></a>Next: <a rel="next" accesskey="n" href="Adding-Symbols-to-the-Hash-Table.html#Adding-Symbols-to-the-Hash-Table">Adding Symbols to the Hash Table</a>,
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								Previous: <a rel="previous" accesskey="p" href="Linker-Functions.html#Linker-Functions">Linker Functions</a>,
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								Up: <a rel="up" accesskey="u" href="Linker-Functions.html#Linker-Functions">Linker Functions</a>
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								</div>
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								<h4 class="subsection">2.17.1 Creating a linker hash table</h4>
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								<p><a name="index-_005fbfd_005flink_005fhash_005ftable_005fcreate-in-target-vector-1369"></a><a name="index-target-vector-_0028_005fbfd_005flink_005fhash_005ftable_005fcreate_0029-1370"></a>The linker routines must create a hash table, which must be
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								derived from <code>struct bfd_link_hash_table</code> described in
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								<code>bfdlink.c</code>.  See <a href="Hash-Tables.html#Hash-Tables">Hash Tables</a>, for information on how to
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								create a derived hash table.  This entry point is called using
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								the target vector of the linker output file.
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								   <p>The <code>_bfd_link_hash_table_create</code> entry point must allocate
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								and initialize an instance of the desired hash table.  If the
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								back end does not require any additional information to be
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								stored with the entries in the hash table, the entry point may
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								simply create a <code>struct bfd_link_hash_table</code>.  Most likely,
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								however, some additional information will be needed.
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								   <p>For example, with each entry in the hash table the a.out
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								linker keeps the index the symbol has in the final output file
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								(this index number is used so that when doing a relocatable
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								link the symbol index used in the output file can be quickly
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								filled in when copying over a reloc).  The a.out linker code
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								defines the required structures and functions for a hash table
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								derived from <code>struct bfd_link_hash_table</code>.  The a.out linker
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								hash table is created by the function
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								<code>NAME(aout,link_hash_table_create)</code>; it simply allocates
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								space for the hash table, initializes it, and returns a
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								pointer to it.
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								   <p>When writing the linker routines for a new back end, you will
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								generally not know exactly which fields will be required until
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								you have finished.  You should simply create a new hash table
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								which defines no additional fields, and then simply add fields
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								as they become necessary.
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