Info Catalog bfd: Linker Functions bfd: Linker Functions bfd: Adding Symbols to the Hash Table

bfd: Creating a Linker Hash Table

 
 2.17.1 Creating a linker hash table
 -----------------------------------
 
 The linker routines must create a hash table, which must be derived from
 'struct bfd_link_hash_table' described in 'bfdlink.c'.  Hash
 Tables, for information on how to create a derived hash table.  This
 entry point is called using the target vector of the linker output file.
 
    The '_bfd_link_hash_table_create' entry point must allocate and
 initialize an instance of the desired hash table.  If the back end does
 not require any additional information to be stored with the entries in
 the hash table, the entry point may simply create a 'struct
 bfd_link_hash_table'.  Most likely, however, some additional information
 will be needed.
 
    For example, with each entry in the hash table the a.out linker keeps
 the index the symbol has in the final output file (this index number is
 used so that when doing a relocatable link the symbol index used in the
 output file can be quickly filled in when copying over a reloc).  The
 a.out linker code defines the required structures and functions for a
 hash table derived from 'struct bfd_link_hash_table'.  The a.out linker
 hash table is created by the function
 'NAME(aout,link_hash_table_create)'; it simply allocates space for the
 hash table, initializes it, and returns a pointer to it.
 
    When writing the linker routines for a new back end, you will
 generally not know exactly which fields will be required until you have
 finished.  You should simply create a new hash table which defines no
 additional fields, and then simply add fields as they become necessary.
 

Info Catalog bfd: Linker Functions bfd: Linker Functions bfd: Adding Symbols to the Hash Table