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(bfd.info)Writing the symbol table

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Writing the symbol table
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   The `_bfd_final_link' function must gather all the symbols in the
input files and write them out.  It must also write out all the symbols
in the global hash table.  This must be controlled by the `strip' and
`discard' fields of the `bfd_link_info' structure.

   The local symbols of the input files will not have been entered into
the linker hash table.  The `_bfd_final_link' routine must consider
each input file and include the symbols in the output file.  It may be
convenient to do this when looking through the `link_order' structures,
or it may be done by stepping through the `input_bfds' list.

   The `_bfd_final_link' routine must also traverse the global hash
table to gather all the externally visible symbols.  It is possible
that most of the externally visible symbols may be written out when
considering the symbols of each input file, but it is still necessary
to traverse the hash table since the linker script may have defined
some symbols that are not in any of the input files.

   The `strip' field of the `bfd_link_info' structure controls which
symbols are written out.  The possible values are listed in
`bfdlink.h'.  If the value is `strip_some', then the `keep_hash' field
of the `bfd_link_info' structure is a hash table of symbols to keep;
each symbol should be looked up in this hash table, and only symbols
which are present should be included in the output file.

   If the `strip' field of the `bfd_link_info' structure permits local
symbols to be written out, the `discard' field is used to further
controls which local symbols are included in the output file.  If the
value is `discard_l', then all local symbols which begin with a certain
prefix are discarded; this is controlled by the
`bfd_is_local_label_name' entry point.

   The a.out backend handles symbols by calling
`aout_link_write_symbols' on each input BFD and then traversing the
global hash table with the function `aout_link_write_other_symbol'.  It
builds a string table while writing out the symbols, which is written
to the output file at the end of `NAME(aout,final_link)'.

`bfd_link_split_section'
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   *Synopsis*
     boolean bfd_link_split_section(bfd *abfd, asection *sec);
   *Description*
Return nonzero if SEC should be split during a reloceatable or final
link.
     #define bfd_link_split_section(abfd, sec) \
            BFD_SEND (abfd, _bfd_link_split_section, (abfd, sec))