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Title=Symbols to Control the Linker
Subsections=control_ref_all, control_tigcc_native, control_nostub, control_nostub_dll, control_fargo, control_flash_os, control_library, control_calc, control_flag, control_version, control_lib_min_version, control_ld_use_fline_jumps, control_ld_use_4byte_fline_jumps, control_ld_omit_bss_init, control_ld_ignore_global_imports

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In addition to options specified in the command line, the TIGCC linker can
be controlled using special symbol names. They should be used directly only
in assembly programs; C programs should rely on the appropriate library
facilities if they are available.
<BR><BR>
These are the symbols the linker treats as control symbols:

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Symbols can be created in a variety of ways; they can be:
<UL>
<LI>labels;</LI>
<LI>undefined exported symbols;</LI>
<LI>imported (used but undefined) symbols;</LI>
<LI>common symbols.</LI>
</UL>
Not all assemblers support all types of symbols; for example, the
<A HREF="$$INFOLINK(a68k)">A68k assembler</A> does not support exporting
symbols which are not defined somewhere in the same file. This assembler is
also somewhat special from the linker's point of view: It only outputs
exported and imported symbols by default; local labels can be supplied in a
symbol table, but since it is optional, the linker does not use it to receive
control information.
<BR><BR>
If a symbol is detected as a control symbol, it is not imported into the
internal data structures as usual. There are two reasons for this: First,
if a user accidentally defines a control symbol somewhere (some traditional
control symbol names are quite short), the resulting error can help detect
this problem. Second, if common symbols are used, they would waste space in
the executable otherwise.
