[16/21] Add AIX weak support

[Nick Clifton]

Hi Richard ,

> include/coff/
> 	* internal.h (C_AIX_WEAKEXT): New macro.
> 	(C_WEAKEXT): Use the GNU definition in the generic part of the file,
> 	and conditionally reset it to C_AIX_WEAKEXT in the XCOFF part of
> 	the file.
> 	(CSECT_SYM_P): New macro.
> 	* xcoff.h (L_WEAK): Define.
> 	(EXTERN_SYM_P): New macro.
> 
> bfd/
> 	* coffcode.h (coff_pointerize_aux_hook): Update CSECT_SYM_P to
> 	check whether a symbol has csect information.
> 	(coff_print_aux): Likewise.
> 	* coff-rs6000.c (_bfd_xcoff_swap_aux_in): Handle auxillary csect
> 	information for C_AIX_WEAKEXT too.
> 	(_bfd_xcoff_swap_aux_out): Likewise.
> 	(xcoff_reloc_type_br): Handle defweak symbols too.
> 	* coff64-rs6000.c (_bfd_xcoff64_swap_aux_in): Handle auxillary csect
> 	information for C_AIX_WEAKEXT too.
> 	(_bfd_xcoff64_swap_aux_out): Likewise.
> 	(xcoff64_reloc_type_br): Handle defweak symbols too.
> 	* coffgen.c (coff_print_symbol): Handle auxillary function
> 	information for C_AIX_WEAKEXT too.
> 	* xcofflink.c (_bfd_xcoff_canonicalize_dynamic_symtab): Set BSF_WEAK
> 	instead of BSF_GLOBAL if the L_WEAK flag is set.
> 	(xcoff_dynamic_definition_p): New function.
> 	(xcoff_link_add_dynamic_symbols): Use it to decide whether ldsym
> 	defines h.  Don't change h if ldsym isn't the definition.  Otherwise,
> 	always take the symbol class from the ldsym.  Use weak bfd symbol
> 	types for weak ldsyms.
> 	(xcoff_link_add_symbols): Use CSECT_SYM_P and EXTERN_SYM_P.
> 	Fix the check for whether a definition is from a shared object.
> 	Allow redefinitions of weak symbols.
> 	(xcoff_link_check_ar_symbols): Use EXTERN_SYM_P.
> 	(xcoff_keep_symbol_p): Likewise.
> 	(bfd_xcoff_size_dynamic_sections): Use CSECT_SYM_P.
> 	(xcoff_link_input_bfd): Use CSECT_SYM_P and EXTERN_SYM_P.
> 	Add .loader entries for C_AIX_WEAKEXT as well as C_EXT symbols,
> 	but mark them as L_WEAK.
> 	(xcoff_write_global_symbol): Treat weak symbols as C_AIX_WEAKEXT
> 	instead of C_EXT if C_AIX_WEAKEXT == C_WEAKEXT.
> 
> gas/
> 	* config/tc-ppc.c (ppc_frob_symbol): Add csect information for
> 	C_AIX_WEAKEXT too.
> 
> ld/testsuite/
> 	* ld-powerpc/aix-glink-2a.s, ld-powerpc/aix-glink-2a.ex,
> 	ld-powerpc/aix-glink-2b.s, ld-powerpc/aix-glink-2c.s,
> 	ld-powerpc/aix-glink-2c.ex, ld-powerpc/aix-glink-2d.s,
> 	ld-powerpc/aix-glink-2-32.dd, ld-powerpc/aix-glink-2-64.dd,
> 	ld-powerpc/aix-weak-1a.s, ld-powerpc/aix-weak-1b.s,
> 	ld-powerpc/aix-weak-1-rel.hd, ld-powerpc/aix-weak-1-rel.nd,
> 	ld-powerpc/aix-weak-1-dso.hd, ld-powerpc/aix-weak-1-dso.nd,
> 	ld-powerpc/aix-weak-1-dso.dnd, ld-powerpc/aix-weak-1.ex,
> 	ld-powerpc/aix-weak-2a.s, ld-powerpc/aix-weak-2a.ex,
> 	ld-powerpc/aix-weak-2a.nd, ld-powerpc/aix-weak-2b.s,
> 	ld-powerpc/aix-weak-2b.nd, ld-powerpc/aix-weak-2c.s,
> 	ld-powerpc/aix-weak-2c.ex, ld-powerpc/aix-weak-2c.nd,
> 	ld-powerpc/aix-weak-2c.od, ld-powerpc/aix-weak-3a.s,
> 	ld-powerpc/aix-weak-3a.ex, ld-powerpc/aix-weak-3b.s,
> 	ld-powerpc/aix-weak-3b.ex, ld-powerpc/aix-weak-3-32.d,
> 	ld-powerpc/aix-weak-3-32.dd, ld-powerpc/aix-weak-3-64.d,
> 	ld-powerpc/aix-weak-3-64.dd: New tests.
> 	* ld-powerpc/aix52.exp: Run them.  Replace tmp/aix-* with
> 	tmp/aix64-* in 64-bit ld options.

Approved - please apply.

Cheers
   Nick