Re: where do undefined symbols get resolved?

[Doug Evans <dje at transmeta dot com>]

Alan Modra writes:
 > On Tue, Jul 23, 2002 at 11:43:36PM -0700, Doug Evans wrote:
 > > Would someone mind pointing me to the source for the code that
 > > resolves undefined symbols?
 > 
 > linker.c:_bfd_generic_link_add_one_symbol.

Ah hah!  I was looking in the wrong place (big surprise).

The version I'm using (2.12.1) has this

/* Return true if section has been discarded.  */
#define elf_discarded_section(sec)					\
  (!bfd_is_abs_section(sec)						\
   && bfd_is_abs_section((sec)->output_section)				\
   && elf_section_data (sec)->sec_info_type != ELF_INFO_TYPE_MERGE)

whereas the current cvs tree has

/* Return true if section has been discarded.  */
#define elf_discarded_section(sec)					\
  (!bfd_is_abs_section(sec)						\
   && bfd_is_abs_section((sec)->output_section)				\
   && elf_section_data (sec)->sec_info_type != ELF_INFO_TYPE_MERGE	\
   && elf_section_data (sec)->sec_info_type != ELF_INFO_TYPE_JUST_SYMS)

Look familiar? ;-)

That's what's causing my "undefined" symbols.
Looks like 2.12.1 --just-syms handling is busted.

The ChangeLog entry accompanying the fix is rather big.
I'm guessing I need to drag in all of this huh?
Or am I on a slippery slope....

2002-05-15  Alan Modra  <amodra@bigpond.net.au>

	* aix5ppc-core.c: Warning fixes.
	* aout-adobe.c (aout_32_bfd_link_just_syms): Define.
	* aout-target.h (MY_bfd_link_just_syms): Define.
	* aout-tic30.c (MY_bfd_link_just_syms): Define.
	* bfd.c (bfd_link_just_syms): Define.
	* binary.c (binary_bfd_link_just_syms): Define.
	* bout.c (b_out_bfd_link_just_syms): Define.
	* coff-rs6000.c (rs6000coff_vec, pmac_xcoff_vec): Update initializer.
	* coff64-rs6000.c (rs6000coff64_vec, aix5coff64_vec): Likewise.
	* coffcode.h (coff_bfd_link_just_syms): Define.
	* elf-bfd.h (enum elf_link_info_type): Add ELF_INFO_TYPE_JUST_SYMS.
	(elf_discarded_section): Check for ELF_INFO_TYPE_JUST_SYMS.
	(_bfd_elf_link_just_syms): Declare.
	* elf.c (_bfd_elf_link_just_syms): New function.
	* elf-eh-frame.c (_bfd_elf_maybe_strip_eh_frame_hdr): Check that
	sections haven't already been discarded by the linker.
	* elflink.h (elf_link_add_object_symbols): Likewise for stab
	sections and SEC_MERGE sections.
	(elf_bfd_discard_info): Similarly here.
	* elfxx-target.h (bfd_elfNN_bfd_link_just_syms): Define.
	* i386msdos.c (msdos_bfd_link_just_syms): Define.
	* i386os9k.c (os9k_bfd_link_just_syms): Define.
	* ieee.c (ieee_bfd_link_just_syms): Define.
	* ihex.c (ihex_bfd_link_just_syms): Define.
	* libbfd-in.h (_bfd_nolink_bfd_link_just_syms): Define.
	(_bfd_generic_link_just_syms): Declare.
	* libecoff.h (_bfd_ecoff_bfd_link_just_syms): Define.
	* linker.c (_bfd_generic_link_just_syms): New function.
	* mmo.c (mmo_bfd_link_just_syms): Define.
	* nlm-target.h (nlm_bfd_link_just_syms): Define.
	* oasys.c (oasys_bfd_link_just_syms): Define.
	* ppcboot.c (ppcboot_bfd_link_just_syms): Define.
	* som.c (som_bfd_link_just_syms): Define.
	* srec.c (srec_bfd_link_just_syms): Define.
	* targets.c (struct bfd_target): Add _bfd_link_just_syms.
	(BFD_JUMP_TABLE_LINK): And here.
	* tekhex.c (tekhex_bfd_link_just_syms): Define.
	* versados.c (versados_bfd_link_just_syms): Define.
	* vms.c (vms_bfd_link_just_syms): Define.
	* libbfd.h: Regenerate.
	* bfd-in2.h: Regenerate.