Add STB_SECONDARY supportusers/hjl/secondary

STB_SECONDARY is similar to STB_WEAK. But a STB_SECONDARY definition
can be overridden by STB_GLOBAL or STB_WEAK definition at link-time
as well as run-time.  Linker also search archive library and extract
archive members to resolve defined and undefined STB_SECONDARY symbol.

bfd/

	* archive.c (_bfd_compute_and_write_armap): Treat BSF_SECONDARY
	symbol as global.
	* elf32-mips.c (mips_elf_sym_is_global): Likewise.
	* elfn32-mips.c (mips_elf_sym_is_global): Likewise.
	* elf.c (sym_is_global): Likewise.
	(swap_out_syms): Output undefined secondary symbols as weak.
	Output defined secondary symbols.
	* elf64-ia64-vms.c (elf64_vms_link_add_object_symbols): Handle
	secondary symbols.
	* elfcode.h (elf_slurp_symbol_table): Likewise.
	* elflink.c (_bfd_elf_merge_symbol): Add a boolean argument to
	indicate if the old definition is secondary.  Set OLDSECONADRY if
	it isn't TRUE.   Treat old secondary symbol as weak.  Allow
	overriding secondary symbols.
	(_bfd_elf_add_default_symbol): Add a boolean argument to if the
	old definition is secondary.  Handle the unversioned
	STB_SECONDARY symbol with the versioned definition.
	* elflink.c (is_global_data_symbol_definition): Renamed to ...
	(is_global_symbol_definition): This.  Add an argument to ignore
	secondary symbols.  If secondary symbols are ignored, count
	function and common symbols as global definition.
	(elf_link_is_defined_archive_symbol): Add an argument to ignore
	secondary symbols.  Updated.
	(elf_link_add_object_symbols): Treat secondary symbols as weak
	symbols.  Allow overriding secondary symbols.  Pass oldsecondary
	to _bfd_elf_merge_symbol and _bfd_elf_add_default_symbol.
	(elf_link_add_archive_symbols): Keep searching if a definition
	is secondary.  Ignore another secondary definition.  Updated.
	(elf_link_output_extsym): Generate STB_SECONDARY symbols if
	needed.
	* linker.c (_bfd_generic_link_add_one_symbol): Treat secondary
	symbol as weak symbol.  Mark secondary symbol.
	* syms.c (BSF_SECONDARY): New.
	(bfd_print_symbol_vandf): Handle SECONDARY symbol.
	(bfd_decode_symclass): Likewise.
	* bfd-in2.h: Regenerated.

binutils/

	* nm.c (filter_symbols): Treat BSF_SECONDARY symbol as global.
	* readelf.c (get_symbol_binding): Handle STB_SECONDARY.

gas/

	* symbols.c (S_IS_SECONDARY): New.
	(S_SET_SECONDARY): Likewise.
	(S_FORCE_RELOC): Handle BSF_SECONDARY like BSF_WEAK.
	(S_SET_EXTERNAL): Likewise.
	(S_CLEAR_EXTERNAL): Likewise.
	(S_CLEAR_WEAKREFD): Likewise.
	(S_SET_WEAK): Also clear BSF_SECONDARY.
	* symbols.h (S_IS_SECONDARY): New.
	(S_SET_SECONDARY): Likewise.
	* config/obj-elf.c (obj_elf_secondary): New.
	(elf_pseudo_table): Add "secondary".
	(obj_elf_weak): Don't set symbol weak on secondary symbol.
	(elf_frob_symbol): Check secondary symbol.  Handle secondary
	symbol for .symver.  Also remove the unused secondary symbol.
	(elf_frob_file_before_adjust): Treat secondary symbols as weak.
	* doc/as.texinfo: Document .secondary directive.

gas/testsuite/

	* gas/elf/common3.d: New file.
	* gas/elf/common3.l: Likewise.
	* gas/elf/common3.s: Likewise.
	* gas/elf/common4.d: Likewise.
	* gas/elf/common4.l: Likewise.
	* gas/elf/common4.s: Likewise.
	* gas/elf/secondary1.e: Likewise.
	* gas/elf/secondary1.s: Likewise.
	* gas/elf/secondary2.e: Likewise.
	* gas/elf/secondary2.s: Likewise.
	* gas/elf/elf.exp: Run common3, common4, secondary1 and
	secondary2.
	* gas/elf/type.s: Add .secondary tests.
	* gas/elf/type.e: Updated.

include/

	* bfdlink.h (bfd_link_hash_entry): Add secondary.
	(bfd_link_info): Add emit_secondary.

include/elf/

	* common.h (STB_SECONDARY): New.

ld/

	* ld.texinfo: Document "-z nosecondary".
	* ldmain.c (main): Initialize link_info.emit_secondary to TRUE.
	* lexsup.c (elf_shlib_list_options): Add "-z nosecondary".
	* emultempl/elf32.em (gld${EMULATION_NAME}_handle_option): Set
	to link_info.emit_secondary to FALSE for "-z nosecondary".
	(gld${EMULATION_NAME}_list_options): Replace "-z secondary" with
	"-z nosecondary".

ld/testsuite/

	* ld-elf/library1.c: New file.
	* ld-elf/library1.out: Likewise.
	* ld-elf/library2.c: Likewise.
	* ld-elf/library2.out: Likewise.
	* ld-elf/library3.out: Likewise.
	* ld-elf/library4.out: Likewise.
	* ld-elf/library5a.c: Likewise.
	* ld-elf/library5b.c: Likewise.
	* ld-elf/library6a.c: Likewise.
	* ld-elf/library6b.c: Likewise.
	* ld-elf/library6c.c: Likewise.
	* ld-elf/library7a.c: Likewise.
	* ld-elf/library7b.c: Likewise.
	* ld-elf/library7c.c: Likewise.
	* ld-elf/library8.map: Likewise.
	* ld-elf/library8a.c: Likewise.
	* ld-elf/library8a.rd: Likewise.
	* ld-elf/library8b.c: Likewise.
	* ld-elf/library8b.rd: Likewise.
	* ld-elf/library8c.c: Likewise.
	* ld-elf/library8c.rd: Likewise.
	* ld-elf/secondary-foo.c: Likewise.
	* ld-elf/secondary-main.c: Likewise.
	* ld-elf/secondary.c: Likewise.
	* ld-elf/secondary.exp: Likewise.
	* ld-elf/secondary.rd: Likewise.
	* ld-elf/secondary1.out: Likewise.
	* ld-elf/secondary1.rd: Likewise.
	* ld-elf/secondary2.rd: Likewise.
	* ld-elf/secondary3.rd: Likewise.
	* ld-elf/secondary3a.s: Likewise.
	* ld-elf/secondary3b.s: Likewise.
	* ld-elf/secondary4.rd: Likewise.
	* ld-elf/secondary4.s: Likewise.
	* ld-elf/secondary5.c: Likewise.
	* ld-elf/secondary5.out: Likewise.
	* ld-elf/secondary6.c: Likewise.
	* ld-elf/secondary6.out: Likewise.
	* ld-elf/secondary7.c: Likewise.
	* ld-elf/secondary7.out: Likewise.
	* ld-elf/secondary8a.c: Likewise.
	* ld-elf/secondary8a.map: Likewise.
	* ld-elf/secondary8a.rd: Likewise.
	* ld-elf/secondary8b.c: Likewise.
	* ld-elf/secondary8b.rd: Likewise.

1 files changed, 8 insertions, 2 deletions

diff --git a/bfd/elf.c b/bfd/elf.c
index 35c0f6cdf43..29cfec333e3 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -3625,7 +3625,10 @@ sym_is_global (bfd *abfd, asymbol *sym)
   if (bed->elf_backend_sym_is_global)
     return (*bed->elf_backend_sym_is_global) (abfd, sym);
 
-  return ((sym->flags & (BSF_GLOBAL | BSF_WEAK | BSF_GNU_UNIQUE)) != 0
+  return ((sym->flags & (BSF_GLOBAL
+			 | BSF_WEAK
+			 | BSF_SECONDARY
+			 | BSF_GNU_UNIQUE)) != 0
 	  || bfd_is_und_section (bfd_get_section (sym))
 	  || bfd_is_com_section (bfd_get_section (sym)));
 }
@@ -7408,8 +7411,9 @@ Unable to find equivalent output section for symbol '%s' from section '%s'"),
 #endif
 	    sym.st_info = ELF_ST_INFO (STB_GLOBAL, type);
 	}
+      /* Output undefined secondary symbols as weak.  */
       else if (bfd_is_und_section (syms[idx]->section))
-	sym.st_info = ELF_ST_INFO (((flags & BSF_WEAK)
+	sym.st_info = ELF_ST_INFO (((flags & (BSF_WEAK | BSF_SECONDARY))
 				    ? STB_WEAK
 				    : STB_GLOBAL),
 				   type);
@@ -7423,6 +7427,8 @@ Unable to find equivalent output section for symbol '%s' from section '%s'"),
 	    bind = STB_LOCAL;
 	  else if (flags & BSF_GNU_UNIQUE)
 	    bind = STB_GNU_UNIQUE;
+	  else if (flags & BSF_SECONDARY)
+	    bind = STB_SECONDARY;
 	  else if (flags & BSF_WEAK)
 	    bind = STB_WEAK;
 	  else if (flags & BSF_GLOBAL)