2010-09-24 Thomas Schwinge <thomas@codesourcery.com>

	* elf32-arm.c, elf32-cris.c, elf32-hppa.c, elf32-i370.c, elf32-m32r.c,
	elf32-m68k.c, elf32-microblaze.c, elf32-ppc.c, elf32-score.c,
	elf32-score7.c, elf32-sh.c, elf32-vax.c, elf32-xtensa.c, elf64-alpha.c,
	elf64-hppa.c, elf64-mips.c, elf64-ppc.c, elf64-sparc.c, elfcode.h,
	elflink.c, elfxx-ia64.c, elfxx-mips.c: Use STN_UNDEF when referring to
	the zero symbol index.

23 files changed, 66 insertions, 59 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 22f9a2049f..b281a04520 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,12 @@
 2010-09-24  Thomas Schwinge  <thomas@codesourcery.com>
 
+	* elf32-arm.c, elf32-cris.c, elf32-hppa.c, elf32-i370.c, elf32-m32r.c,
+	elf32-m68k.c, elf32-microblaze.c, elf32-ppc.c, elf32-score.c,
+	elf32-score7.c, elf32-sh.c, elf32-vax.c, elf32-xtensa.c, elf64-alpha.c,
+	elf64-hppa.c, elf64-mips.c, elf64-ppc.c, elf64-sparc.c, elfcode.h,
+	elflink.c, elfxx-ia64.c, elfxx-mips.c: Use STN_UNDEF when referring to
+	the zero symbol index.
+
 	* elflink.c (bfd_elf_reloc_symbol_deleted_p): Compare the symbol index
 	to STN_UNDEF, not SHN_UNDEF.
 
diff --git a/bfd/elf32-arm.c b/bfd/elf32-arm.c
index 74fb855763..2125582ee8 100644
--- a/bfd/elf32-arm.c
+++ b/bfd/elf32-arm.c
@@ -9063,7 +9063,7 @@ elf32_arm_relocate_section (bfd *                  output_bfd,
 	    name = bfd_section_name (input_bfd, sec);
 	}
 
-      if (r_symndx != 0
+      if (r_symndx != STN_UNDEF
 	  && r_type != R_ARM_NONE
 	  && (h == NULL
 	      || h->root.type == bfd_link_hash_defined
@@ -10902,7 +10902,7 @@ elf32_arm_check_relocs (bfd *abfd, struct bfd_link_info *info,
 	  /* PR 9934: It is possible to have relocations that do not
 	     refer to symbols, thus it is also possible to have an
 	     object file containing relocations but no symbol table.  */
-	  && (r_symndx > 0 || nsyms > 0))
+	  && (r_symndx > STN_UNDEF || nsyms > 0))
 	{
 	  (*_bfd_error_handler) (_("%B: bad symbol index: %d"), abfd,
 				   r_symndx);
diff --git a/bfd/elf32-cris.c b/bfd/elf32-cris.c
index 71634c93eb..f3ed80d18e 100644
--- a/bfd/elf32-cris.c
+++ b/bfd/elf32-cris.c
@@ -1493,7 +1493,7 @@ cris_elf_relocate_section (bfd *output_bfd ATTRIBUTE_UNUSED,
 	case R_CRIS_16:
 	case R_CRIS_32:
 	  if (info->shared
-	      && r_symndx != 0
+	      && r_symndx != STN_UNDEF
 	      && (input_section->flags & SEC_ALLOC) != 0
 	      && ((r_type != R_CRIS_8_PCREL
 		   && r_type != R_CRIS_16_PCREL
diff --git a/bfd/elf32-hppa.c b/bfd/elf32-hppa.c
index 1a6fef8827..3a3a355d6e 100644
--- a/bfd/elf32-hppa.c
+++ b/bfd/elf32-hppa.c
@@ -4472,7 +4472,7 @@ static enum elf_reloc_type_class
 elf32_hppa_reloc_type_class (const Elf_Internal_Rela *rela)
 {
   /* Handle TLS relocs first; we don't want them to be marked
-     relative by the "if (ELF32_R_SYM (rela->r_info) == 0)"
+     relative by the "if (ELF32_R_SYM (rela->r_info) == STN_UNDEF)"
      check below.  */
   switch ((int) ELF32_R_TYPE (rela->r_info))
     {
@@ -4482,7 +4482,7 @@ elf32_hppa_reloc_type_class (const Elf_Internal_Rela *rela)
         return reloc_class_normal;
     }
 
-  if (ELF32_R_SYM (rela->r_info) == 0)
+  if (ELF32_R_SYM (rela->r_info) == STN_UNDEF)
     return reloc_class_relative;
 
   switch ((int) ELF32_R_TYPE (rela->r_info))
diff --git a/bfd/elf32-i370.c b/bfd/elf32-i370.c
index 67e6598523..01f9fb8612 100644
--- a/bfd/elf32-i370.c
+++ b/bfd/elf32-i370.c
@@ -1183,7 +1183,7 @@ i370_elf_relocate_section (bfd *output_bfd,
 	case (int) R_I370_ADDR31:
 	case (int) R_I370_ADDR16:
 	  if (info->shared
-	      && r_symndx != 0)
+	      && r_symndx != STN_UNDEF)
 	    {
 	      Elf_Internal_Rela outrel;
 	      bfd_byte *loc;
diff --git a/bfd/elf32-m32r.c b/bfd/elf32-m32r.c
index 28eff7666c..3df6addb69 100644
--- a/bfd/elf32-m32r.c
+++ b/bfd/elf32-m32r.c
@@ -2897,7 +2897,7 @@ m32r_elf_relocate_section (bfd *output_bfd ATTRIBUTE_UNUSED,
             case R_M32R_HI16_ULO_RELA:
             case R_M32R_LO16_RELA:
               if (info->shared
-                  && r_symndx != 0
+                  && r_symndx != STN_UNDEF
                   && (input_section->flags & SEC_ALLOC) != 0
                   && ((   r_type != R_M32R_10_PCREL_RELA
                        && r_type != R_M32R_18_PCREL_RELA
diff --git a/bfd/elf32-m68k.c b/bfd/elf32-m68k.c
index 7323612176..8d1ee7f5e7 100644
--- a/bfd/elf32-m68k.c
+++ b/bfd/elf32-m68k.c
@@ -4034,7 +4034,7 @@ elf_m68k_relocate_section (output_bfd, info, input_bfd, input_section,
 	case R_68K_PC16:
 	case R_68K_PC32:
 	  if (info->shared
-	      && r_symndx != 0
+	      && r_symndx != STN_UNDEF
 	      && (input_section->flags & SEC_ALLOC) != 0
 	      && (h == NULL
 		  || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
@@ -4169,7 +4169,7 @@ elf_m68k_relocate_section (output_bfd, info, input_bfd, input_section,
 	  return FALSE;
 	}
 
-      if (r_symndx != 0
+      if (r_symndx != STN_UNDEF
 	  && r_type != R_68K_NONE
 	  && (h == NULL
 	      || h->root.type == bfd_link_hash_defined
diff --git a/bfd/elf32-microblaze.c b/bfd/elf32-microblaze.c
index a64926a51e..e260c55577 100644
--- a/bfd/elf32-microblaze.c
+++ b/bfd/elf32-microblaze.c
@@ -1067,10 +1067,10 @@ microblaze_elf_relocate_section (bfd *output_bfd,
 	    case (int) R_MICROBLAZE_64:
 	    case (int) R_MICROBLAZE_32:
 	      {
-		/* r_symndx will be zero only for relocs against symbols
+		/* r_symndx will be STN_UNDEF (zero) only for relocs against symbols
 		   from removed linkonce sections, or sections discarded by
 		   a linker script.  */
-		if (r_symndx == 0 || (input_section->flags & SEC_ALLOC) == 0)
+		if (r_symndx == STN_UNDEF || (input_section->flags & SEC_ALLOC) == 0)
 		  {
 		    relocation += addend;
 		    if (r_type == R_MICROBLAZE_32)
diff --git a/bfd/elf32-ppc.c b/bfd/elf32-ppc.c
index ef0e15927e..2b457d6d9b 100644
--- a/bfd/elf32-ppc.c
+++ b/bfd/elf32-ppc.c
@@ -6985,9 +6985,9 @@ ppc_elf_relocate_section (bfd *output_bfd,
 			if (local_sections[r_symndx] == sec)
 			  break;
 		      if (r_symndx >= symtab_hdr->sh_info)
-			r_symndx = 0;
+			r_symndx = STN_UNDEF;
 		      rel->r_addend = htab->elf.tls_sec->vma + DTP_OFFSET;
-		      if (r_symndx != 0)
+		      if (r_symndx != STN_UNDEF)
 			rel->r_addend -= (local_syms[r_symndx].st_value
 					  + sec->output_offset
 					  + sec->output_section->vma);
@@ -7053,9 +7053,9 @@ ppc_elf_relocate_section (bfd *output_bfd,
 		if (local_sections[r_symndx] == sec)
 		  break;
 	      if (r_symndx >= symtab_hdr->sh_info)
-		r_symndx = 0;
+		r_symndx = STN_UNDEF;
 	      rel->r_addend = htab->elf.tls_sec->vma + DTP_OFFSET;
-	      if (r_symndx != 0)
+	      if (r_symndx != STN_UNDEF)
 		rel->r_addend -= (local_syms[r_symndx].st_value
 				  + sec->output_offset
 				  + sec->output_section->vma);
@@ -7658,7 +7658,7 @@ ppc_elf_relocate_section (bfd *output_bfd,
 			     sym_name);
 			  ret = FALSE;
 			}
-		      else if (r_symndx == 0 || bfd_is_abs_section (sec))
+		      else if (r_symndx == STN_UNDEF || bfd_is_abs_section (sec))
 			;
 		      else if (sec == NULL || sec->owner == NULL)
 			{
diff --git a/bfd/elf32-score.c b/bfd/elf32-score.c
index f1f1aae1e7..fec177af07 100644
--- a/bfd/elf32-score.c
+++ b/bfd/elf32-score.c
@@ -2126,7 +2126,7 @@ score_elf_final_link_relocate (reloc_howto_type *howto,
                && h != NULL
                && h->root.def_dynamic
                && !h->root.def_regular))
-           && r_symndx != 0
+           && r_symndx != STN_UNDEF
            && (input_section->flags & SEC_ALLOC) != 0)
         {
           /* If we're creating a shared library, or this relocation is against a symbol
@@ -2139,8 +2139,8 @@ score_elf_final_link_relocate (reloc_howto_type *howto,
                                                     input_section))
             return bfd_reloc_undefined;
         }
-      else if (r_symndx == 0)
-        /* r_symndx will be zero only for relocs against symbols
+      else if (r_symndx == STN_UNDEF)
+        /* r_symndx will be STN_UNDEF (zero) only for relocs against symbols
            from removed linkonce sections, or sections discarded by
            a linker script.  */
         value = 0;
diff --git a/bfd/elf32-score7.c b/bfd/elf32-score7.c
index 85ce236a4f..f780e56ab7 100644
--- a/bfd/elf32-score7.c
+++ b/bfd/elf32-score7.c
@@ -2025,7 +2025,7 @@ score_elf_final_link_relocate (reloc_howto_type *howto,
                && h != NULL
                && h->root.def_dynamic
                && !h->root.def_regular))
-           && r_symndx != 0
+           && r_symndx != STN_UNDEF
            && (input_section->flags & SEC_ALLOC) != 0)
         {
           /* If we're creating a shared library, or this relocation is against a symbol
@@ -2038,8 +2038,8 @@ score_elf_final_link_relocate (reloc_howto_type *howto,
                                                     input_section))
             return bfd_reloc_undefined;
         }
-      else if (r_symndx == 0)
-        /* r_symndx will be zero only for relocs against symbols
+      else if (r_symndx == STN_UNDEF)
+        /* r_symndx will be STN_UNDEF (zero) only for relocs against symbols
            from removed linkonce sections, or sections discarded by
            a linker script.  */
         value = 0;
diff --git a/bfd/elf32-sh.c b/bfd/elf32-sh.c
index 023ed7ede7..4937643406 100644
--- a/bfd/elf32-sh.c
+++ b/bfd/elf32-sh.c
@@ -4405,7 +4405,7 @@ sh_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
 	      && (h == NULL
 		  || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
 		  || h->root.type != bfd_link_hash_undefweak)
-	      && r_symndx != 0
+	      && r_symndx != STN_UNDEF
 	      && (input_section->flags & SEC_ALLOC) != 0
 	      && !is_vxworks_tls
 	      && (r_type == R_SH_DIR32
diff --git a/bfd/elf32-vax.c b/bfd/elf32-vax.c
index 1582ac764d..db67faf850 100644
--- a/bfd/elf32-vax.c
+++ b/bfd/elf32-vax.c
@@ -1611,7 +1611,7 @@ elf_vax_relocate_section (bfd *output_bfd,
 	case R_VAX_16:
 	case R_VAX_32:
 	  if (info->shared
-	      && r_symndx != 0
+	      && r_symndx != STN_UNDEF
 	      && (input_section->flags & SEC_ALLOC) != 0
 	      && ((r_type != R_VAX_PC8
 		   && r_type != R_VAX_PC16
diff --git a/bfd/elf32-xtensa.c b/bfd/elf32-xtensa.c
index 9b9b5de06a..f9ecde5fa8 100644
--- a/bfd/elf32-xtensa.c
+++ b/bfd/elf32-xtensa.c
@@ -2800,7 +2800,7 @@ elf_xtensa_relocate_section (bfd *output_bfd,
 	    name = bfd_section_name (input_bfd, sec);
 	}
 
-      if (r_symndx != 0
+      if (r_symndx != STN_UNDEF
 	  && r_type != R_XTENSA_NONE
 	  && (h == NULL
 	      || h->root.type == bfd_link_hash_defined
diff --git a/bfd/elf64-alpha.c b/bfd/elf64-alpha.c
index 19326cf81b..1df020c397 100644
--- a/bfd/elf64-alpha.c
+++ b/bfd/elf64-alpha.c
@@ -1866,8 +1866,8 @@ elf64_alpha_check_relocs (bfd *abfd, struct bfd_link_info *info,
 
 	case R_ALPHA_TLSLDM:
 	  /* The symbol for a TLSLDM reloc is ignored.  Collapse the
-	     reloc to the 0 symbol so that they all match.  */
-	  r_symndx = 0;
+	     reloc to the STN_UNDEF (0) symbol so that they all match.  */
+	  r_symndx = STN_UNDEF;
 	  h = 0;
 	  maybe_dynamic = FALSE;
 	  /* FALLTHRU */
@@ -3491,7 +3491,7 @@ elf64_alpha_relax_tls_get_addr (struct alpha_relax_info *info, bfd_vma symval,
      as appropriate.  */
 
   use_gottprel = FALSE;
-  new_symndx = is_gd ? ELF64_R_SYM (irel->r_info) : 0;
+  new_symndx = is_gd ? ELF64_R_SYM (irel->r_info) : STN_UNDEF;
 
   /* Beware of the compiler hoisting part of the sequence out a loop
      and adjusting the destination register for the TLSGD insn.  If this
@@ -3724,8 +3724,8 @@ elf64_alpha_relax_section (bfd *abfd, asection *sec,
 
 	case R_ALPHA_TLSLDM:
 	  /* The symbol for a TLSLDM reloc is ignored.  Collapse the
-             reloc to the 0 symbol so that they all match.  */
-	  r_symndx = 0;
+             reloc to the STN_UNDEF (0) symbol so that they all match.  */
+	  r_symndx = STN_UNDEF;
 	  break;
 
 	default:
@@ -4154,9 +4154,9 @@ elf64_alpha_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
       r_symndx = ELF64_R_SYM(rel->r_info);
 
       /* The symbol for a TLSLDM reloc is ignored.  Collapse the
-	 reloc to the 0 symbol so that they all match.  */
+	 reloc to the STN_UNDEF (0) symbol so that they all match.  */
       if (r_type == R_ALPHA_TLSLDM)
-	r_symndx = 0;
+	r_symndx = STN_UNDEF;
 
       if (r_symndx < symtab_hdr->sh_info)
 	{
@@ -4166,10 +4166,10 @@ elf64_alpha_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
 	  msec = sec;
 	  value = _bfd_elf_rela_local_sym (output_bfd, sym, &msec, rel);
 
-	  /* If this is a tp-relative relocation against sym 0,
+	  /* If this is a tp-relative relocation against sym STN_UNDEF (0),
 	     this is hackery from relax_section.  Force the value to
 	     be the tls module base.  */
-	  if (r_symndx == 0
+	  if (r_symndx == STN_UNDEF
 	      && (r_type == R_ALPHA_TLSLDM
 		  || r_type == R_ALPHA_GOTTPREL
 		  || r_type == R_ALPHA_TPREL64
@@ -4455,7 +4455,7 @@ elf64_alpha_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
 		dynaddend = value - dtp_base;
 	      }
 	    else if (info->shared
-		     && r_symndx != 0
+		     && r_symndx != STN_UNDEF
 		     && (input_section->flags & SEC_ALLOC)
 		     && !undef_weak_ref)
 	      {
@@ -4503,7 +4503,7 @@ elf64_alpha_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
 	  /* ??? .eh_frame references to discarded sections will be smashed
 	     to relocations against SHN_UNDEF.  The .eh_frame format allows
 	     NULL to be encoded as 0 in any format, so this works here.  */
-	  if (r_symndx == 0)
+	  if (r_symndx == STN_UNDEF)
 	    howto = (elf64_alpha_howto_table
 		     + (r_type - R_ALPHA_SREL32 + R_ALPHA_REFLONG));
 	  goto default_reloc;
diff --git a/bfd/elf64-hppa.c b/bfd/elf64-hppa.c
index ba6b1f84c7..4efab4fc26 100644
--- a/bfd/elf64-hppa.c
+++ b/bfd/elf64-hppa.c
@@ -2465,7 +2465,7 @@ elf64_hppa_finalize_dynreloc (struct elf_link_hash_entry *eh,
 static enum elf_reloc_type_class
 elf64_hppa_reloc_type_class (const Elf_Internal_Rela *rela)
 {
-  if (ELF64_R_SYM (rela->r_info) == 0)
+  if (ELF64_R_SYM (rela->r_info) == STN_UNDEF)
     return reloc_class_relative;
 
   switch ((int) ELF64_R_TYPE (rela->r_info))
diff --git a/bfd/elf64-mips.c b/bfd/elf64-mips.c
index bb079cf33e..5001d42315 100644
--- a/bfd/elf64-mips.c
+++ b/bfd/elf64-mips.c
@@ -2619,7 +2619,7 @@ mips_elf64_slurp_one_reloc_table (bfd *abfd, asection *asect,
 	    default:
 	      if (! used_sym)
 		{
-		  if (rela.r_sym == 0)
+		  if (rela.r_sym == STN_UNDEF)
 		    relent->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr;
 		  else
 		    {
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 2073bdc11d..a4f3064a4f 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -11668,7 +11668,7 @@ ppc64_elf_relocate_section (bfd *output_bfd,
 
       /* Check that tls relocs are used with tls syms, and non-tls
 	 relocs are used with non-tls syms.  */
-      if (r_symndx != 0
+      if (r_symndx != STN_UNDEF
 	  && r_type != R_PPC64_NONE
 	  && (h == NULL
 	      || h->elf.root.type == bfd_link_hash_defined
@@ -11917,9 +11917,9 @@ ppc64_elf_relocate_section (bfd *output_bfd,
 			if (local_sections[r_symndx] == sec)
 			  break;
 		      if (r_symndx >= symtab_hdr->sh_info)
-			r_symndx = 0;
+			r_symndx = STN_UNDEF;
 		      rel->r_addend = htab->elf.tls_sec->vma + DTP_OFFSET;
-		      if (r_symndx != 0)
+		      if (r_symndx != STN_UNDEF)
 			rel->r_addend -= (local_syms[r_symndx].st_value
 					  + sec->output_offset
 					  + sec->output_section->vma);
@@ -12025,9 +12025,9 @@ ppc64_elf_relocate_section (bfd *output_bfd,
 		if (local_sections[r_symndx] == sec)
 		  break;
 	      if (r_symndx >= symtab_hdr->sh_info)
-		r_symndx = 0;
+		r_symndx = STN_UNDEF;
 	      rel->r_addend = htab->elf.tls_sec->vma + DTP_OFFSET;
-	      if (r_symndx != 0)
+	      if (r_symndx != STN_UNDEF)
 		rel->r_addend -= (local_syms[r_symndx].st_value
 				  + sec->output_offset
 				  + sec->output_section->vma);
@@ -12569,7 +12569,7 @@ ppc64_elf_relocate_section (bfd *output_bfd,
 	case R_PPC64_TOC:
 	  /* Relocation value is TOC base.  */
 	  relocation = TOCstart;
-	  if (r_symndx == 0)
+	  if (r_symndx == STN_UNDEF)
 	    relocation += htab->stub_group[input_section->id].toc_off;
 	  else if (unresolved_reloc)
 	    ;
@@ -12819,7 +12819,7 @@ ppc64_elf_relocate_section (bfd *output_bfd,
 			     sym_name);
 			  ret = FALSE;
 			}
-		      else if (r_symndx == 0 || bfd_is_abs_section (sec))
+		      else if (r_symndx == STN_UNDEF || bfd_is_abs_section (sec))
 			;
 		      else if (sec == NULL || sec->owner == NULL)
 			{
diff --git a/bfd/elf64-sparc.c b/bfd/elf64-sparc.c
index 5a2fda2684..ca692d291d 100644
--- a/bfd/elf64-sparc.c
+++ b/bfd/elf64-sparc.c
@@ -98,7 +98,7 @@ elf64_sparc_slurp_one_reloc_table (bfd *abfd, asection *asect,
       else
 	relent->address = rela.r_offset - asect->vma;
 
-      if (ELF64_R_SYM (rela.r_info) == 0)
+      if (ELF64_R_SYM (rela.r_info) == STN_UNDEF)
 	relent->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr;
       else
 	{
diff --git a/bfd/elfcode.h b/bfd/elfcode.h
index f7c89263ee..0cd11830bd 100644
--- a/bfd/elfcode.h
+++ b/bfd/elfcode.h
@@ -1466,7 +1466,7 @@ elf_slurp_reloc_table_from_section (bfd *abfd,
       else
 	relent->address = rela.r_offset - asect->vma;
 
-      if (ELF_R_SYM (rela.r_info) == 0)
+      if (ELF_R_SYM (rela.r_info) == STN_UNDEF)
 	relent->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr;
       else if (ELF_R_SYM (rela.r_info) > symcount)
 	{
diff --git a/bfd/elflink.c b/bfd/elflink.c
index bdd69660a5..f4d65991fe 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -2170,7 +2170,7 @@ elf_link_read_relocs_from_section (bfd *abfd,
 	      return FALSE;
 	    }
 	}
-      else if (r_symndx != 0)
+      else if (r_symndx != STN_UNDEF)
 	{
 	  (*_bfd_error_handler)
 	    (_("%B: non-zero symbol index (0x%lx) for offset 0x%lx in section `%A'"
@@ -9500,7 +9500,7 @@ elf_link_input_bfd (struct elf_final_link_info *finfo, bfd *input_bfd)
 		     discarded section.  */
 		  if ((sec = *ps) != NULL && elf_discarded_section (sec))
 		    {
-		      BFD_ASSERT (r_symndx != 0);
+		      BFD_ASSERT (r_symndx != STN_UNDEF);
 		      if (action_discarded & COMPLAIN)
 			(*finfo->info->callbacks->einfo)
 			  (_("%X`%s' referenced in section `%A' of %B: "
@@ -9667,7 +9667,7 @@ elf_link_input_bfd (struct elf_final_link_info *finfo, bfd *input_bfd)
 		      /* I suppose the backend ought to fill in the
 			 section of any STT_SECTION symbol against a
 			 processor specific section.  */
-		      r_symndx = 0;
+		      r_symndx = STN_UNDEF;
 		      if (bfd_is_abs_section (sec))
 			;
 		      else if (sec == NULL || sec->owner == NULL)
@@ -9696,7 +9696,7 @@ elf_link_input_bfd (struct elf_final_link_info *finfo, bfd *input_bfd)
 			  if (!bfd_is_abs_section (osec))
 			    {
 			      r_symndx = osec->target_index;
-			      if (r_symndx == 0)
+			      if (r_symndx == STN_UNDEF)
 				{
 				  struct elf_link_hash_table *htab;
 				  asection *oi;
@@ -9714,7 +9714,7 @@ elf_link_input_bfd (struct elf_final_link_info *finfo, bfd *input_bfd)
 				    }
 				}
 
-			      BFD_ASSERT (r_symndx != 0);
+			      BFD_ASSERT (r_symndx != STN_UNDEF);
 			    }
 			}
 
@@ -11471,7 +11471,7 @@ _bfd_elf_gc_mark_rsec (struct bfd_link_info *info, asection *sec,
   struct elf_link_hash_entry *h;
 
   r_symndx = cookie->rel->r_info >> cookie->r_sym_shift;
-  if (r_symndx == 0)
+  if (r_symndx == STN_UNDEF)
     return NULL;
 
   if (r_symndx >= cookie->locsymcount
diff --git a/bfd/elfxx-ia64.c b/bfd/elfxx-ia64.c
index c8588b9751..d780909838 100644
--- a/bfd/elfxx-ia64.c
+++ b/bfd/elfxx-ia64.c
@@ -4695,7 +4695,7 @@ elfNN_ia64_relocate_section (bfd *output_bfd,
 	case R_IA64_DIR64LSB:
 	  /* Install a dynamic relocation for this reloc.  */
 	  if ((dynamic_symbol_p || info->shared)
-	      && r_symndx != 0
+	      && r_symndx != STN_UNDEF
 	      && (input_section->flags & SEC_ALLOC) != 0)
 	    {
 	      unsigned int dyn_r_type;
@@ -4924,7 +4924,7 @@ elfNN_ia64_relocate_section (bfd *output_bfd,
 	case R_IA64_PCREL64MSB:
 	case R_IA64_PCREL64LSB:
 	  /* Install a dynamic relocation for this reloc.  */
-	  if (dynamic_symbol_p && r_symndx != 0)
+	  if (dynamic_symbol_p && r_symndx != STN_UNDEF)
 	    {
 	      BFD_ASSERT (srel != NULL);
 
diff --git a/bfd/elfxx-mips.c b/bfd/elfxx-mips.c
index 1ee9289ff8..a32a61371b 100644
--- a/bfd/elfxx-mips.c
+++ b/bfd/elfxx-mips.c
@@ -5282,7 +5282,7 @@ mips_elf_calculate_relocation (bfd *abfd, bfd *input_bfd,
 	       && h->root.def_dynamic
 	       && !h->root.def_regular
 	       && !h->has_static_relocs))
-	  && r_symndx != 0
+	  && r_symndx != STN_UNDEF
 	  && (h == NULL
 	      || h->root.root.type != bfd_link_hash_undefweak
 	      || ELF_ST_VISIBILITY (h->root.other) == STV_DEFAULT)
@@ -7752,7 +7752,7 @@ _bfd_mips_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
 	case R_MIPS_TLS_LDM:
 	  if (r_type == R_MIPS_TLS_LDM)
 	    {
-	      r_symndx = 0;
+	      r_symndx = STN_UNDEF;
 	      h = NULL;
 	    }
 	  /* Fall through */
@@ -7778,7 +7778,7 @@ _bfd_mips_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
 	      }
 	    else
 	      {
-		BFD_ASSERT (flag == GOT_TLS_LDM || r_symndx != 0);
+		BFD_ASSERT (flag == GOT_TLS_LDM || r_symndx != STN_UNDEF);
 
 		if (!mips_elf_record_local_got_symbol (abfd, r_symndx,
 						       rel->r_addend,
@@ -7918,7 +7918,7 @@ _bfd_mips_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
 	    case R_MIPS_HIGHEST:
 	      /* Don't refuse a high part relocation if it's against
 		 no symbol (e.g. part of a compound relocation).  */
-	      if (r_symndx == 0)
+	      if (r_symndx == STN_UNDEF)
 		break;
 
 	      /* R_MIPS_HI16 against _gp_disp is used for $gp setup,