2003-05-28 Alan Modra <amodra@bigpond.net.au>
[deliverable/binutils-gdb.git] / bfd / elf32-i386.c
index 69292da7f1613371e32e06ae275d064d910b9d9f..cfcb7b34c195e7501f5dfec0039ea6be850ded2b 100644 (file)
@@ -26,8 +26,6 @@
 
 static reloc_howto_type *elf_i386_reloc_type_lookup
   PARAMS ((bfd *, bfd_reloc_code_real_type));
-static void elf_i386_info_to_howto
-  PARAMS ((bfd *, arelent *, Elf_Internal_Rela *));
 static void elf_i386_info_to_howto_rel
   PARAMS ((bfd *, arelent *, Elf_Internal_Rela *));
 static bfd_boolean elf_i386_is_local_label_name
@@ -372,15 +370,6 @@ elf_i386_reloc_type_lookup (abfd, code)
   return 0;
 }
 
-static void
-elf_i386_info_to_howto (abfd, cache_ptr, dst)
-     bfd *abfd ATTRIBUTE_UNUSED;
-     arelent *cache_ptr ATTRIBUTE_UNUSED;
-     Elf_Internal_Rela *dst ATTRIBUTE_UNUSED;
-{
-  abort ();
-}
-
 static void
 elf_i386_info_to_howto_rel (abfd, cache_ptr, dst)
      bfd *abfd ATTRIBUTE_UNUSED;
@@ -506,6 +495,12 @@ elf_i386_grok_psinfo (abfd, note)
 
 #define ELF_DYNAMIC_INTERPRETER "/usr/lib/libc.so.1"
 
+/* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
+   copying dynamic variables from a shared lib into an app's dynbss
+   section, and instead use a dynamic relocation to point into the
+   shared lib.  */
+#define ELIMINATE_COPY_RELOCS 1
+
 /* The size in bytes of an entry in the procedure linkage table.  */
 
 #define PLT_ENTRY_SIZE 16
@@ -843,7 +838,19 @@ elf_i386_copy_indirect_symbol (bed, dir, ind)
       edir->tls_type = eind->tls_type;
       eind->tls_type = GOT_UNKNOWN;
     }
-  _bfd_elf_link_hash_copy_indirect (bed, dir, ind);
+
+  if (ELIMINATE_COPY_RELOCS
+      && ind->root.type != bfd_link_hash_indirect
+      && (dir->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0)
+    /* If called to transfer flags for a weakdef during processing
+       of elf_adjust_dynamic_symbol, don't copy ELF_LINK_NON_GOT_REF.
+       We clear it ourselves for ELIMINATE_COPY_RELOCS.  */
+    dir->elf_link_hash_flags |=
+      (ind->elf_link_hash_flags & (ELF_LINK_HASH_REF_DYNAMIC
+                                  | ELF_LINK_HASH_REF_REGULAR
+                                  | ELF_LINK_HASH_REF_REGULAR_NONWEAK));
+  else
+    _bfd_elf_link_hash_copy_indirect (bed, dir, ind);
 }
 
 static int
@@ -1106,7 +1113,8 @@ elf_i386_check_relocs (abfd, info, sec, relocs)
                           || h->root.type == bfd_link_hash_defweak
                           || (h->elf_link_hash_flags
                               & ELF_LINK_HASH_DEF_REGULAR) == 0))))
-             || (!info->shared
+             || (ELIMINATE_COPY_RELOCS
+                 && !info->shared
                  && (sec->flags & SEC_ALLOC) != 0
                  && h != NULL
                  && (h->root.type == bfd_link_hash_defweak
@@ -1279,9 +1287,6 @@ elf_i386_gc_sweep_hook (abfd, info, sec, relocs)
   struct elf_link_hash_entry **sym_hashes;
   bfd_signed_vma *local_got_refcounts;
   const Elf_Internal_Rela *rel, *relend;
-  unsigned long r_symndx;
-  int r_type;
-  struct elf_link_hash_entry *h;
 
   elf_section_data (sec)->local_dynrel = NULL;
 
@@ -1291,85 +1296,74 @@ elf_i386_gc_sweep_hook (abfd, info, sec, relocs)
 
   relend = relocs + sec->reloc_count;
   for (rel = relocs; rel < relend; rel++)
-    switch ((r_type = elf_i386_tls_transition (info,
-                                              ELF32_R_TYPE (rel->r_info),
-                                              ELF32_R_SYM (rel->r_info)
-                                              >= symtab_hdr->sh_info)))
-      {
-      case R_386_TLS_LDM:
-       if (elf_i386_hash_table (info)->tls_ldm_got.refcount > 0)
-         elf_i386_hash_table (info)->tls_ldm_got.refcount -= 1;
-       break;
-
-      case R_386_TLS_GD:
-      case R_386_TLS_IE_32:
-      case R_386_TLS_IE:
-      case R_386_TLS_GOTIE:
-      case R_386_GOT32:
-       r_symndx = ELF32_R_SYM (rel->r_info);
-       if (r_symndx >= symtab_hdr->sh_info)
-         {
-           h = sym_hashes[r_symndx - symtab_hdr->sh_info];
-           if (h->got.refcount > 0)
-             h->got.refcount -= 1;
-         }
-       else if (local_got_refcounts != NULL)
-         {
-           if (local_got_refcounts[r_symndx] > 0)
-             local_got_refcounts[r_symndx] -= 1;
-         }
-       if (r_type != R_386_TLS_IE)
-         break;
-       /* Fall through */
+    {
+      unsigned long r_symndx;
+      unsigned int r_type;
+      struct elf_link_hash_entry *h = NULL;
 
-      case R_386_TLS_LE_32:
-      case R_386_TLS_LE:
-        if (!info->shared)
-         break;
-       /* Fall through */
+      r_symndx = ELF32_R_SYM (rel->r_info);
+      if (r_symndx >= symtab_hdr->sh_info)
+       {
+         struct elf_i386_link_hash_entry *eh;
+         struct elf_i386_dyn_relocs **pp;
+         struct elf_i386_dyn_relocs *p;
 
-      case R_386_32:
-      case R_386_PC32:
-       r_symndx = ELF32_R_SYM (rel->r_info);
-       if (r_symndx >= symtab_hdr->sh_info)
-         {
-           struct elf_i386_link_hash_entry *eh;
-           struct elf_i386_dyn_relocs **pp;
-           struct elf_i386_dyn_relocs *p;
+         h = sym_hashes[r_symndx - symtab_hdr->sh_info];
+         eh = (struct elf_i386_link_hash_entry *) h;
 
-           h = sym_hashes[r_symndx - symtab_hdr->sh_info];
+         for (pp = &eh->dyn_relocs; (p = *pp) != NULL; pp = &p->next)
+           if (p->sec == sec)
+             {
+               /* Everything must go for SEC.  */
+               *pp = p->next;
+               break;
+             }
+       }
 
-           if (!info->shared && h->plt.refcount > 0)
-             h->plt.refcount -= 1;
+      r_type = ELF32_R_TYPE (rel->r_info);
+      r_type = elf_i386_tls_transition (info, r_type, h != NULL);
+      switch (r_type)
+       {
+       case R_386_TLS_LDM:
+         if (elf_i386_hash_table (info)->tls_ldm_got.refcount > 0)
+           elf_i386_hash_table (info)->tls_ldm_got.refcount -= 1;
+         break;
 
-           eh = (struct elf_i386_link_hash_entry *) h;
+       case R_386_TLS_GD:
+       case R_386_TLS_IE_32:
+       case R_386_TLS_IE:
+       case R_386_TLS_GOTIE:
+       case R_386_GOT32:
+         if (h != NULL)
+           {
+             if (h->got.refcount > 0)
+               h->got.refcount -= 1;
+           }
+         else if (local_got_refcounts != NULL)
+           {
+             if (local_got_refcounts[r_symndx] > 0)
+               local_got_refcounts[r_symndx] -= 1;
+           }
+         break;
 
-           for (pp = &eh->dyn_relocs; (p = *pp) != NULL; pp = &p->next)
-             if (p->sec == sec)
-               {
-                 if (ELF32_R_TYPE (rel->r_info) == R_386_PC32)
-                   p->pc_count -= 1;
-                 p->count -= 1;
-                 if (p->count == 0)
-                   *pp = p->next;
-                 break;
-               }
-         }
-       break;
+       case R_386_32:
+       case R_386_PC32:
+         if (info->shared)
+           break;
+         /* Fall through */
 
-      case R_386_PLT32:
-       r_symndx = ELF32_R_SYM (rel->r_info);
-       if (r_symndx >= symtab_hdr->sh_info)
-         {
-           h = sym_hashes[r_symndx - symtab_hdr->sh_info];
-           if (h->plt.refcount > 0)
-             h->plt.refcount -= 1;
-         }
-       break;
+       case R_386_PLT32:
+         if (h != NULL)
+           {
+             if (h->plt.refcount > 0)
+               h->plt.refcount -= 1;
+           }
+         break;
 
-      default:
-       break;
-      }
+       default:
+         break;
+       }
+    }
 
   return TRUE;
 }
@@ -1386,8 +1380,6 @@ elf_i386_adjust_dynamic_symbol (info, h)
      struct elf_link_hash_entry *h;
 {
   struct elf_i386_link_hash_table *htab;
-  struct elf_i386_link_hash_entry * eh;
-  struct elf_i386_dyn_relocs *p;
   asection *s;
   unsigned int power_of_two;
 
@@ -1398,11 +1390,9 @@ elf_i386_adjust_dynamic_symbol (info, h)
       || (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0)
     {
       if (h->plt.refcount <= 0
-         || (! info->shared
-             && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
-             && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) == 0
-             && h->root.type != bfd_link_hash_undefweak
-             && h->root.type != bfd_link_hash_undefined))
+         || SYMBOL_CALLS_LOCAL (info, h)
+         || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
+             && h->root.type == bfd_link_hash_undefweak))
        {
          /* This case can occur if we saw a PLT32 reloc in an input
             file, but the symbol was never referred to by a dynamic
@@ -1432,6 +1422,10 @@ elf_i386_adjust_dynamic_symbol (info, h)
                  || h->weakdef->root.type == bfd_link_hash_defweak);
       h->root.u.def.section = h->weakdef->root.u.def.section;
       h->root.u.def.value = h->weakdef->root.u.def.value;
+      if (ELIMINATE_COPY_RELOCS || info->nocopyreloc)
+       h->elf_link_hash_flags
+         = ((h->elf_link_hash_flags & ~ELF_LINK_NON_GOT_REF)
+            | (h->weakdef->elf_link_hash_flags & ELF_LINK_NON_GOT_REF));
       return TRUE;
     }
 
@@ -1457,20 +1451,26 @@ elf_i386_adjust_dynamic_symbol (info, h)
       return TRUE;
     }
 
-  eh = (struct elf_i386_link_hash_entry *) h;
-  for (p = eh->dyn_relocs; p != NULL; p = p->next)
+  if (ELIMINATE_COPY_RELOCS)
     {
-      s = p->sec->output_section;
-      if (s != NULL && (s->flags & SEC_READONLY) != 0)
-       break;
-    }
+      struct elf_i386_link_hash_entry * eh;
+      struct elf_i386_dyn_relocs *p;
 
-  /* If we didn't find any dynamic relocs in read-only sections, then
-     we'll be keeping the dynamic relocs and avoiding the copy reloc.  */
-  if (p == NULL)
-    {
-      h->elf_link_hash_flags &= ~ELF_LINK_NON_GOT_REF;
-      return TRUE;
+      eh = (struct elf_i386_link_hash_entry *) h;
+      for (p = eh->dyn_relocs; p != NULL; p = p->next)
+       {
+         s = p->sec->output_section;
+         if (s != NULL && (s->flags & SEC_READONLY) != 0)
+           break;
+       }
+
+      /* If we didn't find any dynamic relocs in read-only sections, then
+        we'll be keeping the dynamic relocs and avoiding the copy reloc.  */
+      if (p == NULL)
+       {
+         h->elf_link_hash_flags &= ~ELF_LINK_NON_GOT_REF;
+         return TRUE;
+       }
     }
 
   /* We must allocate the symbol in our .dynbss section, which will
@@ -1523,9 +1523,9 @@ elf_i386_adjust_dynamic_symbol (info, h)
    will be called from elflink.h.  If elflink.h doesn't call our
    finish_dynamic_symbol routine, we'll need to do something about
    initializing any .plt and .got entries in elf_i386_relocate_section.  */
-#define WILL_CALL_FINISH_DYNAMIC_SYMBOL(DYN, INFO, H) \
+#define WILL_CALL_FINISH_DYNAMIC_SYMBOL(DYN, SHARED, H) \
   ((DYN)                                                               \
-   && ((INFO)->shared                                                  \
+   && ((SHARED)                                                                \
        || ((H)->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)     \
    && ((H)->dynindx != -1                                              \
        || ((H)->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0))
@@ -1567,7 +1567,8 @@ allocate_dynrelocs (h, inf)
            return FALSE;
        }
 
-      if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, info, h))
+      if (info->shared
+         || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h))
        {
          asection *s = htab->splt;
 
@@ -1653,7 +1654,10 @@ allocate_dynrelocs (h, inf)
        htab->srelgot->_raw_size += sizeof (Elf32_External_Rel);
       else if (tls_type == GOT_TLS_GD)
        htab->srelgot->_raw_size += 2 * sizeof (Elf32_External_Rel);
-      else if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info, h))
+      else if ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+               || h->root.type != bfd_link_hash_undefweak)
+              && (info->shared
+                  || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h)))
        htab->srelgot->_raw_size += sizeof (Elf32_External_Rel);
     }
   else
@@ -1671,9 +1675,13 @@ allocate_dynrelocs (h, inf)
 
   if (info->shared)
     {
-      if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
-         && ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0
-             || info->symbolic))
+      /* The only reloc that uses pc_count is R_386_PC32, which will
+        appear on a call or on something like ".long foo - .".  We
+        want calls to protected symbols to resolve directly to the
+        function rather than going via the plt.  If people want
+        function pointer comparisons to work as expected then they
+        should avoid writing assembly like ".long foo - .".  */
+      if (SYMBOL_CALLS_LOCAL (info, h))
        {
          struct elf_i386_dyn_relocs **pp;
 
@@ -1687,8 +1695,14 @@ allocate_dynrelocs (h, inf)
                pp = &p->next;
            }
        }
+
+      /* Also discard relocs on undefined weak syms with non-default
+        visibility.  */
+      if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
+         && h->root.type == bfd_link_hash_undefweak)
+       eh->dyn_relocs = NULL;
     }
-  else
+  else if (ELIMINATE_COPY_RELOCS)
     {
       /* For the non-shared case, discard space for relocs against
         symbols which turn out to need copy relocs or are not
@@ -2261,7 +2275,6 @@ elf_i386_relocate_section (output_bfd, info, input_bfd, input_section,
          else if (h->root.type == bfd_link_hash_undefweak)
            ;
          else if (info->shared
-                  && (!info->symbolic || info->allow_shlib_undefined)
                   && !info->no_undefined
                   && ELF_ST_VISIBILITY (h->other) == STV_DEFAULT)
            ;
@@ -2290,12 +2303,11 @@ elf_i386_relocate_section (output_bfd, info, input_bfd, input_section,
 
              off = h->got.offset;
              dyn = htab->elf.dynamic_sections_created;
-             if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info, h)
+             if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info->shared, h)
                  || (info->shared
-                     && (info->symbolic
-                         || h->dynindx == -1
-                         || (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL))
-                     && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
+                     && SYMBOL_REFERENCES_LOCAL (info, h))
+                 || (ELF_ST_VISIBILITY (h->other)
+                     && h->root.type == bfd_link_hash_undefweak))
                {
                  /* This is actually a static link, or it is a
                     -Bsymbolic link and the symbol is defined
@@ -2419,13 +2431,14 @@ elf_i386_relocate_section (output_bfd, info, input_bfd, input_section,
            break;
 
          if ((info->shared
+              && (h == NULL
+                  || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+                  || h->root.type != bfd_link_hash_undefweak)
               && (r_type != R_386_PC32
                   || (h != NULL
-                      && h->dynindx != -1
-                      && (! info->symbolic
-                          || (h->elf_link_hash_flags
-                              & ELF_LINK_HASH_DEF_REGULAR) == 0))))
-             || (!info->shared
+                      && !SYMBOL_CALLS_LOCAL (info, h))))
+             || (ELIMINATE_COPY_RELOCS
+                 && !info->shared
                  && h != NULL
                  && h->dynindx != -1
                  && (h->elf_link_hash_flags & ELF_LINK_NON_GOT_REF) == 0
@@ -2627,7 +2640,7 @@ elf_i386_relocate_section (output_bfd, info, input_bfd, input_section,
                      BFD_ASSERT (rel->r_offset >= 2);
                      type = bfd_get_8 (input_bfd, contents + rel->r_offset - 2);
                      switch (type)
-                       {
+                       {
                        case 0x8b:
                          /* movl */
                          BFD_ASSERT ((val & 0xc7) == 0x05);
@@ -2649,7 +2662,7 @@ elf_i386_relocate_section (output_bfd, info, input_bfd, input_section,
                        default:
                          BFD_FAIL ();
                          break;
-                       }
+                       }
                    }
                  bfd_put_32 (output_bfd, -tpoff (info, relocation),
                              contents + rel->r_offset);
@@ -2724,7 +2737,7 @@ elf_i386_relocate_section (output_bfd, info, input_bfd, input_section,
 
          if ((off & 1) != 0)
            off &= ~1;
-          else
+         else
            {
              Elf_Internal_Rela outrel;
              bfd_byte *loc;
@@ -3153,10 +3166,7 @@ elf_i386_finish_dynamic_symbol (output_bfd, info, h, sym)
         The entry in the global offset table will already have been
         initialized in the relocate_section function.  */
       if (info->shared
-         && (info->symbolic
-             || h->dynindx == -1
-             || (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL))
-         && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR))
+         && SYMBOL_REFERENCES_LOCAL (info, h))
        {
          BFD_ASSERT((h->got.offset & 1) != 0);
          rel.r_info = ELF32_R_INFO (0, R_386_RELATIVE);
@@ -3364,7 +3374,8 @@ elf_i386_finish_dynamic_sections (output_bfd, info)
 #define elf_backend_got_header_size    12
 #define elf_backend_plt_header_size    PLT_ENTRY_SIZE
 
-#define elf_info_to_howto                    elf_i386_info_to_howto
+/* Support RELA for objdump of prelink objects.  */
+#define elf_info_to_howto                    elf_i386_info_to_howto_rel
 #define elf_info_to_howto_rel                elf_i386_info_to_howto_rel
 
 #define bfd_elf32_mkobject                   elf_i386_mkobject
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