public inbox for binutils@sourceware.org
 help / color / mirror / Atom feed
* PATCH: Fix ELF visibility handling
@ 2003-04-01 20:20 H. J. Lu
  2003-04-09 16:22 ` H. J. Lu
  0 siblings, 1 reply; 8+ messages in thread
From: H. J. Lu @ 2003-04-01 20:20 UTC (permalink / raw)
  To: binutils

[-- Attachment #1: Type: text/plain, Size: 619 bytes --]

The currenr ELF visibility handling is wrong on several things:

1. Ld doesn't report an error for undefined symbols with non-default
visibility when there is a definition from a shared library.
2. Weak undefined symbols with non-default visibility results in
undetermined run-time behavior depending on if there is a definition
at run-time.
3. Ld gives no warnings when a shared library refeneces a hidden symbol.
4. ld merges visibility with symbols from shared libraries.

This patch fixes those problems with testcases. As for weak undefined 
symbols with non-default visibility, I only fixed x86 and ia64.



H.J.

[-- Attachment #2: binutils-vsb.patch --]
[-- Type: text/plain, Size: 22582 bytes --]

bfd/

2003-04-01  H.J. Lu <hjl@gnu.org>

	* elf-bfd.h (ELF_LINK_DYNAMIC_DEF): New.

	* elf32-i386.c (allocate_dynrelocs): Don't allocate dynamic
	relocation entries for weak undefined symbols with non-default
	visibility.
	(elf_i386_relocate_section): Initialize the GOT entries and
	skip R_386_32/R_386_PC32 for weak undefined symbols with
	non-default visibility. 

	* elfxx-ia64.c (allocate_fptr): Don't allocate function
	descriptors for weak undefined symbols with non-default
	visibility.
	(set_got_entry): Don't install dynamic relocation for weak
	undefined symbols with non-default visibility.
	(set_pltoff_entry): Likewise.
	* elflink.h (ELF_LINK_DYNAMIC_WEAK): New.
	(elf_merge_symbol): Add one argument to indicate if a symbol
	should be skipped. Ignore definitions in dynamic objects for
	symbols with non-default visibility.
	(elf_add_default_symbol): Adjusted.
	(elf_link_add_object_symbols): Check if a symbol should be
	skipped. Don't merge the visibility field with the one from
	a dynamic object.
	(elf_fix_symbol_flags): Hide weak undefined symbols with
	non-default visibility.
	(elf_link_check_versioned_symbol): Use undef_bfd.
	(elf_link_output_extsym): Warn if a forced local symbol is
	referenced from dynamic objects. Make non-weak undefined symbol
	with non-default visibility a fatal error.

ld/testsuite/

2003-04-01  H.J. Lu <hjl@gnu.org>

	* ld-elfvsb/elfvsb.dat: Updated.
	* ld-elfvsb/elfvsb.exp: Likewise.
	* ld-elfvsb/main.c: Likewise.
	* ld-elfvsb/sh1.c: Likewise.
	* ld-elfvsb/sh2.c: Likewise.

--- binutils/bfd/elf-bfd.h.vsb	2003-02-27 11:26:52.000000000 -0800
+++ binutils/bfd/elf-bfd.h	2003-03-31 10:11:34.000000000 -0800
@@ -204,6 +204,10 @@ struct elf_link_hash_entry
   /* Symbol is referenced by a non-GOT/non-PLT relocation.  This is
      not currently set by all the backends.  */
 #define ELF_LINK_NON_GOT_REF 010000
+  /* Symbol has a definition in a shared object.  */
+#define ELF_LINK_DYNAMIC_DEF 020000
+  /* Symbol is weak in all shared objects.  */
+#define ELF_LINK_DYNAMIC_WEAK 040000
 };
 
 /* Records local symbols to be emitted in the dynamic symbol table.  */
--- binutils/bfd/elf32-i386.c.vsb	2003-03-31 10:11:34.000000000 -0800
+++ binutils/bfd/elf32-i386.c	2003-04-01 10:21:52.000000000 -0800
@@ -1569,8 +1569,10 @@ allocate_dynrelocs (h, inf)
 	    return FALSE;
 	}
 
-      if (info->shared
-	  || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h))
+      if ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+	   || h->root.type != bfd_link_hash_undefweak)
+	  && (info->shared
+	      || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h)))
 	{
 	  asection *s = htab->splt;
 
@@ -1656,8 +1658,10 @@ 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 (info->shared
-	       || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, 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
@@ -2298,7 +2302,9 @@ elf_i386_relocate_section (output_bfd, i
 		      && (info->symbolic
 			  || h->dynindx == -1
 			  || (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL))
-		      && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
+		      && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR))
+		  || (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
@@ -2422,6 +2428,9 @@ elf_i386_relocate_section (output_bfd, i
 	    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
--- binutils/bfd/elflink.h.vsb	2003-03-31 10:02:52.000000000 -0800
+++ binutils/bfd/elflink.h	2003-04-01 11:48:42.000000000 -0800
@@ -42,7 +42,7 @@ static bfd_boolean elf_merge_symbol
   PARAMS ((bfd *, struct bfd_link_info *, const char *,
 	   Elf_Internal_Sym *, asection **, bfd_vma *,
 	   struct elf_link_hash_entry **, bfd_boolean *, bfd_boolean *,
-	   bfd_boolean *, bfd_boolean));
+	   bfd_boolean *, bfd_boolean *, bfd_boolean));
 static bfd_boolean elf_add_default_symbol
   PARAMS ((bfd *, struct bfd_link_info *, struct elf_link_hash_entry *,
 	   const char *, Elf_Internal_Sym *, asection **, bfd_vma *,
@@ -463,7 +463,7 @@ elf_link_add_archive_symbols (abfd, info
    a shared object.  */
 
 static bfd_boolean
-elf_merge_symbol (abfd, info, name, sym, psec, pvalue, sym_hash,
+elf_merge_symbol (abfd, info, name, sym, psec, pvalue, sym_hash, skip,
 		  override, type_change_ok, size_change_ok, dt_needed)
      bfd *abfd;
      struct bfd_link_info *info;
@@ -472,6 +472,7 @@ elf_merge_symbol (abfd, info, name, sym,
      asection **psec;
      bfd_vma *pvalue;
      struct elf_link_hash_entry **sym_hash;
+     bfd_boolean *skip;
      bfd_boolean *override;
      bfd_boolean *type_change_ok;
      bfd_boolean *size_change_ok;
@@ -483,6 +484,7 @@ elf_merge_symbol (abfd, info, name, sym,
   bfd *oldbfd;
   bfd_boolean newdyn, olddyn, olddef, newdef, newdyncommon, olddyncommon;
 
+  *skip = FALSE;
   *override = FALSE;
 
   sec = *psec;
@@ -605,6 +607,57 @@ elf_merge_symbol (abfd, info, name, sym,
   else
     olddef = TRUE;
 
+  /* We need to rememeber if a symbol has a definition in a dynamic
+     object or is weak in all dynamic objects. Internal and hidden
+     visibility will make it unavailable to dynamic objects.  */
+  if (newdyn && (h->elf_link_hash_flags & ELF_LINK_DYNAMIC_DEF) == 0)
+    {
+      if (!bfd_is_und_section (sec))
+	h->elf_link_hash_flags |= ELF_LINK_DYNAMIC_DEF;
+      else
+	{
+	  /* Check if this symbol is weak in all dynamic objects. If it
+	     is the first time we see it in a dynamic object, we mark
+	     if it is weak. Otherwise, we clear it.  */
+	  if ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) == 0)
+	    { 
+	      if (bind == STB_WEAK)
+		h->elf_link_hash_flags |= ELF_LINK_DYNAMIC_WEAK;
+	    }
+	  else if (bind != STB_WEAK)
+	    h->elf_link_hash_flags &= ~ELF_LINK_DYNAMIC_WEAK;
+	}
+    }
+
+  /* If the old symbol has non-default visibility, we ignore the new
+     definition from a dynamic object.  */
+  if (newdyn
+      && ELF_ST_VISIBILITY (h->other)
+      && !bfd_is_und_section (sec))
+    {
+      *skip = TRUE;
+      /* Make sure this symbol is dynamic.  */
+      h->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
+      /* FIXME: Should we check type and size for protected symbol?  */
+      return _bfd_elf_link_record_dynamic_symbol (info, h);
+    }
+  else if (!newdyn
+	   && ELF_ST_VISIBILITY (sym->st_other)
+	   && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0)
+    {
+      /* If the new symbol with non-default visibility comes from a
+	 relocatable file and the old definition comes from a dynamic
+	 object, we remove the old definition.  */
+      h->root.type = bfd_link_hash_new;
+      h->root.u.undef.abfd = NULL;
+      h->elf_link_hash_flags &= ~ELF_LINK_HASH_DEF_DYNAMIC;
+      h->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
+      /* FIXME: Should we check type and size for protected symbol?  */
+      h->size = 0;
+      h->type = 0;
+      return TRUE;
+    }
+
   /* NEWDYNCOMMON and OLDDYNCOMMON indicate whether the new or old
      symbol, respectively, appears to be a common symbol in a dynamic
      object.  If a symbol appears in an uninitialized section, and is
@@ -919,6 +972,7 @@ elf_add_default_symbol (abfd, info, h, n
 {
   bfd_boolean type_change_ok;
   bfd_boolean size_change_ok;
+  bfd_boolean skip;
   char *shortname;
   struct elf_link_hash_entry *hi;
   struct bfd_link_hash_entry *bh;
@@ -974,7 +1028,7 @@ elf_add_default_symbol (abfd, info, h, n
   size_change_ok = FALSE;
   sec = *psec;
   if (! elf_merge_symbol (abfd, info, shortname, sym, &sec, value,
-			  &hi, &override, &type_change_ok,
+			  &hi, &skip, &override, &type_change_ok,
 			  &size_change_ok, dt_needed))
     return FALSE;
 
@@ -1083,7 +1137,7 @@ elf_add_default_symbol (abfd, info, h, n
   size_change_ok = FALSE;
   sec = *psec;
   if (! elf_merge_symbol (abfd, info, shortname, sym, &sec, value,
-			  &hi, &override, &type_change_ok,
+			  &hi, &skip, &override, &type_change_ok,
 			  &size_change_ok, dt_needed))
     return FALSE;
 
@@ -1721,6 +1775,7 @@ elf_link_add_object_symbols (abfd, info)
 	{
 	  Elf_Internal_Versym iver;
 	  unsigned int vernum = 0;
+	  bfd_boolean skip;
 
 	  if (ever != NULL)
 	    {
@@ -1818,10 +1873,14 @@ elf_link_add_object_symbols (abfd, info)
 	    }
 
 	  if (! elf_merge_symbol (abfd, info, name, isym, &sec, &value,
-				  sym_hash, &override, &type_change_ok,
-				  &size_change_ok, dt_needed))
+				  sym_hash, &skip, &override,
+				  &type_change_ok, &size_change_ok,
+				  dt_needed))
 	    goto error_free_vers;
 
+	  if (skip)
+	    continue;
+
 	  if (override)
 	    definition = FALSE;
 
@@ -1936,9 +1995,10 @@ elf_link_add_object_symbols (abfd, info)
 	      h->type = ELF_ST_TYPE (isym->st_info);
 	    }
 
-	  /* If st_other has a processor-specific meaning, specific code
-	     might be needed here.  */
-	  if (isym->st_other != 0)
+	  /* If st_other has a processor-specific meaning, specific
+	     code might be needed here. We never merge the visibility
+	     attribute with the one from a dynamic object.  */
+	  if (isym->st_other != 0 && !dynamic)
 	    {
 	      unsigned char hvis, symvis, other, nvis;
 
@@ -2005,7 +2065,7 @@ elf_link_add_object_symbols (abfd, info)
 					  override, dt_needed))
 	      goto error_free_vers;
 
-	  if (definition && (abfd->flags & DYNAMIC) == 0)
+	  if (definition && !dynamic)
 	    {
 	      char *p = strchr (name, ELF_VER_CHR);
 	      if (p != NULL && p[1] != ELF_VER_CHR)
@@ -3941,6 +4001,16 @@ elf_fix_symbol_flags (h, eif)
       (*bed->elf_backend_hide_symbol) (eif->info, h, force_local);
     }
 
+  /* If a weak undefined symbol has non-default visibility, we also
+     hide it from the dynamic linker.  */
+  if (ELF_ST_VISIBILITY (h->other)
+      && h->root.type == bfd_link_hash_undefweak)
+    {
+      struct elf_backend_data *bed;
+      bed = get_elf_backend_data (elf_hash_table (eif->info)->dynobj);
+      (*bed->elf_backend_hide_symbol) (eif->info, h, TRUE);
+    }
+
   /* If this is a weak defined symbol in a dynamic object, and we know
      the real definition in the dynamic object, copy interesting flags
      over to the real definition.  */
@@ -6021,7 +6091,7 @@ elf_link_check_versioned_symbol (info, h
 
   if ((undef_bfd->flags & DYNAMIC) == 0
       || info->hash->creator->flavour != bfd_target_elf_flavour
-      || elf_dt_soname (h->root.u.undef.abfd) == NULL)
+      || elf_dt_soname (undef_bfd) == NULL)
     return FALSE;
 
   for (loaded = elf_hash_table (info)->loaded;
@@ -6188,6 +6258,28 @@ elf_link_output_extsym (h, data)
 	}
     }
 
+  /* We should also warn if a forced local symbol is referenced from
+     shared libraries.  */
+  if (! finfo->info->relocateable
+      && (! finfo->info->shared || ! finfo->info->allow_shlib_undefined)
+      && (h->elf_link_hash_flags
+	  & (ELF_LINK_FORCED_LOCAL | ELF_LINK_HASH_REF_DYNAMIC
+	     | ELF_LINK_DYNAMIC_DEF | ELF_LINK_DYNAMIC_WEAK))
+	 == (ELF_LINK_FORCED_LOCAL | ELF_LINK_HASH_REF_DYNAMIC))
+    {
+      (*_bfd_error_handler)
+	(_("%s: %s symbol `%s' in %s is referenced by DSO"),
+	 bfd_get_filename (finfo->output_bfd),
+	 ELF_ST_VISIBILITY (h->other) == STV_INTERNAL
+	 ? "internal"
+	 : ELF_ST_VISIBILITY (h->other) == STV_HIDDEN
+	   ? "hidden" : "local",
+	 h->root.root.string,
+	 bfd_archive_filename (h->root.u.def.section->owner));
+      eoinfo->failed = TRUE;
+      return FALSE;
+    }
+
   /* We don't want to output symbols that have never been mentioned by
      a regular file, or that we have been told to strip.  However, if
      h->indx is set to -2, the symbol is used by a reloc and we must
@@ -6313,7 +6405,9 @@ elf_link_output_extsym (h, data)
      forced local syms when non-shared is due to a historical quirk.  */
   if ((h->dynindx != -1
        || (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
-      && (finfo->info->shared
+      && ((finfo->info->shared
+	   && (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+	       || h->root.type != bfd_link_hash_undefweak))
 	  || (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
       && elf_hash_table (finfo->info)->dynamic_sections_created)
     {
@@ -6348,10 +6442,25 @@ elf_link_output_extsym (h, data)
       sym.st_info = ELF_ST_INFO (bindtype, ELF_ST_TYPE (sym.st_info));
     }
 
-  /* If a symbol is not defined locally, we clear the visibility field.  */
+  /* If a non-weak symbol with non-default visibility is not defined
+     locally, it is a fatal error.  */
   if (! finfo->info->relocateable
+      && ELF_ST_VISIBILITY (sym.st_other)
+      && ELF_ST_BIND (sym.st_info) != STB_WEAK
+      && h->root.type != bfd_link_hash_undefweak
       && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
-    sym.st_other &= ~ ELF_ST_VISIBILITY (-1);
+    {
+      (*_bfd_error_handler)
+	(_("%s: %s symbol `%s' isn't defined"),
+	  bfd_get_filename (finfo->output_bfd),
+	  ELF_ST_VISIBILITY (sym.st_other) == STV_PROTECTED
+	  ? "protected"
+	  : ELF_ST_VISIBILITY (sym.st_other) == STV_INTERNAL
+	    ? "internal" : "hidden",
+	  h->root.root.string);
+      eoinfo->failed = TRUE;
+      return FALSE;
+    }
 
   /* If this symbol should be put in the .dynsym section, then put it
      there now.  We already know the symbol index.  We also fill in
--- binutils/bfd/elfxx-ia64.c.vsb	2003-03-28 11:58:01.000000000 -0800
+++ binutils/bfd/elfxx-ia64.c	2003-04-01 11:28:33.000000000 -0800
@@ -2613,7 +2613,10 @@ allocate_fptr (dyn_i, data)
 	       || h->root.type == bfd_link_hash_warning)
 	  h = (struct elf_link_hash_entry *) h->root.u.i.link;
 
-      if (x->info->shared
+      if ((x->info->shared
+	   && (!h
+	       || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+	       || h->root.type != bfd_link_hash_undefweak))
 	  /* AIX needs an FPTR in this case. */
 	  || (elfNN_ia64_aix_vec (x->info->hash->creator)
 	      && (!h
@@ -3409,7 +3412,11 @@ set_got_entry (abfd, info, dyn_i, dynind
       bfd_put_64 (abfd, value, got_sec->contents + got_offset);
 
       /* Install a dynamic relocation if needed.  */
-      if ((info->shared && dyn_r_type != R_IA64_DTPREL64LSB)
+      if ((info->shared
+	   && (!dyn_i->h
+	       || ELF_ST_VISIBILITY (dyn_i->h->other) == STV_DEFAULT
+	       || dyn_i->h->root.type != bfd_link_hash_undefweak)
+	   && dyn_r_type != R_IA64_DTPREL64LSB)
           || elfNN_ia64_dynamic_symbol_p (dyn_i->h, info)
 	  || elfNN_ia64_aix_vec (abfd->xvec)
 	  || (dynindx != -1 && dyn_r_type == R_IA64_FPTR64LSB))
@@ -3530,7 +3537,11 @@ set_pltoff_entry (abfd, info, dyn_i, val
       bfd_put_64 (abfd, gp, pltoff_sec->contents + dyn_i->pltoff_offset + 8);
 
       /* Install dynamic relocations if needed.  */
-      if (!is_plt && info->shared)
+      if (!is_plt
+	  && info->shared
+	  && (!dyn_i->h
+	      || ELF_ST_VISIBILITY (dyn_i->h->other) == STV_DEFAULT
+	      || dyn_i->h->root.type != bfd_link_hash_undefweak))
 	{
 	  unsigned int dyn_r_type;
 
--- binutils/ld/testsuite/ld-elfvsb/elfvsb.dat.vsb	2000-06-05 15:55:02.000000000 -0700
+++ binutils/ld/testsuite/ld-elfvsb/elfvsb.dat	2003-03-31 10:11:34.000000000 -0800
@@ -20,3 +20,7 @@ main_visibility_check () == 1
 visibility_checkvar () == 1
 visibility_checkvarptr () == 1
 main_visibility_checkvar () == 1
+main_visibility_checkcom () == 1
+shlib_visibility_checkcom () == 1
+main_visibility_checkweak () == 1
+shlib_visibility_checkweak () == 1
--- binutils/ld/testsuite/ld-elfvsb/elfvsb.exp.vsb	2003-03-31 10:11:34.000000000 -0800
+++ binutils/ld/testsuite/ld-elfvsb/elfvsb.exp	2003-03-31 10:11:34.000000000 -0800
@@ -144,6 +144,8 @@ proc visibility_test { visibility progna
     	    pass "$testname"
 	} else { if { [ string match $visibility "hidden_undef_def" ]
 	     && [regexp ".*/main.c.*: undefined reference to \`visibility\'" $link_output]
+	     && [regexp ".*/main.c.*: undefined reference to \`visibility_def\'" $link_output]
+	     && [regexp ".*/main.c.*: undefined reference to \`visibility_func\'" $link_output]
 	     && [regexp ".*/main.c.*: undefined reference to \`visibility_var\'" $link_output] } {
     	    pass "$testname"
 	} else {
--- binutils/ld/testsuite/ld-elfvsb/main.c.vsb	2000-11-07 16:34:01.000000000 -0800
+++ binutils/ld/testsuite/ld-elfvsb/main.c	2003-03-31 10:11:34.000000000 -0800
@@ -42,6 +42,18 @@ extern int visibility_checkvar ();
 extern int visibility_checkvarptr ();
 extern int visibility_varval ();
 extern void *visibility_varptr ();
+extern int shlib_visibility_checkcom ();
+extern int shlib_visibility_checkweak ();
+
+int shlib_visibility_com = 1;
+
+int shlib_visibility_var_weak = 1;
+
+int
+shlib_visibility_func_weak ()
+{
+  return 1;
+}
 
 #ifdef HIDDEN_WEAK_TEST
 #define WEAK_TEST
@@ -81,6 +93,23 @@ main_visibility_checkvar ()
   return visibility_varval () != visibility_var
 	 && visibility_varptr () != &visibility_var;
 }
+
+#ifndef PROTECTED_UNDEF_TEST
+int shared_data = 1;
+asm (".protected shared_data");
+
+int
+shared_func ()
+{
+  return 1;
+}
+
+asm (".protected shared_func");
+
+extern int * shared_data_p ();
+typedef int (*func) ();
+extern func shared_func_p ();
+#endif
 #else
 static int
 main_visibility_check ()
@@ -121,10 +150,88 @@ shlib_overriddencall2 ()
   return 8;
 }
 
+#ifdef HIDDEN_NORMAL_TEST
+int visibility_com;
+asm (".hidden visibility_com");
+
+int
+main_visibility_checkcom ()
+{
+  return visibility_com == 0;
+}
+
+int
+main_visibility_checkweak ()
+{
+  return 1;
+}
+#elif defined (HIDDEN_WEAK_TEST)
+int
+main_visibility_checkcom ()
+{
+  return 1;
+}
+
+#pragma weak visibility_undef_var_weak
+extern int visibility_undef_var_weak;
+asm (".hidden visibility_undef_var_weak");
+
+#pragma weak visibility_undef_func_weak
+extern int visibility_undef_func_weak ();
+asm (".hidden visibility_undef_func_weak");
+
+#pragma weak visibility_var_weak
+extern int visibility_var_weak;
+asm (".hidden visibility_var_weak");
+
+#pragma weak visibility_func_weak
+extern int visibility_func_weak ();
+asm (".hidden visibility_func_weak");
+
+int
+main_visibility_checkweak ()
+{
+  return &visibility_undef_var_weak == NULL
+	 && &visibility_undef_func_weak == NULL
+	 && &visibility_func_weak == NULL
+	 && &visibility_var_weak == NULL;
+}
+#elif defined (HIDDEN_UNDEF_TEST)
+extern int visibility_def;
+asm (".hidden visibility_def");
+extern int visibility_func ();
+asm (".hidden visibility_func");
+
+int
+main_visibility_checkcom ()
+{
+  return &visibility_def != NULL;
+}
+
+int
+main_visibility_checkweak ()
+{
+  return &visibility_func != NULL;
+}
+#else
+int
+main_visibility_checkcom ()
+{
+  return 1;
+}
+
+int
+main_visibility_checkweak ()
+{
+  return 1;
+}
+#endif
+
 int
 main ()
 {
   int (*p) ();
+  int ret = 0;
 
   printf ("mainvar == %d\n", mainvar);
   printf ("overriddenvar == %d\n", overriddenvar);
@@ -173,6 +280,27 @@ main ()
 	  visibility_checkvarptr ());
   printf ("main_visibility_checkvar () == %d\n",
 	  main_visibility_checkvar ());
-  return 0;
+  printf ("main_visibility_checkcom () == %d\n",
+	  main_visibility_checkcom ());
+  printf ("shlib_visibility_checkcom () == %d\n",
+	  shlib_visibility_checkcom ());
+  printf ("main_visibility_checkweak () == %d\n",
+	  main_visibility_checkweak ());
+  printf ("shlib_visibility_checkweak () == %d\n",
+	  shlib_visibility_checkweak ());
+
+#if !defined (PROTECTED_UNDEF_TEST) && defined (PROTECTED_TEST)
+  if (&shared_data != shared_data_p ())
+    ret = 1;
+  p = shared_func_p ();
+  if (shared_func != p)
+    ret = 1;
+  if (shared_data != *shared_data_p ())
+    ret = 1;
+  if (shared_func () != (*p) () )
+    ret = 1;
+#endif
+
+  return ret;
 }
 #endif
--- binutils/ld/testsuite/ld-elfvsb/sh1.c.vsb	2003-03-31 10:11:34.000000000 -0800
+++ binutils/ld/testsuite/ld-elfvsb/sh1.c	2003-04-01 09:15:57.000000000 -0800
@@ -326,3 +326,85 @@ asm (".protected visibility");
 asm (".protected visibility_var");
 #endif
 #endif
+
+#ifdef HIDDEN_NORMAL_TEST
+int shlib_visibility_com;
+asm (".hidden shlib_visibility_com");
+
+int
+shlib_visibility_checkcom ()
+{
+  return shlib_visibility_com == 0;
+}
+
+int
+shlib_visibility_checkweak ()
+{
+  return 1;
+}
+#elif defined (HIDDEN_WEAK_TEST)
+#pragma weak shlib_visibility_undef_var_weak
+extern int shlib_visibility_undef_var_weak;
+asm (".hidden shlib_visibility_undef_var_weak");
+
+#pragma weak shlib_visibility_undef_func_weak
+extern int shlib_visibility_undef_func_weak ();
+asm (".hidden shlib_visibility_undef_func_weak");
+
+#pragma weak shlib_visibility_var_weak
+extern int shlib_visibility_var_weak;
+asm (".hidden shlib_visibility_var_weak");
+
+#pragma weak shlib_visibility_func_weak
+extern int shlib_visibility_func_weak ();
+asm (".hidden shlib_visibility_func_weak");
+
+int
+shlib_visibility_checkcom ()
+{
+  return 1;
+}
+
+int
+shlib_visibility_checkweak ()
+{
+  return &shlib_visibility_undef_var_weak == NULL
+	 && &shlib_visibility_undef_func_weak == NULL
+	 && &shlib_visibility_func_weak == NULL
+	 && &shlib_visibility_var_weak == NULL;
+}
+#else
+int
+shlib_visibility_checkcom ()
+{
+  return 1;
+}
+
+int
+shlib_visibility_checkweak ()
+{
+  return 1;
+}
+#endif
+
+#ifdef PROTECTED_TEST
+int shared_data = 100;
+ 
+int *
+shared_data_p ()
+{
+  return &shared_data;
+}
+ 
+int
+shared_func ()
+{
+  return 100;
+}
+ 
+void *
+shared_func_p ()
+{
+  return shared_func;
+}
+#endif
--- binutils/ld/testsuite/ld-elfvsb/sh2.c.vsb	2000-06-05 15:55:02.000000000 -0700
+++ binutils/ld/testsuite/ld-elfvsb/sh2.c	2003-03-31 10:11:34.000000000 -0800
@@ -5,6 +5,10 @@
    the shared library.  */
 int shlibvar2 = 4;
 
+/* This variable is defined here, and shouldn't be used to resolve a
+   reference with non-default visibility in another shared library.  */
+int visibility_com = 2;
+
 /* This function is called by another file in the shared library.  */
 
 int
@@ -21,4 +25,22 @@ visibility ()
 }
 
 int visibility_var = 2;
+
+int visibility_def = 2;
+
+int
+visibility_func ()
+{
+  return 2;
+}
+#endif
+
+#ifdef HIDDEN_WEAK_TEST
+int visibility_var_weak = 2;
+
+int
+visibility_func_weak ()
+{
+  return 2;
+}
 #endif

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: PATCH: Fix ELF visibility handling
  2003-04-01 20:20 PATCH: Fix ELF visibility handling H. J. Lu
@ 2003-04-09 16:22 ` H. J. Lu
  2003-04-27 23:08   ` Alan Modra
                     ` (2 more replies)
  0 siblings, 3 replies; 8+ messages in thread
From: H. J. Lu @ 2003-04-09 16:22 UTC (permalink / raw)
  To: binutils; +Cc: amodra

[-- Attachment #1: Type: text/plain, Size: 844 bytes --]

On Tue, Apr 01, 2003 at 12:19:58PM -0800, H. J. Lu wrote:
> The currenr ELF visibility handling is wrong on several things:
> 
> 1. Ld doesn't report an error for undefined symbols with non-default
> visibility when there is a definition from a shared library.
> 2. Weak undefined symbols with non-default visibility results in
> undetermined run-time behavior depending on if there is a definition
> at run-time.
> 3. Ld gives no warnings when a shared library refeneces a hidden symbol.
> 4. ld merges visibility with symbols from shared libraries.
> 
> This patch fixes those problems with testcases. As for weak undefined 
> symbols with non-default visibility, I only fixed x86 and ia64.
> 

I modified the patch to separate handling of weak undefined symbols
with non-default visibility. Alan, could you take a look at it?

Thanks.

H.J.

[-- Attachment #2: binutils-vsb.patch --]
[-- Type: text/plain, Size: 15572 bytes --]

bfd/

2003-04-01  H.J. Lu <hjl@gnu.org>

	* elf-bfd.h (ELF_LINK_DYNAMIC_DEF): New.
	(ELF_LINK_DYNAMIC_WEAK): New.

	* elflink.h (elf_merge_symbol): Add one argument to indicate if
	a symbol should be skipped. Ignore definitions in dynamic
	objects for symbols with non-default visibility.
	(elf_add_default_symbol): Adjusted.
	(elf_link_add_object_symbols): Check if a symbol should be
	skipped. Don't merge the visibility field with the one from
	a dynamic object.
	(elf_link_check_versioned_symbol): Use undef_bfd.
	(elf_link_output_extsym): Warn if a forced local symbol is
	referenced from dynamic objects. Make non-weak undefined symbol
	with non-default visibility a fatal error.

ld/testsuite/

2003-04-01  H.J. Lu <hjl@gnu.org>

	* ld-elfvsb/elfvsb.dat: Updated.
	* ld-elfvsb/elfvsb.exp: Likewise.
	* ld-elfvsb/main.c: Likewise.
	* ld-elfvsb/sh1.c: Likewise.
	* ld-elfvsb/sh2.c: Likewise.

--- binutils/bfd/elf-bfd.h.vsb	2003-02-27 11:26:52.000000000 -0800
+++ binutils/bfd/elf-bfd.h	2003-04-07 17:08:01.000000000 -0700
@@ -204,6 +204,10 @@ struct elf_link_hash_entry
   /* Symbol is referenced by a non-GOT/non-PLT relocation.  This is
      not currently set by all the backends.  */
 #define ELF_LINK_NON_GOT_REF 010000
+  /* Symbol has a definition in a shared object.  */
+#define ELF_LINK_DYNAMIC_DEF 020000
+  /* Symbol is weak in all shared objects.  */
+#define ELF_LINK_DYNAMIC_WEAK 040000
 };
 
 /* Records local symbols to be emitted in the dynamic symbol table.  */
--- binutils/bfd/elflink.h.vsb	2003-04-01 14:28:52.000000000 -0800
+++ binutils/bfd/elflink.h	2003-04-08 08:57:59.000000000 -0700
@@ -42,7 +42,7 @@ static bfd_boolean elf_merge_symbol
   PARAMS ((bfd *, struct bfd_link_info *, const char *,
 	   Elf_Internal_Sym *, asection **, bfd_vma *,
 	   struct elf_link_hash_entry **, bfd_boolean *, bfd_boolean *,
-	   bfd_boolean *, bfd_boolean));
+	   bfd_boolean *, bfd_boolean *, bfd_boolean));
 static bfd_boolean elf_add_default_symbol
   PARAMS ((bfd *, struct bfd_link_info *, struct elf_link_hash_entry *,
 	   const char *, Elf_Internal_Sym *, asection **, bfd_vma *,
@@ -463,7 +463,7 @@ elf_link_add_archive_symbols (abfd, info
    a shared object.  */
 
 static bfd_boolean
-elf_merge_symbol (abfd, info, name, sym, psec, pvalue, sym_hash,
+elf_merge_symbol (abfd, info, name, sym, psec, pvalue, sym_hash, skip,
 		  override, type_change_ok, size_change_ok, dt_needed)
      bfd *abfd;
      struct bfd_link_info *info;
@@ -472,6 +472,7 @@ elf_merge_symbol (abfd, info, name, sym,
      asection **psec;
      bfd_vma *pvalue;
      struct elf_link_hash_entry **sym_hash;
+     bfd_boolean *skip;
      bfd_boolean *override;
      bfd_boolean *type_change_ok;
      bfd_boolean *size_change_ok;
@@ -483,6 +484,7 @@ elf_merge_symbol (abfd, info, name, sym,
   bfd *oldbfd;
   bfd_boolean newdyn, olddyn, olddef, newdef, newdyncommon, olddyncommon;
 
+  *skip = FALSE;
   *override = FALSE;
 
   sec = *psec;
@@ -605,6 +607,57 @@ elf_merge_symbol (abfd, info, name, sym,
   else
     olddef = TRUE;
 
+  /* We need to rememeber if a symbol has a definition in a dynamic
+     object or is weak in all dynamic objects. Internal and hidden
+     visibility will make it unavailable to dynamic objects.  */
+  if (newdyn && (h->elf_link_hash_flags & ELF_LINK_DYNAMIC_DEF) == 0)
+    {
+      if (!bfd_is_und_section (sec))
+	h->elf_link_hash_flags |= ELF_LINK_DYNAMIC_DEF;
+      else
+	{
+	  /* Check if this symbol is weak in all dynamic objects. If it
+	     is the first time we see it in a dynamic object, we mark
+	     if it is weak. Otherwise, we clear it.  */
+	  if ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) == 0)
+	    { 
+	      if (bind == STB_WEAK)
+		h->elf_link_hash_flags |= ELF_LINK_DYNAMIC_WEAK;
+	    }
+	  else if (bind != STB_WEAK)
+	    h->elf_link_hash_flags &= ~ELF_LINK_DYNAMIC_WEAK;
+	}
+    }
+
+  /* If the old symbol has non-default visibility, we ignore the new
+     definition from a dynamic object.  */
+  if (newdyn
+      && ELF_ST_VISIBILITY (h->other)
+      && !bfd_is_und_section (sec))
+    {
+      *skip = TRUE;
+      /* Make sure this symbol is dynamic.  */
+      h->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
+      /* FIXME: Should we check type and size for protected symbol?  */
+      return _bfd_elf_link_record_dynamic_symbol (info, h);
+    }
+  else if (!newdyn
+	   && ELF_ST_VISIBILITY (sym->st_other)
+	   && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0)
+    {
+      /* If the new symbol with non-default visibility comes from a
+	 relocatable file and the old definition comes from a dynamic
+	 object, we remove the old definition.  */
+      h->root.type = bfd_link_hash_new;
+      h->root.u.undef.abfd = NULL;
+      h->elf_link_hash_flags &= ~ELF_LINK_HASH_DEF_DYNAMIC;
+      h->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
+      /* FIXME: Should we check type and size for protected symbol?  */
+      h->size = 0;
+      h->type = 0;
+      return TRUE;
+    }
+
   /* NEWDYNCOMMON and OLDDYNCOMMON indicate whether the new or old
      symbol, respectively, appears to be a common symbol in a dynamic
      object.  If a symbol appears in an uninitialized section, and is
@@ -919,6 +972,7 @@ elf_add_default_symbol (abfd, info, h, n
 {
   bfd_boolean type_change_ok;
   bfd_boolean size_change_ok;
+  bfd_boolean skip;
   char *shortname;
   struct elf_link_hash_entry *hi;
   struct bfd_link_hash_entry *bh;
@@ -974,7 +1028,7 @@ elf_add_default_symbol (abfd, info, h, n
   size_change_ok = FALSE;
   sec = *psec;
   if (! elf_merge_symbol (abfd, info, shortname, sym, &sec, value,
-			  &hi, &override, &type_change_ok,
+			  &hi, &skip, &override, &type_change_ok,
 			  &size_change_ok, dt_needed))
     return FALSE;
 
@@ -1083,7 +1137,7 @@ elf_add_default_symbol (abfd, info, h, n
   size_change_ok = FALSE;
   sec = *psec;
   if (! elf_merge_symbol (abfd, info, shortname, sym, &sec, value,
-			  &hi, &override, &type_change_ok,
+			  &hi, &skip, &override, &type_change_ok,
 			  &size_change_ok, dt_needed))
     return FALSE;
 
@@ -1721,6 +1775,7 @@ elf_link_add_object_symbols (abfd, info)
 	{
 	  Elf_Internal_Versym iver;
 	  unsigned int vernum = 0;
+	  bfd_boolean skip;
 
 	  if (ever != NULL)
 	    {
@@ -1818,10 +1873,14 @@ elf_link_add_object_symbols (abfd, info)
 	    }
 
 	  if (! elf_merge_symbol (abfd, info, name, isym, &sec, &value,
-				  sym_hash, &override, &type_change_ok,
-				  &size_change_ok, dt_needed))
+				  sym_hash, &skip, &override,
+				  &type_change_ok, &size_change_ok,
+				  dt_needed))
 	    goto error_free_vers;
 
+	  if (skip)
+	    continue;
+
 	  if (override)
 	    definition = FALSE;
 
@@ -1936,9 +1995,10 @@ elf_link_add_object_symbols (abfd, info)
 	      h->type = ELF_ST_TYPE (isym->st_info);
 	    }
 
-	  /* If st_other has a processor-specific meaning, specific code
-	     might be needed here.  */
-	  if (isym->st_other != 0)
+	  /* If st_other has a processor-specific meaning, specific
+	     code might be needed here. We never merge the visibility
+	     attribute with the one from a dynamic object.  */
+	  if (isym->st_other != 0 && !dynamic)
 	    {
 	      unsigned char hvis, symvis, other, nvis;
 
@@ -2005,7 +2065,7 @@ elf_link_add_object_symbols (abfd, info)
 					  override, dt_needed))
 	      goto error_free_vers;
 
-	  if (definition && (abfd->flags & DYNAMIC) == 0)
+	  if (definition && !dynamic)
 	    {
 	      char *p = strchr (name, ELF_VER_CHR);
 	      if (p != NULL && p[1] != ELF_VER_CHR)
@@ -6022,7 +6082,7 @@ elf_link_check_versioned_symbol (info, h
 
   if ((undef_bfd->flags & DYNAMIC) == 0
       || info->hash->creator->flavour != bfd_target_elf_flavour
-      || elf_dt_soname (h->root.u.undef.abfd) == NULL)
+      || elf_dt_soname (undef_bfd) == NULL)
     return FALSE;
 
   for (loaded = elf_hash_table (info)->loaded;
@@ -6189,6 +6249,28 @@ elf_link_output_extsym (h, data)
 	}
     }
 
+  /* We should also warn if a forced local symbol is referenced from
+     shared libraries.  */
+  if (! finfo->info->relocateable
+      && (! finfo->info->shared || ! finfo->info->allow_shlib_undefined)
+      && (h->elf_link_hash_flags
+	  & (ELF_LINK_FORCED_LOCAL | ELF_LINK_HASH_REF_DYNAMIC
+	     | ELF_LINK_DYNAMIC_DEF | ELF_LINK_DYNAMIC_WEAK))
+	 == (ELF_LINK_FORCED_LOCAL | ELF_LINK_HASH_REF_DYNAMIC))
+    {
+      (*_bfd_error_handler)
+	(_("%s: %s symbol `%s' in %s is referenced by DSO"),
+	 bfd_get_filename (finfo->output_bfd),
+	 ELF_ST_VISIBILITY (h->other) == STV_INTERNAL
+	 ? "internal"
+	 : ELF_ST_VISIBILITY (h->other) == STV_HIDDEN
+	   ? "hidden" : "local",
+	 h->root.root.string,
+	 bfd_archive_filename (h->root.u.def.section->owner));
+      eoinfo->failed = TRUE;
+      return FALSE;
+    }
+
   /* We don't want to output symbols that have never been mentioned by
      a regular file, or that we have been told to strip.  However, if
      h->indx is set to -2, the symbol is used by a reloc and we must
@@ -6349,10 +6431,25 @@ elf_link_output_extsym (h, data)
       sym.st_info = ELF_ST_INFO (bindtype, ELF_ST_TYPE (sym.st_info));
     }
 
-  /* If a symbol is not defined locally, we clear the visibility field.  */
+  /* If a non-weak symbol with non-default visibility is not defined
+     locally, it is a fatal error.  */
   if (! finfo->info->relocateable
+      && ELF_ST_VISIBILITY (sym.st_other)
+      && ELF_ST_BIND (sym.st_info) != STB_WEAK
+      && h->root.type != bfd_link_hash_undefweak
       && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
-    sym.st_other &= ~ ELF_ST_VISIBILITY (-1);
+    {
+      (*_bfd_error_handler)
+	(_("%s: %s symbol `%s' isn't defined"),
+	  bfd_get_filename (finfo->output_bfd),
+	  ELF_ST_VISIBILITY (sym.st_other) == STV_PROTECTED
+	  ? "protected"
+	  : ELF_ST_VISIBILITY (sym.st_other) == STV_INTERNAL
+	    ? "internal" : "hidden",
+	  h->root.root.string);
+      eoinfo->failed = TRUE;
+      return FALSE;
+    }
 
   /* If this symbol should be put in the .dynsym section, then put it
      there now.  We already know the symbol index.  We also fill in
--- binutils/ld/testsuite/ld-elfvsb/elfvsb.dat.vsb	2000-06-05 15:55:02.000000000 -0700
+++ binutils/ld/testsuite/ld-elfvsb/elfvsb.dat	2003-04-07 17:08:01.000000000 -0700
@@ -20,3 +20,7 @@ main_visibility_check () == 1
 visibility_checkvar () == 1
 visibility_checkvarptr () == 1
 main_visibility_checkvar () == 1
+main_visibility_checkcom () == 1
+shlib_visibility_checkcom () == 1
+main_visibility_checkweak () == 1
+shlib_visibility_checkweak () == 1
--- binutils/ld/testsuite/ld-elfvsb/elfvsb.exp.vsb	2003-02-27 11:27:18.000000000 -0800
+++ binutils/ld/testsuite/ld-elfvsb/elfvsb.exp	2003-04-07 17:08:01.000000000 -0700
@@ -144,6 +144,8 @@ proc visibility_test { visibility progna
     	    pass "$testname"
 	} else { if { [ string match $visibility "hidden_undef_def" ]
 	     && [regexp ".*/main.c.*: undefined reference to \`visibility\'" $link_output]
+	     && [regexp ".*/main.c.*: undefined reference to \`visibility_def\'" $link_output]
+	     && [regexp ".*/main.c.*: undefined reference to \`visibility_func\'" $link_output]
 	     && [regexp ".*/main.c.*: undefined reference to \`visibility_var\'" $link_output] } {
     	    pass "$testname"
 	} else {
--- binutils/ld/testsuite/ld-elfvsb/main.c.vsb	2000-11-07 16:34:01.000000000 -0800
+++ binutils/ld/testsuite/ld-elfvsb/main.c	2003-04-08 09:22:47.000000000 -0700
@@ -42,6 +42,18 @@ extern int visibility_checkvar ();
 extern int visibility_checkvarptr ();
 extern int visibility_varval ();
 extern void *visibility_varptr ();
+extern int shlib_visibility_checkcom ();
+extern int shlib_visibility_checkweak ();
+
+int shlib_visibility_com = 1;
+
+int shlib_visibility_var_weak = 1;
+
+int
+shlib_visibility_func_weak ()
+{
+  return 1;
+}
 
 #ifdef HIDDEN_WEAK_TEST
 #define WEAK_TEST
@@ -81,6 +93,23 @@ main_visibility_checkvar ()
   return visibility_varval () != visibility_var
 	 && visibility_varptr () != &visibility_var;
 }
+
+#ifndef PROTECTED_UNDEF_TEST
+int shared_data = 1;
+asm (".protected shared_data");
+
+int
+shared_func ()
+{
+  return 1;
+}
+
+asm (".protected shared_func");
+
+extern int * shared_data_p ();
+typedef int (*func) ();
+extern func shared_func_p ();
+#endif
 #else
 static int
 main_visibility_check ()
@@ -121,10 +150,57 @@ shlib_overriddencall2 ()
   return 8;
 }
 
+#ifdef HIDDEN_NORMAL_TEST
+int visibility_com;
+asm (".hidden visibility_com");
+
+int
+main_visibility_checkcom ()
+{
+  return visibility_com == 0;
+}
+
+int
+main_visibility_checkweak ()
+{
+  return 1;
+}
+#elif defined (HIDDEN_UNDEF_TEST)
+extern int visibility_def;
+asm (".hidden visibility_def");
+extern int visibility_func ();
+asm (".hidden visibility_func");
+
+int
+main_visibility_checkcom ()
+{
+  return &visibility_def != NULL;
+}
+
+int
+main_visibility_checkweak ()
+{
+  return &visibility_func != NULL;
+}
+#else
+int
+main_visibility_checkcom ()
+{
+  return 1;
+}
+
+int
+main_visibility_checkweak ()
+{
+  return 1;
+}
+#endif
+
 int
 main ()
 {
   int (*p) ();
+  int ret = 0;
 
   printf ("mainvar == %d\n", mainvar);
   printf ("overriddenvar == %d\n", overriddenvar);
@@ -173,6 +249,27 @@ main ()
 	  visibility_checkvarptr ());
   printf ("main_visibility_checkvar () == %d\n",
 	  main_visibility_checkvar ());
-  return 0;
+  printf ("main_visibility_checkcom () == %d\n",
+	  main_visibility_checkcom ());
+  printf ("shlib_visibility_checkcom () == %d\n",
+	  shlib_visibility_checkcom ());
+  printf ("main_visibility_checkweak () == %d\n",
+	  main_visibility_checkweak ());
+  printf ("shlib_visibility_checkweak () == %d\n",
+	  shlib_visibility_checkweak ());
+
+#if !defined (PROTECTED_UNDEF_TEST) && defined (PROTECTED_TEST)
+  if (&shared_data != shared_data_p ())
+    ret = 1;
+  p = shared_func_p ();
+  if (shared_func != p)
+    ret = 1;
+  if (shared_data != *shared_data_p ())
+    ret = 1;
+  if (shared_func () != (*p) () )
+    ret = 1;
+#endif
+
+  return ret;
 }
 #endif
--- binutils/ld/testsuite/ld-elfvsb/sh1.c.vsb	2003-03-28 12:30:50.000000000 -0800
+++ binutils/ld/testsuite/ld-elfvsb/sh1.c	2003-04-08 09:22:18.000000000 -0700
@@ -323,3 +323,54 @@ asm (".protected visibility");
 asm (".protected visibility_var");
 #endif
 #endif
+
+#ifdef HIDDEN_NORMAL_TEST
+int shlib_visibility_com;
+asm (".hidden shlib_visibility_com");
+
+int
+shlib_visibility_checkcom ()
+{
+  return shlib_visibility_com == 0;
+}
+
+int
+shlib_visibility_checkweak ()
+{
+  return 1;
+}
+#else
+int
+shlib_visibility_checkcom ()
+{
+  return 1;
+}
+
+int
+shlib_visibility_checkweak ()
+{
+  return 1;
+}
+#endif
+
+#ifdef PROTECTED_TEST
+int shared_data = 100;
+ 
+int *
+shared_data_p ()
+{
+  return &shared_data;
+}
+ 
+int
+shared_func ()
+{
+  return 100;
+}
+ 
+void *
+shared_func_p ()
+{
+  return shared_func;
+}
+#endif
--- binutils/ld/testsuite/ld-elfvsb/sh2.c.vsb	2000-06-05 15:55:02.000000000 -0700
+++ binutils/ld/testsuite/ld-elfvsb/sh2.c	2003-04-07 17:08:01.000000000 -0700
@@ -5,6 +5,10 @@
    the shared library.  */
 int shlibvar2 = 4;
 
+/* This variable is defined here, and shouldn't be used to resolve a
+   reference with non-default visibility in another shared library.  */
+int visibility_com = 2;
+
 /* This function is called by another file in the shared library.  */
 
 int
@@ -21,4 +25,22 @@ visibility ()
 }
 
 int visibility_var = 2;
+
+int visibility_def = 2;
+
+int
+visibility_func ()
+{
+  return 2;
+}
+#endif
+
+#ifdef HIDDEN_WEAK_TEST
+int visibility_var_weak = 2;
+
+int
+visibility_func_weak ()
+{
+  return 2;
+}
 #endif

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: PATCH: Fix ELF visibility handling
  2003-04-09 16:22 ` H. J. Lu
@ 2003-04-27 23:08   ` Alan Modra
  2003-05-19 22:19   ` Jakub Jelinek
  2013-01-13 12:30   ` Alan Modra
  2 siblings, 0 replies; 8+ messages in thread
From: Alan Modra @ 2003-04-27 23:08 UTC (permalink / raw)
  To: H. J. Lu; +Cc: binutils

On Wed, Apr 09, 2003 at 09:22:52AM -0700, H. J. Lu wrote:
> 	* elf-bfd.h (ELF_LINK_DYNAMIC_DEF): New.
> 	(ELF_LINK_DYNAMIC_WEAK): New.
> 
> 	* elflink.h (elf_merge_symbol): Add one argument to indicate if
> 	a symbol should be skipped. Ignore definitions in dynamic
> 	objects for symbols with non-default visibility.
> 	(elf_add_default_symbol): Adjusted.
> 	(elf_link_add_object_symbols): Check if a symbol should be
> 	skipped. Don't merge the visibility field with the one from
> 	a dynamic object.
> 	(elf_link_check_versioned_symbol): Use undef_bfd.
> 	(elf_link_output_extsym): Warn if a forced local symbol is
> 	referenced from dynamic objects. Make non-weak undefined symbol
> 	with non-default visibility a fatal error.
> 
> ld/testsuite/
> 
> 2003-04-01  H.J. Lu <hjl@gnu.org>
> 
> 	* ld-elfvsb/elfvsb.dat: Updated.
> 	* ld-elfvsb/elfvsb.exp: Likewise.
> 	* ld-elfvsb/main.c: Likewise.
> 	* ld-elfvsb/sh1.c: Likewise.
> 	* ld-elfvsb/sh2.c: Likewise.

OK.

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: PATCH: Fix ELF visibility handling
  2003-04-09 16:22 ` H. J. Lu
  2003-04-27 23:08   ` Alan Modra
@ 2003-05-19 22:19   ` Jakub Jelinek
  2003-05-20  0:38     ` H. J. Lu
  2013-01-13 12:30   ` Alan Modra
  2 siblings, 1 reply; 8+ messages in thread
From: Jakub Jelinek @ 2003-05-19 22:19 UTC (permalink / raw)
  To: H. J. Lu; +Cc: binutils, amodra

On Wed, Apr 09, 2003 at 09:22:52AM -0700, H. J. Lu wrote:
> 2003-04-01  H.J. Lu <hjl@gnu.org>
> 
> 	(elf_link_output_extsym): Warn if a forced local symbol is
> 	referenced from dynamic objects. Make non-weak undefined symbol
> 	with non-default visibility a fatal error.

This change broke static linking with hidden common symbols
(testcase included in the patch below).
Any reason why you use h->root.type != bfd_link_hash_undefweak
which can well be a normal bfd_link_hash_defined symbol?

2003-05-20  Jakub Jelinek  <jakub@redhat.com>

	* elflink.h (elf_link_output_extsym): Only issue error about !=
	STV_DEFAULT symbols if they are bfd_link_hash_undefined.

	* ld-elfvsb/sh3.c: New test.
	* ld-elfvsb/elfvsb.exp: Add sh3.

--- bfd/elflink.h.jj	2003-05-19 17:12:39.000000000 -0400
+++ bfd/elflink.h	2003-05-19 17:43:12.000000000 -0400
@@ -4622,7 +4622,7 @@ elf_link_output_extsym (h, data)
   if (! finfo->info->relocateable
       && ELF_ST_VISIBILITY (sym.st_other) != STV_DEFAULT
       && ELF_ST_BIND (sym.st_info) != STB_WEAK
-      && h->root.type != bfd_link_hash_undefweak
+      && h->root.type == bfd_link_hash_undefined
       && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
     {
       (*_bfd_error_handler)
--- ld/testsuite/ld-elfvsb/sh3.c.jj	2003-05-19 17:51:14.000000000 -0400
+++ ld/testsuite/ld-elfvsb/sh3.c	2003-05-19 17:51:08.000000000 -0400
@@ -0,0 +1,7 @@
+int foo;
+asm (".hidden foo");
+
+int main (void)
+{
+  return foo;
+}
--- ld/testsuite/ld-elfvsb/elfvsb.exp.jj	2003-05-19 17:12:47.000000000 -0400
+++ ld/testsuite/ld-elfvsb/elfvsb.exp	2003-05-19 18:08:22.000000000 -0400
@@ -412,6 +412,16 @@ visibility_run protected_undef_def
 visibility_run protected_weak
 visibility_run normal
 
+if { ![ld_compile "$CC -g $CFLAGS $SHCFLAG" $srcdir/$subdir/sh3.c $tmpdir/sh3.o] } {
+	unresolved "static visibility"
+} else {
+	if ![ld_simple_link $CC $tmpdir/sh3 "-static $tmpdir/sh3.o"] {
+		fail "static visibility"
+	} else {
+		pass "static visibility"
+	}
+}
+
 if { [istarget rs6000*-*-aix*] || [istarget powerpc*-*-aix*] } {
     # Remove the temporary directory.
     catch "exec rm -rf $tmpdir" exec_status


	Jakub

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: PATCH: Fix ELF visibility handling
  2003-05-19 22:19   ` Jakub Jelinek
@ 2003-05-20  0:38     ` H. J. Lu
  2003-05-20  1:27       ` H. J. Lu
  0 siblings, 1 reply; 8+ messages in thread
From: H. J. Lu @ 2003-05-20  0:38 UTC (permalink / raw)
  To: Jakub Jelinek; +Cc: binutils, amodra

On Tue, May 20, 2003 at 12:19:19AM +0200, Jakub Jelinek wrote:
> On Wed, Apr 09, 2003 at 09:22:52AM -0700, H. J. Lu wrote:
> > 2003-04-01  H.J. Lu <hjl@gnu.org>
> > 
> > 	(elf_link_output_extsym): Warn if a forced local symbol is
> > 	referenced from dynamic objects. Make non-weak undefined symbol
> > 	with non-default visibility a fatal error.
> 
> This change broke static linking with hidden common symbols
> (testcase included in the patch below).

I don't think it works with dynamic linking either. I found another
bug. I will post a testcase and a patch later.

> Any reason why you use h->root.type != bfd_link_hash_undefweak
> which can well be a normal bfd_link_hash_defined symbol?

I have an old patch to fix a related problem:

http://sources.redhat.com/ml/binutils/2003-03/msg00080.html

in a different way. Then I changed it and forgot to update another
patch. That is what happened when you had so many patches on top
of each other.

> 
> 2003-05-20  Jakub Jelinek  <jakub@redhat.com>
> 
> 	* elflink.h (elf_link_output_extsym): Only issue error about !=
> 	STV_DEFAULT symbols if they are bfd_link_hash_undefined.
> 
> 	* ld-elfvsb/sh3.c: New test.
> 	* ld-elfvsb/elfvsb.exp: Add sh3.
> 
> --- bfd/elflink.h.jj	2003-05-19 17:12:39.000000000 -0400
> +++ bfd/elflink.h	2003-05-19 17:43:12.000000000 -0400
> @@ -4622,7 +4622,7 @@ elf_link_output_extsym (h, data)
>    if (! finfo->info->relocateable
>        && ELF_ST_VISIBILITY (sym.st_other) != STV_DEFAULT
>        && ELF_ST_BIND (sym.st_info) != STB_WEAK
> -      && h->root.type != bfd_link_hash_undefweak
> +      && h->root.type == bfd_link_hash_undefined
>        && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
>      {
>        (*_bfd_error_handler)
> --- ld/testsuite/ld-elfvsb/sh3.c.jj	2003-05-19 17:51:14.000000000 -0400
> +++ ld/testsuite/ld-elfvsb/sh3.c	2003-05-19 17:51:08.000000000 -0400
> @@ -0,0 +1,7 @@
> +int foo;
> +asm (".hidden foo");
> +
> +int main (void)
> +{
> +  return foo;
> +}
> --- ld/testsuite/ld-elfvsb/elfvsb.exp.jj	2003-05-19 17:12:47.000000000 -0400
> +++ ld/testsuite/ld-elfvsb/elfvsb.exp	2003-05-19 18:08:22.000000000 -0400
> @@ -412,6 +412,16 @@ visibility_run protected_undef_def
>  visibility_run protected_weak
>  visibility_run normal
>  
> +if { ![ld_compile "$CC -g $CFLAGS $SHCFLAG" $srcdir/$subdir/sh3.c $tmpdir/sh3.o] } {
> +	unresolved "static visibility"
> +} else {
> +	if ![ld_simple_link $CC $tmpdir/sh3 "-static $tmpdir/sh3.o"] {
> +		fail "static visibility"
> +	} else {
> +		pass "static visibility"
> +	}
> +}
> +
>  if { [istarget rs6000*-*-aix*] || [istarget powerpc*-*-aix*] } {
>      # Remove the temporary directory.
>      catch "exec rm -rf $tmpdir" exec_status
> 
> 
> 	Jakub

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: PATCH: Fix ELF visibility handling
  2003-05-20  0:38     ` H. J. Lu
@ 2003-05-20  1:27       ` H. J. Lu
  2003-05-20 11:14         ` Alan Modra
  0 siblings, 1 reply; 8+ messages in thread
From: H. J. Lu @ 2003-05-20  1:27 UTC (permalink / raw)
  To: Jakub Jelinek; +Cc: binutils, amodra

[-- Attachment #1: Type: text/plain, Size: 1091 bytes --]

On Mon, May 19, 2003 at 05:38:02PM -0700, H. J. Lu wrote:
> On Tue, May 20, 2003 at 12:19:19AM +0200, Jakub Jelinek wrote:
> > On Wed, Apr 09, 2003 at 09:22:52AM -0700, H. J. Lu wrote:
> > > 2003-04-01  H.J. Lu <hjl@gnu.org>
> > > 
> > > 	(elf_link_output_extsym): Warn if a forced local symbol is
> > > 	referenced from dynamic objects. Make non-weak undefined symbol
> > > 	with non-default visibility a fatal error.
> > 
> > This change broke static linking with hidden common symbols
> > (testcase included in the patch below).
> 
> I don't think it works with dynamic linking either. I found another
> bug. I will post a testcase and a patch later.
> 
> > Any reason why you use h->root.type != bfd_link_hash_undefweak
> > which can well be a normal bfd_link_hash_defined symbol?
> 
> I have an old patch to fix a related problem:
> 
> http://sources.redhat.com/ml/binutils/2003-03/msg00080.html
> 
> in a different way. Then I changed it and forgot to update another
> patch. That is what happened when you had so many patches on top
> of each other.
> 

Here is the new patch.


H.J.

[-- Attachment #2: binutils-vsb-3.patch --]
[-- Type: text/plain, Size: 4340 bytes --]

bfd/

2003-05-20  Jakub Jelinek  <jakub@redhat.com>

	* elflink.h (elf_link_output_extsym): Only issue error about !=
	STV_DEFAULT symbols if they are bfd_link_hash_undefined.

2003-05-20  H.J. Lu <hongjiu.lu@intel.com>

	* elflink.c (_bfd_elf_merge_symbol): Check ELF_LINK_DYNAMIC_DEF
	when removing the old definition for symbols with non-default
	visibility.

ld/testsuite/

2003-05-20  Jakub Jelinek  <jakub@redhat.com>

	* ld-elfvsb/common.c: New file.
	* ld-elfvsb/elfvsb.exp: Add common.

2003-05-20  H.J. Lu <hongjiu.lu@intel.com>

	* ld-elfvsb/sh3.c: New file.
	* ld-elfvsb/test.c: Likewise.

	* ld-elfvsb/elfvsb.exp: Add new weak hidden symbol tests.

--- binutils/bfd/elflink.c.vsb	2003-05-18 21:48:09.000000000 -0700
+++ binutils/bfd/elflink.c	2003-05-19 18:17:55.000000000 -0700
@@ -884,7 +884,8 @@ _bfd_elf_merge_symbol (abfd, info, name,
       if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC)
 	{
 	  h->elf_link_hash_flags &= ~ELF_LINK_HASH_DEF_DYNAMIC;
-	  h->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
+	  h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_DYNAMIC
+				     | ELF_LINK_DYNAMIC_DEF);
 	}
       /* FIXME: Should we check type and size for protected symbol?  */
       h->size = 0;
--- binutils/bfd/elflink.h.vsb	2003-05-18 21:48:10.000000000 -0700
+++ binutils/bfd/elflink.h	2003-05-19 17:42:25.000000000 -0700
@@ -4622,7 +4622,7 @@ elf_link_output_extsym (h, data)
   if (! finfo->info->relocateable
       && ELF_ST_VISIBILITY (sym.st_other) != STV_DEFAULT
       && ELF_ST_BIND (sym.st_info) != STB_WEAK
-      && h->root.type != bfd_link_hash_undefweak
+      && h->root.type == bfd_link_hash_undefined
       && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
     {
       (*_bfd_error_handler)
--- binutils/ld/testsuite/ld-elfvsb/common.c.vsb	2003-05-19 17:42:25.000000000 -0700
+++ binutils/ld/testsuite/ld-elfvsb/common.c	2003-05-19 17:51:43.000000000 -0700
@@ -0,0 +1,14 @@
+int foo;
+asm (".hidden foo");
+
+int
+_start (void)
+{
+  return foo;
+}
+
+int
+__start (void)
+{
+  return _start ();
+}
--- binutils/ld/testsuite/ld-elfvsb/elfvsb.exp.vsb	2003-05-18 21:48:13.000000000 -0700
+++ binutils/ld/testsuite/ld-elfvsb/elfvsb.exp	2003-05-19 18:19:04.000000000 -0700
@@ -412,6 +412,39 @@ visibility_run protected_undef_def
 visibility_run protected_weak
 visibility_run normal
 
+if { ![ld_compile "$CC -g $CFLAGS" $srcdir/$subdir/common.c tmpdir/common.o] } {
+    unresolved "common hidden symbol"
+} else {
+    if ![ld_simple_link $ld tmpdir/common "tmpdir/common.o"] {
+	fail "common hidden symbol"
+    } else {
+	pass "common hidden symbol"
+    }
+}
+
+if { ![ld_compile "$CC -g $CFLAGS" $srcdir/$subdir/test.c tmpdir/test.o] } {
+    unresolved "weak hidden symbol"
+} else {
+   if { ![ld_compile "$CC -g $CFLAGS $picflag" $srcdir/$subdir/sh3.c tmpdir/sh3.o] } {
+	unresolved "weak hidden symbol"
+    } else {
+	if ![ld_simple_link $ld tmpdir/sh3.so "-shared tmpdir/sh3.o"] {
+	    fail "weak hidden symbol"
+	} else {
+	    if ![ld_simple_link $ld tmpdir/weak "tmpdir/test.o tmpdir/sh3.o"] {
+		fail "weak hidden symbol DSO last"
+	    } else {
+		pass "weak hidden symbol DSO last"
+	    }
+	    if ![ld_simple_link $ld tmpdir/weak "tmpdir/sh3.so tmpdir/test.o"] {
+		fail "weak hidden symbol DSO first"
+	    } else {
+		pass "weak hidden symbol DSO first"
+	    }
+	}
+    }
+}
+
 if { [istarget rs6000*-*-aix*] || [istarget powerpc*-*-aix*] } {
     # Remove the temporary directory.
     catch "exec rm -rf $tmpdir" exec_status
--- binutils/ld/testsuite/ld-elfvsb/sh3.c.vsb	2003-05-19 18:17:08.000000000 -0700
+++ binutils/ld/testsuite/ld-elfvsb/sh3.c	2003-05-19 17:58:53.000000000 -0700
@@ -0,0 +1,7 @@
+int main_hidden_data = 1;
+
+int
+main_hidden_func ()
+{
+  return 1;
+}
--- binutils/ld/testsuite/ld-elfvsb/test.c.vsb	2003-05-19 18:17:26.000000000 -0700
+++ binutils/ld/testsuite/ld-elfvsb/test.c	2003-05-19 18:00:38.000000000 -0700
@@ -0,0 +1,26 @@
+#pragma weak main_hidden_data
+extern int main_hidden_data;
+asm (".hidden main_hidden_data");
+ 
+#pragma weak main_hidden_func
+extern int main_hidden_func ();
+asm (".hidden main_hidden_func");
+
+int
+_start (void)
+{
+  int ret = 0;
+
+  if (&main_hidden_data != 0)
+    ret = 1;
+  if (main_hidden_func != 0)
+    ret = 1;
+
+  return ret;
+}
+
+int
+__start (void)
+{
+  return _start ();
+}

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: PATCH: Fix ELF visibility handling
  2003-05-20  1:27       ` H. J. Lu
@ 2003-05-20 11:14         ` Alan Modra
  0 siblings, 0 replies; 8+ messages in thread
From: Alan Modra @ 2003-05-20 11:14 UTC (permalink / raw)
  To: H. J. Lu; +Cc: Jakub Jelinek, binutils

On Mon, May 19, 2003 at 06:27:00PM -0700, H. J. Lu wrote:
> 2003-05-20  Jakub Jelinek  <jakub@redhat.com>
> 
> 	* elflink.h (elf_link_output_extsym): Only issue error about !=
> 	STV_DEFAULT symbols if they are bfd_link_hash_undefined.
> 
> 2003-05-20  H.J. Lu <hongjiu.lu@intel.com>
> 
> 	* elflink.c (_bfd_elf_merge_symbol): Check ELF_LINK_DYNAMIC_DEF
> 	when removing the old definition for symbols with non-default
> 	visibility.
> 
> ld/testsuite/
> 
> 2003-05-20  Jakub Jelinek  <jakub@redhat.com>
> 
> 	* ld-elfvsb/common.c: New file.
> 	* ld-elfvsb/elfvsb.exp: Add common.
> 
> 2003-05-20  H.J. Lu <hongjiu.lu@intel.com>
> 
> 	* ld-elfvsb/sh3.c: New file.
> 	* ld-elfvsb/test.c: Likewise.
> 
> 	* ld-elfvsb/elfvsb.exp: Add new weak hidden symbol tests.

OK.

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: PATCH: Fix ELF visibility handling
  2003-04-09 16:22 ` H. J. Lu
  2003-04-27 23:08   ` Alan Modra
  2003-05-19 22:19   ` Jakub Jelinek
@ 2013-01-13 12:30   ` Alan Modra
  2 siblings, 0 replies; 8+ messages in thread
From: Alan Modra @ 2013-01-13 12:30 UTC (permalink / raw)
  To: binutils

This tidies usage of dynamic_def and dynamic_weak, two flags added a
long time ago http://sourceware.org/ml/binutils/2003-04/msg00239.html
to report errors when symbols referenced by dynamic libraries are
forced local for some reason.  I flipped the sense of dynamic_weak,
calling it ref_dynamic_nonweak (cf. ref_regular_nonweak) since that
simplifies setting of the flag.  There's no need then to special case
the first time setting as was done in _bfd_elf_mark_dynamic_def_weak.
I also moved setting of the flag earlier, before any of the early
returns in _bfd_elf_merge_symbol.  That removes the need to fiddle
with dynamic_def elsewhere.

	* elf-bfd.h (struct elf_link_hash_entry): Delete dynamic_weak.
	Add ref_dynamic_nonweak.
	* elflink.c (_bfd_elf_mark_dynamic_def_weak): Delete.
	(_bfd_elf_merge_symbol): Don't call above function.  Move
	setting of ref_dynamic_nonweak and dynamic_def earlier.  Don't
	clear dynamic_def.
	(elf_link_add_object_symbols): Delete redundant "override" test.
	Don't set dynamic_def here.
	(elf_link_output_extsym): Update.

Index: bfd/elf-bfd.h
===================================================================
RCS file: /cvs/src/src/bfd/elf-bfd.h,v
retrieving revision 1.354
diff -u -p -r1.354 elf-bfd.h
--- bfd/elf-bfd.h	11 Jan 2013 14:09:58 -0000	1.354
+++ bfd/elf-bfd.h	13 Jan 2013 03:08:34 -0000
@@ -191,8 +191,8 @@ struct elf_link_hash_entry
      FIXME: There is no real need for this field if def_dynamic is never
      cleared and all places that test def_dynamic also test def_regular.  */
   unsigned int dynamic_def : 1;
-  /* Symbol is weak in all shared objects.  */
-  unsigned int dynamic_weak : 1;
+  /* Symbol has a non-weak reference from a shared object.  */
+  unsigned int ref_dynamic_nonweak : 1;
   /* Symbol is referenced with a relocation where C/C++ pointer equality
      matters.  */
   unsigned int pointer_equality_needed : 1;
Index: bfd/elflink.c
===================================================================
RCS file: /cvs/src/src/bfd/elflink.c,v
retrieving revision 1.462
diff -u -p -r1.462 elflink.c
--- bfd/elflink.c	11 Jan 2013 14:09:59 -0000	1.462
+++ bfd/elflink.c	13 Jan 2013 05:25:05 -0000
@@ -895,33 +895,6 @@ elf_merge_st_other (bfd *abfd, struct el
     }
 }
 
-/* Mark if a symbol has a definition in a dynamic object or is
-   weak in all dynamic objects.  */
-
-static void
-_bfd_elf_mark_dynamic_def_weak (struct elf_link_hash_entry *h,
-				asection *sec, int bind)
-{
-  if (!h->dynamic_def)
-    {
-      if (!bfd_is_und_section (sec))
-	h->dynamic_def = 1;
-      else
-	{
-	  /* Check if this symbol is weak in all dynamic objects. If it
-	     is the first time we see it in a dynamic object, we mark
-	     if it is weak. Otherwise, we clear it.  */
-	  if (!h->ref_dynamic)
-	    {
-	      if (bind == STB_WEAK)
-		h->dynamic_weak = 1;
-	    }
-	  else if (bind != STB_WEAK)
-	    h->dynamic_weak = 0;
-	}
-    }
-}
-
 /* This function is called when we want to define a new symbol.  It
    handles the various cases which arise when we find a definition in
    a dynamic object, or when there is already a definition in a
@@ -998,10 +971,39 @@ _bfd_elf_merge_symbol (bfd *abfd,
     h = (struct elf_link_hash_entry *) h->root.u.i.link;
 
   /* We have to check it for every instance since the first few may be
-     refereences and not all compilers emit symbol type for undefined
+     references and not all compilers emit symbol type for undefined
      symbols.  */
   bfd_elf_link_mark_dynamic_symbol (info, h, sym);
 
+  /* NEWDYN and OLDDYN indicate whether the new or old symbol,
+     respectively, is from a dynamic object.  */
+
+  newdyn = (abfd->flags & DYNAMIC) != 0;
+
+  /* ref_dynamic_nonweak and dynamic_def flags track actual undefined
+     syms and defined syms in dynamic libraries respectively.
+     ref_dynamic on the other hand can be set for a symbol defined in
+     a dynamic library, and def_dynamic may not be set;  When the
+     definition in a dynamic lib is overridden by a definition in the
+     executable use of the symbol in the dynamic lib becomes a
+     reference to the executable symbol.  */
+  if (newdyn)
+    {
+      if (bfd_is_und_section (sec))
+	{
+	  if (bind != STB_WEAK)
+	    {
+	      h->ref_dynamic_nonweak = 1;
+	      hi->ref_dynamic_nonweak = 1;
+	    }
+	}
+      else
+	{
+	  h->dynamic_def = 1;
+	  hi->dynamic_def = 1;
+	}
+    }
+
   /* If we just created the symbol, mark it as being an ELF symbol.
      Other than that, there is nothing to do--there is no merge issue
      with a newly defined symbol--so we just return.  */
@@ -1059,11 +1061,6 @@ _bfd_elf_merge_symbol (bfd *abfd,
 	  || !h->def_regular))
     return TRUE;
 
-  /* NEWDYN and OLDDYN indicate whether the new or old symbol,
-     respectively, is from a dynamic object.  */
-
-  newdyn = (abfd->flags & DYNAMIC) != 0;
-
   olddyn = FALSE;
   if (oldbfd != NULL)
     olddyn = (oldbfd->flags & DYNAMIC) != 0;
@@ -1167,16 +1164,6 @@ _bfd_elf_merge_symbol (bfd *abfd,
       return FALSE;
     }
 
-  /* We need to remember if a symbol has a definition in a dynamic
-     object or is weak in all dynamic objects. Internal and hidden
-     visibility will make it unavailable to dynamic objects.  */
-  if (newdyn)
-    {
-      _bfd_elf_mark_dynamic_def_weak (h, sec, bind);
-      if (h != hi)
-	_bfd_elf_mark_dynamic_def_weak (hi, sec, bind);
-    }
-
   /* If the old symbol has non-default visibility, we ignore the new
      definition from a dynamic object.  */
   if (newdyn
@@ -1230,7 +1217,6 @@ _bfd_elf_merge_symbol (bfd *abfd,
 		h->ref_dynamic = 1;
 
 	      h->def_dynamic = 0;
-	      h->dynamic_def = 0;
 	      /* FIXME: Should we check type and size for protected symbol?  */
 	      h->size = 0;
 	      h->type = 0;
@@ -1270,7 +1256,6 @@ _bfd_elf_merge_symbol (bfd *abfd,
       else
 	h->ref_dynamic = 1;
       h->def_dynamic = 0;
-      h->dynamic_def = 0;
       /* FIXME: Should we check type and size for protected symbol?  */
       h->size = 0;
       h->type = 0;
@@ -4190,7 +4175,6 @@ error_free_dyn:
 	    }
 
 	  if (elf_tdata (abfd)->verdef != NULL
-	      && ! override
 	      && vernum > 1
 	      && definition)
 	    h->verinfo.verdef = &elf_tdata (abfd)->verdef[vernum - 1];
@@ -4415,9 +4399,7 @@ error_free_dyn:
 	      else
 		{
 		  h->def_dynamic = 1;
-		  h->dynamic_def = 1;
 		  hi->def_dynamic = 1;
-		  hi->dynamic_def = 1;
 		}
 
 	      /* If the indirect symbol has been forced local, don't
@@ -8811,7 +8793,7 @@ elf_link_output_extsym (struct bfd_hash_
       && h->ref_dynamic
       && h->def_regular
       && !h->dynamic_def
-      && !h->dynamic_weak
+      && h->ref_dynamic_nonweak
       && !elf_link_check_versioned_symbol (flinfo->info, bed, h))
     {
       bfd *def_bfd;

-- 
Alan Modra
Australia Development Lab, IBM

^ permalink raw reply	[flat|nested] 8+ messages in thread
end of thread, other threads:[~2013-01-13 12:30 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2003-04-01 20:20 PATCH: Fix ELF visibility handling H. J. Lu
2003-04-09 16:22 ` H. J. Lu
2003-04-27 23:08   ` Alan Modra
2003-05-19 22:19   ` Jakub Jelinek
2003-05-20  0:38     ` H. J. Lu
2003-05-20  1:27       ` H. J. Lu
2003-05-20 11:14         ` Alan Modra
2013-01-13 12:30   ` Alan Modra

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).