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tidy plt entries on x86, ppc


Removes some useless .plt entries, and tidies code a little.

	* elf32-i386.c (elf_i386_adjust_dynamic_symbol): Use SYMBOL_CALLS_LOCAL
	to trim plt entries.  Move undefweak non-default visibility test..
	(allocate_dynrelocs): ..from here.
	* elf32-ppc.c (ppc_elf_adjust_dynamic_symbol): Don't test
	dynamic_sections_created here.  Update comment.  Move undefweak
	non-default visibility test..
	(allocate_dynrelocs): ..from here.  Fix comment.
	* elf64-ppc.c (ppc64_elf_adjust_dynamic_symbol): Use SYMBOL_CALLS_LOCAL
	to trim plt entries.  Move undefweak non-default visibility test..
	(allocate_dynrelocs): ..from here.  Fix comment.
	* elflink.h (elf_link_output_extsym): Compare ELF_ST_VISIBILITY with
	STV_DEFAULT rather than comparing with zero.
	* elflink.c (_bfd_elf_merge_symbol): Likewise.
	(_bfd_elf_fix_symbol_flags): Likewise.  Format comment.

Index: bfd/elf32-i386.c
===================================================================
RCS file: /cvs/src/src/bfd/elf32-i386.c,v
retrieving revision 1.102
diff -u -p -r1.102 elf32-i386.c
--- bfd/elf32-i386.c	15 May 2003 06:35:43 -0000	1.102
+++ bfd/elf32-i386.c	17 May 2003 05:14:44 -0000
@@ -1390,11 +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
@@ -1558,9 +1556,7 @@ allocate_dynrelocs (h, inf)
   htab = elf_i386_hash_table (info);
 
   if (htab->elf.dynamic_sections_created
-      && h->plt.refcount > 0
-      && (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
-	  || h->root.type != bfd_link_hash_undefweak))
+      && h->plt.refcount > 0)
     {
       /* Make sure this symbol is output as a dynamic symbol.
 	 Undefined weak syms won't yet be marked as dynamic.  */
Index: bfd/elf32-ppc.c
===================================================================
RCS file: /cvs/src/src/bfd/elf32-ppc.c,v
retrieving revision 1.80
diff -u -p -r1.80 elf32-ppc.c
--- bfd/elf32-ppc.c	15 May 2003 06:35:43 -0000	1.80
+++ bfd/elf32-ppc.c	17 May 2003 05:14:47 -0000
@@ -2495,19 +2495,21 @@ ppc_elf_adjust_dynamic_symbol (info, h)
     {
       /* Clear procedure linkage table information for any symbol that
 	 won't need a .plt entry.  */
-      if (! htab->elf.dynamic_sections_created
+      if (h->plt.refcount <= 0
 	  || SYMBOL_CALLS_LOCAL (info, h)
-	  || h->plt.refcount <= 0)
+	  || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
+	      && h->root.type == bfd_link_hash_undefweak))
 	{
 	  /* A PLT entry is not required/allowed when:
 
-	  1. We are not using ld.so; because then the PLT entry
-	  can't be set up, so we can't use one.
+	     1. We are not using ld.so; because then the PLT entry
+	     can't be set up, so we can't use one.  In this case,
+	     ppc_elf_adjust_dynamic_symbol won't even be called.
 
-	  2. We know for certain that a call to this symbol
-	  will go to this object.
+	     2. GC has rendered the entry unused.
 
-	  3. GC has rendered the entry unused.  */
+	     3. We know for certain that a call to this symbol
+	     will go to this object, or will remain undefined.  */
 	  h->plt.offset = (bfd_vma) -1;
 	  h->elf_link_hash_flags &= ~ELF_LINK_HASH_NEEDS_PLT;
 	}
@@ -2673,9 +2675,7 @@ allocate_dynrelocs (h, inf)
 
   htab = ppc_elf_hash_table (info);
   if (htab->elf.dynamic_sections_created
-      && h->plt.refcount > 0
-      && (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
-	  || h->root.type != bfd_link_hash_undefweak))
+      && h->plt.refcount > 0)
     {
       /* Make sure this symbol is output as a dynamic symbol.  */
       if (h->dynindx == -1
@@ -2799,12 +2799,12 @@ allocate_dynrelocs (h, inf)
 
   if (info->shared)
     {
-      /* Relocs that use pc_count are those that appear on a call
-	 insn, or certain REL relocs (see MUST_BE_DYN_RELOC) that can
-	 generated via assembly.  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 weird assembly.  */
+      /* Relocs that use pc_count are those that appear on a call insn,
+	 or certain REL relocs (see MUST_BE_DYN_RELOC) that can be
+	 generated via assembly.  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 weird assembly.  */ 
       if (SYMBOL_CALLS_LOCAL (info, h))
 	{
 	  struct ppc_elf_dyn_relocs **pp;
Index: bfd/elf64-ppc.c
===================================================================
RCS file: /cvs/src/src/bfd/elf64-ppc.c,v
retrieving revision 1.97
diff -u -p -r1.97 elf64-ppc.c
--- bfd/elf64-ppc.c	15 May 2003 06:35:43 -0000	1.97
+++ bfd/elf64-ppc.c	17 May 2003 05:14:51 -0000
@@ -4505,10 +4505,9 @@ ppc64_elf_adjust_dynamic_symbol (info, h
 	  break;
       if (!((struct ppc_link_hash_entry *) h)->is_func_descriptor
 	  || ent == NULL
-	  || (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 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))
+	  || SYMBOL_CALLS_LOCAL (info, h)
+	  || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
+	      && h->root.type == bfd_link_hash_undefweak))
 	{
 	  h->plt.plist = NULL;
 	  h->elf_link_hash_flags &= ~ELF_LINK_HASH_NEEDS_PLT;
@@ -5496,9 +5495,7 @@ allocate_dynrelocs (h, inf)
 
   if (htab->elf.dynamic_sections_created
       && h->dynindx != -1
-      && WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, info->shared, h)
-      && (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
-	  || h->root.type != bfd_link_hash_undefweak))
+      && WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, info->shared, h))
     {
       struct plt_entry *pent;
       bfd_boolean doneone = FALSE;
@@ -5621,12 +5618,12 @@ allocate_dynrelocs (h, inf)
 
   if (info->shared)
     {
-      /* Relocs that use pc_count are those that appear on a call
-	 insn, or certain REL relocs (see MUST_BE_DYN_RELOC) that can
-	 generated via assembly.  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 weird assembly.  */
+      /* Relocs that use pc_count are those that appear on a call insn,
+	 or certain REL relocs (see MUST_BE_DYN_RELOC) that can be
+	 generated via assembly.  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 weird assembly.  */
       if (SYMBOL_CALLS_LOCAL (info, h))
 	{
 	  struct ppc_dyn_relocs **pp;
Index: bfd/elflink.c
===================================================================
RCS file: /cvs/src/src/bfd/elflink.c,v
retrieving revision 1.32
diff -u -p -r1.32 elflink.c
--- bfd/elflink.c	15 May 2003 14:54:47 -0000	1.32
+++ bfd/elflink.c	17 May 2003 05:14:53 -0000
@@ -855,7 +855,7 @@ _bfd_elf_merge_symbol (abfd, info, name,
   /* If the old symbol has non-default visibility, we ignore the new
      definition from a dynamic object.  */
   if (newdyn
-      && ELF_ST_VISIBILITY (h->other)
+      && ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
       && !bfd_is_und_section (sec))
     {
       *skip = TRUE;
@@ -871,7 +871,7 @@ _bfd_elf_merge_symbol (abfd, info, name,
 	return TRUE;
     }
   else if (!newdyn
-	   && ELF_ST_VISIBILITY (sym->st_other)
+	   && ELF_ST_VISIBILITY (sym->st_other) != STV_DEFAULT
 	   && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0)
     {
       /* If the new symbol with non-default visibility comes from a
@@ -2427,8 +2427,8 @@ _bfd_elf_fix_symbol_flags (h, eif)
   /* If -Bsymbolic was used (which means to bind references to global
      symbols to the definition within the shared object), and this
      symbol was defined in a regular object, then it actually doesn't
-     need a PLT entry. Likewise, if the symbol has non-default
-     visibility. If the symbol has hidden or internal visibility, we
+     need a PLT entry.  Likewise, if the symbol has non-default
+     visibility.  If the symbol has hidden or internal visibility, we
      will force it local.  */
   if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0
       && eif->info->shared
@@ -2449,7 +2449,7 @@ _bfd_elf_fix_symbol_flags (h, eif)
 
   /* If a weak undefined symbol has non-default visibility, we also
      hide it from the dynamic linker.  */
-  if (ELF_ST_VISIBILITY (h->other)
+  if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
       && h->root.type == bfd_link_hash_undefweak)
     {
       struct elf_backend_data *bed;
Index: bfd/elflink.h
===================================================================
RCS file: /cvs/src/src/bfd/elflink.h,v
retrieving revision 1.223
diff -u -p -r1.223 elflink.h
--- bfd/elflink.h	15 May 2003 13:48:53 -0000	1.223
+++ bfd/elflink.h	17 May 2003 05:14:57 -0000
@@ -4620,7 +4620,7 @@ elf_link_output_extsym (h, data)
   /* 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_VISIBILITY (sym.st_other) != STV_DEFAULT
       && 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)

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre


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