PR ld/11217

	* elf64-ppc.c (ppc64_elf_tls_optimize): Optimize tls sequences
	with relocations against undefined weak symbols.
	(ppc64_elf_relocate_section): Don't optimize calls to undefined
	weak functions if the symbol is dynamic.
	(ppc64_elf_relocate_section): Edit tprel tls sequences.
	* elf32-ppc.c (ppc_elf_relocate_section): Likewise.
	(_bfd_elf_ppc_at_tprel_transform): New function.
	* bfd-in.h (_bfd_elf_ppc_at_tprel_transform): Declare.
	* bfd-in2.h: Regenerate.

5 files changed, 116 insertions, 11 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 714f03fe7d..c9c2d3acad 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,16 @@
+2010-01-25  Alan Modra  <amodra@gmail.com>
+
+	PR ld/11217
+	* elf64-ppc.c (ppc64_elf_tls_optimize): Optimize tls sequences
+	with relocations against undefined weak symbols.
+	(ppc64_elf_relocate_section): Don't optimize calls to undefined
+	weak functions if the symbol is dynamic.
+	(ppc64_elf_relocate_section): Edit tprel tls sequences.
+	* elf32-ppc.c (ppc_elf_relocate_section): Likewise.
+	(_bfd_elf_ppc_at_tprel_transform): New function.
+	* bfd-in.h (_bfd_elf_ppc_at_tprel_transform): Declare.
+	* bfd-in2.h: Regenerate.
+
 2010-01-23  Richard Sandiford  <r.sandiford@uk.ibm.com>
 
 	* coff-rs6000.c (xcoff_howto_table): Change size to 0 and bitsize to 1.
diff --git a/bfd/bfd-in.h b/bfd/bfd-in.h
index 82bf043354..c775a0b5ee 100644
--- a/bfd/bfd-in.h
+++ b/bfd/bfd-in.h
@@ -1,7 +1,7 @@
 /* Main header file for the bfd library -- portable access to object files.
 
    Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
    Free Software Foundation, Inc.
 
    Contributed by Cygnus Support.
@@ -911,6 +911,9 @@ extern bfd_boolean elf32_arm_fix_exidx_coverage
 /* PowerPC @tls opcode transform/validate.  */
 extern unsigned int _bfd_elf_ppc_at_tls_transform
   (unsigned int, unsigned int);
+/* PowerPC @tprel opcode transform/validate.  */
+extern unsigned int _bfd_elf_ppc_at_tprel_transform
+  (unsigned int, unsigned int);
 
 /* TI COFF load page support.  */
 extern void bfd_ticoff_set_section_load_page
diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h
index b17f2e196d..df9b6e0431 100644
--- a/bfd/bfd-in2.h
+++ b/bfd/bfd-in2.h
@@ -8,7 +8,7 @@
 /* Main header file for the bfd library -- portable access to object files.
 
    Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
    Free Software Foundation, Inc.
 
    Contributed by Cygnus Support.
@@ -918,6 +918,9 @@ extern bfd_boolean elf32_arm_fix_exidx_coverage
 /* PowerPC @tls opcode transform/validate.  */
 extern unsigned int _bfd_elf_ppc_at_tls_transform
   (unsigned int, unsigned int);
+/* PowerPC @tprel opcode transform/validate.  */
+extern unsigned int _bfd_elf_ppc_at_tprel_transform
+  (unsigned int, unsigned int);
 
 /* TI COFF load page support.  */
 extern void bfd_ticoff_set_section_load_page
diff --git a/bfd/elf32-ppc.c b/bfd/elf32-ppc.c
index 0c372f00a4..fc4347e444 100644
--- a/bfd/elf32-ppc.c
+++ b/bfd/elf32-ppc.c
@@ -1,6 +1,6 @@
 /* PowerPC-specific support for 32-bit ELF
    Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
-   2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+   2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Cygnus Support.
 
    This file is part of BFD, the Binary File Descriptor library.
@@ -6669,6 +6669,51 @@ _bfd_elf_ppc_at_tls_transform (unsigned int insn, unsigned int reg)
   return insn;
 }
 
+/* If INSN is an opcode that may be used with an @tprel operand, return
+   the transformed insn for an undefined weak symbol, ie. with the
+   thread pointer REG operand removed.  Otherwise return 0.  */
+
+unsigned int
+_bfd_elf_ppc_at_tprel_transform (unsigned int insn, unsigned int reg)
+{
+  if ((insn & (0x1f << 16)) == reg << 16
+      && ((insn & (0x3f << 26)) == 14u << 26 /* addi */
+	  || (insn & (0x3f << 26)) == 15u << 26 /* addis */
+	  || (insn & (0x3f << 26)) == 32u << 26 /* lwz */
+	  || (insn & (0x3f << 26)) == 34u << 26 /* lbz */
+	  || (insn & (0x3f << 26)) == 36u << 26 /* stw */
+	  || (insn & (0x3f << 26)) == 38u << 26 /* stb */
+	  || (insn & (0x3f << 26)) == 40u << 26 /* lhz */
+	  || (insn & (0x3f << 26)) == 42u << 26 /* lha */
+	  || (insn & (0x3f << 26)) == 44u << 26 /* sth */
+	  || (insn & (0x3f << 26)) == 46u << 26 /* lmw */
+	  || (insn & (0x3f << 26)) == 47u << 26 /* stmw */
+	  || (insn & (0x3f << 26)) == 48u << 26 /* lfs */
+	  || (insn & (0x3f << 26)) == 50u << 26 /* lfd */
+	  || (insn & (0x3f << 26)) == 52u << 26 /* stfs */
+	  || (insn & (0x3f << 26)) == 54u << 26 /* stfd */
+	  || ((insn & (0x3f << 26)) == 58u << 26 /* lwa,ld,lmd */
+	      && (insn & 3) != 1)
+	  || ((insn & (0x3f << 26)) == 62u << 26 /* std, stmd */
+	      && ((insn & 3) == 0 || (insn & 3) == 3))))
+    {
+      insn &= ~(0x1f << 16);
+    }
+  else if ((insn & (0x1f << 21)) == reg << 21
+	   && ((insn & (0x3e << 26)) == 24u << 26 /* ori, oris */
+	       || (insn & (0x3e << 26)) == 26u << 26 /* xori,xoris */
+	       || (insn & (0x3e << 26)) == 28u << 26 /* andi,andis */))
+    {
+      insn &= ~(0x1f << 21);
+      insn |= (insn & (0x1f << 16)) << 5;
+      if ((insn & (0x3e << 26)) == 26 << 26 /* xori,xoris */)
+	insn -= 2 >> 26;  /* convert to ori,oris */
+    }
+  else
+    insn = 0;
+  return insn;
+}
+
 /* The RELOCATE_SECTION function is called by the ELF backend linker
    to handle the relocations for a section.
 
@@ -7471,6 +7516,21 @@ ppc_elf_relocate_section (bfd *output_bfd,
 	case R_PPC_TPREL16_LO:
 	case R_PPC_TPREL16_HI:
 	case R_PPC_TPREL16_HA:
+	  if (h != NULL
+	      && h->root.type == bfd_link_hash_undefweak
+	      && h->dynindx == -1)
+	    {
+	      /* Make this relocation against an undefined weak symbol
+		 resolve to zero.  This is really just a tweak, since
+		 code using weak externs ought to check that they are
+		 defined before using them.  */
+	      bfd_byte *p = contents + rel->r_offset - d_offset;
+	      unsigned int insn = bfd_get_32 (output_bfd, p);
+	      insn = _bfd_elf_ppc_at_tprel_transform (insn, 2);
+	      if (insn != 0)
+		bfd_put_32 (output_bfd, insn, p);
+	      break;
+	    }
 	  addend -= htab->elf.tls_sec->vma + TP_OFFSET;
 	  /* The TPREL16 relocs shouldn't really be used in shared
 	     libs as they will result in DT_TEXTREL being set, but
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 6648ddca51..4a468812a5 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -7409,10 +7409,13 @@ ppc64_elf_tls_optimize (bfd *obfd ATTRIBUTE_UNUSED, struct bfd_link_info *info)
 
 		  if (h != NULL)
 		    {
-		      if (h->root.type != bfd_link_hash_defined
-			  && h->root.type != bfd_link_hash_defweak)
+		      if (h->root.type == bfd_link_hash_defined
+			  || h->root.type == bfd_link_hash_defweak)
+			value = h->root.u.def.value;
+		      else if (h->root.type == bfd_link_hash_undefweak)
+			value = 0;
+		      else
 			continue;
-		      value = h->root.u.def.value;
 		    }
 		  else
 		    /* Symbols referenced by TLS relocs must be of type
@@ -7425,11 +7428,17 @@ ppc64_elf_tls_optimize (bfd *obfd ATTRIBUTE_UNUSED, struct bfd_link_info *info)
 		      || !h->def_dynamic)
 		    {
 		      is_local = TRUE;
-		      value += sym_sec->output_offset;
-		      value += sym_sec->output_section->vma;
-		      value -= htab->elf.tls_sec->vma;
-		      ok_tprel = (value + TP_OFFSET + ((bfd_vma) 1 << 31)
-				  < (bfd_vma) 1 << 32);
+		      if (h != NULL
+			  && h->root.type == bfd_link_hash_undefweak)
+			ok_tprel = TRUE;
+		      else
+			{
+			  value += sym_sec->output_offset;
+			  value += sym_sec->output_section->vma;
+			  value -= htab->elf.tls_sec->vma;
+			  ok_tprel = (value + TP_OFFSET + ((bfd_vma) 1 << 31)
+				      < (bfd_vma) 1 << 32);
+			}
 		    }
 
 		  r_type = ELF64_R_TYPE (rel->r_info);
@@ -11498,6 +11507,7 @@ ppc64_elf_relocate_section (bfd *output_bfd,
 	     checking whether the function is defined.  */
 	  else if (h != NULL
 		   && h->elf.root.type == bfd_link_hash_undefweak
+		   && h->elf.dynindx == -1
 		   && r_type == R_PPC64_REL24
 		   && relocation == 0
 		   && addend == 0)
@@ -11833,6 +11843,22 @@ ppc64_elf_relocate_section (bfd *output_bfd,
 	case R_PPC64_TPREL16_HIGHERA:
 	case R_PPC64_TPREL16_HIGHEST:
 	case R_PPC64_TPREL16_HIGHESTA:
+	  if (h != NULL
+	      && h->elf.root.type == bfd_link_hash_undefweak
+	      && h->elf.dynindx == -1)
+	    {
+	      /* Make this relocation against an undefined weak symbol
+		 resolve to zero.  This is really just a tweak, since
+		 code using weak externs ought to check that they are
+		 defined before using them.  */
+	      bfd_byte *p = contents + rel->r_offset - d_offset;
+
+	      insn = bfd_get_32 (output_bfd, p);
+	      insn = _bfd_elf_ppc_at_tprel_transform (insn, 13);
+	      if (insn != 0)
+		bfd_put_32 (output_bfd, insn, p);
+	      break;
+	    }
 	  addend -= htab->elf.tls_sec->vma + TP_OFFSET;
 	  if (info->shared)
 	    /* The TPREL16 relocs shouldn't really be used in shared