include/coff/

* xcoff.h (XCOFF_ALLOCATED): New flag.

bfd/
	* xcofflink.c (xcoff_mark): When walking the relocations,
	only mark the target symbol or the target section, not both.
	(xcoff_final_definition_p): New function.
	(xcoff_keep_symbol_p): Use it to check whether an external XCOFF
	symbol is a valid definition of the associated output symbol.
	Use XCOFF_ALLOCATED to stop the same hash table entry having
	two output symbols.
	(bfd_xcoff_size_dynamic_sections): Set XCOFF_ALLOCATED when
	keeping a symbol.
	(xcoff_link_input_bfd): Use xcoff_final_definition_p.

ld/testsuite/
	* ld-powerpc/aix-no-dup-syms-1a.s, ld-powerpc/aix-no-dup-syms-1b.s,
	ld-powerpc/aix-no-dup-syms-1.ex, ld-powerpc/aix-no-dup-syms-1.im,
	ld-powerpc/aix-no-dup-syms-1-dso.dnd,
	ld-powerpc/aix-no-dup-syms-1-dso.drd,
	ld-powerpc/aix-no-dup-syms-1-dso.nd,
	ld-powerpc/aix-no-dup-syms-1-dso.rd,
	ld-powerpc/aix-no-dup-syms-1-rel.nd,
	ld-powerpc/aix-no-dup-syms-1-rel.rd: New tests.
	* ld-powerpc/aix52.exp: Run them.

bfd/ChangeLog

@@ -1,3 +1,16 @@
+2009-03-14  Richard Sandiford  <r.sandiford@uk.ibm.com>
+
+	* xcofflink.c (xcoff_mark): When walking the relocations,
+	only mark the target symbol or the target section, not both.
+	(xcoff_final_definition_p): New function.
+	(xcoff_keep_symbol_p): Use it to check whether an external XCOFF
+	symbol is a valid definition of the associated output symbol.
+	Use XCOFF_ALLOCATED to stop the same hash table entry having
+	two output symbols.
+	(bfd_xcoff_size_dynamic_sections): Set XCOFF_ALLOCATED when
+	keeping a symbol.
+	(xcoff_link_input_bfd): Use xcoff_final_definition_p.
+
 2009-03-14  Richard Sandiford  <r.sandiford@uk.ibm.com>
 
 	* xcofflink.c (bfd_xcoff_import_symbol): Treat imported absolute

bfd/xcofflink.c

@@ -2504,7 +2504,6 @@ xcoff_mark (struct bfd_link_info *info, asection *sec)
 	  relend = rel + sec->reloc_count;
 	  for (; rel < relend; rel++)
 	    {
-	      asection *rsec;
 	      struct xcoff_link_hash_entry *h;
 
 	      if ((unsigned int) rel->r_symndx
@@ -2512,21 +2511,25 @@ xcoff_mark (struct bfd_link_info *info, asection *sec)
 		continue;
 
 	      h = obj_xcoff_sym_hashes (sec->owner)[rel->r_symndx];
-	      if (h != NULL
+	      if (h != NULL)
-		  && (h->flags & XCOFF_MARK) == 0)
 		{
-		  if (! xcoff_mark_symbol (info, h))
+		  if ((h->flags & XCOFF_MARK) == 0)
-		    return FALSE;
+		    {
+		      if (!xcoff_mark_symbol (info, h))
+			return FALSE;
+		    }
 		}
-
+	      else
-	      rsec = xcoff_data (sec->owner)->csects[rel->r_symndx];
-	      if (rsec != NULL
-		  && !bfd_is_und_section (rsec)
-		  && !bfd_is_abs_section (rsec)
-		  && (rsec->flags & SEC_MARK) == 0)
 		{
-		  if (! xcoff_mark (info, rsec))
+		  asection *rsec;
-		    return FALSE;
+
+		  rsec = xcoff_data (sec->owner)->csects[rel->r_symndx];
+		  if (rsec != NULL
+		      && (rsec->flags & SEC_MARK) == 0)
+		    {
+		      if (!xcoff_mark (info, rsec))
+			return FALSE;
+		    }
 		}
 
 	      /* See if this reloc needs to be copied into the .loader
@@ -2826,6 +2829,36 @@ bfd_xcoff_record_link_assignment (bfd *output_bfd,
 
 /* Add a symbol to the .loader symbols, if necessary.  */
 
+/* INPUT_BFD has an external symbol associated with hash table entry H
+   and csect CSECT.   Return true if INPUT_BFD defines H.  */
+
+static bfd_boolean
+xcoff_final_definition_p (bfd *input_bfd, struct xcoff_link_hash_entry *h,
+			  asection *csect)
+{
+  switch (h->root.type)
+    {
+    case bfd_link_hash_defined:
+    case bfd_link_hash_defweak:
+      /* No input bfd owns absolute symbols.  They are written by
+	 xcoff_write_global_symbol instead.  */
+      return (!bfd_is_abs_section (csect)
+	      && h->root.u.def.section == csect);
+
+    case bfd_link_hash_common:
+      return h->root.u.c.p->section->owner == input_bfd;
+
+    case bfd_link_hash_undefined:
+    case bfd_link_hash_undefweak:
+      /* We can't treat undef.abfd as the owner because that bfd
+	 might be a dynamic object.  Allow any bfd to claim it.  */
+      return TRUE;
+
+    default:
+      abort ();
+    }
+}
+
 static bfd_boolean
 xcoff_build_ldsyms (struct xcoff_link_hash_entry *h, void * p)
 {
@@ -3036,23 +3069,17 @@ xcoff_keep_symbol_p (struct bfd_link_info *info, bfd *input_bfd,
   if (info->strip == strip_all)
     return 0;
 
-  /* We can ignore external references that were resolved by the link.  */
+  /* Discard symbols that are defined elsewhere.  */
-  smtyp = SMTYP_SMTYP (aux->x_csect.x_smtyp);
+  if (isym->n_sclass == C_EXT)
-  if (isym->n_sclass == C_EXT
+    {
-      && smtyp == XTY_ER
+      if ((h->flags & XCOFF_ALLOCATED) != 0)
-      && h->root.type != bfd_link_hash_undefined)
+	return 0;
-    return 0;
+      if (!xcoff_final_definition_p (input_bfd, h, csect))
-
+	return 0;
-  /* We can ignore common symbols if they got defined somewhere else.  */
+    }
-  if (isym->n_sclass == C_EXT
-      && smtyp == XTY_CM
-      && (h->root.type != bfd_link_hash_common
-	  || h->root.u.c.p->section != csect)
-      && (h->root.type != bfd_link_hash_defined
-	  || h->root.u.def.section != csect))
-    return 0;
 
   /* If we're discarding local symbols, check whether ISYM is local.  */
+  smtyp = SMTYP_SMTYP (aux->x_csect.x_smtyp);
   if (info->discard == discard_all
       && isym->n_sclass != C_EXT
       && (isym->n_sclass != C_HIDEXT || smtyp != XTY_SD))
@@ -3513,6 +3540,8 @@ bfd_xcoff_size_dynamic_sections (bfd *output_bfd,
 		}
 	      else
 		*debug_index = -1;
+	      if (*sym_hash != 0)
+		(*sym_hash)->flags |= XCOFF_ALLOCATED;
 	      if (*lineno_counts > 0)
 		csect->output_section->lineno_count += *lineno_counts;
 	    }
@@ -3690,8 +3719,7 @@ xcoff_link_input_bfd (struct xcoff_final_link_info *finfo,
       if (isymp->n_sclass == C_EXT
 	  && *sym_hash != NULL
 	  && (*sym_hash)->ldsym != NULL
-	  && (smtyp != XTY_ER
+	  && xcoff_final_definition_p (input_bfd, *sym_hash, *csectpp))
-	      || (*sym_hash)->root.type == bfd_link_hash_undefined))
 	{
 	  struct xcoff_link_hash_entry *h;
 	  struct internal_ldsym *ldsym;

include/coff/ChangeLog

@@ -1,3 +1,7 @@
+2009-03-14  Richard Sandiford  <r.sandiford@uk.ibm.com>
+
+	* xcoff.h (XCOFF_ALLOCATED): New flag.
+
 2009-03-14  Richard Sandiford  <r.sandiford@uk.ibm.com>
 
 	* xcoff.h (XCOFF_CALLED, XCOFF_IMPORT): Update comments.

include/coff/xcoff.h

@@ -318,6 +318,8 @@ struct xcoff_link_hash_entry
 #define XCOFF_SYSCALL64        0x00010000 
 /* Symbol was not explicitly defined by the time it was marked.  */
 #define XCOFF_WAS_UNDEFINED    0x00020000
+/* We have assigned an output XCOFF entry to this symbol.  */
+#define XCOFF_ALLOCATED	       0x00040000
 
 /* The XCOFF linker hash table.  */
 

ld/testsuite/ChangeLog

@@ -1,3 +1,15 @@
+2009-03-14  Richard Sandiford  <r.sandiford@uk.ibm.com>
+
+	* ld-powerpc/aix-no-dup-syms-1a.s, ld-powerpc/aix-no-dup-syms-1b.s,
+	ld-powerpc/aix-no-dup-syms-1.ex, ld-powerpc/aix-no-dup-syms-1.im,
+	ld-powerpc/aix-no-dup-syms-1-dso.dnd,
+	ld-powerpc/aix-no-dup-syms-1-dso.drd,
+	ld-powerpc/aix-no-dup-syms-1-dso.nd,
+	ld-powerpc/aix-no-dup-syms-1-dso.rd,
+	ld-powerpc/aix-no-dup-syms-1-rel.nd,
+	ld-powerpc/aix-no-dup-syms-1-rel.rd: New tests.
+	* ld-powerpc/aix52.exp: Run them.
+
 2009-03-14  Richard Sandiford  <r.sandiford@uk.ibm.com>
 
 	* ld-powerpc/aix-abs-branch-1.nd,

ld/testsuite/ld-powerpc/aix-no-dup-syms-1-dso.dnd

@@ -0,0 +1,4 @@
+ *         U foo
+0*10000000 D x
+0*10000004 D x1
+0*10000014 D x2

ld/testsuite/ld-powerpc/aix-no-dup-syms-1-dso.drd

@@ -0,0 +1,9 @@
+
+.*
+
+DYNAMIC RELOCATION RECORDS
+OFFSET * TYPE * VALUE 
+0*10000004 R_POS(|_32) * \.data
+0*10000008 R_POS(|_32) * foo
+0*10000014 R_POS(|_32) * \.data
+0*10000018 R_POS(|_32) * foo

ld/testsuite/ld-powerpc/aix-no-dup-syms-1-dso.nd

@@ -0,0 +1,8 @@
+ *         U foo
+0*10000000 d x
+0*10000000 D x
+0*10000010 d x
+0*10000004 d x1
+0*10000004 D x1
+0*10000014 d x2
+0*10000014 D x2

ld/testsuite/ld-powerpc/aix-no-dup-syms-1-dso.rd

@@ -0,0 +1,9 @@
+
+.*
+
+RELOCATION RECORDS FOR \[\.data\]:
+OFFSET * TYPE * VALUE 
+0+04 R_POS(|_32) * x\+0xf*f0000000
+0+08 R_POS(|_32) * foo
+0+14 R_POS(|_32) * x\+0xf*effffff0
+0+18 R_POS(|_32) * foo

ld/testsuite/ld-powerpc/aix-no-dup-syms-1-rel.nd

@@ -0,0 +1,8 @@
+ +   U foo
+0+00 d x
+0+00 D x
+0+10 d x
+0+04 d x1
+0+04 D x1
+0+14 d x2
+0+14 D x2

ld/testsuite/ld-powerpc/aix-no-dup-syms-1-rel.rd

@@ -0,0 +1,9 @@
+
+.*
+
+RELOCATION RECORDS FOR \[\.data\]:
+OFFSET * TYPE * VALUE 
+0+04 R_POS(|_32) * x
+0+08 R_POS(|_32) * foo
+0+14 R_POS(|_32) * x\+0xf+0
+0+18 R_POS(|_32) * foo

ld/testsuite/ld-powerpc/aix-no-dup-syms-1.ex

@@ -0,0 +1,3 @@
+x
+x1
+x2

ld/testsuite/ld-powerpc/aix-no-dup-syms-1.im

@@ -0,0 +1 @@
+foo

ld/testsuite/ld-powerpc/aix-no-dup-syms-1a.s

@@ -0,0 +1,9 @@
+	.globl	x
+	.csect	x[RW]
+x:
+	.long	4
+	.globl	x1
+	.csect	x1[RW]
+x1:
+	.long	x
+	.long	foo

ld/testsuite/ld-powerpc/aix-no-dup-syms-1b.s

@@ -0,0 +1,9 @@
+	.globl	x
+	.csect	x[RW]
+x:
+	.long	8
+	.globl	x2
+	.csect	x2[RW]
+x2:
+	.long	x
+	.long	foo

ld/testsuite/ld-powerpc/aix52.exp

@@ -96,6 +96,18 @@ set aix52tests {
      {{objdump -h aix-core-sec-3.hd}}
      "aix-core-sec-3.so"}
 
+    {"Duplicate symbol check 1 (rel)" "-r"
+     "" {aix-no-dup-syms-1a.s aix-no-dup-syms-1b.s}
+     {{nm {} aix-no-dup-syms-1-rel.nd} {objdump -r aix-no-dup-syms-1-rel.rd}}
+     "aix-no-dup-syms-1.o"}
+
+    {"Duplicate symbol check 1 (shared)"
+     "-shared --allow-multiple-definition -bI:aix-no-dup-syms-1.im -bE:aix-no-dup-syms-1.ex"
+     "" {aix-no-dup-syms-1a.s aix-no-dup-syms-1b.s}
+     {{nm {} aix-no-dup-syms-1-dso.nd} {objdump -r aix-no-dup-syms-1-dso.rd}
+      {nm -D aix-no-dup-syms-1-dso.dnd} {objdump -R aix-no-dup-syms-1-dso.drd}}
+     "aix-no-dup-syms-1.so"}
+
     {"Glink test 1"
      "-shared -bE:aix-glink-1.ex --unresolved-symbols=ignore-all"
      "" {aix-glink-1.s}