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.

16 files changed, 170 insertions, 30 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 6f9011a..a734dfe 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,18 @@
 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
 	symbols as XMC_XO.
 
diff --git a/bfd/xcofflink.c b/bfd/xcofflink.c
index 39d278e..cbc750c 100644
--- a/bfd/xcofflink.c
+++ b/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
-		  && (h->flags & XCOFF_MARK) == 0)
+	      if (h != NULL)
 		{
-		  if (! xcoff_mark_symbol (info, h))
-		    return FALSE;
+		  if ((h->flags & XCOFF_MARK) == 0)
+		    {
+		      if (!xcoff_mark_symbol (info, h))
+			return FALSE;
+		    }
 		}
-
-	      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)
+	      else
 		{
-		  if (! xcoff_mark (info, rsec))
-		    return FALSE;
+		  asection *rsec;
+
+		  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.  */
-  smtyp = SMTYP_SMTYP (aux->x_csect.x_smtyp);
-  if (isym->n_sclass == C_EXT
-      && smtyp == XTY_ER
-      && h->root.type != bfd_link_hash_undefined)
-    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;
+  /* Discard symbols that are defined elsewhere.  */
+  if (isym->n_sclass == C_EXT)
+    {
+      if ((h->flags & XCOFF_ALLOCATED) != 0)
+	return 0;
+      if (!xcoff_final_definition_p (input_bfd, h, 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
-	      || (*sym_hash)->root.type == bfd_link_hash_undefined))
+	  && xcoff_final_definition_p (input_bfd, *sym_hash, *csectpp))
 	{
 	  struct xcoff_link_hash_entry *h;
 	  struct internal_ldsym *ldsym;
diff --git a/include/coff/ChangeLog b/include/coff/ChangeLog
index 91118a1..d96ae1c 100644
--- a/include/coff/ChangeLog
+++ b/include/coff/ChangeLog
@@ -1,5 +1,9 @@
 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.
 	(XCOFF_WAS_UNDEFINED): New flag.
 	(xcoff_link_hash_table): Add an "rtld" field.
diff --git a/include/coff/xcoff.h b/include/coff/xcoff.h
index 7e32d7a..3c3c8e9 100644
--- a/include/coff/xcoff.h
+++ b/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.  */
 
diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog
index 0edc58b..81a6599 100644
--- a/ld/testsuite/ChangeLog
+++ b/ld/testsuite/ChangeLog
@@ -1,5 +1,17 @@
 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-powerpc/aix-abs-reloc-1.nd: New tests.
 	* ld-powerpc/aix52.exp: Run them.
diff --git a/ld/testsuite/ld-powerpc/aix-no-dup-syms-1-dso.dnd b/ld/testsuite/ld-powerpc/aix-no-dup-syms-1-dso.dnd
new file mode 100644
index 0000000..1fccdeb
--- /dev/null
+++ b/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
diff --git a/ld/testsuite/ld-powerpc/aix-no-dup-syms-1-dso.drd b/ld/testsuite/ld-powerpc/aix-no-dup-syms-1-dso.drd
new file mode 100644
index 0000000..f262feb
--- /dev/null
+++ b/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
diff --git a/ld/testsuite/ld-powerpc/aix-no-dup-syms-1-dso.nd b/ld/testsuite/ld-powerpc/aix-no-dup-syms-1-dso.nd
new file mode 100644
index 0000000..be25ff3
--- /dev/null
+++ b/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
diff --git a/ld/testsuite/ld-powerpc/aix-no-dup-syms-1-dso.rd b/ld/testsuite/ld-powerpc/aix-no-dup-syms-1-dso.rd
new file mode 100644
index 0000000..d17151b
--- /dev/null
+++ b/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
diff --git a/ld/testsuite/ld-powerpc/aix-no-dup-syms-1-rel.nd b/ld/testsuite/ld-powerpc/aix-no-dup-syms-1-rel.nd
new file mode 100644
index 0000000..e2bdbc4
--- /dev/null
+++ b/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
diff --git a/ld/testsuite/ld-powerpc/aix-no-dup-syms-1-rel.rd b/ld/testsuite/ld-powerpc/aix-no-dup-syms-1-rel.rd
new file mode 100644
index 0000000..436ad98
--- /dev/null
+++ b/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
diff --git a/ld/testsuite/ld-powerpc/aix-no-dup-syms-1.ex b/ld/testsuite/ld-powerpc/aix-no-dup-syms-1.ex
new file mode 100644
index 0000000..8f1fe4d
--- /dev/null
+++ b/ld/testsuite/ld-powerpc/aix-no-dup-syms-1.ex
@@ -0,0 +1,3 @@
+x
+x1
+x2
diff --git a/ld/testsuite/ld-powerpc/aix-no-dup-syms-1.im b/ld/testsuite/ld-powerpc/aix-no-dup-syms-1.im
new file mode 100644
index 0000000..257cc56
--- /dev/null
+++ b/ld/testsuite/ld-powerpc/aix-no-dup-syms-1.im
@@ -0,0 +1 @@
+foo
diff --git a/ld/testsuite/ld-powerpc/aix-no-dup-syms-1a.s b/ld/testsuite/ld-powerpc/aix-no-dup-syms-1a.s
new file mode 100644
index 0000000..3138670
--- /dev/null
+++ b/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
diff --git a/ld/testsuite/ld-powerpc/aix-no-dup-syms-1b.s b/ld/testsuite/ld-powerpc/aix-no-dup-syms-1b.s
new file mode 100644
index 0000000..c5fcf38
--- /dev/null
+++ b/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
diff --git a/ld/testsuite/ld-powerpc/aix52.exp b/ld/testsuite/ld-powerpc/aix52.exp
index 10e2031..6cd26fe 100644
--- a/ld/testsuite/ld-powerpc/aix52.exp
+++ b/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}