Copy st_other for linker script symbol assignments

[Alan Modra <amodra at gmail dot com>]

This fixes a problem seen on powerpc64le ELFv2 when creating a
function symbol alias with ld --defsym.  st_other needs to be copied
from the source symbol to the alias in order to set up the local entry
offset for the alias.  I decided to make this change in the generic
ELF code rather than in elf64-ppc.c since it looks like other targets
that use st_other bits might benefit too.

Gold has the same problem, but lacks the infrastructure to support
this at the moment.

bfd/
	* elflink.c (_bfd_elf_copy_link_hash_symbol_type): Copy st_other
	bits from source to dest.
	* linker.c (_bfd_generic_copy_link_hash_symbol_type): Update comment.
	* targets.c (struct bfd_target <_bfd_copy_link_hash_symbol_type>):
	Likewise.
	* bfd-in2.h: Regenerate.
ld/testsuite/
	* ld-powerpc/defsym.s, * ld-powerpc/defsym.d: New test.
	* ld-powerpc/powerpc.exp: Run it.

diff --git a/bfd/elflink.c b/bfd/elflink.c
index ee80bcc..46d65f4 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -13044,17 +13044,24 @@ _bfd_elf_make_dynamic_reloc_section (asection *         sec,
   return reloc_sec;
 }
 
-/* Copy the ELF symbol type associated with a linker hash entry.  */
+/* Copy the ELF symbol type and other attributes for a linker script
+   assignment from HSRC to HDEST.  Generally this should be treated as
+   if we found a strong non-dynamic definition for HDEST (except that
+   ld ignores multiple definition errors).  */
 void
-_bfd_elf_copy_link_hash_symbol_type (bfd *abfd ATTRIBUTE_UNUSED,
-    struct bfd_link_hash_entry * hdest,
-    struct bfd_link_hash_entry * hsrc)
+_bfd_elf_copy_link_hash_symbol_type (bfd *abfd,
+				     struct bfd_link_hash_entry *hdest,
+				     struct bfd_link_hash_entry *hsrc)
 {
-  struct elf_link_hash_entry *ehdest = (struct elf_link_hash_entry *)hdest;
-  struct elf_link_hash_entry *ehsrc = (struct elf_link_hash_entry *)hsrc;
+  struct elf_link_hash_entry *ehdest = (struct elf_link_hash_entry *) hdest;
+  struct elf_link_hash_entry *ehsrc = (struct elf_link_hash_entry *) hsrc;
+  Elf_Internal_Sym isym;
 
   ehdest->type = ehsrc->type;
   ehdest->target_internal = ehsrc->target_internal;
+
+  isym.st_other = ehsrc->other;
+  elf_merge_st_other (abfd, ehdest, &isym, TRUE, FALSE);
 }
 
 /* Append a RELA relocation REL to section S in BFD.  */
diff --git a/bfd/linker.c b/bfd/linker.c
index 483a0d4..f6ae4e2 100644
--- a/bfd/linker.c
+++ b/bfd/linker.c
@@ -861,14 +861,13 @@ _bfd_generic_link_just_syms (asection *sec,
   sec->output_offset = sec->vma;
 }
 
-/* Copy the type of a symbol assiciated with a linker hast table entry.
-   Override this so that symbols created in linker scripts get their
-   type from the RHS of the assignment.
+/* Copy the symbol type and other attributes for a linker script
+   assignment from HSRC to HDEST.
    The default implementation does nothing.  */
 void
 _bfd_generic_copy_link_hash_symbol_type (bfd *abfd ATTRIBUTE_UNUSED,
-    struct bfd_link_hash_entry * hdest ATTRIBUTE_UNUSED,
-    struct bfd_link_hash_entry * hsrc ATTRIBUTE_UNUSED)
+    struct bfd_link_hash_entry *hdest ATTRIBUTE_UNUSED,
+    struct bfd_link_hash_entry *hsrc ATTRIBUTE_UNUSED)
 {
 }
 
diff --git a/bfd/targets.c b/bfd/targets.c
index 83131d1..81a3695 100644
--- a/bfd/targets.c
+++ b/bfd/targets.c
@@ -478,7 +478,8 @@ BFD_JUMP_TABLE macros.
 .  {* Indicate that we are only retrieving symbol values from this section.  *}
 .  void        (*_bfd_link_just_syms) (asection *, struct bfd_link_info *);
 .
-.  {* Copy the symbol type of a linker hash table entry.  *}
+.  {* Copy the symbol type and other attributes for a linker script
+.     assignment of one symbol to another.  *}
 .#define bfd_copy_link_hash_symbol_type(b, t, f) \
 .  BFD_SEND (b, _bfd_copy_link_hash_symbol_type, (b, t, f))
 .  void (*_bfd_copy_link_hash_symbol_type)
diff --git a/ld/testsuite/ld-powerpc/defsym.d b/ld/testsuite/ld-powerpc/defsym.d
new file mode 100644
index 0000000..1e5b567
--- /dev/null
+++ b/ld/testsuite/ld-powerpc/defsym.d
@@ -0,0 +1,26 @@
+#source: defsym.s
+#as: -a64
+#ld: -melf64ppc --defsym bar=foo
+#objdump: -Dr
+
+.*:     file format elf64-powerpc.*
+
+Disassembly of section \.text:
+
+0+100000b0 <_start>:
+    100000b0:	(15 00 00 48|48 00 00 15) 	bl      100000c4 <(foo|bar)\+0x8>
+    100000b4:	(11 00 00 48|48 00 00 11) 	bl      100000c4 <(foo|bar)\+0x8>
+    100000b8:	(00 00 00 60|60 00 00 00) 	nop
+
+0+100000bc <(foo|bar)>:
+    100000bc:	(02 10 40 3c|3c 40 10 02) 	lis     r2,4098
+    100000c0:	(c8 80 42 38|38 42 80 c8) 	addi    r2,r2,-32568
+    100000c4:	(20 00 80 4e|4e 80 00 20) 	blr
+
+Disassembly of section \.data:
+
+0+100100c8 .*:
+    100100c8:	(bc 00 00 10|00 00 00 00) 	.*
+    100100cc:	(00 00 00 00|10 00 00 bc) 	.*
+    100100d0:	(bc 00 00 10|00 00 00 00) 	.*
+    100100d4:	(00 00 00 00|10 00 00 bc) 	.*
diff --git a/ld/testsuite/ld-powerpc/defsym.s b/ld/testsuite/ld-powerpc/defsym.s
new file mode 100644
index 0000000..efca072
--- /dev/null
+++ b/ld/testsuite/ld-powerpc/defsym.s
@@ -0,0 +1,19 @@
+ .text
+ .globl _start
+_start:
+ bl foo
+ bl bar
+ nop
+
+ .globl foo
+ .type foo,@function
+foo:
+ addis 2,12,.TOC.-foo@ha
+ addi 2,2,.TOC.-foo@l
+ .localentry foo,.-foo
+ blr
+ .size foo,.-foo
+
+ .data
+ .dc.a foo
+ .dc.a bar
diff --git a/ld/testsuite/ld-powerpc/powerpc.exp b/ld/testsuite/ld-powerpc/powerpc.exp
index 08a7e2b..23572c6 100644
--- a/ld/testsuite/ld-powerpc/powerpc.exp
+++ b/ld/testsuite/ld-powerpc/powerpc.exp
@@ -278,6 +278,7 @@ if [ supports_ppc64 ] then {
     run_dump_test "ambiguousv1b"
     run_dump_test "ambiguousv2"
     run_dump_test "ambiguousv2b"
+    run_dump_test "defsym"
 }
 
 if { [istarget "powerpc*-eabi*"] } {

-- 
Alan Modra
Australia Development Lab, IBM