PowerPC64 dot-symbol compatibility bugfixes

Lots of fixes for the compatibility code that handles linking of
-mcall-aixdesc code (or that generated by 12 year old gcc) with
current ELFv1 ABI code.

1) A reference to a dot-symbol in an object file wasn't satisfied by a
   function descriptor in later object files.
2) The as-needed code had bit-rotted;  Shared libs now need a strong
   reference to be counted as needed.
3) --gc-sections involving dot-symbols was broken, needing
   func_desc_adjust to be run early and lots of other fixes.

bfd/
	* elf64-ppc.c (struct ppc_link_hash_entry): Delete "was_undefined".
	(struct ppc_link_hash_table): Delete "twiddled_syms".  Add
	"need_func_desc_adj".
	(lookup_fdh): Link direct fdh sym via oh field and set flags.
	(make_fdh): Make strong and weak undefined function descriptor
	symbols.
	(ppc64_elf_merge_symbol): New function.
	(elf_backend_merge_symbol): Define.
	(ppc64_elf_archive_symbol_lookup): Don't test undefweak for fake
	function descriptors.
	(add_symbol_adjust): Don't twiddle symbols to undefweak.
	Propagate more ref flags to function descriptor symbol.  Make
	some function descriptor symbols dynamic.
	(ppc64_elf_before_check_relocs): Only run add_symbol_adjust for
	ELFv1.  Set need_func_desc_adj.  Don't fix undefs list.
	(ppc64_elf_check_relocs): Set non_ir_ref for descriptors.
	Don't call lookup_fdh here.
	(ppc64_elf_gc_sections): New function.
	(bfd_elf64_bfd_gc_sections): Define.
	(ppc64_elf_gc_mark_hook): Mark descriptor.
	(func_desc_adjust): Don't make fake function descriptor syms strong
	here.  Exit earlier on non-dotsyms.  Take note of elf.dynamic
	flag when deciding whether a dynamic function descriptor might
	be needed.  Transfer elf.dynamic and set elf.needs_plt.  Move
	plt regardless of visibility.  Make descriptor dynamic if
	entry sym is dynamic, not for other cases.
	(ppc64_elf_func_desc_adjust): Don't run func_desc_adjust if
	already done.
	(ppc64_elf_edit_opd): Use oh field rather than lookup_fdh.
	(ppc64_elf_size_stubs): Likewise.
	(ppc_build_one_stub): Don't clear was_undefined.  Only set sym
	undefweak if stub symbol is defined.
	(undo_symbol_twiddle, ppc64_elf_restore_symbols): Delete.
	* elf64-ppc.h (ppc64_elf_restore_symbols): Don't declare.
ld/
	* emultempl/ppc64elf.em (gld${EMULATION_NAME}_finish): Don't call
	ppc64_elf_restore_symbols.
	* testsuite/ld-powerpc/dotsym1.d: New.
	* testsuite/ld-powerpc/dotsym2.d: New.
	* testsuite/ld-powerpc/dotsym3.d: New.
	* testsuite/ld-powerpc/dotsym4.d: New.
	* testsuite/ld-powerpc/dotsymref.s: New.
	* testsuite/ld-powerpc/nodotsym.s: New.
	* testsuite/ld-powerpc/powerpc.exp: Run new tests.

7 files changed, 83 insertions, 0 deletions

diff --git a/ld/testsuite/ld-powerpc/dotsym1.d b/ld/testsuite/ld-powerpc/dotsym1.d
new file mode 100644
index 0000000..1cb9338
--- /dev/null
+++ b/ld/testsuite/ld-powerpc/dotsym1.d
@@ -0,0 +1,15 @@
+#source: nodotsym.s
+#source: dotsymref.s
+#as: -a64
+#ld: -melf64ppc -Ttext=0x10000000 -e foo
+#objdump: -d
+
+.*:     file format .*
+
+Disassembly of section \.text:
+
+0+10000000 <\.foo>:
+.*:	(4e 80 00 20|20 00 80 4e) 	blr
+.*:	(60 00 00 00|00 00 00 60) 	nop
+.*:	(00 00 00 00|00 00 00 10) 	.*
+.*:	(10 00 00 00|00 00 00 00) 	.*
diff --git a/ld/testsuite/ld-powerpc/dotsym2.d b/ld/testsuite/ld-powerpc/dotsym2.d
new file mode 100644
index 0000000..7704db7
--- /dev/null
+++ b/ld/testsuite/ld-powerpc/dotsym2.d
@@ -0,0 +1,16 @@
+#source: dotsymref.s
+#source: nodotsym.s
+#as: -a64
+#ld: -melf64ppc -Ttext=0x10000000 -e foo
+#objdump: -d
+
+.*:     file format .*
+
+Disassembly of section \.text:
+
+0+10000000 <\.foo-0x8>:
+.*:	(00 00 00 00|08 00 00 10) 	.*
+.*:	(10 00 00 08|00 00 00 00) 	.*
+
+0+10000008 <\.foo>:
+.*:	(4e 80 00 20|20 00 80 4e) 	blr
diff --git a/ld/testsuite/ld-powerpc/dotsym3.d b/ld/testsuite/ld-powerpc/dotsym3.d
new file mode 100644
index 0000000..fac2f8e
--- /dev/null
+++ b/ld/testsuite/ld-powerpc/dotsym3.d
@@ -0,0 +1,16 @@
+#source: nodotsym.s
+#source: dotsymref.s
+#as: -a64
+#ld: -melf64ppc -Ttext=0x1000 -shared
+#objdump: -dR
+
+.*:     file format .*
+
+Disassembly of section \.text:
+
+0+1000 <\.foo>:
+.*:	(4e 80 00 20|20 00 80 4e) 	blr
+.*:	(60 00 00 00|00 00 00 60) 	nop
+.*:	(00 00 00 00|00 10 00 00) 	.*
+.*: R_PPC64_RELATIVE	\*ABS\*\+0x1000
+.*:	(00 00 10 00|00 00 00 00) 	.*
diff --git a/ld/testsuite/ld-powerpc/dotsym4.d b/ld/testsuite/ld-powerpc/dotsym4.d
new file mode 100644
index 0000000..fdd92f3
--- /dev/null
+++ b/ld/testsuite/ld-powerpc/dotsym4.d
@@ -0,0 +1,17 @@
+#source: dotsymref.s
+#source: nodotsym.s
+#as: -a64
+#ld: -melf64ppc -Ttext=0x1000 -shared
+#objdump: -dR
+
+.*:     file format .*
+
+Disassembly of section \.text:
+
+0+1000 <\.foo-0x8>:
+.*:	(00 00 00 00|08 10 00 00) 	.*
+.*: R_PPC64_RELATIVE	\*ABS\*\+0x1008
+.*:	(00 00 10 08|00 00 00 00) 	.*
+
+0+1008 <\.foo>:
+.*:	(4e 80 00 20|20 00 80 4e) 	blr
diff --git a/ld/testsuite/ld-powerpc/dotsymref.s b/ld/testsuite/ld-powerpc/dotsymref.s
new file mode 100644
index 0000000..54c6f5c
--- /dev/null
+++ b/ld/testsuite/ld-powerpc/dotsymref.s
@@ -0,0 +1,4 @@
+ .abiversion 1
+ .text
+ .p2align 3
+ .quad .foo
diff --git a/ld/testsuite/ld-powerpc/nodotsym.s b/ld/testsuite/ld-powerpc/nodotsym.s
new file mode 100644
index 0000000..dbc44ec
--- /dev/null
+++ b/ld/testsuite/ld-powerpc/nodotsym.s
@@ -0,0 +1,11 @@
+ .section .opd,"aw"
+ .p2align 3
+ .global foo
+ .type foo,@function
+foo:
+ .quad .L.foo,.TOC.@tocbase,0
+
+ .text
+.L.foo:
+ blr
+ .size foo,.-.L.foo
diff --git a/ld/testsuite/ld-powerpc/powerpc.exp b/ld/testsuite/ld-powerpc/powerpc.exp
index 07226c6..18a8e62 100644
--- a/ld/testsuite/ld-powerpc/powerpc.exp
+++ b/ld/testsuite/ld-powerpc/powerpc.exp
@@ -299,6 +299,10 @@ if [ supports_ppc64 ] then {
     run_dump_test "tlsld"
     run_dump_test "relocsort"
     run_dump_test "addpcis"
+    run_dump_test "dotsym1"
+    run_dump_test "dotsym2"
+    run_dump_test "dotsym3"
+    run_dump_test "dotsym4"
 }
 
 run_dump_test "tlsld32"