[PATCH] objcopy --weaken-symbol: apply to STB_GNU_UNIQUE symbols

[Fangrui Song]

On 2022-03-01, Fangrui Song via Binutils wrote:
>    PR binutils/28926
>    * objcopy.c (filter_symbols): Apply weaken to STB_GNU_UNIQUE symbols
>    * NEWS: Mention feature.
>    * testsuite/binutils-all/objcopy.exp (objcopy_test_symbol_manipulation): New test.
>    * testsuite/binutils-all/weaken-gnu-unique.s: New.

typo: weaken-gnu-unique.s -> weaken-gnu-unique.d

>---
> binutils/NEWS                                       | 3 +++
> binutils/objcopy.c                                  | 4 ++--
> binutils/testsuite/binutils-all/objcopy.exp         | 4 ++++
> binutils/testsuite/binutils-all/weaken-gnu-unique.d | 8 ++++++++
> 4 files changed, 17 insertions(+), 2 deletions(-)
> create mode 100644 binutils/testsuite/binutils-all/weaken-gnu-unique.d
>
>diff --git a/binutils/NEWS b/binutils/NEWS
>index c188b469a77..06f34c9a992 100644
>--- a/binutils/NEWS
>+++ b/binutils/NEWS
>@@ -1,5 +1,8 @@
> -*- text -*-
>
>+* objcopy --weaken, --weaken-symbol, and --weaken-symbols now make ELF
>+  STB_GNU_UNIQUE symbols weak.
>+
> Changes in 2.38:
>
> * elfedit: Add --output-abiversion option to update ABIVERSION.
>diff --git a/binutils/objcopy.c b/binutils/objcopy.c
>index d53aa5c6000..aaa5aa9b2af 100644
>--- a/binutils/objcopy.c
>+++ b/binutils/objcopy.c
>@@ -1681,11 +1681,11 @@ filter_symbols (bfd *abfd, bfd *obfd, asymbol **osyms,
>
>       if (keep)
> 	{
>-	  if (((flags & BSF_GLOBAL) != 0
>+	  if (((flags & (BSF_GLOBAL | BSF_GNU_UNIQUE))
> 	       || undefined)
> 	      && (weaken || is_specified_symbol (name, weaken_specific_htab)))
> 	    {
>-	      sym->flags &= ~ BSF_GLOBAL;
>+	      sym->flags &= ~ (BSF_GLOBAL | BSF_GNU_UNIQUE);
> 	      sym->flags |= BSF_WEAK;
> 	    }
>
>diff --git a/binutils/testsuite/binutils-all/objcopy.exp b/binutils/testsuite/binutils-all/objcopy.exp
>index 32c76a11f3b..9a5dad5384e 100644
>--- a/binutils/testsuite/binutils-all/objcopy.exp
>+++ b/binutils/testsuite/binutils-all/objcopy.exp
>@@ -1144,6 +1144,10 @@ proc objcopy_test_symbol_manipulation {} {
>         verbose [file rootname $t]
>         run_dump_test [file rootname $t]
>     }
>+
>+    if { [supports_gnu_unique] } {
>+	run_dump_test "weaken-gnu-unique"
>+    }
> }
>
> proc objcopy_test_elf_common_symbols {} {
>diff --git a/binutils/testsuite/binutils-all/weaken-gnu-unique.d b/binutils/testsuite/binutils-all/weaken-gnu-unique.d
>new file mode 100644
>index 00000000000..b0e60c4ff80
>--- /dev/null
>+++ b/binutils/testsuite/binutils-all/weaken-gnu-unique.d
>@@ -0,0 +1,8 @@
>+#name: weaken STB_GNU_UNIQUE symbols
>+#PROG: objcopy
>+#objcopy: -W foo
>+#source: unique.s
>+#readelf: -s
>+
>+#...
>+ +[0-9]+: +[0-9a-f]+ +[0-9]+ +OBJECT +WEAK +DEFAULT +[1-9] foo
>-- 
>2.35.1.574.g5d30c73bfb-goog
>