PR22836, "-r -s" doesn't work with -g3 using GCC 7

This fixes the case where all of a group is removed with ld -r, the
situation in the PR, and failures where part of a group is removed
that contain relocs.

bfd/
	PR 22836
	* elf.c (_bfd_elf_fixup_group_sections): Account for removed
	relocation sections.  If size reduces to just the flag word,
	remove that too and mark with SEC_EXCLUDE.
	* elflink.c (bfd_elf_final_link): Strip empty group sections.
binutils/
	* testsuite/binutils-all/group-7.s,
	* testsuite/binutils-all/group-7a.d,
	* testsuite/binutils-all/group-7b.d,
	* testsuite/binutils-all/group-7c.d: New tests.
	* testsuite/binutils-all/objcopy.exp: Run them.
ld/
	* testsuite/ld-elf/pr22836-2.d,
	* testsuite/ld-elf/pr22836-2.s: New test.

6 files changed, 61 insertions, 0 deletions

diff --git a/binutils/ChangeLog b/binutils/ChangeLog
index 5fe9d97..19b9507 100644
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@@ -1,3 +1,12 @@
+2018-02-13  Alan Modra  <amodra@gmail.com>
+
+	PR 22836
+	* testsuite/binutils-all/group-7.s,
+	* testsuite/binutils-all/group-7a.d,
+	* testsuite/binutils-all/group-7b.d,
+	* testsuite/binutils-all/group-7c.d: New tests.
+	* testsuite/binutils-all/objcopy.exp: Run them.
+
 2018-02-08  Nick Clifton  <nickc@redhat.com>
 
 	PR 22802
diff --git a/binutils/testsuite/binutils-all/group-7.s b/binutils/testsuite/binutils-all/group-7.s
new file mode 100644
index 0000000..5028afc
--- /dev/null
+++ b/binutils/testsuite/binutils-all/group-7.s
@@ -0,0 +1,6 @@
+	.section        .data.foo,"awG",%progbits,foo,comdat
+here:
+	.dc.a	here
+
+	.section        .data2.foo,"awG",%progbits,foo,comdat
+	.dc.a	0
diff --git a/binutils/testsuite/binutils-all/group-7a.d b/binutils/testsuite/binutils-all/group-7a.d
new file mode 100644
index 0000000..fa8db60
--- /dev/null
+++ b/binutils/testsuite/binutils-all/group-7a.d
@@ -0,0 +1,16 @@
+#name: copy removing reloc group member
+#source: group-7.s
+#PROG: objcopy
+#DUMPPROG: readelf
+#objcopy: --remove-section .data.foo
+#readelf: -Sg --wide
+
+#...
+  \[[ 0-9]+\] \.group[ \t]+GROUP[ \t]+.*
+#...
+  \[[ 0-9]+\] \.data2\.foo[ \t]+PROGBITS[ \t0-9a-f]+WAG.*
+#...
+COMDAT group section \[[ 0-9]+\] `\.group' \[foo\] contains 1 section.*
+   \[Index\]    Name
+   \[[ 0-9]+\]   \.data2\.foo
+#pass
diff --git a/binutils/testsuite/binutils-all/group-7b.d b/binutils/testsuite/binutils-all/group-7b.d
new file mode 100644
index 0000000..b674545
--- /dev/null
+++ b/binutils/testsuite/binutils-all/group-7b.d
@@ -0,0 +1,19 @@
+#name: copy removing non-reloc group member
+#source: group-7.s
+#PROG: objcopy
+#DUMPPROG: readelf
+#objcopy: --remove-section .data2.foo
+#readelf: -Sg --wide
+
+#...
+  \[[ 0-9]+\] \.group[ \t]+GROUP[ \t]+.*
+#...
+  \[[ 0-9]+\] \.data\.foo[ \t]+PROGBITS[ \t0-9a-f]+WAG.*
+#...
+  \[[ 0-9]+\] \.rela?\.data\.foo[ \t]+RELA?[ \t0-9a-f]+IG.*
+#...
+COMDAT group section \[[ 0-9]+\] `\.group' \[foo\] contains 2 sections:
+   \[Index\]    Name
+   \[[ 0-9]+\]   \.data\.foo
+   \[[ 0-9]+\]   \.rela?\.data\.foo
+#pass
diff --git a/binutils/testsuite/binutils-all/group-7c.d b/binutils/testsuite/binutils-all/group-7c.d
new file mode 100644
index 0000000..83e9115
--- /dev/null
+++ b/binutils/testsuite/binutils-all/group-7c.d
@@ -0,0 +1,8 @@
+#name: copy removing reloc and non-reloc group member
+#source: group-7.s
+#PROG: objcopy
+#DUMPPROG: readelf
+#objcopy: -R .data.foo -R .data2.foo
+#readelf: -g --wide
+
+There are no section groups in this file\.
diff --git a/binutils/testsuite/binutils-all/objcopy.exp b/binutils/testsuite/binutils-all/objcopy.exp
index 377f88c..f4a7692 100644
--- a/binutils/testsuite/binutils-all/objcopy.exp
+++ b/binutils/testsuite/binutils-all/objcopy.exp
@@ -1051,6 +1051,9 @@ if [is_elf_format] {
     objcopy_test_readelf "GNU_MBIND section" mbind1.s
     run_dump_test "group-5"
     run_dump_test "group-6"
+    run_dump_test "group-7a"
+    run_dump_test "group-7b"
+    run_dump_test "group-7c"
     run_dump_test "copy-1"
     run_dump_test "note-1"
     if [is_elf64 tmpdir/bintest.o] {