Ignore dynamic references on forced local symbols

We should ignore dynamic references on forced local symbols during
garbage collection since they can never be referenced dynamically.

bfd/

	PR ld/22649
	* elflink.c (bfd_elf_gc_mark_dynamic_ref_symbol): Ignore dynamic
	references on forced local symbols.

ld/

	PR ld/22649
	* testsuite/ld-elf/pr22649-1.s: New file.
	* testsuite/ld-elf/pr22649-2a.s: Likewise.
	* testsuite/ld-elf/pr22649-2b.s: Likewise.
	* testsuite/ld-elf/pr22649.msg: Likewise.
	* testsuite/ld-elf/shared.exp: Run ld/22649 tests.

bfd/ChangeLog

@@ -1,3 +1,9 @@
+2018-01-11  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/22649
+	* elflink.c (bfd_elf_gc_mark_dynamic_ref_symbol): Ignore dynamic
+	references on forced local symbols.
+
 2018-01-11  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR ld/22677

bfd/elflink.c

@@ -13277,7 +13277,7 @@ bfd_elf_gc_mark_dynamic_ref_symbol (struct elf_link_hash_entry *h, void *inf)
 
   if ((h->root.type == bfd_link_hash_defined
        || h->root.type == bfd_link_hash_defweak)
-      && (h->ref_dynamic
+      && ((h->ref_dynamic && !h->forced_local)
 	  || ((h->def_regular || ELF_COMMON_DEF_P (h))
 	      && ELF_ST_VISIBILITY (h->other) != STV_INTERNAL
 	      && ELF_ST_VISIBILITY (h->other) != STV_HIDDEN

ld/ChangeLog

@@ -1,3 +1,12 @@
+2018-01-11  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/22649
+	* testsuite/ld-elf/pr22649-1.s: New file.
+	* testsuite/ld-elf/pr22649-2a.s: Likewise.
+	* testsuite/ld-elf/pr22649-2b.s: Likewise.
+	* testsuite/ld-elf/pr22649.msg: Likewise.
+	* testsuite/ld-elf/shared.exp: Run ld/22649 tests.
+
 2018-01-11  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR ld/22677

ld/testsuite/ld-elf/pr22649-1.s

@@ -0,0 +1,4 @@
+	.data
+	.globl foo
+foo:
+	.dc.a bar

ld/testsuite/ld-elf/pr22649-2a.s

@@ -0,0 +1,8 @@
+	.data
+	.hidden foo
+	.hidden bar
+	.globl foo
+	.globl bar
+foo:
+bar:
+	.dc.a foo

ld/testsuite/ld-elf/pr22649-2b.s

@@ -0,0 +1,7 @@
+	.data
+	.hidden foo
+	.globl foo
+	.globl bar
+foo:
+bar:
+	.dc.a foo

ld/testsuite/ld-elf/pr22649.msg

@@ -0,0 +1 @@
+.*: Removing unused section '\.data' in file 'tmpdir/pr22649-2.*\.o'

ld/testsuite/ld-elf/shared.exp

@@ -81,6 +81,51 @@ run_ld_link_tests [list \
 	{} \
 	"pr22471" \
     ] \
+    [list \
+	"Build pr22649-1.so" \
+	"$LFLAGS -shared" \
+	"" \
+	"$AFLAGS_PIC" \
+	{pr22649-1.s} \
+	{} \
+	"pr22649-1.so" \
+    ] \
+    [list \
+	"Build pr22649-2a.so" \
+	"$LFLAGS -shared -gc-sections -print-gc-sections" \
+	"" \
+	"$AFLAGS_PIC" \
+	{pr22649-2a.s} \
+	{{ld pr22649.msg}} \
+	"pr22649-2a.so" \
+    ] \
+    [list \
+	"Build pr22649-2b.so" \
+	"$LFLAGS -shared -gc-sections -print-gc-sections" \
+	"tmpdir/pr22649-1.so" \
+	"$AFLAGS_PIC" \
+	{pr22649-2a.s} \
+	{{ld pr22649.msg}} \
+	"pr22649-2b.so" \
+    ] \
+    [list \
+	"Build pr22649-2c.so" \
+	"$LFLAGS -shared -gc-sections -print-gc-sections" \
+	"" \
+	"$AFLAGS_PIC" \
+	{pr22649-2b.s} \
+	{} \
+	"pr22649-2b.so" \
+    ] \
+    [list \
+	"Build pr22649-2d.so" \
+	"$LFLAGS -shared -gc-sections -print-gc-sections" \
+	"tmpdir/pr22649-1.so" \
+	"$AFLAGS_PIC" \
+	{pr22649-2b.s} \
+	{} \
+	"pr22649-2b.so" \
+    ] \
 ]
 
 run_ld_link_tests [list \