Fixed ld --gc-sections bug

Related CL:
  https://android-review.googlesource.com/#/c/36585/
  https://android-review.googlesource.com/#/c/36608/

Change-Id: I73c5b0afdab582824fb853b89464745d4e5b065f

7 files changed, 53 insertions, 10 deletions

diff --git a/binutils-2.22/bfd/elf32-arm.c b/binutils-2.22/bfd/elf32-arm.c
index b1228d87..46638cb6 100644
--- a/binutils-2.22/bfd/elf32-arm.c
+++ b/binutils-2.22/bfd/elf32-arm.c
@@ -10387,7 +10387,9 @@ elf32_arm_relocate_section (bfd *                  output_bfd,
 	 not process them.  */
       if (unresolved_reloc
           && !((input_section->flags & SEC_DEBUGGING) != 0
-               && h->def_dynamic))
+               && h->def_dynamic)
+	  && _bfd_elf_section_offset (output_bfd, info, input_section,
+				      rel->r_offset) != (bfd_vma) -1)
 	{
 	  (*_bfd_error_handler)
 	    (_("%B(%A+0x%lx): unresolvable %s relocation against symbol `%s'"),
diff --git a/binutils-2.22/bfd/elf32-i386.c b/binutils-2.22/bfd/elf32-i386.c
index d518d014..7ef1fc1e 100644
--- a/binutils-2.22/bfd/elf32-i386.c
+++ b/binutils-2.22/bfd/elf32-i386.c
@@ -4237,7 +4237,9 @@ elf_i386_relocate_section (bfd *output_bfd,
 	 not process them.  */
       if (unresolved_reloc
 	  && !((input_section->flags & SEC_DEBUGGING) != 0
-	       && h->def_dynamic))
+	       && h->def_dynamic)
+	  && _bfd_elf_section_offset (output_bfd, info, input_section,
+				      rel->r_offset) != (bfd_vma) -1)
 	{
 	  (*_bfd_error_handler)
 	    (_("%B(%A+0x%lx): unresolvable %s relocation against symbol `%s'"),
diff --git a/binutils-2.22/bfd/elf64-ppc.c b/binutils-2.22/bfd/elf64-ppc.c
index 93d1314d..351ebc15 100644
--- a/binutils-2.22/bfd/elf64-ppc.c
+++ b/binutils-2.22/bfd/elf64-ppc.c
@@ -13502,7 +13502,9 @@ ppc64_elf_relocate_section (bfd *output_bfd,
 	 not process them.  */
       if (unresolved_reloc
 	  && !((input_section->flags & SEC_DEBUGGING) != 0
-	       && h->elf.def_dynamic))
+	       && h->elf.def_dynamic)
+	  && _bfd_elf_section_offset (output_bfd, info, input_section,
+				      rel->r_offset) != (bfd_vma) -1)
 	{
 	  info->callbacks->einfo
 	    (_("%P: %H: unresolvable %s relocation against symbol `%s'\n"),
diff --git a/binutils-2.22/bfd/elf64-x86-64.c b/binutils-2.22/bfd/elf64-x86-64.c
index 3a2444b9..42ed936a 100644
--- a/binutils-2.22/bfd/elf64-x86-64.c
+++ b/binutils-2.22/bfd/elf64-x86-64.c
@@ -4086,7 +4086,9 @@ elf_x86_64_relocate_section (bfd *output_bfd,
 	 not process them.  */
       if (unresolved_reloc
 	  && !((input_section->flags & SEC_DEBUGGING) != 0
-	       && h->def_dynamic))
+	       && h->def_dynamic)
+          && _bfd_elf_section_offset (output_bfd, info, input_section,
+                                      rel->r_offset) != (bfd_vma) -1)
 	(*_bfd_error_handler)
 	  (_("%B(%A+0x%lx): unresolvable %s relocation against symbol `%s'"),
 	   input_bfd,
diff --git a/binutils-2.22/bfd/elflink.c b/binutils-2.22/bfd/elflink.c
index fc4266b3..1c5abd4b 100644
--- a/binutils-2.22/bfd/elflink.c
+++ b/binutils-2.22/bfd/elflink.c
@@ -11577,6 +11577,13 @@ _bfd_elf_gc_mark_rsec (struct bfd_link_info *info, asection *sec,
       while (h->root.type == bfd_link_hash_indirect
 	     || h->root.type == bfd_link_hash_warning)
 	h = (struct elf_link_hash_entry *) h->root.u.i.link;
+      h->mark = 1;
+      /* If this symbol is weak and there is a non-weak definition, we
+	 keep the non-weak definition because many backends put
+	 dynamic reloc info on the non-weak definition for code
+	 handling copy relocs.  */
+      if (h->u.weakdef != NULL)
+	h->u.weakdef->mark = 1;
       return (*gc_mark_hook) (sec, info, cookie->rel, h, NULL);
     }
 
@@ -11724,14 +11731,21 @@ struct elf_gc_sweep_symbol_info
 static bfd_boolean
 elf_gc_sweep_symbol (struct elf_link_hash_entry *h, void *data)
 {
-  if ((h->root.type == bfd_link_hash_defined
-       || h->root.type == bfd_link_hash_defweak)
-      && !h->root.u.def.section->gc_mark
-      && !(h->root.u.def.section->owner->flags & DYNAMIC))
+  if (!h->mark
+      && (((h->root.type == bfd_link_hash_defined
+	    || h->root.type == bfd_link_hash_defweak)
+	   && !(h->def_regular
+		&& h->root.u.def.section->gc_mark))
+	  || h->root.type == bfd_link_hash_undefined
+	  || h->root.type == bfd_link_hash_undefweak))
     {
-      struct elf_gc_sweep_symbol_info *inf =
-          (struct elf_gc_sweep_symbol_info *) data;
+      struct elf_gc_sweep_symbol_info *inf;
+
+      inf = (struct elf_gc_sweep_symbol_info *) data;
       (*inf->hide_symbol) (inf->info, h, TRUE);
+      h->def_regular = 0;
+      h->ref_regular = 0;
+      h->ref_regular_nonweak = 0;
     }
 
   return TRUE;
diff --git a/binutils-2.22/ld/testsuite/ld-elf/pr13177.d b/binutils-2.22/ld/testsuite/ld-elf/pr13177.d
new file mode 100644
index 00000000..e56e8652
--- /dev/null
+++ b/binutils-2.22/ld/testsuite/ld-elf/pr13177.d
@@ -0,0 +1,12 @@
+#source: pr13177.s
+#ld: --gc-sections -shared
+#readelf: -s -D --wide
+#target: *-*-linux* *-*-gnu*
+#notarget: arc-*-* d30v-*-* dlx-*-* i960-*-* or32-*-* pj*-*-*
+#notarget: hppa64-*-* i370-*-* i860-*-* ia64-*-* mep-*-* mn10200-*-*
+# generic linker targets don't support --gc-sections, nor do a bunch of others
+
+#failif
+#...
+.*: 0+0 +0 +NOTYPE +GLOBAL +DEFAULT +UND bar
+#...
diff --git a/binutils-2.22/ld/testsuite/ld-elf/pr13177.s b/binutils-2.22/ld/testsuite/ld-elf/pr13177.s
new file mode 100644
index 00000000..d7caad36
--- /dev/null
+++ b/binutils-2.22/ld/testsuite/ld-elf/pr13177.s
@@ -0,0 +1,9 @@
+	.section .text.foo,"ax",%progbits
+	.globl	foo
+	.type	foo, %function
+foo:
+	.byte 0
+	.section .data.opt_out,"aw",%progbits
+	.type	opt_out, %object
+opt_out:
+	.dc.a bar