Prevent a call to abort when a relocatable link encounters a relocation against a...

	PR ld/21524
	* elflink.c (elf_link_adjust_relocs): Generate an error when
	encountering a reloc against a symbol removed by garbage
	collection.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index daea1732bc2f40ffedd7715878a8604693a817f3..acddb3a2eec2346149a3bd2d50f88a2e38a932d5 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,10 @@
+2017-06-13  Nick Clifton  <nickc@redhat.com>
+
+       PR ld/21524
+       * elflink.c (elf_link_adjust_relocs): Generate an error when
+       encountering a reloc against a symbol removed by garbage
+       collection.
+
 2017-06-12  H.J. Lu  <hongjiu.lu@intel.com>
 
        * elf-bfd.h (elf_backend_data): Add struct bfd_link_info *

diff --git a/bfd/elflink.c b/bfd/elflink.c
index 1b447bb785081844b2d577f364586d67c81328ce..f0ca33f155b071a82c51a36071a5a28974895223 100644 (file)
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -8547,7 +8547,8 @@ static bfd_boolean
 elf_link_adjust_relocs (bfd *abfd,
                        asection *sec,
                        struct bfd_elf_section_reloc_data *reldata,
-                       bfd_boolean sort)
+                       bfd_boolean sort,
+                       struct bfd_link_info *info)
 {
   unsigned int i;
   const struct elf_backend_data *bed = get_elf_backend_data (abfd);
@@ -8595,6 +8596,20 @@ elf_link_adjust_relocs (bfd *abfd,
       if (*rel_hash == NULL)
        continue;
 
+      if ((*rel_hash)->indx == -2
+         && info->gc_sections
+         && ! info->gc_keep_exported)
+       {
+         /* PR 21524: Let the user know if a symbol was removed by garbage collection.  */
+         _bfd_error_handler (_("%B:%A: error: relocation references symbol %s which was removed by garbage collection."),
+                             abfd, sec,
+                             (*rel_hash)->root.root.string);
+         _bfd_error_handler (_("%B:%A: error: try relinking with --gc-keep-exported enabled."),
+                             abfd, sec,
+                             (*rel_hash)->root.root.string);
+         bfd_set_error (bfd_error_invalid_operation);
+         return FALSE;
+       }
       BFD_ASSERT ((*rel_hash)->indx >= 0);
 
       (*swap_in) (abfd, erela, irela);
@@ -10701,7 +10716,6 @@ elf_link_input_bfd (struct elf_final_link_info *flinfo, bfd *input_bfd)
                         used by a reloc.  */
                      BFD_ASSERT (rh->indx < 0);
                      rh->indx = -2;
-
                      *rel_hash = rh;
 
                      continue;
@@ -12168,15 +12182,16 @@ bfd_elf_final_link (bfd *abfd, struct bfd_link_info *info)
     {
       struct bfd_elf_section_data *esdo = elf_section_data (o);
       bfd_boolean sort;
+
       if ((o->flags & SEC_RELOC) == 0)
        continue;
 
       sort = bed->sort_relocs_p == NULL || (*bed->sort_relocs_p) (o);
       if (esdo->rel.hdr != NULL
-         && !elf_link_adjust_relocs (abfd, o, &esdo->rel, sort))
+         && !elf_link_adjust_relocs (abfd, o, &esdo->rel, sort, info))
        return FALSE;
       if (esdo->rela.hdr != NULL
-         && !elf_link_adjust_relocs (abfd, o, &esdo->rela, sort))
+         && !elf_link_adjust_relocs (abfd, o, &esdo->rela, sort, info))
        return FALSE;
 
       /* Set the reloc_count field to 0 to prevent write_relocs from