Building EFI binaries, particularly larger ones (like e.g. Xen does), on Linux

(where relocatable objects are in ELF format) so far led to all local (aka
static) symbols to be discarded, making debugging quite a bit more difficult
(like Linux, Xen builds an internal symbol lookup table from nm output
generated on the binary produced by an earlier linking pass). Therefore, this
patch arranges to insert all (relevant) local symbols from non-COFF objects
into the final executable's symbol table between those coming from COFF input
files and the global ones.

bfd/
2011-11-02  Jan Beulich  <jbeulich@suse.com>

	* coffgen.c (coff_write_alien_symbol): Make public. Add 'struct
	internal_syment *' parameter. Extend 'dummy' to an array with two
	elements. Set n_numaux early. Handle BSF_FILE.
	(coff_write_symbols): Pass NULL as new third argument to
	coff_write_alien_symbol().
	* cofflink.c (_bfd_coff_final_link): Don't use COFF-specific
	obj_raw_syment_count() on non-COFF input BFD. Insert local symbols
	from non-COFF input BFDs.
	* libcoff-in.h (coff_write_alien_symbol): Declare.
	* libcoff.h (coff_write_alien_symbol): Re-generate.

1 files changed, 87 insertions, 1 deletions

diff --git a/bfd/cofflink.c b/bfd/cofflink.c
index bca136445d..1ebdfdd800 100644
--- a/bfd/cofflink.c
+++ b/bfd/cofflink.c
@@ -866,7 +866,7 @@ _bfd_coff_final_link (bfd *abfd,
       size_t sz;
 
       sub->output_has_begun = FALSE;
-      sz = obj_raw_syment_count (sub);
+      sz = bfd_family_coff (sub) ? obj_raw_syment_count (sub) : 2;
       if (sz > max_sym_count)
 	max_sym_count = sz;
     }
@@ -943,6 +943,92 @@ _bfd_coff_final_link (bfd *abfd,
 	}
     }
 
+  if (finfo.info->strip != strip_all && finfo.info->discard != discard_all)
+    {
+      /* Add local symbols from foreign inputs.  */
+      for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
+	{
+	  unsigned int i;
+
+	  if (bfd_family_coff (sub) || ! bfd_get_outsymbols (sub))
+	    continue;
+	  for (i = 0; i < bfd_get_symcount (sub); ++i)
+	    {
+	      asymbol *sym = bfd_get_outsymbols (sub) [i];
+	      file_ptr pos;
+	      struct internal_syment isym;
+	      bfd_size_type string_size = 0;
+	      bfd_vma written = 0;
+	      bfd_boolean rewrite = FALSE;
+
+	      if (! (sym->flags & BSF_LOCAL)
+		  || (sym->flags & (BSF_SECTION_SYM | BSF_DEBUGGING_RELOC
+				    | BSF_THREAD_LOCAL | BSF_RELC | BSF_SRELC
+				    | BSF_SYNTHETIC))
+		  || ((sym->flags & BSF_DEBUGGING)
+		      && ! (sym->flags & BSF_FILE)))
+		continue;
+
+	      /* See if we are discarding symbols with this name.  */
+	      if ((finfo.info->strip == strip_some
+		   && (bfd_hash_lookup (finfo.info->keep_hash,
+					bfd_asymbol_name(sym), FALSE, FALSE)
+		       == NULL))
+		  || (((finfo.info->discard == discard_sec_merge
+			&& (bfd_get_section (sym)->flags & SEC_MERGE)
+			&& ! finfo.info->relocatable)
+		       || finfo.info->discard == discard_l)
+		      && bfd_is_local_label_name (sub, bfd_asymbol_name(sym))))
+		continue;
+
+	      pos = obj_sym_filepos (abfd) + obj_raw_syment_count (abfd)
+					     * symesz;
+	      if (bfd_seek (abfd, pos, SEEK_SET) != 0)
+		goto error_return;
+	      if (! coff_write_alien_symbol(abfd, sym, &isym, &written,
+					    &string_size, NULL, NULL))
+		goto error_return;
+
+	      if (string_size)
+		{
+		  bfd_boolean hash = ! (abfd->flags & BFD_TRADITIONAL_FORMAT);
+		  bfd_size_type indx;
+
+		  indx = _bfd_stringtab_add (finfo.strtab,
+					     bfd_asymbol_name (sym), hash,
+					     FALSE);
+		  if (indx == (bfd_size_type) -1)
+		    goto error_return;
+		  isym._n._n_n._n_offset = STRING_SIZE_SIZE + indx;
+		  bfd_coff_swap_sym_out (abfd, &isym, finfo.outsyms);
+		  rewrite = TRUE;
+		}
+
+	      if (isym.n_sclass == C_FILE)
+		{
+		  if (finfo.last_file_index != -1)
+		    {
+		      finfo.last_file.n_value = obj_raw_syment_count (abfd);
+		      bfd_coff_swap_sym_out (abfd, &finfo.last_file,
+					     finfo.outsyms);
+		      pos = obj_sym_filepos (abfd) + finfo.last_file_index
+						     * symesz;
+		      rewrite = TRUE;
+		    }
+		  finfo.last_file_index = obj_raw_syment_count (abfd);
+		  finfo.last_file = isym;
+		}
+
+	      if (rewrite
+		  && (bfd_seek (abfd, pos, SEEK_SET) != 0
+		      || bfd_bwrite (finfo.outsyms, symesz, abfd) != symesz))
+		goto error_return;
+
+	      obj_raw_syment_count (abfd) += written;
+	    }
+	}
+    }
+
   if (! bfd_coff_final_link_postscript (abfd, & finfo))
     goto error_return;