Improve objcopy's ability to merge build notes.

	* objcopy.c (merge_gnu_build_notes): Delete empty notes.  Merge
	identical function notes.

diff --git a/binutils/ChangeLog b/binutils/ChangeLog
index ad7a87c3527ff0d9afc8a0b22b17222707222f44..d7648eff785facc74388c306eebb78afa201b4da 100644 (file)
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@@ -1,3 +1,8 @@
+2018-08-03  Nick Clifton  <nickc@redhat.com>
+
+       * objcopy.c (merge_gnu_build_notes): Delete empty notes.  Merge
+       identical function notes.
+
 2018-08-01  Nick Clifton  <nickc@redhat.com>
 
        * README-how-to-make-a-release: Add note about regenerating the

diff --git a/binutils/objcopy.c b/binutils/objcopy.c
index 001cddf14c8448f0d5df3083865922ebe2982d35..6bd933993b39e9f4d3038d3045a1d4096705be3e 100644 (file)
--- a/binutils/objcopy.c
+++ b/binutils/objcopy.c
@@ -2177,7 +2177,7 @@ merge_gnu_build_notes (bfd * abfd, asection * sec, bfd_size_type size, bfd_byte
      3. Eliminate any NT_GNU_BUILD_ATTRIBUTE_OPEN notes that have the same
         full name field as the immediately preceeding note with the same type
        of name and whose address ranges coincide.
-       IE - it there are gaps in the coverage of the notes, then these gaps
+       IE - if there are gaps in the coverage of the notes, then these gaps
        must be preserved.
      4. Combine the numeric value of any NT_GNU_BUILD_ATTRIBUTE_OPEN notes
         of type GNU_BUILD_ATTRIBUTE_STACK_SIZE.
@@ -2185,16 +2185,48 @@ merge_gnu_build_notes (bfd * abfd, asection * sec, bfd_size_type size, bfd_byte
         its description field is empty then the nearest preceeding OPEN note
        with a non-empty description field must also be preserved *OR* the
        description field of the note must be changed to contain the starting
-       address to which it refers.  */
+       address to which it refers.
+     6. Notes with the same start and end address can be deleted.  */
   for (pnote = pnotes + 1; pnote < pnotes_end; pnote ++)
     {
       int                      note_type;
       objcopy_internal_note *  back;
       objcopy_internal_note *  prev_open_with_range = NULL;
 
+      /* Rule 6 - delete 0-range notes.  */
+      if (pnote->start == pnote->end)
+       {
+         duplicate_found = TRUE;
+         pnote->note.type = 0;
+         continue;
+       }
+
       /* Rule 2 - preserve function notes.  */
       if (! is_open_note (pnote))
-       continue;
+       {
+         int iter;
+
+         /* Check to see if there is an identical previous function note.
+            This can happen with overlays for example.  */
+         for (iter = 0, back = pnote -1; back >= pnotes; back --)
+           {
+             if (back->start == pnote->start
+                 && back->end == pnote->end
+                 && back->note.namesz == pnote->note.namesz
+                 && memcmp (back->note.namedata, pnote->note.namedata, pnote->note.namesz) == 0)
+               {
+ fprintf (stderr, "DUP FUNXC\n");
+                 duplicate_found = TRUE;
+                 pnote->note.type = 0;
+                 break;
+               }
+
+             /* Don't scan too far back however.  */
+             if (iter ++ > 16)
+               break;
+           }
+         continue;
+       }
 
       note_type = pnote->note.namedata[attribute_type_byte];