--gc-sections ignored warning patch

[Grant Edwards]

On Tue, Dec 30, 2003 at 11:47:16AM -0500, Ian Lance Taylor wrote:
> Grant Edwards <grante@visi.com> writes:
> 
> > I know the docs say the option is simply ignored if it's not
> > supported, but a warning from the linker sure would have saved
> > me a lot of hours trying to figure out what I was doing wrong.
> 
> Probably a good idea.  The place to patch is elf_gc_sections() in
> bfd/elflink.h.

Here's my first pass at adding warnings when gc-sections is
ignored.  I may have gotten a bit carried away.  Would people
prefer a single more generic warning message?

-- 
Grant Edwards
grante@visi.com
-------------- next part --------------
Index: elflink.h
===================================================================
RCS file: /cvs/src/src/bfd/elflink.h,v
retrieving revision 1.250
diff -U8 -r1.250 elflink.h
--- elflink.h	8 Dec 2003 13:05:10 -0000	1.250
+++ elflink.h	30 Dec 2003 17:31:43 -0000
@@ -5791,22 +5791,36 @@
 elf_gc_sections (bfd *abfd, struct bfd_link_info *info)
 {
   bfd_boolean ok = TRUE;
   bfd *sub;
   asection * (*gc_mark_hook)
     (asection *, struct bfd_link_info *, Elf_Internal_Rela *,
      struct elf_link_hash_entry *h, Elf_Internal_Sym *);
 
-  if (!get_elf_backend_data (abfd)->can_gc_sections
-      || info->relocatable
-      || info->emitrelocations
-      || !is_elf_hash_table (info->hash)
-      || elf_hash_table (info)->dynamic_sections_created)
-    return TRUE;
+  if (!get_elf_backend_data (abfd)->can_gc_sections)
+    {
+      (*_bfd_error_handler)(_("Warning: gc-sections option ignored (not supported by target architecture)."));
+      return TRUE;
+    }
+  if (info->relocatable || info->emitrelocations)
+    {
+      (*_bfd_error_handler)(_("Warning: gc-sections option ignored (only supported for static output)."));
+      return TRUE;
+    }
+  if (!is_elf_hash_table (info->hash))
+    {
+      (*_bfd_error_handler)(_("Warning: gc-sections option ignored (only supported for ELF targets)."));
+      return TRUE;
+    }
+  if (elf_hash_table (info)->dynamic_sections_created)
+    {
+      (*_bfd_error_handler)(_("Warning: gc-sections option ignored (not supported with dynamic libs)."));
+      return TRUE;
+    }
 
   /* Apply transitive closure to the vtable entry usage info.  */
   elf_link_hash_traverse (elf_hash_table (info),
 			  elf_gc_propagate_vtable_entries_used,
 			  &ok);
   if (!ok)
     return FALSE;