PATCH: Improve ELF linker for non-ELF input

[H. J. Lu]

On Thu, Apr 22, 2004 at 01:39:34PM -0700, H. J. Lu wrote:
> The current ELF linker can link in non-ELF input if it doesn't
> reference symbols in DSO. This patch improves it a little bit so
> that simple function call to DSO works.
> 
> 
> H.J.
> ------
> 2004-04-22  H.J. Lu  <hongjiu.lu@intel.com>
> 
> 	* elflink.c (_bfd_elf_link_create_dynamic_sections): Clear
> 	the ELF_LINK_NON_ELF bit on _DYNAMIC.
> 	(_bfd_elf_fix_symbol_flags): Increment PLT count for dynamic
> 	symbols referenced by non-ELF files.
> 

This patch is incomplete. Here is the new one. With it, I can link
non-ELF input on Linux to generate working ELF executable.

H.J.
-------------- next part --------------
2004-04-22  H.J. Lu  <hongjiu.lu@intel.com>

	* elf.c (_bfd_elf_link_hash_copy_indirect): Also copy
	ELF_LINK_NON_ELF.

	* elf32-i386.c (ELIMINATE_COPY_RELOCS): Add hash as an argument.
	FALSE if the ELF_LINK_NON_ELF bit is set. Update usages.

	* elflink.c (_bfd_elf_link_create_dynamic_sections): Clear
	the ELF_LINK_NON_ELF bit on _DYNAMIC.
	(_bfd_elf_fix_symbol_flags): Increment PLT count for dynamic
	function symbols referenced by non-ELF files. Set the
	ELF_LINK_NON_GOT_REF bit for dynamic object symbols
	referenced by non-ELF files.

--- bfd/elf.c.mix	2004-04-22 11:08:27.000000000 -0700
+++ bfd/elf.c	2004-04-22 16:25:06.000000000 -0700
@@ -1360,6 +1360,7 @@ _bfd_elf_link_hash_copy_indirect (const 
 				   | ELF_LINK_HASH_REF_REGULAR
 				   | ELF_LINK_HASH_REF_REGULAR_NONWEAK
 				   | ELF_LINK_NON_GOT_REF
+				   | ELF_LINK_NON_ELF
 				   | ELF_LINK_HASH_NEEDS_PLT
 				   | ELF_LINK_POINTER_EQUALITY_NEEDED);
 
--- bfd/elf32-i386.c.mix	2004-04-22 08:19:28.000000000 -0700
+++ bfd/elf32-i386.c	2004-04-22 14:50:20.000000000 -0700
@@ -464,7 +464,8 @@ elf_i386_grok_psinfo (bfd *abfd, Elf_Int
    copying dynamic variables from a shared lib into an app's dynbss
    section, and instead use a dynamic relocation to point into the
    shared lib.  */
-#define ELIMINATE_COPY_RELOCS 1
+#define ELIMINATE_COPY_RELOCS(h) \
+  (!(h) || !((h)->elf_link_hash_flags & ELF_LINK_NON_ELF))
 
 /* The size in bytes of an entry in the procedure linkage table.  */
 
@@ -782,7 +783,7 @@ elf_i386_copy_indirect_symbol (const str
       eind->tls_type = GOT_UNKNOWN;
     }
 
-  if (ELIMINATE_COPY_RELOCS
+  if (ELIMINATE_COPY_RELOCS (dir)
       && ind->root.type != bfd_link_hash_indirect
       && (dir->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0)
     /* If called to transfer flags for a weakdef during processing
@@ -1056,7 +1057,7 @@ elf_i386_check_relocs (bfd *abfd,
 			   || h->root.type == bfd_link_hash_defweak
 			   || (h->elf_link_hash_flags
 			       & ELF_LINK_HASH_DEF_REGULAR) == 0))))
-	      || (ELIMINATE_COPY_RELOCS
+	      || (ELIMINATE_COPY_RELOCS (h)
 		  && !info->shared
 		  && (sec->flags & SEC_ALLOC) != 0
 		  && h != NULL
@@ -1361,7 +1362,7 @@ elf_i386_adjust_dynamic_symbol (struct b
 		  || h->weakdef->root.type == bfd_link_hash_defweak);
       h->root.u.def.section = h->weakdef->root.u.def.section;
       h->root.u.def.value = h->weakdef->root.u.def.value;
-      if (ELIMINATE_COPY_RELOCS || info->nocopyreloc)
+      if (ELIMINATE_COPY_RELOCS (h) || info->nocopyreloc)
 	h->elf_link_hash_flags
 	  = ((h->elf_link_hash_flags & ~ELF_LINK_NON_GOT_REF)
 	     | (h->weakdef->elf_link_hash_flags & ELF_LINK_NON_GOT_REF));
@@ -1390,7 +1391,7 @@ elf_i386_adjust_dynamic_symbol (struct b
       return TRUE;
     }
 
-  if (ELIMINATE_COPY_RELOCS)
+  if (ELIMINATE_COPY_RELOCS (h))
     {
       struct elf_i386_link_hash_entry * eh;
       struct elf_i386_dyn_relocs *p;
@@ -1628,7 +1629,7 @@ allocate_dynrelocs (struct elf_link_hash
 	  && h->root.type == bfd_link_hash_undefweak)
 	eh->dyn_relocs = NULL;
     }
-  else if (ELIMINATE_COPY_RELOCS)
+  else if (ELIMINATE_COPY_RELOCS (h))
     {
       /* For the non-shared case, discard space for relocs against
 	 symbols which turn out to need copy relocs or are not
@@ -2321,7 +2322,7 @@ elf_i386_relocate_section (bfd *output_b
 		   || h->root.type != bfd_link_hash_undefweak)
 	       && (r_type != R_386_PC32
 		   || !SYMBOL_CALLS_LOCAL (info, h)))
-	      || (ELIMINATE_COPY_RELOCS
+	      || (ELIMINATE_COPY_RELOCS (h)
 		  && !info->shared
 		  && h != NULL
 		  && h->dynindx != -1
--- bfd/elflink.c.mix	2004-04-22 08:20:09.000000000 -0700
+++ bfd/elflink.c	2004-04-22 18:05:35.000000000 -0700
@@ -218,6 +218,7 @@ _bfd_elf_link_create_dynamic_sections (b
     return FALSE;
   h = (struct elf_link_hash_entry *) bh;
   h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
+  h->elf_link_hash_flags &= ~ELF_LINK_NON_ELF;
   h->type = STT_OBJECT;
 
   if (! info->executable
@@ -2087,6 +2088,22 @@ _bfd_elf_fix_symbol_flags (struct elf_li
 	      eif->failed = TRUE;
 	      return FALSE;
 	    }
+
+	  switch (h->type)
+	    {
+	    case STT_OBJECT:
+	      /* It doesn't use GOT.  */
+	      h->elf_link_hash_flags |= ELF_LINK_NON_GOT_REF;
+	      break;
+
+	    case STT_FUNC:
+	      /* We need it to keep the PLT entry.  */
+	      h->plt.refcount++;
+	      break;
+
+	    default:
+	      break;
+	    }
 	}
     }
   else