xcoff: implement linker relaxation

bfd/ChangeLog:

	* coff-rs6000.c (xcoff_reloc_type_noop): Add info argument.
	(xcoff_reloc_type_fail): Likewise.
	(xcoff_reloc_type_pos): Likewise.
	(xcoff_reloc_type_neg): Likewise.
	(xcoff_reloc_type_rel): Likewise.
	(xcoff_reloc_type_toc): Likewise.
	(xcoff_reloc_type_ba): Likewise.
	(xcoff_reloc_type_crel): Likewise.
	(xcoff_reloc_type_tls): Likewise.
	(xcoff_reloc_type_br): Add stub handler.
	(xcoff_ppc_relocate_section): Add info to
	xcoff_calculate_relocation.
	(xcoff_stub_indirect_call_code): New constant.
	(xcoff_stub_shared_call_code): Likewise.
	(bfd_xcoff_backend_data): Add stub code fields.
	(bfd_pmac_xcoff_backend_data): Likewise.
	* coff64-rs6000.c (xcoff64_reloc_type_br): Add stub handler.
	(xcoff64_ppc_relocate_section): Add info to
	xcoff64_calculate_relocation.
	(xcoff64_stub_indirect_call_code): New constant.
	(xcoff64_stub_shared_call_code): Likewise.
	(bfd_xcoff_backend_data): Add stub code fields.
	(bfd_xcoff_aix5_backend_data): Likewise.
	* libxcoff.h (struct xcoff_backend_data_rec): Add stub fields.
	(bfd_xcoff_stub_indirect_call_code): New define.
	(bfd_xcoff_stub_indirect_call_size): New define.
	(bfd_xcoff_stub_shared_call_code): New define.
	(bfd_xcoff_stub_shared_call_size): New define.
	(xcoff_reloc_function): Add info argument.
	(enum xcoff_stub_type): New enum.
	(struct xcoff_stub_hash_entry): New structure.
	* xcofflink.c (struct xcoff_link_hash_table): Add stub hash
	table and params fields.
	(xcoff_stub_hash_entry): New define.
	(xcoff_stub_hash_lookup): New define.
	(stub_hash_newfunc): New function.
	(_bfd_xcoff_bfd_link_hash_table_free): Free the new stub hash
	table.
	(_bfd_xcoff_bfd_link_hash_table_create): Create the new stub
	hash table.
	(xcoff_link_add_symbols): Save rawsize for XTY_SD.
	(bfd_xcoff_link_init): New function.
	(xcoff_stub_csect_name): New function.
	(xcoff_stub_get_csect_in_range): New function.
	(xcoff_stub_name): New function.
	(bfd_xcoff_get_stub_entry): New function.
	(bfd_xcoff_type_of_stub): New function.
	(xcoff_add_stub): New function.
	(xcoff_build_one_stub): New function.
	(bfd_xcoff_size_stubs): New function.
	(bfd_xcoff_build_stubs): New function.
	(xcoff_stub_create_relocations): New function.
	(xcoff_link_input_bfd): Adapt relocations to stub.
	(xcoff_write_global_symbol): Adapt to new TOC entries generated
	for stubs.
	(_bfd_xcoff_bfd_final_link): Handle stub file.
	* xcofflink.h (struct bfd_xcoff_link_params): New structure.

ld/ChangeLog:

	* emultempl/aix.em (params): New variable.
	(stub_file): New variable.
	(xcoff_add_stub_section): New function.
	(xcoff_layout_sections_again): New function
	(hook_in_stub): New function.
	(_after_allocation): Add stub creation.
	(_create_output_section_statements): Allocate stub file and
	pass params to backend.

1 files changed, 88 insertions, 11 deletions

diff --git a/bfd/coff-rs6000.c b/bfd/coff-rs6000.c
index 8656dfdb4c4..8819187ab42 100644
--- a/bfd/coff-rs6000.c
+++ b/bfd/coff-rs6000.c
@@ -2937,7 +2937,8 @@ xcoff_reloc_type_noop (bfd *input_bfd ATTRIBUTE_UNUSED,
 		       bfd_vma val ATTRIBUTE_UNUSED,
 		       bfd_vma addend ATTRIBUTE_UNUSED,
 		       bfd_vma *relocation ATTRIBUTE_UNUSED,
-		       bfd_byte *contents ATTRIBUTE_UNUSED)
+		       bfd_byte *contents ATTRIBUTE_UNUSED,
+		       struct bfd_link_info *info ATTRIBUTE_UNUSED)
 {
   return true;
 }
@@ -2952,7 +2953,8 @@ xcoff_reloc_type_fail (bfd *input_bfd,
 		       bfd_vma val ATTRIBUTE_UNUSED,
 		       bfd_vma addend ATTRIBUTE_UNUSED,
 		       bfd_vma *relocation ATTRIBUTE_UNUSED,
-		       bfd_byte *contents ATTRIBUTE_UNUSED)
+		       bfd_byte *contents ATTRIBUTE_UNUSED,
+		       struct bfd_link_info *info ATTRIBUTE_UNUSED)
 {
   _bfd_error_handler
     /* xgettext: c-format */
@@ -2972,7 +2974,8 @@ xcoff_reloc_type_pos (bfd *input_bfd ATTRIBUTE_UNUSED,
 		      bfd_vma val,
 		      bfd_vma addend,
 		      bfd_vma *relocation,
-		      bfd_byte *contents ATTRIBUTE_UNUSED)
+		      bfd_byte *contents ATTRIBUTE_UNUSED,
+		      struct bfd_link_info *info ATTRIBUTE_UNUSED)
 {
   *relocation = val + addend;
   return true;
@@ -2988,7 +2991,8 @@ xcoff_reloc_type_neg (bfd *input_bfd ATTRIBUTE_UNUSED,
 		      bfd_vma val,
 		      bfd_vma addend,
 		      bfd_vma *relocation,
-		      bfd_byte *contents ATTRIBUTE_UNUSED)
+		      bfd_byte *contents ATTRIBUTE_UNUSED,
+		      struct bfd_link_info *info ATTRIBUTE_UNUSED)
 {
   *relocation = - val - addend;
   return true;
@@ -3004,7 +3008,8 @@ xcoff_reloc_type_rel (bfd *input_bfd ATTRIBUTE_UNUSED,
 		      bfd_vma val,
 		      bfd_vma addend,
 		      bfd_vma *relocation,
-		      bfd_byte *contents ATTRIBUTE_UNUSED)
+		      bfd_byte *contents ATTRIBUTE_UNUSED,
+		      struct bfd_link_info *info ATTRIBUTE_UNUSED)
 {
   howto->pc_relative = true;
 
@@ -3027,7 +3032,8 @@ xcoff_reloc_type_toc (bfd *input_bfd,
 		      bfd_vma val,
 		      bfd_vma addend ATTRIBUTE_UNUSED,
 		      bfd_vma *relocation,
-		      bfd_byte *contents ATTRIBUTE_UNUSED)
+		      bfd_byte *contents ATTRIBUTE_UNUSED,
+		      struct bfd_link_info *info ATTRIBUTE_UNUSED)
 {
   struct xcoff_link_hash_entry *h;
 
@@ -3076,7 +3082,8 @@ xcoff_reloc_type_ba (bfd *input_bfd ATTRIBUTE_UNUSED,
 		     bfd_vma val,
 		     bfd_vma addend,
 		     bfd_vma *relocation,
-		     bfd_byte *contents ATTRIBUTE_UNUSED)
+		     bfd_byte *contents ATTRIBUTE_UNUSED,
+		     struct bfd_link_info *info ATTRIBUTE_UNUSED)
 {
   howto->src_mask &= ~3;
   howto->dst_mask = howto->src_mask;
@@ -3096,10 +3103,13 @@ xcoff_reloc_type_br (bfd *input_bfd,
 		     bfd_vma val,
 		     bfd_vma addend,
 		     bfd_vma *relocation,
-		     bfd_byte *contents)
+		     bfd_byte *contents,
+		     struct bfd_link_info *info)
 {
   struct xcoff_link_hash_entry *h;
   bfd_vma section_offset;
+  struct xcoff_stub_hash_entry *stub_entry = NULL;
+  enum xcoff_stub_type stub_type;
 
   if (0 > rel->r_symndx)
     return false;
@@ -3153,6 +3163,27 @@ xcoff_reloc_type_br (bfd *input_bfd,
       howto->complain_on_overflow = complain_overflow_dont;
     }
 
+  /* Check if a stub is needed.  */
+  stub_type = bfd_xcoff_type_of_stub (input_section, rel, val, h);
+  if (stub_type != xcoff_stub_none)
+    {
+      asection *stub_csect;
+
+      stub_entry = bfd_xcoff_get_stub_entry (input_section, h, info);
+      if (stub_entry == NULL)
+	{
+	  _bfd_error_handler (_("Unable to find the stub entry targeting %s"),
+			      h->root.root.string);
+	  bfd_set_error (bfd_error_bad_value);
+	  return false;
+	}
+
+      stub_csect = stub_entry->hcsect->root.u.def.section;
+      val = (stub_entry->stub_offset
+	     + stub_csect->output_section->vma
+	     + stub_csect->output_offset);
+    }
+
   /* The original PC-relative relocation is biased by -r_vaddr, so adding
      the value below will give the absolute target address.  */
   *relocation = val + addend + rel->r_vaddr;
@@ -3202,7 +3233,8 @@ xcoff_reloc_type_crel (bfd *input_bfd ATTRIBUTE_UNUSED,
 		       bfd_vma val ATTRIBUTE_UNUSED,
 		       bfd_vma addend,
 		       bfd_vma *relocation,
-		       bfd_byte *contents ATTRIBUTE_UNUSED)
+		       bfd_byte *contents ATTRIBUTE_UNUSED,
+		       struct bfd_link_info *info ATTRIBUTE_UNUSED)
 {
   howto->pc_relative = true;
   howto->src_mask &= ~3;
@@ -3227,7 +3259,8 @@ xcoff_reloc_type_tls (bfd *input_bfd ATTRIBUTE_UNUSED,
 		      bfd_vma val,
 		      bfd_vma addend,
 		      bfd_vma *relocation,
-		      bfd_byte *contents ATTRIBUTE_UNUSED)
+		      bfd_byte *contents ATTRIBUTE_UNUSED,
+		      struct bfd_link_info *info ATTRIBUTE_UNUSED)
 {
   struct xcoff_link_hash_entry *h;
 
@@ -3763,7 +3796,7 @@ xcoff_ppc_relocate_section (bfd *output_bfd,
       if (rel->r_type >= XCOFF_MAX_CALCULATE_RELOCATION
 	  || !((*xcoff_calculate_relocation[rel->r_type])
 	       (input_bfd, input_section, output_bfd, rel, sym, &howto, val,
-		addend, &relocation, contents)))
+		addend, &relocation, contents, info)))
 	return false;
 
       /* address */
@@ -4281,6 +4314,34 @@ HOWTO (0,			/* type */
        0xffffffff,		/* dst_mask */
        false);			/* pcrel_offset */
 
+/* Indirect call stub
+   The first word of the code must be modified by filling in
+   the correct TOC offset.  */
+
+static const unsigned long xcoff_stub_indirect_call_code[4] =
+  {
+    0x81820000,	/* lwz r12,0(r2) */
+    0x800c0000,	/* lwz r0,0(r12) */
+    0x7c0903a6,	/* mtctr r0 */
+    0x4e800420,	/* bctr */
+  };
+
+/*  Shared call stub
+    The first word of the code must be modified by filling in
+    the correct TOC offset.
+    This is exactly as the glink code but without the traceback,
+    as it won't be an independent function.  */
+
+static const unsigned long xcoff_stub_shared_call_code[6] =
+  {
+    0x81820000,	/* lwz r12,0(r2) */
+    0x90410014,	/* stw r2,20(r1) */
+    0x800c0000,	/* lwz r0,0(r12) */
+    0x804c0004,	/* lwz r2,4(r12) */
+    0x7c0903a6,	/* mtctr r0 */
+    0x4e800420,	/* bctr */
+  };
+
 /*  glink
 
    The first word of global linkage code must be modified by filling in
@@ -4497,6 +4558,14 @@ static const struct xcoff_backend_data_rec bfd_xcoff_backend_data =
     /* rtinit */
     64,				/* _xcoff_rtinit_size */
     xcoff_generate_rtinit,
+
+    /* Stub indirect call.  */
+    &xcoff_stub_indirect_call_code[0],
+    16,				/* _xcoff_stub_indirect_call_size */
+
+    /* Stub shared call.  */
+    &xcoff_stub_shared_call_code[0],
+    24,				/* _xcoff_stub_shared_call_size */
   };
 
 /* The transfer vector that leads the outside world to all of the above.  */
@@ -4679,6 +4748,14 @@ static const struct xcoff_backend_data_rec bfd_pmac_xcoff_backend_data =
     /* rtinit */
     0,				/* _xcoff_rtinit_size */
     xcoff_generate_rtinit,
+
+    /* Stub indirect call.  */
+    &xcoff_stub_indirect_call_code[0],
+    16,				/* _xcoff_stub_indirect_call_size */
+
+    /* Stub shared call.  */
+    &xcoff_stub_shared_call_code[0],
+    24,				/* _xcoff_stub_shared_call_size */
   };
 
 /* The transfer vector that leads the outside world to all of the above.  */