binutils-gdb/ld/emultempl/ppc64elf.em

# This shell script emits a C file. -*- C -*-
#   Copyright 2002 Free Software Foundation, Inc.
#
# This file is part of GLD, the Gnu Linker.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#

# This file is sourced from elf32.em, and defines extra powerpc64-elf
# specific routines.
#
cat >>e${EMULATION_NAME}.c <<EOF

#include "ldctor.h"
#include "libbfd.h"
#include "elf64-ppc.h"

/* Fake input file for stubs.  */
static lang_input_statement_type *stub_file;

/* Whether we need to call ppc_layout_sections_again.  */
static int need_laying_out = 0;

/* Maximum size of a group of input sections that can be handled by
   one stub section.  A value of +/-1 indicates the bfd back-end
   should use a suitable default size.  */
static bfd_signed_vma group_size = 1;

static void ppc_create_output_section_statements PARAMS ((void));
static asection *ppc_add_stub_section PARAMS ((const char *, asection *));
static void ppc_layout_sections_again PARAMS ((void));
static void gld${EMULATION_NAME}_after_allocation PARAMS ((void));
static void build_section_lists PARAMS ((lang_statement_union_type *));

/* This is called before the input files are opened.  We create a new
   fake input file to hold the stub sections.  */

static void
ppc_create_output_section_statements ()
{
  stub_file = lang_add_input_file ("linker stubs",
				   lang_input_file_is_fake_enum,
				   NULL);
  stub_file->the_bfd = bfd_create ("linker stubs", output_bfd);
  if (stub_file->the_bfd == NULL
      || !bfd_set_arch_mach (stub_file->the_bfd,
			     bfd_get_arch (output_bfd),
			     bfd_get_mach (output_bfd)))
    {
      einfo ("%X%P: can not create BFD %E\n");
      return;
    }

  ldlang_add_file (stub_file);
}


struct hook_stub_info
{
  lang_statement_list_type add;
  asection *input_section;
};

/* Traverse the linker tree to find the spot where the stub goes.  */

static boolean hook_in_stub
  PARAMS ((struct hook_stub_info *, lang_statement_union_type **));

static boolean
hook_in_stub (info, lp)
     struct hook_stub_info *info;
     lang_statement_union_type **lp;
{
  lang_statement_union_type *l;
  boolean ret;

  for (; (l = *lp) != NULL; lp = &l->header.next)
    {
      switch (l->header.type)
	{
	case lang_constructors_statement_enum:
	  ret = hook_in_stub (info, &constructor_list.head);
	  if (ret)
	    return ret;
	  break;

	case lang_output_section_statement_enum:
	  ret = hook_in_stub (info,
			      &l->output_section_statement.children.head);
	  if (ret)
	    return ret;
	  break;

	case lang_wild_statement_enum:
	  ret = hook_in_stub (info, &l->wild_statement.children.head);
	  if (ret)
	    return ret;
	  break;

	case lang_group_statement_enum:
	  ret = hook_in_stub (info, &l->group_statement.children.head);
	  if (ret)
	    return ret;
	  break;

	case lang_input_section_enum:
	  if (l->input_section.section == info->input_section)
	    {
	      /* We've found our section.  Insert the stub immediately
		 before its associated input section.  */
	      *lp = info->add.head;
	      *(info->add.tail) = l;
	      return true;
	    }
	  break;

	case lang_data_statement_enum:
	case lang_reloc_statement_enum:
	case lang_object_symbols_statement_enum:
	case lang_output_statement_enum:
	case lang_target_statement_enum:
	case lang_input_statement_enum:
	case lang_assignment_statement_enum:
	case lang_padding_statement_enum:
	case lang_address_statement_enum:
	case lang_fill_statement_enum:
	  break;

	default:
	  FAIL ();
	  break;
	}
    }
  return false;
}


/* Call-back for ppc64_elf_size_stubs.  */

/* Create a new stub section, and arrange for it to be linked
   immediately before INPUT_SECTION.  */

static asection *
ppc_add_stub_section (stub_sec_name, input_section)
     const char *stub_sec_name;
     asection *input_section;
{
  asection *stub_sec;
  flagword flags;
  asection *output_section;
  const char *secname;
  lang_output_section_statement_type *os;
  struct hook_stub_info info;

  stub_sec = bfd_make_section_anyway (stub_file->the_bfd, stub_sec_name);
  if (stub_sec == NULL)
    goto err_ret;

  flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
	   | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);
  if (!bfd_set_section_flags (stub_file->the_bfd, stub_sec, flags))
    goto err_ret;

  output_section = input_section->output_section;
  secname = bfd_get_section_name (output_section->owner, output_section);
  os = lang_output_section_find (secname);

  info.input_section = input_section;
  lang_list_init (&info.add);
  lang_add_section (&info.add, stub_sec, os, stub_file);

  if (info.add.head == NULL)
    goto err_ret;

  if (hook_in_stub (&info, &os->children.head))
    return stub_sec;

 err_ret:
  einfo ("%X%P: can not make stub section: %E\n");
  return NULL;
}


/* Another call-back for ppc64_elf_size_stubs.  */

static void
ppc_layout_sections_again ()
{
  /* If we have changed sizes of the stub sections, then we need
     to recalculate all the section offsets.  This may mean we need to
     add even more stubs.  */
  need_laying_out = 0;

  lang_reset_memory_regions ();

  /* Resize the sections.  */
  lang_size_sections (stat_ptr->head, abs_output_section,
		      &stat_ptr->head, 0, (bfd_vma) 0, NULL);

  /* Recalculate TOC base.  */
  ldemul_after_allocation ();

  /* Do the assignments again.  */
  lang_do_assignments (stat_ptr->head, abs_output_section,
		       (fill_type *) 0, (bfd_vma) 0);
}


/* Call the back-end function to set TOC base after we have placed all
   the sections.  */
static void
gld${EMULATION_NAME}_after_allocation ()
{
  if (!link_info.relocateable)
    _bfd_set_gp_value (output_bfd, ppc64_elf_toc (output_bfd));
}


static void
build_section_lists (statement)
     lang_statement_union_type *statement;
{
  if (statement->header.type == lang_input_section_enum
      && !statement->input_section.ifile->just_syms_flag
      && statement->input_section.section->output_section != NULL
      && statement->input_section.section->output_section->owner == output_bfd)
    {
      ppc64_elf_next_input_section (&link_info,
				    statement->input_section.section);
    }
}

/* Final emulation specific call.  */

static void
gld${EMULATION_NAME}_finish ()
{
  int ret;

  /* e_entry on PowerPC64 points to the function descriptor for
     _start.  If _start is missing, default to the first function
     descriptor in the .opd section.  */
  entry_section = ".opd";

  /* If generating a relocatable output file, then we don't have any
     stubs.  */
  if (link_info.relocateable)
    return;

  /* bfd_elf64_discard_info just plays with debugging sections,
     ie. doesn't affect any code, so we can delay resizing the
     sections.  It's likely we'll resize everything in the process of
     adding stubs.  */
  if (bfd_elf${ELFSIZE}_discard_info (output_bfd, &link_info))
    need_laying_out = 1;

  ret = ppc64_elf_setup_section_lists (output_bfd, &link_info);
  if (ret != 0)
    {
      if (ret < 0)
	{
	  einfo ("%X%P: can not size stub section: %E\n");
	  return;
	}

      lang_for_each_statement (build_section_lists);

      /* Call into the BFD backend to do the real work.  */
      if (!ppc64_elf_size_stubs (output_bfd,
				 stub_file->the_bfd,
				 &link_info,
				 group_size,
				 &ppc_add_stub_section,
				 &ppc_layout_sections_again))
	{
	  einfo ("%X%P: can not size stub section: %E\n");
	  return;
	}
    }

  if (need_laying_out)
    ppc_layout_sections_again ();

  if (stub_file->the_bfd->sections != NULL)
    {
      if (!ppc64_elf_build_stubs (&link_info))
	einfo ("%X%P: can not build stubs: %E\n");
    }
}


/* Avoid processing the fake stub_file in vercheck, stat_needed and
   check_needed routines.  */

static void ppc_for_each_input_file_wrapper
  PARAMS ((lang_input_statement_type *));
static void ppc_lang_for_each_input_file
  PARAMS ((void (*) (lang_input_statement_type *)));

static void (*real_func) PARAMS ((lang_input_statement_type *));

static void ppc_for_each_input_file_wrapper (l)
     lang_input_statement_type *l;
{
  if (l != stub_file)
    (*real_func) (l);
}

static void
ppc_lang_for_each_input_file (func)
     void (*func) PARAMS ((lang_input_statement_type *));
{
  real_func = func;
  lang_for_each_input_file (&ppc_for_each_input_file_wrapper);
}

#define lang_for_each_input_file ppc_lang_for_each_input_file

EOF

# Define some shell vars to insert bits of code into the standard elf
# parse_args and list_options functions.
#
PARSE_AND_LIST_PROLOGUE='
#define OPTION_STUBGROUP_SIZE		301
'

# The options are repeated below so that no abbreviations are allowed.
# Otherwise -s matches stub-group-size
PARSE_AND_LIST_LONGOPTS='
  { "stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE },
  { "stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE },
'

PARSE_AND_LIST_OPTIONS='
  fprintf (file, _("\
  --stub-group-size=N   Maximum size of a group of input sections that can be\n\
                          handled by one stub section.  A negative value\n\
                          locates all stubs before their branches (with a\n\
                          group size of -N), while a positive value allows\n\
                          two groups of input sections, one before, and one\n\
                          after each stub section.  Values of +/-1 indicate\n\
                          the linker should choose suitable defaults.\n"
		   ));
'

PARSE_AND_LIST_ARGS_CASES='
    case OPTION_STUBGROUP_SIZE:
      {
	const char *end;
        group_size = bfd_scan_vma (optarg, &end, 0);
        if (*end)
	  einfo (_("%P%F: invalid number `%s'\''\n"), optarg);
      }
      break;
'

# Put these extra ppc64elf routines in ld_${EMULATION_NAME}_emulation
#
LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation
LDEMUL_FINISH=gld${EMULATION_NAME}_finish
LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=ppc_create_output_section_statements