ld/emultempl/kvxelf.em

# This shell script emits a C file. -*- C -*-
#   Copyright (C) 2009-2024 Free Software Foundation, Inc.
#   Contributed by Kalray Inc.
#
# This file is part of the GNU Binutils.
#
# 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 3 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; see the file COPYING3. If not,
# see <http://www.gnu.org/licenses/>.
#

# This file is sourced from elf32.em, and defines extra kvx-elf
# specific routines.
#
fragment <<EOF

#include "ldctor.h"
#include "elf/kvx.h"
#include "elfxx-kvx.h"


static void
elf${ELFSIZE}_kvx_before_allocation (void)
{
EOF
if test x"${EMULATION_NAME}" != x"elf64kvx_linux"; then
fragment <<EOF
  if (bfd_link_pie (&link_info)) {
          einfo (_("%F:%P: -pie not supported\n"));
  }
EOF
fi
fragment <<EOF

  /* Call the standard elf routine.  */
  gld${EMULATION_NAME}_before_allocation ();
}



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

/* Whether we need to call gldarm_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;

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 bool
hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
{
  lang_statement_union_type *l;
  bool 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
		 after its associated input section.  */
	      *(info->add.tail) = l->header.next;
	      l->header.next = info->add.head;
	      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 elf${ELFSIZE}_kvx_size_stubs.  */

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

static asection *
elf${ELFSIZE}_kvx_add_stub_section (const char *stub_sec_name,
                                    asection *input_section)
{
  asection *stub_sec;
  flagword flags;
  asection *output_section;
  lang_output_section_statement_type *os;
  struct hook_stub_info info;

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

  bfd_set_section_alignment (stub_sec, 2);

  output_section = input_section->output_section;
  os = lang_output_section_get (output_section);

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

  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 elf${ELFSIZE}_kvx_size_stubs.  */

static void
gldkvx_layout_sections_again (void)
{
  /* 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.  */
  ldelf_map_segments (true);
  need_laying_out = -1;
}

static void
build_section_lists (lang_statement_union_type *statement)
{
  if (statement->header.type == lang_input_section_enum)
    {
      asection *i = statement->input_section.section;

      if (!((lang_input_statement_type *) i->owner->usrdata)->flags.just_syms
	  && (i->flags & SEC_EXCLUDE) == 0
	  && i->output_section != NULL
	  && i->output_section->owner == link_info.output_bfd)
	elf${ELFSIZE}_kvx_next_input_section (& link_info, i);
    }
}

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

  /* bfd_elf32_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.  */
  ret = bfd_elf_discard_info (link_info.output_bfd, & link_info);
  if (ret < 0)
    {
      einfo ("%X%P: .eh_frame/.stab edit: %E\n");
      return;
    }
  else if (ret > 0)
    need_laying_out = 1;

  /* If generating a relocatable output file, then we don't
     have to examine the relocs.  */
  if (stub_file != NULL && !bfd_link_relocatable (&link_info))
    {
      ret = elf${ELFSIZE}_kvx_setup_section_lists (link_info.output_bfd,
						       &link_info);
      if (ret != 0)
	{
	  if (ret < 0)
	    {
	      einfo ("%X%P: could not compute sections lists for stub generation: %E\n");
	      return;
	    }

	  lang_for_each_statement (build_section_lists);

	  /* Call into the BFD backend to do the real work.  */
	  if (! elf${ELFSIZE}_kvx_size_stubs (link_info.output_bfd,
					  stub_file->the_bfd,
					  & link_info,
					  group_size,
					  & elf${ELFSIZE}_kvx_add_stub_section,
					  & gldkvx_layout_sections_again))
	    {
	      einfo ("%X%P: cannot size stub section: %E\n");
	      return;
	    }
	}
    }

  if (need_laying_out != -1)
    ldelf_map_segments (need_laying_out);
}

static void
gld${EMULATION_NAME}_finish (void)
{
  if (!bfd_link_relocatable (&link_info))
    {
      /* Now build the linker stubs.  */
      if (stub_file != NULL
	  && stub_file->the_bfd->sections != NULL)
	{
	  if (! elf${ELFSIZE}_kvx_build_stubs (& link_info))
	    einfo ("%X%P: can not build stubs: %E\n");
	}
    }

  finish_default ();
}

/* This is a convenient point to tell BFD about target specific flags.
   After the output has been created, but before inputs are read.  */
static void
kvx_elf_create_output_section_statements (void)
{
  if (!(bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour
        && elf_object_id (link_info.output_bfd) == KVX_ELF_DATA))
    return;

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

  stub_file->the_bfd->flags |= BFD_LINKER_CREATED;
  ldlang_add_file (stub_file);

  if (!kvx_elf${ELFSIZE}_init_stub_bfd (&link_info, stub_file->the_bfd))
    einfo ("%F%P: can not init BFD: %E\n");
}


#define lang_for_each_input_file kvx_lang_for_each_input_file

EOF

LDEMUL_BEFORE_ALLOCATION=elf${ELFSIZE}_kvx_before_allocation
LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation
LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=kvx_elf_create_output_section_statements

# Call the extra arm-elf function
LDEMUL_FINISH=gld${EMULATION_NAME}_finish