ld/emultempl/nto.em

# This shell script emits a C file. -*- C -*-
#   Copyright 2023 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., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
#

# This file is sourced from elf.em, and defines extra Neutrino
# specific routines.

# NTO templates aims to refine the default ${ARCH}elf.em template.
. "${srcdir}/emultempl/${ARCH}elf.em"

cat >>e${EMULATION_NAME}.c <<EOF

#include "elf/internal.h"
#include "elf/common.h"
#include "elf-bfd.h"
#include "../bfd/libbfd.h"

bool nto_lazy_stack = false;
struct nto_stack_note
{
  unsigned char stacksize[4];
  unsigned char stackalloc[4];
  unsigned char execstack[4];
};

/* Generate the QNT_STACK .note section.  */
static void
nto_add_note_section (void) {
  asection *note_sec;
  flagword flags;
  Elf_External_Note *e_note;
  bfd_size_type size, h_size;
  struct nto_stack_note *n_note;

  /* Don't create a note if the stack size isn't provided.  */
  if (link_info.stacksize <= 0)
    return;

  /* As ${ARCH}elf.em is imported and ${ARCH}_elf_create_output_section_statements
     is called before this function, stub_file should already be defined.  */
  if (!stub_file)
    {
      einfo (_("%F%P: cannot create .note section in stub BFD.\n"));
      return;
    }

  if (nto_lazy_stack && !link_info.stacksize)
    {
      einfo (_("%F%P: error: --lazy-stack must follow -zstack-size=<size>\n"));
      return;
    }

  flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_HAS_CONTENTS
	   | SEC_IN_MEMORY | SEC_LINKER_CREATED);
  note_sec = bfd_make_section_anyway_with_flags (stub_file->the_bfd, ".note", flags);
  if (! note_sec)
    {
      einfo (_("%F%P: failed to create .note section\n"));
      return;
    }

  size = offsetof (Elf_External_Note, name[sizeof "QNX"]);
  size = (size + 3) & -(bfd_size_type) 4;
  h_size = size;
  size += sizeof (struct nto_stack_note);
  note_sec->size = size;

  elf_section_type (note_sec) = SHT_NOTE;
  note_sec->contents = xmalloc (note_sec->size);
  e_note = (Elf_External_Note *) note_sec->contents;
  bfd_h_put_32 (stub_file->the_bfd, sizeof "QNX", &e_note->namesz);
  bfd_h_put_32 (stub_file->the_bfd, sizeof (struct nto_stack_note), &e_note->descsz);
  bfd_h_put_32 (stub_file->the_bfd, QNT_STACK, &e_note->type);
  memcpy (e_note->name, "QNX", sizeof "QNX");


  /* Generate .note content.*/
  n_note = (struct nto_stack_note *) (note_sec->contents + h_size);
  bfd_h_put_32 (stub_file->the_bfd, link_info.stacksize, &n_note->stacksize);

  if (nto_lazy_stack)
    bfd_h_put_32 (stub_file->the_bfd, 4096, &n_note->stackalloc);
  else
    bfd_h_put_32 (stub_file->the_bfd, link_info.stacksize, &n_note->stackalloc);

  if (link_info.execstack != link_info.noexecstack && link_info.execstack)
    bfd_h_put_32 (stub_file->the_bfd, 0, &n_note->execstack);
  else
    bfd_h_put_32 (stub_file->the_bfd, 1, &n_note->execstack);

}

static void
nto_create_output_section_statements (void)
{
  ${ARCH}_elf_create_output_section_statements ();
  nto_add_note_section();
}

EOF

# Define some shell vars to insert bits of code into the standard elf
# parse_args and list_options functions.
#

PARSE_AND_LIST_PROLOGUE=${PARSE_AND_LIST_PROLOGUE}'
enum nto_options
{
  OPTION_STACK = 500,
  OPTION_LAZY_STACK,
};
'

PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
  { "stack", required_argument, NULL, OPTION_STACK },
  { "lazy-stack", no_argument, NULL, OPTION_LAZY_STACK },
'

PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'
  fprintf (file, _("\
  --stack <size>              Set size of the initial stack\n\
  --lazy-stack		      Set lazy allocation of stack\n\
"));
'

PARSE_AND_LIST_ARGS_CASES=${PARSE_AND_LIST_ARGS_CASES}'
    case OPTION_STACK:
      {
        char *end;
        link_info.stacksize = strtoul (optarg, &end, 0);
        if (*end || link_info.stacksize < 0)
          einfo (_("%F%P: invalid stack size `%s'\''\n"), optarg + 11);
        if (!link_info.stacksize)
          /* Use -1 for explicit no-stack, because zero means
             'default'.   */
          link_info.stacksize = -1;
        break;
      }
    case OPTION_LAZY_STACK:
      nto_lazy_stack = true;
      break;
'

# Put these extra Neutrino routines in ld_${EMULATION_NAME}_emulation
#

LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=nto_create_output_section_statements