binutils-gdb/ld/emultempl/cskyelf.em

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# This shell script emits a C file. -*- C -*-
# Copyright (C) 2013-2020 Free Software Foundation, Inc.
#
# This file is part of 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; 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 C-SKY ELF
# specific routines.
#
fragment <<EOF
#include "ldctor.h"
#include "elf/csky.h"
#include "elf32-csky.h"
/* To use branch stub or not. */
extern bfd_boolean use_branch_stub;
/* Fake input file for stubs. */
static lang_input_statement_type *stub_file;
/* Whether we need to call gldcsky_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 bfd_boolean
hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
{
lang_statement_union_type *l;
bfd_boolean ret;
for (l = *lp; l != NULL; lp = &l->header.next, l = *lp)
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;
}
EOF
case ${target} in
csky-*-linux-*)
fragment <<EOF
static void
csky_elf_before_parse (void)
{
use_branch_stub = FALSE;
gld${EMULATION_NAME}_before_parse ();
}
EOF
;;
esac
fragment <<EOF
/* 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
csky_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) == CSKY_ELF_DATA))
use_branch_stub = FALSE;
/* If don't use branch stub, just do not emit stub_file. */
if (!use_branch_stub)
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 (_("%F%P: can not create BFD: %E\n"));
return;
}
stub_file->the_bfd->flags |= BFD_LINKER_CREATED;
ldlang_add_file (stub_file);
}
/* Call-back for elf32_csky_size_stubs. */
/* Create a new stub section, and arrange for it to be linked
immediately after INPUT_SECTION. */
static asection *
elf32_csky_add_stub_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;
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, 3);
output_section = input_section->output_section;
secname = bfd_section_name (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, 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_csky_size_stubs. */
static void
gldcsky_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 (i->sec_info_type != SEC_INFO_TYPE_JUST_SYMS
&& (i->flags & SEC_EXCLUDE) == 0
&& i->output_section != NULL
&& i->output_section->owner == link_info.output_bfd)
elf32_csky_next_input_section (&link_info, i);
}
}
static void
gld${EMULATION_NAME}_after_allocation (void)
{
/* bfd_elf32_discard_info just plays with debugging sections,
ie. doesn't affect any code, so we can delay resizing the
sections. It's likely we'll resize everything in the process of
adding stubs. */
if (bfd_elf_discard_info (link_info.output_bfd, &link_info))
need_laying_out = 1;
/* If generating a relocatable output file, then we don't
have to examine the relocs. */
if (stub_file != NULL && !bfd_link_relocatable (&link_info))
{
int ret = elf32_csky_setup_section_lists (link_info.output_bfd,
&link_info);
if (ret < 0)
{
einfo (_("%X%P: could not compute sections lists for stub generation: %E\n"));
return;
}
else if (ret != 0)
{
lang_for_each_statement (build_section_lists);
/* Call into the BFD backend to do the real work. */
if (! elf32_csky_size_stubs (link_info.output_bfd,
stub_file->the_bfd,
&link_info,
group_size,
&elf32_csky_add_stub_section,
&gldcsky_layout_sections_again))
{
einfo (_("%X%P: cannot size stub section: %E\n"));
return;
}
}
}
if (need_laying_out != -1)
ldelf_map_segments (need_laying_out);
}
static void
gld${EMULATION_NAME}_finish (void)
{
if (stub_file != NULL
&& !bfd_link_relocatable (&link_info)
&& stub_file->the_bfd->sections != NULL
&& !elf32_csky_build_stubs (&link_info))
einfo (_("%X%P: cannot build stubs: %E\n"));
finish_default ();
}
EOF
# This code gets inserted into the generic elf32.sc linker script
# and allows us to define our own command line switches.
PARSE_AND_LIST_PROLOGUE='
#define OPTION_BRANCH_STUB 301
#define OPTION_NO_BRANCH_STUB 302
#define OPTION_STUBGROUP_SIZE 303
'
PARSE_AND_LIST_LONGOPTS='
{"branch-stub", no_argument, NULL, OPTION_BRANCH_STUB},
{"no-branch-stub", no_argument, NULL, OPTION_NO_BRANCH_STUB},
{"stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE},
'
PARSE_AND_LIST_OPTIONS='
fprintf (file, _(" --[no-]branch-stub\n"));
fprintf (file, _("\t\t\tDisable/enable use of stubs to expand branch "
"instructions that cannot reach the target.\n"));
fprintf (file, _(" --stub-group-size=N\n"));
fprintf (file, _("\t\t\tMaximum size of a group of input sections "
"handled by one stub section."));
'
PARSE_AND_LIST_ARGS_CASES='
case OPTION_BRANCH_STUB:
use_branch_stub = TRUE;
break;
case OPTION_NO_BRANCH_STUB:
use_branch_stub = FALSE;
break;
case OPTION_STUBGROUP_SIZE:
{
const char *end;
group_size = bfd_scan_vma (optarg, &end, 0);
if (*end)
einfo (_("%F%P: invalid number `%s'\''\n"), optarg);
}
break;
'
case ${target} in
csky-*-linux-*) LDEMUL_BEFORE_PARSE=csky_elf_before_parse ;;
esac
LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation
LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=csky_elf_create_output_section_statements
LDEMUL_FINISH=gld${EMULATION_NAME}_finish