ld/emultempl/riscvelf.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright (C) 2004-2023 Free Software Foundation, Inc.
   3 #
   4 # This file is part of the GNU Binutils.
   5 #
   6 # This program is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 3 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program; if not, write to the Free Software
  18 # Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  19 # MA 02110-1301, USA.
  20
  21 fragment <<EOF
  22
  23 #include "ldmain.h"
  24 #include "ldctor.h"
  25 #include "elf/riscv.h"
  26 #include "elfxx-riscv.h"
  27
  28 static struct riscv_elf_params params = { .relax_gp = 1,
  29                                           .check_uleb128 = 0};
  30 EOF
  31
  32 # Define some shell vars to insert bits of code into the standard elf
  33 # parse_args and list_options functions.  */
  34 PARSE_AND_LIST_PROLOGUE=${PARSE_AND_LIST_PROLOGUE}'
  35 enum risccv_opt
  36 {
  37   OPTION_RELAX_GP = 321,
  38   OPTION_NO_RELAX_GP,
  39   OPTION_CHECK_ULEB128,
  40   OPTION_NO_CHECK_ULEB128,
  41 };
  42 '
  43
  44 PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
  45     { "relax-gp", no_argument, NULL, OPTION_RELAX_GP },
  46     { "no-relax-gp", no_argument, NULL, OPTION_NO_RELAX_GP },
  47     { "check-uleb128", no_argument, NULL, OPTION_CHECK_ULEB128 },
  48     { "no-check-uleb128", no_argument, NULL, OPTION_NO_CHECK_ULEB128 },
  49 '
  50
  51 PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'
  52   fprintf (file, _("  --relax-gp                  Perform GP relaxation\n"));
  53   fprintf (file, _("  --no-relax-gp               Don'\''t perform GP relaxation\n"));
  54   fprintf (file, _("  --check-uleb128             Check if SUB_ULEB128 has non-zero addend\n"));
  55   fprintf (file, _("  --no-check-uleb128          Don'\''t check if SUB_ULEB128 has non-zero addend\n"));
  56 '
  57
  58 PARSE_AND_LIST_ARGS_CASES=${PARSE_AND_LIST_ARGS_CASES}'
  59     case OPTION_RELAX_GP:
  60       params.relax_gp = 1;
  61       break;
  62
  63     case OPTION_NO_RELAX_GP:
  64       params.relax_gp = 0;
  65       break;
  66
  67     case OPTION_CHECK_ULEB128:
  68       params.check_uleb128 = 1;
  69       break;
  70
  71     case OPTION_NO_CHECK_ULEB128:
  72       params.check_uleb128 = 0;
  73       break;
  74 '
  75
  76 fragment <<EOF
  77 static void
  78 riscv_elf_before_allocation (void)
  79 {
  80   gld${EMULATION_NAME}_before_allocation ();
  81
  82   if (link_info.discard == discard_sec_merge)
  83     link_info.discard = discard_l;
  84
  85   if (!bfd_link_relocatable (&link_info))
  86     {
  87       /* We always need at least some relaxation to handle code alignment.  */
  88       if (RELAXATION_DISABLED_BY_USER)
  89         TARGET_ENABLE_RELAXATION;
  90       else
  91         ENABLE_RELAXATION;
  92     }
  93
  94   link_info.relax_pass = 2;
  95 }
  96
  97 static void
  98 gld${EMULATION_NAME}_after_allocation (void)
  99 {
 100   int need_layout = 0;
 101
 102   /* Don't attempt to discard unused .eh_frame sections until the final link,
 103      as we can't reliably tell if they're used until after relaxation.  */
 104   if (!bfd_link_relocatable (&link_info))
 105     {
 106       need_layout = bfd_elf_discard_info (link_info.output_bfd, &link_info);
 107       if (need_layout < 0)
 108         {
 109           einfo (_("%X%P: .eh_frame/.stab edit: %E\n"));
 110           return;
 111         }
 112     }
 113
 114   /* PR 27566, if the phase of data segment is exp_seg_relro_adjust,
 115      that means we are still adjusting the relro, and shouldn't do the
 116      relaxations at this stage.  Otherwise, we will get the symbol
 117      values beofore handling the relro, and may cause truncated fails
 118      when the relax range crossing the data segment.  One of the solution
 119      is to monitor the data segment phase while relaxing, to know whether
 120      the relro has been handled or not.
 121
 122      I think we probably need to record more information about data
 123      segment or alignments in the future, to make sure it is safe
 124      to doing relaxations.  */
 125   enum phase_enum *phase = &(expld.dataseg.phase);
 126   bfd_elf${ELFSIZE}_riscv_set_data_segment_info (&link_info, (int *) phase);
 127
 128   ldelf_map_segments (need_layout);
 129 }
 130
 131 /* This is a convenient point to tell BFD about target specific flags.
 132    After the output has been created, but before inputs are read.  */
 133
 134 static void
 135 riscv_create_output_section_statements (void)
 136 {
 137   /* See PR 22920 for an example of why this is necessary.  */
 138   if (strstr (bfd_get_target (link_info.output_bfd), "riscv") == NULL)
 139     {
 140       /* The RISC-V backend needs special fields in the output hash structure.
 141          These will only be created if the output format is a RISC-V format,
 142          hence we do not support linking and changing output formats at the
 143          same time.  Use a link followed by objcopy to change output formats.  */
 144       einfo (_("%F%P: error: cannot change output format"
 145                " whilst linking %s binaries\n"), "RISC-V");
 146       return;
 147     }
 148
 149   riscv_elf${ELFSIZE}_set_options (&link_info, &params);
 150 }
 151
 152 EOF
 153
 154 LDEMUL_BEFORE_ALLOCATION=riscv_elf_before_allocation
 155 LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation
 156 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=riscv_create_output_section_statements