1 # This shell script emits a C file. -*- C -*- 2 # Copyright (C) 2001-2016 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 22 # This file is sourced from generic.em. 23 24 fragment <<EOF 25 /* Need to have this macro defined before mmix-elfnmmo, which uses the 26 name for the before_allocation function, defined in ldemul.c (for 27 the mmo "emulation") or in elf32.em (for the elf64mmix 28 "emulation"). */ 29 #define gldmmo_before_allocation before_allocation_default 30 31 /* We include this header *not* because we expect to handle ELF here 32 but because we re-use the map_segments function in elf-generic.em, 33 a file which is rightly somewhat ELF-centric. But this is only to 34 get a weird testcase right; ld-mmix/bpo-22, forcing ELF to be 35 output from the mmo emulation: -m mmo --oformat elf64-mmix! */ 36 #include "elf-bfd.h" 37 38 static void gld${EMULATION_NAME}_after_allocation (void); 39 EOF 40 41 source_em ${srcdir}/emultempl/elf-generic.em 42 source_em ${srcdir}/emultempl/mmix-elfnmmo.em 43 44 fragment <<EOF 45 46 /* Place an orphan section. We use this to put random SEC_CODE or 47 SEC_READONLY sections right after MMO_TEXT_SECTION_NAME. Much borrowed 48 from elf32.em. */ 49 50 static lang_output_section_statement_type * 51 mmo_place_orphan (asection *s, 52 const char *secname, 53 int constraint ATTRIBUTE_UNUSED) 54 { 55 static struct 56 { 57 flagword nonzero_flags; 58 struct orphan_save orphansave; 59 } holds[] = 60 { 61 { 62 SEC_CODE | SEC_READONLY, 63 { 64 MMO_TEXT_SECTION_NAME, 65 SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE, 66 0, 0, 0, 0 67 } 68 }, 69 { 70 SEC_LOAD | SEC_DATA, 71 { 72 MMO_DATA_SECTION_NAME, 73 SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_DATA, 74 0, 0, 0, 0 75 } 76 }, 77 { 78 SEC_ALLOC, 79 { 80 ".bss", 81 SEC_ALLOC, 82 0, 0, 0, 0 83 } 84 } 85 }; 86 87 struct orphan_save *place = NULL; 88 lang_output_section_statement_type *after; 89 lang_output_section_statement_type *os; 90 size_t i; 91 flagword flags; 92 asection *nexts; 93 94 /* We have nothing to say for anything other than a final link or 95 for sections that are excluded. */ 96 if (bfd_link_relocatable (&link_info) 97 || (s->flags & SEC_EXCLUDE) != 0) 98 return NULL; 99 100 os = lang_output_section_find (secname); 101 102 /* We have an output section by this name. Place the section inside it 103 (regardless of whether the linker script lists it as input). */ 104 if (os != NULL) 105 { 106 lang_add_section (&os->children, s, NULL, os); 107 return os; 108 } 109 110 flags = s->flags; 111 if (!bfd_link_relocatable (&link_info)) 112 { 113 nexts = s; 114 while ((nexts = bfd_get_next_section_by_name (nexts->owner, nexts)) 115 != NULL) 116 if (nexts->output_section == NULL 117 && (nexts->flags & SEC_EXCLUDE) == 0 118 && ((nexts->flags ^ flags) & (SEC_LOAD | SEC_ALLOC)) == 0 119 && (nexts->owner->flags & DYNAMIC) == 0 120 && nexts->owner->usrdata != NULL 121 && !(((lang_input_statement_type *) nexts->owner->usrdata) 122 ->flags.just_syms)) 123 flags = (((flags ^ SEC_READONLY) | (nexts->flags ^ SEC_READONLY)) 124 ^ SEC_READONLY); 125 } 126 127 /* Check for matching section type flags for sections we care about. 128 A section without contents can have SEC_LOAD == 0, but we still 129 want it attached to a sane section so the symbols appear as 130 expected. */ 131 132 if ((flags & (SEC_ALLOC | SEC_READONLY)) != SEC_READONLY) 133 for (i = 0; i < sizeof (holds) / sizeof (holds[0]); i++) 134 if ((flags & holds[i].nonzero_flags) != 0) 135 { 136 place = &holds[i].orphansave; 137 if (place->os == NULL) 138 place->os = lang_output_section_find (place->name); 139 break; 140 } 141 142 if (place == NULL) 143 { 144 /* For other combinations, we have to give up, except we make 145 sure not to place the orphan section after the 146 linker-generated register section; that'd make it continue 147 the reg section and we never want that to happen for orphan 148 sections. */ 149 lang_output_section_statement_type *before; 150 lang_output_section_statement_type *lookup; 151 static struct orphan_save hold_nonreg = 152 { 153 NULL, 154 SEC_READONLY, 155 0, 0, 0, 0 156 }; 157 158 if (hold_nonreg.os == NULL) 159 { 160 before = lang_output_section_find (MMIX_REG_CONTENTS_SECTION_NAME); 161 162 /* If we have no such section, all fine; we don't care where 163 it's placed. */ 164 if (before == NULL) 165 return NULL; 166 167 /* We have to find the oss before this one, so we can use that as 168 "after". */ 169 for (lookup = &lang_output_section_statement.head->output_section_statement; 170 lookup != NULL && lookup->next != before; 171 lookup = lookup->next) 172 ; 173 174 hold_nonreg.os = lookup; 175 } 176 177 place = &hold_nonreg; 178 } 179 180 after = place->os; 181 if (after == NULL) 182 return NULL; 183 184 /* If there's an output section by *this* name, we'll use it, regardless 185 of actual section flags, in contrast to what's done in elf32.em. */ 186 os = lang_insert_orphan (s, secname, 0, after, place, NULL, NULL); 187 188 return os; 189 } 190 191 /* Remove the spurious settings of SEC_RELOC that make it to the output at 192 link time. We are as confused as elflink.h:elf_bfd_final_link, and 193 paper over the bug similarly. */ 194 195 static void 196 mmo_wipe_sec_reloc_flag (bfd *abfd, asection *sec, void *ptr ATTRIBUTE_UNUSED) 197 { 198 bfd_set_section_flags (abfd, sec, 199 bfd_get_section_flags (abfd, sec) & ~SEC_RELOC); 200 } 201 202 /* Iterate with bfd_map_over_sections over mmo_wipe_sec_reloc_flag... */ 203 204 static void 205 gld${EMULATION_NAME}_after_allocation (void) 206 { 207 bfd_map_over_sections (link_info.output_bfd, mmo_wipe_sec_reloc_flag, NULL); 208 gld${EMULATION_NAME}_map_segments (FALSE); 209 } 210 212 /* To get on-demand global register allocation right, we need to parse the 213 relocs, like what happens when linking to ELF. It needs to be done 214 before all input sections are supposed to be present. When linking to 215 ELF, it's done when reading symbols. When linking to mmo, we do it 216 when all input files are seen, which is equivalent. */ 217 218 static void 219 mmo_after_open (void) 220 { 221 /* When there's a mismatch between the output format and the emulation 222 (using weird combinations like "-m mmo --oformat elf64-mmix" for 223 example), we'd count relocs twice because they'd also be counted 224 along the usual route for ELF-only linking, which would lead to an 225 internal accounting error. */ 226 if (bfd_get_flavour (link_info.output_bfd) != bfd_target_elf_flavour) 227 { 228 LANG_FOR_EACH_INPUT_STATEMENT (is) 229 { 230 if (bfd_get_flavour (is->the_bfd) == bfd_target_elf_flavour 231 && !_bfd_mmix_check_all_relocs (is->the_bfd, &link_info)) 232 einfo ("%X%P: Internal problems scanning %B after opening it", 233 is->the_bfd); 234 } 235 } 236 after_open_default (); 237 } 238 EOF 239 240 LDEMUL_PLACE_ORPHAN=mmo_place_orphan 241 LDEMUL_AFTER_OPEN=mmo_after_open 242
