1 /* a.out object file format 2 Copyright (C) 1989-2016 Free Software Foundation, Inc. 3 4 This file is part of GAS, the GNU Assembler. 5 6 GAS is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as 8 published by the Free Software Foundation; either version 3, 9 or (at your option) any later version. 10 11 GAS is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See 14 the GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GAS; see the file COPYING. If not, write to the Free 18 Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA 19 02110-1301, USA. */ 20 21 #define OBJ_HEADER "obj-aout.h" 22 23 #include "as.h" 24 #undef NO_RELOC 25 #include "aout/aout64.h" 26 27 void 28 obj_aout_frob_symbol (symbolS *sym, int *punt ATTRIBUTE_UNUSED) 29 { 30 flagword flags; 31 asection *sec; 32 int type; 33 34 flags = symbol_get_bfdsym (sym)->flags; 35 type = aout_symbol (symbol_get_bfdsym (sym))->type; 36 sec = S_GET_SEGMENT (sym); 37 38 /* Only frob simple symbols this way right now. */ 39 if (! (type & ~ (N_TYPE | N_EXT))) 40 { 41 if (type == (N_UNDF | N_EXT) 42 && sec == bfd_abs_section_ptr) 43 { 44 sec = bfd_und_section_ptr; 45 S_SET_SEGMENT (sym, sec); 46 } 47 48 if ((type & N_TYPE) != N_INDR 49 && (type & N_TYPE) != N_SETA 50 && (type & N_TYPE) != N_SETT 51 && (type & N_TYPE) != N_SETD 52 && (type & N_TYPE) != N_SETB 53 && type != N_WARNING 54 && (sec == bfd_abs_section_ptr 55 || sec == bfd_und_section_ptr)) 56 return; 57 if (flags & BSF_EXPORT) 58 type |= N_EXT; 59 60 switch (type & N_TYPE) 61 { 62 case N_SETA: 63 case N_SETT: 64 case N_SETD: 65 case N_SETB: 66 /* Set the debugging flag for constructor symbols so that 67 BFD leaves them alone. */ 68 symbol_get_bfdsym (sym)->flags |= BSF_DEBUGGING; 69 70 /* You can't put a common symbol in a set. The way a set 71 element works is that the symbol has a definition and a 72 name, and the linker adds the definition to the set of 73 that name. That does not work for a common symbol, 74 because the linker can't tell which common symbol the 75 user means. FIXME: Using as_bad here may be 76 inappropriate, since the user may want to force a 77 particular type without regard to the semantics of sets; 78 on the other hand, we certainly don't want anybody to be 79 mislead into thinking that their code will work. */ 80 if (S_IS_COMMON (sym)) 81 as_bad (_("Attempt to put a common symbol into set %s"), 82 S_GET_NAME (sym)); 83 /* Similarly, you can't put an undefined symbol in a set. */ 84 else if (! S_IS_DEFINED (sym)) 85 as_bad (_("Attempt to put an undefined symbol into set %s"), 86 S_GET_NAME (sym)); 87 88 break; 89 case N_INDR: 90 /* Put indirect symbols in the indirect section. */ 91 S_SET_SEGMENT (sym, bfd_ind_section_ptr); 92 symbol_get_bfdsym (sym)->flags |= BSF_INDIRECT; 93 if (type & N_EXT) 94 { 95 symbol_get_bfdsym (sym)->flags |= BSF_EXPORT; 96 symbol_get_bfdsym (sym)->flags &=~ BSF_LOCAL; 97 } 98 break; 99 case N_WARNING: 100 /* Mark warning symbols. */ 101 symbol_get_bfdsym (sym)->flags |= BSF_WARNING; 102 break; 103 } 104 } 105 else 106 symbol_get_bfdsym (sym)->flags |= BSF_DEBUGGING; 107 108 aout_symbol (symbol_get_bfdsym (sym))->type = type; 109 110 /* Double check weak symbols. */ 111 if (S_IS_WEAK (sym) && S_IS_COMMON (sym)) 112 as_bad (_("Symbol `%s' can not be both weak and common"), 113 S_GET_NAME (sym)); 114 } 115 116 void 117 obj_aout_frob_file_before_fix (void) 118 { 119 /* Relocation processing may require knowing the VMAs of the sections. 120 Since writing to a section will cause the BFD back end to compute the 121 VMAs, fake it out here.... */ 122 bfd_byte b = 0; 123 bfd_boolean x = TRUE; 124 if (bfd_section_size (stdoutput, text_section) != 0) 125 x = bfd_set_section_contents (stdoutput, text_section, &b, (file_ptr) 0, 126 (bfd_size_type) 1); 127 else if (bfd_section_size (stdoutput, data_section) != 0) 128 x = bfd_set_section_contents (stdoutput, data_section, &b, (file_ptr) 0, 129 (bfd_size_type) 1); 130 131 gas_assert (x); 132 } 133 134 static void 135 obj_aout_line (int ignore ATTRIBUTE_UNUSED) 136 { 137 /* Assume delimiter is part of expression. 138 BSD4.2 as fails with delightful bug, so we 139 are not being incompatible here. */ 140 new_logical_line ((char *) NULL, (int) (get_absolute_expression ())); 141 demand_empty_rest_of_line (); 142 } 143 144 /* Handle .weak. This is a GNU extension. */ 145 146 static void 147 obj_aout_weak (int ignore ATTRIBUTE_UNUSED) 148 { 149 char *name; 150 int c; 151 symbolS *symbolP; 152 153 do 154 { 155 c = get_symbol_name (&name); 156 symbolP = symbol_find_or_make (name); 157 (void) restore_line_pointer (c); 158 SKIP_WHITESPACE (); 159 S_SET_WEAK (symbolP); 160 if (c == ',') 161 { 162 input_line_pointer++; 163 SKIP_WHITESPACE (); 164 if (*input_line_pointer == '\n') 165 c = '\n'; 166 } 167 } 168 while (c == ','); 169 demand_empty_rest_of_line (); 170 } 171 172 /* Handle .type. On {Net,Open}BSD, this is used to set the n_other field, 173 which is then apparently used when doing dynamic linking. Older 174 versions of gas ignored the .type pseudo-op, so we also ignore it if 175 we can't parse it. */ 176 177 static void 178 obj_aout_type (int ignore ATTRIBUTE_UNUSED) 179 { 180 char *name; 181 int c; 182 symbolS *sym; 183 184 c = get_symbol_name (&name); 185 sym = symbol_find_or_make (name); 186 (void) restore_line_pointer (c); 187 SKIP_WHITESPACE (); 188 if (*input_line_pointer == ',') 189 { 190 ++input_line_pointer; 191 SKIP_WHITESPACE (); 192 if (*input_line_pointer == '@') 193 { 194 ++input_line_pointer; 195 if (strncmp (input_line_pointer, "object", 6) == 0) 196 S_SET_OTHER (sym, 1); 197 else if (strncmp (input_line_pointer, "function", 8) == 0) 198 S_SET_OTHER (sym, 2); 199 } 200 } 201 202 /* Ignore everything else on the line. */ 203 s_ignore (0); 204 } 205 206 /* Support for an AOUT emulation. */ 207 208 static void 209 aout_pop_insert (void) 210 { 211 pop_insert (aout_pseudo_table); 212 } 213 214 static int 215 obj_aout_s_get_other (symbolS *sym) 216 { 217 return aout_symbol (symbol_get_bfdsym (sym))->other; 218 } 219 220 static void 221 obj_aout_s_set_other (symbolS *sym, int o) 222 { 223 aout_symbol (symbol_get_bfdsym (sym))->other = o; 224 } 225 226 static int 227 obj_aout_sec_sym_ok_for_reloc (asection *sec ATTRIBUTE_UNUSED) 228 { 229 return obj_sec_sym_ok_for_reloc (sec); 230 } 231 232 static void 233 obj_aout_process_stab (segT seg ATTRIBUTE_UNUSED, 234 int w, 235 const char *s, 236 int t, 237 int o, 238 int d) 239 { 240 aout_process_stab (w, s, t, o, d); 241 } 242 243 static int 244 obj_aout_s_get_desc (symbolS *sym) 245 { 246 return aout_symbol (symbol_get_bfdsym (sym))->desc; 247 } 248 249 static void 250 obj_aout_s_set_desc (symbolS *sym, int d) 251 { 252 aout_symbol (symbol_get_bfdsym (sym))->desc = d; 253 } 254 255 static int 256 obj_aout_s_get_type (symbolS *sym) 257 { 258 return aout_symbol (symbol_get_bfdsym (sym))->type; 259 } 260 261 static void 262 obj_aout_s_set_type (symbolS *sym, int t) 263 { 264 aout_symbol (symbol_get_bfdsym (sym))->type = t; 265 } 266 267 static int 268 obj_aout_separate_stab_sections (void) 269 { 270 return 0; 271 } 272 273 /* When changed, make sure these table entries match the single-format 274 definitions in obj-aout.h. */ 275 276 const struct format_ops aout_format_ops = 277 { 278 bfd_target_aout_flavour, 279 1, /* dfl_leading_underscore. */ 280 0, /* emit_section_symbols. */ 281 0, /* begin. */ 282 0, /* app_file. */ 283 obj_aout_frob_symbol, 284 0, /* frob_file. */ 285 0, /* frob_file_before_adjust. */ 286 obj_aout_frob_file_before_fix, 287 0, /* frob_file_after_relocs. */ 288 0, /* s_get_size. */ 289 0, /* s_set_size. */ 290 0, /* s_get_align. */ 291 0, /* s_set_align. */ 292 obj_aout_s_get_other, 293 obj_aout_s_set_other, 294 obj_aout_s_get_desc, 295 obj_aout_s_set_desc, 296 obj_aout_s_get_type, 297 obj_aout_s_set_type, 298 0, /* copy_symbol_attributes. */ 299 0, /* generate_asm_lineno. */ 300 obj_aout_process_stab, 301 obj_aout_separate_stab_sections, 302 0, /* init_stab_section. */ 303 obj_aout_sec_sym_ok_for_reloc, 304 aout_pop_insert, 305 0, /* ecoff_set_ext. */ 306 0, /* read_begin_hook. */ 307 0, /* symbol_new_hook. */ 308 0, /* symbol_clone_hook. */ 309 0 /* adjust_symtab. */ 310 }; 311 312 const pseudo_typeS aout_pseudo_table[] = 313 { 314 {"line", obj_aout_line, 0}, /* Source code line number. */ 315 {"ln", obj_aout_line, 0}, /* COFF line number that we use anyway. */ 316 317 {"weak", obj_aout_weak, 0}, /* Mark symbol as weak. */ 318 319 {"type", obj_aout_type, 0}, 320 321 /* coff debug pseudos (ignored) */ 322 {"def", s_ignore, 0}, 323 {"dim", s_ignore, 0}, 324 {"endef", s_ignore, 0}, 325 {"ident", s_ignore, 0}, 326 {"line", s_ignore, 0}, 327 {"ln", s_ignore, 0}, 328 {"scl", s_ignore, 0}, 329 {"size", s_ignore, 0}, 330 {"tag", s_ignore, 0}, 331 {"val", s_ignore, 0}, 332 {"version", s_ignore, 0}, 333 334 {"optim", s_ignore, 0}, /* For sun386i cc (?). */ 335 336 /* other stuff */ 337 {"ABORT", s_abort, 0}, 338 339 {NULL, NULL, 0} 340 }; 341
