| 1 | /* expr.c -operands, expressions- |
| 2 | Copyright (C) 1987, 90, 91, 92, 93, 94, 95, 96, 1997 |
| 3 | Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GAS, the GNU Assembler. |
| 6 | |
| 7 | GAS is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2, or (at your option) |
| 10 | any later version. |
| 11 | |
| 12 | GAS is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with GAS; see the file COPYING. If not, write to the Free |
| 19 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA |
| 20 | 02111-1307, USA. */ |
| 21 | |
| 22 | /* |
| 23 | * This is really a branch office of as-read.c. I split it out to clearly |
| 24 | * distinguish the world of expressions from the world of statements. |
| 25 | * (It also gives smaller files to re-compile.) |
| 26 | * Here, "operand"s are of expressions, not instructions. |
| 27 | */ |
| 28 | |
| 29 | #include <ctype.h> |
| 30 | #include <string.h> |
| 31 | |
| 32 | #include "as.h" |
| 33 | #include "obstack.h" |
| 34 | |
| 35 | static void floating_constant PARAMS ((expressionS * expressionP)); |
| 36 | static void integer_constant PARAMS ((int radix, expressionS * expressionP)); |
| 37 | static void mri_char_constant PARAMS ((expressionS *)); |
| 38 | static void current_location PARAMS ((expressionS *)); |
| 39 | static void clean_up_expression PARAMS ((expressionS * expressionP)); |
| 40 | |
| 41 | extern const char EXP_CHARS[], FLT_CHARS[]; |
| 42 | |
| 43 | /* We keep a mapping of expression symbols to file positions, so that |
| 44 | we can provide better error messages. */ |
| 45 | |
| 46 | struct expr_symbol_line |
| 47 | { |
| 48 | struct expr_symbol_line *next; |
| 49 | symbolS *sym; |
| 50 | char *file; |
| 51 | unsigned int line; |
| 52 | }; |
| 53 | |
| 54 | static struct expr_symbol_line *expr_symbol_lines; |
| 55 | \f |
| 56 | /* Build a dummy symbol to hold a complex expression. This is how we |
| 57 | build expressions up out of other expressions. The symbol is put |
| 58 | into the fake section expr_section. */ |
| 59 | |
| 60 | symbolS * |
| 61 | make_expr_symbol (expressionP) |
| 62 | expressionS *expressionP; |
| 63 | { |
| 64 | const char *fake; |
| 65 | symbolS *symbolP; |
| 66 | struct expr_symbol_line *n; |
| 67 | |
| 68 | if (expressionP->X_op == O_symbol |
| 69 | && expressionP->X_add_number == 0) |
| 70 | return expressionP->X_add_symbol; |
| 71 | |
| 72 | /* FIXME: This should be something which decode_local_label_name |
| 73 | will handle. */ |
| 74 | fake = FAKE_LABEL_NAME; |
| 75 | |
| 76 | /* Putting constant symbols in absolute_section rather than |
| 77 | expr_section is convenient for the old a.out code, for which |
| 78 | S_GET_SEGMENT does not always retrieve the value put in by |
| 79 | S_SET_SEGMENT. */ |
| 80 | symbolP = symbol_create (fake, |
| 81 | (expressionP->X_op == O_constant |
| 82 | ? absolute_section |
| 83 | : expr_section), |
| 84 | 0, &zero_address_frag); |
| 85 | symbolP->sy_value = *expressionP; |
| 86 | |
| 87 | if (expressionP->X_op == O_constant) |
| 88 | resolve_symbol_value (symbolP); |
| 89 | |
| 90 | n = (struct expr_symbol_line *) xmalloc (sizeof *n); |
| 91 | n->sym = symbolP; |
| 92 | as_where (&n->file, &n->line); |
| 93 | n->next = expr_symbol_lines; |
| 94 | expr_symbol_lines = n; |
| 95 | |
| 96 | return symbolP; |
| 97 | } |
| 98 | |
| 99 | /* Return the file and line number for an expr symbol. Return |
| 100 | non-zero if something was found, 0 if no information is known for |
| 101 | the symbol. */ |
| 102 | |
| 103 | int |
| 104 | expr_symbol_where (sym, pfile, pline) |
| 105 | symbolS *sym; |
| 106 | char **pfile; |
| 107 | unsigned int *pline; |
| 108 | { |
| 109 | register struct expr_symbol_line *l; |
| 110 | |
| 111 | for (l = expr_symbol_lines; l != NULL; l = l->next) |
| 112 | { |
| 113 | if (l->sym == sym) |
| 114 | { |
| 115 | *pfile = l->file; |
| 116 | *pline = l->line; |
| 117 | return 1; |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | return 0; |
| 122 | } |
| 123 | \f |
| 124 | /* |
| 125 | * Build any floating-point literal here. |
| 126 | * Also build any bignum literal here. |
| 127 | */ |
| 128 | |
| 129 | /* Seems atof_machine can backscan through generic_bignum and hit whatever |
| 130 | happens to be loaded before it in memory. And its way too complicated |
| 131 | for me to fix right. Thus a hack. JF: Just make generic_bignum bigger, |
| 132 | and never write into the early words, thus they'll always be zero. |
| 133 | I hate Dean's floating-point code. Bleh. */ |
| 134 | LITTLENUM_TYPE generic_bignum[SIZE_OF_LARGE_NUMBER + 6]; |
| 135 | FLONUM_TYPE generic_floating_point_number = |
| 136 | { |
| 137 | &generic_bignum[6], /* low (JF: Was 0) */ |
| 138 | &generic_bignum[SIZE_OF_LARGE_NUMBER + 6 - 1], /* high JF: (added +6) */ |
| 139 | 0, /* leader */ |
| 140 | 0, /* exponent */ |
| 141 | 0 /* sign */ |
| 142 | }; |
| 143 | /* If nonzero, we've been asked to assemble nan, +inf or -inf */ |
| 144 | int generic_floating_point_magic; |
| 145 | \f |
| 146 | static void |
| 147 | floating_constant (expressionP) |
| 148 | expressionS *expressionP; |
| 149 | { |
| 150 | /* input_line_pointer->*/ |
| 151 | /* floating-point constant. */ |
| 152 | int error_code; |
| 153 | |
| 154 | error_code = atof_generic (&input_line_pointer, ".", EXP_CHARS, |
| 155 | &generic_floating_point_number); |
| 156 | |
| 157 | if (error_code) |
| 158 | { |
| 159 | if (error_code == ERROR_EXPONENT_OVERFLOW) |
| 160 | { |
| 161 | as_bad ("bad floating-point constant: exponent overflow, probably assembling junk"); |
| 162 | } |
| 163 | else |
| 164 | { |
| 165 | as_bad ("bad floating-point constant: unknown error code=%d.", error_code); |
| 166 | } |
| 167 | } |
| 168 | expressionP->X_op = O_big; |
| 169 | /* input_line_pointer->just after constant, */ |
| 170 | /* which may point to whitespace. */ |
| 171 | expressionP->X_add_number = -1; |
| 172 | } |
| 173 | |
| 174 | static void |
| 175 | integer_constant (radix, expressionP) |
| 176 | int radix; |
| 177 | expressionS *expressionP; |
| 178 | { |
| 179 | char *start; /* start of number. */ |
| 180 | char *suffix = NULL; |
| 181 | char c; |
| 182 | valueT number; /* offset or (absolute) value */ |
| 183 | short int digit; /* value of next digit in current radix */ |
| 184 | short int maxdig = 0;/* highest permitted digit value. */ |
| 185 | int too_many_digits = 0; /* if we see >= this number of */ |
| 186 | char *name; /* points to name of symbol */ |
| 187 | symbolS *symbolP; /* points to symbol */ |
| 188 | |
| 189 | int small; /* true if fits in 32 bits. */ |
| 190 | |
| 191 | /* May be bignum, or may fit in 32 bits. */ |
| 192 | /* Most numbers fit into 32 bits, and we want this case to be fast. |
| 193 | so we pretend it will fit into 32 bits. If, after making up a 32 |
| 194 | bit number, we realise that we have scanned more digits than |
| 195 | comfortably fit into 32 bits, we re-scan the digits coding them |
| 196 | into a bignum. For decimal and octal numbers we are |
| 197 | conservative: Some numbers may be assumed bignums when in fact |
| 198 | they do fit into 32 bits. Numbers of any radix can have excess |
| 199 | leading zeros: We strive to recognise this and cast them back |
| 200 | into 32 bits. We must check that the bignum really is more than |
| 201 | 32 bits, and change it back to a 32-bit number if it fits. The |
| 202 | number we are looking for is expected to be positive, but if it |
| 203 | fits into 32 bits as an unsigned number, we let it be a 32-bit |
| 204 | number. The cavalier approach is for speed in ordinary cases. */ |
| 205 | /* This has been extended for 64 bits. We blindly assume that if |
| 206 | you're compiling in 64-bit mode, the target is a 64-bit machine. |
| 207 | This should be cleaned up. */ |
| 208 | |
| 209 | #ifdef BFD64 |
| 210 | #define valuesize 64 |
| 211 | #else /* includes non-bfd case, mostly */ |
| 212 | #define valuesize 32 |
| 213 | #endif |
| 214 | |
| 215 | if (flag_m68k_mri && radix == 0) |
| 216 | { |
| 217 | int flt = 0; |
| 218 | |
| 219 | /* In MRI mode, the number may have a suffix indicating the |
| 220 | radix. For that matter, it might actually be a floating |
| 221 | point constant. */ |
| 222 | for (suffix = input_line_pointer; isalnum (*suffix); suffix++) |
| 223 | { |
| 224 | if (*suffix == 'e' || *suffix == 'E') |
| 225 | flt = 1; |
| 226 | } |
| 227 | |
| 228 | if (suffix == input_line_pointer) |
| 229 | { |
| 230 | radix = 10; |
| 231 | suffix = NULL; |
| 232 | } |
| 233 | else |
| 234 | { |
| 235 | c = *--suffix; |
| 236 | if (islower (c)) |
| 237 | c = toupper (c); |
| 238 | if (c == 'B') |
| 239 | radix = 2; |
| 240 | else if (c == 'D') |
| 241 | radix = 10; |
| 242 | else if (c == 'O' || c == 'Q') |
| 243 | radix = 8; |
| 244 | else if (c == 'H') |
| 245 | radix = 16; |
| 246 | else if (suffix[1] == '.' || c == 'E' || flt) |
| 247 | { |
| 248 | floating_constant (expressionP); |
| 249 | return; |
| 250 | } |
| 251 | else |
| 252 | { |
| 253 | radix = 10; |
| 254 | suffix = NULL; |
| 255 | } |
| 256 | } |
| 257 | } |
| 258 | |
| 259 | switch (radix) |
| 260 | { |
| 261 | case 2: |
| 262 | maxdig = 2; |
| 263 | too_many_digits = valuesize + 1; |
| 264 | break; |
| 265 | case 8: |
| 266 | maxdig = radix = 8; |
| 267 | too_many_digits = (valuesize + 2) / 3 + 1; |
| 268 | break; |
| 269 | case 16: |
| 270 | maxdig = radix = 16; |
| 271 | too_many_digits = (valuesize + 3) / 4 + 1; |
| 272 | break; |
| 273 | case 10: |
| 274 | maxdig = radix = 10; |
| 275 | too_many_digits = (valuesize + 12) / 4; /* very rough */ |
| 276 | } |
| 277 | #undef valuesize |
| 278 | start = input_line_pointer; |
| 279 | c = *input_line_pointer++; |
| 280 | for (number = 0; |
| 281 | (digit = hex_value (c)) < maxdig; |
| 282 | c = *input_line_pointer++) |
| 283 | { |
| 284 | number = number * radix + digit; |
| 285 | } |
| 286 | /* c contains character after number. */ |
| 287 | /* input_line_pointer->char after c. */ |
| 288 | small = (input_line_pointer - start - 1) < too_many_digits; |
| 289 | if (!small) |
| 290 | { |
| 291 | /* |
| 292 | * we saw a lot of digits. manufacture a bignum the hard way. |
| 293 | */ |
| 294 | LITTLENUM_TYPE *leader; /*->high order littlenum of the bignum. */ |
| 295 | LITTLENUM_TYPE *pointer; /*->littlenum we are frobbing now. */ |
| 296 | long carry; |
| 297 | |
| 298 | leader = generic_bignum; |
| 299 | generic_bignum[0] = 0; |
| 300 | generic_bignum[1] = 0; |
| 301 | input_line_pointer = start; /*->1st digit. */ |
| 302 | c = *input_line_pointer++; |
| 303 | for (; |
| 304 | (carry = hex_value (c)) < maxdig; |
| 305 | c = *input_line_pointer++) |
| 306 | { |
| 307 | for (pointer = generic_bignum; |
| 308 | pointer <= leader; |
| 309 | pointer++) |
| 310 | { |
| 311 | long work; |
| 312 | |
| 313 | work = carry + radix * *pointer; |
| 314 | *pointer = work & LITTLENUM_MASK; |
| 315 | carry = work >> LITTLENUM_NUMBER_OF_BITS; |
| 316 | } |
| 317 | if (carry) |
| 318 | { |
| 319 | if (leader < generic_bignum + SIZE_OF_LARGE_NUMBER - 1) |
| 320 | { |
| 321 | /* room to grow a longer bignum. */ |
| 322 | *++leader = carry; |
| 323 | } |
| 324 | } |
| 325 | } |
| 326 | /* again, c is char after number, */ |
| 327 | /* input_line_pointer->after c. */ |
| 328 | know (LITTLENUM_NUMBER_OF_BITS == 16); |
| 329 | if (leader < generic_bignum + 2) |
| 330 | { |
| 331 | /* will fit into 32 bits. */ |
| 332 | number = |
| 333 | ((generic_bignum[1] & LITTLENUM_MASK) << LITTLENUM_NUMBER_OF_BITS) |
| 334 | | (generic_bignum[0] & LITTLENUM_MASK); |
| 335 | small = 1; |
| 336 | } |
| 337 | else |
| 338 | { |
| 339 | number = leader - generic_bignum + 1; /* number of littlenums in the bignum. */ |
| 340 | } |
| 341 | } |
| 342 | |
| 343 | if (flag_m68k_mri && suffix != NULL && input_line_pointer - 1 == suffix) |
| 344 | c = *input_line_pointer++; |
| 345 | |
| 346 | if (small) |
| 347 | { |
| 348 | /* |
| 349 | * here with number, in correct radix. c is the next char. |
| 350 | * note that unlike un*x, we allow "011f" "0x9f" to |
| 351 | * both mean the same as the (conventional) "9f". this is simply easier |
| 352 | * than checking for strict canonical form. syntax sux! |
| 353 | */ |
| 354 | |
| 355 | if (LOCAL_LABELS_FB && c == 'b') |
| 356 | { |
| 357 | /* |
| 358 | * backward ref to local label. |
| 359 | * because it is backward, expect it to be defined. |
| 360 | */ |
| 361 | /* Construct a local label. */ |
| 362 | name = fb_label_name ((int) number, 0); |
| 363 | |
| 364 | /* seen before, or symbol is defined: ok */ |
| 365 | symbolP = symbol_find (name); |
| 366 | if ((symbolP != NULL) && (S_IS_DEFINED (symbolP))) |
| 367 | { |
| 368 | /* local labels are never absolute. don't waste time |
| 369 | checking absoluteness. */ |
| 370 | know (SEG_NORMAL (S_GET_SEGMENT (symbolP))); |
| 371 | |
| 372 | expressionP->X_op = O_symbol; |
| 373 | expressionP->X_add_symbol = symbolP; |
| 374 | } |
| 375 | else |
| 376 | { |
| 377 | /* either not seen or not defined. */ |
| 378 | /* @@ Should print out the original string instead of |
| 379 | the parsed number. */ |
| 380 | as_bad ("backw. ref to unknown label \"%d:\", 0 assumed.", |
| 381 | (int) number); |
| 382 | expressionP->X_op = O_constant; |
| 383 | } |
| 384 | |
| 385 | expressionP->X_add_number = 0; |
| 386 | } /* case 'b' */ |
| 387 | else if (LOCAL_LABELS_FB && c == 'f') |
| 388 | { |
| 389 | /* |
| 390 | * forward reference. expect symbol to be undefined or |
| 391 | * unknown. undefined: seen it before. unknown: never seen |
| 392 | * it before. |
| 393 | * construct a local label name, then an undefined symbol. |
| 394 | * don't create a xseg frag for it: caller may do that. |
| 395 | * just return it as never seen before. |
| 396 | */ |
| 397 | name = fb_label_name ((int) number, 1); |
| 398 | symbolP = symbol_find_or_make (name); |
| 399 | /* we have no need to check symbol properties. */ |
| 400 | #ifndef many_segments |
| 401 | /* since "know" puts its arg into a "string", we |
| 402 | can't have newlines in the argument. */ |
| 403 | know (S_GET_SEGMENT (symbolP) == undefined_section || S_GET_SEGMENT (symbolP) == text_section || S_GET_SEGMENT (symbolP) == data_section); |
| 404 | #endif |
| 405 | expressionP->X_op = O_symbol; |
| 406 | expressionP->X_add_symbol = symbolP; |
| 407 | expressionP->X_add_number = 0; |
| 408 | } /* case 'f' */ |
| 409 | else if (LOCAL_LABELS_DOLLAR && c == '$') |
| 410 | { |
| 411 | /* If the dollar label is *currently* defined, then this is just |
| 412 | another reference to it. If it is not *currently* defined, |
| 413 | then this is a fresh instantiation of that number, so create |
| 414 | it. */ |
| 415 | |
| 416 | if (dollar_label_defined ((long) number)) |
| 417 | { |
| 418 | name = dollar_label_name ((long) number, 0); |
| 419 | symbolP = symbol_find (name); |
| 420 | know (symbolP != NULL); |
| 421 | } |
| 422 | else |
| 423 | { |
| 424 | name = dollar_label_name ((long) number, 1); |
| 425 | symbolP = symbol_find_or_make (name); |
| 426 | } |
| 427 | |
| 428 | expressionP->X_op = O_symbol; |
| 429 | expressionP->X_add_symbol = symbolP; |
| 430 | expressionP->X_add_number = 0; |
| 431 | } /* case '$' */ |
| 432 | else |
| 433 | { |
| 434 | expressionP->X_op = O_constant; |
| 435 | #ifdef TARGET_WORD_SIZE |
| 436 | /* Sign extend NUMBER. */ |
| 437 | number |= (-(number >> (TARGET_WORD_SIZE - 1))) << (TARGET_WORD_SIZE - 1); |
| 438 | #endif |
| 439 | expressionP->X_add_number = number; |
| 440 | input_line_pointer--; /* restore following character. */ |
| 441 | } /* really just a number */ |
| 442 | } |
| 443 | else |
| 444 | { |
| 445 | /* not a small number */ |
| 446 | expressionP->X_op = O_big; |
| 447 | expressionP->X_add_number = number; /* number of littlenums */ |
| 448 | input_line_pointer--; /*->char following number. */ |
| 449 | } |
| 450 | } |
| 451 | |
| 452 | /* Parse an MRI multi character constant. */ |
| 453 | |
| 454 | static void |
| 455 | mri_char_constant (expressionP) |
| 456 | expressionS *expressionP; |
| 457 | { |
| 458 | int i; |
| 459 | |
| 460 | if (*input_line_pointer == '\'' |
| 461 | && input_line_pointer[1] != '\'') |
| 462 | { |
| 463 | expressionP->X_op = O_constant; |
| 464 | expressionP->X_add_number = 0; |
| 465 | return; |
| 466 | } |
| 467 | |
| 468 | /* In order to get the correct byte ordering, we must build the |
| 469 | number in reverse. */ |
| 470 | for (i = SIZE_OF_LARGE_NUMBER - 1; i >= 0; i--) |
| 471 | { |
| 472 | int j; |
| 473 | |
| 474 | generic_bignum[i] = 0; |
| 475 | for (j = 0; j < CHARS_PER_LITTLENUM; j++) |
| 476 | { |
| 477 | if (*input_line_pointer == '\'') |
| 478 | { |
| 479 | if (input_line_pointer[1] != '\'') |
| 480 | break; |
| 481 | ++input_line_pointer; |
| 482 | } |
| 483 | generic_bignum[i] <<= 8; |
| 484 | generic_bignum[i] += *input_line_pointer; |
| 485 | ++input_line_pointer; |
| 486 | } |
| 487 | |
| 488 | if (i < SIZE_OF_LARGE_NUMBER - 1) |
| 489 | { |
| 490 | /* If there is more than one littlenum, left justify the |
| 491 | last one to make it match the earlier ones. If there is |
| 492 | only one, we can just use the value directly. */ |
| 493 | for (; j < CHARS_PER_LITTLENUM; j++) |
| 494 | generic_bignum[i] <<= 8; |
| 495 | } |
| 496 | |
| 497 | if (*input_line_pointer == '\'' |
| 498 | && input_line_pointer[1] != '\'') |
| 499 | break; |
| 500 | } |
| 501 | |
| 502 | if (i < 0) |
| 503 | { |
| 504 | as_bad ("Character constant too large"); |
| 505 | i = 0; |
| 506 | } |
| 507 | |
| 508 | if (i > 0) |
| 509 | { |
| 510 | int c; |
| 511 | int j; |
| 512 | |
| 513 | c = SIZE_OF_LARGE_NUMBER - i; |
| 514 | for (j = 0; j < c; j++) |
| 515 | generic_bignum[j] = generic_bignum[i + j]; |
| 516 | i = c; |
| 517 | } |
| 518 | |
| 519 | know (LITTLENUM_NUMBER_OF_BITS == 16); |
| 520 | if (i > 2) |
| 521 | { |
| 522 | expressionP->X_op = O_big; |
| 523 | expressionP->X_add_number = i; |
| 524 | } |
| 525 | else |
| 526 | { |
| 527 | expressionP->X_op = O_constant; |
| 528 | if (i < 2) |
| 529 | expressionP->X_add_number = generic_bignum[0] & LITTLENUM_MASK; |
| 530 | else |
| 531 | expressionP->X_add_number = |
| 532 | (((generic_bignum[1] & LITTLENUM_MASK) |
| 533 | << LITTLENUM_NUMBER_OF_BITS) |
| 534 | | (generic_bignum[0] & LITTLENUM_MASK)); |
| 535 | } |
| 536 | |
| 537 | /* Skip the final closing quote. */ |
| 538 | ++input_line_pointer; |
| 539 | } |
| 540 | |
| 541 | /* Return an expression representing the current location. This |
| 542 | handles the magic symbol `.'. */ |
| 543 | |
| 544 | static void |
| 545 | current_location (expressionp) |
| 546 | expressionS *expressionp; |
| 547 | { |
| 548 | if (now_seg == absolute_section) |
| 549 | { |
| 550 | expressionp->X_op = O_constant; |
| 551 | expressionp->X_add_number = abs_section_offset; |
| 552 | } |
| 553 | else |
| 554 | { |
| 555 | symbolS *symbolp; |
| 556 | |
| 557 | symbolp = symbol_new (FAKE_LABEL_NAME, now_seg, |
| 558 | (valueT) frag_now_fix (), |
| 559 | frag_now); |
| 560 | expressionp->X_op = O_symbol; |
| 561 | expressionp->X_add_symbol = symbolp; |
| 562 | expressionp->X_add_number = 0; |
| 563 | } |
| 564 | } |
| 565 | |
| 566 | /* |
| 567 | * Summary of operand(). |
| 568 | * |
| 569 | * in: Input_line_pointer points to 1st char of operand, which may |
| 570 | * be a space. |
| 571 | * |
| 572 | * out: A expressionS. |
| 573 | * The operand may have been empty: in this case X_op == O_absent. |
| 574 | * Input_line_pointer->(next non-blank) char after operand. |
| 575 | */ |
| 576 | |
| 577 | static segT |
| 578 | operand (expressionP) |
| 579 | expressionS *expressionP; |
| 580 | { |
| 581 | char c; |
| 582 | symbolS *symbolP; /* points to symbol */ |
| 583 | char *name; /* points to name of symbol */ |
| 584 | segT segment; |
| 585 | |
| 586 | /* All integers are regarded as unsigned unless they are negated. |
| 587 | This is because the only thing which cares whether a number is |
| 588 | unsigned is the code in emit_expr which extends constants into |
| 589 | bignums. It should only sign extend negative numbers, so that |
| 590 | something like ``.quad 0x80000000'' is not sign extended even |
| 591 | though it appears negative if valueT is 32 bits. */ |
| 592 | expressionP->X_unsigned = 1; |
| 593 | |
| 594 | /* digits, assume it is a bignum. */ |
| 595 | |
| 596 | SKIP_WHITESPACE (); /* leading whitespace is part of operand. */ |
| 597 | c = *input_line_pointer++; /* input_line_pointer->past char in c. */ |
| 598 | |
| 599 | switch (c) |
| 600 | { |
| 601 | case '1': |
| 602 | case '2': |
| 603 | case '3': |
| 604 | case '4': |
| 605 | case '5': |
| 606 | case '6': |
| 607 | case '7': |
| 608 | case '8': |
| 609 | case '9': |
| 610 | input_line_pointer--; |
| 611 | |
| 612 | integer_constant (flag_m68k_mri ? 0 : 10, expressionP); |
| 613 | break; |
| 614 | |
| 615 | case '0': |
| 616 | /* non-decimal radix */ |
| 617 | |
| 618 | if (flag_m68k_mri) |
| 619 | { |
| 620 | char *s; |
| 621 | |
| 622 | /* Check for a hex constant. */ |
| 623 | for (s = input_line_pointer; hex_p (*s); s++) |
| 624 | ; |
| 625 | if (*s == 'h' || *s == 'H') |
| 626 | { |
| 627 | --input_line_pointer; |
| 628 | integer_constant (0, expressionP); |
| 629 | break; |
| 630 | } |
| 631 | } |
| 632 | |
| 633 | c = *input_line_pointer; |
| 634 | switch (c) |
| 635 | { |
| 636 | case 'o': |
| 637 | case 'O': |
| 638 | case 'q': |
| 639 | case 'Q': |
| 640 | case '8': |
| 641 | case '9': |
| 642 | if (flag_m68k_mri) |
| 643 | { |
| 644 | integer_constant (0, expressionP); |
| 645 | break; |
| 646 | } |
| 647 | /* Fall through. */ |
| 648 | default: |
| 649 | default_case: |
| 650 | if (c && strchr (FLT_CHARS, c)) |
| 651 | { |
| 652 | input_line_pointer++; |
| 653 | floating_constant (expressionP); |
| 654 | expressionP->X_add_number = -(isupper (c) ? tolower (c) : c); |
| 655 | } |
| 656 | else |
| 657 | { |
| 658 | /* The string was only zero */ |
| 659 | expressionP->X_op = O_constant; |
| 660 | expressionP->X_add_number = 0; |
| 661 | } |
| 662 | |
| 663 | break; |
| 664 | |
| 665 | case 'x': |
| 666 | case 'X': |
| 667 | if (flag_m68k_mri) |
| 668 | goto default_case; |
| 669 | input_line_pointer++; |
| 670 | integer_constant (16, expressionP); |
| 671 | break; |
| 672 | |
| 673 | case 'b': |
| 674 | if (LOCAL_LABELS_FB && ! flag_m68k_mri) |
| 675 | { |
| 676 | /* This code used to check for '+' and '-' here, and, in |
| 677 | some conditions, fall through to call |
| 678 | integer_constant. However, that didn't make sense, |
| 679 | as integer_constant only accepts digits. */ |
| 680 | /* Some of our code elsewhere does permit digits greater |
| 681 | than the expected base; for consistency, do the same |
| 682 | here. */ |
| 683 | if (input_line_pointer[1] < '0' |
| 684 | || input_line_pointer[1] > '9') |
| 685 | { |
| 686 | /* Parse this as a back reference to label 0. */ |
| 687 | input_line_pointer--; |
| 688 | integer_constant (10, expressionP); |
| 689 | break; |
| 690 | } |
| 691 | /* Otherwise, parse this as a binary number. */ |
| 692 | } |
| 693 | /* Fall through. */ |
| 694 | case 'B': |
| 695 | input_line_pointer++; |
| 696 | if (flag_m68k_mri) |
| 697 | goto default_case; |
| 698 | integer_constant (2, expressionP); |
| 699 | break; |
| 700 | |
| 701 | case '0': |
| 702 | case '1': |
| 703 | case '2': |
| 704 | case '3': |
| 705 | case '4': |
| 706 | case '5': |
| 707 | case '6': |
| 708 | case '7': |
| 709 | integer_constant (flag_m68k_mri ? 0 : 8, expressionP); |
| 710 | break; |
| 711 | |
| 712 | case 'f': |
| 713 | if (LOCAL_LABELS_FB) |
| 714 | { |
| 715 | /* If it says "0f" and it could possibly be a floating point |
| 716 | number, make it one. Otherwise, make it a local label, |
| 717 | and try to deal with parsing the rest later. */ |
| 718 | if (!input_line_pointer[1] |
| 719 | || (is_end_of_line[0xff & input_line_pointer[1]])) |
| 720 | goto is_0f_label; |
| 721 | { |
| 722 | char *cp = input_line_pointer + 1; |
| 723 | int r = atof_generic (&cp, ".", EXP_CHARS, |
| 724 | &generic_floating_point_number); |
| 725 | switch (r) |
| 726 | { |
| 727 | case 0: |
| 728 | case ERROR_EXPONENT_OVERFLOW: |
| 729 | if (*cp == 'f' || *cp == 'b') |
| 730 | /* looks like a difference expression */ |
| 731 | goto is_0f_label; |
| 732 | else |
| 733 | goto is_0f_float; |
| 734 | default: |
| 735 | as_fatal ("expr.c(operand): bad atof_generic return val %d", |
| 736 | r); |
| 737 | } |
| 738 | } |
| 739 | |
| 740 | /* Okay, now we've sorted it out. We resume at one of these |
| 741 | two labels, depending on what we've decided we're probably |
| 742 | looking at. */ |
| 743 | is_0f_label: |
| 744 | input_line_pointer--; |
| 745 | integer_constant (10, expressionP); |
| 746 | break; |
| 747 | |
| 748 | is_0f_float: |
| 749 | /* fall through */ |
| 750 | ; |
| 751 | } |
| 752 | |
| 753 | case 'd': |
| 754 | case 'D': |
| 755 | if (flag_m68k_mri) |
| 756 | { |
| 757 | integer_constant (0, expressionP); |
| 758 | break; |
| 759 | } |
| 760 | /* Fall through. */ |
| 761 | case 'F': |
| 762 | case 'r': |
| 763 | case 'e': |
| 764 | case 'E': |
| 765 | case 'g': |
| 766 | case 'G': |
| 767 | input_line_pointer++; |
| 768 | floating_constant (expressionP); |
| 769 | expressionP->X_add_number = -(isupper (c) ? tolower (c) : c); |
| 770 | break; |
| 771 | |
| 772 | case '$': |
| 773 | if (LOCAL_LABELS_DOLLAR) |
| 774 | { |
| 775 | integer_constant (10, expressionP); |
| 776 | break; |
| 777 | } |
| 778 | else |
| 779 | goto default_case; |
| 780 | } |
| 781 | |
| 782 | break; |
| 783 | |
| 784 | case '(': |
| 785 | case '[': |
| 786 | /* didn't begin with digit & not a name */ |
| 787 | segment = expression (expressionP); |
| 788 | /* Expression() will pass trailing whitespace */ |
| 789 | if ((c == '(' && *input_line_pointer++ != ')') |
| 790 | || (c == '[' && *input_line_pointer++ != ']')) |
| 791 | { |
| 792 | as_bad ("Missing ')' assumed"); |
| 793 | input_line_pointer--; |
| 794 | } |
| 795 | SKIP_WHITESPACE (); |
| 796 | /* here with input_line_pointer->char after "(...)" */ |
| 797 | return segment; |
| 798 | |
| 799 | case 'E': |
| 800 | if (! flag_m68k_mri || *input_line_pointer != '\'') |
| 801 | goto de_fault; |
| 802 | as_bad ("EBCDIC constants are not supported"); |
| 803 | /* Fall through. */ |
| 804 | case 'A': |
| 805 | if (! flag_m68k_mri || *input_line_pointer != '\'') |
| 806 | goto de_fault; |
| 807 | ++input_line_pointer; |
| 808 | /* Fall through. */ |
| 809 | case '\'': |
| 810 | if (! flag_m68k_mri) |
| 811 | { |
| 812 | /* Warning: to conform to other people's assemblers NO |
| 813 | ESCAPEMENT is permitted for a single quote. The next |
| 814 | character, parity errors and all, is taken as the value |
| 815 | of the operand. VERY KINKY. */ |
| 816 | expressionP->X_op = O_constant; |
| 817 | expressionP->X_add_number = *input_line_pointer++; |
| 818 | break; |
| 819 | } |
| 820 | |
| 821 | mri_char_constant (expressionP); |
| 822 | break; |
| 823 | |
| 824 | case '+': |
| 825 | (void) operand (expressionP); |
| 826 | break; |
| 827 | |
| 828 | case '"': |
| 829 | /* Double quote is the bitwise not operator in MRI mode. */ |
| 830 | if (! flag_m68k_mri) |
| 831 | goto de_fault; |
| 832 | /* Fall through. */ |
| 833 | case '~': |
| 834 | /* ~ is permitted to start a label on the Delta. */ |
| 835 | if (is_name_beginner (c)) |
| 836 | goto isname; |
| 837 | case '!': |
| 838 | case '-': |
| 839 | { |
| 840 | operand (expressionP); |
| 841 | if (expressionP->X_op == O_constant) |
| 842 | { |
| 843 | /* input_line_pointer -> char after operand */ |
| 844 | if (c == '-') |
| 845 | { |
| 846 | expressionP->X_add_number = - expressionP->X_add_number; |
| 847 | /* Notice: '-' may overflow: no warning is given. This is |
| 848 | compatible with other people's assemblers. Sigh. */ |
| 849 | expressionP->X_unsigned = 0; |
| 850 | } |
| 851 | else if (c == '~' || c == '"') |
| 852 | expressionP->X_add_number = ~ expressionP->X_add_number; |
| 853 | else |
| 854 | expressionP->X_add_number = ! expressionP->X_add_number; |
| 855 | } |
| 856 | else if (expressionP->X_op != O_illegal |
| 857 | && expressionP->X_op != O_absent) |
| 858 | { |
| 859 | expressionP->X_add_symbol = make_expr_symbol (expressionP); |
| 860 | if (c == '-') |
| 861 | expressionP->X_op = O_uminus; |
| 862 | else if (c == '~' || c == '"') |
| 863 | expressionP->X_op = O_bit_not; |
| 864 | else |
| 865 | expressionP->X_op = O_logical_not; |
| 866 | expressionP->X_add_number = 0; |
| 867 | } |
| 868 | else |
| 869 | as_warn ("Unary operator %c ignored because bad operand follows", |
| 870 | c); |
| 871 | } |
| 872 | break; |
| 873 | |
| 874 | case '$': |
| 875 | /* $ is the program counter when in MRI mode, or when DOLLAR_DOT |
| 876 | is defined. */ |
| 877 | #ifndef DOLLAR_DOT |
| 878 | if (! flag_m68k_mri) |
| 879 | goto de_fault; |
| 880 | #endif |
| 881 | if (flag_m68k_mri && hex_p (*input_line_pointer)) |
| 882 | { |
| 883 | /* In MRI mode, $ is also used as the prefix for a |
| 884 | hexadecimal constant. */ |
| 885 | integer_constant (16, expressionP); |
| 886 | break; |
| 887 | } |
| 888 | |
| 889 | if (is_part_of_name (*input_line_pointer)) |
| 890 | goto isname; |
| 891 | |
| 892 | current_location (expressionP); |
| 893 | break; |
| 894 | |
| 895 | case '.': |
| 896 | if (!is_part_of_name (*input_line_pointer)) |
| 897 | { |
| 898 | current_location (expressionP); |
| 899 | break; |
| 900 | } |
| 901 | else if ((strncasecmp (input_line_pointer, "startof.", 8) == 0 |
| 902 | && ! is_part_of_name (input_line_pointer[8])) |
| 903 | || (strncasecmp (input_line_pointer, "sizeof.", 7) == 0 |
| 904 | && ! is_part_of_name (input_line_pointer[7]))) |
| 905 | { |
| 906 | int start; |
| 907 | |
| 908 | start = (input_line_pointer[1] == 't' |
| 909 | || input_line_pointer[1] == 'T'); |
| 910 | input_line_pointer += start ? 8 : 7; |
| 911 | SKIP_WHITESPACE (); |
| 912 | if (*input_line_pointer != '(') |
| 913 | as_bad ("syntax error in .startof. or .sizeof."); |
| 914 | else |
| 915 | { |
| 916 | char *buf; |
| 917 | |
| 918 | ++input_line_pointer; |
| 919 | SKIP_WHITESPACE (); |
| 920 | name = input_line_pointer; |
| 921 | c = get_symbol_end (); |
| 922 | |
| 923 | buf = (char *) xmalloc (strlen (name) + 10); |
| 924 | if (start) |
| 925 | sprintf (buf, ".startof.%s", name); |
| 926 | else |
| 927 | sprintf (buf, ".sizeof.%s", name); |
| 928 | symbolP = symbol_make (buf); |
| 929 | free (buf); |
| 930 | |
| 931 | expressionP->X_op = O_symbol; |
| 932 | expressionP->X_add_symbol = symbolP; |
| 933 | expressionP->X_add_number = 0; |
| 934 | |
| 935 | *input_line_pointer = c; |
| 936 | SKIP_WHITESPACE (); |
| 937 | if (*input_line_pointer != ')') |
| 938 | as_bad ("syntax error in .startof. or .sizeof."); |
| 939 | else |
| 940 | ++input_line_pointer; |
| 941 | } |
| 942 | break; |
| 943 | } |
| 944 | else |
| 945 | { |
| 946 | goto isname; |
| 947 | } |
| 948 | case ',': |
| 949 | case '\n': |
| 950 | case '\0': |
| 951 | eol: |
| 952 | /* can't imagine any other kind of operand */ |
| 953 | expressionP->X_op = O_absent; |
| 954 | input_line_pointer--; |
| 955 | break; |
| 956 | |
| 957 | case '%': |
| 958 | if (! flag_m68k_mri) |
| 959 | goto de_fault; |
| 960 | integer_constant (2, expressionP); |
| 961 | break; |
| 962 | |
| 963 | case '@': |
| 964 | if (! flag_m68k_mri) |
| 965 | goto de_fault; |
| 966 | integer_constant (8, expressionP); |
| 967 | break; |
| 968 | |
| 969 | case ':': |
| 970 | if (! flag_m68k_mri) |
| 971 | goto de_fault; |
| 972 | |
| 973 | /* In MRI mode, this is a floating point constant represented |
| 974 | using hexadecimal digits. */ |
| 975 | |
| 976 | ++input_line_pointer; |
| 977 | integer_constant (16, expressionP); |
| 978 | break; |
| 979 | |
| 980 | case '*': |
| 981 | if (! flag_m68k_mri || is_part_of_name (*input_line_pointer)) |
| 982 | goto de_fault; |
| 983 | |
| 984 | current_location (expressionP); |
| 985 | break; |
| 986 | |
| 987 | default: |
| 988 | de_fault: |
| 989 | if (is_end_of_line[(unsigned char) c]) |
| 990 | goto eol; |
| 991 | if (is_name_beginner (c)) /* here if did not begin with a digit */ |
| 992 | { |
| 993 | /* |
| 994 | * Identifier begins here. |
| 995 | * This is kludged for speed, so code is repeated. |
| 996 | */ |
| 997 | isname: |
| 998 | name = --input_line_pointer; |
| 999 | c = get_symbol_end (); |
| 1000 | |
| 1001 | #ifdef md_parse_name |
| 1002 | /* This is a hook for the backend to parse certain names |
| 1003 | specially in certain contexts. If a name always has a |
| 1004 | specific value, it can often be handled by simply |
| 1005 | entering it in the symbol table. */ |
| 1006 | if (md_parse_name (name, expressionP)) |
| 1007 | { |
| 1008 | *input_line_pointer = c; |
| 1009 | break; |
| 1010 | } |
| 1011 | #endif |
| 1012 | |
| 1013 | #ifdef TC_I960 |
| 1014 | /* The MRI i960 assembler permits |
| 1015 | lda sizeof code,g13 |
| 1016 | FIXME: This should use md_parse_name. */ |
| 1017 | if (flag_mri |
| 1018 | && (strcasecmp (name, "sizeof") == 0 |
| 1019 | || strcasecmp (name, "startof") == 0)) |
| 1020 | { |
| 1021 | int start; |
| 1022 | char *buf; |
| 1023 | |
| 1024 | start = (name[1] == 't' |
| 1025 | || name[1] == 'T'); |
| 1026 | |
| 1027 | *input_line_pointer = c; |
| 1028 | SKIP_WHITESPACE (); |
| 1029 | |
| 1030 | name = input_line_pointer; |
| 1031 | c = get_symbol_end (); |
| 1032 | |
| 1033 | buf = (char *) xmalloc (strlen (name) + 10); |
| 1034 | if (start) |
| 1035 | sprintf (buf, ".startof.%s", name); |
| 1036 | else |
| 1037 | sprintf (buf, ".sizeof.%s", name); |
| 1038 | symbolP = symbol_make (buf); |
| 1039 | free (buf); |
| 1040 | |
| 1041 | expressionP->X_op = O_symbol; |
| 1042 | expressionP->X_add_symbol = symbolP; |
| 1043 | expressionP->X_add_number = 0; |
| 1044 | |
| 1045 | *input_line_pointer = c; |
| 1046 | SKIP_WHITESPACE (); |
| 1047 | |
| 1048 | break; |
| 1049 | } |
| 1050 | #endif |
| 1051 | |
| 1052 | symbolP = symbol_find_or_make (name); |
| 1053 | |
| 1054 | /* If we have an absolute symbol or a reg, then we know its |
| 1055 | value now. */ |
| 1056 | segment = S_GET_SEGMENT (symbolP); |
| 1057 | if (segment == absolute_section) |
| 1058 | { |
| 1059 | expressionP->X_op = O_constant; |
| 1060 | expressionP->X_add_number = S_GET_VALUE (symbolP); |
| 1061 | } |
| 1062 | else if (segment == reg_section) |
| 1063 | { |
| 1064 | expressionP->X_op = O_register; |
| 1065 | expressionP->X_add_number = S_GET_VALUE (symbolP); |
| 1066 | } |
| 1067 | else |
| 1068 | { |
| 1069 | expressionP->X_op = O_symbol; |
| 1070 | expressionP->X_add_symbol = symbolP; |
| 1071 | expressionP->X_add_number = 0; |
| 1072 | } |
| 1073 | *input_line_pointer = c; |
| 1074 | } |
| 1075 | else |
| 1076 | { |
| 1077 | /* Let the target try to parse it. Success is indicated by changing |
| 1078 | the X_op field to something other than O_absent and pointing |
| 1079 | input_line_pointer passed the expression. If it can't parse the |
| 1080 | expression, X_op and input_line_pointer should be unchanged. */ |
| 1081 | expressionP->X_op = O_absent; |
| 1082 | --input_line_pointer; |
| 1083 | md_operand (expressionP); |
| 1084 | if (expressionP->X_op == O_absent) |
| 1085 | { |
| 1086 | ++input_line_pointer; |
| 1087 | as_bad ("Bad expression"); |
| 1088 | expressionP->X_op = O_constant; |
| 1089 | expressionP->X_add_number = 0; |
| 1090 | } |
| 1091 | } |
| 1092 | break; |
| 1093 | } |
| 1094 | |
| 1095 | /* |
| 1096 | * It is more 'efficient' to clean up the expressionS when they are created. |
| 1097 | * Doing it here saves lines of code. |
| 1098 | */ |
| 1099 | clean_up_expression (expressionP); |
| 1100 | SKIP_WHITESPACE (); /*->1st char after operand. */ |
| 1101 | know (*input_line_pointer != ' '); |
| 1102 | |
| 1103 | /* The PA port needs this information. */ |
| 1104 | if (expressionP->X_add_symbol) |
| 1105 | expressionP->X_add_symbol->sy_used = 1; |
| 1106 | |
| 1107 | switch (expressionP->X_op) |
| 1108 | { |
| 1109 | default: |
| 1110 | return absolute_section; |
| 1111 | case O_symbol: |
| 1112 | return S_GET_SEGMENT (expressionP->X_add_symbol); |
| 1113 | case O_register: |
| 1114 | return reg_section; |
| 1115 | } |
| 1116 | } /* operand() */ |
| 1117 | \f |
| 1118 | /* Internal. Simplify a struct expression for use by expr() */ |
| 1119 | |
| 1120 | /* |
| 1121 | * In: address of a expressionS. |
| 1122 | * The X_op field of the expressionS may only take certain values. |
| 1123 | * Elsewise we waste time special-case testing. Sigh. Ditto SEG_ABSENT. |
| 1124 | * Out: expressionS may have been modified: |
| 1125 | * 'foo-foo' symbol references cancelled to 0, |
| 1126 | * which changes X_op from O_subtract to O_constant. |
| 1127 | * Unused fields zeroed to help expr(). |
| 1128 | */ |
| 1129 | |
| 1130 | static void |
| 1131 | clean_up_expression (expressionP) |
| 1132 | expressionS *expressionP; |
| 1133 | { |
| 1134 | switch (expressionP->X_op) |
| 1135 | { |
| 1136 | case O_illegal: |
| 1137 | case O_absent: |
| 1138 | expressionP->X_add_number = 0; |
| 1139 | /* Fall through. */ |
| 1140 | case O_big: |
| 1141 | case O_constant: |
| 1142 | case O_register: |
| 1143 | expressionP->X_add_symbol = NULL; |
| 1144 | /* Fall through. */ |
| 1145 | case O_symbol: |
| 1146 | case O_uminus: |
| 1147 | case O_bit_not: |
| 1148 | expressionP->X_op_symbol = NULL; |
| 1149 | break; |
| 1150 | case O_subtract: |
| 1151 | if (expressionP->X_op_symbol == expressionP->X_add_symbol |
| 1152 | || ((expressionP->X_op_symbol->sy_frag |
| 1153 | == expressionP->X_add_symbol->sy_frag) |
| 1154 | && SEG_NORMAL (S_GET_SEGMENT (expressionP->X_add_symbol)) |
| 1155 | && (S_GET_VALUE (expressionP->X_op_symbol) |
| 1156 | == S_GET_VALUE (expressionP->X_add_symbol)))) |
| 1157 | { |
| 1158 | addressT diff = (S_GET_VALUE (expressionP->X_add_symbol) |
| 1159 | - S_GET_VALUE (expressionP->X_op_symbol)); |
| 1160 | |
| 1161 | expressionP->X_op = O_constant; |
| 1162 | expressionP->X_add_symbol = NULL; |
| 1163 | expressionP->X_op_symbol = NULL; |
| 1164 | expressionP->X_add_number += diff; |
| 1165 | } |
| 1166 | break; |
| 1167 | default: |
| 1168 | break; |
| 1169 | } |
| 1170 | } |
| 1171 | \f |
| 1172 | /* Expression parser. */ |
| 1173 | |
| 1174 | /* |
| 1175 | * We allow an empty expression, and just assume (absolute,0) silently. |
| 1176 | * Unary operators and parenthetical expressions are treated as operands. |
| 1177 | * As usual, Q==quantity==operand, O==operator, X==expression mnemonics. |
| 1178 | * |
| 1179 | * We used to do a aho/ullman shift-reduce parser, but the logic got so |
| 1180 | * warped that I flushed it and wrote a recursive-descent parser instead. |
| 1181 | * Now things are stable, would anybody like to write a fast parser? |
| 1182 | * Most expressions are either register (which does not even reach here) |
| 1183 | * or 1 symbol. Then "symbol+constant" and "symbol-symbol" are common. |
| 1184 | * So I guess it doesn't really matter how inefficient more complex expressions |
| 1185 | * are parsed. |
| 1186 | * |
| 1187 | * After expr(RANK,resultP) input_line_pointer->operator of rank <= RANK. |
| 1188 | * Also, we have consumed any leading or trailing spaces (operand does that) |
| 1189 | * and done all intervening operators. |
| 1190 | * |
| 1191 | * This returns the segment of the result, which will be |
| 1192 | * absolute_section or the segment of a symbol. |
| 1193 | */ |
| 1194 | |
| 1195 | #undef __ |
| 1196 | #define __ O_illegal |
| 1197 | |
| 1198 | static operatorT op_encoding[256] = |
| 1199 | { /* maps ASCII->operators */ |
| 1200 | |
| 1201 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1202 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1203 | |
| 1204 | __, O_bit_or_not, __, __, __, O_modulus, O_bit_and, __, |
| 1205 | __, __, O_multiply, O_add, __, O_subtract, __, O_divide, |
| 1206 | __, __, __, __, __, __, __, __, |
| 1207 | __, __, __, __, O_lt, __, O_gt, __, |
| 1208 | __, __, __, __, __, __, __, __, |
| 1209 | __, __, __, __, __, __, __, __, |
| 1210 | __, __, __, __, __, __, __, __, |
| 1211 | __, __, __, __, __, __, O_bit_exclusive_or, __, |
| 1212 | __, __, __, __, __, __, __, __, |
| 1213 | __, __, __, __, __, __, __, __, |
| 1214 | __, __, __, __, __, __, __, __, |
| 1215 | __, __, __, __, O_bit_inclusive_or, __, __, __, |
| 1216 | |
| 1217 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1218 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1219 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1220 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1221 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1222 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1223 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1224 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __ |
| 1225 | }; |
| 1226 | |
| 1227 | |
| 1228 | /* |
| 1229 | * Rank Examples |
| 1230 | * 0 operand, (expression) |
| 1231 | * 1 || |
| 1232 | * 2 && |
| 1233 | * 3 = <> < <= >= > |
| 1234 | * 4 + - |
| 1235 | * 5 used for * / % in MRI mode |
| 1236 | * 6 & ^ ! | |
| 1237 | * 7 * / % << >> |
| 1238 | * 8 unary - unary ~ |
| 1239 | */ |
| 1240 | static operator_rankT op_rank[] = |
| 1241 | { |
| 1242 | 0, /* O_illegal */ |
| 1243 | 0, /* O_absent */ |
| 1244 | 0, /* O_constant */ |
| 1245 | 0, /* O_symbol */ |
| 1246 | 0, /* O_symbol_rva */ |
| 1247 | 0, /* O_register */ |
| 1248 | 0, /* O_bit */ |
| 1249 | 8, /* O_uminus */ |
| 1250 | 8, /* O_bit_not */ |
| 1251 | 8, /* O_logical_not */ |
| 1252 | 7, /* O_multiply */ |
| 1253 | 7, /* O_divide */ |
| 1254 | 7, /* O_modulus */ |
| 1255 | 7, /* O_left_shift */ |
| 1256 | 7, /* O_right_shift */ |
| 1257 | 6, /* O_bit_inclusive_or */ |
| 1258 | 6, /* O_bit_or_not */ |
| 1259 | 6, /* O_bit_exclusive_or */ |
| 1260 | 6, /* O_bit_and */ |
| 1261 | 4, /* O_add */ |
| 1262 | 4, /* O_subtract */ |
| 1263 | 3, /* O_eq */ |
| 1264 | 3, /* O_ne */ |
| 1265 | 3, /* O_lt */ |
| 1266 | 3, /* O_le */ |
| 1267 | 3, /* O_ge */ |
| 1268 | 3, /* O_gt */ |
| 1269 | 2, /* O_logical_and */ |
| 1270 | 1 /* O_logical_or */ |
| 1271 | }; |
| 1272 | |
| 1273 | /* Initialize the expression parser. */ |
| 1274 | |
| 1275 | void |
| 1276 | expr_begin () |
| 1277 | { |
| 1278 | /* In MRI mode for the m68k, multiplication and division have lower |
| 1279 | precedence than the bit wise operators. */ |
| 1280 | if (flag_m68k_mri) |
| 1281 | { |
| 1282 | op_rank[O_multiply] = 5; |
| 1283 | op_rank[O_divide] = 5; |
| 1284 | op_rank[O_modulus] = 5; |
| 1285 | op_encoding['"'] = O_bit_not; |
| 1286 | } |
| 1287 | |
| 1288 | /* Verify that X_op field is wide enough. */ |
| 1289 | { |
| 1290 | expressionS e; |
| 1291 | e.X_op = O_max; |
| 1292 | assert (e.X_op == O_max); |
| 1293 | } |
| 1294 | } |
| 1295 | \f |
| 1296 | /* Return the encoding for the operator at INPUT_LINE_POINTER. |
| 1297 | Advance INPUT_LINE_POINTER to the last character in the operator |
| 1298 | (i.e., don't change it for a single character operator). */ |
| 1299 | |
| 1300 | static inline operatorT |
| 1301 | operator () |
| 1302 | { |
| 1303 | int c; |
| 1304 | operatorT ret; |
| 1305 | |
| 1306 | c = *input_line_pointer; |
| 1307 | |
| 1308 | switch (c) |
| 1309 | { |
| 1310 | default: |
| 1311 | return op_encoding[c]; |
| 1312 | |
| 1313 | case '<': |
| 1314 | switch (input_line_pointer[1]) |
| 1315 | { |
| 1316 | default: |
| 1317 | return op_encoding[c]; |
| 1318 | case '<': |
| 1319 | ret = O_left_shift; |
| 1320 | break; |
| 1321 | case '>': |
| 1322 | ret = O_ne; |
| 1323 | break; |
| 1324 | case '=': |
| 1325 | ret = O_le; |
| 1326 | break; |
| 1327 | } |
| 1328 | ++input_line_pointer; |
| 1329 | return ret; |
| 1330 | |
| 1331 | case '>': |
| 1332 | switch (input_line_pointer[1]) |
| 1333 | { |
| 1334 | default: |
| 1335 | return op_encoding[c]; |
| 1336 | case '>': |
| 1337 | ret = O_right_shift; |
| 1338 | break; |
| 1339 | case '=': |
| 1340 | ret = O_ge; |
| 1341 | break; |
| 1342 | } |
| 1343 | ++input_line_pointer; |
| 1344 | return ret; |
| 1345 | |
| 1346 | case '!': |
| 1347 | /* We accept !! as equivalent to ^ for MRI compatibility. */ |
| 1348 | if (input_line_pointer[1] != '!') |
| 1349 | { |
| 1350 | if (flag_m68k_mri) |
| 1351 | return O_bit_inclusive_or; |
| 1352 | return op_encoding[c]; |
| 1353 | } |
| 1354 | ++input_line_pointer; |
| 1355 | return O_bit_exclusive_or; |
| 1356 | |
| 1357 | case '|': |
| 1358 | if (input_line_pointer[1] != '|') |
| 1359 | return op_encoding[c]; |
| 1360 | |
| 1361 | ++input_line_pointer; |
| 1362 | return O_logical_or; |
| 1363 | |
| 1364 | case '&': |
| 1365 | if (input_line_pointer[1] != '&') |
| 1366 | return op_encoding[c]; |
| 1367 | |
| 1368 | ++input_line_pointer; |
| 1369 | return O_logical_and; |
| 1370 | } |
| 1371 | |
| 1372 | /*NOTREACHED*/ |
| 1373 | } |
| 1374 | |
| 1375 | /* Parse an expression. */ |
| 1376 | |
| 1377 | segT |
| 1378 | expr (rank, resultP) |
| 1379 | operator_rankT rank; /* Larger # is higher rank. */ |
| 1380 | expressionS *resultP; /* Deliver result here. */ |
| 1381 | { |
| 1382 | segT retval; |
| 1383 | expressionS right; |
| 1384 | operatorT op_left; |
| 1385 | operatorT op_right; |
| 1386 | |
| 1387 | know (rank >= 0); |
| 1388 | |
| 1389 | retval = operand (resultP); |
| 1390 | |
| 1391 | know (*input_line_pointer != ' '); /* Operand() gobbles spaces. */ |
| 1392 | |
| 1393 | op_left = operator (); |
| 1394 | while (op_left != O_illegal && op_rank[(int) op_left] > rank) |
| 1395 | { |
| 1396 | segT rightseg; |
| 1397 | |
| 1398 | input_line_pointer++; /*->after 1st character of operator. */ |
| 1399 | |
| 1400 | rightseg = expr (op_rank[(int) op_left], &right); |
| 1401 | if (right.X_op == O_absent) |
| 1402 | { |
| 1403 | as_warn ("missing operand; zero assumed"); |
| 1404 | right.X_op = O_constant; |
| 1405 | right.X_add_number = 0; |
| 1406 | right.X_add_symbol = NULL; |
| 1407 | right.X_op_symbol = NULL; |
| 1408 | } |
| 1409 | |
| 1410 | know (*input_line_pointer != ' '); |
| 1411 | |
| 1412 | if (retval == undefined_section) |
| 1413 | { |
| 1414 | if (SEG_NORMAL (rightseg)) |
| 1415 | retval = rightseg; |
| 1416 | } |
| 1417 | else if (! SEG_NORMAL (retval)) |
| 1418 | retval = rightseg; |
| 1419 | else if (SEG_NORMAL (rightseg) |
| 1420 | && retval != rightseg |
| 1421 | #ifdef DIFF_EXPR_OK |
| 1422 | && op_left != O_subtract |
| 1423 | #endif |
| 1424 | ) |
| 1425 | as_bad ("operation combines symbols in different segments"); |
| 1426 | |
| 1427 | op_right = operator (); |
| 1428 | |
| 1429 | know (op_right == O_illegal || op_rank[(int) op_right] <= op_rank[(int) op_left]); |
| 1430 | know ((int) op_left >= (int) O_multiply |
| 1431 | && (int) op_left <= (int) O_logical_or); |
| 1432 | |
| 1433 | /* input_line_pointer->after right-hand quantity. */ |
| 1434 | /* left-hand quantity in resultP */ |
| 1435 | /* right-hand quantity in right. */ |
| 1436 | /* operator in op_left. */ |
| 1437 | |
| 1438 | if (resultP->X_op == O_big) |
| 1439 | { |
| 1440 | as_warn ("left operand is a %s; integer 0 assumed", |
| 1441 | resultP->X_add_number > 0 ? "bignum" : "float"); |
| 1442 | resultP->X_op = O_constant; |
| 1443 | resultP->X_add_number = 0; |
| 1444 | resultP->X_add_symbol = NULL; |
| 1445 | resultP->X_op_symbol = NULL; |
| 1446 | } |
| 1447 | if (right.X_op == O_big) |
| 1448 | { |
| 1449 | as_warn ("right operand is a %s; integer 0 assumed", |
| 1450 | right.X_add_number > 0 ? "bignum" : "float"); |
| 1451 | right.X_op = O_constant; |
| 1452 | right.X_add_number = 0; |
| 1453 | right.X_add_symbol = NULL; |
| 1454 | right.X_op_symbol = NULL; |
| 1455 | } |
| 1456 | |
| 1457 | /* Optimize common cases. */ |
| 1458 | if (op_left == O_add && right.X_op == O_constant) |
| 1459 | { |
| 1460 | /* X + constant. */ |
| 1461 | resultP->X_add_number += right.X_add_number; |
| 1462 | } |
| 1463 | /* This case comes up in PIC code. */ |
| 1464 | else if (op_left == O_subtract |
| 1465 | && right.X_op == O_symbol |
| 1466 | && resultP->X_op == O_symbol |
| 1467 | && (right.X_add_symbol->sy_frag |
| 1468 | == resultP->X_add_symbol->sy_frag) |
| 1469 | && SEG_NORMAL (S_GET_SEGMENT (right.X_add_symbol))) |
| 1470 | |
| 1471 | { |
| 1472 | resultP->X_add_number += right.X_add_number; |
| 1473 | resultP->X_add_number += (S_GET_VALUE (resultP->X_add_symbol) |
| 1474 | - S_GET_VALUE (right.X_add_symbol)); |
| 1475 | resultP->X_op = O_constant; |
| 1476 | resultP->X_add_symbol = 0; |
| 1477 | } |
| 1478 | else if (op_left == O_subtract && right.X_op == O_constant) |
| 1479 | { |
| 1480 | /* X - constant. */ |
| 1481 | resultP->X_add_number -= right.X_add_number; |
| 1482 | } |
| 1483 | else if (op_left == O_add && resultP->X_op == O_constant) |
| 1484 | { |
| 1485 | /* Constant + X. */ |
| 1486 | resultP->X_op = right.X_op; |
| 1487 | resultP->X_add_symbol = right.X_add_symbol; |
| 1488 | resultP->X_op_symbol = right.X_op_symbol; |
| 1489 | resultP->X_add_number += right.X_add_number; |
| 1490 | retval = rightseg; |
| 1491 | } |
| 1492 | else if (resultP->X_op == O_constant && right.X_op == O_constant) |
| 1493 | { |
| 1494 | /* Constant OP constant. */ |
| 1495 | offsetT v = right.X_add_number; |
| 1496 | if (v == 0 && (op_left == O_divide || op_left == O_modulus)) |
| 1497 | { |
| 1498 | as_warn ("division by zero"); |
| 1499 | v = 1; |
| 1500 | } |
| 1501 | switch (op_left) |
| 1502 | { |
| 1503 | default: abort (); |
| 1504 | case O_multiply: resultP->X_add_number *= v; break; |
| 1505 | case O_divide: resultP->X_add_number /= v; break; |
| 1506 | case O_modulus: resultP->X_add_number %= v; break; |
| 1507 | case O_left_shift: resultP->X_add_number <<= v; break; |
| 1508 | case O_right_shift: |
| 1509 | /* We always use unsigned shifts, to avoid relying on |
| 1510 | characteristics of the compiler used to compile gas. */ |
| 1511 | resultP->X_add_number = |
| 1512 | (offsetT) ((valueT) resultP->X_add_number >> (valueT) v); |
| 1513 | break; |
| 1514 | case O_bit_inclusive_or: resultP->X_add_number |= v; break; |
| 1515 | case O_bit_or_not: resultP->X_add_number |= ~v; break; |
| 1516 | case O_bit_exclusive_or: resultP->X_add_number ^= v; break; |
| 1517 | case O_bit_and: resultP->X_add_number &= v; break; |
| 1518 | case O_add: resultP->X_add_number += v; break; |
| 1519 | case O_subtract: resultP->X_add_number -= v; break; |
| 1520 | case O_eq: |
| 1521 | resultP->X_add_number = |
| 1522 | resultP->X_add_number == v ? ~ (offsetT) 0 : 0; |
| 1523 | break; |
| 1524 | case O_ne: |
| 1525 | resultP->X_add_number = |
| 1526 | resultP->X_add_number != v ? ~ (offsetT) 0 : 0; |
| 1527 | break; |
| 1528 | case O_lt: |
| 1529 | resultP->X_add_number = |
| 1530 | resultP->X_add_number < v ? ~ (offsetT) 0 : 0; |
| 1531 | break; |
| 1532 | case O_le: |
| 1533 | resultP->X_add_number = |
| 1534 | resultP->X_add_number <= v ? ~ (offsetT) 0 : 0; |
| 1535 | break; |
| 1536 | case O_ge: |
| 1537 | resultP->X_add_number = |
| 1538 | resultP->X_add_number >= v ? ~ (offsetT) 0 : 0; |
| 1539 | break; |
| 1540 | case O_gt: |
| 1541 | resultP->X_add_number = |
| 1542 | resultP->X_add_number > v ? ~ (offsetT) 0 : 0; |
| 1543 | break; |
| 1544 | case O_logical_and: |
| 1545 | resultP->X_add_number = resultP->X_add_number && v; |
| 1546 | break; |
| 1547 | case O_logical_or: |
| 1548 | resultP->X_add_number = resultP->X_add_number || v; |
| 1549 | break; |
| 1550 | } |
| 1551 | } |
| 1552 | else if (resultP->X_op == O_symbol |
| 1553 | && right.X_op == O_symbol |
| 1554 | && (op_left == O_add |
| 1555 | || op_left == O_subtract |
| 1556 | || (resultP->X_add_number == 0 |
| 1557 | && right.X_add_number == 0))) |
| 1558 | { |
| 1559 | /* Symbol OP symbol. */ |
| 1560 | resultP->X_op = op_left; |
| 1561 | resultP->X_op_symbol = right.X_add_symbol; |
| 1562 | if (op_left == O_add) |
| 1563 | resultP->X_add_number += right.X_add_number; |
| 1564 | else if (op_left == O_subtract) |
| 1565 | resultP->X_add_number -= right.X_add_number; |
| 1566 | } |
| 1567 | else |
| 1568 | { |
| 1569 | /* The general case. */ |
| 1570 | resultP->X_add_symbol = make_expr_symbol (resultP); |
| 1571 | resultP->X_op_symbol = make_expr_symbol (&right); |
| 1572 | resultP->X_op = op_left; |
| 1573 | resultP->X_add_number = 0; |
| 1574 | resultP->X_unsigned = 1; |
| 1575 | } |
| 1576 | |
| 1577 | op_left = op_right; |
| 1578 | } /* While next operator is >= this rank. */ |
| 1579 | |
| 1580 | /* The PA port needs this information. */ |
| 1581 | if (resultP->X_add_symbol) |
| 1582 | resultP->X_add_symbol->sy_used = 1; |
| 1583 | |
| 1584 | return resultP->X_op == O_constant ? absolute_section : retval; |
| 1585 | } |
| 1586 | \f |
| 1587 | /* |
| 1588 | * get_symbol_end() |
| 1589 | * |
| 1590 | * This lives here because it belongs equally in expr.c & read.c. |
| 1591 | * Expr.c is just a branch office read.c anyway, and putting it |
| 1592 | * here lessens the crowd at read.c. |
| 1593 | * |
| 1594 | * Assume input_line_pointer is at start of symbol name. |
| 1595 | * Advance input_line_pointer past symbol name. |
| 1596 | * Turn that character into a '\0', returning its former value. |
| 1597 | * This allows a string compare (RMS wants symbol names to be strings) |
| 1598 | * of the symbol name. |
| 1599 | * There will always be a char following symbol name, because all good |
| 1600 | * lines end in end-of-line. |
| 1601 | */ |
| 1602 | char |
| 1603 | get_symbol_end () |
| 1604 | { |
| 1605 | char c; |
| 1606 | |
| 1607 | /* We accept \001 in a name in case this is being called with a |
| 1608 | constructed string. */ |
| 1609 | if (is_name_beginner (c = *input_line_pointer++) || c == '\001') |
| 1610 | while (is_part_of_name (c = *input_line_pointer++) |
| 1611 | || c == '\001') |
| 1612 | ; |
| 1613 | *--input_line_pointer = 0; |
| 1614 | return (c); |
| 1615 | } |
| 1616 | |
| 1617 | |
| 1618 | unsigned int |
| 1619 | get_single_number () |
| 1620 | { |
| 1621 | expressionS exp; |
| 1622 | operand (&exp); |
| 1623 | return exp.X_add_number; |
| 1624 | |
| 1625 | } |
| 1626 | |
| 1627 | /* end of expr.c */ |