| 1 | /* expr.c -operands, expressions- |
| 2 | Copyright (C) 1987, 1990, 1991, 1992, 1993, 1994 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 published by |
| 8 | the Free Software Foundation; either version 2, or (at your option) |
| 9 | any later version. |
| 10 | |
| 11 | GAS 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 GAS; see the file COPYING. If not, write to |
| 18 | the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 19 | |
| 20 | /* |
| 21 | * This is really a branch office of as-read.c. I split it out to clearly |
| 22 | * distinguish the world of expressions from the world of statements. |
| 23 | * (It also gives smaller files to re-compile.) |
| 24 | * Here, "operand"s are of expressions, not instructions. |
| 25 | */ |
| 26 | |
| 27 | #include <ctype.h> |
| 28 | #include <string.h> |
| 29 | |
| 30 | #include "as.h" |
| 31 | #include "libiberty.h" |
| 32 | #include "obstack.h" |
| 33 | |
| 34 | static void floating_constant PARAMS ((expressionS * expressionP)); |
| 35 | static void integer_constant PARAMS ((int radix, expressionS * expressionP)); |
| 36 | static void mri_char_constant PARAMS ((expressionS *)); |
| 37 | static void current_location PARAMS ((expressionS *)); |
| 38 | static void clean_up_expression PARAMS ((expressionS * expressionP)); |
| 39 | |
| 40 | extern const char EXP_CHARS[], FLT_CHARS[]; |
| 41 | \f |
| 42 | /* Build a dummy symbol to hold a complex expression. This is how we |
| 43 | build expressions up out of other expressions. The symbol is put |
| 44 | into the fake section expr_section. */ |
| 45 | |
| 46 | symbolS * |
| 47 | make_expr_symbol (expressionP) |
| 48 | expressionS *expressionP; |
| 49 | { |
| 50 | const char *fake; |
| 51 | symbolS *symbolP; |
| 52 | |
| 53 | if (expressionP->X_op == O_symbol |
| 54 | && expressionP->X_add_number == 0) |
| 55 | return expressionP->X_add_symbol; |
| 56 | |
| 57 | /* FIXME: This should be something which decode_local_label_name |
| 58 | will handle. */ |
| 59 | fake = FAKE_LABEL_NAME; |
| 60 | |
| 61 | /* Putting constant symbols in absolute_section rather than |
| 62 | expr_section is convenient for the old a.out code, for which |
| 63 | S_GET_SEGMENT does not always retrieve the value put in by |
| 64 | S_SET_SEGMENT. */ |
| 65 | symbolP = symbol_create (fake, |
| 66 | (expressionP->X_op == O_constant |
| 67 | ? absolute_section |
| 68 | : expr_section), |
| 69 | 0, &zero_address_frag); |
| 70 | symbolP->sy_value = *expressionP; |
| 71 | |
| 72 | if (expressionP->X_op == O_constant) |
| 73 | resolve_symbol_value (symbolP); |
| 74 | |
| 75 | return symbolP; |
| 76 | } |
| 77 | \f |
| 78 | /* |
| 79 | * Build any floating-point literal here. |
| 80 | * Also build any bignum literal here. |
| 81 | */ |
| 82 | |
| 83 | /* Seems atof_machine can backscan through generic_bignum and hit whatever |
| 84 | happens to be loaded before it in memory. And its way too complicated |
| 85 | for me to fix right. Thus a hack. JF: Just make generic_bignum bigger, |
| 86 | and never write into the early words, thus they'll always be zero. |
| 87 | I hate Dean's floating-point code. Bleh. */ |
| 88 | LITTLENUM_TYPE generic_bignum[SIZE_OF_LARGE_NUMBER + 6]; |
| 89 | FLONUM_TYPE generic_floating_point_number = |
| 90 | { |
| 91 | &generic_bignum[6], /* low (JF: Was 0) */ |
| 92 | &generic_bignum[SIZE_OF_LARGE_NUMBER + 6 - 1], /* high JF: (added +6) */ |
| 93 | 0, /* leader */ |
| 94 | 0, /* exponent */ |
| 95 | 0 /* sign */ |
| 96 | }; |
| 97 | /* If nonzero, we've been asked to assemble nan, +inf or -inf */ |
| 98 | int generic_floating_point_magic; |
| 99 | \f |
| 100 | static void |
| 101 | floating_constant (expressionP) |
| 102 | expressionS *expressionP; |
| 103 | { |
| 104 | /* input_line_pointer->*/ |
| 105 | /* floating-point constant. */ |
| 106 | int error_code; |
| 107 | |
| 108 | error_code = atof_generic (&input_line_pointer, ".", EXP_CHARS, |
| 109 | &generic_floating_point_number); |
| 110 | |
| 111 | if (error_code) |
| 112 | { |
| 113 | if (error_code == ERROR_EXPONENT_OVERFLOW) |
| 114 | { |
| 115 | as_bad ("bad floating-point constant: exponent overflow, probably assembling junk"); |
| 116 | } |
| 117 | else |
| 118 | { |
| 119 | as_bad ("bad floating-point constant: unknown error code=%d.", error_code); |
| 120 | } |
| 121 | } |
| 122 | expressionP->X_op = O_big; |
| 123 | /* input_line_pointer->just after constant, */ |
| 124 | /* which may point to whitespace. */ |
| 125 | expressionP->X_add_number = -1; |
| 126 | } |
| 127 | |
| 128 | static void |
| 129 | integer_constant (radix, expressionP) |
| 130 | int radix; |
| 131 | expressionS *expressionP; |
| 132 | { |
| 133 | char *start; /* start of number. */ |
| 134 | char *suffix = NULL; |
| 135 | char c; |
| 136 | valueT number; /* offset or (absolute) value */ |
| 137 | short int digit; /* value of next digit in current radix */ |
| 138 | short int maxdig = 0;/* highest permitted digit value. */ |
| 139 | int too_many_digits = 0; /* if we see >= this number of */ |
| 140 | char *name; /* points to name of symbol */ |
| 141 | symbolS *symbolP; /* points to symbol */ |
| 142 | |
| 143 | int small; /* true if fits in 32 bits. */ |
| 144 | |
| 145 | /* May be bignum, or may fit in 32 bits. */ |
| 146 | /* Most numbers fit into 32 bits, and we want this case to be fast. |
| 147 | so we pretend it will fit into 32 bits. If, after making up a 32 |
| 148 | bit number, we realise that we have scanned more digits than |
| 149 | comfortably fit into 32 bits, we re-scan the digits coding them |
| 150 | into a bignum. For decimal and octal numbers we are |
| 151 | conservative: Some numbers may be assumed bignums when in fact |
| 152 | they do fit into 32 bits. Numbers of any radix can have excess |
| 153 | leading zeros: We strive to recognise this and cast them back |
| 154 | into 32 bits. We must check that the bignum really is more than |
| 155 | 32 bits, and change it back to a 32-bit number if it fits. The |
| 156 | number we are looking for is expected to be positive, but if it |
| 157 | fits into 32 bits as an unsigned number, we let it be a 32-bit |
| 158 | number. The cavalier approach is for speed in ordinary cases. */ |
| 159 | /* This has been extended for 64 bits. We blindly assume that if |
| 160 | you're compiling in 64-bit mode, the target is a 64-bit machine. |
| 161 | This should be cleaned up. */ |
| 162 | |
| 163 | #ifdef BFD64 |
| 164 | #define valuesize 64 |
| 165 | #else /* includes non-bfd case, mostly */ |
| 166 | #define valuesize 32 |
| 167 | #endif |
| 168 | |
| 169 | if (flag_mri && radix == 0) |
| 170 | { |
| 171 | int flt = 0; |
| 172 | |
| 173 | /* In MRI mode, the number may have a suffix indicating the |
| 174 | radix. For that matter, it might actually be a floating |
| 175 | point constant. */ |
| 176 | for (suffix = input_line_pointer; isalnum (*suffix); suffix++) |
| 177 | { |
| 178 | if (*suffix == 'e' || *suffix == 'E') |
| 179 | flt = 1; |
| 180 | } |
| 181 | |
| 182 | if (suffix == input_line_pointer) |
| 183 | { |
| 184 | radix = 10; |
| 185 | suffix = NULL; |
| 186 | } |
| 187 | else |
| 188 | { |
| 189 | c = *--suffix; |
| 190 | if (islower (c)) |
| 191 | c = toupper (c); |
| 192 | if (c == 'B') |
| 193 | radix = 2; |
| 194 | else if (c == 'D') |
| 195 | radix = 10; |
| 196 | else if (c == 'O' || c == 'Q') |
| 197 | radix = 8; |
| 198 | else if (c == 'H') |
| 199 | radix = 16; |
| 200 | else if (suffix[1] == '.' || c == 'E' || flt) |
| 201 | { |
| 202 | floating_constant (expressionP); |
| 203 | return; |
| 204 | } |
| 205 | else |
| 206 | { |
| 207 | radix = 10; |
| 208 | suffix = NULL; |
| 209 | } |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | switch (radix) |
| 214 | { |
| 215 | case 2: |
| 216 | maxdig = 2; |
| 217 | too_many_digits = valuesize + 1; |
| 218 | break; |
| 219 | case 8: |
| 220 | maxdig = radix = 8; |
| 221 | too_many_digits = (valuesize + 2) / 3 + 1; |
| 222 | break; |
| 223 | case 16: |
| 224 | maxdig = radix = 16; |
| 225 | too_many_digits = (valuesize + 3) / 4 + 1; |
| 226 | break; |
| 227 | case 10: |
| 228 | maxdig = radix = 10; |
| 229 | too_many_digits = (valuesize + 12) / 4; /* very rough */ |
| 230 | } |
| 231 | #undef valuesize |
| 232 | start = input_line_pointer; |
| 233 | c = *input_line_pointer++; |
| 234 | for (number = 0; |
| 235 | (digit = hex_value (c)) < maxdig; |
| 236 | c = *input_line_pointer++) |
| 237 | { |
| 238 | number = number * radix + digit; |
| 239 | } |
| 240 | /* c contains character after number. */ |
| 241 | /* input_line_pointer->char after c. */ |
| 242 | small = (input_line_pointer - start - 1) < too_many_digits; |
| 243 | if (!small) |
| 244 | { |
| 245 | /* |
| 246 | * we saw a lot of digits. manufacture a bignum the hard way. |
| 247 | */ |
| 248 | LITTLENUM_TYPE *leader; /*->high order littlenum of the bignum. */ |
| 249 | LITTLENUM_TYPE *pointer; /*->littlenum we are frobbing now. */ |
| 250 | long carry; |
| 251 | |
| 252 | leader = generic_bignum; |
| 253 | generic_bignum[0] = 0; |
| 254 | generic_bignum[1] = 0; |
| 255 | input_line_pointer = start; /*->1st digit. */ |
| 256 | c = *input_line_pointer++; |
| 257 | for (; |
| 258 | (carry = hex_value (c)) < maxdig; |
| 259 | c = *input_line_pointer++) |
| 260 | { |
| 261 | for (pointer = generic_bignum; |
| 262 | pointer <= leader; |
| 263 | pointer++) |
| 264 | { |
| 265 | long work; |
| 266 | |
| 267 | work = carry + radix * *pointer; |
| 268 | *pointer = work & LITTLENUM_MASK; |
| 269 | carry = work >> LITTLENUM_NUMBER_OF_BITS; |
| 270 | } |
| 271 | if (carry) |
| 272 | { |
| 273 | if (leader < generic_bignum + SIZE_OF_LARGE_NUMBER - 1) |
| 274 | { |
| 275 | /* room to grow a longer bignum. */ |
| 276 | *++leader = carry; |
| 277 | } |
| 278 | } |
| 279 | } |
| 280 | /* again, c is char after number, */ |
| 281 | /* input_line_pointer->after c. */ |
| 282 | know (LITTLENUM_NUMBER_OF_BITS == 16); |
| 283 | if (leader < generic_bignum + 2) |
| 284 | { |
| 285 | /* will fit into 32 bits. */ |
| 286 | number = |
| 287 | ((generic_bignum[1] & LITTLENUM_MASK) << LITTLENUM_NUMBER_OF_BITS) |
| 288 | | (generic_bignum[0] & LITTLENUM_MASK); |
| 289 | small = 1; |
| 290 | } |
| 291 | else |
| 292 | { |
| 293 | number = leader - generic_bignum + 1; /* number of littlenums in the bignum. */ |
| 294 | } |
| 295 | } |
| 296 | |
| 297 | if (flag_mri && suffix != NULL && input_line_pointer - 1 == suffix) |
| 298 | c = *input_line_pointer++; |
| 299 | |
| 300 | if (small) |
| 301 | { |
| 302 | /* |
| 303 | * here with number, in correct radix. c is the next char. |
| 304 | * note that unlike un*x, we allow "011f" "0x9f" to |
| 305 | * both mean the same as the (conventional) "9f". this is simply easier |
| 306 | * than checking for strict canonical form. syntax sux! |
| 307 | */ |
| 308 | |
| 309 | if (LOCAL_LABELS_FB && c == 'b') |
| 310 | { |
| 311 | /* |
| 312 | * backward ref to local label. |
| 313 | * because it is backward, expect it to be defined. |
| 314 | */ |
| 315 | /* Construct a local label. */ |
| 316 | name = fb_label_name ((int) number, 0); |
| 317 | |
| 318 | /* seen before, or symbol is defined: ok */ |
| 319 | symbolP = symbol_find (name); |
| 320 | if ((symbolP != NULL) && (S_IS_DEFINED (symbolP))) |
| 321 | { |
| 322 | /* local labels are never absolute. don't waste time |
| 323 | checking absoluteness. */ |
| 324 | know (SEG_NORMAL (S_GET_SEGMENT (symbolP))); |
| 325 | |
| 326 | expressionP->X_op = O_symbol; |
| 327 | expressionP->X_add_symbol = symbolP; |
| 328 | } |
| 329 | else |
| 330 | { |
| 331 | /* either not seen or not defined. */ |
| 332 | /* @@ Should print out the original string instead of |
| 333 | the parsed number. */ |
| 334 | as_bad ("backw. ref to unknown label \"%d:\", 0 assumed.", |
| 335 | (int) number); |
| 336 | expressionP->X_op = O_constant; |
| 337 | } |
| 338 | |
| 339 | expressionP->X_add_number = 0; |
| 340 | } /* case 'b' */ |
| 341 | else if (LOCAL_LABELS_FB && c == 'f') |
| 342 | { |
| 343 | /* |
| 344 | * forward reference. expect symbol to be undefined or |
| 345 | * unknown. undefined: seen it before. unknown: never seen |
| 346 | * it before. |
| 347 | * construct a local label name, then an undefined symbol. |
| 348 | * don't create a xseg frag for it: caller may do that. |
| 349 | * just return it as never seen before. |
| 350 | */ |
| 351 | name = fb_label_name ((int) number, 1); |
| 352 | symbolP = symbol_find_or_make (name); |
| 353 | /* we have no need to check symbol properties. */ |
| 354 | #ifndef many_segments |
| 355 | /* since "know" puts its arg into a "string", we |
| 356 | can't have newlines in the argument. */ |
| 357 | know (S_GET_SEGMENT (symbolP) == undefined_section || S_GET_SEGMENT (symbolP) == text_section || S_GET_SEGMENT (symbolP) == data_section); |
| 358 | #endif |
| 359 | expressionP->X_op = O_symbol; |
| 360 | expressionP->X_add_symbol = symbolP; |
| 361 | expressionP->X_add_number = 0; |
| 362 | } /* case 'f' */ |
| 363 | else if (LOCAL_LABELS_DOLLAR && c == '$') |
| 364 | { |
| 365 | /* If the dollar label is *currently* defined, then this is just |
| 366 | another reference to it. If it is not *currently* defined, |
| 367 | then this is a fresh instantiation of that number, so create |
| 368 | it. */ |
| 369 | |
| 370 | if (dollar_label_defined ((long) number)) |
| 371 | { |
| 372 | name = dollar_label_name ((long) number, 0); |
| 373 | symbolP = symbol_find (name); |
| 374 | know (symbolP != NULL); |
| 375 | } |
| 376 | else |
| 377 | { |
| 378 | name = dollar_label_name ((long) number, 1); |
| 379 | symbolP = symbol_find_or_make (name); |
| 380 | } |
| 381 | |
| 382 | expressionP->X_op = O_symbol; |
| 383 | expressionP->X_add_symbol = symbolP; |
| 384 | expressionP->X_add_number = 0; |
| 385 | } /* case '$' */ |
| 386 | else |
| 387 | { |
| 388 | expressionP->X_op = O_constant; |
| 389 | #ifdef TARGET_WORD_SIZE |
| 390 | /* Sign extend NUMBER. */ |
| 391 | number |= (-(number >> (TARGET_WORD_SIZE - 1))) << (TARGET_WORD_SIZE - 1); |
| 392 | #endif |
| 393 | expressionP->X_add_number = number; |
| 394 | input_line_pointer--; /* restore following character. */ |
| 395 | } /* really just a number */ |
| 396 | } |
| 397 | else |
| 398 | { |
| 399 | /* not a small number */ |
| 400 | expressionP->X_op = O_big; |
| 401 | expressionP->X_add_number = number; /* number of littlenums */ |
| 402 | input_line_pointer--; /*->char following number. */ |
| 403 | } |
| 404 | } |
| 405 | |
| 406 | /* Parse an MRI multi character constant. */ |
| 407 | |
| 408 | static void |
| 409 | mri_char_constant (expressionP) |
| 410 | expressionS *expressionP; |
| 411 | { |
| 412 | int i; |
| 413 | |
| 414 | if (*input_line_pointer == '\'' |
| 415 | && input_line_pointer[1] != '\'') |
| 416 | { |
| 417 | expressionP->X_op = O_constant; |
| 418 | expressionP->X_add_number = 0; |
| 419 | return; |
| 420 | } |
| 421 | |
| 422 | /* In order to get the correct byte ordering, we must build the |
| 423 | number in reverse. */ |
| 424 | for (i = SIZE_OF_LARGE_NUMBER - 1; i >= 0; i--) |
| 425 | { |
| 426 | int j; |
| 427 | |
| 428 | generic_bignum[i] = 0; |
| 429 | for (j = 0; j < CHARS_PER_LITTLENUM; j++) |
| 430 | { |
| 431 | if (*input_line_pointer == '\'') |
| 432 | { |
| 433 | if (input_line_pointer[1] != '\'') |
| 434 | break; |
| 435 | ++input_line_pointer; |
| 436 | } |
| 437 | generic_bignum[i] <<= 8; |
| 438 | generic_bignum[i] += *input_line_pointer; |
| 439 | ++input_line_pointer; |
| 440 | } |
| 441 | |
| 442 | if (i < SIZE_OF_LARGE_NUMBER - 1) |
| 443 | { |
| 444 | /* If there is more than one littlenum, left justify the |
| 445 | last one to make it match the earlier ones. If there is |
| 446 | only one, we can just use the value directly. */ |
| 447 | for (; j < CHARS_PER_LITTLENUM; j++) |
| 448 | generic_bignum[i] <<= 8; |
| 449 | } |
| 450 | |
| 451 | if (*input_line_pointer == '\'' |
| 452 | && input_line_pointer[1] != '\'') |
| 453 | break; |
| 454 | } |
| 455 | |
| 456 | if (i < 0) |
| 457 | { |
| 458 | as_bad ("Character constant too large"); |
| 459 | i = 0; |
| 460 | } |
| 461 | |
| 462 | if (i > 0) |
| 463 | { |
| 464 | int c; |
| 465 | int j; |
| 466 | |
| 467 | c = SIZE_OF_LARGE_NUMBER - i; |
| 468 | for (j = 0; j < c; j++) |
| 469 | generic_bignum[j] = generic_bignum[i + j]; |
| 470 | i = c; |
| 471 | } |
| 472 | |
| 473 | know (LITTLENUM_NUMBER_OF_BITS == 16); |
| 474 | if (i > 2) |
| 475 | { |
| 476 | expressionP->X_op = O_big; |
| 477 | expressionP->X_add_number = i; |
| 478 | } |
| 479 | else |
| 480 | { |
| 481 | expressionP->X_op = O_constant; |
| 482 | if (i < 2) |
| 483 | expressionP->X_add_number = generic_bignum[0] & LITTLENUM_MASK; |
| 484 | else |
| 485 | expressionP->X_add_number = |
| 486 | (((generic_bignum[1] & LITTLENUM_MASK) |
| 487 | << LITTLENUM_NUMBER_OF_BITS) |
| 488 | | (generic_bignum[0] & LITTLENUM_MASK)); |
| 489 | } |
| 490 | |
| 491 | /* Skip the final closing quote. */ |
| 492 | ++input_line_pointer; |
| 493 | } |
| 494 | |
| 495 | /* Return an expression representing the current location. This |
| 496 | handles the magic symbol `.'. */ |
| 497 | |
| 498 | static void |
| 499 | current_location (expressionp) |
| 500 | expressionS *expressionp; |
| 501 | { |
| 502 | if (now_seg == absolute_section) |
| 503 | { |
| 504 | expressionp->X_op = O_constant; |
| 505 | expressionp->X_add_number = abs_section_offset; |
| 506 | } |
| 507 | else |
| 508 | { |
| 509 | symbolS *symbolp; |
| 510 | |
| 511 | symbolp = symbol_new (FAKE_LABEL_NAME, now_seg, |
| 512 | (valueT) frag_now_fix (), |
| 513 | frag_now); |
| 514 | expressionp->X_op = O_symbol; |
| 515 | expressionp->X_add_symbol = symbolp; |
| 516 | expressionp->X_add_number = 0; |
| 517 | } |
| 518 | } |
| 519 | |
| 520 | /* |
| 521 | * Summary of operand(). |
| 522 | * |
| 523 | * in: Input_line_pointer points to 1st char of operand, which may |
| 524 | * be a space. |
| 525 | * |
| 526 | * out: A expressionS. |
| 527 | * The operand may have been empty: in this case X_op == O_absent. |
| 528 | * Input_line_pointer->(next non-blank) char after operand. |
| 529 | */ |
| 530 | |
| 531 | static segT |
| 532 | operand (expressionP) |
| 533 | expressionS *expressionP; |
| 534 | { |
| 535 | char c; |
| 536 | symbolS *symbolP; /* points to symbol */ |
| 537 | char *name; /* points to name of symbol */ |
| 538 | segT segment; |
| 539 | |
| 540 | /* All integers are regarded as unsigned unless they are negated. |
| 541 | This is because the only thing which cares whether a number is |
| 542 | unsigned is the code in emit_expr which extends constants into |
| 543 | bignums. It should only sign extend negative numbers, so that |
| 544 | something like ``.quad 0x80000000'' is not sign extended even |
| 545 | though it appears negative if valueT is 32 bits. */ |
| 546 | expressionP->X_unsigned = 1; |
| 547 | |
| 548 | /* digits, assume it is a bignum. */ |
| 549 | |
| 550 | SKIP_WHITESPACE (); /* leading whitespace is part of operand. */ |
| 551 | c = *input_line_pointer++; /* input_line_pointer->past char in c. */ |
| 552 | |
| 553 | switch (c) |
| 554 | { |
| 555 | case '1': |
| 556 | case '2': |
| 557 | case '3': |
| 558 | case '4': |
| 559 | case '5': |
| 560 | case '6': |
| 561 | case '7': |
| 562 | case '8': |
| 563 | case '9': |
| 564 | input_line_pointer--; |
| 565 | |
| 566 | integer_constant (flag_mri ? 0 : 10, expressionP); |
| 567 | break; |
| 568 | |
| 569 | case '0': |
| 570 | /* non-decimal radix */ |
| 571 | |
| 572 | if (flag_mri) |
| 573 | { |
| 574 | char *s; |
| 575 | |
| 576 | /* Check for a hex constant. */ |
| 577 | for (s = input_line_pointer; hex_p (*s); s++) |
| 578 | ; |
| 579 | if (*s == 'h' || *s == 'H') |
| 580 | { |
| 581 | --input_line_pointer; |
| 582 | integer_constant (0, expressionP); |
| 583 | break; |
| 584 | } |
| 585 | } |
| 586 | |
| 587 | c = *input_line_pointer; |
| 588 | switch (c) |
| 589 | { |
| 590 | case '8': |
| 591 | case '9': |
| 592 | if (flag_mri) |
| 593 | { |
| 594 | integer_constant (0, expressionP); |
| 595 | break; |
| 596 | } |
| 597 | /* Fall through. */ |
| 598 | default: |
| 599 | default_case: |
| 600 | if (c && strchr (FLT_CHARS, c)) |
| 601 | { |
| 602 | input_line_pointer++; |
| 603 | floating_constant (expressionP); |
| 604 | expressionP->X_add_number = -(isupper (c) ? tolower (c) : c); |
| 605 | } |
| 606 | else |
| 607 | { |
| 608 | /* The string was only zero */ |
| 609 | expressionP->X_op = O_constant; |
| 610 | expressionP->X_add_number = 0; |
| 611 | } |
| 612 | |
| 613 | break; |
| 614 | |
| 615 | case 'x': |
| 616 | case 'X': |
| 617 | if (flag_mri) |
| 618 | goto default_case; |
| 619 | input_line_pointer++; |
| 620 | integer_constant (16, expressionP); |
| 621 | break; |
| 622 | |
| 623 | case 'b': |
| 624 | if (LOCAL_LABELS_FB) |
| 625 | { |
| 626 | switch (input_line_pointer[1]) |
| 627 | { |
| 628 | case '+': |
| 629 | case '-': |
| 630 | /* If unambiguously a difference expression, treat |
| 631 | it as one by indicating a label; otherwise, it's |
| 632 | always a binary number. */ |
| 633 | { |
| 634 | char *cp = input_line_pointer + 1; |
| 635 | while (strchr ("0123456789", *++cp)) |
| 636 | ; |
| 637 | if (*cp == 'b' || *cp == 'f') |
| 638 | goto is_0b_label; |
| 639 | } |
| 640 | goto is_0b_binary; |
| 641 | case '0': case '1': |
| 642 | /* Some of our code elsewhere does permit digits |
| 643 | greater than the expected base; for consistency, |
| 644 | do the same here. */ |
| 645 | case '2': case '3': case '4': case '5': |
| 646 | case '6': case '7': case '8': case '9': |
| 647 | goto is_0b_binary; |
| 648 | case 0: |
| 649 | goto is_0b_label; |
| 650 | default: |
| 651 | goto is_0b_label; |
| 652 | } |
| 653 | is_0b_label: |
| 654 | input_line_pointer--; |
| 655 | integer_constant (10, expressionP); |
| 656 | break; |
| 657 | is_0b_binary: |
| 658 | ; |
| 659 | } |
| 660 | case 'B': |
| 661 | input_line_pointer++; |
| 662 | if (flag_mri) |
| 663 | goto default_case; |
| 664 | integer_constant (2, expressionP); |
| 665 | break; |
| 666 | |
| 667 | case '0': |
| 668 | case '1': |
| 669 | case '2': |
| 670 | case '3': |
| 671 | case '4': |
| 672 | case '5': |
| 673 | case '6': |
| 674 | case '7': |
| 675 | integer_constant (flag_mri ? 0 : 8, expressionP); |
| 676 | break; |
| 677 | |
| 678 | case 'f': |
| 679 | if (LOCAL_LABELS_FB) |
| 680 | { |
| 681 | /* If it says "0f" and it could possibly be a floating point |
| 682 | number, make it one. Otherwise, make it a local label, |
| 683 | and try to deal with parsing the rest later. */ |
| 684 | if (!input_line_pointer[1] |
| 685 | || (is_end_of_line[0xff & input_line_pointer[1]])) |
| 686 | goto is_0f_label; |
| 687 | { |
| 688 | char *cp = input_line_pointer + 1; |
| 689 | int r = atof_generic (&cp, ".", EXP_CHARS, |
| 690 | &generic_floating_point_number); |
| 691 | switch (r) |
| 692 | { |
| 693 | case 0: |
| 694 | case ERROR_EXPONENT_OVERFLOW: |
| 695 | if (*cp == 'f' || *cp == 'b') |
| 696 | /* looks like a difference expression */ |
| 697 | goto is_0f_label; |
| 698 | else |
| 699 | goto is_0f_float; |
| 700 | default: |
| 701 | as_fatal ("expr.c(operand): bad atof_generic return val %d", |
| 702 | r); |
| 703 | } |
| 704 | } |
| 705 | |
| 706 | /* Okay, now we've sorted it out. We resume at one of these |
| 707 | two labels, depending on what we've decided we're probably |
| 708 | looking at. */ |
| 709 | is_0f_label: |
| 710 | input_line_pointer--; |
| 711 | integer_constant (10, expressionP); |
| 712 | break; |
| 713 | |
| 714 | is_0f_float: |
| 715 | /* fall through */ |
| 716 | ; |
| 717 | } |
| 718 | |
| 719 | case 'd': |
| 720 | case 'D': |
| 721 | case 'F': |
| 722 | case 'r': |
| 723 | case 'e': |
| 724 | case 'E': |
| 725 | case 'g': |
| 726 | case 'G': |
| 727 | input_line_pointer++; |
| 728 | floating_constant (expressionP); |
| 729 | expressionP->X_add_number = -(isupper (c) ? tolower (c) : c); |
| 730 | break; |
| 731 | |
| 732 | case '$': |
| 733 | if (LOCAL_LABELS_DOLLAR) |
| 734 | { |
| 735 | integer_constant (10, expressionP); |
| 736 | break; |
| 737 | } |
| 738 | else |
| 739 | goto default_case; |
| 740 | } |
| 741 | |
| 742 | break; |
| 743 | |
| 744 | case '(': |
| 745 | case '[': |
| 746 | /* didn't begin with digit & not a name */ |
| 747 | segment = expression (expressionP); |
| 748 | /* Expression() will pass trailing whitespace */ |
| 749 | if ((c == '(' && *input_line_pointer++ != ')') |
| 750 | || (c == '[' && *input_line_pointer++ != ']')) |
| 751 | { |
| 752 | as_bad ("Missing ')' assumed"); |
| 753 | input_line_pointer--; |
| 754 | } |
| 755 | /* here with input_line_pointer->char after "(...)" */ |
| 756 | return segment; |
| 757 | |
| 758 | case 'E': |
| 759 | if (! flag_mri || *input_line_pointer != '\'') |
| 760 | goto de_fault; |
| 761 | as_bad ("EBCDIC constants are not supported"); |
| 762 | /* Fall through. */ |
| 763 | case 'A': |
| 764 | if (! flag_mri || *input_line_pointer != '\'') |
| 765 | goto de_fault; |
| 766 | ++input_line_pointer; |
| 767 | /* Fall through. */ |
| 768 | case '\'': |
| 769 | if (! flag_mri) |
| 770 | { |
| 771 | /* Warning: to conform to other people's assemblers NO |
| 772 | ESCAPEMENT is permitted for a single quote. The next |
| 773 | character, parity errors and all, is taken as the value |
| 774 | of the operand. VERY KINKY. */ |
| 775 | expressionP->X_op = O_constant; |
| 776 | expressionP->X_add_number = *input_line_pointer++; |
| 777 | break; |
| 778 | } |
| 779 | |
| 780 | mri_char_constant (expressionP); |
| 781 | break; |
| 782 | |
| 783 | case '+': |
| 784 | (void) operand (expressionP); |
| 785 | break; |
| 786 | |
| 787 | case '"': |
| 788 | /* Double quote is the logical not operator in MRI mode. */ |
| 789 | if (! flag_mri) |
| 790 | goto de_fault; |
| 791 | /* Fall through. */ |
| 792 | case '~': |
| 793 | case '-': |
| 794 | { |
| 795 | operand (expressionP); |
| 796 | if (expressionP->X_op == O_constant) |
| 797 | { |
| 798 | /* input_line_pointer -> char after operand */ |
| 799 | if (c == '-') |
| 800 | { |
| 801 | expressionP->X_add_number = - expressionP->X_add_number; |
| 802 | /* Notice: '-' may overflow: no warning is given. This is |
| 803 | compatible with other people's assemblers. Sigh. */ |
| 804 | expressionP->X_unsigned = 0; |
| 805 | } |
| 806 | else |
| 807 | expressionP->X_add_number = ~ expressionP->X_add_number; |
| 808 | } |
| 809 | else if (expressionP->X_op != O_illegal |
| 810 | && expressionP->X_op != O_absent) |
| 811 | { |
| 812 | expressionP->X_add_symbol = make_expr_symbol (expressionP); |
| 813 | if (c == '-') |
| 814 | expressionP->X_op = O_uminus; |
| 815 | else |
| 816 | expressionP->X_op = O_bit_not; |
| 817 | expressionP->X_add_number = 0; |
| 818 | } |
| 819 | else |
| 820 | as_warn ("Unary operator %c ignored because bad operand follows", |
| 821 | c); |
| 822 | } |
| 823 | break; |
| 824 | |
| 825 | case '$': |
| 826 | /* $ is the program counter when in MRI mode, or when DOLLAR_DOT |
| 827 | is defined. */ |
| 828 | #ifndef DOLLAR_DOT |
| 829 | if (! flag_mri) |
| 830 | goto de_fault; |
| 831 | #endif |
| 832 | if (flag_mri && hex_p (*input_line_pointer)) |
| 833 | { |
| 834 | /* In MRI mode, $ is also used as the prefix for a |
| 835 | hexadecimal constant. */ |
| 836 | integer_constant (16, expressionP); |
| 837 | break; |
| 838 | } |
| 839 | |
| 840 | if (is_part_of_name (*input_line_pointer)) |
| 841 | goto isname; |
| 842 | |
| 843 | current_location (expressionP); |
| 844 | break; |
| 845 | |
| 846 | case '.': |
| 847 | if (!is_part_of_name (*input_line_pointer)) |
| 848 | { |
| 849 | current_location (expressionP); |
| 850 | break; |
| 851 | } |
| 852 | else if ((strncasecmp (input_line_pointer, "startof.", 8) == 0 |
| 853 | && ! is_part_of_name (input_line_pointer[8])) |
| 854 | || (strncasecmp (input_line_pointer, "sizeof.", 7) == 0 |
| 855 | && ! is_part_of_name (input_line_pointer[7]))) |
| 856 | { |
| 857 | int start; |
| 858 | |
| 859 | start = (input_line_pointer[1] == 't' |
| 860 | || input_line_pointer[1] == 'T'); |
| 861 | input_line_pointer += start ? 8 : 7; |
| 862 | SKIP_WHITESPACE (); |
| 863 | if (*input_line_pointer != '(') |
| 864 | as_bad ("syntax error in .startof. or .sizeof."); |
| 865 | else |
| 866 | { |
| 867 | char *buf; |
| 868 | |
| 869 | ++input_line_pointer; |
| 870 | SKIP_WHITESPACE (); |
| 871 | name = input_line_pointer; |
| 872 | c = get_symbol_end (); |
| 873 | |
| 874 | buf = (char *) xmalloc (strlen (name) + 10); |
| 875 | if (start) |
| 876 | sprintf (buf, ".startof.%s", name); |
| 877 | else |
| 878 | sprintf (buf, ".sizeof.%s", name); |
| 879 | symbolP = symbol_make (buf); |
| 880 | free (buf); |
| 881 | |
| 882 | expressionP->X_op = O_symbol; |
| 883 | expressionP->X_add_symbol = symbolP; |
| 884 | expressionP->X_add_number = 0; |
| 885 | |
| 886 | *input_line_pointer = c; |
| 887 | SKIP_WHITESPACE (); |
| 888 | if (*input_line_pointer != ')') |
| 889 | as_bad ("syntax error in .startof. or .sizeof."); |
| 890 | else |
| 891 | ++input_line_pointer; |
| 892 | } |
| 893 | break; |
| 894 | } |
| 895 | else |
| 896 | { |
| 897 | goto isname; |
| 898 | } |
| 899 | case ',': |
| 900 | case '\n': |
| 901 | case '\0': |
| 902 | eol: |
| 903 | /* can't imagine any other kind of operand */ |
| 904 | expressionP->X_op = O_absent; |
| 905 | input_line_pointer--; |
| 906 | break; |
| 907 | |
| 908 | case '%': |
| 909 | if (! flag_mri) |
| 910 | goto de_fault; |
| 911 | integer_constant (2, expressionP); |
| 912 | break; |
| 913 | |
| 914 | case '@': |
| 915 | if (! flag_mri) |
| 916 | goto de_fault; |
| 917 | integer_constant (8, expressionP); |
| 918 | break; |
| 919 | |
| 920 | case ':': |
| 921 | if (! flag_mri) |
| 922 | goto de_fault; |
| 923 | |
| 924 | /* In MRI mode, this is a floating point constant represented |
| 925 | using hexadecimal digits. */ |
| 926 | |
| 927 | ++input_line_pointer; |
| 928 | integer_constant (16, expressionP); |
| 929 | break; |
| 930 | |
| 931 | case '*': |
| 932 | if (! flag_mri || is_part_of_name (*input_line_pointer)) |
| 933 | goto de_fault; |
| 934 | |
| 935 | current_location (expressionP); |
| 936 | break; |
| 937 | |
| 938 | default: |
| 939 | de_fault: |
| 940 | if (is_end_of_line[(unsigned char) c]) |
| 941 | goto eol; |
| 942 | if (is_name_beginner (c)) /* here if did not begin with a digit */ |
| 943 | { |
| 944 | /* |
| 945 | * Identifier begins here. |
| 946 | * This is kludged for speed, so code is repeated. |
| 947 | */ |
| 948 | isname: |
| 949 | name = --input_line_pointer; |
| 950 | c = get_symbol_end (); |
| 951 | symbolP = symbol_find_or_make (name); |
| 952 | |
| 953 | /* If we have an absolute symbol or a reg, then we know its |
| 954 | value now. */ |
| 955 | segment = S_GET_SEGMENT (symbolP); |
| 956 | if (segment == absolute_section) |
| 957 | { |
| 958 | expressionP->X_op = O_constant; |
| 959 | expressionP->X_add_number = S_GET_VALUE (symbolP); |
| 960 | } |
| 961 | else if (segment == reg_section) |
| 962 | { |
| 963 | expressionP->X_op = O_register; |
| 964 | expressionP->X_add_number = S_GET_VALUE (symbolP); |
| 965 | } |
| 966 | else |
| 967 | { |
| 968 | expressionP->X_op = O_symbol; |
| 969 | expressionP->X_add_symbol = symbolP; |
| 970 | expressionP->X_add_number = 0; |
| 971 | } |
| 972 | *input_line_pointer = c; |
| 973 | } |
| 974 | else |
| 975 | { |
| 976 | /* Let the target try to parse it. Success is indicated by changing |
| 977 | the X_op field to something other than O_absent and pointing |
| 978 | input_line_pointer passed the expression. If it can't parse the |
| 979 | expression, X_op and input_line_pointer should be unchanged. */ |
| 980 | expressionP->X_op = O_absent; |
| 981 | --input_line_pointer; |
| 982 | md_operand (expressionP); |
| 983 | if (expressionP->X_op == O_absent) |
| 984 | { |
| 985 | ++input_line_pointer; |
| 986 | as_bad ("Bad expression"); |
| 987 | expressionP->X_op = O_constant; |
| 988 | expressionP->X_add_number = 0; |
| 989 | } |
| 990 | } |
| 991 | break; |
| 992 | } |
| 993 | |
| 994 | /* |
| 995 | * It is more 'efficient' to clean up the expressionS when they are created. |
| 996 | * Doing it here saves lines of code. |
| 997 | */ |
| 998 | clean_up_expression (expressionP); |
| 999 | SKIP_WHITESPACE (); /*->1st char after operand. */ |
| 1000 | know (*input_line_pointer != ' '); |
| 1001 | |
| 1002 | /* The PA port needs this information. */ |
| 1003 | if (expressionP->X_add_symbol) |
| 1004 | expressionP->X_add_symbol->sy_used = 1; |
| 1005 | |
| 1006 | switch (expressionP->X_op) |
| 1007 | { |
| 1008 | default: |
| 1009 | return absolute_section; |
| 1010 | case O_symbol: |
| 1011 | return S_GET_SEGMENT (expressionP->X_add_symbol); |
| 1012 | case O_register: |
| 1013 | return reg_section; |
| 1014 | } |
| 1015 | } /* operand() */ |
| 1016 | \f |
| 1017 | /* Internal. Simplify a struct expression for use by expr() */ |
| 1018 | |
| 1019 | /* |
| 1020 | * In: address of a expressionS. |
| 1021 | * The X_op field of the expressionS may only take certain values. |
| 1022 | * Elsewise we waste time special-case testing. Sigh. Ditto SEG_ABSENT. |
| 1023 | * Out: expressionS may have been modified: |
| 1024 | * 'foo-foo' symbol references cancelled to 0, |
| 1025 | * which changes X_op from O_subtract to O_constant. |
| 1026 | * Unused fields zeroed to help expr(). |
| 1027 | */ |
| 1028 | |
| 1029 | static void |
| 1030 | clean_up_expression (expressionP) |
| 1031 | expressionS *expressionP; |
| 1032 | { |
| 1033 | switch (expressionP->X_op) |
| 1034 | { |
| 1035 | case O_illegal: |
| 1036 | case O_absent: |
| 1037 | expressionP->X_add_number = 0; |
| 1038 | /* Fall through. */ |
| 1039 | case O_big: |
| 1040 | case O_constant: |
| 1041 | case O_register: |
| 1042 | expressionP->X_add_symbol = NULL; |
| 1043 | /* Fall through. */ |
| 1044 | case O_symbol: |
| 1045 | case O_uminus: |
| 1046 | case O_bit_not: |
| 1047 | expressionP->X_op_symbol = NULL; |
| 1048 | break; |
| 1049 | case O_subtract: |
| 1050 | if (expressionP->X_op_symbol == expressionP->X_add_symbol |
| 1051 | || ((expressionP->X_op_symbol->sy_frag |
| 1052 | == expressionP->X_add_symbol->sy_frag) |
| 1053 | && SEG_NORMAL (S_GET_SEGMENT (expressionP->X_add_symbol)) |
| 1054 | && (S_GET_VALUE (expressionP->X_op_symbol) |
| 1055 | == S_GET_VALUE (expressionP->X_add_symbol)))) |
| 1056 | { |
| 1057 | addressT diff = (S_GET_VALUE (expressionP->X_add_symbol) |
| 1058 | - S_GET_VALUE (expressionP->X_op_symbol)); |
| 1059 | |
| 1060 | expressionP->X_op = O_constant; |
| 1061 | expressionP->X_add_symbol = NULL; |
| 1062 | expressionP->X_op_symbol = NULL; |
| 1063 | expressionP->X_add_number += diff; |
| 1064 | } |
| 1065 | break; |
| 1066 | default: |
| 1067 | break; |
| 1068 | } |
| 1069 | } |
| 1070 | \f |
| 1071 | /* Expression parser. */ |
| 1072 | |
| 1073 | /* |
| 1074 | * We allow an empty expression, and just assume (absolute,0) silently. |
| 1075 | * Unary operators and parenthetical expressions are treated as operands. |
| 1076 | * As usual, Q==quantity==operand, O==operator, X==expression mnemonics. |
| 1077 | * |
| 1078 | * We used to do a aho/ullman shift-reduce parser, but the logic got so |
| 1079 | * warped that I flushed it and wrote a recursive-descent parser instead. |
| 1080 | * Now things are stable, would anybody like to write a fast parser? |
| 1081 | * Most expressions are either register (which does not even reach here) |
| 1082 | * or 1 symbol. Then "symbol+constant" and "symbol-symbol" are common. |
| 1083 | * So I guess it doesn't really matter how inefficient more complex expressions |
| 1084 | * are parsed. |
| 1085 | * |
| 1086 | * After expr(RANK,resultP) input_line_pointer->operator of rank <= RANK. |
| 1087 | * Also, we have consumed any leading or trailing spaces (operand does that) |
| 1088 | * and done all intervening operators. |
| 1089 | * |
| 1090 | * This returns the segment of the result, which will be |
| 1091 | * absolute_section or the segment of a symbol. |
| 1092 | */ |
| 1093 | |
| 1094 | #undef __ |
| 1095 | #define __ O_illegal |
| 1096 | |
| 1097 | static operatorT op_encoding[256] = |
| 1098 | { /* maps ASCII->operators */ |
| 1099 | |
| 1100 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1101 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1102 | |
| 1103 | __, O_bit_or_not, __, __, __, O_modulus, O_bit_and, __, |
| 1104 | __, __, O_multiply, O_add, __, O_subtract, __, O_divide, |
| 1105 | __, __, __, __, __, __, __, __, |
| 1106 | __, __, __, __, O_lt, __, O_gt, __, |
| 1107 | __, __, __, __, __, __, __, __, |
| 1108 | __, __, __, __, __, __, __, __, |
| 1109 | __, __, __, __, __, __, __, __, |
| 1110 | __, __, __, __, __, __, O_bit_exclusive_or, __, |
| 1111 | __, __, __, __, __, __, __, __, |
| 1112 | __, __, __, __, __, __, __, __, |
| 1113 | __, __, __, __, __, __, __, __, |
| 1114 | __, __, __, __, O_bit_inclusive_or, __, __, __, |
| 1115 | |
| 1116 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1117 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1118 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1119 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1120 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1121 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1122 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| 1123 | __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __ |
| 1124 | }; |
| 1125 | |
| 1126 | |
| 1127 | /* |
| 1128 | * Rank Examples |
| 1129 | * 0 operand, (expression) |
| 1130 | * 1 = <> < <= >= > |
| 1131 | * 2 + - |
| 1132 | * 3 used for * / % in MRI mode |
| 1133 | * 4 & ^ ! | |
| 1134 | * 5 * / % << >> |
| 1135 | * 6 unary - unary ~ |
| 1136 | */ |
| 1137 | static operator_rankT op_rank[] = |
| 1138 | { |
| 1139 | 0, /* O_illegal */ |
| 1140 | 0, /* O_absent */ |
| 1141 | 0, /* O_constant */ |
| 1142 | 0, /* O_symbol */ |
| 1143 | 0, /* O_register */ |
| 1144 | 0, /* O_bit */ |
| 1145 | 6, /* O_uminus */ |
| 1146 | 6, /* O_bit_not */ |
| 1147 | 5, /* O_multiply */ |
| 1148 | 5, /* O_divide */ |
| 1149 | 5, /* O_modulus */ |
| 1150 | 5, /* O_left_shift */ |
| 1151 | 5, /* O_right_shift */ |
| 1152 | 4, /* O_bit_inclusive_or */ |
| 1153 | 4, /* O_bit_or_not */ |
| 1154 | 4, /* O_bit_exclusive_or */ |
| 1155 | 4, /* O_bit_and */ |
| 1156 | 2, /* O_add */ |
| 1157 | 2, /* O_subtract */ |
| 1158 | 1, /* O_eq */ |
| 1159 | 1, /* O_ne */ |
| 1160 | 1, /* O_lt */ |
| 1161 | 1, /* O_le */ |
| 1162 | 1, /* O_ge */ |
| 1163 | 1 /* O_gt */ |
| 1164 | }; |
| 1165 | |
| 1166 | /* Initialize the expression parser. */ |
| 1167 | |
| 1168 | void |
| 1169 | expr_begin () |
| 1170 | { |
| 1171 | /* In MRI mode, multiplication and division have lower precedence |
| 1172 | than the bit wise operators. */ |
| 1173 | if (flag_mri) |
| 1174 | { |
| 1175 | op_rank[O_multiply] = 3; |
| 1176 | op_rank[O_divide] = 3; |
| 1177 | op_rank[O_modulus] = 3; |
| 1178 | op_encoding['"'] = O_bit_not; |
| 1179 | } |
| 1180 | } |
| 1181 | \f |
| 1182 | /* Return the encoding for the operator at INPUT_LINE_POINTER. |
| 1183 | Advance INPUT_LINE_POINTER to the last character in the operator |
| 1184 | (i.e., don't change it for a single character operator). */ |
| 1185 | |
| 1186 | static inline operatorT |
| 1187 | operator () |
| 1188 | { |
| 1189 | int c; |
| 1190 | operatorT ret; |
| 1191 | |
| 1192 | c = *input_line_pointer; |
| 1193 | |
| 1194 | switch (c) |
| 1195 | { |
| 1196 | default: |
| 1197 | return op_encoding[c]; |
| 1198 | |
| 1199 | case '<': |
| 1200 | switch (input_line_pointer[1]) |
| 1201 | { |
| 1202 | default: |
| 1203 | return op_encoding[c]; |
| 1204 | case '<': |
| 1205 | ret = O_left_shift; |
| 1206 | break; |
| 1207 | case '>': |
| 1208 | ret = O_ne; |
| 1209 | break; |
| 1210 | case '=': |
| 1211 | ret = O_le; |
| 1212 | break; |
| 1213 | } |
| 1214 | ++input_line_pointer; |
| 1215 | return ret; |
| 1216 | |
| 1217 | case '>': |
| 1218 | switch (input_line_pointer[1]) |
| 1219 | { |
| 1220 | default: |
| 1221 | return op_encoding[c]; |
| 1222 | case '>': |
| 1223 | ret = O_right_shift; |
| 1224 | break; |
| 1225 | case '=': |
| 1226 | ret = O_ge; |
| 1227 | break; |
| 1228 | } |
| 1229 | ++input_line_pointer; |
| 1230 | return ret; |
| 1231 | |
| 1232 | case '!': |
| 1233 | /* We accept !! as equivalent to ^ for MRI compatibility. */ |
| 1234 | if (input_line_pointer[1] != '!') |
| 1235 | { |
| 1236 | if (flag_mri) |
| 1237 | return O_bit_inclusive_or; |
| 1238 | return op_encoding[c]; |
| 1239 | } |
| 1240 | ++input_line_pointer; |
| 1241 | return O_bit_exclusive_or; |
| 1242 | } |
| 1243 | |
| 1244 | /*NOTREACHED*/ |
| 1245 | } |
| 1246 | |
| 1247 | /* Parse an expression. */ |
| 1248 | |
| 1249 | segT |
| 1250 | expr (rank, resultP) |
| 1251 | operator_rankT rank; /* Larger # is higher rank. */ |
| 1252 | expressionS *resultP; /* Deliver result here. */ |
| 1253 | { |
| 1254 | segT retval; |
| 1255 | expressionS right; |
| 1256 | operatorT op_left; |
| 1257 | operatorT op_right; |
| 1258 | |
| 1259 | know (rank >= 0); |
| 1260 | |
| 1261 | retval = operand (resultP); |
| 1262 | |
| 1263 | know (*input_line_pointer != ' '); /* Operand() gobbles spaces. */ |
| 1264 | |
| 1265 | op_left = operator (); |
| 1266 | while (op_left != O_illegal && op_rank[(int) op_left] > rank) |
| 1267 | { |
| 1268 | segT rightseg; |
| 1269 | |
| 1270 | input_line_pointer++; /*->after 1st character of operator. */ |
| 1271 | |
| 1272 | rightseg = expr (op_rank[(int) op_left], &right); |
| 1273 | if (right.X_op == O_absent) |
| 1274 | { |
| 1275 | as_warn ("missing operand; zero assumed"); |
| 1276 | right.X_op = O_constant; |
| 1277 | right.X_add_number = 0; |
| 1278 | right.X_add_symbol = NULL; |
| 1279 | right.X_op_symbol = NULL; |
| 1280 | } |
| 1281 | |
| 1282 | know (*input_line_pointer != ' '); |
| 1283 | |
| 1284 | if (retval == undefined_section) |
| 1285 | { |
| 1286 | if (SEG_NORMAL (rightseg)) |
| 1287 | retval = rightseg; |
| 1288 | } |
| 1289 | else if (! SEG_NORMAL (retval)) |
| 1290 | retval = rightseg; |
| 1291 | else if (SEG_NORMAL (rightseg) |
| 1292 | && retval != rightseg |
| 1293 | #ifdef DIFF_EXPR_OK |
| 1294 | && op_left != O_subtract |
| 1295 | #endif |
| 1296 | ) |
| 1297 | as_bad ("operation combines symbols in different segments"); |
| 1298 | |
| 1299 | op_right = operator (); |
| 1300 | |
| 1301 | know (op_right == O_illegal || op_rank[(int) op_right] <= op_rank[(int) op_left]); |
| 1302 | know ((int) op_left >= (int) O_multiply && (int) op_left <= (int) O_gt); |
| 1303 | |
| 1304 | /* input_line_pointer->after right-hand quantity. */ |
| 1305 | /* left-hand quantity in resultP */ |
| 1306 | /* right-hand quantity in right. */ |
| 1307 | /* operator in op_left. */ |
| 1308 | |
| 1309 | if (resultP->X_op == O_big) |
| 1310 | { |
| 1311 | as_warn ("left operand is a %s; integer 0 assumed", |
| 1312 | resultP->X_add_number > 0 ? "bignum" : "float"); |
| 1313 | resultP->X_op = O_constant; |
| 1314 | resultP->X_add_number = 0; |
| 1315 | resultP->X_add_symbol = NULL; |
| 1316 | resultP->X_op_symbol = NULL; |
| 1317 | } |
| 1318 | if (right.X_op == O_big) |
| 1319 | { |
| 1320 | as_warn ("right operand is a %s; integer 0 assumed", |
| 1321 | right.X_add_number > 0 ? "bignum" : "float"); |
| 1322 | right.X_op = O_constant; |
| 1323 | right.X_add_number = 0; |
| 1324 | right.X_add_symbol = NULL; |
| 1325 | right.X_op_symbol = NULL; |
| 1326 | } |
| 1327 | |
| 1328 | /* Optimize common cases. */ |
| 1329 | if (op_left == O_add && right.X_op == O_constant) |
| 1330 | { |
| 1331 | /* X + constant. */ |
| 1332 | resultP->X_add_number += right.X_add_number; |
| 1333 | } |
| 1334 | /* This case comes up in PIC code. */ |
| 1335 | else if (op_left == O_subtract |
| 1336 | && right.X_op == O_symbol |
| 1337 | && resultP->X_op == O_symbol |
| 1338 | && (right.X_add_symbol->sy_frag |
| 1339 | == resultP->X_add_symbol->sy_frag) |
| 1340 | && SEG_NORMAL (S_GET_SEGMENT (right.X_add_symbol))) |
| 1341 | |
| 1342 | { |
| 1343 | resultP->X_add_number += right.X_add_number; |
| 1344 | resultP->X_add_number += (S_GET_VALUE (resultP->X_add_symbol) |
| 1345 | - S_GET_VALUE (right.X_add_symbol)); |
| 1346 | resultP->X_op = O_constant; |
| 1347 | resultP->X_add_symbol = 0; |
| 1348 | } |
| 1349 | else if (op_left == O_subtract && right.X_op == O_constant) |
| 1350 | { |
| 1351 | /* X - constant. */ |
| 1352 | resultP->X_add_number -= right.X_add_number; |
| 1353 | } |
| 1354 | else if (op_left == O_add && resultP->X_op == O_constant) |
| 1355 | { |
| 1356 | /* Constant + X. */ |
| 1357 | resultP->X_op = right.X_op; |
| 1358 | resultP->X_add_symbol = right.X_add_symbol; |
| 1359 | resultP->X_op_symbol = right.X_op_symbol; |
| 1360 | resultP->X_add_number += right.X_add_number; |
| 1361 | retval = rightseg; |
| 1362 | } |
| 1363 | else if (resultP->X_op == O_constant && right.X_op == O_constant) |
| 1364 | { |
| 1365 | /* Constant OP constant. */ |
| 1366 | offsetT v = right.X_add_number; |
| 1367 | if (v == 0 && (op_left == O_divide || op_left == O_modulus)) |
| 1368 | { |
| 1369 | as_warn ("division by zero"); |
| 1370 | v = 1; |
| 1371 | } |
| 1372 | switch (op_left) |
| 1373 | { |
| 1374 | default: abort (); |
| 1375 | case O_multiply: resultP->X_add_number *= v; break; |
| 1376 | case O_divide: resultP->X_add_number /= v; break; |
| 1377 | case O_modulus: resultP->X_add_number %= v; break; |
| 1378 | case O_left_shift: resultP->X_add_number <<= v; break; |
| 1379 | case O_right_shift: resultP->X_add_number >>= v; break; |
| 1380 | case O_bit_inclusive_or: resultP->X_add_number |= v; break; |
| 1381 | case O_bit_or_not: resultP->X_add_number |= ~v; break; |
| 1382 | case O_bit_exclusive_or: resultP->X_add_number ^= v; break; |
| 1383 | case O_bit_and: resultP->X_add_number &= v; break; |
| 1384 | case O_add: resultP->X_add_number += v; break; |
| 1385 | case O_subtract: resultP->X_add_number -= v; break; |
| 1386 | case O_eq: |
| 1387 | resultP->X_add_number = |
| 1388 | resultP->X_add_number == v ? ~ (offsetT) 0 : 0; |
| 1389 | break; |
| 1390 | case O_ne: |
| 1391 | resultP->X_add_number = |
| 1392 | resultP->X_add_number != v ? ~ (offsetT) 0 : 0; |
| 1393 | break; |
| 1394 | case O_lt: |
| 1395 | resultP->X_add_number = |
| 1396 | resultP->X_add_number < v ? ~ (offsetT) 0 : 0; |
| 1397 | break; |
| 1398 | case O_le: |
| 1399 | resultP->X_add_number = |
| 1400 | resultP->X_add_number <= v ? ~ (offsetT) 0 : 0; |
| 1401 | break; |
| 1402 | case O_ge: |
| 1403 | resultP->X_add_number = |
| 1404 | resultP->X_add_number >= v ? ~ (offsetT) 0 : 0; |
| 1405 | break; |
| 1406 | case O_gt: |
| 1407 | resultP->X_add_number = |
| 1408 | resultP->X_add_number > v ? ~ (offsetT) 0 : 0; |
| 1409 | break; |
| 1410 | } |
| 1411 | } |
| 1412 | else if (resultP->X_op == O_symbol |
| 1413 | && right.X_op == O_symbol |
| 1414 | && (op_left == O_add |
| 1415 | || op_left == O_subtract |
| 1416 | || (resultP->X_add_number == 0 |
| 1417 | && right.X_add_number == 0))) |
| 1418 | { |
| 1419 | /* Symbol OP symbol. */ |
| 1420 | resultP->X_op = op_left; |
| 1421 | resultP->X_op_symbol = right.X_add_symbol; |
| 1422 | if (op_left == O_add) |
| 1423 | resultP->X_add_number += right.X_add_number; |
| 1424 | else if (op_left == O_subtract) |
| 1425 | resultP->X_add_number -= right.X_add_number; |
| 1426 | } |
| 1427 | else |
| 1428 | { |
| 1429 | /* The general case. */ |
| 1430 | resultP->X_add_symbol = make_expr_symbol (resultP); |
| 1431 | resultP->X_op_symbol = make_expr_symbol (&right); |
| 1432 | resultP->X_op = op_left; |
| 1433 | resultP->X_add_number = 0; |
| 1434 | resultP->X_unsigned = 1; |
| 1435 | } |
| 1436 | |
| 1437 | op_left = op_right; |
| 1438 | } /* While next operator is >= this rank. */ |
| 1439 | |
| 1440 | /* The PA port needs this information. */ |
| 1441 | if (resultP->X_add_symbol) |
| 1442 | resultP->X_add_symbol->sy_used = 1; |
| 1443 | |
| 1444 | return resultP->X_op == O_constant ? absolute_section : retval; |
| 1445 | } |
| 1446 | \f |
| 1447 | /* |
| 1448 | * get_symbol_end() |
| 1449 | * |
| 1450 | * This lives here because it belongs equally in expr.c & read.c. |
| 1451 | * Expr.c is just a branch office read.c anyway, and putting it |
| 1452 | * here lessens the crowd at read.c. |
| 1453 | * |
| 1454 | * Assume input_line_pointer is at start of symbol name. |
| 1455 | * Advance input_line_pointer past symbol name. |
| 1456 | * Turn that character into a '\0', returning its former value. |
| 1457 | * This allows a string compare (RMS wants symbol names to be strings) |
| 1458 | * of the symbol name. |
| 1459 | * There will always be a char following symbol name, because all good |
| 1460 | * lines end in end-of-line. |
| 1461 | */ |
| 1462 | char |
| 1463 | get_symbol_end () |
| 1464 | { |
| 1465 | char c; |
| 1466 | |
| 1467 | /* We accept \001 in a name in case this is being called with a |
| 1468 | constructed string. */ |
| 1469 | while (is_part_of_name (c = *input_line_pointer++) |
| 1470 | || c == '\001') |
| 1471 | ; |
| 1472 | *--input_line_pointer = 0; |
| 1473 | return (c); |
| 1474 | } |
| 1475 | |
| 1476 | |
| 1477 | unsigned int |
| 1478 | get_single_number () |
| 1479 | { |
| 1480 | expressionS exp; |
| 1481 | operand (&exp); |
| 1482 | return exp.X_add_number; |
| 1483 | |
| 1484 | } |
| 1485 | |
| 1486 | /* end of expr.c */ |