tree.c revision 1.293
1 /* $NetBSD: tree.c,v 1.293 2021/06/28 10:23:49 rillig Exp $ */ 2 3 /* 4 * Copyright (c) 1994, 1995 Jochen Pohl 5 * All Rights Reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Jochen Pohl for 18 * The NetBSD Project. 19 * 4. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #if HAVE_NBTOOL_CONFIG_H 35 #include "nbtool_config.h" 36 #endif 37 38 #include <sys/cdefs.h> 39 #if defined(__RCSID) && !defined(lint) 40 __RCSID("$NetBSD: tree.c,v 1.293 2021/06/28 10:23:49 rillig Exp $"); 41 #endif 42 43 #include <float.h> 44 #include <limits.h> 45 #include <math.h> 46 #include <signal.h> 47 #include <stdlib.h> 48 #include <string.h> 49 50 #include "lint1.h" 51 #include "cgram.h" 52 53 static tnode_t *expr_new_integer_constant(tspec_t, int64_t); 54 static void check_pointer_comparison(op_t, 55 const tnode_t *, const tnode_t *); 56 static bool check_assign_types_compatible(op_t, int, 57 const tnode_t *, const tnode_t *); 58 static void check_bad_enum_operation(op_t, 59 const tnode_t *, const tnode_t *); 60 static void check_enum_type_mismatch(op_t, int, 61 const tnode_t *, const tnode_t *); 62 static void check_enum_int_mismatch(op_t, int, 63 const tnode_t *, const tnode_t *); 64 static tnode_t *new_tnode(op_t, type_t *, tnode_t *, tnode_t *); 65 static void balance(op_t, tnode_t **, tnode_t **); 66 static void warn_incompatible_types(op_t, const type_t *, tspec_t, 67 const type_t *, tspec_t); 68 static void warn_incompatible_pointers(const mod_t *, 69 const type_t *, const type_t *); 70 static bool has_constant_member(const type_t *); 71 static void check_prototype_conversion(int, tspec_t, tspec_t, type_t *, 72 tnode_t *); 73 static void check_integer_conversion(op_t, int, tspec_t, tspec_t, type_t *, 74 tnode_t *); 75 static void check_pointer_integer_conversion(op_t, tspec_t, type_t *, 76 tnode_t *); 77 static void check_pointer_conversion(tnode_t *, type_t *); 78 static tnode_t *build_struct_access(op_t, tnode_t *, tnode_t *); 79 static tnode_t *build_prepost_incdec(op_t, tnode_t *); 80 static tnode_t *build_real_imag(op_t, tnode_t *); 81 static tnode_t *build_address(tnode_t *, bool); 82 static tnode_t *build_plus_minus(op_t, tnode_t *, tnode_t *); 83 static tnode_t *build_bit_shift(op_t, tnode_t *, tnode_t *); 84 static tnode_t *build_colon(tnode_t *, tnode_t *); 85 static tnode_t *build_assignment(op_t, tnode_t *, tnode_t *); 86 static tnode_t *plength(type_t *); 87 static tnode_t *fold(tnode_t *); 88 static tnode_t *fold_test(tnode_t *); 89 static tnode_t *fold_float(tnode_t *); 90 static tnode_t *check_function_arguments(type_t *, tnode_t *); 91 static tnode_t *check_prototype_argument(int, type_t *, tnode_t *); 92 static void check_null_effect(const tnode_t *); 93 static void display_expression(const tnode_t *, int); 94 static void check_array_index(tnode_t *, bool); 95 static void check_integer_comparison(op_t, tnode_t *, tnode_t *); 96 static void check_precedence_confusion(tnode_t *); 97 98 extern sig_atomic_t fpe; 99 100 static const char * 101 op_name(op_t op) 102 { 103 return modtab[op].m_name; 104 } 105 106 #ifdef DEBUG 107 void 108 debug_node(const tnode_t *tn, int indent) 109 { 110 op_t op; 111 112 if (tn == NULL) { 113 printf("%*s" "null\n", indent, ""); 114 return; 115 } 116 117 op = tn->tn_op; 118 printf("%*s%s with type '%s'%s%s", 119 2 * indent, "", 120 op == CVT && !tn->tn_cast ? "convert" : op_name(op), 121 type_name(tn->tn_type), tn->tn_lvalue ? ", lvalue" : "", 122 tn->tn_parenthesized ? ", parenthesized" : ""); 123 124 if (op == NAME) 125 printf(" %s\n", tn->tn_sym->s_name); 126 else if (op == CON && is_floating(tn->tn_type->t_tspec)) 127 printf(", value %Lg", tn->tn_val->v_ldbl); 128 else if (op == CON && is_uinteger(tn->tn_type->t_tspec)) 129 printf(", value %llu\n", (unsigned long long)tn->tn_val->v_quad); 130 else if (op == CON && is_integer(tn->tn_type->t_tspec)) 131 printf(", value %lld\n", (long long)tn->tn_val->v_quad); 132 else if (op == CON) 133 printf(", unknown value\n"); 134 else if (op == STRING) 135 printf(", length %zu\n", tn->tn_string->st_len); 136 else { 137 printf("\n"); 138 139 debug_node(tn->tn_left, indent + 1); 140 if (modtab[op].m_binary || tn->tn_right != NULL) 141 debug_node(tn->tn_right, indent + 1); 142 } 143 } 144 #endif 145 146 /* Build 'pointer to tp', 'array of tp' or 'function returning tp'. */ 147 type_t * 148 derive_type(type_t *tp, tspec_t t) 149 { 150 type_t *tp2; 151 152 tp2 = getblk(sizeof(*tp2)); 153 tp2->t_tspec = t; 154 tp2->t_subt = tp; 155 return tp2; 156 } 157 158 /* 159 * Build 'pointer to tp', 'array of tp' or 'function returning tp'. The 160 * memory is freed at the end of the current expression. 161 */ 162 type_t * 163 expr_derive_type(type_t *tp, tspec_t t) 164 { 165 type_t *tp2; 166 167 tp2 = expr_zalloc(sizeof(*tp2)); 168 tp2->t_tspec = t; 169 tp2->t_subt = tp; 170 return tp2; 171 } 172 173 /* 174 * Create a node for a constant. 175 */ 176 tnode_t * 177 expr_new_constant(type_t *tp, val_t *v) 178 { 179 tnode_t *n; 180 181 n = expr_zalloc_tnode(); 182 n->tn_op = CON; 183 n->tn_type = tp; 184 n->tn_val = expr_zalloc(sizeof(*n->tn_val)); 185 n->tn_val->v_tspec = tp->t_tspec; 186 n->tn_val->v_unsigned_since_c90 = v->v_unsigned_since_c90; 187 n->tn_val->v_u = v->v_u; 188 free(v); 189 return n; 190 } 191 192 static tnode_t * 193 expr_new_integer_constant(tspec_t t, int64_t q) 194 { 195 tnode_t *n; 196 197 n = expr_zalloc_tnode(); 198 n->tn_op = CON; 199 n->tn_type = gettyp(t); 200 n->tn_val = expr_zalloc(sizeof(*n->tn_val)); 201 n->tn_val->v_tspec = t; 202 n->tn_val->v_quad = q; 203 return n; 204 } 205 206 static void 207 fallback_symbol(sym_t *sym) 208 { 209 210 if (fallback_symbol_strict_bool(sym)) 211 return; 212 213 if (block_level > 0 && (strcmp(sym->s_name, "__FUNCTION__") == 0 || 214 strcmp(sym->s_name, "__PRETTY_FUNCTION__") == 0)) { 215 /* __FUNCTION__/__PRETTY_FUNCTION__ is a GCC extension */ 216 gnuism(316); 217 sym->s_type = derive_type(gettyp(CHAR), PTR); 218 sym->s_type->t_const = true; 219 return; 220 } 221 222 if (block_level > 0 && strcmp(sym->s_name, "__func__") == 0) { 223 if (!Sflag) 224 /* __func__ is a C9X feature */ 225 warning(317); 226 sym->s_type = derive_type(gettyp(CHAR), PTR); 227 sym->s_type->t_const = true; 228 return; 229 } 230 231 /* '%s' undefined */ 232 error(99, sym->s_name); 233 } 234 235 /* 236 * Create a node for a name (symbol table entry). 237 * follow_token is the token which follows the name. 238 */ 239 tnode_t * 240 new_name_node(sym_t *sym, int follow_token) 241 { 242 tnode_t *n; 243 244 if (sym->s_scl == NOSCL) { 245 sym->s_scl = EXTERN; 246 sym->s_def = DECL; 247 if (follow_token == T_LPAREN) { 248 if (sflag) { 249 /* function implicitly declared to ... */ 250 warning(215); 251 } 252 /* 253 * XXX if tflag is set the symbol should be 254 * exported to level 0 255 */ 256 sym->s_type = derive_type(sym->s_type, FUNC); 257 } else { 258 fallback_symbol(sym); 259 } 260 } 261 262 lint_assert(sym->s_kind == FVFT || sym->s_kind == FMEMBER); 263 264 n = expr_zalloc_tnode(); 265 n->tn_type = sym->s_type; 266 if (sym->s_scl != CTCONST) { 267 n->tn_op = NAME; 268 n->tn_sym = sym; 269 if (sym->s_kind == FVFT && sym->s_type->t_tspec != FUNC) 270 n->tn_lvalue = true; 271 } else { 272 n->tn_op = CON; 273 n->tn_val = expr_zalloc(sizeof(*n->tn_val)); 274 *n->tn_val = sym->s_value; 275 } 276 277 return n; 278 } 279 280 tnode_t * 281 new_string_node(strg_t *strg) 282 { 283 size_t len; 284 tnode_t *n; 285 286 len = strg->st_len; 287 288 n = expr_zalloc_tnode(); 289 290 n->tn_op = STRING; 291 n->tn_type = expr_derive_type(gettyp(strg->st_tspec), ARRAY); 292 n->tn_type->t_dim = len + 1; 293 n->tn_lvalue = true; 294 295 n->tn_string = expr_zalloc(sizeof(*n->tn_string)); 296 n->tn_string->st_tspec = strg->st_tspec; 297 n->tn_string->st_len = len; 298 299 if (strg->st_tspec == CHAR) { 300 n->tn_string->st_cp = expr_zalloc(len + 1); 301 (void)memcpy(n->tn_string->st_cp, strg->st_cp, len + 1); 302 free(strg->st_cp); 303 } else { 304 size_t size = (len + 1) * sizeof(*n->tn_string->st_wcp); 305 n->tn_string->st_wcp = expr_zalloc(size); 306 (void)memcpy(n->tn_string->st_wcp, strg->st_wcp, size); 307 free(strg->st_wcp); 308 } 309 free(strg); 310 311 return n; 312 } 313 314 /* 315 * Returns a symbol which has the same name as the msym argument and is a 316 * member of the struct or union specified by the tn argument. 317 */ 318 sym_t * 319 struct_or_union_member(tnode_t *tn, op_t op, sym_t *msym) 320 { 321 struct_or_union *str; 322 type_t *tp; 323 sym_t *sym, *csym; 324 bool eq; 325 tspec_t t; 326 327 /* 328 * Remove the member if it was unknown until now, which means 329 * that no defined struct or union has a member with the same name. 330 */ 331 if (msym->s_scl == NOSCL) { 332 /* type '%s' does not have member '%s' */ 333 error(101, type_name(msym->s_type), msym->s_name); 334 rmsym(msym); 335 msym->s_kind = FMEMBER; 336 msym->s_scl = MOS; 337 msym->s_styp = expr_zalloc(sizeof(*msym->s_styp)); 338 msym->s_styp->sou_tag = expr_zalloc( 339 sizeof(*msym->s_styp->sou_tag)); 340 msym->s_styp->sou_tag->s_name = unnamed; 341 msym->s_value.v_tspec = INT; 342 return msym; 343 } 344 345 /* Set str to the tag of which msym is expected to be a member. */ 346 str = NULL; 347 t = (tp = tn->tn_type)->t_tspec; 348 if (op == POINT) { 349 if (t == STRUCT || t == UNION) 350 str = tp->t_str; 351 } else if (op == ARROW && t == PTR) { 352 t = (tp = tp->t_subt)->t_tspec; 353 if (t == STRUCT || t == UNION) 354 str = tp->t_str; 355 } 356 357 /* 358 * If this struct/union has a member with the name of msym, return it. 359 */ 360 if (str != NULL) { 361 for (sym = msym; sym != NULL; sym = sym->s_link) { 362 if (sym->s_scl != MOS && sym->s_scl != MOU) 363 continue; 364 if (sym->s_styp != str) 365 continue; 366 if (strcmp(sym->s_name, msym->s_name) != 0) 367 continue; 368 return sym; 369 } 370 } 371 372 /* 373 * Set eq to false if there are struct/union members with the same 374 * name and different types and/or offsets. 375 */ 376 eq = true; 377 for (csym = msym; csym != NULL; csym = csym->s_link) { 378 if (csym->s_scl != MOS && csym->s_scl != MOU) 379 continue; 380 if (strcmp(msym->s_name, csym->s_name) != 0) 381 continue; 382 for (sym = csym->s_link ; sym != NULL; sym = sym->s_link) { 383 bool w; 384 385 if (sym->s_scl != MOS && sym->s_scl != MOU) 386 continue; 387 if (strcmp(csym->s_name, sym->s_name) != 0) 388 continue; 389 if (csym->s_value.v_quad != sym->s_value.v_quad) { 390 eq = false; 391 break; 392 } 393 w = false; 394 eq = eqtype(csym->s_type, sym->s_type, 395 false, false, &w) && !w; 396 if (!eq) 397 break; 398 if (csym->s_bitfield != sym->s_bitfield) { 399 eq = false; 400 break; 401 } 402 if (csym->s_bitfield) { 403 type_t *tp1, *tp2; 404 405 tp1 = csym->s_type; 406 tp2 = sym->s_type; 407 if (tp1->t_flen != tp2->t_flen) { 408 eq = false; 409 break; 410 } 411 if (tp1->t_foffs != tp2->t_foffs) { 412 eq = false; 413 break; 414 } 415 } 416 } 417 if (!eq) 418 break; 419 } 420 421 /* 422 * Now handle the case in which the left operand refers really 423 * to a struct/union, but the right operand is not member of it. 424 */ 425 if (str != NULL) { 426 if (eq && tflag) { 427 /* illegal member use: %s */ 428 warning(102, msym->s_name); 429 } else { 430 /* illegal member use: %s */ 431 error(102, msym->s_name); 432 } 433 return msym; 434 } 435 436 /* 437 * Now the left operand of ARROW does not point to a struct/union 438 * or the left operand of POINT is no struct/union. 439 */ 440 if (eq) { 441 if (op == POINT) { 442 if (tflag) { 443 /* left operand of '.' must be struct/... */ 444 warning(103); 445 } else { 446 /* left operand of '.' must be struct/... */ 447 error(103); 448 } 449 } else { 450 if (tflag && tn->tn_type->t_tspec == PTR) { 451 /* left operand of '->' must be pointer ... */ 452 warning(104, type_name(tn->tn_type)); 453 } else { 454 /* left operand of '->' must be pointer ... */ 455 error(104, type_name(tn->tn_type)); 456 } 457 } 458 } else { 459 if (tflag) { 460 /* non-unique member requires struct/union %s */ 461 error(105, op == POINT ? "object" : "pointer"); 462 } else { 463 /* unacceptable operand of '%s' */ 464 error(111, op_name(op)); 465 } 466 } 467 468 return msym; 469 } 470 471 tnode_t * 472 build_generic_selection(const tnode_t *expr, 473 struct generic_association_types *sel) 474 { 475 tnode_t *default_result = NULL; 476 477 for (; sel != NULL; sel = sel->gat_prev) 478 if (expr != NULL && 479 eqtype(sel->gat_arg, expr->tn_type, false, false, NULL)) 480 return sel->gat_result; 481 else if (sel->gat_arg == NULL) 482 default_result = sel->gat_result; 483 return default_result; 484 } 485 486 /* 487 * Create a tree node. Called for most operands except function calls, 488 * sizeof and casts. 489 * 490 * op operator 491 * ln left operand 492 * rn if not NULL, right operand 493 */ 494 tnode_t * 495 build(op_t op, tnode_t *ln, tnode_t *rn) 496 { 497 const mod_t *mp; 498 tnode_t *ntn; 499 type_t *rettp; 500 501 mp = &modtab[op]; 502 503 /* If there was an error in one of the operands, return. */ 504 if (ln == NULL || (mp->m_binary && rn == NULL)) 505 return NULL; 506 507 /* 508 * Apply class conversions to the left operand, but only if its 509 * value is needed or it is compared with null. 510 */ 511 if (mp->m_left_value_context || mp->m_left_test_context) 512 ln = cconv(ln); 513 /* 514 * The right operand is almost always in a test or value context, 515 * except if it is a struct or union member. 516 */ 517 if (mp->m_binary && op != ARROW && op != POINT) 518 rn = cconv(rn); 519 520 /* 521 * Print some warnings for comparisons of unsigned values with 522 * constants lower than or equal to null. This must be done 523 * before promote() because otherwise unsigned char and unsigned 524 * short would be promoted to int. Also types are tested to be 525 * CHAR, which would also become int. 526 */ 527 if (mp->m_comparison) 528 check_integer_comparison(op, ln, rn); 529 530 /* 531 * Promote the left operand if it is in a test or value context 532 */ 533 if (mp->m_left_value_context || mp->m_left_test_context) 534 ln = promote(op, false, ln); 535 /* 536 * Promote the right operand, but only if it is no struct or 537 * union member, or if it is not to be assigned to the left operand 538 */ 539 if (mp->m_binary && op != ARROW && op != POINT && 540 op != ASSIGN && op != RETURN) { 541 rn = promote(op, false, rn); 542 } 543 544 /* 545 * If the result of the operation is different for signed or 546 * unsigned operands and one of the operands is signed only in 547 * ANSI C, print a warning. 548 */ 549 if (mp->m_warn_if_left_unsigned_in_c90 && 550 ln->tn_op == CON && ln->tn_val->v_unsigned_since_c90) { 551 /* ANSI C treats constant as unsigned, op %s */ 552 warning(218, mp->m_name); 553 ln->tn_val->v_unsigned_since_c90 = false; 554 } 555 if (mp->m_warn_if_right_unsigned_in_c90 && 556 rn->tn_op == CON && rn->tn_val->v_unsigned_since_c90) { 557 /* ANSI C treats constant as unsigned, op %s */ 558 warning(218, mp->m_name); 559 rn->tn_val->v_unsigned_since_c90 = false; 560 } 561 562 /* Make sure both operands are of the same type */ 563 if (mp->m_balance_operands || (tflag && (op == SHL || op == SHR))) 564 balance(op, &ln, &rn); 565 566 /* 567 * Check types for compatibility with the operation and mutual 568 * compatibility. Return if there are serious problems. 569 */ 570 if (!typeok(op, 0, ln, rn)) 571 return NULL; 572 573 /* And now create the node. */ 574 switch (op) { 575 case POINT: 576 case ARROW: 577 ntn = build_struct_access(op, ln, rn); 578 break; 579 case INCAFT: 580 case DECAFT: 581 case INCBEF: 582 case DECBEF: 583 ntn = build_prepost_incdec(op, ln); 584 break; 585 case ADDR: 586 ntn = build_address(ln, false); 587 break; 588 case INDIR: 589 ntn = new_tnode(INDIR, ln->tn_type->t_subt, ln, NULL); 590 break; 591 case PLUS: 592 case MINUS: 593 ntn = build_plus_minus(op, ln, rn); 594 break; 595 case SHL: 596 case SHR: 597 ntn = build_bit_shift(op, ln, rn); 598 break; 599 case COLON: 600 ntn = build_colon(ln, rn); 601 break; 602 case ASSIGN: 603 case MULASS: 604 case DIVASS: 605 case MODASS: 606 case ADDASS: 607 case SUBASS: 608 case SHLASS: 609 case SHRASS: 610 case ANDASS: 611 case XORASS: 612 case ORASS: 613 case RETURN: 614 ntn = build_assignment(op, ln, rn); 615 break; 616 case COMMA: 617 case QUEST: 618 ntn = new_tnode(op, rn->tn_type, ln, rn); 619 break; 620 case REAL: 621 case IMAG: 622 ntn = build_real_imag(op, ln); 623 break; 624 default: 625 rettp = mp->m_returns_bool 626 ? gettyp(Tflag ? BOOL : INT) : ln->tn_type; 627 lint_assert(mp->m_binary || rn == NULL); 628 ntn = new_tnode(op, rettp, ln, rn); 629 break; 630 } 631 632 /* Return if an error occurred. */ 633 if (ntn == NULL) 634 return NULL; 635 636 /* Print a warning if precedence confusion is possible */ 637 if (mp->m_possible_precedence_confusion) 638 check_precedence_confusion(ntn); 639 640 /* 641 * Print a warning if one of the operands is in a context where 642 * it is compared with null and if this operand is a constant. 643 */ 644 if (mp->m_left_test_context) { 645 if (ln->tn_op == CON || 646 ((mp->m_binary && op != QUEST) && rn->tn_op == CON)) { 647 if (hflag && !constcond_flag && 648 !ln->tn_system_dependent) 649 /* constant in conditional context */ 650 warning(161); 651 } 652 } 653 654 /* Fold if the operator requires it */ 655 if (mp->m_fold_constant_operands) { 656 if (ln->tn_op == CON && (!mp->m_binary || rn->tn_op == CON)) { 657 if (mp->m_left_test_context) { 658 ntn = fold_test(ntn); 659 } else if (is_floating(ntn->tn_type->t_tspec)) { 660 ntn = fold_float(ntn); 661 } else { 662 ntn = fold(ntn); 663 } 664 } else if (op == QUEST && ln->tn_op == CON) { 665 ntn = ln->tn_val->v_quad != 0 666 ? rn->tn_left : rn->tn_right; 667 } 668 } 669 670 return ntn; 671 } 672 673 /* 674 * Perform class conversions. 675 * 676 * Arrays of type T are converted into pointers to type T. 677 * Functions are converted to pointers to functions. 678 * Lvalues are converted to rvalues. 679 * 680 * C99 6.3 "Conversions" 681 * C99 6.3.2 "Other operands" 682 * C99 6.3.2.1 "Lvalues, arrays, and function designators" 683 */ 684 tnode_t * 685 cconv(tnode_t *tn) 686 { 687 type_t *tp; 688 689 /* 690 * Array-lvalue (array of type T) is converted into rvalue 691 * (pointer to type T) 692 */ 693 if (tn->tn_type->t_tspec == ARRAY) { 694 if (!tn->tn_lvalue) { 695 /* XXX print correct operator */ 696 /* %soperand of '%s' must be lvalue */ 697 gnuism(114, "", op_name(ADDR)); 698 } 699 tn = new_tnode(ADDR, 700 expr_derive_type(tn->tn_type->t_subt, PTR), tn, NULL); 701 } 702 703 /* 704 * Expression of type function (function with return value of type T) 705 * in rvalue-expression (pointer to function with return value 706 * of type T) 707 */ 708 if (tn->tn_type->t_tspec == FUNC) 709 tn = build_address(tn, true); 710 711 /* lvalue to rvalue */ 712 if (tn->tn_lvalue) { 713 tp = expr_dup_type(tn->tn_type); 714 tp->t_const = tp->t_volatile = false; 715 tn = new_tnode(LOAD, tp, tn, NULL); 716 } 717 718 return tn; 719 } 720 721 const tnode_t * 722 before_conversion(const tnode_t *tn) 723 { 724 while (tn->tn_op == CVT && !tn->tn_cast) 725 tn = tn->tn_left; 726 return tn; 727 } 728 729 static bool 730 is_null_pointer(const tnode_t *tn) 731 { 732 tspec_t t = tn->tn_type->t_tspec; 733 734 return ((t == PTR && tn->tn_type->t_subt->t_tspec == VOID) || 735 is_integer(t)) 736 && (tn->tn_op == CON && tn->tn_val->v_quad == 0); 737 } 738 739 static bool 740 typeok_incdec(op_t op, const tnode_t *tn, const type_t *tp) 741 { 742 /* operand has scalar type (checked in typeok) */ 743 if (!tn->tn_lvalue) { 744 if (tn->tn_op == CVT && tn->tn_cast && 745 tn->tn_left->tn_op == LOAD) { 746 if (tn->tn_type->t_tspec == PTR) 747 return true; 748 /* a cast does not yield an lvalue */ 749 error(163); 750 } 751 /* %soperand of '%s' must be lvalue */ 752 error(114, "", op_name(op)); 753 return false; 754 } else if (tp->t_const) { 755 if (!tflag) 756 /* %soperand of '%s' must be modifiable lvalue */ 757 warning(115, "", op_name(op)); 758 } 759 return true; 760 } 761 762 static bool 763 typeok_address(const mod_t *mp, 764 const tnode_t *tn, const type_t *tp, tspec_t t) 765 { 766 if (t == ARRAY || t == FUNC) { 767 /* ok, a warning comes later (in build_address()) */ 768 } else if (!tn->tn_lvalue) { 769 if (tn->tn_op == CVT && tn->tn_cast && 770 tn->tn_left->tn_op == LOAD) { 771 if (tn->tn_type->t_tspec == PTR) 772 return true; 773 /* a cast does not yield an lvalue */ 774 error(163); 775 } 776 /* %soperand of '%s' must be lvalue */ 777 error(114, "", mp->m_name); 778 return false; 779 } else if (is_scalar(t)) { 780 if (tp->t_bitfield) { 781 /* cannot take address of bit-field */ 782 error(112); 783 return false; 784 } 785 } else if (t != STRUCT && t != UNION) { 786 /* unacceptable operand of '%s' */ 787 error(111, mp->m_name); 788 return false; 789 } 790 if (tn->tn_op == NAME && tn->tn_sym->s_reg) { 791 /* cannot take address of register %s */ 792 error(113, tn->tn_sym->s_name); 793 return false; 794 } 795 return true; 796 } 797 798 static bool 799 typeok_star(tspec_t t) 800 { 801 /* until now there were no type checks for this operator */ 802 if (t != PTR) { 803 /* cannot dereference non-pointer type */ 804 error(96); 805 return false; 806 } 807 return true; 808 } 809 810 static bool 811 typeok_plus(op_t op, 812 const type_t *ltp, tspec_t lt, 813 const type_t *rtp, tspec_t rt) 814 { 815 /* operands have scalar types (checked above) */ 816 if ((lt == PTR && !is_integer(rt)) || (rt == PTR && !is_integer(lt))) { 817 warn_incompatible_types(op, ltp, lt, rtp, rt); 818 return false; 819 } 820 return true; 821 } 822 823 static bool 824 typeok_minus(op_t op, 825 const type_t *ltp, tspec_t lt, 826 const type_t *rtp, tspec_t rt) 827 { 828 /* operands have scalar types (checked above) */ 829 if (lt == PTR && (!is_integer(rt) && rt != PTR)) { 830 warn_incompatible_types(op, ltp, lt, rtp, rt); 831 return false; 832 } else if (rt == PTR && lt != PTR) { 833 warn_incompatible_types(op, ltp, lt, rtp, rt); 834 return false; 835 } 836 if (lt == PTR && rt == PTR) { 837 if (!eqtype(ltp->t_subt, rtp->t_subt, true, false, NULL)) { 838 /* illegal pointer subtraction */ 839 error(116); 840 } 841 } 842 return true; 843 } 844 845 static void 846 typeok_shr(const mod_t *mp, 847 const tnode_t *ln, tspec_t lt, 848 const tnode_t *rn, tspec_t rt) 849 { 850 tspec_t olt, ort; 851 852 olt = before_conversion(ln)->tn_type->t_tspec; 853 ort = before_conversion(rn)->tn_type->t_tspec; 854 855 /* operands have integer types (checked above) */ 856 if (pflag && !is_uinteger(lt)) { 857 /* 858 * The left operand is signed. This means that 859 * the operation is (possibly) nonportable. 860 */ 861 if (ln->tn_op != CON) { 862 /* bitwise '%s' on signed value possibly nonportable */ 863 warning(117, mp->m_name); 864 } else if (ln->tn_val->v_quad < 0) { 865 /* bitwise '%s' on signed value nonportable */ 866 warning(120, mp->m_name); 867 } 868 } else if (!tflag && !sflag && !is_uinteger(olt) && is_uinteger(ort)) { 869 /* 870 * The left operand would become unsigned in 871 * traditional C. 872 */ 873 if (hflag && !Sflag && 874 (ln->tn_op != CON || ln->tn_val->v_quad < 0)) { 875 /* semantics of '%s' change in ANSI C; use ... */ 876 warning(118, mp->m_name); 877 } 878 } else if (!tflag && !sflag && !is_uinteger(olt) && !is_uinteger(ort) && 879 portable_size_in_bits(lt) < portable_size_in_bits(rt)) { 880 /* 881 * In traditional C the left operand would be extended, 882 * possibly with 1, and then shifted. 883 */ 884 if (hflag && !Sflag && 885 (ln->tn_op != CON || ln->tn_val->v_quad < 0)) { 886 /* semantics of '%s' change in ANSI C; use ... */ 887 warning(118, mp->m_name); 888 } 889 } 890 } 891 892 static void 893 typeok_shl(const mod_t *mp, tspec_t lt, tspec_t rt) 894 { 895 /* 896 * C90 does not perform balancing for shift operations, 897 * but traditional C does. If the width of the right operand 898 * is greater than the width of the left operand, then in 899 * traditional C the left operand would be extended to the 900 * width of the right operand. For SHL this may result in 901 * different results. 902 */ 903 if (portable_size_in_bits(lt) < portable_size_in_bits(rt)) { 904 /* 905 * XXX If both operands are constant, make sure 906 * that there is really a difference between 907 * ANSI C and traditional C. 908 */ 909 if (hflag && !Sflag) 910 /* semantics of '%s' change in ANSI C; use ... */ 911 warning(118, mp->m_name); 912 } 913 } 914 915 static void 916 typeok_shift(tspec_t lt, const tnode_t *rn, tspec_t rt) 917 { 918 if (rn->tn_op != CON) 919 return; 920 921 if (!is_uinteger(rt) && rn->tn_val->v_quad < 0) { 922 /* negative shift */ 923 warning(121); 924 } else if ((uint64_t)rn->tn_val->v_quad == 925 (uint64_t)size_in_bits(lt)) { 926 /* shift equal to size of object */ 927 warning(267); 928 } else if ((uint64_t)rn->tn_val->v_quad > (uint64_t)size_in_bits(lt)) { 929 /* shift amount %llu is greater than bit-size %llu of '%s' */ 930 warning(122, (unsigned long long)rn->tn_val->v_quad, 931 (unsigned long long)size_in_bits(lt), 932 tspec_name(lt)); 933 } 934 } 935 936 static bool 937 is_typeok_eq(const tnode_t *ln, tspec_t lt, const tnode_t *rn, tspec_t rt) 938 { 939 if (lt == PTR && is_null_pointer(rn)) 940 return true; 941 if (rt == PTR && is_null_pointer(ln)) 942 return true; 943 return false; 944 } 945 946 static bool 947 typeok_ordered_comparison(op_t op, 948 const tnode_t *ln, const type_t *ltp, tspec_t lt, 949 const tnode_t *rn, const type_t *rtp, tspec_t rt) 950 { 951 if (lt == PTR && rt == PTR) { 952 check_pointer_comparison(op, ln, rn); 953 return true; 954 } 955 956 if (lt != PTR && rt != PTR) 957 return true; 958 959 if (!is_integer(lt) && !is_integer(rt)) { 960 warn_incompatible_types(op, ltp, lt, rtp, rt); 961 return false; 962 } 963 964 const char *lx = lt == PTR ? "pointer" : "integer"; 965 const char *rx = rt == PTR ? "pointer" : "integer"; 966 /* illegal combination of %s (%s) and %s (%s), op %s */ 967 warning(123, lx, type_name(ltp), rx, type_name(rtp), op_name(op)); 968 return true; 969 } 970 971 static bool 972 typeok_quest(tspec_t lt, const tnode_t **rn) 973 { 974 if (!is_scalar(lt)) { 975 /* first operand must have scalar type, op ? : */ 976 error(170); 977 return false; 978 } 979 while ((*rn)->tn_op == CVT) 980 *rn = (*rn)->tn_left; 981 lint_assert((*rn)->tn_op == COLON); 982 return true; 983 } 984 985 static void 986 typeok_colon_pointer(const mod_t *mp, const type_t *ltp, const type_t *rtp) 987 { 988 type_t *lstp = ltp->t_subt; 989 type_t *rstp = rtp->t_subt; 990 tspec_t lst = lstp->t_tspec; 991 tspec_t rst = rstp->t_tspec; 992 993 if ((lst == VOID && rst == FUNC) || (lst == FUNC && rst == VOID)) { 994 /* (void *)0 handled above */ 995 if (sflag) 996 /* ANSI C forbids conv. of %s to %s, op %s */ 997 warning(305, "function pointer", "'void *'", 998 mp->m_name); 999 return; 1000 } 1001 1002 if (eqptrtype(lstp, rstp, true)) 1003 return; 1004 if (!eqtype(lstp, rstp, true, false, NULL)) 1005 warn_incompatible_pointers(mp, ltp, rtp); 1006 } 1007 1008 static bool 1009 typeok_colon(const mod_t *mp, 1010 const tnode_t *ln, const type_t *ltp, tspec_t lt, 1011 const tnode_t *rn, const type_t *rtp, tspec_t rt) 1012 { 1013 1014 if (is_arithmetic(lt) && is_arithmetic(rt)) 1015 return true; 1016 if (lt == BOOL && rt == BOOL) 1017 return true; 1018 1019 if (lt == STRUCT && rt == STRUCT && ltp->t_str == rtp->t_str) 1020 return true; 1021 if (lt == UNION && rt == UNION && ltp->t_str == rtp->t_str) 1022 return true; 1023 1024 if (lt == PTR && is_null_pointer(rn)) 1025 return true; 1026 if (rt == PTR && is_null_pointer(ln)) 1027 return true; 1028 1029 if ((lt == PTR && is_integer(rt)) || (is_integer(lt) && rt == PTR)) { 1030 const char *lx = lt == PTR ? "pointer" : "integer"; 1031 const char *rx = rt == PTR ? "pointer" : "integer"; 1032 /* illegal combination of %s (%s) and %s (%s), op %s */ 1033 warning(123, lx, type_name(ltp), 1034 rx, type_name(rtp), mp->m_name); 1035 return true; 1036 } 1037 1038 if (lt == VOID || rt == VOID) { 1039 if (lt != VOID || rt != VOID) 1040 /* incompatible types '%s' and '%s' in conditional */ 1041 warning(126, type_name(ltp), type_name(rtp)); 1042 return true; 1043 } 1044 1045 if (lt == PTR && rt == PTR) { 1046 typeok_colon_pointer(mp, ltp, rtp); 1047 return true; 1048 } 1049 1050 /* incompatible types '%s' and '%s' in conditional */ 1051 error(126, type_name(ltp), type_name(rtp)); 1052 return false; 1053 } 1054 1055 static bool 1056 typeok_assign(const mod_t *mp, const tnode_t *ln, const type_t *ltp, tspec_t lt) 1057 { 1058 if (!ln->tn_lvalue) { 1059 if (ln->tn_op == CVT && ln->tn_cast && 1060 ln->tn_left->tn_op == LOAD) { 1061 if (ln->tn_type->t_tspec == PTR) 1062 return true; 1063 /* a cast does not yield an lvalue */ 1064 error(163); 1065 } 1066 /* %soperand of '%s' must be lvalue */ 1067 error(114, "left ", mp->m_name); 1068 return false; 1069 } else if (ltp->t_const || ((lt == STRUCT || lt == UNION) && 1070 has_constant_member(ltp))) { 1071 if (!tflag) 1072 /* %soperand of '%s' must be modifiable lvalue */ 1073 warning(115, "left ", mp->m_name); 1074 } 1075 return true; 1076 } 1077 1078 1079 1080 /* Check the types using the information from modtab[]. */ 1081 static bool 1082 typeok_scalar(op_t op, const mod_t *mp, 1083 const type_t *ltp, tspec_t lt, 1084 const type_t *rtp, tspec_t rt) 1085 { 1086 if (mp->m_takes_bool && lt == BOOL && rt == BOOL) 1087 return true; 1088 if (mp->m_requires_integer) { 1089 if (!is_integer(lt) || (mp->m_binary && !is_integer(rt))) { 1090 warn_incompatible_types(op, ltp, lt, rtp, rt); 1091 return false; 1092 } 1093 } else if (mp->m_requires_integer_or_complex) { 1094 if ((!is_integer(lt) && !is_complex(lt)) || 1095 (mp->m_binary && (!is_integer(rt) && !is_complex(rt)))) { 1096 warn_incompatible_types(op, ltp, lt, rtp, rt); 1097 return false; 1098 } 1099 } else if (mp->m_requires_scalar) { 1100 if (!is_scalar(lt) || (mp->m_binary && !is_scalar(rt))) { 1101 warn_incompatible_types(op, ltp, lt, rtp, rt); 1102 return false; 1103 } 1104 } else if (mp->m_requires_arith) { 1105 if (!is_arithmetic(lt) || 1106 (mp->m_binary && !is_arithmetic(rt))) { 1107 warn_incompatible_types(op, ltp, lt, rtp, rt); 1108 return false; 1109 } 1110 } 1111 return true; 1112 } 1113 1114 /* Check the types for specific operators and type combinations. */ 1115 static bool 1116 typeok_op(op_t op, const mod_t *mp, int arg, 1117 const tnode_t *ln, const type_t *ltp, tspec_t lt, 1118 const tnode_t *rn, const type_t *rtp, tspec_t rt) 1119 { 1120 switch (op) { 1121 case POINT: 1122 /* 1123 * Most errors required by ANSI C are reported in 1124 * struct_or_union_member(). 1125 * Here we only must check for totally wrong things. 1126 */ 1127 if (lt == FUNC || lt == VOID || ltp->t_bitfield || 1128 ((lt != STRUCT && lt != UNION) && !ln->tn_lvalue)) { 1129 /* Without tflag we got already an error */ 1130 if (tflag) 1131 /* unacceptable operand of '%s' */ 1132 error(111, mp->m_name); 1133 return false; 1134 } 1135 /* Now we have an object we can create a pointer to */ 1136 break; 1137 case ARROW: 1138 if (lt != PTR && !(tflag && is_integer(lt))) { 1139 /* Without tflag we got already an error */ 1140 if (tflag) 1141 /* unacceptable operand of '%s' */ 1142 error(111, mp->m_name); 1143 return false; 1144 } 1145 break; 1146 case INCAFT: 1147 case DECAFT: 1148 case INCBEF: 1149 case DECBEF: 1150 if (!typeok_incdec(op, ln, ltp)) 1151 return false; 1152 break; 1153 case ADDR: 1154 if (!typeok_address(mp, ln, ltp, lt)) 1155 return false; 1156 break; 1157 case INDIR: 1158 if (!typeok_star(lt)) 1159 return false; 1160 break; 1161 case PLUS: 1162 if (!typeok_plus(op, ltp, lt, rtp, rt)) 1163 return false; 1164 break; 1165 case MINUS: 1166 if (!typeok_minus(op, ltp, lt, rtp, rt)) 1167 return false; 1168 break; 1169 case SHR: 1170 typeok_shr(mp, ln, lt, rn, rt); 1171 goto shift; 1172 case SHL: 1173 typeok_shl(mp, lt, rt); 1174 shift: 1175 typeok_shift(lt, rn, rt); 1176 break; 1177 case EQ: 1178 case NE: 1179 /* 1180 * Accept some things which are allowed with EQ and NE, 1181 * but not with ordered comparisons. 1182 */ 1183 if (is_typeok_eq(ln, lt, rn, rt)) 1184 break; 1185 /* FALLTHROUGH */ 1186 case LT: 1187 case GT: 1188 case LE: 1189 case GE: 1190 if (!typeok_ordered_comparison(op, ln, ltp, lt, rn, rtp, rt)) 1191 return false; 1192 break; 1193 case QUEST: 1194 if (!typeok_quest(lt, &rn)) 1195 return false; 1196 break; 1197 case COLON: 1198 if (!typeok_colon(mp, ln, ltp, lt, rn, rtp, rt)) 1199 return false; 1200 break; 1201 case ASSIGN: 1202 case INIT: 1203 case FARG: 1204 case RETURN: 1205 if (!check_assign_types_compatible(op, arg, ln, rn)) 1206 return false; 1207 goto assign; 1208 case MULASS: 1209 case DIVASS: 1210 case MODASS: 1211 goto assign; 1212 case ADDASS: 1213 case SUBASS: 1214 /* operands have scalar types (checked above) */ 1215 if ((lt == PTR && !is_integer(rt)) || rt == PTR) { 1216 warn_incompatible_types(op, ltp, lt, rtp, rt); 1217 return false; 1218 } 1219 goto assign; 1220 case SHLASS: 1221 goto assign; 1222 case SHRASS: 1223 if (pflag && !is_uinteger(lt) && !(tflag && is_uinteger(rt))) { 1224 /* bitwise '%s' on signed value possibly nonportable */ 1225 warning(117, mp->m_name); 1226 } 1227 goto assign; 1228 case ANDASS: 1229 case XORASS: 1230 case ORASS: 1231 goto assign; 1232 assign: 1233 if (!typeok_assign(mp, ln, ltp, lt)) 1234 return false; 1235 break; 1236 case COMMA: 1237 if (!modtab[ln->tn_op].m_has_side_effect) 1238 check_null_effect(ln); 1239 break; 1240 /* LINTED206: (enumeration values not handled in switch) */ 1241 case CON: 1242 case CASE: 1243 case PUSH: 1244 case LOAD: 1245 case ICALL: 1246 case CVT: 1247 case CALL: 1248 case FSEL: 1249 case STRING: 1250 case NAME: 1251 case LOGOR: 1252 case LOGAND: 1253 case BITOR: 1254 case BITXOR: 1255 case BITAND: 1256 case MOD: 1257 case DIV: 1258 case MULT: 1259 case UMINUS: 1260 case UPLUS: 1261 case DEC: 1262 case INC: 1263 case COMPL: 1264 case NOT: 1265 case NOOP: 1266 case REAL: 1267 case IMAG: 1268 break; 1269 } 1270 return true; 1271 } 1272 1273 static void 1274 typeok_enum(op_t op, const mod_t *mp, int arg, 1275 const tnode_t *ln, const type_t *ltp, 1276 const tnode_t *rn, const type_t *rtp) 1277 { 1278 if (mp->m_bad_on_enum && 1279 (ltp->t_is_enum || (mp->m_binary && rtp->t_is_enum))) { 1280 check_bad_enum_operation(op, ln, rn); 1281 } else if (mp->m_valid_on_enum && 1282 (ltp->t_is_enum && rtp != NULL && rtp->t_is_enum)) { 1283 check_enum_type_mismatch(op, arg, ln, rn); 1284 } else if (mp->m_valid_on_enum && 1285 (ltp->t_is_enum || (rtp != NULL && rtp->t_is_enum))) { 1286 check_enum_int_mismatch(op, arg, ln, rn); 1287 } 1288 } 1289 1290 /* Perform most type checks. Return whether the types are ok. */ 1291 bool 1292 typeok(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 1293 { 1294 const mod_t *mp; 1295 tspec_t lt, rt; 1296 type_t *ltp, *rtp; 1297 1298 mp = &modtab[op]; 1299 1300 lint_assert((ltp = ln->tn_type) != NULL); 1301 lt = ltp->t_tspec; 1302 1303 if (mp->m_binary) { 1304 lint_assert((rtp = rn->tn_type) != NULL); 1305 rt = rtp->t_tspec; 1306 } else { 1307 rtp = NULL; 1308 rt = NOTSPEC; 1309 } 1310 1311 if (Tflag && !typeok_scalar_strict_bool(op, mp, arg, ln, rn)) 1312 return false; 1313 if (!typeok_scalar(op, mp, ltp, lt, rtp, rt)) 1314 return false; 1315 1316 if (!typeok_op(op, mp, arg, ln, ltp, lt, rn, rtp, rt)) 1317 return false; 1318 1319 typeok_enum(op, mp, arg, ln, ltp, rn, rtp); 1320 return true; 1321 } 1322 1323 static void 1324 check_pointer_comparison(op_t op, const tnode_t *ln, const tnode_t *rn) 1325 { 1326 type_t *ltp, *rtp; 1327 tspec_t lst, rst; 1328 const char *lsts, *rsts; 1329 1330 lst = (ltp = ln->tn_type)->t_subt->t_tspec; 1331 rst = (rtp = rn->tn_type)->t_subt->t_tspec; 1332 1333 if (lst == VOID || rst == VOID) { 1334 if (sflag && (lst == FUNC || rst == FUNC)) { 1335 /* (void *)0 already handled in typeok() */ 1336 *(lst == FUNC ? &lsts : &rsts) = "function pointer"; 1337 *(lst == VOID ? &lsts : &rsts) = "'void *'"; 1338 /* ANSI C forbids comparison of %s with %s */ 1339 warning(274, lsts, rsts); 1340 } 1341 return; 1342 } 1343 1344 if (!eqtype(ltp->t_subt, rtp->t_subt, true, false, NULL)) { 1345 warn_incompatible_pointers(&modtab[op], ltp, rtp); 1346 return; 1347 } 1348 1349 if (lst == FUNC && rst == FUNC) { 1350 if (sflag && op != EQ && op != NE) 1351 /* ANSI C forbids ordered comparisons of ... */ 1352 warning(125); 1353 } 1354 } 1355 1356 /* 1357 * Checks type compatibility for ASSIGN, INIT, FARG and RETURN 1358 * and prints warnings/errors if necessary. 1359 * If the types are (almost) compatible, 1 is returned, otherwise 0. 1360 */ 1361 static bool 1362 check_assign_types_compatible(op_t op, int arg, 1363 const tnode_t *ln, const tnode_t *rn) 1364 { 1365 tspec_t lt, rt, lst = NOTSPEC, rst = NOTSPEC; 1366 type_t *ltp, *rtp, *lstp = NULL, *rstp = NULL; 1367 const mod_t *mp; 1368 const char *lts, *rts; 1369 1370 if ((lt = (ltp = ln->tn_type)->t_tspec) == PTR) 1371 lst = (lstp = ltp->t_subt)->t_tspec; 1372 if ((rt = (rtp = rn->tn_type)->t_tspec) == PTR) 1373 rst = (rstp = rtp->t_subt)->t_tspec; 1374 mp = &modtab[op]; 1375 1376 if (lt == BOOL && is_scalar(rt)) /* C99 6.3.1.2 */ 1377 return true; 1378 1379 if (is_arithmetic(lt) && (is_arithmetic(rt) || rt == BOOL)) 1380 return true; 1381 1382 if ((lt == STRUCT || lt == UNION) && (rt == STRUCT || rt == UNION)) 1383 /* both are struct or union */ 1384 return ltp->t_str == rtp->t_str; 1385 1386 /* a null pointer may be assigned to any pointer */ 1387 if (lt == PTR && is_null_pointer(rn)) 1388 return true; 1389 1390 if (lt == PTR && rt == PTR && (lst == VOID || rst == VOID)) { 1391 /* two pointers, at least one pointer to void */ 1392 if (sflag && (lst == FUNC || rst == FUNC)) { 1393 /* comb. of ptr to func and ptr to void */ 1394 *(lst == FUNC ? <s : &rts) = "function pointer"; 1395 *(lst == VOID ? <s : &rts) = "'void *'"; 1396 switch (op) { 1397 case INIT: 1398 case RETURN: 1399 /* ANSI C forbids conversion of %s to %s */ 1400 warning(303, rts, lts); 1401 break; 1402 case FARG: 1403 /* ANSI C forbids conv. of %s to %s, arg #%d */ 1404 warning(304, rts, lts, arg); 1405 break; 1406 default: 1407 /* ANSI C forbids conv. of %s to %s, op %s */ 1408 warning(305, rts, lts, mp->m_name); 1409 break; 1410 } 1411 } 1412 } 1413 1414 if (lt == PTR && rt == PTR && (lst == VOID || rst == VOID || 1415 eqtype(lstp, rstp, true, false, NULL))) { 1416 /* compatible pointer types (qualifiers ignored) */ 1417 if (!tflag && 1418 ((!lstp->t_const && rstp->t_const) || 1419 (!lstp->t_volatile && rstp->t_volatile))) { 1420 /* left side has not all qualifiers of right */ 1421 switch (op) { 1422 case INIT: 1423 case RETURN: 1424 /* incompatible pointer types (%s != %s) */ 1425 warning(182, type_name(lstp), type_name(rstp)); 1426 break; 1427 case FARG: 1428 /* converting '%s' to incompatible '%s' ... */ 1429 warning(153, 1430 type_name(rtp), type_name(ltp), arg); 1431 break; 1432 default: 1433 /* operands have incompatible pointer type... */ 1434 warning(128, mp->m_name, 1435 type_name(lstp), type_name(rstp)); 1436 break; 1437 } 1438 } 1439 return true; 1440 } 1441 1442 if ((lt == PTR && is_integer(rt)) || (is_integer(lt) && rt == PTR)) { 1443 const char *lx = lt == PTR ? "pointer" : "integer"; 1444 const char *rx = rt == PTR ? "pointer" : "integer"; 1445 1446 switch (op) { 1447 case INIT: 1448 case RETURN: 1449 /* illegal combination of %s (%s) and %s (%s) */ 1450 warning(183, lx, type_name(ltp), rx, type_name(rtp)); 1451 break; 1452 case FARG: 1453 /* illegal comb. of %s (%s) and %s (%s), arg #%d */ 1454 warning(154, 1455 lx, type_name(ltp), rx, type_name(rtp), arg); 1456 break; 1457 default: 1458 /* illegal combination of %s (%s) and %s (%s), op %s */ 1459 warning(123, 1460 lx, type_name(ltp), rx, type_name(rtp), mp->m_name); 1461 break; 1462 } 1463 return true; 1464 } 1465 1466 if (lt == PTR && rt == PTR) { 1467 switch (op) { 1468 case INIT: 1469 case RETURN: 1470 warn_incompatible_pointers(NULL, ltp, rtp); 1471 break; 1472 case FARG: 1473 /* converting '%s' to incompatible '%s' for ... */ 1474 warning(153, type_name(rtp), type_name(ltp), arg); 1475 break; 1476 default: 1477 warn_incompatible_pointers(mp, ltp, rtp); 1478 break; 1479 } 1480 return true; 1481 } 1482 1483 switch (op) { 1484 case INIT: 1485 /* cannot initialize '%s' from '%s' */ 1486 error(185, type_name(ltp), type_name(rtp)); 1487 break; 1488 case RETURN: 1489 /* return value type mismatch (%s) and (%s) */ 1490 error(211, type_name(ltp), type_name(rtp)); 1491 break; 1492 case FARG: 1493 /* passing '%s' to incompatible '%s', arg #%d */ 1494 warning(155, type_name(rtp), type_name(ltp), arg); 1495 break; 1496 default: 1497 warn_incompatible_types(op, ltp, lt, rtp, rt); 1498 break; 1499 } 1500 1501 return false; 1502 } 1503 1504 /* Prints a warning if a strange operator is used on an enum type. */ 1505 static void 1506 check_bad_enum_operation(op_t op, const tnode_t *ln, const tnode_t *rn) 1507 { 1508 1509 if (!eflag) 1510 return; 1511 1512 if (!(ln->tn_type->t_is_enum || 1513 (modtab[op].m_binary && rn->tn_type->t_is_enum))) { 1514 return; 1515 } 1516 1517 /* 1518 * Enum as offset to a pointer is an exception (otherwise enums 1519 * could not be used as array indices). 1520 */ 1521 if (op == PLUS && 1522 ((ln->tn_type->t_is_enum && rn->tn_type->t_tspec == PTR) || 1523 (rn->tn_type->t_is_enum && ln->tn_type->t_tspec == PTR))) { 1524 return; 1525 } 1526 1527 /* dubious operation on enum, op %s */ 1528 warning(241, op_name(op)); 1529 1530 } 1531 1532 /* 1533 * Prints a warning if an operator is applied to two different enum types. 1534 */ 1535 static void 1536 check_enum_type_mismatch(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 1537 { 1538 const mod_t *mp; 1539 1540 mp = &modtab[op]; 1541 1542 if (ln->tn_type->t_enum != rn->tn_type->t_enum) { 1543 switch (op) { 1544 case INIT: 1545 /* enum type mismatch between '%s' and '%s' in ... */ 1546 warning(210, 1547 type_name(ln->tn_type), type_name(rn->tn_type)); 1548 break; 1549 case FARG: 1550 /* enum type mismatch, arg #%d (%s != %s) */ 1551 warning(156, arg, 1552 type_name(ln->tn_type), type_name(rn->tn_type)); 1553 break; 1554 case RETURN: 1555 /* return value type mismatch (%s) and (%s) */ 1556 warning(211, 1557 type_name(ln->tn_type), type_name(rn->tn_type)); 1558 break; 1559 default: 1560 /* enum type mismatch: '%s' '%s' '%s' */ 1561 warning(130, type_name(ln->tn_type), mp->m_name, 1562 type_name(rn->tn_type)); 1563 break; 1564 } 1565 } else if (Pflag && mp->m_comparison && op != EQ && op != NE) { 1566 if (eflag) 1567 /* dubious comparison of enums, op %s */ 1568 warning(243, mp->m_name); 1569 } 1570 } 1571 1572 /* Prints a warning if the operands mix between enum and integer. */ 1573 static void 1574 check_enum_int_mismatch(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 1575 { 1576 1577 if (!eflag) 1578 return; 1579 1580 switch (op) { 1581 case INIT: 1582 /* 1583 * Initialization with 0 is allowed. Otherwise, all implicit 1584 * initializations would need to be warned upon as well. 1585 */ 1586 if (!rn->tn_type->t_is_enum && rn->tn_op == CON && 1587 is_integer(rn->tn_type->t_tspec) && 1588 rn->tn_val->v_quad == 0) { 1589 return; 1590 } 1591 /* initialization of '%s' with '%s' */ 1592 warning(277, type_name(ln->tn_type), type_name(rn->tn_type)); 1593 break; 1594 case FARG: 1595 /* combination of '%s' and '%s', arg #%d */ 1596 warning(278, 1597 type_name(ln->tn_type), type_name(rn->tn_type), arg); 1598 break; 1599 case RETURN: 1600 /* combination of '%s' and '%s' in return */ 1601 warning(279, type_name(ln->tn_type), type_name(rn->tn_type)); 1602 break; 1603 default: 1604 /* combination of '%s' and '%s', op %s */ 1605 warning(242, type_name(ln->tn_type), type_name(rn->tn_type), 1606 op_name(op)); 1607 break; 1608 } 1609 } 1610 1611 /* 1612 * Build and initialize a new node. 1613 */ 1614 static tnode_t * 1615 new_tnode(op_t op, type_t *type, tnode_t *ln, tnode_t *rn) 1616 { 1617 tnode_t *ntn; 1618 tspec_t t; 1619 #ifdef notyet 1620 size_t l; 1621 uint64_t rnum; 1622 #endif 1623 1624 ntn = expr_zalloc_tnode(); 1625 1626 ntn->tn_op = op; 1627 ntn->tn_type = type; 1628 if (ln->tn_from_system_header) 1629 ntn->tn_from_system_header = true; 1630 if (rn != NULL && rn->tn_from_system_header) 1631 ntn->tn_from_system_header = true; 1632 ntn->tn_left = ln; 1633 ntn->tn_right = rn; 1634 1635 switch (op) { 1636 #ifdef notyet 1637 case SHR: 1638 if (rn->tn_op != CON) 1639 break; 1640 rnum = rn->tn_val->v_quad; 1641 l = type_size_in_bits(ln->tn_type) / CHAR_SIZE; 1642 t = ln->tn_type->t_tspec; 1643 switch (l) { 1644 case 8: 1645 if (rnum >= 56) 1646 t = UCHAR; 1647 else if (rnum >= 48) 1648 t = USHORT; 1649 else if (rnum >= 32) 1650 t = UINT; 1651 break; 1652 case 4: 1653 if (rnum >= 24) 1654 t = UCHAR; 1655 else if (rnum >= 16) 1656 t = USHORT; 1657 break; 1658 case 2: 1659 if (rnum >= 8) 1660 t = UCHAR; 1661 break; 1662 default: 1663 break; 1664 } 1665 if (t != ln->tn_type->t_tspec) 1666 ntn->tn_type->t_tspec = t; 1667 break; 1668 #endif 1669 case INDIR: 1670 case FSEL: 1671 lint_assert(ln->tn_type->t_tspec == PTR); 1672 t = ln->tn_type->t_subt->t_tspec; 1673 if (t != FUNC && t != VOID) 1674 ntn->tn_lvalue = true; 1675 break; 1676 default: 1677 break; 1678 } 1679 1680 return ntn; 1681 } 1682 1683 /* 1684 * Performs the "integer promotions" (C99 6.3.1.1p2), which convert small 1685 * integer types to either int or unsigned int. 1686 * 1687 * If tflag is set or the operand is a function argument with no type 1688 * information (no prototype or variable # of args), converts float to double. 1689 */ 1690 tnode_t * 1691 promote(op_t op, bool farg, tnode_t *tn) 1692 { 1693 tspec_t t; 1694 type_t *ntp; 1695 u_int len; 1696 1697 t = tn->tn_type->t_tspec; 1698 1699 if (!is_arithmetic(t)) 1700 return tn; 1701 1702 if (!tflag) { 1703 /* 1704 * C99 6.3.1.1p2 requires for types with lower rank than int 1705 * that "If an int can represent all the values of the 1706 * original type, the value is converted to an int; otherwise 1707 * it is converted to an unsigned int", and that "All other 1708 * types are unchanged by the integer promotions". 1709 */ 1710 if (tn->tn_type->t_bitfield) { 1711 len = tn->tn_type->t_flen; 1712 if (len < size_in_bits(INT)) { 1713 t = INT; 1714 } else if (len == size_in_bits(INT)) { 1715 t = is_uinteger(t) ? UINT : INT; 1716 } 1717 } else if (t == CHAR || t == UCHAR || t == SCHAR) { 1718 t = (size_in_bits(CHAR) < size_in_bits(INT) 1719 || t != UCHAR) ? INT : UINT; 1720 } else if (t == SHORT || t == USHORT) { 1721 t = (size_in_bits(SHORT) < size_in_bits(INT) 1722 || t == SHORT) ? INT : UINT; 1723 } else if (t == ENUM) { 1724 t = INT; 1725 } else if (farg && t == FLOAT) { 1726 t = DOUBLE; 1727 } 1728 } else { 1729 /* 1730 * In traditional C, keep unsigned and promote FLOAT 1731 * to DOUBLE. 1732 */ 1733 if (t == UCHAR || t == USHORT) { 1734 t = UINT; 1735 } else if (t == CHAR || t == SCHAR || t == SHORT) { 1736 t = INT; 1737 } else if (t == FLOAT) { 1738 t = DOUBLE; 1739 } else if (t == ENUM) { 1740 t = INT; 1741 } 1742 } 1743 1744 if (t != tn->tn_type->t_tspec) { 1745 ntp = expr_dup_type(tn->tn_type); 1746 ntp->t_tspec = t; 1747 /* 1748 * Keep t_is_enum so we are later able to check compatibility 1749 * of enum types. 1750 */ 1751 tn = convert(op, 0, ntp, tn); 1752 } 1753 1754 return tn; 1755 } 1756 1757 /* 1758 * Apply the "usual arithmetic conversions" (C99 6.3.1.8). 1759 * 1760 * This gives both operands the same type. 1761 * This is done in different ways for traditional C and C90. 1762 */ 1763 static void 1764 balance(op_t op, tnode_t **lnp, tnode_t **rnp) 1765 { 1766 tspec_t lt, rt, t; 1767 int i; 1768 bool u; 1769 type_t *ntp; 1770 static const tspec_t tl[] = { 1771 LDOUBLE, DOUBLE, FLOAT, UQUAD, QUAD, ULONG, LONG, UINT, INT, 1772 }; 1773 1774 lt = (*lnp)->tn_type->t_tspec; 1775 rt = (*rnp)->tn_type->t_tspec; 1776 1777 if (!is_arithmetic(lt) || !is_arithmetic(rt)) 1778 return; 1779 1780 if (!tflag) { 1781 if (lt == rt) { 1782 t = lt; 1783 } else if (lt == LCOMPLEX || rt == LCOMPLEX) { 1784 t = LCOMPLEX; 1785 } else if (lt == DCOMPLEX || rt == DCOMPLEX) { 1786 t = DCOMPLEX; 1787 } else if (lt == COMPLEX || rt == COMPLEX) { 1788 t = COMPLEX; 1789 } else if (lt == FCOMPLEX || rt == FCOMPLEX) { 1790 t = FCOMPLEX; 1791 } else if (lt == LDOUBLE || rt == LDOUBLE) { 1792 t = LDOUBLE; 1793 } else if (lt == DOUBLE || rt == DOUBLE) { 1794 t = DOUBLE; 1795 } else if (lt == FLOAT || rt == FLOAT) { 1796 t = FLOAT; 1797 } else { 1798 /* 1799 * If type A has more bits than type B it should 1800 * be able to hold all possible values of type B. 1801 */ 1802 if (size_in_bits(lt) > size_in_bits(rt)) { 1803 t = lt; 1804 } else if (size_in_bits(lt) < size_in_bits(rt)) { 1805 t = rt; 1806 } else { 1807 for (i = 3; tl[i] != INT; i++) { 1808 if (tl[i] == lt || tl[i] == rt) 1809 break; 1810 } 1811 if ((is_uinteger(lt) || is_uinteger(rt)) && 1812 !is_uinteger(tl[i])) { 1813 i--; 1814 } 1815 t = tl[i]; 1816 } 1817 } 1818 } else { 1819 /* Keep unsigned in traditional C */ 1820 u = is_uinteger(lt) || is_uinteger(rt); 1821 for (i = 0; tl[i] != INT; i++) { 1822 if (lt == tl[i] || rt == tl[i]) 1823 break; 1824 } 1825 t = tl[i]; 1826 if (u && is_integer(t) && !is_uinteger(t)) 1827 t = unsigned_type(t); 1828 } 1829 1830 if (t != lt) { 1831 ntp = expr_dup_type((*lnp)->tn_type); 1832 ntp->t_tspec = t; 1833 *lnp = convert(op, 0, ntp, *lnp); 1834 } 1835 if (t != rt) { 1836 ntp = expr_dup_type((*rnp)->tn_type); 1837 ntp->t_tspec = t; 1838 *rnp = convert(op, 0, ntp, *rnp); 1839 } 1840 } 1841 1842 /* 1843 * Insert a conversion operator, which converts the type of the node 1844 * to another given type. 1845 * If op is FARG, arg is the number of the argument (used for warnings). 1846 */ 1847 tnode_t * 1848 convert(op_t op, int arg, type_t *tp, tnode_t *tn) 1849 { 1850 tnode_t *ntn; 1851 tspec_t nt, ot; 1852 1853 nt = tp->t_tspec; 1854 ot = tn->tn_type->t_tspec; 1855 1856 if (!tflag && !sflag && op == FARG) 1857 check_prototype_conversion(arg, nt, ot, tp, tn); 1858 if (is_integer(nt) && is_integer(ot)) { 1859 check_integer_conversion(op, arg, nt, ot, tp, tn); 1860 } else if (nt == PTR && is_null_pointer(tn)) { 1861 /* a null pointer may be assigned to any pointer. */ 1862 } else if (is_integer(nt) && nt != BOOL && ot == PTR) { 1863 check_pointer_integer_conversion(op, nt, tp, tn); 1864 } else if (nt == PTR && ot == PTR && op == CVT) { 1865 check_pointer_conversion(tn, tp); 1866 } 1867 1868 ntn = expr_zalloc_tnode(); 1869 ntn->tn_op = CVT; 1870 ntn->tn_type = tp; 1871 ntn->tn_cast = op == CVT; 1872 ntn->tn_from_system_header |= tn->tn_from_system_header; 1873 ntn->tn_right = NULL; 1874 if (tn->tn_op != CON || nt == VOID) { 1875 ntn->tn_left = tn; 1876 } else { 1877 ntn->tn_op = CON; 1878 ntn->tn_val = expr_zalloc(sizeof(*ntn->tn_val)); 1879 convert_constant(op, arg, ntn->tn_type, ntn->tn_val, 1880 tn->tn_val); 1881 } 1882 1883 return ntn; 1884 } 1885 1886 /* 1887 * Print a warning if a prototype causes a type conversion that is 1888 * different from what would happen to the same argument in the 1889 * absence of a prototype. 1890 * 1891 * Errors/warnings about illegal type combinations are already printed 1892 * in check_assign_types_compatible(). 1893 */ 1894 static void 1895 check_prototype_conversion(int arg, tspec_t nt, tspec_t ot, type_t *tp, 1896 tnode_t *tn) 1897 { 1898 tnode_t *ptn; 1899 1900 if (!is_arithmetic(nt) || !is_arithmetic(ot)) 1901 return; 1902 1903 /* 1904 * If the type of the formal parameter is char/short, a warning 1905 * would be useless, because functions declared the old style 1906 * can't expect char/short arguments. 1907 */ 1908 /* XXX: what about SCHAR? */ 1909 if (nt == CHAR || nt == UCHAR || nt == SHORT || nt == USHORT) 1910 return; 1911 1912 /* get default promotion */ 1913 ptn = promote(NOOP, true, tn); 1914 ot = ptn->tn_type->t_tspec; 1915 1916 /* return if types are the same with and without prototype */ 1917 if (nt == ot || (nt == ENUM && ot == INT)) 1918 return; 1919 1920 if (is_floating(nt) != is_floating(ot) || 1921 portable_size_in_bits(nt) != portable_size_in_bits(ot)) { 1922 /* representation and/or width change */ 1923 if (!is_integer(ot) || 1924 portable_size_in_bits(ot) > portable_size_in_bits(INT)) { 1925 /* argument #%d is converted from '%s' to '%s' ... */ 1926 warning(259, 1927 arg, type_name(tn->tn_type), type_name(tp)); 1928 } 1929 } else if (hflag) { 1930 /* 1931 * they differ in sign or base type (char, short, int, 1932 * long, long long, float, double, long double) 1933 * 1934 * if they differ only in sign and the argument is a constant 1935 * and the msb of the argument is not set, print no warning 1936 */ 1937 if (ptn->tn_op == CON && is_integer(nt) && 1938 signed_type(nt) == signed_type(ot) && 1939 msb(ptn->tn_val->v_quad, ot, -1) == 0) { 1940 /* ok */ 1941 } else { 1942 /* argument #%d is converted from '%s' to '%s' ... */ 1943 warning(259, 1944 arg, type_name(tn->tn_type), type_name(tp)); 1945 } 1946 } 1947 } 1948 1949 /* 1950 * Print warnings for conversions of integer types which may cause problems. 1951 */ 1952 static void 1953 check_integer_conversion(op_t op, int arg, tspec_t nt, tspec_t ot, type_t *tp, 1954 tnode_t *tn) 1955 { 1956 1957 if (tn->tn_op == CON) 1958 return; 1959 1960 if (op == CVT) 1961 return; 1962 1963 if (Sflag && nt == BOOL) 1964 return; /* See C99 6.3.1.2 */ 1965 1966 if (Pflag && portable_size_in_bits(nt) > portable_size_in_bits(ot) && 1967 is_uinteger(nt) != is_uinteger(ot)) { 1968 if (aflag > 0 && pflag) { 1969 if (op == FARG) { 1970 /* conversion to '%s' may sign-extend ... */ 1971 warning(297, type_name(tp), arg); 1972 } else { 1973 /* conversion to '%s' may sign-extend ... */ 1974 warning(131, type_name(tp)); 1975 } 1976 } 1977 } 1978 1979 if (Pflag && portable_size_in_bits(nt) > portable_size_in_bits(ot)) { 1980 switch (tn->tn_op) { 1981 case PLUS: 1982 case MINUS: 1983 case MULT: 1984 case SHL: 1985 /* suggest cast from '%s' to '%s' on op %s to ... */ 1986 warning(324, type_name(gettyp(ot)), type_name(tp), 1987 op_name(tn->tn_op)); 1988 break; 1989 default: 1990 break; 1991 } 1992 } 1993 1994 if (portable_size_in_bits(nt) < portable_size_in_bits(ot) && 1995 (ot == LONG || ot == ULONG || ot == QUAD || ot == UQUAD || 1996 aflag > 1)) { 1997 /* conversion from '%s' may lose accuracy */ 1998 if (aflag > 0) { 1999 if (op == FARG) { 2000 /* conv. from '%s' to '%s' may lose ... */ 2001 warning(298, 2002 type_name(tn->tn_type), type_name(tp), arg); 2003 } else { 2004 /* conv. from '%s' to '%s' may lose accuracy */ 2005 warning(132, 2006 type_name(tn->tn_type), type_name(tp)); 2007 } 2008 } 2009 } 2010 } 2011 2012 /* 2013 * Print warnings for dubious conversions of pointer to integer. 2014 */ 2015 static void 2016 check_pointer_integer_conversion(op_t op, tspec_t nt, type_t *tp, tnode_t *tn) 2017 { 2018 2019 if (tn->tn_op == CON) 2020 return; 2021 if (op != CVT) 2022 return; /* We got already an error. */ 2023 if (portable_size_in_bits(nt) >= portable_size_in_bits(PTR)) 2024 return; 2025 2026 if (pflag && size_in_bits(nt) >= size_in_bits(PTR)) { 2027 /* conversion of pointer to '%s' may lose bits */ 2028 warning(134, type_name(tp)); 2029 } else { 2030 /* conversion of pointer to '%s' loses bits */ 2031 warning(133, type_name(tp)); 2032 } 2033 } 2034 2035 static bool 2036 should_warn_about_pointer_cast(const type_t *nstp, tspec_t nst, 2037 const type_t *ostp, tspec_t ost) 2038 { 2039 /* 2040 * Casting a pointer to 'struct S' to a pointer to another struct that 2041 * has 'struct S' as its first member is ok, see msg_247.c, 'struct 2042 * counter'. 2043 */ 2044 if (nst == STRUCT && ost == STRUCT && 2045 nstp->t_str->sou_first_member != NULL && 2046 nstp->t_str->sou_first_member->s_type == ostp) 2047 return false; 2048 2049 if (is_incomplete(nstp) || is_incomplete(ostp)) 2050 return false; 2051 2052 if ((nst == STRUCT || nst == UNION) && nstp->t_str != ostp->t_str) 2053 return true; 2054 2055 if (nst == CHAR || nst == UCHAR) 2056 return false; /* for the sake of traditional C code */ 2057 2058 return portable_size_in_bits(nst) != portable_size_in_bits(ost); 2059 } 2060 2061 /* 2062 * Warn about questionable pointer conversions. 2063 */ 2064 static void 2065 check_pointer_conversion(tnode_t *tn, type_t *ntp) 2066 { 2067 const type_t *nstp, *otp, *ostp; 2068 tspec_t nst, ost; 2069 const char *nts, *ots; 2070 2071 nstp = ntp->t_subt; 2072 otp = tn->tn_type; 2073 ostp = otp->t_subt; 2074 nst = nstp->t_tspec; 2075 ost = ostp->t_tspec; 2076 2077 if (nst == VOID || ost == VOID) { 2078 if (sflag && (nst == FUNC || ost == FUNC)) { 2079 /* null pointers are already handled in convert() */ 2080 *(nst == FUNC ? &nts : &ots) = "function pointer"; 2081 *(nst == VOID ? &nts : &ots) = "'void *'"; 2082 /* ANSI C forbids conversion of %s to %s */ 2083 warning(303, ots, nts); 2084 } 2085 return; 2086 } else if (nst == FUNC && ost == FUNC) { 2087 return; 2088 } else if (nst == FUNC || ost == FUNC) { 2089 /* converting '%s' to '%s' is questionable */ 2090 warning(229, type_name(otp), type_name(ntp)); 2091 return; 2092 } 2093 2094 if (hflag && alignment_in_bits(nstp) > alignment_in_bits(ostp) && 2095 !is_incomplete(ostp)) { 2096 /* converting '%s' to '%s' may cause alignment problem */ 2097 warning(135, type_name(otp), type_name(ntp)); 2098 } 2099 2100 if (cflag && should_warn_about_pointer_cast(nstp, nst, ostp, ost)) { 2101 /* pointer cast from '%s' to '%s' may be troublesome */ 2102 warning(247, type_name(otp), type_name(ntp)); 2103 } 2104 } 2105 2106 static void 2107 convert_constant_floating(op_t op, int arg, tspec_t ot, const type_t *tp, 2108 tspec_t nt, val_t *v, val_t *nv) 2109 { 2110 ldbl_t max = 0.0, min = 0.0; 2111 2112 switch (nt) { 2113 case CHAR: 2114 max = TARG_CHAR_MAX; min = TARG_CHAR_MIN; break; 2115 case UCHAR: 2116 max = TARG_UCHAR_MAX; min = 0; break; 2117 case SCHAR: 2118 max = TARG_SCHAR_MAX; min = TARG_SCHAR_MIN; break; 2119 case SHORT: 2120 max = TARG_SHRT_MAX; min = TARG_SHRT_MIN; break; 2121 case USHORT: 2122 max = TARG_USHRT_MAX; min = 0; break; 2123 case ENUM: 2124 case INT: 2125 max = TARG_INT_MAX; min = TARG_INT_MIN; break; 2126 case UINT: 2127 max = (u_int)TARG_UINT_MAX;min = 0; break; 2128 case LONG: 2129 max = TARG_LONG_MAX; min = TARG_LONG_MIN; break; 2130 case ULONG: 2131 max = (u_long)TARG_ULONG_MAX; min = 0; break; 2132 case QUAD: 2133 max = QUAD_MAX; min = QUAD_MIN; break; 2134 case UQUAD: 2135 max = (uint64_t)UQUAD_MAX; min = 0; break; 2136 case FLOAT: 2137 case FCOMPLEX: 2138 max = FLT_MAX; min = -FLT_MAX; break; 2139 case DOUBLE: 2140 case DCOMPLEX: 2141 max = DBL_MAX; min = -DBL_MAX; break; 2142 case PTR: 2143 /* Got already an error because of float --> ptr */ 2144 case LDOUBLE: 2145 case LCOMPLEX: 2146 max = LDBL_MAX; min = -LDBL_MAX; break; 2147 default: 2148 lint_assert(/*CONSTCOND*/false); 2149 } 2150 if (v->v_ldbl > max || v->v_ldbl < min) { 2151 lint_assert(nt != LDOUBLE); 2152 if (op == FARG) { 2153 /* conv. of '%s' to '%s' is out of range, ... */ 2154 warning(295, 2155 type_name(gettyp(ot)), type_name(tp), arg); 2156 } else { 2157 /* conversion of '%s' to '%s' is out of range */ 2158 warning(119, 2159 type_name(gettyp(ot)), type_name(tp)); 2160 } 2161 v->v_ldbl = v->v_ldbl > 0 ? max : min; 2162 } 2163 if (nt == FLOAT) { 2164 nv->v_ldbl = (float)v->v_ldbl; 2165 } else if (nt == DOUBLE) { 2166 nv->v_ldbl = (double)v->v_ldbl; 2167 } else if (nt == LDOUBLE) { 2168 nv->v_ldbl = v->v_ldbl; 2169 } else { 2170 nv->v_quad = (nt == PTR || is_uinteger(nt)) ? 2171 (int64_t)v->v_ldbl : (int64_t)v->v_ldbl; 2172 } 2173 } 2174 2175 static bool 2176 convert_constant_to_floating(tspec_t nt, val_t *nv, 2177 tspec_t ot, const val_t *v) 2178 { 2179 if (nt == FLOAT) { 2180 nv->v_ldbl = (ot == PTR || is_uinteger(ot)) ? 2181 (float)(uint64_t)v->v_quad : (float)v->v_quad; 2182 } else if (nt == DOUBLE) { 2183 nv->v_ldbl = (ot == PTR || is_uinteger(ot)) ? 2184 (double)(uint64_t)v->v_quad : (double)v->v_quad; 2185 } else if (nt == LDOUBLE) { 2186 nv->v_ldbl = (ot == PTR || is_uinteger(ot)) ? 2187 (ldbl_t)(uint64_t)v->v_quad : (ldbl_t)v->v_quad; 2188 } else 2189 return false; 2190 return true; 2191 } 2192 2193 /* 2194 * Print a warning if bits which were set are lost due to the conversion. 2195 * This can happen with operator ORASS only. 2196 */ 2197 static void 2198 convert_constant_check_range_bitor(size_t nsz, size_t osz, const val_t *v, 2199 uint64_t xmask, op_t op) 2200 { 2201 if (nsz < osz && (v->v_quad & xmask) != 0) { 2202 /* constant truncated by conv., op %s */ 2203 warning(306, op_name(op)); 2204 } 2205 } 2206 2207 /* 2208 * Print a warning if additional bits are not all 1 2209 * and the most significant bit of the old value is 1, 2210 * or if at least one (but not all) removed bit was 0. 2211 */ 2212 static void 2213 convert_constant_check_range_bitand(size_t nsz, size_t osz, 2214 uint64_t xmask, const val_t *nv, 2215 tspec_t ot, const val_t *v, 2216 const type_t *tp, op_t op) 2217 { 2218 if (nsz > osz && 2219 (nv->v_quad & bit(osz - 1)) != 0 && 2220 (nv->v_quad & xmask) != xmask) { 2221 /* extra bits set to 0 in conversion of '%s' to '%s', ... */ 2222 warning(309, type_name(gettyp(ot)), 2223 type_name(tp), op_name(op)); 2224 } else if (nsz < osz && 2225 (v->v_quad & xmask) != xmask && 2226 (v->v_quad & xmask) != 0) { 2227 /* constant truncated by conversion, op %s */ 2228 warning(306, op_name(op)); 2229 } 2230 } 2231 2232 static void 2233 convert_constant_check_range_signed(op_t op, int arg) 2234 { 2235 if (op == ASSIGN) { 2236 /* assignment of negative constant to unsigned type */ 2237 warning(164); 2238 } else if (op == INIT) { 2239 /* initialization of unsigned with negative constant */ 2240 warning(221); 2241 } else if (op == FARG) { 2242 /* conversion of negative constant to unsigned type, ... */ 2243 warning(296, arg); 2244 } else if (modtab[op].m_comparison) { 2245 /* handled by check_integer_comparison() */ 2246 } else { 2247 /* conversion of negative constant to unsigned type */ 2248 warning(222); 2249 } 2250 } 2251 2252 /* 2253 * Loss of significant bit(s). All truncated bits 2254 * of unsigned types or all truncated bits plus the 2255 * msb of the target for signed types are considered 2256 * to be significant bits. Loss of significant bits 2257 * means that at least on of the bits was set in an 2258 * unsigned type or that at least one, but not all of 2259 * the bits was set in an signed type. 2260 * Loss of significant bits means that it is not 2261 * possible, also not with necessary casts, to convert 2262 * back to the original type. A example for a 2263 * necessary cast is: 2264 * char c; int i; c = 128; 2265 * i = c; ** yields -128 ** 2266 * i = (unsigned char)c; ** yields 128 ** 2267 */ 2268 static void 2269 convert_constant_check_range_truncated(op_t op, int arg, const type_t *tp, 2270 tspec_t ot) 2271 { 2272 if (op == ASSIGN && tp->t_bitfield) { 2273 /* precision lost in bit-field assignment */ 2274 warning(166); 2275 } else if (op == ASSIGN) { 2276 /* constant truncated by assignment */ 2277 warning(165); 2278 } else if (op == INIT && tp->t_bitfield) { 2279 /* bit-field initializer does not fit */ 2280 warning(180); 2281 } else if (op == INIT) { 2282 /* initializer does not fit */ 2283 warning(178); 2284 } else if (op == CASE) { 2285 /* case label affected by conversion */ 2286 warning(196); 2287 } else if (op == FARG) { 2288 /* conversion of '%s' to '%s' is out of range, arg #%d */ 2289 warning(295, 2290 type_name(gettyp(ot)), type_name(tp), arg); 2291 } else { 2292 /* conversion of '%s' to '%s' is out of range */ 2293 warning(119, 2294 type_name(gettyp(ot)), type_name(tp)); 2295 } 2296 } 2297 2298 static void 2299 convert_constant_check_range_loss(op_t op, int arg, const type_t *tp, 2300 tspec_t ot) 2301 { 2302 if (op == ASSIGN && tp->t_bitfield) { 2303 /* precision lost in bit-field assignment */ 2304 warning(166); 2305 } else if (op == INIT && tp->t_bitfield) { 2306 /* bit-field initializer out of range */ 2307 warning(11); 2308 } else if (op == CASE) { 2309 /* case label affected by conversion */ 2310 warning(196); 2311 } else if (op == FARG) { 2312 /* conversion of '%s' to '%s' is out of range, arg #%d */ 2313 warning(295, 2314 type_name(gettyp(ot)), type_name(tp), arg); 2315 } else { 2316 /* conversion of '%s' to '%s' is out of range */ 2317 warning(119, 2318 type_name(gettyp(ot)), type_name(tp)); 2319 } 2320 } 2321 2322 static void 2323 convert_constant_check_range(tspec_t ot, const type_t *tp, tspec_t nt, 2324 op_t op, int arg, const val_t *v, val_t *nv) 2325 { 2326 int osz, nsz; 2327 int64_t xmask, xmsk1; 2328 2329 osz = size_in_bits(ot); 2330 nsz = tp->t_bitfield ? tp->t_flen : size_in_bits(nt); 2331 xmask = value_bits(nsz) ^ value_bits(osz); 2332 xmsk1 = value_bits(nsz) ^ value_bits(osz - 1); 2333 /* 2334 * For bitwise operations we are not interested in the 2335 * value, but in the bits itself. 2336 */ 2337 if (op == ORASS || op == BITOR || op == BITXOR) { 2338 convert_constant_check_range_bitor(nsz, osz, v, xmask, op); 2339 } else if (op == ANDASS || op == BITAND) { 2340 convert_constant_check_range_bitand(nsz, osz, xmask, nv, ot, 2341 v, tp, op); 2342 } else if ((nt != PTR && is_uinteger(nt)) && 2343 (ot != PTR && !is_uinteger(ot)) && 2344 v->v_quad < 0) { 2345 convert_constant_check_range_signed(op, arg); 2346 } else if (nv->v_quad != v->v_quad && nsz <= osz && 2347 (v->v_quad & xmask) != 0 && 2348 (is_uinteger(ot) || (v->v_quad & xmsk1) != xmsk1)) { 2349 convert_constant_check_range_truncated(op, arg, tp, ot); 2350 } else if (nv->v_quad != v->v_quad) { 2351 convert_constant_check_range_loss(op, arg, tp, ot); 2352 } 2353 } 2354 2355 /* 2356 * Converts a typed constant to a constant of another type. 2357 * 2358 * op operator which requires conversion 2359 * arg if op is FARG, # of argument 2360 * tp type in which to convert the constant 2361 * nv new constant 2362 * v old constant 2363 */ 2364 void 2365 convert_constant(op_t op, int arg, const type_t *tp, val_t *nv, val_t *v) 2366 { 2367 tspec_t ot, nt; 2368 int sz; 2369 bool range_check; 2370 2371 /* 2372 * TODO: make 'v' const; the name of this function does not suggest 2373 * that it modifies 'v'. 2374 */ 2375 ot = v->v_tspec; 2376 nt = nv->v_tspec = tp->t_tspec; 2377 range_check = false; 2378 2379 if (nt == BOOL) { /* C99 6.3.1.2 */ 2380 nv->v_unsigned_since_c90 = false; 2381 nv->v_quad = is_nonzero_val(v) ? 1 : 0; 2382 return; 2383 } 2384 2385 if (ot == FLOAT || ot == DOUBLE || ot == LDOUBLE) { 2386 convert_constant_floating(op, arg, ot, tp, nt, v, nv); 2387 } else if (!convert_constant_to_floating(nt, nv, ot, v)) { 2388 range_check = true; /* Check for lost precision. */ 2389 nv->v_quad = v->v_quad; 2390 } 2391 2392 if ((v->v_unsigned_since_c90 && is_floating(nt)) || 2393 (v->v_unsigned_since_c90 && (is_integer(nt) && !is_uinteger(nt) && 2394 portable_size_in_bits(nt) > 2395 portable_size_in_bits(ot)))) { 2396 /* ANSI C treats constant as unsigned */ 2397 warning(157); 2398 v->v_unsigned_since_c90 = false; 2399 } 2400 2401 switch (nt) { 2402 case FLOAT: 2403 case FCOMPLEX: 2404 case DOUBLE: 2405 case DCOMPLEX: 2406 case LDOUBLE: 2407 case LCOMPLEX: 2408 break; 2409 default: 2410 sz = tp->t_bitfield ? tp->t_flen : size_in_bits(nt); 2411 nv->v_quad = xsign(nv->v_quad, nt, sz); 2412 break; 2413 } 2414 2415 if (range_check && op != CVT) 2416 convert_constant_check_range(ot, tp, nt, op, arg, v, nv); 2417 } 2418 2419 /* 2420 * Called if incompatible types were detected. 2421 * Prints a appropriate warning. 2422 */ 2423 static void 2424 warn_incompatible_types(op_t op, 2425 const type_t *ltp, tspec_t lt, 2426 const type_t *rtp, tspec_t rt) 2427 { 2428 const mod_t *mp; 2429 2430 mp = &modtab[op]; 2431 2432 if (lt == VOID || (mp->m_binary && rt == VOID)) { 2433 /* void type illegal in expression */ 2434 error(109); 2435 } else if (op == ASSIGN) { 2436 if ((lt == STRUCT || lt == UNION) && 2437 (rt == STRUCT || rt == UNION)) { 2438 /* assignment of different structures (%s != %s) */ 2439 error(240, tspec_name(lt), tspec_name(rt)); 2440 } else { 2441 /* cannot assign to '%s' from '%s' */ 2442 error(171, type_name(ltp), type_name(rtp)); 2443 } 2444 } else if (mp->m_binary) { 2445 /* operands of '%s' have incompatible types (%s != %s) */ 2446 error(107, mp->m_name, tspec_name(lt), tspec_name(rt)); 2447 } else { 2448 lint_assert(rt == NOTSPEC); 2449 /* operand of '%s' has invalid type (%s) */ 2450 error(108, mp->m_name, tspec_name(lt)); 2451 } 2452 } 2453 2454 /* 2455 * Called if incompatible pointer types are detected. 2456 * Print an appropriate warning. 2457 */ 2458 static void 2459 warn_incompatible_pointers(const mod_t *mp, 2460 const type_t *ltp, const type_t *rtp) 2461 { 2462 tspec_t lt, rt; 2463 2464 lint_assert(ltp->t_tspec == PTR); 2465 lint_assert(rtp->t_tspec == PTR); 2466 2467 lt = ltp->t_subt->t_tspec; 2468 rt = rtp->t_subt->t_tspec; 2469 2470 if ((lt == STRUCT || lt == UNION) && (rt == STRUCT || rt == UNION)) { 2471 if (mp == NULL) { 2472 /* illegal structure pointer combination */ 2473 warning(244); 2474 } else { 2475 /* incompatible structure pointers: '%s' '%s' '%s' */ 2476 warning(245, type_name(ltp), mp->m_name, type_name(rtp)); 2477 } 2478 } else { 2479 if (mp == NULL) { 2480 /* illegal pointer combination */ 2481 warning(184); 2482 } else { 2483 /* illegal pointer combination (%s) and (%s), op %s */ 2484 warning(124, 2485 type_name(ltp), type_name(rtp), mp->m_name); 2486 } 2487 } 2488 } 2489 2490 /* Return a type based on tp1, with added qualifiers from tp2. */ 2491 static type_t * 2492 merge_qualifiers(type_t *tp1, const type_t *tp2) 2493 { 2494 type_t *ntp, *nstp; 2495 2496 lint_assert(tp1->t_tspec == PTR); 2497 lint_assert(tp2->t_tspec == PTR); 2498 2499 bool c1 = tp1->t_subt->t_const; 2500 bool c2 = tp2->t_subt->t_const; 2501 bool v1 = tp1->t_subt->t_volatile; 2502 bool v2 = tp2->t_subt->t_volatile; 2503 2504 if (c1 == (c1 | c2) && v1 == (v1 | v2)) 2505 return tp1; 2506 2507 nstp = expr_dup_type(tp1->t_subt); 2508 nstp->t_const |= c2; 2509 nstp->t_volatile |= v2; 2510 2511 ntp = expr_dup_type(tp1); 2512 ntp->t_subt = nstp; 2513 return ntp; 2514 } 2515 2516 /* 2517 * Returns true if the given structure or union has a constant member 2518 * (maybe recursively). 2519 */ 2520 static bool 2521 has_constant_member(const type_t *tp) 2522 { 2523 sym_t *m; 2524 tspec_t t; 2525 2526 lint_assert((t = tp->t_tspec) == STRUCT || t == UNION); 2527 2528 for (m = tp->t_str->sou_first_member; m != NULL; m = m->s_next) { 2529 tp = m->s_type; 2530 if (tp->t_const) 2531 return true; 2532 if ((t = tp->t_tspec) == STRUCT || t == UNION) { 2533 if (has_constant_member(m->s_type)) 2534 return true; 2535 } 2536 } 2537 return false; 2538 } 2539 2540 /* 2541 * Create a new node for one of the operators POINT and ARROW. 2542 */ 2543 static tnode_t * 2544 build_struct_access(op_t op, tnode_t *ln, tnode_t *rn) 2545 { 2546 tnode_t *ntn, *ctn; 2547 bool nolval; 2548 2549 lint_assert(rn->tn_op == NAME); 2550 lint_assert(rn->tn_sym->s_value.v_tspec == INT); 2551 lint_assert(rn->tn_sym->s_scl == MOS || rn->tn_sym->s_scl == MOU); 2552 2553 /* 2554 * Remember if the left operand is an lvalue (structure members 2555 * are lvalues if and only if the structure itself is an lvalue). 2556 */ 2557 nolval = op == POINT && !ln->tn_lvalue; 2558 2559 if (op == POINT) { 2560 ln = build_address(ln, true); 2561 } else if (ln->tn_type->t_tspec != PTR) { 2562 lint_assert(tflag); 2563 lint_assert(is_integer(ln->tn_type->t_tspec)); 2564 ln = convert(NOOP, 0, expr_derive_type(gettyp(VOID), PTR), ln); 2565 } 2566 2567 ctn = expr_new_integer_constant(PTRDIFF_TSPEC, 2568 rn->tn_sym->s_value.v_quad / CHAR_SIZE); 2569 2570 ntn = new_tnode(PLUS, expr_derive_type(rn->tn_type, PTR), ln, ctn); 2571 if (ln->tn_op == CON) 2572 ntn = fold(ntn); 2573 2574 if (rn->tn_type->t_bitfield) { 2575 ntn = new_tnode(FSEL, ntn->tn_type->t_subt, ntn, NULL); 2576 } else { 2577 ntn = new_tnode(INDIR, ntn->tn_type->t_subt, ntn, NULL); 2578 } 2579 2580 if (nolval) 2581 ntn->tn_lvalue = false; 2582 2583 return ntn; 2584 } 2585 2586 /* 2587 * Create a node for INCAFT, INCBEF, DECAFT and DECBEF. 2588 */ 2589 static tnode_t * 2590 build_prepost_incdec(op_t op, tnode_t *ln) 2591 { 2592 tnode_t *cn, *ntn; 2593 2594 lint_assert(ln != NULL); 2595 2596 if (ln->tn_type->t_tspec == PTR) { 2597 cn = plength(ln->tn_type); 2598 } else { 2599 cn = expr_new_integer_constant(INT, (int64_t)1); 2600 } 2601 ntn = new_tnode(op, ln->tn_type, ln, cn); 2602 2603 return ntn; 2604 } 2605 2606 /* 2607 * Create a node for REAL, IMAG 2608 */ 2609 static tnode_t * 2610 build_real_imag(op_t op, tnode_t *ln) 2611 { 2612 tnode_t *cn, *ntn; 2613 2614 lint_assert(ln != NULL); 2615 2616 if (ln->tn_op == NAME) { 2617 /* 2618 * This may be too much, but it avoids wrong warnings. 2619 * See d_c99_complex_split.c. 2620 */ 2621 mark_as_used(ln->tn_sym, false, false); 2622 mark_as_set(ln->tn_sym); 2623 } 2624 2625 switch (ln->tn_type->t_tspec) { 2626 case LCOMPLEX: 2627 /* XXX: integer and LDOUBLE don't match. */ 2628 cn = expr_new_integer_constant(LDOUBLE, (int64_t)1); 2629 break; 2630 case DCOMPLEX: 2631 /* XXX: integer and DOUBLE don't match. */ 2632 cn = expr_new_integer_constant(DOUBLE, (int64_t)1); 2633 break; 2634 case FCOMPLEX: 2635 /* XXX: integer and FLOAT don't match. */ 2636 cn = expr_new_integer_constant(FLOAT, (int64_t)1); 2637 break; 2638 default: 2639 /* __%s__ is illegal for type %s */ 2640 error(276, op == REAL ? "real" : "imag", 2641 type_name(ln->tn_type)); 2642 return NULL; 2643 } 2644 ntn = new_tnode(op, cn->tn_type, ln, cn); 2645 ntn->tn_lvalue = true; 2646 2647 return ntn; 2648 } 2649 /* 2650 * Create a tree node for the unary & operator 2651 */ 2652 static tnode_t * 2653 build_address(tnode_t *tn, bool noign) 2654 { 2655 tspec_t t; 2656 2657 if (!noign && ((t = tn->tn_type->t_tspec) == ARRAY || t == FUNC)) { 2658 if (tflag) 2659 /* '&' before array or function: ignored */ 2660 warning(127); 2661 return tn; 2662 } 2663 2664 /* eliminate &* */ 2665 if (tn->tn_op == INDIR && 2666 tn->tn_left->tn_type->t_tspec == PTR && 2667 tn->tn_left->tn_type->t_subt == tn->tn_type) { 2668 return tn->tn_left; 2669 } 2670 2671 return new_tnode(ADDR, expr_derive_type(tn->tn_type, PTR), tn, NULL); 2672 } 2673 2674 /* 2675 * Create a node for operators PLUS and MINUS. 2676 */ 2677 static tnode_t * 2678 build_plus_minus(op_t op, tnode_t *ln, tnode_t *rn) 2679 { 2680 tnode_t *ntn, *ctn; 2681 type_t *tp; 2682 2683 /* If pointer and integer, then pointer to the lhs. */ 2684 if (rn->tn_type->t_tspec == PTR && is_integer(ln->tn_type->t_tspec)) { 2685 ntn = ln; 2686 ln = rn; 2687 rn = ntn; 2688 } 2689 2690 if (ln->tn_type->t_tspec == PTR && rn->tn_type->t_tspec != PTR) { 2691 2692 /* XXX: this assertion should be easy to trigger */ 2693 lint_assert(is_integer(rn->tn_type->t_tspec)); 2694 2695 check_ctype_macro_invocation(ln, rn); 2696 2697 ctn = plength(ln->tn_type); 2698 if (rn->tn_type->t_tspec != ctn->tn_type->t_tspec) 2699 rn = convert(NOOP, 0, ctn->tn_type, rn); 2700 rn = new_tnode(MULT, rn->tn_type, rn, ctn); 2701 if (rn->tn_left->tn_op == CON) 2702 rn = fold(rn); 2703 ntn = new_tnode(op, ln->tn_type, ln, rn); 2704 2705 } else if (rn->tn_type->t_tspec == PTR) { 2706 2707 lint_assert(ln->tn_type->t_tspec == PTR); 2708 lint_assert(op == MINUS); 2709 tp = gettyp(PTRDIFF_TSPEC); 2710 ntn = new_tnode(op, tp, ln, rn); 2711 if (ln->tn_op == CON && rn->tn_op == CON) 2712 ntn = fold(ntn); 2713 ctn = plength(ln->tn_type); 2714 balance(NOOP, &ntn, &ctn); 2715 ntn = new_tnode(DIV, tp, ntn, ctn); 2716 2717 } else { 2718 2719 ntn = new_tnode(op, ln->tn_type, ln, rn); 2720 2721 } 2722 return ntn; 2723 } 2724 2725 /* 2726 * Create a node for operators SHL and SHR. 2727 */ 2728 static tnode_t * 2729 build_bit_shift(op_t op, tnode_t *ln, tnode_t *rn) 2730 { 2731 tspec_t t; 2732 tnode_t *ntn; 2733 2734 if ((t = rn->tn_type->t_tspec) != INT && t != UINT) 2735 rn = convert(CVT, 0, gettyp(INT), rn); 2736 ntn = new_tnode(op, ln->tn_type, ln, rn); 2737 return ntn; 2738 } 2739 2740 /* 2741 * Create a node for COLON. 2742 */ 2743 static tnode_t * 2744 build_colon(tnode_t *ln, tnode_t *rn) 2745 { 2746 tspec_t lt, rt, pdt; 2747 type_t *tp; 2748 tnode_t *ntn; 2749 2750 lt = ln->tn_type->t_tspec; 2751 rt = rn->tn_type->t_tspec; 2752 pdt = PTRDIFF_TSPEC; 2753 2754 /* 2755 * Arithmetic types are balanced, all other type combinations 2756 * still need to be handled. 2757 */ 2758 if (is_arithmetic(lt) && is_arithmetic(rt)) { 2759 tp = ln->tn_type; 2760 } else if (lt == BOOL && rt == BOOL) { 2761 tp = ln->tn_type; 2762 } else if (lt == VOID || rt == VOID) { 2763 tp = gettyp(VOID); 2764 } else if (lt == STRUCT || lt == UNION) { 2765 /* Both types must be identical. */ 2766 lint_assert(rt == STRUCT || rt == UNION); 2767 lint_assert(ln->tn_type->t_str == rn->tn_type->t_str); 2768 if (is_incomplete(ln->tn_type)) { 2769 /* unknown operand size, op %s */ 2770 error(138, op_name(COLON)); 2771 return NULL; 2772 } 2773 tp = ln->tn_type; 2774 } else if (lt == PTR && is_integer(rt)) { 2775 if (rt != pdt) { 2776 rn = convert(NOOP, 0, gettyp(pdt), rn); 2777 rt = pdt; 2778 } 2779 tp = ln->tn_type; 2780 } else if (rt == PTR && is_integer(lt)) { 2781 if (lt != pdt) { 2782 ln = convert(NOOP, 0, gettyp(pdt), ln); 2783 lt = pdt; 2784 } 2785 tp = rn->tn_type; 2786 } else if (lt == PTR && ln->tn_type->t_subt->t_tspec == VOID) { 2787 tp = merge_qualifiers(rn->tn_type, ln->tn_type); 2788 } else if (rt == PTR && rn->tn_type->t_subt->t_tspec == VOID) { 2789 tp = merge_qualifiers(ln->tn_type, rn->tn_type); 2790 } else { 2791 /* 2792 * XXX For now we simply take the left type. This is 2793 * probably wrong, if one type contains a function prototype 2794 * and the other one, at the same place, only an old style 2795 * declaration. 2796 */ 2797 tp = merge_qualifiers(ln->tn_type, rn->tn_type); 2798 } 2799 2800 ntn = new_tnode(COLON, tp, ln, rn); 2801 2802 return ntn; 2803 } 2804 2805 /* 2806 * Create a node for an assignment operator (both = and op= ). 2807 */ 2808 static tnode_t * 2809 build_assignment(op_t op, tnode_t *ln, tnode_t *rn) 2810 { 2811 tspec_t lt, rt; 2812 tnode_t *ntn, *ctn; 2813 2814 lint_assert(ln != NULL); 2815 lint_assert(rn != NULL); 2816 2817 lt = ln->tn_type->t_tspec; 2818 rt = rn->tn_type->t_tspec; 2819 2820 if ((op == ADDASS || op == SUBASS) && lt == PTR) { 2821 lint_assert(is_integer(rt)); 2822 ctn = plength(ln->tn_type); 2823 if (rn->tn_type->t_tspec != ctn->tn_type->t_tspec) 2824 rn = convert(NOOP, 0, ctn->tn_type, rn); 2825 rn = new_tnode(MULT, rn->tn_type, rn, ctn); 2826 if (rn->tn_left->tn_op == CON) 2827 rn = fold(rn); 2828 } 2829 2830 if ((op == ASSIGN || op == RETURN) && (lt == STRUCT || rt == STRUCT)) { 2831 lint_assert(lt == rt); 2832 lint_assert(ln->tn_type->t_str == rn->tn_type->t_str); 2833 if (is_incomplete(ln->tn_type)) { 2834 if (op == RETURN) { 2835 /* cannot return incomplete type */ 2836 error(212); 2837 } else { 2838 /* unknown operand size, op %s */ 2839 error(138, op_name(op)); 2840 } 2841 return NULL; 2842 } 2843 } 2844 2845 if (op == SHLASS) { 2846 if (portable_size_in_bits(lt) < portable_size_in_bits(rt)) { 2847 if (hflag) 2848 /* semantics of '%s' change in ANSI C; ... */ 2849 warning(118, "<<="); 2850 } 2851 } else if (op != SHRASS) { 2852 if (op == ASSIGN || lt != PTR) { 2853 if (lt != rt || 2854 (ln->tn_type->t_bitfield && rn->tn_op == CON)) { 2855 rn = convert(op, 0, ln->tn_type, rn); 2856 rt = lt; 2857 } 2858 } 2859 } 2860 2861 ntn = new_tnode(op, ln->tn_type, ln, rn); 2862 2863 return ntn; 2864 } 2865 2866 /* 2867 * Get length of type tp->t_subt. 2868 */ 2869 static tnode_t * 2870 plength(type_t *tp) 2871 { 2872 int elem, elsz; 2873 2874 lint_assert(tp->t_tspec == PTR); 2875 tp = tp->t_subt; 2876 2877 elem = 1; 2878 elsz = 0; 2879 2880 while (tp->t_tspec == ARRAY) { 2881 elem *= tp->t_dim; 2882 tp = tp->t_subt; 2883 } 2884 2885 switch (tp->t_tspec) { 2886 case FUNC: 2887 /* pointer to function is not allowed here */ 2888 error(110); 2889 break; 2890 case VOID: 2891 /* cannot do pointer arithmetic on operand of unknown size */ 2892 gnuism(136); 2893 break; 2894 case STRUCT: 2895 case UNION: 2896 if ((elsz = tp->t_str->sou_size_in_bits) == 0) 2897 /* cannot do pointer arithmetic on operand of ... */ 2898 error(136); 2899 break; 2900 case ENUM: 2901 if (is_incomplete(tp)) { 2902 /* cannot do pointer arithmetic on operand of ... */ 2903 warning(136); 2904 } 2905 /* FALLTHROUGH */ 2906 default: 2907 if ((elsz = size_in_bits(tp->t_tspec)) == 0) { 2908 /* cannot do pointer arithmetic on operand of ... */ 2909 error(136); 2910 } else { 2911 lint_assert(elsz != -1); 2912 } 2913 break; 2914 } 2915 2916 if (elem == 0 && elsz != 0) { 2917 /* cannot do pointer arithmetic on operand of unknown size */ 2918 error(136); 2919 } 2920 2921 if (elsz == 0) 2922 elsz = CHAR_SIZE; 2923 2924 return expr_new_integer_constant(PTRDIFF_TSPEC, 2925 (int64_t)(elem * elsz / CHAR_SIZE)); 2926 } 2927 2928 /* 2929 * XXX 2930 * Note: There appear to be a number of bugs in detecting overflow in 2931 * this function. An audit and a set of proper regression tests are needed. 2932 * --Perry Metzger, Nov. 16, 2001 2933 */ 2934 /* 2935 * Do only as much as necessary to compute constant expressions. 2936 * Called only if the operator allows folding and all operands are constants. 2937 */ 2938 static tnode_t * 2939 fold(tnode_t *tn) 2940 { 2941 val_t *v; 2942 tspec_t t; 2943 bool utyp, ovfl; 2944 int64_t sl, sr = 0, q = 0, mask; 2945 uint64_t ul, ur = 0; 2946 tnode_t *cn; 2947 2948 v = xcalloc(1, sizeof(*v)); 2949 v->v_tspec = t = tn->tn_type->t_tspec; 2950 2951 utyp = t == PTR || is_uinteger(t); 2952 ul = sl = tn->tn_left->tn_val->v_quad; 2953 if (modtab[tn->tn_op].m_binary) 2954 ur = sr = tn->tn_right->tn_val->v_quad; 2955 2956 mask = value_bits(size_in_bits(t)); 2957 ovfl = false; 2958 2959 switch (tn->tn_op) { 2960 case UPLUS: 2961 q = sl; 2962 break; 2963 case UMINUS: 2964 q = -sl; 2965 if (sl != 0 && msb(q, t, -1) == msb(sl, t, -1)) 2966 ovfl = true; 2967 break; 2968 case COMPL: 2969 q = ~sl; 2970 break; 2971 case MULT: 2972 if (utyp) { 2973 q = ul * ur; 2974 if (q != (q & mask)) 2975 ovfl = true; 2976 else if ((ul != 0) && ((q / ul) != ur)) 2977 ovfl = true; 2978 } else { 2979 q = sl * sr; 2980 if (msb(q, t, -1) != (msb(sl, t, -1) ^ msb(sr, t, -1))) 2981 ovfl = true; 2982 } 2983 break; 2984 case DIV: 2985 if (sr == 0) { 2986 /* division by 0 */ 2987 error(139); 2988 q = utyp ? UQUAD_MAX : QUAD_MAX; 2989 } else { 2990 q = utyp ? (int64_t)(ul / ur) : sl / sr; 2991 } 2992 break; 2993 case MOD: 2994 if (sr == 0) { 2995 /* modulus by 0 */ 2996 error(140); 2997 q = 0; 2998 } else { 2999 q = utyp ? (int64_t)(ul % ur) : sl % sr; 3000 } 3001 break; 3002 case PLUS: 3003 q = utyp ? (int64_t)(ul + ur) : sl + sr; 3004 if (msb(sl, t, -1) != 0 && msb(sr, t, -1) != 0) { 3005 if (msb(q, t, -1) == 0) 3006 ovfl = true; 3007 } else if (msb(sl, t, -1) == 0 && msb(sr, t, -1) == 0) { 3008 if (msb(q, t, -1) != 0) 3009 ovfl = true; 3010 } 3011 break; 3012 case MINUS: 3013 q = utyp ? (int64_t)(ul - ur) : sl - sr; 3014 if (msb(sl, t, -1) != 0 && msb(sr, t, -1) == 0) { 3015 if (msb(q, t, -1) == 0) 3016 ovfl = true; 3017 } else if (msb(sl, t, -1) == 0 && msb(sr, t, -1) != 0) { 3018 if (msb(q, t, -1) != 0) 3019 ovfl = true; 3020 } 3021 break; 3022 case SHL: 3023 q = utyp ? (int64_t)(ul << sr) : sl << sr; 3024 break; 3025 case SHR: 3026 /* 3027 * The sign must be explicitly extended because 3028 * shifts of signed values are implementation dependent. 3029 */ 3030 q = ul >> sr; 3031 q = xsign(q, t, size_in_bits(t) - (int)sr); 3032 break; 3033 case LT: 3034 q = (utyp ? ul < ur : sl < sr) ? 1 : 0; 3035 break; 3036 case LE: 3037 q = (utyp ? ul <= ur : sl <= sr) ? 1 : 0; 3038 break; 3039 case GE: 3040 q = (utyp ? ul >= ur : sl >= sr) ? 1 : 0; 3041 break; 3042 case GT: 3043 q = (utyp ? ul > ur : sl > sr) ? 1 : 0; 3044 break; 3045 case EQ: 3046 q = (utyp ? ul == ur : sl == sr) ? 1 : 0; 3047 break; 3048 case NE: 3049 q = (utyp ? ul != ur : sl != sr) ? 1 : 0; 3050 break; 3051 case BITAND: 3052 q = utyp ? (int64_t)(ul & ur) : sl & sr; 3053 break; 3054 case BITXOR: 3055 q = utyp ? (int64_t)(ul ^ ur) : sl ^ sr; 3056 break; 3057 case BITOR: 3058 q = utyp ? (int64_t)(ul | ur) : sl | sr; 3059 break; 3060 default: 3061 lint_assert(/*CONSTCOND*/false); 3062 } 3063 3064 /* XXX does not work for quads. */ 3065 if (ovfl || ((uint64_t)(q | mask) != ~(uint64_t)0 && 3066 (q & ~mask) != 0)) { 3067 if (hflag) 3068 /* integer overflow detected, op %s */ 3069 warning(141, op_name(tn->tn_op)); 3070 } 3071 3072 v->v_quad = xsign(q, t, -1); 3073 3074 cn = expr_new_constant(tn->tn_type, v); 3075 if (tn->tn_left->tn_system_dependent) 3076 cn->tn_system_dependent = true; 3077 if (modtab[tn->tn_op].m_binary && tn->tn_right->tn_system_dependent) 3078 cn->tn_system_dependent = true; 3079 3080 return cn; 3081 } 3082 3083 /* 3084 * Fold constant nodes, as much as is needed for comparing the value with 0 3085 * (test context, for controlling expressions). 3086 */ 3087 static tnode_t * 3088 fold_test(tnode_t *tn) 3089 { 3090 bool l, r; 3091 val_t *v; 3092 3093 v = xcalloc(1, sizeof(*v)); 3094 v->v_tspec = tn->tn_type->t_tspec; 3095 lint_assert(v->v_tspec == INT || (Tflag && v->v_tspec == BOOL)); 3096 3097 l = constant_is_nonzero(tn->tn_left); 3098 r = modtab[tn->tn_op].m_binary && constant_is_nonzero(tn->tn_right); 3099 3100 switch (tn->tn_op) { 3101 case NOT: 3102 if (hflag && !constcond_flag) 3103 /* constant argument to '!' */ 3104 warning(239); 3105 v->v_quad = !l ? 1 : 0; 3106 break; 3107 case LOGAND: 3108 v->v_quad = l && r ? 1 : 0; 3109 break; 3110 case LOGOR: 3111 v->v_quad = l || r ? 1 : 0; 3112 break; 3113 default: 3114 lint_assert(/*CONSTCOND*/false); 3115 } 3116 3117 return expr_new_constant(tn->tn_type, v); 3118 } 3119 3120 /* 3121 * Fold constant nodes having operands with floating point type. 3122 */ 3123 static tnode_t * 3124 fold_float(tnode_t *tn) 3125 { 3126 val_t *v; 3127 tspec_t t; 3128 ldbl_t l, r = 0; 3129 3130 fpe = 0; 3131 v = xcalloc(1, sizeof(*v)); 3132 v->v_tspec = t = tn->tn_type->t_tspec; 3133 3134 lint_assert(is_floating(t)); 3135 lint_assert(t == tn->tn_left->tn_type->t_tspec); 3136 lint_assert(!modtab[tn->tn_op].m_binary || 3137 t == tn->tn_right->tn_type->t_tspec); 3138 3139 l = tn->tn_left->tn_val->v_ldbl; 3140 if (modtab[tn->tn_op].m_binary) 3141 r = tn->tn_right->tn_val->v_ldbl; 3142 3143 switch (tn->tn_op) { 3144 case UPLUS: 3145 v->v_ldbl = l; 3146 break; 3147 case UMINUS: 3148 v->v_ldbl = -l; 3149 break; 3150 case MULT: 3151 v->v_ldbl = l * r; 3152 break; 3153 case DIV: 3154 if (r == 0.0) { 3155 /* division by 0 */ 3156 error(139); 3157 if (t == FLOAT) { 3158 v->v_ldbl = l < 0 ? -FLT_MAX : FLT_MAX; 3159 } else if (t == DOUBLE) { 3160 v->v_ldbl = l < 0 ? -DBL_MAX : DBL_MAX; 3161 } else { 3162 v->v_ldbl = l < 0 ? -LDBL_MAX : LDBL_MAX; 3163 } 3164 } else { 3165 v->v_ldbl = l / r; 3166 } 3167 break; 3168 case PLUS: 3169 v->v_ldbl = l + r; 3170 break; 3171 case MINUS: 3172 v->v_ldbl = l - r; 3173 break; 3174 case LT: 3175 v->v_quad = l < r ? 1 : 0; 3176 break; 3177 case LE: 3178 v->v_quad = l <= r ? 1 : 0; 3179 break; 3180 case GE: 3181 v->v_quad = l >= r ? 1 : 0; 3182 break; 3183 case GT: 3184 v->v_quad = l > r ? 1 : 0; 3185 break; 3186 case EQ: 3187 v->v_quad = l == r ? 1 : 0; 3188 break; 3189 case NE: 3190 v->v_quad = l != r ? 1 : 0; 3191 break; 3192 default: 3193 lint_assert(/*CONSTCOND*/false); 3194 } 3195 3196 lint_assert(fpe != 0 || isnan((double)v->v_ldbl) == 0); 3197 if (fpe != 0 || finite((double)v->v_ldbl) == 0 || 3198 (t == FLOAT && 3199 (v->v_ldbl > FLT_MAX || v->v_ldbl < -FLT_MAX)) || 3200 (t == DOUBLE && 3201 (v->v_ldbl > DBL_MAX || v->v_ldbl < -DBL_MAX))) { 3202 /* floating point overflow detected, op %s */ 3203 warning(142, op_name(tn->tn_op)); 3204 if (t == FLOAT) { 3205 v->v_ldbl = v->v_ldbl < 0 ? -FLT_MAX : FLT_MAX; 3206 } else if (t == DOUBLE) { 3207 v->v_ldbl = v->v_ldbl < 0 ? -DBL_MAX : DBL_MAX; 3208 } else { 3209 v->v_ldbl = v->v_ldbl < 0 ? -LDBL_MAX: LDBL_MAX; 3210 } 3211 fpe = 0; 3212 } 3213 3214 return expr_new_constant(tn->tn_type, v); 3215 } 3216 3217 3218 /* 3219 * Create a constant node for sizeof. 3220 */ 3221 tnode_t * 3222 build_sizeof(const type_t *tp) 3223 { 3224 int64_t size_in_bytes = type_size_in_bits(tp) / CHAR_SIZE; 3225 tnode_t *tn = expr_new_integer_constant(SIZEOF_TSPEC, size_in_bytes); 3226 tn->tn_system_dependent = true; 3227 return tn; 3228 } 3229 3230 /* 3231 * Create a constant node for offsetof. 3232 */ 3233 tnode_t * 3234 build_offsetof(const type_t *tp, const sym_t *sym) 3235 { 3236 tspec_t t = tp->t_tspec; 3237 if (t != STRUCT && t != UNION) 3238 /* unacceptable operand of '%s' */ 3239 error(111, "offsetof"); 3240 3241 // XXX: wrong size, no checking for sym fixme 3242 int64_t offset_in_bytes = type_size_in_bits(tp) / CHAR_SIZE; 3243 tnode_t *tn = expr_new_integer_constant(SIZEOF_TSPEC, offset_in_bytes); 3244 tn->tn_system_dependent = true; 3245 return tn; 3246 } 3247 3248 int64_t 3249 type_size_in_bits(const type_t *tp) 3250 { 3251 int elem, elsz; 3252 bool flex; 3253 3254 elem = 1; 3255 flex = false; 3256 while (tp->t_tspec == ARRAY) { 3257 flex = true; /* allow c99 flex arrays [] [0] */ 3258 elem *= tp->t_dim; 3259 tp = tp->t_subt; 3260 } 3261 if (elem == 0) { 3262 if (!flex) { 3263 /* cannot take size/alignment of incomplete type */ 3264 error(143); 3265 elem = 1; 3266 } 3267 } 3268 switch (tp->t_tspec) { 3269 case FUNC: 3270 /* cannot take size/alignment of function */ 3271 error(144); 3272 elsz = 1; 3273 break; 3274 case STRUCT: 3275 case UNION: 3276 if (is_incomplete(tp)) { 3277 /* cannot take size/alignment of incomplete type */ 3278 error(143); 3279 elsz = 1; 3280 } else { 3281 elsz = tp->t_str->sou_size_in_bits; 3282 } 3283 break; 3284 case ENUM: 3285 if (is_incomplete(tp)) { 3286 /* cannot take size/alignment of incomplete type */ 3287 warning(143); 3288 } 3289 /* FALLTHROUGH */ 3290 default: 3291 if (tp->t_bitfield) { 3292 /* cannot take size/alignment of bit-field */ 3293 error(145); 3294 } 3295 if (tp->t_tspec == VOID) { 3296 /* cannot take size/alignment of void */ 3297 error(146); 3298 elsz = 1; 3299 } else { 3300 elsz = size_in_bits(tp->t_tspec); 3301 lint_assert(elsz > 0); 3302 } 3303 break; 3304 } 3305 3306 return (int64_t)elem * elsz; 3307 } 3308 3309 tnode_t * 3310 build_alignof(const type_t *tp) 3311 { 3312 switch (tp->t_tspec) { 3313 case ARRAY: 3314 break; 3315 3316 case FUNC: 3317 /* cannot take size/alignment of function */ 3318 error(144); 3319 return 0; 3320 3321 case STRUCT: 3322 case UNION: 3323 if (is_incomplete(tp)) { 3324 /* cannot take size/alignment of incomplete type */ 3325 error(143); 3326 return 0; 3327 } 3328 break; 3329 case ENUM: 3330 break; 3331 default: 3332 if (tp->t_bitfield) { 3333 /* cannot take size/alignment of bit-field */ 3334 error(145); 3335 return 0; 3336 } 3337 if (tp->t_tspec == VOID) { 3338 /* cannot take size/alignment of void */ 3339 error(146); 3340 return 0; 3341 } 3342 break; 3343 } 3344 3345 return expr_new_integer_constant(SIZEOF_TSPEC, 3346 (int64_t)alignment_in_bits(tp) / CHAR_SIZE); 3347 } 3348 3349 /* 3350 * Type casts. 3351 */ 3352 tnode_t * 3353 cast(tnode_t *tn, type_t *tp) 3354 { 3355 tspec_t nt, ot; 3356 3357 if (tn == NULL) 3358 return NULL; 3359 3360 /* 3361 * XXX: checking for tp == NULL is only a quick fix for PR 22119. 3362 * The proper fix needs to be investigated properly. 3363 * See d_pr_22119.c for how to get here. 3364 */ 3365 if (tp == NULL) 3366 return NULL; 3367 3368 tn = cconv(tn); 3369 3370 nt = tp->t_tspec; 3371 ot = tn->tn_type->t_tspec; 3372 3373 if (nt == VOID) { 3374 /* 3375 * XXX ANSI C requires scalar types or void (Plauger & Brodie). 3376 * But this seems really questionable. 3377 */ 3378 } else if (nt == UNION) { 3379 sym_t *m; 3380 struct_or_union *str = tp->t_str; 3381 if (!Sflag) { 3382 /* union cast is a C9X feature */ 3383 error(328); 3384 return NULL; 3385 } 3386 for (m = str->sou_first_member; m != NULL; m = m->s_next) { 3387 if (sametype(m->s_type, tn->tn_type)) { 3388 tn = expr_zalloc_tnode(); 3389 tn->tn_op = CVT; 3390 tn->tn_type = tp; 3391 tn->tn_cast = true; 3392 tn->tn_right = NULL; 3393 return tn; 3394 } 3395 } 3396 /* type '%s' is not a member of '%s' */ 3397 error(329, type_name(tn->tn_type), type_name(tp)); 3398 return NULL; 3399 } else if (nt == STRUCT || nt == ARRAY || nt == FUNC) { 3400 if (!Sflag || nt == ARRAY || nt == FUNC) { 3401 /* invalid cast expression */ 3402 error(147); 3403 return NULL; 3404 } 3405 } else if (ot == STRUCT || ot == UNION) { 3406 /* invalid cast expression */ 3407 error(147); 3408 return NULL; 3409 } else if (ot == VOID) { 3410 /* improper cast of void expression */ 3411 error(148); 3412 return NULL; 3413 } else if (is_integer(nt) && is_scalar(ot)) { 3414 /* ok */ 3415 } else if (is_floating(nt) && is_arithmetic(ot)) { 3416 /* ok */ 3417 } else if (nt == PTR && is_integer(ot)) { 3418 /* ok */ 3419 } else if (nt == PTR && ot == PTR) { 3420 if (!tp->t_subt->t_const && tn->tn_type->t_subt->t_const) { 3421 if (hflag) 3422 /* cast discards 'const' from type '%s' */ 3423 warning(275, type_name(tn->tn_type)); 3424 } 3425 } else { 3426 /* invalid cast expression */ 3427 error(147); 3428 return NULL; 3429 } 3430 3431 tn = convert(CVT, 0, tp, tn); 3432 tn->tn_cast = true; 3433 3434 return tn; 3435 } 3436 3437 /* 3438 * Create the node for a function argument. 3439 * All necessary conversions and type checks are done in 3440 * new_function_call_node because new_function_argument_node has no 3441 * information about expected argument types. 3442 */ 3443 tnode_t * 3444 new_function_argument_node(tnode_t *args, tnode_t *arg) 3445 { 3446 tnode_t *ntn; 3447 3448 /* 3449 * If there was a serious error in the expression for the argument, 3450 * create a dummy argument so the positions of the remaining arguments 3451 * will not change. 3452 */ 3453 if (arg == NULL) 3454 arg = expr_new_integer_constant(INT, 0); 3455 3456 ntn = new_tnode(PUSH, arg->tn_type, arg, args); 3457 3458 return ntn; 3459 } 3460 3461 /* 3462 * Create the node for a function call. Also check types of 3463 * function arguments and insert conversions, if necessary. 3464 */ 3465 tnode_t * 3466 new_function_call_node(tnode_t *func, tnode_t *args) 3467 { 3468 tnode_t *ntn; 3469 op_t fcop; 3470 3471 if (func == NULL) 3472 return NULL; 3473 3474 if (func->tn_op == NAME && func->tn_type->t_tspec == FUNC) { 3475 fcop = CALL; 3476 } else { 3477 fcop = ICALL; 3478 } 3479 3480 check_ctype_function_call(func, args); 3481 3482 /* 3483 * after cconv() func will always be a pointer to a function 3484 * if it is a valid function designator. 3485 */ 3486 func = cconv(func); 3487 3488 if (func->tn_type->t_tspec != PTR || 3489 func->tn_type->t_subt->t_tspec != FUNC) { 3490 /* illegal function (type %s) */ 3491 error(149, type_name(func->tn_type)); 3492 return NULL; 3493 } 3494 3495 args = check_function_arguments(func->tn_type->t_subt, args); 3496 3497 ntn = new_tnode(fcop, func->tn_type->t_subt->t_subt, func, args); 3498 3499 return ntn; 3500 } 3501 3502 /* 3503 * Check types of all function arguments and insert conversions, 3504 * if necessary. 3505 */ 3506 static tnode_t * 3507 check_function_arguments(type_t *ftp, tnode_t *args) 3508 { 3509 tnode_t *arg; 3510 sym_t *asym; 3511 tspec_t at; 3512 int narg, npar, n, i; 3513 3514 /* get # of args in the prototype */ 3515 npar = 0; 3516 for (asym = ftp->t_args; asym != NULL; asym = asym->s_next) 3517 npar++; 3518 3519 /* get # of args in function call */ 3520 narg = 0; 3521 for (arg = args; arg != NULL; arg = arg->tn_right) 3522 narg++; 3523 3524 asym = ftp->t_args; 3525 if (ftp->t_proto && npar != narg && !(ftp->t_vararg && npar < narg)) { 3526 /* argument mismatch: %d arg%s passed, %d expected */ 3527 error(150, narg, narg > 1 ? "s" : "", npar); 3528 asym = NULL; 3529 } 3530 3531 for (n = 1; n <= narg; n++) { 3532 3533 /* 3534 * The rightmost argument is at the top of the argument 3535 * subtree. 3536 */ 3537 for (i = narg, arg = args; i > n; i--, arg = arg->tn_right) 3538 continue; 3539 3540 /* some things which are always not allowed */ 3541 if ((at = arg->tn_left->tn_type->t_tspec) == VOID) { 3542 /* void expressions may not be arguments, arg #%d */ 3543 error(151, n); 3544 return NULL; 3545 } else if ((at == STRUCT || at == UNION) && 3546 is_incomplete(arg->tn_left->tn_type)) { 3547 /* argument cannot have unknown size, arg #%d */ 3548 error(152, n); 3549 return NULL; 3550 } else if (is_integer(at) && 3551 arg->tn_left->tn_type->t_is_enum && 3552 is_incomplete(arg->tn_left->tn_type)) { 3553 /* argument cannot have unknown size, arg #%d */ 3554 warning(152, n); 3555 } 3556 3557 /* class conversions (arg in value context) */ 3558 arg->tn_left = cconv(arg->tn_left); 3559 3560 if (asym != NULL) { 3561 arg->tn_left = check_prototype_argument( 3562 n, asym->s_type, arg->tn_left); 3563 } else { 3564 arg->tn_left = promote(NOOP, true, arg->tn_left); 3565 } 3566 arg->tn_type = arg->tn_left->tn_type; 3567 3568 if (asym != NULL) 3569 asym = asym->s_next; 3570 } 3571 3572 return args; 3573 } 3574 3575 /* 3576 * Compare the type of an argument with the corresponding type of a 3577 * prototype parameter. If it is a valid combination, but both types 3578 * are not the same, insert a conversion to convert the argument into 3579 * the type of the parameter. 3580 */ 3581 static tnode_t * 3582 check_prototype_argument( 3583 int n, /* pos of arg */ 3584 type_t *tp, /* expected type (from prototype) */ 3585 tnode_t *tn) /* argument */ 3586 { 3587 tnode_t *ln; 3588 bool dowarn; 3589 3590 ln = xcalloc(1, sizeof(*ln)); 3591 ln->tn_type = expr_dup_type(tp); 3592 ln->tn_type->t_const = false; 3593 ln->tn_lvalue = true; 3594 if (typeok(FARG, n, ln, tn)) { 3595 if (!eqtype(tp, tn->tn_type, 3596 true, false, (dowarn = false, &dowarn)) || dowarn) 3597 tn = convert(FARG, n, tp, tn); 3598 } 3599 free(ln); 3600 return tn; 3601 } 3602 3603 /* 3604 * Return the value of an integral constant expression. 3605 * If the expression is not constant or its type is not an integer 3606 * type, an error message is printed. 3607 */ 3608 val_t * 3609 constant(tnode_t *tn, bool required) 3610 { 3611 val_t *v; 3612 3613 if (tn != NULL) 3614 tn = cconv(tn); 3615 if (tn != NULL) 3616 tn = promote(NOOP, false, tn); 3617 3618 v = xcalloc(1, sizeof(*v)); 3619 3620 if (tn == NULL) { 3621 lint_assert(nerr != 0); 3622 if (dflag) 3623 printf("constant node is null; returning 1 instead\n"); 3624 v->v_tspec = INT; 3625 v->v_quad = 1; 3626 return v; 3627 } 3628 3629 v->v_tspec = tn->tn_type->t_tspec; 3630 3631 if (tn->tn_op == CON) { 3632 lint_assert(tn->tn_type->t_tspec == tn->tn_val->v_tspec); 3633 if (is_integer(tn->tn_val->v_tspec)) { 3634 v->v_unsigned_since_c90 = 3635 tn->tn_val->v_unsigned_since_c90; 3636 v->v_quad = tn->tn_val->v_quad; 3637 return v; 3638 } 3639 v->v_quad = tn->tn_val->v_ldbl; 3640 } else { 3641 v->v_quad = 1; 3642 } 3643 3644 if (required) 3645 /* integral constant expression expected */ 3646 error(55); 3647 else 3648 /* variable array dimension is a C99/GCC extension */ 3649 c99ism(318); 3650 3651 if (!is_integer(v->v_tspec)) 3652 v->v_tspec = INT; 3653 3654 return v; 3655 } 3656 3657 static bool 3658 is_constcond_false(const tnode_t *tn, tspec_t t) 3659 { 3660 return (t == BOOL || t == INT) && 3661 tn->tn_op == CON && tn->tn_val->v_quad == 0; 3662 } 3663 3664 /* 3665 * Perform some tests on expressions which can't be done in build() and 3666 * functions called by build(). These tests must be done here because 3667 * we need some information about the context in which the operations 3668 * are performed. 3669 * After all tests are performed and dofreeblk is true, expr() frees the 3670 * memory which is used for the expression. 3671 */ 3672 void 3673 expr(tnode_t *tn, bool vctx, bool tctx, bool dofreeblk, bool is_do_while) 3674 { 3675 3676 lint_assert(tn != NULL || nerr != 0); 3677 3678 if (tn == NULL) { 3679 expr_free_all(); 3680 return; 3681 } 3682 3683 /* expr() is also called in global initializations */ 3684 if (dcs->d_ctx != EXTERN && !is_do_while) 3685 check_statement_reachable(); 3686 3687 check_expr_misc(tn, vctx, tctx, !tctx, false, false, false); 3688 if (tn->tn_op == ASSIGN) { 3689 if (hflag && tctx) 3690 /* assignment in conditional context */ 3691 warning(159); 3692 } else if (tn->tn_op == CON) { 3693 if (hflag && tctx && !constcond_flag && 3694 !tn->tn_system_dependent && 3695 !(is_do_while && 3696 is_constcond_false(tn, tn->tn_type->t_tspec))) 3697 /* constant in conditional context */ 3698 warning(161); 3699 } 3700 if (!modtab[tn->tn_op].m_has_side_effect) { 3701 /* 3702 * for left operands of COMMA this warning is already 3703 * printed 3704 */ 3705 if (tn->tn_op != COMMA && !vctx && !tctx) 3706 check_null_effect(tn); 3707 } 3708 if (dflag) 3709 display_expression(tn, 0); 3710 3711 /* free the tree memory */ 3712 if (dofreeblk) 3713 expr_free_all(); 3714 } 3715 3716 static bool 3717 has_side_effect(const tnode_t *tn) // NOLINT(misc-no-recursion) 3718 { 3719 op_t op = tn->tn_op; 3720 3721 if (modtab[op].m_has_side_effect) 3722 return true; 3723 3724 if (op == CVT && tn->tn_type->t_tspec == VOID) 3725 return has_side_effect(tn->tn_left); 3726 3727 /* XXX: Why not has_side_effect(tn->tn_left) as well? */ 3728 if (op == LOGAND || op == LOGOR) 3729 return has_side_effect(tn->tn_right); 3730 3731 /* XXX: Why not has_side_effect(tn->tn_left) as well? */ 3732 if (op == QUEST) 3733 return has_side_effect(tn->tn_right); 3734 3735 if (op == COLON || op == COMMA) { 3736 return has_side_effect(tn->tn_left) || 3737 has_side_effect(tn->tn_right); 3738 } 3739 3740 return false; 3741 } 3742 3743 static void 3744 check_null_effect(const tnode_t *tn) 3745 { 3746 3747 if (hflag && !has_side_effect(tn)) { 3748 /* expression has null effect */ 3749 warning(129); 3750 } 3751 } 3752 3753 /* 3754 * Dump an expression to stdout 3755 * only used for debugging 3756 */ 3757 static void 3758 display_expression(const tnode_t *tn, int offs) 3759 { 3760 uint64_t uq; 3761 3762 if (tn == NULL) { 3763 (void)printf("%*s%s\n", offs, "", "NULL"); 3764 return; 3765 } 3766 (void)printf("%*sop %s ", offs, "", op_name(tn->tn_op)); 3767 3768 if (tn->tn_op == NAME) { 3769 (void)printf("%s: %s ", 3770 tn->tn_sym->s_name, 3771 storage_class_name(tn->tn_sym->s_scl)); 3772 } else if (tn->tn_op == CON && is_floating(tn->tn_type->t_tspec)) { 3773 (void)printf("%#g ", (double)tn->tn_val->v_ldbl); 3774 } else if (tn->tn_op == CON && is_integer(tn->tn_type->t_tspec)) { 3775 uq = tn->tn_val->v_quad; 3776 (void)printf("0x %08lx %08lx ", 3777 (long)(uq >> 32) & 0xffffffffl, 3778 (long)uq & 0xffffffffl); 3779 } else if (tn->tn_op == CON) { 3780 lint_assert(tn->tn_type->t_tspec == PTR); 3781 (void)printf("0x%0*lx ", (int)(sizeof(void *) * CHAR_BIT / 4), 3782 (u_long)tn->tn_val->v_quad); 3783 } else if (tn->tn_op == STRING) { 3784 if (tn->tn_string->st_tspec == CHAR) { 3785 (void)printf("\"%s\"", tn->tn_string->st_cp); 3786 } else { 3787 char *s; 3788 size_t n; 3789 n = MB_CUR_MAX * (tn->tn_string->st_len + 1); 3790 s = xmalloc(n); 3791 (void)wcstombs(s, tn->tn_string->st_wcp, n); 3792 (void)printf("L\"%s\"", s); 3793 free(s); 3794 } 3795 (void)printf(" "); 3796 } else if (tn->tn_op == FSEL) { 3797 (void)printf("o=%d, l=%d ", tn->tn_type->t_foffs, 3798 tn->tn_type->t_flen); 3799 } 3800 (void)printf("%s\n", ttos(tn->tn_type)); 3801 if (tn->tn_op == NAME || tn->tn_op == CON || tn->tn_op == STRING) 3802 return; 3803 display_expression(tn->tn_left, offs + 2); 3804 if (modtab[tn->tn_op].m_binary || 3805 (tn->tn_op == PUSH && tn->tn_right != NULL)) { 3806 display_expression(tn->tn_right, offs + 2); 3807 } 3808 } 3809 3810 /* 3811 * Called by expr() to recursively perform some tests. 3812 */ 3813 /* ARGSUSED */ 3814 void 3815 check_expr_misc(const tnode_t *tn, bool vctx, bool tctx, 3816 bool eqwarn, bool fcall, bool rvdisc, bool szof) 3817 { 3818 tnode_t *ln, *rn; 3819 const mod_t *mp; 3820 op_t op; 3821 scl_t sc; 3822 dinfo_t *di; 3823 3824 if (tn == NULL) 3825 return; 3826 3827 ln = tn->tn_left; 3828 rn = tn->tn_right; 3829 mp = &modtab[op = tn->tn_op]; 3830 3831 switch (op) { 3832 case ADDR: 3833 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 3834 if (ln->tn_op == NAME && (reached || !warn_about_unreachable)) { 3835 if (!szof) 3836 mark_as_set(ln->tn_sym); 3837 mark_as_used(ln->tn_sym, fcall, szof); 3838 } 3839 if (ln->tn_op == INDIR && ln->tn_left->tn_op == PLUS) 3840 /* check the range of array indices */ 3841 check_array_index(ln->tn_left, true); 3842 break; 3843 case LOAD: 3844 if (ln->tn_op == INDIR && ln->tn_left->tn_op == PLUS) 3845 /* check the range of array indices */ 3846 check_array_index(ln->tn_left, false); 3847 /* FALLTHROUGH */ 3848 case PUSH: 3849 case INCBEF: 3850 case DECBEF: 3851 case INCAFT: 3852 case DECAFT: 3853 case ADDASS: 3854 case SUBASS: 3855 case MULASS: 3856 case DIVASS: 3857 case MODASS: 3858 case ANDASS: 3859 case ORASS: 3860 case XORASS: 3861 case SHLASS: 3862 case SHRASS: 3863 case REAL: 3864 case IMAG: 3865 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 3866 if (ln->tn_op == NAME && (reached || !warn_about_unreachable)) { 3867 sc = ln->tn_sym->s_scl; 3868 /* 3869 * Look if there was a asm statement in one of the 3870 * compound statements we are in. If not, we don't 3871 * print a warning. 3872 */ 3873 for (di = dcs; di != NULL; di = di->d_next) { 3874 if (di->d_asm) 3875 break; 3876 } 3877 if (sc != EXTERN && sc != STATIC && 3878 !ln->tn_sym->s_set && !szof && di == NULL) { 3879 /* %s may be used before set */ 3880 warning(158, ln->tn_sym->s_name); 3881 mark_as_set(ln->tn_sym); 3882 } 3883 mark_as_used(ln->tn_sym, false, false); 3884 } 3885 break; 3886 case ASSIGN: 3887 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 3888 if (ln->tn_op == NAME && !szof && (reached || !warn_about_unreachable)) { 3889 mark_as_set(ln->tn_sym); 3890 if (ln->tn_sym->s_scl == EXTERN) 3891 outusg(ln->tn_sym); 3892 } 3893 if (ln->tn_op == INDIR && ln->tn_left->tn_op == PLUS) 3894 /* check the range of array indices */ 3895 check_array_index(ln->tn_left, false); 3896 break; 3897 case CALL: 3898 lint_assert(ln->tn_op == ADDR); 3899 lint_assert(ln->tn_left->tn_op == NAME); 3900 if (!szof) 3901 outcall(tn, vctx || tctx, rvdisc); 3902 break; 3903 case EQ: 3904 if (hflag && eqwarn) 3905 /* operator '==' found where '=' was expected */ 3906 warning(160); 3907 break; 3908 case CON: 3909 case NAME: 3910 case STRING: 3911 return; 3912 /* LINTED206: (enumeration values not handled in switch) */ 3913 case BITOR: 3914 case BITXOR: 3915 case NE: 3916 case GE: 3917 case GT: 3918 case LE: 3919 case LT: 3920 case SHR: 3921 case SHL: 3922 case MINUS: 3923 case PLUS: 3924 case MOD: 3925 case DIV: 3926 case MULT: 3927 case INDIR: 3928 case UMINUS: 3929 case UPLUS: 3930 case DEC: 3931 case INC: 3932 case COMPL: 3933 case NOT: 3934 case POINT: 3935 case ARROW: 3936 case NOOP: 3937 case BITAND: 3938 case FARG: 3939 case CASE: 3940 case INIT: 3941 case RETURN: 3942 case ICALL: 3943 case CVT: 3944 case COMMA: 3945 case FSEL: 3946 case COLON: 3947 case QUEST: 3948 case LOGOR: 3949 case LOGAND: 3950 break; 3951 } 3952 3953 bool cvctx = mp->m_left_value_context; 3954 bool ctctx = mp->m_left_test_context; 3955 bool eq = mp->m_warn_if_operand_eq && 3956 !ln->tn_parenthesized && 3957 rn != NULL && !rn->tn_parenthesized; 3958 3959 /* 3960 * values of operands of ':' are not used if the type of at least 3961 * one of the operands (for gcc compatibility) is void 3962 * XXX test/value context of QUEST should probably be used as 3963 * context for both operands of COLON 3964 */ 3965 if (op == COLON && tn->tn_type->t_tspec == VOID) 3966 cvctx = ctctx = false; 3967 bool discard = op == CVT && tn->tn_type->t_tspec == VOID; 3968 check_expr_misc(ln, cvctx, ctctx, eq, op == CALL, discard, szof); 3969 3970 switch (op) { 3971 case PUSH: 3972 if (rn != NULL) 3973 check_expr_misc(rn, false, false, eq, false, false, 3974 szof); 3975 break; 3976 case LOGAND: 3977 case LOGOR: 3978 check_expr_misc(rn, false, true, eq, false, false, szof); 3979 break; 3980 case COLON: 3981 check_expr_misc(rn, cvctx, ctctx, eq, false, false, szof); 3982 break; 3983 case COMMA: 3984 check_expr_misc(rn, vctx, tctx, eq, false, false, szof); 3985 break; 3986 default: 3987 if (mp->m_binary) 3988 check_expr_misc(rn, true, false, eq, false, false, 3989 szof); 3990 break; 3991 } 3992 3993 } 3994 3995 /* 3996 * Checks the range of array indices, if possible. 3997 * amper is set if only the address of the element is used. This 3998 * means that the index is allowed to refer to the first element 3999 * after the array. 4000 */ 4001 static void 4002 check_array_index(tnode_t *tn, bool amper) 4003 { 4004 int dim; 4005 tnode_t *ln, *rn; 4006 int elsz; 4007 int64_t con; 4008 4009 ln = tn->tn_left; 4010 rn = tn->tn_right; 4011 4012 /* We can only check constant indices. */ 4013 if (rn->tn_op != CON) 4014 return; 4015 4016 /* Return if the left node does not stem from an array. */ 4017 if (ln->tn_op != ADDR) 4018 return; 4019 if (ln->tn_left->tn_op != STRING && ln->tn_left->tn_op != NAME) 4020 return; 4021 if (ln->tn_left->tn_type->t_tspec != ARRAY) 4022 return; 4023 4024 /* 4025 * For incomplete array types, we can print a warning only if 4026 * the index is negative. 4027 */ 4028 if (is_incomplete(ln->tn_left->tn_type) && rn->tn_val->v_quad >= 0) 4029 return; 4030 4031 /* Get the size of one array element */ 4032 if ((elsz = length(ln->tn_type->t_subt, NULL)) == 0) 4033 return; 4034 elsz /= CHAR_SIZE; 4035 4036 /* Change the unit of the index from bytes to element size. */ 4037 if (is_uinteger(rn->tn_type->t_tspec)) { 4038 con = (uint64_t)rn->tn_val->v_quad / elsz; 4039 } else { 4040 con = rn->tn_val->v_quad / elsz; 4041 } 4042 4043 dim = ln->tn_left->tn_type->t_dim + (amper ? 1 : 0); 4044 4045 if (!is_uinteger(rn->tn_type->t_tspec) && con < 0) { 4046 /* array subscript cannot be negative: %ld */ 4047 warning(167, (long)con); 4048 } else if (dim > 0 && (uint64_t)con >= (uint64_t)dim) { 4049 /* array subscript cannot be > %d: %ld */ 4050 warning(168, dim - 1, (long)con); 4051 } 4052 } 4053 4054 /* 4055 * Check for ordered comparisons of unsigned values with 0. 4056 */ 4057 static void 4058 check_integer_comparison(op_t op, tnode_t *ln, tnode_t *rn) 4059 { 4060 tspec_t lt, rt; 4061 4062 lt = ln->tn_type->t_tspec; 4063 rt = rn->tn_type->t_tspec; 4064 4065 if (ln->tn_op != CON && rn->tn_op != CON) 4066 return; 4067 4068 if (!is_integer(lt) || !is_integer(rt)) 4069 return; 4070 4071 if ((hflag || pflag) && lt == CHAR && rn->tn_op == CON && 4072 (rn->tn_val->v_quad < 0 || 4073 rn->tn_val->v_quad > (int)~(~0U << (CHAR_SIZE - 1)))) { 4074 /* nonportable character comparison, op %s */ 4075 warning(230, op_name(op)); 4076 return; 4077 } 4078 if ((hflag || pflag) && rt == CHAR && ln->tn_op == CON && 4079 (ln->tn_val->v_quad < 0 || 4080 ln->tn_val->v_quad > (int)~(~0U << (CHAR_SIZE - 1)))) { 4081 /* nonportable character comparison, op %s */ 4082 warning(230, op_name(op)); 4083 return; 4084 } 4085 if (is_uinteger(lt) && !is_uinteger(rt) && 4086 rn->tn_op == CON && rn->tn_val->v_quad <= 0) { 4087 if (rn->tn_val->v_quad < 0) { 4088 /* comparison of %s with %s, op %s */ 4089 warning(162, type_name(ln->tn_type), 4090 "negative constant", op_name(op)); 4091 } else if (op == LT || op == GE || (hflag && op == LE)) { 4092 /* comparison of %s with %s, op %s */ 4093 warning(162, type_name(ln->tn_type), "0", op_name(op)); 4094 } 4095 return; 4096 } 4097 if (is_uinteger(rt) && !is_uinteger(lt) && 4098 ln->tn_op == CON && ln->tn_val->v_quad <= 0) { 4099 if (ln->tn_val->v_quad < 0) { 4100 /* comparison of %s with %s, op %s */ 4101 warning(162, "negative constant", 4102 type_name(rn->tn_type), op_name(op)); 4103 } else if (op == GT || op == LE || (hflag && op == GE)) { 4104 /* comparison of %s with %s, op %s */ 4105 warning(162, "0", type_name(rn->tn_type), op_name(op)); 4106 } 4107 return; 4108 } 4109 } 4110 4111 /* 4112 * Return whether the expression can be used for static initialization. 4113 * 4114 * Constant initialization expressions must be constant or an address 4115 * of a static object with an optional offset. In the first case, 4116 * the result is returned in *offsp. In the second case, the static 4117 * object is returned in *symp and the offset in *offsp. 4118 * 4119 * The expression can consist of PLUS, MINUS, ADDR, NAME, STRING and 4120 * CON. Type conversions are allowed if they do not change binary 4121 * representation (including width). 4122 * 4123 * C99 6.6 "Constant expressions" 4124 * C99 6.7.8p4 restricts initializers for static storage duration 4125 */ 4126 bool 4127 constant_addr(const tnode_t *tn, const sym_t **symp, ptrdiff_t *offsp) 4128 { 4129 const sym_t *sym; 4130 ptrdiff_t offs1, offs2; 4131 tspec_t t, ot; 4132 4133 switch (tn->tn_op) { 4134 case MINUS: 4135 if (tn->tn_right->tn_op == CVT) 4136 return constant_addr(tn->tn_right, symp, offsp); 4137 else if (tn->tn_right->tn_op != CON) 4138 return false; 4139 /* FALLTHROUGH */ 4140 case PLUS: 4141 offs1 = offs2 = 0; 4142 if (tn->tn_left->tn_op == CON) { 4143 offs1 = (ptrdiff_t)tn->tn_left->tn_val->v_quad; 4144 if (!constant_addr(tn->tn_right, &sym, &offs2)) 4145 return false; 4146 } else if (tn->tn_right->tn_op == CON) { 4147 offs2 = (ptrdiff_t)tn->tn_right->tn_val->v_quad; 4148 if (tn->tn_op == MINUS) 4149 offs2 = -offs2; 4150 if (!constant_addr(tn->tn_left, &sym, &offs1)) 4151 return false; 4152 } else { 4153 return false; 4154 } 4155 *symp = sym; 4156 *offsp = offs1 + offs2; 4157 return true; 4158 case ADDR: 4159 if (tn->tn_left->tn_op == NAME) { 4160 *symp = tn->tn_left->tn_sym; 4161 *offsp = 0; 4162 return true; 4163 } else { 4164 /* 4165 * If this would be the front end of a compiler we 4166 * would return a label instead of 0, at least if 4167 * 'tn->tn_left->tn_op == STRING'. 4168 */ 4169 *symp = NULL; 4170 *offsp = 0; 4171 return true; 4172 } 4173 case CVT: 4174 t = tn->tn_type->t_tspec; 4175 ot = tn->tn_left->tn_type->t_tspec; 4176 if ((!is_integer(t) && t != PTR) || 4177 (!is_integer(ot) && ot != PTR)) { 4178 return false; 4179 } 4180 #ifdef notdef 4181 /* 4182 * consider: 4183 * struct foo { 4184 * unsigned char a; 4185 * } f = { 4186 * (u_char)(u_long)(&(((struct foo *)0)->a)) 4187 * }; 4188 * since psize(u_long) != psize(u_char) this fails. 4189 */ 4190 else if (psize(t) != psize(ot)) 4191 return -1; 4192 #endif 4193 return constant_addr(tn->tn_left, symp, offsp); 4194 default: 4195 return false; 4196 } 4197 } 4198 4199 /* 4200 * Concatenate two string constants. 4201 */ 4202 strg_t * 4203 cat_strings(strg_t *strg1, strg_t *strg2) 4204 { 4205 size_t len1, len2, len; 4206 4207 if (strg1->st_tspec != strg2->st_tspec) { 4208 /* cannot concatenate wide and regular string literals */ 4209 error(292); 4210 return strg1; 4211 } 4212 4213 len1 = strg1->st_len; 4214 len2 = strg2->st_len + 1; /* + NUL */ 4215 len = len1 + len2; 4216 4217 #define COPY(F) \ 4218 do { \ 4219 strg1->F = xrealloc(strg1->F, len * sizeof(*strg1->F)); \ 4220 (void)memcpy(strg1->F + len1, strg2->F, len2 * sizeof(*strg1->F)); \ 4221 free(strg2->F); \ 4222 } while (false) 4223 4224 if (strg1->st_tspec == CHAR) 4225 COPY(st_cp); 4226 else 4227 COPY(st_wcp); 4228 4229 strg1->st_len = len - 1; /* - NUL */ 4230 free(strg2); 4231 4232 return strg1; 4233 } 4234 4235 static bool 4236 is_confusing_precedence(op_t op, op_t lop, bool lparen, op_t rop, bool rparen) 4237 { 4238 4239 if (op == SHL || op == SHR) { 4240 if (!lparen && (lop == PLUS || lop == MINUS)) 4241 return true; 4242 if (!rparen && (rop == PLUS || rop == MINUS)) 4243 return true; 4244 return false; 4245 } 4246 4247 if (op == LOGOR) { 4248 if (!lparen && lop == LOGAND) 4249 return true; 4250 if (!rparen && rop == LOGAND) 4251 return true; 4252 return false; 4253 } 4254 4255 lint_assert(op == BITAND || op == BITXOR || op == BITOR); 4256 if (!lparen && lop != op) { 4257 if (lop == PLUS || lop == MINUS) 4258 return true; 4259 if (lop == BITAND || lop == BITXOR) 4260 return true; 4261 } 4262 if (!rparen && rop != op) { 4263 if (rop == PLUS || rop == MINUS) 4264 return true; 4265 if (rop == BITAND || rop == BITXOR) 4266 return true; 4267 } 4268 return false; 4269 } 4270 4271 /* 4272 * Print a warning if the given node has operands which should be 4273 * parenthesized. 4274 * 4275 * XXX Does not work if an operand is a constant expression. Constant 4276 * expressions are already folded. 4277 */ 4278 static void 4279 check_precedence_confusion(tnode_t *tn) 4280 { 4281 tnode_t *ln, *rn; 4282 4283 if (!hflag) 4284 return; 4285 4286 debug_node(tn, 0); 4287 4288 lint_assert(modtab[tn->tn_op].m_binary); 4289 for (ln = tn->tn_left; ln->tn_op == CVT; ln = ln->tn_left) 4290 continue; 4291 for (rn = tn->tn_right; rn->tn_op == CVT; rn = rn->tn_left) 4292 continue; 4293 4294 if (is_confusing_precedence(tn->tn_op, 4295 ln->tn_op, ln->tn_parenthesized, 4296 rn->tn_op, rn->tn_parenthesized)) { 4297 /* precedence confusion possible: parenthesize! */ 4298 warning(169); 4299 } 4300 } 4301
Indexes created Tue Sep 23 07:09:52 GMT 2025