tree.c revision 1.630
1 /* $NetBSD: tree.c,v 1.630 2024/03/30 16:47:44 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) 40 __RCSID("$NetBSD: tree.c,v 1.630 2024/03/30 16:47:44 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 52 53 typedef struct integer_constraints { 54 int64_t smin; /* signed minimum */ 55 int64_t smax; /* signed maximum */ 56 uint64_t umin; /* unsigned minimum */ 57 uint64_t umax; /* unsigned maximum */ 58 uint64_t bset; /* bits that are definitely set */ 59 uint64_t bclr; /* bits that are definitely clear */ 60 } integer_constraints; 61 62 63 static uint64_t 64 u64_fill_right(uint64_t x) 65 { 66 x |= x >> 1; 67 x |= x >> 2; 68 x |= x >> 4; 69 x |= x >> 8; 70 x |= x >> 16; 71 x |= x >> 32; 72 return x; 73 } 74 75 static bool 76 str_ends_with(const char *haystack, const char *needle) 77 { 78 size_t hlen = strlen(haystack); 79 size_t nlen = strlen(needle); 80 81 return nlen <= hlen && 82 memcmp(haystack + hlen - nlen, needle, nlen) == 0; 83 } 84 85 static unsigned 86 width_in_bits(const type_t *tp) 87 { 88 89 lint_assert(is_integer(tp->t_tspec)); 90 return tp->t_bitfield 91 ? tp->t_bit_field_width 92 : size_in_bits(tp->t_tspec); 93 } 94 95 static int 96 portable_rank_cmp(tspec_t t1, tspec_t t2) 97 { 98 const ttab_t *p1 = type_properties(t1), *p2 = type_properties(t2); 99 lint_assert(p1->tt_rank_kind == p2->tt_rank_kind); 100 lint_assert(p1->tt_rank_value > 0); 101 lint_assert(p2->tt_rank_value > 0); 102 return (int)p1->tt_rank_value - (int)p2->tt_rank_value; 103 } 104 105 static bool 106 ic_maybe_signed(const type_t *tp, const integer_constraints *ic) 107 { 108 return !is_uinteger(tp->t_tspec) && ic->bclr >> 63 == 0; 109 } 110 111 static integer_constraints 112 ic_any(const type_t *tp) 113 { 114 integer_constraints c; 115 116 uint64_t vbits = value_bits(width_in_bits(tp)); 117 if (is_uinteger(tp->t_tspec)) { 118 c.smin = INT64_MIN; 119 c.smax = INT64_MAX; 120 c.umin = 0; 121 c.umax = vbits; 122 c.bset = 0; 123 c.bclr = ~c.umax; 124 } else { 125 c.smin = (int64_t)-1 - (int64_t)(vbits >> 1); 126 c.smax = (int64_t)(vbits >> 1); 127 c.umin = 0; 128 c.umax = UINT64_MAX; 129 c.bset = 0; 130 c.bclr = 0; 131 } 132 return c; 133 } 134 135 static integer_constraints 136 ic_con(const type_t *tp, const val_t *v) 137 { 138 integer_constraints c; 139 140 lint_assert(is_integer(tp->t_tspec)); 141 int64_t si = v->u.integer; 142 uint64_t ui = (uint64_t)si; 143 c.smin = si; 144 c.smax = si; 145 c.umin = ui; 146 c.umax = ui; 147 c.bset = ui; 148 c.bclr = ~ui; 149 return c; 150 } 151 152 static integer_constraints 153 ic_cvt(const type_t *ntp, const type_t *otp, integer_constraints a) 154 { 155 unsigned nw = width_in_bits(ntp); 156 unsigned ow = width_in_bits(otp); 157 bool nu = is_uinteger(ntp->t_tspec); 158 bool ou = is_uinteger(otp->t_tspec); 159 160 if (nw >= ow && nu == ou) 161 return a; 162 if (nw > ow && ou) 163 return a; 164 return ic_any(ntp); 165 } 166 167 static integer_constraints 168 ic_bitand(integer_constraints a, integer_constraints b) 169 { 170 integer_constraints c; 171 172 c.smin = INT64_MIN; 173 c.smax = INT64_MAX; 174 c.umin = 0; 175 c.umax = UINT64_MAX; 176 c.bset = a.bset & b.bset; 177 c.bclr = a.bclr | b.bclr; 178 return c; 179 } 180 181 static integer_constraints 182 ic_bitor(integer_constraints a, integer_constraints b) 183 { 184 integer_constraints c; 185 186 c.smin = INT64_MIN; 187 c.smax = INT64_MAX; 188 c.umin = 0; 189 c.umax = UINT64_MAX; 190 c.bset = a.bset | b.bset; 191 c.bclr = a.bclr & b.bclr; 192 return c; 193 } 194 195 static integer_constraints 196 ic_mod(const type_t *tp, integer_constraints a, integer_constraints b) 197 { 198 integer_constraints c; 199 200 if (ic_maybe_signed(tp, &a) || ic_maybe_signed(tp, &b)) 201 return ic_any(tp); 202 203 c.smin = INT64_MIN; 204 c.smax = INT64_MAX; 205 c.umin = 0; 206 c.umax = b.umax - 1; 207 c.bset = 0; 208 c.bclr = ~u64_fill_right(c.umax); 209 return c; 210 } 211 212 static integer_constraints 213 ic_shl(const type_t *tp, integer_constraints a, integer_constraints b) 214 { 215 integer_constraints c; 216 unsigned int amount; 217 218 if (ic_maybe_signed(tp, &a)) 219 return ic_any(tp); 220 221 if (b.smin == b.smax && b.smin >= 0 && b.smin < 64) 222 amount = (unsigned int)b.smin; 223 else if (b.umin == b.umax && b.umin < 64) 224 amount = (unsigned int)b.umin; 225 else 226 return ic_any(tp); 227 228 c.smin = INT64_MIN; 229 c.smax = INT64_MAX; 230 c.umin = 0; 231 c.umax = UINT64_MAX; 232 c.bset = a.bset << amount; 233 c.bclr = a.bclr << amount | (((uint64_t)1 << amount) - 1); 234 return c; 235 } 236 237 static integer_constraints 238 ic_shr(const type_t *tp, integer_constraints a, integer_constraints b) 239 { 240 integer_constraints c; 241 unsigned int amount; 242 243 if (ic_maybe_signed(tp, &a)) 244 return ic_any(tp); 245 246 if (b.smin == b.smax && b.smin >= 0 && b.smin < 64) 247 amount = (unsigned int)b.smin; 248 else if (b.umin == b.umax && b.umin < 64) 249 amount = (unsigned int)b.umin; 250 else 251 return ic_any(tp); 252 253 c.smin = INT64_MIN; 254 c.smax = INT64_MAX; 255 c.umin = 0; 256 c.umax = UINT64_MAX; 257 c.bset = a.bset >> amount; 258 c.bclr = a.bclr >> amount | ~(~(uint64_t)0 >> amount); 259 return c; 260 } 261 262 static integer_constraints 263 ic_cond(integer_constraints a, integer_constraints b) 264 { 265 integer_constraints c; 266 267 c.smin = a.smin < b.smin ? a.smin : b.smin; 268 c.smax = a.smax > b.smax ? a.smax : b.smax; 269 c.umin = a.umin < b.umin ? a.umin : b.umin; 270 c.umax = a.umax > b.umax ? a.umax : b.umax; 271 c.bset = a.bset | b.bset; 272 c.bclr = a.bclr & b.bclr; 273 return c; 274 } 275 276 static integer_constraints 277 ic_expr(const tnode_t *tn) 278 { 279 integer_constraints lc, rc; 280 281 lint_assert(is_integer(tn->tn_type->t_tspec)); 282 283 switch (tn->tn_op) { 284 case CON: 285 return ic_con(tn->tn_type, &tn->u.value); 286 case CVT: 287 if (!is_integer(tn->u.ops.left->tn_type->t_tspec)) 288 return ic_any(tn->tn_type); 289 lc = ic_expr(tn->u.ops.left); 290 return ic_cvt(tn->tn_type, tn->u.ops.left->tn_type, lc); 291 case MOD: 292 lc = ic_expr(before_conversion(tn->u.ops.left)); 293 rc = ic_expr(before_conversion(tn->u.ops.right)); 294 return ic_mod(tn->tn_type, lc, rc); 295 case SHL: 296 lc = ic_expr(tn->u.ops.left); 297 rc = ic_expr(tn->u.ops.right); 298 return ic_shl(tn->tn_type, lc, rc); 299 case SHR: 300 lc = ic_expr(tn->u.ops.left); 301 rc = ic_expr(tn->u.ops.right); 302 return ic_shr(tn->tn_type, lc, rc); 303 case BITAND: 304 lc = ic_expr(tn->u.ops.left); 305 rc = ic_expr(tn->u.ops.right); 306 return ic_bitand(lc, rc); 307 case BITOR: 308 lc = ic_expr(tn->u.ops.left); 309 rc = ic_expr(tn->u.ops.right); 310 return ic_bitor(lc, rc); 311 case QUEST: 312 lc = ic_expr(tn->u.ops.right->u.ops.left); 313 rc = ic_expr(tn->u.ops.right->u.ops.right); 314 return ic_cond(lc, rc); 315 default: 316 return ic_any(tn->tn_type); 317 } 318 } 319 320 uint64_t 321 possible_bits(const tnode_t *tn) 322 { 323 return ~ic_expr(tn).bclr; 324 } 325 326 /* Build 'pointer to tp', 'array of tp' or 'function returning tp'. */ 327 type_t * 328 block_derive_type(type_t *tp, tspec_t t) 329 { 330 331 type_t *tp2 = block_zero_alloc(sizeof(*tp2), "type"); 332 tp2->t_tspec = t; 333 tp2->t_subt = tp; 334 return tp2; 335 } 336 337 /* 338 * Derive 'pointer to tp' or 'function returning tp'. 339 * The memory is freed at the end of the current expression. 340 */ 341 type_t * 342 expr_derive_type(type_t *tp, tspec_t t) 343 { 344 345 type_t *tp2 = expr_zero_alloc(sizeof(*tp2), "type"); 346 tp2->t_tspec = t; 347 tp2->t_subt = tp; 348 return tp2; 349 } 350 351 /* Create an expression from a unary or binary operator and its operands. */ 352 static tnode_t * 353 build_op(op_t op, bool sys, type_t *type, tnode_t *ln, tnode_t *rn) 354 { 355 356 tnode_t *ntn = expr_alloc_tnode(); 357 ntn->tn_op = op; 358 ntn->tn_type = type; 359 ntn->tn_sys = sys; 360 ntn->u.ops.left = ln; 361 ntn->u.ops.right = rn; 362 363 if (op == INDIR || op == FSEL) { 364 lint_assert(ln->tn_type->t_tspec == PTR); 365 tspec_t t = ln->tn_type->t_subt->t_tspec; 366 ntn->tn_lvalue = t != FUNC && t != VOID; 367 } 368 369 return ntn; 370 } 371 372 tnode_t * 373 build_constant(type_t *tp, val_t *v) 374 { 375 376 tnode_t *n = expr_alloc_tnode(); 377 n->tn_op = CON; 378 n->tn_type = tp; 379 n->u.value = *v; 380 n->u.value.v_tspec = tp->t_tspec; 381 free(v); 382 return n; 383 } 384 385 static tnode_t * 386 build_integer_constant(tspec_t t, int64_t si) 387 { 388 389 tnode_t *n = expr_alloc_tnode(); 390 n->tn_op = CON; 391 n->tn_type = gettyp(t); 392 n->u.value.v_tspec = t; 393 n->u.value.v_unsigned_since_c90 = false; 394 n->u.value.v_char_constant = false; 395 n->u.value.u.integer = si; 396 return n; 397 } 398 399 static void 400 fallback_symbol(sym_t *sym) 401 { 402 403 if (Tflag && fallback_symbol_strict_bool(sym)) 404 return; 405 406 if (block_level > 0 && (strcmp(sym->s_name, "__FUNCTION__") == 0 || 407 strcmp(sym->s_name, "__PRETTY_FUNCTION__") == 0)) { 408 /* __FUNCTION__/__PRETTY_FUNCTION__ is a GCC extension */ 409 gnuism(316); 410 // XXX: Should probably be ARRAY instead of PTR. 411 sym->s_type = block_derive_type(gettyp(CHAR), PTR); 412 sym->s_type->t_const = true; 413 return; 414 } 415 416 if (funcsym != NULL && strcmp(sym->s_name, "__func__") == 0) { 417 if (!allow_c99) 418 /* __func__ is a C99 feature */ 419 warning(317); 420 /* C11 6.4.2.2 */ 421 sym->s_type = block_derive_type(gettyp(CHAR), ARRAY); 422 sym->s_type->t_const = true; 423 sym->s_type->u.dimension = (int)strlen(funcsym->s_name) + 1; 424 return; 425 } 426 427 /* '%s' undefined */ 428 error(99, sym->s_name); 429 } 430 431 /* 432 * Functions that are predeclared by GCC or other compilers can be called 433 * with arbitrary arguments. Since lint usually runs after a successful 434 * compilation, it's the compiler's job to catch any errors. 435 */ 436 bool 437 is_compiler_builtin(const char *name) 438 { 439 /* https://gcc.gnu.org/onlinedocs/gcc/C-Extensions.html */ 440 if (allow_gcc) { 441 if (strncmp(name, "__atomic_", 9) == 0 || 442 strncmp(name, "__builtin_", 10) == 0 || 443 strcmp(name, "alloca") == 0 || 444 /* obsolete but still in use, as of 2021 */ 445 strncmp(name, "__sync_", 7) == 0) 446 return true; 447 } 448 449 /* https://software.intel.com/sites/landingpage/IntrinsicsGuide/ */ 450 if (strncmp(name, "_mm_", 4) == 0) 451 return true; 452 453 return false; 454 } 455 456 /* https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins.html */ 457 static bool 458 is_gcc_bool_builtin(const char *name) 459 { 460 return strncmp(name, "__builtin_", 10) == 0 && 461 (str_ends_with(name, "_overflow") || 462 str_ends_with(name, "_overflow_p")); 463 } 464 465 static void 466 build_name_call(sym_t *sym) 467 { 468 469 if (is_compiler_builtin(sym->s_name)) { 470 /* 471 * Do not warn about these, just assume that they are regular 472 * functions compatible with non-prototype calling conventions. 473 */ 474 if (allow_gcc && is_gcc_bool_builtin(sym->s_name)) 475 sym->s_type = gettyp(BOOL); 476 } else if (allow_c99) 477 /* function '%s' implicitly declared to return int */ 478 error(215, sym->s_name); 479 else if (!allow_trad) 480 /* function '%s' implicitly declared to return int */ 481 warning(215, sym->s_name); 482 483 /* XXX if !allow_c90, the symbol should be exported to level 0 */ 484 sym->s_type = block_derive_type(sym->s_type, FUNC); 485 } 486 487 /* Create a node for a name (symbol table entry). */ 488 tnode_t * 489 build_name(sym_t *sym, bool is_funcname) 490 { 491 492 if (sym->s_scl == NO_SCL && !in_gcc_attribute) { 493 sym->s_scl = EXTERN; 494 sym->s_def = DECL; 495 if (is_funcname) 496 build_name_call(sym); 497 else 498 fallback_symbol(sym); 499 } 500 501 lint_assert(sym->s_kind == SK_VCFT || sym->s_kind == SK_MEMBER); 502 503 tnode_t *n = expr_alloc_tnode(); 504 n->tn_type = sym->s_type; 505 if (sym->s_scl == BOOL_CONST) { 506 n->tn_op = CON; 507 n->u.value.v_tspec = BOOL; 508 n->u.value.v_unsigned_since_c90 = false; 509 n->u.value.v_char_constant = false; 510 n->u.value.u.integer = sym->u.s_bool_constant ? 1 : 0; 511 } else if (sym->s_scl == ENUM_CONST) { 512 n->tn_op = CON; 513 n->u.value.v_tspec = INT; /* ENUM is in n->tn_type */ 514 n->u.value.v_unsigned_since_c90 = false; 515 n->u.value.v_char_constant = false; 516 n->u.value.u.integer = sym->u.s_enum_constant; 517 } else { 518 n->tn_op = NAME; 519 n->u.sym = sym; 520 if (sym->s_kind == SK_VCFT && sym->s_type->t_tspec != FUNC) 521 n->tn_lvalue = true; 522 } 523 524 return n; 525 } 526 527 tnode_t * 528 build_string(buffer *lit) 529 { 530 size_t value_len = lit->len; 531 if (lit->data != NULL) { 532 quoted_iterator it = { .end = 0 }; 533 for (value_len = 0; quoted_next(lit, &it); value_len++) 534 continue; 535 } 536 537 type_t *tp = expr_zero_alloc(sizeof(*tp), "type"); 538 tp->t_tspec = ARRAY; 539 tp->t_subt = gettyp(lit->data != NULL ? CHAR : WCHAR_TSPEC); 540 tp->u.dimension = (int)(value_len + 1); 541 542 tnode_t *n = expr_alloc_tnode(); 543 n->tn_op = STRING; 544 n->tn_type = tp; 545 n->tn_lvalue = true; 546 547 n->u.str_literals = expr_zero_alloc(sizeof(*n->u.str_literals), "tnode.string"); 548 n->u.str_literals->len = lit->len; 549 550 if (lit->data != NULL) { 551 n->u.str_literals->data = expr_zero_alloc(lit->len + 1, 552 "tnode.string.data"); 553 (void)memcpy(n->u.str_literals->data, lit->data, lit->len + 1); 554 free(lit->data); 555 } 556 free(lit); 557 558 return n; 559 } 560 561 tnode_t * 562 build_generic_selection(const tnode_t *expr, 563 struct generic_association *sel) 564 { 565 tnode_t *default_result = NULL; 566 567 for (; sel != NULL; sel = sel->ga_prev) { 568 if (expr != NULL && 569 types_compatible(sel->ga_arg, expr->tn_type, 570 false, false, NULL)) 571 return sel->ga_result; 572 else if (sel->ga_arg == NULL) 573 default_result = sel->ga_result; 574 } 575 return default_result; 576 } 577 578 static bool 579 is_out_of_char_range(const tnode_t *tn) 580 { 581 return tn->tn_op == CON && 582 !tn->u.value.v_char_constant && 583 !(0 <= tn->u.value.u.integer && 584 tn->u.value.u.integer < 1 << (CHAR_SIZE - 1)); 585 } 586 587 static bool 588 check_nonportable_char_comparison(op_t op, 589 const tnode_t *ln, tspec_t lt, 590 const tnode_t *rn, tspec_t rt) 591 { 592 if (!(hflag || pflag)) 593 return true; 594 595 if (lt == CHAR && is_out_of_char_range(rn)) { 596 char buf[128]; 597 (void)snprintf(buf, sizeof(buf), "%s %d", 598 op_name(op), (int)rn->u.value.u.integer); 599 /* nonportable character comparison '%s' */ 600 warning(230, buf); 601 return false; 602 } 603 if (rt == CHAR && is_out_of_char_range(ln)) { 604 char buf[128]; 605 (void)snprintf(buf, sizeof(buf), "%d %s ?", 606 (int)ln->u.value.u.integer, op_name(op)); 607 /* nonportable character comparison '%s' */ 608 warning(230, buf); 609 return false; 610 } 611 return true; 612 } 613 614 static void 615 check_integer_comparison(op_t op, tnode_t *ln, tnode_t *rn) 616 { 617 618 tspec_t lt = ln->tn_type->t_tspec; 619 tspec_t rt = rn->tn_type->t_tspec; 620 621 if (ln->tn_op != CON && rn->tn_op != CON) 622 return; 623 624 if (!is_integer(lt) || !is_integer(rt)) 625 return; 626 627 if (any_query_enabled && !in_system_header) { 628 if (lt == CHAR && rn->tn_op == CON && 629 !rn->u.value.v_char_constant) { 630 /* comparison '%s' of 'char' with plain integer %d */ 631 query_message(14, 632 op_name(op), (int)rn->u.value.u.integer); 633 } 634 if (rt == CHAR && ln->tn_op == CON && 635 !ln->u.value.v_char_constant) { 636 /* comparison '%s' of 'char' with plain integer %d */ 637 query_message(14, 638 op_name(op), (int)ln->u.value.u.integer); 639 } 640 } 641 642 if (!check_nonportable_char_comparison(op, ln, lt, rn, rt)) 643 return; 644 645 if (is_uinteger(lt) && !is_uinteger(rt) && 646 rn->tn_op == CON && rn->u.value.u.integer <= 0) { 647 if (rn->u.value.u.integer < 0) { 648 /* operator '%s' compares '%s' with '%s' */ 649 warning(162, op_name(op), 650 type_name(ln->tn_type), "negative constant"); 651 } else if (op == LT || op == GE) 652 /* operator '%s' compares '%s' with '%s' */ 653 warning(162, op_name(op), type_name(ln->tn_type), "0"); 654 return; 655 } 656 if (is_uinteger(rt) && !is_uinteger(lt) && 657 ln->tn_op == CON && ln->u.value.u.integer <= 0) { 658 if (ln->u.value.u.integer < 0) { 659 /* operator '%s' compares '%s' with '%s' */ 660 warning(162, op_name(op), 661 "negative constant", type_name(rn->tn_type)); 662 } else if (op == GT || op == LE) 663 /* operator '%s' compares '%s' with '%s' */ 664 warning(162, op_name(op), "0", type_name(rn->tn_type)); 665 return; 666 } 667 } 668 669 static const tspec_t arith_rank[] = { 670 LDOUBLE, DOUBLE, FLOAT, 671 #ifdef INT128_SIZE 672 UINT128, INT128, 673 #endif 674 ULLONG, LLONG, 675 ULONG, LONG, 676 UINT, INT, 677 }; 678 679 /* Keep unsigned in traditional C */ 680 static tspec_t 681 usual_arithmetic_conversion_trad(tspec_t lt, tspec_t rt) 682 { 683 684 size_t i; 685 for (i = 0; arith_rank[i] != INT; i++) 686 if (lt == arith_rank[i] || rt == arith_rank[i]) 687 break; 688 689 tspec_t t = arith_rank[i]; 690 if (is_uinteger(lt) || is_uinteger(rt)) 691 if (is_integer(t) && !is_uinteger(t)) 692 return unsigned_type(t); 693 return t; 694 } 695 696 static tspec_t 697 usual_arithmetic_conversion_c90(tspec_t lt, tspec_t rt) 698 { 699 700 if (lt == rt) 701 return lt; 702 703 if (lt == LCOMPLEX || rt == LCOMPLEX) 704 return LCOMPLEX; 705 if (lt == DCOMPLEX || rt == DCOMPLEX) 706 return DCOMPLEX; 707 if (lt == FCOMPLEX || rt == FCOMPLEX) 708 return FCOMPLEX; 709 if (lt == LDOUBLE || rt == LDOUBLE) 710 return LDOUBLE; 711 if (lt == DOUBLE || rt == DOUBLE) 712 return DOUBLE; 713 if (lt == FLOAT || rt == FLOAT) 714 return FLOAT; 715 716 if (size_in_bits(lt) > size_in_bits(rt)) 717 return lt; 718 if (size_in_bits(lt) < size_in_bits(rt)) 719 return rt; 720 721 size_t i; 722 for (i = 3; arith_rank[i] != INT; i++) 723 if (arith_rank[i] == lt || arith_rank[i] == rt) 724 break; 725 if ((is_uinteger(lt) || is_uinteger(rt)) && 726 !is_uinteger(arith_rank[i])) 727 i--; 728 return arith_rank[i]; 729 } 730 731 static tnode_t * 732 apply_usual_arithmetic_conversions(op_t op, tnode_t *tn, tspec_t t) 733 { 734 type_t *ntp = expr_dup_type(tn->tn_type); 735 ntp->t_tspec = t; 736 if (tn->tn_op != CON) { 737 /* usual arithmetic conversion for '%s' from '%s' to '%s' */ 738 query_message(4, op_name(op), 739 type_name(tn->tn_type), type_name(ntp)); 740 } 741 return convert(op, 0, ntp, tn); 742 } 743 744 /* 745 * Apply the "usual arithmetic conversions" (C99 6.3.1.8), which gives both 746 * operands the same type. 747 */ 748 static void 749 balance(op_t op, tnode_t **lnp, tnode_t **rnp) 750 { 751 752 tspec_t lt = (*lnp)->tn_type->t_tspec; 753 tspec_t rt = (*rnp)->tn_type->t_tspec; 754 if (!is_arithmetic(lt) || !is_arithmetic(rt)) 755 return; 756 757 tspec_t t = allow_c90 758 ? usual_arithmetic_conversion_c90(lt, rt) 759 : usual_arithmetic_conversion_trad(lt, rt); 760 761 if (t != lt) 762 *lnp = apply_usual_arithmetic_conversions(op, *lnp, t); 763 if (t != rt) 764 *rnp = apply_usual_arithmetic_conversions(op, *rnp, t); 765 766 unsigned lw = (*lnp)->tn_type->t_bit_field_width; 767 unsigned rw = (*rnp)->tn_type->t_bit_field_width; 768 if (lw < rw) 769 *lnp = convert(NOOP, 0, (*rnp)->tn_type, *lnp); 770 if (rw < lw) 771 *rnp = convert(NOOP, 0, (*lnp)->tn_type, *rnp); 772 } 773 774 static tnode_t * 775 build_address(bool sys, tnode_t *tn, bool force) 776 { 777 tspec_t t; 778 779 if (!force && ((t = tn->tn_type->t_tspec) == ARRAY || t == FUNC)) { 780 if (!allow_c90) 781 /* '&' before array or function: ignored */ 782 warning(127); 783 return tn; 784 } 785 786 /* eliminate '&*' */ 787 if (tn->tn_op == INDIR && 788 tn->u.ops.left->tn_type->t_tspec == PTR && 789 tn->u.ops.left->tn_type->t_subt == tn->tn_type) { 790 return tn->u.ops.left; 791 } 792 793 return build_op(ADDR, sys, expr_derive_type(tn->tn_type, PTR), 794 tn, NULL); 795 } 796 797 static uint64_t 798 fold_unsigned_integer(op_t op, uint64_t l, uint64_t r, 799 uint64_t max_value, bool *overflow) 800 { 801 switch (op) { 802 case COMPL: 803 return ~l & max_value; 804 case UPLUS: 805 return +l; 806 case UMINUS: 807 return -l & max_value; 808 case MULT: 809 *overflow = r > 0 && l > max_value / r; 810 return l * r; 811 case DIV: 812 if (r == 0) { 813 /* division by 0 */ 814 error(139); 815 return max_value; 816 } 817 return l / r; 818 case MOD: 819 if (r == 0) { 820 /* modulus by 0 */ 821 error(140); 822 return 0; 823 } 824 return l % r; 825 case PLUS: 826 *overflow = l > max_value - r; 827 return l + r; 828 case MINUS: 829 *overflow = l < r; 830 return l - r; 831 case SHL: 832 /* TODO: warn about out-of-bounds 'r'. */ 833 /* TODO: warn about overflow. */ 834 return l << (r & 63); 835 case SHR: 836 /* TODO: warn about out-of-bounds 'r'. */ 837 return l >> (r & 63); 838 case LT: 839 return l < r ? 1 : 0; 840 case LE: 841 return l <= r ? 1 : 0; 842 case GT: 843 return l > r ? 1 : 0; 844 case GE: 845 return l >= r ? 1 : 0; 846 case EQ: 847 return l == r ? 1 : 0; 848 case NE: 849 return l != r ? 1 : 0; 850 case BITAND: 851 return l & r; 852 case BITXOR: 853 return l ^ r; 854 case BITOR: 855 return l | r; 856 default: 857 lint_assert(/*CONSTCOND*/false); 858 /* NOTREACHED */ 859 } 860 } 861 862 static int64_t 863 fold_signed_integer(op_t op, int64_t l, int64_t r, 864 int64_t min_value, int64_t max_value, bool *overflow) 865 { 866 switch (op) { 867 case COMPL: 868 return ~l; 869 case UPLUS: 870 return +l; 871 case UMINUS: 872 *overflow = l == min_value; 873 return *overflow ? l : -l; 874 case MULT:; 875 uint64_t al = l >= 0 ? (uint64_t)l : -(uint64_t)l; 876 uint64_t ar = r >= 0 ? (uint64_t)r : -(uint64_t)r; 877 bool neg = (l >= 0) != (r >= 0); 878 uint64_t max_prod = (uint64_t)max_value + (neg ? 1 : 0); 879 if (al > 0 && ar > max_prod / al) { 880 *overflow = true; 881 return neg ? min_value : max_value; 882 } 883 return l * r; 884 case DIV: 885 if (r == 0) { 886 /* division by 0 */ 887 error(139); 888 return max_value; 889 } 890 if (l == min_value && r == -1) { 891 *overflow = true; 892 return l; 893 } 894 return l / r; 895 case MOD: 896 if (r == 0) { 897 /* modulus by 0 */ 898 error(140); 899 return 0; 900 } 901 if (l == min_value && r == -1) { 902 *overflow = true; 903 return 0; 904 } 905 return l % r; 906 case PLUS: 907 if (r > 0 && l > max_value - r) { 908 *overflow = true; 909 return max_value; 910 } 911 if (r < 0 && l < min_value - r) { 912 *overflow = true; 913 return min_value; 914 } 915 return l + r; 916 case MINUS: 917 if (r > 0 && l < min_value + r) { 918 *overflow = true; 919 return min_value; 920 } 921 if (r < 0 && l > max_value + r) { 922 *overflow = true; 923 return max_value; 924 } 925 return l - r; 926 case SHL: 927 /* TODO: warn about out-of-bounds 'r'. */ 928 /* TODO: warn about overflow. */ 929 return l << (r & 63); 930 case SHR: 931 /* TODO: warn about out-of-bounds 'r'. */ 932 if (l < 0) 933 return (int64_t)~(~(uint64_t)l >> (r & 63)); 934 return (int64_t)((uint64_t)l >> (r & 63)); 935 case LT: 936 return l < r ? 1 : 0; 937 case LE: 938 return l <= r ? 1 : 0; 939 case GT: 940 return l > r ? 1 : 0; 941 case GE: 942 return l >= r ? 1 : 0; 943 case EQ: 944 return l == r ? 1 : 0; 945 case NE: 946 return l != r ? 1 : 0; 947 case BITAND: 948 return l & r; 949 case BITXOR: 950 return l ^ r; 951 case BITOR: 952 return l | r; 953 default: 954 lint_assert(/*CONSTCOND*/false); 955 /* NOTREACHED */ 956 } 957 } 958 959 static tnode_t * 960 fold_constant_integer(tnode_t *tn) 961 { 962 963 lint_assert(has_operands(tn)); 964 tspec_t t = tn->u.ops.left->tn_type->t_tspec; 965 int64_t l = tn->u.ops.left->u.value.u.integer; 966 int64_t r = is_binary(tn) ? tn->u.ops.right->u.value.u.integer : 0; 967 uint64_t mask = value_bits(size_in_bits(t)); 968 969 int64_t res; 970 bool overflow = false; 971 if (!is_integer(t) || is_uinteger(t)) { 972 uint64_t u_res = fold_unsigned_integer(tn->tn_op, 973 (uint64_t)l, (uint64_t)r, mask, &overflow); 974 if (u_res > mask) 975 overflow = true; 976 res = (int64_t)u_res; 977 if (overflow && hflag) { 978 char buf[128]; 979 if (is_binary(tn)) { 980 snprintf(buf, sizeof(buf), "%ju %s %ju", 981 (uintmax_t)l, op_name(tn->tn_op), 982 (uintmax_t)r); 983 } else { 984 snprintf(buf, sizeof(buf), "%s%ju", 985 op_name(tn->tn_op), (uintmax_t)l); 986 } 987 /* '%s' overflows '%s' */ 988 warning(141, buf, type_name(tn->tn_type)); 989 } 990 } else { 991 int64_t max_value = (int64_t)(mask >> 1); 992 int64_t min_value = -max_value - 1; 993 res = fold_signed_integer(tn->tn_op, 994 l, r, min_value, max_value, &overflow); 995 if (res < min_value || res > max_value) 996 overflow = true; 997 if (overflow && hflag) { 998 char buf[128]; 999 if (is_binary(tn)) { 1000 snprintf(buf, sizeof(buf), "%jd %s %jd", 1001 (intmax_t)l, op_name(tn->tn_op), 1002 (intmax_t)r); 1003 } else if (tn->tn_op == UMINUS && l < 0) { 1004 snprintf(buf, sizeof(buf), "-(%jd)", 1005 (intmax_t)l); 1006 } else { 1007 snprintf(buf, sizeof(buf), "%s%jd", 1008 op_name(tn->tn_op), (intmax_t)l); 1009 } 1010 /* '%s' overflows '%s' */ 1011 warning(141, buf, type_name(tn->tn_type)); 1012 } 1013 } 1014 1015 val_t *v = xcalloc(1, sizeof(*v)); 1016 v->v_tspec = tn->tn_type->t_tspec; 1017 v->u.integer = convert_integer(res, t, size_in_bits(t)); 1018 1019 tnode_t *cn = build_constant(tn->tn_type, v); 1020 if (tn->u.ops.left->tn_system_dependent) 1021 cn->tn_system_dependent = true; 1022 if (is_binary(tn) && tn->u.ops.right->tn_system_dependent) 1023 cn->tn_system_dependent = true; 1024 1025 return cn; 1026 } 1027 1028 static tnode_t * 1029 build_struct_access(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 1030 { 1031 1032 lint_assert(rn->tn_op == NAME); 1033 lint_assert(is_member(rn->u.sym)); 1034 1035 bool lvalue = op == ARROW || ln->tn_lvalue; 1036 1037 if (op == POINT) 1038 ln = build_address(sys, ln, true); 1039 else if (ln->tn_type->t_tspec != PTR) { 1040 lint_assert(!allow_c90); 1041 lint_assert(is_integer(ln->tn_type->t_tspec)); 1042 ln = convert(NOOP, 0, expr_derive_type(gettyp(VOID), PTR), ln); 1043 } 1044 1045 tnode_t *ctn = build_integer_constant(PTRDIFF_TSPEC, 1046 rn->u.sym->u.s_member.sm_offset_in_bits / CHAR_SIZE); 1047 1048 type_t *ptr_tp = expr_derive_type(rn->tn_type, PTR); 1049 tnode_t *ntn = build_op(PLUS, sys, ptr_tp, ln, ctn); 1050 if (ln->tn_op == CON) 1051 ntn = fold_constant_integer(ntn); 1052 1053 op_t nop = rn->tn_type->t_bitfield ? FSEL : INDIR; 1054 ntn = build_op(nop, sys, ntn->tn_type->t_subt, ntn, NULL); 1055 if (!lvalue) 1056 ntn->tn_lvalue = false; 1057 1058 return ntn; 1059 } 1060 1061 /* 1062 * Get the size in bytes of type tp->t_subt, as a constant expression of type 1063 * ptrdiff_t as seen from the target platform. 1064 */ 1065 static tnode_t * 1066 subt_size_in_bytes(type_t *tp) 1067 { 1068 1069 lint_assert(tp->t_tspec == PTR); 1070 tp = tp->t_subt; 1071 1072 int elem = 1; 1073 while (tp->t_tspec == ARRAY) { 1074 elem *= tp->u.dimension; 1075 tp = tp->t_subt; 1076 } 1077 1078 int elsz_in_bits = 0; 1079 switch (tp->t_tspec) { 1080 case FUNC: 1081 /* pointer to function is not allowed here */ 1082 error(110); 1083 break; 1084 case VOID: 1085 /* cannot do pointer arithmetic on operand of unknown size */ 1086 gnuism(136); 1087 break; 1088 case STRUCT: 1089 case UNION: 1090 if ((elsz_in_bits = (int)tp->u.sou->sou_size_in_bits) == 0) 1091 /* cannot do pointer arithmetic on operand of ... */ 1092 error(136); 1093 break; 1094 case ENUM: 1095 if (is_incomplete(tp)) 1096 /* cannot do pointer arithmetic on operand of ... */ 1097 warning(136); 1098 /* FALLTHROUGH */ 1099 default: 1100 if ((elsz_in_bits = size_in_bits(tp->t_tspec)) == 0) 1101 /* cannot do pointer arithmetic on operand of ... */ 1102 error(136); 1103 else 1104 lint_assert(elsz_in_bits != -1); 1105 break; 1106 } 1107 1108 if (elem == 0 && elsz_in_bits != 0) 1109 /* cannot do pointer arithmetic on operand of unknown size */ 1110 error(136); 1111 1112 if (elsz_in_bits == 0) 1113 elsz_in_bits = CHAR_SIZE; 1114 1115 return build_integer_constant(PTRDIFF_TSPEC, 1116 (int64_t)(elem * elsz_in_bits / CHAR_SIZE)); 1117 } 1118 1119 static tnode_t * 1120 build_prepost_incdec(op_t op, bool sys, tnode_t *ln) 1121 { 1122 1123 lint_assert(ln != NULL); 1124 tnode_t *cn = ln->tn_type->t_tspec == PTR 1125 ? subt_size_in_bytes(ln->tn_type) 1126 : build_integer_constant(INT, 1); 1127 return build_op(op, sys, ln->tn_type, ln, cn); 1128 } 1129 1130 static void 1131 check_enum_array_index(const tnode_t *ln, const tnode_t *rn) 1132 { 1133 1134 if (ln->tn_op != ADDR || ln->u.ops.left->tn_op != NAME) 1135 return; 1136 1137 const type_t *ltp = ln->u.ops.left->tn_type; 1138 if (ltp->t_tspec != ARRAY || ltp->t_incomplete_array) 1139 return; 1140 1141 if (rn->tn_op != CVT || !rn->tn_type->t_is_enum) 1142 return; 1143 if (rn->u.ops.left->tn_op != LOAD) 1144 return; 1145 1146 const type_t *rtp = rn->u.ops.left->tn_type; 1147 const sym_t *ec = rtp->u.enumer->en_first_enumerator; 1148 const sym_t *max_ec = ec; 1149 lint_assert(ec != NULL); 1150 for (ec = ec->s_next; ec != NULL; ec = ec->s_next) 1151 if (ec->u.s_enum_constant > max_ec->u.s_enum_constant) 1152 max_ec = ec; 1153 1154 int64_t max_enum_value = max_ec->u.s_enum_constant; 1155 lint_assert(INT_MIN <= max_enum_value && max_enum_value <= INT_MAX); 1156 1157 int max_array_index = ltp->u.dimension - 1; 1158 if (max_enum_value == max_array_index) 1159 return; 1160 1161 if (max_enum_value == max_array_index + 1 && 1162 (strstr(max_ec->s_name, "MAX") != NULL || 1163 strstr(max_ec->s_name, "max") != NULL || 1164 strstr(max_ec->s_name, "NUM") != NULL || 1165 strstr(max_ec->s_name, "num") != NULL)) 1166 return; 1167 1168 /* maximum value %d of '%s' does not match maximum array index %d */ 1169 warning(348, (int)max_enum_value, type_name(rtp), max_array_index); 1170 print_previous_declaration(max_ec); 1171 } 1172 1173 static tnode_t * 1174 build_plus_minus(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 1175 { 1176 1177 if (rn->tn_type->t_tspec == PTR && is_integer(ln->tn_type->t_tspec)) { 1178 tnode_t *tmp = ln; 1179 ln = rn; 1180 rn = tmp; 1181 /* pointer addition has integer on the left-hand side */ 1182 query_message(5); 1183 } 1184 1185 /* pointer +- integer */ 1186 if (ln->tn_type->t_tspec == PTR && rn->tn_type->t_tspec != PTR) { 1187 lint_assert(is_integer(rn->tn_type->t_tspec)); 1188 1189 check_ctype_macro_invocation(ln, rn); 1190 check_enum_array_index(ln, rn); 1191 1192 tnode_t *elsz = subt_size_in_bytes(ln->tn_type); 1193 if (rn->tn_type->t_tspec != elsz->tn_type->t_tspec) 1194 rn = convert(NOOP, 0, elsz->tn_type, rn); 1195 1196 tnode_t *prod = build_op(MULT, sys, rn->tn_type, rn, elsz); 1197 if (rn->tn_op == CON) 1198 prod = fold_constant_integer(prod); 1199 1200 return build_op(op, sys, ln->tn_type, ln, prod); 1201 } 1202 1203 /* pointer - pointer */ 1204 if (rn->tn_type->t_tspec == PTR) { 1205 lint_assert(ln->tn_type->t_tspec == PTR); 1206 lint_assert(op == MINUS); 1207 1208 type_t *ptrdiff = gettyp(PTRDIFF_TSPEC); 1209 tnode_t *raw_diff = build_op(op, sys, ptrdiff, ln, rn); 1210 if (ln->tn_op == CON && rn->tn_op == CON) 1211 raw_diff = fold_constant_integer(raw_diff); 1212 1213 tnode_t *elsz = subt_size_in_bytes(ln->tn_type); 1214 balance(NOOP, &raw_diff, &elsz); 1215 1216 return build_op(DIV, sys, ptrdiff, raw_diff, elsz); 1217 } 1218 1219 return build_op(op, sys, ln->tn_type, ln, rn); 1220 } 1221 1222 static tnode_t * 1223 build_bit_shift(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 1224 { 1225 1226 if (!allow_c90 && rn->tn_type->t_tspec != INT) 1227 // XXX: C1978 7.5 says: "Both [operators] perform the usual 1228 // arithmetic conversions on their operands." 1229 // TODO: Add a test to exercise this part of the code. 1230 rn = convert(NOOP, 0, gettyp(INT), rn); 1231 return build_op(op, sys, ln->tn_type, ln, rn); 1232 } 1233 1234 static bool 1235 is_null_pointer(const tnode_t *tn) 1236 { 1237 tspec_t t = tn->tn_type->t_tspec; 1238 1239 // TODO: Investigate how other pointers are stored, in particular, 1240 // whether a pointer constant can have a non-zero value. 1241 // If not, simplify the code below. 1242 return ((t == PTR && tn->tn_type->t_subt->t_tspec == VOID) 1243 || is_integer(t)) 1244 && (tn->tn_op == CON && tn->u.value.u.integer == 0); 1245 } 1246 1247 /* Return a type based on tp1, with added qualifiers from tp2. */ 1248 static type_t * 1249 merge_qualifiers(type_t *tp1, const type_t *tp2) 1250 { 1251 1252 lint_assert(tp1->t_tspec == PTR); 1253 lint_assert(tp2->t_tspec == PTR); 1254 1255 bool c1 = tp1->t_subt->t_const; 1256 bool c2 = tp2->t_subt->t_const; 1257 bool v1 = tp1->t_subt->t_volatile; 1258 bool v2 = tp2->t_subt->t_volatile; 1259 1260 if (c1 == (c1 | c2) && v1 == (v1 | v2)) 1261 return tp1; 1262 1263 type_t *nstp = expr_dup_type(tp1->t_subt); 1264 nstp->t_const |= c2; 1265 nstp->t_volatile |= v2; 1266 1267 type_t *ntp = expr_dup_type(tp1); 1268 ntp->t_subt = nstp; 1269 return ntp; 1270 } 1271 1272 /* See C99 6.5.15 "Conditional operator". */ 1273 static tnode_t * 1274 build_colon(bool sys, tnode_t *ln, tnode_t *rn) 1275 { 1276 tspec_t lt = ln->tn_type->t_tspec; 1277 tspec_t rt = rn->tn_type->t_tspec; 1278 1279 type_t *tp; 1280 if (is_arithmetic(lt) && is_arithmetic(rt)) 1281 /* The operands were already balanced in build_binary. */ 1282 tp = ln->tn_type; 1283 else if (lt == BOOL && rt == BOOL) 1284 tp = ln->tn_type; 1285 else if (lt == VOID || rt == VOID) 1286 tp = gettyp(VOID); 1287 else if (is_struct_or_union(lt)) { 1288 lint_assert(is_struct_or_union(rt)); 1289 lint_assert(ln->tn_type->u.sou == rn->tn_type->u.sou); 1290 if (is_incomplete(ln->tn_type)) { 1291 /* unknown operand size, op '%s' */ 1292 error(138, op_name(COLON)); 1293 return NULL; 1294 } 1295 tp = ln->tn_type; 1296 } else if (lt == PTR && is_integer(rt)) { 1297 if (rt != PTRDIFF_TSPEC) 1298 rn = convert(NOOP, 0, gettyp(PTRDIFF_TSPEC), rn); 1299 tp = ln->tn_type; 1300 } else if (rt == PTR && is_integer(lt)) { 1301 if (lt != PTRDIFF_TSPEC) 1302 ln = convert(NOOP, 0, gettyp(PTRDIFF_TSPEC), ln); 1303 tp = rn->tn_type; 1304 } else if (lt == PTR && is_null_pointer(rn)) 1305 tp = merge_qualifiers(ln->tn_type, rn->tn_type); 1306 else if (rt == PTR && is_null_pointer(ln)) 1307 tp = merge_qualifiers(rn->tn_type, ln->tn_type); 1308 else if (lt == PTR && ln->tn_type->t_subt->t_tspec == VOID) 1309 tp = merge_qualifiers(ln->tn_type, rn->tn_type); 1310 else if (rt == PTR && rn->tn_type->t_subt->t_tspec == VOID) 1311 tp = merge_qualifiers(rn->tn_type, ln->tn_type); 1312 else { 1313 /* 1314 * XXX For now we simply take the left type. This is probably 1315 * wrong, if one type contains a function prototype and the 1316 * other one, at the same place, only an old-style declaration. 1317 */ 1318 tp = merge_qualifiers(ln->tn_type, rn->tn_type); 1319 } 1320 1321 return build_op(COLON, sys, tp, ln, rn); 1322 } 1323 1324 /* TODO: check for varargs */ 1325 static bool 1326 is_cast_redundant(const tnode_t *tn) 1327 { 1328 const type_t *ntp = tn->tn_type, *otp = tn->u.ops.left->tn_type; 1329 tspec_t nt = ntp->t_tspec, ot = otp->t_tspec; 1330 1331 if (nt == BOOL || ot == BOOL) 1332 return nt == BOOL && ot == BOOL; 1333 1334 if (is_integer(nt) && is_integer(ot)) { 1335 unsigned int nw = width_in_bits(ntp), ow = width_in_bits(otp); 1336 if (is_uinteger(nt) == is_uinteger(ot)) 1337 return nw >= ow; 1338 return is_uinteger(ot) && nw > ow; 1339 } 1340 1341 if (is_complex(nt) || is_complex(ot)) 1342 return is_complex(nt) && is_complex(ot) && 1343 size_in_bits(nt) >= size_in_bits(ot); 1344 1345 if (is_floating(nt) && is_floating(ot)) 1346 return size_in_bits(nt) >= size_in_bits(ot); 1347 1348 if (nt == PTR && ot == PTR) { 1349 if (!ntp->t_subt->t_const && otp->t_subt->t_const) 1350 return false; 1351 if (!ntp->t_subt->t_volatile && otp->t_subt->t_volatile) 1352 return false; 1353 1354 if (ntp->t_subt->t_tspec == VOID || 1355 otp->t_subt->t_tspec == VOID || 1356 types_compatible(ntp->t_subt, otp->t_subt, 1357 false, false, NULL)) 1358 return true; 1359 } 1360 1361 return false; 1362 } 1363 1364 static bool 1365 is_assignment(op_t op) 1366 { 1367 1368 return op == ASSIGN || 1369 op == MULASS || 1370 op == DIVASS || 1371 op == MODASS || 1372 op == ADDASS || 1373 op == SUBASS || 1374 op == SHLASS || 1375 op == SHRASS || 1376 op == ANDASS || 1377 op == XORASS || 1378 op == ORASS || 1379 op == RETURN || 1380 op == INIT; 1381 } 1382 1383 static tnode_t * 1384 build_assignment(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 1385 { 1386 1387 tspec_t lt = ln->tn_type->t_tspec; 1388 tspec_t rt = rn->tn_type->t_tspec; 1389 1390 if (any_query_enabled && is_assignment(rn->tn_op)) { 1391 /* chained assignment with '%s' and '%s' */ 1392 query_message(10, op_name(op), op_name(rn->tn_op)); 1393 } 1394 1395 if ((op == ADDASS || op == SUBASS) && lt == PTR) { 1396 lint_assert(is_integer(rt)); 1397 tnode_t *ctn = subt_size_in_bytes(ln->tn_type); 1398 if (rn->tn_type->t_tspec != ctn->tn_type->t_tspec) 1399 rn = convert(NOOP, 0, ctn->tn_type, rn); 1400 rn = build_op(MULT, sys, rn->tn_type, rn, ctn); 1401 if (rn->u.ops.left->tn_op == CON) 1402 rn = fold_constant_integer(rn); 1403 } 1404 1405 if ((op == ASSIGN || op == RETURN || op == INIT) && 1406 (lt == STRUCT || rt == STRUCT)) { 1407 lint_assert(lt == rt); 1408 lint_assert(ln->tn_type->u.sou == rn->tn_type->u.sou); 1409 if (is_incomplete(ln->tn_type)) { 1410 if (op == RETURN) 1411 /* cannot return incomplete type */ 1412 error(212); 1413 else 1414 /* unknown operand size, op '%s' */ 1415 error(138, op_name(op)); 1416 return NULL; 1417 } 1418 } 1419 1420 if (op == SHLASS && hflag && allow_trad && allow_c90 1421 && portable_rank_cmp(lt, rt) < 0) 1422 /* semantics of '%s' change in C90; ... */ 1423 warning(118, "<<="); 1424 1425 if (op != SHLASS && op != SHRASS 1426 && (op == ASSIGN || lt != PTR) 1427 && (lt != rt || (ln->tn_type->t_bitfield && rn->tn_op == CON))) { 1428 rn = convert(op, 0, ln->tn_type, rn); 1429 rt = lt; 1430 } 1431 1432 if (any_query_enabled && rn->tn_op == CVT && rn->tn_cast && 1433 types_compatible(ln->tn_type, rn->tn_type, false, false, NULL) && 1434 is_cast_redundant(rn)) { 1435 /* redundant cast from '%s' to '%s' before assignment */ 1436 query_message(7, type_name(rn->u.ops.left->tn_type), 1437 type_name(rn->tn_type)); 1438 } 1439 1440 return build_op(op, sys, ln->tn_type, ln, rn); 1441 } 1442 1443 static tnode_t * 1444 build_real_imag(op_t op, bool sys, tnode_t *ln) 1445 { 1446 1447 lint_assert(ln != NULL); 1448 if (ln->tn_op == NAME) { 1449 /* 1450 * This may be too much, but it avoids wrong warnings. See 1451 * d_c99_complex_split.c. 1452 */ 1453 mark_as_used(ln->u.sym, false, false); 1454 mark_as_set(ln->u.sym); 1455 } 1456 1457 tspec_t t; 1458 switch (ln->tn_type->t_tspec) { 1459 case LCOMPLEX: 1460 t = LDOUBLE; 1461 break; 1462 case DCOMPLEX: 1463 t = DOUBLE; 1464 break; 1465 case FCOMPLEX: 1466 t = FLOAT; 1467 break; 1468 default: 1469 /* '__%s__' is illegal for type '%s' */ 1470 error(276, op == REAL ? "real" : "imag", 1471 type_name(ln->tn_type)); 1472 return NULL; 1473 } 1474 1475 tnode_t *ntn = build_op(op, sys, gettyp(t), ln, NULL); 1476 ntn->tn_lvalue = true; 1477 return ntn; 1478 } 1479 1480 static bool 1481 is_confusing_precedence(op_t op, op_t lop, bool lparen, op_t rop, bool rparen) 1482 { 1483 1484 if (op == SHL || op == SHR) { 1485 if (!lparen && (lop == PLUS || lop == MINUS)) 1486 return true; 1487 if (!rparen && (rop == PLUS || rop == MINUS)) 1488 return true; 1489 return false; 1490 } 1491 1492 if (op == LOGOR) { 1493 if (!lparen && lop == LOGAND) 1494 return true; 1495 if (!rparen && rop == LOGAND) 1496 return true; 1497 return false; 1498 } 1499 1500 lint_assert(op == BITAND || op == BITXOR || op == BITOR); 1501 if (!lparen && lop != op) { 1502 if (lop == PLUS || lop == MINUS) 1503 return true; 1504 if (lop == BITAND || lop == BITXOR) 1505 return true; 1506 } 1507 if (!rparen && rop != op) { 1508 if (rop == PLUS || rop == MINUS) 1509 return true; 1510 if (rop == BITAND || rop == BITXOR) 1511 return true; 1512 } 1513 return false; 1514 } 1515 1516 /* 1517 * Print a warning if the given node has operands which should be 1518 * parenthesized. 1519 * 1520 * XXX Does not work if an operand is a constant expression. Constant 1521 * expressions are already folded. 1522 */ 1523 static void 1524 check_precedence_confusion(tnode_t *tn) 1525 { 1526 tnode_t *ln, *rn; 1527 1528 if (!hflag) 1529 return; 1530 1531 debug_node(tn); 1532 1533 lint_assert(is_binary(tn)); 1534 for (ln = tn->u.ops.left; ln->tn_op == CVT; ln = ln->u.ops.left) 1535 continue; 1536 for (rn = tn->u.ops.right; rn->tn_op == CVT; rn = rn->u.ops.left) 1537 continue; 1538 1539 if (is_confusing_precedence(tn->tn_op, 1540 ln->tn_op, ln->tn_parenthesized, 1541 rn->tn_op, rn->tn_parenthesized)) { 1542 /* precedence confusion possible: parenthesize! */ 1543 warning(169); 1544 } 1545 } 1546 1547 static tnode_t * 1548 fold_constant_compare_zero(tnode_t *tn) 1549 { 1550 1551 val_t *v = xcalloc(1, sizeof(*v)); 1552 v->v_tspec = tn->tn_type->t_tspec; 1553 lint_assert(v->v_tspec == INT || (Tflag && v->v_tspec == BOOL)); 1554 1555 lint_assert(has_operands(tn)); 1556 bool l = constant_is_nonzero(tn->u.ops.left); 1557 bool r = is_binary(tn) && constant_is_nonzero(tn->u.ops.right); 1558 1559 switch (tn->tn_op) { 1560 case NOT: 1561 if (hflag && !suppress_constcond) 1562 /* constant operand to '!' */ 1563 warning(239); 1564 v->u.integer = !l ? 1 : 0; 1565 break; 1566 case LOGAND: 1567 v->u.integer = l && r ? 1 : 0; 1568 break; 1569 case LOGOR: 1570 v->u.integer = l || r ? 1 : 0; 1571 break; 1572 default: 1573 lint_assert(/*CONSTCOND*/false); 1574 } 1575 1576 return build_constant(tn->tn_type, v); 1577 } 1578 1579 static long double 1580 floating_error_value(tspec_t t, long double lv) 1581 { 1582 if (t == FLOAT) 1583 return lv < 0 ? -FLT_MAX : FLT_MAX; 1584 if (t == DOUBLE) 1585 return lv < 0 ? -DBL_MAX : DBL_MAX; 1586 /* 1587 * When NetBSD is cross-built in MKLINT=yes mode on x86_64 for sparc64, 1588 * tools/lint checks this code while building usr.bin/xlint. In that 1589 * situation, lint uses the preprocessor for sparc64, in which the type 1590 * 'long double' is IEEE-754-binary128, affecting the macro LDBL_MAX 1591 * below. The type 'long double', as well as the strtold 1592 * implementation, comes from the host platform x86_64 though, where 1593 * 'long double' consumes 128 bits as well but only uses 80 of them. 1594 * The exponent range of the two 'long double' types is the same, but 1595 * the maximum finite value differs due to the extended precision on 1596 * sparc64. 1597 * 1598 * To properly handle the data types of the target platform, lint would 1599 * have to implement the floating-point types in a platform-independent 1600 * way, which is not worth the effort, given how few programs 1601 * practically use 'long double'. 1602 */ 1603 /* LINTED 248: floating-point constant out of range */ 1604 long double max = LDBL_MAX; 1605 return lv < 0 ? -max : max; 1606 } 1607 1608 static bool 1609 is_floating_overflow(tspec_t t, long double val) 1610 { 1611 if (fpe != 0 || isfinite(val) == 0) 1612 return true; 1613 if (t == FLOAT && (val > FLT_MAX || val < -FLT_MAX)) 1614 return true; 1615 if (t == DOUBLE && (val > DBL_MAX || val < -DBL_MAX)) 1616 return true; 1617 return false; 1618 } 1619 1620 static tnode_t * 1621 fold_constant_floating(tnode_t *tn) 1622 { 1623 1624 fpe = 0; 1625 1626 tspec_t t = tn->tn_type->t_tspec; 1627 1628 val_t *v = xcalloc(1, sizeof(*v)); 1629 v->v_tspec = t; 1630 1631 lint_assert(is_floating(t)); 1632 lint_assert(has_operands(tn)); 1633 lint_assert(t == tn->u.ops.left->tn_type->t_tspec); 1634 lint_assert(!is_binary(tn) || t == tn->u.ops.right->tn_type->t_tspec); 1635 1636 long double lv = tn->u.ops.left->u.value.u.floating; 1637 long double rv = is_binary(tn) ? tn->u.ops.right->u.value.u.floating 1638 : 0.0; 1639 1640 switch (tn->tn_op) { 1641 case UPLUS: 1642 v->u.floating = lv; 1643 break; 1644 case UMINUS: 1645 v->u.floating = -lv; 1646 break; 1647 case MULT: 1648 v->u.floating = lv * rv; 1649 break; 1650 case DIV: 1651 if (rv == 0.0) { 1652 /* division by 0 */ 1653 error(139); 1654 v->u.floating = floating_error_value(t, lv); 1655 } else { 1656 v->u.floating = lv / rv; 1657 } 1658 break; 1659 case PLUS: 1660 v->u.floating = lv + rv; 1661 break; 1662 case MINUS: 1663 v->u.floating = lv - rv; 1664 break; 1665 case LT: 1666 v->u.integer = lv < rv ? 1 : 0; 1667 break; 1668 case LE: 1669 v->u.integer = lv <= rv ? 1 : 0; 1670 break; 1671 case GE: 1672 v->u.integer = lv >= rv ? 1 : 0; 1673 break; 1674 case GT: 1675 v->u.integer = lv > rv ? 1 : 0; 1676 break; 1677 case EQ: 1678 v->u.integer = lv == rv ? 1 : 0; 1679 break; 1680 case NE: 1681 v->u.integer = lv != rv ? 1 : 0; 1682 break; 1683 default: 1684 lint_assert(/*CONSTCOND*/false); 1685 } 1686 1687 // XXX: Must not access u.floating after setting u.integer. 1688 lint_assert(fpe != 0 || isnan(v->u.floating) == 0); 1689 if (is_complex(v->v_tspec)) { 1690 /* 1691 * Don't warn, as lint doesn't model the imaginary part of 1692 * complex numbers. 1693 */ 1694 fpe = 0; 1695 } else if (is_floating_overflow(t, v->u.floating)) { 1696 /* operator '%s' produces floating point overflow */ 1697 warning(142, op_name(tn->tn_op)); 1698 v->u.floating = floating_error_value(t, v->u.floating); 1699 fpe = 0; 1700 } 1701 1702 return build_constant(tn->tn_type, v); 1703 } 1704 1705 static void 1706 use(const tnode_t *tn) 1707 { 1708 if (tn == NULL) 1709 return; 1710 switch (tn->tn_op) { 1711 case NAME: 1712 mark_as_used(tn->u.sym, false /* XXX */, false /* XXX */); 1713 break; 1714 case CON: 1715 case STRING: 1716 break; 1717 case CALL: 1718 case ICALL:; 1719 const function_call *call = tn->u.call; 1720 for (size_t i = 0, n = call->args_len; i < n; i++) 1721 use(call->args[i]); 1722 break; 1723 default: 1724 lint_assert(has_operands(tn)); 1725 use(tn->u.ops.left); 1726 if (is_binary(tn)) 1727 use(tn->u.ops.right); 1728 } 1729 } 1730 1731 /* 1732 * Create a tree node for a binary operator and its two operands. Also called 1733 * for unary operators; in that case rn is NULL. 1734 * 1735 * Function calls, sizeof and casts are handled elsewhere. 1736 */ 1737 tnode_t * 1738 build_binary(tnode_t *ln, op_t op, bool sys, tnode_t *rn) 1739 { 1740 const mod_t *mp = &modtab[op]; 1741 1742 /* If there was an error in one of the operands, return. */ 1743 if (ln == NULL || (mp->m_binary && rn == NULL)) 1744 return NULL; 1745 1746 if (mp->m_value_context || mp->m_compares_with_zero) 1747 ln = cconv(ln); 1748 if (mp->m_binary && op != ARROW && op != POINT) 1749 rn = cconv(rn); 1750 1751 if (mp->m_comparison) 1752 check_integer_comparison(op, ln, rn); 1753 1754 if (mp->m_value_context || mp->m_compares_with_zero) 1755 ln = promote(op, false, ln); 1756 if (mp->m_binary && op != ARROW && op != POINT && 1757 op != ASSIGN && op != RETURN && op != INIT) 1758 rn = promote(op, false, rn); 1759 1760 if (mp->m_warn_if_left_unsigned_in_c90 && 1761 ln->tn_op == CON && ln->u.value.v_unsigned_since_c90) { 1762 /* C90 treats constant as unsigned, op '%s' */ 1763 warning(218, op_name(op)); 1764 ln->u.value.v_unsigned_since_c90 = false; 1765 } 1766 if (mp->m_warn_if_right_unsigned_in_c90 && 1767 rn->tn_op == CON && rn->u.value.v_unsigned_since_c90) { 1768 /* C90 treats constant as unsigned, op '%s' */ 1769 warning(218, op_name(op)); 1770 rn->u.value.v_unsigned_since_c90 = false; 1771 } 1772 1773 if (mp->m_balance_operands || (!allow_c90 && (op == SHL || op == SHR))) 1774 balance(op, &ln, &rn); 1775 1776 if (!typeok(op, 0, ln, rn)) 1777 return NULL; 1778 1779 tnode_t *ntn; 1780 switch (op) { 1781 case POINT: 1782 case ARROW: 1783 ntn = build_struct_access(op, sys, ln, rn); 1784 break; 1785 case INCAFT: 1786 case DECAFT: 1787 case INCBEF: 1788 case DECBEF: 1789 ntn = build_prepost_incdec(op, sys, ln); 1790 break; 1791 case ADDR: 1792 ntn = build_address(sys, ln, false); 1793 break; 1794 case INDIR: 1795 ntn = build_op(INDIR, sys, ln->tn_type->t_subt, ln, NULL); 1796 break; 1797 case PLUS: 1798 case MINUS: 1799 ntn = build_plus_minus(op, sys, ln, rn); 1800 break; 1801 case SHL: 1802 case SHR: 1803 ntn = build_bit_shift(op, sys, ln, rn); 1804 break; 1805 case COLON: 1806 ntn = build_colon(sys, ln, rn); 1807 break; 1808 case ASSIGN: 1809 case MULASS: 1810 case DIVASS: 1811 case MODASS: 1812 case ADDASS: 1813 case SUBASS: 1814 case SHLASS: 1815 case SHRASS: 1816 case ANDASS: 1817 case XORASS: 1818 case ORASS: 1819 case RETURN: 1820 case INIT: 1821 ntn = build_assignment(op, sys, ln, rn); 1822 break; 1823 case COMMA: 1824 if (any_query_enabled) { 1825 /* comma operator with types '%s' and '%s' */ 1826 query_message(12, 1827 type_name(ln->tn_type), type_name(rn->tn_type)); 1828 } 1829 /* FALLTHROUGH */ 1830 case QUEST: 1831 ntn = build_op(op, sys, rn->tn_type, ln, rn); 1832 break; 1833 case REAL: 1834 case IMAG: 1835 ntn = build_real_imag(op, sys, ln); 1836 break; 1837 default: 1838 lint_assert(mp->m_binary == (rn != NULL)); 1839 type_t *rettp = mp->m_returns_bool 1840 ? gettyp(Tflag ? BOOL : INT) : ln->tn_type; 1841 ntn = build_op(op, sys, rettp, ln, rn); 1842 break; 1843 } 1844 1845 if (ntn == NULL) 1846 return NULL; 1847 1848 if (mp->m_possible_precedence_confusion) 1849 check_precedence_confusion(ntn); 1850 1851 if (hflag && !suppress_constcond && 1852 mp->m_compares_with_zero && 1853 (ln->tn_op == CON || 1854 (mp->m_binary && op != QUEST && rn->tn_op == CON)) && 1855 /* XXX: rn->tn_system_dependent should be checked as well */ 1856 !ln->tn_system_dependent) 1857 /* constant in conditional context */ 1858 warning(161); 1859 1860 if (mp->m_fold_constant_operands && ln->tn_op == CON) { 1861 if (!mp->m_binary || rn->tn_op == CON) { 1862 if (mp->m_compares_with_zero) 1863 ntn = fold_constant_compare_zero(ntn); 1864 else if (is_floating(ntn->tn_type->t_tspec)) 1865 ntn = fold_constant_floating(ntn); 1866 else 1867 ntn = fold_constant_integer(ntn); 1868 } else if (op == QUEST) { 1869 lint_assert(has_operands(rn)); 1870 use(ln->u.value.u.integer != 0 1871 ? rn->u.ops.right : rn->u.ops.left); 1872 ntn = ln->u.value.u.integer != 0 1873 ? rn->u.ops.left : rn->u.ops.right; 1874 } 1875 } 1876 1877 return ntn; 1878 } 1879 1880 tnode_t * 1881 build_unary(op_t op, bool sys, tnode_t *tn) 1882 { 1883 return build_binary(tn, op, sys, NULL); 1884 } 1885 1886 static bool 1887 are_members_compatible(const sym_t *a, const sym_t *b) 1888 { 1889 if (a->u.s_member.sm_offset_in_bits != b->u.s_member.sm_offset_in_bits) 1890 return false; 1891 1892 const type_t *atp = a->s_type; 1893 const type_t *btp = b->s_type; 1894 bool w = false; 1895 if (!types_compatible(atp, btp, false, false, &w) && !w) 1896 return false; 1897 if (a->s_bitfield != b->s_bitfield) 1898 return false; 1899 if (a->s_bitfield) { 1900 if (atp->t_bit_field_width != btp->t_bit_field_width) 1901 return false; 1902 if (atp->t_bit_field_offset != btp->t_bit_field_offset) 1903 return false; 1904 } 1905 return true; 1906 } 1907 1908 /* 1909 * Return whether all struct/union members with the same name have the same 1910 * type and offset. 1911 */ 1912 static bool 1913 all_members_compatible(const sym_t *msym) 1914 { 1915 for (const sym_t *csym = msym; 1916 csym != NULL; csym = csym->s_symtab_next) { 1917 if (!is_member(csym)) 1918 continue; 1919 if (strcmp(msym->s_name, csym->s_name) != 0) 1920 continue; 1921 1922 for (const sym_t *sym = csym->s_symtab_next; 1923 sym != NULL; sym = sym->s_symtab_next) { 1924 if (is_member(sym) 1925 && strcmp(csym->s_name, sym->s_name) == 0 1926 && !are_members_compatible(csym, sym)) 1927 return false; 1928 } 1929 } 1930 return true; 1931 } 1932 1933 sym_t * 1934 find_member(const struct_or_union *sou, const char *name) 1935 { 1936 for (sym_t *mem = sou->sou_first_member; 1937 mem != NULL; mem = mem->s_next) { 1938 lint_assert(is_member(mem)); 1939 lint_assert(mem->u.s_member.sm_containing_type == sou); 1940 if (strcmp(mem->s_name, name) == 0) 1941 return mem; 1942 } 1943 1944 for (sym_t *mem = sou->sou_first_member; 1945 mem != NULL; mem = mem->s_next) { 1946 if (is_struct_or_union(mem->s_type->t_tspec) 1947 && mem->s_name == unnamed) { 1948 sym_t *nested_mem = 1949 find_member(mem->s_type->u.sou, name); 1950 if (nested_mem != NULL) 1951 return nested_mem; 1952 } 1953 } 1954 return NULL; 1955 } 1956 1957 /* 1958 * Remove the member if it was unknown until now, which means 1959 * that no defined struct or union has a member with the same name. 1960 */ 1961 static void 1962 remove_unknown_member(tnode_t *tn, sym_t *msym) 1963 { 1964 /* type '%s' does not have member '%s' */ 1965 error(101, type_name(tn->tn_type), msym->s_name); 1966 symtab_remove_forever(msym); 1967 msym->s_kind = SK_MEMBER; 1968 msym->s_scl = STRUCT_MEMBER; 1969 1970 struct_or_union *sou = expr_zero_alloc(sizeof(*sou), 1971 "struct_or_union"); 1972 sou->sou_tag = expr_zero_alloc(sizeof(*sou->sou_tag), "sym"); 1973 sou->sou_tag->s_name = unnamed; 1974 1975 msym->u.s_member.sm_containing_type = sou; 1976 /* 1977 * The member sm_offset_in_bits is not needed here since this symbol 1978 * can only be used for error reporting. 1979 */ 1980 } 1981 1982 /* 1983 * Returns a symbol which has the same name as 'msym' and is a member of the 1984 * struct or union specified by 'tn'. 1985 */ 1986 static sym_t * 1987 struct_or_union_member(tnode_t *tn, op_t op, sym_t *msym) 1988 { 1989 1990 /* Determine the tag type of which msym is expected to be a member. */ 1991 const type_t *tp = NULL; 1992 if (op == POINT && is_struct_or_union(tn->tn_type->t_tspec)) 1993 tp = tn->tn_type; 1994 if (op == ARROW && tn->tn_type->t_tspec == PTR 1995 && is_struct_or_union(tn->tn_type->t_subt->t_tspec)) 1996 tp = tn->tn_type->t_subt; 1997 struct_or_union *sou = tp != NULL ? tp->u.sou : NULL; 1998 1999 if (sou != NULL) { 2000 sym_t *nested_mem = find_member(sou, msym->s_name); 2001 if (nested_mem != NULL) 2002 return nested_mem; 2003 } 2004 2005 if (msym->s_scl == NO_SCL) { 2006 remove_unknown_member(tn, msym); 2007 return msym; 2008 } 2009 2010 bool eq = all_members_compatible(msym); 2011 2012 /* 2013 * Now handle the case in which the left operand refers really to a 2014 * struct/union, but the right operand is not member of it. 2015 */ 2016 if (sou != NULL) { 2017 if (eq && !allow_c90) 2018 /* illegal use of member '%s' */ 2019 warning(102, msym->s_name); 2020 else 2021 /* illegal use of member '%s' */ 2022 error(102, msym->s_name); 2023 return msym; 2024 } 2025 2026 if (eq) { 2027 if (op == POINT) { 2028 if (!allow_c90) 2029 /* left operand of '.' must be struct ... */ 2030 warning(103, type_name(tn->tn_type)); 2031 else 2032 /* left operand of '.' must be struct ... */ 2033 error(103, type_name(tn->tn_type)); 2034 } else { 2035 if (!allow_c90 && tn->tn_type->t_tspec == PTR) 2036 /* left operand of '->' must be pointer ... */ 2037 warning(104, type_name(tn->tn_type)); 2038 else 2039 /* left operand of '->' must be pointer ... */ 2040 error(104, type_name(tn->tn_type)); 2041 } 2042 } else { 2043 if (!allow_c90) 2044 /* non-unique member requires struct/union %s */ 2045 error(105, op == POINT ? "object" : "pointer"); 2046 else 2047 /* unacceptable operand of '%s' */ 2048 error(111, op_name(op)); 2049 } 2050 2051 return msym; 2052 } 2053 2054 tnode_t * 2055 build_member_access(tnode_t *ln, op_t op, bool sys, sbuf_t *member) 2056 { 2057 sym_t *msym; 2058 2059 if (ln == NULL) 2060 return NULL; 2061 2062 if (op == ARROW) 2063 /* must do this before struct_or_union_member is called */ 2064 ln = cconv(ln); 2065 msym = struct_or_union_member(ln, op, getsym(member)); 2066 return build_binary(ln, op, sys, build_name(msym, false)); 2067 } 2068 2069 /* 2070 * Perform class conversions. 2071 * 2072 * Arrays of type T are converted into pointers to type T. 2073 * Functions are converted to pointers to functions. 2074 * Lvalues are converted to rvalues. 2075 * 2076 * C99 6.3 "Conversions" 2077 * C99 6.3.2 "Other operands" 2078 * C99 6.3.2.1 "Lvalues, arrays, and function designators" 2079 */ 2080 tnode_t * 2081 cconv(tnode_t *tn) 2082 { 2083 if (tn->tn_type->t_tspec == ARRAY) { 2084 if (!tn->tn_lvalue) { 2085 /* XXX print correct operator */ 2086 /* %soperand of '%s' must be lvalue */ 2087 gnuism(114, "", op_name(ADDR)); 2088 } 2089 tn = build_op(ADDR, tn->tn_sys, 2090 expr_derive_type(tn->tn_type->t_subt, PTR), tn, NULL); 2091 } 2092 2093 if (tn->tn_type->t_tspec == FUNC) 2094 tn = build_address(tn->tn_sys, tn, true); 2095 2096 if (tn->tn_lvalue) { 2097 type_t *tp = expr_dup_type(tn->tn_type); 2098 /* C99 6.3.2.1p2 sentence 2 says to remove the qualifiers. */ 2099 tp->t_const = tp->t_volatile = false; 2100 tn = build_op(LOAD, tn->tn_sys, tp, tn, NULL); 2101 } 2102 2103 return tn; 2104 } 2105 2106 const tnode_t * 2107 before_conversion(const tnode_t *tn) 2108 { 2109 while (tn->tn_op == CVT && !tn->tn_cast) 2110 tn = tn->u.ops.left; 2111 return tn; 2112 } 2113 2114 /* 2115 * Most errors required by C90 are reported in struct_or_union_member(). 2116 * Here we only check for totally wrong things. 2117 */ 2118 static bool 2119 typeok_point(const tnode_t *ln, const type_t *ltp, tspec_t lt) 2120 { 2121 if (is_struct_or_union(lt)) 2122 return true; 2123 2124 if (lt == FUNC || lt == VOID || ltp->t_bitfield) 2125 goto wrong; 2126 2127 /* 2128 * Some C dialects from before C90 tolerated any lvalue on the 2129 * left-hand side of the '.' operator, allowing things like 'char 2130 * st[100]; st.st_mtime', assuming that the member 'st_mtime' only 2131 * occurred in a single struct; see typeok_arrow. 2132 */ 2133 if (ln->tn_lvalue) 2134 return true; 2135 2136 wrong: 2137 /* With allow_c90 we already got an error */ 2138 if (!allow_c90) 2139 /* unacceptable operand of '%s' */ 2140 error(111, op_name(POINT)); 2141 2142 return false; 2143 } 2144 2145 static bool 2146 typeok_arrow(tspec_t lt) 2147 { 2148 /* 2149 * C1978 Appendix A 14.1 says: <quote>In fact, any lvalue is allowed 2150 * before '.', and that lvalue is then assumed to have the form of the 2151 * structure of which the name of the right is a member. [...] Such 2152 * constructions are non-portable.</quote> 2153 */ 2154 if (lt == PTR || (!allow_c90 && is_integer(lt))) 2155 return true; 2156 2157 /* With allow_c90 we already got an error */ 2158 if (!allow_c90) 2159 /* unacceptable operand of '%s' */ 2160 error(111, op_name(ARROW)); 2161 return false; 2162 } 2163 2164 static bool 2165 typeok_incdec(op_t op, const tnode_t *tn, const type_t *tp) 2166 { 2167 /* operand has scalar type (checked in typeok) */ 2168 if (!tn->tn_lvalue) { 2169 if (tn->tn_op == CVT && tn->tn_cast && 2170 tn->u.ops.left->tn_op == LOAD) 2171 /* a cast does not yield an lvalue */ 2172 error(163); 2173 /* %soperand of '%s' must be lvalue */ 2174 error(114, "", op_name(op)); 2175 return false; 2176 } 2177 if (tp->t_const && allow_c90) 2178 /* %soperand of '%s' must be modifiable lvalue */ 2179 warning(115, "", op_name(op)); 2180 return true; 2181 } 2182 2183 static bool 2184 typeok_address(op_t op, const tnode_t *tn, const type_t *tp, tspec_t t) 2185 { 2186 if (t == ARRAY || t == FUNC) { 2187 /* ok, a warning comes later (in build_address()) */ 2188 } else if (!tn->tn_lvalue) { 2189 if (tn->tn_op == CVT && tn->tn_cast && 2190 tn->u.ops.left->tn_op == LOAD) 2191 /* a cast does not yield an lvalue */ 2192 error(163); 2193 /* %soperand of '%s' must be lvalue */ 2194 error(114, "", op_name(op)); 2195 return false; 2196 } else if (is_scalar(t)) { 2197 if (tp->t_bitfield) { 2198 /* cannot take address of bit-field */ 2199 error(112); 2200 return false; 2201 } 2202 } else if (t != STRUCT && t != UNION) { 2203 /* unacceptable operand of '%s' */ 2204 error(111, op_name(op)); 2205 return false; 2206 } 2207 if (tn->tn_op == NAME && tn->u.sym->s_register) { 2208 /* cannot take address of register '%s' */ 2209 error(113, tn->u.sym->s_name); 2210 return false; 2211 } 2212 return true; 2213 } 2214 2215 static bool 2216 typeok_indir(const type_t *tp, tspec_t t) 2217 { 2218 2219 if (t != PTR) { 2220 /* cannot dereference non-pointer type '%s' */ 2221 error(96, type_name(tp)); 2222 return false; 2223 } 2224 return true; 2225 } 2226 2227 static void 2228 warn_incompatible_types(op_t op, 2229 const type_t *ltp, tspec_t lt, 2230 const type_t *rtp, tspec_t rt) 2231 { 2232 bool binary = modtab[op].m_binary; 2233 2234 if (lt == VOID || (binary && rt == VOID)) { 2235 /* void type illegal in expression */ 2236 error(109); 2237 } else if (op == ASSIGN) 2238 /* cannot assign to '%s' from '%s' */ 2239 error(171, type_name(ltp), type_name(rtp)); 2240 else if (binary) 2241 /* operands of '%s' have incompatible types '%s' and '%s' */ 2242 error(107, op_name(op), type_name(ltp), type_name(rtp)); 2243 else { 2244 lint_assert(rt == NO_TSPEC); 2245 /* operand of '%s' has invalid type '%s' */ 2246 error(108, op_name(op), type_name(ltp)); 2247 } 2248 } 2249 2250 static bool 2251 typeok_plus(op_t op, 2252 const type_t *ltp, tspec_t lt, 2253 const type_t *rtp, tspec_t rt) 2254 { 2255 /* operands have scalar types (checked in typeok) */ 2256 if ((lt == PTR && !is_integer(rt)) || (rt == PTR && !is_integer(lt))) { 2257 warn_incompatible_types(op, ltp, lt, rtp, rt); 2258 return false; 2259 } 2260 return true; 2261 } 2262 2263 static bool 2264 typeok_minus(op_t op, 2265 const type_t *ltp, tspec_t lt, 2266 const type_t *rtp, tspec_t rt) 2267 { 2268 /* operands have scalar types (checked in typeok) */ 2269 if ((lt == PTR && rt != PTR && !is_integer(rt)) || 2270 (lt != PTR && rt == PTR)) { 2271 warn_incompatible_types(op, ltp, lt, rtp, rt); 2272 return false; 2273 } 2274 if (lt == PTR && rt == PTR && 2275 !types_compatible(ltp->t_subt, rtp->t_subt, true, false, NULL)) { 2276 /* illegal pointer subtraction */ 2277 error(116); 2278 } 2279 return true; 2280 } 2281 2282 static void 2283 typeok_shr(op_t op, 2284 const tnode_t *ln, tspec_t lt, 2285 const tnode_t *rn, tspec_t rt) 2286 { 2287 tspec_t olt = before_conversion(ln)->tn_type->t_tspec; 2288 tspec_t ort = before_conversion(rn)->tn_type->t_tspec; 2289 2290 /* operands have integer types (checked in typeok) */ 2291 if (pflag && !is_uinteger(olt)) { 2292 integer_constraints lc = ic_expr(ln); 2293 if (!ic_maybe_signed(ln->tn_type, &lc)) 2294 return; 2295 2296 if (ln->tn_op != CON) 2297 /* bitwise '%s' on signed value possibly nonportable */ 2298 warning(117, op_name(op)); 2299 else if (ln->u.value.u.integer < 0) 2300 /* bitwise '%s' on signed value nonportable */ 2301 warning(120, op_name(op)); 2302 } else if (allow_trad && allow_c90 && 2303 !is_uinteger(olt) && is_uinteger(ort)) { 2304 /* The left operand would become unsigned in traditional C. */ 2305 if (hflag && (ln->tn_op != CON || ln->u.value.u.integer < 0)) { 2306 /* semantics of '%s' change in C90; use ... */ 2307 warning(118, op_name(op)); 2308 } 2309 } else if (allow_trad && allow_c90 && 2310 !is_uinteger(olt) && !is_uinteger(ort) && 2311 portable_rank_cmp(lt, rt) < 0) { 2312 /* 2313 * In traditional C, the left operand would be extended 2314 * (possibly sign-extended) and then shifted. 2315 */ 2316 if (hflag && (ln->tn_op != CON || ln->u.value.u.integer < 0)) { 2317 /* semantics of '%s' change in C90; use ... */ 2318 warning(118, op_name(op)); 2319 } 2320 } 2321 } 2322 2323 static void 2324 typeok_shl(op_t op, tspec_t lt, tspec_t rt) 2325 { 2326 /* 2327 * C90 does not perform balancing for shift operations, but traditional 2328 * C does. If the width of the right operand is greater than the width 2329 * of the left operand, then in traditional C the left operand would be 2330 * extended to the width of the right operand. For SHL this may result 2331 * in different results. 2332 */ 2333 if (portable_rank_cmp(lt, rt) < 0) { 2334 /* 2335 * XXX If both operands are constant, make sure that there is 2336 * really a difference between C90 and traditional C. 2337 */ 2338 if (hflag && allow_trad && allow_c90) 2339 /* semantics of '%s' change in C90; use ... */ 2340 warning(118, op_name(op)); 2341 } 2342 } 2343 2344 static void 2345 typeok_shift(const type_t *ltp, tspec_t lt, const tnode_t *rn, tspec_t rt) 2346 { 2347 if (rn->tn_op != CON) 2348 return; 2349 2350 if (!is_uinteger(rt) && rn->u.value.u.integer < 0) 2351 /* negative shift */ 2352 warning(121); 2353 else if ((uint64_t)rn->u.value.u.integer == size_in_bits(lt)) 2354 /* shift amount %u equals bit-size of '%s' */ 2355 warning(267, (unsigned)rn->u.value.u.integer, type_name(ltp)); 2356 else if ((uint64_t)rn->u.value.u.integer > size_in_bits(lt)) { 2357 /* shift amount %llu is greater than bit-size %llu of '%s' */ 2358 warning(122, (unsigned long long)rn->u.value.u.integer, 2359 (unsigned long long)size_in_bits(lt), 2360 tspec_name(lt)); 2361 } 2362 } 2363 2364 static bool 2365 is_typeok_eq(const tnode_t *ln, tspec_t lt, const tnode_t *rn, tspec_t rt) 2366 { 2367 if (lt == PTR && is_null_pointer(rn)) 2368 return true; 2369 if (rt == PTR && is_null_pointer(ln)) 2370 return true; 2371 return false; 2372 } 2373 2374 static void 2375 warn_incompatible_pointers(op_t op, const type_t *ltp, const type_t *rtp) 2376 { 2377 lint_assert(ltp->t_tspec == PTR); 2378 lint_assert(rtp->t_tspec == PTR); 2379 2380 tspec_t lt = ltp->t_subt->t_tspec; 2381 tspec_t rt = rtp->t_subt->t_tspec; 2382 2383 if (is_struct_or_union(lt) && is_struct_or_union(rt)) { 2384 if (op == RETURN) 2385 /* illegal structure pointer combination */ 2386 warning(244); 2387 else { 2388 /* incompatible structure pointers: '%s' '%s' '%s' */ 2389 warning(245, type_name(ltp), 2390 op_name(op), type_name(rtp)); 2391 } 2392 } else { 2393 if (op == RETURN) 2394 /* illegal combination of '%s' and '%s' */ 2395 warning(184, type_name(ltp), type_name(rtp)); 2396 else { 2397 /* illegal combination of '%s' and '%s', op '%s' */ 2398 warning(124, 2399 type_name(ltp), type_name(rtp), op_name(op)); 2400 } 2401 } 2402 } 2403 2404 static void 2405 check_pointer_comparison(op_t op, const tnode_t *ln, const tnode_t *rn) 2406 { 2407 type_t *ltp = ln->tn_type, *rtp = rn->tn_type; 2408 tspec_t lst = ltp->t_subt->t_tspec, rst = rtp->t_subt->t_tspec; 2409 2410 if (lst == VOID || rst == VOID) { 2411 /* TODO: C99 behaves like C90 here. */ 2412 if (!allow_trad && !allow_c99 && 2413 (lst == FUNC || rst == FUNC)) { 2414 /* (void *)0 is already handled in typeok() */ 2415 const char *lsts, *rsts; 2416 *(lst == FUNC ? &lsts : &rsts) = "function pointer"; 2417 *(lst == VOID ? &lsts : &rsts) = "'void *'"; 2418 /* C90 or later forbid comparison of %s with %s */ 2419 warning(274, lsts, rsts); 2420 } 2421 return; 2422 } 2423 2424 if (!types_compatible(ltp->t_subt, rtp->t_subt, true, false, NULL)) { 2425 warn_incompatible_pointers(op, ltp, rtp); 2426 return; 2427 } 2428 2429 if (lst == FUNC && rst == FUNC) { 2430 /* TODO: C99 behaves like C90 here, see C99 6.5.8p2. */ 2431 if (!allow_trad && !allow_c99 && op != EQ && op != NE) 2432 /* pointers to functions can only be compared ... */ 2433 warning(125); 2434 } 2435 } 2436 2437 static bool 2438 typeok_compare(op_t op, 2439 const tnode_t *ln, const type_t *ltp, tspec_t lt, 2440 const tnode_t *rn, const type_t *rtp, tspec_t rt) 2441 { 2442 if (lt == PTR && rt == PTR) { 2443 check_pointer_comparison(op, ln, rn); 2444 return true; 2445 } 2446 2447 if (lt != PTR && rt != PTR) 2448 return true; 2449 2450 if (!is_integer(lt) && !is_integer(rt)) { 2451 warn_incompatible_types(op, ltp, lt, rtp, rt); 2452 return false; 2453 } 2454 2455 const char *lx = lt == PTR ? "pointer" : "integer"; 2456 const char *rx = rt == PTR ? "pointer" : "integer"; 2457 /* illegal combination of %s '%s' and %s '%s', op '%s' */ 2458 warning(123, lx, type_name(ltp), rx, type_name(rtp), op_name(op)); 2459 return true; 2460 } 2461 2462 static bool 2463 typeok_quest(tspec_t lt, const tnode_t *rn) 2464 { 2465 if (!is_scalar(lt)) { 2466 /* first operand of '?' must have scalar type */ 2467 error(170); 2468 return false; 2469 } 2470 lint_assert(before_conversion(rn)->tn_op == COLON); 2471 return true; 2472 } 2473 2474 static void 2475 typeok_colon_pointer(const type_t *ltp, const type_t *rtp) 2476 { 2477 type_t *lstp = ltp->t_subt; 2478 type_t *rstp = rtp->t_subt; 2479 tspec_t lst = lstp->t_tspec; 2480 tspec_t rst = rstp->t_tspec; 2481 2482 if ((lst == VOID && rst == FUNC) || (lst == FUNC && rst == VOID)) { 2483 /* (void *)0 is handled in typeok_colon */ 2484 /* TODO: C99 behaves like C90 here. */ 2485 if (!allow_trad && !allow_c99) 2486 /* conversion of %s to %s requires a cast, op %s */ 2487 warning(305, "function pointer", "'void *'", 2488 op_name(COLON)); 2489 return; 2490 } 2491 2492 if (pointer_types_are_compatible(lstp, rstp, true)) 2493 return; 2494 if (!types_compatible(lstp, rstp, true, false, NULL)) 2495 warn_incompatible_pointers(COLON, ltp, rtp); 2496 } 2497 2498 static bool 2499 typeok_colon(const tnode_t *ln, const type_t *ltp, tspec_t lt, 2500 const tnode_t *rn, const type_t *rtp, tspec_t rt) 2501 { 2502 2503 if (is_arithmetic(lt) && is_arithmetic(rt)) 2504 return true; 2505 if (lt == BOOL && rt == BOOL) 2506 return true; 2507 2508 if (lt == STRUCT && rt == STRUCT && ltp->u.sou == rtp->u.sou) 2509 return true; 2510 if (lt == UNION && rt == UNION && ltp->u.sou == rtp->u.sou) 2511 return true; 2512 2513 if (lt == PTR && is_null_pointer(rn)) 2514 return true; 2515 if (rt == PTR && is_null_pointer(ln)) 2516 return true; 2517 2518 if ((lt == PTR && is_integer(rt)) || (is_integer(lt) && rt == PTR)) { 2519 const char *lx = lt == PTR ? "pointer" : "integer"; 2520 const char *rx = rt == PTR ? "pointer" : "integer"; 2521 /* illegal combination of %s '%s' and %s '%s', op '%s' */ 2522 warning(123, lx, type_name(ltp), 2523 rx, type_name(rtp), op_name(COLON)); 2524 return true; 2525 } 2526 2527 if (lt == VOID || rt == VOID) { 2528 if (lt != VOID || rt != VOID) 2529 /* incompatible types '%s' and '%s' in conditional */ 2530 warning(126, type_name(ltp), type_name(rtp)); 2531 return true; 2532 } 2533 2534 if (lt == PTR && rt == PTR) { 2535 typeok_colon_pointer(ltp, rtp); 2536 return true; 2537 } 2538 2539 /* incompatible types '%s' and '%s' in conditional */ 2540 error(126, type_name(ltp), type_name(rtp)); 2541 return false; 2542 } 2543 2544 static bool 2545 has_constant_member(const type_t *tp) 2546 { 2547 lint_assert(is_struct_or_union(tp->t_tspec)); 2548 2549 for (sym_t *m = tp->u.sou->sou_first_member; 2550 m != NULL; m = m->s_next) { 2551 const type_t *mtp = m->s_type; 2552 if (mtp->t_const) 2553 return true; 2554 if (is_struct_or_union(mtp->t_tspec) && 2555 has_constant_member(mtp)) 2556 return true; 2557 } 2558 return false; 2559 } 2560 2561 static bool 2562 typeok_assign(op_t op, const tnode_t *ln, const type_t *ltp, tspec_t lt) 2563 { 2564 if (op == RETURN || op == INIT || op == FARG) 2565 return true; 2566 2567 if (!ln->tn_lvalue) { 2568 if (ln->tn_op == CVT && ln->tn_cast && 2569 ln->u.ops.left->tn_op == LOAD) 2570 /* a cast does not yield an lvalue */ 2571 error(163); 2572 /* %soperand of '%s' must be lvalue */ 2573 error(114, "left ", op_name(op)); 2574 return false; 2575 } else if (ltp->t_const 2576 || (is_struct_or_union(lt) && has_constant_member(ltp))) { 2577 if (allow_c90) 2578 /* %soperand of '%s' must be modifiable lvalue */ 2579 warning(115, "left ", op_name(op)); 2580 } 2581 return true; 2582 } 2583 2584 static bool 2585 typeok_scalar(op_t op, const mod_t *mp, 2586 const type_t *ltp, tspec_t lt, 2587 const type_t *rtp, tspec_t rt) 2588 { 2589 if (mp->m_takes_bool && lt == BOOL && rt == BOOL) 2590 return true; 2591 if (mp->m_requires_integer) { 2592 if (!is_integer(lt) || (mp->m_binary && !is_integer(rt))) { 2593 warn_incompatible_types(op, ltp, lt, rtp, rt); 2594 return false; 2595 } 2596 } else if (mp->m_requires_integer_or_complex) { 2597 if ((!is_integer(lt) && !is_complex(lt)) || 2598 (mp->m_binary && (!is_integer(rt) && !is_complex(rt)))) { 2599 warn_incompatible_types(op, ltp, lt, rtp, rt); 2600 return false; 2601 } 2602 } else if (mp->m_requires_scalar) { 2603 if (!is_scalar(lt) || (mp->m_binary && !is_scalar(rt))) { 2604 warn_incompatible_types(op, ltp, lt, rtp, rt); 2605 return false; 2606 } 2607 } else if (mp->m_requires_arith) { 2608 if (!is_arithmetic(lt) || 2609 (mp->m_binary && !is_arithmetic(rt))) { 2610 warn_incompatible_types(op, ltp, lt, rtp, rt); 2611 return false; 2612 } 2613 } 2614 return true; 2615 } 2616 2617 static void 2618 check_assign_void_pointer(op_t op, int arg, 2619 tspec_t lt, tspec_t lst, 2620 tspec_t rt, tspec_t rst) 2621 { 2622 2623 if (!(lt == PTR && rt == PTR && (lst == VOID || rst == VOID))) 2624 return; 2625 /* two pointers, at least one pointer to void */ 2626 2627 /* TODO: C99 behaves like C90 here. */ 2628 if (!(!allow_trad && !allow_c99 && (lst == FUNC || rst == FUNC))) 2629 return; 2630 /* comb. of ptr to func and ptr to void */ 2631 2632 const char *lts, *rts; 2633 *(lst == FUNC ? <s : &rts) = "function pointer"; 2634 *(lst == VOID ? <s : &rts) = "'void *'"; 2635 2636 switch (op) { 2637 case INIT: 2638 case RETURN: 2639 /* conversion of %s to %s requires a cast */ 2640 warning(303, rts, lts); 2641 break; 2642 case FARG: 2643 /* conversion of %s to %s requires a cast, arg #%d */ 2644 warning(304, rts, lts, arg); 2645 break; 2646 default: 2647 /* conversion of %s to %s requires a cast, op %s */ 2648 warning(305, rts, lts, op_name(op)); 2649 break; 2650 } 2651 } 2652 2653 static bool 2654 is_direct_function_call(const tnode_t *tn, const char **out_name) 2655 { 2656 2657 if (tn->tn_op == CALL 2658 && tn->u.call->func->tn_op == ADDR 2659 && tn->u.call->func->u.ops.left->tn_op == NAME) { 2660 *out_name = tn->u.call->func->u.ops.left->u.sym->s_name; 2661 return true; 2662 } 2663 return false; 2664 } 2665 2666 static bool 2667 is_unconst_function(const char *name) 2668 { 2669 2670 return strcmp(name, "memchr") == 0 || 2671 strcmp(name, "strchr") == 0 || 2672 strcmp(name, "strpbrk") == 0 || 2673 strcmp(name, "strrchr") == 0 || 2674 strcmp(name, "strstr") == 0; 2675 } 2676 2677 static bool 2678 is_const_char_pointer(const tnode_t *tn) 2679 { 2680 /* 2681 * For traditional reasons, C99 6.4.5p5 defines that string literals 2682 * have type 'char[]'. They are often implicitly converted to 'char 2683 * *', for example when they are passed as function arguments. 2684 * 2685 * C99 6.4.5p6 further defines that modifying a string that is 2686 * constructed from a string literal invokes undefined behavior. 2687 * 2688 * Out of these reasons, string literals are treated as 'effectively 2689 * const' here. 2690 */ 2691 if (tn->tn_op == CVT && 2692 tn->u.ops.left->tn_op == ADDR && 2693 tn->u.ops.left->u.ops.left->tn_op == STRING) 2694 return true; 2695 2696 const type_t *tp = before_conversion(tn)->tn_type; 2697 return tp->t_tspec == PTR && 2698 tp->t_subt->t_tspec == CHAR && 2699 tp->t_subt->t_const; 2700 } 2701 2702 static bool 2703 is_const_pointer(const tnode_t *tn) 2704 { 2705 const type_t *tp = before_conversion(tn)->tn_type; 2706 return tp->t_tspec == PTR && tp->t_subt->t_const; 2707 } 2708 2709 static void 2710 check_unconst_function(const type_t *lstp, const tnode_t *rn) 2711 { 2712 const char *function_name; 2713 2714 if (lstp->t_tspec == CHAR && !lstp->t_const && 2715 is_direct_function_call(rn, &function_name) && 2716 is_unconst_function(function_name) && 2717 rn->u.call->args_len >= 1 && 2718 is_const_char_pointer(rn->u.call->args[0])) { 2719 /* call to '%s' effectively discards 'const' from argument */ 2720 warning(346, function_name); 2721 } 2722 2723 if (!lstp->t_const && 2724 is_direct_function_call(rn, &function_name) && 2725 strcmp(function_name, "bsearch") == 0 && 2726 rn->u.call->args_len >= 2 && 2727 is_const_pointer(rn->u.call->args[1])) { 2728 /* call to '%s' effectively discards 'const' from argument */ 2729 warning(346, function_name); 2730 } 2731 } 2732 2733 static bool 2734 check_assign_void_pointer_compat(op_t op, int arg, 2735 const type_t *ltp, tspec_t lt, 2736 const type_t *lstp, tspec_t lst, 2737 const tnode_t *rn, 2738 const type_t *rtp, tspec_t rt, 2739 const type_t *rstp, tspec_t rst) 2740 { 2741 if (!(lt == PTR && rt == PTR && (lst == VOID || rst == VOID || 2742 types_compatible(lstp, rstp, 2743 true, false, NULL)))) 2744 return false; 2745 2746 /* compatible pointer types (qualifiers ignored) */ 2747 if (allow_c90 && 2748 ((!lstp->t_const && rstp->t_const) || 2749 (!lstp->t_volatile && rstp->t_volatile))) { 2750 /* left side has not all qualifiers of right */ 2751 switch (op) { 2752 case INIT: 2753 case RETURN: 2754 /* incompatible pointer types to '%s' and '%s' */ 2755 warning(182, type_name(lstp), type_name(rstp)); 2756 break; 2757 case FARG: 2758 /* converting '%s' to incompatible '%s' ... */ 2759 warning(153, 2760 type_name(rtp), type_name(ltp), arg); 2761 break; 2762 default: 2763 /* operands of '%s' have incompatible pointer ... */ 2764 warning(128, op_name(op), 2765 type_name(lstp), type_name(rstp)); 2766 break; 2767 } 2768 } 2769 2770 if (allow_c90) 2771 check_unconst_function(lstp, rn); 2772 2773 return true; 2774 } 2775 2776 static bool 2777 check_assign_pointer_integer(op_t op, int arg, 2778 const type_t *ltp, tspec_t lt, 2779 const type_t *rtp, tspec_t rt) 2780 { 2781 2782 if (!((lt == PTR && is_integer(rt)) || (is_integer(lt) && rt == PTR))) 2783 return false; 2784 2785 const char *lx = lt == PTR ? "pointer" : "integer"; 2786 const char *rx = rt == PTR ? "pointer" : "integer"; 2787 2788 switch (op) { 2789 case INIT: 2790 case RETURN: 2791 /* illegal combination of %s '%s' and %s '%s' */ 2792 warning(183, lx, type_name(ltp), rx, type_name(rtp)); 2793 break; 2794 case FARG: 2795 /* illegal combination of %s '%s' and %s '%s', arg #%d */ 2796 warning(154, 2797 lx, type_name(ltp), rx, type_name(rtp), arg); 2798 break; 2799 default: 2800 /* illegal combination of %s '%s' and %s '%s', op '%s' */ 2801 warning(123, 2802 lx, type_name(ltp), rx, type_name(rtp), op_name(op)); 2803 break; 2804 } 2805 return true; 2806 } 2807 2808 static bool 2809 check_assign_pointer(op_t op, int arg, 2810 const type_t *ltp, tspec_t lt, 2811 const type_t *rtp, tspec_t rt) 2812 { 2813 if (!(lt == PTR && rt == PTR)) 2814 return false; 2815 2816 if (op == FARG) 2817 /* converting '%s' to incompatible '%s' for ... */ 2818 warning(153, type_name(rtp), type_name(ltp), arg); 2819 else 2820 warn_incompatible_pointers(op, ltp, rtp); 2821 return true; 2822 } 2823 2824 static void 2825 warn_assign(op_t op, int arg, 2826 const type_t *ltp, tspec_t lt, 2827 const type_t *rtp, tspec_t rt) 2828 { 2829 switch (op) { 2830 case INIT: 2831 /* cannot initialize '%s' from '%s' */ 2832 error(185, type_name(ltp), type_name(rtp)); 2833 break; 2834 case RETURN: 2835 /* function has return type '%s' but returns '%s' */ 2836 error(211, type_name(ltp), type_name(rtp)); 2837 break; 2838 case FARG: 2839 /* passing '%s' to incompatible '%s', arg #%d */ 2840 warning(155, type_name(rtp), type_name(ltp), arg); 2841 break; 2842 default: 2843 warn_incompatible_types(op, ltp, lt, rtp, rt); 2844 break; 2845 } 2846 } 2847 2848 /* 2849 * Checks type compatibility for ASSIGN, INIT, FARG and RETURN 2850 * and prints warnings/errors if necessary. 2851 * Returns whether the types are (almost) compatible. 2852 */ 2853 static bool 2854 check_assign_types_compatible(op_t op, int arg, 2855 const tnode_t *ln, const tnode_t *rn) 2856 { 2857 tspec_t lt, rt, lst = NO_TSPEC, rst = NO_TSPEC; 2858 type_t *ltp, *rtp, *lstp = NULL, *rstp = NULL; 2859 2860 if ((lt = (ltp = ln->tn_type)->t_tspec) == PTR) 2861 lst = (lstp = ltp->t_subt)->t_tspec; 2862 if ((rt = (rtp = rn->tn_type)->t_tspec) == PTR) 2863 rst = (rstp = rtp->t_subt)->t_tspec; 2864 2865 if (lt == BOOL && is_scalar(rt)) /* C99 6.3.1.2 */ 2866 return true; 2867 2868 if (is_arithmetic(lt) && (is_arithmetic(rt) || rt == BOOL)) 2869 return true; 2870 2871 if (is_struct_or_union(lt) && is_struct_or_union(rt)) 2872 return ltp->u.sou == rtp->u.sou; 2873 2874 if (lt == PTR && is_null_pointer(rn)) { 2875 if (is_integer(rn->tn_type->t_tspec)) 2876 /* implicit conversion from integer 0 to pointer ... */ 2877 query_message(15, type_name(ltp)); 2878 return true; 2879 } 2880 2881 check_assign_void_pointer(op, arg, lt, lst, rt, rst); 2882 2883 if (check_assign_void_pointer_compat(op, arg, 2884 ltp, lt, lstp, lst, rn, rtp, rt, rstp, rst)) 2885 return true; 2886 2887 if (check_assign_pointer_integer(op, arg, ltp, lt, rtp, rt)) 2888 return true; 2889 2890 if (check_assign_pointer(op, arg, ltp, lt, rtp, rt)) 2891 return true; 2892 2893 warn_assign(op, arg, ltp, lt, rtp, rt); 2894 return false; 2895 } 2896 2897 static bool 2898 has_side_effect(const tnode_t *tn) /* NOLINT(misc-no-recursion) */ 2899 { 2900 op_t op = tn->tn_op; 2901 2902 if (modtab[op].m_has_side_effect) 2903 return true; 2904 2905 if (op == CVT && tn->tn_type->t_tspec == VOID) 2906 return has_side_effect(tn->u.ops.left); 2907 2908 /* XXX: Why not has_side_effect(tn->u.ops.left) as well? */ 2909 if (op == LOGAND || op == LOGOR) 2910 return has_side_effect(tn->u.ops.right); 2911 2912 /* XXX: Why not has_side_effect(tn->u.ops.left) as well? */ 2913 if (op == QUEST) 2914 return has_side_effect(tn->u.ops.right); 2915 2916 if (op == COLON || op == COMMA) { 2917 return has_side_effect(tn->u.ops.left) || 2918 has_side_effect(tn->u.ops.right); 2919 } 2920 2921 return false; 2922 } 2923 2924 static bool 2925 is_void_cast(const tnode_t *tn) 2926 { 2927 2928 return tn->tn_op == CVT && tn->tn_cast && 2929 tn->tn_type->t_tspec == VOID; 2930 } 2931 2932 static bool 2933 is_local_symbol(const tnode_t *tn) 2934 { 2935 2936 return tn->tn_op == LOAD && 2937 tn->u.ops.left->tn_op == NAME && 2938 tn->u.ops.left->u.sym->s_scl == AUTO; 2939 } 2940 2941 static bool 2942 is_int_constant_zero(const tnode_t *tn) 2943 { 2944 2945 return tn->tn_op == CON && 2946 tn->tn_type->t_tspec == INT && 2947 tn->u.value.u.integer == 0; 2948 } 2949 2950 static void 2951 check_null_effect(const tnode_t *tn) 2952 { 2953 2954 if (hflag && 2955 !has_side_effect(tn) && 2956 !(is_void_cast(tn) && is_local_symbol(tn->u.ops.left)) && 2957 !(is_void_cast(tn) && is_int_constant_zero(tn->u.ops.left))) { 2958 /* expression has null effect */ 2959 warning(129); 2960 } 2961 } 2962 2963 /* 2964 * Check the types for specific operators and type combinations. 2965 * 2966 * At this point, the operands already conform to the type requirements of 2967 * the operator, such as being integer, floating or scalar. 2968 */ 2969 static bool 2970 typeok_op(op_t op, int arg, 2971 const tnode_t *ln, const type_t *ltp, tspec_t lt, 2972 const tnode_t *rn, const type_t *rtp, tspec_t rt) 2973 { 2974 switch (op) { 2975 case ARROW: 2976 return typeok_arrow(lt); 2977 case POINT: 2978 return typeok_point(ln, ltp, lt); 2979 case INCBEF: 2980 case DECBEF: 2981 case INCAFT: 2982 case DECAFT: 2983 return typeok_incdec(op, ln, ltp); 2984 case INDIR: 2985 return typeok_indir(ltp, lt); 2986 case ADDR: 2987 return typeok_address(op, ln, ltp, lt); 2988 case PLUS: 2989 return typeok_plus(op, ltp, lt, rtp, rt); 2990 case MINUS: 2991 return typeok_minus(op, ltp, lt, rtp, rt); 2992 case SHL: 2993 typeok_shl(op, lt, rt); 2994 goto shift; 2995 case SHR: 2996 typeok_shr(op, ln, lt, rn, rt); 2997 shift: 2998 typeok_shift(ltp, lt, rn, rt); 2999 break; 3000 case LT: 3001 case LE: 3002 case GT: 3003 case GE: 3004 compare: 3005 return typeok_compare(op, ln, ltp, lt, rn, rtp, rt); 3006 case EQ: 3007 case NE: 3008 if (is_typeok_eq(ln, lt, rn, rt)) 3009 break; 3010 goto compare; 3011 case QUEST: 3012 return typeok_quest(lt, rn); 3013 case COLON: 3014 return typeok_colon(ln, ltp, lt, rn, rtp, rt); 3015 case ASSIGN: 3016 case INIT: 3017 case FARG: 3018 case RETURN: 3019 if (!check_assign_types_compatible(op, arg, ln, rn)) 3020 return false; 3021 goto assign; 3022 case MULASS: 3023 case DIVASS: 3024 case MODASS: 3025 goto assign; 3026 case ADDASS: 3027 case SUBASS: 3028 if ((lt == PTR && !is_integer(rt)) || rt == PTR) { 3029 warn_incompatible_types(op, ltp, lt, rtp, rt); 3030 return false; 3031 } 3032 goto assign; 3033 case SHLASS: 3034 goto assign; 3035 case SHRASS: 3036 if (pflag && !is_uinteger(lt) && 3037 !(!allow_c90 && is_uinteger(rt))) { 3038 /* bitwise '%s' on signed value possibly nonportable */ 3039 warning(117, op_name(op)); 3040 } 3041 goto assign; 3042 case ANDASS: 3043 case XORASS: 3044 case ORASS: 3045 assign: 3046 return typeok_assign(op, ln, ltp, lt); 3047 case COMMA: 3048 if (!modtab[ln->tn_op].m_has_side_effect) 3049 check_null_effect(ln); 3050 break; 3051 default: 3052 break; 3053 } 3054 return true; 3055 } 3056 3057 static void 3058 check_bad_enum_operation(op_t op, const tnode_t *ln, const tnode_t *rn) 3059 { 3060 3061 if (!eflag) 3062 return; 3063 3064 /* Allow enum in array indices. */ 3065 if (op == PLUS && 3066 ((ln->tn_type->t_is_enum && rn->tn_type->t_tspec == PTR) || 3067 (rn->tn_type->t_is_enum && ln->tn_type->t_tspec == PTR))) { 3068 return; 3069 } 3070 3071 /* dubious operation '%s' on enum */ 3072 warning(241, op_name(op)); 3073 } 3074 3075 static void 3076 check_enum_type_mismatch(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 3077 { 3078 const mod_t *mp = &modtab[op]; 3079 3080 if (ln->tn_type->u.enumer != rn->tn_type->u.enumer) { 3081 switch (op) { 3082 case INIT: 3083 /* enum type mismatch between '%s' and '%s' in ... */ 3084 warning(210, 3085 type_name(ln->tn_type), type_name(rn->tn_type)); 3086 break; 3087 case FARG: 3088 /* function expects '%s', passing '%s' for arg #%d */ 3089 warning(156, 3090 type_name(ln->tn_type), type_name(rn->tn_type), 3091 arg); 3092 break; 3093 case RETURN: 3094 /* function has return type '%s' but returns '%s' */ 3095 warning(211, 3096 type_name(ln->tn_type), type_name(rn->tn_type)); 3097 break; 3098 default: 3099 /* enum type mismatch: '%s' '%s' '%s' */ 3100 warning(130, type_name(ln->tn_type), op_name(op), 3101 type_name(rn->tn_type)); 3102 break; 3103 } 3104 } else if (Pflag && eflag && mp->m_comparison && op != EQ && op != NE) 3105 /* operator '%s' assumes that '%s' is ordered */ 3106 warning(243, op_name(op), type_name(ln->tn_type)); 3107 } 3108 3109 static void 3110 check_enum_int_mismatch(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 3111 { 3112 3113 if (!eflag) 3114 return; 3115 3116 switch (op) { 3117 case INIT: 3118 /* 3119 * Initialization with 0 is allowed. Otherwise, all implicit 3120 * initializations would need to be warned upon as well. 3121 */ 3122 if (!rn->tn_type->t_is_enum && rn->tn_op == CON && 3123 is_integer(rn->tn_type->t_tspec) && 3124 rn->u.value.u.integer == 0) { 3125 return; 3126 } 3127 /* initialization of '%s' with '%s' */ 3128 warning(277, type_name(ln->tn_type), type_name(rn->tn_type)); 3129 break; 3130 case FARG: 3131 /* combination of '%s' and '%s', arg #%d */ 3132 warning(278, 3133 type_name(ln->tn_type), type_name(rn->tn_type), arg); 3134 break; 3135 case RETURN: 3136 /* combination of '%s' and '%s' in return */ 3137 warning(279, type_name(ln->tn_type), type_name(rn->tn_type)); 3138 break; 3139 default: 3140 /* combination of '%s' and '%s', op '%s' */ 3141 warning(242, type_name(ln->tn_type), type_name(rn->tn_type), 3142 op_name(op)); 3143 break; 3144 } 3145 } 3146 3147 static void 3148 typeok_enum(op_t op, const mod_t *mp, int arg, 3149 const tnode_t *ln, const type_t *ltp, 3150 const tnode_t *rn, const type_t *rtp) 3151 { 3152 if (mp->m_bad_on_enum && 3153 (ltp->t_is_enum || (mp->m_binary && rtp->t_is_enum))) { 3154 check_bad_enum_operation(op, ln, rn); 3155 } else if (mp->m_valid_on_enum && 3156 (ltp->t_is_enum && rtp != NULL && rtp->t_is_enum)) { 3157 check_enum_type_mismatch(op, arg, ln, rn); 3158 } else if (mp->m_valid_on_enum && 3159 (ltp->t_is_enum || (rtp != NULL && rtp->t_is_enum))) { 3160 check_enum_int_mismatch(op, arg, ln, rn); 3161 } 3162 } 3163 3164 /* Perform most type checks. Return whether the types are ok. */ 3165 bool 3166 typeok(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 3167 { 3168 3169 const mod_t *mp = &modtab[op]; 3170 3171 type_t *ltp = ln->tn_type; 3172 tspec_t lt = ltp->t_tspec; 3173 3174 type_t *rtp = mp->m_binary ? rn->tn_type : NULL; 3175 tspec_t rt = mp->m_binary ? rtp->t_tspec : NO_TSPEC; 3176 3177 if (Tflag && !typeok_scalar_strict_bool(op, mp, arg, ln, rn)) 3178 return false; 3179 if (!typeok_scalar(op, mp, ltp, lt, rtp, rt)) 3180 return false; 3181 3182 if (!typeok_op(op, arg, ln, ltp, lt, rn, rtp, rt)) 3183 return false; 3184 3185 typeok_enum(op, mp, arg, ln, ltp, rn, rtp); 3186 return true; 3187 } 3188 3189 /* In traditional C, keep unsigned and promote FLOAT to DOUBLE. */ 3190 static tspec_t 3191 promote_trad(tspec_t t) 3192 { 3193 3194 if (t == UCHAR || t == USHORT) 3195 return UINT; 3196 if (t == CHAR || t == SCHAR || t == SHORT) 3197 return INT; 3198 if (t == FLOAT) 3199 return DOUBLE; 3200 if (t == ENUM) 3201 return INT; 3202 return t; 3203 } 3204 3205 /* 3206 * C99 6.3.1.1p2 requires for types with lower rank than int that "If an int 3207 * can represent all the values of the original type, the value is converted 3208 * to an int; otherwise it is converted to an unsigned int", and that "All 3209 * other types are unchanged by the integer promotions". 3210 */ 3211 static tspec_t 3212 promote_c90(const tnode_t *tn, tspec_t t, bool farg) 3213 { 3214 if (tn->tn_type->t_bitfield) { 3215 unsigned int width = tn->tn_type->t_bit_field_width; 3216 unsigned int int_width = size_in_bits(INT); 3217 // XXX: What about _Bool bit-fields, since C99? 3218 if (width < int_width) 3219 return INT; 3220 if (width == int_width) 3221 return is_uinteger(t) ? UINT : INT; 3222 return t; 3223 } 3224 3225 if (t == CHAR || t == SCHAR) 3226 return INT; 3227 if (t == UCHAR) 3228 return size_in_bits(CHAR) < size_in_bits(INT) ? INT : UINT; 3229 if (t == SHORT) 3230 return INT; 3231 if (t == USHORT) 3232 return size_in_bits(SHORT) < size_in_bits(INT) ? INT : UINT; 3233 if (t == ENUM) 3234 return INT; 3235 if (farg && t == FLOAT) 3236 return DOUBLE; 3237 return t; 3238 } 3239 3240 /* 3241 * Performs the "integer promotions" (C99 6.3.1.1p2), which convert small 3242 * integer types to either int or unsigned int. 3243 * 3244 * If allow_c90 is unset or the operand is a function argument with no type 3245 * information (no prototype or variable # of args), converts float to double. 3246 */ 3247 tnode_t * 3248 promote(op_t op, bool farg, tnode_t *tn) 3249 { 3250 3251 const type_t *otp = tn->tn_type; 3252 tspec_t ot = otp->t_tspec; 3253 if (!is_arithmetic(ot)) 3254 return tn; 3255 3256 tspec_t nt = allow_c90 ? promote_c90(tn, ot, farg) : promote_trad(ot); 3257 if (nt == ot) 3258 return tn; 3259 3260 type_t *ntp = expr_dup_type(gettyp(nt)); 3261 ntp->t_tspec = nt; 3262 ntp->t_is_enum = otp->t_is_enum; 3263 if (ntp->t_is_enum) 3264 ntp->u.enumer = otp->u.enumer; 3265 ntp->t_bitfield = otp->t_bitfield; 3266 if (ntp->t_bitfield) { 3267 ntp->t_bit_field_width = otp->t_bit_field_width; 3268 ntp->t_bit_field_offset = otp->t_bit_field_offset; 3269 } 3270 if (ntp->t_bitfield && is_uinteger(ot) && !is_uinteger(nt)) 3271 ntp->t_bit_field_width++; 3272 return convert(op, 0, ntp, tn); 3273 } 3274 3275 static void 3276 convert_integer_from_floating(op_t op, const type_t *tp, const tnode_t *tn) 3277 { 3278 3279 if (op == CVT) 3280 /* cast from floating point '%s' to integer '%s' */ 3281 query_message(2, type_name(tn->tn_type), type_name(tp)); 3282 else 3283 /* implicit conversion from floating point '%s' to ... */ 3284 query_message(1, type_name(tn->tn_type), type_name(tp)); 3285 } 3286 3287 static bool 3288 should_warn_about_prototype_conversion(tspec_t nt, 3289 tspec_t ot, const tnode_t *ptn) 3290 { 3291 3292 if (nt == ot) 3293 return false; 3294 3295 if (nt == ENUM && ot == INT) 3296 return false; 3297 3298 if (is_floating(nt) != is_floating(ot) || 3299 portable_rank_cmp(nt, ot) != 0) { 3300 /* representation and/or width change */ 3301 if (!is_integer(ot)) 3302 return true; 3303 /* 3304 * XXX: Investigate whether this rule makes sense; see 3305 * tests/usr.bin/xlint/lint1/platform_long.c. 3306 */ 3307 return portable_rank_cmp(ot, INT) > 0; 3308 } 3309 3310 if (!hflag) 3311 return false; 3312 3313 /* 3314 * If the types differ only in sign and the argument has the same 3315 * representation in both types, print no warning. 3316 */ 3317 if (ptn->tn_op == CON && is_integer(nt) && 3318 signed_type(nt) == signed_type(ot) && 3319 !msb(ptn->u.value.u.integer, ot)) 3320 return false; 3321 3322 return true; 3323 } 3324 3325 /* 3326 * Warn if a prototype causes a type conversion that is different from what 3327 * would happen to the same argument in the absence of a prototype. This 3328 * check is intended for code that needs to stay compatible with pre-C90 C. 3329 * 3330 * Errors/warnings about illegal type combinations are already printed 3331 * in check_assign_types_compatible(). 3332 */ 3333 static void 3334 check_prototype_conversion(int arg, tspec_t nt, tspec_t ot, type_t *tp, 3335 tnode_t *tn) 3336 { 3337 3338 if (!is_arithmetic(nt) || !is_arithmetic(ot)) 3339 return; 3340 3341 /* 3342 * If the type of the formal parameter is char/short, a warning would 3343 * be useless, because functions declared the old style can't expect 3344 * char/short arguments. 3345 */ 3346 if (nt == CHAR || nt == SCHAR || nt == UCHAR || 3347 nt == SHORT || nt == USHORT) 3348 return; 3349 3350 tnode_t *ptn = promote(NOOP, true, tn); 3351 ot = ptn->tn_type->t_tspec; 3352 3353 if (should_warn_about_prototype_conversion(nt, ot, ptn)) { 3354 /* argument %d is converted from '%s' to '%s' ... */ 3355 warning(259, arg, type_name(tn->tn_type), type_name(tp)); 3356 } 3357 } 3358 3359 /* 3360 * When converting a large integer type to a small integer type, in some 3361 * cases the value of the actual expression is further restricted than the 3362 * type bounds, such as in (expr & 0xFF) or (expr % 100) or (expr >> 24). 3363 */ 3364 static bool 3365 can_represent(const type_t *tp, const tnode_t *tn) 3366 { 3367 3368 debug_step("%s: type '%s'", __func__, type_name(tp)); 3369 debug_node(tn); 3370 3371 uint64_t nmask = value_bits(width_in_bits(tp)); 3372 if (!is_uinteger(tp->t_tspec)) 3373 nmask >>= 1; 3374 3375 integer_constraints c = ic_expr(tn); 3376 if ((~c.bclr & ~nmask) == 0) 3377 return true; 3378 3379 integer_constraints tpc = ic_any(tp); 3380 if (is_uinteger(tp->t_tspec) 3381 ? tpc.umin <= c.umin && tpc.umax >= c.umax 3382 : tpc.smin <= c.smin && tpc.smax >= c.smax) 3383 return true; 3384 3385 return false; 3386 } 3387 3388 static bool 3389 should_warn_about_integer_conversion(const type_t *ntp, tspec_t nt, 3390 const tnode_t *otn, tspec_t ot) 3391 { 3392 3393 // XXX: The portable_rank_cmp aims at portable mode, independent of the 3394 // current platform, while can_represent acts on the actual type sizes 3395 // from the current platform. This mix is inconsistent, but anything 3396 // else would make the exact conditions too complicated to grasp. 3397 if (aflag > 0 && portable_rank_cmp(nt, ot) < 0) { 3398 if (ot == LONG || ot == ULONG 3399 || ot == LLONG || ot == ULLONG 3400 #ifdef INT128_SIZE 3401 || ot == INT128 || ot == UINT128 3402 #endif 3403 || aflag > 1) 3404 return !can_represent(ntp, otn); 3405 } 3406 return false; 3407 } 3408 3409 static void 3410 convert_integer_from_integer(op_t op, int arg, tspec_t nt, tspec_t ot, 3411 type_t *tp, tnode_t *tn) 3412 { 3413 3414 if (tn->tn_op == CON) 3415 return; 3416 3417 if (op == CVT) 3418 return; 3419 3420 if (Pflag && pflag && aflag > 0 && 3421 portable_rank_cmp(nt, ot) > 0 && 3422 is_uinteger(nt) != is_uinteger(ot)) { 3423 if (op == FARG) 3424 /* conversion to '%s' may sign-extend ... */ 3425 warning(297, type_name(tp), arg); 3426 else 3427 /* conversion to '%s' may sign-extend ... */ 3428 warning(131, type_name(tp)); 3429 } 3430 3431 if (Pflag && portable_rank_cmp(nt, ot) > 0 && 3432 (tn->tn_op == PLUS || tn->tn_op == MINUS || tn->tn_op == MULT || 3433 tn->tn_op == SHL)) { 3434 /* suggest cast from '%s' to '%s' on op '%s' to ... */ 3435 warning(324, type_name(gettyp(ot)), type_name(tp), 3436 op_name(tn->tn_op)); 3437 } 3438 3439 if (should_warn_about_integer_conversion(tp, nt, tn, ot)) { 3440 if (op == FARG) { 3441 /* conversion from '%s' to '%s' may lose ... */ 3442 warning(298, 3443 type_name(tn->tn_type), type_name(tp), arg); 3444 } else { 3445 /* conversion from '%s' to '%s' may lose accuracy */ 3446 warning(132, 3447 type_name(tn->tn_type), type_name(tp)); 3448 } 3449 } 3450 3451 if (any_query_enabled && is_uinteger(nt) != is_uinteger(ot)) 3452 /* implicit conversion changes sign from '%s' to '%s' */ 3453 query_message(3, type_name(tn->tn_type), type_name(tp)); 3454 } 3455 3456 static void 3457 convert_integer_from_pointer(op_t op, tspec_t nt, type_t *tp, tnode_t *tn) 3458 { 3459 3460 if (tn->tn_op == CON) 3461 return; 3462 if (op != CVT) 3463 return; /* We already got an error. */ 3464 if (portable_rank_cmp(nt, PTR) >= 0) 3465 return; 3466 3467 if (pflag && size_in_bits(nt) >= size_in_bits(PTR)) { 3468 /* conversion of pointer to '%s' may lose bits */ 3469 warning(134, type_name(tp)); 3470 } else { 3471 /* conversion of pointer to '%s' loses bits */ 3472 warning(133, type_name(tp)); 3473 } 3474 } 3475 3476 static bool 3477 struct_starts_with(const type_t *struct_tp, const type_t *member_tp) 3478 { 3479 3480 return struct_tp->u.sou->sou_first_member != NULL && 3481 types_compatible(struct_tp->u.sou->sou_first_member->s_type, 3482 member_tp, true, false, NULL); 3483 } 3484 3485 static bool 3486 is_byte_array(const type_t *tp) 3487 { 3488 3489 return tp->t_tspec == ARRAY && 3490 (tp->t_subt->t_tspec == CHAR || tp->t_subt->t_tspec == UCHAR); 3491 } 3492 3493 static bool 3494 union_contains(const type_t *utp, const type_t *mtp) 3495 { 3496 for (const sym_t *mem = utp->u.sou->sou_first_member; 3497 mem != NULL; mem = mem->s_next) { 3498 if (types_compatible(mem->s_type, mtp, true, false, NULL)) 3499 return true; 3500 } 3501 return false; 3502 } 3503 3504 static bool 3505 should_warn_about_pointer_cast(const type_t *nstp, tspec_t nst, 3506 const type_t *ostp, tspec_t ost) 3507 { 3508 3509 while (nst == ARRAY) 3510 nstp = nstp->t_subt, nst = nstp->t_tspec; 3511 while (ost == ARRAY) 3512 ostp = ostp->t_subt, ost = ostp->t_tspec; 3513 3514 if (nst == STRUCT && ost == STRUCT && 3515 (struct_starts_with(nstp, ostp) || 3516 struct_starts_with(ostp, nstp))) 3517 return false; 3518 3519 if (is_incomplete(nstp) || is_incomplete(ostp)) 3520 return false; 3521 3522 if (nst == CHAR || nst == UCHAR) 3523 return false; /* for the sake of traditional C code */ 3524 if (ost == CHAR || ost == UCHAR) 3525 return false; /* for the sake of traditional C code */ 3526 3527 /* Allow cast between pointers to sockaddr variants. */ 3528 if (nst == STRUCT && ost == STRUCT) { 3529 const sym_t *nmem = nstp->u.sou->sou_first_member; 3530 const sym_t *omem = ostp->u.sou->sou_first_member; 3531 while (nmem != NULL && omem != NULL && 3532 types_compatible(nmem->s_type, omem->s_type, 3533 true, false, NULL)) 3534 nmem = nmem->s_next, omem = omem->s_next; 3535 if (nmem != NULL && is_byte_array(nmem->s_type)) 3536 return false; 3537 if (omem != NULL && is_byte_array(omem->s_type)) 3538 return false; 3539 if (nmem == NULL && omem == NULL) 3540 return false; 3541 } 3542 3543 if (nst == UNION || ost == UNION) { 3544 const type_t *union_tp = nst == UNION ? nstp : ostp; 3545 const type_t *other_tp = nst == UNION ? ostp : nstp; 3546 if (union_contains(union_tp, other_tp)) 3547 return false; 3548 } 3549 3550 if (is_struct_or_union(nst) && is_struct_or_union(ost)) 3551 return nstp->u.sou != ostp->u.sou; 3552 3553 enum rank_kind rk1 = type_properties(nst)->tt_rank_kind; 3554 enum rank_kind rk2 = type_properties(ost)->tt_rank_kind; 3555 if (rk1 != rk2 || rk1 == RK_NONE) 3556 return true; 3557 3558 return portable_rank_cmp(nst, ost) != 0; 3559 } 3560 3561 static void 3562 convert_pointer_from_pointer(type_t *ntp, tnode_t *tn) 3563 { 3564 const type_t *nstp = ntp->t_subt; 3565 const type_t *otp = tn->tn_type; 3566 const type_t *ostp = otp->t_subt; 3567 tspec_t nst = nstp->t_tspec; 3568 tspec_t ost = ostp->t_tspec; 3569 3570 if (nst == VOID || ost == VOID) { 3571 /* TODO: C99 behaves like C90 here. */ 3572 if (!allow_trad && !allow_c99 && (nst == FUNC || ost == FUNC)) { 3573 const char *nts, *ots; 3574 /* null pointers are already handled in convert() */ 3575 *(nst == FUNC ? &nts : &ots) = "function pointer"; 3576 *(nst == VOID ? &nts : &ots) = "'void *'"; 3577 /* conversion of %s to %s requires a cast */ 3578 warning(303, ots, nts); 3579 } 3580 return; 3581 } 3582 if (nst == FUNC && ost == FUNC) 3583 return; 3584 if (nst == FUNC || ost == FUNC) { 3585 /* converting '%s' to '%s' is questionable */ 3586 warning(229, type_name(otp), type_name(ntp)); 3587 return; 3588 } 3589 3590 if (hflag && alignment_in_bits(nstp) > alignment_in_bits(ostp) && 3591 ost != CHAR && ost != UCHAR && 3592 !is_incomplete(ostp) && 3593 !(nst == UNION && union_contains(nstp, ostp))) { 3594 /* converting '%s' to '%s' increases alignment ... */ 3595 warning(135, type_name(otp), type_name(ntp), 3596 alignment_in_bits(ostp) / CHAR_SIZE, 3597 alignment_in_bits(nstp) / CHAR_SIZE); 3598 } 3599 3600 if (cflag && should_warn_about_pointer_cast(nstp, nst, ostp, ost)) { 3601 /* pointer cast from '%s' to '%s' may be troublesome */ 3602 warning(247, type_name(otp), type_name(ntp)); 3603 } 3604 } 3605 3606 /* 3607 * Insert a conversion operator, which converts the type of the node 3608 * to another given type. 3609 * 3610 * Possible values for 'op': 3611 * CVT a cast-expression 3612 * binary integer promotion for one of the operands, or a usual 3613 * arithmetic conversion 3614 * binary plain or compound assignments to bit-fields 3615 * FARG 'arg' is the number of the parameter (used for warnings) 3616 * NOOP several other implicit conversions 3617 * ... 3618 */ 3619 tnode_t * 3620 convert(op_t op, int arg, type_t *tp, tnode_t *tn) 3621 { 3622 tspec_t nt = tp->t_tspec; 3623 tspec_t ot = tn->tn_type->t_tspec; 3624 3625 if (allow_trad && allow_c90 && op == FARG) 3626 check_prototype_conversion(arg, nt, ot, tp, tn); 3627 3628 if (nt == BOOL) { 3629 /* No further checks. */ 3630 3631 } else if (is_integer(nt)) { 3632 if (ot == BOOL) { 3633 /* No further checks. */ 3634 } else if (is_integer(ot)) 3635 convert_integer_from_integer(op, arg, nt, ot, tp, tn); 3636 else if (is_floating(ot)) 3637 convert_integer_from_floating(op, tp, tn); 3638 else if (ot == PTR) 3639 convert_integer_from_pointer(op, nt, tp, tn); 3640 3641 } else if (is_floating(nt)) { 3642 /* No further checks. */ 3643 3644 } else if (nt == PTR) { 3645 if (is_null_pointer(tn)) { 3646 /* a null pointer may be assigned to any pointer. */ 3647 } else if (ot == PTR && op == CVT) 3648 convert_pointer_from_pointer(tp, tn); 3649 } 3650 3651 tnode_t *ntn = expr_alloc_tnode(); 3652 ntn->tn_op = CVT; 3653 ntn->tn_type = tp; 3654 ntn->tn_cast = op == CVT; 3655 ntn->tn_sys |= tn->tn_sys; 3656 ntn->u.ops.right = NULL; 3657 if (tn->tn_op != CON || nt == VOID) { 3658 ntn->u.ops.left = tn; 3659 } else { 3660 ntn->tn_op = CON; 3661 convert_constant(op, arg, ntn->tn_type, &ntn->u.value, 3662 &tn->u.value); 3663 } 3664 3665 return ntn; 3666 } 3667 3668 static void 3669 convert_constant_floating(op_t op, int arg, tspec_t ot, const type_t *tp, 3670 tspec_t nt, val_t *v, val_t *nv) 3671 { 3672 long double max = 0.0, min = 0.0; 3673 3674 switch (nt) { 3675 case CHAR: 3676 max = TARG_CHAR_MAX; min = TARG_CHAR_MIN; break; 3677 case UCHAR: 3678 max = TARG_UCHAR_MAX; min = 0; break; 3679 case SCHAR: 3680 max = TARG_SCHAR_MAX; min = TARG_SCHAR_MIN; break; 3681 case SHORT: 3682 max = TARG_SHRT_MAX; min = TARG_SHRT_MIN; break; 3683 case USHORT: 3684 max = TARG_USHRT_MAX; min = 0; break; 3685 case ENUM: 3686 case INT: 3687 max = TARG_INT_MAX; min = TARG_INT_MIN; break; 3688 case UINT: 3689 max = TARG_UINT_MAX; min = 0; break; 3690 case LONG: 3691 max = TARG_LONG_MAX; min = TARG_LONG_MIN; break; 3692 case ULONG: 3693 max = TARG_ULONG_MAX; min = 0; break; 3694 case LLONG: 3695 max = LLONG_MAX; min = LLONG_MIN; break; 3696 case ULLONG: 3697 max = ULLONG_MAX; min = 0; break; 3698 case FLOAT: 3699 case FCOMPLEX: 3700 max = FLT_MAX; min = -FLT_MAX; break; 3701 case DOUBLE: 3702 case DCOMPLEX: 3703 max = DBL_MAX; min = -DBL_MAX; break; 3704 case PTR: 3705 /* Already got an error because of float --> ptr */ 3706 case LDOUBLE: 3707 case LCOMPLEX: 3708 /* LINTED 248 */ 3709 max = LDBL_MAX; min = -max; break; 3710 default: 3711 lint_assert(/*CONSTCOND*/false); 3712 } 3713 if (v->u.floating > max || v->u.floating < min) { 3714 lint_assert(nt != LDOUBLE); 3715 if (op == FARG) { 3716 /* conversion of '%s' to '%s' is out of range, ... */ 3717 warning(295, 3718 type_name(gettyp(ot)), type_name(tp), arg); 3719 } else { 3720 /* conversion of '%s' to '%s' is out of range */ 3721 warning(119, type_name(gettyp(ot)), type_name(tp)); 3722 } 3723 v->u.floating = v->u.floating > 0 ? max : min; 3724 } 3725 3726 if (nt == FLOAT || nt == FCOMPLEX) 3727 nv->u.floating = (float)v->u.floating; 3728 else if (nt == DOUBLE || nt == DCOMPLEX) 3729 nv->u.floating = (double)v->u.floating; 3730 else if (nt == LDOUBLE || nt == LCOMPLEX) 3731 nv->u.floating = v->u.floating; 3732 else 3733 nv->u.integer = (int64_t)v->u.floating; 3734 } 3735 3736 static bool 3737 convert_constant_to_floating(tspec_t nt, val_t *nv, 3738 tspec_t ot, const val_t *v) 3739 { 3740 if (nt == FLOAT) { 3741 nv->u.floating = (ot == PTR || is_uinteger(ot)) ? 3742 (float)(uint64_t)v->u.integer : (float)v->u.integer; 3743 } else if (nt == DOUBLE) { 3744 nv->u.floating = (ot == PTR || is_uinteger(ot)) ? 3745 (double)(uint64_t)v->u.integer : (double)v->u.integer; 3746 } else if (nt == LDOUBLE) { 3747 nv->u.floating = (ot == PTR || is_uinteger(ot)) 3748 ? (long double)(uint64_t)v->u.integer 3749 : (long double)v->u.integer; 3750 } else 3751 return false; 3752 return true; 3753 } 3754 3755 /* 3756 * Print a warning if bits which were set are lost due to the conversion. 3757 * This can happen with operator ORASS only. 3758 */ 3759 static void 3760 convert_constant_check_range_bitor(size_t nsz, size_t osz, const val_t *v, 3761 uint64_t xmask, op_t op) 3762 { 3763 if (nsz < osz && (v->u.integer & xmask) != 0) 3764 /* constant truncated by conversion, op '%s' */ 3765 warning(306, op_name(op)); 3766 } 3767 3768 static void 3769 convert_constant_check_range_bitand(size_t nsz, size_t osz, 3770 uint64_t xmask, const val_t *nv, 3771 tspec_t ot, const val_t *v, 3772 const type_t *tp, op_t op) 3773 { 3774 if (nsz > osz && 3775 (nv->u.integer & bit((unsigned int)(osz - 1))) != 0 && 3776 (nv->u.integer & xmask) != xmask) { 3777 /* extra bits set to 0 in conversion of '%s' to '%s', ... */ 3778 warning(309, type_name(gettyp(ot)), 3779 type_name(tp), op_name(op)); 3780 } else if (nsz < osz && 3781 (v->u.integer & xmask) != xmask && 3782 (v->u.integer & xmask) != 0) 3783 /* constant truncated by conversion, op '%s' */ 3784 warning(306, op_name(op)); 3785 } 3786 3787 static void 3788 convert_constant_check_range_signed(op_t op, int arg) 3789 { 3790 if (op == ASSIGN) 3791 /* assignment of negative constant to unsigned type */ 3792 warning(164); 3793 else if (op == INIT) 3794 /* initialization of unsigned with negative constant */ 3795 warning(221); 3796 else if (op == FARG) 3797 /* conversion of negative constant to unsigned type, ... */ 3798 warning(296, arg); 3799 else if (modtab[op].m_comparison) { 3800 /* handled by check_integer_comparison() */ 3801 } else 3802 /* conversion of negative constant to unsigned type */ 3803 warning(222); 3804 } 3805 3806 /* 3807 * Loss of significant bit(s). All truncated bits of unsigned types or all 3808 * truncated bits plus the msb of the target for signed types are considered 3809 * to be significant bits. Loss of significant bits means that at least one 3810 * of the bits was set in an unsigned type or that at least one but not all 3811 * of the bits was set in a signed type. Loss of significant bits means that 3812 * it is not possible, also not with necessary casts, to convert back to the 3813 * original type. An example for a necessary cast is: 3814 * char c; int i; c = 128; 3815 * i = c; ** yields -128 ** 3816 * i = (unsigned char)c; ** yields 128 ** 3817 */ 3818 static void 3819 warn_constant_check_range_truncated(op_t op, int arg, const type_t *tp, 3820 tspec_t ot) 3821 { 3822 if (op == ASSIGN && tp->t_bitfield) 3823 /* precision lost in bit-field assignment */ 3824 warning(166); 3825 else if (op == ASSIGN) 3826 /* constant truncated by assignment */ 3827 warning(165); 3828 else if (op == INIT && tp->t_bitfield) 3829 /* bit-field initializer does not fit */ 3830 warning(180); 3831 else if (op == INIT) 3832 /* initializer does not fit */ 3833 warning(178); 3834 else if (op == CASE) 3835 /* case label affected by conversion */ 3836 warning(196); 3837 else if (op == FARG) 3838 /* conversion of '%s' to '%s' is out of range, arg #%d */ 3839 warning(295, type_name(gettyp(ot)), type_name(tp), arg); 3840 else 3841 /* conversion of '%s' to '%s' is out of range */ 3842 warning(119, type_name(gettyp(ot)), type_name(tp)); 3843 } 3844 3845 static void 3846 warn_constant_check_range_loss(op_t op, int arg, const type_t *tp, 3847 tspec_t ot) 3848 { 3849 if (op == ASSIGN && tp->t_bitfield) 3850 /* precision lost in bit-field assignment */ 3851 warning(166); 3852 else if (op == INIT && tp->t_bitfield) 3853 /* bit-field initializer out of range */ 3854 warning(11); 3855 else if (op == CASE) 3856 /* case label affected by conversion */ 3857 warning(196); 3858 else if (op == FARG) 3859 /* conversion of '%s' to '%s' is out of range, arg #%d */ 3860 warning(295, type_name(gettyp(ot)), type_name(tp), arg); 3861 else 3862 /* conversion of '%s' to '%s' is out of range */ 3863 warning(119, type_name(gettyp(ot)), type_name(tp)); 3864 } 3865 3866 static void 3867 convert_constant_check_range(tspec_t ot, const type_t *tp, tspec_t nt, 3868 op_t op, int arg, const val_t *v, val_t *nv) 3869 { 3870 unsigned int obitsz, nbitsz; 3871 uint64_t xmask, xmsk1; 3872 3873 obitsz = size_in_bits(ot); 3874 nbitsz = tp->t_bitfield ? tp->t_bit_field_width : size_in_bits(nt); 3875 xmask = value_bits(nbitsz) ^ value_bits(obitsz); 3876 xmsk1 = value_bits(nbitsz) ^ value_bits(obitsz - 1); 3877 if (op == ORASS || op == BITOR || op == BITXOR) { 3878 convert_constant_check_range_bitor( 3879 nbitsz, obitsz, v, xmask, op); 3880 } else if (op == ANDASS || op == BITAND) { 3881 convert_constant_check_range_bitand( 3882 nbitsz, obitsz, xmask, nv, ot, v, tp, op); 3883 } else if (nt != PTR && is_uinteger(nt) && 3884 ot != PTR && !is_uinteger(ot) && 3885 v->u.integer < 0) 3886 convert_constant_check_range_signed(op, arg); 3887 else if (nv->u.integer != v->u.integer && nbitsz <= obitsz && 3888 (v->u.integer & xmask) != 0 && 3889 (is_uinteger(ot) || (v->u.integer & xmsk1) != xmsk1)) 3890 warn_constant_check_range_truncated(op, arg, tp, ot); 3891 else if (nv->u.integer != v->u.integer) 3892 warn_constant_check_range_loss(op, arg, tp, ot); 3893 } 3894 3895 /* Converts a typed constant to a constant of another type. */ 3896 void 3897 convert_constant(op_t op, int arg, const type_t *ntp, val_t *nv, val_t *ov) 3898 { 3899 /* 3900 * TODO: make 'ov' const; the name of this function does not suggest 3901 * that it modifies 'ov'. 3902 */ 3903 tspec_t ot = ov->v_tspec; 3904 tspec_t nt = nv->v_tspec = ntp->t_tspec; 3905 bool range_check = false; 3906 3907 if (nt == BOOL) { /* C99 6.3.1.2 */ 3908 nv->v_unsigned_since_c90 = false; 3909 nv->u.integer = is_nonzero_val(ov) ? 1 : 0; 3910 return; 3911 } 3912 3913 if (ot == FLOAT || ot == DOUBLE || ot == LDOUBLE) 3914 convert_constant_floating(op, arg, ot, ntp, nt, ov, nv); 3915 else if (!convert_constant_to_floating(nt, nv, ot, ov)) { 3916 range_check = true; /* Check for lost precision. */ 3917 nv->u.integer = ov->u.integer; 3918 } 3919 3920 if (allow_trad && allow_c90 && ov->v_unsigned_since_c90 && 3921 (is_floating(nt) || ( 3922 (is_integer(nt) && !is_uinteger(nt) && 3923 portable_rank_cmp(nt, ot) > 0)))) { 3924 /* C90 treats constant as unsigned */ 3925 warning(157); 3926 ov->v_unsigned_since_c90 = false; 3927 } 3928 3929 if (is_integer(nt)) { 3930 unsigned int size = ntp->t_bitfield 3931 ? ntp->t_bit_field_width : size_in_bits(nt); 3932 nv->u.integer = convert_integer(nv->u.integer, nt, size); 3933 } 3934 3935 if (range_check && op != CVT) 3936 convert_constant_check_range(ot, ntp, nt, op, arg, ov, nv); 3937 } 3938 3939 tnode_t * 3940 build_sizeof(const type_t *tp) 3941 { 3942 unsigned int size_in_bytes = type_size_in_bits(tp) / CHAR_SIZE; 3943 tnode_t *tn = build_integer_constant(SIZEOF_TSPEC, size_in_bytes); 3944 tn->tn_system_dependent = true; 3945 debug_step("build_sizeof '%s' = %u", type_name(tp), size_in_bytes); 3946 return tn; 3947 } 3948 3949 tnode_t * 3950 build_offsetof(const type_t *tp, designation dn) 3951 { 3952 unsigned int offset_in_bits = 0; 3953 3954 if (!is_struct_or_union(tp->t_tspec)) { 3955 /* unacceptable operand of '%s' */ 3956 error(111, "offsetof"); 3957 goto proceed; 3958 } 3959 for (size_t i = 0; i < dn.dn_len; i++) { 3960 const designator *dr = dn.dn_items + i; 3961 if (dr->dr_kind == DK_SUBSCRIPT) { 3962 if (tp->t_tspec != ARRAY) 3963 goto proceed; /* silent error */ 3964 tp = tp->t_subt; 3965 offset_in_bits += (unsigned) dr->dr_subscript 3966 * type_size_in_bits(tp); 3967 } else { 3968 if (!is_struct_or_union(tp->t_tspec)) 3969 goto proceed; /* silent error */ 3970 const char *name = dr->dr_member->s_name; 3971 sym_t *mem = find_member(tp->u.sou, name); 3972 if (mem == NULL) { 3973 /* type '%s' does not have member '%s' */ 3974 error(101, name, type_name(tp)); 3975 goto proceed; 3976 } 3977 tp = mem->s_type; 3978 offset_in_bits += mem->u.s_member.sm_offset_in_bits; 3979 } 3980 } 3981 free(dn.dn_items); 3982 3983 proceed:; 3984 unsigned int offset_in_bytes = offset_in_bits / CHAR_SIZE; 3985 tnode_t *tn = build_integer_constant(SIZEOF_TSPEC, offset_in_bytes); 3986 tn->tn_system_dependent = true; 3987 return tn; 3988 } 3989 3990 unsigned int 3991 type_size_in_bits(const type_t *tp) 3992 { 3993 3994 unsigned int elem = 1; 3995 bool flex = false; 3996 lint_assert(tp != NULL); 3997 while (tp->t_tspec == ARRAY) { 3998 flex = true; /* allow c99 flex arrays [] [0] */ 3999 elem *= tp->u.dimension; 4000 tp = tp->t_subt; 4001 } 4002 if (elem == 0 && !flex) { 4003 /* cannot take size/alignment of incomplete type */ 4004 error(143); 4005 elem = 1; 4006 } 4007 4008 unsigned int elsz; 4009 switch (tp->t_tspec) { 4010 case VOID: 4011 /* cannot take size/alignment of void */ 4012 error(146); 4013 elsz = 1; 4014 break; 4015 case FUNC: 4016 /* cannot take size/alignment of function type '%s' */ 4017 error(144, type_name(tp)); 4018 elsz = 1; 4019 break; 4020 case STRUCT: 4021 case UNION: 4022 if (is_incomplete(tp)) { 4023 /* cannot take size/alignment of incomplete type */ 4024 error(143); 4025 elsz = 1; 4026 } else 4027 elsz = tp->u.sou->sou_size_in_bits; 4028 break; 4029 case ENUM: 4030 if (is_incomplete(tp)) { 4031 /* cannot take size/alignment of incomplete type */ 4032 warning(143); 4033 } 4034 /* FALLTHROUGH */ 4035 default: 4036 if (tp->t_bitfield) 4037 /* cannot take size/alignment of bit-field */ 4038 error(145); 4039 elsz = size_in_bits(tp->t_tspec); 4040 lint_assert(elsz > 0); 4041 break; 4042 } 4043 4044 return elem * elsz; 4045 } 4046 4047 /* C11 6.5.3.4, GCC */ 4048 tnode_t * 4049 build_alignof(const type_t *tp) 4050 { 4051 if (tp->t_tspec == FUNC) { 4052 /* cannot take size/alignment of function type '%s' */ 4053 error(144, type_name(tp)); 4054 return NULL; 4055 } 4056 if (tp->t_tspec == VOID) { 4057 /* cannot take size/alignment of void */ 4058 error(146); 4059 return NULL; 4060 } 4061 if (is_incomplete(tp)) { 4062 /* cannot take size/alignment of incomplete type */ 4063 error(143); 4064 return NULL; 4065 } 4066 if (tp->t_bitfield) { 4067 /* cannot take size/alignment of bit-field */ 4068 error(145); 4069 return NULL; 4070 } 4071 return build_integer_constant(SIZEOF_TSPEC, 4072 (int64_t)alignment_in_bits(tp) / CHAR_SIZE); 4073 } 4074 4075 static tnode_t * 4076 cast_to_union(tnode_t *otn, bool sys, type_t *ntp) 4077 { 4078 4079 if (!allow_gcc) { 4080 /* union cast is a GCC extension */ 4081 error(328); 4082 return NULL; 4083 } 4084 4085 for (const sym_t *m = ntp->u.sou->sou_first_member; 4086 m != NULL; m = m->s_next) { 4087 if (types_compatible(m->s_type, otn->tn_type, 4088 false, false, NULL)) { 4089 tnode_t *ntn = build_op(CVT, sys, ntp, otn, NULL); 4090 ntn->tn_cast = true; 4091 return ntn; 4092 } 4093 } 4094 4095 /* type '%s' is not a member of '%s' */ 4096 error(329, type_name(otn->tn_type), type_name(ntp)); 4097 return NULL; 4098 } 4099 4100 tnode_t * 4101 cast(tnode_t *tn, bool sys, type_t *tp) 4102 { 4103 4104 if (tn == NULL) 4105 return NULL; 4106 4107 tn = cconv(tn); 4108 4109 lint_assert(tp != NULL); 4110 tspec_t nt = tp->t_tspec; 4111 tspec_t ot = tn->tn_type->t_tspec; 4112 4113 if (nt == VOID) { 4114 /* 4115 * C90 6.3.4, C99 6.5.4p2 and C11 6.5.4p2 allow any type to be 4116 * cast to void. The only other allowed casts are from a 4117 * scalar type to a scalar type. 4118 */ 4119 } else if (nt == UNION) 4120 return cast_to_union(tn, sys, tp); 4121 else if (nt == STRUCT || nt == ARRAY || nt == FUNC) { 4122 /* Casting to a struct is an undocumented GCC extension. */ 4123 if (!(allow_gcc && nt == STRUCT)) 4124 goto invalid_cast; 4125 } else if (is_struct_or_union(ot)) 4126 goto invalid_cast; 4127 else if (ot == VOID) { 4128 /* improper cast of void expression */ 4129 error(148); 4130 return NULL; 4131 } else if (is_integer(nt) && is_scalar(ot)) { 4132 /* ok */ 4133 } else if (is_floating(nt) && is_arithmetic(ot)) { 4134 /* ok */ 4135 } else if (nt == PTR && is_integer(ot)) { 4136 /* ok */ 4137 } else if (nt == PTR && ot == PTR) { 4138 if (!tp->t_subt->t_const && tn->tn_type->t_subt->t_const) { 4139 if (hflag) 4140 /* cast discards 'const' from type '%s' */ 4141 warning(275, type_name(tn->tn_type)); 4142 } 4143 } else 4144 goto invalid_cast; 4145 4146 if (any_query_enabled 4147 && types_compatible(tp, tn->tn_type, false, false, NULL)) 4148 /* no-op cast from '%s' to '%s' */ 4149 query_message(6, type_name(tn->tn_type), type_name(tp)); 4150 4151 tn = convert(CVT, 0, tp, tn); 4152 tn->tn_cast = true; 4153 tn->tn_sys = sys; 4154 4155 return tn; 4156 4157 invalid_cast: 4158 /* invalid cast from '%s' to '%s' */ 4159 error(147, type_name(tn->tn_type), type_name(tp)); 4160 return NULL; 4161 } 4162 4163 void 4164 add_function_argument(function_call *call, tnode_t *arg) 4165 { 4166 /* 4167 * If there was a serious error in the expression for the argument, 4168 * create a dummy argument so the positions of the remaining arguments 4169 * will not change. 4170 */ 4171 if (arg == NULL) 4172 arg = build_integer_constant(INT, 0); 4173 4174 if (call->args_len >= call->args_cap) { 4175 call->args_cap += 8; 4176 tnode_t **new_args = expr_zero_alloc( 4177 call->args_cap * sizeof(*call->args), 4178 "function_call.args"); 4179 memcpy(new_args, call->args, 4180 call->args_len * sizeof(*call->args)); 4181 call->args = new_args; 4182 } 4183 call->args[call->args_len++] = arg; 4184 } 4185 4186 /* 4187 * Compare the type of an argument with the corresponding type of a 4188 * prototype parameter. If it is a valid combination, but both types 4189 * are not the same, insert a conversion to convert the argument into 4190 * the type of the parameter. 4191 */ 4192 static tnode_t * 4193 check_prototype_argument( 4194 int n, /* pos of arg */ 4195 type_t *tp, /* expected type (from prototype) */ 4196 tnode_t *tn) /* argument */ 4197 { 4198 tnode_t *ln = xcalloc(1, sizeof(*ln)); 4199 ln->tn_type = expr_unqualified_type(tp); 4200 ln->tn_lvalue = true; 4201 if (typeok(FARG, n, ln, tn)) { 4202 bool dowarn; 4203 if (!types_compatible(tp, tn->tn_type, 4204 true, false, (dowarn = false, &dowarn)) || dowarn) 4205 tn = convert(FARG, n, tp, tn); 4206 } 4207 free(ln); 4208 return tn; 4209 } 4210 4211 /* 4212 * Check types of all function arguments and insert conversions, 4213 * if necessary. 4214 */ 4215 static void 4216 check_function_arguments(const function_call *call) 4217 { 4218 type_t *ftp = call->func->tn_type->t_subt; 4219 4220 /* get # of parameters in the prototype */ 4221 int npar = 0; 4222 for (const sym_t *p = ftp->u.params; p != NULL; p = p->s_next) 4223 npar++; 4224 4225 int narg = (int)call->args_len; 4226 4227 const sym_t *param = ftp->u.params; 4228 if (ftp->t_proto && npar != narg && !(ftp->t_vararg && npar < narg)) { 4229 /* argument mismatch: %d %s passed, %d expected */ 4230 error(150, narg, narg != 1 ? "arguments" : "argument", npar); 4231 param = NULL; 4232 } 4233 4234 for (int i = 0; i < narg; i++) { 4235 tnode_t *arg = call->args[i]; 4236 4237 /* some things which are always not allowed */ 4238 tspec_t at = arg->tn_type->t_tspec; 4239 if (at == VOID) { 4240 /* void expressions may not be arguments, arg #%d */ 4241 error(151, i + 1); 4242 return; 4243 } 4244 if (is_struct_or_union(at) && is_incomplete(arg->tn_type)) { 4245 /* argument cannot have unknown size, arg #%d */ 4246 error(152, i + 1); 4247 return; 4248 } 4249 if (is_integer(at) && 4250 arg->tn_type->t_is_enum && 4251 is_incomplete(arg->tn_type)) { 4252 /* argument cannot have unknown size, arg #%d */ 4253 warning(152, i + 1); 4254 } 4255 4256 arg = cconv(arg); 4257 call->args[i] = arg; 4258 4259 arg = param != NULL 4260 ? check_prototype_argument(i + 1, param->s_type, arg) 4261 : promote(NOOP, true, arg); 4262 call->args[i] = arg; 4263 4264 if (param != NULL) 4265 param = param->s_next; 4266 } 4267 } 4268 4269 tnode_t * 4270 build_function_call(tnode_t *func, bool sys, function_call *call) 4271 { 4272 4273 if (func == NULL) 4274 return NULL; 4275 4276 op_t op = func->tn_op == NAME && func->tn_type->t_tspec == FUNC 4277 ? CALL : ICALL; 4278 4279 call->func = func; 4280 check_ctype_function_call(call); 4281 4282 func = cconv(func); 4283 call->func = func; 4284 4285 if (func->tn_type->t_tspec != PTR || 4286 func->tn_type->t_subt->t_tspec != FUNC) { 4287 /* cannot call '%s', must be a function */ 4288 error(149, type_name(func->tn_type)); 4289 return NULL; 4290 } 4291 4292 check_function_arguments(call); 4293 4294 tnode_t *ntn = expr_alloc_tnode(); 4295 ntn->tn_op = op; 4296 ntn->tn_type = func->tn_type->t_subt->t_subt; 4297 ntn->tn_sys = sys; 4298 ntn->u.call = call; 4299 return ntn; 4300 } 4301 4302 /* 4303 * Return the value of an integral constant expression. 4304 * If the expression is not constant or its type is not an integer 4305 * type, an error message is printed. 4306 */ 4307 val_t * 4308 integer_constant(tnode_t *tn, bool required) 4309 { 4310 4311 if (tn != NULL) 4312 tn = cconv(tn); 4313 if (tn != NULL) 4314 tn = promote(NOOP, false, tn); 4315 4316 val_t *v = xcalloc(1, sizeof(*v)); 4317 4318 if (tn == NULL) { 4319 lint_assert(seen_error); 4320 debug_step("constant node is null; returning 1 instead"); 4321 v->v_tspec = INT; 4322 v->u.integer = 1; 4323 return v; 4324 } 4325 4326 v->v_tspec = tn->tn_type->t_tspec; 4327 4328 if (tn->tn_op == CON) { 4329 lint_assert(tn->tn_type->t_tspec == tn->u.value.v_tspec); 4330 if (is_integer(tn->u.value.v_tspec)) { 4331 v->v_unsigned_since_c90 = 4332 tn->u.value.v_unsigned_since_c90; 4333 v->u.integer = tn->u.value.u.integer; 4334 return v; 4335 } 4336 v->u.integer = (int64_t)tn->u.value.u.floating; 4337 } else 4338 v->u.integer = 1; 4339 4340 if (required) 4341 /* integral constant expression expected */ 4342 error(55); 4343 else 4344 /* variable array dimension is a C99/GCC extension */ 4345 c99ism(318); 4346 4347 if (!is_integer(v->v_tspec)) 4348 v->v_tspec = INT; 4349 4350 return v; 4351 } 4352 4353 static bool 4354 is_constcond_false(const tnode_t *tn, tspec_t t) 4355 { 4356 return (t == BOOL || t == INT) && 4357 tn->tn_op == CON && tn->u.value.u.integer == 0; 4358 } 4359 4360 /* 4361 * Perform some tests on expressions which can't be done in build_binary() 4362 * and functions called by build_binary(). These tests must be done here 4363 * because we need some information about the context in which the operations 4364 * are performed. 4365 * After all tests are performed and dofreeblk is true, expr() frees the 4366 * memory which is used for the expression. 4367 */ 4368 void 4369 expr(tnode_t *tn, bool vctx, bool cond, bool dofreeblk, bool is_do_while) 4370 { 4371 4372 if (tn == NULL) { /* in case of errors */ 4373 expr_free_all(); 4374 return; 4375 } 4376 4377 /* expr() is also called in global initializations */ 4378 if (dcs->d_kind != DLK_EXTERN && !is_do_while) 4379 check_statement_reachable(); 4380 4381 check_expr_misc(tn, vctx, cond, !cond, false, false, false); 4382 if (tn->tn_op == ASSIGN && !tn->tn_parenthesized) { 4383 if (hflag && cond) 4384 /* assignment in conditional context */ 4385 warning(159); 4386 } else if (tn->tn_op == CON) { 4387 if (hflag && cond && !suppress_constcond && 4388 !tn->tn_system_dependent && 4389 !(is_do_while && 4390 is_constcond_false(tn, tn->tn_type->t_tspec))) 4391 /* constant in conditional context */ 4392 warning(161); 4393 } 4394 if (!modtab[tn->tn_op].m_has_side_effect) { 4395 /* 4396 * for left operands of COMMA this warning is already printed 4397 */ 4398 if (tn->tn_op != COMMA && !vctx && !cond) 4399 check_null_effect(tn); 4400 } 4401 debug_node(tn); 4402 4403 if (dofreeblk) 4404 expr_free_all(); 4405 } 4406 4407 /* If the expression has the form '*(arr + idx)', check the array index. */ 4408 static void 4409 check_array_index(const tnode_t *indir, bool taking_address) 4410 { 4411 const tnode_t *plus, *arr, *idx; 4412 4413 if (indir->tn_op == INDIR 4414 && (plus = indir->u.ops.left, plus->tn_op == PLUS) 4415 && plus->u.ops.left->tn_op == ADDR 4416 && (arr = plus->u.ops.left->u.ops.left, true) 4417 && (arr->tn_op == STRING || arr->tn_op == NAME) 4418 && arr->tn_type->t_tspec == ARRAY 4419 && (idx = plus->u.ops.right, idx->tn_op == CON) 4420 && (!is_incomplete(arr->tn_type) || idx->u.value.u.integer < 0)) 4421 goto proceed; 4422 return; 4423 4424 proceed:; 4425 int elsz = length_in_bits(arr->tn_type->t_subt, NULL); 4426 if (elsz == 0) 4427 return; 4428 elsz /= CHAR_SIZE; 4429 4430 /* Change the unit of the index from bytes to element size. */ 4431 int64_t con = is_uinteger(idx->tn_type->t_tspec) 4432 ? (int64_t)((uint64_t)idx->u.value.u.integer / elsz) 4433 : idx->u.value.u.integer / elsz; 4434 4435 int dim = arr->tn_type->u.dimension + (taking_address ? 1 : 0); 4436 4437 if (!is_uinteger(idx->tn_type->t_tspec) && con < 0) 4438 /* array subscript %jd cannot be negative */ 4439 warning(167, (intmax_t)con); 4440 else if (dim > 0 && (uint64_t)con >= (uint64_t)dim) 4441 /* array subscript %jd cannot be > %d */ 4442 warning(168, (uintmax_t)con, dim - 1); 4443 } 4444 4445 static void 4446 check_expr_addr(const tnode_t *ln, bool szof, bool fcall) 4447 { 4448 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 4449 if (ln->tn_op == NAME && (reached || !warn_about_unreachable)) { 4450 if (!szof) 4451 mark_as_set(ln->u.sym); 4452 mark_as_used(ln->u.sym, fcall, szof); 4453 } 4454 check_array_index(ln, true); 4455 } 4456 4457 /* 4458 * If there is an asm statement in one of the compound statements around, 4459 * there may be other side effects, so don't warn. 4460 */ 4461 static bool 4462 is_asm_around(void) 4463 { 4464 for (decl_level *dl = dcs; dl != NULL; dl = dl->d_enclosing) 4465 if (dl->d_asm) 4466 return true; 4467 return false; 4468 } 4469 4470 static void 4471 check_expr_side_effect(const tnode_t *ln, bool szof) 4472 { 4473 4474 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 4475 if (ln->tn_op == NAME && (reached || !warn_about_unreachable)) { 4476 scl_t sc = ln->u.sym->s_scl; 4477 if (sc != EXTERN && sc != STATIC && 4478 !ln->u.sym->s_set && !szof && !is_asm_around()) { 4479 /* '%s' may be used before set */ 4480 warning(158, ln->u.sym->s_name); 4481 mark_as_set(ln->u.sym); 4482 } 4483 mark_as_used(ln->u.sym, false, false); 4484 } 4485 } 4486 4487 static void 4488 check_expr_assign(const tnode_t *ln, bool szof) 4489 { 4490 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 4491 if (ln->tn_op == NAME && !szof && (reached || !warn_about_unreachable)) { 4492 mark_as_set(ln->u.sym); 4493 if (ln->u.sym->s_scl == EXTERN) 4494 outusg(ln->u.sym); 4495 } 4496 check_array_index(ln, false); 4497 } 4498 4499 static void 4500 check_expr_call(const tnode_t *tn, const tnode_t *ln, 4501 bool szof, bool vctx, bool cond, bool retval_discarded) 4502 { 4503 lint_assert(ln->tn_op == ADDR); 4504 lint_assert(ln->u.ops.left->tn_op == NAME); 4505 if (!szof && !is_compiler_builtin(ln->u.ops.left->u.sym->s_name)) 4506 outcall(tn, vctx || cond, retval_discarded); 4507 check_snprintb(tn); 4508 } 4509 4510 static void 4511 check_expr_op(op_t op, const tnode_t *ln, bool szof, bool fcall, bool eqwarn) 4512 { 4513 switch (op) { 4514 case ADDR: 4515 check_expr_addr(ln, szof, fcall); 4516 break; 4517 case LOAD: 4518 check_array_index(ln, false); 4519 /* FALLTHROUGH */ 4520 case INCBEF: 4521 case DECBEF: 4522 case INCAFT: 4523 case DECAFT: 4524 case ADDASS: 4525 case SUBASS: 4526 case MULASS: 4527 case DIVASS: 4528 case MODASS: 4529 case ANDASS: 4530 case ORASS: 4531 case XORASS: 4532 case SHLASS: 4533 case SHRASS: 4534 case REAL: 4535 case IMAG: 4536 check_expr_side_effect(ln, szof); 4537 break; 4538 case ASSIGN: 4539 check_expr_assign(ln, szof); 4540 break; 4541 case EQ: 4542 if (hflag && eqwarn) 4543 /* operator '==' found where '=' was expected */ 4544 warning(160); 4545 break; 4546 default: 4547 break; 4548 } 4549 } 4550 4551 /* 4552 * vctx ??? 4553 * cond whether the expression is a condition that 4554 * will be compared with 0 4555 * eqwarn whether the operator '==' might be a 4556 * misspelled '=' 4557 * fcall whether the expression is a function call 4558 * retval_discarded whether the return value of a function call 4559 * is discarded; such calls will be analyzed by 4560 * lint2 in messages 4, 8 and 9 4561 * szof whether the expression is part of a sizeof 4562 * expression, which means that its value is 4563 * discarded since only the type is relevant 4564 */ 4565 void 4566 check_expr_misc(const tnode_t *tn, bool vctx, bool cond, 4567 bool eqwarn, bool fcall, bool retval_discarded, bool szof) 4568 { 4569 4570 if (tn == NULL) 4571 return; 4572 op_t op = tn->tn_op; 4573 if (op == NAME || op == CON || op == STRING) 4574 return; 4575 if (op == CALL || op == ICALL) { 4576 const function_call *call = tn->u.call; 4577 if (op == CALL) 4578 check_expr_call(tn, call->func, 4579 szof, vctx, cond, retval_discarded); 4580 bool discard = op == CVT && tn->tn_type->t_tspec == VOID; 4581 check_expr_misc(call->func, false, false, false, op == CALL, 4582 discard, szof); 4583 for (size_t i = 0, n = call->args_len; i < n; i++) 4584 check_expr_misc(call->args[i], 4585 false, false, false, false, false, szof); 4586 return; 4587 } 4588 4589 lint_assert(has_operands(tn)); 4590 tnode_t *ln = tn->u.ops.left; 4591 tnode_t *rn = tn->u.ops.right; 4592 check_expr_op(op, ln, szof, fcall, eqwarn); 4593 4594 const mod_t *mp = &modtab[op]; 4595 bool cvctx = mp->m_value_context; 4596 bool ccond = mp->m_compares_with_zero; 4597 bool eq = mp->m_warn_if_operand_eq && 4598 !ln->tn_parenthesized && 4599 rn != NULL && !rn->tn_parenthesized; 4600 4601 /* 4602 * Values of operands of ':' are not used if the type of at least 4603 * one of the operands (for GCC compatibility) is 'void'. 4604 * 4605 * XXX test/value context of QUEST should probably be used as 4606 * context for both operands of COLON. 4607 */ 4608 if (op == COLON && tn->tn_type->t_tspec == VOID) 4609 cvctx = ccond = false; 4610 bool discard = op == CVT && tn->tn_type->t_tspec == VOID; 4611 check_expr_misc(ln, cvctx, ccond, eq, op == CALL, discard, szof); 4612 4613 switch (op) { 4614 case LOGAND: 4615 case LOGOR: 4616 check_expr_misc(rn, false, true, eq, false, false, szof); 4617 break; 4618 case COLON: 4619 check_expr_misc(rn, cvctx, ccond, eq, false, false, szof); 4620 break; 4621 case COMMA: 4622 check_expr_misc(rn, vctx, cond, false, false, false, szof); 4623 break; 4624 default: 4625 if (mp->m_binary) 4626 check_expr_misc(rn, true, false, eq, false, false, 4627 szof); 4628 break; 4629 } 4630 } 4631 4632 /* 4633 * Return whether the expression can be used for static initialization. 4634 * 4635 * Constant initialization expressions must be constant or an address 4636 * of a static object with an optional offset. In the first case, 4637 * the result is returned in *offsp. In the second case, the static 4638 * object is returned in *symp and the offset in *offsp. 4639 * 4640 * The expression can consist of PLUS, MINUS, ADDR, NAME, STRING and 4641 * CON. Type conversions are allowed if they do not change binary 4642 * representation (including width). 4643 * 4644 * C99 6.6 "Constant expressions" 4645 * C99 6.7.8p4 restricts initializers for static storage duration 4646 */ 4647 bool 4648 constant_addr(const tnode_t *tn, const sym_t **symp, ptrdiff_t *offsp) 4649 { 4650 const sym_t *sym; 4651 ptrdiff_t offs1, offs2; 4652 tspec_t t, ot; 4653 4654 switch (tn->tn_op) { 4655 case MINUS: 4656 if (tn->u.ops.right->tn_op == CVT) 4657 return constant_addr(tn->u.ops.right, symp, offsp); 4658 else if (tn->u.ops.right->tn_op != CON) 4659 return false; 4660 /* FALLTHROUGH */ 4661 case PLUS: 4662 offs1 = offs2 = 0; 4663 if (tn->u.ops.left->tn_op == CON) { 4664 offs1 = (ptrdiff_t)tn->u.ops.left->u.value.u.integer; 4665 if (!constant_addr(tn->u.ops.right, &sym, &offs2)) 4666 return false; 4667 } else if (tn->u.ops.right->tn_op == CON) { 4668 offs2 = (ptrdiff_t)tn->u.ops.right->u.value.u.integer; 4669 if (tn->tn_op == MINUS) 4670 offs2 = -offs2; 4671 if (!constant_addr(tn->u.ops.left, &sym, &offs1)) 4672 return false; 4673 } else { 4674 return false; 4675 } 4676 *symp = sym; 4677 *offsp = offs1 + offs2; 4678 return true; 4679 case ADDR: 4680 if (tn->u.ops.left->tn_op == NAME) { 4681 *symp = tn->u.ops.left->u.sym; 4682 *offsp = 0; 4683 return true; 4684 } else { 4685 /* 4686 * If this were the front end of a compiler, we would 4687 * return a label instead of 0, at least if 4688 * 'tn->u.ops.left->tn_op == STRING'. 4689 */ 4690 *symp = NULL; 4691 *offsp = 0; 4692 return true; 4693 } 4694 case CVT: 4695 t = tn->tn_type->t_tspec; 4696 ot = tn->u.ops.left->tn_type->t_tspec; 4697 if ((!is_integer(t) && t != PTR) || 4698 (!is_integer(ot) && ot != PTR)) { 4699 return false; 4700 } 4701 #if 0 4702 /*- 4703 * consider: 4704 * struct foo { 4705 * unsigned char a; 4706 * } f = { 4707 * (unsigned char)(unsigned long) 4708 * (&(((struct foo *)0)->a)) 4709 * }; 4710 * since psize(unsigned long) != psize(unsigned char), 4711 * this fails. 4712 */ 4713 else if (psize(t) != psize(ot)) 4714 return -1; 4715 #endif 4716 return constant_addr(tn->u.ops.left, symp, offsp); 4717 default: 4718 return false; 4719 } 4720 } 4721 4722 /* Append s2 to s1, then free s2. */ 4723 buffer * 4724 cat_strings(buffer *s1, buffer *s2) 4725 { 4726 4727 if ((s1->data != NULL) != (s2->data != NULL)) { 4728 /* cannot concatenate wide and regular string literals */ 4729 error(292); 4730 return s1; 4731 } 4732 4733 if (s1->data != NULL) { 4734 while (s1->len + s2->len + 1 > s1->cap) 4735 s1->cap *= 2; 4736 s1->data = xrealloc(s1->data, s1->cap); 4737 memcpy(s1->data + s1->len, s2->data, s2->len + 1); 4738 free(s2->data); 4739 } 4740 s1->len += s2->len; 4741 free(s2); 4742 4743 return s1; 4744 } 4745 4746 4747 typedef struct stmt_expr { 4748 memory_pool se_mem; 4749 sym_t *se_sym; 4750 struct stmt_expr *se_enclosing; 4751 } stmt_expr; 4752 4753 static stmt_expr *stmt_exprs; 4754 4755 void 4756 begin_statement_expr(void) 4757 { 4758 debug_enter(); 4759 4760 stmt_expr *se = xmalloc(sizeof(*se)); 4761 se->se_mem = expr_save_memory(); 4762 se->se_sym = NULL; 4763 se->se_enclosing = stmt_exprs; 4764 stmt_exprs = se; 4765 } 4766 4767 void 4768 do_statement_expr(tnode_t *tn) 4769 { 4770 block_level--; 4771 mem_block_level--; 4772 stmt_exprs->se_sym = tn != NULL 4773 ? mktempsym(block_dup_type(tn->tn_type)) 4774 : NULL; /* after a syntax error */ 4775 mem_block_level++; 4776 block_level++; 4777 /* '({ ... })' is a GCC extension */ 4778 gnuism(320); 4779 } 4780 4781 tnode_t * 4782 end_statement_expr(void) 4783 { 4784 tnode_t *tn; 4785 4786 stmt_expr *se = stmt_exprs; 4787 if (se->se_sym == NULL) { 4788 tn = NULL; /* after a syntax error */ 4789 goto end; 4790 } 4791 4792 tn = build_name(se->se_sym, false); 4793 (void)expr_save_memory(); /* leak */ 4794 expr_restore_memory(se->se_mem); 4795 stmt_exprs = se->se_enclosing; 4796 free(se); 4797 4798 end: 4799 debug_leave(); 4800 return tn; 4801 } 4802 4803 bool 4804 in_statement_expr(void) 4805 { 4806 return stmt_exprs != NULL; 4807 } 4808
Indexes created Thu Sep 25 16:09:42 GMT 2025