tree.c revision 1.621
1 /* $NetBSD: tree.c,v 1.621 2024/03/10 15:49:12 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 1.621 2024/03/10 15:49:12 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 } 766 767 static tnode_t * 768 build_address(bool sys, tnode_t *tn, bool force) 769 { 770 tspec_t t; 771 772 if (!force && ((t = tn->tn_type->t_tspec) == ARRAY || t == FUNC)) { 773 if (!allow_c90) 774 /* '&' before array or function: ignored */ 775 warning(127); 776 return tn; 777 } 778 779 /* eliminate '&*' */ 780 if (tn->tn_op == INDIR && 781 tn->u.ops.left->tn_type->t_tspec == PTR && 782 tn->u.ops.left->tn_type->t_subt == tn->tn_type) { 783 return tn->u.ops.left; 784 } 785 786 return build_op(ADDR, sys, expr_derive_type(tn->tn_type, PTR), 787 tn, NULL); 788 } 789 790 static uint64_t 791 fold_unsigned_integer(op_t op, uint64_t l, uint64_t r, 792 uint64_t max_value, bool *overflow) 793 { 794 switch (op) { 795 case COMPL: 796 return ~l & max_value; 797 case UPLUS: 798 return +l; 799 case UMINUS: 800 return -l & max_value; 801 case MULT: 802 *overflow = r > 0 && l > max_value / r; 803 return l * r; 804 case DIV: 805 if (r == 0) { 806 /* division by 0 */ 807 error(139); 808 return max_value; 809 } 810 return l / r; 811 case MOD: 812 if (r == 0) { 813 /* modulus by 0 */ 814 error(140); 815 return 0; 816 } 817 return l % r; 818 case PLUS: 819 *overflow = l > max_value - r; 820 return l + r; 821 case MINUS: 822 *overflow = l < r; 823 return l - r; 824 case SHL: 825 /* TODO: warn about out-of-bounds 'sr'. */ 826 /* TODO: warn about overflow. */ 827 return l << (r & 63); 828 case SHR: 829 /* TODO: warn about out-of-bounds 'sr'. */ 830 return l >> (r & 63); 831 case LT: 832 return l < r ? 1 : 0; 833 case LE: 834 return l <= r ? 1 : 0; 835 case GT: 836 return l > r ? 1 : 0; 837 case GE: 838 return l >= r ? 1 : 0; 839 case EQ: 840 return l == r ? 1 : 0; 841 case NE: 842 return l != r ? 1 : 0; 843 case BITAND: 844 return l & r; 845 case BITXOR: 846 return l ^ r; 847 case BITOR: 848 return l | r; 849 default: 850 lint_assert(/*CONSTCOND*/false); 851 /* NOTREACHED */ 852 } 853 } 854 855 static int64_t 856 fold_signed_integer(op_t op, int64_t l, int64_t r, 857 int64_t min_value, int64_t max_value, bool *overflow) 858 { 859 switch (op) { 860 case COMPL: 861 return ~l; 862 case UPLUS: 863 return +l; 864 case UMINUS: 865 *overflow = l == min_value; 866 return *overflow ? l : -l; 867 case MULT:; 868 uint64_t al = l >= 0 ? (uint64_t)l : -(uint64_t)l; 869 uint64_t ar = r >= 0 ? (uint64_t)r : -(uint64_t)r; 870 bool neg = (l >= 0) != (r >= 0); 871 uint64_t max_prod = (uint64_t)max_value + (neg ? 1 : 0); 872 if (al > 0 && ar > max_prod / al) { 873 *overflow = true; 874 return (int64_t)(al * ar); 875 } 876 return l * r; 877 case DIV: 878 if (r == 0) { 879 /* division by 0 */ 880 error(139); 881 return max_value; 882 } 883 if (l == min_value && r == -1) { 884 *overflow = true; 885 return l; 886 } 887 return l / r; 888 case MOD: 889 if (r == 0) { 890 /* modulus by 0 */ 891 error(140); 892 return 0; 893 } 894 if (l == min_value && r == -1) { 895 *overflow = true; 896 return 0; 897 } 898 return l % r; 899 case PLUS: 900 if (r > 0 && l > max_value - r) { 901 *overflow = true; 902 return max_value; 903 } 904 if (r < 0 && l < min_value - r) { 905 *overflow = true; 906 return min_value; 907 } 908 return l + r; 909 case MINUS: 910 if (r > 0 && l < min_value + r) { 911 *overflow = true; 912 return min_value; 913 } 914 if (r < 0 && l > max_value + r) { 915 *overflow = true; 916 return max_value; 917 } 918 return l - r; 919 case SHL: 920 /* TODO: warn about out-of-bounds 'sr'. */ 921 /* TODO: warn about overflow. */ 922 return l << (r & 63); 923 case SHR: 924 /* TODO: warn about out-of-bounds 'sr'. */ 925 if (l < 0) 926 return (int64_t)~(~(uint64_t)l >> (r & 63)); 927 return (int64_t)((uint64_t)l >> (r & 63)); 928 case LT: 929 return l < r ? 1 : 0; 930 case LE: 931 return l <= r ? 1 : 0; 932 case GT: 933 return l > r ? 1 : 0; 934 case GE: 935 return l >= r ? 1 : 0; 936 case EQ: 937 return l == r ? 1 : 0; 938 case NE: 939 return l != r ? 1 : 0; 940 case BITAND: 941 return l & r; 942 case BITXOR: 943 return l ^ r; 944 case BITOR: 945 return l | r; 946 default: 947 lint_assert(/*CONSTCOND*/false); 948 /* NOTREACHED */ 949 } 950 } 951 952 static tnode_t * 953 fold_constant_integer(tnode_t *tn) 954 { 955 956 lint_assert(has_operands(tn)); 957 tspec_t t = tn->u.ops.left->tn_type->t_tspec; 958 int64_t l = tn->u.ops.left->u.value.u.integer; 959 int64_t r = is_binary(tn) ? tn->u.ops.right->u.value.u.integer : 0; 960 uint64_t mask = value_bits(size_in_bits(t)); 961 962 int64_t res; 963 bool overflow = false; 964 if (!is_integer(t) || is_uinteger(t)) { 965 uint64_t u_res = fold_unsigned_integer(tn->tn_op, 966 (uint64_t)l, (uint64_t)r, mask, &overflow); 967 if (u_res > mask) 968 overflow = true; 969 res = (int64_t)u_res; 970 } else { 971 int64_t max_value = (int64_t)(mask >> 1); 972 int64_t min_value = -max_value - 1; 973 res = fold_signed_integer(tn->tn_op, 974 l, r, min_value, max_value, &overflow); 975 if (res < min_value || res > max_value) 976 overflow = true; 977 } 978 979 if (overflow && hflag) 980 /* operator '%s' produces integer overflow */ 981 warning(141, op_name(tn->tn_op)); 982 983 val_t *v = xcalloc(1, sizeof(*v)); 984 v->v_tspec = tn->tn_type->t_tspec; 985 v->u.integer = convert_integer(res, t, 0); 986 987 tnode_t *cn = build_constant(tn->tn_type, v); 988 if (tn->u.ops.left->tn_system_dependent) 989 cn->tn_system_dependent = true; 990 if (is_binary(tn) && tn->u.ops.right->tn_system_dependent) 991 cn->tn_system_dependent = true; 992 993 return cn; 994 } 995 996 static tnode_t * 997 build_struct_access(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 998 { 999 1000 lint_assert(rn->tn_op == NAME); 1001 lint_assert(is_member(rn->u.sym)); 1002 1003 bool lvalue = op == ARROW || ln->tn_lvalue; 1004 1005 if (op == POINT) 1006 ln = build_address(sys, ln, true); 1007 else if (ln->tn_type->t_tspec != PTR) { 1008 lint_assert(!allow_c90); 1009 lint_assert(is_integer(ln->tn_type->t_tspec)); 1010 ln = convert(NOOP, 0, expr_derive_type(gettyp(VOID), PTR), ln); 1011 } 1012 1013 tnode_t *ctn = build_integer_constant(PTRDIFF_TSPEC, 1014 rn->u.sym->u.s_member.sm_offset_in_bits / CHAR_SIZE); 1015 1016 type_t *ptr_tp = expr_derive_type(rn->tn_type, PTR); 1017 tnode_t *ntn = build_op(PLUS, sys, ptr_tp, ln, ctn); 1018 if (ln->tn_op == CON) 1019 ntn = fold_constant_integer(ntn); 1020 1021 op_t nop = rn->tn_type->t_bitfield ? FSEL : INDIR; 1022 ntn = build_op(nop, sys, ntn->tn_type->t_subt, ntn, NULL); 1023 if (!lvalue) 1024 ntn->tn_lvalue = false; 1025 1026 return ntn; 1027 } 1028 1029 /* 1030 * Get the size in bytes of type tp->t_subt, as a constant expression of type 1031 * ptrdiff_t as seen from the target platform. 1032 */ 1033 static tnode_t * 1034 subt_size_in_bytes(type_t *tp) 1035 { 1036 1037 lint_assert(tp->t_tspec == PTR); 1038 tp = tp->t_subt; 1039 1040 int elem = 1; 1041 while (tp->t_tspec == ARRAY) { 1042 elem *= tp->u.dimension; 1043 tp = tp->t_subt; 1044 } 1045 1046 int elsz_in_bits = 0; 1047 switch (tp->t_tspec) { 1048 case FUNC: 1049 /* pointer to function is not allowed here */ 1050 error(110); 1051 break; 1052 case VOID: 1053 /* cannot do pointer arithmetic on operand of unknown size */ 1054 gnuism(136); 1055 break; 1056 case STRUCT: 1057 case UNION: 1058 if ((elsz_in_bits = (int)tp->u.sou->sou_size_in_bits) == 0) 1059 /* cannot do pointer arithmetic on operand of ... */ 1060 error(136); 1061 break; 1062 case ENUM: 1063 if (is_incomplete(tp)) 1064 /* cannot do pointer arithmetic on operand of ... */ 1065 warning(136); 1066 /* FALLTHROUGH */ 1067 default: 1068 if ((elsz_in_bits = size_in_bits(tp->t_tspec)) == 0) 1069 /* cannot do pointer arithmetic on operand of ... */ 1070 error(136); 1071 else 1072 lint_assert(elsz_in_bits != -1); 1073 break; 1074 } 1075 1076 if (elem == 0 && elsz_in_bits != 0) 1077 /* cannot do pointer arithmetic on operand of unknown size */ 1078 error(136); 1079 1080 if (elsz_in_bits == 0) 1081 elsz_in_bits = CHAR_SIZE; 1082 1083 return build_integer_constant(PTRDIFF_TSPEC, 1084 (int64_t)(elem * elsz_in_bits / CHAR_SIZE)); 1085 } 1086 1087 static tnode_t * 1088 build_prepost_incdec(op_t op, bool sys, tnode_t *ln) 1089 { 1090 1091 lint_assert(ln != NULL); 1092 tnode_t *cn = ln->tn_type->t_tspec == PTR 1093 ? subt_size_in_bytes(ln->tn_type) 1094 : build_integer_constant(INT, 1); 1095 return build_op(op, sys, ln->tn_type, ln, cn); 1096 } 1097 1098 static void 1099 check_enum_array_index(const tnode_t *ln, const tnode_t *rn) 1100 { 1101 1102 if (ln->tn_op != ADDR || ln->u.ops.left->tn_op != NAME) 1103 return; 1104 1105 const type_t *ltp = ln->u.ops.left->tn_type; 1106 if (ltp->t_tspec != ARRAY || ltp->t_incomplete_array) 1107 return; 1108 1109 if (rn->tn_op != CVT || !rn->tn_type->t_is_enum) 1110 return; 1111 if (rn->u.ops.left->tn_op != LOAD) 1112 return; 1113 1114 const type_t *rtp = rn->u.ops.left->tn_type; 1115 const sym_t *ec = rtp->u.enumer->en_first_enumerator; 1116 const sym_t *max_ec = ec; 1117 lint_assert(ec != NULL); 1118 for (ec = ec->s_next; ec != NULL; ec = ec->s_next) 1119 if (ec->u.s_enum_constant > max_ec->u.s_enum_constant) 1120 max_ec = ec; 1121 1122 int64_t max_enum_value = max_ec->u.s_enum_constant; 1123 lint_assert(INT_MIN <= max_enum_value && max_enum_value <= INT_MAX); 1124 1125 int max_array_index = ltp->u.dimension - 1; 1126 if (max_enum_value == max_array_index) 1127 return; 1128 1129 if (max_enum_value == max_array_index + 1 && 1130 (strstr(max_ec->s_name, "MAX") != NULL || 1131 strstr(max_ec->s_name, "max") != NULL || 1132 strstr(max_ec->s_name, "NUM") != NULL || 1133 strstr(max_ec->s_name, "num") != NULL)) 1134 return; 1135 1136 /* maximum value %d of '%s' does not match maximum array index %d */ 1137 warning(348, (int)max_enum_value, type_name(rtp), max_array_index); 1138 print_previous_declaration(max_ec); 1139 } 1140 1141 static tnode_t * 1142 build_plus_minus(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 1143 { 1144 1145 if (rn->tn_type->t_tspec == PTR && is_integer(ln->tn_type->t_tspec)) { 1146 tnode_t *tmp = ln; 1147 ln = rn; 1148 rn = tmp; 1149 /* pointer addition has integer on the left-hand side */ 1150 query_message(5); 1151 } 1152 1153 /* pointer +- integer */ 1154 if (ln->tn_type->t_tspec == PTR && rn->tn_type->t_tspec != PTR) { 1155 lint_assert(is_integer(rn->tn_type->t_tspec)); 1156 1157 check_ctype_macro_invocation(ln, rn); 1158 check_enum_array_index(ln, rn); 1159 1160 tnode_t *elsz = subt_size_in_bytes(ln->tn_type); 1161 if (rn->tn_type->t_tspec != elsz->tn_type->t_tspec) 1162 rn = convert(NOOP, 0, elsz->tn_type, rn); 1163 1164 tnode_t *prod = build_op(MULT, sys, rn->tn_type, rn, elsz); 1165 if (rn->tn_op == CON) 1166 prod = fold_constant_integer(prod); 1167 1168 return build_op(op, sys, ln->tn_type, ln, prod); 1169 } 1170 1171 /* pointer - pointer */ 1172 if (rn->tn_type->t_tspec == PTR) { 1173 lint_assert(ln->tn_type->t_tspec == PTR); 1174 lint_assert(op == MINUS); 1175 1176 type_t *ptrdiff = gettyp(PTRDIFF_TSPEC); 1177 tnode_t *raw_diff = build_op(op, sys, ptrdiff, ln, rn); 1178 if (ln->tn_op == CON && rn->tn_op == CON) 1179 raw_diff = fold_constant_integer(raw_diff); 1180 1181 tnode_t *elsz = subt_size_in_bytes(ln->tn_type); 1182 balance(NOOP, &raw_diff, &elsz); 1183 1184 return build_op(DIV, sys, ptrdiff, raw_diff, elsz); 1185 } 1186 1187 return build_op(op, sys, ln->tn_type, ln, rn); 1188 } 1189 1190 static tnode_t * 1191 build_bit_shift(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 1192 { 1193 1194 if (!allow_c90 && rn->tn_type->t_tspec != INT) 1195 // XXX: C1978 7.5 says: "Both [operators] perform the usual 1196 // arithmetic conversions on their operands." 1197 // TODO: Add a test to exercise this part of the code. 1198 rn = convert(NOOP, 0, gettyp(INT), rn); 1199 return build_op(op, sys, ln->tn_type, ln, rn); 1200 } 1201 1202 static bool 1203 is_null_pointer(const tnode_t *tn) 1204 { 1205 tspec_t t = tn->tn_type->t_tspec; 1206 1207 // TODO: Investigate how other pointers are stored, in particular, 1208 // whether a pointer constant can have a non-zero value. 1209 // If not, simplify the code below. 1210 return ((t == PTR && tn->tn_type->t_subt->t_tspec == VOID) 1211 || is_integer(t)) 1212 && (tn->tn_op == CON && tn->u.value.u.integer == 0); 1213 } 1214 1215 /* Return a type based on tp1, with added qualifiers from tp2. */ 1216 static type_t * 1217 merge_qualifiers(type_t *tp1, const type_t *tp2) 1218 { 1219 1220 lint_assert(tp1->t_tspec == PTR); 1221 lint_assert(tp2->t_tspec == PTR); 1222 1223 bool c1 = tp1->t_subt->t_const; 1224 bool c2 = tp2->t_subt->t_const; 1225 bool v1 = tp1->t_subt->t_volatile; 1226 bool v2 = tp2->t_subt->t_volatile; 1227 1228 if (c1 == (c1 | c2) && v1 == (v1 | v2)) 1229 return tp1; 1230 1231 type_t *nstp = expr_dup_type(tp1->t_subt); 1232 nstp->t_const |= c2; 1233 nstp->t_volatile |= v2; 1234 1235 type_t *ntp = expr_dup_type(tp1); 1236 ntp->t_subt = nstp; 1237 return ntp; 1238 } 1239 1240 /* See C99 6.5.15 "Conditional operator". */ 1241 static tnode_t * 1242 build_colon(bool sys, tnode_t *ln, tnode_t *rn) 1243 { 1244 tspec_t lt = ln->tn_type->t_tspec; 1245 tspec_t rt = rn->tn_type->t_tspec; 1246 1247 type_t *tp; 1248 if (is_arithmetic(lt) && is_arithmetic(rt)) 1249 /* The operands were already balanced in build_binary. */ 1250 tp = ln->tn_type; 1251 else if (lt == BOOL && rt == BOOL) 1252 tp = ln->tn_type; 1253 else if (lt == VOID || rt == VOID) 1254 tp = gettyp(VOID); 1255 else if (is_struct_or_union(lt)) { 1256 lint_assert(is_struct_or_union(rt)); 1257 lint_assert(ln->tn_type->u.sou == rn->tn_type->u.sou); 1258 if (is_incomplete(ln->tn_type)) { 1259 /* unknown operand size, op '%s' */ 1260 error(138, op_name(COLON)); 1261 return NULL; 1262 } 1263 tp = ln->tn_type; 1264 } else if (lt == PTR && is_integer(rt)) { 1265 if (rt != PTRDIFF_TSPEC) 1266 rn = convert(NOOP, 0, gettyp(PTRDIFF_TSPEC), rn); 1267 tp = ln->tn_type; 1268 } else if (rt == PTR && is_integer(lt)) { 1269 if (lt != PTRDIFF_TSPEC) 1270 ln = convert(NOOP, 0, gettyp(PTRDIFF_TSPEC), ln); 1271 tp = rn->tn_type; 1272 } else if (lt == PTR && is_null_pointer(rn)) 1273 tp = merge_qualifiers(ln->tn_type, rn->tn_type); 1274 else if (rt == PTR && is_null_pointer(ln)) 1275 tp = merge_qualifiers(rn->tn_type, ln->tn_type); 1276 else if (lt == PTR && ln->tn_type->t_subt->t_tspec == VOID) 1277 tp = merge_qualifiers(ln->tn_type, rn->tn_type); 1278 else if (rt == PTR && rn->tn_type->t_subt->t_tspec == VOID) 1279 tp = merge_qualifiers(rn->tn_type, ln->tn_type); 1280 else { 1281 /* 1282 * XXX For now we simply take the left type. This is probably 1283 * wrong, if one type contains a function prototype and the 1284 * other one, at the same place, only an old-style declaration. 1285 */ 1286 tp = merge_qualifiers(ln->tn_type, rn->tn_type); 1287 } 1288 1289 return build_op(COLON, sys, tp, ln, rn); 1290 } 1291 1292 /* TODO: check for varargs */ 1293 static bool 1294 is_cast_redundant(const tnode_t *tn) 1295 { 1296 const type_t *ntp = tn->tn_type, *otp = tn->u.ops.left->tn_type; 1297 tspec_t nt = ntp->t_tspec, ot = otp->t_tspec; 1298 1299 if (nt == BOOL || ot == BOOL) 1300 return nt == BOOL && ot == BOOL; 1301 1302 if (is_integer(nt) && is_integer(ot)) { 1303 unsigned int nw = width_in_bits(ntp), ow = width_in_bits(otp); 1304 if (is_uinteger(nt) == is_uinteger(ot)) 1305 return nw >= ow; 1306 return is_uinteger(ot) && nw > ow; 1307 } 1308 1309 if (is_complex(nt) || is_complex(ot)) 1310 return is_complex(nt) && is_complex(ot) && 1311 size_in_bits(nt) >= size_in_bits(ot); 1312 1313 if (is_floating(nt) && is_floating(ot)) 1314 return size_in_bits(nt) >= size_in_bits(ot); 1315 1316 if (nt == PTR && ot == PTR) { 1317 if (!ntp->t_subt->t_const && otp->t_subt->t_const) 1318 return false; 1319 if (!ntp->t_subt->t_volatile && otp->t_subt->t_volatile) 1320 return false; 1321 1322 if (ntp->t_subt->t_tspec == VOID || 1323 otp->t_subt->t_tspec == VOID || 1324 types_compatible(ntp->t_subt, otp->t_subt, 1325 false, false, NULL)) 1326 return true; 1327 } 1328 1329 return false; 1330 } 1331 1332 static bool 1333 is_assignment(op_t op) 1334 { 1335 1336 return op == ASSIGN || 1337 op == MULASS || 1338 op == DIVASS || 1339 op == MODASS || 1340 op == ADDASS || 1341 op == SUBASS || 1342 op == SHLASS || 1343 op == SHRASS || 1344 op == ANDASS || 1345 op == XORASS || 1346 op == ORASS || 1347 op == RETURN || 1348 op == INIT; 1349 } 1350 1351 static tnode_t * 1352 build_assignment(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 1353 { 1354 1355 tspec_t lt = ln->tn_type->t_tspec; 1356 tspec_t rt = rn->tn_type->t_tspec; 1357 1358 if (any_query_enabled && is_assignment(rn->tn_op)) { 1359 /* chained assignment with '%s' and '%s' */ 1360 query_message(10, op_name(op), op_name(rn->tn_op)); 1361 } 1362 1363 if ((op == ADDASS || op == SUBASS) && lt == PTR) { 1364 lint_assert(is_integer(rt)); 1365 tnode_t *ctn = subt_size_in_bytes(ln->tn_type); 1366 if (rn->tn_type->t_tspec != ctn->tn_type->t_tspec) 1367 rn = convert(NOOP, 0, ctn->tn_type, rn); 1368 rn = build_op(MULT, sys, rn->tn_type, rn, ctn); 1369 if (rn->u.ops.left->tn_op == CON) 1370 rn = fold_constant_integer(rn); 1371 } 1372 1373 if ((op == ASSIGN || op == RETURN || op == INIT) && 1374 (lt == STRUCT || rt == STRUCT)) { 1375 lint_assert(lt == rt); 1376 lint_assert(ln->tn_type->u.sou == rn->tn_type->u.sou); 1377 if (is_incomplete(ln->tn_type)) { 1378 if (op == RETURN) 1379 /* cannot return incomplete type */ 1380 error(212); 1381 else 1382 /* unknown operand size, op '%s' */ 1383 error(138, op_name(op)); 1384 return NULL; 1385 } 1386 } 1387 1388 if (op == SHLASS && hflag && allow_trad && allow_c90 1389 && portable_rank_cmp(lt, rt) < 0) 1390 /* semantics of '%s' change in C90; ... */ 1391 warning(118, "<<="); 1392 1393 if (op != SHLASS && op != SHRASS 1394 && (op == ASSIGN || lt != PTR) 1395 && (lt != rt || (ln->tn_type->t_bitfield && rn->tn_op == CON))) { 1396 rn = convert(op, 0, ln->tn_type, rn); 1397 rt = lt; 1398 } 1399 1400 if (any_query_enabled && rn->tn_op == CVT && rn->tn_cast && 1401 types_compatible(ln->tn_type, rn->tn_type, false, false, NULL) && 1402 is_cast_redundant(rn)) { 1403 /* redundant cast from '%s' to '%s' before assignment */ 1404 query_message(7, type_name(rn->u.ops.left->tn_type), 1405 type_name(rn->tn_type)); 1406 } 1407 1408 return build_op(op, sys, ln->tn_type, ln, rn); 1409 } 1410 1411 static tnode_t * 1412 build_real_imag(op_t op, bool sys, tnode_t *ln) 1413 { 1414 1415 lint_assert(ln != NULL); 1416 if (ln->tn_op == NAME) { 1417 /* 1418 * This may be too much, but it avoids wrong warnings. See 1419 * d_c99_complex_split.c. 1420 */ 1421 mark_as_used(ln->u.sym, false, false); 1422 mark_as_set(ln->u.sym); 1423 } 1424 1425 tspec_t t; 1426 switch (ln->tn_type->t_tspec) { 1427 case LCOMPLEX: 1428 t = LDOUBLE; 1429 break; 1430 case DCOMPLEX: 1431 t = DOUBLE; 1432 break; 1433 case FCOMPLEX: 1434 t = FLOAT; 1435 break; 1436 default: 1437 /* '__%s__' is illegal for type '%s' */ 1438 error(276, op == REAL ? "real" : "imag", 1439 type_name(ln->tn_type)); 1440 return NULL; 1441 } 1442 1443 tnode_t *ntn = build_op(op, sys, gettyp(t), ln, NULL); 1444 ntn->tn_lvalue = true; 1445 return ntn; 1446 } 1447 1448 static bool 1449 is_confusing_precedence(op_t op, op_t lop, bool lparen, op_t rop, bool rparen) 1450 { 1451 1452 if (op == SHL || op == SHR) { 1453 if (!lparen && (lop == PLUS || lop == MINUS)) 1454 return true; 1455 if (!rparen && (rop == PLUS || rop == MINUS)) 1456 return true; 1457 return false; 1458 } 1459 1460 if (op == LOGOR) { 1461 if (!lparen && lop == LOGAND) 1462 return true; 1463 if (!rparen && rop == LOGAND) 1464 return true; 1465 return false; 1466 } 1467 1468 lint_assert(op == BITAND || op == BITXOR || op == BITOR); 1469 if (!lparen && lop != op) { 1470 if (lop == PLUS || lop == MINUS) 1471 return true; 1472 if (lop == BITAND || lop == BITXOR) 1473 return true; 1474 } 1475 if (!rparen && rop != op) { 1476 if (rop == PLUS || rop == MINUS) 1477 return true; 1478 if (rop == BITAND || rop == BITXOR) 1479 return true; 1480 } 1481 return false; 1482 } 1483 1484 /* 1485 * Print a warning if the given node has operands which should be 1486 * parenthesized. 1487 * 1488 * XXX Does not work if an operand is a constant expression. Constant 1489 * expressions are already folded. 1490 */ 1491 static void 1492 check_precedence_confusion(tnode_t *tn) 1493 { 1494 tnode_t *ln, *rn; 1495 1496 if (!hflag) 1497 return; 1498 1499 debug_node(tn); 1500 1501 lint_assert(is_binary(tn)); 1502 for (ln = tn->u.ops.left; ln->tn_op == CVT; ln = ln->u.ops.left) 1503 continue; 1504 for (rn = tn->u.ops.right; rn->tn_op == CVT; rn = rn->u.ops.left) 1505 continue; 1506 1507 if (is_confusing_precedence(tn->tn_op, 1508 ln->tn_op, ln->tn_parenthesized, 1509 rn->tn_op, rn->tn_parenthesized)) { 1510 /* precedence confusion possible: parenthesize! */ 1511 warning(169); 1512 } 1513 } 1514 1515 static tnode_t * 1516 fold_constant_compare_zero(tnode_t *tn) 1517 { 1518 1519 val_t *v = xcalloc(1, sizeof(*v)); 1520 v->v_tspec = tn->tn_type->t_tspec; 1521 lint_assert(v->v_tspec == INT || (Tflag && v->v_tspec == BOOL)); 1522 1523 lint_assert(has_operands(tn)); 1524 bool l = constant_is_nonzero(tn->u.ops.left); 1525 bool r = is_binary(tn) && constant_is_nonzero(tn->u.ops.right); 1526 1527 switch (tn->tn_op) { 1528 case NOT: 1529 if (hflag && !suppress_constcond) 1530 /* constant operand to '!' */ 1531 warning(239); 1532 v->u.integer = !l ? 1 : 0; 1533 break; 1534 case LOGAND: 1535 v->u.integer = l && r ? 1 : 0; 1536 break; 1537 case LOGOR: 1538 v->u.integer = l || r ? 1 : 0; 1539 break; 1540 default: 1541 lint_assert(/*CONSTCOND*/false); 1542 } 1543 1544 return build_constant(tn->tn_type, v); 1545 } 1546 1547 static long double 1548 floating_error_value(tspec_t t, long double lv) 1549 { 1550 if (t == FLOAT) 1551 return lv < 0 ? -FLT_MAX : FLT_MAX; 1552 if (t == DOUBLE) 1553 return lv < 0 ? -DBL_MAX : DBL_MAX; 1554 /* 1555 * When NetBSD is cross-built in MKLINT=yes mode on x86_64 for sparc64, 1556 * tools/lint checks this code while building usr.bin/xlint. In that 1557 * situation, lint uses the preprocessor for sparc64, in which the type 1558 * 'long double' is IEEE-754-binary128, affecting the macro LDBL_MAX 1559 * below. The type 'long double', as well as the strtold 1560 * implementation, comes from the host platform x86_64 though, where 1561 * 'long double' consumes 128 bits as well but only uses 80 of them. 1562 * The exponent range of the two 'long double' types is the same, but 1563 * the maximum finite value differs due to the extended precision on 1564 * sparc64. 1565 * 1566 * To properly handle the data types of the target platform, lint would 1567 * have to implement the floating-point types in a platform-independent 1568 * way, which is not worth the effort, given how few programs 1569 * practically use 'long double'. 1570 */ 1571 /* LINTED 248: floating-point constant out of range */ 1572 long double max = LDBL_MAX; 1573 return lv < 0 ? -max : max; 1574 } 1575 1576 static bool 1577 is_floating_overflow(tspec_t t, long double val) 1578 { 1579 if (fpe != 0 || isfinite(val) == 0) 1580 return true; 1581 if (t == FLOAT && (val > FLT_MAX || val < -FLT_MAX)) 1582 return true; 1583 if (t == DOUBLE && (val > DBL_MAX || val < -DBL_MAX)) 1584 return true; 1585 return false; 1586 } 1587 1588 static tnode_t * 1589 fold_constant_floating(tnode_t *tn) 1590 { 1591 1592 fpe = 0; 1593 1594 tspec_t t = tn->tn_type->t_tspec; 1595 1596 val_t *v = xcalloc(1, sizeof(*v)); 1597 v->v_tspec = t; 1598 1599 lint_assert(is_floating(t)); 1600 lint_assert(has_operands(tn)); 1601 lint_assert(t == tn->u.ops.left->tn_type->t_tspec); 1602 lint_assert(!is_binary(tn) || t == tn->u.ops.right->tn_type->t_tspec); 1603 1604 long double lv = tn->u.ops.left->u.value.u.floating; 1605 long double rv = is_binary(tn) ? tn->u.ops.right->u.value.u.floating 1606 : 0.0; 1607 1608 switch (tn->tn_op) { 1609 case UPLUS: 1610 v->u.floating = lv; 1611 break; 1612 case UMINUS: 1613 v->u.floating = -lv; 1614 break; 1615 case MULT: 1616 v->u.floating = lv * rv; 1617 break; 1618 case DIV: 1619 if (rv == 0.0) { 1620 /* division by 0 */ 1621 error(139); 1622 v->u.floating = floating_error_value(t, lv); 1623 } else { 1624 v->u.floating = lv / rv; 1625 } 1626 break; 1627 case PLUS: 1628 v->u.floating = lv + rv; 1629 break; 1630 case MINUS: 1631 v->u.floating = lv - rv; 1632 break; 1633 case LT: 1634 v->u.integer = lv < rv ? 1 : 0; 1635 break; 1636 case LE: 1637 v->u.integer = lv <= rv ? 1 : 0; 1638 break; 1639 case GE: 1640 v->u.integer = lv >= rv ? 1 : 0; 1641 break; 1642 case GT: 1643 v->u.integer = lv > rv ? 1 : 0; 1644 break; 1645 case EQ: 1646 v->u.integer = lv == rv ? 1 : 0; 1647 break; 1648 case NE: 1649 v->u.integer = lv != rv ? 1 : 0; 1650 break; 1651 default: 1652 lint_assert(/*CONSTCOND*/false); 1653 } 1654 1655 // XXX: Must not access u.floating after setting u.integer. 1656 lint_assert(fpe != 0 || isnan(v->u.floating) == 0); 1657 if (is_complex(v->v_tspec)) { 1658 /* 1659 * Don't warn, as lint doesn't model the imaginary part of 1660 * complex numbers. 1661 */ 1662 fpe = 0; 1663 } else if (is_floating_overflow(t, v->u.floating)) { 1664 /* operator '%s' produces floating point overflow */ 1665 warning(142, op_name(tn->tn_op)); 1666 v->u.floating = floating_error_value(t, v->u.floating); 1667 fpe = 0; 1668 } 1669 1670 return build_constant(tn->tn_type, v); 1671 } 1672 1673 static void 1674 use(const tnode_t *tn) 1675 { 1676 if (tn == NULL) 1677 return; 1678 switch (tn->tn_op) { 1679 case NAME: 1680 mark_as_used(tn->u.sym, false /* XXX */, false /* XXX */); 1681 break; 1682 case CON: 1683 case STRING: 1684 break; 1685 case CALL: 1686 case ICALL:; 1687 const function_call *call = tn->u.call; 1688 if (call->args != NULL) 1689 for (size_t i = 0, n = call->args_len; i < n; i++) 1690 use(call->args[i]); 1691 break; 1692 default: 1693 lint_assert(has_operands(tn)); 1694 use(tn->u.ops.left); 1695 if (is_binary(tn)) 1696 use(tn->u.ops.right); 1697 } 1698 } 1699 1700 /* 1701 * Create a tree node for a binary operator and its two operands. Also called 1702 * for unary operators; in that case rn is NULL. 1703 * 1704 * Function calls, sizeof and casts are handled elsewhere. 1705 */ 1706 tnode_t * 1707 build_binary(tnode_t *ln, op_t op, bool sys, tnode_t *rn) 1708 { 1709 const mod_t *mp = &modtab[op]; 1710 1711 /* If there was an error in one of the operands, return. */ 1712 if (ln == NULL || (mp->m_binary && rn == NULL)) 1713 return NULL; 1714 1715 if (mp->m_value_context || mp->m_compares_with_zero) 1716 ln = cconv(ln); 1717 if (mp->m_binary && op != ARROW && op != POINT) 1718 rn = cconv(rn); 1719 1720 if (mp->m_comparison) 1721 check_integer_comparison(op, ln, rn); 1722 1723 if (mp->m_value_context || mp->m_compares_with_zero) 1724 ln = promote(op, false, ln); 1725 if (mp->m_binary && op != ARROW && op != POINT && 1726 op != ASSIGN && op != RETURN && op != INIT) 1727 rn = promote(op, false, rn); 1728 1729 if (mp->m_warn_if_left_unsigned_in_c90 && 1730 ln->tn_op == CON && ln->u.value.v_unsigned_since_c90) { 1731 /* C90 treats constant as unsigned, op '%s' */ 1732 warning(218, op_name(op)); 1733 ln->u.value.v_unsigned_since_c90 = false; 1734 } 1735 if (mp->m_warn_if_right_unsigned_in_c90 && 1736 rn->tn_op == CON && rn->u.value.v_unsigned_since_c90) { 1737 /* C90 treats constant as unsigned, op '%s' */ 1738 warning(218, op_name(op)); 1739 rn->u.value.v_unsigned_since_c90 = false; 1740 } 1741 1742 if (mp->m_balance_operands || (!allow_c90 && (op == SHL || op == SHR))) 1743 balance(op, &ln, &rn); 1744 1745 if (!typeok(op, 0, ln, rn)) 1746 return NULL; 1747 1748 tnode_t *ntn; 1749 switch (op) { 1750 case POINT: 1751 case ARROW: 1752 ntn = build_struct_access(op, sys, ln, rn); 1753 break; 1754 case INCAFT: 1755 case DECAFT: 1756 case INCBEF: 1757 case DECBEF: 1758 ntn = build_prepost_incdec(op, sys, ln); 1759 break; 1760 case ADDR: 1761 ntn = build_address(sys, ln, false); 1762 break; 1763 case INDIR: 1764 ntn = build_op(INDIR, sys, ln->tn_type->t_subt, ln, NULL); 1765 break; 1766 case PLUS: 1767 case MINUS: 1768 ntn = build_plus_minus(op, sys, ln, rn); 1769 break; 1770 case SHL: 1771 case SHR: 1772 ntn = build_bit_shift(op, sys, ln, rn); 1773 break; 1774 case COLON: 1775 ntn = build_colon(sys, ln, rn); 1776 break; 1777 case ASSIGN: 1778 case MULASS: 1779 case DIVASS: 1780 case MODASS: 1781 case ADDASS: 1782 case SUBASS: 1783 case SHLASS: 1784 case SHRASS: 1785 case ANDASS: 1786 case XORASS: 1787 case ORASS: 1788 case RETURN: 1789 case INIT: 1790 ntn = build_assignment(op, sys, ln, rn); 1791 break; 1792 case COMMA: 1793 if (any_query_enabled) { 1794 /* comma operator with types '%s' and '%s' */ 1795 query_message(12, 1796 type_name(ln->tn_type), type_name(rn->tn_type)); 1797 } 1798 /* FALLTHROUGH */ 1799 case QUEST: 1800 ntn = build_op(op, sys, rn->tn_type, ln, rn); 1801 break; 1802 case REAL: 1803 case IMAG: 1804 ntn = build_real_imag(op, sys, ln); 1805 break; 1806 default: 1807 lint_assert(mp->m_binary == (rn != NULL)); 1808 type_t *rettp = mp->m_returns_bool 1809 ? gettyp(Tflag ? BOOL : INT) : ln->tn_type; 1810 ntn = build_op(op, sys, rettp, ln, rn); 1811 break; 1812 } 1813 1814 if (ntn == NULL) 1815 return NULL; 1816 1817 if (mp->m_possible_precedence_confusion) 1818 check_precedence_confusion(ntn); 1819 1820 if (hflag && !suppress_constcond && 1821 mp->m_compares_with_zero && 1822 (ln->tn_op == CON || 1823 (mp->m_binary && op != QUEST && rn->tn_op == CON)) && 1824 /* XXX: rn->tn_system_dependent should be checked as well */ 1825 !ln->tn_system_dependent) 1826 /* constant in conditional context */ 1827 warning(161); 1828 1829 if (mp->m_fold_constant_operands && ln->tn_op == CON) { 1830 if (!mp->m_binary || rn->tn_op == CON) { 1831 if (mp->m_compares_with_zero) 1832 ntn = fold_constant_compare_zero(ntn); 1833 else if (is_floating(ntn->tn_type->t_tspec)) 1834 ntn = fold_constant_floating(ntn); 1835 else 1836 ntn = fold_constant_integer(ntn); 1837 } else if (op == QUEST) { 1838 lint_assert(has_operands(rn)); 1839 use(ln->u.value.u.integer != 0 1840 ? rn->u.ops.right : rn->u.ops.left); 1841 ntn = ln->u.value.u.integer != 0 1842 ? rn->u.ops.left : rn->u.ops.right; 1843 } 1844 } 1845 1846 return ntn; 1847 } 1848 1849 tnode_t * 1850 build_unary(op_t op, bool sys, tnode_t *tn) 1851 { 1852 return build_binary(tn, op, sys, NULL); 1853 } 1854 1855 static bool 1856 are_members_compatible(const sym_t *a, const sym_t *b) 1857 { 1858 if (a->u.s_member.sm_offset_in_bits != b->u.s_member.sm_offset_in_bits) 1859 return false; 1860 1861 const type_t *atp = a->s_type; 1862 const type_t *btp = b->s_type; 1863 bool w = false; 1864 if (!types_compatible(atp, btp, false, false, &w) && !w) 1865 return false; 1866 if (a->s_bitfield != b->s_bitfield) 1867 return false; 1868 if (a->s_bitfield) { 1869 if (atp->t_bit_field_width != btp->t_bit_field_width) 1870 return false; 1871 if (atp->t_bit_field_offset != btp->t_bit_field_offset) 1872 return false; 1873 } 1874 return true; 1875 } 1876 1877 /* 1878 * Return whether all struct/union members with the same name have the same 1879 * type and offset. 1880 */ 1881 static bool 1882 all_members_compatible(const sym_t *msym) 1883 { 1884 for (const sym_t *csym = msym; 1885 csym != NULL; csym = csym->s_symtab_next) { 1886 if (!is_member(csym)) 1887 continue; 1888 if (strcmp(msym->s_name, csym->s_name) != 0) 1889 continue; 1890 1891 for (const sym_t *sym = csym->s_symtab_next; 1892 sym != NULL; sym = sym->s_symtab_next) { 1893 if (is_member(sym) 1894 && strcmp(csym->s_name, sym->s_name) == 0 1895 && !are_members_compatible(csym, sym)) 1896 return false; 1897 } 1898 } 1899 return true; 1900 } 1901 1902 sym_t * 1903 find_member(const struct_or_union *sou, const char *name) 1904 { 1905 for (sym_t *mem = sou->sou_first_member; 1906 mem != NULL; mem = mem->s_next) { 1907 lint_assert(is_member(mem)); 1908 lint_assert(mem->u.s_member.sm_containing_type == sou); 1909 if (strcmp(mem->s_name, name) == 0) 1910 return mem; 1911 } 1912 1913 for (sym_t *mem = sou->sou_first_member; 1914 mem != NULL; mem = mem->s_next) { 1915 if (is_struct_or_union(mem->s_type->t_tspec) 1916 && mem->s_name == unnamed) { 1917 sym_t *nested_mem = 1918 find_member(mem->s_type->u.sou, name); 1919 if (nested_mem != NULL) 1920 return nested_mem; 1921 } 1922 } 1923 return NULL; 1924 } 1925 1926 /* 1927 * Remove the member if it was unknown until now, which means 1928 * that no defined struct or union has a member with the same name. 1929 */ 1930 static void 1931 remove_unknown_member(tnode_t *tn, sym_t *msym) 1932 { 1933 /* type '%s' does not have member '%s' */ 1934 error(101, type_name(tn->tn_type), msym->s_name); 1935 rmsym(msym); 1936 msym->s_kind = SK_MEMBER; 1937 msym->s_scl = STRUCT_MEMBER; 1938 1939 struct_or_union *sou = expr_zero_alloc(sizeof(*sou), 1940 "struct_or_union"); 1941 sou->sou_tag = expr_zero_alloc(sizeof(*sou->sou_tag), "sym"); 1942 sou->sou_tag->s_name = unnamed; 1943 1944 msym->u.s_member.sm_containing_type = sou; 1945 /* 1946 * The member sm_offset_in_bits is not needed here since this symbol 1947 * can only be used for error reporting. 1948 */ 1949 } 1950 1951 /* 1952 * Returns a symbol which has the same name as 'msym' and is a member of the 1953 * struct or union specified by 'tn'. 1954 */ 1955 static sym_t * 1956 struct_or_union_member(tnode_t *tn, op_t op, sym_t *msym) 1957 { 1958 1959 /* Determine the tag type of which msym is expected to be a member. */ 1960 const type_t *tp = NULL; 1961 if (op == POINT && is_struct_or_union(tn->tn_type->t_tspec)) 1962 tp = tn->tn_type; 1963 if (op == ARROW && tn->tn_type->t_tspec == PTR 1964 && is_struct_or_union(tn->tn_type->t_subt->t_tspec)) 1965 tp = tn->tn_type->t_subt; 1966 struct_or_union *sou = tp != NULL ? tp->u.sou : NULL; 1967 1968 if (sou != NULL) { 1969 sym_t *nested_mem = find_member(sou, msym->s_name); 1970 if (nested_mem != NULL) 1971 return nested_mem; 1972 } 1973 1974 if (msym->s_scl == NO_SCL) { 1975 remove_unknown_member(tn, msym); 1976 return msym; 1977 } 1978 1979 bool eq = all_members_compatible(msym); 1980 1981 /* 1982 * Now handle the case in which the left operand refers really to a 1983 * struct/union, but the right operand is not member of it. 1984 */ 1985 if (sou != NULL) { 1986 if (eq && !allow_c90) 1987 /* illegal use of member '%s' */ 1988 warning(102, msym->s_name); 1989 else 1990 /* illegal use of member '%s' */ 1991 error(102, msym->s_name); 1992 return msym; 1993 } 1994 1995 if (eq) { 1996 if (op == POINT) { 1997 if (!allow_c90) 1998 /* left operand of '.' must be struct ... */ 1999 warning(103, type_name(tn->tn_type)); 2000 else 2001 /* left operand of '.' must be struct ... */ 2002 error(103, type_name(tn->tn_type)); 2003 } else { 2004 if (!allow_c90 && tn->tn_type->t_tspec == PTR) 2005 /* left operand of '->' must be pointer ... */ 2006 warning(104, type_name(tn->tn_type)); 2007 else 2008 /* left operand of '->' must be pointer ... */ 2009 error(104, type_name(tn->tn_type)); 2010 } 2011 } else { 2012 if (!allow_c90) 2013 /* non-unique member requires struct/union %s */ 2014 error(105, op == POINT ? "object" : "pointer"); 2015 else 2016 /* unacceptable operand of '%s' */ 2017 error(111, op_name(op)); 2018 } 2019 2020 return msym; 2021 } 2022 2023 tnode_t * 2024 build_member_access(tnode_t *ln, op_t op, bool sys, sbuf_t *member) 2025 { 2026 sym_t *msym; 2027 2028 if (ln == NULL) 2029 return NULL; 2030 2031 if (op == ARROW) 2032 /* must do this before struct_or_union_member is called */ 2033 ln = cconv(ln); 2034 msym = struct_or_union_member(ln, op, getsym(member)); 2035 return build_binary(ln, op, sys, build_name(msym, false)); 2036 } 2037 2038 /* 2039 * Perform class conversions. 2040 * 2041 * Arrays of type T are converted into pointers to type T. 2042 * Functions are converted to pointers to functions. 2043 * Lvalues are converted to rvalues. 2044 * 2045 * C99 6.3 "Conversions" 2046 * C99 6.3.2 "Other operands" 2047 * C99 6.3.2.1 "Lvalues, arrays, and function designators" 2048 */ 2049 tnode_t * 2050 cconv(tnode_t *tn) 2051 { 2052 if (tn->tn_type->t_tspec == ARRAY) { 2053 if (!tn->tn_lvalue) { 2054 /* XXX print correct operator */ 2055 /* %soperand of '%s' must be lvalue */ 2056 gnuism(114, "", op_name(ADDR)); 2057 } 2058 tn = build_op(ADDR, tn->tn_sys, 2059 expr_derive_type(tn->tn_type->t_subt, PTR), tn, NULL); 2060 } 2061 2062 if (tn->tn_type->t_tspec == FUNC) 2063 tn = build_address(tn->tn_sys, tn, true); 2064 2065 if (tn->tn_lvalue) { 2066 type_t *tp = expr_dup_type(tn->tn_type); 2067 /* C99 6.3.2.1p2 sentence 2 says to remove the qualifiers. */ 2068 tp->t_const = tp->t_volatile = false; 2069 tn = build_op(LOAD, tn->tn_sys, tp, tn, NULL); 2070 } 2071 2072 return tn; 2073 } 2074 2075 const tnode_t * 2076 before_conversion(const tnode_t *tn) 2077 { 2078 while (tn->tn_op == CVT && !tn->tn_cast) 2079 tn = tn->u.ops.left; 2080 return tn; 2081 } 2082 2083 /* 2084 * Most errors required by C90 are reported in struct_or_union_member(). 2085 * Here we only check for totally wrong things. 2086 */ 2087 static bool 2088 typeok_point(const tnode_t *ln, const type_t *ltp, tspec_t lt) 2089 { 2090 if (is_struct_or_union(lt)) 2091 return true; 2092 2093 if (lt == FUNC || lt == VOID || ltp->t_bitfield) 2094 goto wrong; 2095 2096 /* 2097 * Some C dialects from before C90 tolerated any lvalue on the 2098 * left-hand side of the '.' operator, allowing things like 'char 2099 * st[100]; st.st_mtime', assuming that the member 'st_mtime' only 2100 * occurred in a single struct; see typeok_arrow. 2101 */ 2102 if (ln->tn_lvalue) 2103 return true; 2104 2105 wrong: 2106 /* With allow_c90 we already got an error */ 2107 if (!allow_c90) 2108 /* unacceptable operand of '%s' */ 2109 error(111, op_name(POINT)); 2110 2111 return false; 2112 } 2113 2114 static bool 2115 typeok_arrow(tspec_t lt) 2116 { 2117 /* 2118 * C1978 Appendix A 14.1 says: <quote>In fact, any lvalue is allowed 2119 * before '.', and that lvalue is then assumed to have the form of the 2120 * structure of which the name of the right is a member. [...] Such 2121 * constructions are non-portable.</quote> 2122 */ 2123 if (lt == PTR || (!allow_c90 && is_integer(lt))) 2124 return true; 2125 2126 /* With allow_c90 we already got an error */ 2127 if (!allow_c90) 2128 /* unacceptable operand of '%s' */ 2129 error(111, op_name(ARROW)); 2130 return false; 2131 } 2132 2133 static bool 2134 typeok_incdec(op_t op, const tnode_t *tn, const type_t *tp) 2135 { 2136 /* operand has scalar type (checked in typeok) */ 2137 if (!tn->tn_lvalue) { 2138 if (tn->tn_op == CVT && tn->tn_cast && 2139 tn->u.ops.left->tn_op == LOAD) 2140 /* a cast does not yield an lvalue */ 2141 error(163); 2142 /* %soperand of '%s' must be lvalue */ 2143 error(114, "", op_name(op)); 2144 return false; 2145 } 2146 if (tp->t_const && allow_c90) 2147 /* %soperand of '%s' must be modifiable lvalue */ 2148 warning(115, "", op_name(op)); 2149 return true; 2150 } 2151 2152 static bool 2153 typeok_address(op_t op, const tnode_t *tn, const type_t *tp, tspec_t t) 2154 { 2155 if (t == ARRAY || t == FUNC) { 2156 /* ok, a warning comes later (in build_address()) */ 2157 } else if (!tn->tn_lvalue) { 2158 if (tn->tn_op == CVT && tn->tn_cast && 2159 tn->u.ops.left->tn_op == LOAD) 2160 /* a cast does not yield an lvalue */ 2161 error(163); 2162 /* %soperand of '%s' must be lvalue */ 2163 error(114, "", op_name(op)); 2164 return false; 2165 } else if (is_scalar(t)) { 2166 if (tp->t_bitfield) { 2167 /* cannot take address of bit-field */ 2168 error(112); 2169 return false; 2170 } 2171 } else if (t != STRUCT && t != UNION) { 2172 /* unacceptable operand of '%s' */ 2173 error(111, op_name(op)); 2174 return false; 2175 } 2176 if (tn->tn_op == NAME && tn->u.sym->s_register) { 2177 /* cannot take address of register '%s' */ 2178 error(113, tn->u.sym->s_name); 2179 return false; 2180 } 2181 return true; 2182 } 2183 2184 static bool 2185 typeok_indir(const type_t *tp, tspec_t t) 2186 { 2187 2188 if (t != PTR) { 2189 /* cannot dereference non-pointer type '%s' */ 2190 error(96, type_name(tp)); 2191 return false; 2192 } 2193 return true; 2194 } 2195 2196 static void 2197 warn_incompatible_types(op_t op, 2198 const type_t *ltp, tspec_t lt, 2199 const type_t *rtp, tspec_t rt) 2200 { 2201 bool binary = modtab[op].m_binary; 2202 2203 if (lt == VOID || (binary && rt == VOID)) { 2204 /* void type illegal in expression */ 2205 error(109); 2206 } else if (op == ASSIGN) 2207 /* cannot assign to '%s' from '%s' */ 2208 error(171, type_name(ltp), type_name(rtp)); 2209 else if (binary) 2210 /* operands of '%s' have incompatible types '%s' and '%s' */ 2211 error(107, op_name(op), type_name(ltp), type_name(rtp)); 2212 else { 2213 lint_assert(rt == NO_TSPEC); 2214 /* operand of '%s' has invalid type '%s' */ 2215 error(108, op_name(op), type_name(ltp)); 2216 } 2217 } 2218 2219 static bool 2220 typeok_plus(op_t op, 2221 const type_t *ltp, tspec_t lt, 2222 const type_t *rtp, tspec_t rt) 2223 { 2224 /* operands have scalar types (checked in typeok) */ 2225 if ((lt == PTR && !is_integer(rt)) || (rt == PTR && !is_integer(lt))) { 2226 warn_incompatible_types(op, ltp, lt, rtp, rt); 2227 return false; 2228 } 2229 return true; 2230 } 2231 2232 static bool 2233 typeok_minus(op_t op, 2234 const type_t *ltp, tspec_t lt, 2235 const type_t *rtp, tspec_t rt) 2236 { 2237 /* operands have scalar types (checked in typeok) */ 2238 if ((lt == PTR && rt != PTR && !is_integer(rt)) || 2239 (lt != PTR && rt == PTR)) { 2240 warn_incompatible_types(op, ltp, lt, rtp, rt); 2241 return false; 2242 } 2243 if (lt == PTR && rt == PTR && 2244 !types_compatible(ltp->t_subt, rtp->t_subt, true, false, NULL)) { 2245 /* illegal pointer subtraction */ 2246 error(116); 2247 } 2248 return true; 2249 } 2250 2251 static void 2252 typeok_shr(op_t op, 2253 const tnode_t *ln, tspec_t lt, 2254 const tnode_t *rn, tspec_t rt) 2255 { 2256 tspec_t olt = before_conversion(ln)->tn_type->t_tspec; 2257 tspec_t ort = before_conversion(rn)->tn_type->t_tspec; 2258 2259 /* operands have integer types (checked in typeok) */ 2260 if (pflag && !is_uinteger(olt)) { 2261 integer_constraints lc = ic_expr(ln); 2262 if (!ic_maybe_signed(ln->tn_type, &lc)) 2263 return; 2264 2265 if (ln->tn_op != CON) 2266 /* bitwise '%s' on signed value possibly nonportable */ 2267 warning(117, op_name(op)); 2268 else if (ln->u.value.u.integer < 0) 2269 /* bitwise '%s' on signed value nonportable */ 2270 warning(120, op_name(op)); 2271 } else if (allow_trad && allow_c90 && 2272 !is_uinteger(olt) && is_uinteger(ort)) { 2273 /* The left operand would become unsigned in traditional C. */ 2274 if (hflag && (ln->tn_op != CON || ln->u.value.u.integer < 0)) { 2275 /* semantics of '%s' change in C90; use ... */ 2276 warning(118, op_name(op)); 2277 } 2278 } else if (allow_trad && allow_c90 && 2279 !is_uinteger(olt) && !is_uinteger(ort) && 2280 portable_rank_cmp(lt, rt) < 0) { 2281 /* 2282 * In traditional C, the left operand would be extended 2283 * (possibly sign-extended) and then shifted. 2284 */ 2285 if (hflag && (ln->tn_op != CON || ln->u.value.u.integer < 0)) { 2286 /* semantics of '%s' change in C90; use ... */ 2287 warning(118, op_name(op)); 2288 } 2289 } 2290 } 2291 2292 static void 2293 typeok_shl(op_t op, tspec_t lt, tspec_t rt) 2294 { 2295 /* 2296 * C90 does not perform balancing for shift operations, but traditional 2297 * C does. If the width of the right operand is greater than the width 2298 * of the left operand, then in traditional C the left operand would be 2299 * extended to the width of the right operand. For SHL this may result 2300 * in different results. 2301 */ 2302 if (portable_rank_cmp(lt, rt) < 0) { 2303 /* 2304 * XXX If both operands are constant, make sure that there is 2305 * really a difference between C90 and traditional C. 2306 */ 2307 if (hflag && allow_trad && allow_c90) 2308 /* semantics of '%s' change in C90; use ... */ 2309 warning(118, op_name(op)); 2310 } 2311 } 2312 2313 static void 2314 typeok_shift(const type_t *ltp, tspec_t lt, const tnode_t *rn, tspec_t rt) 2315 { 2316 if (rn->tn_op != CON) 2317 return; 2318 2319 if (!is_uinteger(rt) && rn->u.value.u.integer < 0) 2320 /* negative shift */ 2321 warning(121); 2322 else if ((uint64_t)rn->u.value.u.integer == size_in_bits(lt)) 2323 /* shift amount %u equals bit-size of '%s' */ 2324 warning(267, (unsigned)rn->u.value.u.integer, type_name(ltp)); 2325 else if ((uint64_t)rn->u.value.u.integer > size_in_bits(lt)) { 2326 /* shift amount %llu is greater than bit-size %llu of '%s' */ 2327 warning(122, (unsigned long long)rn->u.value.u.integer, 2328 (unsigned long long)size_in_bits(lt), 2329 tspec_name(lt)); 2330 } 2331 } 2332 2333 static bool 2334 is_typeok_eq(const tnode_t *ln, tspec_t lt, const tnode_t *rn, tspec_t rt) 2335 { 2336 if (lt == PTR && is_null_pointer(rn)) 2337 return true; 2338 if (rt == PTR && is_null_pointer(ln)) 2339 return true; 2340 return false; 2341 } 2342 2343 static void 2344 warn_incompatible_pointers(op_t op, const type_t *ltp, const type_t *rtp) 2345 { 2346 lint_assert(ltp->t_tspec == PTR); 2347 lint_assert(rtp->t_tspec == PTR); 2348 2349 tspec_t lt = ltp->t_subt->t_tspec; 2350 tspec_t rt = rtp->t_subt->t_tspec; 2351 2352 if (is_struct_or_union(lt) && is_struct_or_union(rt)) { 2353 if (op == RETURN) 2354 /* illegal structure pointer combination */ 2355 warning(244); 2356 else { 2357 /* incompatible structure pointers: '%s' '%s' '%s' */ 2358 warning(245, type_name(ltp), 2359 op_name(op), type_name(rtp)); 2360 } 2361 } else { 2362 if (op == RETURN) 2363 /* illegal combination of '%s' and '%s' */ 2364 warning(184, type_name(ltp), type_name(rtp)); 2365 else { 2366 /* illegal combination of '%s' and '%s', op '%s' */ 2367 warning(124, 2368 type_name(ltp), type_name(rtp), op_name(op)); 2369 } 2370 } 2371 } 2372 2373 static void 2374 check_pointer_comparison(op_t op, const tnode_t *ln, const tnode_t *rn) 2375 { 2376 type_t *ltp = ln->tn_type, *rtp = rn->tn_type; 2377 tspec_t lst = ltp->t_subt->t_tspec, rst = rtp->t_subt->t_tspec; 2378 2379 if (lst == VOID || rst == VOID) { 2380 /* TODO: C99 behaves like C90 here. */ 2381 if (!allow_trad && !allow_c99 && 2382 (lst == FUNC || rst == FUNC)) { 2383 /* (void *)0 is already handled in typeok() */ 2384 const char *lsts, *rsts; 2385 *(lst == FUNC ? &lsts : &rsts) = "function pointer"; 2386 *(lst == VOID ? &lsts : &rsts) = "'void *'"; 2387 /* C90 or later forbid comparison of %s with %s */ 2388 warning(274, lsts, rsts); 2389 } 2390 return; 2391 } 2392 2393 if (!types_compatible(ltp->t_subt, rtp->t_subt, true, false, NULL)) { 2394 warn_incompatible_pointers(op, ltp, rtp); 2395 return; 2396 } 2397 2398 if (lst == FUNC && rst == FUNC) { 2399 /* TODO: C99 behaves like C90 here, see C99 6.5.8p2. */ 2400 if (!allow_trad && !allow_c99 && op != EQ && op != NE) 2401 /* pointers to functions can only be compared ... */ 2402 warning(125); 2403 } 2404 } 2405 2406 static bool 2407 typeok_compare(op_t op, 2408 const tnode_t *ln, const type_t *ltp, tspec_t lt, 2409 const tnode_t *rn, const type_t *rtp, tspec_t rt) 2410 { 2411 if (lt == PTR && rt == PTR) { 2412 check_pointer_comparison(op, ln, rn); 2413 return true; 2414 } 2415 2416 if (lt != PTR && rt != PTR) 2417 return true; 2418 2419 if (!is_integer(lt) && !is_integer(rt)) { 2420 warn_incompatible_types(op, ltp, lt, rtp, rt); 2421 return false; 2422 } 2423 2424 const char *lx = lt == PTR ? "pointer" : "integer"; 2425 const char *rx = rt == PTR ? "pointer" : "integer"; 2426 /* illegal combination of %s '%s' and %s '%s', op '%s' */ 2427 warning(123, lx, type_name(ltp), rx, type_name(rtp), op_name(op)); 2428 return true; 2429 } 2430 2431 static bool 2432 typeok_quest(tspec_t lt, const tnode_t *rn) 2433 { 2434 if (!is_scalar(lt)) { 2435 /* first operand of '?' must have scalar type */ 2436 error(170); 2437 return false; 2438 } 2439 lint_assert(before_conversion(rn)->tn_op == COLON); 2440 return true; 2441 } 2442 2443 static void 2444 typeok_colon_pointer(const type_t *ltp, const type_t *rtp) 2445 { 2446 type_t *lstp = ltp->t_subt; 2447 type_t *rstp = rtp->t_subt; 2448 tspec_t lst = lstp->t_tspec; 2449 tspec_t rst = rstp->t_tspec; 2450 2451 if ((lst == VOID && rst == FUNC) || (lst == FUNC && rst == VOID)) { 2452 /* (void *)0 is handled in typeok_colon */ 2453 /* TODO: C99 behaves like C90 here. */ 2454 if (!allow_trad && !allow_c99) 2455 /* conversion of %s to %s requires a cast, op %s */ 2456 warning(305, "function pointer", "'void *'", 2457 op_name(COLON)); 2458 return; 2459 } 2460 2461 if (pointer_types_are_compatible(lstp, rstp, true)) 2462 return; 2463 if (!types_compatible(lstp, rstp, true, false, NULL)) 2464 warn_incompatible_pointers(COLON, ltp, rtp); 2465 } 2466 2467 static bool 2468 typeok_colon(const tnode_t *ln, const type_t *ltp, tspec_t lt, 2469 const tnode_t *rn, const type_t *rtp, tspec_t rt) 2470 { 2471 2472 if (is_arithmetic(lt) && is_arithmetic(rt)) 2473 return true; 2474 if (lt == BOOL && rt == BOOL) 2475 return true; 2476 2477 if (lt == STRUCT && rt == STRUCT && ltp->u.sou == rtp->u.sou) 2478 return true; 2479 if (lt == UNION && rt == UNION && ltp->u.sou == rtp->u.sou) 2480 return true; 2481 2482 if (lt == PTR && is_null_pointer(rn)) 2483 return true; 2484 if (rt == PTR && is_null_pointer(ln)) 2485 return true; 2486 2487 if ((lt == PTR && is_integer(rt)) || (is_integer(lt) && rt == PTR)) { 2488 const char *lx = lt == PTR ? "pointer" : "integer"; 2489 const char *rx = rt == PTR ? "pointer" : "integer"; 2490 /* illegal combination of %s '%s' and %s '%s', op '%s' */ 2491 warning(123, lx, type_name(ltp), 2492 rx, type_name(rtp), op_name(COLON)); 2493 return true; 2494 } 2495 2496 if (lt == VOID || rt == VOID) { 2497 if (lt != VOID || rt != VOID) 2498 /* incompatible types '%s' and '%s' in conditional */ 2499 warning(126, type_name(ltp), type_name(rtp)); 2500 return true; 2501 } 2502 2503 if (lt == PTR && rt == PTR) { 2504 typeok_colon_pointer(ltp, rtp); 2505 return true; 2506 } 2507 2508 /* incompatible types '%s' and '%s' in conditional */ 2509 error(126, type_name(ltp), type_name(rtp)); 2510 return false; 2511 } 2512 2513 static bool 2514 has_constant_member(const type_t *tp) 2515 { 2516 lint_assert(is_struct_or_union(tp->t_tspec)); 2517 2518 for (sym_t *m = tp->u.sou->sou_first_member; 2519 m != NULL; m = m->s_next) { 2520 const type_t *mtp = m->s_type; 2521 if (mtp->t_const) 2522 return true; 2523 if (is_struct_or_union(mtp->t_tspec) && 2524 has_constant_member(mtp)) 2525 return true; 2526 } 2527 return false; 2528 } 2529 2530 static bool 2531 typeok_assign(op_t op, const tnode_t *ln, const type_t *ltp, tspec_t lt) 2532 { 2533 if (op == RETURN || op == INIT || op == FARG) 2534 return true; 2535 2536 if (!ln->tn_lvalue) { 2537 if (ln->tn_op == CVT && ln->tn_cast && 2538 ln->u.ops.left->tn_op == LOAD) 2539 /* a cast does not yield an lvalue */ 2540 error(163); 2541 /* %soperand of '%s' must be lvalue */ 2542 error(114, "left ", op_name(op)); 2543 return false; 2544 } else if (ltp->t_const 2545 || (is_struct_or_union(lt) && has_constant_member(ltp))) { 2546 if (allow_c90) 2547 /* %soperand of '%s' must be modifiable lvalue */ 2548 warning(115, "left ", op_name(op)); 2549 } 2550 return true; 2551 } 2552 2553 static bool 2554 typeok_scalar(op_t op, const mod_t *mp, 2555 const type_t *ltp, tspec_t lt, 2556 const type_t *rtp, tspec_t rt) 2557 { 2558 if (mp->m_takes_bool && lt == BOOL && rt == BOOL) 2559 return true; 2560 if (mp->m_requires_integer) { 2561 if (!is_integer(lt) || (mp->m_binary && !is_integer(rt))) { 2562 warn_incompatible_types(op, ltp, lt, rtp, rt); 2563 return false; 2564 } 2565 } else if (mp->m_requires_integer_or_complex) { 2566 if ((!is_integer(lt) && !is_complex(lt)) || 2567 (mp->m_binary && (!is_integer(rt) && !is_complex(rt)))) { 2568 warn_incompatible_types(op, ltp, lt, rtp, rt); 2569 return false; 2570 } 2571 } else if (mp->m_requires_scalar) { 2572 if (!is_scalar(lt) || (mp->m_binary && !is_scalar(rt))) { 2573 warn_incompatible_types(op, ltp, lt, rtp, rt); 2574 return false; 2575 } 2576 } else if (mp->m_requires_arith) { 2577 if (!is_arithmetic(lt) || 2578 (mp->m_binary && !is_arithmetic(rt))) { 2579 warn_incompatible_types(op, ltp, lt, rtp, rt); 2580 return false; 2581 } 2582 } 2583 return true; 2584 } 2585 2586 static void 2587 check_assign_void_pointer(op_t op, int arg, 2588 tspec_t lt, tspec_t lst, 2589 tspec_t rt, tspec_t rst) 2590 { 2591 2592 if (!(lt == PTR && rt == PTR && (lst == VOID || rst == VOID))) 2593 return; 2594 /* two pointers, at least one pointer to void */ 2595 2596 /* TODO: C99 behaves like C90 here. */ 2597 if (!(!allow_trad && !allow_c99 && (lst == FUNC || rst == FUNC))) 2598 return; 2599 /* comb. of ptr to func and ptr to void */ 2600 2601 const char *lts, *rts; 2602 *(lst == FUNC ? <s : &rts) = "function pointer"; 2603 *(lst == VOID ? <s : &rts) = "'void *'"; 2604 2605 switch (op) { 2606 case INIT: 2607 case RETURN: 2608 /* conversion of %s to %s requires a cast */ 2609 warning(303, rts, lts); 2610 break; 2611 case FARG: 2612 /* conversion of %s to %s requires a cast, arg #%d */ 2613 warning(304, rts, lts, arg); 2614 break; 2615 default: 2616 /* conversion of %s to %s requires a cast, op %s */ 2617 warning(305, rts, lts, op_name(op)); 2618 break; 2619 } 2620 } 2621 2622 static bool 2623 is_direct_function_call(const tnode_t *tn, const char **out_name) 2624 { 2625 2626 if (tn->tn_op == CALL 2627 && tn->u.call->func->tn_op == ADDR 2628 && tn->u.call->func->u.ops.left->tn_op == NAME) { 2629 *out_name = tn->u.call->func->u.ops.left->u.sym->s_name; 2630 return true; 2631 } 2632 return false; 2633 } 2634 2635 static bool 2636 is_unconst_function(const char *name) 2637 { 2638 2639 return strcmp(name, "memchr") == 0 || 2640 strcmp(name, "strchr") == 0 || 2641 strcmp(name, "strpbrk") == 0 || 2642 strcmp(name, "strrchr") == 0 || 2643 strcmp(name, "strstr") == 0; 2644 } 2645 2646 static bool 2647 is_const_char_pointer(const tnode_t *tn) 2648 { 2649 /* 2650 * For traditional reasons, C99 6.4.5p5 defines that string literals 2651 * have type 'char[]'. They are often implicitly converted to 'char 2652 * *', for example when they are passed as function arguments. 2653 * 2654 * C99 6.4.5p6 further defines that modifying a string that is 2655 * constructed from a string literal invokes undefined behavior. 2656 * 2657 * Out of these reasons, string literals are treated as 'effectively 2658 * const' here. 2659 */ 2660 if (tn->tn_op == CVT && 2661 tn->u.ops.left->tn_op == ADDR && 2662 tn->u.ops.left->u.ops.left->tn_op == STRING) 2663 return true; 2664 2665 const type_t *tp = before_conversion(tn)->tn_type; 2666 return tp->t_tspec == PTR && 2667 tp->t_subt->t_tspec == CHAR && 2668 tp->t_subt->t_const; 2669 } 2670 2671 static bool 2672 is_first_arg_const_char_pointer(const tnode_t *tn) 2673 { 2674 return tn->u.call->args != NULL 2675 && tn->u.call->args_len >= 1 2676 && is_const_char_pointer(tn->u.call->args[0]); 2677 } 2678 2679 static bool 2680 is_const_pointer(const tnode_t *tn) 2681 { 2682 const type_t *tp = before_conversion(tn)->tn_type; 2683 return tp->t_tspec == PTR && tp->t_subt->t_const; 2684 } 2685 2686 static bool 2687 is_second_arg_const_pointer(const tnode_t *tn) 2688 { 2689 return tn->u.call->args_len >= 2 2690 && tn->u.call->args != NULL 2691 && is_const_pointer(tn->u.call->args[1]); 2692 } 2693 2694 static void 2695 check_unconst_function(const type_t *lstp, const tnode_t *rn) 2696 { 2697 const char *function_name; 2698 2699 if (lstp->t_tspec == CHAR && !lstp->t_const && 2700 is_direct_function_call(rn, &function_name) && 2701 is_unconst_function(function_name) && 2702 is_first_arg_const_char_pointer(rn)) { 2703 /* call to '%s' effectively discards 'const' from argument */ 2704 warning(346, function_name); 2705 } 2706 2707 if (!lstp->t_const && 2708 is_direct_function_call(rn, &function_name) && 2709 strcmp(function_name, "bsearch") == 0 && 2710 is_second_arg_const_pointer(rn)) { 2711 /* call to '%s' effectively discards 'const' from argument */ 2712 warning(346, function_name); 2713 } 2714 } 2715 2716 static bool 2717 check_assign_void_pointer_compat(op_t op, int arg, 2718 const type_t *ltp, tspec_t lt, 2719 const type_t *lstp, tspec_t lst, 2720 const tnode_t *rn, 2721 const type_t *rtp, tspec_t rt, 2722 const type_t *rstp, tspec_t rst) 2723 { 2724 if (!(lt == PTR && rt == PTR && (lst == VOID || rst == VOID || 2725 types_compatible(lstp, rstp, 2726 true, false, NULL)))) 2727 return false; 2728 2729 /* compatible pointer types (qualifiers ignored) */ 2730 if (allow_c90 && 2731 ((!lstp->t_const && rstp->t_const) || 2732 (!lstp->t_volatile && rstp->t_volatile))) { 2733 /* left side has not all qualifiers of right */ 2734 switch (op) { 2735 case INIT: 2736 case RETURN: 2737 /* incompatible pointer types to '%s' and '%s' */ 2738 warning(182, type_name(lstp), type_name(rstp)); 2739 break; 2740 case FARG: 2741 /* converting '%s' to incompatible '%s' ... */ 2742 warning(153, 2743 type_name(rtp), type_name(ltp), arg); 2744 break; 2745 default: 2746 /* operands of '%s' have incompatible pointer ... */ 2747 warning(128, op_name(op), 2748 type_name(lstp), type_name(rstp)); 2749 break; 2750 } 2751 } 2752 2753 if (allow_c90) 2754 check_unconst_function(lstp, rn); 2755 2756 return true; 2757 } 2758 2759 static bool 2760 check_assign_pointer_integer(op_t op, int arg, 2761 const type_t *ltp, tspec_t lt, 2762 const type_t *rtp, tspec_t rt) 2763 { 2764 2765 if (!((lt == PTR && is_integer(rt)) || (is_integer(lt) && rt == PTR))) 2766 return false; 2767 2768 const char *lx = lt == PTR ? "pointer" : "integer"; 2769 const char *rx = rt == PTR ? "pointer" : "integer"; 2770 2771 switch (op) { 2772 case INIT: 2773 case RETURN: 2774 /* illegal combination of %s '%s' and %s '%s' */ 2775 warning(183, lx, type_name(ltp), rx, type_name(rtp)); 2776 break; 2777 case FARG: 2778 /* illegal combination of %s '%s' and %s '%s', arg #%d */ 2779 warning(154, 2780 lx, type_name(ltp), rx, type_name(rtp), arg); 2781 break; 2782 default: 2783 /* illegal combination of %s '%s' and %s '%s', op '%s' */ 2784 warning(123, 2785 lx, type_name(ltp), rx, type_name(rtp), op_name(op)); 2786 break; 2787 } 2788 return true; 2789 } 2790 2791 static bool 2792 check_assign_pointer(op_t op, int arg, 2793 const type_t *ltp, tspec_t lt, 2794 const type_t *rtp, tspec_t rt) 2795 { 2796 if (!(lt == PTR && rt == PTR)) 2797 return false; 2798 2799 if (op == FARG) 2800 /* converting '%s' to incompatible '%s' for ... */ 2801 warning(153, type_name(rtp), type_name(ltp), arg); 2802 else 2803 warn_incompatible_pointers(op, ltp, rtp); 2804 return true; 2805 } 2806 2807 static void 2808 warn_assign(op_t op, int arg, 2809 const type_t *ltp, tspec_t lt, 2810 const type_t *rtp, tspec_t rt) 2811 { 2812 switch (op) { 2813 case INIT: 2814 /* cannot initialize '%s' from '%s' */ 2815 error(185, type_name(ltp), type_name(rtp)); 2816 break; 2817 case RETURN: 2818 /* function has return type '%s' but returns '%s' */ 2819 error(211, type_name(ltp), type_name(rtp)); 2820 break; 2821 case FARG: 2822 /* passing '%s' to incompatible '%s', arg #%d */ 2823 warning(155, type_name(rtp), type_name(ltp), arg); 2824 break; 2825 default: 2826 warn_incompatible_types(op, ltp, lt, rtp, rt); 2827 break; 2828 } 2829 } 2830 2831 /* 2832 * Checks type compatibility for ASSIGN, INIT, FARG and RETURN 2833 * and prints warnings/errors if necessary. 2834 * Returns whether the types are (almost) compatible. 2835 */ 2836 static bool 2837 check_assign_types_compatible(op_t op, int arg, 2838 const tnode_t *ln, const tnode_t *rn) 2839 { 2840 tspec_t lt, rt, lst = NO_TSPEC, rst = NO_TSPEC; 2841 type_t *ltp, *rtp, *lstp = NULL, *rstp = NULL; 2842 2843 if ((lt = (ltp = ln->tn_type)->t_tspec) == PTR) 2844 lst = (lstp = ltp->t_subt)->t_tspec; 2845 if ((rt = (rtp = rn->tn_type)->t_tspec) == PTR) 2846 rst = (rstp = rtp->t_subt)->t_tspec; 2847 2848 if (lt == BOOL && is_scalar(rt)) /* C99 6.3.1.2 */ 2849 return true; 2850 2851 if (is_arithmetic(lt) && (is_arithmetic(rt) || rt == BOOL)) 2852 return true; 2853 2854 if (is_struct_or_union(lt) && is_struct_or_union(rt)) 2855 return ltp->u.sou == rtp->u.sou; 2856 2857 if (lt == PTR && is_null_pointer(rn)) { 2858 if (is_integer(rn->tn_type->t_tspec)) 2859 /* implicit conversion from integer 0 to pointer ... */ 2860 query_message(15, type_name(ltp)); 2861 return true; 2862 } 2863 2864 check_assign_void_pointer(op, arg, lt, lst, rt, rst); 2865 2866 if (check_assign_void_pointer_compat(op, arg, 2867 ltp, lt, lstp, lst, rn, rtp, rt, rstp, rst)) 2868 return true; 2869 2870 if (check_assign_pointer_integer(op, arg, ltp, lt, rtp, rt)) 2871 return true; 2872 2873 if (check_assign_pointer(op, arg, ltp, lt, rtp, rt)) 2874 return true; 2875 2876 warn_assign(op, arg, ltp, lt, rtp, rt); 2877 return false; 2878 } 2879 2880 static bool 2881 has_side_effect(const tnode_t *tn) /* NOLINT(misc-no-recursion) */ 2882 { 2883 op_t op = tn->tn_op; 2884 2885 if (modtab[op].m_has_side_effect) 2886 return true; 2887 2888 if (op == CVT && tn->tn_type->t_tspec == VOID) 2889 return has_side_effect(tn->u.ops.left); 2890 2891 /* XXX: Why not has_side_effect(tn->u.ops.left) as well? */ 2892 if (op == LOGAND || op == LOGOR) 2893 return has_side_effect(tn->u.ops.right); 2894 2895 /* XXX: Why not has_side_effect(tn->u.ops.left) as well? */ 2896 if (op == QUEST) 2897 return has_side_effect(tn->u.ops.right); 2898 2899 if (op == COLON || op == COMMA) { 2900 return has_side_effect(tn->u.ops.left) || 2901 has_side_effect(tn->u.ops.right); 2902 } 2903 2904 return false; 2905 } 2906 2907 static bool 2908 is_void_cast(const tnode_t *tn) 2909 { 2910 2911 return tn->tn_op == CVT && tn->tn_cast && 2912 tn->tn_type->t_tspec == VOID; 2913 } 2914 2915 static bool 2916 is_local_symbol(const tnode_t *tn) 2917 { 2918 2919 return tn->tn_op == LOAD && 2920 tn->u.ops.left->tn_op == NAME && 2921 tn->u.ops.left->u.sym->s_scl == AUTO; 2922 } 2923 2924 static bool 2925 is_int_constant_zero(const tnode_t *tn) 2926 { 2927 2928 return tn->tn_op == CON && 2929 tn->tn_type->t_tspec == INT && 2930 tn->u.value.u.integer == 0; 2931 } 2932 2933 static void 2934 check_null_effect(const tnode_t *tn) 2935 { 2936 2937 if (hflag && 2938 !has_side_effect(tn) && 2939 !(is_void_cast(tn) && is_local_symbol(tn->u.ops.left)) && 2940 !(is_void_cast(tn) && is_int_constant_zero(tn->u.ops.left))) { 2941 /* expression has null effect */ 2942 warning(129); 2943 } 2944 } 2945 2946 /* 2947 * Check the types for specific operators and type combinations. 2948 * 2949 * At this point, the operands already conform to the type requirements of 2950 * the operator, such as being integer, floating or scalar. 2951 */ 2952 static bool 2953 typeok_op(op_t op, int arg, 2954 const tnode_t *ln, const type_t *ltp, tspec_t lt, 2955 const tnode_t *rn, const type_t *rtp, tspec_t rt) 2956 { 2957 switch (op) { 2958 case ARROW: 2959 return typeok_arrow(lt); 2960 case POINT: 2961 return typeok_point(ln, ltp, lt); 2962 case INCBEF: 2963 case DECBEF: 2964 case INCAFT: 2965 case DECAFT: 2966 return typeok_incdec(op, ln, ltp); 2967 case INDIR: 2968 return typeok_indir(ltp, lt); 2969 case ADDR: 2970 return typeok_address(op, ln, ltp, lt); 2971 case PLUS: 2972 return typeok_plus(op, ltp, lt, rtp, rt); 2973 case MINUS: 2974 return typeok_minus(op, ltp, lt, rtp, rt); 2975 case SHL: 2976 typeok_shl(op, lt, rt); 2977 goto shift; 2978 case SHR: 2979 typeok_shr(op, ln, lt, rn, rt); 2980 shift: 2981 typeok_shift(ltp, lt, rn, rt); 2982 break; 2983 case LT: 2984 case LE: 2985 case GT: 2986 case GE: 2987 compare: 2988 return typeok_compare(op, ln, ltp, lt, rn, rtp, rt); 2989 case EQ: 2990 case NE: 2991 if (is_typeok_eq(ln, lt, rn, rt)) 2992 break; 2993 goto compare; 2994 case QUEST: 2995 return typeok_quest(lt, rn); 2996 case COLON: 2997 return typeok_colon(ln, ltp, lt, rn, rtp, rt); 2998 case ASSIGN: 2999 case INIT: 3000 case FARG: 3001 case RETURN: 3002 if (!check_assign_types_compatible(op, arg, ln, rn)) 3003 return false; 3004 goto assign; 3005 case MULASS: 3006 case DIVASS: 3007 case MODASS: 3008 goto assign; 3009 case ADDASS: 3010 case SUBASS: 3011 if ((lt == PTR && !is_integer(rt)) || rt == PTR) { 3012 warn_incompatible_types(op, ltp, lt, rtp, rt); 3013 return false; 3014 } 3015 goto assign; 3016 case SHLASS: 3017 goto assign; 3018 case SHRASS: 3019 if (pflag && !is_uinteger(lt) && 3020 !(!allow_c90 && is_uinteger(rt))) { 3021 /* bitwise '%s' on signed value possibly nonportable */ 3022 warning(117, op_name(op)); 3023 } 3024 goto assign; 3025 case ANDASS: 3026 case XORASS: 3027 case ORASS: 3028 assign: 3029 return typeok_assign(op, ln, ltp, lt); 3030 case COMMA: 3031 if (!modtab[ln->tn_op].m_has_side_effect) 3032 check_null_effect(ln); 3033 break; 3034 default: 3035 break; 3036 } 3037 return true; 3038 } 3039 3040 static void 3041 check_bad_enum_operation(op_t op, const tnode_t *ln, const tnode_t *rn) 3042 { 3043 3044 if (!eflag) 3045 return; 3046 3047 /* Allow enum in array indices. */ 3048 if (op == PLUS && 3049 ((ln->tn_type->t_is_enum && rn->tn_type->t_tspec == PTR) || 3050 (rn->tn_type->t_is_enum && ln->tn_type->t_tspec == PTR))) { 3051 return; 3052 } 3053 3054 /* dubious operation '%s' on enum */ 3055 warning(241, op_name(op)); 3056 } 3057 3058 static void 3059 check_enum_type_mismatch(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 3060 { 3061 const mod_t *mp = &modtab[op]; 3062 3063 if (ln->tn_type->u.enumer != rn->tn_type->u.enumer) { 3064 switch (op) { 3065 case INIT: 3066 /* enum type mismatch between '%s' and '%s' in ... */ 3067 warning(210, 3068 type_name(ln->tn_type), type_name(rn->tn_type)); 3069 break; 3070 case FARG: 3071 /* function expects '%s', passing '%s' for arg #%d */ 3072 warning(156, 3073 type_name(ln->tn_type), type_name(rn->tn_type), 3074 arg); 3075 break; 3076 case RETURN: 3077 /* function has return type '%s' but returns '%s' */ 3078 warning(211, 3079 type_name(ln->tn_type), type_name(rn->tn_type)); 3080 break; 3081 default: 3082 /* enum type mismatch: '%s' '%s' '%s' */ 3083 warning(130, type_name(ln->tn_type), op_name(op), 3084 type_name(rn->tn_type)); 3085 break; 3086 } 3087 } else if (Pflag && eflag && mp->m_comparison && op != EQ && op != NE) 3088 /* operator '%s' assumes that '%s' is ordered */ 3089 warning(243, op_name(op), type_name(ln->tn_type)); 3090 } 3091 3092 static void 3093 check_enum_int_mismatch(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 3094 { 3095 3096 if (!eflag) 3097 return; 3098 3099 switch (op) { 3100 case INIT: 3101 /* 3102 * Initialization with 0 is allowed. Otherwise, all implicit 3103 * initializations would need to be warned upon as well. 3104 */ 3105 if (!rn->tn_type->t_is_enum && rn->tn_op == CON && 3106 is_integer(rn->tn_type->t_tspec) && 3107 rn->u.value.u.integer == 0) { 3108 return; 3109 } 3110 /* initialization of '%s' with '%s' */ 3111 warning(277, type_name(ln->tn_type), type_name(rn->tn_type)); 3112 break; 3113 case FARG: 3114 /* combination of '%s' and '%s', arg #%d */ 3115 warning(278, 3116 type_name(ln->tn_type), type_name(rn->tn_type), arg); 3117 break; 3118 case RETURN: 3119 /* combination of '%s' and '%s' in return */ 3120 warning(279, type_name(ln->tn_type), type_name(rn->tn_type)); 3121 break; 3122 default: 3123 /* combination of '%s' and '%s', op '%s' */ 3124 warning(242, type_name(ln->tn_type), type_name(rn->tn_type), 3125 op_name(op)); 3126 break; 3127 } 3128 } 3129 3130 static void 3131 typeok_enum(op_t op, const mod_t *mp, int arg, 3132 const tnode_t *ln, const type_t *ltp, 3133 const tnode_t *rn, const type_t *rtp) 3134 { 3135 if (mp->m_bad_on_enum && 3136 (ltp->t_is_enum || (mp->m_binary && rtp->t_is_enum))) { 3137 check_bad_enum_operation(op, ln, rn); 3138 } else if (mp->m_valid_on_enum && 3139 (ltp->t_is_enum && rtp != NULL && rtp->t_is_enum)) { 3140 check_enum_type_mismatch(op, arg, ln, rn); 3141 } else if (mp->m_valid_on_enum && 3142 (ltp->t_is_enum || (rtp != NULL && rtp->t_is_enum))) { 3143 check_enum_int_mismatch(op, arg, ln, rn); 3144 } 3145 } 3146 3147 /* Perform most type checks. Return whether the types are ok. */ 3148 bool 3149 typeok(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 3150 { 3151 3152 const mod_t *mp = &modtab[op]; 3153 3154 type_t *ltp = ln->tn_type; 3155 tspec_t lt = ltp->t_tspec; 3156 3157 type_t *rtp = mp->m_binary ? rn->tn_type : NULL; 3158 tspec_t rt = mp->m_binary ? rtp->t_tspec : NO_TSPEC; 3159 3160 if (Tflag && !typeok_scalar_strict_bool(op, mp, arg, ln, rn)) 3161 return false; 3162 if (!typeok_scalar(op, mp, ltp, lt, rtp, rt)) 3163 return false; 3164 3165 if (!typeok_op(op, arg, ln, ltp, lt, rn, rtp, rt)) 3166 return false; 3167 3168 typeok_enum(op, mp, arg, ln, ltp, rn, rtp); 3169 return true; 3170 } 3171 3172 /* In traditional C, keep unsigned and promote FLOAT to DOUBLE. */ 3173 static tspec_t 3174 promote_trad(tspec_t t) 3175 { 3176 3177 if (t == UCHAR || t == USHORT) 3178 return UINT; 3179 if (t == CHAR || t == SCHAR || t == SHORT) 3180 return INT; 3181 if (t == FLOAT) 3182 return DOUBLE; 3183 if (t == ENUM) 3184 return INT; 3185 return t; 3186 } 3187 3188 /* 3189 * C99 6.3.1.1p2 requires for types with lower rank than int that "If an int 3190 * can represent all the values of the original type, the value is converted 3191 * to an int; otherwise it is converted to an unsigned int", and that "All 3192 * other types are unchanged by the integer promotions". 3193 */ 3194 static tspec_t 3195 promote_c90(const tnode_t *tn, tspec_t t, bool farg) 3196 { 3197 if (tn->tn_type->t_bitfield) { 3198 unsigned int width = tn->tn_type->t_bit_field_width; 3199 unsigned int int_width = size_in_bits(INT); 3200 // XXX: What about _Bool bit-fields, since C99? 3201 if (width < int_width) 3202 return INT; 3203 if (width == int_width) 3204 return is_uinteger(t) ? UINT : INT; 3205 return t; 3206 } 3207 3208 if (t == CHAR || t == SCHAR) 3209 return INT; 3210 if (t == UCHAR) 3211 return size_in_bits(CHAR) < size_in_bits(INT) ? INT : UINT; 3212 if (t == SHORT) 3213 return INT; 3214 if (t == USHORT) 3215 return size_in_bits(SHORT) < size_in_bits(INT) ? INT : UINT; 3216 if (t == ENUM) 3217 return INT; 3218 if (farg && t == FLOAT) 3219 return DOUBLE; 3220 return t; 3221 } 3222 3223 /* 3224 * Performs the "integer promotions" (C99 6.3.1.1p2), which convert small 3225 * integer types to either int or unsigned int. 3226 * 3227 * If allow_c90 is unset or the operand is a function argument with no type 3228 * information (no prototype or variable # of args), converts float to double. 3229 */ 3230 tnode_t * 3231 promote(op_t op, bool farg, tnode_t *tn) 3232 { 3233 3234 tspec_t ot = tn->tn_type->t_tspec; 3235 if (!is_arithmetic(ot)) 3236 return tn; 3237 3238 tspec_t nt = allow_c90 ? promote_c90(tn, ot, farg) : promote_trad(ot); 3239 if (nt == ot) 3240 return tn; 3241 3242 type_t *ntp = expr_dup_type(tn->tn_type); 3243 ntp->t_tspec = nt; 3244 /* 3245 * Keep t_is_enum even though t_tspec gets converted from ENUM to INT, 3246 * so we are later able to check compatibility of enum types. 3247 */ 3248 return convert(op, 0, ntp, tn); 3249 } 3250 3251 static void 3252 convert_integer_from_floating(op_t op, const type_t *tp, const tnode_t *tn) 3253 { 3254 3255 if (op == CVT) 3256 /* cast from floating point '%s' to integer '%s' */ 3257 query_message(2, type_name(tn->tn_type), type_name(tp)); 3258 else 3259 /* implicit conversion from floating point '%s' to ... */ 3260 query_message(1, type_name(tn->tn_type), type_name(tp)); 3261 } 3262 3263 static bool 3264 should_warn_about_prototype_conversion(tspec_t nt, 3265 tspec_t ot, const tnode_t *ptn) 3266 { 3267 3268 if (nt == ot) 3269 return false; 3270 3271 if (nt == ENUM && ot == INT) 3272 return false; 3273 3274 if (is_floating(nt) != is_floating(ot) || 3275 portable_rank_cmp(nt, ot) != 0) { 3276 /* representation and/or width change */ 3277 if (!is_integer(ot)) 3278 return true; 3279 /* 3280 * XXX: Investigate whether this rule makes sense; see 3281 * tests/usr.bin/xlint/lint1/platform_long.c. 3282 */ 3283 return portable_rank_cmp(ot, INT) > 0; 3284 } 3285 3286 if (!hflag) 3287 return false; 3288 3289 /* 3290 * If the types differ only in sign and the argument has the same 3291 * representation in both types, print no warning. 3292 */ 3293 if (ptn->tn_op == CON && is_integer(nt) && 3294 signed_type(nt) == signed_type(ot) && 3295 !msb(ptn->u.value.u.integer, ot)) 3296 return false; 3297 3298 return true; 3299 } 3300 3301 /* 3302 * Warn if a prototype causes a type conversion that is different from what 3303 * would happen to the same argument in the absence of a prototype. This 3304 * check is intended for code that needs to stay compatible with pre-C90 C. 3305 * 3306 * Errors/warnings about illegal type combinations are already printed 3307 * in check_assign_types_compatible(). 3308 */ 3309 static void 3310 check_prototype_conversion(int arg, tspec_t nt, tspec_t ot, type_t *tp, 3311 tnode_t *tn) 3312 { 3313 3314 if (!is_arithmetic(nt) || !is_arithmetic(ot)) 3315 return; 3316 3317 /* 3318 * If the type of the formal parameter is char/short, a warning would 3319 * be useless, because functions declared the old style can't expect 3320 * char/short arguments. 3321 */ 3322 if (nt == CHAR || nt == SCHAR || nt == UCHAR || 3323 nt == SHORT || nt == USHORT) 3324 return; 3325 3326 tnode_t *ptn = promote(NOOP, true, tn); 3327 ot = ptn->tn_type->t_tspec; 3328 3329 if (should_warn_about_prototype_conversion(nt, ot, ptn)) { 3330 /* argument %d is converted from '%s' to '%s' ... */ 3331 warning(259, arg, type_name(tn->tn_type), type_name(tp)); 3332 } 3333 } 3334 3335 /* 3336 * When converting a large integer type to a small integer type, in some 3337 * cases the value of the actual expression is further restricted than the 3338 * type bounds, such as in (expr & 0xFF) or (expr % 100) or (expr >> 24). 3339 */ 3340 static bool 3341 can_represent(const type_t *tp, const tnode_t *tn) 3342 { 3343 3344 debug_step("%s: type '%s'", __func__, type_name(tp)); 3345 debug_node(tn); 3346 3347 uint64_t nmask = value_bits(width_in_bits(tp)); 3348 if (!is_uinteger(tp->t_tspec)) 3349 nmask >>= 1; 3350 3351 integer_constraints c = ic_expr(tn); 3352 if ((~c.bclr & ~nmask) == 0) 3353 return true; 3354 3355 integer_constraints tpc = ic_any(tp); 3356 if (is_uinteger(tp->t_tspec) 3357 ? tpc.umin <= c.umin && tpc.umax >= c.umax 3358 : tpc.smin <= c.smin && tpc.smax >= c.smax) 3359 return true; 3360 3361 return false; 3362 } 3363 3364 static bool 3365 should_warn_about_integer_conversion(const type_t *ntp, tspec_t nt, 3366 const tnode_t *otn, tspec_t ot) 3367 { 3368 3369 // XXX: The portable_rank_cmp aims at portable mode, independent of the 3370 // current platform, while can_represent acts on the actual type sizes 3371 // from the current platform. This mix is inconsistent, but anything 3372 // else would make the exact conditions too complicated to grasp. 3373 if (aflag > 0 && portable_rank_cmp(nt, ot) < 0) { 3374 if (ot == LONG || ot == ULONG 3375 || ot == LLONG || ot == ULLONG 3376 #ifdef INT128_SIZE 3377 || ot == INT128 || ot == UINT128 3378 #endif 3379 || aflag > 1) 3380 return !can_represent(ntp, otn); 3381 } 3382 return false; 3383 } 3384 3385 static void 3386 convert_integer_from_integer(op_t op, int arg, tspec_t nt, tspec_t ot, 3387 type_t *tp, tnode_t *tn) 3388 { 3389 3390 if (tn->tn_op == CON) 3391 return; 3392 3393 if (op == CVT) 3394 return; 3395 3396 if (Pflag && pflag && aflag > 0 && 3397 portable_rank_cmp(nt, ot) > 0 && 3398 is_uinteger(nt) != is_uinteger(ot)) { 3399 if (op == FARG) 3400 /* conversion to '%s' may sign-extend ... */ 3401 warning(297, type_name(tp), arg); 3402 else 3403 /* conversion to '%s' may sign-extend ... */ 3404 warning(131, type_name(tp)); 3405 } 3406 3407 if (Pflag && portable_rank_cmp(nt, ot) > 0 && 3408 (tn->tn_op == PLUS || tn->tn_op == MINUS || tn->tn_op == MULT || 3409 tn->tn_op == SHL)) { 3410 /* suggest cast from '%s' to '%s' on op '%s' to ... */ 3411 warning(324, type_name(gettyp(ot)), type_name(tp), 3412 op_name(tn->tn_op)); 3413 } 3414 3415 if (should_warn_about_integer_conversion(tp, nt, tn, ot)) { 3416 if (op == FARG) { 3417 /* conversion from '%s' to '%s' may lose ... */ 3418 warning(298, 3419 type_name(tn->tn_type), type_name(tp), arg); 3420 } else { 3421 /* conversion from '%s' to '%s' may lose accuracy */ 3422 warning(132, 3423 type_name(tn->tn_type), type_name(tp)); 3424 } 3425 } 3426 3427 if (any_query_enabled && is_uinteger(nt) != is_uinteger(ot)) 3428 /* implicit conversion changes sign from '%s' to '%s' */ 3429 query_message(3, type_name(tn->tn_type), type_name(tp)); 3430 } 3431 3432 static void 3433 convert_integer_from_pointer(op_t op, tspec_t nt, type_t *tp, tnode_t *tn) 3434 { 3435 3436 if (tn->tn_op == CON) 3437 return; 3438 if (op != CVT) 3439 return; /* We already got an error. */ 3440 if (portable_rank_cmp(nt, PTR) >= 0) 3441 return; 3442 3443 if (pflag && size_in_bits(nt) >= size_in_bits(PTR)) { 3444 /* conversion of pointer to '%s' may lose bits */ 3445 warning(134, type_name(tp)); 3446 } else { 3447 /* conversion of pointer to '%s' loses bits */ 3448 warning(133, type_name(tp)); 3449 } 3450 } 3451 3452 static bool 3453 struct_starts_with(const type_t *struct_tp, const type_t *member_tp) 3454 { 3455 3456 return struct_tp->u.sou->sou_first_member != NULL && 3457 types_compatible(struct_tp->u.sou->sou_first_member->s_type, 3458 member_tp, true, false, NULL); 3459 } 3460 3461 static bool 3462 is_byte_array(const type_t *tp) 3463 { 3464 3465 return tp->t_tspec == ARRAY && 3466 (tp->t_subt->t_tspec == CHAR || tp->t_subt->t_tspec == UCHAR); 3467 } 3468 3469 static bool 3470 union_contains(const type_t *utp, const type_t *mtp) 3471 { 3472 for (const sym_t *mem = utp->u.sou->sou_first_member; 3473 mem != NULL; mem = mem->s_next) { 3474 if (types_compatible(mem->s_type, mtp, true, false, NULL)) 3475 return true; 3476 } 3477 return false; 3478 } 3479 3480 static bool 3481 should_warn_about_pointer_cast(const type_t *nstp, tspec_t nst, 3482 const type_t *ostp, tspec_t ost) 3483 { 3484 3485 while (nst == ARRAY) 3486 nstp = nstp->t_subt, nst = nstp->t_tspec; 3487 while (ost == ARRAY) 3488 ostp = ostp->t_subt, ost = ostp->t_tspec; 3489 3490 if (nst == STRUCT && ost == STRUCT && 3491 (struct_starts_with(nstp, ostp) || 3492 struct_starts_with(ostp, nstp))) 3493 return false; 3494 3495 if (is_incomplete(nstp) || is_incomplete(ostp)) 3496 return false; 3497 3498 if (nst == CHAR || nst == UCHAR) 3499 return false; /* for the sake of traditional C code */ 3500 if (ost == CHAR || ost == UCHAR) 3501 return false; /* for the sake of traditional C code */ 3502 3503 /* Allow cast between pointers to sockaddr variants. */ 3504 if (nst == STRUCT && ost == STRUCT) { 3505 const sym_t *nmem = nstp->u.sou->sou_first_member; 3506 const sym_t *omem = ostp->u.sou->sou_first_member; 3507 while (nmem != NULL && omem != NULL && 3508 types_compatible(nmem->s_type, omem->s_type, 3509 true, false, NULL)) 3510 nmem = nmem->s_next, omem = omem->s_next; 3511 if (nmem != NULL && is_byte_array(nmem->s_type)) 3512 return false; 3513 if (omem != NULL && is_byte_array(omem->s_type)) 3514 return false; 3515 if (nmem == NULL && omem == NULL) 3516 return false; 3517 } 3518 3519 if (nst == UNION || ost == UNION) { 3520 const type_t *union_tp = nst == UNION ? nstp : ostp; 3521 const type_t *other_tp = nst == UNION ? ostp : nstp; 3522 if (union_contains(union_tp, other_tp)) 3523 return false; 3524 } 3525 3526 if (is_struct_or_union(nst) && is_struct_or_union(ost)) 3527 return nstp->u.sou != ostp->u.sou; 3528 3529 enum rank_kind rk1 = type_properties(nst)->tt_rank_kind; 3530 enum rank_kind rk2 = type_properties(ost)->tt_rank_kind; 3531 if (rk1 != rk2 || rk1 == RK_NONE) 3532 return true; 3533 3534 return portable_rank_cmp(nst, ost) != 0; 3535 } 3536 3537 static void 3538 convert_pointer_from_pointer(type_t *ntp, tnode_t *tn) 3539 { 3540 const type_t *nstp = ntp->t_subt; 3541 const type_t *otp = tn->tn_type; 3542 const type_t *ostp = otp->t_subt; 3543 tspec_t nst = nstp->t_tspec; 3544 tspec_t ost = ostp->t_tspec; 3545 3546 if (nst == VOID || ost == VOID) { 3547 /* TODO: C99 behaves like C90 here. */ 3548 if (!allow_trad && !allow_c99 && (nst == FUNC || ost == FUNC)) { 3549 const char *nts, *ots; 3550 /* null pointers are already handled in convert() */ 3551 *(nst == FUNC ? &nts : &ots) = "function pointer"; 3552 *(nst == VOID ? &nts : &ots) = "'void *'"; 3553 /* conversion of %s to %s requires a cast */ 3554 warning(303, ots, nts); 3555 } 3556 return; 3557 } 3558 if (nst == FUNC && ost == FUNC) 3559 return; 3560 if (nst == FUNC || ost == FUNC) { 3561 /* converting '%s' to '%s' is questionable */ 3562 warning(229, type_name(otp), type_name(ntp)); 3563 return; 3564 } 3565 3566 if (hflag && alignment_in_bits(nstp) > alignment_in_bits(ostp) && 3567 ost != CHAR && ost != UCHAR && 3568 !is_incomplete(ostp) && 3569 !(nst == UNION && union_contains(nstp, ostp))) { 3570 /* converting '%s' to '%s' increases alignment ... */ 3571 warning(135, type_name(otp), type_name(ntp), 3572 alignment_in_bits(ostp) / CHAR_SIZE, 3573 alignment_in_bits(nstp) / CHAR_SIZE); 3574 } 3575 3576 if (cflag && should_warn_about_pointer_cast(nstp, nst, ostp, ost)) { 3577 /* pointer cast from '%s' to '%s' may be troublesome */ 3578 warning(247, type_name(otp), type_name(ntp)); 3579 } 3580 } 3581 3582 /* 3583 * Insert a conversion operator, which converts the type of the node 3584 * to another given type. 3585 * 3586 * Possible values for 'op': 3587 * CVT a cast-expression 3588 * binary integer promotion for one of the operands, or a usual 3589 * arithmetic conversion 3590 * binary plain or compound assignments to bit-fields 3591 * FARG 'arg' is the number of the parameter (used for warnings) 3592 * NOOP several other implicit conversions 3593 * ... 3594 */ 3595 tnode_t * 3596 convert(op_t op, int arg, type_t *tp, tnode_t *tn) 3597 { 3598 tspec_t nt = tp->t_tspec; 3599 tspec_t ot = tn->tn_type->t_tspec; 3600 3601 if (allow_trad && allow_c90 && op == FARG) 3602 check_prototype_conversion(arg, nt, ot, tp, tn); 3603 3604 if (nt == BOOL) { 3605 /* No further checks. */ 3606 3607 } else if (is_integer(nt)) { 3608 if (ot == BOOL) { 3609 /* No further checks. */ 3610 } else if (is_integer(ot)) 3611 convert_integer_from_integer(op, arg, nt, ot, tp, tn); 3612 else if (is_floating(ot)) 3613 convert_integer_from_floating(op, tp, tn); 3614 else if (ot == PTR) 3615 convert_integer_from_pointer(op, nt, tp, tn); 3616 3617 } else if (is_floating(nt)) { 3618 /* No further checks. */ 3619 3620 } else if (nt == PTR) { 3621 if (is_null_pointer(tn)) { 3622 /* a null pointer may be assigned to any pointer. */ 3623 } else if (ot == PTR && op == CVT) 3624 convert_pointer_from_pointer(tp, tn); 3625 } 3626 3627 tnode_t *ntn = expr_alloc_tnode(); 3628 ntn->tn_op = CVT; 3629 ntn->tn_type = tp; 3630 ntn->tn_cast = op == CVT; 3631 ntn->tn_sys |= tn->tn_sys; 3632 ntn->u.ops.right = NULL; 3633 if (tn->tn_op != CON || nt == VOID) { 3634 ntn->u.ops.left = tn; 3635 } else { 3636 ntn->tn_op = CON; 3637 convert_constant(op, arg, ntn->tn_type, &ntn->u.value, 3638 &tn->u.value); 3639 } 3640 3641 return ntn; 3642 } 3643 3644 static void 3645 convert_constant_floating(op_t op, int arg, tspec_t ot, const type_t *tp, 3646 tspec_t nt, val_t *v, val_t *nv) 3647 { 3648 long double max = 0.0, min = 0.0; 3649 3650 switch (nt) { 3651 case CHAR: 3652 max = TARG_CHAR_MAX; min = TARG_CHAR_MIN; break; 3653 case UCHAR: 3654 max = TARG_UCHAR_MAX; min = 0; break; 3655 case SCHAR: 3656 max = TARG_SCHAR_MAX; min = TARG_SCHAR_MIN; break; 3657 case SHORT: 3658 max = TARG_SHRT_MAX; min = TARG_SHRT_MIN; break; 3659 case USHORT: 3660 max = TARG_USHRT_MAX; min = 0; break; 3661 case ENUM: 3662 case INT: 3663 max = TARG_INT_MAX; min = TARG_INT_MIN; break; 3664 case UINT: 3665 max = TARG_UINT_MAX; min = 0; break; 3666 case LONG: 3667 max = TARG_LONG_MAX; min = TARG_LONG_MIN; break; 3668 case ULONG: 3669 max = TARG_ULONG_MAX; min = 0; break; 3670 case LLONG: 3671 max = LLONG_MAX; min = LLONG_MIN; break; 3672 case ULLONG: 3673 max = ULLONG_MAX; min = 0; break; 3674 case FLOAT: 3675 case FCOMPLEX: 3676 max = FLT_MAX; min = -FLT_MAX; break; 3677 case DOUBLE: 3678 case DCOMPLEX: 3679 max = DBL_MAX; min = -DBL_MAX; break; 3680 case PTR: 3681 /* Already got an error because of float --> ptr */ 3682 case LDOUBLE: 3683 case LCOMPLEX: 3684 /* LINTED 248 */ 3685 max = LDBL_MAX; min = -max; break; 3686 default: 3687 lint_assert(/*CONSTCOND*/false); 3688 } 3689 if (v->u.floating > max || v->u.floating < min) { 3690 lint_assert(nt != LDOUBLE); 3691 if (op == FARG) { 3692 /* conversion of '%s' to '%s' is out of range, ... */ 3693 warning(295, 3694 type_name(gettyp(ot)), type_name(tp), arg); 3695 } else { 3696 /* conversion of '%s' to '%s' is out of range */ 3697 warning(119, type_name(gettyp(ot)), type_name(tp)); 3698 } 3699 v->u.floating = v->u.floating > 0 ? max : min; 3700 } 3701 3702 if (nt == FLOAT || nt == FCOMPLEX) 3703 nv->u.floating = (float)v->u.floating; 3704 else if (nt == DOUBLE || nt == DCOMPLEX) 3705 nv->u.floating = (double)v->u.floating; 3706 else if (nt == LDOUBLE || nt == LCOMPLEX) 3707 nv->u.floating = v->u.floating; 3708 else 3709 nv->u.integer = (int64_t)v->u.floating; 3710 } 3711 3712 static bool 3713 convert_constant_to_floating(tspec_t nt, val_t *nv, 3714 tspec_t ot, const val_t *v) 3715 { 3716 if (nt == FLOAT) { 3717 nv->u.floating = (ot == PTR || is_uinteger(ot)) ? 3718 (float)(uint64_t)v->u.integer : (float)v->u.integer; 3719 } else if (nt == DOUBLE) { 3720 nv->u.floating = (ot == PTR || is_uinteger(ot)) ? 3721 (double)(uint64_t)v->u.integer : (double)v->u.integer; 3722 } else if (nt == LDOUBLE) { 3723 nv->u.floating = (ot == PTR || is_uinteger(ot)) 3724 ? (long double)(uint64_t)v->u.integer 3725 : (long double)v->u.integer; 3726 } else 3727 return false; 3728 return true; 3729 } 3730 3731 /* 3732 * Print a warning if bits which were set are lost due to the conversion. 3733 * This can happen with operator ORASS only. 3734 */ 3735 static void 3736 convert_constant_check_range_bitor(size_t nsz, size_t osz, const val_t *v, 3737 uint64_t xmask, op_t op) 3738 { 3739 if (nsz < osz && (v->u.integer & xmask) != 0) 3740 /* constant truncated by conversion, op '%s' */ 3741 warning(306, op_name(op)); 3742 } 3743 3744 static void 3745 convert_constant_check_range_bitand(size_t nsz, size_t osz, 3746 uint64_t xmask, const val_t *nv, 3747 tspec_t ot, const val_t *v, 3748 const type_t *tp, op_t op) 3749 { 3750 if (nsz > osz && 3751 (nv->u.integer & bit((unsigned int)(osz - 1))) != 0 && 3752 (nv->u.integer & xmask) != xmask) { 3753 /* extra bits set to 0 in conversion of '%s' to '%s', ... */ 3754 warning(309, type_name(gettyp(ot)), 3755 type_name(tp), op_name(op)); 3756 } else if (nsz < osz && 3757 (v->u.integer & xmask) != xmask && 3758 (v->u.integer & xmask) != 0) 3759 /* constant truncated by conversion, op '%s' */ 3760 warning(306, op_name(op)); 3761 } 3762 3763 static void 3764 convert_constant_check_range_signed(op_t op, int arg) 3765 { 3766 if (op == ASSIGN) 3767 /* assignment of negative constant to unsigned type */ 3768 warning(164); 3769 else if (op == INIT) 3770 /* initialization of unsigned with negative constant */ 3771 warning(221); 3772 else if (op == FARG) 3773 /* conversion of negative constant to unsigned type, ... */ 3774 warning(296, arg); 3775 else if (modtab[op].m_comparison) { 3776 /* handled by check_integer_comparison() */ 3777 } else 3778 /* conversion of negative constant to unsigned type */ 3779 warning(222); 3780 } 3781 3782 /* 3783 * Loss of significant bit(s). All truncated bits of unsigned types or all 3784 * truncated bits plus the msb of the target for signed types are considered 3785 * to be significant bits. Loss of significant bits means that at least one 3786 * of the bits was set in an unsigned type or that at least one but not all 3787 * of the bits was set in a signed type. Loss of significant bits means that 3788 * it is not possible, also not with necessary casts, to convert back to the 3789 * original type. An example for a necessary cast is: 3790 * char c; int i; c = 128; 3791 * i = c; ** yields -128 ** 3792 * i = (unsigned char)c; ** yields 128 ** 3793 */ 3794 static void 3795 warn_constant_check_range_truncated(op_t op, int arg, const type_t *tp, 3796 tspec_t ot) 3797 { 3798 if (op == ASSIGN && tp->t_bitfield) 3799 /* precision lost in bit-field assignment */ 3800 warning(166); 3801 else if (op == ASSIGN) 3802 /* constant truncated by assignment */ 3803 warning(165); 3804 else if (op == INIT && tp->t_bitfield) 3805 /* bit-field initializer does not fit */ 3806 warning(180); 3807 else if (op == INIT) 3808 /* initializer does not fit */ 3809 warning(178); 3810 else if (op == CASE) 3811 /* case label affected by conversion */ 3812 warning(196); 3813 else if (op == FARG) 3814 /* conversion of '%s' to '%s' is out of range, arg #%d */ 3815 warning(295, type_name(gettyp(ot)), type_name(tp), arg); 3816 else 3817 /* conversion of '%s' to '%s' is out of range */ 3818 warning(119, type_name(gettyp(ot)), type_name(tp)); 3819 } 3820 3821 static void 3822 warn_constant_check_range_loss(op_t op, int arg, const type_t *tp, 3823 tspec_t ot) 3824 { 3825 if (op == ASSIGN && tp->t_bitfield) 3826 /* precision lost in bit-field assignment */ 3827 warning(166); 3828 else if (op == INIT && tp->t_bitfield) 3829 /* bit-field initializer out of range */ 3830 warning(11); 3831 else if (op == CASE) 3832 /* case label affected by conversion */ 3833 warning(196); 3834 else if (op == FARG) 3835 /* conversion of '%s' to '%s' is out of range, arg #%d */ 3836 warning(295, type_name(gettyp(ot)), type_name(tp), arg); 3837 else 3838 /* conversion of '%s' to '%s' is out of range */ 3839 warning(119, type_name(gettyp(ot)), type_name(tp)); 3840 } 3841 3842 static void 3843 convert_constant_check_range(tspec_t ot, const type_t *tp, tspec_t nt, 3844 op_t op, int arg, const val_t *v, val_t *nv) 3845 { 3846 unsigned int obitsz, nbitsz; 3847 uint64_t xmask, xmsk1; 3848 3849 obitsz = size_in_bits(ot); 3850 nbitsz = tp->t_bitfield ? tp->t_bit_field_width : size_in_bits(nt); 3851 xmask = value_bits(nbitsz) ^ value_bits(obitsz); 3852 xmsk1 = value_bits(nbitsz) ^ value_bits(obitsz - 1); 3853 if (op == ORASS || op == BITOR || op == BITXOR) { 3854 convert_constant_check_range_bitor( 3855 nbitsz, obitsz, v, xmask, op); 3856 } else if (op == ANDASS || op == BITAND) { 3857 convert_constant_check_range_bitand( 3858 nbitsz, obitsz, xmask, nv, ot, v, tp, op); 3859 } else if (nt != PTR && is_uinteger(nt) && 3860 ot != PTR && !is_uinteger(ot) && 3861 v->u.integer < 0) 3862 convert_constant_check_range_signed(op, arg); 3863 else if (nv->u.integer != v->u.integer && nbitsz <= obitsz && 3864 (v->u.integer & xmask) != 0 && 3865 (is_uinteger(ot) || (v->u.integer & xmsk1) != xmsk1)) 3866 warn_constant_check_range_truncated(op, arg, tp, ot); 3867 else if (nv->u.integer != v->u.integer) 3868 warn_constant_check_range_loss(op, arg, tp, ot); 3869 } 3870 3871 /* Converts a typed constant to a constant of another type. */ 3872 void 3873 convert_constant(op_t op, int arg, const type_t *ntp, val_t *nv, val_t *ov) 3874 { 3875 /* 3876 * TODO: make 'ov' const; the name of this function does not suggest 3877 * that it modifies 'ov'. 3878 */ 3879 tspec_t ot = ov->v_tspec; 3880 tspec_t nt = nv->v_tspec = ntp->t_tspec; 3881 bool range_check = false; 3882 3883 if (nt == BOOL) { /* C99 6.3.1.2 */ 3884 nv->v_unsigned_since_c90 = false; 3885 nv->u.integer = is_nonzero_val(ov) ? 1 : 0; 3886 return; 3887 } 3888 3889 if (ot == FLOAT || ot == DOUBLE || ot == LDOUBLE) 3890 convert_constant_floating(op, arg, ot, ntp, nt, ov, nv); 3891 else if (!convert_constant_to_floating(nt, nv, ot, ov)) { 3892 range_check = true; /* Check for lost precision. */ 3893 nv->u.integer = ov->u.integer; 3894 } 3895 3896 if (allow_trad && allow_c90 && ov->v_unsigned_since_c90 && 3897 (is_floating(nt) || ( 3898 (is_integer(nt) && !is_uinteger(nt) && 3899 portable_rank_cmp(nt, ot) > 0)))) { 3900 /* C90 treats constant as unsigned */ 3901 warning(157); 3902 ov->v_unsigned_since_c90 = false; 3903 } 3904 3905 if (is_integer(nt)) { 3906 unsigned int size = ntp->t_bitfield 3907 ? ntp->t_bit_field_width : size_in_bits(nt); 3908 nv->u.integer = convert_integer(nv->u.integer, nt, size); 3909 } 3910 3911 if (range_check && op != CVT) 3912 convert_constant_check_range(ot, ntp, nt, op, arg, ov, nv); 3913 } 3914 3915 tnode_t * 3916 build_sizeof(const type_t *tp) 3917 { 3918 unsigned int size_in_bytes = type_size_in_bits(tp) / CHAR_SIZE; 3919 tnode_t *tn = build_integer_constant(SIZEOF_TSPEC, size_in_bytes); 3920 tn->tn_system_dependent = true; 3921 debug_step("build_sizeof '%s' = %u", type_name(tp), size_in_bytes); 3922 return tn; 3923 } 3924 3925 tnode_t * 3926 build_offsetof(const type_t *tp, designation dn) 3927 { 3928 unsigned int offset_in_bits = 0; 3929 3930 if (!is_struct_or_union(tp->t_tspec)) { 3931 /* unacceptable operand of '%s' */ 3932 error(111, "offsetof"); 3933 goto proceed; 3934 } 3935 for (size_t i = 0; i < dn.dn_len; i++) { 3936 const designator *dr = dn.dn_items + i; 3937 if (dr->dr_kind == DK_SUBSCRIPT) { 3938 if (tp->t_tspec != ARRAY) 3939 goto proceed; /* silent error */ 3940 tp = tp->t_subt; 3941 offset_in_bits += (unsigned) dr->dr_subscript 3942 * type_size_in_bits(tp); 3943 } else { 3944 if (!is_struct_or_union(tp->t_tspec)) 3945 goto proceed; /* silent error */ 3946 const char *name = dr->dr_member->s_name; 3947 sym_t *mem = find_member(tp->u.sou, name); 3948 if (mem == NULL) { 3949 /* type '%s' does not have member '%s' */ 3950 error(101, name, type_name(tp)); 3951 goto proceed; 3952 } 3953 tp = mem->s_type; 3954 offset_in_bits += mem->u.s_member.sm_offset_in_bits; 3955 } 3956 } 3957 free(dn.dn_items); 3958 3959 proceed:; 3960 unsigned int offset_in_bytes = offset_in_bits / CHAR_SIZE; 3961 tnode_t *tn = build_integer_constant(SIZEOF_TSPEC, offset_in_bytes); 3962 tn->tn_system_dependent = true; 3963 return tn; 3964 } 3965 3966 unsigned int 3967 type_size_in_bits(const type_t *tp) 3968 { 3969 3970 unsigned int elem = 1; 3971 bool flex = false; 3972 lint_assert(tp != NULL); 3973 while (tp->t_tspec == ARRAY) { 3974 flex = true; /* allow c99 flex arrays [] [0] */ 3975 elem *= tp->u.dimension; 3976 tp = tp->t_subt; 3977 } 3978 if (elem == 0 && !flex) { 3979 /* cannot take size/alignment of incomplete type */ 3980 error(143); 3981 elem = 1; 3982 } 3983 3984 unsigned int elsz; 3985 switch (tp->t_tspec) { 3986 case VOID: 3987 /* cannot take size/alignment of void */ 3988 error(146); 3989 elsz = 1; 3990 break; 3991 case FUNC: 3992 /* cannot take size/alignment of function type '%s' */ 3993 error(144, type_name(tp)); 3994 elsz = 1; 3995 break; 3996 case STRUCT: 3997 case UNION: 3998 if (is_incomplete(tp)) { 3999 /* cannot take size/alignment of incomplete type */ 4000 error(143); 4001 elsz = 1; 4002 } else 4003 elsz = tp->u.sou->sou_size_in_bits; 4004 break; 4005 case ENUM: 4006 if (is_incomplete(tp)) { 4007 /* cannot take size/alignment of incomplete type */ 4008 warning(143); 4009 } 4010 /* FALLTHROUGH */ 4011 default: 4012 if (tp->t_bitfield) 4013 /* cannot take size/alignment of bit-field */ 4014 error(145); 4015 elsz = size_in_bits(tp->t_tspec); 4016 lint_assert(elsz > 0); 4017 break; 4018 } 4019 4020 return elem * elsz; 4021 } 4022 4023 /* C11 6.5.3.4, GCC */ 4024 tnode_t * 4025 build_alignof(const type_t *tp) 4026 { 4027 if (tp->t_tspec == FUNC) { 4028 /* cannot take size/alignment of function type '%s' */ 4029 error(144, type_name(tp)); 4030 return NULL; 4031 } 4032 if (tp->t_tspec == VOID) { 4033 /* cannot take size/alignment of void */ 4034 error(146); 4035 return NULL; 4036 } 4037 if (is_incomplete(tp)) { 4038 /* cannot take size/alignment of incomplete type */ 4039 error(143); 4040 return NULL; 4041 } 4042 if (tp->t_bitfield) { 4043 /* cannot take size/alignment of bit-field */ 4044 error(145); 4045 return NULL; 4046 } 4047 return build_integer_constant(SIZEOF_TSPEC, 4048 (int64_t)alignment_in_bits(tp) / CHAR_SIZE); 4049 } 4050 4051 static tnode_t * 4052 cast_to_union(tnode_t *otn, bool sys, type_t *ntp) 4053 { 4054 4055 if (!allow_gcc) { 4056 /* union cast is a GCC extension */ 4057 error(328); 4058 return NULL; 4059 } 4060 4061 for (const sym_t *m = ntp->u.sou->sou_first_member; 4062 m != NULL; m = m->s_next) { 4063 if (types_compatible(m->s_type, otn->tn_type, 4064 false, false, NULL)) { 4065 tnode_t *ntn = build_op(CVT, sys, ntp, otn, NULL); 4066 ntn->tn_cast = true; 4067 return ntn; 4068 } 4069 } 4070 4071 /* type '%s' is not a member of '%s' */ 4072 error(329, type_name(otn->tn_type), type_name(ntp)); 4073 return NULL; 4074 } 4075 4076 tnode_t * 4077 cast(tnode_t *tn, bool sys, type_t *tp) 4078 { 4079 4080 if (tn == NULL) 4081 return NULL; 4082 4083 tn = cconv(tn); 4084 4085 lint_assert(tp != NULL); 4086 tspec_t nt = tp->t_tspec; 4087 tspec_t ot = tn->tn_type->t_tspec; 4088 4089 if (nt == VOID) { 4090 /* 4091 * C90 6.3.4, C99 6.5.4p2 and C11 6.5.4p2 allow any type to be 4092 * cast to void. The only other allowed casts are from a 4093 * scalar type to a scalar type. 4094 */ 4095 } else if (nt == UNION) 4096 return cast_to_union(tn, sys, tp); 4097 else if (nt == STRUCT || nt == ARRAY || nt == FUNC) { 4098 /* Casting to a struct is an undocumented GCC extension. */ 4099 if (!(allow_gcc && nt == STRUCT)) 4100 goto invalid_cast; 4101 } else if (is_struct_or_union(ot)) 4102 goto invalid_cast; 4103 else if (ot == VOID) { 4104 /* improper cast of void expression */ 4105 error(148); 4106 return NULL; 4107 } else if (is_integer(nt) && is_scalar(ot)) { 4108 /* ok */ 4109 } else if (is_floating(nt) && is_arithmetic(ot)) { 4110 /* ok */ 4111 } else if (nt == PTR && is_integer(ot)) { 4112 /* ok */ 4113 } else if (nt == PTR && ot == PTR) { 4114 if (!tp->t_subt->t_const && tn->tn_type->t_subt->t_const) { 4115 if (hflag) 4116 /* cast discards 'const' from type '%s' */ 4117 warning(275, type_name(tn->tn_type)); 4118 } 4119 } else 4120 goto invalid_cast; 4121 4122 if (any_query_enabled 4123 && types_compatible(tp, tn->tn_type, false, false, NULL)) 4124 /* no-op cast from '%s' to '%s' */ 4125 query_message(6, type_name(tn->tn_type), type_name(tp)); 4126 4127 tn = convert(CVT, 0, tp, tn); 4128 tn->tn_cast = true; 4129 tn->tn_sys = sys; 4130 4131 return tn; 4132 4133 invalid_cast: 4134 /* invalid cast from '%s' to '%s' */ 4135 error(147, type_name(tn->tn_type), type_name(tp)); 4136 return NULL; 4137 } 4138 4139 void 4140 add_function_argument(function_call *call, tnode_t *arg) 4141 { 4142 /* 4143 * If there was a serious error in the expression for the argument, 4144 * create a dummy argument so the positions of the remaining arguments 4145 * will not change. 4146 */ 4147 if (arg == NULL) 4148 arg = build_integer_constant(INT, 0); 4149 4150 if (call->args_len >= call->args_cap) { 4151 call->args_cap += 8; 4152 tnode_t **new_args = expr_zero_alloc( 4153 call->args_cap * sizeof(*call->args), 4154 "function_call.args"); 4155 memcpy(new_args, call->args, 4156 call->args_len * sizeof(*call->args)); 4157 call->args = new_args; 4158 } 4159 call->args[call->args_len++] = arg; 4160 } 4161 4162 /* 4163 * Compare the type of an argument with the corresponding type of a 4164 * prototype parameter. If it is a valid combination, but both types 4165 * are not the same, insert a conversion to convert the argument into 4166 * the type of the parameter. 4167 */ 4168 static tnode_t * 4169 check_prototype_argument( 4170 int n, /* pos of arg */ 4171 type_t *tp, /* expected type (from prototype) */ 4172 tnode_t *tn) /* argument */ 4173 { 4174 tnode_t *ln = xcalloc(1, sizeof(*ln)); 4175 ln->tn_type = expr_unqualified_type(tp); 4176 ln->tn_lvalue = true; 4177 if (typeok(FARG, n, ln, tn)) { 4178 bool dowarn; 4179 if (!types_compatible(tp, tn->tn_type, 4180 true, false, (dowarn = false, &dowarn)) || dowarn) 4181 tn = convert(FARG, n, tp, tn); 4182 } 4183 free(ln); 4184 return tn; 4185 } 4186 4187 /* 4188 * Check types of all function arguments and insert conversions, 4189 * if necessary. 4190 */ 4191 static bool 4192 check_function_arguments(const function_call *call) 4193 { 4194 type_t *ftp = call->func->tn_type->t_subt; 4195 4196 /* get # of parameters in the prototype */ 4197 int npar = 0; 4198 for (const sym_t *p = ftp->u.params; p != NULL; p = p->s_next) 4199 npar++; 4200 4201 int narg = (int)call->args_len; 4202 4203 const sym_t *param = ftp->u.params; 4204 if (ftp->t_proto && npar != narg && !(ftp->t_vararg && npar < narg)) { 4205 /* argument mismatch: %d %s passed, %d expected */ 4206 error(150, narg, narg != 1 ? "arguments" : "argument", npar); 4207 param = NULL; 4208 } 4209 4210 for (int n = 1; n <= narg; n++) { 4211 tnode_t *arg = call->args[n - 1]; 4212 4213 /* some things which are always not allowed */ 4214 tspec_t at = arg->tn_type->t_tspec; 4215 if (at == VOID) { 4216 /* void expressions may not be arguments, arg #%d */ 4217 error(151, n); 4218 return false; 4219 } 4220 if (is_struct_or_union(at) && 4221 is_incomplete(arg->tn_type)) { 4222 /* argument cannot have unknown size, arg #%d */ 4223 error(152, n); 4224 return false; 4225 } 4226 if (is_integer(at) && 4227 arg->tn_type->t_is_enum && 4228 is_incomplete(arg->tn_type)) { 4229 /* argument cannot have unknown size, arg #%d */ 4230 warning(152, n); 4231 } 4232 4233 arg = cconv(arg); 4234 call->args[n - 1] = arg; 4235 4236 arg = param != NULL 4237 ? check_prototype_argument(n, param->s_type, arg) 4238 : promote(NOOP, true, arg); 4239 call->args[n - 1] = arg; 4240 4241 if (param != NULL) 4242 param = param->s_next; 4243 } 4244 4245 return true; 4246 } 4247 4248 tnode_t * 4249 build_function_call(tnode_t *func, bool sys, function_call *call) 4250 { 4251 4252 if (func == NULL) 4253 return NULL; 4254 4255 op_t fcop = func->tn_op == NAME && func->tn_type->t_tspec == FUNC 4256 ? CALL : ICALL; 4257 4258 call->func = func; 4259 check_ctype_function_call(call); 4260 4261 func = cconv(func); 4262 call->func = func; 4263 4264 if (func->tn_type->t_tspec != PTR || 4265 func->tn_type->t_subt->t_tspec != FUNC) { 4266 /* cannot call '%s', must be a function */ 4267 error(149, type_name(func->tn_type)); 4268 return NULL; 4269 } 4270 4271 if (!check_function_arguments(call)) 4272 call->args = NULL; 4273 4274 tnode_t *ntn = expr_alloc_tnode(); 4275 ntn->tn_op = fcop; 4276 ntn->tn_type = func->tn_type->t_subt->t_subt; 4277 ntn->tn_sys = sys; 4278 ntn->u.call = call; 4279 return ntn; 4280 } 4281 4282 /* 4283 * Return the value of an integral constant expression. 4284 * If the expression is not constant or its type is not an integer 4285 * type, an error message is printed. 4286 */ 4287 val_t * 4288 integer_constant(tnode_t *tn, bool required) 4289 { 4290 4291 if (tn != NULL) 4292 tn = cconv(tn); 4293 if (tn != NULL) 4294 tn = promote(NOOP, false, tn); 4295 4296 val_t *v = xcalloc(1, sizeof(*v)); 4297 4298 if (tn == NULL) { 4299 lint_assert(seen_error); 4300 debug_step("constant node is null; returning 1 instead"); 4301 v->v_tspec = INT; 4302 v->u.integer = 1; 4303 return v; 4304 } 4305 4306 v->v_tspec = tn->tn_type->t_tspec; 4307 4308 if (tn->tn_op == CON) { 4309 lint_assert(tn->tn_type->t_tspec == tn->u.value.v_tspec); 4310 if (is_integer(tn->u.value.v_tspec)) { 4311 v->v_unsigned_since_c90 = 4312 tn->u.value.v_unsigned_since_c90; 4313 v->u.integer = tn->u.value.u.integer; 4314 return v; 4315 } 4316 v->u.integer = (int64_t)tn->u.value.u.floating; 4317 } else 4318 v->u.integer = 1; 4319 4320 if (required) 4321 /* integral constant expression expected */ 4322 error(55); 4323 else 4324 /* variable array dimension is a C99/GCC extension */ 4325 c99ism(318); 4326 4327 if (!is_integer(v->v_tspec)) 4328 v->v_tspec = INT; 4329 4330 return v; 4331 } 4332 4333 static bool 4334 is_constcond_false(const tnode_t *tn, tspec_t t) 4335 { 4336 return (t == BOOL || t == INT) && 4337 tn->tn_op == CON && tn->u.value.u.integer == 0; 4338 } 4339 4340 /* 4341 * Perform some tests on expressions which can't be done in build_binary() 4342 * and functions called by build_binary(). These tests must be done here 4343 * because we need some information about the context in which the operations 4344 * are performed. 4345 * After all tests are performed and dofreeblk is true, expr() frees the 4346 * memory which is used for the expression. 4347 */ 4348 void 4349 expr(tnode_t *tn, bool vctx, bool cond, bool dofreeblk, bool is_do_while) 4350 { 4351 4352 if (tn == NULL) { /* in case of errors */ 4353 expr_free_all(); 4354 return; 4355 } 4356 4357 /* expr() is also called in global initializations */ 4358 if (dcs->d_kind != DLK_EXTERN && !is_do_while) 4359 check_statement_reachable(); 4360 4361 check_expr_misc(tn, vctx, cond, !cond, false, false, false); 4362 if (tn->tn_op == ASSIGN && !tn->tn_parenthesized) { 4363 if (hflag && cond) 4364 /* assignment in conditional context */ 4365 warning(159); 4366 } else if (tn->tn_op == CON) { 4367 if (hflag && cond && !suppress_constcond && 4368 !tn->tn_system_dependent && 4369 !(is_do_while && 4370 is_constcond_false(tn, tn->tn_type->t_tspec))) 4371 /* constant in conditional context */ 4372 warning(161); 4373 } 4374 if (!modtab[tn->tn_op].m_has_side_effect) { 4375 /* 4376 * for left operands of COMMA this warning is already printed 4377 */ 4378 if (tn->tn_op != COMMA && !vctx && !cond) 4379 check_null_effect(tn); 4380 } 4381 debug_node(tn); 4382 4383 if (dofreeblk) 4384 expr_free_all(); 4385 } 4386 4387 /* If the expression has the form '*(arr + idx)', check the array index. */ 4388 static void 4389 check_array_index(const tnode_t *indir, bool taking_address) 4390 { 4391 const tnode_t *plus, *arr, *idx; 4392 4393 if (indir->tn_op == INDIR 4394 && (plus = indir->u.ops.left, plus->tn_op == PLUS) 4395 && plus->u.ops.left->tn_op == ADDR 4396 && (arr = plus->u.ops.left->u.ops.left, true) 4397 && (arr->tn_op == STRING || arr->tn_op == NAME) 4398 && arr->tn_type->t_tspec == ARRAY 4399 && (idx = plus->u.ops.right, idx->tn_op == CON) 4400 && (!is_incomplete(arr->tn_type) || idx->u.value.u.integer < 0)) 4401 goto proceed; 4402 return; 4403 4404 proceed:; 4405 int elsz = length_in_bits(arr->tn_type->t_subt, NULL); 4406 if (elsz == 0) 4407 return; 4408 elsz /= CHAR_SIZE; 4409 4410 /* Change the unit of the index from bytes to element size. */ 4411 int64_t con = is_uinteger(idx->tn_type->t_tspec) 4412 ? (int64_t)((uint64_t)idx->u.value.u.integer / elsz) 4413 : idx->u.value.u.integer / elsz; 4414 4415 int dim = arr->tn_type->u.dimension + (taking_address ? 1 : 0); 4416 4417 if (!is_uinteger(idx->tn_type->t_tspec) && con < 0) 4418 /* array subscript cannot be negative: %ld */ 4419 warning(167, (long)con); 4420 else if (dim > 0 && (uint64_t)con >= (uint64_t)dim) 4421 /* array subscript cannot be > %d: %ld */ 4422 warning(168, dim - 1, (long)con); 4423 } 4424 4425 static void 4426 check_expr_addr(const tnode_t *ln, bool szof, bool fcall) 4427 { 4428 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 4429 if (ln->tn_op == NAME && (reached || !warn_about_unreachable)) { 4430 if (!szof) 4431 mark_as_set(ln->u.sym); 4432 mark_as_used(ln->u.sym, fcall, szof); 4433 } 4434 check_array_index(ln, true); 4435 } 4436 4437 /* 4438 * If there is an asm statement in one of the compound statements around, 4439 * there may be other side effects, so don't warn. 4440 */ 4441 static bool 4442 is_asm_around(void) 4443 { 4444 for (decl_level *dl = dcs; dl != NULL; dl = dl->d_enclosing) 4445 if (dl->d_asm) 4446 return true; 4447 return false; 4448 } 4449 4450 static void 4451 check_expr_side_effect(const tnode_t *ln, bool szof) 4452 { 4453 4454 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 4455 if (ln->tn_op == NAME && (reached || !warn_about_unreachable)) { 4456 scl_t sc = ln->u.sym->s_scl; 4457 if (sc != EXTERN && sc != STATIC && 4458 !ln->u.sym->s_set && !szof && !is_asm_around()) { 4459 /* '%s' may be used before set */ 4460 warning(158, ln->u.sym->s_name); 4461 mark_as_set(ln->u.sym); 4462 } 4463 mark_as_used(ln->u.sym, false, false); 4464 } 4465 } 4466 4467 static void 4468 check_expr_assign(const tnode_t *ln, bool szof) 4469 { 4470 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 4471 if (ln->tn_op == NAME && !szof && (reached || !warn_about_unreachable)) { 4472 mark_as_set(ln->u.sym); 4473 if (ln->u.sym->s_scl == EXTERN) 4474 outusg(ln->u.sym); 4475 } 4476 check_array_index(ln, false); 4477 } 4478 4479 static void 4480 check_expr_call(const tnode_t *tn, const tnode_t *ln, 4481 bool szof, bool vctx, bool cond, bool retval_discarded) 4482 { 4483 lint_assert(ln->tn_op == ADDR); 4484 lint_assert(ln->u.ops.left->tn_op == NAME); 4485 if (!szof && !is_compiler_builtin(ln->u.ops.left->u.sym->s_name)) 4486 outcall(tn, vctx || cond, retval_discarded); 4487 check_snprintb(tn); 4488 } 4489 4490 static void 4491 check_expr_op(op_t op, const tnode_t *ln, bool szof, bool fcall, bool eqwarn) 4492 { 4493 switch (op) { 4494 case ADDR: 4495 check_expr_addr(ln, szof, fcall); 4496 break; 4497 case LOAD: 4498 check_array_index(ln, false); 4499 /* FALLTHROUGH */ 4500 case INCBEF: 4501 case DECBEF: 4502 case INCAFT: 4503 case DECAFT: 4504 case ADDASS: 4505 case SUBASS: 4506 case MULASS: 4507 case DIVASS: 4508 case MODASS: 4509 case ANDASS: 4510 case ORASS: 4511 case XORASS: 4512 case SHLASS: 4513 case SHRASS: 4514 case REAL: 4515 case IMAG: 4516 check_expr_side_effect(ln, szof); 4517 break; 4518 case ASSIGN: 4519 check_expr_assign(ln, szof); 4520 break; 4521 case EQ: 4522 if (hflag && eqwarn) 4523 /* operator '==' found where '=' was expected */ 4524 warning(160); 4525 break; 4526 default: 4527 break; 4528 } 4529 } 4530 4531 /* 4532 * vctx ??? 4533 * cond whether the expression is a condition that 4534 * will be compared with 0 4535 * eqwarn whether the operator '==' might be a 4536 * misspelled '=' 4537 * fcall whether the expression is a function call 4538 * retval_discarded whether the return value of a function call 4539 * is discarded; such calls will be analyzed by 4540 * lint2 in messages 4, 8 and 9 4541 * szof whether the expression is part of a sizeof 4542 * expression, which means that its value is 4543 * discarded since only the type is relevant 4544 */ 4545 void 4546 check_expr_misc(const tnode_t *tn, bool vctx, bool cond, 4547 bool eqwarn, bool fcall, bool retval_discarded, bool szof) 4548 { 4549 4550 if (tn == NULL) 4551 return; 4552 op_t op = tn->tn_op; 4553 if (op == NAME || op == CON || op == STRING) 4554 return; 4555 if (op == CALL || op == ICALL) { 4556 const function_call *call = tn->u.call; 4557 if (op == CALL) 4558 check_expr_call(tn, call->func, 4559 szof, vctx, cond, retval_discarded); 4560 bool discard = op == CVT && tn->tn_type->t_tspec == VOID; 4561 check_expr_misc(call->func, false, false, false, op == CALL, 4562 discard, szof); 4563 if (call->args != NULL) { 4564 for (size_t i = 0, n = call->args_len; i < n; i++) 4565 check_expr_misc(call->args[i], 4566 false, false, false, false, false, szof); 4567 } 4568 return; 4569 } 4570 4571 lint_assert(has_operands(tn)); 4572 tnode_t *ln = tn->u.ops.left; 4573 tnode_t *rn = tn->u.ops.right; 4574 check_expr_op(op, ln, szof, fcall, eqwarn); 4575 4576 const mod_t *mp = &modtab[op]; 4577 bool cvctx = mp->m_value_context; 4578 bool ccond = mp->m_compares_with_zero; 4579 bool eq = mp->m_warn_if_operand_eq && 4580 !ln->tn_parenthesized && 4581 rn != NULL && !rn->tn_parenthesized; 4582 4583 /* 4584 * Values of operands of ':' are not used if the type of at least 4585 * one of the operands (for GCC compatibility) is 'void'. 4586 * 4587 * XXX test/value context of QUEST should probably be used as 4588 * context for both operands of COLON. 4589 */ 4590 if (op == COLON && tn->tn_type->t_tspec == VOID) 4591 cvctx = ccond = false; 4592 bool discard = op == CVT && tn->tn_type->t_tspec == VOID; 4593 check_expr_misc(ln, cvctx, ccond, eq, op == CALL, discard, szof); 4594 4595 switch (op) { 4596 case LOGAND: 4597 case LOGOR: 4598 check_expr_misc(rn, false, true, eq, false, false, szof); 4599 break; 4600 case COLON: 4601 check_expr_misc(rn, cvctx, ccond, eq, false, false, szof); 4602 break; 4603 case COMMA: 4604 check_expr_misc(rn, vctx, cond, false, false, false, szof); 4605 break; 4606 default: 4607 if (mp->m_binary) 4608 check_expr_misc(rn, true, false, eq, false, false, 4609 szof); 4610 break; 4611 } 4612 } 4613 4614 /* 4615 * Return whether the expression can be used for static initialization. 4616 * 4617 * Constant initialization expressions must be constant or an address 4618 * of a static object with an optional offset. In the first case, 4619 * the result is returned in *offsp. In the second case, the static 4620 * object is returned in *symp and the offset in *offsp. 4621 * 4622 * The expression can consist of PLUS, MINUS, ADDR, NAME, STRING and 4623 * CON. Type conversions are allowed if they do not change binary 4624 * representation (including width). 4625 * 4626 * C99 6.6 "Constant expressions" 4627 * C99 6.7.8p4 restricts initializers for static storage duration 4628 */ 4629 bool 4630 constant_addr(const tnode_t *tn, const sym_t **symp, ptrdiff_t *offsp) 4631 { 4632 const sym_t *sym; 4633 ptrdiff_t offs1, offs2; 4634 tspec_t t, ot; 4635 4636 switch (tn->tn_op) { 4637 case MINUS: 4638 if (tn->u.ops.right->tn_op == CVT) 4639 return constant_addr(tn->u.ops.right, symp, offsp); 4640 else if (tn->u.ops.right->tn_op != CON) 4641 return false; 4642 /* FALLTHROUGH */ 4643 case PLUS: 4644 offs1 = offs2 = 0; 4645 if (tn->u.ops.left->tn_op == CON) { 4646 offs1 = (ptrdiff_t)tn->u.ops.left->u.value.u.integer; 4647 if (!constant_addr(tn->u.ops.right, &sym, &offs2)) 4648 return false; 4649 } else if (tn->u.ops.right->tn_op == CON) { 4650 offs2 = (ptrdiff_t)tn->u.ops.right->u.value.u.integer; 4651 if (tn->tn_op == MINUS) 4652 offs2 = -offs2; 4653 if (!constant_addr(tn->u.ops.left, &sym, &offs1)) 4654 return false; 4655 } else { 4656 return false; 4657 } 4658 *symp = sym; 4659 *offsp = offs1 + offs2; 4660 return true; 4661 case ADDR: 4662 if (tn->u.ops.left->tn_op == NAME) { 4663 *symp = tn->u.ops.left->u.sym; 4664 *offsp = 0; 4665 return true; 4666 } else { 4667 /* 4668 * If this were the front end of a compiler, we would 4669 * return a label instead of 0, at least if 4670 * 'tn->u.ops.left->tn_op == STRING'. 4671 */ 4672 *symp = NULL; 4673 *offsp = 0; 4674 return true; 4675 } 4676 case CVT: 4677 t = tn->tn_type->t_tspec; 4678 ot = tn->u.ops.left->tn_type->t_tspec; 4679 if ((!is_integer(t) && t != PTR) || 4680 (!is_integer(ot) && ot != PTR)) { 4681 return false; 4682 } 4683 #if 0 4684 /*- 4685 * consider: 4686 * struct foo { 4687 * unsigned char a; 4688 * } f = { 4689 * (unsigned char)(unsigned long) 4690 * (&(((struct foo *)0)->a)) 4691 * }; 4692 * since psize(unsigned long) != psize(unsigned char), 4693 * this fails. 4694 */ 4695 else if (psize(t) != psize(ot)) 4696 return -1; 4697 #endif 4698 return constant_addr(tn->u.ops.left, symp, offsp); 4699 default: 4700 return false; 4701 } 4702 } 4703 4704 /* Append s2 to s1, then free s2. */ 4705 buffer * 4706 cat_strings(buffer *s1, buffer *s2) 4707 { 4708 4709 if ((s1->data != NULL) != (s2->data != NULL)) { 4710 /* cannot concatenate wide and regular string literals */ 4711 error(292); 4712 return s1; 4713 } 4714 4715 if (s1->data != NULL) { 4716 while (s1->len + s2->len + 1 > s1->cap) 4717 s1->cap *= 2; 4718 s1->data = xrealloc(s1->data, s1->cap); 4719 memcpy(s1->data + s1->len, s2->data, s2->len + 1); 4720 free(s2->data); 4721 } 4722 s1->len += s2->len; 4723 free(s2); 4724 4725 return s1; 4726 } 4727 4728 4729 typedef struct stmt_expr { 4730 memory_pool se_mem; 4731 sym_t *se_sym; 4732 struct stmt_expr *se_enclosing; 4733 } stmt_expr; 4734 4735 static stmt_expr *stmt_exprs; 4736 4737 void 4738 begin_statement_expr(void) 4739 { 4740 debug_enter(); 4741 4742 stmt_expr *se = xmalloc(sizeof(*se)); 4743 se->se_mem = expr_save_memory(); 4744 se->se_sym = NULL; 4745 se->se_enclosing = stmt_exprs; 4746 stmt_exprs = se; 4747 } 4748 4749 void 4750 do_statement_expr(tnode_t *tn) 4751 { 4752 block_level--; 4753 mem_block_level--; 4754 stmt_exprs->se_sym = tn != NULL 4755 ? mktempsym(block_dup_type(tn->tn_type)) 4756 : NULL; /* after a syntax error */ 4757 mem_block_level++; 4758 block_level++; 4759 /* '({ ... })' is a GCC extension */ 4760 gnuism(320); 4761 } 4762 4763 tnode_t * 4764 end_statement_expr(void) 4765 { 4766 tnode_t *tn; 4767 4768 stmt_expr *se = stmt_exprs; 4769 if (se->se_sym == NULL) { 4770 tn = NULL; /* after a syntax error */ 4771 goto end; 4772 } 4773 4774 tn = build_name(se->se_sym, false); 4775 (void)expr_save_memory(); /* leak */ 4776 expr_restore_memory(se->se_mem); 4777 stmt_exprs = se->se_enclosing; 4778 free(se); 4779 4780 end: 4781 debug_leave(); 4782 return tn; 4783 } 4784 4785 bool 4786 in_statement_expr(void) 4787 { 4788 return stmt_exprs != NULL; 4789 } 4790
Indexes created Sat Sep 27 14:09:57 GMT 2025