tree.c revision 1.603
1 /* $NetBSD: tree.c,v 1.603 2024/02/05 23:11:22 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 1.603 2024/02/05 23:11:22 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->tn_val); 286 case CVT: 287 if (!is_integer(tn->tn_left->tn_type->t_tspec)) 288 return ic_any(tn->tn_type); 289 lc = ic_expr(tn->tn_left); 290 return ic_cvt(tn->tn_type, tn->tn_left->tn_type, lc); 291 case MOD: 292 lc = ic_expr(before_conversion(tn->tn_left)); 293 rc = ic_expr(before_conversion(tn->tn_right)); 294 return ic_mod(tn->tn_type, lc, rc); 295 case SHL: 296 lc = ic_expr(tn->tn_left); 297 rc = ic_expr(tn->tn_right); 298 return ic_shl(tn->tn_type, lc, rc); 299 case SHR: 300 lc = ic_expr(tn->tn_left); 301 rc = ic_expr(tn->tn_right); 302 return ic_shr(tn->tn_type, lc, rc); 303 case BITAND: 304 lc = ic_expr(tn->tn_left); 305 rc = ic_expr(tn->tn_right); 306 return ic_bitand(lc, rc); 307 case BITOR: 308 lc = ic_expr(tn->tn_left); 309 rc = ic_expr(tn->tn_right); 310 return ic_bitor(lc, rc); 311 case QUEST: 312 lc = ic_expr(tn->tn_right->tn_left); 313 rc = ic_expr(tn->tn_right->tn_right); 314 return ic_cond(lc, rc); 315 default: 316 return ic_any(tn->tn_type); 317 } 318 } 319 320 /* Build 'pointer to tp', 'array of tp' or 'function returning tp'. */ 321 type_t * 322 block_derive_type(type_t *tp, tspec_t t) 323 { 324 type_t *tp2; 325 326 tp2 = block_zero_alloc(sizeof(*tp2), "type"); 327 tp2->t_tspec = t; 328 tp2->t_subt = tp; 329 return tp2; 330 } 331 332 /* 333 * Derive 'pointer to tp' or 'function returning tp'. 334 * The memory is freed at the end of the current expression. 335 */ 336 type_t * 337 expr_derive_type(type_t *tp, tspec_t t) 338 { 339 type_t *tp2; 340 341 tp2 = expr_zero_alloc(sizeof(*tp2), "type"); 342 tp2->t_tspec = t; 343 tp2->t_subt = tp; 344 return tp2; 345 } 346 347 /* Create an expression from a unary or binary operator and its operands. */ 348 static tnode_t * 349 build_op(op_t op, bool sys, type_t *type, tnode_t *ln, tnode_t *rn) 350 { 351 352 tnode_t *ntn = expr_alloc_tnode(); 353 ntn->tn_op = op; 354 ntn->tn_type = type; 355 ntn->tn_sys = sys; 356 ntn->tn_left = ln; 357 ntn->tn_right = rn; 358 359 if (op == INDIR || op == FSEL) { 360 lint_assert(ln->tn_type->t_tspec == PTR); 361 tspec_t t = ln->tn_type->t_subt->t_tspec; 362 ntn->tn_lvalue = t != FUNC && t != VOID; 363 } 364 365 return ntn; 366 } 367 368 tnode_t * 369 build_constant(type_t *tp, val_t *v) 370 { 371 372 tnode_t *n = expr_alloc_tnode(); 373 n->tn_op = CON; 374 n->tn_type = tp; 375 n->tn_val = *v; 376 n->tn_val.v_tspec = tp->t_tspec; 377 free(v); 378 return n; 379 } 380 381 static tnode_t * 382 build_integer_constant(tspec_t t, int64_t si) 383 { 384 385 tnode_t *n = expr_alloc_tnode(); 386 n->tn_op = CON; 387 n->tn_type = gettyp(t); 388 n->tn_val.v_tspec = t; 389 n->tn_val.v_unsigned_since_c90 = false; 390 n->tn_val.v_char_constant = false; 391 n->tn_val.u.integer = si; 392 return n; 393 } 394 395 static void 396 fallback_symbol(sym_t *sym) 397 { 398 399 if (Tflag && fallback_symbol_strict_bool(sym)) 400 return; 401 402 if (block_level > 0 && (strcmp(sym->s_name, "__FUNCTION__") == 0 || 403 strcmp(sym->s_name, "__PRETTY_FUNCTION__") == 0)) { 404 /* __FUNCTION__/__PRETTY_FUNCTION__ is a GCC extension */ 405 gnuism(316); 406 // XXX: Should probably be ARRAY instead of PTR. 407 sym->s_type = block_derive_type(gettyp(CHAR), PTR); 408 sym->s_type->t_const = true; 409 return; 410 } 411 412 if (funcsym != NULL && strcmp(sym->s_name, "__func__") == 0) { 413 if (!allow_c99) 414 /* __func__ is a C99 feature */ 415 warning(317); 416 /* C11 6.4.2.2 */ 417 sym->s_type = block_derive_type(gettyp(CHAR), ARRAY); 418 sym->s_type->t_const = true; 419 sym->s_type->t_dim = (int)strlen(funcsym->s_name) + 1; 420 return; 421 } 422 423 /* '%s' undefined */ 424 error(99, sym->s_name); 425 } 426 427 /* 428 * Functions that are predeclared by GCC or other compilers can be called 429 * with arbitrary arguments. Since lint usually runs after a successful 430 * compilation, it's the compiler's job to catch any errors. 431 */ 432 bool 433 is_compiler_builtin(const char *name) 434 { 435 /* https://gcc.gnu.org/onlinedocs/gcc/C-Extensions.html */ 436 if (allow_gcc) { 437 if (strncmp(name, "__atomic_", 9) == 0 || 438 strncmp(name, "__builtin_", 10) == 0 || 439 strcmp(name, "alloca") == 0 || 440 /* obsolete but still in use, as of 2021 */ 441 strncmp(name, "__sync_", 7) == 0) 442 return true; 443 } 444 445 /* https://software.intel.com/sites/landingpage/IntrinsicsGuide/ */ 446 if (strncmp(name, "_mm_", 4) == 0) 447 return true; 448 449 return false; 450 } 451 452 /* https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins.html */ 453 static bool 454 is_gcc_bool_builtin(const char *name) 455 { 456 return strncmp(name, "__builtin_", 10) == 0 && 457 (str_ends_with(name, "_overflow") || 458 str_ends_with(name, "_overflow_p")); 459 } 460 461 static void 462 build_name_call(sym_t *sym) 463 { 464 465 if (is_compiler_builtin(sym->s_name)) { 466 /* 467 * Do not warn about these, just assume that they are regular 468 * functions compatible with non-prototype calling conventions. 469 */ 470 if (allow_gcc && is_gcc_bool_builtin(sym->s_name)) 471 sym->s_type = gettyp(BOOL); 472 } else if (allow_c99) { 473 /* function '%s' implicitly declared to return int */ 474 error(215, sym->s_name); 475 } else if (!allow_trad) { 476 /* function '%s' implicitly declared to return int */ 477 warning(215, sym->s_name); 478 } 479 480 /* XXX if !allow_c90, the symbol should be exported to level 0 */ 481 sym->s_type = block_derive_type(sym->s_type, FUNC); 482 } 483 484 /* Create a node for a name (symbol table entry). */ 485 tnode_t * 486 build_name(sym_t *sym, bool is_funcname) 487 { 488 489 if (sym->s_scl == NO_SCL && !in_gcc_attribute) { 490 sym->s_scl = EXTERN; 491 sym->s_def = DECL; 492 if (is_funcname) 493 build_name_call(sym); 494 else 495 fallback_symbol(sym); 496 } 497 498 lint_assert(sym->s_kind == SK_VCFT || sym->s_kind == SK_MEMBER); 499 500 tnode_t *n = expr_alloc_tnode(); 501 n->tn_type = sym->s_type; 502 if (sym->s_scl == BOOL_CONST) { 503 n->tn_op = CON; 504 n->tn_val.v_tspec = BOOL; 505 n->tn_val.v_unsigned_since_c90 = false; 506 n->tn_val.v_char_constant = false; 507 n->tn_val.u.integer = sym->u.s_bool_constant ? 1 : 0; 508 } else if (sym->s_scl == ENUM_CONST) { 509 n->tn_op = CON; 510 n->tn_val.v_tspec = INT; /* ENUM is in n->tn_type */ 511 n->tn_val.v_unsigned_since_c90 = false; 512 n->tn_val.v_char_constant = false; 513 n->tn_val.u.integer = sym->u.s_enum_constant; 514 } else { 515 n->tn_op = NAME; 516 n->tn_sym = sym; 517 if (sym->s_kind == SK_VCFT && sym->s_type->t_tspec != FUNC) 518 n->tn_lvalue = true; 519 } 520 521 return n; 522 } 523 524 tnode_t * 525 build_string(buffer *lit) 526 { 527 size_t value_len = lit->len; 528 if (lit->data != NULL) { 529 quoted_iterator it = { .start = 0 }; 530 for (value_len = 0; quoted_next(lit, &it); value_len++) 531 continue; 532 } 533 534 type_t *tp = expr_zero_alloc(sizeof(*tp), "type"); 535 tp->t_tspec = ARRAY; 536 tp->t_subt = gettyp(lit->data != NULL ? CHAR : WCHAR_TSPEC); 537 tp->t_dim = (int)(value_len + 1); 538 539 tnode_t *n = expr_alloc_tnode(); 540 n->tn_op = STRING; 541 n->tn_type = tp; 542 n->tn_lvalue = true; 543 544 n->tn_string = expr_zero_alloc(sizeof(*n->tn_string), "tnode.string"); 545 n->tn_string->len = lit->len; 546 547 if (lit->data != NULL) { 548 n->tn_string->data = expr_zero_alloc(lit->len + 1, 549 "tnode.string.data"); 550 (void)memcpy(n->tn_string->data, lit->data, lit->len + 1); 551 free(lit->data); 552 } 553 free(lit); 554 555 return n; 556 } 557 558 tnode_t * 559 build_generic_selection(const tnode_t *expr, 560 struct generic_association *sel) 561 { 562 tnode_t *default_result = NULL; 563 564 for (; sel != NULL; sel = sel->ga_prev) { 565 if (expr != NULL && 566 types_compatible(sel->ga_arg, expr->tn_type, 567 false, false, NULL)) 568 return sel->ga_result; 569 else if (sel->ga_arg == NULL) 570 default_result = sel->ga_result; 571 } 572 return default_result; 573 } 574 575 static bool 576 is_out_of_char_range(const tnode_t *tn) 577 { 578 return tn->tn_op == CON && 579 !tn->tn_val.v_char_constant && 580 !(0 <= tn->tn_val.u.integer && 581 tn->tn_val.u.integer < 1 << (CHAR_SIZE - 1)); 582 } 583 584 static bool 585 check_nonportable_char_comparison(op_t op, 586 const tnode_t *ln, tspec_t lt, 587 const tnode_t *rn, tspec_t rt) 588 { 589 if (!(hflag || pflag)) 590 return true; 591 592 if (lt == CHAR && is_out_of_char_range(rn)) { 593 char buf[128]; 594 (void)snprintf(buf, sizeof(buf), "%s %d", 595 op_name(op), (int)rn->tn_val.u.integer); 596 /* nonportable character comparison '%s' */ 597 warning(230, buf); 598 return false; 599 } 600 if (rt == CHAR && is_out_of_char_range(ln)) { 601 char buf[128]; 602 (void)snprintf(buf, sizeof(buf), "%d %s ?", 603 (int)ln->tn_val.u.integer, op_name(op)); 604 /* nonportable character comparison '%s' */ 605 warning(230, buf); 606 return false; 607 } 608 return true; 609 } 610 611 static void 612 check_integer_comparison(op_t op, tnode_t *ln, tnode_t *rn) 613 { 614 615 tspec_t lt = ln->tn_type->t_tspec; 616 tspec_t rt = rn->tn_type->t_tspec; 617 618 if (ln->tn_op != CON && rn->tn_op != CON) 619 return; 620 621 if (!is_integer(lt) || !is_integer(rt)) 622 return; 623 624 if (any_query_enabled && !in_system_header) { 625 if (lt == CHAR && rn->tn_op == CON && 626 !rn->tn_val.v_char_constant) { 627 /* comparison '%s' of 'char' with plain integer %d */ 628 query_message(14, 629 op_name(op), (int)rn->tn_val.u.integer); 630 } 631 if (rt == CHAR && ln->tn_op == CON && 632 !ln->tn_val.v_char_constant) { 633 /* comparison '%s' of 'char' with plain integer %d */ 634 query_message(14, 635 op_name(op), (int)ln->tn_val.u.integer); 636 } 637 } 638 639 if (!check_nonportable_char_comparison(op, ln, lt, rn, rt)) 640 return; 641 642 if (is_uinteger(lt) && !is_uinteger(rt) && 643 rn->tn_op == CON && rn->tn_val.u.integer <= 0) { 644 if (rn->tn_val.u.integer < 0) { 645 /* operator '%s' compares '%s' with '%s' */ 646 warning(162, op_name(op), 647 type_name(ln->tn_type), "negative constant"); 648 } else if (op == LT || op == GE) { 649 /* operator '%s' compares '%s' with '%s' */ 650 warning(162, op_name(op), type_name(ln->tn_type), "0"); 651 } 652 return; 653 } 654 if (is_uinteger(rt) && !is_uinteger(lt) && 655 ln->tn_op == CON && ln->tn_val.u.integer <= 0) { 656 if (ln->tn_val.u.integer < 0) { 657 /* operator '%s' compares '%s' with '%s' */ 658 warning(162, op_name(op), 659 "negative constant", type_name(rn->tn_type)); 660 } else if (op == GT || op == LE) { 661 /* operator '%s' compares '%s' with '%s' */ 662 warning(162, op_name(op), "0", type_name(rn->tn_type)); 663 } 664 return; 665 } 666 } 667 668 static const tspec_t arith_rank[] = { 669 LDOUBLE, DOUBLE, FLOAT, 670 #ifdef INT128_SIZE 671 UINT128, INT128, 672 #endif 673 ULLONG, LLONG, 674 ULONG, LONG, 675 UINT, INT, 676 }; 677 678 /* Keep unsigned in traditional C */ 679 static tspec_t 680 usual_arithmetic_conversion_trad(tspec_t lt, tspec_t rt) 681 { 682 683 size_t i; 684 for (i = 0; arith_rank[i] != INT; i++) 685 if (lt == arith_rank[i] || rt == arith_rank[i]) 686 break; 687 688 tspec_t t = arith_rank[i]; 689 if (is_uinteger(lt) || is_uinteger(rt)) 690 if (is_integer(t) && !is_uinteger(t)) 691 return unsigned_type(t); 692 return t; 693 } 694 695 static tspec_t 696 usual_arithmetic_conversion_c90(tspec_t lt, tspec_t rt) 697 { 698 699 if (lt == rt) 700 return lt; 701 702 if (lt == LCOMPLEX || rt == LCOMPLEX) 703 return LCOMPLEX; 704 if (lt == DCOMPLEX || rt == DCOMPLEX) 705 return DCOMPLEX; 706 if (lt == FCOMPLEX || rt == FCOMPLEX) 707 return FCOMPLEX; 708 if (lt == LDOUBLE || rt == LDOUBLE) 709 return LDOUBLE; 710 if (lt == DOUBLE || rt == DOUBLE) 711 return DOUBLE; 712 if (lt == FLOAT || rt == FLOAT) 713 return FLOAT; 714 715 if (size_in_bits(lt) > size_in_bits(rt)) 716 return lt; 717 if (size_in_bits(lt) < size_in_bits(rt)) 718 return rt; 719 720 size_t i; 721 for (i = 3; arith_rank[i] != INT; i++) 722 if (arith_rank[i] == lt || arith_rank[i] == rt) 723 break; 724 if ((is_uinteger(lt) || is_uinteger(rt)) && 725 !is_uinteger(arith_rank[i])) 726 i--; 727 return arith_rank[i]; 728 } 729 730 static tnode_t * 731 apply_usual_arithmetic_conversions(op_t op, tnode_t *tn, tspec_t t) 732 { 733 type_t *ntp = expr_dup_type(tn->tn_type); 734 ntp->t_tspec = t; 735 if (tn->tn_op != CON) { 736 /* usual arithmetic conversion for '%s' from '%s' to '%s' */ 737 query_message(4, op_name(op), 738 type_name(tn->tn_type), type_name(ntp)); 739 } 740 return convert(op, 0, ntp, tn); 741 } 742 743 /* 744 * Apply the "usual arithmetic conversions" (C99 6.3.1.8), which gives both 745 * operands the same type. 746 */ 747 static void 748 balance(op_t op, tnode_t **lnp, tnode_t **rnp) 749 { 750 751 tspec_t lt = (*lnp)->tn_type->t_tspec; 752 tspec_t rt = (*rnp)->tn_type->t_tspec; 753 if (!is_arithmetic(lt) || !is_arithmetic(rt)) 754 return; 755 756 tspec_t t = allow_c90 757 ? usual_arithmetic_conversion_c90(lt, rt) 758 : usual_arithmetic_conversion_trad(lt, rt); 759 760 if (t != lt) 761 *lnp = apply_usual_arithmetic_conversions(op, *lnp, t); 762 if (t != rt) 763 *rnp = apply_usual_arithmetic_conversions(op, *rnp, t); 764 } 765 766 static tnode_t * 767 build_address(bool sys, tnode_t *tn, bool force) 768 { 769 tspec_t t; 770 771 if (!force && ((t = tn->tn_type->t_tspec) == ARRAY || t == FUNC)) { 772 if (!allow_c90) 773 /* '&' before array or function: ignored */ 774 warning(127); 775 return tn; 776 } 777 778 /* eliminate '&*' */ 779 if (tn->tn_op == INDIR && 780 tn->tn_left->tn_type->t_tspec == PTR && 781 tn->tn_left->tn_type->t_subt == tn->tn_type) { 782 return tn->tn_left; 783 } 784 785 return build_op(ADDR, sys, expr_derive_type(tn->tn_type, PTR), 786 tn, NULL); 787 } 788 789 /* 790 * XXX 791 * Note: There appear to be a number of bugs in detecting overflow in 792 * this function. An audit and a set of proper regression tests are needed. 793 * --Perry Metzger, Nov. 16, 2001 794 */ 795 static tnode_t * 796 fold_constant_integer(tnode_t *tn) 797 { 798 799 val_t *v = xcalloc(1, sizeof(*v)); 800 v->v_tspec = tn->tn_type->t_tspec; 801 802 lint_assert(has_operands(tn)); 803 tspec_t t = tn->tn_left->tn_type->t_tspec; 804 bool utyp = !is_integer(t) || is_uinteger(t); 805 int64_t sl = tn->tn_left->tn_val.u.integer, sr = 0; 806 uint64_t ul = sl, ur = 0; 807 if (is_binary(tn)) 808 ur = sr = tn->tn_right->tn_val.u.integer; 809 810 uint64_t mask = value_bits(size_in_bits(t)); 811 bool ovfl = false; 812 813 int64_t si; 814 switch (tn->tn_op) { 815 case UPLUS: 816 si = sl; 817 break; 818 case UMINUS: 819 si = sl == INT64_MIN ? sl : -sl; 820 if (sl != 0 && msb(si, t) == msb(sl, t)) 821 ovfl = true; 822 break; 823 case COMPL: 824 si = ~sl; 825 break; 826 case MULT: 827 if (utyp) { 828 si = (int64_t)(ul * ur); 829 if (si != (si & (int64_t)mask)) 830 ovfl = true; 831 else if (ul != 0 && si / ul != ur) 832 ovfl = true; 833 } else { 834 si = sl * sr; 835 if (msb(si, t) != (msb(sl, t) ^ msb(sr, t))) 836 ovfl = true; 837 } 838 break; 839 case DIV: 840 if (sr == 0) { 841 /* division by 0 */ 842 error(139); 843 si = utyp ? -1 : INT64_MAX; 844 } else if (!utyp 845 && (sl & mask) == (mask ^ (mask >> 1)) && sr == -1) { 846 /* operator '%s' produces integer overflow */ 847 warning(141, op_name(DIV)); 848 si = sl; 849 } else { 850 si = utyp ? (int64_t)(ul / ur) : sl / sr; 851 } 852 break; 853 case MOD: 854 if (sr == 0) { 855 /* modulus by 0 */ 856 error(140); 857 si = 0; 858 } else { 859 si = utyp ? (int64_t)(ul % ur) : sl % sr; 860 } 861 break; 862 case PLUS: 863 si = utyp ? (int64_t)(ul + ur) : sl + sr; 864 if (msb(sl, t) && msb(sr, t) && !msb(si, t)) 865 ovfl = true; 866 if (!utyp && !msb(sl, t) && !msb(sr, t) && msb(si, t)) 867 ovfl = true; 868 break; 869 case MINUS: 870 si = utyp ? (int64_t)(ul - ur) : sl - sr; 871 if (!utyp && msb(sl, t) && !msb(sr, t) && !msb(si, t)) 872 ovfl = true; 873 if (!msb(sl, t) && msb(sr, t) && msb(si, t)) 874 ovfl = true; 875 break; 876 case SHL: 877 /* TODO: warn about out-of-bounds 'sr'. */ 878 /* TODO: warn about overflow in signed '<<'. */ 879 si = utyp ? (int64_t)(ul << (sr & 63)) : sl << (sr & 63); 880 break; 881 case SHR: 882 /* 883 * The sign must be explicitly extended because shifts of 884 * signed values are implementation dependent. 885 */ 886 /* TODO: warn about out-of-bounds 'sr'. */ 887 si = (int64_t)(ul >> (sr & 63)); 888 si = convert_integer(si, t, size_in_bits(t) - (int)sr); 889 break; 890 case LT: 891 si = (utyp ? ul < ur : sl < sr) ? 1 : 0; 892 break; 893 case LE: 894 si = (utyp ? ul <= ur : sl <= sr) ? 1 : 0; 895 break; 896 case GE: 897 si = (utyp ? ul >= ur : sl >= sr) ? 1 : 0; 898 break; 899 case GT: 900 si = (utyp ? ul > ur : sl > sr) ? 1 : 0; 901 break; 902 case EQ: 903 si = (utyp ? ul == ur : sl == sr) ? 1 : 0; 904 break; 905 case NE: 906 si = (utyp ? ul != ur : sl != sr) ? 1 : 0; 907 break; 908 case BITAND: 909 si = utyp ? (int64_t)(ul & ur) : sl & sr; 910 break; 911 case BITXOR: 912 si = utyp ? (int64_t)(ul ^ ur) : sl ^ sr; 913 break; 914 case BITOR: 915 si = utyp ? (int64_t)(ul | ur) : sl | sr; 916 break; 917 default: 918 lint_assert(/*CONSTCOND*/false); 919 } 920 921 /* XXX: The overflow check does not work for 64-bit integers. */ 922 if (ovfl || 923 ((si | mask) != ~(uint64_t)0 && (si & ~mask) != 0)) { 924 if (hflag) 925 /* operator '%s' produces integer overflow */ 926 warning(141, op_name(tn->tn_op)); 927 } 928 929 v->u.integer = convert_integer(si, t, 0); 930 931 tnode_t *cn = build_constant(tn->tn_type, v); 932 if (tn->tn_left->tn_system_dependent) 933 cn->tn_system_dependent = true; 934 if (is_binary(tn) && tn->tn_right->tn_system_dependent) 935 cn->tn_system_dependent = true; 936 937 return cn; 938 } 939 940 static tnode_t * 941 build_struct_access(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 942 { 943 944 lint_assert(rn->tn_op == NAME); 945 lint_assert(is_member(rn->tn_sym)); 946 947 bool lvalue = op == ARROW || ln->tn_lvalue; 948 949 if (op == POINT) { 950 ln = build_address(sys, ln, true); 951 } else if (ln->tn_type->t_tspec != PTR) { 952 lint_assert(!allow_c90); 953 lint_assert(is_integer(ln->tn_type->t_tspec)); 954 ln = convert(NOOP, 0, expr_derive_type(gettyp(VOID), PTR), ln); 955 } 956 957 tnode_t *ctn = build_integer_constant(PTRDIFF_TSPEC, 958 rn->tn_sym->u.s_member.sm_offset_in_bits / CHAR_SIZE); 959 960 type_t *ptr_tp = expr_derive_type(rn->tn_type, PTR); 961 tnode_t *ntn = build_op(PLUS, sys, ptr_tp, ln, ctn); 962 if (ln->tn_op == CON) 963 ntn = fold_constant_integer(ntn); 964 965 op_t nop = rn->tn_type->t_bitfield ? FSEL : INDIR; 966 ntn = build_op(nop, sys, ntn->tn_type->t_subt, ntn, NULL); 967 if (!lvalue) 968 ntn->tn_lvalue = false; 969 970 return ntn; 971 } 972 973 /* 974 * Get the size in bytes of type tp->t_subt, as a constant expression of type 975 * ptrdiff_t as seen from the target platform. 976 */ 977 static tnode_t * 978 subt_size_in_bytes(type_t *tp) 979 { 980 981 lint_assert(tp->t_tspec == PTR); 982 tp = tp->t_subt; 983 984 int elem = 1; 985 while (tp->t_tspec == ARRAY) { 986 elem *= tp->t_dim; 987 tp = tp->t_subt; 988 } 989 990 int elsz_in_bits = 0; 991 switch (tp->t_tspec) { 992 case FUNC: 993 /* pointer to function is not allowed here */ 994 error(110); 995 break; 996 case VOID: 997 /* cannot do pointer arithmetic on operand of unknown size */ 998 gnuism(136); 999 break; 1000 case STRUCT: 1001 case UNION: 1002 if ((elsz_in_bits = (int)tp->t_sou->sou_size_in_bits) == 0) 1003 /* cannot do pointer arithmetic on operand of ... */ 1004 error(136); 1005 break; 1006 case ENUM: 1007 if (is_incomplete(tp)) { 1008 /* cannot do pointer arithmetic on operand of ... */ 1009 warning(136); 1010 } 1011 /* FALLTHROUGH */ 1012 default: 1013 if ((elsz_in_bits = size_in_bits(tp->t_tspec)) == 0) { 1014 /* cannot do pointer arithmetic on operand of ... */ 1015 error(136); 1016 } else { 1017 lint_assert(elsz_in_bits != -1); 1018 } 1019 break; 1020 } 1021 1022 if (elem == 0 && elsz_in_bits != 0) { 1023 /* cannot do pointer arithmetic on operand of unknown size */ 1024 error(136); 1025 } 1026 1027 if (elsz_in_bits == 0) 1028 elsz_in_bits = CHAR_SIZE; 1029 1030 return build_integer_constant(PTRDIFF_TSPEC, 1031 (int64_t)(elem * elsz_in_bits / CHAR_SIZE)); 1032 } 1033 1034 static tnode_t * 1035 build_prepost_incdec(op_t op, bool sys, tnode_t *ln) 1036 { 1037 1038 lint_assert(ln != NULL); 1039 tnode_t *cn = ln->tn_type->t_tspec == PTR 1040 ? subt_size_in_bytes(ln->tn_type) 1041 : build_integer_constant(INT, 1); 1042 return build_op(op, sys, ln->tn_type, ln, cn); 1043 } 1044 1045 static void 1046 check_enum_array_index(const tnode_t *ln, const tnode_t *rn) 1047 { 1048 1049 if (ln->tn_op != ADDR || ln->tn_left->tn_op != NAME) 1050 return; 1051 1052 const type_t *ltp = ln->tn_left->tn_type; 1053 if (ltp->t_tspec != ARRAY || ltp->t_incomplete_array) 1054 return; 1055 1056 if (rn->tn_op != CVT || !rn->tn_type->t_is_enum) 1057 return; 1058 if (rn->tn_left->tn_op != LOAD) 1059 return; 1060 1061 const type_t *rtp = rn->tn_left->tn_type; 1062 const sym_t *ec = rtp->t_enum->en_first_enumerator; 1063 const sym_t *max_ec = ec; 1064 lint_assert(ec != NULL); 1065 for (ec = ec->s_next; ec != NULL; ec = ec->s_next) 1066 if (ec->u.s_enum_constant > max_ec->u.s_enum_constant) 1067 max_ec = ec; 1068 1069 int64_t max_enum_value = max_ec->u.s_enum_constant; 1070 lint_assert(INT_MIN <= max_enum_value && max_enum_value <= INT_MAX); 1071 1072 int max_array_index = ltp->t_dim - 1; 1073 if (max_enum_value == max_array_index) 1074 return; 1075 1076 if (max_enum_value == max_array_index + 1 && 1077 (strstr(max_ec->s_name, "MAX") != NULL || 1078 strstr(max_ec->s_name, "max") != NULL || 1079 strstr(max_ec->s_name, "NUM") != NULL || 1080 strstr(max_ec->s_name, "num") != NULL)) 1081 return; 1082 1083 /* maximum value %d of '%s' does not match maximum array index %d */ 1084 warning(348, (int)max_enum_value, type_name(rtp), max_array_index); 1085 print_previous_declaration(max_ec); 1086 } 1087 1088 static tnode_t * 1089 build_plus_minus(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 1090 { 1091 1092 if (rn->tn_type->t_tspec == PTR && is_integer(ln->tn_type->t_tspec)) { 1093 tnode_t *tmp = ln; 1094 ln = rn; 1095 rn = tmp; 1096 /* pointer addition has integer on the left-hand side */ 1097 query_message(5); 1098 } 1099 1100 /* pointer +- integer */ 1101 if (ln->tn_type->t_tspec == PTR && rn->tn_type->t_tspec != PTR) { 1102 lint_assert(is_integer(rn->tn_type->t_tspec)); 1103 1104 check_ctype_macro_invocation(ln, rn); 1105 check_enum_array_index(ln, rn); 1106 1107 tnode_t *elsz = subt_size_in_bytes(ln->tn_type); 1108 if (rn->tn_type->t_tspec != elsz->tn_type->t_tspec) 1109 rn = convert(NOOP, 0, elsz->tn_type, rn); 1110 1111 tnode_t *prod = build_op(MULT, sys, rn->tn_type, rn, elsz); 1112 if (rn->tn_op == CON) 1113 prod = fold_constant_integer(prod); 1114 1115 return build_op(op, sys, ln->tn_type, ln, prod); 1116 } 1117 1118 /* pointer - pointer */ 1119 if (rn->tn_type->t_tspec == PTR) { 1120 lint_assert(ln->tn_type->t_tspec == PTR); 1121 lint_assert(op == MINUS); 1122 1123 type_t *ptrdiff = gettyp(PTRDIFF_TSPEC); 1124 tnode_t *raw_diff = build_op(op, sys, ptrdiff, ln, rn); 1125 if (ln->tn_op == CON && rn->tn_op == CON) 1126 raw_diff = fold_constant_integer(raw_diff); 1127 1128 tnode_t *elsz = subt_size_in_bytes(ln->tn_type); 1129 balance(NOOP, &raw_diff, &elsz); 1130 1131 return build_op(DIV, sys, ptrdiff, raw_diff, elsz); 1132 } 1133 1134 return build_op(op, sys, ln->tn_type, ln, rn); 1135 } 1136 1137 static tnode_t * 1138 build_bit_shift(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 1139 { 1140 1141 if (!allow_c90 && rn->tn_type->t_tspec != INT) 1142 // XXX: C1978 7.5 says: "Both [operators] perform the usual 1143 // arithmetic conversions on their operands." 1144 // TODO: Add a test to exercise this part of the code. 1145 rn = convert(NOOP, 0, gettyp(INT), rn); 1146 return build_op(op, sys, ln->tn_type, ln, rn); 1147 } 1148 1149 static bool 1150 is_null_pointer(const tnode_t *tn) 1151 { 1152 tspec_t t = tn->tn_type->t_tspec; 1153 1154 // TODO: Investigate how other pointers are stored, in particular, 1155 // whether a pointer constant can have a non-zero value. 1156 // If not, simplify the code below. 1157 return ((t == PTR && tn->tn_type->t_subt->t_tspec == VOID) 1158 || is_integer(t)) 1159 && (tn->tn_op == CON && tn->tn_val.u.integer == 0); 1160 } 1161 1162 /* Return a type based on tp1, with added qualifiers from tp2. */ 1163 static type_t * 1164 merge_qualifiers(type_t *tp1, const type_t *tp2) 1165 { 1166 1167 lint_assert(tp1->t_tspec == PTR); 1168 lint_assert(tp2->t_tspec == PTR); 1169 1170 bool c1 = tp1->t_subt->t_const; 1171 bool c2 = tp2->t_subt->t_const; 1172 bool v1 = tp1->t_subt->t_volatile; 1173 bool v2 = tp2->t_subt->t_volatile; 1174 1175 if (c1 == (c1 | c2) && v1 == (v1 | v2)) 1176 return tp1; 1177 1178 type_t *nstp = expr_dup_type(tp1->t_subt); 1179 nstp->t_const |= c2; 1180 nstp->t_volatile |= v2; 1181 1182 type_t *ntp = expr_dup_type(tp1); 1183 ntp->t_subt = nstp; 1184 return ntp; 1185 } 1186 1187 /* See C99 6.5.15 "Conditional operator". */ 1188 static tnode_t * 1189 build_colon(bool sys, tnode_t *ln, tnode_t *rn) 1190 { 1191 tspec_t lt = ln->tn_type->t_tspec; 1192 tspec_t rt = rn->tn_type->t_tspec; 1193 1194 type_t *tp; 1195 if (is_arithmetic(lt) && is_arithmetic(rt)) { 1196 /* The operands were already balanced in build_binary. */ 1197 tp = ln->tn_type; 1198 } else if (lt == BOOL && rt == BOOL) { 1199 tp = ln->tn_type; 1200 } else if (lt == VOID || rt == VOID) { 1201 tp = gettyp(VOID); 1202 } else if (is_struct_or_union(lt)) { 1203 lint_assert(is_struct_or_union(rt)); 1204 lint_assert(ln->tn_type->t_sou == rn->tn_type->t_sou); 1205 if (is_incomplete(ln->tn_type)) { 1206 /* unknown operand size, op '%s' */ 1207 error(138, op_name(COLON)); 1208 return NULL; 1209 } 1210 tp = ln->tn_type; 1211 } else if (lt == PTR && is_integer(rt)) { 1212 if (rt != PTRDIFF_TSPEC) 1213 rn = convert(NOOP, 0, gettyp(PTRDIFF_TSPEC), rn); 1214 tp = ln->tn_type; 1215 } else if (rt == PTR && is_integer(lt)) { 1216 if (lt != PTRDIFF_TSPEC) 1217 ln = convert(NOOP, 0, gettyp(PTRDIFF_TSPEC), ln); 1218 tp = rn->tn_type; 1219 } else if (lt == PTR && is_null_pointer(rn)) { 1220 tp = merge_qualifiers(ln->tn_type, rn->tn_type); 1221 } else if (rt == PTR && is_null_pointer(ln)) { 1222 tp = merge_qualifiers(rn->tn_type, ln->tn_type); 1223 } else if (lt == PTR && ln->tn_type->t_subt->t_tspec == VOID) { 1224 tp = merge_qualifiers(ln->tn_type, rn->tn_type); 1225 } else if (rt == PTR && rn->tn_type->t_subt->t_tspec == VOID) { 1226 tp = merge_qualifiers(rn->tn_type, ln->tn_type); 1227 } else { 1228 /* 1229 * XXX For now we simply take the left type. This is probably 1230 * wrong, if one type contains a function prototype and the 1231 * other one, at the same place, only an old-style declaration. 1232 */ 1233 tp = merge_qualifiers(ln->tn_type, rn->tn_type); 1234 } 1235 1236 return build_op(COLON, sys, tp, ln, rn); 1237 } 1238 1239 /* TODO: check for varargs */ 1240 static bool 1241 is_cast_redundant(const tnode_t *tn) 1242 { 1243 const type_t *ntp = tn->tn_type, *otp = tn_ck_left(tn)->tn_type; 1244 tspec_t nt = ntp->t_tspec, ot = otp->t_tspec; 1245 1246 if (nt == BOOL || ot == BOOL) 1247 return nt == BOOL && ot == BOOL; 1248 1249 if (is_integer(nt) && is_integer(ot)) { 1250 unsigned int nw = width_in_bits(ntp), ow = width_in_bits(otp); 1251 if (is_uinteger(nt) == is_uinteger(ot)) 1252 return nw >= ow; 1253 return is_uinteger(ot) && nw > ow; 1254 } 1255 1256 if (is_complex(nt) || is_complex(ot)) 1257 return is_complex(nt) && is_complex(ot) && 1258 size_in_bits(nt) >= size_in_bits(ot); 1259 1260 if (is_floating(nt) && is_floating(ot)) 1261 return size_in_bits(nt) >= size_in_bits(ot); 1262 1263 if (nt == PTR && ot == PTR) { 1264 if (!ntp->t_subt->t_const && otp->t_subt->t_const) 1265 return false; 1266 if (!ntp->t_subt->t_volatile && otp->t_subt->t_volatile) 1267 return false; 1268 1269 if (ntp->t_subt->t_tspec == VOID || 1270 otp->t_subt->t_tspec == VOID || 1271 types_compatible(ntp->t_subt, otp->t_subt, 1272 false, false, NULL)) 1273 return true; 1274 } 1275 1276 return false; 1277 } 1278 1279 static bool 1280 is_assignment(op_t op) 1281 { 1282 1283 return op == ASSIGN || 1284 op == MULASS || 1285 op == DIVASS || 1286 op == MODASS || 1287 op == ADDASS || 1288 op == SUBASS || 1289 op == SHLASS || 1290 op == SHRASS || 1291 op == ANDASS || 1292 op == XORASS || 1293 op == ORASS || 1294 op == RETURN || 1295 op == INIT; 1296 } 1297 1298 static tnode_t * 1299 build_assignment(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 1300 { 1301 1302 tspec_t lt = ln->tn_type->t_tspec; 1303 tspec_t rt = rn->tn_type->t_tspec; 1304 1305 if (any_query_enabled && is_assignment(rn->tn_op)) { 1306 /* chained assignment with '%s' and '%s' */ 1307 query_message(10, op_name(op), op_name(rn->tn_op)); 1308 } 1309 1310 if ((op == ADDASS || op == SUBASS) && lt == PTR) { 1311 lint_assert(is_integer(rt)); 1312 tnode_t *ctn = subt_size_in_bytes(ln->tn_type); 1313 if (rn->tn_type->t_tspec != ctn->tn_type->t_tspec) 1314 rn = convert(NOOP, 0, ctn->tn_type, rn); 1315 rn = build_op(MULT, sys, rn->tn_type, rn, ctn); 1316 if (rn->tn_left->tn_op == CON) 1317 rn = fold_constant_integer(rn); 1318 } 1319 1320 if ((op == ASSIGN || op == RETURN || op == INIT) && 1321 (lt == STRUCT || rt == STRUCT)) { 1322 lint_assert(lt == rt); 1323 lint_assert(ln->tn_type->t_sou == rn->tn_type->t_sou); 1324 if (is_incomplete(ln->tn_type)) { 1325 if (op == RETURN) { 1326 /* cannot return incomplete type */ 1327 error(212); 1328 } else { 1329 /* unknown operand size, op '%s' */ 1330 error(138, op_name(op)); 1331 } 1332 return NULL; 1333 } 1334 } 1335 1336 if (op == SHLASS && hflag && allow_trad && allow_c90 1337 && portable_rank_cmp(lt, rt) < 0) 1338 /* semantics of '%s' change in C90; ... */ 1339 warning(118, "<<="); 1340 1341 if (op != SHLASS && op != SHRASS 1342 && (op == ASSIGN || lt != PTR) 1343 && (lt != rt || (ln->tn_type->t_bitfield && rn->tn_op == CON))) { 1344 rn = convert(op, 0, ln->tn_type, rn); 1345 rt = lt; 1346 } 1347 1348 if (any_query_enabled && rn->tn_op == CVT && rn->tn_cast && 1349 types_compatible(ln->tn_type, rn->tn_type, false, false, NULL) && 1350 is_cast_redundant(rn)) { 1351 /* redundant cast from '%s' to '%s' before assignment */ 1352 query_message(7, 1353 type_name(rn->tn_left->tn_type), type_name(rn->tn_type)); 1354 } 1355 1356 return build_op(op, sys, ln->tn_type, ln, rn); 1357 } 1358 1359 static tnode_t * 1360 build_real_imag(op_t op, bool sys, tnode_t *ln) 1361 { 1362 1363 lint_assert(ln != NULL); 1364 if (ln->tn_op == NAME) { 1365 /* 1366 * This may be too much, but it avoids wrong warnings. See 1367 * d_c99_complex_split.c. 1368 */ 1369 mark_as_used(ln->tn_sym, false, false); 1370 mark_as_set(ln->tn_sym); 1371 } 1372 1373 tspec_t t; 1374 switch (ln->tn_type->t_tspec) { 1375 case LCOMPLEX: 1376 t = LDOUBLE; 1377 break; 1378 case DCOMPLEX: 1379 t = DOUBLE; 1380 break; 1381 case FCOMPLEX: 1382 t = FLOAT; 1383 break; 1384 default: 1385 /* '__%s__' is illegal for type '%s' */ 1386 error(276, op == REAL ? "real" : "imag", 1387 type_name(ln->tn_type)); 1388 return NULL; 1389 } 1390 1391 tnode_t *ntn = build_op(op, sys, gettyp(t), ln, NULL); 1392 ntn->tn_lvalue = true; 1393 return ntn; 1394 } 1395 1396 static bool 1397 is_confusing_precedence(op_t op, op_t lop, bool lparen, op_t rop, bool rparen) 1398 { 1399 1400 if (op == SHL || op == SHR) { 1401 if (!lparen && (lop == PLUS || lop == MINUS)) 1402 return true; 1403 if (!rparen && (rop == PLUS || rop == MINUS)) 1404 return true; 1405 return false; 1406 } 1407 1408 if (op == LOGOR) { 1409 if (!lparen && lop == LOGAND) 1410 return true; 1411 if (!rparen && rop == LOGAND) 1412 return true; 1413 return false; 1414 } 1415 1416 lint_assert(op == BITAND || op == BITXOR || op == BITOR); 1417 if (!lparen && lop != op) { 1418 if (lop == PLUS || lop == MINUS) 1419 return true; 1420 if (lop == BITAND || lop == BITXOR) 1421 return true; 1422 } 1423 if (!rparen && rop != op) { 1424 if (rop == PLUS || rop == MINUS) 1425 return true; 1426 if (rop == BITAND || rop == BITXOR) 1427 return true; 1428 } 1429 return false; 1430 } 1431 1432 /* 1433 * Print a warning if the given node has operands which should be 1434 * parenthesized. 1435 * 1436 * XXX Does not work if an operand is a constant expression. Constant 1437 * expressions are already folded. 1438 */ 1439 static void 1440 check_precedence_confusion(tnode_t *tn) 1441 { 1442 tnode_t *ln, *rn; 1443 1444 if (!hflag) 1445 return; 1446 1447 debug_node(tn); 1448 1449 lint_assert(is_binary(tn)); 1450 for (ln = tn->tn_left; ln->tn_op == CVT; ln = ln->tn_left) 1451 continue; 1452 for (rn = tn->tn_right; rn->tn_op == CVT; rn = rn->tn_left) 1453 continue; 1454 1455 if (is_confusing_precedence(tn->tn_op, 1456 ln->tn_op, ln->tn_parenthesized, 1457 rn->tn_op, rn->tn_parenthesized)) { 1458 /* precedence confusion possible: parenthesize! */ 1459 warning(169); 1460 } 1461 } 1462 1463 static tnode_t * 1464 fold_constant_compare_zero(tnode_t *tn) 1465 { 1466 1467 val_t *v = xcalloc(1, sizeof(*v)); 1468 v->v_tspec = tn->tn_type->t_tspec; 1469 lint_assert(v->v_tspec == INT || (Tflag && v->v_tspec == BOOL)); 1470 1471 lint_assert(has_operands(tn)); 1472 bool l = constant_is_nonzero(tn->tn_left); 1473 bool r = is_binary(tn) && constant_is_nonzero(tn->tn_right); 1474 1475 switch (tn->tn_op) { 1476 case NOT: 1477 if (hflag && !suppress_constcond) 1478 /* constant operand to '!' */ 1479 warning(239); 1480 v->u.integer = !l ? 1 : 0; 1481 break; 1482 case LOGAND: 1483 v->u.integer = l && r ? 1 : 0; 1484 break; 1485 case LOGOR: 1486 v->u.integer = l || r ? 1 : 0; 1487 break; 1488 default: 1489 lint_assert(/*CONSTCOND*/false); 1490 } 1491 1492 return build_constant(tn->tn_type, v); 1493 } 1494 1495 static long double 1496 floating_error_value(tspec_t t, long double lv) 1497 { 1498 if (t == FLOAT) 1499 return lv < 0 ? -FLT_MAX : FLT_MAX; 1500 if (t == DOUBLE) 1501 return lv < 0 ? -DBL_MAX : DBL_MAX; 1502 /* 1503 * When NetBSD is cross-built in MKLINT=yes mode on x86_64 for sparc64, 1504 * tools/lint checks this code while building usr.bin/xlint. In that 1505 * situation, lint uses the preprocessor for sparc64, in which the type 1506 * 'long double' is IEEE-754-binary128, affecting the macro LDBL_MAX 1507 * below. The type 'long double', as well as the strtold 1508 * implementation, comes from the host platform x86_64 though, where 1509 * 'long double' consumes 128 bits as well but only uses 80 of them. 1510 * The exponent range of the two 'long double' types is the same, but 1511 * the maximum finite value differs due to the extended precision on 1512 * sparc64. 1513 * 1514 * To properly handle the data types of the target platform, lint would 1515 * have to implement the floating-point types in a platform-independent 1516 * way, which is not worth the effort, given how few programs 1517 * practically use 'long double'. 1518 */ 1519 /* LINTED 248: floating-point constant out of range */ 1520 long double max = LDBL_MAX; 1521 return lv < 0 ? -max : max; 1522 } 1523 1524 static bool 1525 is_floating_overflow(tspec_t t, long double val) 1526 { 1527 if (fpe != 0 || isfinite(val) == 0) 1528 return true; 1529 if (t == FLOAT && (val > FLT_MAX || val < -FLT_MAX)) 1530 return true; 1531 if (t == DOUBLE && (val > DBL_MAX || val < -DBL_MAX)) 1532 return true; 1533 return false; 1534 } 1535 1536 static tnode_t * 1537 fold_constant_floating(tnode_t *tn) 1538 { 1539 1540 fpe = 0; 1541 1542 tspec_t t = tn->tn_type->t_tspec; 1543 1544 val_t *v = xcalloc(1, sizeof(*v)); 1545 v->v_tspec = t; 1546 1547 lint_assert(is_floating(t)); 1548 lint_assert(has_operands(tn)); 1549 lint_assert(t == tn->tn_left->tn_type->t_tspec); 1550 lint_assert(!is_binary(tn) || t == tn->tn_right->tn_type->t_tspec); 1551 1552 long double lv = tn->tn_left->tn_val.u.floating; 1553 long double rv = is_binary(tn) ? tn->tn_right->tn_val.u.floating : 0.0; 1554 1555 switch (tn->tn_op) { 1556 case UPLUS: 1557 v->u.floating = lv; 1558 break; 1559 case UMINUS: 1560 v->u.floating = -lv; 1561 break; 1562 case MULT: 1563 v->u.floating = lv * rv; 1564 break; 1565 case DIV: 1566 if (rv == 0.0) { 1567 /* division by 0 */ 1568 error(139); 1569 v->u.floating = floating_error_value(t, lv); 1570 } else { 1571 v->u.floating = lv / rv; 1572 } 1573 break; 1574 case PLUS: 1575 v->u.floating = lv + rv; 1576 break; 1577 case MINUS: 1578 v->u.floating = lv - rv; 1579 break; 1580 case LT: 1581 v->u.integer = lv < rv ? 1 : 0; 1582 break; 1583 case LE: 1584 v->u.integer = lv <= rv ? 1 : 0; 1585 break; 1586 case GE: 1587 v->u.integer = lv >= rv ? 1 : 0; 1588 break; 1589 case GT: 1590 v->u.integer = lv > rv ? 1 : 0; 1591 break; 1592 case EQ: 1593 v->u.integer = lv == rv ? 1 : 0; 1594 break; 1595 case NE: 1596 v->u.integer = lv != rv ? 1 : 0; 1597 break; 1598 default: 1599 lint_assert(/*CONSTCOND*/false); 1600 } 1601 1602 // XXX: Must not access u.floating after setting u.integer. 1603 lint_assert(fpe != 0 || isnan(v->u.floating) == 0); 1604 if (is_complex(v->v_tspec)) { 1605 /* 1606 * Don't warn, as lint doesn't model the imaginary part of 1607 * complex numbers. 1608 */ 1609 fpe = 0; 1610 } else if (is_floating_overflow(t, v->u.floating)) { 1611 /* operator '%s' produces floating point overflow */ 1612 warning(142, op_name(tn->tn_op)); 1613 v->u.floating = floating_error_value(t, v->u.floating); 1614 fpe = 0; 1615 } 1616 1617 return build_constant(tn->tn_type, v); 1618 } 1619 1620 static void 1621 use(const tnode_t *tn) 1622 { 1623 if (tn == NULL) 1624 return; 1625 switch (tn->tn_op) { 1626 case NAME: 1627 mark_as_used(tn->tn_sym, false /* XXX */, false /* XXX */); 1628 break; 1629 case CON: 1630 case STRING: 1631 break; 1632 case CALL: 1633 case ICALL:; 1634 const function_call *call = tn->tn_call; 1635 if (call->args != NULL) 1636 for (size_t i = 0, n = call->args_len; i < n; i++) 1637 use(call->args[i]); 1638 break; 1639 default: 1640 lint_assert(has_operands(tn)); 1641 use(tn->tn_left); 1642 if (is_binary(tn)) 1643 use(tn->tn_right); 1644 } 1645 } 1646 1647 /* 1648 * Create a tree node for a binary operator and its two operands. Also called 1649 * for unary operators; in that case rn is NULL. 1650 * 1651 * Function calls, sizeof and casts are handled elsewhere. 1652 */ 1653 tnode_t * 1654 build_binary(tnode_t *ln, op_t op, bool sys, tnode_t *rn) 1655 { 1656 const mod_t *mp = &modtab[op]; 1657 1658 /* If there was an error in one of the operands, return. */ 1659 if (ln == NULL || (mp->m_binary && rn == NULL)) 1660 return NULL; 1661 1662 if (mp->m_value_context || mp->m_compares_with_zero) 1663 ln = cconv(ln); 1664 if (mp->m_binary && op != ARROW && op != POINT) 1665 rn = cconv(rn); 1666 1667 if (mp->m_comparison) 1668 check_integer_comparison(op, ln, rn); 1669 1670 if (mp->m_value_context || mp->m_compares_with_zero) 1671 ln = promote(op, false, ln); 1672 if (mp->m_binary && op != ARROW && op != POINT && 1673 op != ASSIGN && op != RETURN && op != INIT) 1674 rn = promote(op, false, rn); 1675 1676 if (mp->m_warn_if_left_unsigned_in_c90 && 1677 ln->tn_op == CON && ln->tn_val.v_unsigned_since_c90) { 1678 /* C90 treats constant as unsigned, op '%s' */ 1679 warning(218, op_name(op)); 1680 ln->tn_val.v_unsigned_since_c90 = false; 1681 } 1682 if (mp->m_warn_if_right_unsigned_in_c90 && 1683 rn->tn_op == CON && rn->tn_val.v_unsigned_since_c90) { 1684 /* C90 treats constant as unsigned, op '%s' */ 1685 warning(218, op_name(op)); 1686 rn->tn_val.v_unsigned_since_c90 = false; 1687 } 1688 1689 if (mp->m_balance_operands || (!allow_c90 && (op == SHL || op == SHR))) 1690 balance(op, &ln, &rn); 1691 1692 if (!typeok(op, 0, ln, rn)) 1693 return NULL; 1694 1695 tnode_t *ntn; 1696 switch (op) { 1697 case POINT: 1698 case ARROW: 1699 ntn = build_struct_access(op, sys, ln, rn); 1700 break; 1701 case INCAFT: 1702 case DECAFT: 1703 case INCBEF: 1704 case DECBEF: 1705 ntn = build_prepost_incdec(op, sys, ln); 1706 break; 1707 case ADDR: 1708 ntn = build_address(sys, ln, false); 1709 break; 1710 case INDIR: 1711 ntn = build_op(INDIR, sys, ln->tn_type->t_subt, ln, NULL); 1712 break; 1713 case PLUS: 1714 case MINUS: 1715 ntn = build_plus_minus(op, sys, ln, rn); 1716 break; 1717 case SHL: 1718 case SHR: 1719 ntn = build_bit_shift(op, sys, ln, rn); 1720 break; 1721 case COLON: 1722 ntn = build_colon(sys, ln, rn); 1723 break; 1724 case ASSIGN: 1725 case MULASS: 1726 case DIVASS: 1727 case MODASS: 1728 case ADDASS: 1729 case SUBASS: 1730 case SHLASS: 1731 case SHRASS: 1732 case ANDASS: 1733 case XORASS: 1734 case ORASS: 1735 case RETURN: 1736 case INIT: 1737 ntn = build_assignment(op, sys, ln, rn); 1738 break; 1739 case COMMA: 1740 if (any_query_enabled) { 1741 /* comma operator with types '%s' and '%s' */ 1742 query_message(12, 1743 type_name(ln->tn_type), type_name(rn->tn_type)); 1744 } 1745 /* FALLTHROUGH */ 1746 case QUEST: 1747 ntn = build_op(op, sys, rn->tn_type, ln, rn); 1748 break; 1749 case REAL: 1750 case IMAG: 1751 ntn = build_real_imag(op, sys, ln); 1752 break; 1753 default: 1754 lint_assert(mp->m_binary == (rn != NULL)); 1755 type_t *rettp = mp->m_returns_bool 1756 ? gettyp(Tflag ? BOOL : INT) : ln->tn_type; 1757 ntn = build_op(op, sys, rettp, ln, rn); 1758 break; 1759 } 1760 1761 if (ntn == NULL) 1762 return NULL; 1763 1764 if (mp->m_possible_precedence_confusion) 1765 check_precedence_confusion(ntn); 1766 1767 if (hflag && !suppress_constcond && 1768 mp->m_compares_with_zero && 1769 (ln->tn_op == CON || 1770 (mp->m_binary && op != QUEST && rn->tn_op == CON)) && 1771 /* XXX: rn->tn_system_dependent should be checked as well */ 1772 !ln->tn_system_dependent) { 1773 /* constant in conditional context */ 1774 warning(161); 1775 } 1776 1777 if (mp->m_fold_constant_operands && ln->tn_op == CON) { 1778 if (!mp->m_binary || rn->tn_op == CON) { 1779 if (mp->m_compares_with_zero) 1780 ntn = fold_constant_compare_zero(ntn); 1781 else if (is_floating(ntn->tn_type->t_tspec)) 1782 ntn = fold_constant_floating(ntn); 1783 else 1784 ntn = fold_constant_integer(ntn); 1785 } else if (op == QUEST) { 1786 lint_assert(has_operands(rn)); 1787 use(ln->tn_val.u.integer != 0 1788 ? rn->tn_right : rn->tn_left); 1789 ntn = ln->tn_val.u.integer != 0 1790 ? rn->tn_left : rn->tn_right; 1791 } 1792 } 1793 1794 return ntn; 1795 } 1796 1797 tnode_t * 1798 build_unary(op_t op, bool sys, tnode_t *tn) 1799 { 1800 return build_binary(tn, op, sys, NULL); 1801 } 1802 1803 static bool 1804 are_members_compatible(const sym_t *a, const sym_t *b) 1805 { 1806 if (a->u.s_member.sm_offset_in_bits != b->u.s_member.sm_offset_in_bits) 1807 return false; 1808 1809 const type_t *atp = a->s_type; 1810 const type_t *btp = b->s_type; 1811 bool w = false; 1812 if (!types_compatible(atp, btp, false, false, &w) && !w) 1813 return false; 1814 if (a->s_bitfield != b->s_bitfield) 1815 return false; 1816 if (a->s_bitfield) { 1817 if (atp->t_bit_field_width != btp->t_bit_field_width) 1818 return false; 1819 if (atp->t_bit_field_offset != btp->t_bit_field_offset) 1820 return false; 1821 } 1822 return true; 1823 } 1824 1825 /* 1826 * Return whether all struct/union members with the same name have the same 1827 * type and offset. 1828 */ 1829 static bool 1830 all_members_compatible(const sym_t *msym) 1831 { 1832 for (const sym_t *csym = msym; 1833 csym != NULL; csym = csym->s_symtab_next) { 1834 if (!is_member(csym)) 1835 continue; 1836 if (strcmp(msym->s_name, csym->s_name) != 0) 1837 continue; 1838 1839 for (const sym_t *sym = csym->s_symtab_next; 1840 sym != NULL; sym = sym->s_symtab_next) { 1841 if (is_member(sym) 1842 && strcmp(csym->s_name, sym->s_name) == 0 1843 && !are_members_compatible(csym, sym)) 1844 return false; 1845 } 1846 } 1847 return true; 1848 } 1849 1850 sym_t * 1851 find_member(const struct_or_union *sou, const char *name) 1852 { 1853 for (sym_t *mem = sou->sou_first_member; 1854 mem != NULL; mem = mem->s_next) { 1855 lint_assert(is_member(mem)); 1856 lint_assert(mem->u.s_member.sm_containing_type == sou); 1857 if (strcmp(mem->s_name, name) == 0) 1858 return mem; 1859 } 1860 1861 for (sym_t *mem = sou->sou_first_member; 1862 mem != NULL; mem = mem->s_next) { 1863 if (is_struct_or_union(mem->s_type->t_tspec) 1864 && mem->s_name == unnamed) { 1865 sym_t *nested_mem = 1866 find_member(mem->s_type->t_sou, name); 1867 if (nested_mem != NULL) 1868 return nested_mem; 1869 } 1870 } 1871 return NULL; 1872 } 1873 1874 /* 1875 * Remove the member if it was unknown until now, which means 1876 * that no defined struct or union has a member with the same name. 1877 */ 1878 static void 1879 remove_unknown_member(tnode_t *tn, sym_t *msym) 1880 { 1881 /* type '%s' does not have member '%s' */ 1882 error(101, type_name(tn->tn_type), msym->s_name); 1883 rmsym(msym); 1884 msym->s_kind = SK_MEMBER; 1885 msym->s_scl = STRUCT_MEMBER; 1886 1887 struct_or_union *sou = expr_zero_alloc(sizeof(*sou), 1888 "struct_or_union"); 1889 sou->sou_tag = expr_zero_alloc(sizeof(*sou->sou_tag), "sym"); 1890 sou->sou_tag->s_name = unnamed; 1891 1892 msym->u.s_member.sm_containing_type = sou; 1893 /* 1894 * The member sm_offset_in_bits is not needed here since this symbol 1895 * can only be used for error reporting. 1896 */ 1897 } 1898 1899 /* 1900 * Returns a symbol which has the same name as 'msym' and is a member of the 1901 * struct or union specified by 'tn'. 1902 */ 1903 static sym_t * 1904 struct_or_union_member(tnode_t *tn, op_t op, sym_t *msym) 1905 { 1906 1907 /* Determine the tag type of which msym is expected to be a member. */ 1908 const type_t *tp = NULL; 1909 if (op == POINT && is_struct_or_union(tn->tn_type->t_tspec)) 1910 tp = tn->tn_type; 1911 if (op == ARROW && tn->tn_type->t_tspec == PTR 1912 && is_struct_or_union(tn->tn_type->t_subt->t_tspec)) 1913 tp = tn->tn_type->t_subt; 1914 struct_or_union *sou = tp != NULL ? tp->t_sou : NULL; 1915 1916 if (sou != NULL) { 1917 sym_t *nested_mem = find_member(sou, msym->s_name); 1918 if (nested_mem != NULL) 1919 return nested_mem; 1920 } 1921 1922 if (msym->s_scl == NO_SCL) { 1923 remove_unknown_member(tn, msym); 1924 return msym; 1925 } 1926 1927 bool eq = all_members_compatible(msym); 1928 1929 /* 1930 * Now handle the case in which the left operand refers really to a 1931 * struct/union, but the right operand is not member of it. 1932 */ 1933 if (sou != NULL) { 1934 if (eq && !allow_c90) { 1935 /* illegal use of member '%s' */ 1936 warning(102, msym->s_name); 1937 } else { 1938 /* illegal use of member '%s' */ 1939 error(102, msym->s_name); 1940 } 1941 return msym; 1942 } 1943 1944 if (eq) { 1945 if (op == POINT) { 1946 if (!allow_c90) { 1947 /* left operand of '.' must be struct ... */ 1948 warning(103, type_name(tn->tn_type)); 1949 } else { 1950 /* left operand of '.' must be struct ... */ 1951 error(103, type_name(tn->tn_type)); 1952 } 1953 } else { 1954 if (!allow_c90 && tn->tn_type->t_tspec == PTR) { 1955 /* left operand of '->' must be pointer ... */ 1956 warning(104, type_name(tn->tn_type)); 1957 } else { 1958 /* left operand of '->' must be pointer ... */ 1959 error(104, type_name(tn->tn_type)); 1960 } 1961 } 1962 } else { 1963 if (!allow_c90) { 1964 /* non-unique member requires struct/union %s */ 1965 error(105, op == POINT ? "object" : "pointer"); 1966 } else { 1967 /* unacceptable operand of '%s' */ 1968 error(111, op_name(op)); 1969 } 1970 } 1971 1972 return msym; 1973 } 1974 1975 tnode_t * 1976 build_member_access(tnode_t *ln, op_t op, bool sys, sbuf_t *member) 1977 { 1978 sym_t *msym; 1979 1980 if (ln == NULL) 1981 return NULL; 1982 1983 if (op == ARROW) { 1984 /* must do this before struct_or_union_member is called */ 1985 ln = cconv(ln); 1986 } 1987 msym = struct_or_union_member(ln, op, getsym(member)); 1988 return build_binary(ln, op, sys, build_name(msym, false)); 1989 } 1990 1991 /* 1992 * Perform class conversions. 1993 * 1994 * Arrays of type T are converted into pointers to type T. 1995 * Functions are converted to pointers to functions. 1996 * Lvalues are converted to rvalues. 1997 * 1998 * C99 6.3 "Conversions" 1999 * C99 6.3.2 "Other operands" 2000 * C99 6.3.2.1 "Lvalues, arrays, and function designators" 2001 */ 2002 tnode_t * 2003 cconv(tnode_t *tn) 2004 { 2005 if (tn->tn_type->t_tspec == ARRAY) { 2006 if (!tn->tn_lvalue) { 2007 /* XXX print correct operator */ 2008 /* %soperand of '%s' must be lvalue */ 2009 gnuism(114, "", op_name(ADDR)); 2010 } 2011 tn = build_op(ADDR, tn->tn_sys, 2012 expr_derive_type(tn->tn_type->t_subt, PTR), tn, NULL); 2013 } 2014 2015 if (tn->tn_type->t_tspec == FUNC) 2016 tn = build_address(tn->tn_sys, tn, true); 2017 2018 if (tn->tn_lvalue) { 2019 type_t *tp = expr_dup_type(tn->tn_type); 2020 /* C99 6.3.2.1p2 sentence 2 says to remove the qualifiers. */ 2021 tp->t_const = tp->t_volatile = false; 2022 tn = build_op(LOAD, tn->tn_sys, tp, tn, NULL); 2023 } 2024 2025 return tn; 2026 } 2027 2028 const tnode_t * 2029 before_conversion(const tnode_t *tn) 2030 { 2031 while (tn->tn_op == CVT && !tn->tn_cast) 2032 tn = tn->tn_left; 2033 return tn; 2034 } 2035 2036 /* 2037 * Most errors required by C90 are reported in struct_or_union_member(). 2038 * Here we only check for totally wrong things. 2039 */ 2040 static bool 2041 typeok_point(const tnode_t *ln, const type_t *ltp, tspec_t lt) 2042 { 2043 if (is_struct_or_union(lt)) 2044 return true; 2045 2046 if (lt == FUNC || lt == VOID || ltp->t_bitfield) 2047 goto wrong; 2048 2049 /* 2050 * Some C dialects from before C90 tolerated any lvalue on the 2051 * left-hand side of the '.' operator, allowing things like 'char 2052 * st[100]; st.st_mtime', assuming that the member 'st_mtime' only 2053 * occurred in a single struct; see typeok_arrow. 2054 */ 2055 if (ln->tn_lvalue) 2056 return true; 2057 2058 wrong: 2059 /* With allow_c90 we already got an error */ 2060 if (!allow_c90) 2061 /* unacceptable operand of '%s' */ 2062 error(111, op_name(POINT)); 2063 2064 return false; 2065 } 2066 2067 static bool 2068 typeok_arrow(tspec_t lt) 2069 { 2070 /* 2071 * C1978 Appendix A 14.1 says: <quote>In fact, any lvalue is allowed 2072 * before '.', and that lvalue is then assumed to have the form of the 2073 * structure of which the name of the right is a member. [...] Such 2074 * constructions are non-portable.</quote> 2075 */ 2076 if (lt == PTR || (!allow_c90 && is_integer(lt))) 2077 return true; 2078 2079 /* With allow_c90 we already got an error */ 2080 if (!allow_c90) 2081 /* unacceptable operand of '%s' */ 2082 error(111, op_name(ARROW)); 2083 return false; 2084 } 2085 2086 static bool 2087 typeok_incdec(op_t op, const tnode_t *tn, const type_t *tp) 2088 { 2089 /* operand has scalar type (checked in typeok) */ 2090 if (!tn->tn_lvalue) { 2091 if (tn->tn_op == CVT && tn->tn_cast && 2092 tn->tn_left->tn_op == LOAD) { 2093 /* a cast does not yield an lvalue */ 2094 error(163); 2095 } 2096 /* %soperand of '%s' must be lvalue */ 2097 error(114, "", op_name(op)); 2098 return false; 2099 } 2100 if (tp->t_const && allow_c90) { 2101 /* %soperand of '%s' must be modifiable lvalue */ 2102 warning(115, "", op_name(op)); 2103 } 2104 return true; 2105 } 2106 2107 static bool 2108 typeok_address(op_t op, const tnode_t *tn, const type_t *tp, tspec_t t) 2109 { 2110 if (t == ARRAY || t == FUNC) { 2111 /* ok, a warning comes later (in build_address()) */ 2112 } else if (!tn->tn_lvalue) { 2113 if (tn->tn_op == CVT && tn->tn_cast && 2114 tn->tn_left->tn_op == LOAD) { 2115 /* a cast does not yield an lvalue */ 2116 error(163); 2117 } 2118 /* %soperand of '%s' must be lvalue */ 2119 error(114, "", op_name(op)); 2120 return false; 2121 } else if (is_scalar(t)) { 2122 if (tp->t_bitfield) { 2123 /* cannot take address of bit-field */ 2124 error(112); 2125 return false; 2126 } 2127 } else if (t != STRUCT && t != UNION) { 2128 /* unacceptable operand of '%s' */ 2129 error(111, op_name(op)); 2130 return false; 2131 } 2132 if (tn->tn_op == NAME && tn->tn_sym->s_register) { 2133 /* cannot take address of register '%s' */ 2134 error(113, tn->tn_sym->s_name); 2135 return false; 2136 } 2137 return true; 2138 } 2139 2140 static bool 2141 typeok_indir(const type_t *tp, tspec_t t) 2142 { 2143 2144 if (t != PTR) { 2145 /* cannot dereference non-pointer type '%s' */ 2146 error(96, type_name(tp)); 2147 return false; 2148 } 2149 return true; 2150 } 2151 2152 static void 2153 warn_incompatible_types(op_t op, 2154 const type_t *ltp, tspec_t lt, 2155 const type_t *rtp, tspec_t rt) 2156 { 2157 bool binary = modtab[op].m_binary; 2158 2159 if (lt == VOID || (binary && rt == VOID)) { 2160 /* void type illegal in expression */ 2161 error(109); 2162 } else if (op == ASSIGN) { 2163 /* cannot assign to '%s' from '%s' */ 2164 error(171, type_name(ltp), type_name(rtp)); 2165 } else if (binary) { 2166 /* operands of '%s' have incompatible types '%s' and '%s' */ 2167 error(107, op_name(op), type_name(ltp), type_name(rtp)); 2168 } else { 2169 lint_assert(rt == NO_TSPEC); 2170 /* operand of '%s' has invalid type '%s' */ 2171 error(108, op_name(op), type_name(ltp)); 2172 } 2173 } 2174 2175 static bool 2176 typeok_plus(op_t op, 2177 const type_t *ltp, tspec_t lt, 2178 const type_t *rtp, tspec_t rt) 2179 { 2180 /* operands have scalar types (checked in typeok) */ 2181 if ((lt == PTR && !is_integer(rt)) || (rt == PTR && !is_integer(lt))) { 2182 warn_incompatible_types(op, ltp, lt, rtp, rt); 2183 return false; 2184 } 2185 return true; 2186 } 2187 2188 static bool 2189 typeok_minus(op_t op, 2190 const type_t *ltp, tspec_t lt, 2191 const type_t *rtp, tspec_t rt) 2192 { 2193 /* operands have scalar types (checked in typeok) */ 2194 if ((lt == PTR && rt != PTR && !is_integer(rt)) || 2195 (lt != PTR && rt == PTR)) { 2196 warn_incompatible_types(op, ltp, lt, rtp, rt); 2197 return false; 2198 } 2199 if (lt == PTR && rt == PTR && 2200 !types_compatible(ltp->t_subt, rtp->t_subt, true, false, NULL)) { 2201 /* illegal pointer subtraction */ 2202 error(116); 2203 } 2204 return true; 2205 } 2206 2207 static void 2208 typeok_shr(op_t op, 2209 const tnode_t *ln, tspec_t lt, 2210 const tnode_t *rn, tspec_t rt) 2211 { 2212 tspec_t olt = before_conversion(ln)->tn_type->t_tspec; 2213 tspec_t ort = before_conversion(rn)->tn_type->t_tspec; 2214 2215 /* operands have integer types (checked in typeok) */ 2216 if (pflag && !is_uinteger(olt)) { 2217 integer_constraints lc = ic_expr(ln); 2218 if (!ic_maybe_signed(ln->tn_type, &lc)) 2219 return; 2220 2221 if (ln->tn_op != CON) { 2222 /* bitwise '%s' on signed value possibly nonportable */ 2223 warning(117, op_name(op)); 2224 } else if (ln->tn_val.u.integer < 0) { 2225 /* bitwise '%s' on signed value nonportable */ 2226 warning(120, op_name(op)); 2227 } 2228 } else if (allow_trad && allow_c90 && 2229 !is_uinteger(olt) && is_uinteger(ort)) { 2230 /* The left operand would become unsigned in traditional C. */ 2231 if (hflag && (ln->tn_op != CON || ln->tn_val.u.integer < 0)) { 2232 /* semantics of '%s' change in C90; use ... */ 2233 warning(118, op_name(op)); 2234 } 2235 } else if (allow_trad && allow_c90 && 2236 !is_uinteger(olt) && !is_uinteger(ort) && 2237 portable_rank_cmp(lt, rt) < 0) { 2238 /* 2239 * In traditional C, the left operand would be extended 2240 * (possibly sign-extended) and then shifted. 2241 */ 2242 if (hflag && (ln->tn_op != CON || ln->tn_val.u.integer < 0)) { 2243 /* semantics of '%s' change in C90; use ... */ 2244 warning(118, op_name(op)); 2245 } 2246 } 2247 } 2248 2249 static void 2250 typeok_shl(op_t op, tspec_t lt, tspec_t rt) 2251 { 2252 /* 2253 * C90 does not perform balancing for shift operations, but traditional 2254 * C does. If the width of the right operand is greater than the width 2255 * of the left operand, then in traditional C the left operand would be 2256 * extended to the width of the right operand. For SHL this may result 2257 * in different results. 2258 */ 2259 if (portable_rank_cmp(lt, rt) < 0) { 2260 /* 2261 * XXX If both operands are constant, make sure that there is 2262 * really a difference between C90 and traditional C. 2263 */ 2264 if (hflag && allow_trad && allow_c90) 2265 /* semantics of '%s' change in C90; use ... */ 2266 warning(118, op_name(op)); 2267 } 2268 } 2269 2270 static void 2271 typeok_shift(const type_t *ltp, tspec_t lt, const tnode_t *rn, tspec_t rt) 2272 { 2273 if (rn->tn_op != CON) 2274 return; 2275 2276 if (!is_uinteger(rt) && rn->tn_val.u.integer < 0) { 2277 /* negative shift */ 2278 warning(121); 2279 } else if ((uint64_t)rn->tn_val.u.integer == size_in_bits(lt)) { 2280 /* shift amount %u equals bit-size of '%s' */ 2281 warning(267, (unsigned)rn->tn_val.u.integer, type_name(ltp)); 2282 } else if ((uint64_t)rn->tn_val.u.integer > size_in_bits(lt)) { 2283 /* shift amount %llu is greater than bit-size %llu of '%s' */ 2284 warning(122, (unsigned long long)rn->tn_val.u.integer, 2285 (unsigned long long)size_in_bits(lt), 2286 tspec_name(lt)); 2287 } 2288 } 2289 2290 static bool 2291 is_typeok_eq(const tnode_t *ln, tspec_t lt, const tnode_t *rn, tspec_t rt) 2292 { 2293 if (lt == PTR && is_null_pointer(rn)) 2294 return true; 2295 if (rt == PTR && is_null_pointer(ln)) 2296 return true; 2297 return false; 2298 } 2299 2300 static void 2301 warn_incompatible_pointers(op_t op, const type_t *ltp, const type_t *rtp) 2302 { 2303 lint_assert(ltp->t_tspec == PTR); 2304 lint_assert(rtp->t_tspec == PTR); 2305 2306 tspec_t lt = ltp->t_subt->t_tspec; 2307 tspec_t rt = rtp->t_subt->t_tspec; 2308 2309 if (is_struct_or_union(lt) && is_struct_or_union(rt)) { 2310 if (op == RETURN) { 2311 /* illegal structure pointer combination */ 2312 warning(244); 2313 } else { 2314 /* incompatible structure pointers: '%s' '%s' '%s' */ 2315 warning(245, type_name(ltp), 2316 op_name(op), type_name(rtp)); 2317 } 2318 } else { 2319 if (op == RETURN) { 2320 /* illegal combination of '%s' and '%s' */ 2321 warning(184, type_name(ltp), type_name(rtp)); 2322 } else { 2323 /* illegal combination of '%s' and '%s', op '%s' */ 2324 warning(124, 2325 type_name(ltp), type_name(rtp), op_name(op)); 2326 } 2327 } 2328 } 2329 2330 static void 2331 check_pointer_comparison(op_t op, const tnode_t *ln, const tnode_t *rn) 2332 { 2333 type_t *ltp = ln->tn_type, *rtp = rn->tn_type; 2334 tspec_t lst = ltp->t_subt->t_tspec, rst = rtp->t_subt->t_tspec; 2335 2336 if (lst == VOID || rst == VOID) { 2337 /* TODO: C99 behaves like C90 here. */ 2338 if (!allow_trad && !allow_c99 && 2339 (lst == FUNC || rst == FUNC)) { 2340 /* (void *)0 is already handled in typeok() */ 2341 const char *lsts, *rsts; 2342 *(lst == FUNC ? &lsts : &rsts) = "function pointer"; 2343 *(lst == VOID ? &lsts : &rsts) = "'void *'"; 2344 /* C90 or later forbid comparison of %s with %s */ 2345 warning(274, lsts, rsts); 2346 } 2347 return; 2348 } 2349 2350 if (!types_compatible(ltp->t_subt, rtp->t_subt, true, false, NULL)) { 2351 warn_incompatible_pointers(op, ltp, rtp); 2352 return; 2353 } 2354 2355 if (lst == FUNC && rst == FUNC) { 2356 /* TODO: C99 behaves like C90 here, see C99 6.5.8p2. */ 2357 if (!allow_trad && !allow_c99 && op != EQ && op != NE) 2358 /* pointers to functions can only be compared ... */ 2359 warning(125); 2360 } 2361 } 2362 2363 static bool 2364 typeok_compare(op_t op, 2365 const tnode_t *ln, const type_t *ltp, tspec_t lt, 2366 const tnode_t *rn, const type_t *rtp, tspec_t rt) 2367 { 2368 if (lt == PTR && rt == PTR) { 2369 check_pointer_comparison(op, ln, rn); 2370 return true; 2371 } 2372 2373 if (lt != PTR && rt != PTR) 2374 return true; 2375 2376 if (!is_integer(lt) && !is_integer(rt)) { 2377 warn_incompatible_types(op, ltp, lt, rtp, rt); 2378 return false; 2379 } 2380 2381 const char *lx = lt == PTR ? "pointer" : "integer"; 2382 const char *rx = rt == PTR ? "pointer" : "integer"; 2383 /* illegal combination of %s '%s' and %s '%s', op '%s' */ 2384 warning(123, lx, type_name(ltp), rx, type_name(rtp), op_name(op)); 2385 return true; 2386 } 2387 2388 static bool 2389 typeok_quest(tspec_t lt, const tnode_t *rn) 2390 { 2391 if (!is_scalar(lt)) { 2392 /* first operand of '?' must have scalar type */ 2393 error(170); 2394 return false; 2395 } 2396 lint_assert(before_conversion(rn)->tn_op == COLON); 2397 return true; 2398 } 2399 2400 static void 2401 typeok_colon_pointer(const type_t *ltp, const type_t *rtp) 2402 { 2403 type_t *lstp = ltp->t_subt; 2404 type_t *rstp = rtp->t_subt; 2405 tspec_t lst = lstp->t_tspec; 2406 tspec_t rst = rstp->t_tspec; 2407 2408 if ((lst == VOID && rst == FUNC) || (lst == FUNC && rst == VOID)) { 2409 /* (void *)0 is handled in typeok_colon */ 2410 /* TODO: C99 behaves like C90 here. */ 2411 if (!allow_trad && !allow_c99) 2412 /* conversion of %s to %s requires a cast, op %s */ 2413 warning(305, "function pointer", "'void *'", 2414 op_name(COLON)); 2415 return; 2416 } 2417 2418 if (pointer_types_are_compatible(lstp, rstp, true)) 2419 return; 2420 if (!types_compatible(lstp, rstp, true, false, NULL)) 2421 warn_incompatible_pointers(COLON, ltp, rtp); 2422 } 2423 2424 static bool 2425 typeok_colon(const tnode_t *ln, const type_t *ltp, tspec_t lt, 2426 const tnode_t *rn, const type_t *rtp, tspec_t rt) 2427 { 2428 2429 if (is_arithmetic(lt) && is_arithmetic(rt)) 2430 return true; 2431 if (lt == BOOL && rt == BOOL) 2432 return true; 2433 2434 if (lt == STRUCT && rt == STRUCT && ltp->t_sou == rtp->t_sou) 2435 return true; 2436 if (lt == UNION && rt == UNION && ltp->t_sou == rtp->t_sou) 2437 return true; 2438 2439 if (lt == PTR && is_null_pointer(rn)) 2440 return true; 2441 if (rt == PTR && is_null_pointer(ln)) 2442 return true; 2443 2444 if ((lt == PTR && is_integer(rt)) || (is_integer(lt) && rt == PTR)) { 2445 const char *lx = lt == PTR ? "pointer" : "integer"; 2446 const char *rx = rt == PTR ? "pointer" : "integer"; 2447 /* illegal combination of %s '%s' and %s '%s', op '%s' */ 2448 warning(123, lx, type_name(ltp), 2449 rx, type_name(rtp), op_name(COLON)); 2450 return true; 2451 } 2452 2453 if (lt == VOID || rt == VOID) { 2454 if (lt != VOID || rt != VOID) 2455 /* incompatible types '%s' and '%s' in conditional */ 2456 warning(126, type_name(ltp), type_name(rtp)); 2457 return true; 2458 } 2459 2460 if (lt == PTR && rt == PTR) { 2461 typeok_colon_pointer(ltp, rtp); 2462 return true; 2463 } 2464 2465 /* incompatible types '%s' and '%s' in conditional */ 2466 error(126, type_name(ltp), type_name(rtp)); 2467 return false; 2468 } 2469 2470 static bool 2471 has_constant_member(const type_t *tp) 2472 { 2473 lint_assert(is_struct_or_union(tp->t_tspec)); 2474 2475 for (sym_t *m = tp->t_sou->sou_first_member; 2476 m != NULL; m = m->s_next) { 2477 const type_t *mtp = m->s_type; 2478 if (mtp->t_const) 2479 return true; 2480 if (is_struct_or_union(mtp->t_tspec) && 2481 has_constant_member(mtp)) 2482 return true; 2483 } 2484 return false; 2485 } 2486 2487 static bool 2488 typeok_assign(op_t op, const tnode_t *ln, const type_t *ltp, tspec_t lt) 2489 { 2490 if (op == RETURN || op == INIT || op == FARG) 2491 return true; 2492 2493 if (!ln->tn_lvalue) { 2494 if (ln->tn_op == CVT && ln->tn_cast && 2495 ln->tn_left->tn_op == LOAD) { 2496 /* a cast does not yield an lvalue */ 2497 error(163); 2498 } 2499 /* %soperand of '%s' must be lvalue */ 2500 error(114, "left ", op_name(op)); 2501 return false; 2502 } else if (ltp->t_const 2503 || (is_struct_or_union(lt) && has_constant_member(ltp))) { 2504 if (allow_c90) 2505 /* %soperand of '%s' must be modifiable lvalue */ 2506 warning(115, "left ", op_name(op)); 2507 } 2508 return true; 2509 } 2510 2511 static bool 2512 typeok_scalar(op_t op, const mod_t *mp, 2513 const type_t *ltp, tspec_t lt, 2514 const type_t *rtp, tspec_t rt) 2515 { 2516 if (mp->m_takes_bool && lt == BOOL && rt == BOOL) 2517 return true; 2518 if (mp->m_requires_integer) { 2519 if (!is_integer(lt) || (mp->m_binary && !is_integer(rt))) { 2520 warn_incompatible_types(op, ltp, lt, rtp, rt); 2521 return false; 2522 } 2523 } else if (mp->m_requires_integer_or_complex) { 2524 if ((!is_integer(lt) && !is_complex(lt)) || 2525 (mp->m_binary && (!is_integer(rt) && !is_complex(rt)))) { 2526 warn_incompatible_types(op, ltp, lt, rtp, rt); 2527 return false; 2528 } 2529 } else if (mp->m_requires_scalar) { 2530 if (!is_scalar(lt) || (mp->m_binary && !is_scalar(rt))) { 2531 warn_incompatible_types(op, ltp, lt, rtp, rt); 2532 return false; 2533 } 2534 } else if (mp->m_requires_arith) { 2535 if (!is_arithmetic(lt) || 2536 (mp->m_binary && !is_arithmetic(rt))) { 2537 warn_incompatible_types(op, ltp, lt, rtp, rt); 2538 return false; 2539 } 2540 } 2541 return true; 2542 } 2543 2544 static void 2545 check_assign_void_pointer(op_t op, int arg, 2546 tspec_t lt, tspec_t lst, 2547 tspec_t rt, tspec_t rst) 2548 { 2549 2550 if (!(lt == PTR && rt == PTR && (lst == VOID || rst == VOID))) 2551 return; 2552 /* two pointers, at least one pointer to void */ 2553 2554 /* TODO: C99 behaves like C90 here. */ 2555 if (!(!allow_trad && !allow_c99 && (lst == FUNC || rst == FUNC))) 2556 return; 2557 /* comb. of ptr to func and ptr to void */ 2558 2559 const char *lts, *rts; 2560 *(lst == FUNC ? <s : &rts) = "function pointer"; 2561 *(lst == VOID ? <s : &rts) = "'void *'"; 2562 2563 switch (op) { 2564 case INIT: 2565 case RETURN: 2566 /* conversion of %s to %s requires a cast */ 2567 warning(303, rts, lts); 2568 break; 2569 case FARG: 2570 /* conversion of %s to %s requires a cast, arg #%d */ 2571 warning(304, rts, lts, arg); 2572 break; 2573 default: 2574 /* conversion of %s to %s requires a cast, op %s */ 2575 warning(305, rts, lts, op_name(op)); 2576 break; 2577 } 2578 } 2579 2580 static bool 2581 is_direct_function_call(const tnode_t *tn, const char **out_name) 2582 { 2583 2584 if (tn->tn_op == CALL 2585 && tn->tn_call->func->tn_op == ADDR 2586 && tn->tn_call->func->tn_left->tn_op == NAME) { 2587 *out_name = tn->tn_call->func->tn_left->tn_sym->s_name; 2588 return true; 2589 } 2590 return false; 2591 } 2592 2593 static bool 2594 is_unconst_function(const char *name) 2595 { 2596 2597 return strcmp(name, "memchr") == 0 || 2598 strcmp(name, "strchr") == 0 || 2599 strcmp(name, "strpbrk") == 0 || 2600 strcmp(name, "strrchr") == 0 || 2601 strcmp(name, "strstr") == 0; 2602 } 2603 2604 static bool 2605 is_const_char_pointer(const tnode_t *tn) 2606 { 2607 /* 2608 * For traditional reasons, C99 6.4.5p5 defines that string literals 2609 * have type 'char[]'. They are often implicitly converted to 'char 2610 * *', for example when they are passed as function arguments. 2611 * 2612 * C99 6.4.5p6 further defines that modifying a string that is 2613 * constructed from a string literal invokes undefined behavior. 2614 * 2615 * Out of these reasons, string literals are treated as 'effectively 2616 * const' here. 2617 */ 2618 if (tn->tn_op == CVT && 2619 tn->tn_left->tn_op == ADDR && 2620 tn->tn_left->tn_left->tn_op == STRING) 2621 return true; 2622 2623 const type_t *tp = before_conversion(tn)->tn_type; 2624 return tp->t_tspec == PTR && 2625 tp->t_subt->t_tspec == CHAR && 2626 tp->t_subt->t_const; 2627 } 2628 2629 static bool 2630 is_first_arg_const_char_pointer(const tnode_t *tn) 2631 { 2632 return tn->tn_call->args != NULL 2633 && tn->tn_call->args_len >= 1 2634 && is_const_char_pointer(tn->tn_call->args[0]); 2635 } 2636 2637 static bool 2638 is_const_pointer(const tnode_t *tn) 2639 { 2640 const type_t *tp = before_conversion(tn)->tn_type; 2641 return tp->t_tspec == PTR && tp->t_subt->t_const; 2642 } 2643 2644 static bool 2645 is_second_arg_const_pointer(const tnode_t *tn) 2646 { 2647 return tn->tn_call->args_len >= 2 2648 && tn->tn_call->args != NULL 2649 && is_const_pointer(tn->tn_call->args[1]); 2650 } 2651 2652 static void 2653 check_unconst_function(const type_t *lstp, const tnode_t *rn) 2654 { 2655 const char *function_name; 2656 2657 if (lstp->t_tspec == CHAR && !lstp->t_const && 2658 is_direct_function_call(rn, &function_name) && 2659 is_unconst_function(function_name) && 2660 is_first_arg_const_char_pointer(rn)) { 2661 /* call to '%s' effectively discards 'const' from argument */ 2662 warning(346, function_name); 2663 } 2664 2665 if (!lstp->t_const && 2666 is_direct_function_call(rn, &function_name) && 2667 strcmp(function_name, "bsearch") == 0 && 2668 is_second_arg_const_pointer(rn)) { 2669 /* call to '%s' effectively discards 'const' from argument */ 2670 warning(346, function_name); 2671 } 2672 } 2673 2674 static bool 2675 check_assign_void_pointer_compat(op_t op, int arg, 2676 const type_t *ltp, tspec_t lt, 2677 const type_t *lstp, tspec_t lst, 2678 const tnode_t *rn, 2679 const type_t *rtp, tspec_t rt, 2680 const type_t *rstp, tspec_t rst) 2681 { 2682 if (!(lt == PTR && rt == PTR && (lst == VOID || rst == VOID || 2683 types_compatible(lstp, rstp, 2684 true, false, NULL)))) 2685 return false; 2686 2687 /* compatible pointer types (qualifiers ignored) */ 2688 if (allow_c90 && 2689 ((!lstp->t_const && rstp->t_const) || 2690 (!lstp->t_volatile && rstp->t_volatile))) { 2691 /* left side has not all qualifiers of right */ 2692 switch (op) { 2693 case INIT: 2694 case RETURN: 2695 /* incompatible pointer types to '%s' and '%s' */ 2696 warning(182, type_name(lstp), type_name(rstp)); 2697 break; 2698 case FARG: 2699 /* converting '%s' to incompatible '%s' ... */ 2700 warning(153, 2701 type_name(rtp), type_name(ltp), arg); 2702 break; 2703 default: 2704 /* operands of '%s' have incompatible pointer ... */ 2705 warning(128, op_name(op), 2706 type_name(lstp), type_name(rstp)); 2707 break; 2708 } 2709 } 2710 2711 if (allow_c90) 2712 check_unconst_function(lstp, rn); 2713 2714 return true; 2715 } 2716 2717 static bool 2718 check_assign_pointer_integer(op_t op, int arg, 2719 const type_t *ltp, tspec_t lt, 2720 const type_t *rtp, tspec_t rt) 2721 { 2722 2723 if (!((lt == PTR && is_integer(rt)) || (is_integer(lt) && rt == PTR))) 2724 return false; 2725 2726 const char *lx = lt == PTR ? "pointer" : "integer"; 2727 const char *rx = rt == PTR ? "pointer" : "integer"; 2728 2729 switch (op) { 2730 case INIT: 2731 case RETURN: 2732 /* illegal combination of %s '%s' and %s '%s' */ 2733 warning(183, lx, type_name(ltp), rx, type_name(rtp)); 2734 break; 2735 case FARG: 2736 /* illegal combination of %s '%s' and %s '%s', arg #%d */ 2737 warning(154, 2738 lx, type_name(ltp), rx, type_name(rtp), arg); 2739 break; 2740 default: 2741 /* illegal combination of %s '%s' and %s '%s', op '%s' */ 2742 warning(123, 2743 lx, type_name(ltp), rx, type_name(rtp), op_name(op)); 2744 break; 2745 } 2746 return true; 2747 } 2748 2749 static bool 2750 check_assign_pointer(op_t op, int arg, 2751 const type_t *ltp, tspec_t lt, 2752 const type_t *rtp, tspec_t rt) 2753 { 2754 if (!(lt == PTR && rt == PTR)) 2755 return false; 2756 2757 if (op == FARG) 2758 /* converting '%s' to incompatible '%s' for ... */ 2759 warning(153, type_name(rtp), type_name(ltp), arg); 2760 else 2761 warn_incompatible_pointers(op, ltp, rtp); 2762 return true; 2763 } 2764 2765 static void 2766 warn_assign(op_t op, int arg, 2767 const type_t *ltp, tspec_t lt, 2768 const type_t *rtp, tspec_t rt) 2769 { 2770 switch (op) { 2771 case INIT: 2772 /* cannot initialize '%s' from '%s' */ 2773 error(185, type_name(ltp), type_name(rtp)); 2774 break; 2775 case RETURN: 2776 /* function has return type '%s' but returns '%s' */ 2777 error(211, type_name(ltp), type_name(rtp)); 2778 break; 2779 case FARG: 2780 /* passing '%s' to incompatible '%s', arg #%d */ 2781 warning(155, type_name(rtp), type_name(ltp), arg); 2782 break; 2783 default: 2784 warn_incompatible_types(op, ltp, lt, rtp, rt); 2785 break; 2786 } 2787 } 2788 2789 /* 2790 * Checks type compatibility for ASSIGN, INIT, FARG and RETURN 2791 * and prints warnings/errors if necessary. 2792 * Returns whether the types are (almost) compatible. 2793 */ 2794 static bool 2795 check_assign_types_compatible(op_t op, int arg, 2796 const tnode_t *ln, const tnode_t *rn) 2797 { 2798 tspec_t lt, rt, lst = NO_TSPEC, rst = NO_TSPEC; 2799 type_t *ltp, *rtp, *lstp = NULL, *rstp = NULL; 2800 2801 if ((lt = (ltp = ln->tn_type)->t_tspec) == PTR) 2802 lst = (lstp = ltp->t_subt)->t_tspec; 2803 if ((rt = (rtp = rn->tn_type)->t_tspec) == PTR) 2804 rst = (rstp = rtp->t_subt)->t_tspec; 2805 2806 if (lt == BOOL && is_scalar(rt)) /* C99 6.3.1.2 */ 2807 return true; 2808 2809 if (is_arithmetic(lt) && (is_arithmetic(rt) || rt == BOOL)) 2810 return true; 2811 2812 if (is_struct_or_union(lt) && is_struct_or_union(rt)) 2813 return ltp->t_sou == rtp->t_sou; 2814 2815 if (lt == PTR && is_null_pointer(rn)) { 2816 if (is_integer(rn->tn_type->t_tspec)) 2817 /* implicit conversion from integer 0 to pointer ... */ 2818 query_message(15, type_name(ltp)); 2819 return true; 2820 } 2821 2822 check_assign_void_pointer(op, arg, lt, lst, rt, rst); 2823 2824 if (check_assign_void_pointer_compat(op, arg, 2825 ltp, lt, lstp, lst, rn, rtp, rt, rstp, rst)) 2826 return true; 2827 2828 if (check_assign_pointer_integer(op, arg, ltp, lt, rtp, rt)) 2829 return true; 2830 2831 if (check_assign_pointer(op, arg, ltp, lt, rtp, rt)) 2832 return true; 2833 2834 warn_assign(op, arg, ltp, lt, rtp, rt); 2835 return false; 2836 } 2837 2838 static bool 2839 has_side_effect(const tnode_t *tn) /* NOLINT(misc-no-recursion) */ 2840 { 2841 op_t op = tn->tn_op; 2842 2843 if (modtab[op].m_has_side_effect) 2844 return true; 2845 2846 if (op == CVT && tn->tn_type->t_tspec == VOID) 2847 return has_side_effect(tn->tn_left); 2848 2849 /* XXX: Why not has_side_effect(tn->tn_left) as well? */ 2850 if (op == LOGAND || op == LOGOR) 2851 return has_side_effect(tn->tn_right); 2852 2853 /* XXX: Why not has_side_effect(tn->tn_left) as well? */ 2854 if (op == QUEST) 2855 return has_side_effect(tn->tn_right); 2856 2857 if (op == COLON || op == COMMA) { 2858 return has_side_effect(tn->tn_left) || 2859 has_side_effect(tn->tn_right); 2860 } 2861 2862 return false; 2863 } 2864 2865 static bool 2866 is_void_cast(const tnode_t *tn) 2867 { 2868 2869 return tn->tn_op == CVT && tn->tn_cast && 2870 tn->tn_type->t_tspec == VOID; 2871 } 2872 2873 static bool 2874 is_local_symbol(const tnode_t *tn) 2875 { 2876 2877 return tn->tn_op == LOAD && 2878 tn->tn_left->tn_op == NAME && 2879 tn->tn_left->tn_sym->s_scl == AUTO; 2880 } 2881 2882 static bool 2883 is_int_constant_zero(const tnode_t *tn) 2884 { 2885 2886 return tn->tn_op == CON && 2887 tn->tn_type->t_tspec == INT && 2888 tn->tn_val.u.integer == 0; 2889 } 2890 2891 static void 2892 check_null_effect(const tnode_t *tn) 2893 { 2894 2895 if (hflag && 2896 !has_side_effect(tn) && 2897 !(is_void_cast(tn) && is_local_symbol(tn->tn_left)) && 2898 !(is_void_cast(tn) && is_int_constant_zero(tn->tn_left))) { 2899 /* expression has null effect */ 2900 warning(129); 2901 } 2902 } 2903 2904 /* 2905 * Check the types for specific operators and type combinations. 2906 * 2907 * At this point, the operands already conform to the type requirements of 2908 * the operator, such as being integer, floating or scalar. 2909 */ 2910 static bool 2911 typeok_op(op_t op, int arg, 2912 const tnode_t *ln, const type_t *ltp, tspec_t lt, 2913 const tnode_t *rn, const type_t *rtp, tspec_t rt) 2914 { 2915 switch (op) { 2916 case ARROW: 2917 return typeok_arrow(lt); 2918 case POINT: 2919 return typeok_point(ln, ltp, lt); 2920 case INCBEF: 2921 case DECBEF: 2922 case INCAFT: 2923 case DECAFT: 2924 return typeok_incdec(op, ln, ltp); 2925 case INDIR: 2926 return typeok_indir(ltp, lt); 2927 case ADDR: 2928 return typeok_address(op, ln, ltp, lt); 2929 case PLUS: 2930 return typeok_plus(op, ltp, lt, rtp, rt); 2931 case MINUS: 2932 return typeok_minus(op, ltp, lt, rtp, rt); 2933 case SHL: 2934 typeok_shl(op, lt, rt); 2935 goto shift; 2936 case SHR: 2937 typeok_shr(op, ln, lt, rn, rt); 2938 shift: 2939 typeok_shift(ltp, lt, rn, rt); 2940 break; 2941 case LT: 2942 case LE: 2943 case GT: 2944 case GE: 2945 compare: 2946 return typeok_compare(op, ln, ltp, lt, rn, rtp, rt); 2947 case EQ: 2948 case NE: 2949 if (is_typeok_eq(ln, lt, rn, rt)) 2950 break; 2951 goto compare; 2952 case QUEST: 2953 return typeok_quest(lt, rn); 2954 case COLON: 2955 return typeok_colon(ln, ltp, lt, rn, rtp, rt); 2956 case ASSIGN: 2957 case INIT: 2958 case FARG: 2959 case RETURN: 2960 if (!check_assign_types_compatible(op, arg, ln, rn)) 2961 return false; 2962 goto assign; 2963 case MULASS: 2964 case DIVASS: 2965 case MODASS: 2966 goto assign; 2967 case ADDASS: 2968 case SUBASS: 2969 if ((lt == PTR && !is_integer(rt)) || rt == PTR) { 2970 warn_incompatible_types(op, ltp, lt, rtp, rt); 2971 return false; 2972 } 2973 goto assign; 2974 case SHLASS: 2975 goto assign; 2976 case SHRASS: 2977 if (pflag && !is_uinteger(lt) && 2978 !(!allow_c90 && is_uinteger(rt))) { 2979 /* bitwise '%s' on signed value possibly nonportable */ 2980 warning(117, op_name(op)); 2981 } 2982 goto assign; 2983 case ANDASS: 2984 case XORASS: 2985 case ORASS: 2986 assign: 2987 return typeok_assign(op, ln, ltp, lt); 2988 case COMMA: 2989 if (!modtab[ln->tn_op].m_has_side_effect) 2990 check_null_effect(ln); 2991 break; 2992 default: 2993 break; 2994 } 2995 return true; 2996 } 2997 2998 static void 2999 check_bad_enum_operation(op_t op, const tnode_t *ln, const tnode_t *rn) 3000 { 3001 3002 if (!eflag) 3003 return; 3004 3005 /* Allow enum in array indices. */ 3006 if (op == PLUS && 3007 ((ln->tn_type->t_is_enum && rn->tn_type->t_tspec == PTR) || 3008 (rn->tn_type->t_is_enum && ln->tn_type->t_tspec == PTR))) { 3009 return; 3010 } 3011 3012 /* dubious operation '%s' on enum */ 3013 warning(241, op_name(op)); 3014 } 3015 3016 static void 3017 check_enum_type_mismatch(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 3018 { 3019 const mod_t *mp = &modtab[op]; 3020 3021 if (ln->tn_type->t_enum != rn->tn_type->t_enum) { 3022 switch (op) { 3023 case INIT: 3024 /* enum type mismatch between '%s' and '%s' in ... */ 3025 warning(210, 3026 type_name(ln->tn_type), type_name(rn->tn_type)); 3027 break; 3028 case FARG: 3029 /* function expects '%s', passing '%s' for arg #%d */ 3030 warning(156, 3031 type_name(ln->tn_type), type_name(rn->tn_type), 3032 arg); 3033 break; 3034 case RETURN: 3035 /* function has return type '%s' but returns '%s' */ 3036 warning(211, 3037 type_name(ln->tn_type), type_name(rn->tn_type)); 3038 break; 3039 default: 3040 /* enum type mismatch: '%s' '%s' '%s' */ 3041 warning(130, type_name(ln->tn_type), op_name(op), 3042 type_name(rn->tn_type)); 3043 break; 3044 } 3045 } else if (Pflag && eflag && mp->m_comparison && op != EQ && op != NE) 3046 /* operator '%s' assumes that '%s' is ordered */ 3047 warning(243, op_name(op), type_name(ln->tn_type)); 3048 } 3049 3050 static void 3051 check_enum_int_mismatch(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 3052 { 3053 3054 if (!eflag) 3055 return; 3056 3057 switch (op) { 3058 case INIT: 3059 /* 3060 * Initialization with 0 is allowed. Otherwise, all implicit 3061 * initializations would need to be warned upon as well. 3062 */ 3063 if (!rn->tn_type->t_is_enum && rn->tn_op == CON && 3064 is_integer(rn->tn_type->t_tspec) && 3065 rn->tn_val.u.integer == 0) { 3066 return; 3067 } 3068 /* initialization of '%s' with '%s' */ 3069 warning(277, type_name(ln->tn_type), type_name(rn->tn_type)); 3070 break; 3071 case FARG: 3072 /* combination of '%s' and '%s', arg #%d */ 3073 warning(278, 3074 type_name(ln->tn_type), type_name(rn->tn_type), arg); 3075 break; 3076 case RETURN: 3077 /* combination of '%s' and '%s' in return */ 3078 warning(279, type_name(ln->tn_type), type_name(rn->tn_type)); 3079 break; 3080 default: 3081 /* combination of '%s' and '%s', op '%s' */ 3082 warning(242, type_name(ln->tn_type), type_name(rn->tn_type), 3083 op_name(op)); 3084 break; 3085 } 3086 } 3087 3088 static void 3089 typeok_enum(op_t op, const mod_t *mp, int arg, 3090 const tnode_t *ln, const type_t *ltp, 3091 const tnode_t *rn, const type_t *rtp) 3092 { 3093 if (mp->m_bad_on_enum && 3094 (ltp->t_is_enum || (mp->m_binary && rtp->t_is_enum))) { 3095 check_bad_enum_operation(op, ln, rn); 3096 } else if (mp->m_valid_on_enum && 3097 (ltp->t_is_enum && rtp != NULL && rtp->t_is_enum)) { 3098 check_enum_type_mismatch(op, arg, ln, rn); 3099 } else if (mp->m_valid_on_enum && 3100 (ltp->t_is_enum || (rtp != NULL && rtp->t_is_enum))) { 3101 check_enum_int_mismatch(op, arg, ln, rn); 3102 } 3103 } 3104 3105 /* Perform most type checks. Return whether the types are ok. */ 3106 bool 3107 typeok(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 3108 { 3109 3110 const mod_t *mp = &modtab[op]; 3111 3112 type_t *ltp = ln->tn_type; 3113 tspec_t lt = ltp->t_tspec; 3114 3115 type_t *rtp = mp->m_binary ? rn->tn_type : NULL; 3116 tspec_t rt = mp->m_binary ? rtp->t_tspec : NO_TSPEC; 3117 3118 if (Tflag && !typeok_scalar_strict_bool(op, mp, arg, ln, rn)) 3119 return false; 3120 if (!typeok_scalar(op, mp, ltp, lt, rtp, rt)) 3121 return false; 3122 3123 if (!typeok_op(op, arg, ln, ltp, lt, rn, rtp, rt)) 3124 return false; 3125 3126 typeok_enum(op, mp, arg, ln, ltp, rn, rtp); 3127 return true; 3128 } 3129 3130 /* In traditional C, keep unsigned and promote FLOAT to DOUBLE. */ 3131 static tspec_t 3132 promote_trad(tspec_t t) 3133 { 3134 3135 if (t == UCHAR || t == USHORT) 3136 return UINT; 3137 if (t == CHAR || t == SCHAR || t == SHORT) 3138 return INT; 3139 if (t == FLOAT) 3140 return DOUBLE; 3141 if (t == ENUM) 3142 return INT; 3143 return t; 3144 } 3145 3146 /* 3147 * C99 6.3.1.1p2 requires for types with lower rank than int that "If an int 3148 * can represent all the values of the original type, the value is converted 3149 * to an int; otherwise it is converted to an unsigned int", and that "All 3150 * other types are unchanged by the integer promotions". 3151 */ 3152 static tspec_t 3153 promote_c90(const tnode_t *tn, tspec_t t, bool farg) 3154 { 3155 if (tn->tn_type->t_bitfield) { 3156 unsigned int width = tn->tn_type->t_bit_field_width; 3157 unsigned int int_width = size_in_bits(INT); 3158 // XXX: What about _Bool bit-fields, since C99? 3159 if (width < int_width) 3160 return INT; 3161 if (width == int_width) 3162 return is_uinteger(t) ? UINT : INT; 3163 return t; 3164 } 3165 3166 if (t == CHAR || t == SCHAR) 3167 return INT; 3168 if (t == UCHAR) 3169 return size_in_bits(CHAR) < size_in_bits(INT) ? INT : UINT; 3170 if (t == SHORT) 3171 return INT; 3172 if (t == USHORT) 3173 return size_in_bits(SHORT) < size_in_bits(INT) ? INT : UINT; 3174 if (t == ENUM) 3175 return INT; 3176 if (farg && t == FLOAT) 3177 return DOUBLE; 3178 return t; 3179 } 3180 3181 /* 3182 * Performs the "integer promotions" (C99 6.3.1.1p2), which convert small 3183 * integer types to either int or unsigned int. 3184 * 3185 * If allow_c90 is unset or the operand is a function argument with no type 3186 * information (no prototype or variable # of args), converts float to double. 3187 */ 3188 tnode_t * 3189 promote(op_t op, bool farg, tnode_t *tn) 3190 { 3191 3192 tspec_t ot = tn->tn_type->t_tspec; 3193 if (!is_arithmetic(ot)) 3194 return tn; 3195 3196 tspec_t nt = allow_c90 ? promote_c90(tn, ot, farg) : promote_trad(ot); 3197 if (nt == ot) 3198 return tn; 3199 3200 type_t *ntp = expr_dup_type(tn->tn_type); 3201 ntp->t_tspec = nt; 3202 /* 3203 * Keep t_is_enum even though t_tspec gets converted from ENUM to INT, 3204 * so we are later able to check compatibility of enum types. 3205 */ 3206 return convert(op, 0, ntp, tn); 3207 } 3208 3209 static void 3210 convert_integer_from_floating(op_t op, const type_t *tp, const tnode_t *tn) 3211 { 3212 3213 if (op == CVT) 3214 /* cast from floating point '%s' to integer '%s' */ 3215 query_message(2, type_name(tn->tn_type), type_name(tp)); 3216 else 3217 /* implicit conversion from floating point '%s' to ... */ 3218 query_message(1, type_name(tn->tn_type), type_name(tp)); 3219 } 3220 3221 static bool 3222 should_warn_about_prototype_conversion(tspec_t nt, 3223 tspec_t ot, const tnode_t *ptn) 3224 { 3225 3226 if (nt == ot) 3227 return false; 3228 3229 if (nt == ENUM && ot == INT) 3230 return false; 3231 3232 if (is_floating(nt) != is_floating(ot) || 3233 portable_rank_cmp(nt, ot) != 0) { 3234 /* representation and/or width change */ 3235 if (!is_integer(ot)) 3236 return true; 3237 /* 3238 * XXX: Investigate whether this rule makes sense; see 3239 * tests/usr.bin/xlint/lint1/platform_long.c. 3240 */ 3241 return portable_rank_cmp(ot, INT) > 0; 3242 } 3243 3244 if (!hflag) 3245 return false; 3246 3247 /* 3248 * If the types differ only in sign and the argument has the same 3249 * representation in both types, print no warning. 3250 */ 3251 if (ptn->tn_op == CON && is_integer(nt) && 3252 signed_type(nt) == signed_type(ot) && 3253 !msb(ptn->tn_val.u.integer, ot)) 3254 return false; 3255 3256 return true; 3257 } 3258 3259 /* 3260 * Warn if a prototype causes a type conversion that is different from what 3261 * would happen to the same argument in the absence of a prototype. This 3262 * check is intended for code that needs to stay compatible with pre-C90 C. 3263 * 3264 * Errors/warnings about illegal type combinations are already printed 3265 * in check_assign_types_compatible(). 3266 */ 3267 static void 3268 check_prototype_conversion(int arg, tspec_t nt, tspec_t ot, type_t *tp, 3269 tnode_t *tn) 3270 { 3271 3272 if (!is_arithmetic(nt) || !is_arithmetic(ot)) 3273 return; 3274 3275 /* 3276 * If the type of the formal parameter is char/short, a warning would 3277 * be useless, because functions declared the old style can't expect 3278 * char/short arguments. 3279 */ 3280 if (nt == CHAR || nt == SCHAR || nt == UCHAR || 3281 nt == SHORT || nt == USHORT) 3282 return; 3283 3284 tnode_t *ptn = promote(NOOP, true, tn); 3285 ot = ptn->tn_type->t_tspec; 3286 3287 if (should_warn_about_prototype_conversion(nt, ot, ptn)) { 3288 /* argument %d is converted from '%s' to '%s' ... */ 3289 warning(259, arg, type_name(tn->tn_type), type_name(tp)); 3290 } 3291 } 3292 3293 /* 3294 * When converting a large integer type to a small integer type, in some 3295 * cases the value of the actual expression is further restricted than the 3296 * type bounds, such as in (expr & 0xFF) or (expr % 100) or (expr >> 24). 3297 */ 3298 static bool 3299 can_represent(const type_t *tp, const tnode_t *tn) 3300 { 3301 3302 debug_step("%s: type '%s'", __func__, type_name(tp)); 3303 debug_node(tn); 3304 3305 uint64_t nmask = value_bits(width_in_bits(tp)); 3306 if (!is_uinteger(tp->t_tspec)) 3307 nmask >>= 1; 3308 3309 integer_constraints c = ic_expr(tn); 3310 if ((~c.bclr & ~nmask) == 0) 3311 return true; 3312 3313 integer_constraints tpc = ic_any(tp); 3314 if (is_uinteger(tp->t_tspec) 3315 ? tpc.umin <= c.umin && tpc.umax >= c.umax 3316 : tpc.smin <= c.smin && tpc.smax >= c.smax) 3317 return true; 3318 3319 return false; 3320 } 3321 3322 static bool 3323 should_warn_about_integer_conversion(const type_t *ntp, tspec_t nt, 3324 const tnode_t *otn, tspec_t ot) 3325 { 3326 3327 // XXX: The portable_rank_cmp aims at portable mode, independent of the 3328 // current platform, while can_represent acts on the actual type sizes 3329 // from the current platform. This mix is inconsistent, but anything 3330 // else would make the exact conditions too complicated to grasp. 3331 if (aflag > 0 && portable_rank_cmp(nt, ot) < 0) { 3332 if (ot == LONG || ot == ULONG 3333 || ot == LLONG || ot == ULLONG 3334 #ifdef INT128_SIZE 3335 || ot == INT128 || ot == UINT128 3336 #endif 3337 || aflag > 1) 3338 return !can_represent(ntp, otn); 3339 } 3340 return false; 3341 } 3342 3343 static void 3344 convert_integer_from_integer(op_t op, int arg, tspec_t nt, tspec_t ot, 3345 type_t *tp, tnode_t *tn) 3346 { 3347 3348 if (tn->tn_op == CON) 3349 return; 3350 3351 if (op == CVT) 3352 return; 3353 3354 if (Pflag && pflag && aflag > 0 && 3355 portable_rank_cmp(nt, ot) > 0 && 3356 is_uinteger(nt) != is_uinteger(ot)) { 3357 if (op == FARG) { 3358 /* conversion to '%s' may sign-extend ... */ 3359 warning(297, type_name(tp), arg); 3360 } else { 3361 /* conversion to '%s' may sign-extend ... */ 3362 warning(131, type_name(tp)); 3363 } 3364 } 3365 3366 if (Pflag && portable_rank_cmp(nt, ot) > 0 && 3367 (tn->tn_op == PLUS || tn->tn_op == MINUS || tn->tn_op == MULT || 3368 tn->tn_op == SHL)) { 3369 /* suggest cast from '%s' to '%s' on op '%s' to ... */ 3370 warning(324, type_name(gettyp(ot)), type_name(tp), 3371 op_name(tn->tn_op)); 3372 } 3373 3374 if (should_warn_about_integer_conversion(tp, nt, tn, ot)) { 3375 if (op == FARG) { 3376 /* conversion from '%s' to '%s' may lose ... */ 3377 warning(298, 3378 type_name(tn->tn_type), type_name(tp), arg); 3379 } else { 3380 /* conversion from '%s' to '%s' may lose accuracy */ 3381 warning(132, 3382 type_name(tn->tn_type), type_name(tp)); 3383 } 3384 } 3385 3386 if (any_query_enabled && is_uinteger(nt) != is_uinteger(ot)) 3387 /* implicit conversion changes sign from '%s' to '%s' */ 3388 query_message(3, type_name(tn->tn_type), type_name(tp)); 3389 } 3390 3391 static void 3392 convert_integer_from_pointer(op_t op, tspec_t nt, type_t *tp, tnode_t *tn) 3393 { 3394 3395 if (tn->tn_op == CON) 3396 return; 3397 if (op != CVT) 3398 return; /* We already got an error. */ 3399 if (portable_rank_cmp(nt, PTR) >= 0) 3400 return; 3401 3402 if (pflag && size_in_bits(nt) >= size_in_bits(PTR)) { 3403 /* conversion of pointer to '%s' may lose bits */ 3404 warning(134, type_name(tp)); 3405 } else { 3406 /* conversion of pointer to '%s' loses bits */ 3407 warning(133, type_name(tp)); 3408 } 3409 } 3410 3411 static bool 3412 struct_starts_with(const type_t *struct_tp, const type_t *member_tp) 3413 { 3414 3415 return struct_tp->t_sou->sou_first_member != NULL && 3416 types_compatible(struct_tp->t_sou->sou_first_member->s_type, 3417 member_tp, true, false, NULL); 3418 } 3419 3420 static bool 3421 is_byte_array(const type_t *tp) 3422 { 3423 3424 return tp->t_tspec == ARRAY && 3425 (tp->t_subt->t_tspec == CHAR || tp->t_subt->t_tspec == UCHAR); 3426 } 3427 3428 static bool 3429 union_contains(const type_t *utp, const type_t *mtp) 3430 { 3431 for (const sym_t *mem = utp->t_sou->sou_first_member; 3432 mem != NULL; mem = mem->s_next) { 3433 if (types_compatible(mem->s_type, mtp, true, false, NULL)) 3434 return true; 3435 } 3436 return false; 3437 } 3438 3439 static bool 3440 should_warn_about_pointer_cast(const type_t *nstp, tspec_t nst, 3441 const type_t *ostp, tspec_t ost) 3442 { 3443 3444 while (nst == ARRAY) 3445 nstp = nstp->t_subt, nst = nstp->t_tspec; 3446 while (ost == ARRAY) 3447 ostp = ostp->t_subt, ost = ostp->t_tspec; 3448 3449 if (nst == STRUCT && ost == STRUCT && 3450 (struct_starts_with(nstp, ostp) || 3451 struct_starts_with(ostp, nstp))) 3452 return false; 3453 3454 if (is_incomplete(nstp) || is_incomplete(ostp)) 3455 return false; 3456 3457 if (nst == CHAR || nst == UCHAR) 3458 return false; /* for the sake of traditional C code */ 3459 if (ost == CHAR || ost == UCHAR) 3460 return false; /* for the sake of traditional C code */ 3461 3462 /* Allow cast between pointers to sockaddr variants. */ 3463 if (nst == STRUCT && ost == STRUCT) { 3464 const sym_t *nmem = nstp->t_sou->sou_first_member; 3465 const sym_t *omem = ostp->t_sou->sou_first_member; 3466 while (nmem != NULL && omem != NULL && 3467 types_compatible(nmem->s_type, omem->s_type, 3468 true, false, NULL)) 3469 nmem = nmem->s_next, omem = omem->s_next; 3470 if (nmem != NULL && is_byte_array(nmem->s_type)) 3471 return false; 3472 if (omem != NULL && is_byte_array(omem->s_type)) 3473 return false; 3474 if (nmem == NULL && omem == NULL) 3475 return false; 3476 } 3477 3478 if (nst == UNION || ost == UNION) { 3479 const type_t *union_tp = nst == UNION ? nstp : ostp; 3480 const type_t *other_tp = nst == UNION ? ostp : nstp; 3481 if (union_contains(union_tp, other_tp)) 3482 return false; 3483 } 3484 3485 if (is_struct_or_union(nst) && is_struct_or_union(ost)) 3486 return nstp->t_sou != ostp->t_sou; 3487 3488 enum rank_kind rk1 = type_properties(nst)->tt_rank_kind; 3489 enum rank_kind rk2 = type_properties(ost)->tt_rank_kind; 3490 if (rk1 != rk2 || rk1 == RK_NONE) 3491 return true; 3492 3493 return portable_rank_cmp(nst, ost) != 0; 3494 } 3495 3496 static void 3497 convert_pointer_from_pointer(type_t *ntp, tnode_t *tn) 3498 { 3499 const type_t *nstp = ntp->t_subt; 3500 const type_t *otp = tn->tn_type; 3501 const type_t *ostp = otp->t_subt; 3502 tspec_t nst = nstp->t_tspec; 3503 tspec_t ost = ostp->t_tspec; 3504 3505 if (nst == VOID || ost == VOID) { 3506 /* TODO: C99 behaves like C90 here. */ 3507 if (!allow_trad && !allow_c99 && (nst == FUNC || ost == FUNC)) { 3508 const char *nts, *ots; 3509 /* null pointers are already handled in convert() */ 3510 *(nst == FUNC ? &nts : &ots) = "function pointer"; 3511 *(nst == VOID ? &nts : &ots) = "'void *'"; 3512 /* conversion of %s to %s requires a cast */ 3513 warning(303, ots, nts); 3514 } 3515 return; 3516 } 3517 if (nst == FUNC && ost == FUNC) 3518 return; 3519 if (nst == FUNC || ost == FUNC) { 3520 /* converting '%s' to '%s' is questionable */ 3521 warning(229, type_name(otp), type_name(ntp)); 3522 return; 3523 } 3524 3525 if (hflag && alignment_in_bits(nstp) > alignment_in_bits(ostp) && 3526 ost != CHAR && ost != UCHAR && 3527 !is_incomplete(ostp) && 3528 !(nst == UNION && union_contains(nstp, ostp))) { 3529 /* converting '%s' to '%s' increases alignment ... */ 3530 warning(135, type_name(otp), type_name(ntp), 3531 alignment_in_bits(ostp) / CHAR_SIZE, 3532 alignment_in_bits(nstp) / CHAR_SIZE); 3533 } 3534 3535 if (cflag && should_warn_about_pointer_cast(nstp, nst, ostp, ost)) { 3536 /* pointer cast from '%s' to '%s' may be troublesome */ 3537 warning(247, type_name(otp), type_name(ntp)); 3538 } 3539 } 3540 3541 /* 3542 * Insert a conversion operator, which converts the type of the node 3543 * to another given type. 3544 * 3545 * Possible values for 'op': 3546 * CVT a cast-expression 3547 * binary integer promotion for one of the operands, or a usual 3548 * arithmetic conversion 3549 * binary plain or compound assignments to bit-fields 3550 * FARG 'arg' is the number of the parameter (used for warnings) 3551 * NOOP several other implicit conversions 3552 * ... 3553 */ 3554 tnode_t * 3555 convert(op_t op, int arg, type_t *tp, tnode_t *tn) 3556 { 3557 tspec_t nt = tp->t_tspec; 3558 tspec_t ot = tn->tn_type->t_tspec; 3559 3560 if (allow_trad && allow_c90 && op == FARG) 3561 check_prototype_conversion(arg, nt, ot, tp, tn); 3562 3563 if (nt == BOOL) { 3564 /* No further checks. */ 3565 3566 } else if (is_integer(nt)) { 3567 if (ot == BOOL) { 3568 /* No further checks. */ 3569 } else if (is_integer(ot)) 3570 convert_integer_from_integer(op, arg, nt, ot, tp, tn); 3571 else if (is_floating(ot)) 3572 convert_integer_from_floating(op, tp, tn); 3573 else if (ot == PTR) 3574 convert_integer_from_pointer(op, nt, tp, tn); 3575 3576 } else if (is_floating(nt)) { 3577 /* No further checks. */ 3578 3579 } else if (nt == PTR) { 3580 if (is_null_pointer(tn)) { 3581 /* a null pointer may be assigned to any pointer. */ 3582 } else if (ot == PTR && op == CVT) 3583 convert_pointer_from_pointer(tp, tn); 3584 } 3585 3586 tnode_t *ntn = expr_alloc_tnode(); 3587 ntn->tn_op = CVT; 3588 ntn->tn_type = tp; 3589 ntn->tn_cast = op == CVT; 3590 ntn->tn_sys |= tn->tn_sys; 3591 ntn->tn_right = NULL; 3592 if (tn->tn_op != CON || nt == VOID) { 3593 ntn->tn_left = tn; 3594 } else { 3595 ntn->tn_op = CON; 3596 convert_constant(op, arg, ntn->tn_type, &ntn->tn_val, 3597 &tn->tn_val); 3598 } 3599 3600 return ntn; 3601 } 3602 3603 static void 3604 convert_constant_floating(op_t op, int arg, tspec_t ot, const type_t *tp, 3605 tspec_t nt, val_t *v, val_t *nv) 3606 { 3607 long double max = 0.0, min = 0.0; 3608 3609 switch (nt) { 3610 case CHAR: 3611 max = TARG_CHAR_MAX; min = TARG_CHAR_MIN; break; 3612 case UCHAR: 3613 max = TARG_UCHAR_MAX; min = 0; break; 3614 case SCHAR: 3615 max = TARG_SCHAR_MAX; min = TARG_SCHAR_MIN; break; 3616 case SHORT: 3617 max = TARG_SHRT_MAX; min = TARG_SHRT_MIN; break; 3618 case USHORT: 3619 max = TARG_USHRT_MAX; min = 0; break; 3620 case ENUM: 3621 case INT: 3622 max = TARG_INT_MAX; min = TARG_INT_MIN; break; 3623 case UINT: 3624 max = TARG_UINT_MAX; min = 0; break; 3625 case LONG: 3626 max = TARG_LONG_MAX; min = TARG_LONG_MIN; break; 3627 case ULONG: 3628 max = TARG_ULONG_MAX; min = 0; break; 3629 case LLONG: 3630 max = LLONG_MAX; min = LLONG_MIN; break; 3631 case ULLONG: 3632 max = ULLONG_MAX; min = 0; break; 3633 case FLOAT: 3634 case FCOMPLEX: 3635 max = FLT_MAX; min = -FLT_MAX; break; 3636 case DOUBLE: 3637 case DCOMPLEX: 3638 max = DBL_MAX; min = -DBL_MAX; break; 3639 case PTR: 3640 /* Already got an error because of float --> ptr */ 3641 case LDOUBLE: 3642 case LCOMPLEX: 3643 /* LINTED 248 */ 3644 max = LDBL_MAX; min = -max; break; 3645 default: 3646 lint_assert(/*CONSTCOND*/false); 3647 } 3648 if (v->u.floating > max || v->u.floating < min) { 3649 lint_assert(nt != LDOUBLE); 3650 if (op == FARG) { 3651 /* conversion of '%s' to '%s' is out of range, ... */ 3652 warning(295, 3653 type_name(gettyp(ot)), type_name(tp), arg); 3654 } else { 3655 /* conversion of '%s' to '%s' is out of range */ 3656 warning(119, type_name(gettyp(ot)), type_name(tp)); 3657 } 3658 v->u.floating = v->u.floating > 0 ? max : min; 3659 } 3660 3661 if (nt == FLOAT || nt == FCOMPLEX) 3662 nv->u.floating = (float)v->u.floating; 3663 else if (nt == DOUBLE || nt == DCOMPLEX) 3664 nv->u.floating = (double)v->u.floating; 3665 else if (nt == LDOUBLE || nt == LCOMPLEX) 3666 nv->u.floating = v->u.floating; 3667 else 3668 nv->u.integer = (int64_t)v->u.floating; 3669 } 3670 3671 static bool 3672 convert_constant_to_floating(tspec_t nt, val_t *nv, 3673 tspec_t ot, const val_t *v) 3674 { 3675 if (nt == FLOAT) { 3676 nv->u.floating = (ot == PTR || is_uinteger(ot)) ? 3677 (float)(uint64_t)v->u.integer : (float)v->u.integer; 3678 } else if (nt == DOUBLE) { 3679 nv->u.floating = (ot == PTR || is_uinteger(ot)) ? 3680 (double)(uint64_t)v->u.integer : (double)v->u.integer; 3681 } else if (nt == LDOUBLE) { 3682 nv->u.floating = (ot == PTR || is_uinteger(ot)) 3683 ? (long double)(uint64_t)v->u.integer 3684 : (long double)v->u.integer; 3685 } else 3686 return false; 3687 return true; 3688 } 3689 3690 /* 3691 * Print a warning if bits which were set are lost due to the conversion. 3692 * This can happen with operator ORASS only. 3693 */ 3694 static void 3695 convert_constant_check_range_bitor(size_t nsz, size_t osz, const val_t *v, 3696 uint64_t xmask, op_t op) 3697 { 3698 if (nsz < osz && (v->u.integer & xmask) != 0) { 3699 /* constant truncated by conversion, op '%s' */ 3700 warning(306, op_name(op)); 3701 } 3702 } 3703 3704 static void 3705 convert_constant_check_range_bitand(size_t nsz, size_t osz, 3706 uint64_t xmask, const val_t *nv, 3707 tspec_t ot, const val_t *v, 3708 const type_t *tp, op_t op) 3709 { 3710 if (nsz > osz && 3711 (nv->u.integer & bit((unsigned int)(osz - 1))) != 0 && 3712 (nv->u.integer & xmask) != xmask) { 3713 /* extra bits set to 0 in conversion of '%s' to '%s', ... */ 3714 warning(309, type_name(gettyp(ot)), 3715 type_name(tp), op_name(op)); 3716 } else if (nsz < osz && 3717 (v->u.integer & xmask) != xmask && 3718 (v->u.integer & xmask) != 0) { 3719 /* constant truncated by conversion, op '%s' */ 3720 warning(306, op_name(op)); 3721 } 3722 } 3723 3724 static void 3725 convert_constant_check_range_signed(op_t op, int arg) 3726 { 3727 if (op == ASSIGN) { 3728 /* assignment of negative constant to unsigned type */ 3729 warning(164); 3730 } else if (op == INIT) { 3731 /* initialization of unsigned with negative constant */ 3732 warning(221); 3733 } else if (op == FARG) { 3734 /* conversion of negative constant to unsigned type, ... */ 3735 warning(296, arg); 3736 } else if (modtab[op].m_comparison) { 3737 /* handled by check_integer_comparison() */ 3738 } else { 3739 /* conversion of negative constant to unsigned type */ 3740 warning(222); 3741 } 3742 } 3743 3744 /* 3745 * Loss of significant bit(s). All truncated bits of unsigned types or all 3746 * truncated bits plus the msb of the target for signed types are considered 3747 * to be significant bits. Loss of significant bits means that at least one 3748 * of the bits was set in an unsigned type or that at least one but not all 3749 * of the bits was set in a signed type. Loss of significant bits means that 3750 * it is not possible, also not with necessary casts, to convert back to the 3751 * original type. An example for a necessary cast is: 3752 * char c; int i; c = 128; 3753 * i = c; ** yields -128 ** 3754 * i = (unsigned char)c; ** yields 128 ** 3755 */ 3756 static void 3757 warn_constant_check_range_truncated(op_t op, int arg, const type_t *tp, 3758 tspec_t ot) 3759 { 3760 if (op == ASSIGN && tp->t_bitfield) 3761 /* precision lost in bit-field assignment */ 3762 warning(166); 3763 else if (op == ASSIGN) 3764 /* constant truncated by assignment */ 3765 warning(165); 3766 else if (op == INIT && tp->t_bitfield) 3767 /* bit-field initializer does not fit */ 3768 warning(180); 3769 else if (op == INIT) 3770 /* initializer does not fit */ 3771 warning(178); 3772 else if (op == CASE) 3773 /* case label affected by conversion */ 3774 warning(196); 3775 else if (op == FARG) 3776 /* conversion of '%s' to '%s' is out of range, arg #%d */ 3777 warning(295, type_name(gettyp(ot)), type_name(tp), arg); 3778 else 3779 /* conversion of '%s' to '%s' is out of range */ 3780 warning(119, type_name(gettyp(ot)), type_name(tp)); 3781 } 3782 3783 static void 3784 warn_constant_check_range_loss(op_t op, int arg, const type_t *tp, 3785 tspec_t ot) 3786 { 3787 if (op == ASSIGN && tp->t_bitfield) 3788 /* precision lost in bit-field assignment */ 3789 warning(166); 3790 else if (op == INIT && tp->t_bitfield) 3791 /* bit-field initializer out of range */ 3792 warning(11); 3793 else if (op == CASE) 3794 /* case label affected by conversion */ 3795 warning(196); 3796 else if (op == FARG) 3797 /* conversion of '%s' to '%s' is out of range, arg #%d */ 3798 warning(295, type_name(gettyp(ot)), type_name(tp), arg); 3799 else 3800 /* conversion of '%s' to '%s' is out of range */ 3801 warning(119, type_name(gettyp(ot)), type_name(tp)); 3802 } 3803 3804 static void 3805 convert_constant_check_range(tspec_t ot, const type_t *tp, tspec_t nt, 3806 op_t op, int arg, const val_t *v, val_t *nv) 3807 { 3808 unsigned int obitsz, nbitsz; 3809 uint64_t xmask, xmsk1; 3810 3811 obitsz = size_in_bits(ot); 3812 nbitsz = tp->t_bitfield ? tp->t_bit_field_width : size_in_bits(nt); 3813 xmask = value_bits(nbitsz) ^ value_bits(obitsz); 3814 xmsk1 = value_bits(nbitsz) ^ value_bits(obitsz - 1); 3815 if (op == ORASS || op == BITOR || op == BITXOR) { 3816 convert_constant_check_range_bitor( 3817 nbitsz, obitsz, v, xmask, op); 3818 } else if (op == ANDASS || op == BITAND) { 3819 convert_constant_check_range_bitand( 3820 nbitsz, obitsz, xmask, nv, ot, v, tp, op); 3821 } else if (nt != PTR && is_uinteger(nt) && 3822 ot != PTR && !is_uinteger(ot) && 3823 v->u.integer < 0) 3824 convert_constant_check_range_signed(op, arg); 3825 else if (nv->u.integer != v->u.integer && nbitsz <= obitsz && 3826 (v->u.integer & xmask) != 0 && 3827 (is_uinteger(ot) || (v->u.integer & xmsk1) != xmsk1)) 3828 warn_constant_check_range_truncated(op, arg, tp, ot); 3829 else if (nv->u.integer != v->u.integer) 3830 warn_constant_check_range_loss(op, arg, tp, ot); 3831 } 3832 3833 /*- 3834 * Converts a typed constant to a constant of another type. 3835 * 3836 * op operator which requires conversion 3837 * arg if op is FARG, # of parameter 3838 * tp type to which to convert the constant 3839 * nv new constant 3840 * v old constant 3841 */ 3842 void 3843 convert_constant(op_t op, int arg, const type_t *tp, val_t *nv, val_t *v) 3844 { 3845 /* 3846 * TODO: make 'v' const; the name of this function does not suggest 3847 * that it modifies 'v'. 3848 */ 3849 tspec_t ot = v->v_tspec; 3850 tspec_t nt = nv->v_tspec = tp->t_tspec; 3851 bool range_check = false; 3852 3853 if (nt == BOOL) { /* C99 6.3.1.2 */ 3854 nv->v_unsigned_since_c90 = false; 3855 nv->u.integer = is_nonzero_val(v) ? 1 : 0; 3856 return; 3857 } 3858 3859 if (ot == FLOAT || ot == DOUBLE || ot == LDOUBLE) 3860 convert_constant_floating(op, arg, ot, tp, nt, v, nv); 3861 else if (!convert_constant_to_floating(nt, nv, ot, v)) { 3862 range_check = true; /* Check for lost precision. */ 3863 nv->u.integer = v->u.integer; 3864 } 3865 3866 if (allow_trad && allow_c90 && v->v_unsigned_since_c90 && 3867 (is_floating(nt) || ( 3868 (is_integer(nt) && !is_uinteger(nt) && 3869 portable_rank_cmp(nt, ot) > 0)))) { 3870 /* C90 treats constant as unsigned */ 3871 warning(157); 3872 v->v_unsigned_since_c90 = false; 3873 } 3874 3875 if (is_integer(nt)) { 3876 nv->u.integer = convert_integer(nv->u.integer, nt, 3877 tp->t_bitfield ? tp->t_bit_field_width : size_in_bits(nt)); 3878 } 3879 3880 if (range_check && op != CVT) 3881 convert_constant_check_range(ot, tp, nt, op, arg, v, nv); 3882 } 3883 3884 tnode_t * 3885 build_sizeof(const type_t *tp) 3886 { 3887 unsigned int size_in_bytes = type_size_in_bits(tp) / CHAR_SIZE; 3888 tnode_t *tn = build_integer_constant(SIZEOF_TSPEC, size_in_bytes); 3889 tn->tn_system_dependent = true; 3890 debug_step("build_sizeof '%s' = %u", type_name(tp), size_in_bytes); 3891 return tn; 3892 } 3893 3894 tnode_t * 3895 build_offsetof(const type_t *tp, designation dn) 3896 { 3897 unsigned int offset_in_bits = 0; 3898 3899 if (!is_struct_or_union(tp->t_tspec)) { 3900 /* unacceptable operand of '%s' */ 3901 error(111, "offsetof"); 3902 goto proceed; 3903 } 3904 for (size_t i = 0; i < dn.dn_len; i++) { 3905 const designator *dr = dn.dn_items + i; 3906 if (dr->dr_kind == DK_SUBSCRIPT) { 3907 if (tp->t_tspec != ARRAY) 3908 goto proceed; /* silent error */ 3909 tp = tp->t_subt; 3910 offset_in_bits += (unsigned) dr->dr_subscript 3911 * type_size_in_bits(tp); 3912 } else { 3913 if (!is_struct_or_union(tp->t_tspec)) 3914 goto proceed; /* silent error */ 3915 const char *name = dr->dr_member->s_name; 3916 sym_t *mem = find_member(tp->t_sou, name); 3917 if (mem == NULL) { 3918 /* type '%s' does not have member '%s' */ 3919 error(101, name, type_name(tp)); 3920 goto proceed; 3921 } 3922 tp = mem->s_type; 3923 offset_in_bits += mem->u.s_member.sm_offset_in_bits; 3924 } 3925 } 3926 free(dn.dn_items); 3927 3928 proceed:; 3929 unsigned int offset_in_bytes = offset_in_bits / CHAR_SIZE; 3930 tnode_t *tn = build_integer_constant(SIZEOF_TSPEC, offset_in_bytes); 3931 tn->tn_system_dependent = true; 3932 return tn; 3933 } 3934 3935 unsigned int 3936 type_size_in_bits(const type_t *tp) 3937 { 3938 3939 unsigned int elem = 1; 3940 bool flex = false; 3941 lint_assert(tp != NULL); 3942 while (tp->t_tspec == ARRAY) { 3943 flex = true; /* allow c99 flex arrays [] [0] */ 3944 elem *= tp->t_dim; 3945 tp = tp->t_subt; 3946 } 3947 if (elem == 0 && !flex) { 3948 /* cannot take size/alignment of incomplete type */ 3949 error(143); 3950 elem = 1; 3951 } 3952 3953 unsigned int elsz; 3954 switch (tp->t_tspec) { 3955 case VOID: 3956 /* cannot take size/alignment of void */ 3957 error(146); 3958 elsz = 1; 3959 break; 3960 case FUNC: 3961 /* cannot take size/alignment of function type '%s' */ 3962 error(144, type_name(tp)); 3963 elsz = 1; 3964 break; 3965 case STRUCT: 3966 case UNION: 3967 if (is_incomplete(tp)) { 3968 /* cannot take size/alignment of incomplete type */ 3969 error(143); 3970 elsz = 1; 3971 } else { 3972 elsz = tp->t_sou->sou_size_in_bits; 3973 } 3974 break; 3975 case ENUM: 3976 if (is_incomplete(tp)) { 3977 /* cannot take size/alignment of incomplete type */ 3978 warning(143); 3979 } 3980 /* FALLTHROUGH */ 3981 default: 3982 if (tp->t_bitfield) { 3983 /* cannot take size/alignment of bit-field */ 3984 error(145); 3985 } 3986 elsz = size_in_bits(tp->t_tspec); 3987 lint_assert(elsz > 0); 3988 break; 3989 } 3990 3991 return elem * elsz; 3992 } 3993 3994 /* C11 6.5.3.4, GCC */ 3995 tnode_t * 3996 build_alignof(const type_t *tp) 3997 { 3998 if (tp->t_tspec == FUNC) { 3999 /* cannot take size/alignment of function type '%s' */ 4000 error(144, type_name(tp)); 4001 return NULL; 4002 } 4003 if (tp->t_tspec == VOID) { 4004 /* cannot take size/alignment of void */ 4005 error(146); 4006 return NULL; 4007 } 4008 if (is_incomplete(tp)) { 4009 /* cannot take size/alignment of incomplete type */ 4010 error(143); 4011 return NULL; 4012 } 4013 if (tp->t_bitfield) { 4014 /* cannot take size/alignment of bit-field */ 4015 error(145); 4016 return NULL; 4017 } 4018 return build_integer_constant(SIZEOF_TSPEC, 4019 (int64_t)alignment_in_bits(tp) / CHAR_SIZE); 4020 } 4021 4022 static tnode_t * 4023 cast_to_union(tnode_t *otn, bool sys, type_t *ntp) 4024 { 4025 4026 if (!allow_gcc) { 4027 /* union cast is a GCC extension */ 4028 error(328); 4029 return NULL; 4030 } 4031 4032 for (const sym_t *m = ntp->t_sou->sou_first_member; 4033 m != NULL; m = m->s_next) { 4034 if (types_compatible(m->s_type, otn->tn_type, 4035 false, false, NULL)) { 4036 tnode_t *ntn = build_op(CVT, sys, ntp, otn, NULL); 4037 ntn->tn_cast = true; 4038 return ntn; 4039 } 4040 } 4041 4042 /* type '%s' is not a member of '%s' */ 4043 error(329, type_name(otn->tn_type), type_name(ntp)); 4044 return NULL; 4045 } 4046 4047 tnode_t * 4048 cast(tnode_t *tn, bool sys, type_t *tp) 4049 { 4050 4051 if (tn == NULL) 4052 return NULL; 4053 4054 tn = cconv(tn); 4055 4056 lint_assert(tp != NULL); 4057 tspec_t nt = tp->t_tspec; 4058 tspec_t ot = tn->tn_type->t_tspec; 4059 4060 if (nt == VOID) { 4061 /* 4062 * C90 6.3.4, C99 6.5.4p2 and C11 6.5.4p2 allow any type to be 4063 * cast to void. The only other allowed casts are from a 4064 * scalar type to a scalar type. 4065 */ 4066 } else if (nt == UNION) 4067 return cast_to_union(tn, sys, tp); 4068 else if (nt == STRUCT || nt == ARRAY || nt == FUNC) { 4069 /* Casting to a struct is an undocumented GCC extension. */ 4070 if (!(allow_gcc && nt == STRUCT)) 4071 goto invalid_cast; 4072 } else if (is_struct_or_union(ot)) 4073 goto invalid_cast; 4074 else if (ot == VOID) { 4075 /* improper cast of void expression */ 4076 error(148); 4077 return NULL; 4078 } else if (is_integer(nt) && is_scalar(ot)) { 4079 /* ok */ 4080 } else if (is_floating(nt) && is_arithmetic(ot)) { 4081 /* ok */ 4082 } else if (nt == PTR && is_integer(ot)) { 4083 /* ok */ 4084 } else if (nt == PTR && ot == PTR) { 4085 if (!tp->t_subt->t_const && tn->tn_type->t_subt->t_const) { 4086 if (hflag) 4087 /* cast discards 'const' from type '%s' */ 4088 warning(275, type_name(tn->tn_type)); 4089 } 4090 } else 4091 goto invalid_cast; 4092 4093 if (any_query_enabled && types_compatible(tp, tn->tn_type, 4094 false, false, NULL)) { 4095 /* no-op cast from '%s' to '%s' */ 4096 query_message(6, type_name(tn->tn_type), type_name(tp)); 4097 } 4098 4099 tn = convert(CVT, 0, tp, tn); 4100 tn->tn_cast = true; 4101 tn->tn_sys = sys; 4102 4103 return tn; 4104 4105 invalid_cast: 4106 /* invalid cast from '%s' to '%s' */ 4107 error(147, type_name(tn->tn_type), type_name(tp)); 4108 return NULL; 4109 } 4110 4111 void 4112 add_function_argument(function_call *call, tnode_t *arg) 4113 { 4114 /* 4115 * If there was a serious error in the expression for the argument, 4116 * create a dummy argument so the positions of the remaining arguments 4117 * will not change. 4118 */ 4119 if (arg == NULL) 4120 arg = build_integer_constant(INT, 0); 4121 4122 if (call->args_len >= call->args_cap) { 4123 call->args_cap += 8; 4124 tnode_t **new_args = expr_zero_alloc( 4125 call->args_cap * sizeof(*call->args), 4126 "function_call.args"); 4127 memcpy(new_args, call->args, 4128 call->args_len * sizeof(*call->args)); 4129 call->args = new_args; 4130 } 4131 call->args[call->args_len++] = arg; 4132 } 4133 4134 /* 4135 * Compare the type of an argument with the corresponding type of a 4136 * prototype parameter. If it is a valid combination, but both types 4137 * are not the same, insert a conversion to convert the argument into 4138 * the type of the parameter. 4139 */ 4140 static tnode_t * 4141 check_prototype_argument( 4142 int n, /* pos of arg */ 4143 type_t *tp, /* expected type (from prototype) */ 4144 tnode_t *tn) /* argument */ 4145 { 4146 tnode_t *ln = xcalloc(1, sizeof(*ln)); 4147 ln->tn_type = expr_unqualified_type(tp); 4148 ln->tn_lvalue = true; 4149 if (typeok(FARG, n, ln, tn)) { 4150 bool dowarn; 4151 if (!types_compatible(tp, tn->tn_type, 4152 true, false, (dowarn = false, &dowarn)) || dowarn) 4153 tn = convert(FARG, n, tp, tn); 4154 } 4155 free(ln); 4156 return tn; 4157 } 4158 4159 /* 4160 * Check types of all function arguments and insert conversions, 4161 * if necessary. 4162 */ 4163 static bool 4164 check_function_arguments(const function_call *call) 4165 { 4166 type_t *ftp = call->func->tn_type->t_subt; 4167 4168 /* get # of parameters in the prototype */ 4169 int npar = 0; 4170 for (const sym_t *p = ftp->t_params; p != NULL; p = p->s_next) 4171 npar++; 4172 4173 int narg = (int)call->args_len; 4174 4175 const sym_t *param = ftp->t_params; 4176 if (ftp->t_proto && npar != narg && !(ftp->t_vararg && npar < narg)) { 4177 /* argument mismatch: %d %s passed, %d expected */ 4178 error(150, narg, narg != 1 ? "arguments" : "argument", npar); 4179 param = NULL; 4180 } 4181 4182 for (int n = 1; n <= narg; n++) { 4183 tnode_t *arg = call->args[n - 1]; 4184 4185 /* some things which are always not allowed */ 4186 tspec_t at = arg->tn_type->t_tspec; 4187 if (at == VOID) { 4188 /* void expressions may not be arguments, arg #%d */ 4189 error(151, n); 4190 return false; 4191 } 4192 if (is_struct_or_union(at) && 4193 is_incomplete(arg->tn_type)) { 4194 /* argument cannot have unknown size, arg #%d */ 4195 error(152, n); 4196 return false; 4197 } 4198 if (is_integer(at) && 4199 arg->tn_type->t_is_enum && 4200 is_incomplete(arg->tn_type)) { 4201 /* argument cannot have unknown size, arg #%d */ 4202 warning(152, n); 4203 } 4204 4205 arg = cconv(arg); 4206 call->args[n - 1] = arg; 4207 4208 arg = param != NULL 4209 ? check_prototype_argument(n, param->s_type, arg) 4210 : promote(NOOP, true, arg); 4211 call->args[n - 1] = arg; 4212 4213 if (param != NULL) 4214 param = param->s_next; 4215 } 4216 4217 return true; 4218 } 4219 4220 tnode_t * 4221 build_function_call(tnode_t *func, bool sys, function_call *call) 4222 { 4223 4224 if (func == NULL) 4225 return NULL; 4226 4227 op_t fcop = func->tn_op == NAME && func->tn_type->t_tspec == FUNC 4228 ? CALL : ICALL; 4229 4230 call->func = func; 4231 check_ctype_function_call(call); 4232 4233 func = cconv(func); 4234 call->func = func; 4235 4236 if (func->tn_type->t_tspec != PTR || 4237 func->tn_type->t_subt->t_tspec != FUNC) { 4238 /* cannot call '%s', must be a function */ 4239 error(149, type_name(func->tn_type)); 4240 return NULL; 4241 } 4242 4243 if (!check_function_arguments(call)) 4244 call->args = NULL; 4245 4246 tnode_t *ntn = expr_alloc_tnode(); 4247 ntn->tn_op = fcop; 4248 ntn->tn_type = func->tn_type->t_subt->t_subt; 4249 ntn->tn_sys = sys; 4250 ntn->tn_call = call; 4251 return ntn; 4252 } 4253 4254 /* 4255 * Return the value of an integral constant expression. 4256 * If the expression is not constant or its type is not an integer 4257 * type, an error message is printed. 4258 */ 4259 val_t * 4260 integer_constant(tnode_t *tn, bool required) 4261 { 4262 4263 if (tn != NULL) 4264 tn = cconv(tn); 4265 if (tn != NULL) 4266 tn = promote(NOOP, false, tn); 4267 4268 val_t *v = xcalloc(1, sizeof(*v)); 4269 4270 if (tn == NULL) { 4271 lint_assert(seen_error); 4272 debug_step("constant node is null; returning 1 instead"); 4273 v->v_tspec = INT; 4274 v->u.integer = 1; 4275 return v; 4276 } 4277 4278 v->v_tspec = tn->tn_type->t_tspec; 4279 4280 if (tn->tn_op == CON) { 4281 lint_assert(tn->tn_type->t_tspec == tn->tn_val.v_tspec); 4282 if (is_integer(tn->tn_val.v_tspec)) { 4283 v->v_unsigned_since_c90 = 4284 tn->tn_val.v_unsigned_since_c90; 4285 v->u.integer = tn->tn_val.u.integer; 4286 return v; 4287 } 4288 v->u.integer = (int64_t)tn->tn_val.u.floating; 4289 } else { 4290 v->u.integer = 1; 4291 } 4292 4293 if (required) 4294 /* integral constant expression expected */ 4295 error(55); 4296 else 4297 /* variable array dimension is a C99/GCC extension */ 4298 c99ism(318); 4299 4300 if (!is_integer(v->v_tspec)) 4301 v->v_tspec = INT; 4302 4303 return v; 4304 } 4305 4306 static bool 4307 is_constcond_false(const tnode_t *tn, tspec_t t) 4308 { 4309 return (t == BOOL || t == INT) && 4310 tn->tn_op == CON && tn->tn_val.u.integer == 0; 4311 } 4312 4313 /* 4314 * Perform some tests on expressions which can't be done in build_binary() 4315 * and functions called by build_binary(). These tests must be done here 4316 * because we need some information about the context in which the operations 4317 * are performed. 4318 * After all tests are performed and dofreeblk is true, expr() frees the 4319 * memory which is used for the expression. 4320 */ 4321 void 4322 expr(tnode_t *tn, bool vctx, bool cond, bool dofreeblk, bool is_do_while) 4323 { 4324 4325 if (tn == NULL) { /* in case of errors */ 4326 expr_free_all(); 4327 return; 4328 } 4329 4330 /* expr() is also called in global initializations */ 4331 if (dcs->d_kind != DLK_EXTERN && !is_do_while) 4332 check_statement_reachable(); 4333 4334 check_expr_misc(tn, vctx, cond, !cond, false, false, false); 4335 if (tn->tn_op == ASSIGN && !tn->tn_parenthesized) { 4336 if (hflag && cond) 4337 /* assignment in conditional context */ 4338 warning(159); 4339 } else if (tn->tn_op == CON) { 4340 if (hflag && cond && !suppress_constcond && 4341 !tn->tn_system_dependent && 4342 !(is_do_while && 4343 is_constcond_false(tn, tn->tn_type->t_tspec))) 4344 /* constant in conditional context */ 4345 warning(161); 4346 } 4347 if (!modtab[tn->tn_op].m_has_side_effect) { 4348 /* 4349 * for left operands of COMMA this warning is already printed 4350 */ 4351 if (tn->tn_op != COMMA && !vctx && !cond) 4352 check_null_effect(tn); 4353 } 4354 debug_node(tn); 4355 4356 if (dofreeblk) 4357 expr_free_all(); 4358 } 4359 4360 /* 4361 * Checks the range of array indices, if possible. 4362 * amper is set if only the address of the element is used. This 4363 * means that the index is allowed to refer to the first element 4364 * after the array. 4365 */ 4366 static void 4367 check_array_index(tnode_t *tn, bool amper) 4368 { 4369 lint_assert(has_operands(tn)); 4370 const tnode_t *ln = tn->tn_left; 4371 const tnode_t *rn = tn->tn_right; 4372 4373 /* We can only check constant indices. */ 4374 if (rn->tn_op != CON) 4375 return; 4376 4377 /* Return if the left node does not stem from an array. */ 4378 if (ln->tn_op != ADDR) 4379 return; 4380 if (ln->tn_left->tn_op != STRING && ln->tn_left->tn_op != NAME) 4381 return; 4382 if (ln->tn_left->tn_type->t_tspec != ARRAY) 4383 return; 4384 4385 /* 4386 * For incomplete array types, we can print a warning only if the index 4387 * is negative. 4388 */ 4389 if (is_incomplete(ln->tn_left->tn_type) && rn->tn_val.u.integer >= 0) 4390 return; 4391 4392 int elsz = length_in_bits(ln->tn_type->t_subt, NULL); 4393 if (elsz == 0) 4394 return; 4395 elsz /= CHAR_SIZE; 4396 4397 /* Change the unit of the index from bytes to element size. */ 4398 int64_t con = is_uinteger(rn->tn_type->t_tspec) 4399 ? (int64_t)((uint64_t)rn->tn_val.u.integer / elsz) 4400 : rn->tn_val.u.integer / elsz; 4401 4402 int dim = ln->tn_left->tn_type->t_dim + (amper ? 1 : 0); 4403 4404 if (!is_uinteger(rn->tn_type->t_tspec) && con < 0) { 4405 /* array subscript cannot be negative: %ld */ 4406 warning(167, (long)con); 4407 } else if (dim > 0 && (uint64_t)con >= (uint64_t)dim) { 4408 /* array subscript cannot be > %d: %ld */ 4409 warning(168, dim - 1, (long)con); 4410 } 4411 } 4412 4413 static void 4414 check_expr_addr(const tnode_t *ln, bool szof, bool fcall) 4415 { 4416 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 4417 if (ln->tn_op == NAME && (reached || !warn_about_unreachable)) { 4418 if (!szof) 4419 mark_as_set(ln->tn_sym); 4420 mark_as_used(ln->tn_sym, fcall, szof); 4421 } 4422 if (ln->tn_op == INDIR && ln->tn_left->tn_op == PLUS) 4423 check_array_index(ln->tn_left, true); 4424 } 4425 4426 static void 4427 check_expr_load(const tnode_t *ln) 4428 { 4429 if (ln->tn_op == INDIR && ln->tn_left->tn_op == PLUS) 4430 check_array_index(ln->tn_left, false); 4431 } 4432 4433 /* 4434 * If there is an asm statement in one of the compound statements around, 4435 * there may be other side effects, so don't warn. 4436 */ 4437 static bool 4438 is_asm_around(void) 4439 { 4440 for (decl_level *dl = dcs; dl != NULL; dl = dl->d_enclosing) 4441 if (dl->d_asm) 4442 return true; 4443 return false; 4444 } 4445 4446 static void 4447 check_expr_side_effect(const tnode_t *ln, bool szof) 4448 { 4449 4450 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 4451 if (ln->tn_op == NAME && (reached || !warn_about_unreachable)) { 4452 scl_t sc = ln->tn_sym->s_scl; 4453 if (sc != EXTERN && sc != STATIC && 4454 !ln->tn_sym->s_set && !szof && !is_asm_around()) { 4455 /* '%s' may be used before set */ 4456 warning(158, ln->tn_sym->s_name); 4457 mark_as_set(ln->tn_sym); 4458 } 4459 mark_as_used(ln->tn_sym, false, false); 4460 } 4461 } 4462 4463 static void 4464 check_expr_assign(const tnode_t *ln, bool szof) 4465 { 4466 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 4467 if (ln->tn_op == NAME && !szof && (reached || !warn_about_unreachable)) { 4468 mark_as_set(ln->tn_sym); 4469 if (ln->tn_sym->s_scl == EXTERN) 4470 outusg(ln->tn_sym); 4471 } 4472 if (ln->tn_op == INDIR && ln->tn_left->tn_op == PLUS) 4473 /* check the range of array indices */ 4474 check_array_index(ln->tn_left, false); 4475 } 4476 4477 static void 4478 check_expr_call(const tnode_t *tn, const tnode_t *ln, 4479 bool szof, bool vctx, bool cond, bool retval_discarded) 4480 { 4481 lint_assert(ln->tn_op == ADDR); 4482 lint_assert(ln->tn_left->tn_op == NAME); 4483 if (!szof && !is_compiler_builtin(ln->tn_left->tn_sym->s_name)) 4484 outcall(tn, vctx || cond, retval_discarded); 4485 } 4486 4487 static void 4488 check_expr_op(op_t op, const tnode_t *ln, bool szof, bool fcall, bool eqwarn) 4489 { 4490 switch (op) { 4491 case ADDR: 4492 check_expr_addr(ln, szof, fcall); 4493 break; 4494 case LOAD: 4495 check_expr_load(ln); 4496 /* FALLTHROUGH */ 4497 case INCBEF: 4498 case DECBEF: 4499 case INCAFT: 4500 case DECAFT: 4501 case ADDASS: 4502 case SUBASS: 4503 case MULASS: 4504 case DIVASS: 4505 case MODASS: 4506 case ANDASS: 4507 case ORASS: 4508 case XORASS: 4509 case SHLASS: 4510 case SHRASS: 4511 case REAL: 4512 case IMAG: 4513 check_expr_side_effect(ln, szof); 4514 break; 4515 case ASSIGN: 4516 check_expr_assign(ln, szof); 4517 break; 4518 case EQ: 4519 if (hflag && eqwarn) 4520 /* operator '==' found where '=' was expected */ 4521 warning(160); 4522 break; 4523 default: 4524 break; 4525 } 4526 } 4527 4528 /* 4529 * vctx ??? 4530 * cond whether the expression is a condition that 4531 * will be compared with 0 4532 * eqwarn whether the operator '==' might be a 4533 * misspelled '=' 4534 * fcall whether the expression is a function call 4535 * retval_discarded whether the return value of a function call 4536 * is discarded; such calls will be analyzed by 4537 * lint2 in messages 4, 8 and 9 4538 * szof whether the expression is part of a sizeof 4539 * expression, which means that its value is 4540 * discarded since only the type is relevant 4541 */ 4542 void 4543 check_expr_misc(const tnode_t *tn, bool vctx, bool cond, 4544 bool eqwarn, bool fcall, bool retval_discarded, bool szof) 4545 { 4546 4547 if (tn == NULL) 4548 return; 4549 op_t op = tn->tn_op; 4550 if (op == NAME || op == CON || op == STRING) 4551 return; 4552 if (op == CALL || op == ICALL) { 4553 const function_call *call = tn->tn_call; 4554 if (op == CALL) 4555 check_expr_call(tn, call->func, 4556 szof, vctx, cond, retval_discarded); 4557 bool discard = op == CVT && tn->tn_type->t_tspec == VOID; 4558 check_expr_misc(call->func, false, false, false, op == CALL, 4559 discard, szof); 4560 if (call->args != NULL) { 4561 for (size_t i = 0, n = call->args_len; i < n; i++) 4562 check_expr_misc(call->args[i], 4563 false, false, false, false, false, szof); 4564 } 4565 return; 4566 } 4567 4568 lint_assert(has_operands(tn)); 4569 tnode_t *ln = tn->tn_left; 4570 tnode_t *rn = tn->tn_right; 4571 check_expr_op(op, ln, szof, fcall, eqwarn); 4572 4573 const mod_t *mp = &modtab[op]; 4574 bool cvctx = mp->m_value_context; 4575 bool ccond = mp->m_compares_with_zero; 4576 bool eq = mp->m_warn_if_operand_eq && 4577 !ln->tn_parenthesized && 4578 rn != NULL && !rn->tn_parenthesized; 4579 4580 /* 4581 * Values of operands of ':' are not used if the type of at least 4582 * one of the operands (for GCC compatibility) is 'void'. 4583 * 4584 * XXX test/value context of QUEST should probably be used as 4585 * context for both operands of COLON. 4586 */ 4587 if (op == COLON && tn->tn_type->t_tspec == VOID) 4588 cvctx = ccond = false; 4589 bool discard = op == CVT && tn->tn_type->t_tspec == VOID; 4590 check_expr_misc(ln, cvctx, ccond, eq, op == CALL, discard, szof); 4591 4592 switch (op) { 4593 case LOGAND: 4594 case LOGOR: 4595 check_expr_misc(rn, false, true, eq, false, false, szof); 4596 break; 4597 case COLON: 4598 check_expr_misc(rn, cvctx, ccond, eq, false, false, szof); 4599 break; 4600 case COMMA: 4601 check_expr_misc(rn, vctx, cond, false, false, false, szof); 4602 break; 4603 default: 4604 if (mp->m_binary) 4605 check_expr_misc(rn, true, false, eq, false, false, 4606 szof); 4607 break; 4608 } 4609 } 4610 4611 /* 4612 * Return whether the expression can be used for static initialization. 4613 * 4614 * Constant initialization expressions must be constant or an address 4615 * of a static object with an optional offset. In the first case, 4616 * the result is returned in *offsp. In the second case, the static 4617 * object is returned in *symp and the offset in *offsp. 4618 * 4619 * The expression can consist of PLUS, MINUS, ADDR, NAME, STRING and 4620 * CON. Type conversions are allowed if they do not change binary 4621 * representation (including width). 4622 * 4623 * C99 6.6 "Constant expressions" 4624 * C99 6.7.8p4 restricts initializers for static storage duration 4625 */ 4626 bool 4627 constant_addr(const tnode_t *tn, const sym_t **symp, ptrdiff_t *offsp) 4628 { 4629 const sym_t *sym; 4630 ptrdiff_t offs1, offs2; 4631 tspec_t t, ot; 4632 4633 switch (tn->tn_op) { 4634 case MINUS: 4635 if (tn->tn_right->tn_op == CVT) 4636 return constant_addr(tn->tn_right, symp, offsp); 4637 else if (tn->tn_right->tn_op != CON) 4638 return false; 4639 /* FALLTHROUGH */ 4640 case PLUS: 4641 offs1 = offs2 = 0; 4642 if (tn->tn_left->tn_op == CON) { 4643 offs1 = (ptrdiff_t)tn->tn_left->tn_val.u.integer; 4644 if (!constant_addr(tn->tn_right, &sym, &offs2)) 4645 return false; 4646 } else if (tn->tn_right->tn_op == CON) { 4647 offs2 = (ptrdiff_t)tn->tn_right->tn_val.u.integer; 4648 if (tn->tn_op == MINUS) 4649 offs2 = -offs2; 4650 if (!constant_addr(tn->tn_left, &sym, &offs1)) 4651 return false; 4652 } else { 4653 return false; 4654 } 4655 *symp = sym; 4656 *offsp = offs1 + offs2; 4657 return true; 4658 case ADDR: 4659 if (tn->tn_left->tn_op == NAME) { 4660 *symp = tn->tn_left->tn_sym; 4661 *offsp = 0; 4662 return true; 4663 } else { 4664 /* 4665 * If this were the front end of a compiler, we would 4666 * return a label instead of 0, at least if 4667 * 'tn->tn_left->tn_op == STRING'. 4668 */ 4669 *symp = NULL; 4670 *offsp = 0; 4671 return true; 4672 } 4673 case CVT: 4674 t = tn->tn_type->t_tspec; 4675 ot = tn->tn_left->tn_type->t_tspec; 4676 if ((!is_integer(t) && t != PTR) || 4677 (!is_integer(ot) && ot != PTR)) { 4678 return false; 4679 } 4680 #if 0 4681 /*- 4682 * consider: 4683 * struct foo { 4684 * unsigned char a; 4685 * } f = { 4686 * (unsigned char)(unsigned long) 4687 * (&(((struct foo *)0)->a)) 4688 * }; 4689 * since psize(unsigned long) != psize(unsigned char), 4690 * this fails. 4691 */ 4692 else if (psize(t) != psize(ot)) 4693 return -1; 4694 #endif 4695 return constant_addr(tn->tn_left, symp, offsp); 4696 default: 4697 return false; 4698 } 4699 } 4700 4701 /* Append s2 to s1, then free s2. */ 4702 buffer * 4703 cat_strings(buffer *s1, buffer *s2) 4704 { 4705 4706 if ((s1->data != NULL) != (s2->data != NULL)) { 4707 /* cannot concatenate wide and regular string literals */ 4708 error(292); 4709 return s1; 4710 } 4711 4712 if (s1->data != NULL) { 4713 while (s1->len + s2->len + 1 > s1->cap) 4714 s1->cap *= 2; 4715 s1->data = xrealloc(s1->data, s1->cap); 4716 memcpy(s1->data + s1->len, s2->data, s2->len + 1); 4717 free(s2->data); 4718 } 4719 s1->len += s2->len; 4720 free(s2); 4721 4722 return s1; 4723 } 4724 4725 4726 typedef struct stmt_expr { 4727 memory_pool se_mem; 4728 sym_t *se_sym; 4729 struct stmt_expr *se_enclosing; 4730 } stmt_expr; 4731 4732 static stmt_expr *stmt_exprs; 4733 4734 void 4735 begin_statement_expr(void) 4736 { 4737 debug_enter(); 4738 4739 stmt_expr *se = xmalloc(sizeof(*se)); 4740 se->se_mem = expr_save_memory(); 4741 se->se_sym = NULL; 4742 se->se_enclosing = stmt_exprs; 4743 stmt_exprs = se; 4744 } 4745 4746 void 4747 do_statement_expr(tnode_t *tn) 4748 { 4749 block_level--; 4750 mem_block_level--; 4751 stmt_exprs->se_sym = tn != NULL 4752 ? mktempsym(block_dup_type(tn->tn_type)) 4753 : NULL; /* after a syntax error */ 4754 mem_block_level++; 4755 block_level++; 4756 /* '({ ... })' is a GCC extension */ 4757 gnuism(320); 4758 } 4759 4760 tnode_t * 4761 end_statement_expr(void) 4762 { 4763 tnode_t *tn; 4764 4765 stmt_expr *se = stmt_exprs; 4766 if (se->se_sym == NULL) { 4767 tn = NULL; /* after a syntax error */ 4768 goto end; 4769 } 4770 4771 tn = build_name(se->se_sym, false); 4772 (void)expr_save_memory(); /* leak */ 4773 expr_restore_memory(se->se_mem); 4774 stmt_exprs = se->se_enclosing; 4775 free(se); 4776 4777 end: 4778 debug_leave(); 4779 return tn; 4780 } 4781 4782 bool 4783 in_statement_expr(void) 4784 { 4785 return stmt_exprs != NULL; 4786 } 4787
Indexes created Wed Sep 24 05:09:52 GMT 2025