tree.c revision 1.590
1 /* $NetBSD: tree.c,v 1.590 2024/01/07 12:20:42 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 1.590 2024/01/07 12:20:42 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 (block_level > 0 && 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 == FVFT || sym->s_kind == FMEMBER); 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 == FVFT && sym->s_type->t_tspec != FUNC) 518 n->tn_lvalue = true; 519 } 520 521 return n; 522 } 523 524 tnode_t * 525 build_string(strg_t *strg) 526 { 527 size_t len = strg->st_len; 528 529 type_t *tp = expr_zero_alloc(sizeof(*tp), "type"); 530 tp->t_tspec = ARRAY; 531 tp->t_subt = gettyp(strg->st_char ? CHAR : WCHAR_TSPEC); 532 tp->t_dim = (int)(len + 1); 533 534 tnode_t *n = expr_alloc_tnode(); 535 n->tn_op = STRING; 536 n->tn_type = tp; 537 n->tn_lvalue = true; 538 539 n->tn_string = expr_zero_alloc(sizeof(*n->tn_string), "tnode.string"); 540 n->tn_string->st_char = strg->st_char; 541 n->tn_string->st_len = len; 542 543 size_t chsize = strg->st_char ? sizeof(char) : sizeof(wchar_t); 544 size_t size = (len + 1) * chsize; 545 n->tn_string->st_mem = expr_zero_alloc(size, "tnode.string.data"); 546 (void)memcpy(n->tn_string->st_mem, strg->st_mem, size); 547 free(strg->st_mem); 548 free(strg); 549 550 return n; 551 } 552 553 tnode_t * 554 build_generic_selection(const tnode_t *expr, 555 struct generic_association *sel) 556 { 557 tnode_t *default_result = NULL; 558 559 for (; sel != NULL; sel = sel->ga_prev) { 560 if (expr != NULL && 561 types_compatible(sel->ga_arg, expr->tn_type, 562 false, false, NULL)) 563 return sel->ga_result; 564 else if (sel->ga_arg == NULL) 565 default_result = sel->ga_result; 566 } 567 return default_result; 568 } 569 570 static bool 571 is_out_of_char_range(const tnode_t *tn) 572 { 573 return tn->tn_op == CON && 574 !tn->tn_val.v_char_constant && 575 !(0 <= tn->tn_val.u.integer && 576 tn->tn_val.u.integer < 1 << (CHAR_SIZE - 1)); 577 } 578 579 static bool 580 check_nonportable_char_comparison(op_t op, 581 const tnode_t *ln, tspec_t lt, 582 const tnode_t *rn, tspec_t rt) 583 { 584 if (!(hflag || pflag)) 585 return true; 586 587 if (lt == CHAR && is_out_of_char_range(rn)) { 588 char buf[128]; 589 (void)snprintf(buf, sizeof(buf), "%s %d", 590 op_name(op), (int)rn->tn_val.u.integer); 591 /* nonportable character comparison '%s' */ 592 warning(230, buf); 593 return false; 594 } 595 if (rt == CHAR && is_out_of_char_range(ln)) { 596 char buf[128]; 597 (void)snprintf(buf, sizeof(buf), "%d %s ?", 598 (int)ln->tn_val.u.integer, op_name(op)); 599 /* nonportable character comparison '%s' */ 600 warning(230, buf); 601 return false; 602 } 603 return true; 604 } 605 606 static void 607 check_integer_comparison(op_t op, tnode_t *ln, tnode_t *rn) 608 { 609 610 tspec_t lt = ln->tn_type->t_tspec; 611 tspec_t rt = rn->tn_type->t_tspec; 612 613 if (ln->tn_op != CON && rn->tn_op != CON) 614 return; 615 616 if (!is_integer(lt) || !is_integer(rt)) 617 return; 618 619 if (any_query_enabled && !in_system_header) { 620 if (lt == CHAR && rn->tn_op == CON && 621 !rn->tn_val.v_char_constant) { 622 /* comparison '%s' of 'char' with plain integer %d */ 623 query_message(14, 624 op_name(op), (int)rn->tn_val.u.integer); 625 } 626 if (rt == CHAR && ln->tn_op == CON && 627 !ln->tn_val.v_char_constant) { 628 /* comparison '%s' of 'char' with plain integer %d */ 629 query_message(14, 630 op_name(op), (int)ln->tn_val.u.integer); 631 } 632 } 633 634 if (!check_nonportable_char_comparison(op, ln, lt, rn, rt)) 635 return; 636 637 if (is_uinteger(lt) && !is_uinteger(rt) && 638 rn->tn_op == CON && rn->tn_val.u.integer <= 0) { 639 if (rn->tn_val.u.integer < 0) { 640 /* operator '%s' compares '%s' with '%s' */ 641 warning(162, op_name(op), 642 type_name(ln->tn_type), "negative constant"); 643 } else if (op == LT || op == GE) { 644 /* operator '%s' compares '%s' with '%s' */ 645 warning(162, op_name(op), type_name(ln->tn_type), "0"); 646 } 647 return; 648 } 649 if (is_uinteger(rt) && !is_uinteger(lt) && 650 ln->tn_op == CON && ln->tn_val.u.integer <= 0) { 651 if (ln->tn_val.u.integer < 0) { 652 /* operator '%s' compares '%s' with '%s' */ 653 warning(162, op_name(op), 654 "negative constant", type_name(rn->tn_type)); 655 } else if (op == GT || op == LE) { 656 /* operator '%s' compares '%s' with '%s' */ 657 warning(162, op_name(op), "0", type_name(rn->tn_type)); 658 } 659 return; 660 } 661 } 662 663 static const tspec_t arith_rank[] = { 664 LDOUBLE, DOUBLE, FLOAT, 665 #ifdef INT128_SIZE 666 UINT128, INT128, 667 #endif 668 ULLONG, LLONG, 669 ULONG, LONG, 670 UINT, INT, 671 }; 672 673 /* Keep unsigned in traditional C */ 674 static tspec_t 675 usual_arithmetic_conversion_trad(tspec_t lt, tspec_t rt) 676 { 677 678 size_t i; 679 for (i = 0; arith_rank[i] != INT; i++) 680 if (lt == arith_rank[i] || rt == arith_rank[i]) 681 break; 682 683 tspec_t t = arith_rank[i]; 684 if (is_uinteger(lt) || is_uinteger(rt)) 685 if (is_integer(t) && !is_uinteger(t)) 686 return unsigned_type(t); 687 return t; 688 } 689 690 static tspec_t 691 usual_arithmetic_conversion_c90(tspec_t lt, tspec_t rt) 692 { 693 694 if (lt == rt) 695 return lt; 696 697 if (lt == LCOMPLEX || rt == LCOMPLEX) 698 return LCOMPLEX; 699 if (lt == DCOMPLEX || rt == DCOMPLEX) 700 return DCOMPLEX; 701 if (lt == FCOMPLEX || rt == FCOMPLEX) 702 return FCOMPLEX; 703 if (lt == LDOUBLE || rt == LDOUBLE) 704 return LDOUBLE; 705 if (lt == DOUBLE || rt == DOUBLE) 706 return DOUBLE; 707 if (lt == FLOAT || rt == FLOAT) 708 return FLOAT; 709 710 if (size_in_bits(lt) > size_in_bits(rt)) 711 return lt; 712 if (size_in_bits(lt) < size_in_bits(rt)) 713 return rt; 714 715 size_t i; 716 for (i = 3; arith_rank[i] != INT; i++) 717 if (arith_rank[i] == lt || arith_rank[i] == rt) 718 break; 719 if ((is_uinteger(lt) || is_uinteger(rt)) && 720 !is_uinteger(arith_rank[i])) 721 i--; 722 return arith_rank[i]; 723 } 724 725 static tnode_t * 726 apply_usual_arithmetic_conversions(op_t op, tnode_t *tn, tspec_t t) 727 { 728 type_t *ntp = expr_dup_type(tn->tn_type); 729 ntp->t_tspec = t; 730 if (tn->tn_op != CON) { 731 /* usual arithmetic conversion for '%s' from '%s' to '%s' */ 732 query_message(4, op_name(op), 733 type_name(tn->tn_type), type_name(ntp)); 734 } 735 return convert(op, 0, ntp, tn); 736 } 737 738 /* 739 * Apply the "usual arithmetic conversions" (C99 6.3.1.8), which gives both 740 * operands the same type. 741 */ 742 static void 743 balance(op_t op, tnode_t **lnp, tnode_t **rnp) 744 { 745 746 tspec_t lt = (*lnp)->tn_type->t_tspec; 747 tspec_t rt = (*rnp)->tn_type->t_tspec; 748 if (!is_arithmetic(lt) || !is_arithmetic(rt)) 749 return; 750 751 tspec_t t = allow_c90 752 ? usual_arithmetic_conversion_c90(lt, rt) 753 : usual_arithmetic_conversion_trad(lt, rt); 754 755 if (t != lt) 756 *lnp = apply_usual_arithmetic_conversions(op, *lnp, t); 757 if (t != rt) 758 *rnp = apply_usual_arithmetic_conversions(op, *rnp, t); 759 } 760 761 static tnode_t * 762 build_address(bool sys, tnode_t *tn, bool force) 763 { 764 tspec_t t; 765 766 if (!force && ((t = tn->tn_type->t_tspec) == ARRAY || t == FUNC)) { 767 if (!allow_c90) 768 /* '&' before array or function: ignored */ 769 warning(127); 770 return tn; 771 } 772 773 /* eliminate '&*' */ 774 if (tn->tn_op == INDIR && 775 tn->tn_left->tn_type->t_tspec == PTR && 776 tn->tn_left->tn_type->t_subt == tn->tn_type) { 777 return tn->tn_left; 778 } 779 780 return build_op(ADDR, sys, expr_derive_type(tn->tn_type, PTR), 781 tn, NULL); 782 } 783 784 /* 785 * XXX 786 * Note: There appear to be a number of bugs in detecting overflow in 787 * this function. An audit and a set of proper regression tests are needed. 788 * --Perry Metzger, Nov. 16, 2001 789 */ 790 static tnode_t * 791 fold_constant_integer(tnode_t *tn) 792 { 793 794 val_t *v = xcalloc(1, sizeof(*v)); 795 v->v_tspec = tn->tn_type->t_tspec; 796 797 lint_assert(has_operands(tn)); 798 tspec_t t = tn->tn_left->tn_type->t_tspec; 799 bool utyp = !is_integer(t) || is_uinteger(t); 800 int64_t sl = tn->tn_left->tn_val.u.integer, sr = 0; 801 uint64_t ul = sl, ur = 0; 802 if (is_binary(tn)) 803 ur = sr = tn->tn_right->tn_val.u.integer; 804 805 int64_t mask = (int64_t)value_bits(size_in_bits(t)); 806 bool ovfl = false; 807 808 int64_t si; 809 switch (tn->tn_op) { 810 case UPLUS: 811 si = sl; 812 break; 813 case UMINUS: 814 si = sl == INT64_MIN ? sl : -sl; 815 if (sl != 0 && msb(si, t) == msb(sl, t)) 816 ovfl = true; 817 break; 818 case COMPL: 819 si = ~sl; 820 break; 821 case MULT: 822 if (utyp) { 823 si = (int64_t)(ul * ur); 824 if (si != (si & mask)) 825 ovfl = true; 826 else if (ul != 0 && si / ul != ur) 827 ovfl = true; 828 } else { 829 si = sl * sr; 830 if (msb(si, t) != (msb(sl, t) ^ msb(sr, t))) 831 ovfl = true; 832 } 833 break; 834 case DIV: 835 if (sr == 0) { 836 /* division by 0 */ 837 error(139); 838 si = utyp ? -1 : INT64_MAX; 839 } else { 840 si = utyp ? (int64_t)(ul / ur) : sl / sr; 841 } 842 break; 843 case MOD: 844 if (sr == 0) { 845 /* modulus by 0 */ 846 error(140); 847 si = 0; 848 } else { 849 si = utyp ? (int64_t)(ul % ur) : sl % sr; 850 } 851 break; 852 case PLUS: 853 si = utyp ? (int64_t)(ul + ur) : sl + sr; 854 if (msb(sl, t) && msb(sr, t) && !msb(si, t)) 855 ovfl = true; 856 if (!utyp && !msb(sl, t) && !msb(sr, t) && msb(si, t)) 857 ovfl = true; 858 break; 859 case MINUS: 860 si = utyp ? (int64_t)(ul - ur) : sl - sr; 861 if (!utyp && msb(sl, t) && !msb(sr, t) && !msb(si, t)) 862 ovfl = true; 863 if (!msb(sl, t) && msb(sr, t) && msb(si, t)) 864 ovfl = true; 865 break; 866 case SHL: 867 /* TODO: warn about out-of-bounds 'sr'. */ 868 /* TODO: warn about overflow in signed '<<'. */ 869 si = utyp ? (int64_t)(ul << (sr & 63)) : sl << (sr & 63); 870 break; 871 case SHR: 872 /* 873 * The sign must be explicitly extended because shifts of 874 * signed values are implementation dependent. 875 */ 876 /* TODO: warn about out-of-bounds 'sr'. */ 877 si = (int64_t)(ul >> (sr & 63)); 878 si = convert_integer(si, t, size_in_bits(t) - (int)sr); 879 break; 880 case LT: 881 si = (utyp ? ul < ur : sl < sr) ? 1 : 0; 882 break; 883 case LE: 884 si = (utyp ? ul <= ur : sl <= sr) ? 1 : 0; 885 break; 886 case GE: 887 si = (utyp ? ul >= ur : sl >= sr) ? 1 : 0; 888 break; 889 case GT: 890 si = (utyp ? ul > ur : sl > sr) ? 1 : 0; 891 break; 892 case EQ: 893 si = (utyp ? ul == ur : sl == sr) ? 1 : 0; 894 break; 895 case NE: 896 si = (utyp ? ul != ur : sl != sr) ? 1 : 0; 897 break; 898 case BITAND: 899 si = utyp ? (int64_t)(ul & ur) : sl & sr; 900 break; 901 case BITXOR: 902 si = utyp ? (int64_t)(ul ^ ur) : sl ^ sr; 903 break; 904 case BITOR: 905 si = utyp ? (int64_t)(ul | ur) : sl | sr; 906 break; 907 default: 908 lint_assert(/*CONSTCOND*/false); 909 } 910 911 /* XXX: The overflow check does not work for 64-bit integers. */ 912 if (ovfl || 913 ((uint64_t)(si | mask) != ~(uint64_t)0 && (si & ~mask) != 0)) { 914 if (hflag) 915 /* operator '%s' produces integer overflow */ 916 warning(141, op_name(tn->tn_op)); 917 } 918 919 v->u.integer = convert_integer(si, t, 0); 920 921 tnode_t *cn = build_constant(tn->tn_type, v); 922 if (tn->tn_left->tn_system_dependent) 923 cn->tn_system_dependent = true; 924 if (is_binary(tn) && tn->tn_right->tn_system_dependent) 925 cn->tn_system_dependent = true; 926 927 return cn; 928 } 929 930 static tnode_t * 931 build_struct_access(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 932 { 933 934 lint_assert(rn->tn_op == NAME); 935 lint_assert(is_member(rn->tn_sym)); 936 937 bool lvalue = op == ARROW || ln->tn_lvalue; 938 939 if (op == POINT) { 940 ln = build_address(sys, ln, true); 941 } else if (ln->tn_type->t_tspec != PTR) { 942 lint_assert(!allow_c90); 943 lint_assert(is_integer(ln->tn_type->t_tspec)); 944 ln = convert(NOOP, 0, expr_derive_type(gettyp(VOID), PTR), ln); 945 } 946 947 tnode_t *ctn = build_integer_constant(PTRDIFF_TSPEC, 948 rn->tn_sym->u.s_member.sm_offset_in_bits / CHAR_SIZE); 949 950 type_t *ptr_tp = expr_derive_type(rn->tn_type, PTR); 951 tnode_t *ntn = build_op(PLUS, sys, ptr_tp, ln, ctn); 952 if (ln->tn_op == CON) 953 ntn = fold_constant_integer(ntn); 954 955 op_t nop = rn->tn_type->t_bitfield ? FSEL : INDIR; 956 ntn = build_op(nop, sys, ntn->tn_type->t_subt, ntn, NULL); 957 if (!lvalue) 958 ntn->tn_lvalue = false; 959 960 return ntn; 961 } 962 963 /* 964 * Get the size in bytes of type tp->t_subt, as a constant expression of type 965 * ptrdiff_t as seen from the target platform. 966 */ 967 static tnode_t * 968 subt_size_in_bytes(type_t *tp) 969 { 970 971 lint_assert(tp->t_tspec == PTR); 972 tp = tp->t_subt; 973 974 int elem = 1; 975 while (tp->t_tspec == ARRAY) { 976 elem *= tp->t_dim; 977 tp = tp->t_subt; 978 } 979 980 int elsz_in_bits = 0; 981 switch (tp->t_tspec) { 982 case FUNC: 983 /* pointer to function is not allowed here */ 984 error(110); 985 break; 986 case VOID: 987 /* cannot do pointer arithmetic on operand of unknown size */ 988 gnuism(136); 989 break; 990 case STRUCT: 991 case UNION: 992 if ((elsz_in_bits = (int)tp->t_sou->sou_size_in_bits) == 0) 993 /* cannot do pointer arithmetic on operand of ... */ 994 error(136); 995 break; 996 case ENUM: 997 if (is_incomplete(tp)) { 998 /* cannot do pointer arithmetic on operand of ... */ 999 warning(136); 1000 } 1001 /* FALLTHROUGH */ 1002 default: 1003 if ((elsz_in_bits = size_in_bits(tp->t_tspec)) == 0) { 1004 /* cannot do pointer arithmetic on operand of ... */ 1005 error(136); 1006 } else { 1007 lint_assert(elsz_in_bits != -1); 1008 } 1009 break; 1010 } 1011 1012 if (elem == 0 && elsz_in_bits != 0) { 1013 /* cannot do pointer arithmetic on operand of unknown size */ 1014 error(136); 1015 } 1016 1017 if (elsz_in_bits == 0) 1018 elsz_in_bits = CHAR_SIZE; 1019 1020 return build_integer_constant(PTRDIFF_TSPEC, 1021 (int64_t)(elem * elsz_in_bits / CHAR_SIZE)); 1022 } 1023 1024 static tnode_t * 1025 build_prepost_incdec(op_t op, bool sys, tnode_t *ln) 1026 { 1027 1028 lint_assert(ln != NULL); 1029 tnode_t *cn = ln->tn_type->t_tspec == PTR 1030 ? subt_size_in_bytes(ln->tn_type) 1031 : build_integer_constant(INT, 1); 1032 return build_op(op, sys, ln->tn_type, ln, cn); 1033 } 1034 1035 static void 1036 check_enum_array_index(const tnode_t *ln, const tnode_t *rn) 1037 { 1038 1039 if (ln->tn_op != ADDR || ln->tn_left->tn_op != NAME) 1040 return; 1041 1042 const type_t *ltp = ln->tn_left->tn_type; 1043 if (ltp->t_tspec != ARRAY || ltp->t_incomplete_array) 1044 return; 1045 1046 if (rn->tn_op != CVT || !rn->tn_type->t_is_enum) 1047 return; 1048 if (rn->tn_left->tn_op != LOAD) 1049 return; 1050 1051 const type_t *rtp = rn->tn_left->tn_type; 1052 const sym_t *ec = rtp->t_enum->en_first_enumerator; 1053 const sym_t *max_ec = ec; 1054 lint_assert(ec != NULL); 1055 for (ec = ec->s_next; ec != NULL; ec = ec->s_next) 1056 if (ec->u.s_enum_constant > max_ec->u.s_enum_constant) 1057 max_ec = ec; 1058 1059 int64_t max_enum_value = max_ec->u.s_enum_constant; 1060 lint_assert(INT_MIN <= max_enum_value && max_enum_value <= INT_MAX); 1061 1062 int max_array_index = ltp->t_dim - 1; 1063 if (max_enum_value == max_array_index) 1064 return; 1065 1066 if (max_enum_value == max_array_index + 1 && 1067 (strstr(max_ec->s_name, "MAX") != NULL || 1068 strstr(max_ec->s_name, "max") != NULL || 1069 strstr(max_ec->s_name, "NUM") != NULL || 1070 strstr(max_ec->s_name, "num") != NULL)) 1071 return; 1072 1073 /* maximum value %d of '%s' does not match maximum array index %d */ 1074 warning(348, (int)max_enum_value, type_name(rtp), max_array_index); 1075 print_previous_declaration(max_ec); 1076 } 1077 1078 static tnode_t * 1079 build_plus_minus(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 1080 { 1081 1082 if (rn->tn_type->t_tspec == PTR && is_integer(ln->tn_type->t_tspec)) { 1083 tnode_t *tmp = ln; 1084 ln = rn; 1085 rn = tmp; 1086 /* pointer addition has integer on the left-hand side */ 1087 query_message(5); 1088 } 1089 1090 /* pointer +- integer */ 1091 if (ln->tn_type->t_tspec == PTR && rn->tn_type->t_tspec != PTR) { 1092 lint_assert(is_integer(rn->tn_type->t_tspec)); 1093 1094 check_ctype_macro_invocation(ln, rn); 1095 check_enum_array_index(ln, rn); 1096 1097 tnode_t *elsz = subt_size_in_bytes(ln->tn_type); 1098 if (rn->tn_type->t_tspec != elsz->tn_type->t_tspec) 1099 rn = convert(NOOP, 0, elsz->tn_type, rn); 1100 1101 tnode_t *prod = build_op(MULT, sys, rn->tn_type, rn, elsz); 1102 if (rn->tn_op == CON) 1103 prod = fold_constant_integer(prod); 1104 1105 return build_op(op, sys, ln->tn_type, ln, prod); 1106 } 1107 1108 /* pointer - pointer */ 1109 if (rn->tn_type->t_tspec == PTR) { 1110 lint_assert(ln->tn_type->t_tspec == PTR); 1111 lint_assert(op == MINUS); 1112 1113 type_t *ptrdiff = gettyp(PTRDIFF_TSPEC); 1114 tnode_t *raw_diff = build_op(op, sys, ptrdiff, ln, rn); 1115 if (ln->tn_op == CON && rn->tn_op == CON) 1116 raw_diff = fold_constant_integer(raw_diff); 1117 1118 tnode_t *elsz = subt_size_in_bytes(ln->tn_type); 1119 balance(NOOP, &raw_diff, &elsz); 1120 1121 return build_op(DIV, sys, ptrdiff, raw_diff, elsz); 1122 } 1123 1124 return build_op(op, sys, ln->tn_type, ln, rn); 1125 } 1126 1127 static tnode_t * 1128 build_bit_shift(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 1129 { 1130 1131 if (!allow_c90 && rn->tn_type->t_tspec != INT) 1132 // XXX: C1978 7.5 says: "Both [operators] perform the usual 1133 // arithmetic conversions on their operands." 1134 // TODO: Add a test to exercise this part of the code. 1135 rn = convert(NOOP, 0, gettyp(INT), rn); 1136 return build_op(op, sys, ln->tn_type, ln, rn); 1137 } 1138 1139 static bool 1140 is_null_pointer(const tnode_t *tn) 1141 { 1142 tspec_t t = tn->tn_type->t_tspec; 1143 1144 // TODO: Investigate how other pointers are stored, in particular, 1145 // whether a pointer constant can have a non-zero value. 1146 // If not, simplify the code below. 1147 return ((t == PTR && tn->tn_type->t_subt->t_tspec == VOID) 1148 || is_integer(t)) 1149 && (tn->tn_op == CON && tn->tn_val.u.integer == 0); 1150 } 1151 1152 /* Return a type based on tp1, with added qualifiers from tp2. */ 1153 static type_t * 1154 merge_qualifiers(type_t *tp1, const type_t *tp2) 1155 { 1156 1157 lint_assert(tp1->t_tspec == PTR); 1158 lint_assert(tp2->t_tspec == PTR); 1159 1160 bool c1 = tp1->t_subt->t_const; 1161 bool c2 = tp2->t_subt->t_const; 1162 bool v1 = tp1->t_subt->t_volatile; 1163 bool v2 = tp2->t_subt->t_volatile; 1164 1165 if (c1 == (c1 | c2) && v1 == (v1 | v2)) 1166 return tp1; 1167 1168 type_t *nstp = expr_dup_type(tp1->t_subt); 1169 nstp->t_const |= c2; 1170 nstp->t_volatile |= v2; 1171 1172 type_t *ntp = expr_dup_type(tp1); 1173 ntp->t_subt = nstp; 1174 return ntp; 1175 } 1176 1177 /* See C99 6.5.15 "Conditional operator". */ 1178 static tnode_t * 1179 build_colon(bool sys, tnode_t *ln, tnode_t *rn) 1180 { 1181 tspec_t lt = ln->tn_type->t_tspec; 1182 tspec_t rt = rn->tn_type->t_tspec; 1183 1184 type_t *tp; 1185 if (is_arithmetic(lt) && is_arithmetic(rt)) { 1186 /* The operands were already balanced in build_binary. */ 1187 tp = ln->tn_type; 1188 } else if (lt == BOOL && rt == BOOL) { 1189 tp = ln->tn_type; 1190 } else if (lt == VOID || rt == VOID) { 1191 tp = gettyp(VOID); 1192 } else if (is_struct_or_union(lt)) { 1193 lint_assert(is_struct_or_union(rt)); 1194 lint_assert(ln->tn_type->t_sou == rn->tn_type->t_sou); 1195 if (is_incomplete(ln->tn_type)) { 1196 /* unknown operand size, op '%s' */ 1197 error(138, op_name(COLON)); 1198 return NULL; 1199 } 1200 tp = ln->tn_type; 1201 } else if (lt == PTR && is_integer(rt)) { 1202 if (rt != PTRDIFF_TSPEC) 1203 rn = convert(NOOP, 0, gettyp(PTRDIFF_TSPEC), rn); 1204 tp = ln->tn_type; 1205 } else if (rt == PTR && is_integer(lt)) { 1206 if (lt != PTRDIFF_TSPEC) 1207 ln = convert(NOOP, 0, gettyp(PTRDIFF_TSPEC), ln); 1208 tp = rn->tn_type; 1209 } else if (lt == PTR && is_null_pointer(rn)) { 1210 tp = merge_qualifiers(ln->tn_type, rn->tn_type); 1211 } else if (rt == PTR && is_null_pointer(ln)) { 1212 tp = merge_qualifiers(rn->tn_type, ln->tn_type); 1213 } else if (lt == PTR && ln->tn_type->t_subt->t_tspec == VOID) { 1214 tp = merge_qualifiers(ln->tn_type, rn->tn_type); 1215 } else if (rt == PTR && rn->tn_type->t_subt->t_tspec == VOID) { 1216 tp = merge_qualifiers(rn->tn_type, ln->tn_type); 1217 } else { 1218 /* 1219 * XXX For now we simply take the left type. This is probably 1220 * wrong, if one type contains a function prototype and the 1221 * other one, at the same place, only an old-style declaration. 1222 */ 1223 tp = merge_qualifiers(ln->tn_type, rn->tn_type); 1224 } 1225 1226 return build_op(COLON, sys, tp, ln, rn); 1227 } 1228 1229 /* TODO: check for varargs */ 1230 static bool 1231 is_cast_redundant(const tnode_t *tn) 1232 { 1233 const type_t *ntp = tn->tn_type, *otp = tn_ck_left(tn)->tn_type; 1234 tspec_t nt = ntp->t_tspec, ot = otp->t_tspec; 1235 1236 if (nt == BOOL || ot == BOOL) 1237 return nt == BOOL && ot == BOOL; 1238 1239 if (is_integer(nt) && is_integer(ot)) { 1240 unsigned int nw = width_in_bits(ntp), ow = width_in_bits(otp); 1241 if (is_uinteger(nt) == is_uinteger(ot)) 1242 return nw >= ow; 1243 return is_uinteger(ot) && nw > ow; 1244 } 1245 1246 if (is_complex(nt) || is_complex(ot)) 1247 return is_complex(nt) && is_complex(ot) && 1248 size_in_bits(nt) >= size_in_bits(ot); 1249 1250 if (is_floating(nt) && is_floating(ot)) 1251 return size_in_bits(nt) >= size_in_bits(ot); 1252 1253 if (nt == PTR && ot == PTR) { 1254 if (!ntp->t_subt->t_const && otp->t_subt->t_const) 1255 return false; 1256 if (!ntp->t_subt->t_volatile && otp->t_subt->t_volatile) 1257 return false; 1258 1259 if (ntp->t_subt->t_tspec == VOID || 1260 otp->t_subt->t_tspec == VOID || 1261 types_compatible(ntp->t_subt, otp->t_subt, 1262 false, false, NULL)) 1263 return true; 1264 } 1265 1266 return false; 1267 } 1268 1269 static bool 1270 is_assignment(op_t op) 1271 { 1272 1273 return op == ASSIGN || 1274 op == MULASS || 1275 op == DIVASS || 1276 op == MODASS || 1277 op == ADDASS || 1278 op == SUBASS || 1279 op == SHLASS || 1280 op == SHRASS || 1281 op == ANDASS || 1282 op == XORASS || 1283 op == ORASS || 1284 op == RETURN || 1285 op == INIT; 1286 } 1287 1288 static tnode_t * 1289 build_assignment(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 1290 { 1291 1292 tspec_t lt = ln->tn_type->t_tspec; 1293 tspec_t rt = rn->tn_type->t_tspec; 1294 1295 if (any_query_enabled && is_assignment(rn->tn_op)) { 1296 /* chained assignment with '%s' and '%s' */ 1297 query_message(10, op_name(op), op_name(rn->tn_op)); 1298 } 1299 1300 if ((op == ADDASS || op == SUBASS) && lt == PTR) { 1301 lint_assert(is_integer(rt)); 1302 tnode_t *ctn = subt_size_in_bytes(ln->tn_type); 1303 if (rn->tn_type->t_tspec != ctn->tn_type->t_tspec) 1304 rn = convert(NOOP, 0, ctn->tn_type, rn); 1305 rn = build_op(MULT, sys, rn->tn_type, rn, ctn); 1306 if (rn->tn_left->tn_op == CON) 1307 rn = fold_constant_integer(rn); 1308 } 1309 1310 if ((op == ASSIGN || op == RETURN || op == INIT) && 1311 (lt == STRUCT || rt == STRUCT)) { 1312 lint_assert(lt == rt); 1313 lint_assert(ln->tn_type->t_sou == rn->tn_type->t_sou); 1314 if (is_incomplete(ln->tn_type)) { 1315 if (op == RETURN) { 1316 /* cannot return incomplete type */ 1317 error(212); 1318 } else { 1319 /* unknown operand size, op '%s' */ 1320 error(138, op_name(op)); 1321 } 1322 return NULL; 1323 } 1324 } 1325 1326 if (op == SHLASS && hflag && allow_trad && allow_c90 1327 && portable_rank_cmp(lt, rt) < 0) 1328 /* semantics of '%s' change in C90; ... */ 1329 warning(118, "<<="); 1330 1331 if (op != SHLASS && op != SHRASS 1332 && (op == ASSIGN || lt != PTR) 1333 && (lt != rt || (ln->tn_type->t_bitfield && rn->tn_op == CON))) { 1334 rn = convert(op, 0, ln->tn_type, rn); 1335 rt = lt; 1336 } 1337 1338 if (any_query_enabled && rn->tn_op == CVT && rn->tn_cast && 1339 types_compatible(ln->tn_type, rn->tn_type, false, false, NULL) && 1340 is_cast_redundant(rn)) { 1341 /* redundant cast from '%s' to '%s' before assignment */ 1342 query_message(7, 1343 type_name(rn->tn_left->tn_type), type_name(rn->tn_type)); 1344 } 1345 1346 return build_op(op, sys, ln->tn_type, ln, rn); 1347 } 1348 1349 static tnode_t * 1350 build_real_imag(op_t op, bool sys, tnode_t *ln) 1351 { 1352 1353 lint_assert(ln != NULL); 1354 if (ln->tn_op == NAME) { 1355 /* 1356 * This may be too much, but it avoids wrong warnings. See 1357 * d_c99_complex_split.c. 1358 */ 1359 mark_as_used(ln->tn_sym, false, false); 1360 mark_as_set(ln->tn_sym); 1361 } 1362 1363 tspec_t t; 1364 switch (ln->tn_type->t_tspec) { 1365 case LCOMPLEX: 1366 t = LDOUBLE; 1367 break; 1368 case DCOMPLEX: 1369 t = DOUBLE; 1370 break; 1371 case FCOMPLEX: 1372 t = FLOAT; 1373 break; 1374 default: 1375 /* '__%s__' is illegal for type '%s' */ 1376 error(276, op == REAL ? "real" : "imag", 1377 type_name(ln->tn_type)); 1378 return NULL; 1379 } 1380 1381 tnode_t *ntn = build_op(op, sys, gettyp(t), ln, NULL); 1382 ntn->tn_lvalue = true; 1383 return ntn; 1384 } 1385 1386 static bool 1387 is_confusing_precedence(op_t op, op_t lop, bool lparen, op_t rop, bool rparen) 1388 { 1389 1390 if (op == SHL || op == SHR) { 1391 if (!lparen && (lop == PLUS || lop == MINUS)) 1392 return true; 1393 if (!rparen && (rop == PLUS || rop == MINUS)) 1394 return true; 1395 return false; 1396 } 1397 1398 if (op == LOGOR) { 1399 if (!lparen && lop == LOGAND) 1400 return true; 1401 if (!rparen && rop == LOGAND) 1402 return true; 1403 return false; 1404 } 1405 1406 lint_assert(op == BITAND || op == BITXOR || op == BITOR); 1407 if (!lparen && lop != op) { 1408 if (lop == PLUS || lop == MINUS) 1409 return true; 1410 if (lop == BITAND || lop == BITXOR) 1411 return true; 1412 } 1413 if (!rparen && rop != op) { 1414 if (rop == PLUS || rop == MINUS) 1415 return true; 1416 if (rop == BITAND || rop == BITXOR) 1417 return true; 1418 } 1419 return false; 1420 } 1421 1422 /* 1423 * Print a warning if the given node has operands which should be 1424 * parenthesized. 1425 * 1426 * XXX Does not work if an operand is a constant expression. Constant 1427 * expressions are already folded. 1428 */ 1429 static void 1430 check_precedence_confusion(tnode_t *tn) 1431 { 1432 tnode_t *ln, *rn; 1433 1434 if (!hflag) 1435 return; 1436 1437 debug_node(tn); 1438 1439 lint_assert(is_binary(tn)); 1440 for (ln = tn->tn_left; ln->tn_op == CVT; ln = ln->tn_left) 1441 continue; 1442 for (rn = tn->tn_right; rn->tn_op == CVT; rn = rn->tn_left) 1443 continue; 1444 1445 if (is_confusing_precedence(tn->tn_op, 1446 ln->tn_op, ln->tn_parenthesized, 1447 rn->tn_op, rn->tn_parenthesized)) { 1448 /* precedence confusion possible: parenthesize! */ 1449 warning(169); 1450 } 1451 } 1452 1453 static tnode_t * 1454 fold_constant_compare_zero(tnode_t *tn) 1455 { 1456 1457 val_t *v = xcalloc(1, sizeof(*v)); 1458 v->v_tspec = tn->tn_type->t_tspec; 1459 lint_assert(v->v_tspec == INT || (Tflag && v->v_tspec == BOOL)); 1460 1461 lint_assert(has_operands(tn)); 1462 bool l = constant_is_nonzero(tn->tn_left); 1463 bool r = is_binary(tn) && constant_is_nonzero(tn->tn_right); 1464 1465 switch (tn->tn_op) { 1466 case NOT: 1467 if (hflag && !suppress_constcond) 1468 /* constant operand to '!' */ 1469 warning(239); 1470 v->u.integer = !l ? 1 : 0; 1471 break; 1472 case LOGAND: 1473 v->u.integer = l && r ? 1 : 0; 1474 break; 1475 case LOGOR: 1476 v->u.integer = l || r ? 1 : 0; 1477 break; 1478 default: 1479 lint_assert(/*CONSTCOND*/false); 1480 } 1481 1482 return build_constant(tn->tn_type, v); 1483 } 1484 1485 static long double 1486 floating_error_value(tspec_t t, long double lv) 1487 { 1488 if (t == FLOAT) 1489 return lv < 0 ? -FLT_MAX : FLT_MAX; 1490 if (t == DOUBLE) 1491 return lv < 0 ? -DBL_MAX : DBL_MAX; 1492 /* 1493 * When NetBSD is cross-built in MKLINT=yes mode on x86_64 for sparc64, 1494 * tools/lint checks this code while building usr.bin/xlint. In that 1495 * situation, lint uses the preprocessor for sparc64, in which the type 1496 * 'long double' is IEEE-754-binary128, affecting the macro LDBL_MAX 1497 * below. The type 'long double', as well as the strtold 1498 * implementation, comes from the host platform x86_64 though, where 1499 * 'long double' consumes 128 bits as well but only uses 80 of them. 1500 * The exponent range of the two 'long double' types is the same, but 1501 * the maximum finite value differs due to the extended precision on 1502 * sparc64. 1503 * 1504 * To properly handle the data types of the target platform, lint would 1505 * have to implement the floating-point types in a platform-independent 1506 * way, which is not worth the effort, given how few programs 1507 * practically use 'long double'. 1508 */ 1509 /* LINTED 248: floating-point constant out of range */ 1510 long double max = LDBL_MAX; 1511 return lv < 0 ? -max : max; 1512 } 1513 1514 static bool 1515 is_floating_overflow(tspec_t t, long double val) 1516 { 1517 if (fpe != 0 || isfinite(val) == 0) 1518 return true; 1519 if (t == FLOAT && (val > FLT_MAX || val < -FLT_MAX)) 1520 return true; 1521 if (t == DOUBLE && (val > DBL_MAX || val < -DBL_MAX)) 1522 return true; 1523 return false; 1524 } 1525 1526 static tnode_t * 1527 fold_constant_floating(tnode_t *tn) 1528 { 1529 1530 fpe = 0; 1531 1532 tspec_t t = tn->tn_type->t_tspec; 1533 1534 val_t *v = xcalloc(1, sizeof(*v)); 1535 v->v_tspec = t; 1536 1537 lint_assert(is_floating(t)); 1538 lint_assert(has_operands(tn)); 1539 lint_assert(t == tn->tn_left->tn_type->t_tspec); 1540 lint_assert(!is_binary(tn) || t == tn->tn_right->tn_type->t_tspec); 1541 1542 long double lv = tn->tn_left->tn_val.u.floating; 1543 long double rv = is_binary(tn) ? tn->tn_right->tn_val.u.floating : 0.0; 1544 1545 switch (tn->tn_op) { 1546 case UPLUS: 1547 v->u.floating = lv; 1548 break; 1549 case UMINUS: 1550 v->u.floating = -lv; 1551 break; 1552 case MULT: 1553 v->u.floating = lv * rv; 1554 break; 1555 case DIV: 1556 if (rv == 0.0) { 1557 /* division by 0 */ 1558 error(139); 1559 v->u.floating = floating_error_value(t, lv); 1560 } else { 1561 v->u.floating = lv / rv; 1562 } 1563 break; 1564 case PLUS: 1565 v->u.floating = lv + rv; 1566 break; 1567 case MINUS: 1568 v->u.floating = lv - rv; 1569 break; 1570 case LT: 1571 v->u.integer = lv < rv ? 1 : 0; 1572 break; 1573 case LE: 1574 v->u.integer = lv <= rv ? 1 : 0; 1575 break; 1576 case GE: 1577 v->u.integer = lv >= rv ? 1 : 0; 1578 break; 1579 case GT: 1580 v->u.integer = lv > rv ? 1 : 0; 1581 break; 1582 case EQ: 1583 v->u.integer = lv == rv ? 1 : 0; 1584 break; 1585 case NE: 1586 v->u.integer = lv != rv ? 1 : 0; 1587 break; 1588 default: 1589 lint_assert(/*CONSTCOND*/false); 1590 } 1591 1592 // XXX: Must not access u.floating after setting u.integer. 1593 lint_assert(fpe != 0 || isnan(v->u.floating) == 0); 1594 if (is_complex(v->v_tspec)) { 1595 /* 1596 * Don't warn, as lint doesn't model the imaginary part of 1597 * complex numbers. 1598 */ 1599 fpe = 0; 1600 } else if (is_floating_overflow(t, v->u.floating)) { 1601 /* operator '%s' produces floating point overflow */ 1602 warning(142, op_name(tn->tn_op)); 1603 v->u.floating = floating_error_value(t, v->u.floating); 1604 fpe = 0; 1605 } 1606 1607 return build_constant(tn->tn_type, v); 1608 } 1609 1610 static void 1611 use(const tnode_t *tn) 1612 { 1613 if (tn == NULL) 1614 return; 1615 switch (tn->tn_op) { 1616 case NAME: 1617 mark_as_used(tn->tn_sym, false /* XXX */, false /* XXX */); 1618 break; 1619 case CON: 1620 case STRING: 1621 break; 1622 default: 1623 lint_assert(has_operands(tn)); 1624 use(tn->tn_left); 1625 if (is_binary(tn) || tn->tn_op == PUSH) 1626 use(tn->tn_right); 1627 } 1628 } 1629 1630 /* 1631 * Create a tree node for a binary operator and its two operands. Also called 1632 * for unary operators; in that case rn is NULL. 1633 * 1634 * Function calls, sizeof and casts are handled elsewhere. 1635 */ 1636 tnode_t * 1637 build_binary(tnode_t *ln, op_t op, bool sys, tnode_t *rn) 1638 { 1639 const mod_t *mp = &modtab[op]; 1640 1641 /* If there was an error in one of the operands, return. */ 1642 if (ln == NULL || (mp->m_binary && rn == NULL)) 1643 return NULL; 1644 1645 if (mp->m_value_context || mp->m_compares_with_zero) 1646 ln = cconv(ln); 1647 if (mp->m_binary && op != ARROW && op != POINT) 1648 rn = cconv(rn); 1649 1650 if (mp->m_comparison) 1651 check_integer_comparison(op, ln, rn); 1652 1653 if (mp->m_value_context || mp->m_compares_with_zero) 1654 ln = promote(op, false, ln); 1655 if (mp->m_binary && op != ARROW && op != POINT && 1656 op != ASSIGN && op != RETURN && op != INIT) 1657 rn = promote(op, false, rn); 1658 1659 if (mp->m_warn_if_left_unsigned_in_c90 && 1660 ln->tn_op == CON && ln->tn_val.v_unsigned_since_c90) { 1661 /* C90 treats constant as unsigned, op '%s' */ 1662 warning(218, op_name(op)); 1663 ln->tn_val.v_unsigned_since_c90 = false; 1664 } 1665 if (mp->m_warn_if_right_unsigned_in_c90 && 1666 rn->tn_op == CON && rn->tn_val.v_unsigned_since_c90) { 1667 /* C90 treats constant as unsigned, op '%s' */ 1668 warning(218, op_name(op)); 1669 rn->tn_val.v_unsigned_since_c90 = false; 1670 } 1671 1672 if (mp->m_balance_operands || (!allow_c90 && (op == SHL || op == SHR))) 1673 balance(op, &ln, &rn); 1674 1675 if (!typeok(op, 0, ln, rn)) 1676 return NULL; 1677 1678 tnode_t *ntn; 1679 switch (op) { 1680 case POINT: 1681 case ARROW: 1682 ntn = build_struct_access(op, sys, ln, rn); 1683 break; 1684 case INCAFT: 1685 case DECAFT: 1686 case INCBEF: 1687 case DECBEF: 1688 ntn = build_prepost_incdec(op, sys, ln); 1689 break; 1690 case ADDR: 1691 ntn = build_address(sys, ln, false); 1692 break; 1693 case INDIR: 1694 ntn = build_op(INDIR, sys, ln->tn_type->t_subt, ln, NULL); 1695 break; 1696 case PLUS: 1697 case MINUS: 1698 ntn = build_plus_minus(op, sys, ln, rn); 1699 break; 1700 case SHL: 1701 case SHR: 1702 ntn = build_bit_shift(op, sys, ln, rn); 1703 break; 1704 case COLON: 1705 ntn = build_colon(sys, ln, rn); 1706 break; 1707 case ASSIGN: 1708 case MULASS: 1709 case DIVASS: 1710 case MODASS: 1711 case ADDASS: 1712 case SUBASS: 1713 case SHLASS: 1714 case SHRASS: 1715 case ANDASS: 1716 case XORASS: 1717 case ORASS: 1718 case RETURN: 1719 case INIT: 1720 ntn = build_assignment(op, sys, ln, rn); 1721 break; 1722 case COMMA: 1723 if (any_query_enabled) { 1724 /* comma operator with types '%s' and '%s' */ 1725 query_message(12, 1726 type_name(ln->tn_type), type_name(rn->tn_type)); 1727 } 1728 /* FALLTHROUGH */ 1729 case QUEST: 1730 ntn = build_op(op, sys, rn->tn_type, ln, rn); 1731 break; 1732 case REAL: 1733 case IMAG: 1734 ntn = build_real_imag(op, sys, ln); 1735 break; 1736 default: 1737 lint_assert(mp->m_binary == (rn != NULL)); 1738 type_t *rettp = mp->m_returns_bool 1739 ? gettyp(Tflag ? BOOL : INT) : ln->tn_type; 1740 ntn = build_op(op, sys, rettp, ln, rn); 1741 break; 1742 } 1743 1744 if (ntn == NULL) 1745 return NULL; 1746 1747 if (mp->m_possible_precedence_confusion) 1748 check_precedence_confusion(ntn); 1749 1750 if (hflag && !suppress_constcond && 1751 mp->m_compares_with_zero && 1752 (ln->tn_op == CON || 1753 (mp->m_binary && op != QUEST && rn->tn_op == CON)) && 1754 /* XXX: rn->tn_system_dependent should be checked as well */ 1755 !ln->tn_system_dependent) { 1756 /* constant in conditional context */ 1757 warning(161); 1758 } 1759 1760 if (mp->m_fold_constant_operands && ln->tn_op == CON) { 1761 if (!mp->m_binary || rn->tn_op == CON) { 1762 if (mp->m_compares_with_zero) 1763 ntn = fold_constant_compare_zero(ntn); 1764 else if (is_floating(ntn->tn_type->t_tspec)) 1765 ntn = fold_constant_floating(ntn); 1766 else 1767 ntn = fold_constant_integer(ntn); 1768 } else if (op == QUEST) { 1769 lint_assert(has_operands(rn)); 1770 use(ln->tn_val.u.integer != 0 1771 ? rn->tn_right : rn->tn_left); 1772 ntn = ln->tn_val.u.integer != 0 1773 ? rn->tn_left : rn->tn_right; 1774 } 1775 } 1776 1777 return ntn; 1778 } 1779 1780 tnode_t * 1781 build_unary(op_t op, bool sys, tnode_t *tn) 1782 { 1783 return build_binary(tn, op, sys, NULL); 1784 } 1785 1786 static bool 1787 are_members_compatible(const sym_t *a, const sym_t *b) 1788 { 1789 if (a->u.s_member.sm_offset_in_bits != b->u.s_member.sm_offset_in_bits) 1790 return false; 1791 1792 const type_t *atp = a->s_type; 1793 const type_t *btp = b->s_type; 1794 bool w = false; 1795 if (!types_compatible(atp, btp, false, false, &w) && !w) 1796 return false; 1797 if (a->s_bitfield != b->s_bitfield) 1798 return false; 1799 if (a->s_bitfield) { 1800 if (atp->t_bit_field_width != btp->t_bit_field_width) 1801 return false; 1802 if (atp->t_bit_field_offset != btp->t_bit_field_offset) 1803 return false; 1804 } 1805 return true; 1806 } 1807 1808 /* 1809 * Return whether all struct/union members with the same name have the same 1810 * type and offset. 1811 */ 1812 static bool 1813 all_members_compatible(const sym_t *msym) 1814 { 1815 for (const sym_t *csym = msym; 1816 csym != NULL; csym = csym->s_symtab_next) { 1817 if (!is_member(csym)) 1818 continue; 1819 if (strcmp(msym->s_name, csym->s_name) != 0) 1820 continue; 1821 1822 for (const sym_t *sym = csym->s_symtab_next; 1823 sym != NULL; sym = sym->s_symtab_next) { 1824 if (is_member(sym) 1825 && strcmp(csym->s_name, sym->s_name) == 0 1826 && !are_members_compatible(csym, sym)) 1827 return false; 1828 } 1829 } 1830 return true; 1831 } 1832 1833 sym_t * 1834 find_member(const struct_or_union *sou, const char *name) 1835 { 1836 for (sym_t *mem = sou->sou_first_member; 1837 mem != NULL; mem = mem->s_next) { 1838 lint_assert(is_member(mem)); 1839 lint_assert(mem->u.s_member.sm_containing_type == sou); 1840 if (strcmp(mem->s_name, name) == 0) 1841 return mem; 1842 } 1843 1844 for (sym_t *mem = sou->sou_first_member; 1845 mem != NULL; mem = mem->s_next) { 1846 if (is_struct_or_union(mem->s_type->t_tspec) 1847 && mem->s_name == unnamed) { 1848 sym_t *nested_mem = 1849 find_member(mem->s_type->t_sou, name); 1850 if (nested_mem != NULL) 1851 return nested_mem; 1852 } 1853 } 1854 return NULL; 1855 } 1856 1857 /* 1858 * Remove the member if it was unknown until now, which means 1859 * that no defined struct or union has a member with the same name. 1860 */ 1861 static void 1862 remove_unknown_member(tnode_t *tn, sym_t *msym) 1863 { 1864 /* type '%s' does not have member '%s' */ 1865 error(101, type_name(tn->tn_type), msym->s_name); 1866 rmsym(msym); 1867 msym->s_kind = FMEMBER; 1868 msym->s_scl = STRUCT_MEMBER; 1869 1870 struct_or_union *sou = expr_zero_alloc(sizeof(*sou), 1871 "struct_or_union"); 1872 sou->sou_tag = expr_zero_alloc(sizeof(*sou->sou_tag), "sym"); 1873 sou->sou_tag->s_name = unnamed; 1874 1875 msym->u.s_member.sm_containing_type = sou; 1876 /* 1877 * The member sm_offset_in_bits is not needed here since this symbol 1878 * can only be used for error reporting. 1879 */ 1880 } 1881 1882 /* 1883 * Returns a symbol which has the same name as 'msym' and is a member of the 1884 * struct or union specified by 'tn'. 1885 */ 1886 static sym_t * 1887 struct_or_union_member(tnode_t *tn, op_t op, sym_t *msym) 1888 { 1889 1890 /* Determine the tag type of which msym is expected to be a member. */ 1891 const type_t *tp = NULL; 1892 if (op == POINT && is_struct_or_union(tn->tn_type->t_tspec)) 1893 tp = tn->tn_type; 1894 if (op == ARROW && tn->tn_type->t_tspec == PTR 1895 && is_struct_or_union(tn->tn_type->t_subt->t_tspec)) 1896 tp = tn->tn_type->t_subt; 1897 struct_or_union *sou = tp != NULL ? tp->t_sou : NULL; 1898 1899 if (sou != NULL) { 1900 sym_t *nested_mem = find_member(sou, msym->s_name); 1901 if (nested_mem != NULL) 1902 return nested_mem; 1903 } 1904 1905 if (msym->s_scl == NO_SCL) { 1906 remove_unknown_member(tn, msym); 1907 return msym; 1908 } 1909 1910 bool eq = all_members_compatible(msym); 1911 1912 /* 1913 * Now handle the case in which the left operand refers really to a 1914 * struct/union, but the right operand is not member of it. 1915 */ 1916 if (sou != NULL) { 1917 if (eq && !allow_c90) { 1918 /* illegal use of member '%s' */ 1919 warning(102, msym->s_name); 1920 } else { 1921 /* illegal use of member '%s' */ 1922 error(102, msym->s_name); 1923 } 1924 return msym; 1925 } 1926 1927 if (eq) { 1928 if (op == POINT) { 1929 if (!allow_c90) { 1930 /* left operand of '.' must be struct ... */ 1931 warning(103, type_name(tn->tn_type)); 1932 } else { 1933 /* left operand of '.' must be struct ... */ 1934 error(103, type_name(tn->tn_type)); 1935 } 1936 } else { 1937 if (!allow_c90 && tn->tn_type->t_tspec == PTR) { 1938 /* left operand of '->' must be pointer ... */ 1939 warning(104, type_name(tn->tn_type)); 1940 } else { 1941 /* left operand of '->' must be pointer ... */ 1942 error(104, type_name(tn->tn_type)); 1943 } 1944 } 1945 } else { 1946 if (!allow_c90) { 1947 /* non-unique member requires struct/union %s */ 1948 error(105, op == POINT ? "object" : "pointer"); 1949 } else { 1950 /* unacceptable operand of '%s' */ 1951 error(111, op_name(op)); 1952 } 1953 } 1954 1955 return msym; 1956 } 1957 1958 tnode_t * 1959 build_member_access(tnode_t *ln, op_t op, bool sys, sbuf_t *member) 1960 { 1961 sym_t *msym; 1962 1963 if (ln == NULL) 1964 return NULL; 1965 1966 if (op == ARROW) { 1967 /* must do this before struct_or_union_member is called */ 1968 ln = cconv(ln); 1969 } 1970 msym = struct_or_union_member(ln, op, getsym(member)); 1971 return build_binary(ln, op, sys, build_name(msym, false)); 1972 } 1973 1974 /* 1975 * Perform class conversions. 1976 * 1977 * Arrays of type T are converted into pointers to type T. 1978 * Functions are converted to pointers to functions. 1979 * Lvalues are converted to rvalues. 1980 * 1981 * C99 6.3 "Conversions" 1982 * C99 6.3.2 "Other operands" 1983 * C99 6.3.2.1 "Lvalues, arrays, and function designators" 1984 */ 1985 tnode_t * 1986 cconv(tnode_t *tn) 1987 { 1988 if (tn->tn_type->t_tspec == ARRAY) { 1989 if (!tn->tn_lvalue) { 1990 /* XXX print correct operator */ 1991 /* %soperand of '%s' must be lvalue */ 1992 gnuism(114, "", op_name(ADDR)); 1993 } 1994 tn = build_op(ADDR, tn->tn_sys, 1995 expr_derive_type(tn->tn_type->t_subt, PTR), tn, NULL); 1996 } 1997 1998 if (tn->tn_type->t_tspec == FUNC) 1999 tn = build_address(tn->tn_sys, tn, true); 2000 2001 if (tn->tn_lvalue) { 2002 type_t *tp = expr_dup_type(tn->tn_type); 2003 /* C99 6.3.2.1p2 sentence 2 says to remove the qualifiers. */ 2004 tp->t_const = tp->t_volatile = false; 2005 tn = build_op(LOAD, tn->tn_sys, tp, tn, NULL); 2006 } 2007 2008 return tn; 2009 } 2010 2011 const tnode_t * 2012 before_conversion(const tnode_t *tn) 2013 { 2014 while (tn->tn_op == CVT && !tn->tn_cast) 2015 tn = tn->tn_left; 2016 return tn; 2017 } 2018 2019 /* 2020 * Most errors required by C90 are reported in struct_or_union_member(). 2021 * Here we only check for totally wrong things. 2022 */ 2023 static bool 2024 typeok_point(const tnode_t *ln, const type_t *ltp, tspec_t lt) 2025 { 2026 if (is_struct_or_union(lt)) 2027 return true; 2028 2029 if (lt == FUNC || lt == VOID || ltp->t_bitfield) 2030 goto wrong; 2031 2032 /* 2033 * Some C dialects from before C90 tolerated any lvalue on the 2034 * left-hand side of the '.' operator, allowing things like 'char 2035 * st[100]; st.st_mtime', assuming that the member 'st_mtime' only 2036 * occurred in a single struct; see typeok_arrow. 2037 */ 2038 if (ln->tn_lvalue) 2039 return true; 2040 2041 wrong: 2042 /* With allow_c90 we already got an error */ 2043 if (!allow_c90) 2044 /* unacceptable operand of '%s' */ 2045 error(111, op_name(POINT)); 2046 2047 return false; 2048 } 2049 2050 static bool 2051 typeok_arrow(tspec_t lt) 2052 { 2053 /* 2054 * C1978 Appendix A 14.1 says: <quote>In fact, any lvalue is allowed 2055 * before '.', and that lvalue is then assumed to have the form of the 2056 * structure of which the name of the right is a member. [...] Such 2057 * constructions are non-portable.</quote> 2058 */ 2059 if (lt == PTR || (!allow_c90 && is_integer(lt))) 2060 return true; 2061 2062 /* With allow_c90 we already got an error */ 2063 if (!allow_c90) 2064 /* unacceptable operand of '%s' */ 2065 error(111, op_name(ARROW)); 2066 return false; 2067 } 2068 2069 static bool 2070 typeok_incdec(op_t op, const tnode_t *tn, const type_t *tp) 2071 { 2072 /* operand has scalar type (checked in typeok) */ 2073 if (!tn->tn_lvalue) { 2074 if (tn->tn_op == CVT && tn->tn_cast && 2075 tn->tn_left->tn_op == LOAD) { 2076 /* a cast does not yield an lvalue */ 2077 error(163); 2078 } 2079 /* %soperand of '%s' must be lvalue */ 2080 error(114, "", op_name(op)); 2081 return false; 2082 } 2083 if (tp->t_const && allow_c90) { 2084 /* %soperand of '%s' must be modifiable lvalue */ 2085 warning(115, "", op_name(op)); 2086 } 2087 return true; 2088 } 2089 2090 static bool 2091 typeok_address(op_t op, const tnode_t *tn, const type_t *tp, tspec_t t) 2092 { 2093 if (t == ARRAY || t == FUNC) { 2094 /* ok, a warning comes later (in build_address()) */ 2095 } else if (!tn->tn_lvalue) { 2096 if (tn->tn_op == CVT && tn->tn_cast && 2097 tn->tn_left->tn_op == LOAD) { 2098 /* a cast does not yield an lvalue */ 2099 error(163); 2100 } 2101 /* %soperand of '%s' must be lvalue */ 2102 error(114, "", op_name(op)); 2103 return false; 2104 } else if (is_scalar(t)) { 2105 if (tp->t_bitfield) { 2106 /* cannot take address of bit-field */ 2107 error(112); 2108 return false; 2109 } 2110 } else if (t != STRUCT && t != UNION) { 2111 /* unacceptable operand of '%s' */ 2112 error(111, op_name(op)); 2113 return false; 2114 } 2115 if (tn->tn_op == NAME && tn->tn_sym->s_register) { 2116 /* cannot take address of register '%s' */ 2117 error(113, tn->tn_sym->s_name); 2118 return false; 2119 } 2120 return true; 2121 } 2122 2123 static bool 2124 typeok_indir(const type_t *tp, tspec_t t) 2125 { 2126 2127 if (t != PTR) { 2128 /* cannot dereference non-pointer type '%s' */ 2129 error(96, type_name(tp)); 2130 return false; 2131 } 2132 return true; 2133 } 2134 2135 static void 2136 warn_incompatible_types(op_t op, 2137 const type_t *ltp, tspec_t lt, 2138 const type_t *rtp, tspec_t rt) 2139 { 2140 bool binary = modtab[op].m_binary; 2141 2142 if (lt == VOID || (binary && rt == VOID)) { 2143 /* void type illegal in expression */ 2144 error(109); 2145 } else if (op == ASSIGN) { 2146 /* cannot assign to '%s' from '%s' */ 2147 error(171, type_name(ltp), type_name(rtp)); 2148 } else if (binary) { 2149 /* operands of '%s' have incompatible types '%s' and '%s' */ 2150 error(107, op_name(op), type_name(ltp), type_name(rtp)); 2151 } else { 2152 lint_assert(rt == NO_TSPEC); 2153 /* operand of '%s' has invalid type '%s' */ 2154 error(108, op_name(op), type_name(ltp)); 2155 } 2156 } 2157 2158 static bool 2159 typeok_plus(op_t op, 2160 const type_t *ltp, tspec_t lt, 2161 const type_t *rtp, tspec_t rt) 2162 { 2163 /* operands have scalar types (checked in typeok) */ 2164 if ((lt == PTR && !is_integer(rt)) || (rt == PTR && !is_integer(lt))) { 2165 warn_incompatible_types(op, ltp, lt, rtp, rt); 2166 return false; 2167 } 2168 return true; 2169 } 2170 2171 static bool 2172 typeok_minus(op_t op, 2173 const type_t *ltp, tspec_t lt, 2174 const type_t *rtp, tspec_t rt) 2175 { 2176 /* operands have scalar types (checked in typeok) */ 2177 if ((lt == PTR && rt != PTR && !is_integer(rt)) || 2178 (lt != PTR && rt == PTR)) { 2179 warn_incompatible_types(op, ltp, lt, rtp, rt); 2180 return false; 2181 } 2182 if (lt == PTR && rt == PTR && 2183 !types_compatible(ltp->t_subt, rtp->t_subt, true, false, NULL)) { 2184 /* illegal pointer subtraction */ 2185 error(116); 2186 } 2187 return true; 2188 } 2189 2190 static void 2191 typeok_shr(op_t op, 2192 const tnode_t *ln, tspec_t lt, 2193 const tnode_t *rn, tspec_t rt) 2194 { 2195 tspec_t olt = before_conversion(ln)->tn_type->t_tspec; 2196 tspec_t ort = before_conversion(rn)->tn_type->t_tspec; 2197 2198 /* operands have integer types (checked in typeok) */ 2199 if (pflag && !is_uinteger(olt)) { 2200 integer_constraints lc = ic_expr(ln); 2201 if (!ic_maybe_signed(ln->tn_type, &lc)) 2202 return; 2203 2204 if (ln->tn_op != CON) { 2205 /* bitwise '%s' on signed value possibly nonportable */ 2206 warning(117, op_name(op)); 2207 } else if (ln->tn_val.u.integer < 0) { 2208 /* bitwise '%s' on signed value nonportable */ 2209 warning(120, op_name(op)); 2210 } 2211 } else if (allow_trad && allow_c90 && 2212 !is_uinteger(olt) && is_uinteger(ort)) { 2213 /* The left operand would become unsigned in traditional C. */ 2214 if (hflag && (ln->tn_op != CON || ln->tn_val.u.integer < 0)) { 2215 /* semantics of '%s' change in C90; use ... */ 2216 warning(118, op_name(op)); 2217 } 2218 } else if (allow_trad && allow_c90 && 2219 !is_uinteger(olt) && !is_uinteger(ort) && 2220 portable_rank_cmp(lt, rt) < 0) { 2221 /* 2222 * In traditional C, the left operand would be extended 2223 * (possibly sign-extended) and then shifted. 2224 */ 2225 if (hflag && (ln->tn_op != CON || ln->tn_val.u.integer < 0)) { 2226 /* semantics of '%s' change in C90; use ... */ 2227 warning(118, op_name(op)); 2228 } 2229 } 2230 } 2231 2232 static void 2233 typeok_shl(op_t op, tspec_t lt, tspec_t rt) 2234 { 2235 /* 2236 * C90 does not perform balancing for shift operations, but traditional 2237 * C does. If the width of the right operand is greater than the width 2238 * of the left operand, then in traditional C the left operand would be 2239 * extended to the width of the right operand. For SHL this may result 2240 * in different results. 2241 */ 2242 if (portable_rank_cmp(lt, rt) < 0) { 2243 /* 2244 * XXX If both operands are constant, make sure that there is 2245 * really a difference between C90 and traditional C. 2246 */ 2247 if (hflag && allow_trad && allow_c90) 2248 /* semantics of '%s' change in C90; use ... */ 2249 warning(118, op_name(op)); 2250 } 2251 } 2252 2253 static void 2254 typeok_shift(const type_t *ltp, tspec_t lt, const tnode_t *rn, tspec_t rt) 2255 { 2256 if (rn->tn_op != CON) 2257 return; 2258 2259 if (!is_uinteger(rt) && rn->tn_val.u.integer < 0) { 2260 /* negative shift */ 2261 warning(121); 2262 } else if ((uint64_t)rn->tn_val.u.integer == size_in_bits(lt)) { 2263 /* shift amount %u equals bit-size of '%s' */ 2264 warning(267, (unsigned)rn->tn_val.u.integer, type_name(ltp)); 2265 } else if ((uint64_t)rn->tn_val.u.integer > size_in_bits(lt)) { 2266 /* shift amount %llu is greater than bit-size %llu of '%s' */ 2267 warning(122, (unsigned long long)rn->tn_val.u.integer, 2268 (unsigned long long)size_in_bits(lt), 2269 tspec_name(lt)); 2270 } 2271 } 2272 2273 static bool 2274 is_typeok_eq(const tnode_t *ln, tspec_t lt, const tnode_t *rn, tspec_t rt) 2275 { 2276 if (lt == PTR && is_null_pointer(rn)) 2277 return true; 2278 if (rt == PTR && is_null_pointer(ln)) 2279 return true; 2280 return false; 2281 } 2282 2283 static void 2284 warn_incompatible_pointers(op_t op, const type_t *ltp, const type_t *rtp) 2285 { 2286 lint_assert(ltp->t_tspec == PTR); 2287 lint_assert(rtp->t_tspec == PTR); 2288 2289 tspec_t lt = ltp->t_subt->t_tspec; 2290 tspec_t rt = rtp->t_subt->t_tspec; 2291 2292 if (is_struct_or_union(lt) && is_struct_or_union(rt)) { 2293 if (op == RETURN) { 2294 /* illegal structure pointer combination */ 2295 warning(244); 2296 } else { 2297 /* incompatible structure pointers: '%s' '%s' '%s' */ 2298 warning(245, type_name(ltp), 2299 op_name(op), type_name(rtp)); 2300 } 2301 } else { 2302 if (op == RETURN) { 2303 /* illegal combination of '%s' and '%s' */ 2304 warning(184, type_name(ltp), type_name(rtp)); 2305 } else { 2306 /* illegal combination of '%s' and '%s', op '%s' */ 2307 warning(124, 2308 type_name(ltp), type_name(rtp), op_name(op)); 2309 } 2310 } 2311 } 2312 2313 static void 2314 check_pointer_comparison(op_t op, const tnode_t *ln, const tnode_t *rn) 2315 { 2316 type_t *ltp = ln->tn_type, *rtp = rn->tn_type; 2317 tspec_t lst = ltp->t_subt->t_tspec, rst = rtp->t_subt->t_tspec; 2318 2319 if (lst == VOID || rst == VOID) { 2320 /* TODO: C99 behaves like C90 here. */ 2321 if (!allow_trad && !allow_c99 && 2322 (lst == FUNC || rst == FUNC)) { 2323 /* (void *)0 is already handled in typeok() */ 2324 const char *lsts, *rsts; 2325 *(lst == FUNC ? &lsts : &rsts) = "function pointer"; 2326 *(lst == VOID ? &lsts : &rsts) = "'void *'"; 2327 /* C90 or later forbid comparison of %s with %s */ 2328 warning(274, lsts, rsts); 2329 } 2330 return; 2331 } 2332 2333 if (!types_compatible(ltp->t_subt, rtp->t_subt, true, false, NULL)) { 2334 warn_incompatible_pointers(op, ltp, rtp); 2335 return; 2336 } 2337 2338 if (lst == FUNC && rst == FUNC) { 2339 /* TODO: C99 behaves like C90 here, see C99 6.5.8p2. */ 2340 if (!allow_trad && !allow_c99 && op != EQ && op != NE) 2341 /* pointers to functions can only be compared ... */ 2342 warning(125); 2343 } 2344 } 2345 2346 static bool 2347 typeok_compare(op_t op, 2348 const tnode_t *ln, const type_t *ltp, tspec_t lt, 2349 const tnode_t *rn, const type_t *rtp, tspec_t rt) 2350 { 2351 if (lt == PTR && rt == PTR) { 2352 check_pointer_comparison(op, ln, rn); 2353 return true; 2354 } 2355 2356 if (lt != PTR && rt != PTR) 2357 return true; 2358 2359 if (!is_integer(lt) && !is_integer(rt)) { 2360 warn_incompatible_types(op, ltp, lt, rtp, rt); 2361 return false; 2362 } 2363 2364 const char *lx = lt == PTR ? "pointer" : "integer"; 2365 const char *rx = rt == PTR ? "pointer" : "integer"; 2366 /* illegal combination of %s '%s' and %s '%s', op '%s' */ 2367 warning(123, lx, type_name(ltp), rx, type_name(rtp), op_name(op)); 2368 return true; 2369 } 2370 2371 static bool 2372 typeok_quest(tspec_t lt, const tnode_t *rn) 2373 { 2374 if (!is_scalar(lt)) { 2375 /* first operand of '?' must have scalar type */ 2376 error(170); 2377 return false; 2378 } 2379 lint_assert(before_conversion(rn)->tn_op == COLON); 2380 return true; 2381 } 2382 2383 static void 2384 typeok_colon_pointer(const type_t *ltp, const type_t *rtp) 2385 { 2386 type_t *lstp = ltp->t_subt; 2387 type_t *rstp = rtp->t_subt; 2388 tspec_t lst = lstp->t_tspec; 2389 tspec_t rst = rstp->t_tspec; 2390 2391 if ((lst == VOID && rst == FUNC) || (lst == FUNC && rst == VOID)) { 2392 /* (void *)0 is handled in typeok_colon */ 2393 /* TODO: C99 behaves like C90 here. */ 2394 if (!allow_trad && !allow_c99) 2395 /* conversion of %s to %s requires a cast, op %s */ 2396 warning(305, "function pointer", "'void *'", 2397 op_name(COLON)); 2398 return; 2399 } 2400 2401 if (pointer_types_are_compatible(lstp, rstp, true)) 2402 return; 2403 if (!types_compatible(lstp, rstp, true, false, NULL)) 2404 warn_incompatible_pointers(COLON, ltp, rtp); 2405 } 2406 2407 static bool 2408 typeok_colon(const tnode_t *ln, const type_t *ltp, tspec_t lt, 2409 const tnode_t *rn, const type_t *rtp, tspec_t rt) 2410 { 2411 2412 if (is_arithmetic(lt) && is_arithmetic(rt)) 2413 return true; 2414 if (lt == BOOL && rt == BOOL) 2415 return true; 2416 2417 if (lt == STRUCT && rt == STRUCT && ltp->t_sou == rtp->t_sou) 2418 return true; 2419 if (lt == UNION && rt == UNION && ltp->t_sou == rtp->t_sou) 2420 return true; 2421 2422 if (lt == PTR && is_null_pointer(rn)) 2423 return true; 2424 if (rt == PTR && is_null_pointer(ln)) 2425 return true; 2426 2427 if ((lt == PTR && is_integer(rt)) || (is_integer(lt) && rt == PTR)) { 2428 const char *lx = lt == PTR ? "pointer" : "integer"; 2429 const char *rx = rt == PTR ? "pointer" : "integer"; 2430 /* illegal combination of %s '%s' and %s '%s', op '%s' */ 2431 warning(123, lx, type_name(ltp), 2432 rx, type_name(rtp), op_name(COLON)); 2433 return true; 2434 } 2435 2436 if (lt == VOID || rt == VOID) { 2437 if (lt != VOID || rt != VOID) 2438 /* incompatible types '%s' and '%s' in conditional */ 2439 warning(126, type_name(ltp), type_name(rtp)); 2440 return true; 2441 } 2442 2443 if (lt == PTR && rt == PTR) { 2444 typeok_colon_pointer(ltp, rtp); 2445 return true; 2446 } 2447 2448 /* incompatible types '%s' and '%s' in conditional */ 2449 error(126, type_name(ltp), type_name(rtp)); 2450 return false; 2451 } 2452 2453 static bool 2454 has_constant_member(const type_t *tp) 2455 { 2456 lint_assert(is_struct_or_union(tp->t_tspec)); 2457 2458 for (sym_t *m = tp->t_sou->sou_first_member; 2459 m != NULL; m = m->s_next) { 2460 const type_t *mtp = m->s_type; 2461 if (mtp->t_const) 2462 return true; 2463 if (is_struct_or_union(mtp->t_tspec) && 2464 has_constant_member(mtp)) 2465 return true; 2466 } 2467 return false; 2468 } 2469 2470 static bool 2471 typeok_assign(op_t op, const tnode_t *ln, const type_t *ltp, tspec_t lt) 2472 { 2473 if (op == RETURN || op == INIT || op == FARG) 2474 return true; 2475 2476 if (!ln->tn_lvalue) { 2477 if (ln->tn_op == CVT && ln->tn_cast && 2478 ln->tn_left->tn_op == LOAD) { 2479 /* a cast does not yield an lvalue */ 2480 error(163); 2481 } 2482 /* %soperand of '%s' must be lvalue */ 2483 error(114, "left ", op_name(op)); 2484 return false; 2485 } else if (ltp->t_const 2486 || (is_struct_or_union(lt) && has_constant_member(ltp))) { 2487 if (allow_c90) 2488 /* %soperand of '%s' must be modifiable lvalue */ 2489 warning(115, "left ", op_name(op)); 2490 } 2491 return true; 2492 } 2493 2494 static bool 2495 typeok_scalar(op_t op, const mod_t *mp, 2496 const type_t *ltp, tspec_t lt, 2497 const type_t *rtp, tspec_t rt) 2498 { 2499 if (mp->m_takes_bool && lt == BOOL && rt == BOOL) 2500 return true; 2501 if (mp->m_requires_integer) { 2502 if (!is_integer(lt) || (mp->m_binary && !is_integer(rt))) { 2503 warn_incompatible_types(op, ltp, lt, rtp, rt); 2504 return false; 2505 } 2506 } else if (mp->m_requires_integer_or_complex) { 2507 if ((!is_integer(lt) && !is_complex(lt)) || 2508 (mp->m_binary && (!is_integer(rt) && !is_complex(rt)))) { 2509 warn_incompatible_types(op, ltp, lt, rtp, rt); 2510 return false; 2511 } 2512 } else if (mp->m_requires_scalar) { 2513 if (!is_scalar(lt) || (mp->m_binary && !is_scalar(rt))) { 2514 warn_incompatible_types(op, ltp, lt, rtp, rt); 2515 return false; 2516 } 2517 } else if (mp->m_requires_arith) { 2518 if (!is_arithmetic(lt) || 2519 (mp->m_binary && !is_arithmetic(rt))) { 2520 warn_incompatible_types(op, ltp, lt, rtp, rt); 2521 return false; 2522 } 2523 } 2524 return true; 2525 } 2526 2527 static void 2528 check_assign_void_pointer(op_t op, int arg, 2529 tspec_t lt, tspec_t lst, 2530 tspec_t rt, tspec_t rst) 2531 { 2532 2533 if (!(lt == PTR && rt == PTR && (lst == VOID || rst == VOID))) 2534 return; 2535 /* two pointers, at least one pointer to void */ 2536 2537 /* TODO: C99 behaves like C90 here. */ 2538 if (!(!allow_trad && !allow_c99 && (lst == FUNC || rst == FUNC))) 2539 return; 2540 /* comb. of ptr to func and ptr to void */ 2541 2542 const char *lts, *rts; 2543 *(lst == FUNC ? <s : &rts) = "function pointer"; 2544 *(lst == VOID ? <s : &rts) = "'void *'"; 2545 2546 switch (op) { 2547 case INIT: 2548 case RETURN: 2549 /* conversion of %s to %s requires a cast */ 2550 warning(303, rts, lts); 2551 break; 2552 case FARG: 2553 /* conversion of %s to %s requires a cast, arg #%d */ 2554 warning(304, rts, lts, arg); 2555 break; 2556 default: 2557 /* conversion of %s to %s requires a cast, op %s */ 2558 warning(305, rts, lts, op_name(op)); 2559 break; 2560 } 2561 } 2562 2563 static bool 2564 is_direct_function_call(const tnode_t *tn, const char **out_name) 2565 { 2566 2567 if (!(tn->tn_op == CALL && 2568 tn->tn_left->tn_op == ADDR && 2569 tn->tn_left->tn_left->tn_op == NAME)) 2570 return false; 2571 2572 *out_name = tn->tn_left->tn_left->tn_sym->s_name; 2573 return true; 2574 } 2575 2576 static bool 2577 is_unconst_function(const char *name) 2578 { 2579 2580 return strcmp(name, "memchr") == 0 || 2581 strcmp(name, "strchr") == 0 || 2582 strcmp(name, "strpbrk") == 0 || 2583 strcmp(name, "strrchr") == 0 || 2584 strcmp(name, "strstr") == 0; 2585 } 2586 2587 static bool 2588 is_const_char_pointer(const tnode_t *tn) 2589 { 2590 /* 2591 * For traditional reasons, C99 6.4.5p5 defines that string literals 2592 * have type 'char[]'. They are often implicitly converted to 'char 2593 * *', for example when they are passed as function arguments. 2594 * 2595 * C99 6.4.5p6 further defines that modifying a string that is 2596 * constructed from a string literal invokes undefined behavior. 2597 * 2598 * Out of these reasons, string literals are treated as 'effectively 2599 * const' here. 2600 */ 2601 if (tn->tn_op == CVT && 2602 tn->tn_left->tn_op == ADDR && 2603 tn->tn_left->tn_left->tn_op == STRING) 2604 return true; 2605 2606 const type_t *tp = before_conversion(tn)->tn_type; 2607 return tp->t_tspec == PTR && 2608 tp->t_subt->t_tspec == CHAR && 2609 tp->t_subt->t_const; 2610 } 2611 2612 static bool 2613 is_first_arg_const_char_pointer(const tnode_t *tn) 2614 { 2615 lint_assert(has_operands(tn)); 2616 const tnode_t *an = tn->tn_right; 2617 if (an == NULL) 2618 return false; 2619 2620 while (tn_ck_right(an) != NULL) 2621 an = an->tn_right; 2622 return is_const_char_pointer(an->tn_left); 2623 } 2624 2625 static bool 2626 is_const_pointer(const tnode_t *tn) 2627 { 2628 const type_t *tp = before_conversion(tn)->tn_type; 2629 return tp->t_tspec == PTR && tp->t_subt->t_const; 2630 } 2631 2632 static bool 2633 is_second_arg_const_pointer(const tnode_t *tn) 2634 { 2635 const tnode_t *an = tn_ck_right(tn); 2636 if (an == NULL || tn_ck_right(an) == NULL) 2637 return false; 2638 2639 while (tn_ck_right(an->tn_right) != NULL) 2640 an = an->tn_right; 2641 return is_const_pointer(an->tn_left); 2642 } 2643 2644 static void 2645 check_unconst_function(const type_t *lstp, const tnode_t *rn) 2646 { 2647 const char *function_name; 2648 2649 if (lstp->t_tspec == CHAR && !lstp->t_const && 2650 is_direct_function_call(rn, &function_name) && 2651 is_unconst_function(function_name) && 2652 is_first_arg_const_char_pointer(rn)) { 2653 /* call to '%s' effectively discards 'const' from argument */ 2654 warning(346, function_name); 2655 } 2656 2657 if (!lstp->t_const && 2658 is_direct_function_call(rn, &function_name) && 2659 strcmp(function_name, "bsearch") == 0 && 2660 is_second_arg_const_pointer(rn)) { 2661 /* call to '%s' effectively discards 'const' from argument */ 2662 warning(346, function_name); 2663 } 2664 } 2665 2666 static bool 2667 check_assign_void_pointer_compat(op_t op, int arg, 2668 const type_t *const ltp, tspec_t const lt, 2669 const type_t *const lstp, tspec_t const lst, 2670 const tnode_t *const rn, 2671 const type_t *const rtp, tspec_t const rt, 2672 const type_t *const rstp, tspec_t const rst) 2673 { 2674 if (!(lt == PTR && rt == PTR && (lst == VOID || rst == VOID || 2675 types_compatible(lstp, rstp, 2676 true, false, NULL)))) 2677 return false; 2678 2679 /* compatible pointer types (qualifiers ignored) */ 2680 if (allow_c90 && 2681 ((!lstp->t_const && rstp->t_const) || 2682 (!lstp->t_volatile && rstp->t_volatile))) { 2683 /* left side has not all qualifiers of right */ 2684 switch (op) { 2685 case INIT: 2686 case RETURN: 2687 /* incompatible pointer types to '%s' and '%s' */ 2688 warning(182, type_name(lstp), type_name(rstp)); 2689 break; 2690 case FARG: 2691 /* converting '%s' to incompatible '%s' ... */ 2692 warning(153, 2693 type_name(rtp), type_name(ltp), arg); 2694 break; 2695 default: 2696 /* operands of '%s' have incompatible pointer ... */ 2697 warning(128, op_name(op), 2698 type_name(lstp), type_name(rstp)); 2699 break; 2700 } 2701 } 2702 2703 if (allow_c90) 2704 check_unconst_function(lstp, rn); 2705 2706 return true; 2707 } 2708 2709 static bool 2710 check_assign_pointer_integer(op_t op, int arg, 2711 const type_t *const ltp, tspec_t const lt, 2712 const type_t *const rtp, tspec_t const rt) 2713 { 2714 2715 if (!((lt == PTR && is_integer(rt)) || (is_integer(lt) && rt == PTR))) 2716 return false; 2717 2718 const char *lx = lt == PTR ? "pointer" : "integer"; 2719 const char *rx = rt == PTR ? "pointer" : "integer"; 2720 2721 switch (op) { 2722 case INIT: 2723 case RETURN: 2724 /* illegal combination of %s '%s' and %s '%s' */ 2725 warning(183, lx, type_name(ltp), rx, type_name(rtp)); 2726 break; 2727 case FARG: 2728 /* illegal combination of %s '%s' and %s '%s', arg #%d */ 2729 warning(154, 2730 lx, type_name(ltp), rx, type_name(rtp), arg); 2731 break; 2732 default: 2733 /* illegal combination of %s '%s' and %s '%s', op '%s' */ 2734 warning(123, 2735 lx, type_name(ltp), rx, type_name(rtp), op_name(op)); 2736 break; 2737 } 2738 return true; 2739 } 2740 2741 static bool 2742 check_assign_pointer(op_t op, int arg, 2743 const type_t *ltp, tspec_t lt, 2744 const type_t *rtp, tspec_t rt) 2745 { 2746 if (!(lt == PTR && rt == PTR)) 2747 return false; 2748 2749 if (op == FARG) 2750 /* converting '%s' to incompatible '%s' for ... */ 2751 warning(153, type_name(rtp), type_name(ltp), arg); 2752 else 2753 warn_incompatible_pointers(op, ltp, rtp); 2754 return true; 2755 } 2756 2757 static void 2758 warn_assign(op_t op, int arg, 2759 const type_t *ltp, tspec_t lt, 2760 const type_t *rtp, tspec_t rt) 2761 { 2762 switch (op) { 2763 case INIT: 2764 /* cannot initialize '%s' from '%s' */ 2765 error(185, type_name(ltp), type_name(rtp)); 2766 break; 2767 case RETURN: 2768 /* function has return type '%s' but returns '%s' */ 2769 error(211, type_name(ltp), type_name(rtp)); 2770 break; 2771 case FARG: 2772 /* passing '%s' to incompatible '%s', arg #%d */ 2773 warning(155, type_name(rtp), type_name(ltp), arg); 2774 break; 2775 default: 2776 warn_incompatible_types(op, ltp, lt, rtp, rt); 2777 break; 2778 } 2779 } 2780 2781 /* 2782 * Checks type compatibility for ASSIGN, INIT, FARG and RETURN 2783 * and prints warnings/errors if necessary. 2784 * Returns whether the types are (almost) compatible. 2785 */ 2786 static bool 2787 check_assign_types_compatible(op_t op, int arg, 2788 const tnode_t *ln, const tnode_t *rn) 2789 { 2790 tspec_t lt, rt, lst = NO_TSPEC, rst = NO_TSPEC; 2791 type_t *ltp, *rtp, *lstp = NULL, *rstp = NULL; 2792 2793 if ((lt = (ltp = ln->tn_type)->t_tspec) == PTR) 2794 lst = (lstp = ltp->t_subt)->t_tspec; 2795 if ((rt = (rtp = rn->tn_type)->t_tspec) == PTR) 2796 rst = (rstp = rtp->t_subt)->t_tspec; 2797 2798 if (lt == BOOL && is_scalar(rt)) /* C99 6.3.1.2 */ 2799 return true; 2800 2801 if (is_arithmetic(lt) && (is_arithmetic(rt) || rt == BOOL)) 2802 return true; 2803 2804 if (is_struct_or_union(lt) && is_struct_or_union(rt)) 2805 return ltp->t_sou == rtp->t_sou; 2806 2807 if (lt == PTR && is_null_pointer(rn)) { 2808 if (is_integer(rn->tn_type->t_tspec)) 2809 /* implicit conversion from integer 0 to pointer ... */ 2810 query_message(15, type_name(ltp)); 2811 return true; 2812 } 2813 2814 check_assign_void_pointer(op, arg, lt, lst, rt, rst); 2815 2816 if (check_assign_void_pointer_compat(op, arg, 2817 ltp, lt, lstp, lst, rn, rtp, rt, rstp, rst)) 2818 return true; 2819 2820 if (check_assign_pointer_integer(op, arg, ltp, lt, rtp, rt)) 2821 return true; 2822 2823 if (check_assign_pointer(op, arg, ltp, lt, rtp, rt)) 2824 return true; 2825 2826 warn_assign(op, arg, ltp, lt, rtp, rt); 2827 return false; 2828 } 2829 2830 static bool 2831 has_side_effect(const tnode_t *tn) /* NOLINT(misc-no-recursion) */ 2832 { 2833 op_t op = tn->tn_op; 2834 2835 if (modtab[op].m_has_side_effect) 2836 return true; 2837 2838 if (op == CVT && tn->tn_type->t_tspec == VOID) 2839 return has_side_effect(tn->tn_left); 2840 2841 /* XXX: Why not has_side_effect(tn->tn_left) as well? */ 2842 if (op == LOGAND || op == LOGOR) 2843 return has_side_effect(tn->tn_right); 2844 2845 /* XXX: Why not has_side_effect(tn->tn_left) as well? */ 2846 if (op == QUEST) 2847 return has_side_effect(tn->tn_right); 2848 2849 if (op == COLON || op == COMMA) { 2850 return has_side_effect(tn->tn_left) || 2851 has_side_effect(tn->tn_right); 2852 } 2853 2854 return false; 2855 } 2856 2857 static bool 2858 is_void_cast(const tnode_t *tn) 2859 { 2860 2861 return tn->tn_op == CVT && tn->tn_cast && 2862 tn->tn_type->t_tspec == VOID; 2863 } 2864 2865 static bool 2866 is_local_symbol(const tnode_t *tn) 2867 { 2868 2869 return tn->tn_op == LOAD && 2870 tn->tn_left->tn_op == NAME && 2871 tn->tn_left->tn_sym->s_scl == AUTO; 2872 } 2873 2874 static bool 2875 is_int_constant_zero(const tnode_t *tn) 2876 { 2877 2878 return tn->tn_op == CON && 2879 tn->tn_type->t_tspec == INT && 2880 tn->tn_val.u.integer == 0; 2881 } 2882 2883 static void 2884 check_null_effect(const tnode_t *tn) 2885 { 2886 2887 if (hflag && 2888 !has_side_effect(tn) && 2889 !(is_void_cast(tn) && is_local_symbol(tn->tn_left)) && 2890 !(is_void_cast(tn) && is_int_constant_zero(tn->tn_left))) { 2891 /* expression has null effect */ 2892 warning(129); 2893 } 2894 } 2895 2896 /* 2897 * Check the types for specific operators and type combinations. 2898 * 2899 * At this point, the operands already conform to the type requirements of 2900 * the operator, such as being integer, floating or scalar. 2901 */ 2902 static bool 2903 typeok_op(op_t op, int arg, 2904 const tnode_t *ln, const type_t *ltp, tspec_t lt, 2905 const tnode_t *rn, const type_t *rtp, tspec_t rt) 2906 { 2907 switch (op) { 2908 case ARROW: 2909 return typeok_arrow(lt); 2910 case POINT: 2911 return typeok_point(ln, ltp, lt); 2912 case INCBEF: 2913 case DECBEF: 2914 case INCAFT: 2915 case DECAFT: 2916 return typeok_incdec(op, ln, ltp); 2917 case INDIR: 2918 return typeok_indir(ltp, lt); 2919 case ADDR: 2920 return typeok_address(op, ln, ltp, lt); 2921 case PLUS: 2922 return typeok_plus(op, ltp, lt, rtp, rt); 2923 case MINUS: 2924 return typeok_minus(op, ltp, lt, rtp, rt); 2925 case SHL: 2926 typeok_shl(op, lt, rt); 2927 goto shift; 2928 case SHR: 2929 typeok_shr(op, ln, lt, rn, rt); 2930 shift: 2931 typeok_shift(ltp, lt, rn, rt); 2932 break; 2933 case LT: 2934 case LE: 2935 case GT: 2936 case GE: 2937 compare: 2938 return typeok_compare(op, ln, ltp, lt, rn, rtp, rt); 2939 case EQ: 2940 case NE: 2941 if (is_typeok_eq(ln, lt, rn, rt)) 2942 break; 2943 goto compare; 2944 case QUEST: 2945 return typeok_quest(lt, rn); 2946 case COLON: 2947 return typeok_colon(ln, ltp, lt, rn, rtp, rt); 2948 case ASSIGN: 2949 case INIT: 2950 case FARG: 2951 case RETURN: 2952 if (!check_assign_types_compatible(op, arg, ln, rn)) 2953 return false; 2954 goto assign; 2955 case MULASS: 2956 case DIVASS: 2957 case MODASS: 2958 goto assign; 2959 case ADDASS: 2960 case SUBASS: 2961 if ((lt == PTR && !is_integer(rt)) || rt == PTR) { 2962 warn_incompatible_types(op, ltp, lt, rtp, rt); 2963 return false; 2964 } 2965 goto assign; 2966 case SHLASS: 2967 goto assign; 2968 case SHRASS: 2969 if (pflag && !is_uinteger(lt) && 2970 !(!allow_c90 && is_uinteger(rt))) { 2971 /* bitwise '%s' on signed value possibly nonportable */ 2972 warning(117, op_name(op)); 2973 } 2974 goto assign; 2975 case ANDASS: 2976 case XORASS: 2977 case ORASS: 2978 assign: 2979 return typeok_assign(op, ln, ltp, lt); 2980 case COMMA: 2981 if (!modtab[ln->tn_op].m_has_side_effect) 2982 check_null_effect(ln); 2983 break; 2984 default: 2985 break; 2986 } 2987 return true; 2988 } 2989 2990 static void 2991 check_bad_enum_operation(op_t op, const tnode_t *ln, const tnode_t *rn) 2992 { 2993 2994 if (!eflag) 2995 return; 2996 2997 /* Allow enum in array indices. */ 2998 if (op == PLUS && 2999 ((ln->tn_type->t_is_enum && rn->tn_type->t_tspec == PTR) || 3000 (rn->tn_type->t_is_enum && ln->tn_type->t_tspec == PTR))) { 3001 return; 3002 } 3003 3004 /* dubious operation '%s' on enum */ 3005 warning(241, op_name(op)); 3006 } 3007 3008 static void 3009 check_enum_type_mismatch(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 3010 { 3011 const mod_t *mp = &modtab[op]; 3012 3013 if (ln->tn_type->t_enum != rn->tn_type->t_enum) { 3014 switch (op) { 3015 case INIT: 3016 /* enum type mismatch between '%s' and '%s' in ... */ 3017 warning(210, 3018 type_name(ln->tn_type), type_name(rn->tn_type)); 3019 break; 3020 case FARG: 3021 /* function expects '%s', passing '%s' for arg #%d */ 3022 warning(156, 3023 type_name(ln->tn_type), type_name(rn->tn_type), 3024 arg); 3025 break; 3026 case RETURN: 3027 /* function has return type '%s' but returns '%s' */ 3028 warning(211, 3029 type_name(ln->tn_type), type_name(rn->tn_type)); 3030 break; 3031 default: 3032 /* enum type mismatch: '%s' '%s' '%s' */ 3033 warning(130, type_name(ln->tn_type), op_name(op), 3034 type_name(rn->tn_type)); 3035 break; 3036 } 3037 } else if (Pflag && eflag && mp->m_comparison && op != EQ && op != NE) 3038 /* operator '%s' assumes that '%s' is ordered */ 3039 warning(243, op_name(op), type_name(ln->tn_type)); 3040 } 3041 3042 static void 3043 check_enum_int_mismatch(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 3044 { 3045 3046 if (!eflag) 3047 return; 3048 3049 switch (op) { 3050 case INIT: 3051 /* 3052 * Initialization with 0 is allowed. Otherwise, all implicit 3053 * initializations would need to be warned upon as well. 3054 */ 3055 if (!rn->tn_type->t_is_enum && rn->tn_op == CON && 3056 is_integer(rn->tn_type->t_tspec) && 3057 rn->tn_val.u.integer == 0) { 3058 return; 3059 } 3060 /* initialization of '%s' with '%s' */ 3061 warning(277, type_name(ln->tn_type), type_name(rn->tn_type)); 3062 break; 3063 case FARG: 3064 /* combination of '%s' and '%s', arg #%d */ 3065 warning(278, 3066 type_name(ln->tn_type), type_name(rn->tn_type), arg); 3067 break; 3068 case RETURN: 3069 /* combination of '%s' and '%s' in return */ 3070 warning(279, type_name(ln->tn_type), type_name(rn->tn_type)); 3071 break; 3072 default: 3073 /* combination of '%s' and '%s', op '%s' */ 3074 warning(242, type_name(ln->tn_type), type_name(rn->tn_type), 3075 op_name(op)); 3076 break; 3077 } 3078 } 3079 3080 static void 3081 typeok_enum(op_t op, const mod_t *mp, int arg, 3082 const tnode_t *ln, const type_t *ltp, 3083 const tnode_t *rn, const type_t *rtp) 3084 { 3085 if (mp->m_bad_on_enum && 3086 (ltp->t_is_enum || (mp->m_binary && rtp->t_is_enum))) { 3087 check_bad_enum_operation(op, ln, rn); 3088 } else if (mp->m_valid_on_enum && 3089 (ltp->t_is_enum && rtp != NULL && rtp->t_is_enum)) { 3090 check_enum_type_mismatch(op, arg, ln, rn); 3091 } else if (mp->m_valid_on_enum && 3092 (ltp->t_is_enum || (rtp != NULL && rtp->t_is_enum))) { 3093 check_enum_int_mismatch(op, arg, ln, rn); 3094 } 3095 } 3096 3097 /* Perform most type checks. Return whether the types are ok. */ 3098 bool 3099 typeok(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 3100 { 3101 3102 const mod_t *mp = &modtab[op]; 3103 3104 type_t *ltp = ln->tn_type; 3105 tspec_t lt = ltp->t_tspec; 3106 3107 type_t *rtp = mp->m_binary ? rn->tn_type : NULL; 3108 tspec_t rt = mp->m_binary ? rtp->t_tspec : NO_TSPEC; 3109 3110 if (Tflag && !typeok_scalar_strict_bool(op, mp, arg, ln, rn)) 3111 return false; 3112 if (!typeok_scalar(op, mp, ltp, lt, rtp, rt)) 3113 return false; 3114 3115 if (!typeok_op(op, arg, ln, ltp, lt, rn, rtp, rt)) 3116 return false; 3117 3118 typeok_enum(op, mp, arg, ln, ltp, rn, rtp); 3119 return true; 3120 } 3121 3122 /* In traditional C, keep unsigned and promote FLOAT to DOUBLE. */ 3123 static tspec_t 3124 promote_trad(tspec_t t) 3125 { 3126 3127 if (t == UCHAR || t == USHORT) 3128 return UINT; 3129 if (t == CHAR || t == SCHAR || t == SHORT) 3130 return INT; 3131 if (t == FLOAT) 3132 return DOUBLE; 3133 if (t == ENUM) 3134 return INT; 3135 return t; 3136 } 3137 3138 /* 3139 * C99 6.3.1.1p2 requires for types with lower rank than int that "If an int 3140 * can represent all the values of the original type, the value is converted 3141 * to an int; otherwise it is converted to an unsigned int", and that "All 3142 * other types are unchanged by the integer promotions". 3143 */ 3144 static tspec_t 3145 promote_c90(const tnode_t *tn, tspec_t t, bool farg) 3146 { 3147 if (tn->tn_type->t_bitfield) { 3148 unsigned int width = tn->tn_type->t_bit_field_width; 3149 unsigned int int_width = size_in_bits(INT); 3150 // XXX: What about _Bool bit-fields, since C99? 3151 if (width < int_width) 3152 return INT; 3153 if (width == int_width) 3154 return is_uinteger(t) ? UINT : INT; 3155 return t; 3156 } 3157 3158 if (t == CHAR || t == SCHAR) 3159 return INT; 3160 if (t == UCHAR) 3161 return size_in_bits(CHAR) < size_in_bits(INT) ? INT : UINT; 3162 if (t == SHORT) 3163 return INT; 3164 if (t == USHORT) 3165 return size_in_bits(SHORT) < size_in_bits(INT) ? INT : UINT; 3166 if (t == ENUM) 3167 return INT; 3168 if (farg && t == FLOAT) 3169 return DOUBLE; 3170 return t; 3171 } 3172 3173 /* 3174 * Performs the "integer promotions" (C99 6.3.1.1p2), which convert small 3175 * integer types to either int or unsigned int. 3176 * 3177 * If allow_c90 is unset or the operand is a function argument with no type 3178 * information (no prototype or variable # of args), converts float to double. 3179 */ 3180 tnode_t * 3181 promote(op_t op, bool farg, tnode_t *tn) 3182 { 3183 3184 tspec_t ot = tn->tn_type->t_tspec; 3185 if (!is_arithmetic(ot)) 3186 return tn; 3187 3188 tspec_t nt = allow_c90 ? promote_c90(tn, ot, farg) : promote_trad(ot); 3189 if (nt == ot) 3190 return tn; 3191 3192 type_t *ntp = expr_dup_type(tn->tn_type); 3193 ntp->t_tspec = nt; 3194 /* 3195 * Keep t_is_enum even though t_tspec gets converted from ENUM to INT, 3196 * so we are later able to check compatibility of enum types. 3197 */ 3198 return convert(op, 0, ntp, tn); 3199 } 3200 3201 static void 3202 convert_integer_from_floating(op_t op, const type_t *tp, const tnode_t *tn) 3203 { 3204 3205 if (op == CVT) 3206 /* cast from floating point '%s' to integer '%s' */ 3207 query_message(2, type_name(tn->tn_type), type_name(tp)); 3208 else 3209 /* implicit conversion from floating point '%s' to ... */ 3210 query_message(1, type_name(tn->tn_type), type_name(tp)); 3211 } 3212 3213 static bool 3214 should_warn_about_prototype_conversion(tspec_t nt, 3215 tspec_t ot, const tnode_t *ptn) 3216 { 3217 3218 if (nt == ot) 3219 return false; 3220 3221 if (nt == ENUM && ot == INT) 3222 return false; 3223 3224 if (is_floating(nt) != is_floating(ot) || 3225 portable_rank_cmp(nt, ot) != 0) { 3226 /* representation and/or width change */ 3227 if (!is_integer(ot)) 3228 return true; 3229 /* 3230 * XXX: Investigate whether this rule makes sense; see 3231 * tests/usr.bin/xlint/lint1/platform_long.c. 3232 */ 3233 return portable_rank_cmp(ot, INT) > 0; 3234 } 3235 3236 if (!hflag) 3237 return false; 3238 3239 /* 3240 * If the types differ only in sign and the argument has the same 3241 * representation in both types, print no warning. 3242 */ 3243 if (ptn->tn_op == CON && is_integer(nt) && 3244 signed_type(nt) == signed_type(ot) && 3245 !msb(ptn->tn_val.u.integer, ot)) 3246 return false; 3247 3248 return true; 3249 } 3250 3251 /* 3252 * Warn if a prototype causes a type conversion that is different from what 3253 * would happen to the same argument in the absence of a prototype. This 3254 * check is intended for code that needs to stay compatible with pre-C90 C. 3255 * 3256 * Errors/warnings about illegal type combinations are already printed 3257 * in check_assign_types_compatible(). 3258 */ 3259 static void 3260 check_prototype_conversion(int arg, tspec_t nt, tspec_t ot, type_t *tp, 3261 tnode_t *tn) 3262 { 3263 3264 if (!is_arithmetic(nt) || !is_arithmetic(ot)) 3265 return; 3266 3267 /* 3268 * If the type of the formal parameter is char/short, a warning would 3269 * be useless, because functions declared the old style can't expect 3270 * char/short arguments. 3271 */ 3272 if (nt == CHAR || nt == SCHAR || nt == UCHAR || 3273 nt == SHORT || nt == USHORT) 3274 return; 3275 3276 tnode_t *ptn = promote(NOOP, true, tn); 3277 ot = ptn->tn_type->t_tspec; 3278 3279 if (should_warn_about_prototype_conversion(nt, ot, ptn)) { 3280 /* argument %d is converted from '%s' to '%s' ... */ 3281 warning(259, arg, type_name(tn->tn_type), type_name(tp)); 3282 } 3283 } 3284 3285 /* 3286 * When converting a large integer type to a small integer type, in some 3287 * cases the value of the actual expression is further restricted than the 3288 * type bounds, such as in (expr & 0xFF) or (expr % 100) or (expr >> 24). 3289 */ 3290 static bool 3291 can_represent(const type_t *tp, const tnode_t *tn) 3292 { 3293 3294 debug_step("%s: type '%s'", __func__, type_name(tp)); 3295 debug_node(tn); 3296 3297 uint64_t nmask = value_bits(width_in_bits(tp)); 3298 if (!is_uinteger(tp->t_tspec)) 3299 nmask >>= 1; 3300 3301 integer_constraints c = ic_expr(tn); 3302 if ((~c.bclr & ~nmask) == 0) 3303 return true; 3304 3305 integer_constraints tpc = ic_any(tp); 3306 if (is_uinteger(tp->t_tspec) 3307 ? tpc.umin <= c.umin && tpc.umax >= c.umax 3308 : tpc.smin <= c.smin && tpc.smax >= c.smax) 3309 return true; 3310 3311 return false; 3312 } 3313 3314 static bool 3315 should_warn_about_integer_conversion(const type_t *ntp, tspec_t nt, 3316 const tnode_t *otn, tspec_t ot) 3317 { 3318 3319 // XXX: The portable_rank_cmp aims at portable mode, independent of the 3320 // current platform, while can_represent acts on the actual type sizes 3321 // from the current platform. This mix is inconsistent, but anything 3322 // else would make the exact conditions too complicated to grasp. 3323 if (aflag > 0 && portable_rank_cmp(nt, ot) < 0) { 3324 if (ot == LONG || ot == ULONG 3325 || ot == LLONG || ot == ULLONG 3326 #ifdef INT128_SIZE 3327 || ot == INT128 || ot == UINT128 3328 #endif 3329 || aflag > 1) 3330 return !can_represent(ntp, otn); 3331 } 3332 return false; 3333 } 3334 3335 static void 3336 convert_integer_from_integer(op_t op, int arg, tspec_t nt, tspec_t ot, 3337 type_t *tp, tnode_t *tn) 3338 { 3339 3340 if (tn->tn_op == CON) 3341 return; 3342 3343 if (op == CVT) 3344 return; 3345 3346 if (Pflag && pflag && aflag > 0 && 3347 portable_rank_cmp(nt, ot) > 0 && 3348 is_uinteger(nt) != is_uinteger(ot)) { 3349 if (op == FARG) { 3350 /* conversion to '%s' may sign-extend ... */ 3351 warning(297, type_name(tp), arg); 3352 } else { 3353 /* conversion to '%s' may sign-extend ... */ 3354 warning(131, type_name(tp)); 3355 } 3356 } 3357 3358 if (Pflag && portable_rank_cmp(nt, ot) > 0 && 3359 (tn->tn_op == PLUS || tn->tn_op == MINUS || tn->tn_op == MULT || 3360 tn->tn_op == SHL)) { 3361 /* suggest cast from '%s' to '%s' on op '%s' to ... */ 3362 warning(324, type_name(gettyp(ot)), type_name(tp), 3363 op_name(tn->tn_op)); 3364 } 3365 3366 if (should_warn_about_integer_conversion(tp, nt, tn, ot)) { 3367 if (op == FARG) { 3368 /* conversion from '%s' to '%s' may lose ... */ 3369 warning(298, 3370 type_name(tn->tn_type), type_name(tp), arg); 3371 } else { 3372 /* conversion from '%s' to '%s' may lose accuracy */ 3373 warning(132, 3374 type_name(tn->tn_type), type_name(tp)); 3375 } 3376 } 3377 3378 if (any_query_enabled && is_uinteger(nt) != is_uinteger(ot)) 3379 /* implicit conversion changes sign from '%s' to '%s' */ 3380 query_message(3, type_name(tn->tn_type), type_name(tp)); 3381 } 3382 3383 static void 3384 convert_integer_from_pointer(op_t op, tspec_t nt, type_t *tp, tnode_t *tn) 3385 { 3386 3387 if (tn->tn_op == CON) 3388 return; 3389 if (op != CVT) 3390 return; /* We already got an error. */ 3391 if (portable_rank_cmp(nt, PTR) >= 0) 3392 return; 3393 3394 if (pflag && size_in_bits(nt) >= size_in_bits(PTR)) { 3395 /* conversion of pointer to '%s' may lose bits */ 3396 warning(134, type_name(tp)); 3397 } else { 3398 /* conversion of pointer to '%s' loses bits */ 3399 warning(133, type_name(tp)); 3400 } 3401 } 3402 3403 static bool 3404 struct_starts_with(const type_t *struct_tp, const type_t *member_tp) 3405 { 3406 3407 return struct_tp->t_sou->sou_first_member != NULL && 3408 types_compatible(struct_tp->t_sou->sou_first_member->s_type, 3409 member_tp, true, false, NULL); 3410 } 3411 3412 static bool 3413 is_byte_array(const type_t *tp) 3414 { 3415 3416 return tp->t_tspec == ARRAY && 3417 (tp->t_subt->t_tspec == CHAR || tp->t_subt->t_tspec == UCHAR); 3418 } 3419 3420 static bool 3421 union_contains(const type_t *utp, const type_t *mtp) 3422 { 3423 for (const sym_t *mem = utp->t_sou->sou_first_member; 3424 mem != NULL; mem = mem->s_next) { 3425 if (types_compatible(mem->s_type, mtp, true, false, NULL)) 3426 return true; 3427 } 3428 return false; 3429 } 3430 3431 static bool 3432 should_warn_about_pointer_cast(const type_t *nstp, tspec_t nst, 3433 const type_t *ostp, tspec_t ost) 3434 { 3435 3436 while (nst == ARRAY) 3437 nstp = nstp->t_subt, nst = nstp->t_tspec; 3438 while (ost == ARRAY) 3439 ostp = ostp->t_subt, ost = ostp->t_tspec; 3440 3441 if (nst == STRUCT && ost == STRUCT && 3442 (struct_starts_with(nstp, ostp) || 3443 struct_starts_with(ostp, nstp))) 3444 return false; 3445 3446 if (is_incomplete(nstp) || is_incomplete(ostp)) 3447 return false; 3448 3449 if (nst == CHAR || nst == UCHAR) 3450 return false; /* for the sake of traditional C code */ 3451 if (ost == CHAR || ost == UCHAR) 3452 return false; /* for the sake of traditional C code */ 3453 3454 /* Allow cast between pointers to sockaddr variants. */ 3455 if (nst == STRUCT && ost == STRUCT) { 3456 const sym_t *nmem = nstp->t_sou->sou_first_member; 3457 const sym_t *omem = ostp->t_sou->sou_first_member; 3458 while (nmem != NULL && omem != NULL && 3459 types_compatible(nmem->s_type, omem->s_type, 3460 true, false, NULL)) 3461 nmem = nmem->s_next, omem = omem->s_next; 3462 if (nmem != NULL && is_byte_array(nmem->s_type)) 3463 return false; 3464 if (omem != NULL && is_byte_array(omem->s_type)) 3465 return false; 3466 if (nmem == NULL && omem == NULL) 3467 return false; 3468 } 3469 3470 if (nst == UNION || ost == UNION) { 3471 const type_t *union_tp = nst == UNION ? nstp : ostp; 3472 const type_t *other_tp = nst == UNION ? ostp : nstp; 3473 if (union_contains(union_tp, other_tp)) 3474 return false; 3475 } 3476 3477 if (is_struct_or_union(nst) && is_struct_or_union(ost)) 3478 return nstp->t_sou != ostp->t_sou; 3479 3480 enum rank_kind rk1 = type_properties(nst)->tt_rank_kind; 3481 enum rank_kind rk2 = type_properties(ost)->tt_rank_kind; 3482 if (rk1 != rk2 || rk1 == RK_NONE) 3483 return true; 3484 3485 return portable_rank_cmp(nst, ost) != 0; 3486 } 3487 3488 static void 3489 convert_pointer_from_pointer(type_t *ntp, tnode_t *tn) 3490 { 3491 const type_t *nstp = ntp->t_subt; 3492 const type_t *otp = tn->tn_type; 3493 const type_t *ostp = otp->t_subt; 3494 tspec_t nst = nstp->t_tspec; 3495 tspec_t ost = ostp->t_tspec; 3496 3497 if (nst == VOID || ost == VOID) { 3498 /* TODO: C99 behaves like C90 here. */ 3499 if (!allow_trad && !allow_c99 && (nst == FUNC || ost == FUNC)) { 3500 const char *nts, *ots; 3501 /* null pointers are already handled in convert() */ 3502 *(nst == FUNC ? &nts : &ots) = "function pointer"; 3503 *(nst == VOID ? &nts : &ots) = "'void *'"; 3504 /* conversion of %s to %s requires a cast */ 3505 warning(303, ots, nts); 3506 } 3507 return; 3508 } 3509 if (nst == FUNC && ost == FUNC) 3510 return; 3511 if (nst == FUNC || ost == FUNC) { 3512 /* converting '%s' to '%s' is questionable */ 3513 warning(229, type_name(otp), type_name(ntp)); 3514 return; 3515 } 3516 3517 if (hflag && alignment_in_bits(nstp) > alignment_in_bits(ostp) && 3518 ost != CHAR && ost != UCHAR && 3519 !is_incomplete(ostp) && 3520 !(nst == UNION && union_contains(nstp, ostp))) { 3521 /* converting '%s' to '%s' increases alignment ... */ 3522 warning(135, type_name(otp), type_name(ntp), 3523 alignment_in_bits(ostp) / CHAR_SIZE, 3524 alignment_in_bits(nstp) / CHAR_SIZE); 3525 } 3526 3527 if (cflag && should_warn_about_pointer_cast(nstp, nst, ostp, ost)) { 3528 /* pointer cast from '%s' to '%s' may be troublesome */ 3529 warning(247, type_name(otp), type_name(ntp)); 3530 } 3531 } 3532 3533 /* 3534 * Insert a conversion operator, which converts the type of the node 3535 * to another given type. 3536 * 3537 * Possible values for 'op': 3538 * CVT a cast-expression 3539 * binary integer promotion for one of the operands, or a usual 3540 * arithmetic conversion 3541 * binary plain or compound assignments to bit-fields 3542 * FARG 'arg' is the number of the parameter (used for warnings) 3543 * NOOP several other implicit conversions 3544 * ... 3545 */ 3546 tnode_t * 3547 convert(op_t op, int arg, type_t *tp, tnode_t *tn) 3548 { 3549 tspec_t nt = tp->t_tspec; 3550 tspec_t ot = tn->tn_type->t_tspec; 3551 3552 if (allow_trad && allow_c90 && op == FARG) 3553 check_prototype_conversion(arg, nt, ot, tp, tn); 3554 3555 if (nt == BOOL) { 3556 /* No further checks. */ 3557 3558 } else if (is_integer(nt)) { 3559 if (ot == BOOL) { 3560 /* No further checks. */ 3561 } else if (is_integer(ot)) 3562 convert_integer_from_integer(op, arg, nt, ot, tp, tn); 3563 else if (is_floating(ot)) 3564 convert_integer_from_floating(op, tp, tn); 3565 else if (ot == PTR) 3566 convert_integer_from_pointer(op, nt, tp, tn); 3567 3568 } else if (is_floating(nt)) { 3569 /* No further checks. */ 3570 3571 } else if (nt == PTR) { 3572 if (is_null_pointer(tn)) { 3573 /* a null pointer may be assigned to any pointer. */ 3574 } else if (ot == PTR && op == CVT) 3575 convert_pointer_from_pointer(tp, tn); 3576 } 3577 3578 tnode_t *ntn = expr_alloc_tnode(); 3579 ntn->tn_op = CVT; 3580 ntn->tn_type = tp; 3581 ntn->tn_cast = op == CVT; 3582 ntn->tn_sys |= tn->tn_sys; 3583 ntn->tn_right = NULL; 3584 if (tn->tn_op != CON || nt == VOID) { 3585 ntn->tn_left = tn; 3586 } else { 3587 ntn->tn_op = CON; 3588 convert_constant(op, arg, ntn->tn_type, &ntn->tn_val, 3589 &tn->tn_val); 3590 } 3591 3592 return ntn; 3593 } 3594 3595 static void 3596 convert_constant_floating(op_t op, int arg, tspec_t ot, const type_t *tp, 3597 tspec_t nt, val_t *v, val_t *nv) 3598 { 3599 long double max = 0.0, min = 0.0; 3600 3601 switch (nt) { 3602 case CHAR: 3603 max = TARG_CHAR_MAX; min = TARG_CHAR_MIN; break; 3604 case UCHAR: 3605 max = TARG_UCHAR_MAX; min = 0; break; 3606 case SCHAR: 3607 max = TARG_SCHAR_MAX; min = TARG_SCHAR_MIN; break; 3608 case SHORT: 3609 max = TARG_SHRT_MAX; min = TARG_SHRT_MIN; break; 3610 case USHORT: 3611 max = TARG_USHRT_MAX; min = 0; break; 3612 case ENUM: 3613 case INT: 3614 max = TARG_INT_MAX; min = TARG_INT_MIN; break; 3615 case UINT: 3616 max = TARG_UINT_MAX; min = 0; break; 3617 case LONG: 3618 max = TARG_LONG_MAX; min = TARG_LONG_MIN; break; 3619 case ULONG: 3620 max = TARG_ULONG_MAX; min = 0; break; 3621 case LLONG: 3622 max = LLONG_MAX; min = LLONG_MIN; break; 3623 case ULLONG: 3624 max = ULLONG_MAX; min = 0; break; 3625 case FLOAT: 3626 case FCOMPLEX: 3627 max = FLT_MAX; min = -FLT_MAX; break; 3628 case DOUBLE: 3629 case DCOMPLEX: 3630 max = DBL_MAX; min = -DBL_MAX; break; 3631 case PTR: 3632 /* Already got an error because of float --> ptr */ 3633 case LDOUBLE: 3634 case LCOMPLEX: 3635 /* LINTED 248 */ 3636 max = LDBL_MAX; min = -max; break; 3637 default: 3638 lint_assert(/*CONSTCOND*/false); 3639 } 3640 if (v->u.floating > max || v->u.floating < min) { 3641 lint_assert(nt != LDOUBLE); 3642 if (op == FARG) { 3643 /* conversion of '%s' to '%s' is out of range, ... */ 3644 warning(295, 3645 type_name(gettyp(ot)), type_name(tp), arg); 3646 } else { 3647 /* conversion of '%s' to '%s' is out of range */ 3648 warning(119, type_name(gettyp(ot)), type_name(tp)); 3649 } 3650 v->u.floating = v->u.floating > 0 ? max : min; 3651 } 3652 3653 if (nt == FLOAT || nt == FCOMPLEX) 3654 nv->u.floating = (float)v->u.floating; 3655 else if (nt == DOUBLE || nt == DCOMPLEX) 3656 nv->u.floating = (double)v->u.floating; 3657 else if (nt == LDOUBLE || nt == LCOMPLEX) 3658 nv->u.floating = v->u.floating; 3659 else 3660 nv->u.integer = (int64_t)v->u.floating; 3661 } 3662 3663 static bool 3664 convert_constant_to_floating(tspec_t nt, val_t *nv, 3665 tspec_t ot, const val_t *v) 3666 { 3667 if (nt == FLOAT) { 3668 nv->u.floating = (ot == PTR || is_uinteger(ot)) ? 3669 (float)(uint64_t)v->u.integer : (float)v->u.integer; 3670 } else if (nt == DOUBLE) { 3671 nv->u.floating = (ot == PTR || is_uinteger(ot)) ? 3672 (double)(uint64_t)v->u.integer : (double)v->u.integer; 3673 } else if (nt == LDOUBLE) { 3674 nv->u.floating = (ot == PTR || is_uinteger(ot)) 3675 ? (long double)(uint64_t)v->u.integer 3676 : (long double)v->u.integer; 3677 } else 3678 return false; 3679 return true; 3680 } 3681 3682 /* 3683 * Print a warning if bits which were set are lost due to the conversion. 3684 * This can happen with operator ORASS only. 3685 */ 3686 static void 3687 convert_constant_check_range_bitor(size_t nsz, size_t osz, const val_t *v, 3688 uint64_t xmask, op_t op) 3689 { 3690 if (nsz < osz && (v->u.integer & xmask) != 0) { 3691 /* constant truncated by conversion, op '%s' */ 3692 warning(306, op_name(op)); 3693 } 3694 } 3695 3696 static void 3697 convert_constant_check_range_bitand(size_t nsz, size_t osz, 3698 uint64_t xmask, const val_t *nv, 3699 tspec_t ot, const val_t *v, 3700 const type_t *tp, op_t op) 3701 { 3702 if (nsz > osz && 3703 (nv->u.integer & bit((unsigned int)(osz - 1))) != 0 && 3704 (nv->u.integer & xmask) != xmask) { 3705 /* extra bits set to 0 in conversion of '%s' to '%s', ... */ 3706 warning(309, type_name(gettyp(ot)), 3707 type_name(tp), op_name(op)); 3708 } else if (nsz < osz && 3709 (v->u.integer & xmask) != xmask && 3710 (v->u.integer & xmask) != 0) { 3711 /* constant truncated by conversion, op '%s' */ 3712 warning(306, op_name(op)); 3713 } 3714 } 3715 3716 static void 3717 convert_constant_check_range_signed(op_t op, int arg) 3718 { 3719 if (op == ASSIGN) { 3720 /* assignment of negative constant to unsigned type */ 3721 warning(164); 3722 } else if (op == INIT) { 3723 /* initialization of unsigned with negative constant */ 3724 warning(221); 3725 } else if (op == FARG) { 3726 /* conversion of negative constant to unsigned type, ... */ 3727 warning(296, arg); 3728 } else if (modtab[op].m_comparison) { 3729 /* handled by check_integer_comparison() */ 3730 } else { 3731 /* conversion of negative constant to unsigned type */ 3732 warning(222); 3733 } 3734 } 3735 3736 /* 3737 * Loss of significant bit(s). All truncated bits of unsigned types or all 3738 * truncated bits plus the msb of the target for signed types are considered 3739 * to be significant bits. Loss of significant bits means that at least one 3740 * of the bits was set in an unsigned type or that at least one but not all 3741 * of the bits was set in a signed type. Loss of significant bits means that 3742 * it is not possible, also not with necessary casts, to convert back to the 3743 * original type. An example for a necessary cast is: 3744 * char c; int i; c = 128; 3745 * i = c; ** yields -128 ** 3746 * i = (unsigned char)c; ** yields 128 ** 3747 */ 3748 static void 3749 warn_constant_check_range_truncated(op_t op, int arg, const type_t *tp, 3750 tspec_t ot) 3751 { 3752 if (op == ASSIGN && tp->t_bitfield) 3753 /* precision lost in bit-field assignment */ 3754 warning(166); 3755 else if (op == ASSIGN) 3756 /* constant truncated by assignment */ 3757 warning(165); 3758 else if (op == INIT && tp->t_bitfield) 3759 /* bit-field initializer does not fit */ 3760 warning(180); 3761 else if (op == INIT) 3762 /* initializer does not fit */ 3763 warning(178); 3764 else if (op == CASE) 3765 /* case label affected by conversion */ 3766 warning(196); 3767 else if (op == FARG) 3768 /* conversion of '%s' to '%s' is out of range, arg #%d */ 3769 warning(295, type_name(gettyp(ot)), type_name(tp), arg); 3770 else 3771 /* conversion of '%s' to '%s' is out of range */ 3772 warning(119, type_name(gettyp(ot)), type_name(tp)); 3773 } 3774 3775 static void 3776 warn_constant_check_range_loss(op_t op, int arg, const type_t *tp, 3777 tspec_t ot) 3778 { 3779 if (op == ASSIGN && tp->t_bitfield) 3780 /* precision lost in bit-field assignment */ 3781 warning(166); 3782 else if (op == INIT && tp->t_bitfield) 3783 /* bit-field initializer out of range */ 3784 warning(11); 3785 else if (op == CASE) 3786 /* case label affected by conversion */ 3787 warning(196); 3788 else if (op == FARG) 3789 /* conversion of '%s' to '%s' is out of range, arg #%d */ 3790 warning(295, type_name(gettyp(ot)), type_name(tp), arg); 3791 else 3792 /* conversion of '%s' to '%s' is out of range */ 3793 warning(119, type_name(gettyp(ot)), type_name(tp)); 3794 } 3795 3796 static void 3797 convert_constant_check_range(tspec_t ot, const type_t *tp, tspec_t nt, 3798 op_t op, int arg, const val_t *v, val_t *nv) 3799 { 3800 unsigned int obitsz, nbitsz; 3801 uint64_t xmask, xmsk1; 3802 3803 obitsz = size_in_bits(ot); 3804 nbitsz = tp->t_bitfield ? tp->t_bit_field_width : size_in_bits(nt); 3805 xmask = value_bits(nbitsz) ^ value_bits(obitsz); 3806 xmsk1 = value_bits(nbitsz) ^ value_bits(obitsz - 1); 3807 if (op == ORASS || op == BITOR || op == BITXOR) { 3808 convert_constant_check_range_bitor( 3809 nbitsz, obitsz, v, xmask, op); 3810 } else if (op == ANDASS || op == BITAND) { 3811 convert_constant_check_range_bitand( 3812 nbitsz, obitsz, xmask, nv, ot, v, tp, op); 3813 } else if (nt != PTR && is_uinteger(nt) && 3814 ot != PTR && !is_uinteger(ot) && 3815 v->u.integer < 0) 3816 convert_constant_check_range_signed(op, arg); 3817 else if (nv->u.integer != v->u.integer && nbitsz <= obitsz && 3818 (v->u.integer & xmask) != 0 && 3819 (is_uinteger(ot) || (v->u.integer & xmsk1) != xmsk1)) 3820 warn_constant_check_range_truncated(op, arg, tp, ot); 3821 else if (nv->u.integer != v->u.integer) 3822 warn_constant_check_range_loss(op, arg, tp, ot); 3823 } 3824 3825 /*- 3826 * Converts a typed constant to a constant of another type. 3827 * 3828 * op operator which requires conversion 3829 * arg if op is FARG, # of parameter 3830 * tp type to which to convert the constant 3831 * nv new constant 3832 * v old constant 3833 */ 3834 void 3835 convert_constant(op_t op, int arg, const type_t *tp, val_t *nv, val_t *v) 3836 { 3837 /* 3838 * TODO: make 'v' const; the name of this function does not suggest 3839 * that it modifies 'v'. 3840 */ 3841 tspec_t ot = v->v_tspec; 3842 tspec_t nt = nv->v_tspec = tp->t_tspec; 3843 bool range_check = false; 3844 3845 if (nt == BOOL) { /* C99 6.3.1.2 */ 3846 nv->v_unsigned_since_c90 = false; 3847 nv->u.integer = is_nonzero_val(v) ? 1 : 0; 3848 return; 3849 } 3850 3851 if (ot == FLOAT || ot == DOUBLE || ot == LDOUBLE) 3852 convert_constant_floating(op, arg, ot, tp, nt, v, nv); 3853 else if (!convert_constant_to_floating(nt, nv, ot, v)) { 3854 range_check = true; /* Check for lost precision. */ 3855 nv->u.integer = v->u.integer; 3856 } 3857 3858 if (allow_trad && allow_c90 && v->v_unsigned_since_c90 && 3859 (is_floating(nt) || ( 3860 (is_integer(nt) && !is_uinteger(nt) && 3861 portable_rank_cmp(nt, ot) > 0)))) { 3862 /* C90 treats constant as unsigned */ 3863 warning(157); 3864 v->v_unsigned_since_c90 = false; 3865 } 3866 3867 if (is_integer(nt)) { 3868 nv->u.integer = convert_integer(nv->u.integer, nt, 3869 tp->t_bitfield ? tp->t_bit_field_width : size_in_bits(nt)); 3870 } 3871 3872 if (range_check && op != CVT) 3873 convert_constant_check_range(ot, tp, nt, op, arg, v, nv); 3874 } 3875 3876 tnode_t * 3877 build_sizeof(const type_t *tp) 3878 { 3879 unsigned int size_in_bytes = type_size_in_bits(tp) / CHAR_SIZE; 3880 tnode_t *tn = build_integer_constant(SIZEOF_TSPEC, size_in_bytes); 3881 tn->tn_system_dependent = true; 3882 debug_step("build_sizeof '%s' = %u", type_name(tp), size_in_bytes); 3883 return tn; 3884 } 3885 3886 tnode_t * 3887 build_offsetof(const type_t *tp, const sym_t *sym) 3888 { 3889 unsigned int offset_in_bits = 0; 3890 3891 if (!is_struct_or_union(tp->t_tspec)) { 3892 /* unacceptable operand of '%s' */ 3893 error(111, "offsetof"); 3894 goto proceed; 3895 } 3896 sym_t *mem = find_member(tp->t_sou, sym->s_name); 3897 if (mem == NULL) { 3898 /* type '%s' does not have member '%s' */ 3899 error(101, sym->s_name, type_name(tp)); 3900 goto proceed; 3901 } 3902 offset_in_bits = mem->u.s_member.sm_offset_in_bits; 3903 3904 proceed:; 3905 unsigned int offset_in_bytes = offset_in_bits / CHAR_SIZE; 3906 tnode_t *tn = build_integer_constant(SIZEOF_TSPEC, offset_in_bytes); 3907 tn->tn_system_dependent = true; 3908 return tn; 3909 } 3910 3911 unsigned int 3912 type_size_in_bits(const type_t *tp) 3913 { 3914 3915 unsigned int elem = 1; 3916 bool flex = false; 3917 lint_assert(tp != NULL); 3918 while (tp->t_tspec == ARRAY) { 3919 flex = true; /* allow c99 flex arrays [] [0] */ 3920 elem *= tp->t_dim; 3921 tp = tp->t_subt; 3922 } 3923 if (elem == 0 && !flex) { 3924 /* cannot take size/alignment of incomplete type */ 3925 error(143); 3926 elem = 1; 3927 } 3928 3929 unsigned int elsz; 3930 switch (tp->t_tspec) { 3931 case VOID: 3932 /* cannot take size/alignment of void */ 3933 error(146); 3934 elsz = 1; 3935 break; 3936 case FUNC: 3937 /* cannot take size/alignment of function type '%s' */ 3938 error(144, type_name(tp)); 3939 elsz = 1; 3940 break; 3941 case STRUCT: 3942 case UNION: 3943 if (is_incomplete(tp)) { 3944 /* cannot take size/alignment of incomplete type */ 3945 error(143); 3946 elsz = 1; 3947 } else { 3948 elsz = tp->t_sou->sou_size_in_bits; 3949 } 3950 break; 3951 case ENUM: 3952 if (is_incomplete(tp)) { 3953 /* cannot take size/alignment of incomplete type */ 3954 warning(143); 3955 } 3956 /* FALLTHROUGH */ 3957 default: 3958 if (tp->t_bitfield) { 3959 /* cannot take size/alignment of bit-field */ 3960 error(145); 3961 } 3962 elsz = size_in_bits(tp->t_tspec); 3963 lint_assert(elsz > 0); 3964 break; 3965 } 3966 3967 return elem * elsz; 3968 } 3969 3970 /* C11 6.5.3.4, GCC */ 3971 tnode_t * 3972 build_alignof(const type_t *tp) 3973 { 3974 if (tp->t_tspec == FUNC) { 3975 /* cannot take size/alignment of function type '%s' */ 3976 error(144, type_name(tp)); 3977 return NULL; 3978 } 3979 if (tp->t_tspec == VOID) { 3980 /* cannot take size/alignment of void */ 3981 error(146); 3982 return NULL; 3983 } 3984 if (is_incomplete(tp)) { 3985 /* cannot take size/alignment of incomplete type */ 3986 error(143); 3987 return NULL; 3988 } 3989 if (tp->t_bitfield) { 3990 /* cannot take size/alignment of bit-field */ 3991 error(145); 3992 return NULL; 3993 } 3994 return build_integer_constant(SIZEOF_TSPEC, 3995 (int64_t)alignment_in_bits(tp) / CHAR_SIZE); 3996 } 3997 3998 static tnode_t * 3999 cast_to_union(tnode_t *otn, type_t *ntp) 4000 { 4001 4002 if (!allow_gcc) { 4003 /* union cast is a GCC extension */ 4004 error(328); 4005 return NULL; 4006 } 4007 4008 for (const sym_t *m = ntp->t_sou->sou_first_member; 4009 m != NULL; m = m->s_next) { 4010 if (types_compatible(m->s_type, otn->tn_type, 4011 false, false, NULL)) { 4012 tnode_t *ntn = expr_alloc_tnode(); 4013 ntn->tn_op = CVT; 4014 ntn->tn_type = ntp; 4015 ntn->tn_cast = true; 4016 ntn->tn_left = otn; 4017 ntn->tn_right = NULL; 4018 return ntn; 4019 } 4020 } 4021 4022 /* type '%s' is not a member of '%s' */ 4023 error(329, type_name(otn->tn_type), type_name(ntp)); 4024 return NULL; 4025 } 4026 4027 tnode_t * 4028 cast(tnode_t *tn, type_t *tp) 4029 { 4030 4031 if (tn == NULL) 4032 return NULL; 4033 4034 tn = cconv(tn); 4035 4036 lint_assert(tp != NULL); 4037 tspec_t nt = tp->t_tspec; 4038 tspec_t ot = tn->tn_type->t_tspec; 4039 4040 if (nt == VOID) { 4041 /* 4042 * C90 6.3.4, C99 6.5.4p2 and C11 6.5.4p2 allow any type to be 4043 * cast to void. The only other allowed casts are from a 4044 * scalar type to a scalar type. 4045 */ 4046 } else if (nt == UNION) 4047 return cast_to_union(tn, tp); 4048 else if (nt == STRUCT || nt == ARRAY || nt == FUNC) { 4049 /* Casting to a struct is an undocumented GCC extension. */ 4050 if (!(allow_gcc && nt == STRUCT)) 4051 goto invalid_cast; 4052 } else if (is_struct_or_union(ot)) 4053 goto invalid_cast; 4054 else if (ot == VOID) { 4055 /* improper cast of void expression */ 4056 error(148); 4057 return NULL; 4058 } else if (is_integer(nt) && is_scalar(ot)) { 4059 /* ok */ 4060 } else if (is_floating(nt) && is_arithmetic(ot)) { 4061 /* ok */ 4062 } else if (nt == PTR && is_integer(ot)) { 4063 /* ok */ 4064 } else if (nt == PTR && ot == PTR) { 4065 if (!tp->t_subt->t_const && tn->tn_type->t_subt->t_const) { 4066 if (hflag) 4067 /* cast discards 'const' from type '%s' */ 4068 warning(275, type_name(tn->tn_type)); 4069 } 4070 } else 4071 goto invalid_cast; 4072 4073 if (any_query_enabled && types_compatible(tp, tn->tn_type, 4074 false, false, NULL)) { 4075 /* no-op cast from '%s' to '%s' */ 4076 query_message(6, type_name(tn->tn_type), type_name(tp)); 4077 } 4078 4079 tn = convert(CVT, 0, tp, tn); 4080 tn->tn_cast = true; 4081 4082 return tn; 4083 4084 invalid_cast: 4085 /* invalid cast from '%s' to '%s' */ 4086 error(147, type_name(tn->tn_type), type_name(tp)); 4087 return NULL; 4088 } 4089 4090 /* 4091 * Create the node for a function argument. 4092 * All necessary conversions and type checks are done in 4093 * build_function_call because build_function_argument has no 4094 * information about the expected parameter types. 4095 */ 4096 tnode_t * 4097 build_function_argument(tnode_t *args, tnode_t *arg) 4098 { 4099 /* 4100 * If there was a serious error in the expression for the argument, 4101 * create a dummy argument so the positions of the remaining arguments 4102 * will not change. 4103 */ 4104 if (arg == NULL) 4105 arg = build_integer_constant(INT, 0); 4106 4107 return build_op(PUSH, arg->tn_sys, arg->tn_type, arg, args); 4108 } 4109 4110 /* 4111 * Compare the type of an argument with the corresponding type of a 4112 * prototype parameter. If it is a valid combination, but both types 4113 * are not the same, insert a conversion to convert the argument into 4114 * the type of the parameter. 4115 */ 4116 static tnode_t * 4117 check_prototype_argument( 4118 int n, /* pos of arg */ 4119 type_t *tp, /* expected type (from prototype) */ 4120 tnode_t *tn) /* argument */ 4121 { 4122 tnode_t *ln = xcalloc(1, sizeof(*ln)); 4123 ln->tn_type = expr_unqualified_type(tp); 4124 ln->tn_lvalue = true; 4125 if (typeok(FARG, n, ln, tn)) { 4126 bool dowarn; 4127 if (!types_compatible(tp, tn->tn_type, 4128 true, false, (dowarn = false, &dowarn)) || dowarn) 4129 tn = convert(FARG, n, tp, tn); 4130 } 4131 free(ln); 4132 return tn; 4133 } 4134 4135 /* 4136 * Check types of all function arguments and insert conversions, 4137 * if necessary. 4138 */ 4139 static tnode_t * 4140 check_function_arguments(type_t *ftp, tnode_t *args) 4141 { 4142 /* get # of parameters in the prototype */ 4143 int npar = 0; 4144 for (const sym_t *p = ftp->t_params; p != NULL; p = p->s_next) 4145 npar++; 4146 4147 /* get # of arguments in the function call */ 4148 int narg = 0; 4149 for (const tnode_t *arg = args; arg != NULL; arg = tn_ck_right(arg)) 4150 narg++; 4151 4152 const sym_t *param = ftp->t_params; 4153 if (ftp->t_proto && npar != narg && !(ftp->t_vararg && npar < narg)) { 4154 /* argument mismatch: %d %s passed, %d expected */ 4155 error(150, narg, narg != 1 ? "arguments" : "argument", npar); 4156 param = NULL; 4157 } 4158 4159 for (int n = 1; n <= narg; n++) { 4160 4161 // The rightmost argument starts the argument list. 4162 tnode_t *arg = args; 4163 for (int i = narg; i > n; i--, arg = arg->tn_right) 4164 continue; 4165 4166 /* some things which are always not allowed */ 4167 tspec_t at = arg->tn_left->tn_type->t_tspec; 4168 if (at == VOID) { 4169 /* void expressions may not be arguments, arg #%d */ 4170 error(151, n); 4171 return NULL; 4172 } 4173 if (is_struct_or_union(at) && 4174 is_incomplete(arg->tn_left->tn_type)) { 4175 /* argument cannot have unknown size, arg #%d */ 4176 error(152, n); 4177 return NULL; 4178 } 4179 if (is_integer(at) && 4180 arg->tn_left->tn_type->t_is_enum && 4181 is_incomplete(arg->tn_left->tn_type)) { 4182 /* argument cannot have unknown size, arg #%d */ 4183 warning(152, n); 4184 } 4185 4186 arg->tn_left = cconv(arg->tn_left); 4187 4188 if (param != NULL) { 4189 arg->tn_left = check_prototype_argument( 4190 n, param->s_type, arg->tn_left); 4191 } else 4192 arg->tn_left = promote(NOOP, true, arg->tn_left); 4193 arg->tn_type = arg->tn_left->tn_type; 4194 4195 if (param != NULL) 4196 param = param->s_next; 4197 } 4198 4199 return args; 4200 } 4201 4202 tnode_t * 4203 build_function_call(tnode_t *func, bool sys, tnode_t *args) 4204 { 4205 4206 if (func == NULL) 4207 return NULL; 4208 4209 op_t fcop = func->tn_op == NAME && func->tn_type->t_tspec == FUNC 4210 ? CALL : ICALL; 4211 4212 check_ctype_function_call(func, args); 4213 4214 func = cconv(func); 4215 4216 if (func->tn_type->t_tspec != PTR || 4217 func->tn_type->t_subt->t_tspec != FUNC) { 4218 /* cannot call '%s', must be a function */ 4219 error(149, type_name(func->tn_type)); 4220 return NULL; 4221 } 4222 4223 args = check_function_arguments(func->tn_type->t_subt, args); 4224 4225 return build_op(fcop, sys, func->tn_type->t_subt->t_subt, func, args); 4226 } 4227 4228 /* 4229 * Return the value of an integral constant expression. 4230 * If the expression is not constant or its type is not an integer 4231 * type, an error message is printed. 4232 */ 4233 val_t * 4234 integer_constant(tnode_t *tn, bool required) 4235 { 4236 4237 if (tn != NULL) 4238 tn = cconv(tn); 4239 if (tn != NULL) 4240 tn = promote(NOOP, false, tn); 4241 4242 val_t *v = xcalloc(1, sizeof(*v)); 4243 4244 if (tn == NULL) { 4245 lint_assert(seen_error); 4246 debug_step("constant node is null; returning 1 instead"); 4247 v->v_tspec = INT; 4248 v->u.integer = 1; 4249 return v; 4250 } 4251 4252 v->v_tspec = tn->tn_type->t_tspec; 4253 4254 if (tn->tn_op == CON) { 4255 lint_assert(tn->tn_type->t_tspec == tn->tn_val.v_tspec); 4256 if (is_integer(tn->tn_val.v_tspec)) { 4257 v->v_unsigned_since_c90 = 4258 tn->tn_val.v_unsigned_since_c90; 4259 v->u.integer = tn->tn_val.u.integer; 4260 return v; 4261 } 4262 v->u.integer = (int64_t)tn->tn_val.u.floating; 4263 } else { 4264 v->u.integer = 1; 4265 } 4266 4267 if (required) 4268 /* integral constant expression expected */ 4269 error(55); 4270 else 4271 /* variable array dimension is a C99/GCC extension */ 4272 c99ism(318); 4273 4274 if (!is_integer(v->v_tspec)) 4275 v->v_tspec = INT; 4276 4277 return v; 4278 } 4279 4280 static bool 4281 is_constcond_false(const tnode_t *tn, tspec_t t) 4282 { 4283 return (t == BOOL || t == INT) && 4284 tn->tn_op == CON && tn->tn_val.u.integer == 0; 4285 } 4286 4287 /* 4288 * Perform some tests on expressions which can't be done in build_binary() 4289 * and functions called by build_binary(). These tests must be done here 4290 * because we need some information about the context in which the operations 4291 * are performed. 4292 * After all tests are performed and dofreeblk is true, expr() frees the 4293 * memory which is used for the expression. 4294 */ 4295 void 4296 expr(tnode_t *tn, bool vctx, bool cond, bool dofreeblk, bool is_do_while) 4297 { 4298 4299 if (tn == NULL) { /* in case of errors */ 4300 expr_free_all(); 4301 return; 4302 } 4303 4304 /* expr() is also called in global initializations */ 4305 if (dcs->d_kind != DLK_EXTERN && !is_do_while) 4306 check_statement_reachable(); 4307 4308 check_expr_misc(tn, vctx, cond, !cond, false, false, false); 4309 if (tn->tn_op == ASSIGN && !tn->tn_parenthesized) { 4310 if (hflag && cond) 4311 /* assignment in conditional context */ 4312 warning(159); 4313 } else if (tn->tn_op == CON) { 4314 if (hflag && cond && !suppress_constcond && 4315 !tn->tn_system_dependent && 4316 !(is_do_while && 4317 is_constcond_false(tn, tn->tn_type->t_tspec))) 4318 /* constant in conditional context */ 4319 warning(161); 4320 } 4321 if (!modtab[tn->tn_op].m_has_side_effect) { 4322 /* 4323 * for left operands of COMMA this warning is already printed 4324 */ 4325 if (tn->tn_op != COMMA && !vctx && !cond) 4326 check_null_effect(tn); 4327 } 4328 debug_node(tn); 4329 4330 if (dofreeblk) 4331 expr_free_all(); 4332 } 4333 4334 /* 4335 * Checks the range of array indices, if possible. 4336 * amper is set if only the address of the element is used. This 4337 * means that the index is allowed to refer to the first element 4338 * after the array. 4339 */ 4340 static void 4341 check_array_index(tnode_t *tn, bool amper) 4342 { 4343 lint_assert(has_operands(tn)); 4344 const tnode_t *ln = tn->tn_left; 4345 const tnode_t *rn = tn->tn_right; 4346 4347 /* We can only check constant indices. */ 4348 if (rn->tn_op != CON) 4349 return; 4350 4351 /* Return if the left node does not stem from an array. */ 4352 if (ln->tn_op != ADDR) 4353 return; 4354 if (ln->tn_left->tn_op != STRING && ln->tn_left->tn_op != NAME) 4355 return; 4356 if (ln->tn_left->tn_type->t_tspec != ARRAY) 4357 return; 4358 4359 /* 4360 * For incomplete array types, we can print a warning only if the index 4361 * is negative. 4362 */ 4363 if (is_incomplete(ln->tn_left->tn_type) && rn->tn_val.u.integer >= 0) 4364 return; 4365 4366 int elsz = length_in_bits(ln->tn_type->t_subt, NULL); 4367 if (elsz == 0) 4368 return; 4369 elsz /= CHAR_SIZE; 4370 4371 /* Change the unit of the index from bytes to element size. */ 4372 int64_t con = is_uinteger(rn->tn_type->t_tspec) 4373 ? (int64_t)((uint64_t)rn->tn_val.u.integer / elsz) 4374 : rn->tn_val.u.integer / elsz; 4375 4376 int dim = ln->tn_left->tn_type->t_dim + (amper ? 1 : 0); 4377 4378 if (!is_uinteger(rn->tn_type->t_tspec) && con < 0) { 4379 /* array subscript cannot be negative: %ld */ 4380 warning(167, (long)con); 4381 } else if (dim > 0 && (uint64_t)con >= (uint64_t)dim) { 4382 /* array subscript cannot be > %d: %ld */ 4383 warning(168, dim - 1, (long)con); 4384 } 4385 } 4386 4387 static void 4388 check_expr_addr(const tnode_t *ln, bool szof, bool fcall) 4389 { 4390 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 4391 if (ln->tn_op == NAME && (reached || !warn_about_unreachable)) { 4392 if (!szof) 4393 mark_as_set(ln->tn_sym); 4394 mark_as_used(ln->tn_sym, fcall, szof); 4395 } 4396 if (ln->tn_op == INDIR && ln->tn_left->tn_op == PLUS) 4397 check_array_index(ln->tn_left, true); 4398 } 4399 4400 static void 4401 check_expr_load(const tnode_t *ln) 4402 { 4403 if (ln->tn_op == INDIR && ln->tn_left->tn_op == PLUS) 4404 check_array_index(ln->tn_left, false); 4405 } 4406 4407 /* 4408 * If there is an asm statement in one of the compound statements around, 4409 * there may be other side effects, so don't warn. 4410 */ 4411 static bool 4412 is_asm_around(void) 4413 { 4414 for (decl_level *dl = dcs; dl != NULL; dl = dl->d_enclosing) 4415 if (dl->d_asm) 4416 return true; 4417 return false; 4418 } 4419 4420 static void 4421 check_expr_side_effect(const tnode_t *ln, bool szof) 4422 { 4423 4424 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 4425 if (ln->tn_op == NAME && (reached || !warn_about_unreachable)) { 4426 scl_t sc = ln->tn_sym->s_scl; 4427 if (sc != EXTERN && sc != STATIC && 4428 !ln->tn_sym->s_set && !szof && !is_asm_around()) { 4429 /* '%s' may be used before set */ 4430 warning(158, ln->tn_sym->s_name); 4431 mark_as_set(ln->tn_sym); 4432 } 4433 mark_as_used(ln->tn_sym, false, false); 4434 } 4435 } 4436 4437 static void 4438 check_expr_assign(const tnode_t *ln, bool szof) 4439 { 4440 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 4441 if (ln->tn_op == NAME && !szof && (reached || !warn_about_unreachable)) { 4442 mark_as_set(ln->tn_sym); 4443 if (ln->tn_sym->s_scl == EXTERN) 4444 outusg(ln->tn_sym); 4445 } 4446 if (ln->tn_op == INDIR && ln->tn_left->tn_op == PLUS) 4447 /* check the range of array indices */ 4448 check_array_index(ln->tn_left, false); 4449 } 4450 4451 static void 4452 check_expr_call(const tnode_t *tn, const tnode_t *ln, 4453 bool szof, bool vctx, bool cond, bool retval_discarded) 4454 { 4455 lint_assert(ln->tn_op == ADDR); 4456 lint_assert(ln->tn_left->tn_op == NAME); 4457 if (!szof && !is_compiler_builtin(ln->tn_left->tn_sym->s_name)) 4458 outcall(tn, vctx || cond, retval_discarded); 4459 } 4460 4461 static void 4462 check_expr_op(const tnode_t *tn, op_t op, const tnode_t *ln, 4463 bool szof, bool fcall, bool vctx, bool cond, 4464 bool retval_discarded, bool eqwarn) 4465 { 4466 switch (op) { 4467 case ADDR: 4468 check_expr_addr(ln, szof, fcall); 4469 break; 4470 case LOAD: 4471 check_expr_load(ln); 4472 /* FALLTHROUGH */ 4473 case PUSH: 4474 case INCBEF: 4475 case DECBEF: 4476 case INCAFT: 4477 case DECAFT: 4478 case ADDASS: 4479 case SUBASS: 4480 case MULASS: 4481 case DIVASS: 4482 case MODASS: 4483 case ANDASS: 4484 case ORASS: 4485 case XORASS: 4486 case SHLASS: 4487 case SHRASS: 4488 case REAL: 4489 case IMAG: 4490 check_expr_side_effect(ln, szof); 4491 break; 4492 case ASSIGN: 4493 check_expr_assign(ln, szof); 4494 break; 4495 case CALL: 4496 check_expr_call(tn, ln, szof, vctx, cond, retval_discarded); 4497 break; 4498 case EQ: 4499 if (hflag && eqwarn) 4500 /* operator '==' found where '=' was expected */ 4501 warning(160); 4502 break; 4503 default: 4504 break; 4505 } 4506 } 4507 4508 /* 4509 * vctx ??? 4510 * cond whether the expression is a condition that 4511 * will be compared with 0 4512 * eqwarn whether the operator '==' might be a 4513 * misspelled '=' 4514 * fcall whether the expression is a function call 4515 * retval_discarded whether the return value of a function call 4516 * is discarded; such calls will be analyzed by 4517 * lint2 in messages 4, 8 and 9 4518 * szof whether the expression is part of a sizeof 4519 * expression, which means that its value is 4520 * discarded since only the type is relevant 4521 */ 4522 void 4523 check_expr_misc(const tnode_t *tn, bool vctx, bool cond, 4524 bool eqwarn, bool fcall, bool retval_discarded, bool szof) 4525 { 4526 4527 if (tn == NULL) 4528 return; 4529 op_t op = tn->tn_op; 4530 if (op == NAME || op == CON || op == STRING) 4531 return; 4532 4533 lint_assert(has_operands(tn)); 4534 tnode_t *ln = tn->tn_left; 4535 tnode_t *rn = tn->tn_right; 4536 check_expr_op(tn, op, ln, 4537 szof, fcall, vctx, cond, retval_discarded, eqwarn); 4538 4539 const mod_t *mp = &modtab[op]; 4540 bool cvctx = mp->m_value_context; 4541 bool ccond = mp->m_compares_with_zero; 4542 bool eq = mp->m_warn_if_operand_eq && 4543 !ln->tn_parenthesized && 4544 rn != NULL && !rn->tn_parenthesized; 4545 4546 /* 4547 * Values of operands of ':' are not used if the type of at least 4548 * one of the operands (for GCC compatibility) is 'void'. 4549 * 4550 * XXX test/value context of QUEST should probably be used as 4551 * context for both operands of COLON. 4552 */ 4553 if (op == COLON && tn->tn_type->t_tspec == VOID) 4554 cvctx = ccond = false; 4555 bool discard = op == CVT && tn->tn_type->t_tspec == VOID; 4556 check_expr_misc(ln, cvctx, ccond, eq, op == CALL, discard, szof); 4557 4558 switch (op) { 4559 case PUSH: 4560 if (rn != NULL) 4561 check_expr_misc(rn, false, false, eq, false, false, 4562 szof); 4563 break; 4564 case LOGAND: 4565 case LOGOR: 4566 check_expr_misc(rn, false, true, eq, false, false, szof); 4567 break; 4568 case COLON: 4569 check_expr_misc(rn, cvctx, ccond, eq, false, false, szof); 4570 break; 4571 case COMMA: 4572 check_expr_misc(rn, vctx, cond, false, false, false, szof); 4573 break; 4574 default: 4575 if (mp->m_binary) 4576 check_expr_misc(rn, true, false, eq, false, false, 4577 szof); 4578 break; 4579 } 4580 } 4581 4582 /* 4583 * Return whether the expression can be used for static initialization. 4584 * 4585 * Constant initialization expressions must be constant or an address 4586 * of a static object with an optional offset. In the first case, 4587 * the result is returned in *offsp. In the second case, the static 4588 * object is returned in *symp and the offset in *offsp. 4589 * 4590 * The expression can consist of PLUS, MINUS, ADDR, NAME, STRING and 4591 * CON. Type conversions are allowed if they do not change binary 4592 * representation (including width). 4593 * 4594 * C99 6.6 "Constant expressions" 4595 * C99 6.7.8p4 restricts initializers for static storage duration 4596 */ 4597 bool 4598 constant_addr(const tnode_t *tn, const sym_t **symp, ptrdiff_t *offsp) 4599 { 4600 const sym_t *sym; 4601 ptrdiff_t offs1, offs2; 4602 tspec_t t, ot; 4603 4604 switch (tn->tn_op) { 4605 case MINUS: 4606 if (tn->tn_right->tn_op == CVT) 4607 return constant_addr(tn->tn_right, symp, offsp); 4608 else if (tn->tn_right->tn_op != CON) 4609 return false; 4610 /* FALLTHROUGH */ 4611 case PLUS: 4612 offs1 = offs2 = 0; 4613 if (tn->tn_left->tn_op == CON) { 4614 offs1 = (ptrdiff_t)tn->tn_left->tn_val.u.integer; 4615 if (!constant_addr(tn->tn_right, &sym, &offs2)) 4616 return false; 4617 } else if (tn->tn_right->tn_op == CON) { 4618 offs2 = (ptrdiff_t)tn->tn_right->tn_val.u.integer; 4619 if (tn->tn_op == MINUS) 4620 offs2 = -offs2; 4621 if (!constant_addr(tn->tn_left, &sym, &offs1)) 4622 return false; 4623 } else { 4624 return false; 4625 } 4626 *symp = sym; 4627 *offsp = offs1 + offs2; 4628 return true; 4629 case ADDR: 4630 if (tn->tn_left->tn_op == NAME) { 4631 *symp = tn->tn_left->tn_sym; 4632 *offsp = 0; 4633 return true; 4634 } else { 4635 /* 4636 * If this were the front end of a compiler, we would 4637 * return a label instead of 0, at least if 4638 * 'tn->tn_left->tn_op == STRING'. 4639 */ 4640 *symp = NULL; 4641 *offsp = 0; 4642 return true; 4643 } 4644 case CVT: 4645 t = tn->tn_type->t_tspec; 4646 ot = tn->tn_left->tn_type->t_tspec; 4647 if ((!is_integer(t) && t != PTR) || 4648 (!is_integer(ot) && ot != PTR)) { 4649 return false; 4650 } 4651 #if 0 4652 /*- 4653 * consider: 4654 * struct foo { 4655 * unsigned char a; 4656 * } f = { 4657 * (unsigned char)(unsigned long) 4658 * (&(((struct foo *)0)->a)) 4659 * }; 4660 * since psize(unsigned long) != psize(unsigned char), 4661 * this fails. 4662 */ 4663 else if (psize(t) != psize(ot)) 4664 return -1; 4665 #endif 4666 return constant_addr(tn->tn_left, symp, offsp); 4667 default: 4668 return false; 4669 } 4670 } 4671 4672 /* Append s2 to s1, then free s2. */ 4673 strg_t * 4674 cat_strings(strg_t *s1, strg_t *s2) 4675 { 4676 4677 if (s1->st_char != s2->st_char) { 4678 /* cannot concatenate wide and regular string literals */ 4679 error(292); 4680 return s1; 4681 } 4682 4683 size_t len1 = s1->st_len; 4684 size_t len2 = s2->st_len; 4685 size_t chsize = s1->st_char ? sizeof(char) : sizeof(wchar_t); 4686 size_t size1 = len1 * chsize; 4687 size_t size2 = (len2 + 1) * chsize; 4688 s1->st_mem = xrealloc(s1->st_mem, size1 + size2); 4689 memcpy((char *)s1->st_mem + size1, s2->st_mem, size2); 4690 free(s2->st_mem); 4691 4692 s1->st_len = len1 + len2; 4693 free(s2); 4694 4695 return s1; 4696 } 4697 4698 4699 typedef struct stmt_expr { 4700 memory_pool se_mem; 4701 sym_t *se_sym; 4702 struct stmt_expr *se_enclosing; 4703 } stmt_expr; 4704 4705 static stmt_expr *stmt_exprs; 4706 4707 void 4708 begin_statement_expr(void) 4709 { 4710 debug_enter(); 4711 4712 stmt_expr *se = xmalloc(sizeof(*se)); 4713 se->se_mem = expr_save_memory(); 4714 se->se_sym = NULL; 4715 se->se_enclosing = stmt_exprs; 4716 stmt_exprs = se; 4717 } 4718 4719 void 4720 do_statement_expr(tnode_t *tn) 4721 { 4722 block_level--; 4723 mem_block_level--; 4724 stmt_exprs->se_sym = tn != NULL 4725 ? mktempsym(block_dup_type(tn->tn_type)) 4726 : NULL; /* after a syntax error */ 4727 mem_block_level++; 4728 block_level++; 4729 /* '({ ... })' is a GCC extension */ 4730 gnuism(320); 4731 } 4732 4733 tnode_t * 4734 end_statement_expr(void) 4735 { 4736 tnode_t *tn; 4737 4738 stmt_expr *se = stmt_exprs; 4739 if (se->se_sym == NULL) { 4740 tn = NULL; /* after a syntax error */ 4741 goto end; 4742 } 4743 4744 tn = build_name(se->se_sym, false); 4745 (void)expr_save_memory(); /* leak */ 4746 expr_restore_memory(se->se_mem); 4747 stmt_exprs = se->se_enclosing; 4748 free(se); 4749 4750 end: 4751 debug_leave(); 4752 return tn; 4753 } 4754 4755 bool 4756 in_statement_expr(void) 4757 { 4758 return stmt_exprs != NULL; 4759 } 4760
Indexes created Mon Sep 22 21:09:42 GMT 2025