tree.c revision 1.471
1 /* $NetBSD: tree.c,v 1.471 2022/07/05 22:50:41 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 1.471 2022/07/05 22:50:41 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 typedef struct integer_constraints { 53 int64_t smin; /* signed minimum */ 54 int64_t smax; /* signed maximum */ 55 uint64_t umin; /* unsigned minimum */ 56 uint64_t umax; /* unsigned maximum */ 57 uint64_t bset; /* bits that are definitely set */ 58 uint64_t bclr; /* bits that are definitely clear */ 59 } integer_constraints; 60 61 static tnode_t *build_integer_constant(tspec_t, int64_t); 62 static void check_pointer_comparison(op_t, 63 const tnode_t *, const tnode_t *); 64 static bool check_assign_types_compatible(op_t, int, 65 const tnode_t *, const tnode_t *); 66 static void check_bad_enum_operation(op_t, 67 const tnode_t *, const tnode_t *); 68 static void check_enum_type_mismatch(op_t, int, 69 const tnode_t *, const tnode_t *); 70 static void check_enum_int_mismatch(op_t, int, 71 const tnode_t *, const tnode_t *); 72 static tnode_t *new_tnode(op_t, bool, type_t *, tnode_t *, tnode_t *); 73 static void balance(op_t, tnode_t **, tnode_t **); 74 static void warn_incompatible_types(op_t, const type_t *, tspec_t, 75 const type_t *, tspec_t); 76 static void warn_incompatible_pointers(const mod_t *, 77 const type_t *, const type_t *); 78 static bool has_constant_member(const type_t *); 79 static void check_prototype_conversion(int, tspec_t, tspec_t, type_t *, 80 tnode_t *); 81 static void convert_integer_from_integer(op_t, int, tspec_t, tspec_t, 82 type_t *, tnode_t *); 83 static void convert_integer_from_pointer(op_t, tspec_t, type_t *, 84 tnode_t *); 85 static void convert_pointer_from_pointer(type_t *, tnode_t *); 86 static tnode_t *build_struct_access(op_t, bool, tnode_t *, tnode_t *); 87 static tnode_t *build_prepost_incdec(op_t, bool, tnode_t *); 88 static tnode_t *build_real_imag(op_t, bool, tnode_t *); 89 static tnode_t *build_address(bool, tnode_t *, bool); 90 static tnode_t *build_plus_minus(op_t, bool, tnode_t *, tnode_t *); 91 static tnode_t *build_bit_shift(op_t, bool, tnode_t *, tnode_t *); 92 static tnode_t *build_colon(bool, tnode_t *, tnode_t *); 93 static tnode_t *build_assignment(op_t, bool, tnode_t *, tnode_t *); 94 static tnode_t *subt_size_in_bytes(type_t *); 95 static tnode_t *fold(tnode_t *); 96 static tnode_t *fold_bool(tnode_t *); 97 static tnode_t *fold_float(tnode_t *); 98 static tnode_t *check_function_arguments(type_t *, tnode_t *); 99 static tnode_t *check_prototype_argument(int, type_t *, tnode_t *); 100 static void check_null_effect(const tnode_t *); 101 static void check_array_index(tnode_t *, bool); 102 static void check_integer_comparison(op_t, tnode_t *, tnode_t *); 103 static void check_precedence_confusion(tnode_t *); 104 105 extern sig_atomic_t fpe; 106 107 static bool 108 ic_maybe_signed(const type_t *tp, const integer_constraints *ic) 109 { 110 111 return !is_uinteger(tp->t_tspec) && 112 (ic->bclr & ((uint64_t)1 << 63)) == 0; 113 } 114 115 static unsigned 116 ic_length_in_bits(const type_t *tp) 117 { 118 119 lint_assert(is_integer(tp->t_tspec)); 120 return tp->t_bitfield ? tp->t_flen : size_in_bits(tp->t_tspec); 121 } 122 123 static integer_constraints 124 ic_any(const type_t *tp) 125 { 126 integer_constraints c; 127 128 uint64_t vbits = value_bits(ic_length_in_bits(tp)); 129 if (is_uinteger(tp->t_tspec)) { 130 c.smin = INT64_MIN; 131 c.smax = INT64_MAX; 132 c.umin = 0; 133 c.umax = vbits; 134 c.bset = 0; 135 c.bclr = ~c.umax; 136 } else { 137 c.smin = (int64_t)-1 - (int64_t)(vbits >> 1); 138 c.smax = (int64_t)(vbits >> 1); 139 c.umin = 0; 140 c.umax = UINT64_MAX; 141 c.bset = 0; 142 c.bclr = 0; 143 } 144 return c; 145 } 146 147 static integer_constraints 148 ic_con(const type_t *tp, const val_t *v) 149 { 150 integer_constraints c; 151 152 lint_assert(is_integer(tp->t_tspec)); 153 int64_t s = v->v_quad; 154 uint64_t u = (uint64_t)s; 155 c.smin = s; 156 c.smax = s; 157 c.umin = u; 158 c.umax = u; 159 c.bset = u; 160 c.bclr = ~u; 161 return c; 162 } 163 164 static integer_constraints 165 ic_cvt(const type_t *ntp, const type_t *otp, integer_constraints a) 166 { 167 168 if (ic_length_in_bits(ntp) > ic_length_in_bits(otp) && 169 is_uinteger(otp->t_tspec)) 170 return a; 171 return ic_any(ntp); 172 } 173 174 static integer_constraints 175 ic_bitand(integer_constraints a, integer_constraints b) 176 { 177 integer_constraints c; 178 179 c.smin = INT64_MIN; 180 c.smax = INT64_MAX; 181 c.umin = 0; 182 c.umax = UINT64_MAX; 183 c.bset = a.bset & b.bset; 184 c.bclr = a.bclr | b.bclr; 185 return c; 186 } 187 188 static integer_constraints 189 ic_bitor(integer_constraints a, integer_constraints b) 190 { 191 integer_constraints c; 192 193 c.smin = INT64_MIN; 194 c.smax = INT64_MAX; 195 c.umin = 0; 196 c.umax = UINT64_MAX; 197 c.bset = a.bset | b.bset; 198 c.bclr = a.bclr & b.bclr; 199 return c; 200 } 201 202 static integer_constraints 203 ic_shl(const type_t *tp, integer_constraints a, integer_constraints b) 204 { 205 integer_constraints c; 206 unsigned int amount; 207 208 if (ic_maybe_signed(tp, &a)) 209 return ic_any(tp); 210 211 if (b.smin == b.smax && b.smin >= 0 && b.smin < 64) 212 amount = (unsigned int)b.smin; 213 else if (b.umin == b.umax && b.umin < 64) 214 amount = (unsigned int)b.umin; 215 else 216 return ic_any(tp); 217 218 c.smin = INT64_MIN; 219 c.smax = INT64_MAX; 220 c.umin = 0; 221 c.umax = UINT64_MAX; 222 c.bset = a.bset << amount; 223 c.bclr = a.bclr << amount | (((uint64_t)1 << amount) - 1); 224 return c; 225 } 226 227 static integer_constraints 228 ic_shr(const type_t *tp, integer_constraints a, integer_constraints b) 229 { 230 integer_constraints c; 231 unsigned int amount; 232 233 if (ic_maybe_signed(tp, &a)) 234 return ic_any(tp); 235 236 if (b.smin == b.smax && b.smin >= 0 && b.smin < 64) 237 amount = (unsigned int)b.smin; 238 else if (b.umin == b.umax && b.umin < 64) 239 amount = (unsigned int)b.umin; 240 else 241 return ic_any(tp); 242 243 c.smin = INT64_MIN; 244 c.smax = INT64_MAX; 245 c.umin = 0; 246 c.umax = UINT64_MAX; 247 c.bset = a.bset >> amount; 248 c.bclr = a.bclr >> amount | ~(~(uint64_t)0 >> amount); 249 return c; 250 } 251 252 static integer_constraints 253 ic_expr(const tnode_t *tn) 254 { 255 integer_constraints lc, rc; 256 257 lint_assert(is_integer(tn->tn_type->t_tspec)); 258 259 switch (tn->tn_op) { 260 case CON: 261 return ic_con(tn->tn_type, tn->tn_val); 262 case CVT: 263 if (!is_integer(tn->tn_left->tn_type->t_tspec)) 264 return ic_any(tn->tn_type); 265 lc = ic_expr(tn->tn_left); 266 return ic_cvt(tn->tn_type, tn->tn_left->tn_type, lc); 267 case SHL: 268 lc = ic_expr(tn->tn_left); 269 rc = ic_expr(tn->tn_right); 270 return ic_shl(tn->tn_type, lc, rc); 271 case SHR: 272 lc = ic_expr(tn->tn_left); 273 rc = ic_expr(tn->tn_right); 274 return ic_shr(tn->tn_type, lc, rc); 275 case BITAND: 276 lc = ic_expr(tn->tn_left); 277 rc = ic_expr(tn->tn_right); 278 return ic_bitand(lc, rc); 279 case BITOR: 280 lc = ic_expr(tn->tn_left); 281 rc = ic_expr(tn->tn_right); 282 return ic_bitor(lc, rc); 283 default: 284 return ic_any(tn->tn_type); 285 } 286 } 287 288 static const char * 289 op_name(op_t op) 290 { 291 return modtab[op].m_name; 292 } 293 294 /* Build 'pointer to tp', 'array of tp' or 'function returning tp'. */ 295 type_t * 296 block_derive_type(type_t *tp, tspec_t t) 297 { 298 type_t *tp2; 299 300 tp2 = block_zero_alloc(sizeof(*tp2)); 301 tp2->t_tspec = t; 302 tp2->t_subt = tp; 303 return tp2; 304 } 305 306 /* 307 * Derive 'pointer to tp' or 'function returning tp'. 308 * The memory is freed at the end of the current expression. 309 */ 310 type_t * 311 expr_derive_type(type_t *tp, tspec_t t) 312 { 313 type_t *tp2; 314 315 tp2 = expr_zero_alloc(sizeof(*tp2)); 316 tp2->t_tspec = t; 317 tp2->t_subt = tp; 318 return tp2; 319 } 320 321 /* 322 * Create a node for a constant. 323 */ 324 tnode_t * 325 build_constant(type_t *tp, val_t *v) 326 { 327 tnode_t *n; 328 329 n = expr_alloc_tnode(); 330 n->tn_op = CON; 331 n->tn_type = tp; 332 n->tn_val = expr_zero_alloc(sizeof(*n->tn_val)); 333 n->tn_val->v_tspec = tp->t_tspec; 334 n->tn_val->v_unsigned_since_c90 = v->v_unsigned_since_c90; 335 n->tn_val->v_u = v->v_u; 336 free(v); 337 return n; 338 } 339 340 static tnode_t * 341 build_integer_constant(tspec_t t, int64_t q) 342 { 343 tnode_t *n; 344 345 n = expr_alloc_tnode(); 346 n->tn_op = CON; 347 n->tn_type = gettyp(t); 348 n->tn_val = expr_zero_alloc(sizeof(*n->tn_val)); 349 n->tn_val->v_tspec = t; 350 n->tn_val->v_quad = q; 351 return n; 352 } 353 354 static void 355 fallback_symbol(sym_t *sym) 356 { 357 358 if (fallback_symbol_strict_bool(sym)) 359 return; 360 361 if (block_level > 0 && (strcmp(sym->s_name, "__FUNCTION__") == 0 || 362 strcmp(sym->s_name, "__PRETTY_FUNCTION__") == 0)) { 363 /* __FUNCTION__/__PRETTY_FUNCTION__ is a GCC extension */ 364 gnuism(316); 365 sym->s_type = block_derive_type(gettyp(CHAR), PTR); 366 sym->s_type->t_const = true; 367 return; 368 } 369 370 if (block_level > 0 && strcmp(sym->s_name, "__func__") == 0) { 371 if (!allow_c99) 372 /* __func__ is a C99 feature */ 373 warning(317); 374 sym->s_type = block_derive_type(gettyp(CHAR), PTR); 375 sym->s_type->t_const = true; 376 return; 377 } 378 379 /* '%s' undefined */ 380 error(99, sym->s_name); 381 } 382 383 /* 384 * Functions that are predeclared by GCC or other compilers can be called 385 * with arbitrary arguments. Since lint usually runs after a successful 386 * compilation, it's the compiler's job to catch any errors. 387 */ 388 bool 389 is_compiler_builtin(const char *name) 390 { 391 /* https://gcc.gnu.org/onlinedocs/gcc/C-Extensions.html */ 392 if (allow_gcc) { 393 if (strncmp(name, "__atomic_", 9) == 0 || 394 strncmp(name, "__builtin_", 10) == 0 || 395 strcmp(name, "alloca") == 0 || 396 /* obsolete but still in use, as of 2021 */ 397 strncmp(name, "__sync_", 7) == 0) 398 return true; 399 } 400 401 /* https://software.intel.com/sites/landingpage/IntrinsicsGuide/ */ 402 if (strncmp(name, "_mm_", 4) == 0) 403 return true; 404 405 return false; 406 } 407 408 static bool 409 str_endswith(const char *haystack, const char *needle) 410 { 411 size_t hlen = strlen(haystack); 412 size_t nlen = strlen(needle); 413 414 return nlen <= hlen && 415 memcmp(haystack + hlen - nlen, needle, nlen) == 0; 416 } 417 418 /* https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins.html */ 419 static bool 420 is_gcc_bool_builtin(const char *name) 421 { 422 return strncmp(name, "__builtin_", 10) == 0 && 423 (str_endswith(name, "_overflow") || 424 str_endswith(name, "_overflow_p")); 425 } 426 427 static void 428 build_name_call(sym_t *sym) 429 { 430 431 if (is_compiler_builtin(sym->s_name)) { 432 /* 433 * Do not warn about these, just assume that 434 * they are regular functions compatible with 435 * non-prototype calling conventions. 436 */ 437 if (allow_gcc && is_gcc_bool_builtin(sym->s_name)) 438 sym->s_type = gettyp(BOOL); 439 440 } else if (allow_c99) { 441 /* function '%s' implicitly declared to return int */ 442 error(215, sym->s_name); 443 } else if (!allow_trad) { 444 /* function '%s' implicitly declared to return int */ 445 warning(215, sym->s_name); 446 } 447 448 /* XXX if !allow_c90, the symbol should be exported to level 0 */ 449 sym->s_type = block_derive_type(sym->s_type, FUNC); 450 } 451 452 /* Create a node for a name (symbol table entry). */ 453 tnode_t * 454 build_name(sym_t *sym, bool is_funcname) 455 { 456 tnode_t *n; 457 458 if (sym->s_scl == NOSCL) { 459 sym->s_scl = EXTERN; 460 sym->s_def = DECL; 461 if (is_funcname) 462 build_name_call(sym); 463 else 464 fallback_symbol(sym); 465 } 466 467 lint_assert(sym->s_kind == FVFT || sym->s_kind == FMEMBER); 468 469 n = expr_alloc_tnode(); 470 n->tn_type = sym->s_type; 471 if (sym->s_scl == BOOL_CONST) { 472 n->tn_op = CON; 473 n->tn_val = expr_zero_alloc(sizeof(*n->tn_val)); 474 n->tn_val->v_tspec = BOOL; 475 n->tn_val->v_quad = sym->u.s_bool_constant ? 1 : 0; 476 } else if (sym->s_scl == ENUM_CONST) { 477 n->tn_op = CON; 478 n->tn_val = expr_zero_alloc(sizeof(*n->tn_val)); 479 n->tn_val->v_tspec = INT; /* ENUM is in n->tn_type */ 480 n->tn_val->v_quad = sym->u.s_enum_constant; 481 } else { 482 n->tn_op = NAME; 483 n->tn_sym = sym; 484 if (sym->s_kind == FVFT && sym->s_type->t_tspec != FUNC) 485 n->tn_lvalue = true; 486 } 487 488 return n; 489 } 490 491 tnode_t * 492 build_string(strg_t *strg) 493 { 494 size_t len; 495 tnode_t *n; 496 type_t *tp; 497 498 len = strg->st_len; 499 500 n = expr_alloc_tnode(); 501 502 tp = expr_zero_alloc(sizeof(*tp)); 503 tp->t_tspec = ARRAY; 504 tp->t_subt = gettyp(strg->st_char ? CHAR : WCHAR); 505 tp->t_dim = (int)(len + 1); 506 507 n->tn_op = STRING; 508 n->tn_type = tp; 509 n->tn_lvalue = true; 510 511 n->tn_string = expr_zero_alloc(sizeof(*n->tn_string)); 512 n->tn_string->st_char = strg->st_char; 513 n->tn_string->st_len = len; 514 515 size_t chsize = strg->st_char ? sizeof(char) : sizeof(wchar_t); 516 size_t size = (len + 1) * chsize; 517 n->tn_string->st_mem = expr_zero_alloc(size); 518 (void)memcpy(n->tn_string->st_mem, strg->st_mem, size); 519 free(strg->st_mem); 520 free(strg); 521 522 return n; 523 } 524 525 /* 526 * Returns a symbol which has the same name as the msym argument and is a 527 * member of the struct or union specified by the tn argument. 528 */ 529 static sym_t * 530 struct_or_union_member(tnode_t *tn, op_t op, sym_t *msym) 531 { 532 struct_or_union *str; 533 type_t *tp; 534 sym_t *sym, *csym; 535 bool eq; 536 tspec_t t; 537 538 /* 539 * Remove the member if it was unknown until now, which means 540 * that no defined struct or union has a member with the same name. 541 */ 542 if (msym->s_scl == NOSCL) { 543 /* type '%s' does not have member '%s' */ 544 error(101, type_name(tn->tn_type), msym->s_name); 545 rmsym(msym); 546 msym->s_kind = FMEMBER; 547 msym->s_scl = MOS; 548 549 struct_or_union *sou = expr_zero_alloc(sizeof(*sou)); 550 sou->sou_tag = expr_zero_alloc(sizeof(*sou->sou_tag)); 551 sou->sou_tag->s_name = unnamed; 552 553 msym->u.s_member.sm_sou_type = sou; 554 /* 555 * The member sm_offset_in_bits is not needed here since this 556 * symbol can only be used for error reporting. 557 */ 558 return msym; 559 } 560 561 /* Set str to the tag of which msym is expected to be a member. */ 562 str = NULL; 563 t = (tp = tn->tn_type)->t_tspec; 564 if (op == POINT) { 565 if (is_struct_or_union(t)) 566 str = tp->t_str; 567 } else if (op == ARROW && t == PTR) { 568 t = (tp = tp->t_subt)->t_tspec; 569 if (is_struct_or_union(t)) 570 str = tp->t_str; 571 } 572 573 /* 574 * If this struct/union has a member with the name of msym, return it. 575 */ 576 if (str != NULL) { 577 for (sym = msym; sym != NULL; sym = sym->s_symtab_next) { 578 if (!is_member(sym)) 579 continue; 580 if (sym->u.s_member.sm_sou_type != str) 581 continue; 582 if (strcmp(sym->s_name, msym->s_name) != 0) 583 continue; 584 return sym; 585 } 586 } 587 588 /* 589 * Set eq to false if there are struct/union members with the same 590 * name and different types and/or offsets. 591 */ 592 eq = true; 593 for (csym = msym; csym != NULL; csym = csym->s_symtab_next) { 594 if (csym->s_scl != MOS && csym->s_scl != MOU) 595 continue; 596 if (strcmp(msym->s_name, csym->s_name) != 0) 597 continue; 598 for (sym = csym->s_symtab_next; sym != NULL; 599 sym = sym->s_symtab_next) { 600 bool w; 601 602 if (sym->s_scl != MOS && sym->s_scl != MOU) 603 continue; 604 if (strcmp(csym->s_name, sym->s_name) != 0) 605 continue; 606 if (csym->u.s_member.sm_offset_in_bits != 607 sym->u.s_member.sm_offset_in_bits) { 608 eq = false; 609 break; 610 } 611 w = false; 612 eq = eqtype(csym->s_type, sym->s_type, 613 false, false, &w) && !w; 614 if (!eq) 615 break; 616 if (csym->s_bitfield != sym->s_bitfield) { 617 eq = false; 618 break; 619 } 620 if (csym->s_bitfield) { 621 type_t *tp1, *tp2; 622 623 tp1 = csym->s_type; 624 tp2 = sym->s_type; 625 if (tp1->t_flen != tp2->t_flen) { 626 eq = false; 627 break; 628 } 629 if (tp1->t_foffs != tp2->t_foffs) { 630 eq = false; 631 break; 632 } 633 } 634 } 635 if (!eq) 636 break; 637 } 638 639 /* 640 * Now handle the case in which the left operand refers really 641 * to a struct/union, but the right operand is not member of it. 642 */ 643 if (str != NULL) { 644 if (eq && !allow_c90) { 645 /* illegal use of member '%s' */ 646 warning(102, msym->s_name); 647 } else { 648 /* illegal use of member '%s' */ 649 error(102, msym->s_name); 650 } 651 return msym; 652 } 653 654 /* 655 * Now the left operand of ARROW does not point to a struct/union 656 * or the left operand of POINT is no struct/union. 657 */ 658 if (eq) { 659 if (op == POINT) { 660 if (!allow_c90) { 661 /* left operand of '.' must be struct ... */ 662 warning(103, type_name(tn->tn_type)); 663 } else { 664 /* left operand of '.' must be struct ... */ 665 error(103, type_name(tn->tn_type)); 666 } 667 } else { 668 if (!allow_c90 && tn->tn_type->t_tspec == PTR) { 669 /* left operand of '->' must be pointer ... */ 670 warning(104, type_name(tn->tn_type)); 671 } else { 672 /* left operand of '->' must be pointer ... */ 673 error(104, type_name(tn->tn_type)); 674 } 675 } 676 } else { 677 if (!allow_c90) { 678 /* non-unique member requires struct/union %s */ 679 error(105, op == POINT ? "object" : "pointer"); 680 } else { 681 /* unacceptable operand of '%s' */ 682 error(111, op_name(op)); 683 } 684 } 685 686 return msym; 687 } 688 689 tnode_t * 690 build_generic_selection(const tnode_t *expr, 691 struct generic_association *sel) 692 { 693 tnode_t *default_result = NULL; 694 695 for (; sel != NULL; sel = sel->ga_prev) { 696 if (expr != NULL && 697 eqtype(sel->ga_arg, expr->tn_type, false, false, NULL)) 698 return sel->ga_result; 699 else if (sel->ga_arg == NULL) 700 default_result = sel->ga_result; 701 } 702 return default_result; 703 } 704 705 /* 706 * Create a tree node for a binary operator and its two operands. Also called 707 * for unary operators; in that case rn is NULL. 708 * 709 * Function calls, sizeof and casts are handled elsewhere. 710 */ 711 tnode_t * 712 build_binary(tnode_t *ln, op_t op, bool sys, tnode_t *rn) 713 { 714 const mod_t *mp; 715 tnode_t *ntn; 716 type_t *rettp; 717 718 mp = &modtab[op]; 719 720 /* If there was an error in one of the operands, return. */ 721 if (ln == NULL || (mp->m_binary && rn == NULL)) 722 return NULL; 723 724 /* 725 * Apply class conversions to the left operand, but only if its 726 * value is needed or it is compared with zero. 727 */ 728 if (mp->m_value_context || mp->m_compares_with_zero) 729 ln = cconv(ln); 730 /* 731 * The right operand is almost always in a test or value context, 732 * except if it is a struct or union member. 733 */ 734 if (mp->m_binary && op != ARROW && op != POINT) 735 rn = cconv(rn); 736 737 /* 738 * Print some warnings for comparisons of unsigned values with 739 * constants lower than or equal to null. This must be done 740 * before promote() because otherwise unsigned char and unsigned 741 * short would be promoted to int. Types are also tested to be 742 * CHAR, which would also become int. 743 */ 744 if (mp->m_comparison) 745 check_integer_comparison(op, ln, rn); 746 747 if (mp->m_value_context || mp->m_compares_with_zero) 748 ln = promote(op, false, ln); 749 if (mp->m_binary && op != ARROW && op != POINT && 750 op != ASSIGN && op != RETURN && op != INIT) { 751 rn = promote(op, false, rn); 752 } 753 754 /* 755 * If the result of the operation is different for signed or 756 * unsigned operands and one of the operands is signed only in 757 * ANSI C, print a warning. 758 */ 759 if (mp->m_warn_if_left_unsigned_in_c90 && 760 ln->tn_op == CON && ln->tn_val->v_unsigned_since_c90) { 761 /* ANSI C treats constant as unsigned, op '%s' */ 762 warning(218, mp->m_name); 763 ln->tn_val->v_unsigned_since_c90 = false; 764 } 765 if (mp->m_warn_if_right_unsigned_in_c90 && 766 rn->tn_op == CON && rn->tn_val->v_unsigned_since_c90) { 767 /* ANSI C treats constant as unsigned, op '%s' */ 768 warning(218, mp->m_name); 769 rn->tn_val->v_unsigned_since_c90 = false; 770 } 771 772 /* Make sure both operands are of the same type */ 773 if (mp->m_balance_operands || (!allow_c90 && (op == SHL || op == SHR))) 774 balance(op, &ln, &rn); 775 776 /* 777 * Check types for compatibility with the operation and mutual 778 * compatibility. Return if there are serious problems. 779 */ 780 if (!typeok(op, 0, ln, rn)) 781 return NULL; 782 783 /* And now create the node. */ 784 switch (op) { 785 case POINT: 786 case ARROW: 787 ntn = build_struct_access(op, sys, ln, rn); 788 break; 789 case INCAFT: 790 case DECAFT: 791 case INCBEF: 792 case DECBEF: 793 ntn = build_prepost_incdec(op, sys, ln); 794 break; 795 case ADDR: 796 ntn = build_address(sys, ln, false); 797 break; 798 case INDIR: 799 ntn = new_tnode(INDIR, sys, ln->tn_type->t_subt, ln, NULL); 800 break; 801 case PLUS: 802 case MINUS: 803 ntn = build_plus_minus(op, sys, ln, rn); 804 break; 805 case SHL: 806 case SHR: 807 ntn = build_bit_shift(op, sys, ln, rn); 808 break; 809 case COLON: 810 ntn = build_colon(sys, ln, rn); 811 break; 812 case ASSIGN: 813 case MULASS: 814 case DIVASS: 815 case MODASS: 816 case ADDASS: 817 case SUBASS: 818 case SHLASS: 819 case SHRASS: 820 case ANDASS: 821 case XORASS: 822 case ORASS: 823 case RETURN: 824 case INIT: 825 ntn = build_assignment(op, sys, ln, rn); 826 break; 827 case COMMA: 828 case QUEST: 829 ntn = new_tnode(op, sys, rn->tn_type, ln, rn); 830 break; 831 case REAL: 832 case IMAG: 833 ntn = build_real_imag(op, sys, ln); 834 break; 835 default: 836 rettp = mp->m_returns_bool 837 ? gettyp(Tflag ? BOOL : INT) : ln->tn_type; 838 lint_assert(mp->m_binary == (rn != NULL)); 839 ntn = new_tnode(op, sys, rettp, ln, rn); 840 break; 841 } 842 843 /* Return if an error occurred. */ 844 if (ntn == NULL) 845 return NULL; 846 847 /* Print a warning if precedence confusion is possible */ 848 if (mp->m_possible_precedence_confusion) 849 check_precedence_confusion(ntn); 850 851 /* 852 * Print a warning if one of the operands is in a context where 853 * it is compared with zero and if this operand is a constant. 854 */ 855 if (hflag && !constcond_flag && 856 mp->m_compares_with_zero && 857 (ln->tn_op == CON || 858 ((mp->m_binary && op != QUEST) && rn->tn_op == CON)) && 859 /* XXX: rn->tn_system_dependent should be checked as well */ 860 !ln->tn_system_dependent) { 861 /* constant in conditional context */ 862 warning(161); 863 } 864 865 /* Fold if the operator requires it */ 866 if (mp->m_fold_constant_operands) { 867 if (ln->tn_op == CON && (!mp->m_binary || rn->tn_op == CON)) { 868 if (mp->m_compares_with_zero) { 869 ntn = fold_bool(ntn); 870 } else if (is_floating(ntn->tn_type->t_tspec)) { 871 ntn = fold_float(ntn); 872 } else { 873 ntn = fold(ntn); 874 } 875 } else if (op == QUEST && ln->tn_op == CON) { 876 ntn = ln->tn_val->v_quad != 0 877 ? rn->tn_left : rn->tn_right; 878 } 879 } 880 881 return ntn; 882 } 883 884 tnode_t * 885 build_unary(op_t op, bool sys, tnode_t *tn) 886 { 887 return build_binary(tn, op, sys, NULL); 888 } 889 890 tnode_t * 891 build_member_access(tnode_t *ln, op_t op, bool sys, sbuf_t *member) 892 { 893 sym_t *msym; 894 895 if (ln == NULL) 896 return NULL; 897 898 if (op == ARROW) { 899 /* must do this before struct_or_union_member is called */ 900 ln = cconv(ln); 901 } 902 msym = struct_or_union_member(ln, op, getsym(member)); 903 return build_binary(ln, op, sys, build_name(msym, false)); 904 } 905 906 /* 907 * Perform class conversions. 908 * 909 * Arrays of type T are converted into pointers to type T. 910 * Functions are converted to pointers to functions. 911 * Lvalues are converted to rvalues. 912 * 913 * C99 6.3 "Conversions" 914 * C99 6.3.2 "Other operands" 915 * C99 6.3.2.1 "Lvalues, arrays, and function designators" 916 */ 917 tnode_t * 918 cconv(tnode_t *tn) 919 { 920 type_t *tp; 921 922 /* 923 * Array-lvalue (array of type T) is converted into rvalue 924 * (pointer to type T) 925 */ 926 if (tn->tn_type->t_tspec == ARRAY) { 927 if (!tn->tn_lvalue) { 928 /* XXX print correct operator */ 929 /* %soperand of '%s' must be lvalue */ 930 gnuism(114, "", op_name(ADDR)); 931 } 932 tn = new_tnode(ADDR, tn->tn_sys, 933 expr_derive_type(tn->tn_type->t_subt, PTR), tn, NULL); 934 } 935 936 /* 937 * Expression of type function (function with return value of type T) 938 * in rvalue-expression (pointer to function with return value 939 * of type T) 940 */ 941 if (tn->tn_type->t_tspec == FUNC) 942 tn = build_address(tn->tn_sys, tn, true); 943 944 /* lvalue to rvalue */ 945 if (tn->tn_lvalue) { 946 tp = expr_dup_type(tn->tn_type); 947 /* C99 6.3.2.1p2 sentence 2 says to remove the qualifiers. */ 948 tp->t_const = tp->t_volatile = false; 949 tn = new_tnode(LOAD, tn->tn_sys, tp, tn, NULL); 950 } 951 952 return tn; 953 } 954 955 const tnode_t * 956 before_conversion(const tnode_t *tn) 957 { 958 while (tn->tn_op == CVT && !tn->tn_cast) 959 tn = tn->tn_left; 960 return tn; 961 } 962 963 static bool 964 is_null_pointer(const tnode_t *tn) 965 { 966 tspec_t t = tn->tn_type->t_tspec; 967 968 return ((t == PTR && tn->tn_type->t_subt->t_tspec == VOID) || 969 is_integer(t)) 970 && (tn->tn_op == CON && tn->tn_val->v_quad == 0); 971 } 972 973 /* 974 * Most errors required by ANSI C are reported in struct_or_union_member(). 975 * Here we only check for totally wrong things. 976 */ 977 static bool 978 typeok_point(const tnode_t *ln, const type_t *ltp, tspec_t lt) 979 { 980 if (is_struct_or_union(lt)) 981 return true; 982 983 if (lt == FUNC || lt == VOID || ltp->t_bitfield) 984 goto wrong; 985 986 /* 987 * Some C dialects from before C90 tolerated any lvalue on the 988 * left-hand side of the '.' operator, allowing things like 989 * char st[100]; st.st_mtime, assuming that the member 'st_mtime' 990 * only occurred in a single struct; see typeok_arrow. 991 */ 992 if (ln->tn_lvalue) 993 return true; 994 995 wrong: 996 /* With allow_c90 we already got an error */ 997 if (!allow_c90) 998 /* unacceptable operand of '%s' */ 999 error(111, op_name(POINT)); 1000 1001 return false; 1002 } 1003 1004 static bool 1005 typeok_arrow(tspec_t lt) 1006 { 1007 /* 1008 * C1978 Appendix A 14.1 says: <quote>In fact, any lvalue is allowed 1009 * before '.', and that lvalue is then assumed to have the form of 1010 * the structure of which the name of the right is a member. [...] 1011 * Such constructions are non-portable.</quote> 1012 */ 1013 if (lt == PTR || (!allow_c90 && is_integer(lt))) 1014 return true; 1015 1016 /* With allow_c90 we already got an error */ 1017 if (!allow_c90) 1018 /* unacceptable operand of '%s' */ 1019 error(111, op_name(ARROW)); 1020 return false; 1021 } 1022 1023 static bool 1024 typeok_incdec(op_t op, const tnode_t *tn, const type_t *tp) 1025 { 1026 /* operand has scalar type (checked in typeok) */ 1027 if (!tn->tn_lvalue) { 1028 if (tn->tn_op == CVT && tn->tn_cast && 1029 tn->tn_left->tn_op == LOAD) { 1030 /* a cast does not yield an lvalue */ 1031 error(163); 1032 } 1033 /* %soperand of '%s' must be lvalue */ 1034 error(114, "", op_name(op)); 1035 return false; 1036 } else if (tp->t_const) { 1037 if (allow_c90) 1038 /* %soperand of '%s' must be modifiable lvalue */ 1039 warning(115, "", op_name(op)); 1040 } 1041 return true; 1042 } 1043 1044 static bool 1045 typeok_address(const mod_t *mp, 1046 const tnode_t *tn, const type_t *tp, tspec_t t) 1047 { 1048 if (t == ARRAY || t == FUNC) { 1049 /* ok, a warning comes later (in build_address()) */ 1050 } else if (!tn->tn_lvalue) { 1051 if (tn->tn_op == CVT && tn->tn_cast && 1052 tn->tn_left->tn_op == LOAD) { 1053 /* a cast does not yield an lvalue */ 1054 error(163); 1055 } 1056 /* %soperand of '%s' must be lvalue */ 1057 error(114, "", mp->m_name); 1058 return false; 1059 } else if (is_scalar(t)) { 1060 if (tp->t_bitfield) { 1061 /* cannot take address of bit-field */ 1062 error(112); 1063 return false; 1064 } 1065 } else if (t != STRUCT && t != UNION) { 1066 /* unacceptable operand of '%s' */ 1067 error(111, mp->m_name); 1068 return false; 1069 } 1070 if (tn->tn_op == NAME && tn->tn_sym->s_register) { 1071 /* cannot take address of register '%s' */ 1072 error(113, tn->tn_sym->s_name); 1073 return false; 1074 } 1075 return true; 1076 } 1077 1078 static bool 1079 typeok_indir(const type_t *tp, tspec_t t) 1080 { 1081 1082 if (t != PTR) { 1083 /* cannot dereference non-pointer type '%s' */ 1084 error(96, type_name(tp)); 1085 return false; 1086 } 1087 return true; 1088 } 1089 1090 static bool 1091 typeok_plus(op_t op, 1092 const type_t *ltp, tspec_t lt, 1093 const type_t *rtp, tspec_t rt) 1094 { 1095 /* operands have scalar types (checked in typeok) */ 1096 if ((lt == PTR && !is_integer(rt)) || (rt == PTR && !is_integer(lt))) { 1097 warn_incompatible_types(op, ltp, lt, rtp, rt); 1098 return false; 1099 } 1100 return true; 1101 } 1102 1103 static bool 1104 typeok_minus(op_t op, 1105 const type_t *ltp, tspec_t lt, 1106 const type_t *rtp, tspec_t rt) 1107 { 1108 /* operands have scalar types (checked in typeok) */ 1109 if ((lt == PTR && rt != PTR && !is_integer(rt)) || 1110 (lt != PTR && rt == PTR)) { 1111 warn_incompatible_types(op, ltp, lt, rtp, rt); 1112 return false; 1113 } 1114 if (lt == PTR && rt == PTR) { 1115 if (!eqtype(ltp->t_subt, rtp->t_subt, true, false, NULL)) { 1116 /* illegal pointer subtraction */ 1117 error(116); 1118 } 1119 } 1120 return true; 1121 } 1122 1123 static void 1124 typeok_shr(const mod_t *mp, 1125 const tnode_t *ln, tspec_t lt, 1126 const tnode_t *rn, tspec_t rt) 1127 { 1128 tspec_t olt, ort; 1129 1130 olt = before_conversion(ln)->tn_type->t_tspec; 1131 ort = before_conversion(rn)->tn_type->t_tspec; 1132 1133 /* operands have integer types (checked in typeok) */ 1134 if (pflag && !is_uinteger(olt)) { 1135 /* 1136 * The left operand is signed. This means that 1137 * the operation is (possibly) nonportable. 1138 */ 1139 if (ln->tn_op != CON) { 1140 /* bitwise '%s' on signed value possibly nonportable */ 1141 warning(117, mp->m_name); 1142 } else if (ln->tn_val->v_quad < 0) { 1143 /* bitwise '%s' on signed value nonportable */ 1144 warning(120, mp->m_name); 1145 } 1146 } else if (allow_trad && allow_c90 && 1147 !is_uinteger(olt) && is_uinteger(ort)) { 1148 /* 1149 * The left operand would become unsigned in 1150 * traditional C. 1151 */ 1152 if (hflag && (ln->tn_op != CON || ln->tn_val->v_quad < 0)) { 1153 /* semantics of '%s' change in ANSI C; use ... */ 1154 warning(118, mp->m_name); 1155 } 1156 } else if (allow_trad && allow_c90 && 1157 !is_uinteger(olt) && !is_uinteger(ort) && 1158 portable_size_in_bits(lt) < portable_size_in_bits(rt)) { 1159 /* 1160 * In traditional C the left operand would be extended 1161 * (possibly sign-extended) and then shifted. 1162 */ 1163 if (hflag && (ln->tn_op != CON || ln->tn_val->v_quad < 0)) { 1164 /* semantics of '%s' change in ANSI C; use ... */ 1165 warning(118, mp->m_name); 1166 } 1167 } 1168 } 1169 1170 static void 1171 typeok_shl(const mod_t *mp, tspec_t lt, tspec_t rt) 1172 { 1173 /* 1174 * C90 does not perform balancing for shift operations, 1175 * but traditional C does. If the width of the right operand 1176 * is greater than the width of the left operand, then in 1177 * traditional C the left operand would be extended to the 1178 * width of the right operand. For SHL this may result in 1179 * different results. 1180 */ 1181 if (portable_size_in_bits(lt) < portable_size_in_bits(rt)) { 1182 /* 1183 * XXX If both operands are constant, make sure 1184 * that there is really a difference between 1185 * ANSI C and traditional C. 1186 */ 1187 if (hflag && !allow_c99) 1188 /* semantics of '%s' change in ANSI C; use ... */ 1189 warning(118, mp->m_name); 1190 } 1191 } 1192 1193 static void 1194 typeok_shift(tspec_t lt, const tnode_t *rn, tspec_t rt) 1195 { 1196 if (rn->tn_op != CON) 1197 return; 1198 1199 if (!is_uinteger(rt) && rn->tn_val->v_quad < 0) { 1200 /* negative shift */ 1201 warning(121); 1202 } else if ((uint64_t)rn->tn_val->v_quad == 1203 (uint64_t)size_in_bits(lt)) { 1204 /* shift equal to size of object */ 1205 warning(267); 1206 } else if ((uint64_t)rn->tn_val->v_quad > (uint64_t)size_in_bits(lt)) { 1207 /* shift amount %llu is greater than bit-size %llu of '%s' */ 1208 warning(122, (unsigned long long)rn->tn_val->v_quad, 1209 (unsigned long long)size_in_bits(lt), 1210 tspec_name(lt)); 1211 } 1212 } 1213 1214 static bool 1215 is_typeok_eq(const tnode_t *ln, tspec_t lt, const tnode_t *rn, tspec_t rt) 1216 { 1217 if (lt == PTR && is_null_pointer(rn)) 1218 return true; 1219 if (rt == PTR && is_null_pointer(ln)) 1220 return true; 1221 return false; 1222 } 1223 1224 static bool 1225 typeok_compare(op_t op, 1226 const tnode_t *ln, const type_t *ltp, tspec_t lt, 1227 const tnode_t *rn, const type_t *rtp, tspec_t rt) 1228 { 1229 const char *lx, *rx; 1230 1231 if (lt == PTR && rt == PTR) { 1232 check_pointer_comparison(op, ln, rn); 1233 return true; 1234 } 1235 1236 if (lt != PTR && rt != PTR) 1237 return true; 1238 1239 if (!is_integer(lt) && !is_integer(rt)) { 1240 warn_incompatible_types(op, ltp, lt, rtp, rt); 1241 return false; 1242 } 1243 1244 lx = lt == PTR ? "pointer" : "integer"; 1245 rx = rt == PTR ? "pointer" : "integer"; 1246 /* illegal combination of %s '%s' and %s '%s', op '%s' */ 1247 warning(123, lx, type_name(ltp), rx, type_name(rtp), op_name(op)); 1248 return true; 1249 } 1250 1251 static bool 1252 typeok_quest(tspec_t lt, const tnode_t *rn) 1253 { 1254 if (!is_scalar(lt)) { 1255 /* first operand must have scalar type, op ? : */ 1256 error(170); 1257 return false; 1258 } 1259 lint_assert(before_conversion(rn)->tn_op == COLON); 1260 return true; 1261 } 1262 1263 static void 1264 typeok_colon_pointer(const mod_t *mp, const type_t *ltp, const type_t *rtp) 1265 { 1266 type_t *lstp = ltp->t_subt; 1267 type_t *rstp = rtp->t_subt; 1268 tspec_t lst = lstp->t_tspec; 1269 tspec_t rst = rstp->t_tspec; 1270 1271 if ((lst == VOID && rst == FUNC) || (lst == FUNC && rst == VOID)) { 1272 /* (void *)0 is handled in typeok_colon */ 1273 /* TODO: C99 behaves like C90 here. */ 1274 if (!allow_trad && !allow_c99) 1275 /* ANSI C forbids conversion of %s to %s, op %s */ 1276 warning(305, "function pointer", "'void *'", 1277 mp->m_name); 1278 return; 1279 } 1280 1281 if (eqptrtype(lstp, rstp, true)) 1282 return; 1283 if (!eqtype(lstp, rstp, true, false, NULL)) 1284 warn_incompatible_pointers(mp, ltp, rtp); 1285 } 1286 1287 static bool 1288 typeok_colon(const mod_t *mp, 1289 const tnode_t *ln, const type_t *ltp, tspec_t lt, 1290 const tnode_t *rn, const type_t *rtp, tspec_t rt) 1291 { 1292 1293 if (is_arithmetic(lt) && is_arithmetic(rt)) 1294 return true; 1295 if (lt == BOOL && rt == BOOL) 1296 return true; 1297 1298 if (lt == STRUCT && rt == STRUCT && ltp->t_str == rtp->t_str) 1299 return true; 1300 if (lt == UNION && rt == UNION && ltp->t_str == rtp->t_str) 1301 return true; 1302 1303 if (lt == PTR && is_null_pointer(rn)) 1304 return true; 1305 if (rt == PTR && is_null_pointer(ln)) 1306 return true; 1307 1308 if ((lt == PTR && is_integer(rt)) || (is_integer(lt) && rt == PTR)) { 1309 const char *lx = lt == PTR ? "pointer" : "integer"; 1310 const char *rx = rt == PTR ? "pointer" : "integer"; 1311 /* illegal combination of %s '%s' and %s '%s', op '%s' */ 1312 warning(123, lx, type_name(ltp), 1313 rx, type_name(rtp), mp->m_name); 1314 return true; 1315 } 1316 1317 if (lt == VOID || rt == VOID) { 1318 if (lt != VOID || rt != VOID) 1319 /* incompatible types '%s' and '%s' in conditional */ 1320 warning(126, type_name(ltp), type_name(rtp)); 1321 return true; 1322 } 1323 1324 if (lt == PTR && rt == PTR) { 1325 typeok_colon_pointer(mp, ltp, rtp); 1326 return true; 1327 } 1328 1329 /* incompatible types '%s' and '%s' in conditional */ 1330 error(126, type_name(ltp), type_name(rtp)); 1331 return false; 1332 } 1333 1334 static bool 1335 typeok_assign(op_t op, const tnode_t *ln, const type_t *ltp, tspec_t lt) 1336 { 1337 if (op == RETURN || op == INIT || op == FARG) 1338 return true; 1339 1340 if (!ln->tn_lvalue) { 1341 if (ln->tn_op == CVT && ln->tn_cast && 1342 ln->tn_left->tn_op == LOAD) { 1343 /* a cast does not yield an lvalue */ 1344 error(163); 1345 } 1346 /* %soperand of '%s' must be lvalue */ 1347 error(114, "left ", op_name(op)); 1348 return false; 1349 } else if (ltp->t_const || (is_struct_or_union(lt) && 1350 has_constant_member(ltp))) { 1351 if (allow_c90) 1352 /* %soperand of '%s' must be modifiable lvalue */ 1353 warning(115, "left ", op_name(op)); 1354 } 1355 return true; 1356 } 1357 1358 /* Check the types using the information from modtab[]. */ 1359 static bool 1360 typeok_scalar(op_t op, const mod_t *mp, 1361 const type_t *ltp, tspec_t lt, 1362 const type_t *rtp, tspec_t rt) 1363 { 1364 if (mp->m_takes_bool && lt == BOOL && rt == BOOL) 1365 return true; 1366 if (mp->m_requires_integer) { 1367 if (!is_integer(lt) || (mp->m_binary && !is_integer(rt))) { 1368 warn_incompatible_types(op, ltp, lt, rtp, rt); 1369 return false; 1370 } 1371 } else if (mp->m_requires_integer_or_complex) { 1372 if ((!is_integer(lt) && !is_complex(lt)) || 1373 (mp->m_binary && (!is_integer(rt) && !is_complex(rt)))) { 1374 warn_incompatible_types(op, ltp, lt, rtp, rt); 1375 return false; 1376 } 1377 } else if (mp->m_requires_scalar) { 1378 if (!is_scalar(lt) || (mp->m_binary && !is_scalar(rt))) { 1379 warn_incompatible_types(op, ltp, lt, rtp, rt); 1380 return false; 1381 } 1382 } else if (mp->m_requires_arith) { 1383 if (!is_arithmetic(lt) || 1384 (mp->m_binary && !is_arithmetic(rt))) { 1385 warn_incompatible_types(op, ltp, lt, rtp, rt); 1386 return false; 1387 } 1388 } 1389 return true; 1390 } 1391 1392 /* 1393 * Check the types for specific operators and type combinations. 1394 * 1395 * At this point, the operands already conform to the type requirements of 1396 * the operator, such as being integer, floating or scalar. 1397 */ 1398 static bool 1399 typeok_op(op_t op, const mod_t *mp, int arg, 1400 const tnode_t *ln, const type_t *ltp, tspec_t lt, 1401 const tnode_t *rn, const type_t *rtp, tspec_t rt) 1402 { 1403 switch (op) { 1404 case ARROW: 1405 return typeok_arrow(lt); 1406 case POINT: 1407 return typeok_point(ln, ltp, lt); 1408 case INCBEF: 1409 case DECBEF: 1410 case INCAFT: 1411 case DECAFT: 1412 return typeok_incdec(op, ln, ltp); 1413 case INDIR: 1414 return typeok_indir(ltp, lt); 1415 case ADDR: 1416 return typeok_address(mp, ln, ltp, lt); 1417 case PLUS: 1418 return typeok_plus(op, ltp, lt, rtp, rt); 1419 case MINUS: 1420 return typeok_minus(op, ltp, lt, rtp, rt); 1421 case SHL: 1422 typeok_shl(mp, lt, rt); 1423 goto shift; 1424 case SHR: 1425 typeok_shr(mp, ln, lt, rn, rt); 1426 shift: 1427 typeok_shift(lt, rn, rt); 1428 break; 1429 case LT: 1430 case LE: 1431 case GT: 1432 case GE: 1433 compare: 1434 return typeok_compare(op, ln, ltp, lt, rn, rtp, rt); 1435 case EQ: 1436 case NE: 1437 if (is_typeok_eq(ln, lt, rn, rt)) 1438 break; 1439 goto compare; 1440 case QUEST: 1441 return typeok_quest(lt, rn); 1442 case COLON: 1443 return typeok_colon(mp, ln, ltp, lt, rn, rtp, rt); 1444 case ASSIGN: 1445 case INIT: 1446 case FARG: 1447 case RETURN: 1448 if (!check_assign_types_compatible(op, arg, ln, rn)) 1449 return false; 1450 goto assign; 1451 case MULASS: 1452 case DIVASS: 1453 case MODASS: 1454 goto assign; 1455 case ADDASS: 1456 case SUBASS: 1457 if ((lt == PTR && !is_integer(rt)) || rt == PTR) { 1458 warn_incompatible_types(op, ltp, lt, rtp, rt); 1459 return false; 1460 } 1461 goto assign; 1462 case SHLASS: 1463 goto assign; 1464 case SHRASS: 1465 if (pflag && !is_uinteger(lt) && 1466 !(!allow_c90 && is_uinteger(rt))) { 1467 /* bitwise '%s' on signed value possibly nonportable */ 1468 warning(117, mp->m_name); 1469 } 1470 goto assign; 1471 case ANDASS: 1472 case XORASS: 1473 case ORASS: 1474 assign: 1475 return typeok_assign(op, ln, ltp, lt); 1476 case COMMA: 1477 if (!modtab[ln->tn_op].m_has_side_effect) 1478 check_null_effect(ln); 1479 break; 1480 default: 1481 break; 1482 } 1483 return true; 1484 } 1485 1486 static void 1487 typeok_enum(op_t op, const mod_t *mp, int arg, 1488 const tnode_t *ln, const type_t *ltp, 1489 const tnode_t *rn, const type_t *rtp) 1490 { 1491 if (mp->m_bad_on_enum && 1492 (ltp->t_is_enum || (mp->m_binary && rtp->t_is_enum))) { 1493 check_bad_enum_operation(op, ln, rn); 1494 } else if (mp->m_valid_on_enum && 1495 (ltp->t_is_enum && rtp != NULL && rtp->t_is_enum)) { 1496 check_enum_type_mismatch(op, arg, ln, rn); 1497 } else if (mp->m_valid_on_enum && 1498 (ltp->t_is_enum || (rtp != NULL && rtp->t_is_enum))) { 1499 check_enum_int_mismatch(op, arg, ln, rn); 1500 } 1501 } 1502 1503 /* Perform most type checks. Return whether the types are ok. */ 1504 bool 1505 typeok(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 1506 { 1507 const mod_t *mp; 1508 tspec_t lt, rt; 1509 type_t *ltp, *rtp; 1510 1511 mp = &modtab[op]; 1512 1513 lint_assert((ltp = ln->tn_type) != NULL); 1514 lt = ltp->t_tspec; 1515 1516 if (mp->m_binary) { 1517 lint_assert((rtp = rn->tn_type) != NULL); 1518 rt = rtp->t_tspec; 1519 } else { 1520 rtp = NULL; 1521 rt = NOTSPEC; 1522 } 1523 1524 if (Tflag && !typeok_scalar_strict_bool(op, mp, arg, ln, rn)) 1525 return false; 1526 if (!typeok_scalar(op, mp, ltp, lt, rtp, rt)) 1527 return false; 1528 1529 if (!typeok_op(op, mp, arg, ln, ltp, lt, rn, rtp, rt)) 1530 return false; 1531 1532 typeok_enum(op, mp, arg, ln, ltp, rn, rtp); 1533 return true; 1534 } 1535 1536 static void 1537 check_pointer_comparison(op_t op, const tnode_t *ln, const tnode_t *rn) 1538 { 1539 type_t *ltp, *rtp; 1540 tspec_t lst, rst; 1541 const char *lsts, *rsts; 1542 1543 lst = (ltp = ln->tn_type)->t_subt->t_tspec; 1544 rst = (rtp = rn->tn_type)->t_subt->t_tspec; 1545 1546 if (lst == VOID || rst == VOID) { 1547 /* TODO: C99 behaves like C90 here. */ 1548 if ((!allow_trad && !allow_c99) && 1549 (lst == FUNC || rst == FUNC)) { 1550 /* (void *)0 already handled in typeok() */ 1551 *(lst == FUNC ? &lsts : &rsts) = "function pointer"; 1552 *(lst == VOID ? &lsts : &rsts) = "'void *'"; 1553 /* ANSI C forbids comparison of %s with %s */ 1554 warning(274, lsts, rsts); 1555 } 1556 return; 1557 } 1558 1559 if (!eqtype(ltp->t_subt, rtp->t_subt, true, false, NULL)) { 1560 warn_incompatible_pointers(&modtab[op], ltp, rtp); 1561 return; 1562 } 1563 1564 if (lst == FUNC && rst == FUNC) { 1565 /* TODO: C99 behaves like C90 here, see C99 6.5.8p2. */ 1566 if ((!allow_trad && !allow_c99) && op != EQ && op != NE) 1567 /* ANSI C forbids ordered comparisons of ... */ 1568 warning(125); 1569 } 1570 } 1571 1572 static bool 1573 is_direct_function_call(const tnode_t *tn, const char **out_name) 1574 { 1575 1576 if (!(tn->tn_op == CALL && 1577 tn->tn_left->tn_op == ADDR && 1578 tn->tn_left->tn_left->tn_op == NAME)) 1579 return false; 1580 1581 *out_name = tn->tn_left->tn_left->tn_sym->s_name; 1582 return true; 1583 } 1584 1585 static bool 1586 is_unconst_function(const char *name) 1587 { 1588 1589 return strcmp(name, "memchr") == 0 || 1590 strcmp(name, "strchr") == 0 || 1591 strcmp(name, "strpbrk") == 0 || 1592 strcmp(name, "strrchr") == 0 || 1593 strcmp(name, "strstr") == 0; 1594 } 1595 1596 static bool 1597 is_const_char_pointer(const tnode_t *tn) 1598 { 1599 const type_t *tp; 1600 1601 /* 1602 * For traditional reasons, C99 6.4.5p5 defines that string literals 1603 * have type 'char[]'. They are often implicitly converted to 1604 * 'char *', for example when they are passed as function arguments. 1605 * 1606 * C99 6.4.5p6 further defines that modifying a string that is 1607 * constructed from a string literal invokes undefined behavior. 1608 * 1609 * Out of these reasons, string literals are treated as 'effectively 1610 * const' here. 1611 */ 1612 if (tn->tn_op == CVT && 1613 tn->tn_left->tn_op == ADDR && 1614 tn->tn_left->tn_left->tn_op == STRING) 1615 return true; 1616 1617 tp = before_conversion(tn)->tn_type; 1618 return tp->t_tspec == PTR && 1619 tp->t_subt->t_tspec == CHAR && 1620 tp->t_subt->t_const; 1621 } 1622 1623 static bool 1624 is_const_pointer(const tnode_t *tn) 1625 { 1626 const type_t *tp; 1627 1628 tp = before_conversion(tn)->tn_type; 1629 return tp->t_tspec == PTR && tp->t_subt->t_const; 1630 } 1631 1632 static bool 1633 is_first_arg_const_char_pointer(const tnode_t *tn) 1634 { 1635 const tnode_t *an; 1636 1637 an = tn->tn_right; 1638 if (an == NULL) 1639 return false; 1640 1641 while (an->tn_right != NULL) 1642 an = an->tn_right; 1643 return is_const_char_pointer(an->tn_left); 1644 } 1645 1646 static bool 1647 is_second_arg_const_pointer(const tnode_t *tn) 1648 { 1649 const tnode_t *an; 1650 1651 an = tn->tn_right; 1652 if (an == NULL || an->tn_right == NULL) 1653 return false; 1654 1655 while (an->tn_right->tn_right != NULL) 1656 an = an->tn_right; 1657 return is_const_pointer(an->tn_left); 1658 } 1659 1660 static void 1661 check_unconst_function(const type_t *lstp, const tnode_t *rn) 1662 { 1663 const char *function_name; 1664 1665 if (lstp->t_tspec == CHAR && !lstp->t_const && 1666 is_direct_function_call(rn, &function_name) && 1667 is_unconst_function(function_name) && 1668 is_first_arg_const_char_pointer(rn)) { 1669 /* call to '%s' effectively discards 'const' from argument */ 1670 warning(346, function_name); 1671 } 1672 1673 if (!lstp->t_const && 1674 is_direct_function_call(rn, &function_name) && 1675 strcmp(function_name, "bsearch") == 0 && 1676 is_second_arg_const_pointer(rn)) { 1677 /* call to '%s' effectively discards 'const' from argument */ 1678 warning(346, function_name); 1679 } 1680 } 1681 1682 static void 1683 check_assign_void_pointer(op_t op, int arg, 1684 tspec_t lt, tspec_t lst, 1685 tspec_t rt, tspec_t rst) 1686 { 1687 const char *lts, *rts; 1688 1689 if (!(lt == PTR && rt == PTR && (lst == VOID || rst == VOID))) 1690 return; 1691 /* two pointers, at least one pointer to void */ 1692 1693 /* TODO: C99 behaves like C90 here. */ 1694 if (!((!allow_trad && !allow_c99) && (lst == FUNC || rst == FUNC))) 1695 return; 1696 /* comb. of ptr to func and ptr to void */ 1697 1698 *(lst == FUNC ? <s : &rts) = "function pointer"; 1699 *(lst == VOID ? <s : &rts) = "'void *'"; 1700 1701 switch (op) { 1702 case INIT: 1703 case RETURN: 1704 /* ANSI C forbids conversion of %s to %s */ 1705 warning(303, rts, lts); 1706 break; 1707 case FARG: 1708 /* ANSI C forbids conversion of %s to %s, arg #%d */ 1709 warning(304, rts, lts, arg); 1710 break; 1711 default: 1712 /* ANSI C forbids conversion of %s to %s, op %s */ 1713 warning(305, rts, lts, op_name(op)); 1714 break; 1715 } 1716 } 1717 1718 static bool 1719 check_assign_void_pointer_compat(op_t op, int arg, 1720 const type_t *const ltp, tspec_t const lt, 1721 const type_t *const lstp, tspec_t const lst, 1722 const tnode_t *const rn, 1723 const type_t *const rtp, tspec_t const rt, 1724 const type_t *const rstp, tspec_t const rst) 1725 { 1726 if (!(lt == PTR && rt == PTR && (lst == VOID || rst == VOID || 1727 eqtype(lstp, rstp, true, false, NULL)))) 1728 return false; 1729 1730 /* compatible pointer types (qualifiers ignored) */ 1731 if (allow_c90 && 1732 ((!lstp->t_const && rstp->t_const) || 1733 (!lstp->t_volatile && rstp->t_volatile))) { 1734 /* left side has not all qualifiers of right */ 1735 switch (op) { 1736 case INIT: 1737 case RETURN: 1738 /* incompatible pointer types to '%s' and '%s' */ 1739 warning(182, type_name(lstp), type_name(rstp)); 1740 break; 1741 case FARG: 1742 /* converting '%s' to incompatible '%s' ... */ 1743 warning(153, 1744 type_name(rtp), type_name(ltp), arg); 1745 break; 1746 default: 1747 /* operands of '%s' have incompatible pointer ... */ 1748 warning(128, op_name(op), 1749 type_name(lstp), type_name(rstp)); 1750 break; 1751 } 1752 } 1753 1754 if (allow_c90) 1755 check_unconst_function(lstp, rn); 1756 1757 return true; 1758 } 1759 1760 static bool 1761 check_assign_pointer_integer(op_t op, int arg, 1762 const type_t *const ltp, tspec_t const lt, 1763 const type_t *const rtp, tspec_t const rt) 1764 { 1765 const char *lx, *rx; 1766 1767 if (!((lt == PTR && is_integer(rt)) || (is_integer(lt) && rt == PTR))) 1768 return false; 1769 1770 lx = lt == PTR ? "pointer" : "integer"; 1771 rx = rt == PTR ? "pointer" : "integer"; 1772 1773 switch (op) { 1774 case INIT: 1775 case RETURN: 1776 /* illegal combination of %s '%s' and %s '%s' */ 1777 warning(183, lx, type_name(ltp), rx, type_name(rtp)); 1778 break; 1779 case FARG: 1780 /* illegal combination of %s '%s' and %s '%s', arg #%d */ 1781 warning(154, 1782 lx, type_name(ltp), rx, type_name(rtp), arg); 1783 break; 1784 default: 1785 /* illegal combination of %s '%s' and %s '%s', op '%s' */ 1786 warning(123, 1787 lx, type_name(ltp), rx, type_name(rtp), op_name(op)); 1788 break; 1789 } 1790 return true; 1791 } 1792 1793 static bool 1794 check_assign_pointer(op_t op, int arg, 1795 const type_t *ltp, tspec_t lt, 1796 const type_t *rtp, tspec_t rt) 1797 { 1798 if (!(lt == PTR && rt == PTR)) 1799 return false; 1800 1801 switch (op) { 1802 case RETURN: 1803 warn_incompatible_pointers(NULL, ltp, rtp); 1804 break; 1805 case FARG: 1806 /* converting '%s' to incompatible '%s' for ... */ 1807 warning(153, type_name(rtp), type_name(ltp), arg); 1808 break; 1809 default: 1810 warn_incompatible_pointers(&modtab[op], ltp, rtp); 1811 break; 1812 } 1813 return true; 1814 } 1815 1816 static void 1817 warn_assign(op_t op, int arg, 1818 const type_t *ltp, tspec_t lt, 1819 const type_t *rtp, tspec_t rt) 1820 { 1821 switch (op) { 1822 case INIT: 1823 /* cannot initialize '%s' from '%s' */ 1824 error(185, type_name(ltp), type_name(rtp)); 1825 break; 1826 case RETURN: 1827 /* function has return type '%s' but returns '%s' */ 1828 error(211, type_name(ltp), type_name(rtp)); 1829 break; 1830 case FARG: 1831 /* passing '%s' to incompatible '%s', arg #%d */ 1832 warning(155, type_name(rtp), type_name(ltp), arg); 1833 break; 1834 default: 1835 warn_incompatible_types(op, ltp, lt, rtp, rt); 1836 break; 1837 } 1838 } 1839 1840 /* 1841 * Checks type compatibility for ASSIGN, INIT, FARG and RETURN 1842 * and prints warnings/errors if necessary. 1843 * Returns whether the types are (almost) compatible. 1844 */ 1845 static bool 1846 check_assign_types_compatible(op_t op, int arg, 1847 const tnode_t *ln, const tnode_t *rn) 1848 { 1849 tspec_t lt, rt, lst = NOTSPEC, rst = NOTSPEC; 1850 type_t *ltp, *rtp, *lstp = NULL, *rstp = NULL; 1851 1852 if ((lt = (ltp = ln->tn_type)->t_tspec) == PTR) 1853 lst = (lstp = ltp->t_subt)->t_tspec; 1854 if ((rt = (rtp = rn->tn_type)->t_tspec) == PTR) 1855 rst = (rstp = rtp->t_subt)->t_tspec; 1856 1857 if (lt == BOOL && is_scalar(rt)) /* C99 6.3.1.2 */ 1858 return true; 1859 1860 if (is_arithmetic(lt) && (is_arithmetic(rt) || rt == BOOL)) 1861 return true; 1862 1863 if (is_struct_or_union(lt) && is_struct_or_union(rt)) 1864 /* both are struct or union */ 1865 return ltp->t_str == rtp->t_str; 1866 1867 /* a null pointer may be assigned to any pointer */ 1868 if (lt == PTR && is_null_pointer(rn)) 1869 return true; 1870 1871 check_assign_void_pointer(op, arg, lt, lst, rt, rst); 1872 1873 if (check_assign_void_pointer_compat(op, arg, 1874 ltp, lt, lstp, lst, rn, rtp, rt, rstp, rst)) 1875 return true; 1876 1877 if (check_assign_pointer_integer(op, arg, ltp, lt, rtp, rt)) 1878 return true; 1879 1880 if (check_assign_pointer(op, arg, ltp, lt, rtp, rt)) 1881 return true; 1882 1883 warn_assign(op, arg, ltp, lt, rtp, rt); 1884 return false; 1885 } 1886 1887 /* Prints a warning if a strange operator is used on an enum type. */ 1888 static void 1889 check_bad_enum_operation(op_t op, const tnode_t *ln, const tnode_t *rn) 1890 { 1891 1892 if (!eflag) 1893 return; 1894 1895 /* 1896 * Enum as offset to a pointer is an exception (otherwise enums 1897 * could not be used as array indices). 1898 */ 1899 if (op == PLUS && 1900 ((ln->tn_type->t_is_enum && rn->tn_type->t_tspec == PTR) || 1901 (rn->tn_type->t_is_enum && ln->tn_type->t_tspec == PTR))) { 1902 return; 1903 } 1904 1905 /* dubious operation on enum, op '%s' */ 1906 warning(241, op_name(op)); 1907 } 1908 1909 /* 1910 * Prints a warning if an operator is applied to two different enum types. 1911 */ 1912 static void 1913 check_enum_type_mismatch(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 1914 { 1915 const mod_t *mp; 1916 1917 mp = &modtab[op]; 1918 1919 if (ln->tn_type->t_enum != rn->tn_type->t_enum) { 1920 switch (op) { 1921 case INIT: 1922 /* enum type mismatch between '%s' and '%s' in ... */ 1923 warning(210, 1924 type_name(ln->tn_type), type_name(rn->tn_type)); 1925 break; 1926 case FARG: 1927 /* function expects '%s', passing '%s' for arg #%d */ 1928 warning(156, 1929 type_name(ln->tn_type), type_name(rn->tn_type), 1930 arg); 1931 break; 1932 case RETURN: 1933 /* function has return type '%s' but returns '%s' */ 1934 warning(211, 1935 type_name(ln->tn_type), type_name(rn->tn_type)); 1936 break; 1937 default: 1938 /* enum type mismatch: '%s' '%s' '%s' */ 1939 warning(130, type_name(ln->tn_type), mp->m_name, 1940 type_name(rn->tn_type)); 1941 break; 1942 } 1943 } else if (Pflag && mp->m_comparison && op != EQ && op != NE) { 1944 if (eflag) 1945 /* dubious comparison of enums, op '%s' */ 1946 warning(243, mp->m_name); 1947 } 1948 } 1949 1950 /* Prints a warning if the operands mix between enum and integer. */ 1951 static void 1952 check_enum_int_mismatch(op_t op, int arg, const tnode_t *ln, const tnode_t *rn) 1953 { 1954 1955 if (!eflag) 1956 return; 1957 1958 switch (op) { 1959 case INIT: 1960 /* 1961 * Initialization with 0 is allowed. Otherwise, all implicit 1962 * initializations would need to be warned upon as well. 1963 */ 1964 if (!rn->tn_type->t_is_enum && rn->tn_op == CON && 1965 is_integer(rn->tn_type->t_tspec) && 1966 rn->tn_val->v_quad == 0) { 1967 return; 1968 } 1969 /* initialization of '%s' with '%s' */ 1970 warning(277, type_name(ln->tn_type), type_name(rn->tn_type)); 1971 break; 1972 case FARG: 1973 /* combination of '%s' and '%s', arg #%d */ 1974 warning(278, 1975 type_name(ln->tn_type), type_name(rn->tn_type), arg); 1976 break; 1977 case RETURN: 1978 /* combination of '%s' and '%s' in return */ 1979 warning(279, type_name(ln->tn_type), type_name(rn->tn_type)); 1980 break; 1981 default: 1982 /* combination of '%s' and '%s', op '%s' */ 1983 warning(242, type_name(ln->tn_type), type_name(rn->tn_type), 1984 op_name(op)); 1985 break; 1986 } 1987 } 1988 1989 static void 1990 check_enum_array_index(const tnode_t *ln, const tnode_t *rn) 1991 { 1992 int max_array_index; 1993 int64_t max_enum_value; 1994 const struct sym *ec, *max_ec; 1995 const type_t *lt, *rt; 1996 1997 if (ln->tn_op != ADDR || ln->tn_left->tn_op != NAME) 1998 return; 1999 2000 lt = ln->tn_left->tn_type; 2001 if (lt->t_tspec != ARRAY || lt->t_incomplete_array) 2002 return; 2003 2004 if (rn->tn_op != CVT || !rn->tn_type->t_is_enum) 2005 return; 2006 if (rn->tn_left->tn_op != LOAD) 2007 return; 2008 2009 rt = rn->tn_left->tn_type; 2010 ec = rt->t_enum->en_first_enumerator; 2011 max_ec = ec; 2012 lint_assert(ec != NULL); 2013 for (ec = ec->s_next; ec != NULL; ec = ec->s_next) 2014 if (ec->u.s_enum_constant > max_ec->u.s_enum_constant) 2015 max_ec = ec; 2016 2017 max_enum_value = max_ec->u.s_enum_constant; 2018 lint_assert(INT_MIN <= max_enum_value && max_enum_value <= INT_MAX); 2019 2020 max_array_index = lt->t_dim - 1; 2021 if (max_enum_value == max_array_index) 2022 return; 2023 2024 /* 2025 * If the largest enum constant is named '*_NUM_*', it is typically 2026 * not part of the allowed enum values but a marker for the number 2027 * of actual enum values. 2028 */ 2029 if (max_enum_value == max_array_index + 1 && 2030 (strstr(max_ec->s_name, "NUM") != NULL || 2031 strstr(max_ec->s_name, "num") != NULL)) 2032 return; 2033 2034 /* maximum value %d of '%s' does not match maximum array index %d */ 2035 warning(348, (int)max_enum_value, type_name(rt), max_array_index); 2036 print_previous_declaration(-1, max_ec); 2037 } 2038 2039 /* 2040 * Build and initialize a new node. 2041 */ 2042 static tnode_t * 2043 new_tnode(op_t op, bool sys, type_t *type, tnode_t *ln, tnode_t *rn) 2044 { 2045 tnode_t *ntn; 2046 tspec_t t; 2047 #if 0 /* not yet */ 2048 size_t l; 2049 uint64_t rnum; 2050 #endif 2051 2052 ntn = expr_alloc_tnode(); 2053 2054 ntn->tn_op = op; 2055 ntn->tn_type = type; 2056 ntn->tn_sys = sys; 2057 ntn->tn_left = ln; 2058 ntn->tn_right = rn; 2059 2060 switch (op) { 2061 #if 0 /* not yet */ 2062 case SHR: 2063 if (rn->tn_op != CON) 2064 break; 2065 rnum = rn->tn_val->v_quad; 2066 l = type_size_in_bits(ln->tn_type) / CHAR_SIZE; 2067 t = ln->tn_type->t_tspec; 2068 switch (l) { 2069 case 8: 2070 if (rnum >= 56) 2071 t = UCHAR; 2072 else if (rnum >= 48) 2073 t = USHORT; 2074 else if (rnum >= 32) 2075 t = UINT; 2076 break; 2077 case 4: 2078 if (rnum >= 24) 2079 t = UCHAR; 2080 else if (rnum >= 16) 2081 t = USHORT; 2082 break; 2083 case 2: 2084 if (rnum >= 8) 2085 t = UCHAR; 2086 break; 2087 default: 2088 break; 2089 } 2090 if (t != ln->tn_type->t_tspec) 2091 ntn->tn_type->t_tspec = t; 2092 break; 2093 #endif 2094 case INDIR: 2095 case FSEL: 2096 lint_assert(ln->tn_type->t_tspec == PTR); 2097 t = ln->tn_type->t_subt->t_tspec; 2098 if (t != FUNC && t != VOID) 2099 ntn->tn_lvalue = true; 2100 break; 2101 default: 2102 break; 2103 } 2104 2105 return ntn; 2106 } 2107 2108 /* 2109 * Performs the "integer promotions" (C99 6.3.1.1p2), which convert small 2110 * integer types to either int or unsigned int. 2111 * 2112 * If allow_c90 is unset or the operand is a function argument with no type 2113 * information (no prototype or variable # of args), converts float to double. 2114 */ 2115 tnode_t * 2116 promote(op_t op, bool farg, tnode_t *tn) 2117 { 2118 tspec_t t; 2119 type_t *ntp; 2120 unsigned int len; 2121 2122 t = tn->tn_type->t_tspec; 2123 2124 if (!is_arithmetic(t)) 2125 return tn; 2126 2127 if (allow_c90) { 2128 /* 2129 * C99 6.3.1.1p2 requires for types with lower rank than int 2130 * that "If an int can represent all the values of the 2131 * original type, the value is converted to an int; otherwise 2132 * it is converted to an unsigned int", and that "All other 2133 * types are unchanged by the integer promotions". 2134 */ 2135 if (tn->tn_type->t_bitfield) { 2136 len = tn->tn_type->t_flen; 2137 if (len < size_in_bits(INT)) { 2138 t = INT; 2139 } else if (len == size_in_bits(INT)) { 2140 t = is_uinteger(t) ? UINT : INT; 2141 } 2142 } else if (t == CHAR || t == UCHAR || t == SCHAR) { 2143 t = (size_in_bits(CHAR) < size_in_bits(INT) 2144 || t != UCHAR) ? INT : UINT; 2145 } else if (t == SHORT || t == USHORT) { 2146 t = (size_in_bits(SHORT) < size_in_bits(INT) 2147 || t == SHORT) ? INT : UINT; 2148 } else if (t == ENUM) { 2149 t = INT; 2150 } else if (farg && t == FLOAT) { 2151 t = DOUBLE; 2152 } 2153 } else { 2154 /* 2155 * In traditional C, keep unsigned and promote FLOAT 2156 * to DOUBLE. 2157 */ 2158 if (t == UCHAR || t == USHORT) { 2159 t = UINT; 2160 } else if (t == CHAR || t == SCHAR || t == SHORT) { 2161 t = INT; 2162 } else if (t == FLOAT) { 2163 t = DOUBLE; 2164 } else if (t == ENUM) { 2165 t = INT; 2166 } 2167 } 2168 2169 if (t != tn->tn_type->t_tspec) { 2170 ntp = expr_dup_type(tn->tn_type); 2171 ntp->t_tspec = t; 2172 /* 2173 * Keep t_is_enum even though t_tspec gets converted from 2174 * ENUM to INT, so we are later able to check compatibility 2175 * of enum types. 2176 */ 2177 tn = convert(op, 0, ntp, tn); 2178 } 2179 2180 return tn; 2181 } 2182 2183 /* 2184 * Apply the "usual arithmetic conversions" (C99 6.3.1.8). 2185 * 2186 * This gives both operands the same type. 2187 * This is done in different ways for traditional C and C90. 2188 */ 2189 static void 2190 balance(op_t op, tnode_t **lnp, tnode_t **rnp) 2191 { 2192 tspec_t lt, rt, t; 2193 int i; 2194 bool u; 2195 type_t *ntp; 2196 static const tspec_t tl[] = { 2197 LDOUBLE, DOUBLE, FLOAT, 2198 #ifdef INT128_SIZE 2199 UINT128, INT128, 2200 #endif 2201 UQUAD, QUAD, 2202 ULONG, LONG, 2203 UINT, INT, 2204 }; 2205 2206 lt = (*lnp)->tn_type->t_tspec; 2207 rt = (*rnp)->tn_type->t_tspec; 2208 2209 if (!is_arithmetic(lt) || !is_arithmetic(rt)) 2210 return; 2211 2212 if (allow_c90) { 2213 if (lt == rt) { 2214 t = lt; 2215 } else if (lt == LCOMPLEX || rt == LCOMPLEX) { 2216 t = LCOMPLEX; 2217 } else if (lt == DCOMPLEX || rt == DCOMPLEX) { 2218 t = DCOMPLEX; 2219 } else if (lt == FCOMPLEX || rt == FCOMPLEX) { 2220 t = FCOMPLEX; 2221 } else if (lt == LDOUBLE || rt == LDOUBLE) { 2222 t = LDOUBLE; 2223 } else if (lt == DOUBLE || rt == DOUBLE) { 2224 t = DOUBLE; 2225 } else if (lt == FLOAT || rt == FLOAT) { 2226 t = FLOAT; 2227 } else { 2228 /* 2229 * If type A has more bits than type B it should 2230 * be able to hold all possible values of type B. 2231 */ 2232 if (size_in_bits(lt) > size_in_bits(rt)) { 2233 t = lt; 2234 } else if (size_in_bits(lt) < size_in_bits(rt)) { 2235 t = rt; 2236 } else { 2237 for (i = 3; tl[i] != INT; i++) { 2238 if (tl[i] == lt || tl[i] == rt) 2239 break; 2240 } 2241 if ((is_uinteger(lt) || is_uinteger(rt)) && 2242 !is_uinteger(tl[i])) { 2243 i--; 2244 } 2245 t = tl[i]; 2246 } 2247 } 2248 } else { 2249 /* Keep unsigned in traditional C */ 2250 u = is_uinteger(lt) || is_uinteger(rt); 2251 for (i = 0; tl[i] != INT; i++) { 2252 if (lt == tl[i] || rt == tl[i]) 2253 break; 2254 } 2255 t = tl[i]; 2256 if (u && is_integer(t) && !is_uinteger(t)) 2257 t = unsigned_type(t); 2258 } 2259 2260 if (t != lt) { 2261 ntp = expr_dup_type((*lnp)->tn_type); 2262 ntp->t_tspec = t; 2263 /* usual arithmetic conversion for '%s' from '%s' to '%s' */ 2264 query_message(4, op_name(op), 2265 type_name((*lnp)->tn_type), type_name(ntp)); 2266 *lnp = convert(op, 0, ntp, *lnp); 2267 } 2268 if (t != rt) { 2269 ntp = expr_dup_type((*rnp)->tn_type); 2270 ntp->t_tspec = t; 2271 /* usual arithmetic conversion for '%s' from '%s' to '%s' */ 2272 query_message(4, op_name(op), 2273 type_name((*rnp)->tn_type), type_name(ntp)); 2274 *rnp = convert(op, 0, ntp, *rnp); 2275 } 2276 } 2277 2278 static void 2279 convert_integer_from_floating(op_t op, const type_t *tp, const tnode_t *tn) 2280 { 2281 2282 if (op == CVT) 2283 /* cast from floating point '%s' to integer '%s' */ 2284 query_message(2, type_name(tn->tn_type), type_name(tp)); 2285 else 2286 /* implicit conversion from floating point '%s' to ... */ 2287 query_message(1, type_name(tn->tn_type), type_name(tp)); 2288 } 2289 2290 /* 2291 * Insert a conversion operator, which converts the type of the node 2292 * to another given type. 2293 * 2294 * Possible values for 'op': 2295 * CVT a cast-expression 2296 * binary integer promotion for one of the operands, or a usual 2297 * arithmetic conversion 2298 * binary plain or compound assignments to bit-fields 2299 * FARG 'arg' is the number of the argument (used for warnings) 2300 * NOOP several other implicit conversions 2301 * ... 2302 */ 2303 tnode_t * 2304 convert(op_t op, int arg, type_t *tp, tnode_t *tn) 2305 { 2306 tnode_t *ntn; 2307 tspec_t nt, ot; 2308 2309 nt = tp->t_tspec; 2310 ot = tn->tn_type->t_tspec; 2311 2312 if (allow_trad && allow_c90 && op == FARG) 2313 check_prototype_conversion(arg, nt, ot, tp, tn); 2314 2315 if (nt == BOOL) { 2316 /* No further checks. */ 2317 2318 } else if (is_integer(nt)) { 2319 if (ot == BOOL) { 2320 /* No further checks. */ 2321 } else if (is_integer(ot)) { 2322 convert_integer_from_integer(op, arg, nt, ot, tp, tn); 2323 } else if (is_floating(ot)) { 2324 convert_integer_from_floating(op, tp, tn); 2325 } else if (ot == PTR) { 2326 convert_integer_from_pointer(op, nt, tp, tn); 2327 } 2328 2329 } else if (is_floating(nt)) { 2330 /* No further checks. */ 2331 2332 } else if (nt == PTR) { 2333 if (is_null_pointer(tn)) { 2334 /* a null pointer may be assigned to any pointer. */ 2335 } else if (ot == PTR && op == CVT) { 2336 convert_pointer_from_pointer(tp, tn); 2337 } 2338 } 2339 2340 ntn = expr_alloc_tnode(); 2341 ntn->tn_op = CVT; 2342 ntn->tn_type = tp; 2343 ntn->tn_cast = op == CVT; 2344 ntn->tn_sys |= tn->tn_sys; 2345 ntn->tn_right = NULL; 2346 if (tn->tn_op != CON || nt == VOID) { 2347 ntn->tn_left = tn; 2348 } else { 2349 ntn->tn_op = CON; 2350 ntn->tn_val = expr_zero_alloc(sizeof(*ntn->tn_val)); 2351 convert_constant(op, arg, ntn->tn_type, ntn->tn_val, 2352 tn->tn_val); 2353 } 2354 2355 return ntn; 2356 } 2357 2358 static bool 2359 should_warn_about_prototype_conversion(tspec_t nt, 2360 tspec_t ot, const tnode_t *ptn) 2361 { 2362 2363 if (nt == ot) 2364 return false; 2365 2366 if (nt == ENUM && ot == INT) 2367 return false; 2368 2369 if (is_floating(nt) != is_floating(ot) || 2370 portable_size_in_bits(nt) != portable_size_in_bits(ot)) { 2371 /* representation and/or width change */ 2372 if (!is_integer(ot)) 2373 return true; 2374 /* 2375 * XXX: Investigate whether this rule makes sense; see 2376 * tests/usr.bin/xlint/lint1/platform_long.c. 2377 */ 2378 return portable_size_in_bits(ot) > portable_size_in_bits(INT); 2379 } 2380 2381 if (!hflag) 2382 return false; 2383 2384 /* 2385 * If the types differ only in sign and the argument has the same 2386 * representation in both types, print no warning. 2387 */ 2388 if (ptn->tn_op == CON && is_integer(nt) && 2389 signed_type(nt) == signed_type(ot) && 2390 !msb(ptn->tn_val->v_quad, ot)) 2391 return false; 2392 2393 return true; 2394 } 2395 2396 /* 2397 * Warn if a prototype causes a type conversion that is different from what 2398 * would happen to the same argument in the absence of a prototype. This 2399 * check is intended for code that needs to stay compatible with pre-C90 C. 2400 * 2401 * Errors/warnings about illegal type combinations are already printed 2402 * in check_assign_types_compatible(). 2403 */ 2404 static void 2405 check_prototype_conversion(int arg, tspec_t nt, tspec_t ot, type_t *tp, 2406 tnode_t *tn) 2407 { 2408 tnode_t *ptn; 2409 2410 if (!is_arithmetic(nt) || !is_arithmetic(ot)) 2411 return; 2412 2413 /* 2414 * If the type of the formal parameter is char/short, a warning 2415 * would be useless, because functions declared the old style 2416 * can't expect char/short arguments. 2417 */ 2418 if (nt == CHAR || nt == SCHAR || nt == UCHAR || 2419 nt == SHORT || nt == USHORT) 2420 return; 2421 2422 /* apply the default promotion */ 2423 ptn = promote(NOOP, true, tn); 2424 ot = ptn->tn_type->t_tspec; 2425 2426 if (should_warn_about_prototype_conversion(nt, ot, ptn)) { 2427 /* argument #%d is converted from '%s' to '%s' ... */ 2428 warning(259, arg, type_name(tn->tn_type), type_name(tp)); 2429 } 2430 } 2431 2432 /* 2433 * When converting a large integer type to a small integer type, in some 2434 * cases the value of the actual expression is further restricted than the 2435 * type bounds, such as in (expr & 0xFF) or (expr % 100) or (expr >> 24). 2436 * 2437 * See new_tnode, the '#if 0' code for SHR. 2438 */ 2439 static bool 2440 can_represent(const type_t *tp, const tnode_t *tn) 2441 { 2442 2443 debug_step("%s: type '%s'", __func__, type_name(tp)); 2444 debug_node(tn); 2445 2446 uint64_t nmask = value_bits(ic_length_in_bits(tp)); 2447 if (!is_uinteger(tp->t_tspec)) 2448 nmask >>= 1; 2449 2450 integer_constraints c = ic_expr(tn); 2451 if ((~c.bclr & ~nmask) == 0) 2452 return true; 2453 2454 return false; 2455 } 2456 2457 static void 2458 convert_integer_from_integer(op_t op, int arg, tspec_t nt, tspec_t ot, 2459 type_t *tp, tnode_t *tn) 2460 { 2461 2462 if (tn->tn_op == CON) 2463 return; 2464 2465 if (op == CVT) 2466 return; 2467 2468 if (Pflag && pflag && aflag > 0 && 2469 portable_size_in_bits(nt) > portable_size_in_bits(ot) && 2470 is_uinteger(nt) != is_uinteger(ot)) { 2471 if (op == FARG) { 2472 /* conversion to '%s' may sign-extend ... */ 2473 warning(297, type_name(tp), arg); 2474 } else { 2475 /* conversion to '%s' may sign-extend ... */ 2476 warning(131, type_name(tp)); 2477 } 2478 } 2479 2480 if (Pflag && portable_size_in_bits(nt) > portable_size_in_bits(ot) && 2481 (tn->tn_op == PLUS || tn->tn_op == MINUS || tn->tn_op == MULT || 2482 tn->tn_op == SHL)) { 2483 /* suggest cast from '%s' to '%s' on op '%s' to ... */ 2484 warning(324, type_name(gettyp(ot)), type_name(tp), 2485 op_name(tn->tn_op)); 2486 } 2487 2488 if (aflag > 0 && 2489 portable_size_in_bits(nt) < portable_size_in_bits(ot) && 2490 (ot == LONG || ot == ULONG || ot == QUAD || ot == UQUAD || 2491 aflag > 1) && 2492 !can_represent(tp, tn)) { 2493 if (op == FARG) { 2494 /* conversion from '%s' to '%s' may lose ... */ 2495 warning(298, 2496 type_name(tn->tn_type), type_name(tp), arg); 2497 } else { 2498 /* conversion from '%s' to '%s' may lose accuracy */ 2499 warning(132, 2500 type_name(tn->tn_type), type_name(tp)); 2501 } 2502 } 2503 2504 if (is_uinteger(nt) != is_uinteger(ot)) 2505 /* implicit conversion changes sign from '%s' to '%s' */ 2506 query_message(3, type_name(tn->tn_type), type_name(tp)); 2507 } 2508 2509 static void 2510 convert_integer_from_pointer(op_t op, tspec_t nt, type_t *tp, tnode_t *tn) 2511 { 2512 2513 if (tn->tn_op == CON) 2514 return; 2515 if (op != CVT) 2516 return; /* We got already an error. */ 2517 if (portable_size_in_bits(nt) >= portable_size_in_bits(PTR)) 2518 return; 2519 2520 if (pflag && size_in_bits(nt) >= size_in_bits(PTR)) { 2521 /* conversion of pointer to '%s' may lose bits */ 2522 warning(134, type_name(tp)); 2523 } else { 2524 /* conversion of pointer to '%s' loses bits */ 2525 warning(133, type_name(tp)); 2526 } 2527 } 2528 2529 static bool 2530 struct_starts_with(const type_t *struct_tp, const type_t *member_tp) 2531 { 2532 2533 return struct_tp->t_str->sou_first_member != NULL && 2534 eqtype(struct_tp->t_str->sou_first_member->s_type, member_tp, 2535 true, false, NULL); 2536 } 2537 2538 static bool 2539 is_byte_array(const type_t *tp) 2540 { 2541 2542 return tp->t_tspec == ARRAY && 2543 (tp->t_subt->t_tspec == CHAR || tp->t_subt->t_tspec == UCHAR); 2544 } 2545 2546 static bool 2547 should_warn_about_pointer_cast(const type_t *nstp, tspec_t nst, 2548 const type_t *ostp, tspec_t ost) 2549 { 2550 2551 while (nst == ARRAY) 2552 nstp = nstp->t_subt, nst = nstp->t_tspec; 2553 while (ost == ARRAY) 2554 ostp = ostp->t_subt, ost = ostp->t_tspec; 2555 2556 if (nst == STRUCT && ost == STRUCT && 2557 (struct_starts_with(nstp, ostp) || 2558 struct_starts_with(ostp, nstp))) 2559 return false; 2560 2561 if (is_incomplete(nstp) || is_incomplete(ostp)) 2562 return false; 2563 2564 if (nst == CHAR || nst == UCHAR) 2565 return false; /* for the sake of traditional C code */ 2566 if (ost == CHAR || ost == UCHAR) 2567 return false; /* for the sake of traditional C code */ 2568 2569 /* Allow cast between pointers to sockaddr variants. */ 2570 if (nst == STRUCT && ost == STRUCT) { 2571 debug_type(nstp); 2572 debug_type(ostp); 2573 const sym_t *nmem = nstp->t_str->sou_first_member; 2574 const sym_t *omem = ostp->t_str->sou_first_member; 2575 while (nmem != NULL && omem != NULL && 2576 eqtype(nmem->s_type, omem->s_type, true, false, NULL)) 2577 nmem = nmem->s_next, omem = omem->s_next; 2578 if (nmem != NULL && is_byte_array(nmem->s_type)) 2579 return false; 2580 if (omem != NULL && is_byte_array(omem->s_type)) 2581 return false; 2582 if (nmem == NULL && omem == NULL) 2583 return false; 2584 } 2585 2586 if (is_struct_or_union(nst) && nstp->t_str != ostp->t_str) 2587 return true; 2588 2589 return portable_size_in_bits(nst) != portable_size_in_bits(ost); 2590 } 2591 2592 static void 2593 convert_pointer_from_pointer(type_t *ntp, tnode_t *tn) 2594 { 2595 const type_t *nstp, *otp, *ostp; 2596 tspec_t nst, ost; 2597 const char *nts, *ots; 2598 2599 nstp = ntp->t_subt; 2600 otp = tn->tn_type; 2601 ostp = otp->t_subt; 2602 nst = nstp->t_tspec; 2603 ost = ostp->t_tspec; 2604 2605 if (nst == VOID || ost == VOID) { 2606 /* TODO: C99 behaves like C90 here. */ 2607 if ((!allow_trad && !allow_c99) && (nst == FUNC || ost == FUNC)) { 2608 /* null pointers are already handled in convert() */ 2609 *(nst == FUNC ? &nts : &ots) = "function pointer"; 2610 *(nst == VOID ? &nts : &ots) = "'void *'"; 2611 /* ANSI C forbids conversion of %s to %s */ 2612 warning(303, ots, nts); 2613 } 2614 return; 2615 } else if (nst == FUNC && ost == FUNC) { 2616 return; 2617 } else if (nst == FUNC || ost == FUNC) { 2618 /* converting '%s' to '%s' is questionable */ 2619 warning(229, type_name(otp), type_name(ntp)); 2620 return; 2621 } 2622 2623 if (hflag && alignment_in_bits(nstp) > alignment_in_bits(ostp) && 2624 ost != CHAR && ost != UCHAR && 2625 !is_incomplete(ostp)) { 2626 /* converting '%s' to '%s' may cause alignment problem */ 2627 warning(135, type_name(otp), type_name(ntp)); 2628 } 2629 2630 if (cflag && should_warn_about_pointer_cast(nstp, nst, ostp, ost)) { 2631 /* pointer cast from '%s' to '%s' may be troublesome */ 2632 warning(247, type_name(otp), type_name(ntp)); 2633 } 2634 } 2635 2636 static void 2637 convert_constant_floating(op_t op, int arg, tspec_t ot, const type_t *tp, 2638 tspec_t nt, val_t *v, val_t *nv) 2639 { 2640 ldbl_t max = 0.0, min = 0.0; 2641 2642 switch (nt) { 2643 case CHAR: 2644 max = TARG_CHAR_MAX; min = TARG_CHAR_MIN; break; 2645 case UCHAR: 2646 max = TARG_UCHAR_MAX; min = 0; break; 2647 case SCHAR: 2648 max = TARG_SCHAR_MAX; min = TARG_SCHAR_MIN; break; 2649 case SHORT: 2650 max = TARG_SHRT_MAX; min = TARG_SHRT_MIN; break; 2651 case USHORT: 2652 max = TARG_USHRT_MAX; min = 0; break; 2653 case ENUM: 2654 case INT: 2655 max = TARG_INT_MAX; min = TARG_INT_MIN; break; 2656 case UINT: 2657 max = TARG_UINT_MAX; min = 0; break; 2658 case LONG: 2659 max = TARG_LONG_MAX; min = TARG_LONG_MIN; break; 2660 case ULONG: 2661 max = TARG_ULONG_MAX; min = 0; break; 2662 case QUAD: 2663 max = QUAD_MAX; min = QUAD_MIN; break; 2664 case UQUAD: 2665 max = UQUAD_MAX; min = 0; break; 2666 case FLOAT: 2667 case FCOMPLEX: 2668 max = FLT_MAX; min = -FLT_MAX; break; 2669 case DOUBLE: 2670 case DCOMPLEX: 2671 max = DBL_MAX; min = -DBL_MAX; break; 2672 case PTR: 2673 /* Got already an error because of float --> ptr */ 2674 case LDOUBLE: 2675 case LCOMPLEX: 2676 /* LINTED 248 */ 2677 max = LDBL_MAX; min = -max; break; 2678 default: 2679 lint_assert(/*CONSTCOND*/false); 2680 } 2681 if (v->v_ldbl > max || v->v_ldbl < min) { 2682 lint_assert(nt != LDOUBLE); 2683 if (op == FARG) { 2684 /* conversion of '%s' to '%s' is out of range, ... */ 2685 warning(295, 2686 type_name(gettyp(ot)), type_name(tp), arg); 2687 } else { 2688 /* conversion of '%s' to '%s' is out of range */ 2689 warning(119, 2690 type_name(gettyp(ot)), type_name(tp)); 2691 } 2692 v->v_ldbl = v->v_ldbl > 0 ? max : min; 2693 } 2694 2695 if (nt == FLOAT) { 2696 nv->v_ldbl = (float)v->v_ldbl; 2697 } else if (nt == DOUBLE) { 2698 nv->v_ldbl = (double)v->v_ldbl; 2699 } else if (nt == LDOUBLE) { 2700 nv->v_ldbl = v->v_ldbl; 2701 } else { 2702 nv->v_quad = (int64_t)v->v_ldbl; 2703 } 2704 } 2705 2706 static bool 2707 convert_constant_to_floating(tspec_t nt, val_t *nv, 2708 tspec_t ot, const val_t *v) 2709 { 2710 if (nt == FLOAT) { 2711 nv->v_ldbl = (ot == PTR || is_uinteger(ot)) ? 2712 (float)(uint64_t)v->v_quad : (float)v->v_quad; 2713 } else if (nt == DOUBLE) { 2714 nv->v_ldbl = (ot == PTR || is_uinteger(ot)) ? 2715 (double)(uint64_t)v->v_quad : (double)v->v_quad; 2716 } else if (nt == LDOUBLE) { 2717 nv->v_ldbl = (ot == PTR || is_uinteger(ot)) ? 2718 (ldbl_t)(uint64_t)v->v_quad : (ldbl_t)v->v_quad; 2719 } else 2720 return false; 2721 return true; 2722 } 2723 2724 /* 2725 * Print a warning if bits which were set are lost due to the conversion. 2726 * This can happen with operator ORASS only. 2727 */ 2728 static void 2729 convert_constant_check_range_bitor(size_t nsz, size_t osz, const val_t *v, 2730 uint64_t xmask, op_t op) 2731 { 2732 if (nsz < osz && (v->v_quad & xmask) != 0) { 2733 /* constant truncated by conversion, op '%s' */ 2734 warning(306, op_name(op)); 2735 } 2736 } 2737 2738 /* 2739 * Print a warning if additional bits are not all 1 2740 * and the most significant bit of the old value is 1, 2741 * or if at least one (but not all) removed bit was 0. 2742 */ 2743 static void 2744 convert_constant_check_range_bitand(size_t nsz, size_t osz, 2745 uint64_t xmask, const val_t *nv, 2746 tspec_t ot, const val_t *v, 2747 const type_t *tp, op_t op) 2748 { 2749 if (nsz > osz && 2750 (nv->v_quad & bit((unsigned int)(osz - 1))) != 0 && 2751 (nv->v_quad & xmask) != xmask) { 2752 /* extra bits set to 0 in conversion of '%s' to '%s', ... */ 2753 warning(309, type_name(gettyp(ot)), 2754 type_name(tp), op_name(op)); 2755 } else if (nsz < osz && 2756 (v->v_quad & xmask) != xmask && 2757 (v->v_quad & xmask) != 0) { 2758 /* constant truncated by conversion, op '%s' */ 2759 warning(306, op_name(op)); 2760 } 2761 } 2762 2763 static void 2764 convert_constant_check_range_signed(op_t op, int arg) 2765 { 2766 if (op == ASSIGN) { 2767 /* assignment of negative constant to unsigned type */ 2768 warning(164); 2769 } else if (op == INIT) { 2770 /* initialization of unsigned with negative constant */ 2771 warning(221); 2772 } else if (op == FARG) { 2773 /* conversion of negative constant to unsigned type, ... */ 2774 warning(296, arg); 2775 } else if (modtab[op].m_comparison) { 2776 /* handled by check_integer_comparison() */ 2777 } else { 2778 /* conversion of negative constant to unsigned type */ 2779 warning(222); 2780 } 2781 } 2782 2783 /* 2784 * Loss of significant bit(s). All truncated bits 2785 * of unsigned types or all truncated bits plus the 2786 * msb of the target for signed types are considered 2787 * to be significant bits. Loss of significant bits 2788 * means that at least one of the bits was set in an 2789 * unsigned type or that at least one but not all of 2790 * the bits was set in a signed type. 2791 * Loss of significant bits means that it is not 2792 * possible, also not with necessary casts, to convert 2793 * back to the original type. A example for a 2794 * necessary cast is: 2795 * char c; int i; c = 128; 2796 * i = c; ** yields -128 ** 2797 * i = (unsigned char)c; ** yields 128 ** 2798 */ 2799 static void 2800 convert_constant_check_range_truncated(op_t op, int arg, const type_t *tp, 2801 tspec_t ot) 2802 { 2803 if (op == ASSIGN && tp->t_bitfield) { 2804 /* precision lost in bit-field assignment */ 2805 warning(166); 2806 } else if (op == ASSIGN) { 2807 /* constant truncated by assignment */ 2808 warning(165); 2809 } else if (op == INIT && tp->t_bitfield) { 2810 /* bit-field initializer does not fit */ 2811 warning(180); 2812 } else if (op == INIT) { 2813 /* initializer does not fit */ 2814 warning(178); 2815 } else if (op == CASE) { 2816 /* case label affected by conversion */ 2817 warning(196); 2818 } else if (op == FARG) { 2819 /* conversion of '%s' to '%s' is out of range, arg #%d */ 2820 warning(295, 2821 type_name(gettyp(ot)), type_name(tp), arg); 2822 } else { 2823 /* conversion of '%s' to '%s' is out of range */ 2824 warning(119, 2825 type_name(gettyp(ot)), type_name(tp)); 2826 } 2827 } 2828 2829 static void 2830 convert_constant_check_range_loss(op_t op, int arg, const type_t *tp, 2831 tspec_t ot) 2832 { 2833 if (op == ASSIGN && tp->t_bitfield) { 2834 /* precision lost in bit-field assignment */ 2835 warning(166); 2836 } else if (op == INIT && tp->t_bitfield) { 2837 /* bit-field initializer out of range */ 2838 warning(11); 2839 } else if (op == CASE) { 2840 /* case label affected by conversion */ 2841 warning(196); 2842 } else if (op == FARG) { 2843 /* conversion of '%s' to '%s' is out of range, arg #%d */ 2844 warning(295, 2845 type_name(gettyp(ot)), type_name(tp), arg); 2846 } else { 2847 /* conversion of '%s' to '%s' is out of range */ 2848 warning(119, 2849 type_name(gettyp(ot)), type_name(tp)); 2850 } 2851 } 2852 2853 static void 2854 convert_constant_check_range(tspec_t ot, const type_t *tp, tspec_t nt, 2855 op_t op, int arg, const val_t *v, val_t *nv) 2856 { 2857 unsigned int osz, nsz; 2858 uint64_t xmask, xmsk1; 2859 2860 osz = size_in_bits(ot); 2861 nsz = tp->t_bitfield ? tp->t_flen : size_in_bits(nt); 2862 xmask = value_bits(nsz) ^ value_bits(osz); 2863 xmsk1 = value_bits(nsz) ^ value_bits(osz - 1); 2864 /* 2865 * For bitwise operations we are not interested in the 2866 * value, but in the bits itself. 2867 */ 2868 if (op == ORASS || op == BITOR || op == BITXOR) { 2869 convert_constant_check_range_bitor(nsz, osz, v, xmask, op); 2870 } else if (op == ANDASS || op == BITAND) { 2871 convert_constant_check_range_bitand(nsz, osz, xmask, nv, ot, 2872 v, tp, op); 2873 } else if ((nt != PTR && is_uinteger(nt)) && 2874 (ot != PTR && !is_uinteger(ot)) && 2875 v->v_quad < 0) { 2876 convert_constant_check_range_signed(op, arg); 2877 } else if (nv->v_quad != v->v_quad && nsz <= osz && 2878 (v->v_quad & xmask) != 0 && 2879 (is_uinteger(ot) || (v->v_quad & xmsk1) != xmsk1)) { 2880 convert_constant_check_range_truncated(op, arg, tp, ot); 2881 } else if (nv->v_quad != v->v_quad) { 2882 convert_constant_check_range_loss(op, arg, tp, ot); 2883 } 2884 } 2885 2886 /* 2887 * Converts a typed constant to a constant of another type. 2888 * 2889 * op operator which requires conversion 2890 * arg if op is FARG, # of argument 2891 * tp type in which to convert the constant 2892 * nv new constant 2893 * v old constant 2894 */ 2895 void 2896 convert_constant(op_t op, int arg, const type_t *tp, val_t *nv, val_t *v) 2897 { 2898 tspec_t ot, nt; 2899 unsigned int sz; 2900 bool range_check; 2901 2902 /* 2903 * TODO: make 'v' const; the name of this function does not suggest 2904 * that it modifies 'v'. 2905 */ 2906 ot = v->v_tspec; 2907 nt = nv->v_tspec = tp->t_tspec; 2908 range_check = false; 2909 2910 if (nt == BOOL) { /* C99 6.3.1.2 */ 2911 nv->v_unsigned_since_c90 = false; 2912 nv->v_quad = is_nonzero_val(v) ? 1 : 0; 2913 return; 2914 } 2915 2916 if (ot == FLOAT || ot == DOUBLE || ot == LDOUBLE) { 2917 convert_constant_floating(op, arg, ot, tp, nt, v, nv); 2918 } else if (!convert_constant_to_floating(nt, nv, ot, v)) { 2919 range_check = true; /* Check for lost precision. */ 2920 nv->v_quad = v->v_quad; 2921 } 2922 2923 if (allow_trad && allow_c90 && v->v_unsigned_since_c90 && 2924 (is_floating(nt) || ( 2925 (is_integer(nt) && !is_uinteger(nt) && 2926 portable_size_in_bits(nt) > portable_size_in_bits(ot))))) { 2927 /* ANSI C treats constant as unsigned */ 2928 warning(157); 2929 v->v_unsigned_since_c90 = false; 2930 } 2931 2932 if (is_integer(nt)) { 2933 sz = tp->t_bitfield ? tp->t_flen : size_in_bits(nt); 2934 nv->v_quad = convert_integer(nv->v_quad, nt, sz); 2935 } 2936 2937 if (range_check && op != CVT) 2938 convert_constant_check_range(ot, tp, nt, op, arg, v, nv); 2939 } 2940 2941 /* 2942 * Called if incompatible types were detected. 2943 * Prints a appropriate warning. 2944 */ 2945 static void 2946 warn_incompatible_types(op_t op, 2947 const type_t *ltp, tspec_t lt, 2948 const type_t *rtp, tspec_t rt) 2949 { 2950 const mod_t *mp; 2951 2952 mp = &modtab[op]; 2953 2954 if (lt == VOID || (mp->m_binary && rt == VOID)) { 2955 /* void type illegal in expression */ 2956 error(109); 2957 } else if (op == ASSIGN) { 2958 /* cannot assign to '%s' from '%s' */ 2959 error(171, type_name(ltp), type_name(rtp)); 2960 } else if (mp->m_binary) { 2961 /* operands of '%s' have incompatible types '%s' and '%s' */ 2962 error(107, mp->m_name, tspec_name(lt), tspec_name(rt)); 2963 } else { 2964 lint_assert(rt == NOTSPEC); 2965 /* operand of '%s' has invalid type '%s' */ 2966 error(108, mp->m_name, type_name(ltp)); 2967 } 2968 } 2969 2970 /* 2971 * Called if incompatible pointer types are detected. 2972 * Print an appropriate warning. 2973 */ 2974 static void 2975 warn_incompatible_pointers(const mod_t *mp, 2976 const type_t *ltp, const type_t *rtp) 2977 { 2978 tspec_t lt, rt; 2979 2980 lint_assert(ltp->t_tspec == PTR); 2981 lint_assert(rtp->t_tspec == PTR); 2982 2983 lt = ltp->t_subt->t_tspec; 2984 rt = rtp->t_subt->t_tspec; 2985 2986 if (is_struct_or_union(lt) && is_struct_or_union(rt)) { 2987 if (mp == NULL) { 2988 /* illegal structure pointer combination */ 2989 warning(244); 2990 } else { 2991 /* incompatible structure pointers: '%s' '%s' '%s' */ 2992 warning(245, type_name(ltp), mp->m_name, type_name(rtp)); 2993 } 2994 } else { 2995 if (mp == NULL) { 2996 /* illegal combination of '%s' and '%s' */ 2997 warning(184, type_name(ltp), type_name(rtp)); 2998 } else { 2999 /* illegal combination of '%s' and '%s', op '%s' */ 3000 warning(124, 3001 type_name(ltp), type_name(rtp), mp->m_name); 3002 } 3003 } 3004 } 3005 3006 /* Return a type based on tp1, with added qualifiers from tp2. */ 3007 static type_t * 3008 merge_qualifiers(type_t *tp1, const type_t *tp2) 3009 { 3010 type_t *ntp, *nstp; 3011 bool c1, c2, v1, v2; 3012 3013 lint_assert(tp1->t_tspec == PTR); 3014 lint_assert(tp2->t_tspec == PTR); 3015 3016 c1 = tp1->t_subt->t_const; 3017 c2 = tp2->t_subt->t_const; 3018 v1 = tp1->t_subt->t_volatile; 3019 v2 = tp2->t_subt->t_volatile; 3020 3021 if (c1 == (c1 | c2) && v1 == (v1 | v2)) 3022 return tp1; 3023 3024 nstp = expr_dup_type(tp1->t_subt); 3025 nstp->t_const |= c2; 3026 nstp->t_volatile |= v2; 3027 3028 ntp = expr_dup_type(tp1); 3029 ntp->t_subt = nstp; 3030 return ntp; 3031 } 3032 3033 /* 3034 * Returns true if the given structure or union has a constant member 3035 * (maybe recursively). 3036 */ 3037 static bool 3038 has_constant_member(const type_t *tp) 3039 { 3040 sym_t *m; 3041 3042 lint_assert(is_struct_or_union(tp->t_tspec)); 3043 3044 for (m = tp->t_str->sou_first_member; m != NULL; m = m->s_next) { 3045 const type_t *mtp = m->s_type; 3046 if (mtp->t_const) 3047 return true; 3048 if (is_struct_or_union(mtp->t_tspec) && 3049 has_constant_member(mtp)) 3050 return true; 3051 } 3052 return false; 3053 } 3054 3055 /* 3056 * Create a new node for one of the operators POINT and ARROW. 3057 */ 3058 static tnode_t * 3059 build_struct_access(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 3060 { 3061 tnode_t *ntn, *ctn; 3062 bool nolval; 3063 3064 lint_assert(rn->tn_op == NAME); 3065 lint_assert(is_member(rn->tn_sym)); 3066 3067 /* 3068 * Remember if the left operand is an lvalue (structure members 3069 * are lvalues if and only if the structure itself is an lvalue). 3070 */ 3071 nolval = op == POINT && !ln->tn_lvalue; 3072 3073 if (op == POINT) { 3074 ln = build_address(sys, ln, true); 3075 } else if (ln->tn_type->t_tspec != PTR) { 3076 lint_assert(!allow_c90); 3077 lint_assert(is_integer(ln->tn_type->t_tspec)); 3078 ln = convert(NOOP, 0, expr_derive_type(gettyp(VOID), PTR), ln); 3079 } 3080 3081 ctn = build_integer_constant(PTRDIFF_TSPEC, 3082 rn->tn_sym->u.s_member.sm_offset_in_bits / CHAR_SIZE); 3083 3084 ntn = new_tnode(PLUS, sys, expr_derive_type(rn->tn_type, PTR), 3085 ln, ctn); 3086 if (ln->tn_op == CON) 3087 ntn = fold(ntn); 3088 3089 if (rn->tn_type->t_bitfield) { 3090 ntn = new_tnode(FSEL, sys, ntn->tn_type->t_subt, ntn, NULL); 3091 } else { 3092 ntn = new_tnode(INDIR, sys, ntn->tn_type->t_subt, ntn, NULL); 3093 } 3094 3095 if (nolval) 3096 ntn->tn_lvalue = false; 3097 3098 return ntn; 3099 } 3100 3101 /* 3102 * Create a node for INCAFT, INCBEF, DECAFT and DECBEF. 3103 */ 3104 static tnode_t * 3105 build_prepost_incdec(op_t op, bool sys, tnode_t *ln) 3106 { 3107 tnode_t *cn, *ntn; 3108 3109 lint_assert(ln != NULL); 3110 3111 if (ln->tn_type->t_tspec == PTR) { 3112 cn = subt_size_in_bytes(ln->tn_type); 3113 } else { 3114 cn = build_integer_constant(INT, (int64_t)1); 3115 } 3116 ntn = new_tnode(op, sys, ln->tn_type, ln, cn); 3117 3118 return ntn; 3119 } 3120 3121 /* 3122 * Create a node for REAL, IMAG 3123 */ 3124 static tnode_t * 3125 build_real_imag(op_t op, bool sys, tnode_t *ln) 3126 { 3127 tnode_t *cn, *ntn; 3128 3129 lint_assert(ln != NULL); 3130 3131 if (ln->tn_op == NAME) { 3132 /* 3133 * This may be too much, but it avoids wrong warnings. 3134 * See d_c99_complex_split.c. 3135 */ 3136 mark_as_used(ln->tn_sym, false, false); 3137 mark_as_set(ln->tn_sym); 3138 } 3139 3140 switch (ln->tn_type->t_tspec) { 3141 case LCOMPLEX: 3142 /* XXX: integer and LDOUBLE don't match. */ 3143 cn = build_integer_constant(LDOUBLE, (int64_t)1); 3144 break; 3145 case DCOMPLEX: 3146 /* XXX: integer and DOUBLE don't match. */ 3147 cn = build_integer_constant(DOUBLE, (int64_t)1); 3148 break; 3149 case FCOMPLEX: 3150 /* XXX: integer and FLOAT don't match. */ 3151 cn = build_integer_constant(FLOAT, (int64_t)1); 3152 break; 3153 default: 3154 /* '__%s__' is illegal for type '%s' */ 3155 error(276, op == REAL ? "real" : "imag", 3156 type_name(ln->tn_type)); 3157 return NULL; 3158 } 3159 ntn = new_tnode(op, sys, cn->tn_type, ln, cn); 3160 ntn->tn_lvalue = true; 3161 3162 return ntn; 3163 } 3164 3165 /* 3166 * Create a tree node for the unary & operator 3167 */ 3168 static tnode_t * 3169 build_address(bool sys, tnode_t *tn, bool noign) 3170 { 3171 tspec_t t; 3172 3173 if (!noign && ((t = tn->tn_type->t_tspec) == ARRAY || t == FUNC)) { 3174 if (!allow_c90) 3175 /* '&' before array or function: ignored */ 3176 warning(127); 3177 return tn; 3178 } 3179 3180 /* eliminate &* */ 3181 if (tn->tn_op == INDIR && 3182 tn->tn_left->tn_type->t_tspec == PTR && 3183 tn->tn_left->tn_type->t_subt == tn->tn_type) { 3184 return tn->tn_left; 3185 } 3186 3187 return new_tnode(ADDR, sys, expr_derive_type(tn->tn_type, PTR), 3188 tn, NULL); 3189 } 3190 3191 /* 3192 * Create a node for operators PLUS and MINUS. 3193 */ 3194 static tnode_t * 3195 build_plus_minus(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 3196 { 3197 3198 /* If pointer and integer, then pointer to the lhs. */ 3199 if (rn->tn_type->t_tspec == PTR && is_integer(ln->tn_type->t_tspec)) { 3200 tnode_t *tmp = ln; 3201 ln = rn; 3202 rn = tmp; 3203 /* pointer addition has integer on the left-hand side */ 3204 query_message(5); 3205 } 3206 3207 /* pointer +- integer */ 3208 if (ln->tn_type->t_tspec == PTR && rn->tn_type->t_tspec != PTR) { 3209 lint_assert(is_integer(rn->tn_type->t_tspec)); 3210 3211 check_ctype_macro_invocation(ln, rn); 3212 check_enum_array_index(ln, rn); 3213 3214 tnode_t *elsz = subt_size_in_bytes(ln->tn_type); 3215 if (rn->tn_type->t_tspec != elsz->tn_type->t_tspec) 3216 rn = convert(NOOP, 0, elsz->tn_type, rn); 3217 3218 tnode_t *prod = new_tnode(MULT, sys, rn->tn_type, rn, elsz); 3219 if (rn->tn_op == CON) 3220 prod = fold(prod); 3221 3222 return new_tnode(op, sys, ln->tn_type, ln, prod); 3223 } 3224 3225 /* pointer - pointer */ 3226 if (rn->tn_type->t_tspec == PTR) { 3227 lint_assert(ln->tn_type->t_tspec == PTR); 3228 lint_assert(op == MINUS); 3229 3230 type_t *ptrdiff = gettyp(PTRDIFF_TSPEC); 3231 tnode_t *raw_diff = new_tnode(op, sys, ptrdiff, ln, rn); 3232 if (ln->tn_op == CON && rn->tn_op == CON) 3233 raw_diff = fold(raw_diff); 3234 3235 tnode_t *elsz = subt_size_in_bytes(ln->tn_type); 3236 balance(NOOP, &raw_diff, &elsz); 3237 3238 return new_tnode(DIV, sys, ptrdiff, raw_diff, elsz); 3239 } 3240 3241 return new_tnode(op, sys, ln->tn_type, ln, rn); 3242 } 3243 3244 /* 3245 * Create a node for operators SHL and SHR. 3246 */ 3247 static tnode_t * 3248 build_bit_shift(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 3249 { 3250 3251 if (!allow_c90 && rn->tn_type->t_tspec != INT) 3252 rn = convert(NOOP, 0, gettyp(INT), rn); 3253 return new_tnode(op, sys, ln->tn_type, ln, rn); 3254 } 3255 3256 /* 3257 * Create a node for COLON. 3258 */ 3259 static tnode_t * 3260 build_colon(bool sys, tnode_t *ln, tnode_t *rn) 3261 { 3262 tspec_t lt, rt, pdt; 3263 type_t *tp; 3264 tnode_t *ntn; 3265 3266 lt = ln->tn_type->t_tspec; 3267 rt = rn->tn_type->t_tspec; 3268 pdt = PTRDIFF_TSPEC; 3269 3270 /* 3271 * Arithmetic types are balanced, all other type combinations 3272 * still need to be handled. 3273 */ 3274 if (is_arithmetic(lt) && is_arithmetic(rt)) { 3275 tp = ln->tn_type; 3276 } else if (lt == BOOL && rt == BOOL) { 3277 tp = ln->tn_type; 3278 } else if (lt == VOID || rt == VOID) { 3279 tp = gettyp(VOID); 3280 } else if (is_struct_or_union(lt)) { 3281 /* Both types must be identical. */ 3282 lint_assert(is_struct_or_union(rt)); 3283 lint_assert(ln->tn_type->t_str == rn->tn_type->t_str); 3284 if (is_incomplete(ln->tn_type)) { 3285 /* unknown operand size, op '%s' */ 3286 error(138, op_name(COLON)); 3287 return NULL; 3288 } 3289 tp = ln->tn_type; 3290 } else if (lt == PTR && is_integer(rt)) { 3291 if (rt != pdt) { 3292 rn = convert(NOOP, 0, gettyp(pdt), rn); 3293 rt = pdt; 3294 } 3295 tp = ln->tn_type; 3296 } else if (rt == PTR && is_integer(lt)) { 3297 if (lt != pdt) { 3298 ln = convert(NOOP, 0, gettyp(pdt), ln); 3299 lt = pdt; 3300 } 3301 tp = rn->tn_type; 3302 } else if (lt == PTR && ln->tn_type->t_subt->t_tspec == VOID) { 3303 tp = merge_qualifiers(rn->tn_type, ln->tn_type); 3304 } else if (rt == PTR && rn->tn_type->t_subt->t_tspec == VOID) { 3305 tp = merge_qualifiers(ln->tn_type, rn->tn_type); 3306 } else { 3307 /* 3308 * XXX For now we simply take the left type. This is 3309 * probably wrong, if one type contains a function prototype 3310 * and the other one, at the same place, only an old style 3311 * declaration. 3312 */ 3313 tp = merge_qualifiers(ln->tn_type, rn->tn_type); 3314 } 3315 3316 ntn = new_tnode(COLON, sys, tp, ln, rn); 3317 3318 return ntn; 3319 } 3320 3321 /* 3322 * Create a node for an assignment operator (both = and op= ). 3323 */ 3324 static tnode_t * 3325 build_assignment(op_t op, bool sys, tnode_t *ln, tnode_t *rn) 3326 { 3327 tspec_t lt, rt; 3328 tnode_t *ntn, *ctn; 3329 3330 lint_assert(ln != NULL); 3331 lint_assert(rn != NULL); 3332 3333 lt = ln->tn_type->t_tspec; 3334 rt = rn->tn_type->t_tspec; 3335 3336 if ((op == ADDASS || op == SUBASS) && lt == PTR) { 3337 lint_assert(is_integer(rt)); 3338 ctn = subt_size_in_bytes(ln->tn_type); 3339 if (rn->tn_type->t_tspec != ctn->tn_type->t_tspec) 3340 rn = convert(NOOP, 0, ctn->tn_type, rn); 3341 rn = new_tnode(MULT, sys, rn->tn_type, rn, ctn); 3342 if (rn->tn_left->tn_op == CON) 3343 rn = fold(rn); 3344 } 3345 3346 if ((op == ASSIGN || op == RETURN || op == INIT) && 3347 (lt == STRUCT || rt == STRUCT)) { 3348 lint_assert(lt == rt); 3349 lint_assert(ln->tn_type->t_str == rn->tn_type->t_str); 3350 if (is_incomplete(ln->tn_type)) { 3351 if (op == RETURN) { 3352 /* cannot return incomplete type */ 3353 error(212); 3354 } else { 3355 /* unknown operand size, op '%s' */ 3356 error(138, op_name(op)); 3357 } 3358 return NULL; 3359 } 3360 } 3361 3362 if (op == SHLASS) { 3363 if (portable_size_in_bits(lt) < portable_size_in_bits(rt)) { 3364 if (hflag) 3365 /* semantics of '%s' change in ANSI C; ... */ 3366 warning(118, "<<="); 3367 } 3368 } else if (op != SHRASS) { 3369 if (op == ASSIGN || lt != PTR) { 3370 if (lt != rt || 3371 (ln->tn_type->t_bitfield && rn->tn_op == CON)) { 3372 rn = convert(op, 0, ln->tn_type, rn); 3373 rt = lt; 3374 } 3375 } 3376 } 3377 3378 if (any_query_enabled && rn->tn_op == CVT && rn->tn_cast && 3379 eqtype(ln->tn_type, rn->tn_type, false, false, NULL)) { 3380 /* redundant cast from '%s' to '%s' before assignment */ 3381 query_message(7, 3382 type_name(rn->tn_left->tn_type), type_name(rn->tn_type)); 3383 } 3384 3385 ntn = new_tnode(op, sys, ln->tn_type, ln, rn); 3386 3387 return ntn; 3388 } 3389 3390 /* 3391 * Get the size in bytes of type tp->t_subt, as a constant expression of type 3392 * ptrdiff_t as seen from the target platform. 3393 */ 3394 static tnode_t * 3395 subt_size_in_bytes(type_t *tp) 3396 { 3397 int elem, elsz_in_bits; 3398 3399 lint_assert(tp->t_tspec == PTR); 3400 tp = tp->t_subt; 3401 3402 elem = 1; 3403 elsz_in_bits = 0; 3404 3405 while (tp->t_tspec == ARRAY) { 3406 elem *= tp->t_dim; 3407 tp = tp->t_subt; 3408 } 3409 3410 switch (tp->t_tspec) { 3411 case FUNC: 3412 /* pointer to function is not allowed here */ 3413 error(110); 3414 break; 3415 case VOID: 3416 /* cannot do pointer arithmetic on operand of unknown size */ 3417 gnuism(136); 3418 break; 3419 case STRUCT: 3420 case UNION: 3421 if ((elsz_in_bits = tp->t_str->sou_size_in_bits) == 0) 3422 /* cannot do pointer arithmetic on operand of ... */ 3423 error(136); 3424 break; 3425 case ENUM: 3426 if (is_incomplete(tp)) { 3427 /* cannot do pointer arithmetic on operand of ... */ 3428 warning(136); 3429 } 3430 /* FALLTHROUGH */ 3431 default: 3432 if ((elsz_in_bits = size_in_bits(tp->t_tspec)) == 0) { 3433 /* cannot do pointer arithmetic on operand of ... */ 3434 error(136); 3435 } else { 3436 lint_assert(elsz_in_bits != -1); 3437 } 3438 break; 3439 } 3440 3441 if (elem == 0 && elsz_in_bits != 0) { 3442 /* cannot do pointer arithmetic on operand of unknown size */ 3443 error(136); 3444 } 3445 3446 if (elsz_in_bits == 0) 3447 elsz_in_bits = CHAR_SIZE; 3448 3449 return build_integer_constant(PTRDIFF_TSPEC, 3450 (int64_t)(elem * elsz_in_bits / CHAR_SIZE)); 3451 } 3452 3453 /* 3454 * XXX 3455 * Note: There appear to be a number of bugs in detecting overflow in 3456 * this function. An audit and a set of proper regression tests are needed. 3457 * --Perry Metzger, Nov. 16, 2001 3458 */ 3459 /* 3460 * Do only as much as necessary to compute constant expressions. 3461 * Called only if the operator allows folding and all operands are constants. 3462 */ 3463 static tnode_t * 3464 fold(tnode_t *tn) 3465 { 3466 val_t *v; 3467 tspec_t t; 3468 bool utyp, ovfl; 3469 int64_t sl, sr = 0, q = 0, mask; 3470 uint64_t ul, ur = 0; 3471 tnode_t *cn; 3472 3473 v = xcalloc(1, sizeof(*v)); 3474 v->v_tspec = tn->tn_type->t_tspec; 3475 3476 t = tn->tn_left->tn_type->t_tspec; 3477 utyp = !is_integer(t) || is_uinteger(t); 3478 ul = sl = tn->tn_left->tn_val->v_quad; 3479 if (is_binary(tn)) 3480 ur = sr = tn->tn_right->tn_val->v_quad; 3481 3482 mask = value_bits(size_in_bits(t)); 3483 ovfl = false; 3484 3485 switch (tn->tn_op) { 3486 case UPLUS: 3487 q = sl; 3488 break; 3489 case UMINUS: 3490 q = sl == INT64_MIN ? sl : -sl; 3491 if (sl != 0 && msb(q, t) == msb(sl, t)) 3492 ovfl = true; 3493 break; 3494 case COMPL: 3495 q = ~sl; 3496 break; 3497 case MULT: 3498 if (utyp) { 3499 q = ul * ur; 3500 if (q != (q & mask)) 3501 ovfl = true; 3502 else if ((ul != 0) && ((q / ul) != ur)) 3503 ovfl = true; 3504 } else { 3505 q = sl * sr; 3506 if (msb(q, t) != (msb(sl, t) ^ msb(sr, t))) 3507 ovfl = true; 3508 } 3509 break; 3510 case DIV: 3511 if (sr == 0) { 3512 /* division by 0 */ 3513 error(139); 3514 q = utyp ? -1 : INT64_MAX; 3515 } else { 3516 q = utyp ? (int64_t)(ul / ur) : sl / sr; 3517 } 3518 break; 3519 case MOD: 3520 if (sr == 0) { 3521 /* modulus by 0 */ 3522 error(140); 3523 q = 0; 3524 } else { 3525 q = utyp ? (int64_t)(ul % ur) : sl % sr; 3526 } 3527 break; 3528 case PLUS: 3529 q = utyp ? (int64_t)(ul + ur) : sl + sr; 3530 if (msb(sl, t) && msb(sr, t) && !msb(q, t)) 3531 ovfl = true; 3532 if (!utyp && !msb(sl, t) && !msb(sr, t) && msb(q, t)) 3533 ovfl = true; 3534 break; 3535 case MINUS: 3536 q = utyp ? (int64_t)(ul - ur) : sl - sr; 3537 if (!utyp && msb(sl, t) && !msb(sr, t) && !msb(q, t)) 3538 ovfl = true; 3539 if (!msb(sl, t) && msb(sr, t) && msb(q, t)) 3540 ovfl = true; 3541 break; 3542 case SHL: 3543 /* TODO: warn about out-of-bounds 'sr'. */ 3544 q = utyp ? (int64_t)(ul << (sr & 63)) : sl << (sr & 63); 3545 break; 3546 case SHR: 3547 /* 3548 * The sign must be explicitly extended because 3549 * shifts of signed values are implementation dependent. 3550 */ 3551 /* TODO: warn about out-of-bounds 'sr'. */ 3552 q = ul >> (sr & 63); 3553 q = convert_integer(q, t, size_in_bits(t) - (int)sr); 3554 break; 3555 case LT: 3556 q = (utyp ? ul < ur : sl < sr) ? 1 : 0; 3557 break; 3558 case LE: 3559 q = (utyp ? ul <= ur : sl <= sr) ? 1 : 0; 3560 break; 3561 case GE: 3562 q = (utyp ? ul >= ur : sl >= sr) ? 1 : 0; 3563 break; 3564 case GT: 3565 q = (utyp ? ul > ur : sl > sr) ? 1 : 0; 3566 break; 3567 case EQ: 3568 q = (utyp ? ul == ur : sl == sr) ? 1 : 0; 3569 break; 3570 case NE: 3571 q = (utyp ? ul != ur : sl != sr) ? 1 : 0; 3572 break; 3573 case BITAND: 3574 q = utyp ? (int64_t)(ul & ur) : sl & sr; 3575 break; 3576 case BITXOR: 3577 q = utyp ? (int64_t)(ul ^ ur) : sl ^ sr; 3578 break; 3579 case BITOR: 3580 q = utyp ? (int64_t)(ul | ur) : sl | sr; 3581 break; 3582 default: 3583 lint_assert(/*CONSTCOND*/false); 3584 } 3585 3586 /* XXX does not work for quads. */ 3587 if (ovfl || 3588 ((uint64_t)(q | mask) != ~(uint64_t)0 && (q & ~mask) != 0)) { 3589 if (hflag) 3590 /* integer overflow detected, op '%s' */ 3591 warning(141, op_name(tn->tn_op)); 3592 } 3593 3594 v->v_quad = convert_integer(q, t, 0); 3595 3596 cn = build_constant(tn->tn_type, v); 3597 if (tn->tn_left->tn_system_dependent) 3598 cn->tn_system_dependent = true; 3599 if (is_binary(tn) && tn->tn_right->tn_system_dependent) 3600 cn->tn_system_dependent = true; 3601 3602 return cn; 3603 } 3604 3605 /* 3606 * Fold constant nodes, as much as is needed for comparing the value with 0. 3607 */ 3608 static tnode_t * 3609 fold_bool(tnode_t *tn) 3610 { 3611 bool l, r; 3612 val_t *v; 3613 3614 v = xcalloc(1, sizeof(*v)); 3615 v->v_tspec = tn->tn_type->t_tspec; 3616 lint_assert(v->v_tspec == INT || (Tflag && v->v_tspec == BOOL)); 3617 3618 l = constant_is_nonzero(tn->tn_left); 3619 r = is_binary(tn) && constant_is_nonzero(tn->tn_right); 3620 3621 switch (tn->tn_op) { 3622 case NOT: 3623 if (hflag && !constcond_flag) 3624 /* constant argument to '!' */ 3625 warning(239); 3626 v->v_quad = !l ? 1 : 0; 3627 break; 3628 case LOGAND: 3629 v->v_quad = l && r ? 1 : 0; 3630 break; 3631 case LOGOR: 3632 v->v_quad = l || r ? 1 : 0; 3633 break; 3634 default: 3635 lint_assert(/*CONSTCOND*/false); 3636 } 3637 3638 return build_constant(tn->tn_type, v); 3639 } 3640 3641 static ldbl_t 3642 floating_error_value(tspec_t t, ldbl_t lv) 3643 { 3644 if (t == FLOAT) { 3645 return lv < 0 ? -FLT_MAX : FLT_MAX; 3646 } else if (t == DOUBLE) { 3647 return lv < 0 ? -DBL_MAX : DBL_MAX; 3648 } else { 3649 /* LINTED 248: floating-point constant out of range */ 3650 ldbl_t max = LDBL_MAX; 3651 return lv < 0 ? -max : max; 3652 } 3653 } 3654 3655 /* 3656 * Fold constant nodes having operands with floating point type. 3657 */ 3658 static tnode_t * 3659 fold_float(tnode_t *tn) 3660 { 3661 val_t *v; 3662 tspec_t t; 3663 ldbl_t lv, rv = 0; 3664 3665 fpe = 0; 3666 v = xcalloc(1, sizeof(*v)); 3667 v->v_tspec = t = tn->tn_type->t_tspec; 3668 3669 lint_assert(is_floating(t)); 3670 lint_assert(t == tn->tn_left->tn_type->t_tspec); 3671 lint_assert(!is_binary(tn) || t == tn->tn_right->tn_type->t_tspec); 3672 3673 lv = tn->tn_left->tn_val->v_ldbl; 3674 if (is_binary(tn)) 3675 rv = tn->tn_right->tn_val->v_ldbl; 3676 3677 switch (tn->tn_op) { 3678 case UPLUS: 3679 v->v_ldbl = lv; 3680 break; 3681 case UMINUS: 3682 v->v_ldbl = -lv; 3683 break; 3684 case MULT: 3685 v->v_ldbl = lv * rv; 3686 break; 3687 case DIV: 3688 if (rv == 0.0) { 3689 /* division by 0 */ 3690 error(139); 3691 v->v_ldbl = floating_error_value(t, lv); 3692 } else { 3693 v->v_ldbl = lv / rv; 3694 } 3695 break; 3696 case PLUS: 3697 v->v_ldbl = lv + rv; 3698 break; 3699 case MINUS: 3700 v->v_ldbl = lv - rv; 3701 break; 3702 case LT: 3703 v->v_quad = lv < rv ? 1 : 0; 3704 break; 3705 case LE: 3706 v->v_quad = lv <= rv ? 1 : 0; 3707 break; 3708 case GE: 3709 v->v_quad = lv >= rv ? 1 : 0; 3710 break; 3711 case GT: 3712 v->v_quad = lv > rv ? 1 : 0; 3713 break; 3714 case EQ: 3715 v->v_quad = lv == rv ? 1 : 0; 3716 break; 3717 case NE: 3718 v->v_quad = lv != rv ? 1 : 0; 3719 break; 3720 default: 3721 lint_assert(/*CONSTCOND*/false); 3722 } 3723 3724 lint_assert(fpe != 0 || isnan((double)v->v_ldbl) == 0); 3725 if (fpe != 0 || isfinite((double)v->v_ldbl) == 0 || 3726 (t == FLOAT && 3727 (v->v_ldbl > FLT_MAX || v->v_ldbl < -FLT_MAX)) || 3728 (t == DOUBLE && 3729 (v->v_ldbl > DBL_MAX || v->v_ldbl < -DBL_MAX))) { 3730 /* floating point overflow on operator '%s' */ 3731 warning(142, op_name(tn->tn_op)); 3732 v->v_ldbl = floating_error_value(t, v->v_ldbl); 3733 fpe = 0; 3734 } 3735 3736 return build_constant(tn->tn_type, v); 3737 } 3738 3739 3740 /* 3741 * Create a constant node for sizeof. 3742 */ 3743 tnode_t * 3744 build_sizeof(const type_t *tp) 3745 { 3746 unsigned int size_in_bytes = type_size_in_bits(tp) / CHAR_SIZE; 3747 tnode_t *tn = build_integer_constant(SIZEOF_TSPEC, size_in_bytes); 3748 tn->tn_system_dependent = true; 3749 debug_step("build_sizeof '%s' = %u", type_name(tp), size_in_bytes); 3750 return tn; 3751 } 3752 3753 /* 3754 * Create a constant node for offsetof. 3755 */ 3756 /* ARGSUSED */ /* See implementation comments. */ 3757 tnode_t * 3758 build_offsetof(const type_t *tp, const sym_t *sym) 3759 { 3760 unsigned int offset_in_bytes; 3761 tnode_t *tn; 3762 3763 if (!is_struct_or_union(tp->t_tspec)) 3764 /* unacceptable operand of '%s' */ 3765 error(111, "offsetof"); 3766 3767 /* XXX: wrong size, no checking for sym fixme */ 3768 offset_in_bytes = type_size_in_bits(tp) / CHAR_SIZE; 3769 tn = build_integer_constant(SIZEOF_TSPEC, offset_in_bytes); 3770 tn->tn_system_dependent = true; 3771 return tn; 3772 } 3773 3774 unsigned int 3775 type_size_in_bits(const type_t *tp) 3776 { 3777 unsigned int elem, elsz; 3778 bool flex; 3779 3780 elem = 1; 3781 flex = false; 3782 lint_assert(tp != NULL); 3783 while (tp->t_tspec == ARRAY) { 3784 flex = true; /* allow c99 flex arrays [] [0] */ 3785 elem *= tp->t_dim; 3786 tp = tp->t_subt; 3787 } 3788 if (elem == 0) { 3789 if (!flex) { 3790 /* cannot take size/alignment of incomplete type */ 3791 error(143); 3792 elem = 1; 3793 } 3794 } 3795 switch (tp->t_tspec) { 3796 case FUNC: 3797 /* cannot take size/alignment of function type '%s' */ 3798 error(144, type_name(tp)); 3799 elsz = 1; 3800 break; 3801 case STRUCT: 3802 case UNION: 3803 if (is_incomplete(tp)) { 3804 /* cannot take size/alignment of incomplete type */ 3805 error(143); 3806 elsz = 1; 3807 } else { 3808 elsz = tp->t_str->sou_size_in_bits; 3809 } 3810 break; 3811 case ENUM: 3812 if (is_incomplete(tp)) { 3813 /* cannot take size/alignment of incomplete type */ 3814 warning(143); 3815 } 3816 /* FALLTHROUGH */ 3817 default: 3818 if (tp->t_bitfield) { 3819 /* cannot take size/alignment of bit-field */ 3820 error(145); 3821 } 3822 if (tp->t_tspec == VOID) { 3823 /* cannot take size/alignment of void */ 3824 error(146); 3825 elsz = 1; 3826 } else { 3827 elsz = size_in_bits(tp->t_tspec); 3828 lint_assert(elsz > 0); 3829 } 3830 break; 3831 } 3832 3833 return elem * elsz; 3834 } 3835 3836 tnode_t * 3837 build_alignof(const type_t *tp) 3838 { 3839 switch (tp->t_tspec) { 3840 case ARRAY: 3841 break; 3842 3843 case FUNC: 3844 /* cannot take size/alignment of function type '%s' */ 3845 error(144, type_name(tp)); 3846 return 0; 3847 3848 case STRUCT: 3849 case UNION: 3850 if (is_incomplete(tp)) { 3851 /* cannot take size/alignment of incomplete type */ 3852 error(143); 3853 return 0; 3854 } 3855 break; 3856 case ENUM: 3857 break; 3858 default: 3859 if (tp->t_bitfield) { 3860 /* cannot take size/alignment of bit-field */ 3861 error(145); 3862 return 0; 3863 } 3864 if (tp->t_tspec == VOID) { 3865 /* cannot take size/alignment of void */ 3866 error(146); 3867 return 0; 3868 } 3869 break; 3870 } 3871 3872 return build_integer_constant(SIZEOF_TSPEC, 3873 (int64_t)alignment_in_bits(tp) / CHAR_SIZE); 3874 } 3875 3876 /* 3877 * Type casts. 3878 */ 3879 tnode_t * 3880 cast(tnode_t *tn, type_t *tp) 3881 { 3882 tspec_t nt, ot; 3883 3884 if (tn == NULL) 3885 return NULL; 3886 3887 tn = cconv(tn); 3888 3889 lint_assert(tp != NULL); 3890 nt = tp->t_tspec; 3891 ot = tn->tn_type->t_tspec; 3892 3893 if (nt == VOID) { 3894 /* 3895 * C90 6.3.4, C99 6.5.4p2 and C11 6.5.4p2 allow any type to 3896 * be cast to void. The only other allowed casts are from a 3897 * scalar type to a scalar type. 3898 */ 3899 } else if (nt == UNION) { 3900 sym_t *m; 3901 struct_or_union *str = tp->t_str; 3902 if (!allow_gcc) { 3903 /* union cast is a GCC extension */ 3904 error(328); 3905 return NULL; 3906 } 3907 for (m = str->sou_first_member; m != NULL; m = m->s_next) { 3908 if (eqtype(m->s_type, tn->tn_type, 3909 false, false, NULL)) { 3910 tn = expr_alloc_tnode(); 3911 tn->tn_op = CVT; 3912 tn->tn_type = tp; 3913 tn->tn_cast = true; 3914 tn->tn_right = NULL; 3915 return tn; 3916 } 3917 } 3918 /* type '%s' is not a member of '%s' */ 3919 error(329, type_name(tn->tn_type), type_name(tp)); 3920 return NULL; 3921 } else if (nt == STRUCT || nt == ARRAY || nt == FUNC) { 3922 /* Casting to a struct is an undocumented GCC extension. */ 3923 if (!(allow_gcc && nt == STRUCT)) 3924 goto invalid_cast; 3925 } else if (is_struct_or_union(ot)) { 3926 goto invalid_cast; 3927 } else if (ot == VOID) { 3928 /* improper cast of void expression */ 3929 error(148); 3930 return NULL; 3931 } else if (is_integer(nt) && is_scalar(ot)) { 3932 /* ok */ 3933 } else if (is_floating(nt) && is_arithmetic(ot)) { 3934 /* ok */ 3935 } else if (nt == PTR && is_integer(ot)) { 3936 /* ok */ 3937 } else if (nt == PTR && ot == PTR) { 3938 if (!tp->t_subt->t_const && tn->tn_type->t_subt->t_const) { 3939 if (hflag) 3940 /* cast discards 'const' from type '%s' */ 3941 warning(275, type_name(tn->tn_type)); 3942 } 3943 } else 3944 goto invalid_cast; 3945 3946 if (any_query_enabled && eqtype(tp, tn->tn_type, false, false, NULL)) 3947 /* no-op cast from '%s' to '%s' */ 3948 query_message(6, type_name(tn->tn_type), type_name(tp)); 3949 3950 tn = convert(CVT, 0, tp, tn); 3951 tn->tn_cast = true; 3952 3953 return tn; 3954 3955 invalid_cast: 3956 /* invalid cast from '%s' to '%s' */ 3957 error(147, type_name(tn->tn_type), type_name(tp)); 3958 return NULL; 3959 } 3960 3961 /* 3962 * Create the node for a function argument. 3963 * All necessary conversions and type checks are done in 3964 * build_function_call because build_function_argument has no 3965 * information about expected argument types. 3966 */ 3967 tnode_t * 3968 build_function_argument(tnode_t *args, tnode_t *arg) 3969 { 3970 tnode_t *ntn; 3971 3972 /* 3973 * If there was a serious error in the expression for the argument, 3974 * create a dummy argument so the positions of the remaining arguments 3975 * will not change. 3976 */ 3977 if (arg == NULL) 3978 arg = build_integer_constant(INT, 0); 3979 3980 ntn = new_tnode(PUSH, arg->tn_sys, arg->tn_type, arg, args); 3981 3982 return ntn; 3983 } 3984 3985 /* 3986 * Create the node for a function call. Also check types of 3987 * function arguments and insert conversions, if necessary. 3988 */ 3989 tnode_t * 3990 build_function_call(tnode_t *func, bool sys, tnode_t *args) 3991 { 3992 tnode_t *ntn; 3993 op_t fcop; 3994 3995 if (func == NULL) 3996 return NULL; 3997 3998 if (func->tn_op == NAME && func->tn_type->t_tspec == FUNC) { 3999 fcop = CALL; 4000 } else { 4001 fcop = ICALL; 4002 } 4003 4004 check_ctype_function_call(func, args); 4005 4006 /* 4007 * after cconv() func will always be a pointer to a function 4008 * if it is a valid function designator. 4009 */ 4010 func = cconv(func); 4011 4012 if (func->tn_type->t_tspec != PTR || 4013 func->tn_type->t_subt->t_tspec != FUNC) { 4014 /* cannot call '%s', must be a function */ 4015 error(149, type_name(func->tn_type)); 4016 return NULL; 4017 } 4018 4019 args = check_function_arguments(func->tn_type->t_subt, args); 4020 4021 ntn = new_tnode(fcop, sys, func->tn_type->t_subt->t_subt, func, args); 4022 4023 return ntn; 4024 } 4025 4026 /* 4027 * Check types of all function arguments and insert conversions, 4028 * if necessary. 4029 */ 4030 static tnode_t * 4031 check_function_arguments(type_t *ftp, tnode_t *args) 4032 { 4033 tnode_t *arg; 4034 sym_t *asym; 4035 tspec_t at; 4036 int narg, npar, n, i; 4037 4038 /* get # of args in the prototype */ 4039 npar = 0; 4040 for (asym = ftp->t_args; asym != NULL; asym = asym->s_next) 4041 npar++; 4042 4043 /* get # of args in function call */ 4044 narg = 0; 4045 for (arg = args; arg != NULL; arg = arg->tn_right) 4046 narg++; 4047 4048 asym = ftp->t_args; 4049 if (ftp->t_proto && npar != narg && !(ftp->t_vararg && npar < narg)) { 4050 /* argument mismatch: %d %s passed, %d expected */ 4051 error(150, narg, narg > 1 ? "arguments" : "argument", npar); 4052 asym = NULL; 4053 } 4054 4055 for (n = 1; n <= narg; n++) { 4056 4057 /* 4058 * The rightmost argument is at the top of the argument 4059 * subtree. 4060 */ 4061 for (i = narg, arg = args; i > n; i--, arg = arg->tn_right) 4062 continue; 4063 4064 /* some things which are always not allowed */ 4065 if ((at = arg->tn_left->tn_type->t_tspec) == VOID) { 4066 /* void expressions may not be arguments, arg #%d */ 4067 error(151, n); 4068 return NULL; 4069 } else if (is_struct_or_union(at) && 4070 is_incomplete(arg->tn_left->tn_type)) { 4071 /* argument cannot have unknown size, arg #%d */ 4072 error(152, n); 4073 return NULL; 4074 } else if (is_integer(at) && 4075 arg->tn_left->tn_type->t_is_enum && 4076 is_incomplete(arg->tn_left->tn_type)) { 4077 /* argument cannot have unknown size, arg #%d */ 4078 warning(152, n); 4079 } 4080 4081 /* class conversions (arg in value context) */ 4082 arg->tn_left = cconv(arg->tn_left); 4083 4084 if (asym != NULL) { 4085 arg->tn_left = check_prototype_argument( 4086 n, asym->s_type, arg->tn_left); 4087 } else { 4088 arg->tn_left = promote(NOOP, true, arg->tn_left); 4089 } 4090 arg->tn_type = arg->tn_left->tn_type; 4091 4092 if (asym != NULL) 4093 asym = asym->s_next; 4094 } 4095 4096 return args; 4097 } 4098 4099 /* 4100 * Compare the type of an argument with the corresponding type of a 4101 * prototype parameter. If it is a valid combination, but both types 4102 * are not the same, insert a conversion to convert the argument into 4103 * the type of the parameter. 4104 */ 4105 static tnode_t * 4106 check_prototype_argument( 4107 int n, /* pos of arg */ 4108 type_t *tp, /* expected type (from prototype) */ 4109 tnode_t *tn) /* argument */ 4110 { 4111 tnode_t *ln; 4112 bool dowarn; 4113 4114 ln = xcalloc(1, sizeof(*ln)); 4115 ln->tn_type = expr_unqualified_type(tp); 4116 ln->tn_lvalue = true; 4117 if (typeok(FARG, n, ln, tn)) { 4118 if (!eqtype(tp, tn->tn_type, 4119 true, false, (dowarn = false, &dowarn)) || dowarn) 4120 tn = convert(FARG, n, tp, tn); 4121 } 4122 free(ln); 4123 return tn; 4124 } 4125 4126 /* 4127 * Return the value of an integral constant expression. 4128 * If the expression is not constant or its type is not an integer 4129 * type, an error message is printed. 4130 */ 4131 val_t * 4132 constant(tnode_t *tn, bool required) 4133 { 4134 val_t *v; 4135 4136 if (tn != NULL) 4137 tn = cconv(tn); 4138 if (tn != NULL) 4139 tn = promote(NOOP, false, tn); 4140 4141 v = xcalloc(1, sizeof(*v)); 4142 4143 if (tn == NULL) { 4144 lint_assert(nerr != 0); 4145 debug_step("constant node is null; returning 1 instead"); 4146 v->v_tspec = INT; 4147 v->v_quad = 1; 4148 return v; 4149 } 4150 4151 v->v_tspec = tn->tn_type->t_tspec; 4152 4153 if (tn->tn_op == CON) { 4154 lint_assert(tn->tn_type->t_tspec == tn->tn_val->v_tspec); 4155 if (is_integer(tn->tn_val->v_tspec)) { 4156 v->v_unsigned_since_c90 = 4157 tn->tn_val->v_unsigned_since_c90; 4158 v->v_quad = tn->tn_val->v_quad; 4159 return v; 4160 } 4161 v->v_quad = tn->tn_val->v_ldbl; 4162 } else { 4163 v->v_quad = 1; 4164 } 4165 4166 if (required) 4167 /* integral constant expression expected */ 4168 error(55); 4169 else 4170 /* variable array dimension is a C99/GCC extension */ 4171 c99ism(318); 4172 4173 if (!is_integer(v->v_tspec)) 4174 v->v_tspec = INT; 4175 4176 return v; 4177 } 4178 4179 static bool 4180 is_constcond_false(const tnode_t *tn, tspec_t t) 4181 { 4182 return (t == BOOL || t == INT) && 4183 tn->tn_op == CON && tn->tn_val->v_quad == 0; 4184 } 4185 4186 /* 4187 * Perform some tests on expressions which can't be done in build_binary() 4188 * and functions called by build_binary(). These tests must be done here 4189 * because we need some information about the context in which the operations 4190 * are performed. 4191 * After all tests are performed and dofreeblk is true, expr() frees the 4192 * memory which is used for the expression. 4193 */ 4194 void 4195 expr(tnode_t *tn, bool vctx, bool cond, bool dofreeblk, bool is_do_while) 4196 { 4197 4198 if (tn == NULL) { /* in case of errors */ 4199 expr_free_all(); 4200 return; 4201 } 4202 4203 /* expr() is also called in global initializations */ 4204 if (dcs->d_kind != DK_EXTERN && !is_do_while) 4205 check_statement_reachable(); 4206 4207 check_expr_misc(tn, vctx, cond, !cond, false, false, false); 4208 if (tn->tn_op == ASSIGN) { 4209 if (hflag && cond) 4210 /* assignment in conditional context */ 4211 warning(159); 4212 } else if (tn->tn_op == CON) { 4213 if (hflag && cond && !constcond_flag && 4214 !tn->tn_system_dependent && 4215 !(is_do_while && 4216 is_constcond_false(tn, tn->tn_type->t_tspec))) 4217 /* constant in conditional context */ 4218 warning(161); 4219 } 4220 if (!modtab[tn->tn_op].m_has_side_effect) { 4221 /* 4222 * for left operands of COMMA this warning is already 4223 * printed 4224 */ 4225 if (tn->tn_op != COMMA && !vctx && !cond) 4226 check_null_effect(tn); 4227 } 4228 debug_node(tn); 4229 4230 /* free the tree memory */ 4231 if (dofreeblk) 4232 expr_free_all(); 4233 } 4234 4235 static bool 4236 has_side_effect(const tnode_t *tn) /* NOLINT(misc-no-recursion) */ 4237 { 4238 op_t op = tn->tn_op; 4239 4240 if (modtab[op].m_has_side_effect) 4241 return true; 4242 4243 if (op == CVT && tn->tn_type->t_tspec == VOID) 4244 return has_side_effect(tn->tn_left); 4245 4246 /* XXX: Why not has_side_effect(tn->tn_left) as well? */ 4247 if (op == LOGAND || op == LOGOR) 4248 return has_side_effect(tn->tn_right); 4249 4250 /* XXX: Why not has_side_effect(tn->tn_left) as well? */ 4251 if (op == QUEST) 4252 return has_side_effect(tn->tn_right); 4253 4254 if (op == COLON || op == COMMA) { 4255 return has_side_effect(tn->tn_left) || 4256 has_side_effect(tn->tn_right); 4257 } 4258 4259 return false; 4260 } 4261 4262 static bool 4263 is_void_cast(const tnode_t *tn) 4264 { 4265 4266 return tn->tn_op == CVT && tn->tn_cast && 4267 tn->tn_type->t_tspec == VOID; 4268 } 4269 4270 static bool 4271 is_local_symbol(const tnode_t *tn) 4272 { 4273 4274 return tn->tn_op == LOAD && 4275 tn->tn_left->tn_op == NAME && 4276 tn->tn_left->tn_sym->s_scl == AUTO; 4277 } 4278 4279 static bool 4280 is_int_constant_zero(const tnode_t *tn) 4281 { 4282 4283 return tn->tn_op == CON && 4284 tn->tn_type->t_tspec == INT && 4285 tn->tn_val->v_quad == 0; 4286 } 4287 4288 static void 4289 check_null_effect(const tnode_t *tn) 4290 { 4291 4292 if (!hflag) 4293 return; 4294 if (has_side_effect(tn)) 4295 return; 4296 if (is_void_cast(tn) && is_local_symbol(tn->tn_left)) 4297 return; 4298 if (is_void_cast(tn) && is_int_constant_zero(tn->tn_left)) 4299 return; 4300 4301 /* expression has null effect */ 4302 warning(129); 4303 } 4304 4305 static void 4306 check_expr_addr(const tnode_t *ln, bool szof, bool fcall) 4307 { 4308 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 4309 if (ln->tn_op == NAME && (reached || !warn_about_unreachable)) { 4310 if (!szof) 4311 mark_as_set(ln->tn_sym); 4312 mark_as_used(ln->tn_sym, fcall, szof); 4313 } 4314 if (ln->tn_op == INDIR && ln->tn_left->tn_op == PLUS) 4315 /* check the range of array indices */ 4316 check_array_index(ln->tn_left, true); 4317 } 4318 4319 static void 4320 check_expr_load(const tnode_t *ln) 4321 { 4322 if (ln->tn_op == INDIR && ln->tn_left->tn_op == PLUS) 4323 /* check the range of array indices */ 4324 check_array_index(ln->tn_left, false); 4325 } 4326 4327 static void 4328 check_expr_side_effect(const tnode_t *ln, bool szof) 4329 { 4330 scl_t sc; 4331 dinfo_t *di; 4332 4333 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 4334 if (ln->tn_op == NAME && (reached || !warn_about_unreachable)) { 4335 sc = ln->tn_sym->s_scl; 4336 /* 4337 * Look if there was a asm statement in one of the 4338 * compound statements we are in. If not, we don't 4339 * print a warning. 4340 */ 4341 for (di = dcs; di != NULL; di = di->d_enclosing) { 4342 if (di->d_asm) 4343 break; 4344 } 4345 if (sc != EXTERN && sc != STATIC && 4346 !ln->tn_sym->s_set && !szof && di == NULL) { 4347 /* '%s' may be used before set */ 4348 warning(158, ln->tn_sym->s_name); 4349 mark_as_set(ln->tn_sym); 4350 } 4351 mark_as_used(ln->tn_sym, false, false); 4352 } 4353 } 4354 4355 static void 4356 check_expr_assign(const tnode_t *ln, bool szof) 4357 { 4358 /* XXX: Taking warn_about_unreachable into account here feels wrong. */ 4359 if (ln->tn_op == NAME && !szof && (reached || !warn_about_unreachable)) { 4360 mark_as_set(ln->tn_sym); 4361 if (ln->tn_sym->s_scl == EXTERN) 4362 outusg(ln->tn_sym); 4363 } 4364 if (ln->tn_op == INDIR && ln->tn_left->tn_op == PLUS) 4365 /* check the range of array indices */ 4366 check_array_index(ln->tn_left, false); 4367 } 4368 4369 static void 4370 check_expr_call(const tnode_t *tn, const tnode_t *ln, 4371 bool szof, bool vctx, bool cond, bool retval_discarded) 4372 { 4373 lint_assert(ln->tn_op == ADDR); 4374 lint_assert(ln->tn_left->tn_op == NAME); 4375 if (!szof && 4376 !is_compiler_builtin(ln->tn_left->tn_sym->s_name)) 4377 outcall(tn, vctx || cond, retval_discarded); 4378 } 4379 4380 static bool 4381 check_expr_op(const tnode_t *tn, op_t op, const tnode_t *ln, 4382 bool szof, bool fcall, bool vctx, bool cond, 4383 bool retval_discarded, bool eqwarn) 4384 { 4385 switch (op) { 4386 case ADDR: 4387 check_expr_addr(ln, szof, fcall); 4388 break; 4389 case LOAD: 4390 check_expr_load(ln); 4391 /* FALLTHROUGH */ 4392 case PUSH: 4393 case INCBEF: 4394 case DECBEF: 4395 case INCAFT: 4396 case DECAFT: 4397 case ADDASS: 4398 case SUBASS: 4399 case MULASS: 4400 case DIVASS: 4401 case MODASS: 4402 case ANDASS: 4403 case ORASS: 4404 case XORASS: 4405 case SHLASS: 4406 case SHRASS: 4407 case REAL: 4408 case IMAG: 4409 check_expr_side_effect(ln, szof); 4410 break; 4411 case ASSIGN: 4412 check_expr_assign(ln, szof); 4413 break; 4414 case CALL: 4415 check_expr_call(tn, ln, szof, vctx, cond, retval_discarded); 4416 break; 4417 case EQ: 4418 if (hflag && eqwarn) 4419 /* operator '==' found where '=' was expected */ 4420 warning(160); 4421 break; 4422 case CON: 4423 case NAME: 4424 case STRING: 4425 return false; 4426 default: 4427 break; 4428 } 4429 return true; 4430 } 4431 4432 /* 4433 * vctx ??? 4434 * cond whether the expression is a condition that 4435 * will be compared with 0 4436 * eqwarn whether the operator '==' might be a 4437 * misspelled '=' 4438 * fcall whether the expression is a function call 4439 * retval_discarded whether the return value of a function call 4440 * is discarded; such calls will be analyzed by 4441 * lint2 in messages 4, 8 and 9 4442 * szof whether the expression is part of a sizeof 4443 * expression, which means that its value is 4444 * discarded since only the type is relevant 4445 */ 4446 void 4447 check_expr_misc(const tnode_t *tn, bool vctx, bool cond, 4448 bool eqwarn, bool fcall, bool retval_discarded, bool szof) 4449 { 4450 tnode_t *ln, *rn; 4451 const mod_t *mp; 4452 op_t op; 4453 bool cvctx, ccond, eq, discard; 4454 4455 if (tn == NULL) 4456 return; 4457 4458 ln = tn->tn_left; 4459 rn = tn->tn_right; 4460 mp = &modtab[op = tn->tn_op]; 4461 4462 if (!check_expr_op(tn, op, ln, 4463 szof, fcall, vctx, cond, retval_discarded, eqwarn)) 4464 return; 4465 4466 cvctx = mp->m_value_context; 4467 ccond = mp->m_compares_with_zero; 4468 eq = mp->m_warn_if_operand_eq && 4469 !ln->tn_parenthesized && 4470 rn != NULL && !rn->tn_parenthesized; 4471 4472 /* 4473 * values of operands of ':' are not used if the type of at least 4474 * one of the operands (for gcc compatibility) is void 4475 * XXX test/value context of QUEST should probably be used as 4476 * context for both operands of COLON 4477 */ 4478 if (op == COLON && tn->tn_type->t_tspec == VOID) 4479 cvctx = ccond = false; 4480 discard = op == CVT && tn->tn_type->t_tspec == VOID; 4481 check_expr_misc(ln, cvctx, ccond, eq, op == CALL, discard, szof); 4482 4483 switch (op) { 4484 case PUSH: 4485 if (rn != NULL) 4486 check_expr_misc(rn, false, false, eq, false, false, 4487 szof); 4488 break; 4489 case LOGAND: 4490 case LOGOR: 4491 check_expr_misc(rn, false, true, eq, false, false, szof); 4492 break; 4493 case COLON: 4494 check_expr_misc(rn, cvctx, ccond, eq, false, false, szof); 4495 break; 4496 case COMMA: 4497 check_expr_misc(rn, vctx, cond, false, false, false, szof); 4498 break; 4499 default: 4500 if (mp->m_binary) 4501 check_expr_misc(rn, true, false, eq, false, false, 4502 szof); 4503 break; 4504 } 4505 } 4506 4507 /* 4508 * Checks the range of array indices, if possible. 4509 * amper is set if only the address of the element is used. This 4510 * means that the index is allowed to refer to the first element 4511 * after the array. 4512 */ 4513 static void 4514 check_array_index(tnode_t *tn, bool amper) 4515 { 4516 int dim; 4517 tnode_t *ln, *rn; 4518 int elsz; 4519 int64_t con; 4520 4521 ln = tn->tn_left; 4522 rn = tn->tn_right; 4523 4524 /* We can only check constant indices. */ 4525 if (rn->tn_op != CON) 4526 return; 4527 4528 /* Return if the left node does not stem from an array. */ 4529 if (ln->tn_op != ADDR) 4530 return; 4531 if (ln->tn_left->tn_op != STRING && ln->tn_left->tn_op != NAME) 4532 return; 4533 if (ln->tn_left->tn_type->t_tspec != ARRAY) 4534 return; 4535 4536 /* 4537 * For incomplete array types, we can print a warning only if 4538 * the index is negative. 4539 */ 4540 if (is_incomplete(ln->tn_left->tn_type) && rn->tn_val->v_quad >= 0) 4541 return; 4542 4543 /* Get the size of one array element */ 4544 if ((elsz = length_in_bits(ln->tn_type->t_subt, NULL)) == 0) 4545 return; 4546 elsz /= CHAR_SIZE; 4547 4548 /* Change the unit of the index from bytes to element size. */ 4549 if (is_uinteger(rn->tn_type->t_tspec)) { 4550 con = (uint64_t)rn->tn_val->v_quad / elsz; 4551 } else { 4552 con = rn->tn_val->v_quad / elsz; 4553 } 4554 4555 dim = ln->tn_left->tn_type->t_dim + (amper ? 1 : 0); 4556 4557 if (!is_uinteger(rn->tn_type->t_tspec) && con < 0) { 4558 /* array subscript cannot be negative: %ld */ 4559 warning(167, (long)con); 4560 } else if (dim > 0 && (uint64_t)con >= (uint64_t)dim) { 4561 /* array subscript cannot be > %d: %ld */ 4562 warning(168, dim - 1, (long)con); 4563 } 4564 } 4565 4566 static bool 4567 is_out_of_char_range(const tnode_t *tn) 4568 { 4569 return tn->tn_op == CON && 4570 !(0 <= tn->tn_val->v_quad && 4571 tn->tn_val->v_quad < 1 << (CHAR_SIZE - 1)); 4572 } 4573 4574 /* 4575 * Check for ordered comparisons of unsigned values with 0. 4576 */ 4577 static void 4578 check_integer_comparison(op_t op, tnode_t *ln, tnode_t *rn) 4579 { 4580 tspec_t lt, rt; 4581 4582 lt = ln->tn_type->t_tspec; 4583 rt = rn->tn_type->t_tspec; 4584 4585 if (ln->tn_op != CON && rn->tn_op != CON) 4586 return; 4587 4588 if (!is_integer(lt) || !is_integer(rt)) 4589 return; 4590 4591 if (hflag || pflag) { 4592 if (lt == CHAR && is_out_of_char_range(rn)) { 4593 /* nonportable character comparison '%s %d' */ 4594 warning(230, op_name(op), (int)rn->tn_val->v_quad); 4595 return; 4596 } 4597 if (rt == CHAR && is_out_of_char_range(ln)) { 4598 /* nonportable character comparison '%s %d' */ 4599 warning(230, op_name(op), (int)ln->tn_val->v_quad); 4600 return; 4601 } 4602 } 4603 4604 if (is_uinteger(lt) && !is_uinteger(rt) && 4605 rn->tn_op == CON && rn->tn_val->v_quad <= 0) { 4606 if (rn->tn_val->v_quad < 0) { 4607 /* operator '%s' compares '%s' with '%s' */ 4608 warning(162, op_name(op), 4609 type_name(ln->tn_type), "negative constant"); 4610 } else if (op == LT || op == GE) { 4611 /* operator '%s' compares '%s' with '%s' */ 4612 warning(162, op_name(op), type_name(ln->tn_type), "0"); 4613 } 4614 return; 4615 } 4616 if (is_uinteger(rt) && !is_uinteger(lt) && 4617 ln->tn_op == CON && ln->tn_val->v_quad <= 0) { 4618 if (ln->tn_val->v_quad < 0) { 4619 /* operator '%s' compares '%s' with '%s' */ 4620 warning(162, op_name(op), 4621 "negative constant", type_name(rn->tn_type)); 4622 } else if (op == GT || op == LE) { 4623 /* operator '%s' compares '%s' with '%s' */ 4624 warning(162, op_name(op), "0", type_name(rn->tn_type)); 4625 } 4626 return; 4627 } 4628 } 4629 4630 /* 4631 * Return whether the expression can be used for static initialization. 4632 * 4633 * Constant initialization expressions must be constant or an address 4634 * of a static object with an optional offset. In the first case, 4635 * the result is returned in *offsp. In the second case, the static 4636 * object is returned in *symp and the offset in *offsp. 4637 * 4638 * The expression can consist of PLUS, MINUS, ADDR, NAME, STRING and 4639 * CON. Type conversions are allowed if they do not change binary 4640 * representation (including width). 4641 * 4642 * C99 6.6 "Constant expressions" 4643 * C99 6.7.8p4 restricts initializers for static storage duration 4644 */ 4645 bool 4646 constant_addr(const tnode_t *tn, const sym_t **symp, ptrdiff_t *offsp) 4647 { 4648 const sym_t *sym; 4649 ptrdiff_t offs1, offs2; 4650 tspec_t t, ot; 4651 4652 switch (tn->tn_op) { 4653 case MINUS: 4654 if (tn->tn_right->tn_op == CVT) 4655 return constant_addr(tn->tn_right, symp, offsp); 4656 else if (tn->tn_right->tn_op != CON) 4657 return false; 4658 /* FALLTHROUGH */ 4659 case PLUS: 4660 offs1 = offs2 = 0; 4661 if (tn->tn_left->tn_op == CON) { 4662 offs1 = (ptrdiff_t)tn->tn_left->tn_val->v_quad; 4663 if (!constant_addr(tn->tn_right, &sym, &offs2)) 4664 return false; 4665 } else if (tn->tn_right->tn_op == CON) { 4666 offs2 = (ptrdiff_t)tn->tn_right->tn_val->v_quad; 4667 if (tn->tn_op == MINUS) 4668 offs2 = -offs2; 4669 if (!constant_addr(tn->tn_left, &sym, &offs1)) 4670 return false; 4671 } else { 4672 return false; 4673 } 4674 *symp = sym; 4675 *offsp = offs1 + offs2; 4676 return true; 4677 case ADDR: 4678 if (tn->tn_left->tn_op == NAME) { 4679 *symp = tn->tn_left->tn_sym; 4680 *offsp = 0; 4681 return true; 4682 } else { 4683 /* 4684 * If this would be the front end of a compiler we 4685 * would return a label instead of 0, at least if 4686 * 'tn->tn_left->tn_op == STRING'. 4687 */ 4688 *symp = NULL; 4689 *offsp = 0; 4690 return true; 4691 } 4692 case CVT: 4693 t = tn->tn_type->t_tspec; 4694 ot = tn->tn_left->tn_type->t_tspec; 4695 if ((!is_integer(t) && t != PTR) || 4696 (!is_integer(ot) && ot != PTR)) { 4697 return false; 4698 } 4699 #if 0 4700 /* 4701 * consider: 4702 * struct foo { 4703 * unsigned char a; 4704 * } f = { 4705 * (unsigned char)(unsigned long) 4706 * (&(((struct foo *)0)->a)) 4707 * }; 4708 * since psize(unsigned long) != psize(unsigned char), 4709 * this fails. 4710 */ 4711 else if (psize(t) != psize(ot)) 4712 return -1; 4713 #endif 4714 return constant_addr(tn->tn_left, symp, offsp); 4715 default: 4716 return false; 4717 } 4718 } 4719 4720 /* Append s2 to s1, then free s2. */ 4721 strg_t * 4722 cat_strings(strg_t *s1, strg_t *s2) 4723 { 4724 4725 if (s1->st_char != s2->st_char) { 4726 /* cannot concatenate wide and regular string literals */ 4727 error(292); 4728 return s1; 4729 } 4730 4731 size_t len1 = s1->st_len; 4732 size_t len2 = s2->st_len; 4733 size_t chsize = s1->st_char ? sizeof(char) : sizeof(wchar_t); 4734 size_t size1 = len1 * chsize; 4735 size_t size2 = (len2 + 1) * chsize; 4736 s1->st_mem = xrealloc(s1->st_mem, size1 + size2); 4737 memcpy((char *)s1->st_mem + size1, s2->st_mem, size2); 4738 free(s2->st_mem); 4739 4740 s1->st_len = len1 + len2; 4741 free(s2); 4742 4743 return s1; 4744 } 4745 4746 static bool 4747 is_confusing_precedence(op_t op, op_t lop, bool lparen, op_t rop, bool rparen) 4748 { 4749 4750 if (op == SHL || op == SHR) { 4751 if (!lparen && (lop == PLUS || lop == MINUS)) 4752 return true; 4753 if (!rparen && (rop == PLUS || rop == MINUS)) 4754 return true; 4755 return false; 4756 } 4757 4758 if (op == LOGOR) { 4759 if (!lparen && lop == LOGAND) 4760 return true; 4761 if (!rparen && rop == LOGAND) 4762 return true; 4763 return false; 4764 } 4765 4766 lint_assert(op == BITAND || op == BITXOR || op == BITOR); 4767 if (!lparen && lop != op) { 4768 if (lop == PLUS || lop == MINUS) 4769 return true; 4770 if (lop == BITAND || lop == BITXOR) 4771 return true; 4772 } 4773 if (!rparen && rop != op) { 4774 if (rop == PLUS || rop == MINUS) 4775 return true; 4776 if (rop == BITAND || rop == BITXOR) 4777 return true; 4778 } 4779 return false; 4780 } 4781 4782 /* 4783 * Print a warning if the given node has operands which should be 4784 * parenthesized. 4785 * 4786 * XXX Does not work if an operand is a constant expression. Constant 4787 * expressions are already folded. 4788 */ 4789 static void 4790 check_precedence_confusion(tnode_t *tn) 4791 { 4792 tnode_t *ln, *rn; 4793 4794 if (!hflag) 4795 return; 4796 4797 debug_node(tn); 4798 4799 lint_assert(is_binary(tn)); 4800 for (ln = tn->tn_left; ln->tn_op == CVT; ln = ln->tn_left) 4801 continue; 4802 for (rn = tn->tn_right; rn->tn_op == CVT; rn = rn->tn_left) 4803 continue; 4804 4805 if (is_confusing_precedence(tn->tn_op, 4806 ln->tn_op, ln->tn_parenthesized, 4807 rn->tn_op, rn->tn_parenthesized)) { 4808 /* precedence confusion possible: parenthesize! */ 4809 warning(169); 4810 } 4811 } 4812 4813 typedef struct stmt_expr { 4814 struct memory_block *se_mem; 4815 sym_t *se_sym; 4816 struct stmt_expr *se_enclosing; 4817 } stmt_expr; 4818 4819 static stmt_expr *stmt_exprs; 4820 4821 void 4822 begin_statement_expr(void) 4823 { 4824 stmt_expr *se = xmalloc(sizeof(*se)); 4825 se->se_mem = expr_save_memory(); 4826 se->se_sym = NULL; 4827 se->se_enclosing = stmt_exprs; 4828 stmt_exprs = se; 4829 } 4830 4831 void 4832 do_statement_expr(tnode_t *tn) 4833 { 4834 block_level--; 4835 mem_block_level--; 4836 stmt_exprs->se_sym = tn != NULL 4837 ? mktempsym(block_dup_type(tn->tn_type)) 4838 : NULL; /* after a syntax error */ 4839 mem_block_level++; 4840 block_level++; 4841 /* ({ }) is a GCC extension */ 4842 gnuism(320); 4843 } 4844 4845 tnode_t * 4846 end_statement_expr(void) 4847 { 4848 stmt_expr *se = stmt_exprs; 4849 if (se->se_sym == NULL) 4850 return NULL; /* after a syntax error */ 4851 tnode_t *tn = build_name(se->se_sym, false); 4852 (void)expr_save_memory(); /* leak */ 4853 expr_restore_memory(se->se_mem); 4854 stmt_exprs = se->se_enclosing; 4855 free(se); 4856 return tn; 4857 } 4858
Indexes created Wed Sep 24 02:09:48 GMT 2025