1 /* $NetBSD: chk.c,v 1.72 2025/05/24 07:38:59 rillig Exp $ */ 2 3 /* 4 * Copyright (c) 1996 Christopher G. Demetriou. All Rights Reserved. 5 * Copyright (c) 1994, 1995 Jochen Pohl 6 * All Rights Reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by Jochen Pohl for 19 * The NetBSD Project. 20 * 4. The name of the author may not be used to endorse or promote products 21 * derived from this software without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 #if HAVE_NBTOOL_CONFIG_H 36 #include "nbtool_config.h" 37 #endif 38 39 #include <sys/cdefs.h> 40 #if defined(__RCSID) 41 __RCSID("$NetBSD: chk.c,v 1.72 2025/05/24 07:38:59 rillig Exp $"); 42 #endif 43 44 #include <ctype.h> 45 #include <limits.h> 46 #include <stdlib.h> 47 #include <string.h> 48 49 #include "lint2.h" 50 51 static void check_used_not_defined(const hte_t *); 52 static void check_defined_not_used(const hte_t *); 53 static void check_declared_not_used_or_defined(const hte_t *); 54 static void check_multiple_definitions(const hte_t *); 55 static void chkvtui(const hte_t *, const sym_t *, const sym_t *); 56 static void chkvtdi(const hte_t *, const sym_t *, const sym_t *); 57 static void chkfaui(const hte_t *, const sym_t *, const sym_t *); 58 static void chkau(const hte_t *, int, const sym_t *, const sym_t *, 59 const pos_t *, const fcall_t *, const fcall_t *, 60 const type_t *, const type_t *); 61 static void check_return_values(const hte_t *, const sym_t *); 62 static void check_argument_declarations(const hte_t *, 63 const sym_t *, const sym_t *); 64 static void printflike(const hte_t *, const fcall_t *, 65 int, const char *, const type_t **); 66 static void scanflike(const hte_t *, const fcall_t *, 67 int, const char *, const type_t **); 68 static void bad_format_string(const hte_t *, const fcall_t *); 69 static void inconsistent_arguments(const hte_t *, const fcall_t *, int); 70 static void too_few_arguments(const hte_t *, const fcall_t *); 71 static void too_many_arguments(const hte_t *, const fcall_t *); 72 static bool types_compatible(const type_t *, const type_t *, 73 bool, bool, bool, bool *); 74 static bool prototypes_compatible(const type_t *, const type_t *, bool *); 75 static bool matches_no_arg_function(const type_t *, bool *); 76 77 78 /* 79 * If there is a symbol named "main", mark it as used. 80 */ 81 void 82 mark_main_as_used(void) 83 { 84 hte_t *hte; 85 86 if ((hte = htab_search("main", false)) != NULL) 87 hte->h_used = true; 88 } 89 90 /* 91 * Performs all tests for a single name 92 */ 93 void 94 check_name(const hte_t *hte) 95 { 96 sym_t *sym, *def, *pdecl, *decl; 97 98 if (!uflag) { 99 check_used_not_defined(hte); 100 check_defined_not_used(hte); 101 if (xflag) 102 check_declared_not_used_or_defined(hte); 103 } 104 check_multiple_definitions(hte); 105 106 /* Get definition, prototype declaration and declaration */ 107 def = pdecl = decl = NULL; 108 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 109 if (def == NULL && (sym->s_def == DEF || sym->s_def == TDEF)) 110 def = sym; 111 if (pdecl == NULL && sym->s_def == DECL && 112 TP(sym->s_type)->t_tspec == FUNC && 113 TP(sym->s_type)->t_proto) { 114 pdecl = sym; 115 } 116 if (decl == NULL && sym->s_def == DECL) 117 decl = sym; 118 } 119 120 /* A prototype is better than an old-style declaration. */ 121 if (pdecl != NULL) 122 decl = pdecl; 123 124 chkvtui(hte, def, decl); 125 126 chkvtdi(hte, def, decl); 127 128 chkfaui(hte, def, decl); 129 130 check_return_values(hte, def); 131 132 check_argument_declarations(hte, def, decl); 133 } 134 135 /* 136 * Print a warning if the name has been used, but not defined. 137 */ 138 static void 139 check_used_not_defined(const hte_t *hte) 140 { 141 fcall_t *fcall; 142 usym_t *usym; 143 144 if (!hte->h_used || hte->h_def) 145 return; 146 147 if ((fcall = hte->h_calls) != NULL) { 148 /* %s is used in %s but never defined */ 149 msg(0, hte->h_name, mkpos(&fcall->f_pos)); 150 } else if ((usym = hte->h_usyms) != NULL) { 151 /* %s is used in %s but never defined */ 152 msg(0, hte->h_name, mkpos(&usym->u_pos)); 153 } 154 } 155 156 /* 157 * Print a warning if the name has been defined, but never used. 158 */ 159 static void 160 check_defined_not_used(const hte_t *hte) 161 { 162 sym_t *sym; 163 164 if (!hte->h_def || hte->h_used) 165 return; 166 167 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 168 if (sym->s_def == DEF || sym->s_def == TDEF) { 169 /* %s is defined in %s but never used */ 170 msg(1, hte->h_name, mkpos(&sym->s_pos)); 171 break; 172 } 173 } 174 } 175 176 /* 177 * Print a warning if the variable has been declared, but is not used 178 * or defined. 179 */ 180 static void 181 check_declared_not_used_or_defined(const hte_t *hte) 182 { 183 sym_t *sym; 184 185 if (hte->h_syms == NULL || hte->h_used || hte->h_def) 186 return; 187 188 sym = hte->h_syms; 189 if (TP(sym->s_type)->t_tspec == FUNC) 190 return; 191 192 if (sym->s_def != DECL) 193 errx(1, "internal error: check_declared_not_used_or_defined"); 194 /* %s is declared in %s but never used or defined */ 195 msg(2, hte->h_name, mkpos(&sym->s_pos)); 196 } 197 198 /* 199 * Print a warning if there is more than one definition for 200 * this name. 201 */ 202 static void 203 check_multiple_definitions(const hte_t *hte) 204 { 205 sym_t *sym, *def1; 206 207 if (!hte->h_def) 208 return; 209 210 def1 = NULL; 211 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 212 /* 213 * C90 allows tentative definitions of the same name in only 214 * one compilation unit. 215 */ 216 if (sym->s_def != DEF && (!sflag || sym->s_def != TDEF)) 217 continue; 218 if (sym->s_inline) 219 continue; 220 if (def1 == NULL) { 221 def1 = sym; 222 continue; 223 } 224 /* %s has multiple definitions in %s and %s */ 225 msg(3, hte->h_name, mkpos(&def1->s_pos), mkpos(&sym->s_pos)); 226 } 227 } 228 229 /* 230 * Print a warning if the return value assumed for a function call 231 * differs from the return value of the function definition or 232 * function declaration. 233 * 234 * If no definition/declaration can be found, the assumed return values 235 * are always int. So there is no need to compare with another function 236 * call as it's done for function arguments. 237 */ 238 static void 239 chkvtui(const hte_t *hte, const sym_t *def, const sym_t *decl) 240 { 241 fcall_t *call; 242 type_t *tp1, *tp2; 243 bool dowarn, eq; 244 tspec_t t1; 245 246 if (hte->h_calls == NULL) 247 return; 248 249 if (def == NULL) 250 def = decl; 251 if (def == NULL) 252 return; 253 254 t1 = (tp1 = TP(def->s_type)->t_subt)->t_tspec; 255 for (call = hte->h_calls; call != NULL; call = call->f_next) { 256 tp2 = TP(call->f_type)->t_subt; 257 eq = types_compatible(tp1, tp2, 258 true, false, false, (dowarn = false, &dowarn)); 259 if (!call->f_rused) { 260 /* no return value used */ 261 if ((t1 == STRUCT || t1 == UNION) && !eq) { 262 /* 263 * If a function returns a struct or union, it 264 * must be declared to return a struct or 265 * union, even if the return value is ignored. 266 * This is necessary because the caller must 267 * allocate stack space for the return value. 268 * If it does not, the return value would 269 * overwrite other data. 270 * 271 * XXX: The following message may be confusing 272 * because it occurs also if the return value 273 * was declared inconsistently. But this 274 * behavior matches pcc-based lint, so it is 275 * accepted for now. 276 */ 277 /* %s's return type in %s must be decl... */ 278 msg(17, hte->h_name, 279 mkpos(&def->s_pos), mkpos(&call->f_pos)); 280 } 281 continue; 282 } 283 if (!eq || (sflag && dowarn)) { 284 /* %s has its return value used inconsistently ... */ 285 msg(4, hte->h_name, 286 mkpos(&def->s_pos), mkpos(&call->f_pos)); 287 } 288 } 289 } 290 291 /* 292 * Print a warning if a definition/declaration does not match another 293 * definition/declaration of the same name. For functions, only the 294 * types of return values are tested. 295 */ 296 static void 297 chkvtdi(const hte_t *hte, const sym_t *def, const sym_t *decl) 298 { 299 if (def == NULL) 300 def = decl; 301 if (def == NULL) 302 return; 303 304 const type_t *tp1 = TP(def->s_type); 305 for (sym_t *sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 306 if (sym == def) 307 continue; 308 const type_t *tp2 = TP(sym->s_type); 309 bool dowarn = false; 310 bool is_func = tp1->t_tspec == FUNC && tp2->t_tspec == FUNC; 311 const type_t *xt1 = is_func ? tp1->t_subt : tp1; 312 const type_t *xt2 = is_func ? tp2->t_subt : tp2; 313 bool eq = types_compatible(xt1, xt2, 314 is_func, false, false, &dowarn); 315 if (!eq || (sflag && dowarn)) { 316 /* %s %s '%s' at %s, versus '%s' at %s */ 317 msg(5, hte->h_name, 318 is_func ? "returns" : "has type", 319 type_name(xt1), mkpos(&def->s_pos), 320 type_name(xt2), mkpos(&sym->s_pos)); 321 } 322 } 323 } 324 325 static int 326 total_args(int n, const type_t **tpp) 327 { 328 for (; *tpp != NULL; tpp++) 329 n++; 330 return n; 331 } 332 333 /* 334 * Print a warning if a function is called with arguments which does 335 * not match the function definition, declaration or another call 336 * of the same function. 337 */ 338 static void 339 chkfaui(const hte_t *hte, const sym_t *def, const sym_t *decl) 340 { 341 const type_t *tp1, *tp2, **ap1, **ap2; 342 const pos_t *pos1p = NULL; 343 fcall_t *calls, *call, *call1; 344 int n, as; 345 arginf_t *ai; 346 347 if ((calls = hte->h_calls) == NULL) 348 return; 349 350 /* 351 * If we find a function definition, we use this for comparison, 352 * otherwise the first prototype we can find. If there is no definition 353 * or prototype declaration, the first function call is used. 354 */ 355 tp1 = NULL; 356 call1 = NULL; 357 if (def != NULL) { 358 if ((tp1 = TP(def->s_type))->t_tspec != FUNC) 359 return; 360 pos1p = &def->s_pos; 361 } else if (decl != NULL && TP(decl->s_type)->t_proto) { 362 if ((tp1 = TP(decl->s_type))->t_tspec != FUNC) 363 return; 364 pos1p = &decl->s_pos; 365 } 366 if (tp1 == NULL) { 367 call1 = calls; 368 calls = calls->f_next; 369 if ((tp1 = TP(call1->f_type))->t_tspec != FUNC) 370 return; 371 pos1p = &call1->f_pos; 372 } 373 374 n = 1; 375 for (call = calls; call != NULL; call = call->f_next) { 376 if ((tp2 = TP(call->f_type))->t_tspec != FUNC) 377 continue; 378 ap1 = tp1->t_args; 379 ap2 = tp2->t_args; 380 n = 0; 381 while (*ap1 != NULL && *ap2 != NULL) { 382 if (def != NULL && def->s_check_only_first_args && 383 n >= def->s_check_num_args) 384 break; 385 n++; 386 chkau(hte, n, def, decl, pos1p, call1, call, 387 *ap1, *ap2); 388 ap1++; 389 ap2++; 390 } 391 if (*ap1 == *ap2) { 392 /* equal # of arguments */ 393 } else if (def != NULL && def->s_check_only_first_args && 394 n >= def->s_check_num_args) { 395 /* 396 * function definition with VARARGS; The # of arguments 397 * of the call must be at least as large as the 398 * parameter of VARARGS. 399 */ 400 } else if (*ap2 != NULL && tp1->t_proto && tp1->t_vararg) { 401 /* 402 * prototype with ... and function call with at least 403 * the same # of arguments as declared in the 404 * prototype. 405 */ 406 } else { 407 /* %s has %d parameters in %s, versus %d ... */ 408 msg(7, hte->h_name, total_args(n, ap1), mkpos(pos1p), 409 total_args(n, ap2), mkpos(&call->f_pos)); 410 continue; 411 } 412 413 /* perform SCANFLIKE/PRINTFLIKE tests */ 414 if (def == NULL || (!def->s_printflike && !def->s_scanflike)) 415 continue; 416 as = def->s_printflike 417 ? def->s_printflike_arg 418 : def->s_scanflike_arg; 419 for (ai = call->f_args; ai != NULL; ai = ai->a_next) { 420 if (ai->a_num == as) 421 break; 422 } 423 if (ai == NULL || !ai->a_fmt) 424 continue; 425 if (def->s_printflike) { 426 printflike(hte, call, n, ai->a_fstrg, ap2); 427 } else { 428 scanflike(hte, call, n, ai->a_fstrg, ap2); 429 } 430 } 431 } 432 433 /* 434 * Check a single argument in a function call. 435 * 436 * hte a pointer to the hash table entry of the function 437 * n the number of the argument (1..) 438 * def the function definition or NULL 439 * decl prototype declaration, old-style declaration or NULL 440 * pos1p position of definition, declaration of first call 441 * call1 first call, if both def and decl are old-style def/decl 442 * call checked call 443 * arg1 currently checked argument of def/decl/call1 444 * arg2 currently checked argument of call 445 */ 446 static void 447 chkau(const hte_t *hte, 448 int n, const sym_t *def, const sym_t *decl, 449 const pos_t *pos1p, const fcall_t *call1, const fcall_t *call, 450 const type_t *arg1, const type_t *arg2) 451 { 452 bool promote, asgn, dowarn; 453 tspec_t t1, t2; 454 arginf_t *ai, *ai1; 455 456 /* 457 * If a function definition is available (def != NULL), we compare the 458 * function call (call) with the definition. Otherwise, if a function 459 * definition is available and it is not an old-style definition (decl 460 * != NULL && TP(decl->s_type)->t_proto), we compare the call with this 461 * declaration. Otherwise we compare it with the first call we have 462 * found (call1). 463 */ 464 465 /* arg1 must be promoted if it stems from an old-style definition */ 466 promote = def != NULL && def->s_old_style_function; 467 468 /* 469 * If we compare with a definition or declaration, we must perform the 470 * same checks for qualifiers in indirected types as in assignments. 471 */ 472 asgn = def != NULL || (decl != NULL && TP(decl->s_type)->t_proto); 473 474 dowarn = false; 475 if (types_compatible(arg1, arg2, true, promote, asgn, &dowarn) && 476 (!sflag || !dowarn)) 477 return; 478 479 /*- 480 * Other lint implementations print warnings as soon as the type of an 481 * argument does not match exactly the expected type. The result are 482 * lots of warnings which are really not necessary. 483 * We print a warning only if 484 * (0) at least one type is not an integer type and types differ 485 * (1) hflag is set and types differ 486 * (2) types differ, except in signedness 487 * 488 * If the argument is an integer constant whose msb is not set, 489 * signedness is ignored (e.g. 0 matches both signed and unsigned int). 490 * This is with and without hflag. 491 * 492 * If the argument is an integer constant with value 0 and the expected 493 * argument is of type pointer and the width of the integer constant is 494 * the same as the width of the pointer, no warning is printed. 495 */ 496 t1 = arg1->t_tspec; 497 t2 = arg2->t_tspec; 498 if (is_integer(t1) && is_integer(t2) && 499 !arg1->t_is_enum && !arg2->t_is_enum) { 500 if (promote) { 501 /* 502 * XXX Here is a problem: Although it is possible to 503 * pass an int where a char/short it expected, there 504 * may be loss in significant digits. We should first 505 * check for const arguments if they can be converted 506 * into the original parameter type. 507 */ 508 if (t1 == FLOAT) { 509 t1 = DOUBLE; 510 } else if (t1 == CHAR || t1 == SCHAR) { 511 t1 = INT; 512 } else if (t1 == UCHAR) { 513 t1 = tflag ? UINT : INT; 514 } else if (t1 == SHORT) { 515 t1 = INT; 516 } else if (t1 == USHORT) { 517 t1 = INT_MAX < USHRT_MAX || tflag ? UINT : INT; 518 } 519 } 520 521 if (signed_type(t1) == signed_type(t2)) { 522 523 /* 524 * types differ only in signedness; get information 525 * about arguments 526 */ 527 528 /* 529 * treat a definition like a call with variable 530 * arguments 531 */ 532 ai1 = call1 != NULL ? call1->f_args : NULL; 533 534 /* 535 * if two calls are compared, ai1 is set to the 536 * information for the n-th argument, if this was a 537 * constant, otherwise to NULL 538 */ 539 for ( ; ai1 != NULL; ai1 = ai1->a_next) { 540 if (ai1->a_num == n) 541 break; 542 } 543 /* 544 * ai is set to the information of the n-th arg of the 545 * (second) call, if this was a constant, otherwise to 546 * NULL 547 */ 548 for (ai = call->f_args; ai != NULL; ai = ai->a_next) { 549 if (ai->a_num == n) 550 break; 551 } 552 553 if (ai1 == NULL && ai == NULL) { 554 /* no constant at all */ 555 if (!hflag) 556 return; 557 } else if (ai1 == NULL || ai == NULL) { 558 /* one constant */ 559 if (ai == NULL) 560 ai = ai1; 561 if (ai->a_zero || ai->a_pcon) 562 /* same value in signed and unsigned */ 563 return; 564 /* value (not representation) differently */ 565 } else { 566 /* 567 * two constants, one signed, one unsigned; if 568 * the msb of one of the constants is set, the 569 * argument is used inconsistently. 570 */ 571 if (!ai1->a_ncon && !ai->a_ncon) 572 return; 573 } 574 } 575 576 } else if (t1 == PTR && is_integer(t2)) { 577 for (ai = call->f_args; ai != NULL; ai = ai->a_next) { 578 if (ai->a_num == n) 579 break; 580 } 581 /* 582 * Vendor implementations of lint (e.g. HP-UX, Digital UNIX) 583 * don't care about the size of the integer argument, only 584 * whether or not it is zero. We do the same. 585 */ 586 if (ai != NULL && ai->a_zero) 587 return; 588 } 589 590 /* %s has argument %d with type '%s' at %s, versus '%s' at %s */ 591 msg(6, hte->h_name, n, type_name(arg1), mkpos(pos1p), 592 type_name(arg2), mkpos(&call->f_pos)); 593 } 594 595 /* 596 * Compare the types in the NULL-terminated array ap with the format 597 * string fmt. 598 */ 599 static void 600 printflike(const hte_t *hte, const fcall_t *call, 601 int n, const char *fmt, const type_t **ap) 602 { 603 const char *fp; 604 char fc; 605 bool fwidth, prec, left, sign, space, alt, zero; 606 tspec_t sz, t1, t2 = NO_TSPEC; 607 const type_t *tp; 608 609 fp = fmt; 610 fc = *fp++; 611 612 for (;;) { 613 if (fc == '\0') { 614 if (*ap != NULL) 615 too_many_arguments(hte, call); 616 break; 617 } 618 if (fc != '%') { 619 bad_format_string(hte, call); 620 break; 621 } 622 fc = *fp++; 623 fwidth = prec = left = sign = space = alt = zero = false; 624 sz = NO_TSPEC; 625 626 /* Flags */ 627 for (;;) { 628 if (fc == '-') { 629 if (left) 630 break; 631 left = true; 632 } else if (fc == '+') { 633 if (sign) 634 break; 635 sign = true; 636 } else if (fc == ' ') { 637 if (space) 638 break; 639 space = true; 640 } else if (fc == '#') { 641 if (alt) 642 break; 643 alt = true; 644 } else if (fc == '0') { 645 if (zero) 646 break; 647 zero = true; 648 } else { 649 break; 650 } 651 fc = *fp++; 652 } 653 654 /* field width */ 655 if (ch_isdigit(fc)) { 656 fwidth = true; 657 do { fc = *fp++; } while (ch_isdigit(fc)); 658 } else if (fc == '*') { 659 fwidth = true; 660 fc = *fp++; 661 if ((tp = *ap++) == NULL) { 662 too_few_arguments(hte, call); 663 break; 664 } 665 n++; 666 if ((t1 = tp->t_tspec) != INT && (hflag || t1 != UINT)) 667 inconsistent_arguments(hte, call, n); 668 } 669 670 /* precision */ 671 if (fc == '.') { 672 fc = *fp++; 673 prec = true; 674 if (ch_isdigit(fc)) { 675 do { 676 fc = *fp++; 677 } while (ch_isdigit(fc)); 678 } else if (fc == '*') { 679 fc = *fp++; 680 if ((tp = *ap++) == NULL) { 681 too_few_arguments(hte, call); 682 break; 683 } 684 n++; 685 if (tp->t_tspec != INT) 686 inconsistent_arguments(hte, call, n); 687 } else { 688 bad_format_string(hte, call); 689 break; 690 } 691 } 692 693 if (fc == 'h') { 694 sz = SHORT; 695 } else if (fc == 'l') { 696 sz = LONG; 697 } else if (fc == 'q') { 698 sz = LLONG; 699 } else if (fc == 'L') { 700 sz = LDOUBLE; 701 } 702 if (sz != NO_TSPEC) 703 fc = *fp++; 704 705 if (fc == '%') { 706 if (sz != NO_TSPEC || left || sign || space || 707 alt || zero || prec || fwidth) { 708 bad_format_string(hte, call); 709 } 710 fc = *fp++; 711 continue; 712 } 713 714 if (fc == '\0') { 715 bad_format_string(hte, call); 716 break; 717 } 718 719 if ((tp = *ap++) == NULL) { 720 too_few_arguments(hte, call); 721 break; 722 } 723 n++; 724 if ((t1 = tp->t_tspec) == PTR) 725 t2 = tp->t_subt->t_tspec; 726 727 if (fc == 'd' || fc == 'i') { 728 if (alt || sz == LDOUBLE) { 729 bad_format_string(hte, call); 730 break; 731 } 732 int_conv: 733 if (sz == LONG) { 734 if (t1 != LONG && (hflag || t1 != ULONG)) 735 inconsistent_arguments(hte, call, n); 736 } else if (sz == LLONG) { 737 if (t1 != LLONG && (hflag || t1 != ULLONG)) 738 inconsistent_arguments(hte, call, n); 739 } else { 740 /* 741 * SHORT is always promoted to INT, USHORT to 742 * INT or UINT. 743 */ 744 if (t1 != INT && (hflag || t1 != UINT)) 745 inconsistent_arguments(hte, call, n); 746 } 747 } else if (fc == 'o' || fc == 'u' || fc == 'x' || fc == 'X') { 748 if ((alt && fc == 'u') || sz == LDOUBLE) 749 bad_format_string(hte, call); 750 uint_conv: 751 if (sz == LONG) { 752 if (t1 != ULONG && (hflag || t1 != LONG)) 753 inconsistent_arguments(hte, call, n); 754 } else if (sz == LLONG) { 755 if (t1 != ULLONG && (hflag || t1 != LLONG)) 756 inconsistent_arguments(hte, call, n); 757 } else if (sz == SHORT) { 758 /* USHORT was promoted to INT or UINT */ 759 if (t1 != UINT && t1 != INT) 760 inconsistent_arguments(hte, call, n); 761 } else { 762 if (t1 != UINT && (hflag || t1 != INT)) 763 inconsistent_arguments(hte, call, n); 764 } 765 } else if (fc == 'D' || fc == 'O' || fc == 'U') { 766 if ((alt && fc != 'O') || sz != NO_TSPEC || !tflag) 767 bad_format_string(hte, call); 768 sz = LONG; 769 if (fc == 'D') { 770 goto int_conv; 771 } else { 772 goto uint_conv; 773 } 774 } else if (fc == 'f' || fc == 'e' || fc == 'E' || 775 fc == 'g' || fc == 'G') { 776 if (sz == NO_TSPEC) 777 sz = DOUBLE; 778 if (sz != DOUBLE && sz != LDOUBLE) 779 bad_format_string(hte, call); 780 if (t1 != sz) 781 inconsistent_arguments(hte, call, n); 782 } else if (fc == 'c') { 783 if (sz != NO_TSPEC || alt || zero) 784 bad_format_string(hte, call); 785 if (t1 != INT) 786 inconsistent_arguments(hte, call, n); 787 } else if (fc == 's') { 788 if (sz != NO_TSPEC || alt || zero) 789 bad_format_string(hte, call); 790 if (t1 != PTR || 791 (t2 != CHAR && t2 != UCHAR && t2 != SCHAR)) { 792 inconsistent_arguments(hte, call, n); 793 } 794 } else if (fc == 'p') { 795 if (fwidth || prec || sz != NO_TSPEC || alt || zero) 796 bad_format_string(hte, call); 797 if (t1 != PTR || (hflag && t2 != VOID)) 798 inconsistent_arguments(hte, call, n); 799 } else if (fc == 'n') { 800 if (fwidth || prec || alt || zero || sz == LDOUBLE) 801 bad_format_string(hte, call); 802 if (t1 != PTR) { 803 inconsistent_arguments(hte, call, n); 804 } else if (sz == LONG) { 805 if (t2 != LONG && t2 != ULONG) 806 inconsistent_arguments(hte, call, n); 807 } else if (sz == SHORT) { 808 if (t2 != SHORT && t2 != USHORT) 809 inconsistent_arguments(hte, call, n); 810 } else { 811 if (t2 != INT && t2 != UINT) 812 inconsistent_arguments(hte, call, n); 813 } 814 } else { 815 bad_format_string(hte, call); 816 break; 817 } 818 819 fc = *fp++; 820 } 821 } 822 823 /* 824 * Compare the types in the NULL-terminated array ap with the format 825 * string fmt. 826 */ 827 static void 828 scanflike(const hte_t *hte, const fcall_t *call, 829 int n, const char *fmt, const type_t **ap) 830 { 831 const char *fp; 832 char fc; 833 bool noasgn, fwidth; 834 tspec_t sz, t1 = NO_TSPEC, t2 = NO_TSPEC; 835 const type_t *tp = NULL; 836 837 fp = fmt; 838 fc = *fp++; 839 840 for (;;) { 841 if (fc == '\0') { 842 if (*ap != NULL) 843 too_many_arguments(hte, call); 844 break; 845 } 846 if (fc != '%') { 847 bad_format_string(hte, call); 848 break; 849 } 850 fc = *fp++; 851 852 noasgn = fwidth = false; 853 sz = NO_TSPEC; 854 855 if (fc == '*') { 856 noasgn = true; 857 fc = *fp++; 858 } 859 860 if (ch_isdigit(fc)) { 861 fwidth = true; 862 do { fc = *fp++; } while (ch_isdigit(fc)); 863 } 864 865 if (fc == 'h') { 866 sz = SHORT; 867 } else if (fc == 'l') { 868 sz = LONG; 869 } else if (fc == 'q') { 870 sz = LLONG; 871 } else if (fc == 'L') { 872 sz = LDOUBLE; 873 } 874 if (sz != NO_TSPEC) 875 fc = *fp++; 876 877 if (fc == '%') { 878 if (sz != NO_TSPEC || noasgn || fwidth) 879 bad_format_string(hte, call); 880 fc = *fp++; 881 continue; 882 } 883 884 if (!noasgn) { 885 if ((tp = *ap++) == NULL) { 886 too_few_arguments(hte, call); 887 break; 888 } 889 n++; 890 if ((t1 = tp->t_tspec) == PTR) 891 t2 = tp->t_subt->t_tspec; 892 } 893 894 if (fc == 'd' || fc == 'i' || fc == 'n') { 895 if (sz == LDOUBLE) 896 bad_format_string(hte, call); 897 if (sz != SHORT && sz != LONG && sz != LLONG) 898 sz = INT; 899 conv: 900 if (!noasgn) { 901 if (t1 != PTR) { 902 inconsistent_arguments(hte, call, n); 903 } else if (t2 != signed_type(sz)) { 904 inconsistent_arguments(hte, call, n); 905 } else if (hflag && t2 != sz) { 906 inconsistent_arguments(hte, call, n); 907 } else if (tp->t_subt->t_const) { 908 inconsistent_arguments(hte, call, n); 909 } 910 } 911 } else if (fc == 'o' || fc == 'u' || fc == 'x') { 912 if (sz == LDOUBLE) 913 bad_format_string(hte, call); 914 if (sz == SHORT) { 915 sz = USHORT; 916 } else if (sz == LONG) { 917 sz = ULONG; 918 } else if (sz == LLONG) { 919 sz = ULLONG; 920 } else { 921 sz = UINT; 922 } 923 goto conv; 924 } else if (fc == 'D') { 925 if (sz != NO_TSPEC || !tflag) 926 bad_format_string(hte, call); 927 sz = LONG; 928 goto conv; 929 } else if (fc == 'O') { 930 if (sz != NO_TSPEC || !tflag) 931 bad_format_string(hte, call); 932 sz = ULONG; 933 goto conv; 934 } else if (fc == 'X') { 935 /* 936 * XXX valid in C90, but in NetBSD's libc implemented 937 * as "lx". That's why it should be avoided. 938 */ 939 if (sz != NO_TSPEC || !tflag) 940 bad_format_string(hte, call); 941 sz = ULONG; 942 goto conv; 943 } else if (fc == 'E') { 944 /* 945 * XXX valid in C90, but in NetBSD's libc implemented 946 * as "lf". That's why it should be avoided. 947 */ 948 if (sz != NO_TSPEC || !tflag) 949 bad_format_string(hte, call); 950 sz = DOUBLE; 951 goto conv; 952 } else if (fc == 'F') { 953 /* XXX only for backward compatibility */ 954 if (sz != NO_TSPEC || !tflag) 955 bad_format_string(hte, call); 956 sz = DOUBLE; 957 goto conv; 958 } else if (fc == 'G') { 959 /* 960 * XXX valid in C90, but in NetBSD's libc not 961 * implemented 962 */ 963 if (sz != NO_TSPEC && sz != LONG && sz != LDOUBLE) 964 bad_format_string(hte, call); 965 goto fconv; 966 } else if (fc == 'e' || fc == 'f' || fc == 'g') { 967 fconv: 968 if (sz == NO_TSPEC) { 969 sz = FLOAT; 970 } else if (sz == LONG) { 971 sz = DOUBLE; 972 } else if (sz != LDOUBLE) { 973 bad_format_string(hte, call); 974 sz = FLOAT; 975 } 976 goto conv; 977 } else if (fc == 's' || fc == '[' || fc == 'c') { 978 if (sz != NO_TSPEC) 979 bad_format_string(hte, call); 980 if (fc == '[') { 981 if ((fc = *fp++) == '-') { 982 bad_format_string(hte, call); 983 fc = *fp++; 984 } 985 if (fc != ']') { 986 bad_format_string(hte, call); 987 if (fc == '\0') 988 break; 989 } 990 } 991 if (!noasgn) { 992 if (t1 != PTR) { 993 inconsistent_arguments(hte, call, n); 994 } else if (t2 != CHAR && t2 != UCHAR && 995 t2 != SCHAR) { 996 inconsistent_arguments(hte, call, n); 997 } 998 } 999 } else if (fc == 'p') { 1000 if (sz != NO_TSPEC) 1001 bad_format_string(hte, call); 1002 if (!noasgn) { 1003 if (t1 != PTR || t2 != PTR) { 1004 inconsistent_arguments(hte, call, n); 1005 } else if (tp->t_subt->t_subt->t_tspec!=VOID) { 1006 if (hflag) 1007 inconsistent_arguments(hte, call, n); 1008 } 1009 } 1010 } else { 1011 bad_format_string(hte, call); 1012 break; 1013 } 1014 1015 fc = *fp++; 1016 } 1017 } 1018 1019 static void 1020 bad_format_string(const hte_t *hte, const fcall_t *call) 1021 { 1022 1023 /* %s is called with a malformed format string in %s */ 1024 msg(13, hte->h_name, mkpos(&call->f_pos)); 1025 } 1026 1027 static void 1028 inconsistent_arguments(const hte_t *hte, const fcall_t *call, int n) 1029 { 1030 1031 /* %s is called in %s with argument %d being incompatible with ... */ 1032 msg(14, hte->h_name, mkpos(&call->f_pos), n); 1033 } 1034 1035 static void 1036 too_few_arguments(const hte_t *hte, const fcall_t *call) 1037 { 1038 1039 /* %s is called in %s with too few arguments for format string */ 1040 msg(15, hte->h_name, mkpos(&call->f_pos)); 1041 } 1042 1043 static void 1044 too_many_arguments(const hte_t *hte, const fcall_t *call) 1045 { 1046 1047 /* %s is called in %s with too many arguments for format string */ 1048 msg(16, hte->h_name, mkpos(&call->f_pos)); 1049 } 1050 1051 /* 1052 * List of functions where we usually don't care about their result. 1053 * NB: Must be sorted. 1054 */ 1055 static const char ignorelist[][8] = { 1056 "memcpy", 1057 "memmove", 1058 "memset", 1059 "printf", 1060 "strcat", 1061 "strcpy", 1062 "vprintf", 1063 }; 1064 1065 /* 1066 * Print warnings for return values which are used but not returned, 1067 * or return values which are always or sometimes ignored. 1068 */ 1069 static void 1070 check_return_values(const hte_t *hte, const sym_t *def) 1071 { 1072 fcall_t *call; 1073 bool used, ignored; 1074 1075 if (def == NULL) 1076 /* don't know whether or not the functions returns a value */ 1077 return; 1078 1079 if (hte->h_calls == NULL) 1080 return; 1081 1082 if (def->s_function_has_return_value) { 1083 /* 1084 * XXX as soon as we are able to disable single warnings, the 1085 * following dependencies from hflag should be removed. But for 1086 * now I don't want to be bothered by these warnings which are 1087 * almost always useless. 1088 */ 1089 if (!hflag) 1090 return; 1091 if (hflag && bsearch(hte->h_name, ignorelist, 1092 sizeof(ignorelist) / sizeof(ignorelist[0]), 1093 sizeof(ignorelist[0]), 1094 (int (*)(const void *, const void *))strcmp) != NULL) 1095 return; 1096 1097 /* function has return value */ 1098 used = ignored = false; 1099 for (call = hte->h_calls; call != NULL; call = call->f_next) { 1100 used |= call->f_rused || call->f_rdisc; 1101 ignored |= !call->f_rused && !call->f_rdisc; 1102 } 1103 if (!used && ignored) { 1104 /* %s returns a value that is always ignored */ 1105 msg(8, hte->h_name); 1106 } else if (used && ignored) { 1107 /* %s returns a value that is sometimes ignored */ 1108 msg(9, hte->h_name); 1109 } 1110 } else { 1111 /* function has no return value */ 1112 for (call = hte->h_calls; call != NULL; call = call->f_next) { 1113 if (call->f_rused) 1114 /* %s has its return value used in %s but doesn't return one */ 1115 msg(10, hte->h_name, mkpos(&call->f_pos)); 1116 } 1117 } 1118 } 1119 1120 /* 1121 * Print warnings for inconsistent argument declarations. 1122 */ 1123 static void 1124 check_argument_declarations(const hte_t *hte, 1125 const sym_t *def, const sym_t *decl) 1126 { 1127 bool osdef, eq, dowarn; 1128 int n; 1129 const sym_t *sym1, *sym; 1130 const type_t **ap1, **ap2, *tp1, *tp2; 1131 1132 osdef = false; 1133 if (def != NULL) { 1134 osdef = def->s_old_style_function; 1135 sym1 = def; 1136 } else if (decl != NULL && TP(decl->s_type)->t_proto) { 1137 sym1 = decl; 1138 } else { 1139 return; 1140 } 1141 if (TP(sym1->s_type)->t_tspec != FUNC) 1142 return; 1143 1144 /* 1145 * XXX Prototypes should also be compared with old-style function 1146 * declarations. 1147 */ 1148 1149 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 1150 if (sym == sym1 || !TP(sym->s_type)->t_proto) 1151 continue; 1152 ap1 = TP(sym1->s_type)->t_args; 1153 ap2 = TP(sym->s_type)->t_args; 1154 n = 0; 1155 while (*ap1 != NULL && *ap2 != NULL) { 1156 const type_t *xt1, *xt2; 1157 dowarn = false; 1158 eq = types_compatible(xt1 = *ap1, xt2 = *ap2, 1159 true, osdef, false, &dowarn); 1160 if (!eq || dowarn) { 1161 /* %s has parameter %d declared as '%s' ... */ 1162 msg(11, hte->h_name, n + 1, 1163 type_name(xt1), mkpos(&sym1->s_pos), 1164 type_name(xt2), mkpos(&sym->s_pos)); 1165 } 1166 n++; 1167 ap1++; 1168 ap2++; 1169 } 1170 if (*ap1 == *ap2) { 1171 tp1 = TP(sym1->s_type); 1172 tp2 = TP(sym->s_type); 1173 if (tp1->t_vararg == tp2->t_vararg) 1174 continue; 1175 if (tp2->t_vararg && sym1->s_check_only_first_args && 1176 sym1->s_check_num_args == n && !sflag) { 1177 continue; 1178 } 1179 } 1180 /* %s has %d parameters in %s, versus %d in %s */ 1181 msg(12, hte->h_name, 1182 total_args(n, ap1), mkpos(&sym1->s_pos), 1183 total_args(n, ap2), mkpos(&sym->s_pos)); 1184 } 1185 } 1186 1187 1188 /* 1189 * Check compatibility of two types. Returns whether types are compatible. 1190 * 1191 * ignqual if set, ignore qualifiers of outermost type; used for 1192 * function arguments 1193 * promote if set, promote left type before comparison; used for 1194 * comparisons of arguments with parameters of old-style 1195 * definitions 1196 * asgn left indirected type must have at least the same qualifiers 1197 * like right indirected type (for assignments and function 1198 * arguments) 1199 * *dowarn set to true if an old-style declaration was compared with 1200 * an incompatible prototype declaration 1201 */ 1202 static bool 1203 types_compatible(const type_t *tp1, const type_t *tp2, 1204 bool ignqual, bool promot, bool asgn, bool *dowarn) 1205 { 1206 tspec_t t, to; 1207 int indir; 1208 1209 to = NO_TSPEC; 1210 indir = 0; 1211 1212 while (tp1 != NULL && tp2 != NULL) { 1213 1214 t = tp1->t_tspec; 1215 if (promot) { 1216 if (t == FLOAT) { 1217 t = DOUBLE; 1218 } else if (t == CHAR || t == SCHAR) { 1219 t = INT; 1220 } else if (t == UCHAR) { 1221 t = tflag ? UINT : INT; 1222 } else if (t == SHORT) { 1223 t = INT; 1224 } else if (t == USHORT) { 1225 t = INT_MAX < USHRT_MAX || tflag ? UINT : INT; 1226 } 1227 } 1228 1229 if (asgn && to == PTR) { 1230 if (indir == 1 && (t == VOID || tp2->t_tspec == VOID)) 1231 return true; 1232 } 1233 1234 if (t != tp2->t_tspec) { 1235 /* 1236 * Give pointer to types which differ only in 1237 * signedness a chance if not sflag and not hflag. 1238 */ 1239 if (sflag || hflag || to != PTR) 1240 return false; 1241 if (signed_type(t) != signed_type(tp2->t_tspec)) 1242 return false; 1243 } 1244 1245 if (tp1->t_is_enum && tp2->t_is_enum) { 1246 if (tp1->t_istag && tp2->t_istag) { 1247 return tp1->t_tag == tp2->t_tag; 1248 } else if (tp1->t_istynam && tp2->t_istynam) { 1249 return tp1->t_tynam == tp2->t_tynam; 1250 } else if (tp1->t_isuniqpos && tp2->t_isuniqpos) { 1251 return (tp1->t_uniqpos.p_line == 1252 tp2->t_uniqpos.p_line && 1253 tp1->t_uniqpos.p_file == 1254 tp2->t_uniqpos.p_file && 1255 tp1->t_uniqpos.p_uniq == 1256 tp2->t_uniqpos.p_uniq); 1257 } else { 1258 return false; 1259 } 1260 } 1261 1262 /* 1263 * XXX Handle combinations of enum and int if eflag is set. But 1264 * note: enum and 0 should be allowed. 1265 */ 1266 1267 if (asgn && indir == 1) { 1268 if (!tp1->t_const && tp2->t_const) 1269 return false; 1270 if (!tp1->t_volatile && tp2->t_volatile) 1271 return false; 1272 } else if (!ignqual && !tflag) { 1273 if (tp1->t_const != tp2->t_const) 1274 return false; 1275 if (tp1->t_const != tp2->t_const) 1276 return false; 1277 } 1278 1279 if (t == STRUCT || t == UNION) { 1280 if (tp1->t_istag && tp2->t_istag) { 1281 return tp1->t_tag == tp2->t_tag; 1282 } else if (tp1->t_istynam && tp2->t_istynam) { 1283 return tp1->t_tynam == tp2->t_tynam; 1284 } else if (tp1->t_isuniqpos && tp2->t_isuniqpos) { 1285 return (tp1->t_uniqpos.p_line == 1286 tp2->t_uniqpos.p_line && 1287 tp1->t_uniqpos.p_file == 1288 tp2->t_uniqpos.p_file && 1289 tp1->t_uniqpos.p_uniq == 1290 tp2->t_uniqpos.p_uniq); 1291 } else { 1292 return false; 1293 } 1294 } 1295 1296 if (t == ARRAY && tp1->t_dim != tp2->t_dim) { 1297 if (tp1->t_dim != 0 && tp2->t_dim != 0) 1298 return false; 1299 } 1300 1301 if (t == FUNC) { 1302 if (tp1->t_proto && tp2->t_proto) { 1303 if (!prototypes_compatible(tp1, tp2, dowarn)) 1304 return false; 1305 } else if (tp1->t_proto) { 1306 if (!matches_no_arg_function(tp1, dowarn)) 1307 return false; 1308 } else if (tp2->t_proto) { 1309 if (!matches_no_arg_function(tp2, dowarn)) 1310 return false; 1311 } 1312 } 1313 1314 tp1 = tp1->t_subt; 1315 tp2 = tp2->t_subt; 1316 ignqual = promot = false; 1317 to = t; 1318 indir++; 1319 } 1320 1321 return tp1 == tp2; 1322 } 1323 1324 /* 1325 * Compares arguments of two prototypes 1326 */ 1327 static bool 1328 prototypes_compatible(const type_t *tp1, const type_t *tp2, bool *dowarn) 1329 { 1330 1331 if (tp1->t_vararg != tp2->t_vararg) 1332 return false; 1333 1334 const type_t **a1 = tp1->t_args; 1335 const type_t **a2 = tp2->t_args; 1336 1337 for (; *a1 != NULL && *a2 != NULL; a1++, a2++) 1338 if (!types_compatible(*a1, *a2, true, false, false, dowarn)) 1339 return false; 1340 return *a1 == *a2; 1341 } 1342 1343 /* 1344 * Returns whether all parameters of a prototype are compatible with an 1345 * old-style function declaration. 1346 * 1347 * This is the case if the following conditions are met: 1348 * 1. the prototype must have a fixed number of parameters 1349 * 2. no parameter is of type float 1350 * 3. no parameter is converted to another type if integer promotion 1351 * is applied on it 1352 */ 1353 static bool 1354 matches_no_arg_function(const type_t *tp, bool *dowarn) 1355 { 1356 if (tp->t_vararg && dowarn != NULL) 1357 *dowarn = true; 1358 for (const type_t **arg = tp->t_args; *arg != NULL; arg++) { 1359 tspec_t t = (*arg)->t_tspec; 1360 if (t == FLOAT) 1361 return false; 1362 if (t == CHAR || t == SCHAR || t == UCHAR) 1363 return false; 1364 if (t == SHORT || t == USHORT) 1365 return false; 1366 } 1367 return true; 1368 } 1369
Indexes created Sat Sep 20 22:09:52 GMT 2025