chk.c revision 1.71
1 /* $NetBSD: chk.c,v 1.71 2025/05/24 07:00:32 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 1.71 2025/05/24 07:00:32 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 *, sym_t *, sym_t *); 56 static void chkvtdi(const hte_t *, sym_t *, sym_t *); 57 static void chkfaui(const hte_t *, sym_t *, sym_t *); 58 static void chkau(const hte_t *, int, sym_t *, sym_t *, pos_t *, 59 fcall_t *, fcall_t *, type_t *, type_t *); 60 static void check_return_values(const hte_t *, sym_t *); 61 static void check_argument_declarations(const hte_t *, sym_t *, sym_t *); 62 static void printflike(const hte_t *, fcall_t *, int, const char *, type_t **); 63 static void scanflike(const hte_t *, fcall_t *, int, const char *, type_t **); 64 static void bad_format_string(const hte_t *, fcall_t *); 65 static void inconsistent_arguments(const hte_t *, fcall_t *, int); 66 static void too_few_arguments(const hte_t *, fcall_t *); 67 static void too_many_arguments(const hte_t *, fcall_t *); 68 static bool types_compatible(type_t *, type_t *, bool, bool, bool, bool *); 69 static bool prototypes_compatible(type_t *, type_t *, bool *); 70 static bool matches_no_arg_function(type_t *, bool *); 71 72 73 /* 74 * If there is a symbol named "main", mark it as used. 75 */ 76 void 77 mark_main_as_used(void) 78 { 79 hte_t *hte; 80 81 if ((hte = htab_search("main", false)) != NULL) 82 hte->h_used = true; 83 } 84 85 /* 86 * Performs all tests for a single name 87 */ 88 void 89 check_name(const hte_t *hte) 90 { 91 sym_t *sym, *def, *pdecl, *decl; 92 93 if (!uflag) { 94 check_used_not_defined(hte); 95 check_defined_not_used(hte); 96 if (xflag) 97 check_declared_not_used_or_defined(hte); 98 } 99 check_multiple_definitions(hte); 100 101 /* Get definition, prototype declaration and declaration */ 102 def = pdecl = decl = NULL; 103 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 104 if (def == NULL && (sym->s_def == DEF || sym->s_def == TDEF)) 105 def = sym; 106 if (pdecl == NULL && sym->s_def == DECL && 107 TP(sym->s_type)->t_tspec == FUNC && 108 TP(sym->s_type)->t_proto) { 109 pdecl = sym; 110 } 111 if (decl == NULL && sym->s_def == DECL) 112 decl = sym; 113 } 114 115 /* A prototype is better than an old-style declaration. */ 116 if (pdecl != NULL) 117 decl = pdecl; 118 119 chkvtui(hte, def, decl); 120 121 chkvtdi(hte, def, decl); 122 123 chkfaui(hte, def, decl); 124 125 check_return_values(hte, def); 126 127 check_argument_declarations(hte, def, decl); 128 } 129 130 /* 131 * Print a warning if the name has been used, but not defined. 132 */ 133 static void 134 check_used_not_defined(const hte_t *hte) 135 { 136 fcall_t *fcall; 137 usym_t *usym; 138 139 if (!hte->h_used || hte->h_def) 140 return; 141 142 if ((fcall = hte->h_calls) != NULL) { 143 /* %s is used in %s but never defined */ 144 msg(0, hte->h_name, mkpos(&fcall->f_pos)); 145 } else if ((usym = hte->h_usyms) != NULL) { 146 /* %s is used in %s but never defined */ 147 msg(0, hte->h_name, mkpos(&usym->u_pos)); 148 } 149 } 150 151 /* 152 * Print a warning if the name has been defined, but never used. 153 */ 154 static void 155 check_defined_not_used(const hte_t *hte) 156 { 157 sym_t *sym; 158 159 if (!hte->h_def || hte->h_used) 160 return; 161 162 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 163 if (sym->s_def == DEF || sym->s_def == TDEF) { 164 /* %s is defined in %s but never used */ 165 msg(1, hte->h_name, mkpos(&sym->s_pos)); 166 break; 167 } 168 } 169 } 170 171 /* 172 * Print a warning if the variable has been declared, but is not used 173 * or defined. 174 */ 175 static void 176 check_declared_not_used_or_defined(const hte_t *hte) 177 { 178 sym_t *sym; 179 180 if (hte->h_syms == NULL || hte->h_used || hte->h_def) 181 return; 182 183 sym = hte->h_syms; 184 if (TP(sym->s_type)->t_tspec == FUNC) 185 return; 186 187 if (sym->s_def != DECL) 188 errx(1, "internal error: check_declared_not_used_or_defined"); 189 /* %s is declared in %s but never used or defined */ 190 msg(2, hte->h_name, mkpos(&sym->s_pos)); 191 } 192 193 /* 194 * Print a warning if there is more than one definition for 195 * this name. 196 */ 197 static void 198 check_multiple_definitions(const hte_t *hte) 199 { 200 sym_t *sym, *def1; 201 202 if (!hte->h_def) 203 return; 204 205 def1 = NULL; 206 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 207 /* 208 * C90 allows tentative definitions of the same name in only 209 * one compilation unit. 210 */ 211 if (sym->s_def != DEF && (!sflag || sym->s_def != TDEF)) 212 continue; 213 if (sym->s_inline) 214 continue; 215 if (def1 == NULL) { 216 def1 = sym; 217 continue; 218 } 219 /* %s has multiple definitions in %s and %s */ 220 msg(3, hte->h_name, mkpos(&def1->s_pos), mkpos(&sym->s_pos)); 221 } 222 } 223 224 /* 225 * Print a warning if the return value assumed for a function call 226 * differs from the return value of the function definition or 227 * function declaration. 228 * 229 * If no definition/declaration can be found, the assumed return values 230 * are always int. So there is no need to compare with another function 231 * call as it's done for function arguments. 232 */ 233 static void 234 chkvtui(const hte_t *hte, sym_t *def, sym_t *decl) 235 { 236 fcall_t *call; 237 type_t *tp1, *tp2; 238 bool dowarn, eq; 239 tspec_t t1; 240 241 if (hte->h_calls == NULL) 242 return; 243 244 if (def == NULL) 245 def = decl; 246 if (def == NULL) 247 return; 248 249 t1 = (tp1 = TP(def->s_type)->t_subt)->t_tspec; 250 for (call = hte->h_calls; call != NULL; call = call->f_next) { 251 tp2 = TP(call->f_type)->t_subt; 252 eq = types_compatible(tp1, tp2, 253 true, false, false, (dowarn = false, &dowarn)); 254 if (!call->f_rused) { 255 /* no return value used */ 256 if ((t1 == STRUCT || t1 == UNION) && !eq) { 257 /* 258 * If a function returns a struct or union, it 259 * must be declared to return a struct or 260 * union, even if the return value is ignored. 261 * This is necessary because the caller must 262 * allocate stack space for the return value. 263 * If it does not, the return value would 264 * overwrite other data. 265 * 266 * XXX: The following message may be confusing 267 * because it occurs also if the return value 268 * was declared inconsistently. But this 269 * behavior matches pcc-based lint, so it is 270 * accepted for now. 271 */ 272 /* %s's return type in %s must be decl... */ 273 msg(17, hte->h_name, 274 mkpos(&def->s_pos), mkpos(&call->f_pos)); 275 } 276 continue; 277 } 278 if (!eq || (sflag && dowarn)) { 279 /* %s has its return value used inconsistently ... */ 280 msg(4, hte->h_name, 281 mkpos(&def->s_pos), mkpos(&call->f_pos)); 282 } 283 } 284 } 285 286 /* 287 * Print a warning if a definition/declaration does not match another 288 * definition/declaration of the same name. For functions, only the 289 * types of return values are tested. 290 */ 291 static void 292 chkvtdi(const hte_t *hte, sym_t *def, sym_t *decl) 293 { 294 if (def == NULL) 295 def = decl; 296 if (def == NULL) 297 return; 298 299 type_t *tp1 = TP(def->s_type); 300 for (sym_t *sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 301 if (sym == def) 302 continue; 303 type_t *tp2 = TP(sym->s_type); 304 bool dowarn = false; 305 bool is_func = tp1->t_tspec == FUNC && tp2->t_tspec == FUNC; 306 type_t *xt1 = is_func ? tp1->t_subt : tp1; 307 type_t *xt2 = is_func ? tp2->t_subt : tp2; 308 bool eq = types_compatible(xt1, xt2, 309 is_func, false, false, &dowarn); 310 if (!eq || (sflag && dowarn)) { 311 /* %s %s '%s' at %s, versus '%s' at %s */ 312 msg(5, hte->h_name, 313 is_func ? "returns" : "has type", 314 type_name(xt1), mkpos(&def->s_pos), 315 type_name(xt2), mkpos(&sym->s_pos)); 316 } 317 } 318 } 319 320 static int 321 total_args(int n, type_t **tpp) 322 { 323 for (; *tpp != NULL; tpp++) 324 n++; 325 return n; 326 } 327 328 /* 329 * Print a warning if a function is called with arguments which does 330 * not match the function definition, declaration or another call 331 * of the same function. 332 */ 333 static void 334 chkfaui(const hte_t *hte, sym_t *def, sym_t *decl) 335 { 336 type_t *tp1, *tp2, **ap1, **ap2; 337 pos_t *pos1p = NULL; 338 fcall_t *calls, *call, *call1; 339 int n, as; 340 arginf_t *ai; 341 342 if ((calls = hte->h_calls) == NULL) 343 return; 344 345 /* 346 * If we find a function definition, we use this for comparison, 347 * otherwise the first prototype we can find. If there is no definition 348 * or prototype declaration, the first function call is used. 349 */ 350 tp1 = NULL; 351 call1 = NULL; 352 if (def != NULL) { 353 if ((tp1 = TP(def->s_type))->t_tspec != FUNC) 354 return; 355 pos1p = &def->s_pos; 356 } else if (decl != NULL && TP(decl->s_type)->t_proto) { 357 if ((tp1 = TP(decl->s_type))->t_tspec != FUNC) 358 return; 359 pos1p = &decl->s_pos; 360 } 361 if (tp1 == NULL) { 362 call1 = calls; 363 calls = calls->f_next; 364 if ((tp1 = TP(call1->f_type))->t_tspec != FUNC) 365 return; 366 pos1p = &call1->f_pos; 367 } 368 369 n = 1; 370 for (call = calls; call != NULL; call = call->f_next) { 371 if ((tp2 = TP(call->f_type))->t_tspec != FUNC) 372 continue; 373 ap1 = tp1->t_args; 374 ap2 = tp2->t_args; 375 n = 0; 376 while (*ap1 != NULL && *ap2 != NULL) { 377 if (def != NULL && def->s_check_only_first_args && 378 n >= def->s_check_num_args) 379 break; 380 n++; 381 chkau(hte, n, def, decl, pos1p, call1, call, 382 *ap1, *ap2); 383 ap1++; 384 ap2++; 385 } 386 if (*ap1 == *ap2) { 387 /* equal # of arguments */ 388 } else if (def != NULL && def->s_check_only_first_args && 389 n >= def->s_check_num_args) { 390 /* 391 * function definition with VARARGS; The # of arguments 392 * of the call must be at least as large as the 393 * parameter of VARARGS. 394 */ 395 } else if (*ap2 != NULL && tp1->t_proto && tp1->t_vararg) { 396 /* 397 * prototype with ... and function call with at least 398 * the same # of arguments as declared in the 399 * prototype. 400 */ 401 } else { 402 /* %s has %d parameters in %s, versus %d ... */ 403 msg(7, hte->h_name, total_args(n, ap1), mkpos(pos1p), 404 total_args(n, ap2), mkpos(&call->f_pos)); 405 continue; 406 } 407 408 /* perform SCANFLIKE/PRINTFLIKE tests */ 409 if (def == NULL || (!def->s_printflike && !def->s_scanflike)) 410 continue; 411 as = def->s_printflike 412 ? def->s_printflike_arg 413 : def->s_scanflike_arg; 414 for (ai = call->f_args; ai != NULL; ai = ai->a_next) { 415 if (ai->a_num == as) 416 break; 417 } 418 if (ai == NULL || !ai->a_fmt) 419 continue; 420 if (def->s_printflike) { 421 printflike(hte, call, n, ai->a_fstrg, ap2); 422 } else { 423 scanflike(hte, call, n, ai->a_fstrg, ap2); 424 } 425 } 426 } 427 428 /* 429 * Check a single argument in a function call. 430 * 431 * hte a pointer to the hash table entry of the function 432 * n the number of the argument (1..) 433 * def the function definition or NULL 434 * decl prototype declaration, old-style declaration or NULL 435 * pos1p position of definition, declaration of first call 436 * call1 first call, if both def and decl are old-style def/decl 437 * call checked call 438 * arg1 currently checked argument of def/decl/call1 439 * arg2 currently checked argument of call 440 */ 441 static void 442 chkau(const hte_t *hte, int n, sym_t *def, sym_t *decl, pos_t *pos1p, 443 fcall_t *call1, fcall_t *call, type_t *arg1, type_t *arg2) 444 { 445 bool promote, asgn, dowarn; 446 tspec_t t1, t2; 447 arginf_t *ai, *ai1; 448 449 /* 450 * If a function definition is available (def != NULL), we compare the 451 * function call (call) with the definition. Otherwise, if a function 452 * definition is available and it is not an old-style definition (decl 453 * != NULL && TP(decl->s_type)->t_proto), we compare the call with this 454 * declaration. Otherwise we compare it with the first call we have 455 * found (call1). 456 */ 457 458 /* arg1 must be promoted if it stems from an old-style definition */ 459 promote = def != NULL && def->s_old_style_function; 460 461 /* 462 * If we compare with a definition or declaration, we must perform the 463 * same checks for qualifiers in indirected types as in assignments. 464 */ 465 asgn = def != NULL || (decl != NULL && TP(decl->s_type)->t_proto); 466 467 dowarn = false; 468 if (types_compatible(arg1, arg2, true, promote, asgn, &dowarn) && 469 (!sflag || !dowarn)) 470 return; 471 472 /*- 473 * Other lint implementations print warnings as soon as the type of an 474 * argument does not match exactly the expected type. The result are 475 * lots of warnings which are really not necessary. 476 * We print a warning only if 477 * (0) at least one type is not an integer type and types differ 478 * (1) hflag is set and types differ 479 * (2) types differ, except in signedness 480 * 481 * If the argument is an integer constant whose msb is not set, 482 * signedness is ignored (e.g. 0 matches both signed and unsigned int). 483 * This is with and without hflag. 484 * 485 * If the argument is an integer constant with value 0 and the expected 486 * argument is of type pointer and the width of the integer constant is 487 * the same as the width of the pointer, no warning is printed. 488 */ 489 t1 = arg1->t_tspec; 490 t2 = arg2->t_tspec; 491 if (is_integer(t1) && is_integer(t2) && 492 !arg1->t_is_enum && !arg2->t_is_enum) { 493 if (promote) { 494 /* 495 * XXX Here is a problem: Although it is possible to 496 * pass an int where a char/short it expected, there 497 * may be loss in significant digits. We should first 498 * check for const arguments if they can be converted 499 * into the original parameter type. 500 */ 501 if (t1 == FLOAT) { 502 t1 = DOUBLE; 503 } else if (t1 == CHAR || t1 == SCHAR) { 504 t1 = INT; 505 } else if (t1 == UCHAR) { 506 t1 = tflag ? UINT : INT; 507 } else if (t1 == SHORT) { 508 t1 = INT; 509 } else if (t1 == USHORT) { 510 t1 = INT_MAX < USHRT_MAX || tflag ? UINT : INT; 511 } 512 } 513 514 if (signed_type(t1) == signed_type(t2)) { 515 516 /* 517 * types differ only in signedness; get information 518 * about arguments 519 */ 520 521 /* 522 * treat a definition like a call with variable 523 * arguments 524 */ 525 ai1 = call1 != NULL ? call1->f_args : NULL; 526 527 /* 528 * if two calls are compared, ai1 is set to the 529 * information for the n-th argument, if this was a 530 * constant, otherwise to NULL 531 */ 532 for ( ; ai1 != NULL; ai1 = ai1->a_next) { 533 if (ai1->a_num == n) 534 break; 535 } 536 /* 537 * ai is set to the information of the n-th arg of the 538 * (second) call, if this was a constant, otherwise to 539 * NULL 540 */ 541 for (ai = call->f_args; ai != NULL; ai = ai->a_next) { 542 if (ai->a_num == n) 543 break; 544 } 545 546 if (ai1 == NULL && ai == NULL) { 547 /* no constant at all */ 548 if (!hflag) 549 return; 550 } else if (ai1 == NULL || ai == NULL) { 551 /* one constant */ 552 if (ai == NULL) 553 ai = ai1; 554 if (ai->a_zero || ai->a_pcon) 555 /* same value in signed and unsigned */ 556 return; 557 /* value (not representation) differently */ 558 } else { 559 /* 560 * two constants, one signed, one unsigned; if 561 * the msb of one of the constants is set, the 562 * argument is used inconsistently. 563 */ 564 if (!ai1->a_ncon && !ai->a_ncon) 565 return; 566 } 567 } 568 569 } else if (t1 == PTR && is_integer(t2)) { 570 for (ai = call->f_args; ai != NULL; ai = ai->a_next) { 571 if (ai->a_num == n) 572 break; 573 } 574 /* 575 * Vendor implementations of lint (e.g. HP-UX, Digital UNIX) 576 * don't care about the size of the integer argument, only 577 * whether or not it is zero. We do the same. 578 */ 579 if (ai != NULL && ai->a_zero) 580 return; 581 } 582 583 /* %s has argument %d with type '%s' at %s, versus '%s' at %s */ 584 msg(6, hte->h_name, n, type_name(arg1), mkpos(pos1p), 585 type_name(arg2), mkpos(&call->f_pos)); 586 } 587 588 /* 589 * Compare the types in the NULL-terminated array ap with the format 590 * string fmt. 591 */ 592 static void 593 printflike(const hte_t *hte, fcall_t *call, int n, const char *fmt, type_t **ap) 594 { 595 const char *fp; 596 char fc; 597 bool fwidth, prec, left, sign, space, alt, zero; 598 tspec_t sz, t1, t2 = NO_TSPEC; 599 type_t *tp; 600 601 fp = fmt; 602 fc = *fp++; 603 604 for (;;) { 605 if (fc == '\0') { 606 if (*ap != NULL) 607 too_many_arguments(hte, call); 608 break; 609 } 610 if (fc != '%') { 611 bad_format_string(hte, call); 612 break; 613 } 614 fc = *fp++; 615 fwidth = prec = left = sign = space = alt = zero = false; 616 sz = NO_TSPEC; 617 618 /* Flags */ 619 for (;;) { 620 if (fc == '-') { 621 if (left) 622 break; 623 left = true; 624 } else if (fc == '+') { 625 if (sign) 626 break; 627 sign = true; 628 } else if (fc == ' ') { 629 if (space) 630 break; 631 space = true; 632 } else if (fc == '#') { 633 if (alt) 634 break; 635 alt = true; 636 } else if (fc == '0') { 637 if (zero) 638 break; 639 zero = true; 640 } else { 641 break; 642 } 643 fc = *fp++; 644 } 645 646 /* field width */ 647 if (ch_isdigit(fc)) { 648 fwidth = true; 649 do { fc = *fp++; } while (ch_isdigit(fc)); 650 } else if (fc == '*') { 651 fwidth = true; 652 fc = *fp++; 653 if ((tp = *ap++) == NULL) { 654 too_few_arguments(hte, call); 655 break; 656 } 657 n++; 658 if ((t1 = tp->t_tspec) != INT && (hflag || t1 != UINT)) 659 inconsistent_arguments(hte, call, n); 660 } 661 662 /* precision */ 663 if (fc == '.') { 664 fc = *fp++; 665 prec = true; 666 if (ch_isdigit(fc)) { 667 do { 668 fc = *fp++; 669 } while (ch_isdigit(fc)); 670 } else if (fc == '*') { 671 fc = *fp++; 672 if ((tp = *ap++) == NULL) { 673 too_few_arguments(hte, call); 674 break; 675 } 676 n++; 677 if (tp->t_tspec != INT) 678 inconsistent_arguments(hte, call, n); 679 } else { 680 bad_format_string(hte, call); 681 break; 682 } 683 } 684 685 if (fc == 'h') { 686 sz = SHORT; 687 } else if (fc == 'l') { 688 sz = LONG; 689 } else if (fc == 'q') { 690 sz = LLONG; 691 } else if (fc == 'L') { 692 sz = LDOUBLE; 693 } 694 if (sz != NO_TSPEC) 695 fc = *fp++; 696 697 if (fc == '%') { 698 if (sz != NO_TSPEC || left || sign || space || 699 alt || zero || prec || fwidth) { 700 bad_format_string(hte, call); 701 } 702 fc = *fp++; 703 continue; 704 } 705 706 if (fc == '\0') { 707 bad_format_string(hte, call); 708 break; 709 } 710 711 if ((tp = *ap++) == NULL) { 712 too_few_arguments(hte, call); 713 break; 714 } 715 n++; 716 if ((t1 = tp->t_tspec) == PTR) 717 t2 = tp->t_subt->t_tspec; 718 719 if (fc == 'd' || fc == 'i') { 720 if (alt || sz == LDOUBLE) { 721 bad_format_string(hte, call); 722 break; 723 } 724 int_conv: 725 if (sz == LONG) { 726 if (t1 != LONG && (hflag || t1 != ULONG)) 727 inconsistent_arguments(hte, call, n); 728 } else if (sz == LLONG) { 729 if (t1 != LLONG && (hflag || t1 != ULLONG)) 730 inconsistent_arguments(hte, call, n); 731 } else { 732 /* 733 * SHORT is always promoted to INT, USHORT to 734 * INT or UINT. 735 */ 736 if (t1 != INT && (hflag || t1 != UINT)) 737 inconsistent_arguments(hte, call, n); 738 } 739 } else if (fc == 'o' || fc == 'u' || fc == 'x' || fc == 'X') { 740 if ((alt && fc == 'u') || sz == LDOUBLE) 741 bad_format_string(hte, call); 742 uint_conv: 743 if (sz == LONG) { 744 if (t1 != ULONG && (hflag || t1 != LONG)) 745 inconsistent_arguments(hte, call, n); 746 } else if (sz == LLONG) { 747 if (t1 != ULLONG && (hflag || t1 != LLONG)) 748 inconsistent_arguments(hte, call, n); 749 } else if (sz == SHORT) { 750 /* USHORT was promoted to INT or UINT */ 751 if (t1 != UINT && t1 != INT) 752 inconsistent_arguments(hte, call, n); 753 } else { 754 if (t1 != UINT && (hflag || t1 != INT)) 755 inconsistent_arguments(hte, call, n); 756 } 757 } else if (fc == 'D' || fc == 'O' || fc == 'U') { 758 if ((alt && fc != 'O') || sz != NO_TSPEC || !tflag) 759 bad_format_string(hte, call); 760 sz = LONG; 761 if (fc == 'D') { 762 goto int_conv; 763 } else { 764 goto uint_conv; 765 } 766 } else if (fc == 'f' || fc == 'e' || fc == 'E' || 767 fc == 'g' || fc == 'G') { 768 if (sz == NO_TSPEC) 769 sz = DOUBLE; 770 if (sz != DOUBLE && sz != LDOUBLE) 771 bad_format_string(hte, call); 772 if (t1 != sz) 773 inconsistent_arguments(hte, call, n); 774 } else if (fc == 'c') { 775 if (sz != NO_TSPEC || alt || zero) 776 bad_format_string(hte, call); 777 if (t1 != INT) 778 inconsistent_arguments(hte, call, n); 779 } else if (fc == 's') { 780 if (sz != NO_TSPEC || alt || zero) 781 bad_format_string(hte, call); 782 if (t1 != PTR || 783 (t2 != CHAR && t2 != UCHAR && t2 != SCHAR)) { 784 inconsistent_arguments(hte, call, n); 785 } 786 } else if (fc == 'p') { 787 if (fwidth || prec || sz != NO_TSPEC || alt || zero) 788 bad_format_string(hte, call); 789 if (t1 != PTR || (hflag && t2 != VOID)) 790 inconsistent_arguments(hte, call, n); 791 } else if (fc == 'n') { 792 if (fwidth || prec || alt || zero || sz == LDOUBLE) 793 bad_format_string(hte, call); 794 if (t1 != PTR) { 795 inconsistent_arguments(hte, call, n); 796 } else if (sz == LONG) { 797 if (t2 != LONG && t2 != ULONG) 798 inconsistent_arguments(hte, call, n); 799 } else if (sz == SHORT) { 800 if (t2 != SHORT && t2 != USHORT) 801 inconsistent_arguments(hte, call, n); 802 } else { 803 if (t2 != INT && t2 != UINT) 804 inconsistent_arguments(hte, call, n); 805 } 806 } else { 807 bad_format_string(hte, call); 808 break; 809 } 810 811 fc = *fp++; 812 } 813 } 814 815 /* 816 * Compare the types in the NULL-terminated array ap with the format 817 * string fmt. 818 */ 819 static void 820 scanflike(const hte_t *hte, fcall_t *call, int n, const char *fmt, type_t **ap) 821 { 822 const char *fp; 823 char fc; 824 bool noasgn, fwidth; 825 tspec_t sz, t1 = NO_TSPEC, t2 = NO_TSPEC; 826 type_t *tp = NULL; 827 828 fp = fmt; 829 fc = *fp++; 830 831 for (;;) { 832 if (fc == '\0') { 833 if (*ap != NULL) 834 too_many_arguments(hte, call); 835 break; 836 } 837 if (fc != '%') { 838 bad_format_string(hte, call); 839 break; 840 } 841 fc = *fp++; 842 843 noasgn = fwidth = false; 844 sz = NO_TSPEC; 845 846 if (fc == '*') { 847 noasgn = true; 848 fc = *fp++; 849 } 850 851 if (ch_isdigit(fc)) { 852 fwidth = true; 853 do { fc = *fp++; } while (ch_isdigit(fc)); 854 } 855 856 if (fc == 'h') { 857 sz = SHORT; 858 } else if (fc == 'l') { 859 sz = LONG; 860 } else if (fc == 'q') { 861 sz = LLONG; 862 } else if (fc == 'L') { 863 sz = LDOUBLE; 864 } 865 if (sz != NO_TSPEC) 866 fc = *fp++; 867 868 if (fc == '%') { 869 if (sz != NO_TSPEC || noasgn || fwidth) 870 bad_format_string(hte, call); 871 fc = *fp++; 872 continue; 873 } 874 875 if (!noasgn) { 876 if ((tp = *ap++) == NULL) { 877 too_few_arguments(hte, call); 878 break; 879 } 880 n++; 881 if ((t1 = tp->t_tspec) == PTR) 882 t2 = tp->t_subt->t_tspec; 883 } 884 885 if (fc == 'd' || fc == 'i' || fc == 'n') { 886 if (sz == LDOUBLE) 887 bad_format_string(hte, call); 888 if (sz != SHORT && sz != LONG && sz != LLONG) 889 sz = INT; 890 conv: 891 if (!noasgn) { 892 if (t1 != PTR) { 893 inconsistent_arguments(hte, call, n); 894 } else if (t2 != signed_type(sz)) { 895 inconsistent_arguments(hte, call, n); 896 } else if (hflag && t2 != sz) { 897 inconsistent_arguments(hte, call, n); 898 } else if (tp->t_subt->t_const) { 899 inconsistent_arguments(hte, call, n); 900 } 901 } 902 } else if (fc == 'o' || fc == 'u' || fc == 'x') { 903 if (sz == LDOUBLE) 904 bad_format_string(hte, call); 905 if (sz == SHORT) { 906 sz = USHORT; 907 } else if (sz == LONG) { 908 sz = ULONG; 909 } else if (sz == LLONG) { 910 sz = ULLONG; 911 } else { 912 sz = UINT; 913 } 914 goto conv; 915 } else if (fc == 'D') { 916 if (sz != NO_TSPEC || !tflag) 917 bad_format_string(hte, call); 918 sz = LONG; 919 goto conv; 920 } else if (fc == 'O') { 921 if (sz != NO_TSPEC || !tflag) 922 bad_format_string(hte, call); 923 sz = ULONG; 924 goto conv; 925 } else if (fc == 'X') { 926 /* 927 * XXX valid in C90, but in NetBSD's libc implemented 928 * as "lx". That's why it should be avoided. 929 */ 930 if (sz != NO_TSPEC || !tflag) 931 bad_format_string(hte, call); 932 sz = ULONG; 933 goto conv; 934 } else if (fc == 'E') { 935 /* 936 * XXX valid in C90, but in NetBSD's libc implemented 937 * as "lf". That's why it should be avoided. 938 */ 939 if (sz != NO_TSPEC || !tflag) 940 bad_format_string(hte, call); 941 sz = DOUBLE; 942 goto conv; 943 } else if (fc == 'F') { 944 /* XXX only for backward compatibility */ 945 if (sz != NO_TSPEC || !tflag) 946 bad_format_string(hte, call); 947 sz = DOUBLE; 948 goto conv; 949 } else if (fc == 'G') { 950 /* 951 * XXX valid in C90, but in NetBSD's libc not 952 * implemented 953 */ 954 if (sz != NO_TSPEC && sz != LONG && sz != LDOUBLE) 955 bad_format_string(hte, call); 956 goto fconv; 957 } else if (fc == 'e' || fc == 'f' || fc == 'g') { 958 fconv: 959 if (sz == NO_TSPEC) { 960 sz = FLOAT; 961 } else if (sz == LONG) { 962 sz = DOUBLE; 963 } else if (sz != LDOUBLE) { 964 bad_format_string(hte, call); 965 sz = FLOAT; 966 } 967 goto conv; 968 } else if (fc == 's' || fc == '[' || fc == 'c') { 969 if (sz != NO_TSPEC) 970 bad_format_string(hte, call); 971 if (fc == '[') { 972 if ((fc = *fp++) == '-') { 973 bad_format_string(hte, call); 974 fc = *fp++; 975 } 976 if (fc != ']') { 977 bad_format_string(hte, call); 978 if (fc == '\0') 979 break; 980 } 981 } 982 if (!noasgn) { 983 if (t1 != PTR) { 984 inconsistent_arguments(hte, call, n); 985 } else if (t2 != CHAR && t2 != UCHAR && 986 t2 != SCHAR) { 987 inconsistent_arguments(hte, call, n); 988 } 989 } 990 } else if (fc == 'p') { 991 if (sz != NO_TSPEC) 992 bad_format_string(hte, call); 993 if (!noasgn) { 994 if (t1 != PTR || t2 != PTR) { 995 inconsistent_arguments(hte, call, n); 996 } else if (tp->t_subt->t_subt->t_tspec!=VOID) { 997 if (hflag) 998 inconsistent_arguments(hte, call, n); 999 } 1000 } 1001 } else { 1002 bad_format_string(hte, call); 1003 break; 1004 } 1005 1006 fc = *fp++; 1007 } 1008 } 1009 1010 static void 1011 bad_format_string(const hte_t *hte, fcall_t *call) 1012 { 1013 1014 /* %s is called with a malformed format string in %s */ 1015 msg(13, hte->h_name, mkpos(&call->f_pos)); 1016 } 1017 1018 static void 1019 inconsistent_arguments(const hte_t *hte, fcall_t *call, int n) 1020 { 1021 1022 /* %s is called in %s with argument %d being incompatible with ... */ 1023 msg(14, hte->h_name, mkpos(&call->f_pos), n); 1024 } 1025 1026 static void 1027 too_few_arguments(const hte_t *hte, fcall_t *call) 1028 { 1029 1030 /* %s is called in %s with too few arguments for format string */ 1031 msg(15, hte->h_name, mkpos(&call->f_pos)); 1032 } 1033 1034 static void 1035 too_many_arguments(const hte_t *hte, fcall_t *call) 1036 { 1037 1038 /* %s is called in %s with too many arguments for format string */ 1039 msg(16, hte->h_name, mkpos(&call->f_pos)); 1040 } 1041 1042 /* 1043 * List of functions where we usually don't care about their result. 1044 * NB: Must be sorted. 1045 */ 1046 static const char ignorelist[][8] = { 1047 "memcpy", 1048 "memmove", 1049 "memset", 1050 "printf", 1051 "strcat", 1052 "strcpy", 1053 "vprintf", 1054 }; 1055 1056 /* 1057 * Print warnings for return values which are used but not returned, 1058 * or return values which are always or sometimes ignored. 1059 */ 1060 static void 1061 check_return_values(const hte_t *hte, sym_t *def) 1062 { 1063 fcall_t *call; 1064 bool used, ignored; 1065 1066 if (def == NULL) 1067 /* don't know whether or not the functions returns a value */ 1068 return; 1069 1070 if (hte->h_calls == NULL) 1071 return; 1072 1073 if (def->s_function_has_return_value) { 1074 /* 1075 * XXX as soon as we are able to disable single warnings, the 1076 * following dependencies from hflag should be removed. But for 1077 * now I don't want to be bothered by these warnings which are 1078 * almost always useless. 1079 */ 1080 if (!hflag) 1081 return; 1082 if (hflag && bsearch(hte->h_name, ignorelist, 1083 sizeof(ignorelist) / sizeof(ignorelist[0]), 1084 sizeof(ignorelist[0]), 1085 (int (*)(const void *, const void *))strcmp) != NULL) 1086 return; 1087 1088 /* function has return value */ 1089 used = ignored = false; 1090 for (call = hte->h_calls; call != NULL; call = call->f_next) { 1091 used |= call->f_rused || call->f_rdisc; 1092 ignored |= !call->f_rused && !call->f_rdisc; 1093 } 1094 if (!used && ignored) { 1095 /* %s returns a value that is always ignored */ 1096 msg(8, hte->h_name); 1097 } else if (used && ignored) { 1098 /* %s returns a value that is sometimes ignored */ 1099 msg(9, hte->h_name); 1100 } 1101 } else { 1102 /* function has no return value */ 1103 for (call = hte->h_calls; call != NULL; call = call->f_next) { 1104 if (call->f_rused) 1105 /* %s has its return value used in %s but doesn't return one */ 1106 msg(10, hte->h_name, mkpos(&call->f_pos)); 1107 } 1108 } 1109 } 1110 1111 /* 1112 * Print warnings for inconsistent argument declarations. 1113 */ 1114 static void 1115 check_argument_declarations(const hte_t *hte, sym_t *def, sym_t *decl) 1116 { 1117 bool osdef, eq, dowarn; 1118 int n; 1119 sym_t *sym1, *sym; 1120 type_t **ap1, **ap2, *tp1, *tp2; 1121 1122 osdef = false; 1123 if (def != NULL) { 1124 osdef = def->s_old_style_function; 1125 sym1 = def; 1126 } else if (decl != NULL && TP(decl->s_type)->t_proto) { 1127 sym1 = decl; 1128 } else { 1129 return; 1130 } 1131 if (TP(sym1->s_type)->t_tspec != FUNC) 1132 return; 1133 1134 /* 1135 * XXX Prototypes should also be compared with old-style function 1136 * declarations. 1137 */ 1138 1139 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 1140 if (sym == sym1 || !TP(sym->s_type)->t_proto) 1141 continue; 1142 ap1 = TP(sym1->s_type)->t_args; 1143 ap2 = TP(sym->s_type)->t_args; 1144 n = 0; 1145 while (*ap1 != NULL && *ap2 != NULL) { 1146 type_t *xt1, *xt2; 1147 dowarn = false; 1148 eq = types_compatible(xt1 = *ap1, xt2 = *ap2, 1149 true, osdef, false, &dowarn); 1150 if (!eq || dowarn) { 1151 /* %s has parameter %d declared as '%s' ... */ 1152 msg(11, hte->h_name, n + 1, 1153 type_name(xt1), mkpos(&sym1->s_pos), 1154 type_name(xt2), mkpos(&sym->s_pos)); 1155 } 1156 n++; 1157 ap1++; 1158 ap2++; 1159 } 1160 if (*ap1 == *ap2) { 1161 tp1 = TP(sym1->s_type); 1162 tp2 = TP(sym->s_type); 1163 if (tp1->t_vararg == tp2->t_vararg) 1164 continue; 1165 if (tp2->t_vararg && sym1->s_check_only_first_args && 1166 sym1->s_check_num_args == n && !sflag) { 1167 continue; 1168 } 1169 } 1170 /* %s has %d parameters in %s, versus %d in %s */ 1171 msg(12, hte->h_name, 1172 total_args(n, ap1), mkpos(&sym1->s_pos), 1173 total_args(n, ap2), mkpos(&sym->s_pos)); 1174 } 1175 } 1176 1177 1178 /* 1179 * Check compatibility of two types. Returns whether types are compatible. 1180 * 1181 * ignqual if set, ignore qualifiers of outermost type; used for 1182 * function arguments 1183 * promote if set, promote left type before comparison; used for 1184 * comparisons of arguments with parameters of old-style 1185 * definitions 1186 * asgn left indirected type must have at least the same qualifiers 1187 * like right indirected type (for assignments and function 1188 * arguments) 1189 * *dowarn set to true if an old-style declaration was compared with 1190 * an incompatible prototype declaration 1191 */ 1192 static bool 1193 types_compatible(type_t *tp1, type_t *tp2, 1194 bool ignqual, bool promot, bool asgn, bool *dowarn) 1195 { 1196 tspec_t t, to; 1197 int indir; 1198 1199 to = NO_TSPEC; 1200 indir = 0; 1201 1202 while (tp1 != NULL && tp2 != NULL) { 1203 1204 t = tp1->t_tspec; 1205 if (promot) { 1206 if (t == FLOAT) { 1207 t = DOUBLE; 1208 } else if (t == CHAR || t == SCHAR) { 1209 t = INT; 1210 } else if (t == UCHAR) { 1211 t = tflag ? UINT : INT; 1212 } else if (t == SHORT) { 1213 t = INT; 1214 } else if (t == USHORT) { 1215 t = INT_MAX < USHRT_MAX || tflag ? UINT : INT; 1216 } 1217 } 1218 1219 if (asgn && to == PTR) { 1220 if (indir == 1 && (t == VOID || tp2->t_tspec == VOID)) 1221 return true; 1222 } 1223 1224 if (t != tp2->t_tspec) { 1225 /* 1226 * Give pointer to types which differ only in 1227 * signedness a chance if not sflag and not hflag. 1228 */ 1229 if (sflag || hflag || to != PTR) 1230 return false; 1231 if (signed_type(t) != signed_type(tp2->t_tspec)) 1232 return false; 1233 } 1234 1235 if (tp1->t_is_enum && tp2->t_is_enum) { 1236 if (tp1->t_istag && tp2->t_istag) { 1237 return tp1->t_tag == tp2->t_tag; 1238 } else if (tp1->t_istynam && tp2->t_istynam) { 1239 return tp1->t_tynam == tp2->t_tynam; 1240 } else if (tp1->t_isuniqpos && tp2->t_isuniqpos) { 1241 return (tp1->t_uniqpos.p_line == 1242 tp2->t_uniqpos.p_line && 1243 tp1->t_uniqpos.p_file == 1244 tp2->t_uniqpos.p_file && 1245 tp1->t_uniqpos.p_uniq == 1246 tp2->t_uniqpos.p_uniq); 1247 } else { 1248 return false; 1249 } 1250 } 1251 1252 /* 1253 * XXX Handle combinations of enum and int if eflag is set. But 1254 * note: enum and 0 should be allowed. 1255 */ 1256 1257 if (asgn && indir == 1) { 1258 if (!tp1->t_const && tp2->t_const) 1259 return false; 1260 if (!tp1->t_volatile && tp2->t_volatile) 1261 return false; 1262 } else if (!ignqual && !tflag) { 1263 if (tp1->t_const != tp2->t_const) 1264 return false; 1265 if (tp1->t_const != tp2->t_const) 1266 return false; 1267 } 1268 1269 if (t == STRUCT || t == UNION) { 1270 if (tp1->t_istag && tp2->t_istag) { 1271 return tp1->t_tag == tp2->t_tag; 1272 } else if (tp1->t_istynam && tp2->t_istynam) { 1273 return tp1->t_tynam == tp2->t_tynam; 1274 } else if (tp1->t_isuniqpos && tp2->t_isuniqpos) { 1275 return (tp1->t_uniqpos.p_line == 1276 tp2->t_uniqpos.p_line && 1277 tp1->t_uniqpos.p_file == 1278 tp2->t_uniqpos.p_file && 1279 tp1->t_uniqpos.p_uniq == 1280 tp2->t_uniqpos.p_uniq); 1281 } else { 1282 return false; 1283 } 1284 } 1285 1286 if (t == ARRAY && tp1->t_dim != tp2->t_dim) { 1287 if (tp1->t_dim != 0 && tp2->t_dim != 0) 1288 return false; 1289 } 1290 1291 if (t == FUNC) { 1292 if (tp1->t_proto && tp2->t_proto) { 1293 if (!prototypes_compatible(tp1, tp2, dowarn)) 1294 return false; 1295 } else if (tp1->t_proto) { 1296 if (!matches_no_arg_function(tp1, dowarn)) 1297 return false; 1298 } else if (tp2->t_proto) { 1299 if (!matches_no_arg_function(tp2, dowarn)) 1300 return false; 1301 } 1302 } 1303 1304 tp1 = tp1->t_subt; 1305 tp2 = tp2->t_subt; 1306 ignqual = promot = false; 1307 to = t; 1308 indir++; 1309 } 1310 1311 return tp1 == tp2; 1312 } 1313 1314 /* 1315 * Compares arguments of two prototypes 1316 */ 1317 static bool 1318 prototypes_compatible(type_t *tp1, type_t *tp2, bool *dowarn) 1319 { 1320 type_t **a1, **a2; 1321 1322 if (tp1->t_vararg != tp2->t_vararg) 1323 return false; 1324 1325 a1 = tp1->t_args; 1326 a2 = tp2->t_args; 1327 1328 while (*a1 != NULL && *a2 != NULL) { 1329 1330 if (!types_compatible(*a1, *a2, true, false, false, dowarn)) 1331 return false; 1332 1333 a1++; 1334 a2++; 1335 } 1336 1337 return *a1 == *a2; 1338 } 1339 1340 /* 1341 * Returns whether all parameters of a prototype are compatible with an 1342 * old-style function declaration. 1343 * 1344 * This is the case if the following conditions are met: 1345 * 1. the prototype must have a fixed number of parameters 1346 * 2. no parameter is of type float 1347 * 3. no parameter is converted to another type if integer promotion 1348 * is applied on it 1349 */ 1350 static bool 1351 matches_no_arg_function(type_t *tp, bool *dowarn) 1352 { 1353 type_t **arg; 1354 tspec_t t; 1355 1356 if (tp->t_vararg && dowarn != NULL) 1357 *dowarn = true; 1358 for (arg = tp->t_args; *arg != NULL; arg++) { 1359 if ((t = (*arg)->t_tspec) == FLOAT) 1360 return false; 1361 if (t == CHAR || t == SCHAR || t == UCHAR) 1362 return false; 1363 if (t == SHORT || t == USHORT) 1364 return false; 1365 } 1366 return true; 1367 } 1368
Indexes created Tue Oct 14 21:09:58 GMT 2025