1 /* $NetBSD: chk.c,v 1.42 2021/04/02 12:16:50 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) && !defined(lint) 41 __RCSID("$NetBSD: chk.c,v 1.42 2021/04/02 12:16:50 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 chkund(hte_t *); 52 static void chkdnu(hte_t *); 53 static void chkdnud(hte_t *); 54 static void chkmd(hte_t *); 55 static void chkvtui(hte_t *, sym_t *, sym_t *); 56 static void chkvtdi(hte_t *, sym_t *, sym_t *); 57 static void chkfaui(hte_t *, sym_t *, sym_t *); 58 static void chkau(hte_t *, int, sym_t *, sym_t *, pos_t *, 59 fcall_t *, fcall_t *, type_t *, type_t *); 60 static void chkrvu(hte_t *, sym_t *); 61 static void chkadecl(hte_t *, sym_t *, sym_t *); 62 static void printflike(hte_t *,fcall_t *, int, const char *, type_t **); 63 static void scanflike(hte_t *, fcall_t *, int, const char *, type_t **); 64 static void badfmt(hte_t *, fcall_t *); 65 static void inconarg(hte_t *, fcall_t *, int); 66 static void tofewarg(hte_t *, fcall_t *); 67 static void tomanyarg(hte_t *, fcall_t *); 68 static bool eqtype(type_t *, type_t *, bool, bool, bool, bool *); 69 static bool eqargs(type_t *, type_t *, bool *); 70 static bool mnoarg(type_t *, bool *); 71 72 73 /* 74 * If there is a symbol named "main", mark it as used. 75 */ 76 void 77 mainused(void) 78 { 79 hte_t *hte; 80 81 if ((hte = hsearch("main", false)) != NULL) 82 hte->h_used = true; 83 } 84 85 /* 86 * Performs all tests for a single name 87 */ 88 void 89 chkname(hte_t *hte) 90 { 91 sym_t *sym, *def, *pdecl, *decl; 92 93 if (uflag) { 94 chkund(hte); 95 chkdnu(hte); 96 if (xflag) 97 chkdnud(hte); 98 } 99 chkmd(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 chkrvu(hte, def); 126 127 chkadecl(hte, def, decl); 128 } 129 130 /* 131 * Print a warning if the name has been used, but not defined. 132 */ 133 static void 134 chkund(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 used( %s ), but not defined */ 144 msg(0, hte->h_name, mkpos(&fcall->f_pos)); 145 } else if ((usym = hte->h_usyms) != NULL) { 146 /* %s used( %s ), but not 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 chkdnu(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 defined( %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 chkdnud(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: chkdnud() 1"); 189 /* %s declared( %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 chkmd(hte_t *hte) 199 { 200 sym_t *sym, *def1; 201 char *pos1; 202 203 if (!hte->h_def) 204 return; 205 206 def1 = NULL; 207 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 208 /* 209 * ANSI C allows tentative definitions of the same name in 210 * only one compilation unit. 211 */ 212 if (sym->s_def != DEF && (!sflag || sym->s_def != TDEF)) 213 continue; 214 if (sym->s_inline) 215 continue; 216 if (def1 == NULL) { 217 def1 = sym; 218 continue; 219 } 220 pos1 = xstrdup(mkpos(&def1->s_pos)); 221 /* %s multiply defined \t%s :: %s */ 222 msg(3, hte->h_name, pos1, mkpos(&sym->s_pos)); 223 free(pos1); 224 } 225 } 226 227 /* 228 * Print a warning if the return value assumed for a function call 229 * differs from the return value of the function definition or 230 * function declaration. 231 * 232 * If no definition/declaration can be found, the assumed return values 233 * are always int. So there is no need to compare with another function 234 * call as it's done for function arguments. 235 */ 236 static void 237 chkvtui(hte_t *hte, sym_t *def, sym_t *decl) 238 { 239 fcall_t *call; 240 char *pos1; 241 type_t *tp1, *tp2; 242 bool dowarn, eq; 243 tspec_t t1; 244 245 if (hte->h_calls == NULL) 246 return; 247 248 if (def == NULL) 249 def = decl; 250 if (def == NULL) 251 return; 252 253 t1 = (tp1 = TP(def->s_type)->t_subt)->t_tspec; 254 for (call = hte->h_calls; call != NULL; call = call->f_next) { 255 tp2 = TP(call->f_type)->t_subt; 256 eq = eqtype(tp1, tp2, 257 true, false, false, (dowarn = false, &dowarn)); 258 if (!call->f_rused) { 259 /* no return value used */ 260 if ((t1 == STRUCT || t1 == UNION) && !eq) { 261 /* 262 * If a function returns a struct or union it 263 * must be declared to return a struct or 264 * union, also if the return value is ignored. 265 * This is necessary because the caller must 266 * allocate stack space for the return value. 267 * If it does not, the return value would over- 268 * write other data. 269 * XXX Following massage may be confusing 270 * because it appears also if the return value 271 * was declared inconsistently. But this 272 * behavior matches pcc based lint, so it is 273 * accepted for now. 274 */ 275 pos1 = xstrdup(mkpos(&def->s_pos)); 276 /* %s function value must be declared ... */ 277 msg(17, hte->h_name, 278 pos1, mkpos(&call->f_pos)); 279 free(pos1); 280 } 281 continue; 282 } 283 if (!eq || (sflag && dowarn)) { 284 pos1 = xstrdup(mkpos(&def->s_pos)); 285 /* %s value used inconsistently \t%s :: %s */ 286 msg(4, hte->h_name, pos1, mkpos(&call->f_pos)); 287 free(pos1); 288 } 289 } 290 } 291 292 /* 293 * Print a warning if a definition/declaration does not match another 294 * definition/declaration of the same name. For functions, only the 295 * types of return values are tested. 296 */ 297 static void 298 chkvtdi(hte_t *hte, sym_t *def, sym_t *decl) 299 { 300 sym_t *sym; 301 type_t *tp1, *tp2; 302 bool eq, dowarn; 303 char *pos1; 304 305 if (def == NULL) 306 def = decl; 307 if (def == NULL) 308 return; 309 310 tp1 = TP(def->s_type); 311 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 312 type_t *xt1, *xt2; 313 if (sym == def) 314 continue; 315 tp2 = TP(sym->s_type); 316 dowarn = false; 317 if (tp1->t_tspec == FUNC && tp2->t_tspec == FUNC) { 318 eq = eqtype(xt1 = tp1->t_subt, xt2 = tp2->t_subt, 319 true, false, false, &dowarn); 320 } else { 321 eq = eqtype(xt1 = tp1, xt2 = tp2, 322 false, false, false, &dowarn); 323 } 324 if (!eq || (sflag && dowarn)) { 325 pos1 = xstrdup(mkpos(&def->s_pos)); 326 /* %s value declared inconsistently (%s != %s) \t... */ 327 msg(5, hte->h_name, type_name(xt1), type_name(xt2), 328 pos1, mkpos(&sym->s_pos)); 329 free(pos1); 330 } 331 } 332 } 333 334 /* 335 * Print a warning if a function is called with arguments which does 336 * not match the function definition, declaration or another call 337 * of the same function. 338 */ 339 static void 340 chkfaui(hte_t *hte, sym_t *def, sym_t *decl) 341 { 342 type_t *tp1, *tp2, **ap1, **ap2; 343 pos_t *pos1p = NULL; 344 fcall_t *calls, *call, *call1; 345 int n, as; 346 char *pos1; 347 arginf_t *ai; 348 349 if ((calls = hte->h_calls) == NULL) 350 return; 351 352 /* 353 * If we find a function definition, we use this for comparison, 354 * otherwise the first prototype we can find. If there is no 355 * definition or prototype declaration, the first function call 356 * is used. 357 */ 358 tp1 = NULL; 359 call1 = NULL; 360 if (def != NULL) { 361 if ((tp1 = TP(def->s_type))->t_tspec != FUNC) 362 return; 363 pos1p = &def->s_pos; 364 } else if (decl != NULL && TP(decl->s_type)->t_proto) { 365 if ((tp1 = TP(decl->s_type))->t_tspec != FUNC) 366 return; 367 pos1p = &decl->s_pos; 368 } 369 if (tp1 == NULL) { 370 call1 = calls; 371 calls = calls->f_next; 372 if ((tp1 = TP(call1->f_type))->t_tspec != FUNC) 373 return; 374 pos1p = &call1->f_pos; 375 } 376 377 n = 1; 378 for (call = calls; call != NULL; call = call->f_next) { 379 if ((tp2 = TP(call->f_type))->t_tspec != FUNC) 380 continue; 381 ap1 = tp1->t_args; 382 ap2 = tp2->t_args; 383 n = 0; 384 while (*ap1 != NULL && *ap2 != NULL) { 385 if (def != NULL && def->s_va && n >= def->s_nva) 386 break; 387 n++; 388 chkau(hte, n, def, decl, pos1p, call1, call, 389 *ap1, *ap2); 390 ap1++; 391 ap2++; 392 } 393 if (*ap1 == *ap2) { 394 /* equal # of arguments */ 395 } else if (def != NULL && def->s_va && n >= def->s_nva) { 396 /* 397 * function definition with VARARGS; The # of 398 * arguments of the call must be at least as large 399 * as the parameter of VARARGS. 400 */ 401 } else if (*ap2 != NULL && tp1->t_proto && tp1->t_vararg) { 402 /* 403 * prototype with ... and function call with 404 * at least the same # of arguments as declared 405 * in the prototype. 406 */ 407 } else { 408 pos1 = xstrdup(mkpos(pos1p)); 409 /* %s: variable # of args \t%s :: %s */ 410 msg(7, hte->h_name, pos1, mkpos(&call->f_pos)); 411 free(pos1); 412 continue; 413 } 414 415 /* perform SCANFLIKE/PRINTFLIKE tests */ 416 if (def == NULL || (!def->s_prfl && !def->s_scfl)) 417 continue; 418 as = def->s_prfl ? def->s_nprfl : def->s_nscfl; 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_prfl) { 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 */ 447 static void 448 chkau(hte_t *hte, int n, sym_t *def, sym_t *decl, pos_t *pos1p, 449 fcall_t *call1, fcall_t *call, type_t *arg1, type_t *arg2) 450 { 451 bool promote, asgn, dowarn; 452 tspec_t t1, t2; 453 arginf_t *ai, *ai1; 454 char *pos1; 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 460 * (decl != NULL && TP(decl->s_type)->t_proto), we compare the call 461 * with this declaration. Otherwise we compare it with the first 462 * call we have found (call1). 463 */ 464 465 /* arg1 must be promoted if it stems from an old style definition */ 466 promote = def != NULL && def->s_osdef; 467 468 /* 469 * If we compare with a definition or declaration, we must perform 470 * the same checks for qualifiers in indirected types as in 471 * assignments. 472 */ 473 asgn = def != NULL || (decl != NULL && TP(decl->s_type)->t_proto); 474 475 dowarn = false; 476 if (eqtype(arg1, arg2, true, promote, asgn, &dowarn) && 477 (!sflag || !dowarn)) 478 return; 479 480 /* 481 * Other lint implementations print warnings as soon as the type 482 * of an argument does not match exactly the expected type. The 483 * result are lots of warnings which are really not necessary. 484 * We print a warning only if 485 * (0) at least one type is not an integer type and types differ 486 * (1) hflag is set and types differ 487 * (2) types differ, except in signedness 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 490 * int). This is with and without hflag. 491 * If the argument is an integer constant with value 0 and the 492 * expected argument is of type pointer and the width of the 493 * integer constant is the same as the width of the pointer, 494 * 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 /* CONSTCOND */ 518 t1 = INT_MAX < USHRT_MAX || tflag ? UINT : INT; 519 } 520 } 521 522 if (signed_type(t1) == signed_type(t2)) { 523 524 /* 525 * types differ only in signedness; get information 526 * about arguments 527 */ 528 529 /* 530 * treat a definition like a call with variable 531 * arguments 532 */ 533 ai1 = call1 != NULL ? call1->f_args : NULL; 534 535 /* 536 * if two calls are compared, ai1 is set to the 537 * information for the n-th argument, if this was 538 * a constant, otherwise to NULL 539 */ 540 for ( ; ai1 != NULL; ai1 = ai1->a_next) { 541 if (ai1->a_num == n) 542 break; 543 } 544 /* 545 * ai is set to the information of the n-th arg 546 * of the (second) call, if this was a constant, 547 * otherwise to NULL 548 */ 549 for (ai = call->f_args; ai != NULL; ai = ai->a_next) { 550 if (ai->a_num == n) 551 break; 552 } 553 554 if (ai1 == NULL && ai == NULL) { 555 /* no constant at all */ 556 if (!hflag) 557 return; 558 } else if (ai1 == NULL || ai == NULL) { 559 /* one constant */ 560 if (ai == NULL) 561 ai = ai1; 562 if (ai->a_zero || ai->a_pcon) 563 /* same value in signed and unsigned */ 564 return; 565 /* value (not representation) differently */ 566 } else { 567 /* 568 * two constants, one signed, one unsigned; 569 * if the msb of one of the constants is set, 570 * the argument is used inconsistently. 571 */ 572 if (!ai1->a_ncon && !ai->a_ncon) 573 return; 574 } 575 } 576 577 } else if (t1 == PTR && is_integer(t2)) { 578 for (ai = call->f_args; ai != NULL; ai = ai->a_next) { 579 if (ai->a_num == n) 580 break; 581 } 582 /* 583 * Vendor implementations of lint (e.g. HP-UX, Digital UNIX) 584 * don't care about the size of the integer argument, 585 * only whether or not it is zero. We do the same. 586 */ 587 if (ai != NULL && ai->a_zero) 588 return; 589 } 590 591 pos1 = xstrdup(mkpos(pos1p)); 592 /* %s, arg %d used inconsistently \t%s[%s] :: %s[%s] */ 593 msg(6, hte->h_name, n, pos1, type_name(arg1), 594 mkpos(&call->f_pos), type_name(arg2)); 595 free(pos1); 596 } 597 598 /* 599 * Compare the types in the NULL-terminated array ap with the format 600 * string fmt. 601 */ 602 static void 603 printflike(hte_t *hte, fcall_t *call, int n, const char *fmt, type_t **ap) 604 { 605 const char *fp; 606 int fc; 607 bool fwidth, prec, left, sign, space, alt, zero; 608 tspec_t sz, t1, t2 = NOTSPEC; 609 type_t *tp; 610 611 fp = fmt; 612 fc = *fp++; 613 614 for (;;) { 615 if (fc == '\0') { 616 if (*ap != NULL) 617 tomanyarg(hte, call); 618 break; 619 } 620 if (fc != '%') { 621 badfmt(hte, call); 622 break; 623 } 624 fc = *fp++; 625 fwidth = prec = left = sign = space = alt = zero = false; 626 sz = NOTSPEC; 627 628 /* Flags */ 629 for (;;) { 630 if (fc == '-') { 631 if (left) 632 break; 633 left = true; 634 } else if (fc == '+') { 635 if (sign) 636 break; 637 sign = true; 638 } else if (fc == ' ') { 639 if (space) 640 break; 641 space = true; 642 } else if (fc == '#') { 643 if (alt) 644 break; 645 alt = true; 646 } else if (fc == '0') { 647 if (zero) 648 break; 649 zero = true; 650 } else { 651 break; 652 } 653 fc = *fp++; 654 } 655 656 /* field width */ 657 if (ch_isdigit(fc)) { 658 fwidth = true; 659 do { fc = *fp++; } while (ch_isdigit(fc)); 660 } else if (fc == '*') { 661 fwidth = true; 662 fc = *fp++; 663 if ((tp = *ap++) == NULL) { 664 tofewarg(hte, call); 665 break; 666 } 667 n++; 668 if ((t1 = tp->t_tspec) != INT && (hflag || t1 != UINT)) 669 inconarg(hte, call, n); 670 } 671 672 /* precision */ 673 if (fc == '.') { 674 fc = *fp++; 675 prec = true; 676 if (ch_isdigit(fc)) { 677 do { fc = *fp++; } while (ch_isdigit(fc)); 678 } else if (fc == '*') { 679 fc = *fp++; 680 if ((tp = *ap++) == NULL) { 681 tofewarg(hte, call); 682 break; 683 } 684 n++; 685 if (tp->t_tspec != INT) 686 inconarg(hte, call, n); 687 } else { 688 badfmt(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 = QUAD; 699 } else if (fc == 'L') { 700 sz = LDOUBLE; 701 } 702 if (sz != NOTSPEC) 703 fc = *fp++; 704 705 if (fc == '%') { 706 if (sz != NOTSPEC || left || sign || space || 707 alt || zero || prec || fwidth) { 708 badfmt(hte, call); 709 } 710 fc = *fp++; 711 continue; 712 } 713 714 if (fc == '\0') { 715 badfmt(hte, call); 716 break; 717 } 718 719 if ((tp = *ap++) == NULL) { 720 tofewarg(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 badfmt(hte, call); 730 break; 731 } 732 int_conv: 733 if (sz == LONG) { 734 if (t1 != LONG && (hflag || t1 != ULONG)) 735 inconarg(hte, call, n); 736 } else if (sz == QUAD) { 737 if (t1 != QUAD && (hflag || t1 != UQUAD)) 738 inconarg(hte, call, n); 739 } else { 740 /* 741 * SHORT is always promoted to INT, USHORT 742 * to INT or UINT. 743 */ 744 if (t1 != INT && (hflag || t1 != UINT)) 745 inconarg(hte, call, n); 746 } 747 } else if (fc == 'o' || fc == 'u' || fc == 'x' || fc == 'X') { 748 if ((alt && fc == 'u') || sz == LDOUBLE) 749 badfmt(hte, call); 750 uint_conv: 751 if (sz == LONG) { 752 if (t1 != ULONG && (hflag || t1 != LONG)) 753 inconarg(hte, call, n); 754 } else if (sz == QUAD) { 755 if (t1 != UQUAD && (hflag || t1 != QUAD)) 756 inconarg(hte, call, n); 757 } else if (sz == SHORT) { 758 /* USHORT was promoted to INT or UINT */ 759 if (t1 != UINT && t1 != INT) 760 inconarg(hte, call, n); 761 } else { 762 if (t1 != UINT && (hflag || t1 != INT)) 763 inconarg(hte, call, n); 764 } 765 } else if (fc == 'D' || fc == 'O' || fc == 'U') { 766 if ((alt && fc != 'O') || sz != NOTSPEC || !tflag) 767 badfmt(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 == NOTSPEC) 777 sz = DOUBLE; 778 if (sz != DOUBLE && sz != LDOUBLE) 779 badfmt(hte, call); 780 if (t1 != sz) 781 inconarg(hte, call, n); 782 } else if (fc == 'c') { 783 if (sz != NOTSPEC || alt || zero) 784 badfmt(hte, call); 785 if (t1 != INT) 786 inconarg(hte, call, n); 787 } else if (fc == 's') { 788 if (sz != NOTSPEC || alt || zero) 789 badfmt(hte, call); 790 if (t1 != PTR || 791 (t2 != CHAR && t2 != UCHAR && t2 != SCHAR)) { 792 inconarg(hte, call, n); 793 } 794 } else if (fc == 'p') { 795 if (fwidth || prec || sz != NOTSPEC || alt || zero) 796 badfmt(hte, call); 797 if (t1 != PTR || (hflag && t2 != VOID)) 798 inconarg(hte, call, n); 799 } else if (fc == 'n') { 800 if (fwidth || prec || alt || zero || sz == LDOUBLE) 801 badfmt(hte, call); 802 if (t1 != PTR) { 803 inconarg(hte, call, n); 804 } else if (sz == LONG) { 805 if (t2 != LONG && t2 != ULONG) 806 inconarg(hte, call, n); 807 } else if (sz == SHORT) { 808 if (t2 != SHORT && t2 != USHORT) 809 inconarg(hte, call, n); 810 } else { 811 if (t2 != INT && t2 != UINT) 812 inconarg(hte, call, n); 813 } 814 } else { 815 badfmt(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(hte_t *hte, fcall_t *call, int n, const char *fmt, type_t **ap) 829 { 830 const char *fp; 831 int fc; 832 bool noasgn, fwidth; 833 tspec_t sz, t1 = NOTSPEC, t2 = NOTSPEC; 834 type_t *tp = NULL; 835 836 fp = fmt; 837 fc = *fp++; 838 839 for (;;) { 840 if (fc == '\0') { 841 if (*ap != NULL) 842 tomanyarg(hte, call); 843 break; 844 } 845 if (fc != '%') { 846 badfmt(hte, call); 847 break; 848 } 849 fc = *fp++; 850 851 noasgn = fwidth = false; 852 sz = NOTSPEC; 853 854 if (fc == '*') { 855 noasgn = true; 856 fc = *fp++; 857 } 858 859 if (ch_isdigit(fc)) { 860 fwidth = true; 861 do { fc = *fp++; } while (ch_isdigit(fc)); 862 } 863 864 if (fc == 'h') { 865 sz = SHORT; 866 } else if (fc == 'l') { 867 sz = LONG; 868 } else if (fc == 'q') { 869 sz = QUAD; 870 } else if (fc == 'L') { 871 sz = LDOUBLE; 872 } 873 if (sz != NOTSPEC) 874 fc = *fp++; 875 876 if (fc == '%') { 877 if (sz != NOTSPEC || noasgn || fwidth) 878 badfmt(hte, call); 879 fc = *fp++; 880 continue; 881 } 882 883 if (!noasgn) { 884 if ((tp = *ap++) == NULL) { 885 tofewarg(hte, call); 886 break; 887 } 888 n++; 889 if ((t1 = tp->t_tspec) == PTR) 890 t2 = tp->t_subt->t_tspec; 891 } 892 893 if (fc == 'd' || fc == 'i' || fc == 'n') { 894 if (sz == LDOUBLE) 895 badfmt(hte, call); 896 if (sz != SHORT && sz != LONG && sz != QUAD) 897 sz = INT; 898 conv: 899 if (!noasgn) { 900 if (t1 != PTR) { 901 inconarg(hte, call, n); 902 } else if (t2 != signed_type(sz)) { 903 inconarg(hte, call, n); 904 } else if (hflag && t2 != sz) { 905 inconarg(hte, call, n); 906 } else if (tp->t_subt->t_const) { 907 inconarg(hte, call, n); 908 } 909 } 910 } else if (fc == 'o' || fc == 'u' || fc == 'x') { 911 if (sz == LDOUBLE) 912 badfmt(hte, call); 913 if (sz == SHORT) { 914 sz = USHORT; 915 } else if (sz == LONG) { 916 sz = ULONG; 917 } else if (sz == QUAD) { 918 sz = UQUAD; 919 } else { 920 sz = UINT; 921 } 922 goto conv; 923 } else if (fc == 'D') { 924 if (sz != NOTSPEC || !tflag) 925 badfmt(hte, call); 926 sz = LONG; 927 goto conv; 928 } else if (fc == 'O') { 929 if (sz != NOTSPEC || !tflag) 930 badfmt(hte, call); 931 sz = ULONG; 932 goto conv; 933 } else if (fc == 'X') { 934 /* 935 * XXX valid in ANSI C, but in NetBSD's libc imple- 936 * mented as "lx". That's why it should be avoided. 937 */ 938 if (sz != NOTSPEC || !tflag) 939 badfmt(hte, call); 940 sz = ULONG; 941 goto conv; 942 } else if (fc == 'E') { 943 /* 944 * XXX valid in ANSI C, but in NetBSD's libc imple- 945 * mented as "lf". That's why it should be avoided. 946 */ 947 if (sz != NOTSPEC || !tflag) 948 badfmt(hte, call); 949 sz = DOUBLE; 950 goto conv; 951 } else if (fc == 'F') { 952 /* XXX only for backward compatibility */ 953 if (sz != NOTSPEC || !tflag) 954 badfmt(hte, call); 955 sz = DOUBLE; 956 goto conv; 957 } else if (fc == 'G') { 958 /* 959 * XXX valid in ANSI C, but in NetBSD's libc not 960 * implemented 961 */ 962 if (sz != NOTSPEC && sz != LONG && sz != LDOUBLE) 963 badfmt(hte, call); 964 goto fconv; 965 } else if (fc == 'e' || fc == 'f' || fc == 'g') { 966 fconv: 967 if (sz == NOTSPEC) { 968 sz = FLOAT; 969 } else if (sz == LONG) { 970 sz = DOUBLE; 971 } else if (sz != LDOUBLE) { 972 badfmt(hte, call); 973 sz = FLOAT; 974 } 975 goto conv; 976 } else if (fc == 's' || fc == '[' || fc == 'c') { 977 if (sz != NOTSPEC) 978 badfmt(hte, call); 979 if (fc == '[') { 980 if ((fc = *fp++) == '-') { 981 badfmt(hte, call); 982 fc = *fp++; 983 } 984 if (fc != ']') { 985 badfmt(hte, call); 986 if (fc == '\0') 987 break; 988 } 989 } 990 if (!noasgn) { 991 if (t1 != PTR) { 992 inconarg(hte, call, n); 993 } else if (t2 != CHAR && t2 != UCHAR && 994 t2 != SCHAR) { 995 inconarg(hte, call, n); 996 } 997 } 998 } else if (fc == 'p') { 999 if (sz != NOTSPEC) 1000 badfmt(hte, call); 1001 if (!noasgn) { 1002 if (t1 != PTR || t2 != PTR) { 1003 inconarg(hte, call, n); 1004 } else if (tp->t_subt->t_subt->t_tspec!=VOID) { 1005 if (hflag) 1006 inconarg(hte, call, n); 1007 } 1008 } 1009 } else { 1010 badfmt(hte, call); 1011 break; 1012 } 1013 1014 fc = *fp++; 1015 } 1016 } 1017 1018 static void 1019 badfmt(hte_t *hte, fcall_t *call) 1020 { 1021 1022 /* %s: malformed format string \t%s */ 1023 msg(13, hte->h_name, mkpos(&call->f_pos)); 1024 } 1025 1026 static void 1027 inconarg(hte_t *hte, fcall_t *call, int n) 1028 { 1029 1030 /* %s, arg %d inconsistent with format \t%s */ 1031 msg(14, hte->h_name, n, mkpos(&call->f_pos)); 1032 } 1033 1034 static void 1035 tofewarg(hte_t *hte, fcall_t *call) 1036 { 1037 1038 /* %s: too few args for format \t%s */ 1039 msg(15, hte->h_name, mkpos(&call->f_pos)); 1040 } 1041 1042 static void 1043 tomanyarg(hte_t *hte, fcall_t *call) 1044 { 1045 1046 /* %s: too many args for format \t%s */ 1047 msg(16, hte->h_name, mkpos(&call->f_pos)); 1048 } 1049 1050 /* 1051 * List of functions where we usually don't care about their result. 1052 * NB: Must be sorted. 1053 */ 1054 static const char ignorelist[][8] = { 1055 "memcpy", 1056 "memmove", 1057 "memset", 1058 "printf", 1059 "strcat", 1060 "strcpy", 1061 "vprintf", 1062 }; 1063 1064 /* 1065 * Print warnings for return values which are used, but not returned, 1066 * or return values which are always or sometimes ignored. 1067 */ 1068 static void 1069 chkrvu(hte_t *hte, sym_t *def) 1070 { 1071 fcall_t *call; 1072 bool used, ignored; 1073 1074 if (def == NULL) 1075 /* don't know whether or not the functions returns a value */ 1076 return; 1077 1078 if (hte->h_calls == NULL) 1079 return; 1080 1081 if (def->s_rval) { 1082 /* 1083 * XXX as soon as we are able to disable single warnings 1084 * the following dependencies from hflag should be removed. 1085 * but for now I don't want to be bothered by this warnings 1086 * which are almost always useless. 1087 */ 1088 if (hflag == 0) 1089 return; 1090 if (hflag == 1 && bsearch(hte->h_name, ignorelist, 1091 __arraycount(ignorelist), sizeof(ignorelist[0]), 1092 (int (*)(const void *, const void *))strcmp) != NULL) 1093 return; 1094 1095 /* function has return value */ 1096 used = ignored = false; 1097 for (call = hte->h_calls; call != NULL; call = call->f_next) { 1098 used |= call->f_rused || call->f_rdisc; 1099 ignored |= !call->f_rused && !call->f_rdisc; 1100 } 1101 if (!used && ignored) { 1102 /* %s returns value which is always ignored */ 1103 msg(8, hte->h_name); 1104 } else if (used && ignored) { 1105 /* %s returns value which is sometimes ignored */ 1106 msg(9, hte->h_name); 1107 } 1108 } else { 1109 /* function has no return value */ 1110 for (call = hte->h_calls; call != NULL; call = call->f_next) { 1111 if (call->f_rused) 1112 /* %s value is used( %s ), but none returned */ 1113 msg(10, hte->h_name, mkpos(&call->f_pos)); 1114 } 1115 } 1116 } 1117 1118 /* 1119 * Print warnings for inconsistent argument declarations. 1120 */ 1121 static void 1122 chkadecl(hte_t *hte, sym_t *def, sym_t *decl) 1123 { 1124 bool osdef, eq, dowarn; 1125 int n; 1126 sym_t *sym1, *sym; 1127 type_t **ap1, **ap2, *tp1, *tp2; 1128 char *pos1; 1129 const char *pos2; 1130 1131 osdef = false; 1132 if (def != NULL) { 1133 osdef = def->s_osdef; 1134 sym1 = def; 1135 } else if (decl != NULL && TP(decl->s_type)->t_proto) { 1136 sym1 = decl; 1137 } else { 1138 return; 1139 } 1140 if (TP(sym1->s_type)->t_tspec != FUNC) 1141 return; 1142 1143 /* 1144 * XXX Prototypes should also be compared with old style function 1145 * declarations. 1146 */ 1147 1148 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 1149 if (sym == sym1 || !TP(sym->s_type)->t_proto) 1150 continue; 1151 ap1 = TP(sym1->s_type)->t_args; 1152 ap2 = TP(sym->s_type)->t_args; 1153 n = 0; 1154 while (*ap1 != NULL && *ap2 != NULL) { 1155 type_t *xt1, *xt2; 1156 dowarn = false; 1157 eq = eqtype(xt1 = *ap1, xt2 = *ap2, 1158 true, osdef, false, &dowarn); 1159 if (!eq || dowarn) { 1160 pos1 = xstrdup(mkpos(&sym1->s_pos)); 1161 pos2 = mkpos(&sym->s_pos); 1162 /* %s, arg %d declared inconsistently ... */ 1163 msg(11, hte->h_name, n + 1, 1164 type_name(xt1), type_name(xt2), pos1, pos2); 1165 free(pos1); 1166 } 1167 n++; 1168 ap1++; 1169 ap2++; 1170 } 1171 if (*ap1 == *ap2) { 1172 tp1 = TP(sym1->s_type); 1173 tp2 = TP(sym->s_type); 1174 if (tp1->t_vararg == tp2->t_vararg) 1175 continue; 1176 if (tp2->t_vararg && 1177 sym1->s_va && sym1->s_nva == n && !sflag) { 1178 continue; 1179 } 1180 } 1181 pos1 = xstrdup(mkpos(&sym1->s_pos)); 1182 /* %s: variable # of args declared \t%s :: %s */ 1183 msg(12, hte->h_name, pos1, mkpos(&sym->s_pos)); 1184 free(pos1); 1185 } 1186 } 1187 1188 1189 /* 1190 * Check compatibility of two types. Returns whether types are compatible. 1191 * 1192 * ignqual if set, ignore qualifiers of outermost type; used for 1193 * function arguments 1194 * promote if set, promote left type before comparison; used for 1195 * comparisons of arguments with parameters of old style 1196 * definitions 1197 * asgn left indirected type must have at least the same qualifiers 1198 * like right indirected type (for assignments and function 1199 * arguments) 1200 * *dowarn set to true if an old style declaration was compared with 1201 * an incompatible prototype declaration 1202 */ 1203 static bool 1204 eqtype(type_t *tp1, type_t *tp2, bool ignqual, bool promot, bool asgn, 1205 bool *dowarn) 1206 { 1207 tspec_t t, to; 1208 int indir; 1209 1210 to = NOTSPEC; 1211 indir = 0; 1212 1213 while (tp1 != NULL && tp2 != NULL) { 1214 1215 t = tp1->t_tspec; 1216 if (promot) { 1217 if (t == FLOAT) { 1218 t = DOUBLE; 1219 } else if (t == CHAR || t == SCHAR) { 1220 t = INT; 1221 } else if (t == UCHAR) { 1222 t = tflag ? UINT : INT; 1223 } else if (t == SHORT) { 1224 t = INT; 1225 } else if (t == USHORT) { 1226 /* CONSTCOND */ 1227 t = INT_MAX < USHRT_MAX || tflag ? UINT : INT; 1228 } 1229 } 1230 1231 if (asgn && to == PTR) { 1232 if (indir == 1 && (t == VOID || tp2->t_tspec == VOID)) 1233 return true; 1234 } 1235 1236 if (t != tp2->t_tspec) { 1237 /* 1238 * Give pointer to types which differ only in 1239 * signedness a chance if not sflag and not hflag. 1240 */ 1241 if (sflag || hflag || to != PTR) 1242 return false; 1243 if (signed_type(t) != signed_type(tp2->t_tspec)) 1244 return false; 1245 } 1246 1247 if (tp1->t_is_enum && tp2->t_is_enum) { 1248 if (tp1->t_istag && tp2->t_istag) { 1249 return tp1->t_tag == tp2->t_tag; 1250 } else if (tp1->t_istynam && tp2->t_istynam) { 1251 return tp1->t_tynam == tp2->t_tynam; 1252 } else if (tp1->t_isuniqpos && tp2->t_isuniqpos) { 1253 return (tp1->t_uniqpos.p_line == 1254 tp2->t_uniqpos.p_line && 1255 tp1->t_uniqpos.p_file == 1256 tp2->t_uniqpos.p_file && 1257 tp1->t_uniqpos.p_uniq == 1258 tp2->t_uniqpos.p_uniq); 1259 } else { 1260 return false; 1261 } 1262 } 1263 1264 /* 1265 * XXX Handle combinations of enum and int if eflag is set. 1266 * But note: enum and 0 should be allowed. 1267 */ 1268 1269 if (asgn && indir == 1) { 1270 if (!tp1->t_const && tp2->t_const) 1271 return false; 1272 if (!tp1->t_volatile && tp2->t_volatile) 1273 return false; 1274 } else if (!ignqual && !tflag) { 1275 if (tp1->t_const != tp2->t_const) 1276 return false; 1277 if (tp1->t_const != tp2->t_const) 1278 return false; 1279 } 1280 1281 if (t == STRUCT || t == UNION) { 1282 if (tp1->t_istag && tp2->t_istag) { 1283 return tp1->t_tag == tp2->t_tag; 1284 } else if (tp1->t_istynam && tp2->t_istynam) { 1285 return tp1->t_tynam == tp2->t_tynam; 1286 } else if (tp1->t_isuniqpos && tp2->t_isuniqpos) { 1287 return (tp1->t_uniqpos.p_line == 1288 tp2->t_uniqpos.p_line && 1289 tp1->t_uniqpos.p_file == 1290 tp2->t_uniqpos.p_file && 1291 tp1->t_uniqpos.p_uniq == 1292 tp2->t_uniqpos.p_uniq); 1293 } else { 1294 return false; 1295 } 1296 } 1297 1298 if (t == ARRAY && tp1->t_dim != tp2->t_dim) { 1299 if (tp1->t_dim != 0 && tp2->t_dim != 0) 1300 return false; 1301 } 1302 1303 if (t == FUNC) { 1304 if (tp1->t_proto && tp2->t_proto) { 1305 if (!eqargs(tp1, tp2, dowarn)) 1306 return false; 1307 } else if (tp1->t_proto) { 1308 if (!mnoarg(tp1, dowarn)) 1309 return false; 1310 } else if (tp2->t_proto) { 1311 if (!mnoarg(tp2, dowarn)) 1312 return false; 1313 } 1314 } 1315 1316 tp1 = tp1->t_subt; 1317 tp2 = tp2->t_subt; 1318 ignqual = promot = false; 1319 to = t; 1320 indir++; 1321 1322 } 1323 1324 return tp1 == tp2; 1325 } 1326 1327 /* 1328 * Compares arguments of two prototypes 1329 */ 1330 static bool 1331 eqargs(type_t *tp1, type_t *tp2, bool *dowarn) 1332 { 1333 type_t **a1, **a2; 1334 1335 if (tp1->t_vararg != tp2->t_vararg) 1336 return false; 1337 1338 a1 = tp1->t_args; 1339 a2 = tp2->t_args; 1340 1341 while (*a1 != NULL && *a2 != NULL) { 1342 1343 if (eqtype(*a1, *a2, true, false, false, dowarn) == 0) 1344 return false; 1345 1346 a1++; 1347 a2++; 1348 1349 } 1350 1351 return *a1 == *a2; 1352 } 1353 1354 /* 1355 * mnoarg() (matches functions with no argument type information) 1356 * returns true if all parameters of a prototype are compatible with 1357 * and old style function declaration. 1358 * This is the case if following conditions are met: 1359 * 1. the prototype must have a fixed number of parameters 1360 * 2. no parameter is of type float 1361 * 3. no parameter is converted to another type if integer promotion 1362 * is applied on it 1363 */ 1364 static bool 1365 mnoarg(type_t *tp, bool *dowarn) 1366 { 1367 type_t **arg; 1368 tspec_t t; 1369 1370 if (tp->t_vararg && dowarn != NULL) 1371 *dowarn = true; 1372 for (arg = tp->t_args; *arg != NULL; arg++) { 1373 if ((t = (*arg)->t_tspec) == FLOAT) 1374 return false; 1375 if (t == CHAR || t == SCHAR || t == UCHAR) 1376 return false; 1377 if (t == SHORT || t == USHORT) 1378 return false; 1379 } 1380 return true; 1381 } 1382