1/* $NetBSD: chk.c,v 1.67 2024/05/12 18:49:36 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 1.67 2024/05/12 18:49:36 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 51static void check_used_not_defined(const hte_t *); 52static void check_defined_not_used(const hte_t *); 53static void check_declared_not_used_or_defined(const hte_t *); 54static void check_multiple_definitions(const hte_t *); 55static void chkvtui(const hte_t *, sym_t *, sym_t *); 56static void chkvtdi(const hte_t *, sym_t *, sym_t *); 57static void chkfaui(const hte_t *, sym_t *, sym_t *); 58static void chkau(const hte_t *, int, sym_t *, sym_t *, pos_t *, 59 fcall_t *, fcall_t *, type_t *, type_t *); 60static void check_return_values(const hte_t *, sym_t *); 61static void check_argument_declarations(const hte_t *, sym_t *, sym_t *); 62static void printflike(const hte_t *, fcall_t *, int, const char *, type_t **); 63static void scanflike(const hte_t *, fcall_t *, int, const char *, type_t **); 64static void bad_format_string(const hte_t *, fcall_t *); 65static void inconsistent_arguments(const hte_t *, fcall_t *, int); 66static void too_few_arguments(const hte_t *, fcall_t *); 67static void too_many_arguments(const hte_t *, fcall_t *); 68static bool types_compatible(type_t *, type_t *, bool, bool, bool, bool *); 69static bool prototypes_compatible(type_t *, type_t *, bool *); 70static bool matches_no_arg_function(type_t *, bool *); 71 72 73/* 74 * If there is a symbol named "main", mark it as used. 75 */ 76void 77mark_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 */ 88void 89check_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 */ 133static void 134check_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 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 */ 154static void 155check_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 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 */ 175static void 176check_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 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 */ 197static void 198check_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 multiply defined \t%s :: %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 */ 233static void 234chkvtui(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, also 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 Following message may be confusing 267 * because it appears 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 function value must be declared ... */ 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 value used inconsistently \t%s :: %s */ 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 */ 291static void 292chkvtdi(const hte_t *hte, sym_t *def, sym_t *decl) 293{ 294 sym_t *sym; 295 type_t *tp1, *tp2; 296 bool eq, dowarn; 297 298 if (def == NULL) 299 def = decl; 300 if (def == NULL) 301 return; 302 303 tp1 = TP(def->s_type); 304 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 305 type_t *xt1, *xt2; 306 if (sym == def) 307 continue; 308 tp2 = TP(sym->s_type); 309 dowarn = false; 310 if (tp1->t_tspec == FUNC && tp2->t_tspec == FUNC) { 311 eq = types_compatible(xt1 = tp1->t_subt, 312 xt2 = tp2->t_subt, true, false, false, &dowarn); 313 } else { 314 eq = types_compatible(xt1 = tp1, xt2 = tp2, 315 false, false, false, &dowarn); 316 } 317 if (!eq || (sflag && dowarn)) { 318 /* %s value declared inconsistently (%s != %s) \t... */ 319 msg(5, hte->h_name, type_name(xt1), type_name(xt2), 320 mkpos(&def->s_pos), mkpos(&sym->s_pos)); 321 } 322 } 323} 324 325/* 326 * Print a warning if a function is called with arguments which does 327 * not match the function definition, declaration or another call 328 * of the same function. 329 */ 330static void 331chkfaui(const hte_t *hte, sym_t *def, sym_t *decl) 332{ 333 type_t *tp1, *tp2, **ap1, **ap2; 334 pos_t *pos1p = NULL; 335 fcall_t *calls, *call, *call1; 336 int n, as; 337 arginf_t *ai; 338 339 if ((calls = hte->h_calls) == NULL) 340 return; 341 342 /* 343 * If we find a function definition, we use this for comparison, 344 * otherwise the first prototype we can find. If there is no definition 345 * or prototype declaration, the first function call is used. 346 */ 347 tp1 = NULL; 348 call1 = NULL; 349 if (def != NULL) { 350 if ((tp1 = TP(def->s_type))->t_tspec != FUNC) 351 return; 352 pos1p = &def->s_pos; 353 } else if (decl != NULL && TP(decl->s_type)->t_proto) { 354 if ((tp1 = TP(decl->s_type))->t_tspec != FUNC) 355 return; 356 pos1p = &decl->s_pos; 357 } 358 if (tp1 == NULL) { 359 call1 = calls; 360 calls = calls->f_next; 361 if ((tp1 = TP(call1->f_type))->t_tspec != FUNC) 362 return; 363 pos1p = &call1->f_pos; 364 } 365 366 n = 1; 367 for (call = calls; call != NULL; call = call->f_next) { 368 if ((tp2 = TP(call->f_type))->t_tspec != FUNC) 369 continue; 370 ap1 = tp1->t_args; 371 ap2 = tp2->t_args; 372 n = 0; 373 while (*ap1 != NULL && *ap2 != NULL) { 374 if (def != NULL && def->s_check_only_first_args && 375 n >= def->s_check_num_args) 376 break; 377 n++; 378 chkau(hte, n, def, decl, pos1p, call1, call, 379 *ap1, *ap2); 380 ap1++; 381 ap2++; 382 } 383 if (*ap1 == *ap2) { 384 /* equal # of arguments */ 385 } else if (def != NULL && def->s_check_only_first_args && 386 n >= def->s_check_num_args) { 387 /* 388 * function definition with VARARGS; The # of arguments 389 * of the call must be at least as large as the 390 * parameter of VARARGS. 391 */ 392 } else if (*ap2 != NULL && tp1->t_proto && tp1->t_vararg) { 393 /* 394 * prototype with ... and function call with at least 395 * the same # of arguments as declared in the 396 * prototype. 397 */ 398 } else { 399 /* %s: variable # of args \t%s :: %s */ 400 msg(7, hte->h_name, mkpos(pos1p), mkpos(&call->f_pos)); 401 continue; 402 } 403 404 /* perform SCANFLIKE/PRINTFLIKE tests */ 405 if (def == NULL || (!def->s_printflike && !def->s_scanflike)) 406 continue; 407 as = def->s_printflike 408 ? def->s_printflike_arg 409 : def->s_scanflike_arg; 410 for (ai = call->f_args; ai != NULL; ai = ai->a_next) { 411 if (ai->a_num == as) 412 break; 413 } 414 if (ai == NULL || !ai->a_fmt) 415 continue; 416 if (def->s_printflike) { 417 printflike(hte, call, n, ai->a_fstrg, ap2); 418 } else { 419 scanflike(hte, call, n, ai->a_fstrg, ap2); 420 } 421 } 422} 423 424/* 425 * Check a single argument in a function call. 426 * 427 * hte a pointer to the hash table entry of the function 428 * n the number of the argument (1..) 429 * def the function definition or NULL 430 * decl prototype declaration, old-style declaration or NULL 431 * pos1p position of definition, declaration of first call 432 * call1 first call, if both def and decl are old-style def/decl 433 * call checked call 434 * arg1 currently checked argument of def/decl/call1 435 * arg2 currently checked argument of call 436 * 437 */ 438static void 439chkau(const hte_t *hte, int n, sym_t *def, sym_t *decl, pos_t *pos1p, 440 fcall_t *call1, fcall_t *call, type_t *arg1, type_t *arg2) 441{ 442 bool promote, asgn, dowarn; 443 tspec_t t1, t2; 444 arginf_t *ai, *ai1; 445 446 /* 447 * If a function definition is available (def != NULL), we compare the 448 * function call (call) with the definition. Otherwise, if a function 449 * definition is available and it is not an old-style definition (decl 450 * != NULL && TP(decl->s_type)->t_proto), we compare the call with this 451 * declaration. Otherwise we compare it with the first call we have 452 * found (call1). 453 */ 454 455 /* arg1 must be promoted if it stems from an old-style definition */ 456 promote = def != NULL && def->s_old_style_function; 457 458 /* 459 * If we compare with a definition or declaration, we must perform the 460 * same checks for qualifiers in indirected types as in assignments. 461 */ 462 asgn = def != NULL || (decl != NULL && TP(decl->s_type)->t_proto); 463 464 dowarn = false; 465 if (types_compatible(arg1, arg2, true, promote, asgn, &dowarn) && 466 (!sflag || !dowarn)) 467 return; 468 469 /*- 470 * Other lint implementations print warnings as soon as the type of an 471 * argument does not match exactly the expected type. The result are 472 * lots of warnings which are really not necessary. 473 * We print a warning only if 474 * (0) at least one type is not an integer type and types differ 475 * (1) hflag is set and types differ 476 * (2) types differ, except in signedness 477 * 478 * If the argument is an integer constant whose msb is not set, 479 * signedness is ignored (e.g. 0 matches both signed and unsigned int). 480 * This is with and without hflag. 481 * 482 * If the argument is an integer constant with value 0 and the expected 483 * argument is of type pointer and the width of the integer constant is 484 * the same as the width of the pointer, no warning is printed. 485 */ 486 t1 = arg1->t_tspec; 487 t2 = arg2->t_tspec; 488 if (is_integer(t1) && is_integer(t2) && 489 !arg1->t_is_enum && !arg2->t_is_enum) { 490 if (promote) { 491 /* 492 * XXX Here is a problem: Although it is possible to 493 * pass an int where a char/short it expected, there 494 * may be loss in significant digits. We should first 495 * check for const arguments if they can be converted 496 * into the original parameter type. 497 */ 498 if (t1 == FLOAT) { 499 t1 = DOUBLE; 500 } else if (t1 == CHAR || t1 == SCHAR) { 501 t1 = INT; 502 } else if (t1 == UCHAR) { 503 t1 = tflag ? UINT : INT; 504 } else if (t1 == SHORT) { 505 t1 = INT; 506 } else if (t1 == USHORT) { 507 /* CONSTCOND */ 508 t1 = INT_MAX < USHRT_MAX || tflag ? UINT : INT; 509 } 510 } 511 512 if (signed_type(t1) == signed_type(t2)) { 513 514 /* 515 * types differ only in signedness; get information 516 * about arguments 517 */ 518 519 /* 520 * treat a definition like a call with variable 521 * arguments 522 */ 523 ai1 = call1 != NULL ? call1->f_args : NULL; 524 525 /* 526 * if two calls are compared, ai1 is set to the 527 * information for the n-th argument, if this was a 528 * constant, otherwise to NULL 529 */ 530 for ( ; ai1 != NULL; ai1 = ai1->a_next) { 531 if (ai1->a_num == n) 532 break; 533 } 534 /* 535 * ai is set to the information of the n-th arg of the 536 * (second) call, if this was a constant, otherwise to 537 * NULL 538 */ 539 for (ai = call->f_args; ai != NULL; ai = ai->a_next) { 540 if (ai->a_num == n) 541 break; 542 } 543 544 if (ai1 == NULL && ai == NULL) { 545 /* no constant at all */ 546 if (!hflag) 547 return; 548 } else if (ai1 == NULL || ai == NULL) { 549 /* one constant */ 550 if (ai == NULL) 551 ai = ai1; 552 if (ai->a_zero || ai->a_pcon) 553 /* same value in signed and unsigned */ 554 return; 555 /* value (not representation) differently */ 556 } else { 557 /* 558 * two constants, one signed, one unsigned; if 559 * the msb of one of the constants is set, the 560 * argument is used inconsistently. 561 */ 562 if (!ai1->a_ncon && !ai->a_ncon) 563 return; 564 } 565 } 566 567 } else if (t1 == PTR && is_integer(t2)) { 568 for (ai = call->f_args; ai != NULL; ai = ai->a_next) { 569 if (ai->a_num == n) 570 break; 571 } 572 /* 573 * Vendor implementations of lint (e.g. HP-UX, Digital UNIX) 574 * don't care about the size of the integer argument, only 575 * whether or not it is zero. We do the same. 576 */ 577 if (ai != NULL && ai->a_zero) 578 return; 579 } 580 581 /* %s, arg %d used inconsistently \t%s[%s] :: %s[%s] */ 582 msg(6, hte->h_name, n, mkpos(pos1p), type_name(arg1), 583 mkpos(&call->f_pos), type_name(arg2)); 584} 585 586/* 587 * Compare the types in the NULL-terminated array ap with the format 588 * string fmt. 589 */ 590static void 591printflike(const hte_t *hte, fcall_t *call, int n, const char *fmt, type_t **ap) 592{ 593 const char *fp; 594 char fc; 595 bool fwidth, prec, left, sign, space, alt, zero; 596 tspec_t sz, t1, t2 = NO_TSPEC; 597 type_t *tp; 598 599 fp = fmt; 600 fc = *fp++; 601 602 for (;;) { 603 if (fc == '\0') { 604 if (*ap != NULL) 605 too_many_arguments(hte, call); 606 break; 607 } 608 if (fc != '%') { 609 bad_format_string(hte, call); 610 break; 611 } 612 fc = *fp++; 613 fwidth = prec = left = sign = space = alt = zero = false; 614 sz = NO_TSPEC; 615 616 /* Flags */ 617 for (;;) { 618 if (fc == '-') { 619 if (left) 620 break; 621 left = true; 622 } else if (fc == '+') { 623 if (sign) 624 break; 625 sign = true; 626 } else if (fc == ' ') { 627 if (space) 628 break; 629 space = true; 630 } else if (fc == '#') { 631 if (alt) 632 break; 633 alt = true; 634 } else if (fc == '0') { 635 if (zero) 636 break; 637 zero = true; 638 } else { 639 break; 640 } 641 fc = *fp++; 642 } 643 644 /* field width */ 645 if (ch_isdigit(fc)) { 646 fwidth = true; 647 do { fc = *fp++; } while (ch_isdigit(fc)); 648 } else if (fc == '*') { 649 fwidth = true; 650 fc = *fp++; 651 if ((tp = *ap++) == NULL) { 652 too_few_arguments(hte, call); 653 break; 654 } 655 n++; 656 if ((t1 = tp->t_tspec) != INT && (hflag || t1 != UINT)) 657 inconsistent_arguments(hte, call, n); 658 } 659 660 /* precision */ 661 if (fc == '.') { 662 fc = *fp++; 663 prec = true; 664 if (ch_isdigit(fc)) { 665 do { 666 fc = *fp++; 667 } while (ch_isdigit(fc)); 668 } else if (fc == '*') { 669 fc = *fp++; 670 if ((tp = *ap++) == NULL) { 671 too_few_arguments(hte, call); 672 break; 673 } 674 n++; 675 if (tp->t_tspec != INT) 676 inconsistent_arguments(hte, call, n); 677 } else { 678 bad_format_string(hte, call); 679 break; 680 } 681 } 682 683 if (fc == 'h') { 684 sz = SHORT; 685 } else if (fc == 'l') { 686 sz = LONG; 687 } else if (fc == 'q') { 688 sz = LLONG; 689 } else if (fc == 'L') { 690 sz = LDOUBLE; 691 } 692 if (sz != NO_TSPEC) 693 fc = *fp++; 694 695 if (fc == '%') { 696 if (sz != NO_TSPEC || left || sign || space || 697 alt || zero || prec || fwidth) { 698 bad_format_string(hte, call); 699 } 700 fc = *fp++; 701 continue; 702 } 703 704 if (fc == '\0') { 705 bad_format_string(hte, call); 706 break; 707 } 708 709 if ((tp = *ap++) == NULL) { 710 too_few_arguments(hte, call); 711 break; 712 } 713 n++; 714 if ((t1 = tp->t_tspec) == PTR) 715 t2 = tp->t_subt->t_tspec; 716 717 if (fc == 'd' || fc == 'i') { 718 if (alt || sz == LDOUBLE) { 719 bad_format_string(hte, call); 720 break; 721 } 722 int_conv: 723 if (sz == LONG) { 724 if (t1 != LONG && (hflag || t1 != ULONG)) 725 inconsistent_arguments(hte, call, n); 726 } else if (sz == LLONG) { 727 if (t1 != LLONG && (hflag || t1 != ULLONG)) 728 inconsistent_arguments(hte, call, n); 729 } else { 730 /* 731 * SHORT is always promoted to INT, USHORT to 732 * INT or UINT. 733 */ 734 if (t1 != INT && (hflag || t1 != UINT)) 735 inconsistent_arguments(hte, call, n); 736 } 737 } else if (fc == 'o' || fc == 'u' || fc == 'x' || fc == 'X') { 738 if ((alt && fc == 'u') || sz == LDOUBLE) 739 bad_format_string(hte, call); 740 uint_conv: 741 if (sz == LONG) { 742 if (t1 != ULONG && (hflag || t1 != LONG)) 743 inconsistent_arguments(hte, call, n); 744 } else if (sz == LLONG) { 745 if (t1 != ULLONG && (hflag || t1 != LLONG)) 746 inconsistent_arguments(hte, call, n); 747 } else if (sz == SHORT) { 748 /* USHORT was promoted to INT or UINT */ 749 if (t1 != UINT && t1 != INT) 750 inconsistent_arguments(hte, call, n); 751 } else { 752 if (t1 != UINT && (hflag || t1 != INT)) 753 inconsistent_arguments(hte, call, n); 754 } 755 } else if (fc == 'D' || fc == 'O' || fc == 'U') { 756 if ((alt && fc != 'O') || sz != NO_TSPEC || !tflag) 757 bad_format_string(hte, call); 758 sz = LONG; 759 if (fc == 'D') { 760 goto int_conv; 761 } else { 762 goto uint_conv; 763 } 764 } else if (fc == 'f' || fc == 'e' || fc == 'E' || 765 fc == 'g' || fc == 'G') { 766 if (sz == NO_TSPEC) 767 sz = DOUBLE; 768 if (sz != DOUBLE && sz != LDOUBLE) 769 bad_format_string(hte, call); 770 if (t1 != sz) 771 inconsistent_arguments(hte, call, n); 772 } else if (fc == 'c') { 773 if (sz != NO_TSPEC || alt || zero) 774 bad_format_string(hte, call); 775 if (t1 != INT) 776 inconsistent_arguments(hte, call, n); 777 } else if (fc == 's') { 778 if (sz != NO_TSPEC || alt || zero) 779 bad_format_string(hte, call); 780 if (t1 != PTR || 781 (t2 != CHAR && t2 != UCHAR && t2 != SCHAR)) { 782 inconsistent_arguments(hte, call, n); 783 } 784 } else if (fc == 'p') { 785 if (fwidth || prec || sz != NO_TSPEC || alt || zero) 786 bad_format_string(hte, call); 787 if (t1 != PTR || (hflag && t2 != VOID)) 788 inconsistent_arguments(hte, call, n); 789 } else if (fc == 'n') { 790 if (fwidth || prec || alt || zero || sz == LDOUBLE) 791 bad_format_string(hte, call); 792 if (t1 != PTR) { 793 inconsistent_arguments(hte, call, n); 794 } else if (sz == LONG) { 795 if (t2 != LONG && t2 != ULONG) 796 inconsistent_arguments(hte, call, n); 797 } else if (sz == SHORT) { 798 if (t2 != SHORT && t2 != USHORT) 799 inconsistent_arguments(hte, call, n); 800 } else { 801 if (t2 != INT && t2 != UINT) 802 inconsistent_arguments(hte, call, n); 803 } 804 } else { 805 bad_format_string(hte, call); 806 break; 807 } 808 809 fc = *fp++; 810 } 811} 812 813/* 814 * Compare the types in the NULL-terminated array ap with the format 815 * string fmt. 816 */ 817static void 818scanflike(const hte_t *hte, fcall_t *call, int n, const char *fmt, type_t **ap) 819{ 820 const char *fp; 821 char fc; 822 bool noasgn, fwidth; 823 tspec_t sz, t1 = NO_TSPEC, t2 = NO_TSPEC; 824 type_t *tp = NULL; 825 826 fp = fmt; 827 fc = *fp++; 828 829 for (;;) { 830 if (fc == '\0') { 831 if (*ap != NULL) 832 too_many_arguments(hte, call); 833 break; 834 } 835 if (fc != '%') { 836 bad_format_string(hte, call); 837 break; 838 } 839 fc = *fp++; 840 841 noasgn = fwidth = false; 842 sz = NO_TSPEC; 843 844 if (fc == '*') { 845 noasgn = true; 846 fc = *fp++; 847 } 848 849 if (ch_isdigit(fc)) { 850 fwidth = true; 851 do { fc = *fp++; } while (ch_isdigit(fc)); 852 } 853 854 if (fc == 'h') { 855 sz = SHORT; 856 } else if (fc == 'l') { 857 sz = LONG; 858 } else if (fc == 'q') { 859 sz = LLONG; 860 } else if (fc == 'L') { 861 sz = LDOUBLE; 862 } 863 if (sz != NO_TSPEC) 864 fc = *fp++; 865 866 if (fc == '%') { 867 if (sz != NO_TSPEC || noasgn || fwidth) 868 bad_format_string(hte, call); 869 fc = *fp++; 870 continue; 871 } 872 873 if (!noasgn) { 874 if ((tp = *ap++) == NULL) { 875 too_few_arguments(hte, call); 876 break; 877 } 878 n++; 879 if ((t1 = tp->t_tspec) == PTR) 880 t2 = tp->t_subt->t_tspec; 881 } 882 883 if (fc == 'd' || fc == 'i' || fc == 'n') { 884 if (sz == LDOUBLE) 885 bad_format_string(hte, call); 886 if (sz != SHORT && sz != LONG && sz != LLONG) 887 sz = INT; 888 conv: 889 if (!noasgn) { 890 if (t1 != PTR) { 891 inconsistent_arguments(hte, call, n); 892 } else if (t2 != signed_type(sz)) { 893 inconsistent_arguments(hte, call, n); 894 } else if (hflag && t2 != sz) { 895 inconsistent_arguments(hte, call, n); 896 } else if (tp->t_subt->t_const) { 897 inconsistent_arguments(hte, call, n); 898 } 899 } 900 } else if (fc == 'o' || fc == 'u' || fc == 'x') { 901 if (sz == LDOUBLE) 902 bad_format_string(hte, call); 903 if (sz == SHORT) { 904 sz = USHORT; 905 } else if (sz == LONG) { 906 sz = ULONG; 907 } else if (sz == LLONG) { 908 sz = ULLONG; 909 } else { 910 sz = UINT; 911 } 912 goto conv; 913 } else if (fc == 'D') { 914 if (sz != NO_TSPEC || !tflag) 915 bad_format_string(hte, call); 916 sz = LONG; 917 goto conv; 918 } else if (fc == 'O') { 919 if (sz != NO_TSPEC || !tflag) 920 bad_format_string(hte, call); 921 sz = ULONG; 922 goto conv; 923 } else if (fc == 'X') { 924 /* 925 * XXX valid in C90, but in NetBSD's libc implemented 926 * as "lx". That's why it should be avoided. 927 */ 928 if (sz != NO_TSPEC || !tflag) 929 bad_format_string(hte, call); 930 sz = ULONG; 931 goto conv; 932 } else if (fc == 'E') { 933 /* 934 * XXX valid in C90, but in NetBSD's libc implemented 935 * as "lf". That's why it should be avoided. 936 */ 937 if (sz != NO_TSPEC || !tflag) 938 bad_format_string(hte, call); 939 sz = DOUBLE; 940 goto conv; 941 } else if (fc == 'F') { 942 /* XXX only for backward compatibility */ 943 if (sz != NO_TSPEC || !tflag) 944 bad_format_string(hte, call); 945 sz = DOUBLE; 946 goto conv; 947 } else if (fc == 'G') { 948 /* 949 * XXX valid in C90, but in NetBSD's libc not 950 * implemented 951 */ 952 if (sz != NO_TSPEC && sz != LONG && sz != LDOUBLE) 953 bad_format_string(hte, call); 954 goto fconv; 955 } else if (fc == 'e' || fc == 'f' || fc == 'g') { 956 fconv: 957 if (sz == NO_TSPEC) { 958 sz = FLOAT; 959 } else if (sz == LONG) { 960 sz = DOUBLE; 961 } else if (sz != LDOUBLE) { 962 bad_format_string(hte, call); 963 sz = FLOAT; 964 } 965 goto conv; 966 } else if (fc == 's' || fc == '[' || fc == 'c') { 967 if (sz != NO_TSPEC) 968 bad_format_string(hte, call); 969 if (fc == '[') { 970 if ((fc = *fp++) == '-') { 971 bad_format_string(hte, call); 972 fc = *fp++; 973 } 974 if (fc != ']') { 975 bad_format_string(hte, call); 976 if (fc == '\0') 977 break; 978 } 979 } 980 if (!noasgn) { 981 if (t1 != PTR) { 982 inconsistent_arguments(hte, call, n); 983 } else if (t2 != CHAR && t2 != UCHAR && 984 t2 != SCHAR) { 985 inconsistent_arguments(hte, call, n); 986 } 987 } 988 } else if (fc == 'p') { 989 if (sz != NO_TSPEC) 990 bad_format_string(hte, call); 991 if (!noasgn) { 992 if (t1 != PTR || t2 != PTR) { 993 inconsistent_arguments(hte, call, n); 994 } else if (tp->t_subt->t_subt->t_tspec!=VOID) { 995 if (hflag) 996 inconsistent_arguments(hte, call, n); 997 } 998 } 999 } else { 1000 bad_format_string(hte, call); 1001 break; 1002 } 1003 1004 fc = *fp++; 1005 } 1006} 1007 1008static void 1009bad_format_string(const hte_t *hte, fcall_t *call) 1010{ 1011 1012 /* %s: malformed format string \t%s */ 1013 msg(13, hte->h_name, mkpos(&call->f_pos)); 1014} 1015 1016static void 1017inconsistent_arguments(const hte_t *hte, fcall_t *call, int n) 1018{ 1019 1020 /* %s, arg %d inconsistent with format \t%s */ 1021 msg(14, hte->h_name, n, mkpos(&call->f_pos)); 1022} 1023 1024static void 1025too_few_arguments(const hte_t *hte, fcall_t *call) 1026{ 1027 1028 /* %s: too few args for format \t%s */ 1029 msg(15, hte->h_name, mkpos(&call->f_pos)); 1030} 1031 1032static void 1033too_many_arguments(const hte_t *hte, fcall_t *call) 1034{ 1035 1036 /* %s: too many args for format \t%s */ 1037 msg(16, hte->h_name, mkpos(&call->f_pos)); 1038} 1039 1040/* 1041 * List of functions where we usually don't care about their result. 1042 * NB: Must be sorted. 1043 */ 1044static const char ignorelist[][8] = { 1045 "memcpy", 1046 "memmove", 1047 "memset", 1048 "printf", 1049 "strcat", 1050 "strcpy", 1051 "vprintf", 1052}; 1053 1054/* 1055 * Print warnings for return values which are used but not returned, 1056 * or return values which are always or sometimes ignored. 1057 */ 1058static void 1059check_return_values(const hte_t *hte, sym_t *def) 1060{ 1061 fcall_t *call; 1062 bool used, ignored; 1063 1064 if (def == NULL) 1065 /* don't know whether or not the functions returns a value */ 1066 return; 1067 1068 if (hte->h_calls == NULL) 1069 return; 1070 1071 if (def->s_function_has_return_value) { 1072 /* 1073 * XXX as soon as we are able to disable single warnings, the 1074 * following dependencies from hflag should be removed. But for 1075 * now I don't want to be bothered by these warnings which are 1076 * almost always useless. 1077 */ 1078 if (!hflag) 1079 return; 1080 if (hflag && bsearch(hte->h_name, ignorelist, 1081 sizeof(ignorelist) / sizeof(ignorelist[0]), 1082 sizeof(ignorelist[0]), 1083 (int (*)(const void *, const void *))strcmp) != NULL) 1084 return; 1085 1086 /* function has return value */ 1087 used = ignored = false; 1088 for (call = hte->h_calls; call != NULL; call = call->f_next) { 1089 used |= call->f_rused || call->f_rdisc; 1090 ignored |= !call->f_rused && !call->f_rdisc; 1091 } 1092 if (!used && ignored) { 1093 /* %s returns value which is always ignored */ 1094 msg(8, hte->h_name); 1095 } else if (used && ignored) { 1096 /* %s returns value which is sometimes ignored */ 1097 msg(9, hte->h_name); 1098 } 1099 } else { 1100 /* function has no return value */ 1101 for (call = hte->h_calls; call != NULL; call = call->f_next) { 1102 if (call->f_rused) 1103 /* %s value is used( %s ), but none returned */ 1104 msg(10, hte->h_name, mkpos(&call->f_pos)); 1105 } 1106 } 1107} 1108 1109/* 1110 * Print warnings for inconsistent argument declarations. 1111 */ 1112static void 1113check_argument_declarations(const hte_t *hte, sym_t *def, sym_t *decl) 1114{ 1115 bool osdef, eq, dowarn; 1116 int n; 1117 sym_t *sym1, *sym; 1118 type_t **ap1, **ap2, *tp1, *tp2; 1119 1120 osdef = false; 1121 if (def != NULL) { 1122 osdef = def->s_old_style_function; 1123 sym1 = def; 1124 } else if (decl != NULL && TP(decl->s_type)->t_proto) { 1125 sym1 = decl; 1126 } else { 1127 return; 1128 } 1129 if (TP(sym1->s_type)->t_tspec != FUNC) 1130 return; 1131 1132 /* 1133 * XXX Prototypes should also be compared with old-style function 1134 * declarations. 1135 */ 1136 1137 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 1138 if (sym == sym1 || !TP(sym->s_type)->t_proto) 1139 continue; 1140 ap1 = TP(sym1->s_type)->t_args; 1141 ap2 = TP(sym->s_type)->t_args; 1142 n = 0; 1143 while (*ap1 != NULL && *ap2 != NULL) { 1144 type_t *xt1, *xt2; 1145 dowarn = false; 1146 eq = types_compatible(xt1 = *ap1, xt2 = *ap2, 1147 true, osdef, false, &dowarn); 1148 if (!eq || dowarn) { 1149 /* %s, arg %d declared inconsistently ... */ 1150 msg(11, hte->h_name, n + 1, 1151 type_name(xt1), type_name(xt2), 1152 mkpos(&sym1->s_pos), mkpos(&sym->s_pos)); 1153 } 1154 n++; 1155 ap1++; 1156 ap2++; 1157 } 1158 if (*ap1 == *ap2) { 1159 tp1 = TP(sym1->s_type); 1160 tp2 = TP(sym->s_type); 1161 if (tp1->t_vararg == tp2->t_vararg) 1162 continue; 1163 if (tp2->t_vararg && sym1->s_check_only_first_args && 1164 sym1->s_check_num_args == n && !sflag) { 1165 continue; 1166 } 1167 } 1168 /* %s: variable # of args declared \t%s :: %s */ 1169 msg(12, hte->h_name, mkpos(&sym1->s_pos), mkpos(&sym->s_pos)); 1170 } 1171} 1172 1173 1174/* 1175 * Check compatibility of two types. Returns whether types are compatible. 1176 * 1177 * ignqual if set, ignore qualifiers of outermost type; used for 1178 * function arguments 1179 * promote if set, promote left type before comparison; used for 1180 * comparisons of arguments with parameters of old-style 1181 * definitions 1182 * asgn left indirected type must have at least the same qualifiers 1183 * like right indirected type (for assignments and function 1184 * arguments) 1185 * *dowarn set to true if an old-style declaration was compared with 1186 * an incompatible prototype declaration 1187 */ 1188static bool 1189types_compatible(type_t *tp1, type_t *tp2, 1190 bool ignqual, bool promot, bool asgn, bool *dowarn) 1191{ 1192 tspec_t t, to; 1193 int indir; 1194 1195 to = NO_TSPEC; 1196 indir = 0; 1197 1198 while (tp1 != NULL && tp2 != NULL) { 1199 1200 t = tp1->t_tspec; 1201 if (promot) { 1202 if (t == FLOAT) { 1203 t = DOUBLE; 1204 } else if (t == CHAR || t == SCHAR) { 1205 t = INT; 1206 } else if (t == UCHAR) { 1207 t = tflag ? UINT : INT; 1208 } else if (t == SHORT) { 1209 t = INT; 1210 } else if (t == USHORT) { 1211 /* CONSTCOND */ 1212 t = INT_MAX < USHRT_MAX || tflag ? UINT : INT; 1213 } 1214 } 1215 1216 if (asgn && to == PTR) { 1217 if (indir == 1 && (t == VOID || tp2->t_tspec == VOID)) 1218 return true; 1219 } 1220 1221 if (t != tp2->t_tspec) { 1222 /* 1223 * Give pointer to types which differ only in 1224 * signedness a chance if not sflag and not hflag. 1225 */ 1226 if (sflag || hflag || to != PTR) 1227 return false; 1228 if (signed_type(t) != signed_type(tp2->t_tspec)) 1229 return false; 1230 } 1231 1232 if (tp1->t_is_enum && tp2->t_is_enum) { 1233 if (tp1->t_istag && tp2->t_istag) { 1234 return tp1->t_tag == tp2->t_tag; 1235 } else if (tp1->t_istynam && tp2->t_istynam) { 1236 return tp1->t_tynam == tp2->t_tynam; 1237 } else if (tp1->t_isuniqpos && tp2->t_isuniqpos) { 1238 return (tp1->t_uniqpos.p_line == 1239 tp2->t_uniqpos.p_line && 1240 tp1->t_uniqpos.p_file == 1241 tp2->t_uniqpos.p_file && 1242 tp1->t_uniqpos.p_uniq == 1243 tp2->t_uniqpos.p_uniq); 1244 } else { 1245 return false; 1246 } 1247 } 1248 1249 /* 1250 * XXX Handle combinations of enum and int if eflag is set. But 1251 * note: enum and 0 should be allowed. 1252 */ 1253 1254 if (asgn && indir == 1) { 1255 if (!tp1->t_const && tp2->t_const) 1256 return false; 1257 if (!tp1->t_volatile && tp2->t_volatile) 1258 return false; 1259 } else if (!ignqual && !tflag) { 1260 if (tp1->t_const != tp2->t_const) 1261 return false; 1262 if (tp1->t_const != tp2->t_const) 1263 return false; 1264 } 1265 1266 if (t == STRUCT || t == UNION) { 1267 if (tp1->t_istag && tp2->t_istag) { 1268 return tp1->t_tag == tp2->t_tag; 1269 } else if (tp1->t_istynam && tp2->t_istynam) { 1270 return tp1->t_tynam == tp2->t_tynam; 1271 } else if (tp1->t_isuniqpos && tp2->t_isuniqpos) { 1272 return (tp1->t_uniqpos.p_line == 1273 tp2->t_uniqpos.p_line && 1274 tp1->t_uniqpos.p_file == 1275 tp2->t_uniqpos.p_file && 1276 tp1->t_uniqpos.p_uniq == 1277 tp2->t_uniqpos.p_uniq); 1278 } else { 1279 return false; 1280 } 1281 } 1282 1283 if (t == ARRAY && tp1->t_dim != tp2->t_dim) { 1284 if (tp1->t_dim != 0 && tp2->t_dim != 0) 1285 return false; 1286 } 1287 1288 if (t == FUNC) { 1289 if (tp1->t_proto && tp2->t_proto) { 1290 if (!prototypes_compatible(tp1, tp2, dowarn)) 1291 return false; 1292 } else if (tp1->t_proto) { 1293 if (!matches_no_arg_function(tp1, dowarn)) 1294 return false; 1295 } else if (tp2->t_proto) { 1296 if (!matches_no_arg_function(tp2, dowarn)) 1297 return false; 1298 } 1299 } 1300 1301 tp1 = tp1->t_subt; 1302 tp2 = tp2->t_subt; 1303 ignqual = promot = false; 1304 to = t; 1305 indir++; 1306 } 1307 1308 return tp1 == tp2; 1309} 1310 1311/* 1312 * Compares arguments of two prototypes 1313 */ 1314static bool 1315prototypes_compatible(type_t *tp1, type_t *tp2, bool *dowarn) 1316{ 1317 type_t **a1, **a2; 1318 1319 if (tp1->t_vararg != tp2->t_vararg) 1320 return false; 1321 1322 a1 = tp1->t_args; 1323 a2 = tp2->t_args; 1324 1325 while (*a1 != NULL && *a2 != NULL) { 1326 1327 if (!types_compatible(*a1, *a2, true, false, false, dowarn)) 1328 return false; 1329 1330 a1++; 1331 a2++; 1332 } 1333 1334 return *a1 == *a2; 1335} 1336 1337/* 1338 * Returns whether all parameters of a prototype are compatible with an 1339 * old-style function declaration. 1340 * 1341 * This is the case if the following conditions are met: 1342 * 1. the prototype must have a fixed number of parameters 1343 * 2. no parameter is of type float 1344 * 3. no parameter is converted to another type if integer promotion 1345 * is applied on it 1346 */ 1347static bool 1348matches_no_arg_function(type_t *tp, bool *dowarn) 1349{ 1350 type_t **arg; 1351 tspec_t t; 1352 1353 if (tp->t_vararg && dowarn != NULL) 1354 *dowarn = true; 1355 for (arg = tp->t_args; *arg != NULL; arg++) { 1356 if ((t = (*arg)->t_tspec) == FLOAT) 1357 return false; 1358 if (t == CHAR || t == SCHAR || t == UCHAR) 1359 return false; 1360 if (t == SHORT || t == USHORT) 1361 return false; 1362 } 1363 return true; 1364} 1365