/* $NetBSD: chk.c,v 1.72 2025/05/24 07:38:59 rillig Exp $ */ /* * Copyright (c) 1996 Christopher G. Demetriou. All Rights Reserved. * Copyright (c) 1994, 1995 Jochen Pohl * All Rights Reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Jochen Pohl for * The NetBSD Project. * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #if HAVE_NBTOOL_CONFIG_H #include "nbtool_config.h" #endif #include #if defined(__RCSID) __RCSID("$NetBSD: chk.c,v 1.72 2025/05/24 07:38:59 rillig Exp $"); #endif #include #include #include #include #include "lint2.h" static void check_used_not_defined(const hte_t *); static void check_defined_not_used(const hte_t *); static void check_declared_not_used_or_defined(const hte_t *); static void check_multiple_definitions(const hte_t *); static void chkvtui(const hte_t *, const sym_t *, const sym_t *); static void chkvtdi(const hte_t *, const sym_t *, const sym_t *); static void chkfaui(const hte_t *, const sym_t *, const sym_t *); static void chkau(const hte_t *, int, const sym_t *, const sym_t *, const pos_t *, const fcall_t *, const fcall_t *, const type_t *, const type_t *); static void check_return_values(const hte_t *, const sym_t *); static void check_argument_declarations(const hte_t *, const sym_t *, const sym_t *); static void printflike(const hte_t *, const fcall_t *, int, const char *, const type_t **); static void scanflike(const hte_t *, const fcall_t *, int, const char *, const type_t **); static void bad_format_string(const hte_t *, const fcall_t *); static void inconsistent_arguments(const hte_t *, const fcall_t *, int); static void too_few_arguments(const hte_t *, const fcall_t *); static void too_many_arguments(const hte_t *, const fcall_t *); static bool types_compatible(const type_t *, const type_t *, bool, bool, bool, bool *); static bool prototypes_compatible(const type_t *, const type_t *, bool *); static bool matches_no_arg_function(const type_t *, bool *); /* * If there is a symbol named "main", mark it as used. */ void mark_main_as_used(void) { hte_t *hte; if ((hte = htab_search("main", false)) != NULL) hte->h_used = true; } /* * Performs all tests for a single name */ void check_name(const hte_t *hte) { sym_t *sym, *def, *pdecl, *decl; if (!uflag) { check_used_not_defined(hte); check_defined_not_used(hte); if (xflag) check_declared_not_used_or_defined(hte); } check_multiple_definitions(hte); /* Get definition, prototype declaration and declaration */ def = pdecl = decl = NULL; for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { if (def == NULL && (sym->s_def == DEF || sym->s_def == TDEF)) def = sym; if (pdecl == NULL && sym->s_def == DECL && TP(sym->s_type)->t_tspec == FUNC && TP(sym->s_type)->t_proto) { pdecl = sym; } if (decl == NULL && sym->s_def == DECL) decl = sym; } /* A prototype is better than an old-style declaration. */ if (pdecl != NULL) decl = pdecl; chkvtui(hte, def, decl); chkvtdi(hte, def, decl); chkfaui(hte, def, decl); check_return_values(hte, def); check_argument_declarations(hte, def, decl); } /* * Print a warning if the name has been used, but not defined. */ static void check_used_not_defined(const hte_t *hte) { fcall_t *fcall; usym_t *usym; if (!hte->h_used || hte->h_def) return; if ((fcall = hte->h_calls) != NULL) { /* %s is used in %s but never defined */ msg(0, hte->h_name, mkpos(&fcall->f_pos)); } else if ((usym = hte->h_usyms) != NULL) { /* %s is used in %s but never defined */ msg(0, hte->h_name, mkpos(&usym->u_pos)); } } /* * Print a warning if the name has been defined, but never used. */ static void check_defined_not_used(const hte_t *hte) { sym_t *sym; if (!hte->h_def || hte->h_used) return; for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { if (sym->s_def == DEF || sym->s_def == TDEF) { /* %s is defined in %s but never used */ msg(1, hte->h_name, mkpos(&sym->s_pos)); break; } } } /* * Print a warning if the variable has been declared, but is not used * or defined. */ static void check_declared_not_used_or_defined(const hte_t *hte) { sym_t *sym; if (hte->h_syms == NULL || hte->h_used || hte->h_def) return; sym = hte->h_syms; if (TP(sym->s_type)->t_tspec == FUNC) return; if (sym->s_def != DECL) errx(1, "internal error: check_declared_not_used_or_defined"); /* %s is declared in %s but never used or defined */ msg(2, hte->h_name, mkpos(&sym->s_pos)); } /* * Print a warning if there is more than one definition for * this name. */ static void check_multiple_definitions(const hte_t *hte) { sym_t *sym, *def1; if (!hte->h_def) return; def1 = NULL; for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { /* * C90 allows tentative definitions of the same name in only * one compilation unit. */ if (sym->s_def != DEF && (!sflag || sym->s_def != TDEF)) continue; if (sym->s_inline) continue; if (def1 == NULL) { def1 = sym; continue; } /* %s has multiple definitions in %s and %s */ msg(3, hte->h_name, mkpos(&def1->s_pos), mkpos(&sym->s_pos)); } } /* * Print a warning if the return value assumed for a function call * differs from the return value of the function definition or * function declaration. * * If no definition/declaration can be found, the assumed return values * are always int. So there is no need to compare with another function * call as it's done for function arguments. */ static void chkvtui(const hte_t *hte, const sym_t *def, const sym_t *decl) { fcall_t *call; type_t *tp1, *tp2; bool dowarn, eq; tspec_t t1; if (hte->h_calls == NULL) return; if (def == NULL) def = decl; if (def == NULL) return; t1 = (tp1 = TP(def->s_type)->t_subt)->t_tspec; for (call = hte->h_calls; call != NULL; call = call->f_next) { tp2 = TP(call->f_type)->t_subt; eq = types_compatible(tp1, tp2, true, false, false, (dowarn = false, &dowarn)); if (!call->f_rused) { /* no return value used */ if ((t1 == STRUCT || t1 == UNION) && !eq) { /* * If a function returns a struct or union, it * must be declared to return a struct or * union, even if the return value is ignored. * This is necessary because the caller must * allocate stack space for the return value. * If it does not, the return value would * overwrite other data. * * XXX: The following message may be confusing * because it occurs also if the return value * was declared inconsistently. But this * behavior matches pcc-based lint, so it is * accepted for now. */ /* %s's return type in %s must be decl... */ msg(17, hte->h_name, mkpos(&def->s_pos), mkpos(&call->f_pos)); } continue; } if (!eq || (sflag && dowarn)) { /* %s has its return value used inconsistently ... */ msg(4, hte->h_name, mkpos(&def->s_pos), mkpos(&call->f_pos)); } } } /* * Print a warning if a definition/declaration does not match another * definition/declaration of the same name. For functions, only the * types of return values are tested. */ static void chkvtdi(const hte_t *hte, const sym_t *def, const sym_t *decl) { if (def == NULL) def = decl; if (def == NULL) return; const type_t *tp1 = TP(def->s_type); for (sym_t *sym = hte->h_syms; sym != NULL; sym = sym->s_next) { if (sym == def) continue; const type_t *tp2 = TP(sym->s_type); bool dowarn = false; bool is_func = tp1->t_tspec == FUNC && tp2->t_tspec == FUNC; const type_t *xt1 = is_func ? tp1->t_subt : tp1; const type_t *xt2 = is_func ? tp2->t_subt : tp2; bool eq = types_compatible(xt1, xt2, is_func, false, false, &dowarn); if (!eq || (sflag && dowarn)) { /* %s %s '%s' at %s, versus '%s' at %s */ msg(5, hte->h_name, is_func ? "returns" : "has type", type_name(xt1), mkpos(&def->s_pos), type_name(xt2), mkpos(&sym->s_pos)); } } } static int total_args(int n, const type_t **tpp) { for (; *tpp != NULL; tpp++) n++; return n; } /* * Print a warning if a function is called with arguments which does * not match the function definition, declaration or another call * of the same function. */ static void chkfaui(const hte_t *hte, const sym_t *def, const sym_t *decl) { const type_t *tp1, *tp2, **ap1, **ap2; const pos_t *pos1p = NULL; fcall_t *calls, *call, *call1; int n, as; arginf_t *ai; if ((calls = hte->h_calls) == NULL) return; /* * If we find a function definition, we use this for comparison, * otherwise the first prototype we can find. If there is no definition * or prototype declaration, the first function call is used. */ tp1 = NULL; call1 = NULL; if (def != NULL) { if ((tp1 = TP(def->s_type))->t_tspec != FUNC) return; pos1p = &def->s_pos; } else if (decl != NULL && TP(decl->s_type)->t_proto) { if ((tp1 = TP(decl->s_type))->t_tspec != FUNC) return; pos1p = &decl->s_pos; } if (tp1 == NULL) { call1 = calls; calls = calls->f_next; if ((tp1 = TP(call1->f_type))->t_tspec != FUNC) return; pos1p = &call1->f_pos; } n = 1; for (call = calls; call != NULL; call = call->f_next) { if ((tp2 = TP(call->f_type))->t_tspec != FUNC) continue; ap1 = tp1->t_args; ap2 = tp2->t_args; n = 0; while (*ap1 != NULL && *ap2 != NULL) { if (def != NULL && def->s_check_only_first_args && n >= def->s_check_num_args) break; n++; chkau(hte, n, def, decl, pos1p, call1, call, *ap1, *ap2); ap1++; ap2++; } if (*ap1 == *ap2) { /* equal # of arguments */ } else if (def != NULL && def->s_check_only_first_args && n >= def->s_check_num_args) { /* * function definition with VARARGS; The # of arguments * of the call must be at least as large as the * parameter of VARARGS. */ } else if (*ap2 != NULL && tp1->t_proto && tp1->t_vararg) { /* * prototype with ... and function call with at least * the same # of arguments as declared in the * prototype. */ } else { /* %s has %d parameters in %s, versus %d ... */ msg(7, hte->h_name, total_args(n, ap1), mkpos(pos1p), total_args(n, ap2), mkpos(&call->f_pos)); continue; } /* perform SCANFLIKE/PRINTFLIKE tests */ if (def == NULL || (!def->s_printflike && !def->s_scanflike)) continue; as = def->s_printflike ? def->s_printflike_arg : def->s_scanflike_arg; for (ai = call->f_args; ai != NULL; ai = ai->a_next) { if (ai->a_num == as) break; } if (ai == NULL || !ai->a_fmt) continue; if (def->s_printflike) { printflike(hte, call, n, ai->a_fstrg, ap2); } else { scanflike(hte, call, n, ai->a_fstrg, ap2); } } } /* * Check a single argument in a function call. * * hte a pointer to the hash table entry of the function * n the number of the argument (1..) * def the function definition or NULL * decl prototype declaration, old-style declaration or NULL * pos1p position of definition, declaration of first call * call1 first call, if both def and decl are old-style def/decl * call checked call * arg1 currently checked argument of def/decl/call1 * arg2 currently checked argument of call */ static void chkau(const hte_t *hte, int n, const sym_t *def, const sym_t *decl, const pos_t *pos1p, const fcall_t *call1, const fcall_t *call, const type_t *arg1, const type_t *arg2) { bool promote, asgn, dowarn; tspec_t t1, t2; arginf_t *ai, *ai1; /* * If a function definition is available (def != NULL), we compare the * function call (call) with the definition. Otherwise, if a function * definition is available and it is not an old-style definition (decl * != NULL && TP(decl->s_type)->t_proto), we compare the call with this * declaration. Otherwise we compare it with the first call we have * found (call1). */ /* arg1 must be promoted if it stems from an old-style definition */ promote = def != NULL && def->s_old_style_function; /* * If we compare with a definition or declaration, we must perform the * same checks for qualifiers in indirected types as in assignments. */ asgn = def != NULL || (decl != NULL && TP(decl->s_type)->t_proto); dowarn = false; if (types_compatible(arg1, arg2, true, promote, asgn, &dowarn) && (!sflag || !dowarn)) return; /*- * Other lint implementations print warnings as soon as the type of an * argument does not match exactly the expected type. The result are * lots of warnings which are really not necessary. * We print a warning only if * (0) at least one type is not an integer type and types differ * (1) hflag is set and types differ * (2) types differ, except in signedness * * If the argument is an integer constant whose msb is not set, * signedness is ignored (e.g. 0 matches both signed and unsigned int). * This is with and without hflag. * * If the argument is an integer constant with value 0 and the expected * argument is of type pointer and the width of the integer constant is * the same as the width of the pointer, no warning is printed. */ t1 = arg1->t_tspec; t2 = arg2->t_tspec; if (is_integer(t1) && is_integer(t2) && !arg1->t_is_enum && !arg2->t_is_enum) { if (promote) { /* * XXX Here is a problem: Although it is possible to * pass an int where a char/short it expected, there * may be loss in significant digits. We should first * check for const arguments if they can be converted * into the original parameter type. */ if (t1 == FLOAT) { t1 = DOUBLE; } else if (t1 == CHAR || t1 == SCHAR) { t1 = INT; } else if (t1 == UCHAR) { t1 = tflag ? UINT : INT; } else if (t1 == SHORT) { t1 = INT; } else if (t1 == USHORT) { t1 = INT_MAX < USHRT_MAX || tflag ? UINT : INT; } } if (signed_type(t1) == signed_type(t2)) { /* * types differ only in signedness; get information * about arguments */ /* * treat a definition like a call with variable * arguments */ ai1 = call1 != NULL ? call1->f_args : NULL; /* * if two calls are compared, ai1 is set to the * information for the n-th argument, if this was a * constant, otherwise to NULL */ for ( ; ai1 != NULL; ai1 = ai1->a_next) { if (ai1->a_num == n) break; } /* * ai is set to the information of the n-th arg of the * (second) call, if this was a constant, otherwise to * NULL */ for (ai = call->f_args; ai != NULL; ai = ai->a_next) { if (ai->a_num == n) break; } if (ai1 == NULL && ai == NULL) { /* no constant at all */ if (!hflag) return; } else if (ai1 == NULL || ai == NULL) { /* one constant */ if (ai == NULL) ai = ai1; if (ai->a_zero || ai->a_pcon) /* same value in signed and unsigned */ return; /* value (not representation) differently */ } else { /* * two constants, one signed, one unsigned; if * the msb of one of the constants is set, the * argument is used inconsistently. */ if (!ai1->a_ncon && !ai->a_ncon) return; } } } else if (t1 == PTR && is_integer(t2)) { for (ai = call->f_args; ai != NULL; ai = ai->a_next) { if (ai->a_num == n) break; } /* * Vendor implementations of lint (e.g. HP-UX, Digital UNIX) * don't care about the size of the integer argument, only * whether or not it is zero. We do the same. */ if (ai != NULL && ai->a_zero) return; } /* %s has argument %d with type '%s' at %s, versus '%s' at %s */ msg(6, hte->h_name, n, type_name(arg1), mkpos(pos1p), type_name(arg2), mkpos(&call->f_pos)); } /* * Compare the types in the NULL-terminated array ap with the format * string fmt. */ static void printflike(const hte_t *hte, const fcall_t *call, int n, const char *fmt, const type_t **ap) { const char *fp; char fc; bool fwidth, prec, left, sign, space, alt, zero; tspec_t sz, t1, t2 = NO_TSPEC; const type_t *tp; fp = fmt; fc = *fp++; for (;;) { if (fc == '\0') { if (*ap != NULL) too_many_arguments(hte, call); break; } if (fc != '%') { bad_format_string(hte, call); break; } fc = *fp++; fwidth = prec = left = sign = space = alt = zero = false; sz = NO_TSPEC; /* Flags */ for (;;) { if (fc == '-') { if (left) break; left = true; } else if (fc == '+') { if (sign) break; sign = true; } else if (fc == ' ') { if (space) break; space = true; } else if (fc == '#') { if (alt) break; alt = true; } else if (fc == '0') { if (zero) break; zero = true; } else { break; } fc = *fp++; } /* field width */ if (ch_isdigit(fc)) { fwidth = true; do { fc = *fp++; } while (ch_isdigit(fc)); } else if (fc == '*') { fwidth = true; fc = *fp++; if ((tp = *ap++) == NULL) { too_few_arguments(hte, call); break; } n++; if ((t1 = tp->t_tspec) != INT && (hflag || t1 != UINT)) inconsistent_arguments(hte, call, n); } /* precision */ if (fc == '.') { fc = *fp++; prec = true; if (ch_isdigit(fc)) { do { fc = *fp++; } while (ch_isdigit(fc)); } else if (fc == '*') { fc = *fp++; if ((tp = *ap++) == NULL) { too_few_arguments(hte, call); break; } n++; if (tp->t_tspec != INT) inconsistent_arguments(hte, call, n); } else { bad_format_string(hte, call); break; } } if (fc == 'h') { sz = SHORT; } else if (fc == 'l') { sz = LONG; } else if (fc == 'q') { sz = LLONG; } else if (fc == 'L') { sz = LDOUBLE; } if (sz != NO_TSPEC) fc = *fp++; if (fc == '%') { if (sz != NO_TSPEC || left || sign || space || alt || zero || prec || fwidth) { bad_format_string(hte, call); } fc = *fp++; continue; } if (fc == '\0') { bad_format_string(hte, call); break; } if ((tp = *ap++) == NULL) { too_few_arguments(hte, call); break; } n++; if ((t1 = tp->t_tspec) == PTR) t2 = tp->t_subt->t_tspec; if (fc == 'd' || fc == 'i') { if (alt || sz == LDOUBLE) { bad_format_string(hte, call); break; } int_conv: if (sz == LONG) { if (t1 != LONG && (hflag || t1 != ULONG)) inconsistent_arguments(hte, call, n); } else if (sz == LLONG) { if (t1 != LLONG && (hflag || t1 != ULLONG)) inconsistent_arguments(hte, call, n); } else { /* * SHORT is always promoted to INT, USHORT to * INT or UINT. */ if (t1 != INT && (hflag || t1 != UINT)) inconsistent_arguments(hte, call, n); } } else if (fc == 'o' || fc == 'u' || fc == 'x' || fc == 'X') { if ((alt && fc == 'u') || sz == LDOUBLE) bad_format_string(hte, call); uint_conv: if (sz == LONG) { if (t1 != ULONG && (hflag || t1 != LONG)) inconsistent_arguments(hte, call, n); } else if (sz == LLONG) { if (t1 != ULLONG && (hflag || t1 != LLONG)) inconsistent_arguments(hte, call, n); } else if (sz == SHORT) { /* USHORT was promoted to INT or UINT */ if (t1 != UINT && t1 != INT) inconsistent_arguments(hte, call, n); } else { if (t1 != UINT && (hflag || t1 != INT)) inconsistent_arguments(hte, call, n); } } else if (fc == 'D' || fc == 'O' || fc == 'U') { if ((alt && fc != 'O') || sz != NO_TSPEC || !tflag) bad_format_string(hte, call); sz = LONG; if (fc == 'D') { goto int_conv; } else { goto uint_conv; } } else if (fc == 'f' || fc == 'e' || fc == 'E' || fc == 'g' || fc == 'G') { if (sz == NO_TSPEC) sz = DOUBLE; if (sz != DOUBLE && sz != LDOUBLE) bad_format_string(hte, call); if (t1 != sz) inconsistent_arguments(hte, call, n); } else if (fc == 'c') { if (sz != NO_TSPEC || alt || zero) bad_format_string(hte, call); if (t1 != INT) inconsistent_arguments(hte, call, n); } else if (fc == 's') { if (sz != NO_TSPEC || alt || zero) bad_format_string(hte, call); if (t1 != PTR || (t2 != CHAR && t2 != UCHAR && t2 != SCHAR)) { inconsistent_arguments(hte, call, n); } } else if (fc == 'p') { if (fwidth || prec || sz != NO_TSPEC || alt || zero) bad_format_string(hte, call); if (t1 != PTR || (hflag && t2 != VOID)) inconsistent_arguments(hte, call, n); } else if (fc == 'n') { if (fwidth || prec || alt || zero || sz == LDOUBLE) bad_format_string(hte, call); if (t1 != PTR) { inconsistent_arguments(hte, call, n); } else if (sz == LONG) { if (t2 != LONG && t2 != ULONG) inconsistent_arguments(hte, call, n); } else if (sz == SHORT) { if (t2 != SHORT && t2 != USHORT) inconsistent_arguments(hte, call, n); } else { if (t2 != INT && t2 != UINT) inconsistent_arguments(hte, call, n); } } else { bad_format_string(hte, call); break; } fc = *fp++; } } /* * Compare the types in the NULL-terminated array ap with the format * string fmt. */ static void scanflike(const hte_t *hte, const fcall_t *call, int n, const char *fmt, const type_t **ap) { const char *fp; char fc; bool noasgn, fwidth; tspec_t sz, t1 = NO_TSPEC, t2 = NO_TSPEC; const type_t *tp = NULL; fp = fmt; fc = *fp++; for (;;) { if (fc == '\0') { if (*ap != NULL) too_many_arguments(hte, call); break; } if (fc != '%') { bad_format_string(hte, call); break; } fc = *fp++; noasgn = fwidth = false; sz = NO_TSPEC; if (fc == '*') { noasgn = true; fc = *fp++; } if (ch_isdigit(fc)) { fwidth = true; do { fc = *fp++; } while (ch_isdigit(fc)); } if (fc == 'h') { sz = SHORT; } else if (fc == 'l') { sz = LONG; } else if (fc == 'q') { sz = LLONG; } else if (fc == 'L') { sz = LDOUBLE; } if (sz != NO_TSPEC) fc = *fp++; if (fc == '%') { if (sz != NO_TSPEC || noasgn || fwidth) bad_format_string(hte, call); fc = *fp++; continue; } if (!noasgn) { if ((tp = *ap++) == NULL) { too_few_arguments(hte, call); break; } n++; if ((t1 = tp->t_tspec) == PTR) t2 = tp->t_subt->t_tspec; } if (fc == 'd' || fc == 'i' || fc == 'n') { if (sz == LDOUBLE) bad_format_string(hte, call); if (sz != SHORT && sz != LONG && sz != LLONG) sz = INT; conv: if (!noasgn) { if (t1 != PTR) { inconsistent_arguments(hte, call, n); } else if (t2 != signed_type(sz)) { inconsistent_arguments(hte, call, n); } else if (hflag && t2 != sz) { inconsistent_arguments(hte, call, n); } else if (tp->t_subt->t_const) { inconsistent_arguments(hte, call, n); } } } else if (fc == 'o' || fc == 'u' || fc == 'x') { if (sz == LDOUBLE) bad_format_string(hte, call); if (sz == SHORT) { sz = USHORT; } else if (sz == LONG) { sz = ULONG; } else if (sz == LLONG) { sz = ULLONG; } else { sz = UINT; } goto conv; } else if (fc == 'D') { if (sz != NO_TSPEC || !tflag) bad_format_string(hte, call); sz = LONG; goto conv; } else if (fc == 'O') { if (sz != NO_TSPEC || !tflag) bad_format_string(hte, call); sz = ULONG; goto conv; } else if (fc == 'X') { /* * XXX valid in C90, but in NetBSD's libc implemented * as "lx". That's why it should be avoided. */ if (sz != NO_TSPEC || !tflag) bad_format_string(hte, call); sz = ULONG; goto conv; } else if (fc == 'E') { /* * XXX valid in C90, but in NetBSD's libc implemented * as "lf". That's why it should be avoided. */ if (sz != NO_TSPEC || !tflag) bad_format_string(hte, call); sz = DOUBLE; goto conv; } else if (fc == 'F') { /* XXX only for backward compatibility */ if (sz != NO_TSPEC || !tflag) bad_format_string(hte, call); sz = DOUBLE; goto conv; } else if (fc == 'G') { /* * XXX valid in C90, but in NetBSD's libc not * implemented */ if (sz != NO_TSPEC && sz != LONG && sz != LDOUBLE) bad_format_string(hte, call); goto fconv; } else if (fc == 'e' || fc == 'f' || fc == 'g') { fconv: if (sz == NO_TSPEC) { sz = FLOAT; } else if (sz == LONG) { sz = DOUBLE; } else if (sz != LDOUBLE) { bad_format_string(hte, call); sz = FLOAT; } goto conv; } else if (fc == 's' || fc == '[' || fc == 'c') { if (sz != NO_TSPEC) bad_format_string(hte, call); if (fc == '[') { if ((fc = *fp++) == '-') { bad_format_string(hte, call); fc = *fp++; } if (fc != ']') { bad_format_string(hte, call); if (fc == '\0') break; } } if (!noasgn) { if (t1 != PTR) { inconsistent_arguments(hte, call, n); } else if (t2 != CHAR && t2 != UCHAR && t2 != SCHAR) { inconsistent_arguments(hte, call, n); } } } else if (fc == 'p') { if (sz != NO_TSPEC) bad_format_string(hte, call); if (!noasgn) { if (t1 != PTR || t2 != PTR) { inconsistent_arguments(hte, call, n); } else if (tp->t_subt->t_subt->t_tspec!=VOID) { if (hflag) inconsistent_arguments(hte, call, n); } } } else { bad_format_string(hte, call); break; } fc = *fp++; } } static void bad_format_string(const hte_t *hte, const fcall_t *call) { /* %s is called with a malformed format string in %s */ msg(13, hte->h_name, mkpos(&call->f_pos)); } static void inconsistent_arguments(const hte_t *hte, const fcall_t *call, int n) { /* %s is called in %s with argument %d being incompatible with ... */ msg(14, hte->h_name, mkpos(&call->f_pos), n); } static void too_few_arguments(const hte_t *hte, const fcall_t *call) { /* %s is called in %s with too few arguments for format string */ msg(15, hte->h_name, mkpos(&call->f_pos)); } static void too_many_arguments(const hte_t *hte, const fcall_t *call) { /* %s is called in %s with too many arguments for format string */ msg(16, hte->h_name, mkpos(&call->f_pos)); } /* * List of functions where we usually don't care about their result. * NB: Must be sorted. */ static const char ignorelist[][8] = { "memcpy", "memmove", "memset", "printf", "strcat", "strcpy", "vprintf", }; /* * Print warnings for return values which are used but not returned, * or return values which are always or sometimes ignored. */ static void check_return_values(const hte_t *hte, const sym_t *def) { fcall_t *call; bool used, ignored; if (def == NULL) /* don't know whether or not the functions returns a value */ return; if (hte->h_calls == NULL) return; if (def->s_function_has_return_value) { /* * XXX as soon as we are able to disable single warnings, the * following dependencies from hflag should be removed. But for * now I don't want to be bothered by these warnings which are * almost always useless. */ if (!hflag) return; if (hflag && bsearch(hte->h_name, ignorelist, sizeof(ignorelist) / sizeof(ignorelist[0]), sizeof(ignorelist[0]), (int (*)(const void *, const void *))strcmp) != NULL) return; /* function has return value */ used = ignored = false; for (call = hte->h_calls; call != NULL; call = call->f_next) { used |= call->f_rused || call->f_rdisc; ignored |= !call->f_rused && !call->f_rdisc; } if (!used && ignored) { /* %s returns a value that is always ignored */ msg(8, hte->h_name); } else if (used && ignored) { /* %s returns a value that is sometimes ignored */ msg(9, hte->h_name); } } else { /* function has no return value */ for (call = hte->h_calls; call != NULL; call = call->f_next) { if (call->f_rused) /* %s has its return value used in %s but doesn't return one */ msg(10, hte->h_name, mkpos(&call->f_pos)); } } } /* * Print warnings for inconsistent argument declarations. */ static void check_argument_declarations(const hte_t *hte, const sym_t *def, const sym_t *decl) { bool osdef, eq, dowarn; int n; const sym_t *sym1, *sym; const type_t **ap1, **ap2, *tp1, *tp2; osdef = false; if (def != NULL) { osdef = def->s_old_style_function; sym1 = def; } else if (decl != NULL && TP(decl->s_type)->t_proto) { sym1 = decl; } else { return; } if (TP(sym1->s_type)->t_tspec != FUNC) return; /* * XXX Prototypes should also be compared with old-style function * declarations. */ for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { if (sym == sym1 || !TP(sym->s_type)->t_proto) continue; ap1 = TP(sym1->s_type)->t_args; ap2 = TP(sym->s_type)->t_args; n = 0; while (*ap1 != NULL && *ap2 != NULL) { const type_t *xt1, *xt2; dowarn = false; eq = types_compatible(xt1 = *ap1, xt2 = *ap2, true, osdef, false, &dowarn); if (!eq || dowarn) { /* %s has parameter %d declared as '%s' ... */ msg(11, hte->h_name, n + 1, type_name(xt1), mkpos(&sym1->s_pos), type_name(xt2), mkpos(&sym->s_pos)); } n++; ap1++; ap2++; } if (*ap1 == *ap2) { tp1 = TP(sym1->s_type); tp2 = TP(sym->s_type); if (tp1->t_vararg == tp2->t_vararg) continue; if (tp2->t_vararg && sym1->s_check_only_first_args && sym1->s_check_num_args == n && !sflag) { continue; } } /* %s has %d parameters in %s, versus %d in %s */ msg(12, hte->h_name, total_args(n, ap1), mkpos(&sym1->s_pos), total_args(n, ap2), mkpos(&sym->s_pos)); } } /* * Check compatibility of two types. Returns whether types are compatible. * * ignqual if set, ignore qualifiers of outermost type; used for * function arguments * promote if set, promote left type before comparison; used for * comparisons of arguments with parameters of old-style * definitions * asgn left indirected type must have at least the same qualifiers * like right indirected type (for assignments and function * arguments) * *dowarn set to true if an old-style declaration was compared with * an incompatible prototype declaration */ static bool types_compatible(const type_t *tp1, const type_t *tp2, bool ignqual, bool promot, bool asgn, bool *dowarn) { tspec_t t, to; int indir; to = NO_TSPEC; indir = 0; while (tp1 != NULL && tp2 != NULL) { t = tp1->t_tspec; if (promot) { if (t == FLOAT) { t = DOUBLE; } else if (t == CHAR || t == SCHAR) { t = INT; } else if (t == UCHAR) { t = tflag ? UINT : INT; } else if (t == SHORT) { t = INT; } else if (t == USHORT) { t = INT_MAX < USHRT_MAX || tflag ? UINT : INT; } } if (asgn && to == PTR) { if (indir == 1 && (t == VOID || tp2->t_tspec == VOID)) return true; } if (t != tp2->t_tspec) { /* * Give pointer to types which differ only in * signedness a chance if not sflag and not hflag. */ if (sflag || hflag || to != PTR) return false; if (signed_type(t) != signed_type(tp2->t_tspec)) return false; } if (tp1->t_is_enum && tp2->t_is_enum) { if (tp1->t_istag && tp2->t_istag) { return tp1->t_tag == tp2->t_tag; } else if (tp1->t_istynam && tp2->t_istynam) { return tp1->t_tynam == tp2->t_tynam; } else if (tp1->t_isuniqpos && tp2->t_isuniqpos) { return (tp1->t_uniqpos.p_line == tp2->t_uniqpos.p_line && tp1->t_uniqpos.p_file == tp2->t_uniqpos.p_file && tp1->t_uniqpos.p_uniq == tp2->t_uniqpos.p_uniq); } else { return false; } } /* * XXX Handle combinations of enum and int if eflag is set. But * note: enum and 0 should be allowed. */ if (asgn && indir == 1) { if (!tp1->t_const && tp2->t_const) return false; if (!tp1->t_volatile && tp2->t_volatile) return false; } else if (!ignqual && !tflag) { if (tp1->t_const != tp2->t_const) return false; if (tp1->t_const != tp2->t_const) return false; } if (t == STRUCT || t == UNION) { if (tp1->t_istag && tp2->t_istag) { return tp1->t_tag == tp2->t_tag; } else if (tp1->t_istynam && tp2->t_istynam) { return tp1->t_tynam == tp2->t_tynam; } else if (tp1->t_isuniqpos && tp2->t_isuniqpos) { return (tp1->t_uniqpos.p_line == tp2->t_uniqpos.p_line && tp1->t_uniqpos.p_file == tp2->t_uniqpos.p_file && tp1->t_uniqpos.p_uniq == tp2->t_uniqpos.p_uniq); } else { return false; } } if (t == ARRAY && tp1->t_dim != tp2->t_dim) { if (tp1->t_dim != 0 && tp2->t_dim != 0) return false; } if (t == FUNC) { if (tp1->t_proto && tp2->t_proto) { if (!prototypes_compatible(tp1, tp2, dowarn)) return false; } else if (tp1->t_proto) { if (!matches_no_arg_function(tp1, dowarn)) return false; } else if (tp2->t_proto) { if (!matches_no_arg_function(tp2, dowarn)) return false; } } tp1 = tp1->t_subt; tp2 = tp2->t_subt; ignqual = promot = false; to = t; indir++; } return tp1 == tp2; } /* * Compares arguments of two prototypes */ static bool prototypes_compatible(const type_t *tp1, const type_t *tp2, bool *dowarn) { if (tp1->t_vararg != tp2->t_vararg) return false; const type_t **a1 = tp1->t_args; const type_t **a2 = tp2->t_args; for (; *a1 != NULL && *a2 != NULL; a1++, a2++) if (!types_compatible(*a1, *a2, true, false, false, dowarn)) return false; return *a1 == *a2; } /* * Returns whether all parameters of a prototype are compatible with an * old-style function declaration. * * This is the case if the following conditions are met: * 1. the prototype must have a fixed number of parameters * 2. no parameter is of type float * 3. no parameter is converted to another type if integer promotion * is applied on it */ static bool matches_no_arg_function(const type_t *tp, bool *dowarn) { if (tp->t_vararg && dowarn != NULL) *dowarn = true; for (const type_t **arg = tp->t_args; *arg != NULL; arg++) { tspec_t t = (*arg)->t_tspec; if (t == FLOAT) return false; if (t == CHAR || t == SCHAR || t == UCHAR) return false; if (t == SHORT || t == USHORT) return false; } return true; }