1 /* $NetBSD: ckctype.c,v 1.13 2024/12/18 18:14:54 rillig Exp $ */ 2 3 /*- 4 * Copyright (c) 2021 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Roland Illig <rillig@NetBSD.org>. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #if HAVE_NBTOOL_CONFIG_H 33 #include "nbtool_config.h" 34 #endif 35 36 #include <sys/cdefs.h> 37 38 #if defined(__RCSID) 39 __RCSID("$NetBSD: ckctype.c,v 1.13 2024/12/18 18:14:54 rillig Exp $"); 40 #endif 41 42 #include <string.h> 43 44 #include "lint1.h" 45 46 /* 47 * Check that the functions from <ctype.h> are used properly. They must not 48 * be called with an argument of type 'char'. In such a case, the argument 49 * must be converted to 'unsigned char'. The tricky thing is that even though 50 * the parameter type is declared as 'int', a 'char' argument must not be 51 * directly cast to 'int', as that would preserve negative argument values. 52 * 53 * See also: 54 * ctype(3) 55 * https://stackoverflow.com/a/60696378 56 */ 57 58 static bool 59 is_ctype_function(const char *name) 60 { 61 62 if (name[0] == 'i' && name[1] == 's') 63 return strcmp(name, "isalnum") == 0 || 64 strcmp(name, "isalpha") == 0 || 65 strcmp(name, "isblank") == 0 || 66 strcmp(name, "iscntrl") == 0 || 67 strcmp(name, "isdigit") == 0 || 68 strcmp(name, "isgraph") == 0 || 69 strcmp(name, "islower") == 0 || 70 strcmp(name, "isprint") == 0 || 71 strcmp(name, "ispunct") == 0 || 72 strcmp(name, "isspace") == 0 || 73 strcmp(name, "isupper") == 0 || 74 strcmp(name, "isxdigit") == 0; 75 76 if (name[0] == 't' && name[1] == 'o') 77 return strcmp(name, "tolower") == 0 || 78 strcmp(name, "toupper") == 0; 79 80 return false; 81 } 82 83 static bool 84 is_ctype_table(const char *name) 85 { 86 87 /* NetBSD sys/ctype_bits.h 1.6 from 2016-01-22 */ 88 if (strcmp(name, "_ctype_tab_") == 0 || 89 strcmp(name, "_tolower_tab_") == 0 || 90 strcmp(name, "_toupper_tab_") == 0) 91 return true; 92 93 /* NetBSD sys/ctype_bits.h 1.1 from 2010-06-01 */ 94 return strcmp(name, "_ctype_") == 0; 95 } 96 97 static void 98 check_ctype_arg(const char *func, const tnode_t *arg) 99 { 100 const tnode_t *on, *cn; 101 102 for (on = arg; on->tn_op == CVT; on = on->u.ops.left) 103 if (on->tn_type->t_tspec == UCHAR) 104 return; 105 if (on->tn_type->t_tspec == UCHAR) 106 return; 107 108 if (arg->tn_op == CVT && arg->tn_cast) { 109 /* argument to '%s' must be cast to 'unsigned char', not ... */ 110 warning(342, func, type_name(arg->tn_type)); 111 return; 112 } 113 114 cn = before_conversion(arg); 115 if (cn->tn_type->t_tspec != UCHAR && cn->tn_type->t_tspec != INT) { 116 /* argument to '%s' must be 'unsigned char' or EOF, not '%s' */ 117 warning(341, func, type_name(cn->tn_type)); 118 return; 119 } 120 } 121 122 void 123 check_ctype_function_call(const function_call *call) 124 { 125 126 if (call->args_len == 1 && 127 call->func->tn_op == NAME && 128 is_ctype_function(call->func->u.sym->s_name)) 129 check_ctype_arg(call->func->u.sym->s_name, call->args[0]); 130 } 131 132 void 133 check_ctype_macro_invocation(const tnode_t *ln, const tnode_t *rn) 134 { 135 136 if (ln->tn_op == PLUS && 137 ln->u.ops.left != NULL && 138 ln->u.ops.left->tn_op == LOAD && 139 ln->u.ops.left->u.ops.left != NULL && 140 ln->u.ops.left->u.ops.left->tn_op == NAME && 141 is_ctype_table(ln->u.ops.left->u.ops.left->u.sym->s_name)) 142 check_ctype_arg("function from <ctype.h>", rn); 143 } 144